X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=dc6528013bb0a7fded44e17a9e84e3eb5473b9f8;hp=97ff320bc8320c82b3d2f44b72f08dfe31eea4f7;hb=1c8da044469acabcfc479ba3276954da53210830;hpb=5f8cc96a0301c1177b11dd2e89370ef0b2ef577b diff --git a/src/shared/util.c b/src/shared/util.c index 97ff320bc..dc6528013 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -25,6 +25,8 @@ #include #include #include +#include +#include #include #include #include @@ -39,8 +41,7 @@ #include #include #include -#include -#include +#include #include #include #include @@ -60,6 +61,14 @@ #include #include #include +#include +#include +#include +#include + +/* When we include libgen.h because we need dirname() we immediately + * undefine basename() since libgen.h defines it as a macro to the XDG + * version which is really broken. */ #include #undef basename @@ -67,6 +76,7 @@ #include #endif +#include "config.h" #include "macro.h" #include "util.h" #include "ioprio.h" @@ -85,6 +95,7 @@ #include "gunicode.h" #include "virt.h" #include "def.h" +#include "sparse-endian.h" int saved_argc = 0; char **saved_argv = NULL; @@ -503,18 +514,24 @@ int safe_atolli(const char *s, long long int *ret_lli) { int safe_atod(const char *s, double *ret_d) { char *x = NULL; double d = 0; + locale_t loc; assert(s); assert(ret_d); - RUN_WITH_LOCALE(LC_NUMERIC_MASK, "C") { - errno = 0; - d = strtod(s, &x); - } + loc = newlocale(LC_NUMERIC_MASK, "C", (locale_t) 0); + if (loc == (locale_t) 0) + return -errno; - if (!x || x == s || *x || errno) + errno = 0; + d = strtod_l(s, &x, loc); + + if (!x || x == s || *x || errno) { + freelocale(loc); return errno ? -errno : -EINVAL; + } + freelocale(loc); *ret_d = (double) d; return 0; } @@ -1151,7 +1168,7 @@ 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 +1181,17 @@ 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 +1366,19 @@ 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 +1421,12 @@ 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 +1449,13 @@ 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 +1469,6 @@ 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 +1477,6 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre } } -finish: *t = 0; return r; } @@ -1524,6 +1546,10 @@ _pure_ static bool hidden_file_allow_backup(const char *filename) { endswith(filename, ".dpkg-old") || endswith(filename, ".dpkg-new") || endswith(filename, ".dpkg-tmp") || + endswith(filename, ".dpkg-dist") || + endswith(filename, ".dpkg-bak") || + endswith(filename, ".dpkg-backup") || + endswith(filename, ".dpkg-remove") || endswith(filename, ".swp"); } @@ -2106,7 +2132,7 @@ 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 +2155,7 @@ int acquire_terminal( } } - l = read(notify, buffer, sizeof(buffer)); + l = read(notify, &buffer, sizeof(buffer)); if (l < 0) { if (errno == EINTR || errno == EAGAIN) continue; @@ -3455,7 +3481,7 @@ unsigned columns(void) { c = 80; cached_columns = c; - return c; + return cached_columns; } int fd_lines(int fd) { @@ -3472,7 +3498,7 @@ int fd_lines(int fd) { unsigned lines(void) { const char *e; - unsigned l; + int l; if (_likely_(cached_lines > 0)) return cached_lines; @@ -3480,7 +3506,7 @@ 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); @@ -4003,7 +4029,7 @@ 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) { @@ -4034,64 +4060,66 @@ bool dirent_is_file_with_suffix(const struct dirent *de, const char *suffix) { 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; - - assert(directory); +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; - /* Executes all binaries in a directory in parallel and waits - * for them to finish. Optionally a timeout is applied. */ + /* We fork this all off from a child process so that we can + * somewhat cleanly make use of SIGALRM to set a time limit */ - 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"); @@ -4109,45 +4137,68 @@ 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) { @@ -4204,6 +4255,11 @@ bool hostname_is_valid(const char *s) { if (isempty(s)) return false; + /* Doesn't accept empty hostnames, hostnames with trailing or + * leading dots, and hostnames with multiple dots in a + * sequence. Also ensures that the length stays below + * HOST_NAME_MAX. */ + for (p = s, dot = true; *p; p++) { if (*p == '.') { if (dot) @@ -4270,23 +4326,6 @@ 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, @@ -5183,6 +5222,9 @@ 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) { @@ -5432,25 +5474,56 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value) { return r; } -bool is_valid_documentation_url(const char *url) { - assert(url); +bool http_etag_is_valid(const char *etag) { + if (isempty(etag)) + return false; - if (startswith(url, "http://") && url[7]) - return true; + if (!endswith(etag, "\"")) + return false; - if (startswith(url, "https://") && url[8]) - return true; + if (!startswith(etag, "\"") && !startswith(etag, "W/\"")) + return false; - if (startswith(url, "file:") && url[5]) - return true; + return true; +} - if (startswith(url, "info:") && url[5]) - return true; +bool http_url_is_valid(const char *url) { + const char *p; - if (startswith(url, "man:") && url[4]) + if (isempty(url)) + return false; + + p = startswith(url, "http://"); + if (!p) + p = startswith(url, "https://"); + if (!p) + return false; + + if (isempty(p)) + return false; + + return ascii_is_valid(p); +} + +bool documentation_url_is_valid(const char *url) { + const char *p; + + if (isempty(url)) + return false; + + if (http_url_is_valid(url)) return true; - return false; + p = startswith(url, "file:/"); + if (!p) + p = startswith(url, "info:"); + if (!p) + p = startswith(url, "man:"); + + if (isempty(p)) + return false; + + return ascii_is_valid(p); } bool in_initrd(void) { @@ -5712,6 +5785,11 @@ void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size, return NULL; } +void init_gettext(void) { + setlocale(LC_ALL, ""); + textdomain(GETTEXT_PACKAGE); +} + bool is_locale_utf8(void) { const char *set; static int cached_answer = -1; @@ -6386,7 +6464,7 @@ int container_get_leader(const char *machine, pid_t *pid) { assert(machine); assert(pid); - p = strappenda("/run/systemd/machines/", machine); + p = strjoina("/run/systemd/machines/", machine); r = parse_env_file(p, NEWLINE, "LEADER", &s, "CLASS", &class, NULL); if (r == -ENOENT) return -EHOSTDOWN; @@ -6625,7 +6703,7 @@ int open_tmpfile(const char *path, int flags) { #endif /* Fall back to unguessable name + unlinking */ - p = strappenda(path, "/systemd-tmp-XXXXXX"); + p = strjoina(path, "/systemd-tmp-XXXXXX"); fd = mkostemp_safe(p, flags); if (fd < 0) @@ -6713,23 +6791,6 @@ 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; @@ -6854,6 +6915,15 @@ 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; @@ -6888,6 +6958,7 @@ 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) @@ -6965,7 +7036,11 @@ 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); @@ -6985,7 +7060,14 @@ 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 */ @@ -7150,7 +7232,7 @@ int take_password_lock(const char *root) { * awfully racy, and thus we just won't do them. */ if (root) - path = strappenda(root, "/etc/.pwd.lock"); + path = strjoina(root, "/etc/.pwd.lock"); else path = "/etc/.pwd.lock"; @@ -7559,3 +7641,482 @@ int openpt_in_namespace(pid_t pid, int flags) { 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_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); + if (fd < 0) + return -errno; + + return chattr_fd(fd, b, mask); +} + +int read_attr_fd(int fd, unsigned *ret) { + assert(fd >= 0); + + if (ioctl(fd, FS_IOC_GETFLAGS, ret) < 0) + return -errno; + + return 0; +} + +int read_attr_path(const char *p, unsigned *ret) { + _cleanup_close_ int fd = -1; + + assert(p); + assert(ret); + + fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); + if (fd < 0) + return -errno; + + return read_attr_fd(fd, ret); +} + +int make_lock_file(const char *p, int operation, LockFile *ret) { + _cleanup_close_ int fd = -1; + _cleanup_free_ char *t = NULL; + int r; + + /* + * We use UNPOSIX locks if they are available. They have nice + * semantics, and are mostly compatible with NFS. However, + * they are only available on new kernels. When we detect we + * are running on an older kernel, then we fall back to good + * old BSD locks. They also have nice semantics, but are + * slightly problematic on NFS, where they are upgraded to + * POSIX locks, even though locally they are orthogonal to + * POSIX locks. + */ + + t = strdup(p); + if (!t) + return -ENOMEM; + + for (;;) { + struct flock fl = { + .l_type = (operation & ~LOCK_NB) == LOCK_EX ? F_WRLCK : F_RDLCK, + .l_whence = SEEK_SET, + }; + struct stat st; + + fd = open(p, O_CREAT|O_RDWR|O_NOFOLLOW|O_CLOEXEC|O_NOCTTY, 0600); + if (fd < 0) + return -errno; + + r = fcntl(fd, (operation & LOCK_NB) ? F_OFD_SETLK : F_OFD_SETLKW, &fl); + if (r < 0) { + + /* If the kernel is too old, use good old BSD locks */ + if (errno == EINVAL) + r = flock(fd, operation); + + if (r < 0) + return errno == EAGAIN ? -EBUSY : -errno; + } + + /* If we acquired the lock, let's check if the file + * still exists in the file system. If not, then the + * previous exclusive owner removed it and then closed + * it. In such a case our acquired lock is worthless, + * hence try again. */ + + r = fstat(fd, &st); + if (r < 0) + return -errno; + if (st.st_nlink > 0) + break; + + fd = safe_close(fd); + } + + ret->path = t; + ret->fd = fd; + ret->operation = operation; + + fd = -1; + t = NULL; + + return r; +} + +int make_lock_file_for(const char *p, int operation, LockFile *ret) { + const char *fn; + char *t; + + assert(p); + assert(ret); + + fn = basename(p); + if (!filename_is_valid(fn)) + return -EINVAL; + + t = newa(char, strlen(p) + 2 + 4 + 1); + stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn), ".lck"); + + return make_lock_file(t, operation, ret); +} + +void release_lock_file(LockFile *f) { + int r; + + if (!f) + return; + + if (f->path) { + + /* If we are the exclusive owner we can safely delete + * the lock file itself. If we are not the exclusive + * owner, we can try becoming it. */ + + if (f->fd >= 0 && + (f->operation & ~LOCK_NB) == LOCK_SH) { + static const struct flock fl = { + .l_type = F_WRLCK, + .l_whence = SEEK_SET, + }; + + r = fcntl(f->fd, F_OFD_SETLK, &fl); + if (r < 0 && errno == EINVAL) + r = flock(f->fd, LOCK_EX|LOCK_NB); + + if (r >= 0) + f->operation = LOCK_EX|LOCK_NB; + } + + if ((f->operation & ~LOCK_NB) == LOCK_EX) + unlink_noerrno(f->path); + + free(f->path); + f->path = NULL; + } + + f->fd = safe_close(f->fd); + f->operation = 0; +} + +static size_t nul_length(const uint8_t *p, size_t sz) { + size_t n = 0; + + while (sz > 0) { + if (*p != 0) + break; + + n++; + p++; + sz--; + } + + return n; +} + +ssize_t sparse_write(int fd, const void *p, size_t sz, size_t run_length) { + const uint8_t *q, *w, *e; + ssize_t l; + + q = w = p; + e = q + sz; + while (q < e) { + size_t n; + + n = nul_length(q, e - q); + + /* If there are more than the specified run length of + * NUL bytes, or if this is the beginning or the end + * of the buffer, then seek instead of write */ + if ((n > run_length) || + (n > 0 && q == p) || + (n > 0 && q + n >= e)) { + if (q > w) { + l = write(fd, w, q - w); + if (l < 0) + return -errno; + if (l != q -w) + return -EIO; + } + + if (lseek(fd, n, SEEK_CUR) == (off_t) -1) + return -errno; + + q += n; + w = q; + } else if (n > 0) + q += n; + else + q ++; + } + + if (q > w) { + l = write(fd, w, q - w); + if (l < 0) + return -errno; + if (l != q - w) + return -EIO; + } + + return q - (const uint8_t*) p; +} + +void sigkill_wait(pid_t *pid) { + if (!pid) + return; + if (*pid <= 1) + return; + + if (kill(*pid, SIGKILL) > 0) + (void) wait_for_terminate(*pid, NULL); +} + +int syslog_parse_priority(const char **p, int *priority, bool with_facility) { + int a = 0, b = 0, c = 0; + int k; + + assert(p); + assert(*p); + assert(priority); + + if ((*p)[0] != '<') + return 0; + + if (!strchr(*p, '>')) + return 0; + + if ((*p)[2] == '>') { + c = undecchar((*p)[1]); + k = 3; + } else if ((*p)[3] == '>') { + b = undecchar((*p)[1]); + c = undecchar((*p)[2]); + k = 4; + } else if ((*p)[4] == '>') { + a = undecchar((*p)[1]); + b = undecchar((*p)[2]); + c = undecchar((*p)[3]); + k = 5; + } else + return 0; + + if (a < 0 || b < 0 || c < 0 || + (!with_facility && (a || b || c > 7))) + return 0; + + if (with_facility) + *priority = a*100 + b*10 + c; + else + *priority = (*priority & LOG_FACMASK) | c; + + *p += k; + return 1; +} + +ssize_t string_table_lookup(const char * const *table, size_t len, const char *key) { + size_t i; + + if (!key) + return -1; + + for (i = 0; i < len; ++i) + if (streq_ptr(table[i], key)) + return (ssize_t)i; + + return -1; +} + +void cmsg_close_all(struct msghdr *mh) { + struct cmsghdr *cmsg; + + assert(mh); + + for (cmsg = CMSG_FIRSTHDR(mh); cmsg; cmsg = CMSG_NXTHDR(mh, cmsg)) + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) + close_many((int*) CMSG_DATA(cmsg), (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int)); +}