chiark / gitweb /
Extract looping over /proc/cmdline into a shared function
[elogind.git] / src / shared / util.c
index 6b6722c2780200a62f128e24674ac27f68c7ba1a..d95a4b4ab117ce6d8062b43ec85560dcd7abe8cc 100644 (file)
@@ -359,8 +359,23 @@ int safe_atod(const char *s, double *ret_d) {
         return 0;
 }
 
+static size_t strcspn_escaped(const char *s, const char *reject) {
+        bool escaped = false;
+        size_t n;
+
+        for (n=0; s[n]; n++) {
+                if (escaped)
+                        escaped = false;
+                else if (s[n] == '\\')
+                        escaped = true;
+                else if (strchr(reject, s[n]))
+                        return n;
+        }
+        return n;
+}
+
 /* Split a string into words. */
-char *split(const char *c, size_t *l, const char *separator, char **state) {
+char *split(const char *c, size_t *l, const char *separator, bool quoted, char **state) {
         char *current;
 
         current = *state ? *state : (char*) c;
@@ -369,70 +384,19 @@ char *split(const char *c, size_t *l, const char *separator, char **state) {
                 return NULL;
 
         current += strspn(current, separator);
-        *l = strcspn(current, separator);
-        *state = current+*l;
-
-        return (char*) current;
-}
-
-/* Split a string into words, but consider strings enclosed in '' and
- * "" as words even if they include spaces. */
-char *split_quoted(const char *c, size_t *l, char **state) {
-        const char *current, *e;
-        bool escaped = false;
-
-        assert(c);
-        assert(l);
-        assert(state);
-
-        current = *state ? *state : c;
-
-        current += strspn(current, WHITESPACE);
-
-        if (*current == 0)
+        if (!*current)
                 return NULL;
 
-        else if (*current == '\'') {
-                current ++;
-
-                for (e = current; *e; e++) {
-                        if (escaped)
-                                escaped = false;
-                        else if (*e == '\\')
-                                escaped = true;
-                        else if (*e == '\'')
-                                break;
-                }
-
-                *l = e-current;
-                *state = (char*) (*e == 0 ? e : e+1);
-
-        } else if (*current == '\"') {
-                current ++;
-
-                for (e = current; *e; e++) {
-                        if (escaped)
-                                escaped = false;
-                        else if (*e == '\\')
-                                escaped = true;
-                        else if (*e == '\"')
-                                break;
-                }
-
-                *l = e-current;
-                *state = (char*) (*e == 0 ? e : e+1);
-
+        if (quoted && strchr("\'\"", *current)) {
+                char quotechar = *(current++);
+                *l = strcspn_escaped(current, (char[]){quotechar, '\0'});
+                *state = current+*l+1;
+        } else if (quoted) {
+                *l = strcspn_escaped(current, separator);
+                *state = current+*l;
         } else {
-                for (e = current; *e; e++) {
-                        if (escaped)
-                                escaped = false;
-                        else if (*e == '\\')
-                                escaped = true;
-                        else if (strchr(WHITESPACE, *e))
-                                break;
-                }
-                *l = e-current;
-                *state = (char*) e;
+                *l = strcspn(current, separator);
+                *state = current+*l;
         }
 
         return (char*) current;
@@ -440,8 +404,7 @@ char *split_quoted(const char *c, size_t *l, char **state) {
 
 int get_parent_of_pid(pid_t pid, pid_t *_ppid) {
         int r;
-        _cleanup_fclose_ FILE *f = NULL;
-        char line[LINE_MAX];
+        _cleanup_free_ char *line = NULL;
         long unsigned ppid;
         const char *p;
 
@@ -454,14 +417,9 @@ int get_parent_of_pid(pid_t pid, pid_t *_ppid) {
         }
 
         p = procfs_file_alloca(pid, "stat");
-        f = fopen(p, "re");
-        if (!f)
-                return -errno;
-
-        if (!fgets(line, sizeof(line), f)) {
-                r = feof(f) ? -EIO : -errno;
+        r = read_one_line_file(p, &line);
+        if (r < 0)
                 return r;
-        }
 
         /* Let's skip the pid and comm fields. The latter is enclosed
          * in () but does not escape any () in its value, so let's
@@ -488,28 +446,17 @@ int get_parent_of_pid(pid_t pid, pid_t *_ppid) {
 }
 
 int get_starttime_of_pid(pid_t pid, unsigned long long *st) {
-        _cleanup_fclose_ FILE *f = NULL;
-        char line[LINE_MAX];
+        int r;
+        _cleanup_free_ char *line = NULL;
         const char *p;
 
         assert(pid >= 0);
         assert(st);
 
-        if (pid == 0)
-                p = "/proc/self/stat";
-        else
-                p = procfs_file_alloca(pid, "stat");
-
-        f = fopen(p, "re");
-        if (!f)
-                return errno == ENOENT ? -ESRCH : -errno;
-
-        if (!fgets(line, sizeof(line), f)) {
-                if (ferror(f))
-                        return -errno;
-
-                return -EIO;
-        }
+        p = procfs_file_alloca(pid, "stat");
+        r = read_one_line_file(p, &line);
+        if (r < 0)
+                return r;
 
         /* Let's skip the pid and comm fields. The latter is enclosed
          * in () but does not escape any () in its value, so let's
@@ -566,6 +513,31 @@ char *truncate_nl(char *s) {
         return s;
 }
 
+int get_process_state(pid_t pid) {
+        const char *p;
+        char state;
+        int r;
+        _cleanup_free_ char *line = NULL;
+
+        assert(pid >= 0);
+
+        p = procfs_file_alloca(pid, "stat");
+        r = read_one_line_file(p, &line);
+        if (r < 0)
+                return r;
+
+        p = strrchr(line, ')');
+        if (!p)
+                return -EIO;
+
+        p++;
+
+        if (sscanf(p, " %c", &state) != 1)
+                return -EIO;
+
+        return (unsigned char) state;
+}
+
 int get_process_comm(pid_t pid, char **name) {
         const char *p;
         int r;
@@ -573,10 +545,7 @@ int get_process_comm(pid_t pid, char **name) {
         assert(name);
         assert(pid >= 0);
 
-        if (pid == 0)
-                p = "/proc/self/comm";
-        else
-                p = procfs_file_alloca(pid, "comm");
+        p = procfs_file_alloca(pid, "comm");
 
         r = read_one_line_file(p, name);
         if (r == -ENOENT)
@@ -594,10 +563,7 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char *
         assert(line);
         assert(pid >= 0);
 
-        if (pid == 0)
-                p = "/proc/self/cmdline";
-        else
-                p = procfs_file_alloca(pid, "cmdline");
+        p = procfs_file_alloca(pid, "cmdline");
 
         f = fopen(p, "re");
         if (!f)
@@ -716,10 +682,7 @@ int get_process_capeff(pid_t pid, char **capeff) {
         assert(capeff);
         assert(pid >= 0);
 
-        if (pid == 0)
-                p = "/proc/self/status";
-        else
-                p = procfs_file_alloca(pid, "status");
+        p = procfs_file_alloca(pid, "status");
 
         return get_status_field(p, "\nCapEff:", capeff);
 }
@@ -732,10 +695,7 @@ int get_process_exe(pid_t pid, char **name) {
         assert(pid >= 0);
         assert(name);
 
-        if (pid == 0)
-                p = "/proc/self/exe";
-        else
-                p = procfs_file_alloca(pid, "exe");
+        p = procfs_file_alloca(pid, "exe");
 
         r = readlink_malloc(p, name);
         if (r < 0)
@@ -826,28 +786,31 @@ char *strappend(const char *s, const char *suffix) {
         return strnappend(s, suffix, suffix ? strlen(suffix) : 0);
 }
 
-int readlink_malloc(const char *p, char **r) {
+int readlink_malloc(const char *p, char **ret) {
         size_t l = 100;
+        int r;
 
         assert(p);
-        assert(r);
+        assert(ret);
 
         for (;;) {
                 char *c;
                 ssize_t n;
 
-                if (!(c = new(char, l)))
+                c = new(char, l);
+                if (!c)
                         return -ENOMEM;
 
-                if ((n = readlink(p, c, l-1)) < 0) {
-                        int ret = -errno;
+                n = readlink(p, c, l-1);
+                if (n < 0) {
+                        r = -errno;
                         free(c);
-                        return ret;
+                        return r;
                 }
 
                 if ((size_t) n < l-1) {
                         c[n] = 0;
-                        *r = c;
+                        *ret = c;
                         return 0;
                 }
 
@@ -2102,45 +2065,31 @@ int close_pipe(int p[]) {
 }
 
 ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
-        uint8_t *p;
+        uint8_t *p = buf;
         ssize_t n = 0;
 
         assert(fd >= 0);
         assert(buf);
 
-        p = buf;
-
         while (nbytes > 0) {
                 ssize_t k;
 
-                if ((k = read(fd, p, nbytes)) <= 0) {
-
-                        if (k < 0 && errno == EINTR)
-                                continue;
-
-                        if (k < 0 && errno == EAGAIN && do_poll) {
-                                struct pollfd pollfd = {
-                                        .fd = fd,
-                                        .events = POLLIN,
-                                };
-
-                                if (poll(&pollfd, 1, -1) < 0) {
-                                        if (errno == EINTR)
-                                                continue;
+                k = read(fd, p, nbytes);
+                if (k < 0 && errno == EINTR)
+                        continue;
 
-                                        return n > 0 ? n : -errno;
-                                }
+                if (k < 0 && errno == EAGAIN && do_poll) {
 
-                                /* We knowingly ignore the revents value here,
-                                 * and expect that any error/EOF is reported
-                                 * via read()/write()
-                                 */
+                        /* We knowingly ignore any return value here,
+                         * and expect that any error/EOF is reported
+                         * via read() */
 
-                                continue;
-                        }
+                        fd_wait_for_event(fd, POLLIN, (usec_t) -1);
+                        continue;
+                }
 
+                if (k <= 0)
                         return n > 0 ? n : (k < 0 ? -errno : 0);
-                }
 
                 p += k;
                 nbytes -= k;
@@ -2151,46 +2100,31 @@ ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
 }
 
 ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
-        const uint8_t *p;
+        const uint8_t *p = buf;
         ssize_t n = 0;
 
         assert(fd >= 0);
         assert(buf);
 
-        p = buf;
-
         while (nbytes > 0) {
                 ssize_t k;
 
                 k = write(fd, p, nbytes);
-                if (k <= 0) {
-
-                        if (k < 0 && errno == EINTR)
-                                continue;
-
-                        if (k < 0 && errno == EAGAIN && do_poll) {
-                                struct pollfd pollfd = {
-                                        .fd = fd,
-                                        .events = POLLOUT,
-                                };
-
-                                if (poll(&pollfd, 1, -1) < 0) {
-                                        if (errno == EINTR)
-                                                continue;
+                if (k < 0 && errno == EINTR)
+                        continue;
 
-                                        return n > 0 ? n : -errno;
-                                }
+                if (k < 0 && errno == EAGAIN && do_poll) {
 
-                                /* We knowingly ignore the revents value here,
-                                 * and expect that any error/EOF is reported
-                                 * via read()/write()
-                                 */
+                        /* We knowingly ignore any return value here,
+                         * and expect that any error/EOF is reported
+                         * via write() */
 
-                                continue;
-                        }
+                        fd_wait_for_event(fd, POLLOUT, (usec_t) -1);
+                        continue;
+                }
 
+                if (k <= 0)
                         return n > 0 ? n : (k < 0 ? -errno : 0);
-                }
 
                 p += k;
                 nbytes -= k;
@@ -2349,25 +2283,37 @@ char* dirname_malloc(const char *path) {
         return dir;
 }
 
-void random_bytes(void *p, size_t n) {
-        static bool srand_called = false;
+int dev_urandom(void *p, size_t n) {
         _cleanup_close_ int fd;
         ssize_t k;
-        uint8_t *q;
 
         fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
         if (fd < 0)
-                goto fallback;
+                return errno == ENOENT ? -ENOSYS : -errno;
 
         k = loop_read(fd, p, n, true);
-        if (k < 0 || (size_t) k != n)
-                goto fallback;
+        if (k < 0)
+                return (int) k;
+        if ((size_t) k != n)
+                return -EIO;
 
-        return;
+        return 0;
+}
 
-fallback:
+void random_bytes(void *p, size_t n) {
+        static bool srand_called = false;
+        uint8_t *q;
+        int r;
+
+        r = dev_urandom(p, n);
+        if (r >= 0)
+                return;
+
+        /* If some idiot made /dev/urandom unavailable to us, he'll
+         * get a PRNG instead. */
 
         if (!srand_called) {
+                unsigned x = 0;
 
 #ifdef HAVE_SYS_AUXV_H
                 /* The kernel provides us with a bit of entropy in
@@ -2379,16 +2325,16 @@ fallback:
 
                 auxv = (void*) getauxval(AT_RANDOM);
                 if (auxv)
-                        srand(*(unsigned*) auxv);
-                else
+                        x ^= *(unsigned*) auxv;
 #endif
-                        srand(time(NULL) + gettid());
 
+                x ^= (unsigned) now(CLOCK_REALTIME);
+                x ^= (unsigned) gettid();
+
+                srand(x);
                 srand_called = true;
         }
 
-        /* If some idiot made /dev/urandom unavailable to us, he'll
-         * get a PRNG instead. */
         for (q = p; q < (uint8_t*) p + n; q ++)
                 *q = rand();
 }
@@ -2419,7 +2365,7 @@ void rename_process(const char name[8]) {
                         if (!saved_argv[i])
                                 break;
 
-                        memset(saved_argv[i], 0, strlen(saved_argv[i]));
+                        memzero(saved_argv[i], strlen(saved_argv[i]));
                 }
         }
 }
@@ -2542,24 +2488,17 @@ int getttyname_harder(int fd, char **r) {
 }
 
 int get_ctty_devnr(pid_t pid, dev_t *d) {
-        _cleanup_fclose_ FILE *f = NULL;
-        char line[LINE_MAX], *p;
+        int r;
+        _cleanup_free_ char *line = NULL;
+        const char *p;
         unsigned long ttynr;
-        const char *fn;
 
         assert(pid >= 0);
 
-        if (pid == 0)
-                fn = "/proc/self/stat";
-        else
-                fn = procfs_file_alloca(pid, "stat");
-
-        f = fopen(fn, "re");
-        if (!f)
-                return -errno;
-
-        if (!fgets(line, sizeof(line), f))
-                return feof(f) ? -EIO : -errno;
+        p = procfs_file_alloca(pid, "stat");
+        r = read_one_line_file(p, &line);
+        if (r < 0)
+                return r;
 
         p = strrchr(line, ')');
         if (!p)
@@ -3924,12 +3863,13 @@ char* hostname_cleanup(char *s, bool lowercase) {
 }
 
 int pipe_eof(int fd) {
-        int r;
         struct pollfd pollfd = {
                 .fd = fd,
                 .events = POLLIN|POLLHUP,
         };
 
+        int r;
+
         r = poll(&pollfd, 1, 0);
         if (r < 0)
                 return -errno;
@@ -3941,13 +3881,16 @@ int pipe_eof(int fd) {
 }
 
 int fd_wait_for_event(int fd, int event, usec_t t) {
-        int r;
+
         struct pollfd pollfd = {
                 .fd = fd,
                 .events = event,
         };
 
-        r = poll(&pollfd, 1, t == (usec_t) -1 ? -1 : (int) (t / USEC_PER_MSEC));
+        struct timespec ts;
+        int r;
+
+        r = ppoll(&pollfd, 1, t == (usec_t) -1 ? NULL : timespec_store(&ts, t), NULL);
         if (r < 0)
                 return -errno;
 
@@ -3978,7 +3921,7 @@ int fopen_temporary(const char *path, FILE **_f, char **_temp_path) {
         t[k] = '.';
         stpcpy(stpcpy(t+k+1, fn), "XXXXXX");
 
-        fd = mkostemp(t, O_WRONLY|O_CLOEXEC);
+        fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC);
         if (fd < 0) {
                 free(t);
                 return -errno;
@@ -5095,10 +5038,7 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value) {
         assert(field);
         assert(_value);
 
-        if (pid == 0)
-                path = "/proc/self/environ";
-        else
-                path = procfs_file_alloca(pid, "environ");
+        path = procfs_file_alloca(pid, "environ");
 
         f = fopen(path, "re");
         if (!f)
@@ -5698,7 +5638,7 @@ static int search_and_fopen_internal(const char *path, const char *mode, char **
         assert(mode);
         assert(_f);
 
-        if (!path_strv_canonicalize_uniq(search))
+        if (!path_strv_canonicalize_absolute_uniq(search, NULL))
                 return -ENOMEM;
 
         STRV_FOREACH(i, search) {
@@ -5880,7 +5820,7 @@ void* greedy_realloc0(void **p, size_t *allocated, size_t need) {
                 return NULL;
 
         if (*allocated > prev)
-                memset(&q[prev], 0, *allocated - prev);
+                memzero(&q[prev], *allocated - prev);
 
         return q;
 }
@@ -5926,20 +5866,6 @@ bool id128_is_valid(const char *s) {
         return true;
 }
 
-void parse_user_at_host(char *arg, char **user, char **host) {
-        assert(arg);
-        assert(user);
-        assert(host);
-
-        *host = strchr(arg, '@');
-        if (*host == NULL)
-                *host = arg;
-        else {
-                *host[0]++ = '\0';
-                *user = arg;
-        }
-}
-
 int split_pair(const char *s, const char *sep, char **l, char **r) {
         char *x, *a, *b;
 
@@ -6017,6 +5943,35 @@ int proc_cmdline(char **ret) {
         return 1;
 }
 
+int parse_proc_cmdline(int (*parse_word)(const char *word)) {
+        _cleanup_free_ char *line = NULL;
+        char *w, *state;
+        size_t l;
+        int r;
+
+        r = proc_cmdline(&line);
+        if (r < 0)
+                log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
+        if (r <= 0)
+                return 0;
+
+        FOREACH_WORD_QUOTED(w, l, line, state) {
+                _cleanup_free_ char *word;
+
+                word = strndup(w, l);
+                if (!word)
+                        return log_oom();
+
+                r = parse_word(word);
+                if (r < 0) {
+                        log_error("Failed on cmdline argument %s: %s", word, strerror(-r));
+                        return r;
+                }
+        }
+
+        return 0;
+}
+
 int container_get_leader(const char *machine, pid_t *pid) {
         _cleanup_free_ char *s = NULL, *class = NULL;
         const char *p;
@@ -6172,6 +6127,69 @@ int getpeersec(int fd, char **ret) {
                 }
         }
 
+        if (isempty(s)) {
+                free(s);
+                return -ENOTSUP;
+        }
+
         *ret = s;
         return 0;
 }
+
+/* This is much like like mkostemp() but is subject to umask(). */
+int mkostemp_safe(char *pattern, int flags) {
+        _cleanup_umask_ mode_t u;
+        int fd;
+
+        assert(pattern);
+
+        u = umask(077);
+
+        fd = mkostemp(pattern, flags);
+        if (fd < 0)
+                return -errno;
+
+        return fd;
+}
+
+int open_tmpfile(const char *path, int flags) {
+        char *p;
+        int fd;
+
+        assert(path);
+
+#ifdef O_TMPFILE
+        /* Try O_TMPFILE first, if it is supported */
+        fd = open(path, flags|O_TMPFILE, S_IRUSR|S_IWUSR);
+        if (fd >= 0)
+                return fd;
+#endif
+
+        /* Fall back to unguessable name + unlinking */
+        p = strappenda(path, "/systemd-tmp-XXXXXX");
+
+        fd = mkostemp_safe(p, flags);
+        if (fd < 0)
+                return fd;
+
+        unlink(p);
+        return fd;
+}
+
+int fd_warn_permissions(const char *path, int fd) {
+        struct stat st;
+
+        if (fstat(fd, &st) < 0)
+                return -errno;
+
+        if (st.st_mode & 0111)
+                log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path);
+
+        if (st.st_mode & 0002)
+                log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path);
+
+        if (getpid() == 1 && (st.st_mode & 0044) != 0044)
+                log_warning("Configuration file %s is marked world-inaccessible. This has no effect as configuration data is accessible via APIs without restrictions. Proceeding anyway.", path);
+
+        return 0;
+}