chiark / gitweb /
util: reset signals when we fork off agents
[elogind.git] / src / shared / util.c
index 0cc51e0962607fbdc36bf32e851836415c68401e..98c07163da28e8e871ef976392300c67f8d94bbe 100644 (file)
@@ -54,6 +54,7 @@
 #include <grp.h>
 #include <sys/mman.h>
 #include <sys/vfs.h>
+#include <sys/mount.h>
 #include <linux/magic.h>
 #include <limits.h>
 #include <langinfo.h>
@@ -73,6 +74,7 @@
 #include "log.h"
 #include "strv.h"
 #include "label.h"
+#include "mkdir.h"
 #include "path-util.h"
 #include "exit-status.h"
 #include "hashmap.h"
@@ -138,48 +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;
 
-        return s[wl] == 0 ||
-                strchr(WHITESPACE, s[wl]);
+        if (!strchr(WHITESPACE, *p))
+                return NULL;
+
+        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) {
@@ -229,9 +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;
@@ -278,6 +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;
 }
@@ -322,6 +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;
@@ -385,37 +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) {
@@ -802,7 +856,7 @@ char *strappend(const char *s, const char *suffix) {
         return strnappend(s, suffix, suffix ? strlen(suffix) : 0);
 }
 
-int readlink_malloc(const char *p, char **ret) {
+int readlinkat_malloc(int fd, const char *p, char **ret) {
         size_t l = 100;
         int r;
 
@@ -817,7 +871,7 @@ int readlink_malloc(const char *p, char **ret) {
                 if (!c)
                         return -ENOMEM;
 
-                n = readlink(p, c, l-1);
+                n = readlinkat(fd, p, c, l-1);
                 if (n < 0) {
                         r = -errno;
                         free(c);
@@ -835,6 +889,10 @@ int readlink_malloc(const char *p, char **ret) {
         }
 }
 
+int readlink_malloc(const char *p, char **ret) {
+        return readlinkat_malloc(AT_FDCWD, p, ret);
+}
+
 int readlink_and_make_absolute(const char *p, char **r) {
         _cleanup_free_ char *target = NULL;
         char *k;
@@ -879,7 +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 = {
@@ -887,16 +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;
 }
 
@@ -1024,7 +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) {
@@ -1079,7 +1150,7 @@ int unoctchar(char c) {
         if (c >= '0' && c <= '7')
                 return c - '0';
 
-        return -1;
+        return -EINVAL;
 }
 
 char decchar(int x) {
@@ -1091,7 +1162,7 @@ int undecchar(char c) {
         if (c >= '0' && c <= '9')
                 return c - '0';
 
-        return -1;
+        return -EINVAL;
 }
 
 char *cescape(const char *s) {
@@ -1183,7 +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);
@@ -1242,7 +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';
@@ -1269,7 +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];
@@ -1363,6 +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");
 }
 
@@ -1370,44 +1442,52 @@ bool ignore_file(const char *filename) {
         assert(filename);
 
         if (endswith(filename, "~"))
-                return false;
+                return true;
 
         return ignore_file_allow_backup(filename);
 }
 
 int fd_nonblock(int fd, bool nonblock) {
-        int flags;
+        int flags, nflags;
 
         assert(fd >= 0);
 
-        if ((flags = fcntl(fd, F_GETFL, 0)) < 0)
+        flags = fcntl(fd, F_GETFL, 0);
+        if (flags < 0)
                 return -errno;
 
         if (nonblock)
-                flags |= O_NONBLOCK;
+                nflags = flags | O_NONBLOCK;
         else
-                flags &= ~O_NONBLOCK;
+                nflags = flags & ~O_NONBLOCK;
+
+        if (nflags == flags)
+                return 0;
 
-        if (fcntl(fd, F_SETFL, flags) < 0)
+        if (fcntl(fd, F_SETFL, nflags) < 0)
                 return -errno;
 
         return 0;
 }
 
 int fd_cloexec(int fd, bool cloexec) {
-        int flags;
+        int flags, nflags;
 
         assert(fd >= 0);
 
-        if ((flags = fcntl(fd, F_GETFD, 0)) < 0)
+        flags = fcntl(fd, F_GETFD, 0);
+        if (flags < 0)
                 return -errno;
 
         if (cloexec)
-                flags |= FD_CLOEXEC;
+                nflags = flags | FD_CLOEXEC;
         else
-                flags &= ~FD_CLOEXEC;
+                nflags = flags & ~FD_CLOEXEC;
+
+        if (nflags == flags)
+                return 0;
 
-        if (fcntl(fd, F_SETFD, flags) < 0)
+        if (fcntl(fd, F_SETFD, nflags) < 0)
                 return -errno;
 
         return 0;
@@ -1426,7 +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;
 
@@ -1481,7 +1561,6 @@ int close_all_fds(const int except[], unsigned n_except) {
                 }
         }
 
-        closedir(d);
         return r;
 }
 
@@ -1500,6 +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"
@@ -1544,8 +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);
@@ -1560,7 +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;
@@ -1582,12 +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);
 
@@ -1601,7 +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);
@@ -1610,7 +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())
@@ -1625,7 +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) {
@@ -1649,6 +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;
@@ -1832,11 +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;
@@ -1900,7 +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);
@@ -1972,12 +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)
@@ -2082,7 +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;
                 }
 
@@ -2117,7 +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;
                 }
 
@@ -2657,7 +2783,7 @@ finish:
 }
 
 int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) {
-        DIR *d;
+        _cleanup_closedir_ DIR *d = NULL;
         int ret = 0;
 
         assert(fd >= 0);
@@ -2680,15 +2806,12 @@ int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct
 
                 errno = 0;
                 de = readdir(d);
-                if (!de && errno != 0) {
-                        if (ret == 0)
+                if (!de) {
+                        if (errno != 0 && ret == 0)
                                 ret = -errno;
-                        break;
+                        return ret;
                 }
 
-                if (!de)
-                        break;
-
                 if (streq(de->d_name, ".") || streq(de->d_name, ".."))
                         continue;
 
@@ -2744,10 +2867,6 @@ int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct
                         }
                 }
         }
-
-        closedir(d);
-
-        return ret;
 }
 
 _pure_ static int is_temporary_fs(struct statfs *s) {
@@ -2951,7 +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;
@@ -3071,12 +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) {
@@ -3089,10 +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
@@ -3101,16 +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);
                         }
 
@@ -3119,14 +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) {
@@ -3344,22 +3469,49 @@ char *ellipsize(const char *s, size_t length, unsigned percent) {
         return ellipsize_mem(s, strlen(s), length, percent);
 }
 
-int touch(const char *path) {
+int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) {
         _cleanup_close_ int fd;
+        int r;
 
         assert(path);
 
-        /* This just opens the file for writing, ensuring it
-         * exists. It doesn't call utimensat() the way /usr/bin/touch
-         * does it. */
+        if (parents)
+                mkdir_parents(path, 0755);
 
-        fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0644);
+        fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode > 0 ? mode : 0644);
         if (fd < 0)
                 return -errno;
 
+        if (mode > 0) {
+                r = fchmod(fd, mode);
+                if (r < 0)
+                        return -errno;
+        }
+
+        if (uid != (uid_t) -1 || gid != (gid_t) -1) {
+                r = fchown(fd, uid, gid);
+                if (r < 0)
+                        return -errno;
+        }
+
+        if (stamp != USEC_INFINITY) {
+                struct timespec ts[2];
+
+                timespec_store(&ts[0], stamp);
+                ts[1] = ts[0];
+                r = futimens(fd, ts);
+        } else
+                r = futimens(fd, NULL);
+        if (r < 0)
+                return -errno;
+
         return 0;
 }
 
+int touch(const char *path) {
+        return touch_file(path, false, USEC_INFINITY, (uid_t) -1, (gid_t) -1, 0);
+}
+
 char *unquote(const char *s, const char* quotes) {
         size_t l;
         assert(s);
@@ -3440,6 +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;
@@ -3507,6 +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;
@@ -3578,9 +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;
 }
 
@@ -3756,7 +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);
                         }
@@ -3782,7 +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);
@@ -3798,7 +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)) {
@@ -3925,6 +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,
@@ -3953,7 +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;
 
@@ -3966,24 +4152,16 @@ int fd_wait_for_event(int fd, int event, usec_t t) {
 int fopen_temporary(const char *path, FILE **_f, char **_temp_path) {
         FILE *f;
         char *t;
-        const char *fn;
-        size_t k;
         int fd;
 
         assert(path);
         assert(_f);
         assert(_temp_path);
 
-        t = new(char, strlen(path) + 1 + 6 + 1);
+        t = tempfn_xxxxxx(path);
         if (!t)
                 return -ENOMEM;
 
-        fn = basename(path);
-        k = fn - path;
-        memcpy(t, path, k);
-        t[k] = '.';
-        stpcpy(stpcpy(t+k+1, fn), "XXXXXX");
-
         fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC);
         if (fd < 0) {
                 free(t);
@@ -4091,97 +4269,62 @@ int vt_disallocate(const char *name) {
         return 0;
 }
 
-int copy_file(const char *from, const char *to, int flags) {
-        _cleanup_close_ int fdf = -1;
-        int r, fdt;
+int symlink_atomic(const char *from, const char *to) {
+        _cleanup_free_ char *t = NULL;
 
         assert(from);
         assert(to);
 
-        fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
-        if (fdf < 0)
-                return -errno;
+        t = tempfn_random(to);
+        if (!t)
+                return -ENOMEM;
 
-        fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0644);
-        if (fdt < 0)
+        if (symlink(from, t) < 0)
                 return -errno;
 
-        for (;;) {
-                char buf[PIPE_BUF];
-                ssize_t n, k;
-
-                n = read(fdf, buf, sizeof(buf));
-                if (n < 0) {
-                        r = -errno;
-
-                        close_nointr(fdt);
-                        unlink(to);
-
-                        return r;
-                }
+        if (rename(t, to) < 0) {
+                unlink_noerrno(t);
+                return -errno;
+        }
 
-                if (n == 0)
-                        break;
+        return 0;
+}
 
-                errno = 0;
-                k = loop_write(fdt, buf, n, false);
-                if (n != k) {
-                        r = k < 0 ? k : (errno ? -errno : -EIO);
+int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
+        _cleanup_free_ char *t = NULL;
 
-                        close_nointr(fdt);
-                        unlink(to);
+        assert(path);
 
-                        return r;
-                }
-        }
+        t = tempfn_random(path);
+        if (!t)
+                return -ENOMEM;
 
-        r = close_nointr(fdt);
+        if (mknod(t, mode, dev) < 0)
+                return -errno;
 
-        if (r < 0) {
-                unlink(to);
-                return r;
+        if (rename(t, path) < 0) {
+                unlink_noerrno(t);
+                return -errno;
         }
 
         return 0;
 }
 
-int symlink_atomic(const char *from, const char *to) {
-        char *x;
-        _cleanup_free_ char *t;
-        const char *fn;
-        size_t k;
-        uint64_t u;
-        unsigned i;
-        int r;
+int mkfifo_atomic(const char *path, mode_t mode) {
+        _cleanup_free_ char *t = NULL;
 
-        assert(from);
-        assert(to);
+        assert(path);
 
-        t = new(char, strlen(to) + 1 + 16 + 1);
+        t = tempfn_random(path);
         if (!t)
                 return -ENOMEM;
 
-        fn = basename(to);
-        k = fn-to;
-        memcpy(t, to, k);
-        t[k] = '.';
-        x = stpcpy(t+k+1, fn);
-
-        u = random_u64();
-        for (i = 0; i < 16; i++) {
-                *(x++) = hexchar(u & 0xF);
-                u >>= 4;
-        }
-
-        *x = 0;
-
-        if (symlink(from, t) < 0)
+        if (mkfifo(t, mode) < 0)
                 return -errno;
 
-        if (rename(t, to) < 0) {
-                r = -errno;
-                unlink(t);
-                return r;
+        if (rename(t, path) < 0) {
+                unlink_noerrno(t);
+                return -errno;
         }
 
         return 0;
@@ -4465,22 +4608,6 @@ int dirent_ensure_type(DIR *d, struct dirent *de) {
         return 0;
 }
 
-int in_search_path(const char *path, char **search) {
-        char **i;
-        _cleanup_free_ char *parent = NULL;
-        int r;
-
-        r = path_get_parent(path, &parent);
-        if (r < 0)
-                return r;
-
-        STRV_FOREACH(i, search)
-                if (path_equal(parent, *i))
-                        return 1;
-
-        return 0;
-}
-
 int get_files_in_directory(const char *path, char ***list) {
         _cleanup_closedir_ DIR *d = NULL;
         size_t bufsize = 0, n = 0;
@@ -4842,7 +4969,7 @@ int signal_from_string(const char *s) {
                 if (signo > 0 && signo < _NSIG)
                         return signo;
         }
-        return -1;
+        return -EINVAL;
 }
 
 bool kexec_loaded(void) {
@@ -5016,6 +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);
 
@@ -5211,7 +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;
@@ -5235,8 +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;
@@ -5343,13 +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;
         }
 
@@ -5357,18 +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')
-                        return true;
-
+        for (t = p; *t; t++) {
+                if (ok && strchr(ok, *t))
+                        continue;
+
+                if (*t > 0 && *t < ' ')
+                        return true;
+
+                if (*t == 127)
+                        return true;
+        }
+
         return false;
 }
 
@@ -5470,6 +5611,7 @@ const char *draw_special_char(DrawSpecialChar ch) {
                         [DRAW_TRIANGULAR_BULLET]  = "\342\200\243",             /* ‣ */
                         [DRAW_BLACK_CIRCLE]       = "\342\227\217",             /* ● */
                         [DRAW_ARROW]              = "\342\206\222",             /* → */
+                        [DRAW_DASH]               = "\342\200\223",             /* – */
                 },
 
                 /* ASCII fallback */ {
@@ -5480,6 +5622,7 @@ const char *draw_special_char(DrawSpecialChar ch) {
                         [DRAW_TRIANGULAR_BULLET]  = ">",
                         [DRAW_BLACK_CIRCLE]       = "*",
                         [DRAW_ARROW]              = "->",
+                        [DRAW_DASH]               = "-",
                 }
         };
 
@@ -5702,14 +5845,17 @@ static int search_and_fopen_internal(const char *path, const char *mode, const c
         assert(mode);
         assert(_f);
 
-        if (!path_strv_canonicalize_absolute_uniq(search, root))
+        if (!path_strv_resolve_uniq(search, root))
                 return -ENOMEM;
 
         STRV_FOREACH(i, search) {
                 _cleanup_free_ char *p = NULL;
                 FILE *f;
 
-                p = strjoin(*i, "/", path, NULL);
+                if (root)
+                        p = strjoin(root, *i, "/", path, NULL);
+                else
+                        p = strjoin(*i, "/", path, NULL);
                 if (!p)
                         return -ENOMEM;
 
@@ -5964,7 +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;
 
@@ -5976,12 +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=");
@@ -6025,7 +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;
 
@@ -6093,7 +6239,7 @@ int container_get_leader(const char *machine, pid_t *pid) {
 
 int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *root_fd) {
         _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, netnsfd = -1;
-        int rfd;
+        int rfd = -1;
 
         assert(pid >= 0);
 
@@ -6452,8 +6598,7 @@ void hexdump(FILE *f, const void *p, size_t s) {
         }
 }
 
-int update_reboot_param_file(const char *param)
-{
+int update_reboot_param_file(const char *param) {
         int r = 0;
 
         if (param) {
@@ -6467,3 +6612,568 @@ int update_reboot_param_file(const char *param)
 
         return r;
 }
+
+int umount_recursive(const char *prefix, int flags) {
+        bool again;
+        int n = 0, r;
+
+        /* Try to umount everything recursively below a
+         * directory. Also, take care of stacked mounts, and keep
+         * unmounting them until they are gone. */
+
+        do {
+                _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
+
+                again = false;
+                r = 0;
+
+                proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
+                if (!proc_self_mountinfo)
+                        return -errno;
+
+                for (;;) {
+                        _cleanup_free_ char *path = NULL, *p = NULL;
+                        int k;
+
+                        k = fscanf(proc_self_mountinfo,
+                                   "%*s "       /* (1) mount id */
+                                   "%*s "       /* (2) parent id */
+                                   "%*s "       /* (3) major:minor */
+                                   "%*s "       /* (4) root */
+                                   "%ms "       /* (5) mount point */
+                                   "%*s"        /* (6) mount options */
+                                   "%*[^-]"     /* (7) optional fields */
+                                   "- "         /* (8) separator */
+                                   "%*s "       /* (9) file system type */
+                                   "%*s"        /* (10) mount source */
+                                   "%*s"        /* (11) mount options 2 */
+                                   "%*[^\n]",   /* some rubbish at the end */
+                                   &path);
+                        if (k != 1) {
+                                if (k == EOF)
+                                        break;
+
+                                continue;
+                        }
+
+                        p = cunescape(path);
+                        if (!p)
+                                return -ENOMEM;
+
+                        if (!path_startswith(p, prefix))
+                                continue;
+
+                        if (umount2(p, flags) < 0) {
+                                r = -errno;
+                                continue;
+                        }
+
+                        again = true;
+                        n++;
+
+                        break;
+                }
+
+        } while (again);
+
+        return r ? r : n;
+}
+
+int bind_remount_recursive(const char *prefix, bool ro) {
+        _cleanup_set_free_free_ Set *done = NULL;
+        _cleanup_free_ char *cleaned = NULL;
+        int r;
+
+        /* Recursively remount a directory (and all its submounts)
+         * read-only or read-write. If the directory is already
+         * mounted, we reuse the mount and simply mark it
+         * MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write
+         * operation). If it isn't we first make it one. Afterwards we
+         * apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to all
+         * submounts we can access, too. When mounts are stacked on
+         * the same mount point we only care for each individual
+         * "top-level" mount on each point, as we cannot
+         * influence/access the underlying mounts anyway. We do not
+         * have any effect on future submounts that might get
+         * propagated, they migt be writable. This includes future
+         * submounts that have been triggered via autofs. */
+
+        cleaned = strdup(prefix);
+        if (!cleaned)
+                return -ENOMEM;
+
+        path_kill_slashes(cleaned);
+
+        done = set_new(string_hash_func, string_compare_func);
+        if (!done)
+                return -ENOMEM;
+
+        for (;;) {
+                _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
+                _cleanup_set_free_free_ Set *todo = NULL;
+                bool top_autofs = false;
+                char *x;
+
+                todo = set_new(string_hash_func, string_compare_func);
+                if (!todo)
+                        return -ENOMEM;
+
+                proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
+                if (!proc_self_mountinfo)
+                        return -errno;
+
+                for (;;) {
+                        _cleanup_free_ char *path = NULL, *p = NULL, *type = NULL;
+                        int k;
+
+                        k = fscanf(proc_self_mountinfo,
+                                   "%*s "       /* (1) mount id */
+                                   "%*s "       /* (2) parent id */
+                                   "%*s "       /* (3) major:minor */
+                                   "%*s "       /* (4) root */
+                                   "%ms "       /* (5) mount point */
+                                   "%*s"        /* (6) mount options (superblock) */
+                                   "%*[^-]"     /* (7) optional fields */
+                                   "- "         /* (8) separator */
+                                   "%ms "       /* (9) file system type */
+                                   "%*s"        /* (10) mount source */
+                                   "%*s"        /* (11) mount options (bind mount) */
+                                   "%*[^\n]",   /* some rubbish at the end */
+                                   &path,
+                                   &type);
+                        if (k != 2) {
+                                if (k == EOF)
+                                        break;
+
+                                continue;
+                        }
+
+                        p = cunescape(path);
+                        if (!p)
+                                return -ENOMEM;
+
+                        /* Let's ignore autofs mounts.  If they aren't
+                         * triggered yet, we want to avoid triggering
+                         * them, as we don't make any guarantees for
+                         * future submounts anyway.  If they are
+                         * already triggered, then we will find
+                         * another entry for this. */
+                        if (streq(type, "autofs")) {
+                                top_autofs = top_autofs || path_equal(cleaned, p);
+                                continue;
+                        }
+
+                        if (path_startswith(p, cleaned) &&
+                            !set_contains(done, p)) {
+
+                                r = set_consume(todo, p);
+                                p = NULL;
+
+                                if (r == -EEXIST)
+                                        continue;
+                                if (r < 0)
+                                        return r;
+                        }
+                }
+
+                /* If we have no submounts to process anymore and if
+                 * the root is either already done, or an autofs, we
+                 * are done */
+                if (set_isempty(todo) &&
+                    (top_autofs || set_contains(done, cleaned)))
+                        return 0;
+
+                if (!set_contains(done, cleaned) &&
+                    !set_contains(todo, cleaned)) {
+                        /* The prefix directory itself is not yet a
+                         * mount, make it one. */
+                        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)
+                                return -errno;
+
+                        x = strdup(cleaned);
+                        if (!x)
+                                return -ENOMEM;
+
+                        r = set_consume(done, x);
+                        if (r < 0)
+                                return r;
+                }
+
+                while ((x = set_steal_first(todo))) {
+
+                        r = set_consume(done, x);
+                        if (r == -EEXIST)
+                                continue;
+                        if (r < 0)
+                                return r;
+
+                        if (mount(NULL, x, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) {
+
+                                /* Deal with mount points that are
+                                 * obstructed by a later mount */
+
+                                if (errno != ENOENT)
+                                        return -errno;
+                        }
+
+                }
+        }
+}
+
+int fflush_and_check(FILE *f) {
+        assert(f);
+
+        errno = 0;
+        fflush(f);
+
+        if (ferror(f))
+                return errno ? -errno : -EIO;
+
+        return 0;
+}
+
+char *tempfn_xxxxxx(const char *p) {
+        const char *fn;
+        char *t;
+        size_t k;
+
+        assert(p);
+
+        t = new(char, strlen(p) + 1 + 6 + 1);
+        if (!t)
+                return NULL;
+
+        fn = basename(p);
+        k = fn - p;
+
+        strcpy(stpcpy(stpcpy(mempcpy(t, p, k), "."), fn), "XXXXXX");
+
+        return t;
+}
+
+char *tempfn_random(const char *p) {
+        const char *fn;
+        char *t, *x;
+        uint64_t u;
+        size_t k;
+        unsigned i;
+
+        assert(p);
+
+        t = new(char, strlen(p) + 1 + 16 + 1);
+        if (!t)
+                return NULL;
+
+        fn = basename(p);
+        k = fn - p;
+
+        x = stpcpy(stpcpy(mempcpy(t, p, k), "."), fn);
+
+        u = random_u64();
+        for (i = 0; i < 16; i++) {
+                *(x++) = hexchar(u & 0xF);
+                u >>= 4;
+        }
+
+        *x = 0;
+
+        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;
+}