From 1cba5984a68a489c4a56691032e4c87991c678f4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Na=C3=AFm=20Favier?= Date: Wed, 25 Jan 2023 15:10:35 +0100 Subject: [PATCH] getDefaultNixPath: actually respect `{restrict,pure}-eval` Previously, getDefaultNixPath was called too early: at initialisation time, before CLI and config have been processed, when `restrictEval` and `pureEval` both have their default value `false`. Call it when initialising the EvalState instead, and use `setDefault`. --- src/libexpr/eval.cc | 36 +++++++++++++++++++++--------------- src/libexpr/eval.hh | 4 ++-- tests/nix_path.sh | 5 +++++ tests/restricted.sh | 3 +++ 4 files changed, 31 insertions(+), 17 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 1828b8c2e..a48968656 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -519,6 +519,7 @@ EvalState::EvalState( static_assert(sizeof(Env) <= 16, "environment must be <= 16 bytes"); /* Initialise the Nix expression search path. */ + evalSettings.nixPath.setDefault(evalSettings.getDefaultNixPath()); if (!evalSettings.pureEval) { for (auto & i : _searchPath) addToSearchPath(i); for (auto & i : evalSettings.nixPath.get()) addToSearchPath(i); @@ -2472,30 +2473,35 @@ std::ostream & operator << (std::ostream & str, const ExternalValueBase & v) { EvalSettings::EvalSettings() { - auto var = getEnv("NIX_PATH"); - if (var) nixPath = parseNixPath(*var); } +/* impure => NIX_PATH or a default path + * restrict-eval => NIX_PATH + * pure-eval => empty + */ Strings EvalSettings::getDefaultNixPath() { - Strings res; - auto add = [&](const Path & p, const std::string & s = std::string()) { - if (pathExists(p)) { - if (s.empty()) { - res.push_back(p); - } else { - res.push_back(s + "=" + p); - } - } - }; + if (pureEval) + return {}; + + auto var = getEnv("NIX_PATH"); + if (var) { + return parseNixPath(*var); + } else if (restrictEval) { + return {}; + } else { + Strings res; + auto add = [&](const Path & p, const std::optional & s = std::nullopt) { + if (pathExists(p)) + res.push_back(s ? *s + "=" + p : p); + }; - if (!evalSettings.restrictEval && !evalSettings.pureEval) { add(getHome() + "/.nix-defexpr/channels"); add(settings.nixStateDir + "/profiles/per-user/root/channels/nixpkgs", "nixpkgs"); add(settings.nixStateDir + "/profiles/per-user/root/channels"); - } - return res; + return res; + } } bool EvalSettings::isPseudoUrl(std::string_view s) diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh index e4d5906bd..876a6ae0e 100644 --- a/src/libexpr/eval.hh +++ b/src/libexpr/eval.hh @@ -570,7 +570,7 @@ struct EvalSettings : Config { EvalSettings(); - static Strings getDefaultNixPath(); + Strings getDefaultNixPath(); static bool isPseudoUrl(std::string_view s); @@ -580,7 +580,7 @@ struct EvalSettings : Config "Whether builtin functions that allow executing native code should be enabled."}; Setting nixPath{ - this, getDefaultNixPath(), "nix-path", + this, {}, "nix-path", "List of directories to be searched for `<...>` file references."}; Setting restrictEval{ diff --git a/tests/nix_path.sh b/tests/nix_path.sh index 2b222b4a1..d16fb4bb2 100644 --- a/tests/nix_path.sh +++ b/tests/nix_path.sh @@ -12,3 +12,8 @@ nix-instantiate --eval -E '' --restrict-eval [[ $(nix-instantiate --find-file by-absolute-path/simple.nix) = $PWD/simple.nix ]] [[ $(nix-instantiate --find-file by-relative-path/simple.nix) = $PWD/simple.nix ]] + +unset NIX_PATH + +[[ $(nix-instantiate --option nix-path by-relative-path=. --find-file by-relative-path/simple.nix) = "$PWD/simple.nix" ]] +[[ $(NIX_PATH= nix-instantiate --option nix-path by-relative-path=. --find-file by-relative-path/simple.nix) = "$PWD/simple.nix" ]] diff --git a/tests/restricted.sh b/tests/restricted.sh index 9bd16cf51..3b6ee2af1 100644 --- a/tests/restricted.sh +++ b/tests/restricted.sh @@ -17,6 +17,9 @@ nix-instantiate --restrict-eval --eval -E 'builtins.readDir ../src/nix-channel' (! nix-instantiate --restrict-eval --eval -E 'let __nixPath = [ { prefix = "foo"; path = ./.; } ]; in ') nix-instantiate --restrict-eval --eval -E 'let __nixPath = [ { prefix = "foo"; path = ./.; } ]; in ' -I src=. +# no default NIX_PATH +(unset NIX_PATH; ! nix-instantiate --restrict-eval --find-file .) + p=$(nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval --allowed-uris "file://$(pwd)") cmp $p restricted.sh