diff --git a/src/shared/copy.c b/src/shared/copy.c index f27eccd83c..51dbf080ad 100644 --- a/src/shared/copy.c +++ b/src/shared/copy.c @@ -459,6 +459,46 @@ int copy_bytes_full( return max_bytes <= 0; /* return 0 if we hit EOF earlier than the size limit */ } +/* Check whether *ts is within [epoch; clamp] */ +static bool timespec_within(const struct timespec *ts, usec_t ts_clamp) { + assert(ts); + + return ts->tv_sec < 0 || /* Date pre-1970, cannot clamp these */ + timespec_load(ts) <= ts_clamp; /* Date in [epoch; clamp] */ +} + +/* See ts_clamp in copy.h. */ +static void clamp_inode_times(const struct stat *st, usec_t ts_clamp, struct timespec ret[static 2]) { + assert(st); + assert(ret); + + ret[0] = timespec_within(&st->st_atim, ts_clamp) ? st->st_atim : *TIMESPEC_STORE(ts_clamp); + ret[1] = timespec_within(&st->st_mtim, ts_clamp) ? st->st_mtim : *TIMESPEC_STORE(ts_clamp); +} + +/* Put *st's clamped times on the inode referred to by fdt */ +static int clamp_futimens(int fdt, const struct stat *st, usec_t ts_clamp) { + struct timespec times[2]; + + assert(fdt >= 0); + assert(st); + + clamp_inode_times(st, ts_clamp, times); + return RET_NERRNO(futimens(fdt, times)); +} + +/* Same for (dt, to) */ +static int clamp_utimensat(int dt, const char *to, const struct stat *st, usec_t ts_clamp) { + struct timespec times[2]; + + assert(dt >= 0 || dt == AT_FDCWD); + assert(to); + assert(st); + + clamp_inode_times(st, ts_clamp, times); + return RET_NERRNO(utimensat(dt, to, times, AT_SYMLINK_NOFOLLOW)); +} + static int fd_copy_symlink( int df, const char *from, @@ -467,7 +507,8 @@ static int fd_copy_symlink( const char *to, uid_t override_uid, gid_t override_gid, - CopyFlags copy_flags) { + CopyFlags copy_flags, + usec_t ts_clamp) { _cleanup_free_ char *target = NULL; int r; @@ -506,7 +547,8 @@ static int fd_copy_symlink( r = -errno; (void) copy_xattr(df, from, dt, to, copy_flags); - (void) utimensat(dt, to, (struct timespec[]) { st->st_atim, st->st_mtim }, AT_SYMLINK_NOFOLLOW); + + (void) clamp_utimensat(dt, to, st, ts_clamp); return r; } @@ -798,6 +840,7 @@ static int fd_copy_tree_generic( uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, + usec_t ts_clamp, Hashmap *denylist, Hashmap *subvolumes, HardlinkContext *hardlink_context, @@ -815,6 +858,7 @@ static int fd_copy_regular( uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, + usec_t ts_clamp, HardlinkContext *hardlink_context, copy_progress_bytes_t progress, void *userdata) { @@ -862,7 +906,7 @@ static int fd_copy_regular( if (fchmod(fdt, st->st_mode & 07777) < 0) r = -errno; - (void) futimens(fdt, (struct timespec[]) { st->st_atim, st->st_mtim }); + (void) clamp_futimens(fdt, st, ts_clamp); (void) copy_xattr(fdf, NULL, fdt, NULL, copy_flags); if (FLAGS_SET(copy_flags, COPY_VERIFY_LINKED)) { @@ -910,6 +954,7 @@ static int fd_copy_fifo( uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, + usec_t ts_clamp, HardlinkContext *hardlink_context) { int r; @@ -948,7 +993,7 @@ static int fd_copy_fifo( if (fchmodat(dt, to, st->st_mode & 07777, AT_SYMLINK_NOFOLLOW) < 0) r = -errno; - (void) utimensat(dt, to, (struct timespec[]) { st->st_atim, st->st_mtim }, AT_SYMLINK_NOFOLLOW); + (void) clamp_utimensat(dt, to, st, ts_clamp); (void) memorize_hardlink(hardlink_context, st, dt, to); return r; @@ -963,6 +1008,7 @@ static int fd_copy_node( uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, + usec_t ts_clamp, HardlinkContext *hardlink_context) { int r; @@ -1001,7 +1047,7 @@ static int fd_copy_node( if (fchmodat(dt, to, st->st_mode & 07777, AT_SYMLINK_NOFOLLOW) < 0) r = -errno; - (void) utimensat(dt, to, (struct timespec[]) { st->st_atim, st->st_mtim }, AT_SYMLINK_NOFOLLOW); + (void) clamp_utimensat(dt, to, st, ts_clamp); (void) memorize_hardlink(hardlink_context, st, dt, to); return r; @@ -1018,6 +1064,7 @@ static int fd_copy_directory( uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, + usec_t ts_clamp, Hashmap *denylist, Hashmap *subvolumes, HardlinkContext *hardlink_context, @@ -1169,7 +1216,7 @@ static int fd_copy_directory( r = fd_copy_tree_generic(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, depth_left-1, override_uid, override_gid, copy_flags & ~COPY_LOCK_BSD, - denylist, subvolumes, hardlink_context, child_display_path, progress_path, + ts_clamp, denylist, subvolumes, hardlink_context, child_display_path, progress_path, progress_bytes, userdata); /* Propagate SIGINT/SIGTERM, ENOSPC, and fs-verity fails up instantly */ @@ -1193,7 +1240,8 @@ finish: /* Run hardlink context cleanup now because it potentially changes timestamps */ hardlink_context_destroy(&our_hardlink_context); (void) copy_xattr(dirfd(d), NULL, fdt, NULL, copy_flags); - (void) futimens(fdt, (struct timespec[]) { st->st_atim, st->st_mtim }); + + (void) clamp_futimens(fdt, st, ts_clamp); } else if (FLAGS_SET(copy_flags, COPY_RESTORE_DIRECTORY_TIMESTAMPS)) { /* Run hardlink context cleanup now because it potentially changes timestamps */ hardlink_context_destroy(&our_hardlink_context); @@ -1221,6 +1269,7 @@ static int fd_copy_leaf( uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, + usec_t ts_clamp, HardlinkContext *hardlink_context, const char *display_path, copy_progress_bytes_t progress_bytes, @@ -1228,13 +1277,13 @@ static int fd_copy_leaf( int r; if (S_ISREG(st->st_mode)) - r = fd_copy_regular(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context, progress_bytes, userdata); + r = fd_copy_regular(df, from, st, dt, to, override_uid, override_gid, copy_flags, ts_clamp, hardlink_context, progress_bytes, userdata); else if (S_ISLNK(st->st_mode)) - r = fd_copy_symlink(df, from, st, dt, to, override_uid, override_gid, copy_flags); + r = fd_copy_symlink(df, from, st, dt, to, override_uid, override_gid, copy_flags, ts_clamp); else if (S_ISFIFO(st->st_mode)) - r = fd_copy_fifo(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context); + r = fd_copy_fifo(df, from, st, dt, to, override_uid, override_gid, copy_flags, ts_clamp, hardlink_context); else if (S_ISBLK(st->st_mode) || S_ISCHR(st->st_mode) || S_ISSOCK(st->st_mode)) - r = fd_copy_node(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context); + r = fd_copy_node(df, from, st, dt, to, override_uid, override_gid, copy_flags, ts_clamp, hardlink_context); else r = -EOPNOTSUPP; @@ -1252,6 +1301,7 @@ static int fd_copy_tree_generic( uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, + usec_t ts_clamp, Hashmap *denylist, Hashmap *subvolumes, HardlinkContext *hardlink_context, @@ -1266,7 +1316,7 @@ static int fd_copy_tree_generic( if (S_ISDIR(st->st_mode)) return fd_copy_directory(df, from, st, dt, to, original_device, depth_left-1, override_uid, - override_gid, copy_flags, denylist, subvolumes, hardlink_context, + override_gid, copy_flags, ts_clamp, denylist, subvolumes, hardlink_context, display_path, progress_path, progress_bytes, userdata); /* Only if we are copying a directory we are fine if the target dir is referenced by fd only */ @@ -1280,14 +1330,14 @@ static int fd_copy_tree_generic( } else if (t == DENY_CONTENTS) log_debug("%s is configured to have its contents excluded, but is not a directory", from ?: "file to copy"); - r = fd_copy_leaf(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context, display_path, progress_bytes, userdata); + r = fd_copy_leaf(df, from, st, dt, to, override_uid, override_gid, copy_flags, ts_clamp, hardlink_context, display_path, progress_bytes, userdata); /* We just tried to copy a leaf node of the tree. If it failed because the node already exists *and* the COPY_REPLACE flag has been provided, we should unlink the node and re-copy. */ if (r == -EEXIST && (copy_flags & COPY_REPLACE)) { /* This codepath is us trying to address an error to copy, if the unlink fails, lets just return the original error. */ if (unlinkat(dt, to, 0) < 0) return r; - r = fd_copy_leaf(df, from, st, dt, to, override_uid, override_gid, copy_flags, hardlink_context, display_path, progress_bytes, userdata); + r = fd_copy_leaf(df, from, st, dt, to, override_uid, override_gid, copy_flags, ts_clamp, hardlink_context, display_path, progress_bytes, userdata); } return r; @@ -1301,6 +1351,7 @@ int copy_tree_at_full( uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, + usec_t ts_clamp, Hashmap *denylist, Hashmap *subvolumes, copy_progress_path_t progress_path, @@ -1316,7 +1367,7 @@ int copy_tree_at_full( return -errno; r = fd_copy_tree_generic(fdf, from, &st, fdt, to, st.st_dev, COPY_DEPTH_MAX, override_uid, - override_gid, copy_flags, denylist, subvolumes, NULL, NULL, progress_path, + override_gid, copy_flags, ts_clamp, denylist, subvolumes, NULL, NULL, progress_path, progress_bytes, userdata); if (r < 0) return r; @@ -1388,6 +1439,7 @@ int copy_directory_at_full( override_uid, override_gid, copy_flags, + /* ts_clamp= */ USEC_INFINITY, /* denylist= */ NULL, /* subvolumes= */ NULL, /* hardlink_context= */ NULL, @@ -1639,8 +1691,9 @@ fail: return r; } -int copy_times(int fdf, int fdt, CopyFlags flags) { +int copy_times_full(int fdf, int fdt, CopyFlags flags, usec_t ts_clamp) { struct stat st; + int r; assert(fdf >= 0); assert(fdt >= 0); @@ -1648,14 +1701,15 @@ int copy_times(int fdf, int fdt, CopyFlags flags) { if (fstat(fdf, &st) < 0) return -errno; - if (futimens(fdt, (struct timespec[2]) { st.st_atim, st.st_mtim }) < 0) - return -errno; + r = clamp_futimens(fdt, &st, ts_clamp); + if (r < 0) + return r; if (FLAGS_SET(flags, COPY_CRTIME)) { usec_t crtime; if (fd_getcrtime(fdf, &crtime) >= 0) - (void) fd_setcrtime(fdt, crtime); + (void) fd_setcrtime(fdt, MIN(crtime, ts_clamp)); } return 0; diff --git a/src/shared/copy.h b/src/shared/copy.h index 975b1e9942..9cc856515f 100644 --- a/src/shared/copy.h +++ b/src/shared/copy.h @@ -81,12 +81,15 @@ static inline int copy_file_atomic(const char *from, const char *to, mode_t mode return copy_file_atomic_full(from, to, mode, 0, 0, copy_flags, NULL, NULL); } -int copy_tree_at_full(int fdf, const char *from, int fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, Hashmap *denylist, Hashmap *subvolumes, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata); +/* ts_clamp: upper bound for the timestamps of created inodes. $SOURCE_DATE_EPOCH semantic, see + * https://reproducible-builds.org/specs/source-date-epoch/. USEC_INFINITY clamps nothing, i.e. keeps + * the source's own timestamps. */ +int copy_tree_at_full(int fdf, const char *from, int fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, usec_t ts_clamp, Hashmap *denylist, Hashmap *subvolumes, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata); static inline int copy_tree_at(int fdf, const char *from, int fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, Hashmap *denylist, Hashmap *subvolumes) { - return copy_tree_at_full(fdf, from, fdt, to, override_uid, override_gid, copy_flags, denylist, subvolumes, NULL, NULL, NULL); + return copy_tree_at_full(fdf, from, fdt, to, override_uid, override_gid, copy_flags, USEC_INFINITY, denylist, subvolumes, NULL, NULL, NULL); } static inline int copy_tree(const char *from, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, Hashmap *denylist, Hashmap *subvolumes) { - return copy_tree_at_full(AT_FDCWD, from, AT_FDCWD, to, override_uid, override_gid, copy_flags, denylist, subvolumes, NULL, NULL, NULL); + return copy_tree_at_full(AT_FDCWD, from, AT_FDCWD, to, override_uid, override_gid, copy_flags, USEC_INFINITY, denylist, subvolumes, NULL, NULL, NULL); } int copy_directory_at_full(int dir_fdf, const char *from, int dir_fdt, const char *to, uid_t override_uid, gid_t override_gid, CopyFlags copy_flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata); @@ -99,7 +102,11 @@ static inline int copy_bytes(int fdf, int fdt, uint64_t max_bytes, CopyFlags cop return copy_bytes_full(fdf, fdt, max_bytes, copy_flags, NULL, NULL, NULL, NULL); } -int copy_times(int fdf, int fdt, CopyFlags flags); +/* See ts_clamp above. Covers atime, mtime, and with COPY_CRTIME the birth time. */ +int copy_times_full(int fdf, int fdt, CopyFlags flags, usec_t ts_clamp); +static inline int copy_times(int fdf, int fdt, CopyFlags flags) { + return copy_times_full(fdf, fdt, flags, USEC_INFINITY); +} int copy_access(int fdf, int fdt); int copy_owner(int fdf, int fdt); int copy_rights_with_fallback(int fdf, int fdt, const char *patht); diff --git a/src/test/test-copy.c b/src/test/test-copy.c index e3e93f3642..feed013351 100644 --- a/src/test/test-copy.c +++ b/src/test/test-copy.c @@ -26,6 +26,7 @@ #include "string-util.h" #include "strv.h" #include "tests.h" +#include "time-util.h" #include "tmpfile-util.h" #include "xattr-util.h" @@ -798,4 +799,62 @@ TEST_RET(copy_with_verity) { return 0; } +static void test_copy_times_one( + const struct timespec source[static 2], + usec_t ts_clamp, + const struct timespec expect[static 2]) { + _cleanup_(unlink_tempfilep) char in_fn[] = "/tmp/test-copy-times-in-XXXXXX"; + _cleanup_(unlink_tempfilep) char out_fn[] = "/tmp/test-copy-times-out-XXXXXX"; + _cleanup_close_ int in_fd = -EBADF, out_fd = -EBADF; + struct stat st; + + in_fd = mkostemp_safe(in_fn); + assert_se(in_fd >= 0); + out_fd = mkostemp_safe(out_fn); + assert_se(out_fd >= 0); + + assert_se(futimens(in_fd, source) >= 0); + + ASSERT_OK(copy_times_full(in_fd, out_fd, /* flags= */ 0, ts_clamp)); + + assert_se(fstat(out_fd, &st) >= 0); + ASSERT_EQ(st.st_atim.tv_sec, expect[0].tv_sec); + ASSERT_EQ(st.st_atim.tv_nsec, expect[0].tv_nsec); + ASSERT_EQ(st.st_mtim.tv_sec, expect[1].tv_sec); + ASSERT_EQ(st.st_mtim.tv_nsec, expect[1].tv_nsec); +} + +#define TIMESPEC_PAIR(a, m) ((const struct timespec[2]) { { .tv_sec = (a) }, { .tv_sec = (m) } }) + +TEST(copy_times_clamp) { + const time_t before = 1600000000, epoch = 1700000000, after = 1750000000; + const usec_t clamp = epoch * USEC_PER_SEC; + + /* Older than the clamp: kept. */ + test_copy_times_one(TIMESPEC_PAIR(before, before), clamp, TIMESPEC_PAIR(before, before)); + + /* Newer: pulled back onto the clamp. */ + test_copy_times_one(TIMESPEC_PAIR(after, after), clamp, TIMESPEC_PAIR(epoch, epoch)); + + /* Exactly on it: kept, the clamp is an inclusive upper bound. The comparison runs at microsecond + * resolution, so a nanosecond past the clamp still counts as "on it". */ + test_copy_times_one( + (const struct timespec[2]) { { .tv_sec = epoch, .tv_nsec = 1 }, + { .tv_sec = epoch, .tv_nsec = 1 } }, + clamp, + (const struct timespec[2]) { { .tv_sec = epoch, .tv_nsec = 1 }, + { .tv_sec = epoch, .tv_nsec = 1 } }); + + /* atime and mtime are decided independently: a file that was merely read after the epoch + * loses its atime and keeps its mtime. */ + test_copy_times_one(TIMESPEC_PAIR(after, before), clamp, TIMESPEC_PAIR(epoch, before)); + test_copy_times_one(TIMESPEC_PAIR(before, after), clamp, TIMESPEC_PAIR(before, epoch)); + + /* Before 1970: older than any epoch, so kept rather than pushed forward. */ + test_copy_times_one(TIMESPEC_PAIR(-1, -1), clamp, TIMESPEC_PAIR(-1, -1)); + + /* No clamp requested: the source's own timestamps. */ + test_copy_times_one(TIMESPEC_PAIR(after, after), USEC_INFINITY, TIMESPEC_PAIR(after, after)); +} + DEFINE_TEST_MAIN(LOG_DEBUG);