Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753480AbaKDKC2 (ORCPT ); Tue, 4 Nov 2014 05:02:28 -0500 Received: from mail-wi0-f202.google.com ([209.85.212.202]:59367 "EHLO mail-wi0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753090AbaKDKCV (ORCPT ); Tue, 4 Nov 2014 05:02:21 -0500 From: David Drysdale To: linux-kernel@vger.kernel.org, Alexander Viro , Kees Cook , "Eric W. Biederman" Cc: Greg Kroah-Hartman , Meredydd Luff , Will Drewry , Jorge Lucangeli Obes , Ricky Zhou , Lee Campbell , Julien Tinnes , Mike Depinet , James Morris , Andy Lutomirski , Paolo Bonzini , Paul Moore , Christoph Hellwig , linux-api@vger.kernel.org, linux-security-module@vger.kernel.org, David Drysdale Subject: [PATCHv2 2/3] selftests: Add test of O_BENEATH & openat(2) Date: Tue, 4 Nov 2014 09:54:43 +0000 Message-Id: <1415094884-18349-3-git-send-email-drysdale@google.com> X-Mailer: git-send-email 2.1.0.rc2.206.gedb03e5 In-Reply-To: <1415094884-18349-1-git-send-email-drysdale@google.com> References: <1415094884-18349-1-git-send-email-drysdale@google.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add simple tests of openat(2) variations, including examples that check the new O_BENEATH flag. Signed-off-by: David Drysdale --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/openat/.gitignore | 4 + tools/testing/selftests/openat/Makefile | 28 +++++ tools/testing/selftests/openat/openat.c | 180 ++++++++++++++++++++++++++++++ 4 files changed, 213 insertions(+) create mode 100644 tools/testing/selftests/openat/.gitignore create mode 100644 tools/testing/selftests/openat/Makefile create mode 100644 tools/testing/selftests/openat/openat.c diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 36ff2e4c7b6f..812e973233d2 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -14,6 +14,7 @@ TARGETS += powerpc TARGETS += user TARGETS += sysctl TARGETS += firmware +TARGETS += openat TARGETS_HOTPLUG = cpu-hotplug TARGETS_HOTPLUG += memory-hotplug diff --git a/tools/testing/selftests/openat/.gitignore b/tools/testing/selftests/openat/.gitignore new file mode 100644 index 000000000000..835b2dcd8678 --- /dev/null +++ b/tools/testing/selftests/openat/.gitignore @@ -0,0 +1,4 @@ +openat +subdir +topfile +symlinkdown \ No newline at end of file diff --git a/tools/testing/selftests/openat/Makefile b/tools/testing/selftests/openat/Makefile new file mode 100644 index 000000000000..84cd06e7ee82 --- /dev/null +++ b/tools/testing/selftests/openat/Makefile @@ -0,0 +1,28 @@ +CC = $(CROSS_COMPILE)gcc +CFLAGS = -Wall +BINARIES = openat +DEPS = subdir topfile symlinkdown subdir/bottomfile subdir/symlinkup subdir/symlinkout subdir/symlinkin +all: $(BINARIES) $(DEPS) + +subdir: + mkdir -p subdir +topfile: + echo 0123456789 > $@ +subdir/bottomfile: | subdir + echo 0123456789 > $@ +subdir/symlinkup: | subdir + ln -s ../topfile $@ +subdir/symlinkout: | subdir + ln -s /etc/passwd $@ +subdir/symlinkin: | subdir + ln -s bottomfile $@ +symlinkdown: + ln -s subdir/bottomfile $@ +%: %.c + $(CC) $(CFLAGS) -o $@ $^ + +run_tests: all + ./openat + +clean: + rm -rf $(BINARIES) $(DEPS) diff --git a/tools/testing/selftests/openat/openat.c b/tools/testing/selftests/openat/openat.c new file mode 100644 index 000000000000..0c030cbd10dc --- /dev/null +++ b/tools/testing/selftests/openat/openat.c @@ -0,0 +1,180 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* Bypass glibc */ +static int openat_(int dirfd, const char *pathname, int flags) +{ + return syscall(__NR_openat, dirfd, pathname, flags); +} + +static int openat_or_die(int dfd, const char *path, int flags) +{ + int fd = openat_(dfd, path, flags); + + if (fd < 0) { + printf("Failed to openat(%d, '%s'); " + "check prerequisites are available\n", dfd, path); + exit(1); + } + return fd; +} + +static int check_openat(int dfd, const char *path, int flags) +{ + int rc; + int fd; + char buffer[4]; + + errno = 0; + printf("Check success of openat(%d, '%s', %x)... ", + dfd, path?:"(null)", flags); + fd = openat_(dfd, path, flags); + if (fd < 0) { + printf("[FAIL]: openat() failed, rc=%d errno=%d (%s)\n", + fd, errno, strerror(errno)); + return 1; + } + errno = 0; + rc = read(fd, buffer, sizeof(buffer)); + if (rc < 0) { + printf("[FAIL]: read() failed, rc=%d errno=%d (%s)\n", + rc, errno, strerror(errno)); + return 1; + } + close(fd); + printf("[OK]\n"); + return 0; +} + +#define check_openat_fail(dfd, path, flags, errno) \ + _check_openat_fail(dfd, path, flags, errno, #errno) +static int _check_openat_fail(int dfd, const char *path, int flags, + int expected_errno, const char *errno_str) +{ + int rc; + + errno = 0; + printf("Check failure of openat(%d, '%s', %x) with %s... ", + dfd, path?:"(null)", flags, errno_str); + rc = openat_(dfd, path, flags); + if (rc > 0) { + printf("[FAIL] (unexpected success from openat(2))\n"); + close(rc); + return 1; + } + if (errno != expected_errno) { + printf("[FAIL] (expected errno %d (%s) not %d (%s)\n", + expected_errno, strerror(expected_errno), + errno, strerror(errno)); + return 1; + } + printf("[OK]\n"); + return 0; +} + +int check_proc(void) +{ + int proc_dfd = openat_(AT_FDCWD, "/proc/self", O_RDONLY); + int fail = 0; + + if (proc_dfd < 0) { + printf("'/proc/self' unavailable (errno=%d '%s'), skipping\n", + errno, strerror(errno)); + return 1; + } + fail |= check_openat(proc_dfd, "root/etc/passwd", O_RDONLY); +#ifdef O_BENEATH + fail |= check_openat_fail(proc_dfd, "root/etc/passwd", + O_RDONLY|O_BENEATH, EPERM); +#endif + return fail; +} + +int main(int argc, char *argv[]) +{ + int fail = 0; + int dot_dfd = openat_or_die(AT_FDCWD, ".", O_RDONLY); + int subdir_dfd = openat_or_die(AT_FDCWD, "subdir", O_RDONLY); + int file_fd = openat_or_die(AT_FDCWD, "topfile", O_RDONLY); + + /* Sanity check normal behavior */ + fail |= check_openat(AT_FDCWD, "topfile", O_RDONLY); + fail |= check_openat(AT_FDCWD, "subdir/bottomfile", O_RDONLY); + + fail |= check_openat(dot_dfd, "topfile", O_RDONLY); + fail |= check_openat(dot_dfd, "subdir/bottomfile", O_RDONLY); + fail |= check_openat(dot_dfd, "subdir/../topfile", O_RDONLY); + + fail |= check_openat(subdir_dfd, "../topfile", O_RDONLY); + fail |= check_openat(subdir_dfd, "bottomfile", O_RDONLY); + fail |= check_openat(subdir_dfd, "../subdir/bottomfile", O_RDONLY); + fail |= check_openat(subdir_dfd, "symlinkup", O_RDONLY); + fail |= check_openat(subdir_dfd, "symlinkout", O_RDONLY); + + fail |= check_openat(AT_FDCWD, "/etc/passwd", O_RDONLY); + fail |= check_openat(dot_dfd, "/etc/passwd", O_RDONLY); + fail |= check_openat(subdir_dfd, "/etc/passwd", O_RDONLY); + + fail |= check_openat_fail(AT_FDCWD, "bogus", O_RDONLY, ENOENT); + fail |= check_openat_fail(dot_dfd, "bogus", O_RDONLY, ENOENT); + fail |= check_openat_fail(999, "bogus", O_RDONLY, EBADF); + fail |= check_openat_fail(file_fd, "bogus", O_RDONLY, ENOTDIR); + +#ifdef O_BENEATH + /* Test out O_BENEATH */ + fail |= check_openat(AT_FDCWD, "topfile", O_RDONLY|O_BENEATH); + fail |= check_openat(AT_FDCWD, "subdir/bottomfile", + O_RDONLY|O_BENEATH); + + fail |= check_openat(dot_dfd, "topfile", O_RDONLY|O_BENEATH); + fail |= check_openat(dot_dfd, "subdir/bottomfile", + O_RDONLY|O_BENEATH); + fail |= check_openat(subdir_dfd, "bottomfile", O_RDONLY|O_BENEATH); + + /* Symlinks without .. or leading / are OK */ + fail |= check_openat(dot_dfd, "symlinkdown", O_RDONLY|O_BENEATH); + fail |= check_openat(dot_dfd, "subdir/symlinkin", O_RDONLY|O_BENEATH); + fail |= check_openat(subdir_dfd, "symlinkin", O_RDONLY|O_BENEATH); + /* ... unless of course we specify O_NOFOLLOW */ + fail |= check_openat_fail(dot_dfd, "symlinkdown", + O_RDONLY|O_BENEATH|O_NOFOLLOW, ELOOP); + fail |= check_openat_fail(dot_dfd, "subdir/symlinkin", + O_RDONLY|O_BENEATH|O_NOFOLLOW, ELOOP); + fail |= check_openat_fail(subdir_dfd, "symlinkin", + O_RDONLY|O_BENEATH|O_NOFOLLOW, ELOOP); + + /* Can't open paths with ".." in them */ + fail |= check_openat_fail(dot_dfd, "subdir/../topfile", + O_RDONLY|O_BENEATH, EPERM); + fail |= check_openat_fail(subdir_dfd, "../topfile", + O_RDONLY|O_BENEATH, EPERM); + fail |= check_openat_fail(subdir_dfd, "../subdir/bottomfile", + O_RDONLY|O_BENEATH, EPERM); + + /* Can't open paths starting with "/" */ + fail |= check_openat_fail(AT_FDCWD, "/etc/passwd", + O_RDONLY|O_BENEATH, EPERM); + fail |= check_openat_fail(dot_dfd, "/etc/passwd", + O_RDONLY|O_BENEATH, EPERM); + fail |= check_openat_fail(subdir_dfd, "/etc/passwd", + O_RDONLY|O_BENEATH, EPERM); + /* Can't sneak around constraints with symlinks */ + fail |= check_openat_fail(subdir_dfd, "symlinkup", + O_RDONLY|O_BENEATH, EPERM); + fail |= check_openat_fail(subdir_dfd, "symlinkout", + O_RDONLY|O_BENEATH, EPERM); +#else + printf("Skipping O_BENEATH tests due to missing #define\n"); +#endif + fail |= check_proc(); + + return fail ? -1 : 0; +} -- 2.1.0.rc2.206.gedb03e5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/