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Revert "Merge branch 'seccomp' of https://github.com/aszlig/nix"

Browse source 
This reverts commit 9f3f2e21ed, reversing
changes made to 47f587700d.
This commit is contained in:
Eelco Dolstra 2016-12-19 11:52:57 +01:00
parent 11f0680f69
commit 3a4bd320c2
No known key found for this signature in database
GPG key ID: 8170B4726D7198DE
6 changed files with 30 additions and 139 deletions
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1
Makefile.config.in
View file

@ -10,7 +10,6 @@ OPENSSL_LIBS = @OPENSSL_LIBS@
PACKAGE_NAME = @PACKAGE_NAME@
PACKAGE_VERSION = @PACKAGE_VERSION@
SODIUM_LIBS = @SODIUM_LIBS@
LIBSECCOMP_LIBS = @LIBSECCOMP_LIBS@
LIBLZMA_LIBS = @LIBLZMA_LIBS@
SQLITE3_LIBS = @SQLITE3_LIBS@
bash = @bash@

9
configure.ac
View file

@ -193,15 +193,6 @@ AC_SUBST(HAVE_SODIUM, [$have_sodium])
PKG_CHECK_MODULES([LIBLZMA], [liblzma], [CXXFLAGS="$LIBLZMA_CFLAGS $CXXFLAGS"])
# Look for libseccomp, required for Linux sandboxing.
if test "$sys_name" = linux; then
PKG_CHECK_MODULES([LIBSECCOMP], [libseccomp],
[CXXFLAGS="$LIBSECCOMP_CFLAGS $CXXFLAGS"])
# AC_CHECK_LIB([seccomp], [seccomp_init], [true],
# [AC_MSG_ERROR([Nix requires libseccomp for sandboxing. See https://github.com/seccomp/libseccomp.])])
fi
# Look for aws-cpp-sdk-s3.
AC_LANG_PUSH(C++)
AC_CHECK_HEADERS([aws/s3/S3Client.h],

7
release.nix
View file

@ -25,7 +25,7 @@ let
buildInputs =
[ curl bison flex perl libxml2 libxslt bzip2 xz
pkgconfig sqlite libsodium libseccomp boehmgc
pkgconfig sqlite libsodium boehmgc
docbook5 docbook5_xsl
autoconf-archive
] ++ lib.optional (!lib.inNixShell) git;
@ -74,7 +74,6 @@ let
buildInputs =
[ curl perl bzip2 xz openssl pkgconfig sqlite boehmgc ]
++ lib.optional stdenv.isLinux libsodium
++ lib.optional stdenv.isLinux libseccomp
++ lib.optional stdenv.isLinux
(aws-sdk-cpp.override {
apis = ["s3"];
@ -197,10 +196,6 @@ let
nix = build.x86_64-linux; system = "x86_64-linux";
});
tests.sandbox = (import ./tests/sandbox.nix rec {
nix = build.x86_64-linux; system = "x86_64-linux";
});
tests.binaryTarball =
with import <nixpkgs> { system = "x86_64-linux"; };
vmTools.runInLinuxImage (runCommand "nix-binary-tarball-test"

90
src/libstore/build.cc
View file

@ -54,7 +54,6 @@
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/syscall.h>
#include <seccomp.h>
#define pivot_root(new_root, put_old) (syscall(SYS_pivot_root, new_root, put_old))
#endif
@ -815,6 +814,9 @@ private:
result. */
ValidPathInfos prevInfos;
const uid_t sandboxUid = 1000;
const gid_t sandboxGid = 100;
public:
DerivationGoal(const Path & drvPath, const StringSet & wantedOutputs,
Worker & worker, BuildMode buildMode = bmNormal);
@ -1642,56 +1644,8 @@ void chmod_(const Path & path, mode_t mode)
}
#if __linux__
#define FORCE_SUCCESS(syscall) \
if (seccomp_rule_add(ctx, SCMP_ACT_ERRNO(0), SCMP_SYS(syscall), 0) != 0) { \
seccomp_release(ctx); \
throw SysError("unable to add seccomp rule for " #syscall); \
}
void setupSeccomp(void) {
scmp_filter_ctx ctx;
if ((ctx = seccomp_init(SCMP_ACT_ALLOW)) == NULL)
throw SysError("unable to initialize seccomp mode 2");
#if defined(__x86_64__)
if (seccomp_arch_add(ctx, SCMP_ARCH_X86) != 0) {
seccomp_release(ctx);
throw SysError("unable to add 32bit seccomp architecture");
}
#endif
FORCE_SUCCESS(chown32);
FORCE_SUCCESS(fchown32);
FORCE_SUCCESS(lchown32);
FORCE_SUCCESS(chown);
FORCE_SUCCESS(fchown);
FORCE_SUCCESS(fchownat);
FORCE_SUCCESS(lchown);
FORCE_SUCCESS(setxattr);
FORCE_SUCCESS(lsetxattr);
FORCE_SUCCESS(fsetxattr);
if (seccomp_load(ctx) != 0) {
seccomp_release(ctx);
throw SysError("unable to load seccomp BPF program");
}
seccomp_release(ctx);
}
#undef FORCE_SUCCESS
#endif
int childEntry(void * arg)
{
setupSeccomp();
((DerivationGoal *) arg)->runChild();
return 1;
}
@ -2011,14 +1965,18 @@ void DerivationGoal::startBuilder()
createDirs(chrootRootDir + "/etc");
writeFile(chrootRootDir + "/etc/passwd",
(format(
"root:x:0:0:Nix build user:/:/noshell\n"
"nobody:x:65534:65534:Nobody:/:/noshell\n");
"nixbld:x:%1%:%2%:Nix build user:/:/noshell\n"
"nobody:x:65534:65534:Nobody:/:/noshell\n") % sandboxUid % sandboxGid).str());
/* Declare the build user's group so that programs get a consistent
view of the system (e.g., "id -gn"). */
writeFile(chrootRootDir + "/etc/group",
(format(
"root:x:0:\n"
"nobody:x:65534:\n");
"nixbld:!:%1%:\n"
"nogroup:x:65534:\n") % sandboxGid).str());
/* Create /etc/hosts with localhost entry. */
if (!fixedOutput)
@ -2202,7 +2160,12 @@ void DerivationGoal::startBuilder()
Pid helper = startProcess([&]() {
/* Drop additional groups here because we can't do it
after we've created the new user namespace. */
after we've created the new user namespace. FIXME:
this means that if we're not root in the parent
namespace, we can't drop additional groups; they will
be mapped to nogroup in the child namespace. There does
not seem to be a workaround for this. (But who can tell
from reading user_namespaces(7)?)*/
if (getuid() == 0 && setgroups(0, 0) == -1)
throw SysError("setgroups failed");
@ -2235,19 +2198,19 @@ void DerivationGoal::startBuilder()
if (!string2Int<pid_t>(readLine(builderOut.readSide.get()), tmp)) abort();
pid = tmp;
/* Set the UID/GID mapping of the builder's user
namespace such that root maps to the build user, or to the
calling user (if build users are disabled). */
uid_t targetUid = buildUser.enabled() ? buildUser.getUID() : getuid();
uid_t targetGid = buildUser.enabled() ? buildUser.getGID() : getgid();
/* Set the UID/GID mapping of the builder's user namespace
such that the sandbox user maps to the build user, or to
the calling user (if build users are disabled). */
uid_t hostUid = buildUser.enabled() ? buildUser.getUID() : getuid();
uid_t hostGid = buildUser.enabled() ? buildUser.getGID() : getgid();
writeFile("/proc/" + std::to_string(pid) + "/uid_map",
(format("0 %d 1") % targetUid).str());
(format("%d %d 1") % sandboxUid % hostUid).str());
writeFile("/proc/" + std::to_string(pid) + "/setgroups", "deny");
writeFile("/proc/" + std::to_string(pid) + "/gid_map",
(format("0 %d 1") % targetGid).str());
(format("%d %d 1") % sandboxGid % hostGid).str());
/* Signal the builder that we've updated its user
namespace. */
@ -2457,11 +2420,12 @@ void DerivationGoal::runChild()
if (rmdir("real-root") == -1)
throw SysError("cannot remove real-root directory");
/* Become root in the user namespace, which corresponds to
the build user or calling user in the parent namespace. */
if (setgid(0) == -1)
/* Switch to the sandbox uid/gid in the user namespace,
which corresponds to the build user or calling user in
the parent namespace. */
if (setgid(sandboxGid) == -1)
throw SysError("setgid failed");
if (setuid(0) == -1)
if (setuid(sandboxUid) == -1)
throw SysError("setuid failed");
setUser = false;

4
src/libstore/local.mk
View file

@ -18,10 +18,6 @@ ifeq ($(OS), SunOS)
libstore_LDFLAGS += -lsocket
endif
ifeq ($(OS), Linux)
libstore_LDFLAGS += -lseccomp
endif
libstore_CXXFLAGS = \
-DNIX_PREFIX=\"$(prefix)\" \
-DNIX_STORE_DIR=\"$(storedir)\" \

54
tests/sandbox.nix
View file

@ -1,54 +0,0 @@
# Test Nix builder sandbox.
{ system, nix }:
with import <nixpkgs/nixos/lib/testing.nix> { inherit system; };
let
mkUtils = pkgs: pkgs.buildEnv {
name = "sandbox-utils";
paths = [ pkgs.coreutils pkgs.utillinux pkgs.bash ];
pathsToLink = [ "/bin" "/sbin" ];
};
utils32 = mkUtils pkgs.pkgsi686Linux;
utils64 = mkUtils pkgs;
sandboxTestScript = pkgs.writeText "sandbox-testscript.sh" ''
[ $(id -u) -eq 0 ]
cp -p "$testfile" foo
chown 1024:1024 foo
touch "$out"
'';
testExpr = arch: pkgs.writeText "sandbox-test.nix" ''
let
utils = builtins.storePath
${if arch == "i686-linux" then utils32 else utils64};
in derivation {
name = "sandbox-test";
system = "${arch}";
builder = "''${utils}/bin/bash";
args = ["-e" ${sandboxTestScript}];
PATH = "''${utils}/bin";
testfile = builtins.toFile "test" "i am a test file";
}
'';
in makeTest {
name = "nix-sandbox";
machine = { pkgs, ... }: {
nix.package = nix;
nix.useSandbox = true;
nix.binaryCaches = [];
virtualisation.writableStore = true;
virtualisation.pathsInNixDB = [ utils32 utils64 ];
};
testScript = ''
$machine->waitForUnit("multi-user.target");
$machine->succeed("nix-build ${testExpr "x86_64-linux"}");
$machine->succeed("nix-build ${testExpr "i686-linux"}");
'';
}