X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=98c07163da28e8e871ef976392300c67f8d94bbe;hp=aaf109ea63e6f89d7c7edc8bfd7aea5f88d9034b;hb=1dedb74a2e1d840b531b76b01a76979f3b57456b;hpb=375eadd911a9f83f89f1e7de5e05f44cc81e3642 diff --git a/src/shared/util.c b/src/shared/util.c index aaf109ea6..98c07163d 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -140,48 +140,59 @@ char* endswith(const char *s, const char *postfix) { return (char*) s + sl - pl; } -bool first_word(const char *s, const char *word) { +char* first_word(const char *s, const char *word) { size_t sl, wl; + const char *p; assert(s); assert(word); + /* Checks if the string starts with the specified word, either + * followed by NUL or by whitespace. Returns a pointer to the + * NUL or the first character after the whitespace. */ + sl = strlen(s); wl = strlen(word); if (sl < wl) - return false; + return NULL; if (wl == 0) - return true; + return (char*) s; if (memcmp(s, word, wl) != 0) - return false; + return NULL; + + p = s + wl; + if (*p == 0) + return (char*) p; + + if (!strchr(WHITESPACE, *p)) + return NULL; - return s[wl] == 0 || - strchr(WHITESPACE, s[wl]); + p += strspn(p, WHITESPACE); + return (char*) p; } int close_nointr(int fd) { - int r; - assert(fd >= 0); - r = close(fd); - if (r >= 0) - return r; - else if (errno == EINTR) - /* - * Just ignore EINTR; a retry loop is the wrong - * thing to do on Linux. - * - * http://lkml.indiana.edu/hypermail/linux/kernel/0509.1/0877.html - * https://bugzilla.gnome.org/show_bug.cgi?id=682819 - * http://utcc.utoronto.ca/~cks/space/blog/unix/CloseEINTR - * https://sites.google.com/site/michaelsafyan/software-engineering/checkforeintrwheninvokingclosethinkagain - */ + + if (close(fd) >= 0) return 0; - else - return -errno; + + /* + * Just ignore EINTR; a retry loop is the wrong thing to do on + * Linux. + * + * http://lkml.indiana.edu/hypermail/linux/kernel/0509.1/0877.html + * https://bugzilla.gnome.org/show_bug.cgi?id=682819 + * http://utcc.utoronto.ca/~cks/space/blog/unix/CloseEINTR + * https://sites.google.com/site/michaelsafyan/software-engineering/checkforeintrwheninvokingclosethinkagain + */ + if (errno == EINTR) + return 0; + + return -errno; } int safe_close(int fd) { @@ -231,9 +242,9 @@ int unlink_noerrno(const char *path) { int parse_boolean(const char *v) { assert(v); - if (streq(v, "1") || v[0] == 'y' || v[0] == 'Y' || v[0] == 't' || v[0] == 'T' || strcaseeq(v, "on")) + if (streq(v, "1") || strcaseeq(v, "yes") || strcaseeq(v, "y") || strcaseeq(v, "true") || strcaseeq(v, "t") || strcaseeq(v, "on")) return 1; - else if (streq(v, "0") || v[0] == 'n' || v[0] == 'N' || v[0] == 'f' || v[0] == 'F' || strcaseeq(v, "off")) + else if (streq(v, "0") || strcaseeq(v, "no") || strcaseeq(v, "n") || strcaseeq(v, "false") || strcaseeq(v, "f") || strcaseeq(v, "off")) return 0; return -EINVAL; @@ -280,6 +291,14 @@ int parse_uid(const char *s, uid_t* ret_uid) { if ((unsigned long) uid != ul) return -ERANGE; + /* Some libc APIs use (uid_t) -1 as special placeholder */ + if (uid == (uid_t) 0xFFFFFFFF) + return -ENXIO; + + /* A long time ago UIDs where 16bit, hence explicitly avoid the 16bit -1 too */ + if (uid == (uid_t) 0xFFFF) + return -ENXIO; + *ret_uid = uid; return 0; } @@ -324,6 +343,26 @@ int safe_atoi(const char *s, int *ret_i) { return 0; } +int safe_atou8(const char *s, uint8_t *ret) { + char *x = NULL; + unsigned long l; + + assert(s); + assert(ret); + + errno = 0; + l = strtoul(s, &x, 0); + + if (!x || x == s || *x || errno) + return errno > 0 ? -errno : -EINVAL; + + if ((unsigned long) (uint8_t) l != l) + return -ERANGE; + + *ret = (uint8_t) l; + return 0; +} + int safe_atollu(const char *s, long long unsigned *ret_llu) { char *x = NULL; unsigned long long l; @@ -387,37 +426,50 @@ static size_t strcspn_escaped(const char *s, const char *reject) { else if (s[n] == '\\') escaped = true; else if (strchr(reject, s[n])) - return n; + break; } - return n; + /* if s ends in \, return index of previous char */ + return n - escaped; } /* Split a string into words. */ -char *split(const char *c, size_t *l, const char *separator, bool quoted, char **state) { - char *current; +const char* split(const char **state, size_t *l, const char *separator, bool quoted) { + const char *current; - current = *state ? *state : (char*) c; + current = *state; - if (!*current || *c == 0) + if (!*current) { + assert(**state == '\0'); return NULL; + } current += strspn(current, separator); - if (!*current) + if (!*current) { + *state = current; return NULL; + } if (quoted && strchr("\'\"", *current)) { - char quotechar = *(current++); - *l = strcspn_escaped(current, (char[]){quotechar, '\0'}); - *state = current+*l+1; + char quotechars[2] = {*current, '\0'}; + + *l = strcspn_escaped(current + 1, quotechars); + if (current[*l + 1] == '\0' || + (current[*l + 2] && !strchr(separator, current[*l + 2]))) { + /* right quote missing or garbage at the end*/ + *state = current; + return NULL; + } + assert(current[*l + 1] == quotechars[0]); + *state = current++ + *l + 2; } else if (quoted) { *l = strcspn_escaped(current, separator); - *state = current+*l; + *state = current + *l; } else { *l = strcspn(current, separator); - *state = current+*l; + *state = current + *l; } - return (char*) current; + return current; } int get_parent_of_pid(pid_t pid, pid_t *_ppid) { @@ -885,7 +937,7 @@ int readlink_and_canonicalize(const char *p, char **r) { } int reset_all_signal_handlers(void) { - int sig; + int sig, r = 0; for (sig = 1; sig < _NSIG; sig++) { struct sigaction sa = { @@ -893,16 +945,29 @@ int reset_all_signal_handlers(void) { .sa_flags = SA_RESTART, }; + /* These two cannot be caught... */ if (sig == SIGKILL || sig == SIGSTOP) continue; /* On Linux the first two RT signals are reserved by * glibc, and sigaction() will return EINVAL for them. */ if ((sigaction(sig, &sa, NULL) < 0)) - if (errno != EINVAL) - return -errno; + if (errno != EINVAL && r == 0) + r = -errno; } + return r; +} + +int reset_signal_mask(void) { + sigset_t ss; + + if (sigemptyset(&ss) < 0) + return -errno; + + if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0) + return -errno; + return 0; } @@ -1030,7 +1095,7 @@ int unhexchar(char c) { if (c >= 'A' && c <= 'F') return c - 'A' + 10; - return -1; + return -EINVAL; } char *hexmem(const void *p, size_t l) { @@ -1085,7 +1150,7 @@ int unoctchar(char c) { if (c >= '0' && c <= '7') return c - '0'; - return -1; + return -EINVAL; } char decchar(int x) { @@ -1097,7 +1162,7 @@ int undecchar(char c) { if (c >= '0' && c <= '9') return c - '0'; - return -1; + return -EINVAL; } char *cescape(const char *s) { @@ -1189,7 +1254,7 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre r = new(char, pl+length+1); if (!r) - return r; + return NULL; if (prefix) memcpy(r, prefix, pl); @@ -1248,7 +1313,7 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre a = unhexchar(f[1]); b = unhexchar(f[2]); - if (a < 0 || b < 0) { + if (a < 0 || b < 0 || (a == 0 && b == 0)) { /* Invalid escape code, let's take it literal then */ *(t++) = '\\'; *(t++) = 'x'; @@ -1275,7 +1340,7 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre b = unoctchar(f[1]); c = unoctchar(f[2]); - if (a < 0 || b < 0 || c < 0) { + if (a < 0 || b < 0 || c < 0 || (a == 0 && b == 0 && c == 0)) { /* Invalid escape code, let's take it literal then */ *(t++) = '\\'; *(t++) = f[0]; @@ -1369,6 +1434,7 @@ _pure_ static bool ignore_file_allow_backup(const char *filename) { endswith(filename, ".rpmorig") || endswith(filename, ".dpkg-old") || endswith(filename, ".dpkg-new") || + endswith(filename, ".dpkg-tmp") || endswith(filename, ".swp"); } @@ -1440,7 +1506,7 @@ _pure_ static bool fd_in_set(int fd, const int fdset[], unsigned n_fdset) { } int close_all_fds(const int except[], unsigned n_except) { - DIR *d; + _cleanup_closedir_ DIR *d = NULL; struct dirent *de; int r = 0; @@ -1495,7 +1561,6 @@ int close_all_fds(const int except[], unsigned n_except) { } } - closedir(d); return r; } @@ -1514,6 +1579,7 @@ bool fstype_is_network(const char *fstype) { static const char table[] = "cifs\0" "smbfs\0" + "sshfs\0" "ncpfs\0" "ncp\0" "nfs\0" @@ -1558,8 +1624,7 @@ int chvt(int vt) { int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) { struct termios old_termios, new_termios; - char c; - char line[LINE_MAX]; + char c, line[LINE_MAX]; assert(f); assert(ret); @@ -1574,7 +1639,7 @@ int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) { if (tcsetattr(fileno(f), TCSADRAIN, &new_termios) >= 0) { size_t k; - if (t != (usec_t) -1) { + if (t != USEC_INFINITY) { if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0) { tcsetattr(fileno(f), TCSADRAIN, &old_termios); return -ETIMEDOUT; @@ -1596,12 +1661,14 @@ int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) { } } - if (t != (usec_t) -1) + if (t != USEC_INFINITY) { if (fd_wait_for_event(fileno(f), POLLIN, t) <= 0) return -ETIMEDOUT; + } + errno = 0; if (!fgets(line, sizeof(line), f)) - return -EIO; + return errno ? -errno : -EIO; truncate_nl(line); @@ -1615,7 +1682,8 @@ int read_one_char(FILE *f, char *ret, usec_t t, bool *need_nl) { return 0; } -int ask(char *ret, const char *replies, const char *text, ...) { +int ask_char(char *ret, const char *replies, const char *text, ...) { + int r; assert(ret); assert(replies); @@ -1624,7 +1692,6 @@ int ask(char *ret, const char *replies, const char *text, ...) { for (;;) { va_list ap; char c; - int r; bool need_nl = true; if (on_tty()) @@ -1639,7 +1706,7 @@ int ask(char *ret, const char *replies, const char *text, ...) { fflush(stdout); - r = read_one_char(stdin, &c, (usec_t) -1, &need_nl); + r = read_one_char(stdin, &c, USEC_INFINITY, &need_nl); if (r < 0) { if (r == -EBADMSG) { @@ -1663,6 +1730,49 @@ int ask(char *ret, const char *replies, const char *text, ...) { } } +int ask_string(char **ret, const char *text, ...) { + assert(ret); + assert(text); + + for (;;) { + char line[LINE_MAX]; + va_list ap; + + if (on_tty()) + fputs(ANSI_HIGHLIGHT_ON, stdout); + + va_start(ap, text); + vprintf(text, ap); + va_end(ap); + + if (on_tty()) + fputs(ANSI_HIGHLIGHT_OFF, stdout); + + fflush(stdout); + + errno = 0; + if (!fgets(line, sizeof(line), stdin)) + return errno ? -errno : -EIO; + + if (!endswith(line, "\n")) + putchar('\n'); + else { + char *s; + + if (isempty(line)) + continue; + + truncate_nl(line); + s = strdup(line); + if (!s) + return -ENOMEM; + + *ret = s; + return 0; + } + } +} + int reset_terminal_fd(int fd, bool switch_to_text) { struct termios termios; int r = 0; @@ -1846,11 +1956,11 @@ int acquire_terminal( * on the same tty as an untrusted user this should not be a * problem. (Which he probably should not do anyway.) */ - if (timeout != (usec_t) -1) + if (timeout != USEC_INFINITY) ts = now(CLOCK_MONOTONIC); if (!fail && !force) { - notify = inotify_init1(IN_CLOEXEC | (timeout != (usec_t) -1 ? IN_NONBLOCK : 0)); + notify = inotify_init1(IN_CLOEXEC | (timeout != USEC_INFINITY ? IN_NONBLOCK : 0)); if (notify < 0) { r = -errno; goto fail; @@ -1914,7 +2024,7 @@ int acquire_terminal( ssize_t l; struct inotify_event *e; - if (timeout != (usec_t) -1) { + if (timeout != USEC_INFINITY) { usec_t n; n = now(CLOCK_MONOTONIC); @@ -1986,12 +2096,14 @@ fail: } int release_terminal(void) { - int r = 0; - struct sigaction sa_old, sa_new = { + static const struct sigaction sa_new = { .sa_handler = SIG_IGN, .sa_flags = SA_RESTART, }; - _cleanup_close_ int fd; + + _cleanup_close_ int fd = -1; + struct sigaction sa_old; + int r = 0; fd = open("/dev/tty", O_RDWR|O_NOCTTY|O_NDELAY|O_CLOEXEC); if (fd < 0) @@ -2096,7 +2208,7 @@ ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) { * and expect that any error/EOF is reported * via read() */ - fd_wait_for_event(fd, POLLIN, (usec_t) -1); + fd_wait_for_event(fd, POLLIN, USEC_INFINITY); continue; } @@ -2131,7 +2243,7 @@ ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) { * and expect that any error/EOF is reported * via write() */ - fd_wait_for_event(fd, POLLOUT, (usec_t) -1); + fd_wait_for_event(fd, POLLOUT, USEC_INFINITY); continue; } @@ -2958,7 +3070,7 @@ int status_vprintf(const char *status, bool ellipse, bool ephemeral, const char if (emax < 3) emax = 3; - e = ellipsize(s, emax, 75); + e = ellipsize(s, emax, 50); if (e) { free(s); s = e; @@ -3078,12 +3190,13 @@ fail: } char **replace_env_argv(char **argv, char **env) { - char **r, **i; + char **ret, **i; unsigned k = 0, l = 0; l = strv_length(argv); - if (!(r = new(char*, l+1))) + ret = new(char*, l+1); + if (!ret) return NULL; STRV_FOREACH(i, argv) { @@ -3096,10 +3209,12 @@ char **replace_env_argv(char **argv, char **env) { e = strv_env_get(env, *i+1); if (e) { + int r; - if (!(m = strv_split_quoted(e))) { - r[k] = NULL; - strv_free(r); + r = strv_split_quoted(&m, e); + if (r < 0) { + ret[k] = NULL; + strv_free(ret); return NULL; } } else @@ -3108,16 +3223,17 @@ char **replace_env_argv(char **argv, char **env) { q = strv_length(m); l = l + q - 1; - if (!(w = realloc(r, sizeof(char*) * (l+1)))) { - r[k] = NULL; - strv_free(r); + w = realloc(ret, sizeof(char*) * (l+1)); + if (!w) { + ret[k] = NULL; + strv_free(ret); strv_free(m); return NULL; } - r = w; + ret = w; if (m) { - memcpy(r + k, m, q * sizeof(char*)); + memcpy(ret + k, m, q * sizeof(char*)); free(m); } @@ -3126,14 +3242,16 @@ char **replace_env_argv(char **argv, char **env) { } /* If ${FOO} appears as part of a word, replace it by the variable as-is */ - if (!(r[k++] = replace_env(*i, env))) { - strv_free(r); + ret[k] = replace_env(*i, env); + if (!ret[k]) { + strv_free(ret); return NULL; } + k++; } - r[k] = NULL; - return r; + ret[k] = NULL; + return ret; } int fd_columns(int fd) { @@ -3376,7 +3494,7 @@ int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gi return -errno; } - if (stamp != (usec_t) -1) { + if (stamp != USEC_INFINITY) { struct timespec ts[2]; timespec_store(&ts[0], stamp); @@ -3391,7 +3509,7 @@ int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gi } int touch(const char *path) { - return touch_file(path, false, (usec_t) -1, (uid_t) -1, (gid_t) -1, 0); + return touch_file(path, false, USEC_INFINITY, (uid_t) -1, (gid_t) -1, 0); } char *unquote(const char *s, const char* quotes) { @@ -3474,6 +3592,17 @@ int wait_for_terminate(pid_t pid, siginfo_t *status) { } } +/* + * Return values: + * < 0 : wait_for_terminate() failed to get the state of the + * process, the process was terminated by a signal, or + * failed for an unknown reason. + * >=0 : The process terminated normally, and its exit code is + * returned. + * + * That is, success is indicated by a return value of zero, and an + * error is indicated by a non-zero value. + */ int wait_for_terminate_and_warn(const char *name, pid_t pid) { int r; siginfo_t status; @@ -3541,6 +3670,17 @@ int null_or_empty_path(const char *fn) { return null_or_empty(&st); } +int null_or_empty_fd(int fd) { + struct stat st; + + assert(fd >= 0); + + if (fstat(fd, &st) < 0) + return -errno; + + return null_or_empty(&st); +} + DIR *xopendirat(int fd, const char *name, int flags) { int nfd; DIR *d; @@ -3612,9 +3752,6 @@ char *fstab_node_to_udev_node(const char *p) { bool tty_is_vc(const char *tty) { assert(tty); - if (startswith(tty, "/dev/")) - tty += 5; - return vtnr_from_tty(tty) >= 0; } @@ -3790,7 +3927,8 @@ void execute_directory(const char *directory, DIR *d, usec_t timeout, char *argv if (!dirent_is_file(de)) continue; - if (asprintf(&path, "%s/%s", directory, de->d_name) < 0) { + path = strjoin(directory, "/", de->d_name, NULL); + if (!path) { log_oom(); _exit(EXIT_FAILURE); } @@ -3816,7 +3954,6 @@ void execute_directory(const char *directory, DIR *d, usec_t timeout, char *argv _exit(EXIT_FAILURE); } - log_debug("Spawned %s as " PID_FMT ".", path, pid); r = hashmap_put(pids, UINT_TO_PTR(pid), path); @@ -3832,7 +3969,7 @@ void execute_directory(const char *directory, DIR *d, usec_t timeout, char *argv * timout. We simply rely on SIGALRM as default action * terminating the process, and turn on alarm(). */ - if (timeout != (usec_t) -1) + if (timeout != USEC_INFINITY) alarm((timeout + USEC_PER_SEC - 1) / USEC_PER_SEC); while (!hashmap_isempty(pids)) { @@ -3959,6 +4096,21 @@ char* hostname_cleanup(char *s, bool lowercase) { return s; } +bool machine_name_is_valid(const char *s) { + + if (!hostname_is_valid(s)) + return false; + + /* Machine names should be useful hostnames, but also be + * useful in unit names, hence we enforce a stricter length + * limitation. */ + + if (strlen(s) > 64) + return false; + + return true; +} + int pipe_eof(int fd) { struct pollfd pollfd = { .fd = fd, @@ -3987,7 +4139,7 @@ int fd_wait_for_event(int fd, int event, usec_t t) { struct timespec ts; int r; - r = ppoll(&pollfd, 1, t == (usec_t) -1 ? NULL : timespec_store(&ts, t), NULL); + r = ppoll(&pollfd, 1, t == USEC_INFINITY ? NULL : timespec_store(&ts, t), NULL); if (r < 0) return -errno; @@ -4817,7 +4969,7 @@ int signal_from_string(const char *s) { if (signo > 0 && signo < _NSIG) return signo; } - return -1; + return -EINVAL; } bool kexec_loaded(void) { @@ -4991,6 +5143,12 @@ int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *pa /* Don't leak fds to the agent */ close_all_fds(except, n_except); + /* Make sure we actually can kill the agent, if we need to, in + * case somebody invoked us from a shell script that trapped + * SIGTERM or so... */ + reset_all_signal_handlers(); + reset_signal_mask(); + stdout_is_tty = isatty(STDOUT_FILENO); stderr_is_tty = isatty(STDERR_FILENO); @@ -5186,7 +5344,7 @@ int make_console_stdio(void) { /* Make /dev/console the controlling terminal and stdin/stdout/stderr */ - fd = acquire_terminal("/dev/console", false, true, true, (usec_t) -1); + fd = acquire_terminal("/dev/console", false, true, true, USEC_INFINITY); if (fd < 0) { log_error("Failed to acquire terminal: %s", strerror(-fd)); return fd; @@ -5210,8 +5368,8 @@ int get_home_dir(char **_h) { assert(_h); /* Take the user specified one */ - e = getenv("HOME"); - if (e) { + e = secure_getenv("HOME"); + if (e && path_is_absolute(e)) { h = strdup(e); if (!h) return -ENOMEM; @@ -5318,13 +5476,14 @@ bool filename_is_safe(const char *p) { bool string_is_safe(const char *p) { const char *t; - assert(p); + if (!p) + return false; for (t = p; *t; t++) { if (*t > 0 && *t < ' ') return false; - if (strchr("\\\"\'", *t)) + if (strchr("\\\"\'\0x7f", *t)) return false; } @@ -5332,18 +5491,25 @@ bool string_is_safe(const char *p) { } /** - * Check if a string contains control characters. - * Spaces and tabs are not considered control characters. + * Check if a string contains control characters. If 'ok' is non-NULL + * it may be a string containing additional CCs to be considered OK. */ -bool string_has_cc(const char *p) { +bool string_has_cc(const char *p, const char *ok) { const char *t; assert(p); - for (t = p; *t; t++) - if (*t > 0 && *t < ' ' && *t != '\t') + for (t = p; *t; t++) { + if (ok && strchr(ok, *t)) + continue; + + if (*t > 0 && *t < ' ') return true; + if (*t == 127) + return true; + } + return false; } @@ -5944,7 +6110,7 @@ int split_pair(const char *s, const char *sep, char **l, char **r) { int shall_restore_state(void) { _cleanup_free_ char *line = NULL; - char *w, *state; + const char *word, *state; size_t l; int r; @@ -5956,12 +6122,12 @@ int shall_restore_state(void) { r = 1; - FOREACH_WORD_QUOTED(w, l, line, state) { + FOREACH_WORD_QUOTED(word, l, line, state) { const char *e; char n[l+1]; int k; - memcpy(n, w, l); + memcpy(n, word, l); n[l] = 0; e = startswith(n, "systemd.restore_state="); @@ -6005,7 +6171,7 @@ int proc_cmdline(char **ret) { int parse_proc_cmdline(int (*parse_item)(const char *key, const char *value)) { _cleanup_free_ char *line = NULL; - char *w, *state; + const char *w, *state; size_t l; int r; @@ -6716,3 +6882,298 @@ char *tempfn_random(const char *p) { return t; } + +/* make sure the hostname is not "localhost" */ +bool is_localhost(const char *hostname) { + assert(hostname); + + /* This tries to identify local host and domain names + * described in RFC6761 plus the redhatism of .localdomain */ + + return streq(hostname, "localhost") || + streq(hostname, "localhost.") || + streq(hostname, "localdomain.") || + streq(hostname, "localdomain") || + endswith(hostname, ".localhost") || + endswith(hostname, ".localhost.") || + endswith(hostname, ".localdomain") || + endswith(hostname, ".localdomain."); +} + +int take_password_lock(const char *root) { + + struct flock flock = { + .l_type = F_WRLCK, + .l_whence = SEEK_SET, + .l_start = 0, + .l_len = 0, + }; + + const char *path; + int fd, r; + + /* This is roughly the same as lckpwdf(), but not as awful. We + * don't want to use alarm() and signals, hence we implement + * our own trivial version of this. + * + * Note that shadow-utils also takes per-database locks in + * addition to lckpwdf(). However, we don't given that they + * are redundant as they they invoke lckpwdf() first and keep + * it during everything they do. The per-database locks are + * awfully racy, and thus we just won't do them. */ + + if (root) + path = strappenda(root, "/etc/.pwd.lock"); + else + path = "/etc/.pwd.lock"; + + fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600); + if (fd < 0) + return -errno; + + r = fcntl(fd, F_SETLKW, &flock); + if (r < 0) { + safe_close(fd); + return -errno; + } + + return fd; +} + +int is_symlink(const char *path) { + struct stat info; + + if (lstat(path, &info) < 0) + return -errno; + + if (S_ISLNK(info.st_mode)) + return 1; + + return 0; +} + +int unquote_first_word(const char **p, char **ret) { + _cleanup_free_ char *s = NULL; + size_t allocated = 0, sz = 0; + + enum { + START, + VALUE, + VALUE_ESCAPE, + SINGLE_QUOTE, + SINGLE_QUOTE_ESCAPE, + DOUBLE_QUOTE, + DOUBLE_QUOTE_ESCAPE, + SPACE, + } state = START; + + assert(p); + assert(*p); + assert(ret); + + /* Parses the first word of a string, and returns it in + * *ret. Removes all quotes in the process. When parsing fails + * (because of an uneven number of quotes or similar), leaves + * the pointer *p at the first invalid character. */ + + for (;;) { + char c = **p; + + switch (state) { + + case START: + if (c == 0) + goto finish; + else if (strchr(WHITESPACE, c)) + break; + + state = VALUE; + /* fallthrough */ + + case VALUE: + if (c == 0) + goto finish; + else if (c == '\'') + state = SINGLE_QUOTE; + else if (c == '\\') + state = VALUE_ESCAPE; + else if (c == '\"') + state = DOUBLE_QUOTE; + else if (strchr(WHITESPACE, c)) + state = SPACE; + else { + if (!GREEDY_REALLOC(s, allocated, sz+2)) + return -ENOMEM; + + s[sz++] = c; + } + + break; + + case VALUE_ESCAPE: + if (c == 0) + return -EINVAL; + + if (!GREEDY_REALLOC(s, allocated, sz+2)) + return -ENOMEM; + + s[sz++] = c; + state = VALUE; + + break; + + case SINGLE_QUOTE: + if (c == 0) + return -EINVAL; + else if (c == '\'') + state = VALUE; + else if (c == '\\') + state = SINGLE_QUOTE_ESCAPE; + else { + if (!GREEDY_REALLOC(s, allocated, sz+2)) + return -ENOMEM; + + s[sz++] = c; + } + + break; + + case SINGLE_QUOTE_ESCAPE: + if (c == 0) + return -EINVAL; + + if (!GREEDY_REALLOC(s, allocated, sz+2)) + return -ENOMEM; + + s[sz++] = c; + state = SINGLE_QUOTE; + break; + + case DOUBLE_QUOTE: + if (c == 0) + return -EINVAL; + else if (c == '\"') + state = VALUE; + else if (c == '\\') + state = DOUBLE_QUOTE_ESCAPE; + else { + if (!GREEDY_REALLOC(s, allocated, sz+2)) + return -ENOMEM; + + s[sz++] = c; + } + + break; + + case DOUBLE_QUOTE_ESCAPE: + if (c == 0) + return -EINVAL; + + if (!GREEDY_REALLOC(s, allocated, sz+2)) + return -ENOMEM; + + s[sz++] = c; + state = DOUBLE_QUOTE; + break; + + case SPACE: + if (c == 0) + goto finish; + if (!strchr(WHITESPACE, c)) + goto finish; + + break; + } + + (*p) ++; + } + +finish: + if (!s) { + *ret = NULL; + return 0; + } + + s[sz] = 0; + *ret = s; + s = NULL; + + return 1; +} + +int unquote_many_words(const char **p, ...) { + va_list ap; + char **l; + int n = 0, i, c, r; + + /* Parses a number of words from a string, stripping any + * quotes if necessary. */ + + assert(p); + + /* Count how many words are expected */ + va_start(ap, p); + for (;;) { + if (!va_arg(ap, char **)) + break; + n++; + } + va_end(ap); + + if (n <= 0) + return 0; + + /* Read all words into a temporary array */ + l = newa0(char*, n); + for (c = 0; c < n; c++) { + + r = unquote_first_word(p, &l[c]); + if (r < 0) { + int j; + + for (j = 0; j < c; j++) + free(l[j]); + + return r; + } + + if (r == 0) + break; + } + + /* If we managed to parse all words, return them in the passed + * in parameters */ + va_start(ap, p); + for (i = 0; i < n; i++) { + char **v; + + v = va_arg(ap, char **); + assert(v); + + *v = l[i]; + } + va_end(ap); + + return c; +} + +int free_and_strdup(char **p, const char *s) { + char *t; + + assert(p); + + /* Replaces a string pointer with an strdup()ed new string, + * possibly freeing the old one. */ + + if (s) { + t = strdup(s); + if (!t) + return -ENOMEM; + } else + t = NULL; + + free(*p); + *p = t; + + return 0; +}