+int copy_file(const char *from, const char *to) {
+ int r, fdf, fdt;
+
+ assert(from);
+ assert(to);
+
+ fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ if (fdf < 0)
+ return -errno;
+
+ fdt = open(to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY, 0644);
+ if (fdt < 0) {
+ close_nointr_nofail(fdf);
+ return -errno;
+ }
+
+ for (;;) {
+ char buf[PIPE_BUF];
+ ssize_t n, k;
+
+ n = read(fdf, buf, sizeof(buf));
+ if (n < 0) {
+ r = -errno;
+
+ close_nointr_nofail(fdf);
+ close_nointr(fdt);
+ unlink(to);
+
+ return r;
+ }
+
+ if (n == 0)
+ break;
+
+ errno = 0;
+ k = loop_write(fdt, buf, n, false);
+ if (n != k) {
+ r = k < 0 ? k : (errno ? -errno : -EIO);
+
+ close_nointr_nofail(fdf);
+ close_nointr(fdt);
+
+ unlink(to);
+ return r;
+ }
+ }
+
+ close_nointr_nofail(fdf);
+ r = close_nointr(fdt);
+
+ if (r < 0) {
+ unlink(to);
+ return r;
+ }
+
+ return 0;
+}
+
+int symlink_or_copy(const char *from, const char *to) {
+ char *pf = NULL, *pt = NULL;
+ struct stat a, b;
+ int r;
+
+ assert(from);
+ assert(to);
+
+ if (parent_of_path(from, &pf) < 0 ||
+ parent_of_path(to, &pt) < 0) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if (stat(pf, &a) < 0 ||
+ stat(pt, &b) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ if (a.st_dev != b.st_dev) {
+ free(pf);
+ free(pt);
+
+ return copy_file(from, to);
+ }
+
+ if (symlink(from, to) < 0) {
+ r = -errno;
+ goto finish;
+ }
+
+ r = 0;
+
+finish:
+ free(pf);
+ free(pt);
+
+ return r;
+}
+
+int symlink_or_copy_atomic(const char *from, const char *to) {
+ char *t, *x;
+ const char *fn;
+ size_t k;
+ unsigned long long ull;
+ unsigned i;
+ int r;
+
+ assert(from);
+ assert(to);
+
+ t = new(char, strlen(to) + 1 + 16 + 1);
+ if (!t)
+ return -ENOMEM;
+
+ fn = file_name_from_path(to);
+ k = fn-to;
+ memcpy(t, to, k);
+ t[k] = '.';
+ x = stpcpy(t+k+1, fn);
+
+ ull = random_ull();
+ for (i = 0; i < 16; i++) {
+ *(x++) = hexchar(ull & 0xF);
+ ull >>= 4;
+ }
+
+ *x = 0;
+
+ r = symlink_or_copy(from, t);
+ if (r < 0) {
+ unlink(t);
+ free(t);
+ return r;
+ }
+
+ if (rename(t, to) < 0) {
+ r = -errno;
+ unlink(t);
+ free(t);
+ return r;
+ }
+
+ free(t);
+ return r;
+}
+
+int audit_session_from_pid(pid_t pid, uint32_t *id) {
+ char *s;
+ uint32_t u;
+ int r;
+
+ assert(id);
+
+ if (have_effective_cap(CAP_AUDIT_CONTROL) <= 0)
+ return -ENOENT;
+
+ if (pid == 0)
+ r = read_one_line_file("/proc/self/sessionid", &s);
+ else {
+ char *p;
+
+ if (asprintf(&p, "/proc/%lu/sessionid", (unsigned long) pid) < 0)
+ return -ENOMEM;
+
+ r = read_one_line_file(p, &s);
+ free(p);
+ }
+
+ if (r < 0)
+ return r;
+
+ r = safe_atou32(s, &u);
+ free(s);
+
+ if (r < 0)
+ return r;
+
+ if (u == (uint32_t) -1 || u <= 0)
+ return -ENOENT;
+
+ *id = u;
+ return 0;
+}
+
+int audit_loginuid_from_pid(pid_t pid, uid_t *uid) {
+ char *s;
+ uid_t u;
+ int r;
+
+ assert(uid);
+
+ /* Only use audit login uid if we are executed with sufficient
+ * capabilities so that pam_loginuid could do its job. If we
+ * are lacking the CAP_AUDIT_CONTROL capabality we most likely
+ * are being run in a container and /proc/self/loginuid is
+ * useless since it probably contains a uid of the host
+ * system. */
+
+ if (have_effective_cap(CAP_AUDIT_CONTROL) <= 0)
+ return -ENOENT;
+
+ if (pid == 0)
+ r = read_one_line_file("/proc/self/loginuid", &s);
+ else {
+ char *p;
+
+ if (asprintf(&p, "/proc/%lu/loginuid", (unsigned long) pid) < 0)
+ return -ENOMEM;
+
+ r = read_one_line_file(p, &s);
+ free(p);
+ }
+
+ if (r < 0)
+ return r;
+
+ r = parse_uid(s, &u);
+ free(s);
+
+ if (r < 0)
+ return r;
+
+ if (u == (uid_t) -1)
+ return -ENOENT;
+
+ *uid = (uid_t) u;
+ return 0;
+}
+
+bool display_is_local(const char *display) {
+ assert(display);
+
+ return
+ display[0] == ':' &&
+ display[1] >= '0' &&
+ display[1] <= '9';
+}
+
+int socket_from_display(const char *display, char **path) {
+ size_t k;
+ char *f, *c;
+
+ assert(display);
+ assert(path);
+
+ if (!display_is_local(display))
+ return -EINVAL;
+
+ k = strspn(display+1, "0123456789");
+
+ f = new(char, sizeof("/tmp/.X11-unix/X") + k);
+ if (!f)
+ return -ENOMEM;
+
+ c = stpcpy(f, "/tmp/.X11-unix/X");
+ memcpy(c, display+1, k);
+ c[k] = 0;
+
+ *path = f;
+
+ return 0;
+}
+
+int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home) {
+ struct passwd *p;
+ uid_t u;
+
+ assert(username);
+ assert(*username);
+
+ /* We enforce some special rules for uid=0: in order to avoid
+ * NSS lookups for root we hardcode its data. */
+
+ if (streq(*username, "root") || streq(*username, "0")) {
+ *username = "root";
+
+ if (uid)
+ *uid = 0;
+
+ if (gid)
+ *gid = 0;
+
+ if (home)
+ *home = "/root";
+ return 0;
+ }
+
+ if (parse_uid(*username, &u) >= 0) {
+ errno = 0;
+ p = getpwuid(u);
+
+ /* If there are multiple users with the same id, make
+ * sure to leave $USER to the configured value instead
+ * of the first occurrence in the database. However if
+ * the uid was configured by a numeric uid, then let's
+ * pick the real username from /etc/passwd. */
+ if (p)
+ *username = p->pw_name;
+ } else {
+ errno = 0;
+ p = getpwnam(*username);
+ }
+
+ if (!p)
+ return errno != 0 ? -errno : -ESRCH;
+
+ if (uid)
+ *uid = p->pw_uid;
+
+ if (gid)
+ *gid = p->pw_gid;
+
+ if (home)
+ *home = p->pw_dir;
+
+ return 0;
+}
+
+int get_group_creds(const char **groupname, gid_t *gid) {
+ struct group *g;
+ gid_t id;
+
+ assert(groupname);
+
+ /* We enforce some special rules for gid=0: in order to avoid
+ * NSS lookups for root we hardcode its data. */
+
+ if (streq(*groupname, "root") || streq(*groupname, "0")) {
+ *groupname = "root";
+
+ if (gid)
+ *gid = 0;
+
+ return 0;
+ }
+
+ if (parse_gid(*groupname, &id) >= 0) {
+ errno = 0;
+ g = getgrgid(id);
+
+ if (g)
+ *groupname = g->gr_name;
+ } else {
+ errno = 0;
+ g = getgrnam(*groupname);
+ }
+
+ if (!g)
+ return errno != 0 ? -errno : -ESRCH;
+
+ if (gid)
+ *gid = g->gr_gid;
+
+ return 0;
+}
+
+int glob_exists(const char *path) {
+ glob_t g;
+ int r, k;
+
+ assert(path);
+
+ zero(g);
+ errno = 0;
+ k = glob(path, GLOB_NOSORT|GLOB_BRACE, NULL, &g);
+
+ if (k == GLOB_NOMATCH)
+ r = 0;
+ else if (k == GLOB_NOSPACE)
+ r = -ENOMEM;
+ else if (k == 0)
+ r = !strv_isempty(g.gl_pathv);
+ else
+ r = errno ? -errno : -EIO;
+
+ globfree(&g);
+
+ return r;
+}
+
+int dirent_ensure_type(DIR *d, struct dirent *de) {
+ struct stat st;
+
+ assert(d);
+ assert(de);
+
+ if (de->d_type != DT_UNKNOWN)
+ return 0;
+
+ if (fstatat(dirfd(d), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0)
+ return -errno;
+
+ de->d_type =
+ S_ISREG(st.st_mode) ? DT_REG :
+ S_ISDIR(st.st_mode) ? DT_DIR :
+ S_ISLNK(st.st_mode) ? DT_LNK :
+ S_ISFIFO(st.st_mode) ? DT_FIFO :
+ S_ISSOCK(st.st_mode) ? DT_SOCK :
+ S_ISCHR(st.st_mode) ? DT_CHR :
+ S_ISBLK(st.st_mode) ? DT_BLK :
+ DT_UNKNOWN;
+
+ return 0;
+}
+
+int in_search_path(const char *path, char **search) {
+ char **i, *parent;
+ int r;
+
+ r = parent_of_path(path, &parent);
+ if (r < 0)
+ return r;
+
+ r = 0;
+
+ STRV_FOREACH(i, search) {
+ if (path_equal(parent, *i)) {
+ r = 1;
+ break;
+ }
+ }
+
+ free(parent);
+
+ return r;
+}
+
+int get_files_in_directory(const char *path, char ***list) {
+ DIR *d;
+ int r = 0;
+ unsigned n = 0;
+ char **l = NULL;
+
+ assert(path);
+
+ /* Returns all files in a directory in *list, and the number
+ * of files as return value. If list is NULL returns only the
+ * number */
+
+ d = opendir(path);
+ if (!d)
+ return -errno;
+
+ for (;;) {
+ struct dirent buffer, *de;
+ int k;
+
+ k = readdir_r(d, &buffer, &de);
+ if (k != 0) {
+ r = -k;
+ goto finish;
+ }
+
+ if (!de)
+ break;
+
+ dirent_ensure_type(d, de);
+
+ if (!dirent_is_file(de))
+ continue;
+
+ if (list) {
+ if ((unsigned) r >= n) {
+ char **t;
+
+ n = MAX(16, 2*r);
+ t = realloc(l, sizeof(char*) * n);
+ if (!t) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ l = t;
+ }
+
+ assert((unsigned) r < n);
+
+ l[r] = strdup(de->d_name);
+ if (!l[r]) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ l[++r] = NULL;
+ } else
+ r++;
+ }
+
+finish:
+ if (d)
+ closedir(d);
+
+ if (r >= 0) {
+ if (list)
+ *list = l;
+ } else
+ strv_free(l);
+
+ return r;
+}
+
+char *join(const char *x, ...) {
+ va_list ap;
+ size_t l;
+ char *r, *p;
+
+ va_start(ap, x);
+
+ if (x) {
+ l = strlen(x);
+
+ for (;;) {
+ const char *t;
+
+ t = va_arg(ap, const char *);
+ if (!t)
+ break;
+
+ l += strlen(t);
+ }
+ } else
+ l = 0;
+
+ va_end(ap);
+
+ r = new(char, l+1);
+ if (!r)
+ return NULL;
+
+ if (x) {
+ p = stpcpy(r, x);
+
+ va_start(ap, x);
+
+ for (;;) {
+ const char *t;
+
+ t = va_arg(ap, const char *);
+ if (!t)
+ break;
+
+ p = stpcpy(p, t);
+ }
+
+ va_end(ap);
+ } else
+ r[0] = 0;
+
+ return r;
+}
+
+bool is_main_thread(void) {
+ static __thread int cached = 0;
+
+ if (_unlikely_(cached == 0))
+ cached = getpid() == gettid() ? 1 : -1;
+
+ return cached > 0;
+}
+
+int block_get_whole_disk(dev_t d, dev_t *ret) {
+ char *p, *s;
+ int r;
+ unsigned n, m;
+
+ assert(ret);
+
+ /* If it has a queue this is good enough for us */
+ if (asprintf(&p, "/sys/dev/block/%u:%u/queue", major(d), minor(d)) < 0)
+ return -ENOMEM;
+
+ r = access(p, F_OK);
+ free(p);
+
+ if (r >= 0) {
+ *ret = d;
+ return 0;
+ }
+
+ /* If it is a partition find the originating device */
+ if (asprintf(&p, "/sys/dev/block/%u:%u/partition", major(d), minor(d)) < 0)
+ return -ENOMEM;
+
+ r = access(p, F_OK);
+ free(p);
+
+ if (r < 0)
+ return -ENOENT;
+
+ /* Get parent dev_t */
+ if (asprintf(&p, "/sys/dev/block/%u:%u/../dev", major(d), minor(d)) < 0)
+ return -ENOMEM;
+
+ r = read_one_line_file(p, &s);
+ free(p);
+
+ if (r < 0)
+ return r;
+
+ r = sscanf(s, "%u:%u", &m, &n);
+ free(s);
+
+ if (r != 2)
+ return -EINVAL;
+
+ /* Only return this if it is really good enough for us. */
+ if (asprintf(&p, "/sys/dev/block/%u:%u/queue", m, n) < 0)
+ return -ENOMEM;
+
+ r = access(p, F_OK);
+ free(p);
+
+ if (r >= 0) {
+ *ret = makedev(m, n);
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
+int file_is_sticky(const char *p) {
+ struct stat st;
+
+ assert(p);
+
+ if (lstat(p, &st) < 0)
+ return -errno;
+
+ return
+ st.st_uid == 0 &&
+ (st.st_mode & S_ISVTX);
+}
+