X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=9fd2d89556819500d9c602cce6f99a60cf45c02c;hb=45030287af1e8e76b0feb1cfc3011a0ef2b37d0d;hp=dbae55fe38d127014d1c9b107695d4c48a5246fb;hpb=e02d225b1eaead537243293a9c02f6baa8aaf55d;p=elogind.git diff --git a/src/shared/util.c b/src/shared/util.c index dbae55fe3..9fd2d8955 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -39,7 +39,6 @@ #include #include #include -#include #include #include #include @@ -60,7 +59,10 @@ #include #include #include +#include #include +#include +#include #undef basename #ifdef HAVE_SYS_AUXV_H @@ -85,6 +87,7 @@ #include "gunicode.h" #include "virt.h" #include "def.h" +#include "sparse-endian.h" int saved_argc = 0; char **saved_argv = NULL; @@ -1151,7 +1154,7 @@ char *delete_chars(char *s, const char *bad) { } char *file_in_same_dir(const char *path, const char *filename) { - char *e, *r; + char *e, *ret; size_t k; assert(path); @@ -1164,17 +1167,17 @@ char *file_in_same_dir(const char *path, const char *filename) { if (path_is_absolute(filename)) return strdup(filename); - if (!(e = strrchr(path, '/'))) + e = strrchr(path, '/'); + if (!e) return strdup(filename); k = strlen(filename); - if (!(r = new(char, e-path+1+k+1))) + ret = new(char, (e + 1 - path) + k + 1); + if (!ret) return NULL; - memcpy(r, path, e-path+1); - memcpy(r+(e-path)+1, filename, k+1); - - return r; + memcpy(mempcpy(ret, path, e + 1 - path), filename, k + 1); + return ret; } int rmdir_parents(const char *path, const char *stop) { @@ -1349,12 +1352,19 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre memcpy(r, prefix, pl); for (f = s, t = r + pl; f < s + length; f++) { + size_t remaining = s + length - f; + assert(remaining > 0); - if (*f != '\\') { + if (*f != '\\') { /* a literal literal */ *(t++) = *f; continue; } + if (--remaining == 0) { /* copy trailing backslash verbatim */ + *(t++) = *f; + break; + } + f++; switch (*f) { @@ -1397,10 +1407,12 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre case 'x': { /* hexadecimal encoding */ - int a, b; + int a = -1, b = -1; - a = unhexchar(f[1]); - b = unhexchar(f[2]); + if (remaining >= 2) { + a = unhexchar(f[1]); + b = unhexchar(f[2]); + } if (a < 0 || b < 0 || (a == 0 && b == 0)) { /* Invalid escape code, let's take it literal then */ @@ -1423,11 +1435,13 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre case '6': case '7': { /* octal encoding */ - int a, b, c; + int a = -1, b = -1, c = -1; - a = unoctchar(f[0]); - b = unoctchar(f[1]); - c = unoctchar(f[2]); + if (remaining >= 3) { + a = unoctchar(f[0]); + b = unoctchar(f[1]); + c = unoctchar(f[2]); + } if (a < 0 || b < 0 || c < 0 || (a == 0 && b == 0 && c == 0)) { /* Invalid escape code, let's take it literal then */ @@ -1441,11 +1455,6 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre break; } - case 0: - /* premature end of string. */ - *(t++) = '\\'; - goto finish; - default: /* Invalid escape code, let's take it literal then */ *(t++) = '\\'; @@ -1454,7 +1463,6 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre } } -finish: *t = 0; return r; } @@ -1510,7 +1518,7 @@ char *ascii_strlower(char *t) { return t; } -_pure_ static bool ignore_file_allow_backup(const char *filename) { +_pure_ static bool hidden_file_allow_backup(const char *filename) { assert(filename); return @@ -1527,13 +1535,13 @@ _pure_ static bool ignore_file_allow_backup(const char *filename) { endswith(filename, ".swp"); } -bool ignore_file(const char *filename) { +bool hidden_file(const char *filename) { assert(filename); if (endswith(filename, "~")) return true; - return ignore_file_allow_backup(filename); + return hidden_file_allow_backup(filename); } int fd_nonblock(int fd, bool nonblock) { @@ -1627,7 +1635,7 @@ int close_all_fds(const int except[], unsigned n_except) { while ((de = readdir(d))) { int fd = -1; - if (ignore_file(de->d_name)) + if (hidden_file(de->d_name)) continue; if (safe_atoi(de->d_name, &fd) < 0) @@ -2106,7 +2114,7 @@ int acquire_terminal( assert(notify >= 0); for (;;) { - uint8_t buffer[INOTIFY_EVENT_MAX] _alignas_(struct inotify_event); + union inotify_event_buffer buffer; struct inotify_event *e; ssize_t l; @@ -2129,7 +2137,7 @@ int acquire_terminal( } } - l = read(notify, buffer, sizeof(buffer)); + l = read(notify, &buffer, sizeof(buffer)); if (l < 0) { if (errno == EINTR || errno == EAGAIN) continue; @@ -2531,7 +2539,7 @@ int dir_is_empty(const char *path) { if (!de) return 1; - if (!ignore_file(de->d_name)) + if (!hidden_file(de->d_name)) return 0; } } @@ -2785,23 +2793,36 @@ char *getusername_malloc(void) { return lookup_uid(getuid()); } -int getttyname_malloc(int fd, char **r) { - char path[PATH_MAX], *c; - int k; +int getttyname_malloc(int fd, char **ret) { + size_t l = 100; + int r; - assert(r); + assert(fd >= 0); + assert(ret); - k = ttyname_r(fd, path, sizeof(path)); - if (k > 0) - return -k; + for (;;) { + char path[l]; - char_array_0(path); + r = ttyname_r(fd, path, sizeof(path)); + if (r == 0) { + const char *p; + char *c; - c = strdup(startswith(path, "/dev/") ? path + 5 : path); - if (!c) - return -ENOMEM; + p = startswith(path, "/dev/"); + c = strdup(p ?: path); + if (!c) + return -ENOMEM; + + *ret = c; + return 0; + } + + if (r != ERANGE) + return -r; + + l *= 2; + } - *r = c; return 0; } @@ -3442,7 +3463,7 @@ unsigned columns(void) { c = 80; cached_columns = c; - return c; + return cached_columns; } int fd_lines(int fd) { @@ -3459,7 +3480,7 @@ int fd_lines(int fd) { unsigned lines(void) { const char *e; - unsigned l; + int l; if (_likely_(cached_lines > 0)) return cached_lines; @@ -3467,7 +3488,7 @@ unsigned lines(void) { l = 0; e = getenv("LINES"); if (e) - (void) safe_atou(e, &l); + (void) safe_atoi(e, &l); if (l <= 0) l = fd_lines(STDOUT_FILENO); @@ -3990,13 +4011,13 @@ bool tty_is_vc_resolve(const char *tty) { const char *default_term_for_tty(const char *tty) { assert(tty); - return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt102"; + return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt220"; } bool dirent_is_file(const struct dirent *de) { assert(de); - if (ignore_file(de->d_name)) + if (hidden_file(de->d_name)) return false; if (de->d_type != DT_REG && @@ -4015,70 +4036,72 @@ bool dirent_is_file_with_suffix(const struct dirent *de, const char *suffix) { de->d_type != DT_UNKNOWN) return false; - if (ignore_file_allow_backup(de->d_name)) + if (hidden_file_allow_backup(de->d_name)) return false; return endswith(de->d_name, suffix); } -void execute_directory(const char *directory, DIR *d, usec_t timeout, char *argv[]) { - pid_t executor_pid; - int r; +static int do_execute(char **directories, usec_t timeout, char *argv[]) { + _cleanup_hashmap_free_free_ Hashmap *pids = NULL; + _cleanup_set_free_free_ Set *seen = NULL; + char **directory; - assert(directory); + /* We fork this all off from a child process so that we can + * somewhat cleanly make use of SIGALRM to set a time limit */ - /* Executes all binaries in a directory in parallel and waits - * for them to finish. Optionally a timeout is applied. */ - - executor_pid = fork(); - if (executor_pid < 0) { - log_error_errno(errno, "Failed to fork: %m"); - return; + reset_all_signal_handlers(); + reset_signal_mask(); - } else if (executor_pid == 0) { - _cleanup_hashmap_free_free_ Hashmap *pids = NULL; - _cleanup_closedir_ DIR *_d = NULL; - struct dirent *de; + assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0); - /* We fork this all off from a child process so that - * we can somewhat cleanly make use of SIGALRM to set - * a time limit */ + pids = hashmap_new(NULL); + if (!pids) + return log_oom(); - reset_all_signal_handlers(); - reset_signal_mask(); + seen = set_new(&string_hash_ops); + if (!seen) + return log_oom(); - assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0); + STRV_FOREACH(directory, directories) { + _cleanup_closedir_ DIR *d; + struct dirent *de; + d = opendir(*directory); if (!d) { - d = _d = opendir(directory); - if (!d) { - if (errno == ENOENT) - _exit(EXIT_SUCCESS); - - log_error_errno(errno, "Failed to enumerate directory %s: %m", directory); - _exit(EXIT_FAILURE); - } - } + if (errno == ENOENT) + continue; - pids = hashmap_new(NULL); - if (!pids) { - log_oom(); - _exit(EXIT_FAILURE); + return log_error_errno(errno, "Failed to open directory %s: %m", *directory); } FOREACH_DIRENT(de, d, break) { _cleanup_free_ char *path = NULL; pid_t pid; + int r; if (!dirent_is_file(de)) continue; - path = strjoin(directory, "/", de->d_name, NULL); - if (!path) { - log_oom(); - _exit(EXIT_FAILURE); + if (set_contains(seen, de->d_name)) { + log_debug("%1$s/%2$s skipped (%2$s was already seen).", *directory, de->d_name); + continue; } + r = set_put_strdup(seen, de->d_name); + if (r < 0) + return log_oom(); + + path = strjoin(*directory, "/", de->d_name, NULL); + if (!path) + return log_oom(); + + if (null_or_empty_path(path)) { + log_debug("%s is empty (a mask).", path); + continue; + } else + log_debug("%s will be executed.", path); + pid = fork(); if (pid < 0) { log_error_errno(errno, "Failed to fork: %m"); @@ -4096,45 +4119,68 @@ void execute_directory(const char *directory, DIR *d, usec_t timeout, char *argv argv[0] = path; execv(path, argv); - log_error_errno(errno, "Failed to execute %s: %m", path); - _exit(EXIT_FAILURE); + return log_error_errno(errno, "Failed to execute %s: %m", path); } log_debug("Spawned %s as " PID_FMT ".", path, pid); r = hashmap_put(pids, UINT_TO_PTR(pid), path); - if (r < 0) { - log_oom(); - _exit(EXIT_FAILURE); - } - + if (r < 0) + return log_oom(); path = NULL; } + } - /* Abort execution of this process after the - * timout. We simply rely on SIGALRM as default action - * terminating the process, and turn on alarm(). */ + /* Abort execution of this process after the timout. We simply + * rely on SIGALRM as default action terminating the process, + * and turn on alarm(). */ - if (timeout != USEC_INFINITY) - alarm((timeout + USEC_PER_SEC - 1) / USEC_PER_SEC); + if (timeout != USEC_INFINITY) + alarm((timeout + USEC_PER_SEC - 1) / USEC_PER_SEC); - while (!hashmap_isempty(pids)) { - _cleanup_free_ char *path = NULL; - pid_t pid; + while (!hashmap_isempty(pids)) { + _cleanup_free_ char *path = NULL; + pid_t pid; - pid = PTR_TO_UINT(hashmap_first_key(pids)); - assert(pid > 0); + pid = PTR_TO_UINT(hashmap_first_key(pids)); + assert(pid > 0); - path = hashmap_remove(pids, UINT_TO_PTR(pid)); - assert(path); + path = hashmap_remove(pids, UINT_TO_PTR(pid)); + assert(path); - wait_for_terminate_and_warn(path, pid, true); - } + wait_for_terminate_and_warn(path, pid, true); + } - _exit(EXIT_SUCCESS); + return 0; +} + +void execute_directories(const char* const* directories, usec_t timeout, char *argv[]) { + pid_t executor_pid; + int r; + char *name; + char **dirs = (char**) directories; + + assert(!strv_isempty(dirs)); + + name = basename(dirs[0]); + assert(!isempty(name)); + + /* Executes all binaries in the directories in parallel and waits + * for them to finish. Optionally a timeout is applied. If a file + * with the same name exists in more than one directory, the + * earliest one wins. */ + + executor_pid = fork(); + if (executor_pid < 0) { + log_error_errno(errno, "Failed to fork: %m"); + return; + + } else if (executor_pid == 0) { + r = do_execute(dirs, timeout, argv); + _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); } - wait_for_terminate_and_warn(directory, executor_pid, true); + wait_for_terminate_and_warn(name, executor_pid, true); } int kill_and_sigcont(pid_t pid, int sig) { @@ -4257,6 +4303,23 @@ bool machine_name_is_valid(const char *s) { return true; } +bool image_name_is_valid(const char *s) { + if (!filename_is_valid(s)) + return false; + + if (string_has_cc(s, NULL)) + return false; + + if (!utf8_is_valid(s)) + return false; + + /* Temporary files for atomically creating new files */ + if (startswith(s, ".#")) + return false; + + return true; +} + int pipe_eof(int fd) { struct pollfd pollfd = { .fd = fd, @@ -5153,6 +5216,9 @@ char *format_bytes(char *buf, size_t l, off_t t) { { "K", 1024ULL }, }; + if (t == (off_t) -1) + return NULL; + for (i = 0; i < ELEMENTSOF(table); i++) { if (t >= table[i].factor) { @@ -5909,7 +5975,7 @@ int on_ac_power(void) { if (!de) break; - if (ignore_file(de->d_name)) + if (hidden_file(de->d_name)) continue; device = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY|O_CLOEXEC|O_NOCTTY); @@ -6683,23 +6749,6 @@ uint64_t physical_memory(void) { return (uint64_t) mem * (uint64_t) page_size(); } -char* mount_test_option(const char *haystack, const char *needle) { - - struct mntent me = { - .mnt_opts = (char*) haystack - }; - - assert(needle); - - /* Like glibc's hasmntopt(), but works on a string, not a - * struct mntent */ - - if (!haystack) - return NULL; - - return hasmntopt(&me, needle); -} - void hexdump(FILE *f, const void *p, size_t s) { const uint8_t *b = p; unsigned n = 0; @@ -6824,6 +6873,15 @@ int umount_recursive(const char *prefix, int flags) { return r ? r : n; } +static int get_mount_flags(const char *path, unsigned long *flags) { + struct statvfs buf; + + if (statvfs(path, &buf) < 0) + return -errno; + *flags = buf.f_flag; + return 0; +} + int bind_remount_recursive(const char *prefix, bool ro) { _cleanup_set_free_free_ Set *done = NULL; _cleanup_free_ char *cleaned = NULL; @@ -6858,6 +6916,7 @@ int bind_remount_recursive(const char *prefix, bool ro) { _cleanup_set_free_free_ Set *todo = NULL; bool top_autofs = false; char *x; + unsigned long orig_flags; todo = set_new(&string_hash_ops); if (!todo) @@ -6935,7 +6994,11 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (mount(cleaned, cleaned, NULL, MS_BIND|MS_REC, NULL) < 0) return -errno; - if (mount(NULL, prefix, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) + orig_flags = 0; + (void) get_mount_flags(cleaned, &orig_flags); + orig_flags &= ~MS_RDONLY; + + if (mount(NULL, prefix, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) return -errno; x = strdup(cleaned); @@ -6955,7 +7018,14 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (r < 0) return r; - if (mount(NULL, x, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) { + /* Try to reuse the original flag set, but + * don't care for errors, in case of + * obstructed mounts */ + orig_flags = 0; + (void) get_mount_flags(x, &orig_flags); + orig_flags &= ~MS_RDONLY; + + if (mount(NULL, x, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) { /* Deal with mount points that are * obstructed by a later mount */ @@ -6992,18 +7062,18 @@ int tempfn_xxxxxx(const char *p, char **ret) { * /foo/bar/waldo * * Into this: - * /foo/bar/.waldoXXXXXX + * /foo/bar/.#waldoXXXXXX */ fn = basename(p); if (!filename_is_valid(fn)) return -EINVAL; - t = new(char, strlen(p) + 1 + 6 + 1); + t = new(char, strlen(p) + 2 + 6 + 1); if (!t) return -ENOMEM; - strcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), "."), fn), "XXXXXX"); + strcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn), "XXXXXX"); *ret = path_kill_slashes(t); return 0; @@ -7023,18 +7093,18 @@ int tempfn_random(const char *p, char **ret) { * /foo/bar/waldo * * Into this: - * /foo/bar/.waldobaa2a261115984a9 + * /foo/bar/.#waldobaa2a261115984a9 */ fn = basename(p); if (!filename_is_valid(fn)) return -EINVAL; - t = new(char, strlen(p) + 1 + 16 + 1); + t = new(char, strlen(p) + 2 + 16 + 1); if (!t) return -ENOMEM; - x = stpcpy(stpcpy(mempcpy(t, p, fn - p), "."), fn); + x = stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn); u = random_u64(); for (i = 0; i < 16; i++) { @@ -7059,14 +7129,14 @@ int tempfn_random_child(const char *p, char **ret) { /* Turns this: * /foo/bar/waldo * Into this: - * /foo/bar/waldo/.3c2b6219aa75d7d0 + * /foo/bar/waldo/.#3c2b6219aa75d7d0 */ - t = new(char, strlen(p) + 2 + 16 + 1); + t = new(char, strlen(p) + 3 + 16 + 1); if (!t) return -ENOMEM; - x = stpcpy(stpcpy(t, p), "/."); + x = stpcpy(stpcpy(t, p), "/.#"); u = random_u64(); for (i = 0; i < 16; i++) { @@ -7416,3 +7486,314 @@ int sethostname_idempotent(const char *s) { return 1; } + +int ptsname_malloc(int fd, char **ret) { + size_t l = 100; + + assert(fd >= 0); + assert(ret); + + for (;;) { + char *c; + + c = new(char, l); + if (!c) + return -ENOMEM; + + if (ptsname_r(fd, c, l) == 0) { + *ret = c; + return 0; + } + if (errno != ERANGE) { + free(c); + return -errno; + } + + free(c); + l *= 2; + } +} + +int openpt_in_namespace(pid_t pid, int flags) { + _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, rootfd = -1; + _cleanup_close_pair_ int pair[2] = { -1, -1 }; + union { + struct cmsghdr cmsghdr; + uint8_t buf[CMSG_SPACE(sizeof(int))]; + } control = {}; + struct msghdr mh = { + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + struct cmsghdr *cmsg; + siginfo_t si; + pid_t child; + int r; + + assert(pid > 0); + + r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &rootfd); + if (r < 0) + return r; + + if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0) + return -errno; + + child = fork(); + if (child < 0) + return -errno; + + if (child == 0) { + int master; + + pair[0] = safe_close(pair[0]); + + r = namespace_enter(pidnsfd, mntnsfd, -1, rootfd); + if (r < 0) + _exit(EXIT_FAILURE); + + master = posix_openpt(flags); + if (master < 0) + _exit(EXIT_FAILURE); + + cmsg = CMSG_FIRSTHDR(&mh); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + memcpy(CMSG_DATA(cmsg), &master, sizeof(int)); + + mh.msg_controllen = cmsg->cmsg_len; + + if (sendmsg(pair[1], &mh, MSG_NOSIGNAL) < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + pair[1] = safe_close(pair[1]); + + r = wait_for_terminate(child, &si); + if (r < 0) + return r; + if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS) + return -EIO; + + if (recvmsg(pair[0], &mh, MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) < 0) + return -errno; + + for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { + int *fds; + unsigned n_fds; + + fds = (int*) CMSG_DATA(cmsg); + n_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); + + if (n_fds != 1) { + close_many(fds, n_fds); + return -EIO; + } + + return fds[0]; + } + + return -EIO; +} + +ssize_t fgetxattrat_fake(int dirfd, const char *filename, const char *attribute, void *value, size_t size, int flags) { + _cleanup_close_ int fd = -1; + ssize_t l; + + /* The kernel doesn't have a fgetxattrat() command, hence let's emulate one */ + + fd = openat(dirfd, filename, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOATIME|(flags & AT_SYMLINK_NOFOLLOW ? O_NOFOLLOW : 0)); + if (fd < 0) + return -errno; + + l = fgetxattr(fd, attribute, value, size); + if (l < 0) + return -errno; + + return l; +} + +static int parse_crtime(le64_t le, usec_t *usec) { + uint64_t u; + + assert(usec); + + u = le64toh(le); + if (u == 0 || u == (uint64_t) -1) + return -EIO; + + *usec = (usec_t) u; + return 0; +} + +int fd_getcrtime(int fd, usec_t *usec) { + le64_t le; + ssize_t n; + + assert(fd >= 0); + assert(usec); + + /* Until Linux gets a real concept of birthtime/creation time, + * let's fake one with xattrs */ + + n = fgetxattr(fd, "user.crtime_usec", &le, sizeof(le)); + if (n < 0) + return -errno; + if (n != sizeof(le)) + return -EIO; + + return parse_crtime(le, usec); +} + +int fd_getcrtime_at(int dirfd, const char *name, usec_t *usec, int flags) { + le64_t le; + ssize_t n; + + n = fgetxattrat_fake(dirfd, name, "user.crtime_usec", &le, sizeof(le), flags); + if (n < 0) + return -errno; + if (n != sizeof(le)) + return -EIO; + + return parse_crtime(le, usec); +} + +int path_getcrtime(const char *p, usec_t *usec) { + le64_t le; + ssize_t n; + + assert(p); + assert(usec); + + n = getxattr(p, "user.crtime_usec", &le, sizeof(le)); + if (n < 0) + return -errno; + if (n != sizeof(le)) + return -EIO; + + return parse_crtime(le, usec); +} + +int fd_setcrtime(int fd, usec_t usec) { + le64_t le; + + assert(fd >= 0); + + if (usec <= 0) + usec = now(CLOCK_REALTIME); + + le = htole64((uint64_t) usec); + if (fsetxattr(fd, "user.crtime_usec", &le, sizeof(le), 0) < 0) + return -errno; + + return 0; +} + +int same_fd(int a, int b) { + struct stat sta, stb; + pid_t pid; + int r, fa, fb; + + assert(a >= 0); + assert(b >= 0); + + /* Compares two file descriptors. Note that semantics are + * quite different depending on whether we have kcmp() or we + * don't. If we have kcmp() this will only return true for + * dup()ed file descriptors, but not otherwise. If we don't + * have kcmp() this will also return true for two fds of the same + * file, created by separate open() calls. Since we use this + * call mostly for filtering out duplicates in the fd store + * this difference hopefully doesn't matter too much. */ + + if (a == b) + return true; + + /* Try to use kcmp() if we have it. */ + pid = getpid(); + r = kcmp(pid, pid, KCMP_FILE, a, b); + if (r == 0) + return true; + if (r > 0) + return false; + if (errno != ENOSYS) + return -errno; + + /* We don't have kcmp(), use fstat() instead. */ + if (fstat(a, &sta) < 0) + return -errno; + + if (fstat(b, &stb) < 0) + return -errno; + + if ((sta.st_mode & S_IFMT) != (stb.st_mode & S_IFMT)) + return false; + + /* We consider all device fds different, since two device fds + * might refer to quite different device contexts even though + * they share the same inode and backing dev_t. */ + + if (S_ISCHR(sta.st_mode) || S_ISBLK(sta.st_mode)) + return false; + + if (sta.st_dev != stb.st_dev || sta.st_ino != stb.st_ino) + return false; + + /* The fds refer to the same inode on disk, let's also check + * if they have the same fd flags. This is useful to + * distuingish the read and write side of a pipe created with + * pipe(). */ + fa = fcntl(a, F_GETFL); + if (fa < 0) + return -errno; + + fb = fcntl(b, F_GETFL); + if (fb < 0) + return -errno; + + return fa == fb; +} + +int chattr_fd(int fd, bool b, unsigned mask) { + unsigned old_attr, new_attr; + + assert(fd >= 0); + + if (mask == 0) + return 0; + + if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0) + return -errno; + + if (b) + new_attr = old_attr | mask; + else + new_attr = old_attr & ~mask; + + if (new_attr == old_attr) + return 0; + + if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) < 0) + return -errno; + + return 0; +} + +int chattr_path(const char *p, bool b, unsigned mask) { + _cleanup_close_ int fd = -1; + + assert(p); + + if (mask == 0) + return 0; + + fd = open(p, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); + if (fd < 0) + return -errno; + + return chattr_fd(fd, b, mask); +}