From 2678b51b31febdc6464935e1680d2272a954c3b5 Mon Sep 17 00:00:00 2001 From: John Ericson Date: Sun, 5 Nov 2023 12:17:33 -0500 Subject: [PATCH 1/2] Narrower scope for `nativeSystem` I don't think we need a CPP defininition and a header entry, and this way allows constant expression elimination. --- src/libstore/build/local-derivation-goal.cc | 2 ++ src/libutil/error.cc | 2 -- src/libutil/util.hh | 6 ------ 3 files changed, 2 insertions(+), 8 deletions(-) diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc index dcb7dc6bc..e1794139f 100644 --- a/src/libstore/build/local-derivation-goal.cc +++ b/src/libstore/build/local-derivation-goal.cc @@ -1620,6 +1620,8 @@ void setupSeccomp() seccomp_release(ctx); }); + constexpr std::string_view nativeSystem = SYSTEM; + if (nativeSystem == "x86_64-linux" && seccomp_arch_add(ctx, SCMP_ARCH_X86) != 0) throw SysError("unable to add 32-bit seccomp architecture"); diff --git a/src/libutil/error.cc b/src/libutil/error.cc index dd9612471..1badc1069 100644 --- a/src/libutil/error.cc +++ b/src/libutil/error.cc @@ -7,8 +7,6 @@ namespace nix { -const std::string nativeSystem = SYSTEM; - void BaseError::addTrace(std::shared_ptr && e, hintformat hint, bool frame) { err.traces.push_front(Trace { .pos = std::move(e), .hint = hint, .frame = frame }); diff --git a/src/libutil/util.hh b/src/libutil/util.hh index b302d6f45..75683f8fe 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -34,12 +34,6 @@ struct Source; void initLibUtil(); -/** - * The system for which Nix is compiled. - */ -extern const std::string nativeSystem; - - /** * @return an environment variable. */ From ac89bb064aeea85a62b82a6daf0ecca7190a28b7 Mon Sep 17 00:00:00 2001 From: John Ericson Date: Wed, 25 Oct 2023 00:43:36 -0400 Subject: [PATCH 2/2] Split up `util.{hh,cc}` All OS and IO operations should be moved out, leaving only some misc portable pure functions. This is useful to avoid copious CPP when doing things like Windows and Emscripten ports. Newly exposed functions to break cycles: - `restoreSignals` - `updateWindowSize` --- perl/lib/Nix/Store.xs | 1 - src/libcmd/built-path.hh | 3 + src/libcmd/common-eval-args.cc | 1 - src/libcmd/editor-for.cc | 2 +- src/libcmd/installable-attr-path.hh | 1 - src/libcmd/installables.cc | 1 + src/libcmd/installables.hh | 1 - src/libcmd/markdown.cc | 1 + src/libcmd/repl.cc | 3 + src/libexpr/attr-path.cc | 1 - src/libexpr/eval-cache.cc | 1 + src/libexpr/eval-settings.cc | 1 + src/libexpr/eval-settings.hh | 2 + src/libexpr/eval.cc | 1 + src/libexpr/flake/config.cc | 3 +- src/libexpr/flake/flake.cc | 1 + src/libexpr/get-drvs.cc | 1 - src/libexpr/parser.y | 1 + src/libexpr/primops.cc | 1 + src/libexpr/search-path.cc | 1 - src/libexpr/value-to-json.cc | 2 +- src/libexpr/value-to-xml.cc | 2 +- src/libexpr/value/context.cc | 1 + src/libexpr/value/context.hh | 1 - src/libfetchers/cache.cc | 1 + src/libfetchers/fetch-settings.hh | 1 - src/libfetchers/git.cc | 3 +- src/libfetchers/input-accessor.hh | 2 + src/libfetchers/mercurial.cc | 2 + src/libfetchers/registry.cc | 2 +- src/libmain/common-args.cc | 2 + src/libmain/loggers.cc | 2 +- src/libmain/progress-bar.cc | 2 +- src/libmain/shared.cc | 3 +- src/libmain/shared.hh | 2 +- src/libstore/binary-cache-store.cc | 1 + src/libstore/build/child.cc | 37 + src/libstore/build/child.hh | 11 + src/libstore/build/hook-instance.cc | 2 + src/libstore/build/hook-instance.hh | 1 + src/libstore/build/local-derivation-goal.cc | 3 + src/libstore/build/local-derivation-goal.hh | 1 + src/libstore/build/worker.cc | 1 + src/libstore/common-protocol.cc | 1 - src/libstore/crypto.cc | 1 + src/libstore/derived-path-map.cc | 1 + src/libstore/derived-path-map.hh | 1 + src/libstore/derived-path.hh | 2 +- src/libstore/filetransfer.cc | 3 +- src/libstore/gc.cc | 7 + src/libstore/globals.cc | 13 +- src/libstore/globals.hh | 2 +- src/libstore/local-store.cc | 1 + src/libstore/local-store.hh | 1 - src/libstore/lock.cc | 1 + src/libstore/machines.cc | 1 - src/libstore/nar-info-disk-cache.cc | 1 + src/libstore/optimise-store.cc | 2 +- src/libstore/path-references.cc | 1 - src/libstore/path-references.hh | 1 + src/libstore/pathlocks.cc | 1 + src/libstore/pathlocks.hh | 2 +- src/libstore/profiles.cc | 2 +- src/libstore/remote-store-connection.hh | 3 + src/libstore/serve-protocol.cc | 1 - src/libstore/sqlite.cc | 1 + src/libstore/ssh.cc | 3 + src/libstore/ssh.hh | 3 +- src/libstore/store-api.cc | 2 + src/libstore/tests/machines.cc | 2 + src/libstore/tests/protocol.hh | 3 + src/libstore/uds-remote-store.cc | 1 + src/libstore/worker-protocol.cc | 1 - src/libutil/archive.cc | 3 +- src/libutil/args.cc | 3 + src/libutil/args.hh | 5 +- src/libutil/canon-path.cc | 2 +- src/libutil/cgroup.cc | 1 + src/libutil/compression.cc | 2 +- src/libutil/config.cc | 2 + src/libutil/current-process.cc | 110 + src/libutil/current-process.hh | 34 + src/libutil/environment-variables.cc | 49 + src/libutil/environment-variables.hh | 41 + src/libutil/error.cc | 3 + src/libutil/file-descriptor.cc | 254 +++ src/libutil/file-descriptor.hh | 84 + src/libutil/file-system.cc | 647 ++++++ src/libutil/file-system.hh | 238 +++ src/libutil/filesystem.cc | 162 -- src/libutil/fs-sink.hh | 1 + src/libutil/hash.cc | 1 - src/libutil/hash.hh | 1 + src/libutil/logging.cc | 3 + src/libutil/monitor-fd.hh | 2 + src/libutil/namespaces.cc | 69 +- src/libutil/namespaces.hh | 23 + src/libutil/posix-source-accessor.cc | 1 + src/libutil/processes.cc | 421 ++++ src/libutil/processes.hh | 123 ++ src/libutil/references.cc | 1 - src/libutil/serialise.cc | 2 +- src/libutil/serialise.hh | 1 + src/libutil/signals.cc | 188 ++ src/libutil/signals.hh | 104 + src/libutil/suggestions.cc | 4 +- src/libutil/tarfile.cc | 1 + src/libutil/terminal.cc | 108 + src/libutil/terminal.hh | 38 + src/libutil/tests/logging.cc | 1 - src/libutil/tests/tests.cc | 3 + src/libutil/thread-pool.cc | 2 + src/libutil/thread-pool.hh | 2 +- src/libutil/unix-domain-socket.cc | 100 + src/libutil/unix-domain-socket.hh | 31 + src/libutil/users.cc | 116 ++ src/libutil/users.hh | 58 + src/libutil/util.cc | 1816 +---------------- src/libutil/util.hh | 617 ------ src/nix-build/nix-build.cc | 2 +- src/nix-channel/nix-channel.cc | 2 +- .../nix-collect-garbage.cc | 2 + src/nix-env/nix-env.cc | 2 +- src/nix-env/user-env.cc | 1 - src/nix-instantiate/nix-instantiate.cc | 1 - src/nix-store/dotgraph.cc | 1 - src/nix-store/graphml.cc | 1 - src/nix-store/nix-store.cc | 1 - src/nix/daemon.cc | 3 +- src/nix/develop.cc | 1 - src/nix/doctor.cc | 1 - src/nix/edit.cc | 1 + src/nix/flake.cc | 1 + src/nix/main.cc | 2 + src/nix/run.cc | 1 + src/nix/sigs.cc | 1 + src/nix/upgrade-nix.cc | 1 + src/nix/verify.cc | 1 + 138 files changed, 3028 insertions(+), 2654 deletions(-) create mode 100644 src/libstore/build/child.cc create mode 100644 src/libstore/build/child.hh create mode 100644 src/libutil/current-process.cc create mode 100644 src/libutil/current-process.hh create mode 100644 src/libutil/environment-variables.cc create mode 100644 src/libutil/environment-variables.hh create mode 100644 src/libutil/file-descriptor.cc create mode 100644 src/libutil/file-descriptor.hh create mode 100644 src/libutil/file-system.cc create mode 100644 src/libutil/file-system.hh delete mode 100644 src/libutil/filesystem.cc create mode 100644 src/libutil/processes.cc create mode 100644 src/libutil/processes.hh create mode 100644 src/libutil/signals.cc create mode 100644 src/libutil/signals.hh create mode 100644 src/libutil/terminal.cc create mode 100644 src/libutil/terminal.hh create mode 100644 src/libutil/unix-domain-socket.cc create mode 100644 src/libutil/unix-domain-socket.hh create mode 100644 src/libutil/users.cc create mode 100644 src/libutil/users.hh diff --git a/perl/lib/Nix/Store.xs b/perl/lib/Nix/Store.xs index 08f812b31..f89ac4077 100644 --- a/perl/lib/Nix/Store.xs +++ b/perl/lib/Nix/Store.xs @@ -11,7 +11,6 @@ #include "derivations.hh" #include "globals.hh" #include "store-api.hh" -#include "util.hh" #include "crypto.hh" #include diff --git a/src/libcmd/built-path.hh b/src/libcmd/built-path.hh index e677bc810..7154cc504 100644 --- a/src/libcmd/built-path.hh +++ b/src/libcmd/built-path.hh @@ -1,3 +1,6 @@ +#pragma once +///@file + #include "derived-path.hh" #include "realisation.hh" diff --git a/src/libcmd/common-eval-args.cc b/src/libcmd/common-eval-args.cc index e53bc4c01..91fa881b1 100644 --- a/src/libcmd/common-eval-args.cc +++ b/src/libcmd/common-eval-args.cc @@ -2,7 +2,6 @@ #include "common-eval-args.hh" #include "shared.hh" #include "filetransfer.hh" -#include "util.hh" #include "eval.hh" #include "fetchers.hh" #include "registry.hh" diff --git a/src/libcmd/editor-for.cc b/src/libcmd/editor-for.cc index a17c6f12a..619d3673f 100644 --- a/src/libcmd/editor-for.cc +++ b/src/libcmd/editor-for.cc @@ -1,5 +1,5 @@ -#include "util.hh" #include "editor-for.hh" +#include "environment-variables.hh" namespace nix { diff --git a/src/libcmd/installable-attr-path.hh b/src/libcmd/installable-attr-path.hh index e9f0c33da..86c2f8219 100644 --- a/src/libcmd/installable-attr-path.hh +++ b/src/libcmd/installable-attr-path.hh @@ -4,7 +4,6 @@ #include "globals.hh" #include "installable-value.hh" #include "outputs-spec.hh" -#include "util.hh" #include "command.hh" #include "attr-path.hh" #include "common-eval-args.hh" diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc index bc0b8a988..e7f58556f 100644 --- a/src/libcmd/installables.cc +++ b/src/libcmd/installables.cc @@ -4,6 +4,7 @@ #include "installable-attr-path.hh" #include "installable-flake.hh" #include "outputs-spec.hh" +#include "users.hh" #include "util.hh" #include "command.hh" #include "attr-path.hh" diff --git a/src/libcmd/installables.hh b/src/libcmd/installables.hh index b0dc0dc02..e087f935c 100644 --- a/src/libcmd/installables.hh +++ b/src/libcmd/installables.hh @@ -1,7 +1,6 @@ #pragma once ///@file -#include "util.hh" #include "path.hh" #include "outputs-spec.hh" #include "derived-path.hh" diff --git a/src/libcmd/markdown.cc b/src/libcmd/markdown.cc index 668a07763..8b3bbc1b5 100644 --- a/src/libcmd/markdown.cc +++ b/src/libcmd/markdown.cc @@ -1,6 +1,7 @@ #include "markdown.hh" #include "util.hh" #include "finally.hh" +#include "terminal.hh" #include #include diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc index 2e17a29a7..bf5643a5c 100644 --- a/src/libcmd/repl.cc +++ b/src/libcmd/repl.cc @@ -22,6 +22,7 @@ extern "C" { #include "repl.hh" #include "ansicolor.hh" +#include "signals.hh" #include "shared.hh" #include "eval.hh" #include "eval-cache.hh" @@ -36,6 +37,8 @@ extern "C" { #include "globals.hh" #include "flake/flake.hh" #include "flake/lockfile.hh" +#include "users.hh" +#include "terminal.hh" #include "editor-for.hh" #include "finally.hh" #include "markdown.hh" diff --git a/src/libexpr/attr-path.cc b/src/libexpr/attr-path.cc index d12345710..7481a2232 100644 --- a/src/libexpr/attr-path.cc +++ b/src/libexpr/attr-path.cc @@ -1,6 +1,5 @@ #include "attr-path.hh" #include "eval-inline.hh" -#include "util.hh" namespace nix { diff --git a/src/libexpr/eval-cache.cc b/src/libexpr/eval-cache.cc index 10fc799a9..6c0e33709 100644 --- a/src/libexpr/eval-cache.cc +++ b/src/libexpr/eval-cache.cc @@ -1,3 +1,4 @@ +#include "users.hh" #include "eval-cache.hh" #include "sqlite.hh" #include "eval.hh" diff --git a/src/libexpr/eval-settings.cc b/src/libexpr/eval-settings.cc index 93b4a5289..444a7d7d6 100644 --- a/src/libexpr/eval-settings.cc +++ b/src/libexpr/eval-settings.cc @@ -1,3 +1,4 @@ +#include "users.hh" #include "globals.hh" #include "profiles.hh" #include "eval.hh" diff --git a/src/libexpr/eval-settings.hh b/src/libexpr/eval-settings.hh index 5473d688e..db2971acb 100644 --- a/src/libexpr/eval-settings.hh +++ b/src/libexpr/eval-settings.hh @@ -1,4 +1,6 @@ #pragma once +///@file + #include "config.hh" namespace nix { diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index d26cde423..dfe81cbf7 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -14,6 +14,7 @@ #include "print.hh" #include "fs-input-accessor.hh" #include "memory-input-accessor.hh" +#include "signals.hh" #include #include diff --git a/src/libexpr/flake/config.cc b/src/libexpr/flake/config.cc index e89014862..3c7ed5d8a 100644 --- a/src/libexpr/flake/config.cc +++ b/src/libexpr/flake/config.cc @@ -1,6 +1,7 @@ -#include "flake.hh" +#include "users.hh" #include "globals.hh" #include "fetch-settings.hh" +#include "flake.hh" #include diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc index ded132695..54de53e0b 100644 --- a/src/libexpr/flake/flake.cc +++ b/src/libexpr/flake/flake.cc @@ -1,3 +1,4 @@ +#include "terminal.hh" #include "flake.hh" #include "eval.hh" #include "eval-settings.hh" diff --git a/src/libexpr/get-drvs.cc b/src/libexpr/get-drvs.cc index fe3e6f7ee..d4e946d81 100644 --- a/src/libexpr/get-drvs.cc +++ b/src/libexpr/get-drvs.cc @@ -1,5 +1,4 @@ #include "get-drvs.hh" -#include "util.hh" #include "eval-inline.hh" #include "derivations.hh" #include "store-api.hh" diff --git a/src/libexpr/parser.y b/src/libexpr/parser.y index 607795937..b86cef217 100644 --- a/src/libexpr/parser.y +++ b/src/libexpr/parser.y @@ -19,6 +19,7 @@ #include #include "util.hh" +#include "users.hh" #include "nixexpr.hh" #include "eval.hh" diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc index e3c775d90..36340d0f9 100644 --- a/src/libexpr/primops.cc +++ b/src/libexpr/primops.cc @@ -10,6 +10,7 @@ #include "path-references.hh" #include "store-api.hh" #include "util.hh" +#include "processes.hh" #include "value-to-json.hh" #include "value-to-xml.hh" #include "primops.hh" diff --git a/src/libexpr/search-path.cc b/src/libexpr/search-path.cc index 180d5f8b1..a25767496 100644 --- a/src/libexpr/search-path.cc +++ b/src/libexpr/search-path.cc @@ -1,5 +1,4 @@ #include "search-path.hh" -#include "util.hh" namespace nix { diff --git a/src/libexpr/value-to-json.cc b/src/libexpr/value-to-json.cc index cbc91f509..74b3ebf13 100644 --- a/src/libexpr/value-to-json.cc +++ b/src/libexpr/value-to-json.cc @@ -1,7 +1,7 @@ #include "value-to-json.hh" #include "eval-inline.hh" -#include "util.hh" #include "store-api.hh" +#include "signals.hh" #include #include diff --git a/src/libexpr/value-to-xml.cc b/src/libexpr/value-to-xml.cc index bd7a4ae30..5032115bb 100644 --- a/src/libexpr/value-to-xml.cc +++ b/src/libexpr/value-to-xml.cc @@ -1,7 +1,7 @@ #include "value-to-xml.hh" #include "xml-writer.hh" #include "eval-inline.hh" -#include "util.hh" +#include "signals.hh" #include diff --git a/src/libexpr/value/context.cc b/src/libexpr/value/context.cc index 22361d8fa..6d9633268 100644 --- a/src/libexpr/value/context.cc +++ b/src/libexpr/value/context.cc @@ -1,3 +1,4 @@ +#include "util.hh" #include "value/context.hh" #include diff --git a/src/libexpr/value/context.hh b/src/libexpr/value/context.hh index 9f1d59317..51fd30a44 100644 --- a/src/libexpr/value/context.hh +++ b/src/libexpr/value/context.hh @@ -1,7 +1,6 @@ #pragma once ///@file -#include "util.hh" #include "comparator.hh" #include "derived-path.hh" #include "variant-wrapper.hh" diff --git a/src/libfetchers/cache.cc b/src/libfetchers/cache.cc index 0c8ecac9d..b72a464e8 100644 --- a/src/libfetchers/cache.cc +++ b/src/libfetchers/cache.cc @@ -1,4 +1,5 @@ #include "cache.hh" +#include "users.hh" #include "sqlite.hh" #include "sync.hh" #include "store-api.hh" diff --git a/src/libfetchers/fetch-settings.hh b/src/libfetchers/fetch-settings.hh index 6108a179c..f095963a8 100644 --- a/src/libfetchers/fetch-settings.hh +++ b/src/libfetchers/fetch-settings.hh @@ -3,7 +3,6 @@ #include "types.hh" #include "config.hh" -#include "util.hh" #include #include diff --git a/src/libfetchers/git.cc b/src/libfetchers/git.cc index 72fba0582..cc735996b 100644 --- a/src/libfetchers/git.cc +++ b/src/libfetchers/git.cc @@ -1,11 +1,12 @@ #include "fetchers.hh" +#include "users.hh" #include "cache.hh" #include "globals.hh" #include "tarfile.hh" #include "store-api.hh" #include "url-parts.hh" #include "pathlocks.hh" -#include "util.hh" +#include "processes.hh" #include "git.hh" #include "fetch-settings.hh" diff --git a/src/libfetchers/input-accessor.hh b/src/libfetchers/input-accessor.hh index 5dc05a363..6857ce156 100644 --- a/src/libfetchers/input-accessor.hh +++ b/src/libfetchers/input-accessor.hh @@ -1,8 +1,10 @@ #pragma once +///@file #include "source-accessor.hh" #include "ref.hh" #include "types.hh" +#include "file-system.hh" #include "repair-flag.hh" #include "content-address.hh" diff --git a/src/libfetchers/mercurial.cc b/src/libfetchers/mercurial.cc index eda33dfe7..9244acf39 100644 --- a/src/libfetchers/mercurial.cc +++ b/src/libfetchers/mercurial.cc @@ -1,4 +1,6 @@ #include "fetchers.hh" +#include "processes.hh" +#include "users.hh" #include "cache.hh" #include "globals.hh" #include "tarfile.hh" diff --git a/src/libfetchers/registry.cc b/src/libfetchers/registry.cc index a0fff9ceb..9c7bc0cfe 100644 --- a/src/libfetchers/registry.cc +++ b/src/libfetchers/registry.cc @@ -1,6 +1,6 @@ #include "registry.hh" #include "tarball.hh" -#include "util.hh" +#include "users.hh" #include "globals.hh" #include "store-api.hh" #include "local-fs-store.hh" diff --git a/src/libmain/common-args.cc b/src/libmain/common-args.cc index 205b77808..5b49aaabc 100644 --- a/src/libmain/common-args.cc +++ b/src/libmain/common-args.cc @@ -1,7 +1,9 @@ #include "common-args.hh" #include "args/root.hh" #include "globals.hh" +#include "logging.hh" #include "loggers.hh" +#include "util.hh" namespace nix { diff --git a/src/libmain/loggers.cc b/src/libmain/loggers.cc index cda5cb939..9829859de 100644 --- a/src/libmain/loggers.cc +++ b/src/libmain/loggers.cc @@ -1,6 +1,6 @@ #include "loggers.hh" +#include "environment-variables.hh" #include "progress-bar.hh" -#include "util.hh" namespace nix { diff --git a/src/libmain/progress-bar.cc b/src/libmain/progress-bar.cc index 45b1fdfd1..a7aee47c3 100644 --- a/src/libmain/progress-bar.cc +++ b/src/libmain/progress-bar.cc @@ -1,5 +1,5 @@ #include "progress-bar.hh" -#include "util.hh" +#include "terminal.hh" #include "sync.hh" #include "store-api.hh" #include "names.hh" diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc index 9c2ad039a..862ef355b 100644 --- a/src/libmain/shared.cc +++ b/src/libmain/shared.cc @@ -1,10 +1,11 @@ #include "globals.hh" +#include "current-process.hh" #include "shared.hh" #include "store-api.hh" #include "gc-store.hh" -#include "util.hh" #include "loggers.hh" #include "progress-bar.hh" +#include "signals.hh" #include #include diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh index 3159fe479..c68f6cd83 100644 --- a/src/libmain/shared.hh +++ b/src/libmain/shared.hh @@ -1,7 +1,7 @@ #pragma once ///@file -#include "util.hh" +#include "processes.hh" #include "args.hh" #include "args/root.hh" #include "common-args.hh" diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc index 6a52c4c51..ae483c95e 100644 --- a/src/libstore/binary-cache-store.cc +++ b/src/libstore/binary-cache-store.cc @@ -11,6 +11,7 @@ #include "nar-accessor.hh" #include "thread-pool.hh" #include "callback.hh" +#include "signals.hh" #include #include diff --git a/src/libstore/build/child.cc b/src/libstore/build/child.cc new file mode 100644 index 000000000..aa31c3caf --- /dev/null +++ b/src/libstore/build/child.cc @@ -0,0 +1,37 @@ +#include "child.hh" +#include "current-process.hh" +#include "logging.hh" + +#include +#include + +namespace nix { + +void commonChildInit() +{ + logger = makeSimpleLogger(); + + const static std::string pathNullDevice = "/dev/null"; + restoreProcessContext(false); + + /* Put the child in a separate session (and thus a separate + process group) so that it has no controlling terminal (meaning + that e.g. ssh cannot open /dev/tty) and it doesn't receive + terminal signals. */ + if (setsid() == -1) + throw SysError("creating a new session"); + + /* Dup stderr to stdout. */ + if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1) + throw SysError("cannot dup stderr into stdout"); + + /* Reroute stdin to /dev/null. */ + int fdDevNull = open(pathNullDevice.c_str(), O_RDWR); + if (fdDevNull == -1) + throw SysError("cannot open '%1%'", pathNullDevice); + if (dup2(fdDevNull, STDIN_FILENO) == -1) + throw SysError("cannot dup null device into stdin"); + close(fdDevNull); +} + +} diff --git a/src/libstore/build/child.hh b/src/libstore/build/child.hh new file mode 100644 index 000000000..3dfc552b9 --- /dev/null +++ b/src/libstore/build/child.hh @@ -0,0 +1,11 @@ +#pragma once +///@file + +namespace nix { + +/** + * Common initialisation performed in child processes. + */ +void commonChildInit(); + +} diff --git a/src/libstore/build/hook-instance.cc b/src/libstore/build/hook-instance.cc index 337c60bd4..5d045ec3d 100644 --- a/src/libstore/build/hook-instance.cc +++ b/src/libstore/build/hook-instance.cc @@ -1,5 +1,7 @@ #include "globals.hh" #include "hook-instance.hh" +#include "file-system.hh" +#include "child.hh" namespace nix { diff --git a/src/libstore/build/hook-instance.hh b/src/libstore/build/hook-instance.hh index d84f62877..61cf534f4 100644 --- a/src/libstore/build/hook-instance.hh +++ b/src/libstore/build/hook-instance.hh @@ -3,6 +3,7 @@ #include "logging.hh" #include "serialise.hh" +#include "processes.hh" namespace nix { diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc index e1794139f..adb011e30 100644 --- a/src/libstore/build/local-derivation-goal.cc +++ b/src/libstore/build/local-derivation-goal.cc @@ -15,7 +15,10 @@ #include "json-utils.hh" #include "cgroup.hh" #include "personality.hh" +#include "current-process.hh" #include "namespaces.hh" +#include "child.hh" +#include "unix-domain-socket.hh" #include #include diff --git a/src/libstore/build/local-derivation-goal.hh b/src/libstore/build/local-derivation-goal.hh index 1cb68a869..88152a645 100644 --- a/src/libstore/build/local-derivation-goal.hh +++ b/src/libstore/build/local-derivation-goal.hh @@ -3,6 +3,7 @@ #include "derivation-goal.hh" #include "local-store.hh" +#include "processes.hh" namespace nix { diff --git a/src/libstore/build/worker.cc b/src/libstore/build/worker.cc index 37cb86b91..01914e2d6 100644 --- a/src/libstore/build/worker.cc +++ b/src/libstore/build/worker.cc @@ -4,6 +4,7 @@ #include "drv-output-substitution-goal.hh" #include "local-derivation-goal.hh" #include "hook-instance.hh" +#include "signals.hh" #include diff --git a/src/libstore/common-protocol.cc b/src/libstore/common-protocol.cc index f906814bc..68445258f 100644 --- a/src/libstore/common-protocol.cc +++ b/src/libstore/common-protocol.cc @@ -1,5 +1,4 @@ #include "serialise.hh" -#include "util.hh" #include "path-with-outputs.hh" #include "store-api.hh" #include "build-result.hh" diff --git a/src/libstore/crypto.cc b/src/libstore/crypto.cc index 1027469c9..1b705733c 100644 --- a/src/libstore/crypto.cc +++ b/src/libstore/crypto.cc @@ -1,4 +1,5 @@ #include "crypto.hh" +#include "file-system.hh" #include "util.hh" #include "globals.hh" diff --git a/src/libstore/derived-path-map.cc b/src/libstore/derived-path-map.cc index 5982c04b3..4c1ea417a 100644 --- a/src/libstore/derived-path-map.cc +++ b/src/libstore/derived-path-map.cc @@ -1,4 +1,5 @@ #include "derived-path-map.hh" +#include "util.hh" namespace nix { diff --git a/src/libstore/derived-path-map.hh b/src/libstore/derived-path-map.hh index 4d72b301e..393cdedf7 100644 --- a/src/libstore/derived-path-map.hh +++ b/src/libstore/derived-path-map.hh @@ -1,4 +1,5 @@ #pragma once +///@file #include "types.hh" #include "derived-path.hh" diff --git a/src/libstore/derived-path.hh b/src/libstore/derived-path.hh index 4d7033df2..6c5dfeed9 100644 --- a/src/libstore/derived-path.hh +++ b/src/libstore/derived-path.hh @@ -1,10 +1,10 @@ #pragma once ///@file -#include "util.hh" #include "path.hh" #include "outputs-spec.hh" #include "comparator.hh" +#include "config.hh" #include diff --git a/src/libstore/filetransfer.cc b/src/libstore/filetransfer.cc index a283af5a2..dcbec4acd 100644 --- a/src/libstore/filetransfer.cc +++ b/src/libstore/filetransfer.cc @@ -1,11 +1,12 @@ #include "filetransfer.hh" -#include "util.hh" +#include "namespaces.hh" #include "globals.hh" #include "store-api.hh" #include "s3.hh" #include "compression.hh" #include "finally.hh" #include "callback.hh" +#include "signals.hh" #if ENABLE_S3 #include diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc index fb7895817..8d05ae4bd 100644 --- a/src/libstore/gc.cc +++ b/src/libstore/gc.cc @@ -2,6 +2,13 @@ #include "globals.hh" #include "local-store.hh" #include "finally.hh" +#include "unix-domain-socket.hh" +#include "signals.hh" + +#if !defined(__linux__) +// For shelling out to lsof +# include "processes.hh" +#endif #include #include diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc index 9c25d9868..cc416a4d6 100644 --- a/src/libstore/globals.cc +++ b/src/libstore/globals.cc @@ -1,7 +1,8 @@ #include "globals.hh" -#include "util.hh" +#include "current-process.hh" #include "archive.hh" #include "args.hh" +#include "users.hh" #include "abstract-setting-to-json.hh" #include "compute-levels.hh" @@ -17,9 +18,13 @@ #include #ifdef __GLIBC__ -#include -#include -#include +# include +# include +# include +#endif + +#if __APPLE__ +# include "processes.hh" #endif #include "config-impl.hh" diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh index 12fb48d93..8e034f5a9 100644 --- a/src/libstore/globals.hh +++ b/src/libstore/globals.hh @@ -3,7 +3,7 @@ #include "types.hh" #include "config.hh" -#include "util.hh" +#include "environment-variables.hh" #include "experimental-features.hh" #include diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc index a5e9426f8..2a3582ad8 100644 --- a/src/libstore/local-store.cc +++ b/src/libstore/local-store.cc @@ -10,6 +10,7 @@ #include "topo-sort.hh" #include "finally.hh" #include "compression.hh" +#include "signals.hh" #include #include diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh index fe26a0f27..6d589bee5 100644 --- a/src/libstore/local-store.hh +++ b/src/libstore/local-store.hh @@ -7,7 +7,6 @@ #include "store-api.hh" #include "indirect-root-store.hh" #include "sync.hh" -#include "util.hh" #include #include diff --git a/src/libstore/lock.cc b/src/libstore/lock.cc index 165e4969f..87f55ce49 100644 --- a/src/libstore/lock.cc +++ b/src/libstore/lock.cc @@ -1,4 +1,5 @@ #include "lock.hh" +#include "file-system.hh" #include "globals.hh" #include "pathlocks.hh" diff --git a/src/libstore/machines.cc b/src/libstore/machines.cc index e87f46980..512115893 100644 --- a/src/libstore/machines.cc +++ b/src/libstore/machines.cc @@ -1,5 +1,4 @@ #include "machines.hh" -#include "util.hh" #include "globals.hh" #include "store-api.hh" diff --git a/src/libstore/nar-info-disk-cache.cc b/src/libstore/nar-info-disk-cache.cc index cdbcf7e74..e50c15939 100644 --- a/src/libstore/nar-info-disk-cache.cc +++ b/src/libstore/nar-info-disk-cache.cc @@ -1,4 +1,5 @@ #include "nar-info-disk-cache.hh" +#include "users.hh" #include "sync.hh" #include "sqlite.hh" #include "globals.hh" diff --git a/src/libstore/optimise-store.cc b/src/libstore/optimise-store.cc index 23c6a41e4..a4ac413b3 100644 --- a/src/libstore/optimise-store.cc +++ b/src/libstore/optimise-store.cc @@ -1,6 +1,6 @@ -#include "util.hh" #include "local-store.hh" #include "globals.hh" +#include "signals.hh" #include #include diff --git a/src/libstore/path-references.cc b/src/libstore/path-references.cc index 33cf66ce3..274b596c0 100644 --- a/src/libstore/path-references.cc +++ b/src/libstore/path-references.cc @@ -1,6 +1,5 @@ #include "path-references.hh" #include "hash.hh" -#include "util.hh" #include "archive.hh" #include diff --git a/src/libstore/path-references.hh b/src/libstore/path-references.hh index 7b44e3261..0553003f8 100644 --- a/src/libstore/path-references.hh +++ b/src/libstore/path-references.hh @@ -1,4 +1,5 @@ #pragma once +///@file #include "references.hh" #include "path.hh" diff --git a/src/libstore/pathlocks.cc b/src/libstore/pathlocks.cc index adc763e6a..2b5b8dfe7 100644 --- a/src/libstore/pathlocks.cc +++ b/src/libstore/pathlocks.cc @@ -1,6 +1,7 @@ #include "pathlocks.hh" #include "util.hh" #include "sync.hh" +#include "signals.hh" #include #include diff --git a/src/libstore/pathlocks.hh b/src/libstore/pathlocks.hh index 4921df352..7fcfa2e40 100644 --- a/src/libstore/pathlocks.hh +++ b/src/libstore/pathlocks.hh @@ -1,7 +1,7 @@ #pragma once ///@file -#include "util.hh" +#include "file-descriptor.hh" namespace nix { diff --git a/src/libstore/profiles.cc b/src/libstore/profiles.cc index 239047dd6..e8b88693d 100644 --- a/src/libstore/profiles.cc +++ b/src/libstore/profiles.cc @@ -1,7 +1,7 @@ #include "profiles.hh" #include "store-api.hh" #include "local-fs-store.hh" -#include "util.hh" +#include "users.hh" #include #include diff --git a/src/libstore/remote-store-connection.hh b/src/libstore/remote-store-connection.hh index e4a9cacb9..44328b06b 100644 --- a/src/libstore/remote-store-connection.hh +++ b/src/libstore/remote-store-connection.hh @@ -1,3 +1,6 @@ +#pragma once +///@file + #include "remote-store.hh" #include "worker-protocol.hh" #include "pool.hh" diff --git a/src/libstore/serve-protocol.cc b/src/libstore/serve-protocol.cc index 97a0ddf0e..9bfcc279c 100644 --- a/src/libstore/serve-protocol.cc +++ b/src/libstore/serve-protocol.cc @@ -1,5 +1,4 @@ #include "serialise.hh" -#include "util.hh" #include "path-with-outputs.hh" #include "store-api.hh" #include "build-result.hh" diff --git a/src/libstore/sqlite.cc b/src/libstore/sqlite.cc index 7c8decb74..d7432a305 100644 --- a/src/libstore/sqlite.cc +++ b/src/libstore/sqlite.cc @@ -2,6 +2,7 @@ #include "globals.hh" #include "util.hh" #include "url.hh" +#include "signals.hh" #include diff --git a/src/libstore/ssh.cc b/src/libstore/ssh.cc index da32f1b79..03b2f0be9 100644 --- a/src/libstore/ssh.cc +++ b/src/libstore/ssh.cc @@ -1,5 +1,8 @@ #include "ssh.hh" #include "finally.hh" +#include "current-process.hh" +#include "environment-variables.hh" +#include "util.hh" namespace nix { diff --git a/src/libstore/ssh.hh b/src/libstore/ssh.hh index 94b952af9..bfcd6f21c 100644 --- a/src/libstore/ssh.hh +++ b/src/libstore/ssh.hh @@ -1,8 +1,9 @@ #pragma once ///@file -#include "util.hh" #include "sync.hh" +#include "processes.hh" +#include "file-system.hh" namespace nix { diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc index 646b0ec7d..c9ebb6c14 100644 --- a/src/libstore/store-api.cc +++ b/src/libstore/store-api.cc @@ -14,6 +14,8 @@ // FIXME this should not be here, see TODO below on // `addMultipleToStore`. #include "worker-protocol.hh" +#include "signals.hh" +#include "users.hh" #include #include diff --git a/src/libstore/tests/machines.cc b/src/libstore/tests/machines.cc index f51052b14..fede328ea 100644 --- a/src/libstore/tests/machines.cc +++ b/src/libstore/tests/machines.cc @@ -1,5 +1,7 @@ #include "machines.hh" #include "globals.hh" +#include "file-system.hh" +#include "util.hh" #include diff --git a/src/libstore/tests/protocol.hh b/src/libstore/tests/protocol.hh index 0378b3e1f..466032a79 100644 --- a/src/libstore/tests/protocol.hh +++ b/src/libstore/tests/protocol.hh @@ -1,3 +1,6 @@ +#pragma once +///@file + #include #include diff --git a/src/libstore/uds-remote-store.cc b/src/libstore/uds-remote-store.cc index 99589f8b2..226cdf717 100644 --- a/src/libstore/uds-remote-store.cc +++ b/src/libstore/uds-remote-store.cc @@ -1,4 +1,5 @@ #include "uds-remote-store.hh" +#include "unix-domain-socket.hh" #include "worker-protocol.hh" #include diff --git a/src/libstore/worker-protocol.cc b/src/libstore/worker-protocol.cc index d618b9bd8..1d202f8d1 100644 --- a/src/libstore/worker-protocol.cc +++ b/src/libstore/worker-protocol.cc @@ -1,5 +1,4 @@ #include "serialise.hh" -#include "util.hh" #include "path-with-outputs.hh" #include "store-api.hh" #include "build-result.hh" diff --git a/src/libutil/archive.cc b/src/libutil/archive.cc index 4ca84d357..465df2073 100644 --- a/src/libutil/archive.cc +++ b/src/libutil/archive.cc @@ -6,9 +6,10 @@ #include // for strcasecmp #include "archive.hh" -#include "util.hh" #include "config.hh" #include "posix-source-accessor.hh" +#include "file-system.hh" +#include "signals.hh" namespace nix { diff --git a/src/libutil/args.cc b/src/libutil/args.cc index 811353c18..0b65519a3 100644 --- a/src/libutil/args.cc +++ b/src/libutil/args.cc @@ -1,6 +1,9 @@ #include "args.hh" #include "args/root.hh" #include "hash.hh" +#include "environment-variables.hh" +#include "signals.hh" +#include "users.hh" #include "json-utils.hh" #include diff --git a/src/libutil/args.hh b/src/libutil/args.hh index e3b41313f..45fd678e7 100644 --- a/src/libutil/args.hh +++ b/src/libutil/args.hh @@ -2,12 +2,15 @@ ///@file #include +#include #include #include +#include #include -#include "util.hh" +#include "types.hh" +#include "experimental-features.hh" namespace nix { diff --git a/src/libutil/canon-path.cc b/src/libutil/canon-path.cc index 040464532..f678fae94 100644 --- a/src/libutil/canon-path.cc +++ b/src/libutil/canon-path.cc @@ -1,5 +1,5 @@ #include "canon-path.hh" -#include "util.hh" +#include "file-system.hh" namespace nix { diff --git a/src/libutil/cgroup.cc b/src/libutil/cgroup.cc index a008481ca..4c2bf31ff 100644 --- a/src/libutil/cgroup.cc +++ b/src/libutil/cgroup.cc @@ -2,6 +2,7 @@ #include "cgroup.hh" #include "util.hh" +#include "file-system.hh" #include "finally.hh" #include diff --git a/src/libutil/compression.cc b/src/libutil/compression.cc index ba0847cde..d06f1f87b 100644 --- a/src/libutil/compression.cc +++ b/src/libutil/compression.cc @@ -1,6 +1,6 @@ #include "compression.hh" +#include "signals.hh" #include "tarfile.hh" -#include "util.hh" #include "finally.hh" #include "logging.hh" diff --git a/src/libutil/config.cc b/src/libutil/config.cc index 8e06273ee..0bf36c987 100644 --- a/src/libutil/config.cc +++ b/src/libutil/config.cc @@ -2,6 +2,8 @@ #include "args.hh" #include "abstract-setting-to-json.hh" #include "experimental-features.hh" +#include "util.hh" +#include "file-system.hh" #include "config-impl.hh" diff --git a/src/libutil/current-process.cc b/src/libutil/current-process.cc new file mode 100644 index 000000000..352a6a0fb --- /dev/null +++ b/src/libutil/current-process.cc @@ -0,0 +1,110 @@ +#include "current-process.hh" +#include "namespaces.hh" +#include "util.hh" +#include "finally.hh" +#include "file-system.hh" +#include "processes.hh" +#include "signals.hh" + +#ifdef __APPLE__ +# include +#endif + +#if __linux__ +# include +# include +# include "cgroup.hh" +#endif + +#include + +namespace nix { + +unsigned int getMaxCPU() +{ + #if __linux__ + try { + auto cgroupFS = getCgroupFS(); + if (!cgroupFS) return 0; + + auto cgroups = getCgroups("/proc/self/cgroup"); + auto cgroup = cgroups[""]; + if (cgroup == "") return 0; + + auto cpuFile = *cgroupFS + "/" + cgroup + "/cpu.max"; + + auto cpuMax = readFile(cpuFile); + auto cpuMaxParts = tokenizeString>(cpuMax, " \n"); + auto quota = cpuMaxParts[0]; + auto period = cpuMaxParts[1]; + if (quota != "max") + return std::ceil(std::stoi(quota) / std::stof(period)); + } catch (Error &) { ignoreException(lvlDebug); } + #endif + + return 0; +} + + +////////////////////////////////////////////////////////////////////// + + +#if __linux__ +rlim_t savedStackSize = 0; +#endif + +void setStackSize(size_t stackSize) +{ + #if __linux__ + struct rlimit limit; + if (getrlimit(RLIMIT_STACK, &limit) == 0 && limit.rlim_cur < stackSize) { + savedStackSize = limit.rlim_cur; + limit.rlim_cur = stackSize; + setrlimit(RLIMIT_STACK, &limit); + } + #endif +} + +void restoreProcessContext(bool restoreMounts) +{ + restoreSignals(); + if (restoreMounts) { + restoreMountNamespace(); + } + + #if __linux__ + if (savedStackSize) { + struct rlimit limit; + if (getrlimit(RLIMIT_STACK, &limit) == 0) { + limit.rlim_cur = savedStackSize; + setrlimit(RLIMIT_STACK, &limit); + } + } + #endif +} + + +////////////////////////////////////////////////////////////////////// + + +std::optional getSelfExe() +{ + static auto cached = []() -> std::optional + { + #if __linux__ + return readLink("/proc/self/exe"); + #elif __APPLE__ + char buf[1024]; + uint32_t size = sizeof(buf); + if (_NSGetExecutablePath(buf, &size) == 0) + return buf; + else + return std::nullopt; + #else + return std::nullopt; + #endif + }(); + return cached; +} + +} diff --git a/src/libutil/current-process.hh b/src/libutil/current-process.hh new file mode 100644 index 000000000..826d6fe20 --- /dev/null +++ b/src/libutil/current-process.hh @@ -0,0 +1,34 @@ +#pragma once +///@file + +#include + +#include "types.hh" + +namespace nix { + +/** + * If cgroups are active, attempt to calculate the number of CPUs available. + * If cgroups are unavailable or if cpu.max is set to "max", return 0. + */ +unsigned int getMaxCPU(); + +/** + * Change the stack size. + */ +void setStackSize(size_t stackSize); + +/** + * Restore the original inherited Unix process context (such as signal + * masks, stack size). + + * See startSignalHandlerThread(), saveSignalMask(). + */ +void restoreProcessContext(bool restoreMounts = true); + +/** + * @return the path of the current executable. + */ +std::optional getSelfExe(); + +} diff --git a/src/libutil/environment-variables.cc b/src/libutil/environment-variables.cc new file mode 100644 index 000000000..6618d7872 --- /dev/null +++ b/src/libutil/environment-variables.cc @@ -0,0 +1,49 @@ +#include "util.hh" +#include "environment-variables.hh" + +extern char * * environ __attribute__((weak)); + +namespace nix { + +std::optional getEnv(const std::string & key) +{ + char * value = getenv(key.c_str()); + if (!value) return {}; + return std::string(value); +} + +std::optional getEnvNonEmpty(const std::string & key) { + auto value = getEnv(key); + if (value == "") return {}; + return value; +} + +std::map getEnv() +{ + std::map env; + for (size_t i = 0; environ[i]; ++i) { + auto s = environ[i]; + auto eq = strchr(s, '='); + if (!eq) + // invalid env, just keep going + continue; + env.emplace(std::string(s, eq), std::string(eq + 1)); + } + return env; +} + + +void clearEnv() +{ + for (auto & name : getEnv()) + unsetenv(name.first.c_str()); +} + +void replaceEnv(const std::map & newEnv) +{ + clearEnv(); + for (auto & newEnvVar : newEnv) + setenv(newEnvVar.first.c_str(), newEnvVar.second.c_str(), 1); +} + +} diff --git a/src/libutil/environment-variables.hh b/src/libutil/environment-variables.hh new file mode 100644 index 000000000..21eb4619b --- /dev/null +++ b/src/libutil/environment-variables.hh @@ -0,0 +1,41 @@ +#pragma once +/** + * @file + * + * Utilities for working with the current process's environment + * variables. + */ + +#include + +#include "types.hh" + +namespace nix { + +/** + * @return an environment variable. + */ +std::optional getEnv(const std::string & key); + +/** + * @return a non empty environment variable. Returns nullopt if the env + * variable is set to "" + */ +std::optional getEnvNonEmpty(const std::string & key); + +/** + * Get the entire environment. + */ +std::map getEnv(); + +/** + * Clear the environment. + */ +void clearEnv(); + +/** + * Replace the entire environment with the given one. + */ +void replaceEnv(const std::map & newEnv); + +} diff --git a/src/libutil/error.cc b/src/libutil/error.cc index 1badc1069..8488e7e21 100644 --- a/src/libutil/error.cc +++ b/src/libutil/error.cc @@ -1,4 +1,7 @@ #include "error.hh" +#include "environment-variables.hh" +#include "signals.hh" +#include "terminal.hh" #include #include diff --git a/src/libutil/file-descriptor.cc b/src/libutil/file-descriptor.cc new file mode 100644 index 000000000..38dd70c8e --- /dev/null +++ b/src/libutil/file-descriptor.cc @@ -0,0 +1,254 @@ +#include "file-system.hh" +#include "signals.hh" +#include "finally.hh" +#include "serialise.hh" + +#include +#include + +namespace nix { + +std::string readFile(int fd) +{ + struct stat st; + if (fstat(fd, &st) == -1) + throw SysError("statting file"); + + return drainFD(fd, true, st.st_size); +} + + +void readFull(int fd, char * buf, size_t count) +{ + while (count) { + checkInterrupt(); + ssize_t res = read(fd, buf, count); + if (res == -1) { + if (errno == EINTR) continue; + throw SysError("reading from file"); + } + if (res == 0) throw EndOfFile("unexpected end-of-file"); + count -= res; + buf += res; + } +} + + +void writeFull(int fd, std::string_view s, bool allowInterrupts) +{ + while (!s.empty()) { + if (allowInterrupts) checkInterrupt(); + ssize_t res = write(fd, s.data(), s.size()); + if (res == -1 && errno != EINTR) + throw SysError("writing to file"); + if (res > 0) + s.remove_prefix(res); + } +} + + +std::string readLine(int fd) +{ + std::string s; + while (1) { + checkInterrupt(); + char ch; + // FIXME: inefficient + ssize_t rd = read(fd, &ch, 1); + if (rd == -1) { + if (errno != EINTR) + throw SysError("reading a line"); + } else if (rd == 0) + throw EndOfFile("unexpected EOF reading a line"); + else { + if (ch == '\n') return s; + s += ch; + } + } +} + + +void writeLine(int fd, std::string s) +{ + s += '\n'; + writeFull(fd, s); +} + + +std::string drainFD(int fd, bool block, const size_t reserveSize) +{ + // the parser needs two extra bytes to append terminating characters, other users will + // not care very much about the extra memory. + StringSink sink(reserveSize + 2); + drainFD(fd, sink, block); + return std::move(sink.s); +} + + +void drainFD(int fd, Sink & sink, bool block) +{ + // silence GCC maybe-uninitialized warning in finally + int saved = 0; + + if (!block) { + saved = fcntl(fd, F_GETFL); + if (fcntl(fd, F_SETFL, saved | O_NONBLOCK) == -1) + throw SysError("making file descriptor non-blocking"); + } + + Finally finally([&]() { + if (!block) { + if (fcntl(fd, F_SETFL, saved) == -1) + throw SysError("making file descriptor blocking"); + } + }); + + std::vector buf(64 * 1024); + while (1) { + checkInterrupt(); + ssize_t rd = read(fd, buf.data(), buf.size()); + if (rd == -1) { + if (!block && (errno == EAGAIN || errno == EWOULDBLOCK)) + break; + if (errno != EINTR) + throw SysError("reading from file"); + } + else if (rd == 0) break; + else sink({(char *) buf.data(), (size_t) rd}); + } +} + +////////////////////////////////////////////////////////////////////// + +AutoCloseFD::AutoCloseFD() : fd{-1} {} + + +AutoCloseFD::AutoCloseFD(int fd) : fd{fd} {} + + +AutoCloseFD::AutoCloseFD(AutoCloseFD && that) : fd{that.fd} +{ + that.fd = -1; +} + + +AutoCloseFD & AutoCloseFD::operator =(AutoCloseFD && that) +{ + close(); + fd = that.fd; + that.fd = -1; + return *this; +} + + +AutoCloseFD::~AutoCloseFD() +{ + try { + close(); + } catch (...) { + ignoreException(); + } +} + + +int AutoCloseFD::get() const +{ + return fd; +} + + +void AutoCloseFD::close() +{ + if (fd != -1) { + if (::close(fd) == -1) + /* This should never happen. */ + throw SysError("closing file descriptor %1%", fd); + fd = -1; + } +} + +void AutoCloseFD::fsync() +{ + if (fd != -1) { + int result; +#if __APPLE__ + result = ::fcntl(fd, F_FULLFSYNC); +#else + result = ::fsync(fd); +#endif + if (result == -1) + throw SysError("fsync file descriptor %1%", fd); + } +} + + +AutoCloseFD::operator bool() const +{ + return fd != -1; +} + + +int AutoCloseFD::release() +{ + int oldFD = fd; + fd = -1; + return oldFD; +} + + +void Pipe::create() +{ + int fds[2]; +#if HAVE_PIPE2 + if (pipe2(fds, O_CLOEXEC) != 0) throw SysError("creating pipe"); +#else + if (pipe(fds) != 0) throw SysError("creating pipe"); + closeOnExec(fds[0]); + closeOnExec(fds[1]); +#endif + readSide = fds[0]; + writeSide = fds[1]; +} + + +void Pipe::close() +{ + readSide.close(); + writeSide.close(); +} + +////////////////////////////////////////////////////////////////////// + +void closeMostFDs(const std::set & exceptions) +{ +#if __linux__ + try { + for (auto & s : readDirectory("/proc/self/fd")) { + auto fd = std::stoi(s.name); + if (!exceptions.count(fd)) { + debug("closing leaked FD %d", fd); + close(fd); + } + } + return; + } catch (SysError &) { + } +#endif + + int maxFD = 0; + maxFD = sysconf(_SC_OPEN_MAX); + for (int fd = 0; fd < maxFD; ++fd) + if (!exceptions.count(fd)) + close(fd); /* ignore result */ +} + + +void closeOnExec(int fd) +{ + int prev; + if ((prev = fcntl(fd, F_GETFD, 0)) == -1 || + fcntl(fd, F_SETFD, prev | FD_CLOEXEC) == -1) + throw SysError("setting close-on-exec flag"); +} + +} diff --git a/src/libutil/file-descriptor.hh b/src/libutil/file-descriptor.hh new file mode 100644 index 000000000..80ec86135 --- /dev/null +++ b/src/libutil/file-descriptor.hh @@ -0,0 +1,84 @@ +#pragma once +///@file + +#include "types.hh" +#include "error.hh" + +namespace nix { + +struct Sink; +struct Source; + +/** + * Read the contents of a resource into a string. + */ +std::string readFile(int fd); + +/** + * Wrappers arount read()/write() that read/write exactly the + * requested number of bytes. + */ +void readFull(int fd, char * buf, size_t count); + +void writeFull(int fd, std::string_view s, bool allowInterrupts = true); + +/** + * Read a line from a file descriptor. + */ +std::string readLine(int fd); + +/** + * Write a line to a file descriptor. + */ +void writeLine(int fd, std::string s); + +/** + * Read a file descriptor until EOF occurs. + */ +std::string drainFD(int fd, bool block = true, const size_t reserveSize=0); + +void drainFD(int fd, Sink & sink, bool block = true); + +/** + * Automatic cleanup of resources. + */ +class AutoCloseFD +{ + int fd; +public: + AutoCloseFD(); + AutoCloseFD(int fd); + AutoCloseFD(const AutoCloseFD & fd) = delete; + AutoCloseFD(AutoCloseFD&& fd); + ~AutoCloseFD(); + AutoCloseFD& operator =(const AutoCloseFD & fd) = delete; + AutoCloseFD& operator =(AutoCloseFD&& fd); + int get() const; + explicit operator bool() const; + int release(); + void close(); + void fsync(); +}; + +class Pipe +{ +public: + AutoCloseFD readSide, writeSide; + void create(); + void close(); +}; + +/** + * Close all file descriptors except those listed in the given set. + * Good practice in child processes. + */ +void closeMostFDs(const std::set & exceptions); + +/** + * Set the close-on-exec flag for the given file descriptor. + */ +void closeOnExec(int fd); + +MakeError(EndOfFile, Error); + +} diff --git a/src/libutil/file-system.cc b/src/libutil/file-system.cc new file mode 100644 index 000000000..c96effff9 --- /dev/null +++ b/src/libutil/file-system.cc @@ -0,0 +1,647 @@ +#include "environment-variables.hh" +#include "file-system.hh" +#include "signals.hh" +#include "finally.hh" +#include "serialise.hh" + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +namespace fs = std::filesystem; + +namespace nix { + +Path absPath(Path path, std::optional dir, bool resolveSymlinks) +{ + if (path[0] != '/') { + if (!dir) { +#ifdef __GNU__ + /* GNU (aka. GNU/Hurd) doesn't have any limitation on path + lengths and doesn't define `PATH_MAX'. */ + char *buf = getcwd(NULL, 0); + if (buf == NULL) +#else + char buf[PATH_MAX]; + if (!getcwd(buf, sizeof(buf))) +#endif + throw SysError("cannot get cwd"); + path = concatStrings(buf, "/", path); +#ifdef __GNU__ + free(buf); +#endif + } else + path = concatStrings(*dir, "/", path); + } + return canonPath(path, resolveSymlinks); +} + + +Path canonPath(PathView path, bool resolveSymlinks) +{ + assert(path != ""); + + std::string s; + s.reserve(256); + + if (path[0] != '/') + throw Error("not an absolute path: '%1%'", path); + + std::string temp; + + /* Count the number of times we follow a symlink and stop at some + arbitrary (but high) limit to prevent infinite loops. */ + unsigned int followCount = 0, maxFollow = 1024; + + while (1) { + + /* Skip slashes. */ + while (!path.empty() && path[0] == '/') path.remove_prefix(1); + if (path.empty()) break; + + /* Ignore `.'. */ + if (path == "." || path.substr(0, 2) == "./") + path.remove_prefix(1); + + /* If `..', delete the last component. */ + else if (path == ".." || path.substr(0, 3) == "../") + { + if (!s.empty()) s.erase(s.rfind('/')); + path.remove_prefix(2); + } + + /* Normal component; copy it. */ + else { + s += '/'; + if (const auto slash = path.find('/'); slash == std::string::npos) { + s += path; + path = {}; + } else { + s += path.substr(0, slash); + path = path.substr(slash); + } + + /* If s points to a symlink, resolve it and continue from there */ + if (resolveSymlinks && isLink(s)) { + if (++followCount >= maxFollow) + throw Error("infinite symlink recursion in path '%1%'", path); + temp = concatStrings(readLink(s), path); + path = temp; + if (!temp.empty() && temp[0] == '/') { + s.clear(); /* restart for symlinks pointing to absolute path */ + } else { + s = dirOf(s); + if (s == "/") { // we don’t want trailing slashes here, which dirOf only produces if s = / + s.clear(); + } + } + } + } + } + + return s.empty() ? "/" : std::move(s); +} + + +Path dirOf(const PathView path) +{ + Path::size_type pos = path.rfind('/'); + if (pos == std::string::npos) + return "."; + return pos == 0 ? "/" : Path(path, 0, pos); +} + + +std::string_view baseNameOf(std::string_view path) +{ + if (path.empty()) + return ""; + + auto last = path.size() - 1; + if (path[last] == '/' && last > 0) + last -= 1; + + auto pos = path.rfind('/', last); + if (pos == std::string::npos) + pos = 0; + else + pos += 1; + + return path.substr(pos, last - pos + 1); +} + + +bool isInDir(std::string_view path, std::string_view dir) +{ + return path.substr(0, 1) == "/" + && path.substr(0, dir.size()) == dir + && path.size() >= dir.size() + 2 + && path[dir.size()] == '/'; +} + + +bool isDirOrInDir(std::string_view path, std::string_view dir) +{ + return path == dir || isInDir(path, dir); +} + + +struct stat stat(const Path & path) +{ + struct stat st; + if (stat(path.c_str(), &st)) + throw SysError("getting status of '%1%'", path); + return st; +} + + +struct stat lstat(const Path & path) +{ + struct stat st; + if (lstat(path.c_str(), &st)) + throw SysError("getting status of '%1%'", path); + return st; +} + + +bool pathExists(const Path & path) +{ + int res; + struct stat st; + res = lstat(path.c_str(), &st); + if (!res) return true; + if (errno != ENOENT && errno != ENOTDIR) + throw SysError("getting status of %1%", path); + return false; +} + +bool pathAccessible(const Path & path) +{ + try { + return pathExists(path); + } catch (SysError & e) { + // swallow EPERM + if (e.errNo == EPERM) return false; + throw; + } +} + + +Path readLink(const Path & path) +{ + checkInterrupt(); + std::vector buf; + for (ssize_t bufSize = PATH_MAX/4; true; bufSize += bufSize/2) { + buf.resize(bufSize); + ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize); + if (rlSize == -1) + if (errno == EINVAL) + throw Error("'%1%' is not a symlink", path); + else + throw SysError("reading symbolic link '%1%'", path); + else if (rlSize < bufSize) + return std::string(buf.data(), rlSize); + } +} + + +bool isLink(const Path & path) +{ + struct stat st = lstat(path); + return S_ISLNK(st.st_mode); +} + + +DirEntries readDirectory(DIR *dir, const Path & path) +{ + DirEntries entries; + entries.reserve(64); + + struct dirent * dirent; + while (errno = 0, dirent = readdir(dir)) { /* sic */ + checkInterrupt(); + std::string name = dirent->d_name; + if (name == "." || name == "..") continue; + entries.emplace_back(name, dirent->d_ino, +#ifdef HAVE_STRUCT_DIRENT_D_TYPE + dirent->d_type +#else + DT_UNKNOWN +#endif + ); + } + if (errno) throw SysError("reading directory '%1%'", path); + + return entries; +} + +DirEntries readDirectory(const Path & path) +{ + AutoCloseDir dir(opendir(path.c_str())); + if (!dir) throw SysError("opening directory '%1%'", path); + + return readDirectory(dir.get(), path); +} + + +unsigned char getFileType(const Path & path) +{ + struct stat st = lstat(path); + if (S_ISDIR(st.st_mode)) return DT_DIR; + if (S_ISLNK(st.st_mode)) return DT_LNK; + if (S_ISREG(st.st_mode)) return DT_REG; + return DT_UNKNOWN; +} + + +std::string readFile(const Path & path) +{ + AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_CLOEXEC); + if (!fd) + throw SysError("opening file '%1%'", path); + return readFile(fd.get()); +} + + +void readFile(const Path & path, Sink & sink) +{ + AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_CLOEXEC); + if (!fd) + throw SysError("opening file '%s'", path); + drainFD(fd.get(), sink); +} + + +void writeFile(const Path & path, std::string_view s, mode_t mode, bool sync) +{ + AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode); + if (!fd) + throw SysError("opening file '%1%'", path); + try { + writeFull(fd.get(), s); + } catch (Error & e) { + e.addTrace({}, "writing file '%1%'", path); + throw; + } + if (sync) + fd.fsync(); + // Explicitly close to make sure exceptions are propagated. + fd.close(); + if (sync) + syncParent(path); +} + + +void writeFile(const Path & path, Source & source, mode_t mode, bool sync) +{ + AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode); + if (!fd) + throw SysError("opening file '%1%'", path); + + std::vector buf(64 * 1024); + + try { + while (true) { + try { + auto n = source.read(buf.data(), buf.size()); + writeFull(fd.get(), {buf.data(), n}); + } catch (EndOfFile &) { break; } + } + } catch (Error & e) { + e.addTrace({}, "writing file '%1%'", path); + throw; + } + if (sync) + fd.fsync(); + // Explicitly close to make sure exceptions are propagated. + fd.close(); + if (sync) + syncParent(path); +} + +void syncParent(const Path & path) +{ + AutoCloseFD fd = open(dirOf(path).c_str(), O_RDONLY, 0); + if (!fd) + throw SysError("opening file '%1%'", path); + fd.fsync(); +} + + +static void _deletePath(int parentfd, const Path & path, uint64_t & bytesFreed) +{ + checkInterrupt(); + + std::string name(baseNameOf(path)); + + struct stat st; + if (fstatat(parentfd, name.c_str(), &st, AT_SYMLINK_NOFOLLOW) == -1) { + if (errno == ENOENT) return; + throw SysError("getting status of '%1%'", path); + } + + if (!S_ISDIR(st.st_mode)) { + /* We are about to delete a file. Will it likely free space? */ + + switch (st.st_nlink) { + /* Yes: last link. */ + case 1: + bytesFreed += st.st_size; + break; + /* Maybe: yes, if 'auto-optimise-store' or manual optimisation + was performed. Instead of checking for real let's assume + it's an optimised file and space will be freed. + + In worst case we will double count on freed space for files + with exactly two hardlinks for unoptimised packages. + */ + case 2: + bytesFreed += st.st_size; + break; + /* No: 3+ links. */ + default: + break; + } + } + + if (S_ISDIR(st.st_mode)) { + /* Make the directory accessible. */ + const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR; + if ((st.st_mode & PERM_MASK) != PERM_MASK) { + if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1) + throw SysError("chmod '%1%'", path); + } + + int fd = openat(parentfd, path.c_str(), O_RDONLY); + if (fd == -1) + throw SysError("opening directory '%1%'", path); + AutoCloseDir dir(fdopendir(fd)); + if (!dir) + throw SysError("opening directory '%1%'", path); + for (auto & i : readDirectory(dir.get(), path)) + _deletePath(dirfd(dir.get()), path + "/" + i.name, bytesFreed); + } + + int flags = S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0; + if (unlinkat(parentfd, name.c_str(), flags) == -1) { + if (errno == ENOENT) return; + throw SysError("cannot unlink '%1%'", path); + } +} + +static void _deletePath(const Path & path, uint64_t & bytesFreed) +{ + Path dir = dirOf(path); + if (dir == "") + dir = "/"; + + AutoCloseFD dirfd{open(dir.c_str(), O_RDONLY)}; + if (!dirfd) { + if (errno == ENOENT) return; + throw SysError("opening directory '%1%'", path); + } + + _deletePath(dirfd.get(), path, bytesFreed); +} + + +void deletePath(const Path & path) +{ + uint64_t dummy; + deletePath(path, dummy); +} + + +Paths createDirs(const Path & path) +{ + Paths created; + if (path == "/") return created; + + struct stat st; + if (lstat(path.c_str(), &st) == -1) { + created = createDirs(dirOf(path)); + if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST) + throw SysError("creating directory '%1%'", path); + st = lstat(path); + created.push_back(path); + } + + if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1) + throw SysError("statting symlink '%1%'", path); + + if (!S_ISDIR(st.st_mode)) throw Error("'%1%' is not a directory", path); + + return created; +} + + +void deletePath(const Path & path, uint64_t & bytesFreed) +{ + //Activity act(*logger, lvlDebug, "recursively deleting path '%1%'", path); + bytesFreed = 0; + _deletePath(path, bytesFreed); +} + + +////////////////////////////////////////////////////////////////////// + +AutoDelete::AutoDelete() : del{false} {} + +AutoDelete::AutoDelete(const std::string & p, bool recursive) : path(p) +{ + del = true; + this->recursive = recursive; +} + +AutoDelete::~AutoDelete() +{ + try { + if (del) { + if (recursive) + deletePath(path); + else { + if (remove(path.c_str()) == -1) + throw SysError("cannot unlink '%1%'", path); + } + } + } catch (...) { + ignoreException(); + } +} + +void AutoDelete::cancel() +{ + del = false; +} + +void AutoDelete::reset(const Path & p, bool recursive) { + path = p; + this->recursive = recursive; + del = true; +} + +////////////////////////////////////////////////////////////////////// + +////////////////////////////////////////////////////////////////////// + +static Path tempName(Path tmpRoot, const Path & prefix, bool includePid, + std::atomic & counter) +{ + tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true); + if (includePid) + return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++); + else + return fmt("%1%/%2%-%3%", tmpRoot, prefix, counter++); +} + +Path createTempDir(const Path & tmpRoot, const Path & prefix, + bool includePid, bool useGlobalCounter, mode_t mode) +{ + static std::atomic globalCounter = 0; + std::atomic localCounter = 0; + auto & counter(useGlobalCounter ? globalCounter : localCounter); + + while (1) { + checkInterrupt(); + Path tmpDir = tempName(tmpRoot, prefix, includePid, counter); + if (mkdir(tmpDir.c_str(), mode) == 0) { +#if __FreeBSD__ + /* Explicitly set the group of the directory. This is to + work around around problems caused by BSD's group + ownership semantics (directories inherit the group of + the parent). For instance, the group of /tmp on + FreeBSD is "wheel", so all directories created in /tmp + will be owned by "wheel"; but if the user is not in + "wheel", then "tar" will fail to unpack archives that + have the setgid bit set on directories. */ + if (chown(tmpDir.c_str(), (uid_t) -1, getegid()) != 0) + throw SysError("setting group of directory '%1%'", tmpDir); +#endif + return tmpDir; + } + if (errno != EEXIST) + throw SysError("creating directory '%1%'", tmpDir); + } +} + + +std::pair createTempFile(const Path & prefix) +{ + Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX"); + // Strictly speaking, this is UB, but who cares... + // FIXME: use O_TMPFILE. + AutoCloseFD fd(mkstemp((char *) tmpl.c_str())); + if (!fd) + throw SysError("creating temporary file '%s'", tmpl); + closeOnExec(fd.get()); + return {std::move(fd), tmpl}; +} + +void createSymlink(const Path & target, const Path & link) +{ + if (symlink(target.c_str(), link.c_str())) + throw SysError("creating symlink from '%1%' to '%2%'", link, target); +} + +void replaceSymlink(const Path & target, const Path & link) +{ + for (unsigned int n = 0; true; n++) { + Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link))); + + try { + createSymlink(target, tmp); + } catch (SysError & e) { + if (e.errNo == EEXIST) continue; + throw; + } + + renameFile(tmp, link); + + break; + } +} + +void setWriteTime(const fs::path & p, const struct stat & st) +{ + struct timeval times[2]; + times[0] = { + .tv_sec = st.st_atime, + .tv_usec = 0, + }; + times[1] = { + .tv_sec = st.st_mtime, + .tv_usec = 0, + }; + if (lutimes(p.c_str(), times) != 0) + throw SysError("changing modification time of '%s'", p); +} + +void copy(const fs::directory_entry & from, const fs::path & to, bool andDelete) +{ + // TODO: Rewrite the `is_*` to use `symlink_status()` + auto statOfFrom = lstat(from.path().c_str()); + auto fromStatus = from.symlink_status(); + + // Mark the directory as writable so that we can delete its children + if (andDelete && fs::is_directory(fromStatus)) { + fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow); + } + + + if (fs::is_symlink(fromStatus) || fs::is_regular_file(fromStatus)) { + fs::copy(from.path(), to, fs::copy_options::copy_symlinks | fs::copy_options::overwrite_existing); + } else if (fs::is_directory(fromStatus)) { + fs::create_directory(to); + for (auto & entry : fs::directory_iterator(from.path())) { + copy(entry, to / entry.path().filename(), andDelete); + } + } else { + throw Error("file '%s' has an unsupported type", from.path()); + } + + setWriteTime(to, statOfFrom); + if (andDelete) { + if (!fs::is_symlink(fromStatus)) + fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow); + fs::remove(from.path()); + } +} + +void renameFile(const Path & oldName, const Path & newName) +{ + fs::rename(oldName, newName); +} + +void moveFile(const Path & oldName, const Path & newName) +{ + try { + renameFile(oldName, newName); + } catch (fs::filesystem_error & e) { + auto oldPath = fs::path(oldName); + auto newPath = fs::path(newName); + // For the move to be as atomic as possible, copy to a temporary + // directory + fs::path temp = createTempDir(newPath.parent_path(), "rename-tmp"); + Finally removeTemp = [&]() { fs::remove(temp); }; + auto tempCopyTarget = temp / "copy-target"; + if (e.code().value() == EXDEV) { + fs::remove(newPath); + warn("Can’t rename %s as %s, copying instead", oldName, newName); + copy(fs::directory_entry(oldPath), tempCopyTarget, true); + renameFile(tempCopyTarget, newPath); + } + } +} + +////////////////////////////////////////////////////////////////////// + +} diff --git a/src/libutil/file-system.hh b/src/libutil/file-system.hh new file mode 100644 index 000000000..4637507b3 --- /dev/null +++ b/src/libutil/file-system.hh @@ -0,0 +1,238 @@ +#pragma once +/** + * @file + * + * Utiltities for working with the file sytem and file paths. + */ + +#include "types.hh" +#include "error.hh" +#include "logging.hh" +#include "file-descriptor.hh" + +#include +#include +#include +#include +#include + +#include + +#include +#include +#include +#include +#include + +#ifndef HAVE_STRUCT_DIRENT_D_TYPE +#define DT_UNKNOWN 0 +#define DT_REG 1 +#define DT_LNK 2 +#define DT_DIR 3 +#endif + +namespace nix { + +struct Sink; +struct Source; + +/** + * @return An absolutized path, resolving paths relative to the + * specified directory, or the current directory otherwise. The path + * is also canonicalised. + */ +Path absPath(Path path, + std::optional dir = {}, + bool resolveSymlinks = false); + +/** + * Canonicalise a path by removing all `.` or `..` components and + * double or trailing slashes. Optionally resolves all symlink + * components such that each component of the resulting path is *not* + * a symbolic link. + */ +Path canonPath(PathView path, bool resolveSymlinks = false); + +/** + * @return The directory part of the given canonical path, i.e., + * everything before the final `/`. If the path is the root or an + * immediate child thereof (e.g., `/foo`), this means `/` + * is returned. + */ +Path dirOf(const PathView path); + +/** + * @return the base name of the given canonical path, i.e., everything + * following the final `/` (trailing slashes are removed). + */ +std::string_view baseNameOf(std::string_view path); + +/** + * Check whether 'path' is a descendant of 'dir'. Both paths must be + * canonicalized. + */ +bool isInDir(std::string_view path, std::string_view dir); + +/** + * Check whether 'path' is equal to 'dir' or a descendant of + * 'dir'. Both paths must be canonicalized. + */ +bool isDirOrInDir(std::string_view path, std::string_view dir); + +/** + * Get status of `path`. + */ +struct stat stat(const Path & path); +struct stat lstat(const Path & path); + +/** + * @return true iff the given path exists. + */ +bool pathExists(const Path & path); + +/** + * A version of pathExists that returns false on a permission error. + * Useful for inferring default paths across directories that might not + * be readable. + * @return true iff the given path can be accessed and exists + */ +bool pathAccessible(const Path & path); + +/** + * Read the contents (target) of a symbolic link. The result is not + * in any way canonicalised. + */ +Path readLink(const Path & path); + +bool isLink(const Path & path); + +/** + * Read the contents of a directory. The entries `.` and `..` are + * removed. + */ +struct DirEntry +{ + std::string name; + ino_t ino; + /** + * one of DT_* + */ + unsigned char type; + DirEntry(std::string name, ino_t ino, unsigned char type) + : name(std::move(name)), ino(ino), type(type) { } +}; + +typedef std::vector DirEntries; + +DirEntries readDirectory(const Path & path); + +unsigned char getFileType(const Path & path); + +/** + * Read the contents of a file into a string. + */ +std::string readFile(const Path & path); +void readFile(const Path & path, Sink & sink); + +/** + * Write a string to a file. + */ +void writeFile(const Path & path, std::string_view s, mode_t mode = 0666, bool sync = false); + +void writeFile(const Path & path, Source & source, mode_t mode = 0666, bool sync = false); + +/** + * Flush a file's parent directory to disk + */ +void syncParent(const Path & path); + +/** + * Delete a path; i.e., in the case of a directory, it is deleted + * recursively. It's not an error if the path does not exist. The + * second variant returns the number of bytes and blocks freed. + */ +void deletePath(const Path & path); + +void deletePath(const Path & path, uint64_t & bytesFreed); + +/** + * Create a directory and all its parents, if necessary. Returns the + * list of created directories, in order of creation. + */ +Paths createDirs(const Path & path); +inline Paths createDirs(PathView path) +{ + return createDirs(Path(path)); +} + +/** + * Create a symlink. + */ +void createSymlink(const Path & target, const Path & link); + +/** + * Atomically create or replace a symlink. + */ +void replaceSymlink(const Path & target, const Path & link); + +void renameFile(const Path & src, const Path & dst); + +/** + * Similar to 'renameFile', but fallback to a copy+remove if `src` and `dst` + * are on a different filesystem. + * + * Beware that this might not be atomic because of the copy that happens behind + * the scenes + */ +void moveFile(const Path & src, const Path & dst); + + +/** + * Automatic cleanup of resources. + */ +class AutoDelete +{ + Path path; + bool del; + bool recursive; +public: + AutoDelete(); + AutoDelete(const Path & p, bool recursive = true); + ~AutoDelete(); + void cancel(); + void reset(const Path & p, bool recursive = true); + operator Path() const { return path; } + operator PathView() const { return path; } +}; + + +struct DIRDeleter +{ + void operator()(DIR * dir) const { + closedir(dir); + } +}; + +typedef std::unique_ptr AutoCloseDir; + + +/** + * Create a temporary directory. + */ +Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix", + bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755); + +/** + * Create a temporary file, returning a file handle and its path. + */ +std::pair createTempFile(const Path & prefix = "nix"); + + +/** + * Used in various places. + */ +typedef std::function PathFilter; + +extern PathFilter defaultPathFilter; + +} diff --git a/src/libutil/filesystem.cc b/src/libutil/filesystem.cc deleted file mode 100644 index 11cc0c0e7..000000000 --- a/src/libutil/filesystem.cc +++ /dev/null @@ -1,162 +0,0 @@ -#include -#include -#include - -#include "finally.hh" -#include "util.hh" -#include "types.hh" - -namespace fs = std::filesystem; - -namespace nix { - -static Path tempName(Path tmpRoot, const Path & prefix, bool includePid, - std::atomic & counter) -{ - tmpRoot = canonPath(tmpRoot.empty() ? getEnv("TMPDIR").value_or("/tmp") : tmpRoot, true); - if (includePid) - return fmt("%1%/%2%-%3%-%4%", tmpRoot, prefix, getpid(), counter++); - else - return fmt("%1%/%2%-%3%", tmpRoot, prefix, counter++); -} - -Path createTempDir(const Path & tmpRoot, const Path & prefix, - bool includePid, bool useGlobalCounter, mode_t mode) -{ - static std::atomic globalCounter = 0; - std::atomic localCounter = 0; - auto & counter(useGlobalCounter ? globalCounter : localCounter); - - while (1) { - checkInterrupt(); - Path tmpDir = tempName(tmpRoot, prefix, includePid, counter); - if (mkdir(tmpDir.c_str(), mode) == 0) { -#if __FreeBSD__ - /* Explicitly set the group of the directory. This is to - work around around problems caused by BSD's group - ownership semantics (directories inherit the group of - the parent). For instance, the group of /tmp on - FreeBSD is "wheel", so all directories created in /tmp - will be owned by "wheel"; but if the user is not in - "wheel", then "tar" will fail to unpack archives that - have the setgid bit set on directories. */ - if (chown(tmpDir.c_str(), (uid_t) -1, getegid()) != 0) - throw SysError("setting group of directory '%1%'", tmpDir); -#endif - return tmpDir; - } - if (errno != EEXIST) - throw SysError("creating directory '%1%'", tmpDir); - } -} - - -std::pair createTempFile(const Path & prefix) -{ - Path tmpl(getEnv("TMPDIR").value_or("/tmp") + "/" + prefix + ".XXXXXX"); - // Strictly speaking, this is UB, but who cares... - // FIXME: use O_TMPFILE. - AutoCloseFD fd(mkstemp((char *) tmpl.c_str())); - if (!fd) - throw SysError("creating temporary file '%s'", tmpl); - closeOnExec(fd.get()); - return {std::move(fd), tmpl}; -} - -void createSymlink(const Path & target, const Path & link) -{ - if (symlink(target.c_str(), link.c_str())) - throw SysError("creating symlink from '%1%' to '%2%'", link, target); -} - -void replaceSymlink(const Path & target, const Path & link) -{ - for (unsigned int n = 0; true; n++) { - Path tmp = canonPath(fmt("%s/.%d_%s", dirOf(link), n, baseNameOf(link))); - - try { - createSymlink(target, tmp); - } catch (SysError & e) { - if (e.errNo == EEXIST) continue; - throw; - } - - renameFile(tmp, link); - - break; - } -} - -void setWriteTime(const fs::path & p, const struct stat & st) -{ - struct timeval times[2]; - times[0] = { - .tv_sec = st.st_atime, - .tv_usec = 0, - }; - times[1] = { - .tv_sec = st.st_mtime, - .tv_usec = 0, - }; - if (lutimes(p.c_str(), times) != 0) - throw SysError("changing modification time of '%s'", p); -} - -void copy(const fs::directory_entry & from, const fs::path & to, bool andDelete) -{ - // TODO: Rewrite the `is_*` to use `symlink_status()` - auto statOfFrom = lstat(from.path().c_str()); - auto fromStatus = from.symlink_status(); - - // Mark the directory as writable so that we can delete its children - if (andDelete && fs::is_directory(fromStatus)) { - fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow); - } - - - if (fs::is_symlink(fromStatus) || fs::is_regular_file(fromStatus)) { - fs::copy(from.path(), to, fs::copy_options::copy_symlinks | fs::copy_options::overwrite_existing); - } else if (fs::is_directory(fromStatus)) { - fs::create_directory(to); - for (auto & entry : fs::directory_iterator(from.path())) { - copy(entry, to / entry.path().filename(), andDelete); - } - } else { - throw Error("file '%s' has an unsupported type", from.path()); - } - - setWriteTime(to, statOfFrom); - if (andDelete) { - if (!fs::is_symlink(fromStatus)) - fs::permissions(from.path(), fs::perms::owner_write, fs::perm_options::add | fs::perm_options::nofollow); - fs::remove(from.path()); - } -} - -void renameFile(const Path & oldName, const Path & newName) -{ - fs::rename(oldName, newName); -} - -void moveFile(const Path & oldName, const Path & newName) -{ - try { - renameFile(oldName, newName); - } catch (fs::filesystem_error & e) { - auto oldPath = fs::path(oldName); - auto newPath = fs::path(newName); - // For the move to be as atomic as possible, copy to a temporary - // directory - fs::path temp = createTempDir(newPath.parent_path(), "rename-tmp"); - Finally removeTemp = [&]() { fs::remove(temp); }; - auto tempCopyTarget = temp / "copy-target"; - if (e.code().value() == EXDEV) { - fs::remove(newPath); - warn("Can’t rename %s as %s, copying instead", oldName, newName); - copy(fs::directory_entry(oldPath), tempCopyTarget, true); - renameFile(tempCopyTarget, newPath); - } - } -} - -} diff --git a/src/libutil/fs-sink.hh b/src/libutil/fs-sink.hh index c22edd390..bf54b7301 100644 --- a/src/libutil/fs-sink.hh +++ b/src/libutil/fs-sink.hh @@ -4,6 +4,7 @@ #include "types.hh" #include "serialise.hh" #include "source-accessor.hh" +#include "file-system.hh" namespace nix { diff --git a/src/libutil/hash.cc b/src/libutil/hash.cc index e297c245b..144f7ae7e 100644 --- a/src/libutil/hash.cc +++ b/src/libutil/hash.cc @@ -9,7 +9,6 @@ #include "hash.hh" #include "archive.hh" #include "split.hh" -#include "util.hh" #include #include diff --git a/src/libutil/hash.hh b/src/libutil/hash.hh index cab3e6eca..6ade6555c 100644 --- a/src/libutil/hash.hh +++ b/src/libutil/hash.hh @@ -3,6 +3,7 @@ #include "types.hh" #include "serialise.hh" +#include "file-system.hh" namespace nix { diff --git a/src/libutil/logging.cc b/src/libutil/logging.cc index 9d7a141b3..60b0865bf 100644 --- a/src/libutil/logging.cc +++ b/src/libutil/logging.cc @@ -1,4 +1,7 @@ #include "logging.hh" +#include "file-descriptor.hh" +#include "environment-variables.hh" +#include "terminal.hh" #include "util.hh" #include "config.hh" diff --git a/src/libutil/monitor-fd.hh b/src/libutil/monitor-fd.hh index 86d0115fc..228fb13f8 100644 --- a/src/libutil/monitor-fd.hh +++ b/src/libutil/monitor-fd.hh @@ -10,6 +10,8 @@ #include #include +#include "signals.hh" + namespace nix { diff --git a/src/libutil/namespaces.cc b/src/libutil/namespaces.cc index f66accb10..a789b321e 100644 --- a/src/libutil/namespaces.cc +++ b/src/libutil/namespaces.cc @@ -1,13 +1,22 @@ -#if __linux__ - -#include "namespaces.hh" +#include "current-process.hh" #include "util.hh" #include "finally.hh" +#include "file-system.hh" +#include "processes.hh" +#include "signals.hh" + +#if __linux__ +# include +# include +# include "cgroup.hh" +#endif #include namespace nix { +#if __linux__ + bool userNamespacesSupported() { static auto res = [&]() -> bool @@ -92,6 +101,60 @@ bool mountAndPidNamespacesSupported() return res; } +#endif + + +////////////////////////////////////////////////////////////////////// + +#if __linux__ +static AutoCloseFD fdSavedMountNamespace; +static AutoCloseFD fdSavedRoot; +#endif + +void saveMountNamespace() +{ +#if __linux__ + static std::once_flag done; + std::call_once(done, []() { + fdSavedMountNamespace = open("/proc/self/ns/mnt", O_RDONLY); + if (!fdSavedMountNamespace) + throw SysError("saving parent mount namespace"); + + fdSavedRoot = open("/proc/self/root", O_RDONLY); + }); +#endif } +void restoreMountNamespace() +{ +#if __linux__ + try { + auto savedCwd = absPath("."); + + if (fdSavedMountNamespace && setns(fdSavedMountNamespace.get(), CLONE_NEWNS) == -1) + throw SysError("restoring parent mount namespace"); + + if (fdSavedRoot) { + if (fchdir(fdSavedRoot.get())) + throw SysError("chdir into saved root"); + if (chroot(".")) + throw SysError("chroot into saved root"); + } + + if (chdir(savedCwd.c_str()) == -1) + throw SysError("restoring cwd"); + } catch (Error & e) { + debug(e.msg()); + } #endif +} + +void unshareFilesystem() +{ +#ifdef __linux__ + if (unshare(CLONE_FS) != 0 && errno != EPERM) + throw SysError("unsharing filesystem state in download thread"); +#endif +} + +} diff --git a/src/libutil/namespaces.hh b/src/libutil/namespaces.hh index 0b7eeb66c..7e4e921a8 100644 --- a/src/libutil/namespaces.hh +++ b/src/libutil/namespaces.hh @@ -1,8 +1,31 @@ #pragma once ///@file +#include + +#include "types.hh" + namespace nix { +/** + * Save the current mount namespace. Ignored if called more than + * once. + */ +void saveMountNamespace(); + +/** + * Restore the mount namespace saved by saveMountNamespace(). Ignored + * if saveMountNamespace() was never called. + */ +void restoreMountNamespace(); + +/** + * Cause this thread to not share any FS attributes with the main + * thread, because this causes setns() in restoreMountNamespace() to + * fail. + */ +void unshareFilesystem(); + #if __linux__ bool userNamespacesSupported(); diff --git a/src/libutil/posix-source-accessor.cc b/src/libutil/posix-source-accessor.cc index d5e32d989..dc96f84e5 100644 --- a/src/libutil/posix-source-accessor.cc +++ b/src/libutil/posix-source-accessor.cc @@ -1,4 +1,5 @@ #include "posix-source-accessor.hh" +#include "signals.hh" namespace nix { diff --git a/src/libutil/processes.cc b/src/libutil/processes.cc new file mode 100644 index 000000000..91a0ea66f --- /dev/null +++ b/src/libutil/processes.cc @@ -0,0 +1,421 @@ +#include "current-process.hh" +#include "environment-variables.hh" +#include "signals.hh" +#include "processes.hh" +#include "finally.hh" +#include "serialise.hh" + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#ifdef __APPLE__ +# include +#endif + +#ifdef __linux__ +# include +# include +#endif + + +namespace nix { + +Pid::Pid() +{ +} + + +Pid::Pid(pid_t pid) + : pid(pid) +{ +} + + +Pid::~Pid() +{ + if (pid != -1) kill(); +} + + +void Pid::operator =(pid_t pid) +{ + if (this->pid != -1 && this->pid != pid) kill(); + this->pid = pid; + killSignal = SIGKILL; // reset signal to default +} + + +Pid::operator pid_t() +{ + return pid; +} + + +int Pid::kill() +{ + assert(pid != -1); + + debug("killing process %1%", pid); + + /* Send the requested signal to the child. If it has its own + process group, send the signal to every process in the child + process group (which hopefully includes *all* its children). */ + if (::kill(separatePG ? -pid : pid, killSignal) != 0) { + /* On BSDs, killing a process group will return EPERM if all + processes in the group are zombies (or something like + that). So try to detect and ignore that situation. */ +#if __FreeBSD__ || __APPLE__ + if (errno != EPERM || ::kill(pid, 0) != 0) +#endif + logError(SysError("killing process %d", pid).info()); + } + + return wait(); +} + + +int Pid::wait() +{ + assert(pid != -1); + while (1) { + int status; + int res = waitpid(pid, &status, 0); + if (res == pid) { + pid = -1; + return status; + } + if (errno != EINTR) + throw SysError("cannot get exit status of PID %d", pid); + checkInterrupt(); + } +} + + +void Pid::setSeparatePG(bool separatePG) +{ + this->separatePG = separatePG; +} + + +void Pid::setKillSignal(int signal) +{ + this->killSignal = signal; +} + + +pid_t Pid::release() +{ + pid_t p = pid; + pid = -1; + return p; +} + + +void killUser(uid_t uid) +{ + debug("killing all processes running under uid '%1%'", uid); + + assert(uid != 0); /* just to be safe... */ + + /* The system call kill(-1, sig) sends the signal `sig' to all + users to which the current process can send signals. So we + fork a process, switch to uid, and send a mass kill. */ + + Pid pid = startProcess([&]() { + + if (setuid(uid) == -1) + throw SysError("setting uid"); + + while (true) { +#ifdef __APPLE__ + /* OSX's kill syscall takes a third parameter that, among + other things, determines if kill(-1, signo) affects the + calling process. In the OSX libc, it's set to true, + which means "follow POSIX", which we don't want here + */ + if (syscall(SYS_kill, -1, SIGKILL, false) == 0) break; +#else + if (kill(-1, SIGKILL) == 0) break; +#endif + if (errno == ESRCH || errno == EPERM) break; /* no more processes */ + if (errno != EINTR) + throw SysError("cannot kill processes for uid '%1%'", uid); + } + + _exit(0); + }); + + int status = pid.wait(); + if (status != 0) + throw Error("cannot kill processes for uid '%1%': %2%", uid, statusToString(status)); + + /* !!! We should really do some check to make sure that there are + no processes left running under `uid', but there is no portable + way to do so (I think). The most reliable way may be `ps -eo + uid | grep -q $uid'. */ +} + + +////////////////////////////////////////////////////////////////////// + + +/* Wrapper around vfork to prevent the child process from clobbering + the caller's stack frame in the parent. */ +static pid_t doFork(bool allowVfork, std::function fun) __attribute__((noinline)); +static pid_t doFork(bool allowVfork, std::function fun) +{ +#ifdef __linux__ + pid_t pid = allowVfork ? vfork() : fork(); +#else + pid_t pid = fork(); +#endif + if (pid != 0) return pid; + fun(); + abort(); +} + + +#if __linux__ +static int childEntry(void * arg) +{ + auto main = (std::function *) arg; + (*main)(); + return 1; +} +#endif + + +pid_t startProcess(std::function fun, const ProcessOptions & options) +{ + std::function wrapper = [&]() { + if (!options.allowVfork) + logger = makeSimpleLogger(); + try { +#if __linux__ + if (options.dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1) + throw SysError("setting death signal"); +#endif + fun(); + } catch (std::exception & e) { + try { + std::cerr << options.errorPrefix << e.what() << "\n"; + } catch (...) { } + } catch (...) { } + if (options.runExitHandlers) + exit(1); + else + _exit(1); + }; + + pid_t pid = -1; + + if (options.cloneFlags) { + #ifdef __linux__ + // Not supported, since then we don't know when to free the stack. + assert(!(options.cloneFlags & CLONE_VM)); + + size_t stackSize = 1 * 1024 * 1024; + auto stack = (char *) mmap(0, stackSize, + PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); + if (stack == MAP_FAILED) throw SysError("allocating stack"); + + Finally freeStack([&]() { munmap(stack, stackSize); }); + + pid = clone(childEntry, stack + stackSize, options.cloneFlags | SIGCHLD, &wrapper); + #else + throw Error("clone flags are only supported on Linux"); + #endif + } else + pid = doFork(options.allowVfork, wrapper); + + if (pid == -1) throw SysError("unable to fork"); + + return pid; +} + + +std::string runProgram(Path program, bool searchPath, const Strings & args, + const std::optional & input, bool isInteractive) +{ + auto res = runProgram(RunOptions {.program = program, .searchPath = searchPath, .args = args, .input = input, .isInteractive = isInteractive}); + + if (!statusOk(res.first)) + throw ExecError(res.first, "program '%1%' %2%", program, statusToString(res.first)); + + return res.second; +} + +// Output = error code + "standard out" output stream +std::pair runProgram(RunOptions && options) +{ + StringSink sink; + options.standardOut = &sink; + + int status = 0; + + try { + runProgram2(options); + } catch (ExecError & e) { + status = e.status; + } + + return {status, std::move(sink.s)}; +} + +void runProgram2(const RunOptions & options) +{ + checkInterrupt(); + + assert(!(options.standardIn && options.input)); + + std::unique_ptr source_; + Source * source = options.standardIn; + + if (options.input) { + source_ = std::make_unique(*options.input); + source = source_.get(); + } + + /* Create a pipe. */ + Pipe out, in; + if (options.standardOut) out.create(); + if (source) in.create(); + + ProcessOptions processOptions; + // vfork implies that the environment of the main process and the fork will + // be shared (technically this is undefined, but in practice that's the + // case), so we can't use it if we alter the environment + processOptions.allowVfork = !options.environment; + + std::optional>> resumeLoggerDefer; + if (options.isInteractive) { + logger->pause(); + resumeLoggerDefer.emplace( + []() { + logger->resume(); + } + ); + } + + /* Fork. */ + Pid pid = startProcess([&]() { + if (options.environment) + replaceEnv(*options.environment); + if (options.standardOut && dup2(out.writeSide.get(), STDOUT_FILENO) == -1) + throw SysError("dupping stdout"); + if (options.mergeStderrToStdout) + if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1) + throw SysError("cannot dup stdout into stderr"); + if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1) + throw SysError("dupping stdin"); + + if (options.chdir && chdir((*options.chdir).c_str()) == -1) + throw SysError("chdir failed"); + if (options.gid && setgid(*options.gid) == -1) + throw SysError("setgid failed"); + /* Drop all other groups if we're setgid. */ + if (options.gid && setgroups(0, 0) == -1) + throw SysError("setgroups failed"); + if (options.uid && setuid(*options.uid) == -1) + throw SysError("setuid failed"); + + Strings args_(options.args); + args_.push_front(options.program); + + restoreProcessContext(); + + if (options.searchPath) + execvp(options.program.c_str(), stringsToCharPtrs(args_).data()); + // This allows you to refer to a program with a pathname relative + // to the PATH variable. + else + execv(options.program.c_str(), stringsToCharPtrs(args_).data()); + + throw SysError("executing '%1%'", options.program); + }, processOptions); + + out.writeSide.close(); + + std::thread writerThread; + + std::promise promise; + + Finally doJoin([&]() { + if (writerThread.joinable()) + writerThread.join(); + }); + + + if (source) { + in.readSide.close(); + writerThread = std::thread([&]() { + try { + std::vector buf(8 * 1024); + while (true) { + size_t n; + try { + n = source->read(buf.data(), buf.size()); + } catch (EndOfFile &) { + break; + } + writeFull(in.writeSide.get(), {buf.data(), n}); + } + promise.set_value(); + } catch (...) { + promise.set_exception(std::current_exception()); + } + in.writeSide.close(); + }); + } + + if (options.standardOut) + drainFD(out.readSide.get(), *options.standardOut); + + /* Wait for the child to finish. */ + int status = pid.wait(); + + /* Wait for the writer thread to finish. */ + if (source) promise.get_future().get(); + + if (status) + throw ExecError(status, "program '%1%' %2%", options.program, statusToString(status)); +} + +////////////////////////////////////////////////////////////////////// + +std::string statusToString(int status) +{ + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { + if (WIFEXITED(status)) + return fmt("failed with exit code %1%", WEXITSTATUS(status)); + else if (WIFSIGNALED(status)) { + int sig = WTERMSIG(status); +#if HAVE_STRSIGNAL + const char * description = strsignal(sig); + return fmt("failed due to signal %1% (%2%)", sig, description); +#else + return fmt("failed due to signal %1%", sig); +#endif + } + else + return "died abnormally"; + } else return "succeeded"; +} + + +bool statusOk(int status) +{ + return WIFEXITED(status) && WEXITSTATUS(status) == 0; +} + +} diff --git a/src/libutil/processes.hh b/src/libutil/processes.hh new file mode 100644 index 000000000..978c37105 --- /dev/null +++ b/src/libutil/processes.hh @@ -0,0 +1,123 @@ +#pragma once +///@file + +#include "types.hh" +#include "error.hh" +#include "logging.hh" +#include "ansicolor.hh" + +#include +#include +#include +#include +#include + +#include + +#include +#include +#include +#include +#include + +namespace nix { + +struct Sink; +struct Source; + +class Pid +{ + pid_t pid = -1; + bool separatePG = false; + int killSignal = SIGKILL; +public: + Pid(); + Pid(pid_t pid); + ~Pid(); + void operator =(pid_t pid); + operator pid_t(); + int kill(); + int wait(); + + void setSeparatePG(bool separatePG); + void setKillSignal(int signal); + pid_t release(); +}; + + +/** + * Kill all processes running under the specified uid by sending them + * a SIGKILL. + */ +void killUser(uid_t uid); + + +/** + * Fork a process that runs the given function, and return the child + * pid to the caller. + */ +struct ProcessOptions +{ + std::string errorPrefix = ""; + bool dieWithParent = true; + bool runExitHandlers = false; + bool allowVfork = false; + /** + * use clone() with the specified flags (Linux only) + */ + int cloneFlags = 0; +}; + +pid_t startProcess(std::function fun, const ProcessOptions & options = ProcessOptions()); + + +/** + * Run a program and return its stdout in a string (i.e., like the + * shell backtick operator). + */ +std::string runProgram(Path program, bool searchPath = false, + const Strings & args = Strings(), + const std::optional & input = {}, bool isInteractive = false); + +struct RunOptions +{ + Path program; + bool searchPath = true; + Strings args; + std::optional uid; + std::optional gid; + std::optional chdir; + std::optional> environment; + std::optional input; + Source * standardIn = nullptr; + Sink * standardOut = nullptr; + bool mergeStderrToStdout = false; + bool isInteractive = false; +}; + +std::pair runProgram(RunOptions && options); + +void runProgram2(const RunOptions & options); + + +class ExecError : public Error +{ +public: + int status; + + template + ExecError(int status, const Args & ... args) + : Error(args...), status(status) + { } +}; + + +/** + * Convert the exit status of a child as returned by wait() into an + * error string. + */ +std::string statusToString(int status); + +bool statusOk(int status); + +} diff --git a/src/libutil/references.cc b/src/libutil/references.cc index 7f59b4c09..9d75606ef 100644 --- a/src/libutil/references.cc +++ b/src/libutil/references.cc @@ -1,6 +1,5 @@ #include "references.hh" #include "hash.hh" -#include "util.hh" #include "archive.hh" #include diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc index 3d5121a19..725ddbb8d 100644 --- a/src/libutil/serialise.cc +++ b/src/libutil/serialise.cc @@ -1,5 +1,5 @@ #include "serialise.hh" -#include "util.hh" +#include "signals.hh" #include #include diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh index 333c254ea..9e07226bf 100644 --- a/src/libutil/serialise.hh +++ b/src/libutil/serialise.hh @@ -5,6 +5,7 @@ #include "types.hh" #include "util.hh" +#include "file-descriptor.hh" namespace boost::context { struct stack_context; } diff --git a/src/libutil/signals.cc b/src/libutil/signals.cc new file mode 100644 index 000000000..4632aa319 --- /dev/null +++ b/src/libutil/signals.cc @@ -0,0 +1,188 @@ +#include "signals.hh" +#include "util.hh" +#include "error.hh" +#include "sync.hh" +#include "terminal.hh" + +#include + +namespace nix { + +std::atomic _isInterrupted = false; + +static thread_local bool interruptThrown = false; +thread_local std::function interruptCheck; + +void setInterruptThrown() +{ + interruptThrown = true; +} + +void _interrupted() +{ + /* Block user interrupts while an exception is being handled. + Throwing an exception while another exception is being handled + kills the program! */ + if (!interruptThrown && !std::uncaught_exceptions()) { + interruptThrown = true; + throw Interrupted("interrupted by the user"); + } +} + + +////////////////////////////////////////////////////////////////////// + + +/* We keep track of interrupt callbacks using integer tokens, so we can iterate + safely without having to lock the data structure while executing arbitrary + functions. + */ +struct InterruptCallbacks { + typedef int64_t Token; + + /* We use unique tokens so that we can't accidentally delete the wrong + handler because of an erroneous double delete. */ + Token nextToken = 0; + + /* Used as a list, see InterruptCallbacks comment. */ + std::map> callbacks; +}; + +static Sync _interruptCallbacks; + +static void signalHandlerThread(sigset_t set) +{ + while (true) { + int signal = 0; + sigwait(&set, &signal); + + if (signal == SIGINT || signal == SIGTERM || signal == SIGHUP) + triggerInterrupt(); + + else if (signal == SIGWINCH) { + updateWindowSize(); + } + } +} + +void triggerInterrupt() +{ + _isInterrupted = true; + + { + InterruptCallbacks::Token i = 0; + while (true) { + std::function callback; + { + auto interruptCallbacks(_interruptCallbacks.lock()); + auto lb = interruptCallbacks->callbacks.lower_bound(i); + if (lb == interruptCallbacks->callbacks.end()) + break; + + callback = lb->second; + i = lb->first + 1; + } + + try { + callback(); + } catch (...) { + ignoreException(); + } + } + } +} + + +static sigset_t savedSignalMask; +static bool savedSignalMaskIsSet = false; + +void setChildSignalMask(sigset_t * sigs) +{ + assert(sigs); // C style function, but think of sigs as a reference + +#if _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE + sigemptyset(&savedSignalMask); + // There's no "assign" or "copy" function, so we rely on (math) idempotence + // of the or operator: a or a = a. + sigorset(&savedSignalMask, sigs, sigs); +#else + // Without sigorset, our best bet is to assume that sigset_t is a type that + // can be assigned directly, such as is the case for a sigset_t defined as + // an integer type. + savedSignalMask = *sigs; +#endif + + savedSignalMaskIsSet = true; +} + +void saveSignalMask() { + if (sigprocmask(SIG_BLOCK, nullptr, &savedSignalMask)) + throw SysError("querying signal mask"); + + savedSignalMaskIsSet = true; +} + +void startSignalHandlerThread() +{ + updateWindowSize(); + + saveSignalMask(); + + sigset_t set; + sigemptyset(&set); + sigaddset(&set, SIGINT); + sigaddset(&set, SIGTERM); + sigaddset(&set, SIGHUP); + sigaddset(&set, SIGPIPE); + sigaddset(&set, SIGWINCH); + if (pthread_sigmask(SIG_BLOCK, &set, nullptr)) + throw SysError("blocking signals"); + + std::thread(signalHandlerThread, set).detach(); +} + +void restoreSignals() +{ + // If startSignalHandlerThread wasn't called, that means we're not running + // in a proper libmain process, but a process that presumably manages its + // own signal handlers. Such a process should call either + // - initNix(), to be a proper libmain process + // - startSignalHandlerThread(), to resemble libmain regarding signal + // handling only + // - saveSignalMask(), for processes that define their own signal handling + // thread + // TODO: Warn about this? Have a default signal mask? The latter depends on + // whether we should generally inherit signal masks from the caller. + // I don't know what the larger unix ecosystem expects from us here. + if (!savedSignalMaskIsSet) + return; + + if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr)) + throw SysError("restoring signals"); +} + + +/* RAII helper to automatically deregister a callback. */ +struct InterruptCallbackImpl : InterruptCallback +{ + InterruptCallbacks::Token token; + ~InterruptCallbackImpl() override + { + auto interruptCallbacks(_interruptCallbacks.lock()); + interruptCallbacks->callbacks.erase(token); + } +}; + +std::unique_ptr createInterruptCallback(std::function callback) +{ + auto interruptCallbacks(_interruptCallbacks.lock()); + auto token = interruptCallbacks->nextToken++; + interruptCallbacks->callbacks.emplace(token, callback); + + auto res = std::make_unique(); + res->token = token; + + return std::unique_ptr(res.release()); +} + +} diff --git a/src/libutil/signals.hh b/src/libutil/signals.hh new file mode 100644 index 000000000..7e8beff33 --- /dev/null +++ b/src/libutil/signals.hh @@ -0,0 +1,104 @@ +#pragma once +///@file + +#include "types.hh" +#include "error.hh" +#include "logging.hh" +#include "ansicolor.hh" + +#include +#include +#include +#include +#include + +#include + +#include +#include +#include +#include +#include + +namespace nix { + +/* User interruption. */ + +extern std::atomic _isInterrupted; + +extern thread_local std::function interruptCheck; + +void setInterruptThrown(); + +void _interrupted(); + +void inline checkInterrupt() +{ + if (_isInterrupted || (interruptCheck && interruptCheck())) + _interrupted(); +} + +MakeError(Interrupted, BaseError); + + +/** + * Start a thread that handles various signals. Also block those signals + * on the current thread (and thus any threads created by it). + * Saves the signal mask before changing the mask to block those signals. + * See saveSignalMask(). + */ +void startSignalHandlerThread(); + +/** + * Saves the signal mask, which is the signal mask that nix will restore + * before creating child processes. + * See setChildSignalMask() to set an arbitrary signal mask instead of the + * current mask. + */ +void saveSignalMask(); + +/** + * To use in a process that already called `startSignalHandlerThread()` + * or `saveSignalMask()` first. + */ +void restoreSignals(); + +/** + * Sets the signal mask. Like saveSignalMask() but for a signal set that doesn't + * necessarily match the current thread's mask. + * See saveSignalMask() to set the saved mask to the current mask. + */ +void setChildSignalMask(sigset_t *sigs); + +struct InterruptCallback +{ + virtual ~InterruptCallback() { }; +}; + +/** + * Register a function that gets called on SIGINT (in a non-signal + * context). + */ +std::unique_ptr createInterruptCallback( + std::function callback); + +void triggerInterrupt(); + +/** + * A RAII class that causes the current thread to receive SIGUSR1 when + * the signal handler thread receives SIGINT. That is, this allows + * SIGINT to be multiplexed to multiple threads. + */ +struct ReceiveInterrupts +{ + pthread_t target; + std::unique_ptr callback; + + ReceiveInterrupts() + : target(pthread_self()) + , callback(createInterruptCallback([&]() { pthread_kill(target, SIGUSR1); })) + { } +}; + + +} diff --git a/src/libutil/suggestions.cc b/src/libutil/suggestions.cc index 9510a5f0c..e67e986fb 100644 --- a/src/libutil/suggestions.cc +++ b/src/libutil/suggestions.cc @@ -1,7 +1,9 @@ #include "suggestions.hh" #include "ansicolor.hh" -#include "util.hh" +#include "terminal.hh" + #include +#include namespace nix { diff --git a/src/libutil/tarfile.cc b/src/libutil/tarfile.cc index 5060a8f24..1733c791c 100644 --- a/src/libutil/tarfile.cc +++ b/src/libutil/tarfile.cc @@ -3,6 +3,7 @@ #include "serialise.hh" #include "tarfile.hh" +#include "file-system.hh" namespace nix { diff --git a/src/libutil/terminal.cc b/src/libutil/terminal.cc new file mode 100644 index 000000000..8febc8771 --- /dev/null +++ b/src/libutil/terminal.cc @@ -0,0 +1,108 @@ +#include "terminal.hh" +#include "environment-variables.hh" +#include "sync.hh" + +#include +#include + +namespace nix { + +bool shouldANSI() +{ + return isatty(STDERR_FILENO) + && getEnv("TERM").value_or("dumb") != "dumb" + && !(getEnv("NO_COLOR").has_value() || getEnv("NOCOLOR").has_value()); +} + +std::string filterANSIEscapes(std::string_view s, bool filterAll, unsigned int width) +{ + std::string t, e; + size_t w = 0; + auto i = s.begin(); + + while (w < (size_t) width && i != s.end()) { + + if (*i == '\e') { + std::string e; + e += *i++; + char last = 0; + + if (i != s.end() && *i == '[') { + e += *i++; + // eat parameter bytes + while (i != s.end() && *i >= 0x30 && *i <= 0x3f) e += *i++; + // eat intermediate bytes + while (i != s.end() && *i >= 0x20 && *i <= 0x2f) e += *i++; + // eat final byte + if (i != s.end() && *i >= 0x40 && *i <= 0x7e) e += last = *i++; + } else { + if (i != s.end() && *i >= 0x40 && *i <= 0x5f) e += *i++; + } + + if (!filterAll && last == 'm') + t += e; + } + + else if (*i == '\t') { + i++; t += ' '; w++; + while (w < (size_t) width && w % 8) { + t += ' '; w++; + } + } + + else if (*i == '\r' || *i == '\a') + // do nothing for now + i++; + + else { + w++; + // Copy one UTF-8 character. + if ((*i & 0xe0) == 0xc0) { + t += *i++; + if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++; + } else if ((*i & 0xf0) == 0xe0) { + t += *i++; + if (i != s.end() && ((*i & 0xc0) == 0x80)) { + t += *i++; + if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++; + } + } else if ((*i & 0xf8) == 0xf0) { + t += *i++; + if (i != s.end() && ((*i & 0xc0) == 0x80)) { + t += *i++; + if (i != s.end() && ((*i & 0xc0) == 0x80)) { + t += *i++; + if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++; + } + } + } else + t += *i++; + } + } + + return t; +} + + +////////////////////////////////////////////////////////////////////// + +static Sync> windowSize{{0, 0}}; + + +void updateWindowSize() +{ + struct winsize ws; + if (ioctl(2, TIOCGWINSZ, &ws) == 0) { + auto windowSize_(windowSize.lock()); + windowSize_->first = ws.ws_row; + windowSize_->second = ws.ws_col; + } +} + + +std::pair getWindowSize() +{ + return *windowSize.lock(); +} + +} diff --git a/src/libutil/terminal.hh b/src/libutil/terminal.hh new file mode 100644 index 000000000..9cb191308 --- /dev/null +++ b/src/libutil/terminal.hh @@ -0,0 +1,38 @@ +#pragma once +///@file + +#include "types.hh" + +namespace nix { +/** + * Determine whether ANSI escape sequences are appropriate for the + * present output. + */ +bool shouldANSI(); + +/** + * Truncate a string to 'width' printable characters. If 'filterAll' + * is true, all ANSI escape sequences are filtered out. Otherwise, + * some escape sequences (such as colour setting) are copied but not + * included in the character count. Also, tabs are expanded to + * spaces. + */ +std::string filterANSIEscapes(std::string_view s, + bool filterAll = false, + unsigned int width = std::numeric_limits::max()); + +/** + * Recalculate the window size, updating a global variable. Used in the + * `SIGWINCH` signal handler. + */ +void updateWindowSize(); + +/** + * @return the number of rows and columns of the terminal. + * + * The value is cached so this is quick. The cached result is computed + * by `updateWindowSize()`. + */ +std::pair getWindowSize(); + +} diff --git a/src/libutil/tests/logging.cc b/src/libutil/tests/logging.cc index 2ffdc2e9b..c6dfe63d3 100644 --- a/src/libutil/tests/logging.cc +++ b/src/libutil/tests/logging.cc @@ -2,7 +2,6 @@ #include "logging.hh" #include "nixexpr.hh" -#include "util.hh" #include #include diff --git a/src/libutil/tests/tests.cc b/src/libutil/tests/tests.cc index f3c1e8248..568f03f70 100644 --- a/src/libutil/tests/tests.cc +++ b/src/libutil/tests/tests.cc @@ -1,5 +1,8 @@ #include "util.hh" #include "types.hh" +#include "file-system.hh" +#include "processes.hh" +#include "terminal.hh" #include #include diff --git a/src/libutil/thread-pool.cc b/src/libutil/thread-pool.cc index dc4067f1b..c5e735617 100644 --- a/src/libutil/thread-pool.cc +++ b/src/libutil/thread-pool.cc @@ -1,4 +1,6 @@ #include "thread-pool.hh" +#include "signals.hh" +#include "util.hh" namespace nix { diff --git a/src/libutil/thread-pool.hh b/src/libutil/thread-pool.hh index 0e09fae97..02765badc 100644 --- a/src/libutil/thread-pool.hh +++ b/src/libutil/thread-pool.hh @@ -1,8 +1,8 @@ #pragma once ///@file +#include "error.hh" #include "sync.hh" -#include "util.hh" #include #include diff --git a/src/libutil/unix-domain-socket.cc b/src/libutil/unix-domain-socket.cc new file mode 100644 index 000000000..8949461d2 --- /dev/null +++ b/src/libutil/unix-domain-socket.cc @@ -0,0 +1,100 @@ +#include "file-system.hh" +#include "processes.hh" +#include "unix-domain-socket.hh" + +#include +#include +#include + +namespace nix { + +AutoCloseFD createUnixDomainSocket() +{ + AutoCloseFD fdSocket = socket(PF_UNIX, SOCK_STREAM + #ifdef SOCK_CLOEXEC + | SOCK_CLOEXEC + #endif + , 0); + if (!fdSocket) + throw SysError("cannot create Unix domain socket"); + closeOnExec(fdSocket.get()); + return fdSocket; +} + + +AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode) +{ + auto fdSocket = nix::createUnixDomainSocket(); + + bind(fdSocket.get(), path); + + if (chmod(path.c_str(), mode) == -1) + throw SysError("changing permissions on '%1%'", path); + + if (listen(fdSocket.get(), 100) == -1) + throw SysError("cannot listen on socket '%1%'", path); + + return fdSocket; +} + + +void bind(int fd, const std::string & path) +{ + unlink(path.c_str()); + + struct sockaddr_un addr; + addr.sun_family = AF_UNIX; + + if (path.size() + 1 >= sizeof(addr.sun_path)) { + Pid pid = startProcess([&]() { + Path dir = dirOf(path); + if (chdir(dir.c_str()) == -1) + throw SysError("chdir to '%s' failed", dir); + std::string base(baseNameOf(path)); + if (base.size() + 1 >= sizeof(addr.sun_path)) + throw Error("socket path '%s' is too long", base); + memcpy(addr.sun_path, base.c_str(), base.size() + 1); + if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) + throw SysError("cannot bind to socket '%s'", path); + _exit(0); + }); + int status = pid.wait(); + if (status != 0) + throw Error("cannot bind to socket '%s'", path); + } else { + memcpy(addr.sun_path, path.c_str(), path.size() + 1); + if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) + throw SysError("cannot bind to socket '%s'", path); + } +} + + +void connect(int fd, const std::string & path) +{ + struct sockaddr_un addr; + addr.sun_family = AF_UNIX; + + if (path.size() + 1 >= sizeof(addr.sun_path)) { + Pid pid = startProcess([&]() { + Path dir = dirOf(path); + if (chdir(dir.c_str()) == -1) + throw SysError("chdir to '%s' failed", dir); + std::string base(baseNameOf(path)); + if (base.size() + 1 >= sizeof(addr.sun_path)) + throw Error("socket path '%s' is too long", base); + memcpy(addr.sun_path, base.c_str(), base.size() + 1); + if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) + throw SysError("cannot connect to socket at '%s'", path); + _exit(0); + }); + int status = pid.wait(); + if (status != 0) + throw Error("cannot connect to socket at '%s'", path); + } else { + memcpy(addr.sun_path, path.c_str(), path.size() + 1); + if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) + throw SysError("cannot connect to socket at '%s'", path); + } +} + +} diff --git a/src/libutil/unix-domain-socket.hh b/src/libutil/unix-domain-socket.hh new file mode 100644 index 000000000..b78feb454 --- /dev/null +++ b/src/libutil/unix-domain-socket.hh @@ -0,0 +1,31 @@ +#pragma once +///@file + +#include "types.hh" +#include "file-descriptor.hh" + +#include + +namespace nix { + +/** + * Create a Unix domain socket. + */ +AutoCloseFD createUnixDomainSocket(); + +/** + * Create a Unix domain socket in listen mode. + */ +AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode); + +/** + * Bind a Unix domain socket to a path. + */ +void bind(int fd, const std::string & path); + +/** + * Connect to a Unix domain socket. + */ +void connect(int fd, const std::string & path); + +} diff --git a/src/libutil/users.cc b/src/libutil/users.cc new file mode 100644 index 000000000..95a641322 --- /dev/null +++ b/src/libutil/users.cc @@ -0,0 +1,116 @@ +#include "util.hh" +#include "users.hh" +#include "environment-variables.hh" +#include "file-system.hh" + +#include +#include +#include + +namespace nix { + +std::string getUserName() +{ + auto pw = getpwuid(geteuid()); + std::string name = pw ? pw->pw_name : getEnv("USER").value_or(""); + if (name.empty()) + throw Error("cannot figure out user name"); + return name; +} + +Path getHomeOf(uid_t userId) +{ + std::vector buf(16384); + struct passwd pwbuf; + struct passwd * pw; + if (getpwuid_r(userId, &pwbuf, buf.data(), buf.size(), &pw) != 0 + || !pw || !pw->pw_dir || !pw->pw_dir[0]) + throw Error("cannot determine user's home directory"); + return pw->pw_dir; +} + +Path getHome() +{ + static Path homeDir = []() + { + std::optional unownedUserHomeDir = {}; + auto homeDir = getEnv("HOME"); + if (homeDir) { + // Only use $HOME if doesn't exist or is owned by the current user. + struct stat st; + int result = stat(homeDir->c_str(), &st); + if (result != 0) { + if (errno != ENOENT) { + warn("couldn't stat $HOME ('%s') for reason other than not existing ('%d'), falling back to the one defined in the 'passwd' file", *homeDir, errno); + homeDir.reset(); + } + } else if (st.st_uid != geteuid()) { + unownedUserHomeDir.swap(homeDir); + } + } + if (!homeDir) { + homeDir = getHomeOf(geteuid()); + if (unownedUserHomeDir.has_value() && unownedUserHomeDir != homeDir) { + warn("$HOME ('%s') is not owned by you, falling back to the one defined in the 'passwd' file ('%s')", *unownedUserHomeDir, *homeDir); + } + } + return *homeDir; + }(); + return homeDir; +} + + +Path getCacheDir() +{ + auto cacheDir = getEnv("XDG_CACHE_HOME"); + return cacheDir ? *cacheDir : getHome() + "/.cache"; +} + + +Path getConfigDir() +{ + auto configDir = getEnv("XDG_CONFIG_HOME"); + return configDir ? *configDir : getHome() + "/.config"; +} + +std::vector getConfigDirs() +{ + Path configHome = getConfigDir(); + auto configDirs = getEnv("XDG_CONFIG_DIRS").value_or("/etc/xdg"); + std::vector result = tokenizeString>(configDirs, ":"); + result.insert(result.begin(), configHome); + return result; +} + + +Path getDataDir() +{ + auto dataDir = getEnv("XDG_DATA_HOME"); + return dataDir ? *dataDir : getHome() + "/.local/share"; +} + +Path getStateDir() +{ + auto stateDir = getEnv("XDG_STATE_HOME"); + return stateDir ? *stateDir : getHome() + "/.local/state"; +} + +Path createNixStateDir() +{ + Path dir = getStateDir() + "/nix"; + createDirs(dir); + return dir; +} + + +std::string expandTilde(std::string_view path) +{ + // TODO: expand ~user ? + auto tilde = path.substr(0, 2); + if (tilde == "~/" || tilde == "~") + return getHome() + std::string(path.substr(1)); + else + return std::string(path); +} + +} diff --git a/src/libutil/users.hh b/src/libutil/users.hh new file mode 100644 index 000000000..cecbb8bfb --- /dev/null +++ b/src/libutil/users.hh @@ -0,0 +1,58 @@ +#pragma once +///@file + +#include "types.hh" + +#include + +namespace nix { + +std::string getUserName(); + +/** + * @return the given user's home directory from /etc/passwd. + */ +Path getHomeOf(uid_t userId); + +/** + * @return $HOME or the user's home directory from /etc/passwd. + */ +Path getHome(); + +/** + * @return $XDG_CACHE_HOME or $HOME/.cache. + */ +Path getCacheDir(); + +/** + * @return $XDG_CONFIG_HOME or $HOME/.config. + */ +Path getConfigDir(); + +/** + * @return the directories to search for user configuration files + */ +std::vector getConfigDirs(); + +/** + * @return $XDG_DATA_HOME or $HOME/.local/share. + */ +Path getDataDir(); + +/** + * @return $XDG_STATE_HOME or $HOME/.local/state. + */ +Path getStateDir(); + +/** + * Create the Nix state directory and return the path to it. + */ +Path createNixStateDir(); + +/** + * Perform tilde expansion on a path, replacing tilde with the user's + * home directory. + */ +std::string expandTilde(std::string_view path); + +} diff --git a/src/libutil/util.cc b/src/libutil/util.cc index 3b4c181e5..ee7a22849 100644 --- a/src/libutil/util.cc +++ b/src/libutil/util.cc @@ -1,49 +1,10 @@ #include "util.hh" -#include "sync.hh" -#include "finally.hh" -#include "serialise.hh" -#include "cgroup.hh" +#include "fmt.hh" #include #include -#include -#include -#include -#include -#include -#include #include -#include -#include -#include - -#include #include -#include -#include -#include -#include -#include -#include -#include -#include - -#ifdef __APPLE__ -#include -#include -#endif - -#ifdef __linux__ -#include -#include -#include - -#include -#endif - - -extern char * * environ __attribute__((weak)); - namespace nix { @@ -67,1099 +28,8 @@ void initLibUtil() { assert(caught); } -std::optional getEnv(const std::string & key) -{ - char * value = getenv(key.c_str()); - if (!value) return {}; - return std::string(value); -} - -std::optional getEnvNonEmpty(const std::string & key) { - auto value = getEnv(key); - if (value == "") return {}; - return value; -} - -std::map getEnv() -{ - std::map env; - for (size_t i = 0; environ[i]; ++i) { - auto s = environ[i]; - auto eq = strchr(s, '='); - if (!eq) - // invalid env, just keep going - continue; - env.emplace(std::string(s, eq), std::string(eq + 1)); - } - return env; -} - - -void clearEnv() -{ - for (auto & name : getEnv()) - unsetenv(name.first.c_str()); -} - -void replaceEnv(const std::map & newEnv) -{ - clearEnv(); - for (auto & newEnvVar : newEnv) - setenv(newEnvVar.first.c_str(), newEnvVar.second.c_str(), 1); -} - - -Path absPath(Path path, std::optional dir, bool resolveSymlinks) -{ - if (path[0] != '/') { - if (!dir) { -#ifdef __GNU__ - /* GNU (aka. GNU/Hurd) doesn't have any limitation on path - lengths and doesn't define `PATH_MAX'. */ - char *buf = getcwd(NULL, 0); - if (buf == NULL) -#else - char buf[PATH_MAX]; - if (!getcwd(buf, sizeof(buf))) -#endif - throw SysError("cannot get cwd"); - path = concatStrings(buf, "/", path); -#ifdef __GNU__ - free(buf); -#endif - } else - path = concatStrings(*dir, "/", path); - } - return canonPath(path, resolveSymlinks); -} - - -Path canonPath(PathView path, bool resolveSymlinks) -{ - assert(path != ""); - - std::string s; - s.reserve(256); - - if (path[0] != '/') - throw Error("not an absolute path: '%1%'", path); - - std::string temp; - - /* Count the number of times we follow a symlink and stop at some - arbitrary (but high) limit to prevent infinite loops. */ - unsigned int followCount = 0, maxFollow = 1024; - - while (1) { - - /* Skip slashes. */ - while (!path.empty() && path[0] == '/') path.remove_prefix(1); - if (path.empty()) break; - - /* Ignore `.'. */ - if (path == "." || path.substr(0, 2) == "./") - path.remove_prefix(1); - - /* If `..', delete the last component. */ - else if (path == ".." || path.substr(0, 3) == "../") - { - if (!s.empty()) s.erase(s.rfind('/')); - path.remove_prefix(2); - } - - /* Normal component; copy it. */ - else { - s += '/'; - if (const auto slash = path.find('/'); slash == std::string::npos) { - s += path; - path = {}; - } else { - s += path.substr(0, slash); - path = path.substr(slash); - } - - /* If s points to a symlink, resolve it and continue from there */ - if (resolveSymlinks && isLink(s)) { - if (++followCount >= maxFollow) - throw Error("infinite symlink recursion in path '%1%'", path); - temp = concatStrings(readLink(s), path); - path = temp; - if (!temp.empty() && temp[0] == '/') { - s.clear(); /* restart for symlinks pointing to absolute path */ - } else { - s = dirOf(s); - if (s == "/") { // we don’t want trailing slashes here, which dirOf only produces if s = / - s.clear(); - } - } - } - } - } - - return s.empty() ? "/" : std::move(s); -} - - -Path dirOf(const PathView path) -{ - Path::size_type pos = path.rfind('/'); - if (pos == std::string::npos) - return "."; - return pos == 0 ? "/" : Path(path, 0, pos); -} - - -std::string_view baseNameOf(std::string_view path) -{ - if (path.empty()) - return ""; - - auto last = path.size() - 1; - if (path[last] == '/' && last > 0) - last -= 1; - - auto pos = path.rfind('/', last); - if (pos == std::string::npos) - pos = 0; - else - pos += 1; - - return path.substr(pos, last - pos + 1); -} - - -std::string expandTilde(std::string_view path) -{ - // TODO: expand ~user ? - auto tilde = path.substr(0, 2); - if (tilde == "~/" || tilde == "~") - return getHome() + std::string(path.substr(1)); - else - return std::string(path); -} - - -bool isInDir(std::string_view path, std::string_view dir) -{ - return path.substr(0, 1) == "/" - && path.substr(0, dir.size()) == dir - && path.size() >= dir.size() + 2 - && path[dir.size()] == '/'; -} - - -bool isDirOrInDir(std::string_view path, std::string_view dir) -{ - return path == dir || isInDir(path, dir); -} - - -struct stat stat(const Path & path) -{ - struct stat st; - if (stat(path.c_str(), &st)) - throw SysError("getting status of '%1%'", path); - return st; -} - - -struct stat lstat(const Path & path) -{ - struct stat st; - if (lstat(path.c_str(), &st)) - throw SysError("getting status of '%1%'", path); - return st; -} - - -bool pathExists(const Path & path) -{ - int res; - struct stat st; - res = lstat(path.c_str(), &st); - if (!res) return true; - if (errno != ENOENT && errno != ENOTDIR) - throw SysError("getting status of %1%", path); - return false; -} - -bool pathAccessible(const Path & path) -{ - try { - return pathExists(path); - } catch (SysError & e) { - // swallow EPERM - if (e.errNo == EPERM) return false; - throw; - } -} - - -Path readLink(const Path & path) -{ - checkInterrupt(); - std::vector buf; - for (ssize_t bufSize = PATH_MAX/4; true; bufSize += bufSize/2) { - buf.resize(bufSize); - ssize_t rlSize = readlink(path.c_str(), buf.data(), bufSize); - if (rlSize == -1) - if (errno == EINVAL) - throw Error("'%1%' is not a symlink", path); - else - throw SysError("reading symbolic link '%1%'", path); - else if (rlSize < bufSize) - return std::string(buf.data(), rlSize); - } -} - - -bool isLink(const Path & path) -{ - struct stat st = lstat(path); - return S_ISLNK(st.st_mode); -} - - -DirEntries readDirectory(DIR *dir, const Path & path) -{ - DirEntries entries; - entries.reserve(64); - - struct dirent * dirent; - while (errno = 0, dirent = readdir(dir)) { /* sic */ - checkInterrupt(); - std::string name = dirent->d_name; - if (name == "." || name == "..") continue; - entries.emplace_back(name, dirent->d_ino, -#ifdef HAVE_STRUCT_DIRENT_D_TYPE - dirent->d_type -#else - DT_UNKNOWN -#endif - ); - } - if (errno) throw SysError("reading directory '%1%'", path); - - return entries; -} - -DirEntries readDirectory(const Path & path) -{ - AutoCloseDir dir(opendir(path.c_str())); - if (!dir) throw SysError("opening directory '%1%'", path); - - return readDirectory(dir.get(), path); -} - - -unsigned char getFileType(const Path & path) -{ - struct stat st = lstat(path); - if (S_ISDIR(st.st_mode)) return DT_DIR; - if (S_ISLNK(st.st_mode)) return DT_LNK; - if (S_ISREG(st.st_mode)) return DT_REG; - return DT_UNKNOWN; -} - - -std::string readFile(int fd) -{ - struct stat st; - if (fstat(fd, &st) == -1) - throw SysError("statting file"); - - return drainFD(fd, true, st.st_size); -} - - -std::string readFile(const Path & path) -{ - AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_CLOEXEC); - if (!fd) - throw SysError("opening file '%1%'", path); - return readFile(fd.get()); -} - - -void readFile(const Path & path, Sink & sink) -{ - AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_CLOEXEC); - if (!fd) - throw SysError("opening file '%s'", path); - drainFD(fd.get(), sink); -} - - -void writeFile(const Path & path, std::string_view s, mode_t mode, bool sync) -{ - AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode); - if (!fd) - throw SysError("opening file '%1%'", path); - try { - writeFull(fd.get(), s); - } catch (Error & e) { - e.addTrace({}, "writing file '%1%'", path); - throw; - } - if (sync) - fd.fsync(); - // Explicitly close to make sure exceptions are propagated. - fd.close(); - if (sync) - syncParent(path); -} - - -void writeFile(const Path & path, Source & source, mode_t mode, bool sync) -{ - AutoCloseFD fd = open(path.c_str(), O_WRONLY | O_TRUNC | O_CREAT | O_CLOEXEC, mode); - if (!fd) - throw SysError("opening file '%1%'", path); - - std::vector buf(64 * 1024); - - try { - while (true) { - try { - auto n = source.read(buf.data(), buf.size()); - writeFull(fd.get(), {buf.data(), n}); - } catch (EndOfFile &) { break; } - } - } catch (Error & e) { - e.addTrace({}, "writing file '%1%'", path); - throw; - } - if (sync) - fd.fsync(); - // Explicitly close to make sure exceptions are propagated. - fd.close(); - if (sync) - syncParent(path); -} - -void syncParent(const Path & path) -{ - AutoCloseFD fd = open(dirOf(path).c_str(), O_RDONLY, 0); - if (!fd) - throw SysError("opening file '%1%'", path); - fd.fsync(); -} - -std::string readLine(int fd) -{ - std::string s; - while (1) { - checkInterrupt(); - char ch; - // FIXME: inefficient - ssize_t rd = read(fd, &ch, 1); - if (rd == -1) { - if (errno != EINTR) - throw SysError("reading a line"); - } else if (rd == 0) - throw EndOfFile("unexpected EOF reading a line"); - else { - if (ch == '\n') return s; - s += ch; - } - } -} - - -void writeLine(int fd, std::string s) -{ - s += '\n'; - writeFull(fd, s); -} - - -static void _deletePath(int parentfd, const Path & path, uint64_t & bytesFreed) -{ - checkInterrupt(); - - std::string name(baseNameOf(path)); - - struct stat st; - if (fstatat(parentfd, name.c_str(), &st, AT_SYMLINK_NOFOLLOW) == -1) { - if (errno == ENOENT) return; - throw SysError("getting status of '%1%'", path); - } - - if (!S_ISDIR(st.st_mode)) { - /* We are about to delete a file. Will it likely free space? */ - - switch (st.st_nlink) { - /* Yes: last link. */ - case 1: - bytesFreed += st.st_size; - break; - /* Maybe: yes, if 'auto-optimise-store' or manual optimisation - was performed. Instead of checking for real let's assume - it's an optimised file and space will be freed. - - In worst case we will double count on freed space for files - with exactly two hardlinks for unoptimised packages. - */ - case 2: - bytesFreed += st.st_size; - break; - /* No: 3+ links. */ - default: - break; - } - } - - if (S_ISDIR(st.st_mode)) { - /* Make the directory accessible. */ - const auto PERM_MASK = S_IRUSR | S_IWUSR | S_IXUSR; - if ((st.st_mode & PERM_MASK) != PERM_MASK) { - if (fchmodat(parentfd, name.c_str(), st.st_mode | PERM_MASK, 0) == -1) - throw SysError("chmod '%1%'", path); - } - - int fd = openat(parentfd, path.c_str(), O_RDONLY); - if (fd == -1) - throw SysError("opening directory '%1%'", path); - AutoCloseDir dir(fdopendir(fd)); - if (!dir) - throw SysError("opening directory '%1%'", path); - for (auto & i : readDirectory(dir.get(), path)) - _deletePath(dirfd(dir.get()), path + "/" + i.name, bytesFreed); - } - - int flags = S_ISDIR(st.st_mode) ? AT_REMOVEDIR : 0; - if (unlinkat(parentfd, name.c_str(), flags) == -1) { - if (errno == ENOENT) return; - throw SysError("cannot unlink '%1%'", path); - } -} - -static void _deletePath(const Path & path, uint64_t & bytesFreed) -{ - Path dir = dirOf(path); - if (dir == "") - dir = "/"; - - AutoCloseFD dirfd{open(dir.c_str(), O_RDONLY)}; - if (!dirfd) { - if (errno == ENOENT) return; - throw SysError("opening directory '%1%'", path); - } - - _deletePath(dirfd.get(), path, bytesFreed); -} - - -void deletePath(const Path & path) -{ - uint64_t dummy; - deletePath(path, dummy); -} - - -void deletePath(const Path & path, uint64_t & bytesFreed) -{ - //Activity act(*logger, lvlDebug, "recursively deleting path '%1%'", path); - bytesFreed = 0; - _deletePath(path, bytesFreed); -} - - -std::string getUserName() -{ - auto pw = getpwuid(geteuid()); - std::string name = pw ? pw->pw_name : getEnv("USER").value_or(""); - if (name.empty()) - throw Error("cannot figure out user name"); - return name; -} - -Path getHomeOf(uid_t userId) -{ - std::vector buf(16384); - struct passwd pwbuf; - struct passwd * pw; - if (getpwuid_r(userId, &pwbuf, buf.data(), buf.size(), &pw) != 0 - || !pw || !pw->pw_dir || !pw->pw_dir[0]) - throw Error("cannot determine user's home directory"); - return pw->pw_dir; -} - -Path getHome() -{ - static Path homeDir = []() - { - std::optional unownedUserHomeDir = {}; - auto homeDir = getEnv("HOME"); - if (homeDir) { - // Only use $HOME if doesn't exist or is owned by the current user. - struct stat st; - int result = stat(homeDir->c_str(), &st); - if (result != 0) { - if (errno != ENOENT) { - warn("couldn't stat $HOME ('%s') for reason other than not existing ('%d'), falling back to the one defined in the 'passwd' file", *homeDir, errno); - homeDir.reset(); - } - } else if (st.st_uid != geteuid()) { - unownedUserHomeDir.swap(homeDir); - } - } - if (!homeDir) { - homeDir = getHomeOf(geteuid()); - if (unownedUserHomeDir.has_value() && unownedUserHomeDir != homeDir) { - warn("$HOME ('%s') is not owned by you, falling back to the one defined in the 'passwd' file ('%s')", *unownedUserHomeDir, *homeDir); - } - } - return *homeDir; - }(); - return homeDir; -} - - -Path getCacheDir() -{ - auto cacheDir = getEnv("XDG_CACHE_HOME"); - return cacheDir ? *cacheDir : getHome() + "/.cache"; -} - - -Path getConfigDir() -{ - auto configDir = getEnv("XDG_CONFIG_HOME"); - return configDir ? *configDir : getHome() + "/.config"; -} - -std::vector getConfigDirs() -{ - Path configHome = getConfigDir(); - auto configDirs = getEnv("XDG_CONFIG_DIRS").value_or("/etc/xdg"); - std::vector result = tokenizeString>(configDirs, ":"); - result.insert(result.begin(), configHome); - return result; -} - - -Path getDataDir() -{ - auto dataDir = getEnv("XDG_DATA_HOME"); - return dataDir ? *dataDir : getHome() + "/.local/share"; -} - -Path getStateDir() -{ - auto stateDir = getEnv("XDG_STATE_HOME"); - return stateDir ? *stateDir : getHome() + "/.local/state"; -} - -Path createNixStateDir() -{ - Path dir = getStateDir() + "/nix"; - createDirs(dir); - return dir; -} - - -std::optional getSelfExe() -{ - static auto cached = []() -> std::optional - { - #if __linux__ - return readLink("/proc/self/exe"); - #elif __APPLE__ - char buf[1024]; - uint32_t size = sizeof(buf); - if (_NSGetExecutablePath(buf, &size) == 0) - return buf; - else - return std::nullopt; - #else - return std::nullopt; - #endif - }(); - return cached; -} - - -Paths createDirs(const Path & path) -{ - Paths created; - if (path == "/") return created; - - struct stat st; - if (lstat(path.c_str(), &st) == -1) { - created = createDirs(dirOf(path)); - if (mkdir(path.c_str(), 0777) == -1 && errno != EEXIST) - throw SysError("creating directory '%1%'", path); - st = lstat(path); - created.push_back(path); - } - - if (S_ISLNK(st.st_mode) && stat(path.c_str(), &st) == -1) - throw SysError("statting symlink '%1%'", path); - - if (!S_ISDIR(st.st_mode)) throw Error("'%1%' is not a directory", path); - - return created; -} - - -void readFull(int fd, char * buf, size_t count) -{ - while (count) { - checkInterrupt(); - ssize_t res = read(fd, buf, count); - if (res == -1) { - if (errno == EINTR) continue; - throw SysError("reading from file"); - } - if (res == 0) throw EndOfFile("unexpected end-of-file"); - count -= res; - buf += res; - } -} - - -void writeFull(int fd, std::string_view s, bool allowInterrupts) -{ - while (!s.empty()) { - if (allowInterrupts) checkInterrupt(); - ssize_t res = write(fd, s.data(), s.size()); - if (res == -1 && errno != EINTR) - throw SysError("writing to file"); - if (res > 0) - s.remove_prefix(res); - } -} - - -std::string drainFD(int fd, bool block, const size_t reserveSize) -{ - // the parser needs two extra bytes to append terminating characters, other users will - // not care very much about the extra memory. - StringSink sink(reserveSize + 2); - drainFD(fd, sink, block); - return std::move(sink.s); -} - - -void drainFD(int fd, Sink & sink, bool block) -{ - // silence GCC maybe-uninitialized warning in finally - int saved = 0; - - if (!block) { - saved = fcntl(fd, F_GETFL); - if (fcntl(fd, F_SETFL, saved | O_NONBLOCK) == -1) - throw SysError("making file descriptor non-blocking"); - } - - Finally finally([&]() { - if (!block) { - if (fcntl(fd, F_SETFL, saved) == -1) - throw SysError("making file descriptor blocking"); - } - }); - - std::vector buf(64 * 1024); - while (1) { - checkInterrupt(); - ssize_t rd = read(fd, buf.data(), buf.size()); - if (rd == -1) { - if (!block && (errno == EAGAIN || errno == EWOULDBLOCK)) - break; - if (errno != EINTR) - throw SysError("reading from file"); - } - else if (rd == 0) break; - else sink({(char *) buf.data(), (size_t) rd}); - } -} - ////////////////////////////////////////////////////////////////////// -unsigned int getMaxCPU() -{ - #if __linux__ - try { - auto cgroupFS = getCgroupFS(); - if (!cgroupFS) return 0; - - auto cgroups = getCgroups("/proc/self/cgroup"); - auto cgroup = cgroups[""]; - if (cgroup == "") return 0; - - auto cpuFile = *cgroupFS + "/" + cgroup + "/cpu.max"; - - auto cpuMax = readFile(cpuFile); - auto cpuMaxParts = tokenizeString>(cpuMax, " \n"); - auto quota = cpuMaxParts[0]; - auto period = cpuMaxParts[1]; - if (quota != "max") - return std::ceil(std::stoi(quota) / std::stof(period)); - } catch (Error &) { ignoreException(lvlDebug); } - #endif - - return 0; -} - -////////////////////////////////////////////////////////////////////// - - -AutoDelete::AutoDelete() : del{false} {} - -AutoDelete::AutoDelete(const std::string & p, bool recursive) : path(p) -{ - del = true; - this->recursive = recursive; -} - -AutoDelete::~AutoDelete() -{ - try { - if (del) { - if (recursive) - deletePath(path); - else { - if (remove(path.c_str()) == -1) - throw SysError("cannot unlink '%1%'", path); - } - } - } catch (...) { - ignoreException(); - } -} - -void AutoDelete::cancel() -{ - del = false; -} - -void AutoDelete::reset(const Path & p, bool recursive) { - path = p; - this->recursive = recursive; - del = true; -} - - - -////////////////////////////////////////////////////////////////////// - - -AutoCloseFD::AutoCloseFD() : fd{-1} {} - - -AutoCloseFD::AutoCloseFD(int fd) : fd{fd} {} - - -AutoCloseFD::AutoCloseFD(AutoCloseFD && that) : fd{that.fd} -{ - that.fd = -1; -} - - -AutoCloseFD & AutoCloseFD::operator =(AutoCloseFD && that) -{ - close(); - fd = that.fd; - that.fd = -1; - return *this; -} - - -AutoCloseFD::~AutoCloseFD() -{ - try { - close(); - } catch (...) { - ignoreException(); - } -} - - -int AutoCloseFD::get() const -{ - return fd; -} - - -void AutoCloseFD::close() -{ - if (fd != -1) { - if (::close(fd) == -1) - /* This should never happen. */ - throw SysError("closing file descriptor %1%", fd); - fd = -1; - } -} - -void AutoCloseFD::fsync() -{ - if (fd != -1) { - int result; -#if __APPLE__ - result = ::fcntl(fd, F_FULLFSYNC); -#else - result = ::fsync(fd); -#endif - if (result == -1) - throw SysError("fsync file descriptor %1%", fd); - } -} - - -AutoCloseFD::operator bool() const -{ - return fd != -1; -} - - -int AutoCloseFD::release() -{ - int oldFD = fd; - fd = -1; - return oldFD; -} - - -void Pipe::create() -{ - int fds[2]; -#if HAVE_PIPE2 - if (pipe2(fds, O_CLOEXEC) != 0) throw SysError("creating pipe"); -#else - if (pipe(fds) != 0) throw SysError("creating pipe"); - closeOnExec(fds[0]); - closeOnExec(fds[1]); -#endif - readSide = fds[0]; - writeSide = fds[1]; -} - - -void Pipe::close() -{ - readSide.close(); - writeSide.close(); -} - - -////////////////////////////////////////////////////////////////////// - - -Pid::Pid() -{ -} - - -Pid::Pid(pid_t pid) - : pid(pid) -{ -} - - -Pid::~Pid() -{ - if (pid != -1) kill(); -} - - -void Pid::operator =(pid_t pid) -{ - if (this->pid != -1 && this->pid != pid) kill(); - this->pid = pid; - killSignal = SIGKILL; // reset signal to default -} - - -Pid::operator pid_t() -{ - return pid; -} - - -int Pid::kill() -{ - assert(pid != -1); - - debug("killing process %1%", pid); - - /* Send the requested signal to the child. If it has its own - process group, send the signal to every process in the child - process group (which hopefully includes *all* its children). */ - if (::kill(separatePG ? -pid : pid, killSignal) != 0) { - /* On BSDs, killing a process group will return EPERM if all - processes in the group are zombies (or something like - that). So try to detect and ignore that situation. */ -#if __FreeBSD__ || __APPLE__ - if (errno != EPERM || ::kill(pid, 0) != 0) -#endif - logError(SysError("killing process %d", pid).info()); - } - - return wait(); -} - - -int Pid::wait() -{ - assert(pid != -1); - while (1) { - int status; - int res = waitpid(pid, &status, 0); - if (res == pid) { - pid = -1; - return status; - } - if (errno != EINTR) - throw SysError("cannot get exit status of PID %d", pid); - checkInterrupt(); - } -} - - -void Pid::setSeparatePG(bool separatePG) -{ - this->separatePG = separatePG; -} - - -void Pid::setKillSignal(int signal) -{ - this->killSignal = signal; -} - - -pid_t Pid::release() -{ - pid_t p = pid; - pid = -1; - return p; -} - - -void killUser(uid_t uid) -{ - debug("killing all processes running under uid '%1%'", uid); - - assert(uid != 0); /* just to be safe... */ - - /* The system call kill(-1, sig) sends the signal `sig' to all - users to which the current process can send signals. So we - fork a process, switch to uid, and send a mass kill. */ - - Pid pid = startProcess([&]() { - - if (setuid(uid) == -1) - throw SysError("setting uid"); - - while (true) { -#ifdef __APPLE__ - /* OSX's kill syscall takes a third parameter that, among - other things, determines if kill(-1, signo) affects the - calling process. In the OSX libc, it's set to true, - which means "follow POSIX", which we don't want here - */ - if (syscall(SYS_kill, -1, SIGKILL, false) == 0) break; -#else - if (kill(-1, SIGKILL) == 0) break; -#endif - if (errno == ESRCH || errno == EPERM) break; /* no more processes */ - if (errno != EINTR) - throw SysError("cannot kill processes for uid '%1%'", uid); - } - - _exit(0); - }); - - int status = pid.wait(); - if (status != 0) - throw Error("cannot kill processes for uid '%1%': %2%", uid, statusToString(status)); - - /* !!! We should really do some check to make sure that there are - no processes left running under `uid', but there is no portable - way to do so (I think). The most reliable way may be `ps -eo - uid | grep -q $uid'. */ -} - - -////////////////////////////////////////////////////////////////////// - - -/* Wrapper around vfork to prevent the child process from clobbering - the caller's stack frame in the parent. */ -static pid_t doFork(bool allowVfork, std::function fun) __attribute__((noinline)); -static pid_t doFork(bool allowVfork, std::function fun) -{ -#ifdef __linux__ - pid_t pid = allowVfork ? vfork() : fork(); -#else - pid_t pid = fork(); -#endif - if (pid != 0) return pid; - fun(); - abort(); -} - - -#if __linux__ -static int childEntry(void * arg) -{ - auto main = (std::function *) arg; - (*main)(); - return 1; -} -#endif - - -pid_t startProcess(std::function fun, const ProcessOptions & options) -{ - std::function wrapper = [&]() { - if (!options.allowVfork) - logger = makeSimpleLogger(); - try { -#if __linux__ - if (options.dieWithParent && prctl(PR_SET_PDEATHSIG, SIGKILL) == -1) - throw SysError("setting death signal"); -#endif - fun(); - } catch (std::exception & e) { - try { - std::cerr << options.errorPrefix << e.what() << "\n"; - } catch (...) { } - } catch (...) { } - if (options.runExitHandlers) - exit(1); - else - _exit(1); - }; - - pid_t pid = -1; - - if (options.cloneFlags) { - #ifdef __linux__ - // Not supported, since then we don't know when to free the stack. - assert(!(options.cloneFlags & CLONE_VM)); - - size_t stackSize = 1 * 1024 * 1024; - auto stack = (char *) mmap(0, stackSize, - PROT_WRITE | PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); - if (stack == MAP_FAILED) throw SysError("allocating stack"); - - Finally freeStack([&]() { munmap(stack, stackSize); }); - - pid = clone(childEntry, stack + stackSize, options.cloneFlags | SIGCHLD, &wrapper); - #else - throw Error("clone flags are only supported on Linux"); - #endif - } else - pid = doFork(options.allowVfork, wrapper); - - if (pid == -1) throw SysError("unable to fork"); - - return pid; -} - - std::vector stringsToCharPtrs(const Strings & ss) { std::vector res; @@ -1168,211 +38,6 @@ std::vector stringsToCharPtrs(const Strings & ss) return res; } -std::string runProgram(Path program, bool searchPath, const Strings & args, - const std::optional & input, bool isInteractive) -{ - auto res = runProgram(RunOptions {.program = program, .searchPath = searchPath, .args = args, .input = input, .isInteractive = isInteractive}); - - if (!statusOk(res.first)) - throw ExecError(res.first, "program '%1%' %2%", program, statusToString(res.first)); - - return res.second; -} - -// Output = error code + "standard out" output stream -std::pair runProgram(RunOptions && options) -{ - StringSink sink; - options.standardOut = &sink; - - int status = 0; - - try { - runProgram2(options); - } catch (ExecError & e) { - status = e.status; - } - - return {status, std::move(sink.s)}; -} - -void runProgram2(const RunOptions & options) -{ - checkInterrupt(); - - assert(!(options.standardIn && options.input)); - - std::unique_ptr source_; - Source * source = options.standardIn; - - if (options.input) { - source_ = std::make_unique(*options.input); - source = source_.get(); - } - - /* Create a pipe. */ - Pipe out, in; - if (options.standardOut) out.create(); - if (source) in.create(); - - ProcessOptions processOptions; - // vfork implies that the environment of the main process and the fork will - // be shared (technically this is undefined, but in practice that's the - // case), so we can't use it if we alter the environment - processOptions.allowVfork = !options.environment; - - std::optional>> resumeLoggerDefer; - if (options.isInteractive) { - logger->pause(); - resumeLoggerDefer.emplace( - []() { - logger->resume(); - } - ); - } - - /* Fork. */ - Pid pid = startProcess([&]() { - if (options.environment) - replaceEnv(*options.environment); - if (options.standardOut && dup2(out.writeSide.get(), STDOUT_FILENO) == -1) - throw SysError("dupping stdout"); - if (options.mergeStderrToStdout) - if (dup2(STDOUT_FILENO, STDERR_FILENO) == -1) - throw SysError("cannot dup stdout into stderr"); - if (source && dup2(in.readSide.get(), STDIN_FILENO) == -1) - throw SysError("dupping stdin"); - - if (options.chdir && chdir((*options.chdir).c_str()) == -1) - throw SysError("chdir failed"); - if (options.gid && setgid(*options.gid) == -1) - throw SysError("setgid failed"); - /* Drop all other groups if we're setgid. */ - if (options.gid && setgroups(0, 0) == -1) - throw SysError("setgroups failed"); - if (options.uid && setuid(*options.uid) == -1) - throw SysError("setuid failed"); - - Strings args_(options.args); - args_.push_front(options.program); - - restoreProcessContext(); - - if (options.searchPath) - execvp(options.program.c_str(), stringsToCharPtrs(args_).data()); - // This allows you to refer to a program with a pathname relative - // to the PATH variable. - else - execv(options.program.c_str(), stringsToCharPtrs(args_).data()); - - throw SysError("executing '%1%'", options.program); - }, processOptions); - - out.writeSide.close(); - - std::thread writerThread; - - std::promise promise; - - Finally doJoin([&]() { - if (writerThread.joinable()) - writerThread.join(); - }); - - - if (source) { - in.readSide.close(); - writerThread = std::thread([&]() { - try { - std::vector buf(8 * 1024); - while (true) { - size_t n; - try { - n = source->read(buf.data(), buf.size()); - } catch (EndOfFile &) { - break; - } - writeFull(in.writeSide.get(), {buf.data(), n}); - } - promise.set_value(); - } catch (...) { - promise.set_exception(std::current_exception()); - } - in.writeSide.close(); - }); - } - - if (options.standardOut) - drainFD(out.readSide.get(), *options.standardOut); - - /* Wait for the child to finish. */ - int status = pid.wait(); - - /* Wait for the writer thread to finish. */ - if (source) promise.get_future().get(); - - if (status) - throw ExecError(status, "program '%1%' %2%", options.program, statusToString(status)); -} - - -void closeMostFDs(const std::set & exceptions) -{ -#if __linux__ - try { - for (auto & s : readDirectory("/proc/self/fd")) { - auto fd = std::stoi(s.name); - if (!exceptions.count(fd)) { - debug("closing leaked FD %d", fd); - close(fd); - } - } - return; - } catch (SysError &) { - } -#endif - - int maxFD = 0; - maxFD = sysconf(_SC_OPEN_MAX); - for (int fd = 0; fd < maxFD; ++fd) - if (!exceptions.count(fd)) - close(fd); /* ignore result */ -} - - -void closeOnExec(int fd) -{ - int prev; - if ((prev = fcntl(fd, F_GETFD, 0)) == -1 || - fcntl(fd, F_SETFD, prev | FD_CLOEXEC) == -1) - throw SysError("setting close-on-exec flag"); -} - - -////////////////////////////////////////////////////////////////////// - - -std::atomic _isInterrupted = false; - -static thread_local bool interruptThrown = false; -thread_local std::function interruptCheck; - -void setInterruptThrown() -{ - interruptThrown = true; -} - -void _interrupted() -{ - /* Block user interrupts while an exception is being handled. - Throwing an exception while another exception is being handled - kills the program! */ - if (!interruptThrown && !std::uncaught_exceptions()) { - interruptThrown = true; - throw Interrupted("interrupted by the user"); - } -} - ////////////////////////////////////////////////////////////////////// @@ -1438,32 +103,6 @@ std::string rewriteStrings(std::string s, const StringMap & rewrites) } -std::string statusToString(int status) -{ - if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { - if (WIFEXITED(status)) - return fmt("failed with exit code %1%", WEXITSTATUS(status)); - else if (WIFSIGNALED(status)) { - int sig = WTERMSIG(status); -#if HAVE_STRSIGNAL - const char * description = strsignal(sig); - return fmt("failed due to signal %1% (%2%)", sig, description); -#else - return fmt("failed due to signal %1%", sig); -#endif - } - else - return "died abnormally"; - } else return "succeeded"; -} - - -bool statusOk(int status) -{ - return WIFEXITED(status) && WEXITSTATUS(status) == 0; -} - - bool hasPrefix(std::string_view s, std::string_view prefix) { return s.compare(0, prefix.size(), prefix) == 0; @@ -1511,82 +150,6 @@ void ignoreException(Verbosity lvl) } catch (...) { } } -bool shouldANSI() -{ - return isatty(STDERR_FILENO) - && getEnv("TERM").value_or("dumb") != "dumb" - && !(getEnv("NO_COLOR").has_value() || getEnv("NOCOLOR").has_value()); -} - -std::string filterANSIEscapes(std::string_view s, bool filterAll, unsigned int width) -{ - std::string t, e; - size_t w = 0; - auto i = s.begin(); - - while (w < (size_t) width && i != s.end()) { - - if (*i == '\e') { - std::string e; - e += *i++; - char last = 0; - - if (i != s.end() && *i == '[') { - e += *i++; - // eat parameter bytes - while (i != s.end() && *i >= 0x30 && *i <= 0x3f) e += *i++; - // eat intermediate bytes - while (i != s.end() && *i >= 0x20 && *i <= 0x2f) e += *i++; - // eat final byte - if (i != s.end() && *i >= 0x40 && *i <= 0x7e) e += last = *i++; - } else { - if (i != s.end() && *i >= 0x40 && *i <= 0x5f) e += *i++; - } - - if (!filterAll && last == 'm') - t += e; - } - - else if (*i == '\t') { - i++; t += ' '; w++; - while (w < (size_t) width && w % 8) { - t += ' '; w++; - } - } - - else if (*i == '\r' || *i == '\a') - // do nothing for now - i++; - - else { - w++; - // Copy one UTF-8 character. - if ((*i & 0xe0) == 0xc0) { - t += *i++; - if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++; - } else if ((*i & 0xf0) == 0xe0) { - t += *i++; - if (i != s.end() && ((*i & 0xc0) == 0x80)) { - t += *i++; - if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++; - } - } else if ((*i & 0xf8) == 0xf0) { - t += *i++; - if (i != s.end() && ((*i & 0xc0) == 0x80)) { - t += *i++; - if (i != s.end() && ((*i & 0xc0) == 0x80)) { - t += *i++; - if (i != s.end() && ((*i & 0xc0) == 0x80)) t += *i++; - } - } - } else - t += *i++; - } - } - - return t; -} - constexpr char base64Chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; @@ -1703,386 +266,9 @@ std::pair getLine(std::string_view s) } -////////////////////////////////////////////////////////////////////// - -static Sync> windowSize{{0, 0}}; - - -static void updateWindowSize() -{ - struct winsize ws; - if (ioctl(2, TIOCGWINSZ, &ws) == 0) { - auto windowSize_(windowSize.lock()); - windowSize_->first = ws.ws_row; - windowSize_->second = ws.ws_col; - } -} - - -std::pair getWindowSize() -{ - return *windowSize.lock(); -} - - -/* We keep track of interrupt callbacks using integer tokens, so we can iterate - safely without having to lock the data structure while executing arbitrary - functions. - */ -struct InterruptCallbacks { - typedef int64_t Token; - - /* We use unique tokens so that we can't accidentally delete the wrong - handler because of an erroneous double delete. */ - Token nextToken = 0; - - /* Used as a list, see InterruptCallbacks comment. */ - std::map> callbacks; -}; - -static Sync _interruptCallbacks; - -static void signalHandlerThread(sigset_t set) -{ - while (true) { - int signal = 0; - sigwait(&set, &signal); - - if (signal == SIGINT || signal == SIGTERM || signal == SIGHUP) - triggerInterrupt(); - - else if (signal == SIGWINCH) { - updateWindowSize(); - } - } -} - -void triggerInterrupt() -{ - _isInterrupted = true; - - { - InterruptCallbacks::Token i = 0; - while (true) { - std::function callback; - { - auto interruptCallbacks(_interruptCallbacks.lock()); - auto lb = interruptCallbacks->callbacks.lower_bound(i); - if (lb == interruptCallbacks->callbacks.end()) - break; - - callback = lb->second; - i = lb->first + 1; - } - - try { - callback(); - } catch (...) { - ignoreException(); - } - } - } -} - -static sigset_t savedSignalMask; -static bool savedSignalMaskIsSet = false; - -void setChildSignalMask(sigset_t * sigs) -{ - assert(sigs); // C style function, but think of sigs as a reference - -#if _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE - sigemptyset(&savedSignalMask); - // There's no "assign" or "copy" function, so we rely on (math) idempotence - // of the or operator: a or a = a. - sigorset(&savedSignalMask, sigs, sigs); -#else - // Without sigorset, our best bet is to assume that sigset_t is a type that - // can be assigned directly, such as is the case for a sigset_t defined as - // an integer type. - savedSignalMask = *sigs; -#endif - - savedSignalMaskIsSet = true; -} - -void saveSignalMask() { - if (sigprocmask(SIG_BLOCK, nullptr, &savedSignalMask)) - throw SysError("querying signal mask"); - - savedSignalMaskIsSet = true; -} - -void startSignalHandlerThread() -{ - updateWindowSize(); - - saveSignalMask(); - - sigset_t set; - sigemptyset(&set); - sigaddset(&set, SIGINT); - sigaddset(&set, SIGTERM); - sigaddset(&set, SIGHUP); - sigaddset(&set, SIGPIPE); - sigaddset(&set, SIGWINCH); - if (pthread_sigmask(SIG_BLOCK, &set, nullptr)) - throw SysError("blocking signals"); - - std::thread(signalHandlerThread, set).detach(); -} - -static void restoreSignals() -{ - // If startSignalHandlerThread wasn't called, that means we're not running - // in a proper libmain process, but a process that presumably manages its - // own signal handlers. Such a process should call either - // - initNix(), to be a proper libmain process - // - startSignalHandlerThread(), to resemble libmain regarding signal - // handling only - // - saveSignalMask(), for processes that define their own signal handling - // thread - // TODO: Warn about this? Have a default signal mask? The latter depends on - // whether we should generally inherit signal masks from the caller. - // I don't know what the larger unix ecosystem expects from us here. - if (!savedSignalMaskIsSet) - return; - - if (sigprocmask(SIG_SETMASK, &savedSignalMask, nullptr)) - throw SysError("restoring signals"); -} - -#if __linux__ -rlim_t savedStackSize = 0; -#endif - -void setStackSize(size_t stackSize) -{ - #if __linux__ - struct rlimit limit; - if (getrlimit(RLIMIT_STACK, &limit) == 0 && limit.rlim_cur < stackSize) { - savedStackSize = limit.rlim_cur; - limit.rlim_cur = stackSize; - setrlimit(RLIMIT_STACK, &limit); - } - #endif -} - -#if __linux__ -static AutoCloseFD fdSavedMountNamespace; -static AutoCloseFD fdSavedRoot; -#endif - -void saveMountNamespace() -{ -#if __linux__ - static std::once_flag done; - std::call_once(done, []() { - fdSavedMountNamespace = open("/proc/self/ns/mnt", O_RDONLY); - if (!fdSavedMountNamespace) - throw SysError("saving parent mount namespace"); - - fdSavedRoot = open("/proc/self/root", O_RDONLY); - }); -#endif -} - -void restoreMountNamespace() -{ -#if __linux__ - try { - auto savedCwd = absPath("."); - - if (fdSavedMountNamespace && setns(fdSavedMountNamespace.get(), CLONE_NEWNS) == -1) - throw SysError("restoring parent mount namespace"); - - if (fdSavedRoot) { - if (fchdir(fdSavedRoot.get())) - throw SysError("chdir into saved root"); - if (chroot(".")) - throw SysError("chroot into saved root"); - } - - if (chdir(savedCwd.c_str()) == -1) - throw SysError("restoring cwd"); - } catch (Error & e) { - debug(e.msg()); - } -#endif -} - -void unshareFilesystem() -{ -#ifdef __linux__ - if (unshare(CLONE_FS) != 0 && errno != EPERM) - throw SysError("unsharing filesystem state in download thread"); -#endif -} - -void restoreProcessContext(bool restoreMounts) -{ - restoreSignals(); - if (restoreMounts) { - restoreMountNamespace(); - } - - #if __linux__ - if (savedStackSize) { - struct rlimit limit; - if (getrlimit(RLIMIT_STACK, &limit) == 0) { - limit.rlim_cur = savedStackSize; - setrlimit(RLIMIT_STACK, &limit); - } - } - #endif -} - -/* RAII helper to automatically deregister a callback. */ -struct InterruptCallbackImpl : InterruptCallback -{ - InterruptCallbacks::Token token; - ~InterruptCallbackImpl() override - { - auto interruptCallbacks(_interruptCallbacks.lock()); - interruptCallbacks->callbacks.erase(token); - } -}; - -std::unique_ptr createInterruptCallback(std::function callback) -{ - auto interruptCallbacks(_interruptCallbacks.lock()); - auto token = interruptCallbacks->nextToken++; - interruptCallbacks->callbacks.emplace(token, callback); - - auto res = std::make_unique(); - res->token = token; - - return std::unique_ptr(res.release()); -} - - -AutoCloseFD createUnixDomainSocket() -{ - AutoCloseFD fdSocket = socket(PF_UNIX, SOCK_STREAM - #ifdef SOCK_CLOEXEC - | SOCK_CLOEXEC - #endif - , 0); - if (!fdSocket) - throw SysError("cannot create Unix domain socket"); - closeOnExec(fdSocket.get()); - return fdSocket; -} - - -AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode) -{ - auto fdSocket = nix::createUnixDomainSocket(); - - bind(fdSocket.get(), path); - - if (chmod(path.c_str(), mode) == -1) - throw SysError("changing permissions on '%1%'", path); - - if (listen(fdSocket.get(), 100) == -1) - throw SysError("cannot listen on socket '%1%'", path); - - return fdSocket; -} - - -void bind(int fd, const std::string & path) -{ - unlink(path.c_str()); - - struct sockaddr_un addr; - addr.sun_family = AF_UNIX; - - if (path.size() + 1 >= sizeof(addr.sun_path)) { - Pid pid = startProcess([&]() { - Path dir = dirOf(path); - if (chdir(dir.c_str()) == -1) - throw SysError("chdir to '%s' failed", dir); - std::string base(baseNameOf(path)); - if (base.size() + 1 >= sizeof(addr.sun_path)) - throw Error("socket path '%s' is too long", base); - memcpy(addr.sun_path, base.c_str(), base.size() + 1); - if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) - throw SysError("cannot bind to socket '%s'", path); - _exit(0); - }); - int status = pid.wait(); - if (status != 0) - throw Error("cannot bind to socket '%s'", path); - } else { - memcpy(addr.sun_path, path.c_str(), path.size() + 1); - if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) - throw SysError("cannot bind to socket '%s'", path); - } -} - - -void connect(int fd, const std::string & path) -{ - struct sockaddr_un addr; - addr.sun_family = AF_UNIX; - - if (path.size() + 1 >= sizeof(addr.sun_path)) { - Pid pid = startProcess([&]() { - Path dir = dirOf(path); - if (chdir(dir.c_str()) == -1) - throw SysError("chdir to '%s' failed", dir); - std::string base(baseNameOf(path)); - if (base.size() + 1 >= sizeof(addr.sun_path)) - throw Error("socket path '%s' is too long", base); - memcpy(addr.sun_path, base.c_str(), base.size() + 1); - if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) - throw SysError("cannot connect to socket at '%s'", path); - _exit(0); - }); - int status = pid.wait(); - if (status != 0) - throw Error("cannot connect to socket at '%s'", path); - } else { - memcpy(addr.sun_path, path.c_str(), path.size() + 1); - if (connect(fd, (struct sockaddr *) &addr, sizeof(addr)) == -1) - throw SysError("cannot connect to socket at '%s'", path); - } -} - - std::string showBytes(uint64_t bytes) { return fmt("%.2f MiB", bytes / (1024.0 * 1024.0)); } - -// FIXME: move to libstore/build -void commonChildInit() -{ - logger = makeSimpleLogger(); - - const static std::string pathNullDevice = "/dev/null"; - restoreProcessContext(false); - - /* Put the child in a separate session (and thus a separate - process group) so that it has no controlling terminal (meaning - that e.g. ssh cannot open /dev/tty) and it doesn't receive - terminal signals. */ - if (setsid() == -1) - throw SysError("creating a new session"); - - /* Dup stderr to stdout. */ - if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1) - throw SysError("cannot dup stderr into stdout"); - - /* Reroute stdin to /dev/null. */ - int fdDevNull = open(pathNullDevice.c_str(), O_RDWR); - if (fdDevNull == -1) - throw SysError("cannot open '%1%'", pathNullDevice); - if (dup2(fdDevNull, STDIN_FILENO) == -1) - throw SysError("cannot dup null device into stdin"); - close(fdDevNull); -} - } diff --git a/src/libutil/util.hh b/src/libutil/util.hh index 75683f8fe..5f730eaf6 100644 --- a/src/libutil/util.hh +++ b/src/libutil/util.hh @@ -4,485 +4,18 @@ #include "types.hh" #include "error.hh" #include "logging.hh" -#include "ansicolor.hh" - -#include -#include -#include -#include -#include #include -#include #include #include #include #include -#ifndef HAVE_STRUCT_DIRENT_D_TYPE -#define DT_UNKNOWN 0 -#define DT_REG 1 -#define DT_LNK 2 -#define DT_DIR 3 -#endif - namespace nix { -struct Sink; -struct Source; - void initLibUtil(); -/** - * @return an environment variable. - */ -std::optional getEnv(const std::string & key); - -/** - * @return a non empty environment variable. Returns nullopt if the env - * variable is set to "" - */ -std::optional getEnvNonEmpty(const std::string & key); - -/** - * Get the entire environment. - */ -std::map getEnv(); - -/** - * Clear the environment. - */ -void clearEnv(); - -/** - * @return An absolutized path, resolving paths relative to the - * specified directory, or the current directory otherwise. The path - * is also canonicalised. - */ -Path absPath(Path path, - std::optional dir = {}, - bool resolveSymlinks = false); - -/** - * Canonicalise a path by removing all `.` or `..` components and - * double or trailing slashes. Optionally resolves all symlink - * components such that each component of the resulting path is *not* - * a symbolic link. - */ -Path canonPath(PathView path, bool resolveSymlinks = false); - -/** - * @return The directory part of the given canonical path, i.e., - * everything before the final `/`. If the path is the root or an - * immediate child thereof (e.g., `/foo`), this means `/` - * is returned. - */ -Path dirOf(const PathView path); - -/** - * @return the base name of the given canonical path, i.e., everything - * following the final `/` (trailing slashes are removed). - */ -std::string_view baseNameOf(std::string_view path); - -/** - * Perform tilde expansion on a path. - */ -std::string expandTilde(std::string_view path); - -/** - * Check whether 'path' is a descendant of 'dir'. Both paths must be - * canonicalized. - */ -bool isInDir(std::string_view path, std::string_view dir); - -/** - * Check whether 'path' is equal to 'dir' or a descendant of - * 'dir'. Both paths must be canonicalized. - */ -bool isDirOrInDir(std::string_view path, std::string_view dir); - -/** - * Get status of `path`. - */ -struct stat stat(const Path & path); -struct stat lstat(const Path & path); - -/** - * @return true iff the given path exists. - */ -bool pathExists(const Path & path); - -/** - * A version of pathExists that returns false on a permission error. - * Useful for inferring default paths across directories that might not - * be readable. - * @return true iff the given path can be accessed and exists - */ -bool pathAccessible(const Path & path); - -/** - * Read the contents (target) of a symbolic link. The result is not - * in any way canonicalised. - */ -Path readLink(const Path & path); - -bool isLink(const Path & path); - -/** - * Read the contents of a directory. The entries `.` and `..` are - * removed. - */ -struct DirEntry -{ - std::string name; - ino_t ino; - /** - * one of DT_* - */ - unsigned char type; - DirEntry(std::string name, ino_t ino, unsigned char type) - : name(std::move(name)), ino(ino), type(type) { } -}; - -typedef std::vector DirEntries; - -DirEntries readDirectory(const Path & path); - -unsigned char getFileType(const Path & path); - -/** - * Read the contents of a file into a string. - */ -std::string readFile(int fd); -std::string readFile(const Path & path); -void readFile(const Path & path, Sink & sink); - -/** - * Write a string to a file. - */ -void writeFile(const Path & path, std::string_view s, mode_t mode = 0666, bool sync = false); - -void writeFile(const Path & path, Source & source, mode_t mode = 0666, bool sync = false); - -/** - * Flush a file's parent directory to disk - */ -void syncParent(const Path & path); - -/** - * Read a line from a file descriptor. - */ -std::string readLine(int fd); - -/** - * Write a line to a file descriptor. - */ -void writeLine(int fd, std::string s); - -/** - * Delete a path; i.e., in the case of a directory, it is deleted - * recursively. It's not an error if the path does not exist. The - * second variant returns the number of bytes and blocks freed. - */ -void deletePath(const Path & path); - -void deletePath(const Path & path, uint64_t & bytesFreed); - -std::string getUserName(); - -/** - * @return the given user's home directory from /etc/passwd. - */ -Path getHomeOf(uid_t userId); - -/** - * @return $HOME or the user's home directory from /etc/passwd. - */ -Path getHome(); - -/** - * @return $XDG_CACHE_HOME or $HOME/.cache. - */ -Path getCacheDir(); - -/** - * @return $XDG_CONFIG_HOME or $HOME/.config. - */ -Path getConfigDir(); - -/** - * @return the directories to search for user configuration files - */ -std::vector getConfigDirs(); - -/** - * @return $XDG_DATA_HOME or $HOME/.local/share. - */ -Path getDataDir(); - -/** - * @return the path of the current executable. - */ -std::optional getSelfExe(); - -/** - * @return $XDG_STATE_HOME or $HOME/.local/state. - */ -Path getStateDir(); - -/** - * Create the Nix state directory and return the path to it. - */ -Path createNixStateDir(); - -/** - * Create a directory and all its parents, if necessary. Returns the - * list of created directories, in order of creation. - */ -Paths createDirs(const Path & path); -inline Paths createDirs(PathView path) -{ - return createDirs(Path(path)); -} - -/** - * Create a symlink. - */ -void createSymlink(const Path & target, const Path & link); - -/** - * Atomically create or replace a symlink. - */ -void replaceSymlink(const Path & target, const Path & link); - -void renameFile(const Path & src, const Path & dst); - -/** - * Similar to 'renameFile', but fallback to a copy+remove if `src` and `dst` - * are on a different filesystem. - * - * Beware that this might not be atomic because of the copy that happens behind - * the scenes - */ -void moveFile(const Path & src, const Path & dst); - - -/** - * Wrappers arount read()/write() that read/write exactly the - * requested number of bytes. - */ -void readFull(int fd, char * buf, size_t count); -void writeFull(int fd, std::string_view s, bool allowInterrupts = true); - -MakeError(EndOfFile, Error); - - -/** - * Read a file descriptor until EOF occurs. - */ -std::string drainFD(int fd, bool block = true, const size_t reserveSize=0); - -void drainFD(int fd, Sink & sink, bool block = true); - -/** - * If cgroups are active, attempt to calculate the number of CPUs available. - * If cgroups are unavailable or if cpu.max is set to "max", return 0. - */ -unsigned int getMaxCPU(); - -/** - * Automatic cleanup of resources. - */ - - -class AutoDelete -{ - Path path; - bool del; - bool recursive; -public: - AutoDelete(); - AutoDelete(const Path & p, bool recursive = true); - ~AutoDelete(); - void cancel(); - void reset(const Path & p, bool recursive = true); - operator Path() const { return path; } - operator PathView() const { return path; } -}; - - -class AutoCloseFD -{ - int fd; -public: - AutoCloseFD(); - AutoCloseFD(int fd); - AutoCloseFD(const AutoCloseFD & fd) = delete; - AutoCloseFD(AutoCloseFD&& fd); - ~AutoCloseFD(); - AutoCloseFD& operator =(const AutoCloseFD & fd) = delete; - AutoCloseFD& operator =(AutoCloseFD&& fd); - int get() const; - explicit operator bool() const; - int release(); - void close(); - void fsync(); -}; - - -/** - * Create a temporary directory. - */ -Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix", - bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755); - -/** - * Create a temporary file, returning a file handle and its path. - */ -std::pair createTempFile(const Path & prefix = "nix"); - - -class Pipe -{ -public: - AutoCloseFD readSide, writeSide; - void create(); - void close(); -}; - - -struct DIRDeleter -{ - void operator()(DIR * dir) const { - closedir(dir); - } -}; - -typedef std::unique_ptr AutoCloseDir; - - -class Pid -{ - pid_t pid = -1; - bool separatePG = false; - int killSignal = SIGKILL; -public: - Pid(); - Pid(pid_t pid); - ~Pid(); - void operator =(pid_t pid); - operator pid_t(); - int kill(); - int wait(); - - void setSeparatePG(bool separatePG); - void setKillSignal(int signal); - pid_t release(); -}; - - -/** - * Kill all processes running under the specified uid by sending them - * a SIGKILL. - */ -void killUser(uid_t uid); - - -/** - * Fork a process that runs the given function, and return the child - * pid to the caller. - */ -struct ProcessOptions -{ - std::string errorPrefix = ""; - bool dieWithParent = true; - bool runExitHandlers = false; - bool allowVfork = false; - /** - * use clone() with the specified flags (Linux only) - */ - int cloneFlags = 0; -}; - -pid_t startProcess(std::function fun, const ProcessOptions & options = ProcessOptions()); - - -/** - * Run a program and return its stdout in a string (i.e., like the - * shell backtick operator). - */ -std::string runProgram(Path program, bool searchPath = false, - const Strings & args = Strings(), - const std::optional & input = {}, bool isInteractive = false); - -struct RunOptions -{ - Path program; - bool searchPath = true; - Strings args; - std::optional uid; - std::optional gid; - std::optional chdir; - std::optional> environment; - std::optional input; - Source * standardIn = nullptr; - Sink * standardOut = nullptr; - bool mergeStderrToStdout = false; - bool isInteractive = false; -}; - -std::pair runProgram(RunOptions && options); - -void runProgram2(const RunOptions & options); - - -/** - * Change the stack size. - */ -void setStackSize(size_t stackSize); - - -/** - * Restore the original inherited Unix process context (such as signal - * masks, stack size). - - * See startSignalHandlerThread(), saveSignalMask(). - */ -void restoreProcessContext(bool restoreMounts = true); - -/** - * Save the current mount namespace. Ignored if called more than - * once. - */ -void saveMountNamespace(); - -/** - * Restore the mount namespace saved by saveMountNamespace(). Ignored - * if saveMountNamespace() was never called. - */ -void restoreMountNamespace(); - -/** - * Cause this thread to not share any FS attributes with the main - * thread, because this causes setns() in restoreMountNamespace() to - * fail. - */ -void unshareFilesystem(); - - -class ExecError : public Error -{ -public: - int status; - - template - ExecError(int status, const Args & ... args) - : Error(args...), status(status) - { } -}; - /** * Convert a list of strings to a null-terminated vector of `char * *`s. The result must not be accessed beyond the lifetime of the @@ -490,36 +23,6 @@ public: */ std::vector stringsToCharPtrs(const Strings & ss); -/** - * Close all file descriptors except those listed in the given set. - * Good practice in child processes. - */ -void closeMostFDs(const std::set & exceptions); - -/** - * Set the close-on-exec flag for the given file descriptor. - */ -void closeOnExec(int fd); - - -/* User interruption. */ - -extern std::atomic _isInterrupted; - -extern thread_local std::function interruptCheck; - -void setInterruptThrown(); - -void _interrupted(); - -void inline checkInterrupt() -{ - if (_isInterrupted || (interruptCheck && interruptCheck())) - _interrupted(); -} - -MakeError(Interrupted, BaseError); - MakeError(FormatError, Error); @@ -595,15 +98,6 @@ std::string replaceStrings( std::string rewriteStrings(std::string s, const StringMap & rewrites); -/** - * Convert the exit status of a child as returned by wait() into an - * error string. - */ -std::string statusToString(int status); - -bool statusOk(int status); - - /** * Parse a string into an integer. */ @@ -711,23 +205,6 @@ constexpr char treeLast[] = "└───"; constexpr char treeLine[] = "│ "; constexpr char treeNull[] = " "; -/** - * Determine whether ANSI escape sequences are appropriate for the - * present output. - */ -bool shouldANSI(); - -/** - * Truncate a string to 'width' printable characters. If 'filterAll' - * is true, all ANSI escape sequences are filtered out. Otherwise, - * some escape sequences (such as colour setting) are copied but not - * included in the character count. Also, tabs are expanded to - * spaces. - */ -std::string filterANSIEscapes(std::string_view s, - bool filterAll = false, - unsigned int width = std::numeric_limits::max()); - /** * Base64 encoding/decoding. @@ -815,61 +292,6 @@ template class Callback; -/** - * Start a thread that handles various signals. Also block those signals - * on the current thread (and thus any threads created by it). - * Saves the signal mask before changing the mask to block those signals. - * See saveSignalMask(). - */ -void startSignalHandlerThread(); - -/** - * Saves the signal mask, which is the signal mask that nix will restore - * before creating child processes. - * See setChildSignalMask() to set an arbitrary signal mask instead of the - * current mask. - */ -void saveSignalMask(); - -/** - * Sets the signal mask. Like saveSignalMask() but for a signal set that doesn't - * necessarily match the current thread's mask. - * See saveSignalMask() to set the saved mask to the current mask. - */ -void setChildSignalMask(sigset_t *sigs); - -struct InterruptCallback -{ - virtual ~InterruptCallback() { }; -}; - -/** - * Register a function that gets called on SIGINT (in a non-signal - * context). - */ -std::unique_ptr createInterruptCallback( - std::function callback); - -void triggerInterrupt(); - -/** - * A RAII class that causes the current thread to receive SIGUSR1 when - * the signal handler thread receives SIGINT. That is, this allows - * SIGINT to be multiplexed to multiple threads. - */ -struct ReceiveInterrupts -{ - pthread_t target; - std::unique_ptr callback; - - ReceiveInterrupts() - : target(pthread_self()) - , callback(createInterruptCallback([&]() { pthread_kill(target, SIGUSR1); })) - { } -}; - - - /** * A RAII helper that increments a counter on construction and * decrements it on destruction. @@ -884,45 +306,6 @@ struct MaintainCount }; -/** - * @return the number of rows and columns of the terminal. - */ -std::pair getWindowSize(); - - -/** - * Used in various places. - */ -typedef std::function PathFilter; - -extern PathFilter defaultPathFilter; - -/** - * Common initialisation performed in child processes. - */ -void commonChildInit(); - -/** - * Create a Unix domain socket. - */ -AutoCloseFD createUnixDomainSocket(); - -/** - * Create a Unix domain socket in listen mode. - */ -AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode); - -/** - * Bind a Unix domain socket to a path. - */ -void bind(int fd, const std::string & path); - -/** - * Connect to a Unix domain socket. - */ -void connect(int fd, const std::string & path); - - /** * A Rust/Python-like enumerate() iterator adapter. * diff --git a/src/nix-build/nix-build.cc b/src/nix-build/nix-build.cc index 60bc08146..75ce12a8c 100644 --- a/src/nix-build/nix-build.cc +++ b/src/nix-build/nix-build.cc @@ -9,12 +9,12 @@ #include +#include "current-process.hh" #include "parsed-derivations.hh" #include "store-api.hh" #include "local-fs-store.hh" #include "globals.hh" #include "derivations.hh" -#include "util.hh" #include "shared.hh" #include "path-with-outputs.hh" #include "eval.hh" diff --git a/src/nix-channel/nix-channel.cc b/src/nix-channel/nix-channel.cc index 4504441fa..79db78236 100644 --- a/src/nix-channel/nix-channel.cc +++ b/src/nix-channel/nix-channel.cc @@ -5,7 +5,7 @@ #include "store-api.hh" #include "legacy.hh" #include "eval-settings.hh" // for defexpr -#include "util.hh" +#include "users.hh" #include "tarball.hh" #include diff --git a/src/nix-collect-garbage/nix-collect-garbage.cc b/src/nix-collect-garbage/nix-collect-garbage.cc index 70af53b28..bb3f1bc6a 100644 --- a/src/nix-collect-garbage/nix-collect-garbage.cc +++ b/src/nix-collect-garbage/nix-collect-garbage.cc @@ -1,3 +1,5 @@ +#include "file-system.hh" +#include "signals.hh" #include "store-api.hh" #include "store-cast.hh" #include "gc-store.hh" diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc index 25068f801..213a20d93 100644 --- a/src/nix-env/nix-env.cc +++ b/src/nix-env/nix-env.cc @@ -1,3 +1,4 @@ +#include "users.hh" #include "attr-path.hh" #include "common-eval-args.hh" #include "derivations.hh" @@ -11,7 +12,6 @@ #include "store-api.hh" #include "local-fs-store.hh" #include "user-env.hh" -#include "util.hh" #include "value-to-json.hh" #include "xml-writer.hh" #include "legacy.hh" diff --git a/src/nix-env/user-env.cc b/src/nix-env/user-env.cc index d12d70f33..250224e7d 100644 --- a/src/nix-env/user-env.cc +++ b/src/nix-env/user-env.cc @@ -1,5 +1,4 @@ #include "user-env.hh" -#include "util.hh" #include "derivations.hh" #include "store-api.hh" #include "path-with-outputs.hh" diff --git a/src/nix-instantiate/nix-instantiate.cc b/src/nix-instantiate/nix-instantiate.cc index d40196497..c67409e89 100644 --- a/src/nix-instantiate/nix-instantiate.cc +++ b/src/nix-instantiate/nix-instantiate.cc @@ -6,7 +6,6 @@ #include "attr-path.hh" #include "value-to-xml.hh" #include "value-to-json.hh" -#include "util.hh" #include "store-api.hh" #include "local-fs-store.hh" #include "common-eval-args.hh" diff --git a/src/nix-store/dotgraph.cc b/src/nix-store/dotgraph.cc index 577cadceb..2c530999b 100644 --- a/src/nix-store/dotgraph.cc +++ b/src/nix-store/dotgraph.cc @@ -1,5 +1,4 @@ #include "dotgraph.hh" -#include "util.hh" #include "store-api.hh" #include diff --git a/src/nix-store/graphml.cc b/src/nix-store/graphml.cc index 439557658..3e789a2d8 100644 --- a/src/nix-store/graphml.cc +++ b/src/nix-store/graphml.cc @@ -1,5 +1,4 @@ #include "graphml.hh" -#include "util.hh" #include "store-api.hh" #include "derivations.hh" diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc index e4dd94585..123283dfe 100644 --- a/src/nix-store/nix-store.cc +++ b/src/nix-store/nix-store.cc @@ -11,7 +11,6 @@ #include "serve-protocol.hh" #include "serve-protocol-impl.hh" #include "shared.hh" -#include "util.hh" #include "graphml.hh" #include "legacy.hh" #include "path-with-outputs.hh" diff --git a/src/nix/daemon.cc b/src/nix/daemon.cc index af428018a..373dedf7c 100644 --- a/src/nix/daemon.cc +++ b/src/nix/daemon.cc @@ -1,11 +1,12 @@ ///@file +#include "signals.hh" +#include "unix-domain-socket.hh" #include "command.hh" #include "shared.hh" #include "local-store.hh" #include "remote-store.hh" #include "remote-store-connection.hh" -#include "util.hh" #include "serialise.hh" #include "archive.hh" #include "globals.hh" diff --git a/src/nix/develop.cc b/src/nix/develop.cc index b080a3939..38482ed42 100644 --- a/src/nix/develop.cc +++ b/src/nix/develop.cc @@ -8,7 +8,6 @@ #include "derivations.hh" #include "progress-bar.hh" #include "run.hh" -#include "util.hh" #include #include diff --git a/src/nix/doctor.cc b/src/nix/doctor.cc index 1aa6831d3..59f9e3e5d 100644 --- a/src/nix/doctor.cc +++ b/src/nix/doctor.cc @@ -6,7 +6,6 @@ #include "shared.hh" #include "store-api.hh" #include "local-fs-store.hh" -#include "util.hh" #include "worker-protocol.hh" using namespace nix; diff --git a/src/nix/edit.cc b/src/nix/edit.cc index 66629fab0..9cbab230b 100644 --- a/src/nix/edit.cc +++ b/src/nix/edit.cc @@ -1,3 +1,4 @@ +#include "current-process.hh" #include "command-installable-value.hh" #include "shared.hh" #include "eval.hh" diff --git a/src/nix/flake.cc b/src/nix/flake.cc index e8906a252..38938f09e 100644 --- a/src/nix/flake.cc +++ b/src/nix/flake.cc @@ -15,6 +15,7 @@ #include "registry.hh" #include "eval-cache.hh" #include "markdown.hh" +#include "users.hh" #include #include diff --git a/src/nix/main.cc b/src/nix/main.cc index d20bc1f8a..b582fc166 100644 --- a/src/nix/main.cc +++ b/src/nix/main.cc @@ -1,6 +1,8 @@ #include #include "args/root.hh" +#include "current-process.hh" +#include "namespaces.hh" #include "command.hh" #include "common-args.hh" #include "eval.hh" diff --git a/src/nix/run.cc b/src/nix/run.cc index 1465e8cde..ea0a17897 100644 --- a/src/nix/run.cc +++ b/src/nix/run.cc @@ -1,3 +1,4 @@ +#include "current-process.hh" #include "run.hh" #include "command-installable-value.hh" #include "common-args.hh" diff --git a/src/nix/sigs.cc b/src/nix/sigs.cc index 45cd2e1a6..a68616355 100644 --- a/src/nix/sigs.cc +++ b/src/nix/sigs.cc @@ -1,3 +1,4 @@ +#include "signals.hh" #include "command.hh" #include "shared.hh" #include "store-api.hh" diff --git a/src/nix/upgrade-nix.cc b/src/nix/upgrade-nix.cc index d238456db..c529c2363 100644 --- a/src/nix/upgrade-nix.cc +++ b/src/nix/upgrade-nix.cc @@ -1,3 +1,4 @@ +#include "processes.hh" #include "command.hh" #include "common-args.hh" #include "store-api.hh" diff --git a/src/nix/verify.cc b/src/nix/verify.cc index adaa33c0c..78cb765ce 100644 --- a/src/nix/verify.cc +++ b/src/nix/verify.cc @@ -4,6 +4,7 @@ #include "sync.hh" #include "thread-pool.hh" #include "references.hh" +#include "signals.hh" #include