+
+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;
+ pid_t leader;
+ int r;
+
+ assert(machine);
+ assert(pid);
+
+ p = strappenda("/run/systemd/machines/", machine);
+ r = parse_env_file(p, NEWLINE, "LEADER", &s, "CLASS", &class, NULL);
+ if (r == -ENOENT)
+ return -EHOSTDOWN;
+ if (r < 0)
+ return r;
+ if (!s)
+ return -EIO;
+
+ if (!streq_ptr(class, "container"))
+ return -EIO;
+
+ r = parse_pid(s, &leader);
+ if (r < 0)
+ return r;
+ if (leader <= 1)
+ return -EIO;
+
+ *pid = leader;
+ return 0;
+}
+
+int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *root_fd) {
+ _cleanup_close_ int pidnsfd = -1, mntnsfd = -1;
+ const char *pidns, *mntns, *root;
+ int rfd;
+
+ assert(pid >= 0);
+ assert(pidns_fd);
+ assert(mntns_fd);
+ assert(root_fd);
+
+ mntns = procfs_file_alloca(pid, "ns/mnt");
+ mntnsfd = open(mntns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+ if (mntnsfd < 0)
+ return -errno;
+
+ pidns = procfs_file_alloca(pid, "ns/pid");
+ pidnsfd = open(pidns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+ if (pidnsfd < 0)
+ return -errno;
+
+ root = procfs_file_alloca(pid, "root");
+ rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+ if (rfd < 0)
+ return -errno;
+
+ *pidns_fd = pidnsfd;
+ *mntns_fd = mntnsfd;
+ *root_fd = rfd;
+ pidnsfd = -1;
+ mntnsfd = -1;
+
+ return 0;
+}
+
+int namespace_enter(int pidns_fd, int mntns_fd, int root_fd) {
+ assert(pidns_fd >= 0);
+ assert(mntns_fd >= 0);
+ assert(root_fd >= 0);
+
+ if (setns(pidns_fd, CLONE_NEWPID) < 0)
+ return -errno;
+
+ if (setns(mntns_fd, CLONE_NEWNS) < 0)
+ return -errno;
+
+ if (fchdir(root_fd) < 0)
+ return -errno;
+
+ if (chroot(".") < 0)
+ return -errno;
+
+ if (setresgid(0, 0, 0) < 0)
+ return -errno;
+
+ if (setresuid(0, 0, 0) < 0)
+ return -errno;
+
+ return 0;
+}
+
+bool pid_is_unwaited(pid_t pid) {
+ /* Checks whether a PID is still valid at all, including a zombie */
+
+ if (pid <= 0)
+ return false;
+
+ if (kill(pid, 0) >= 0)
+ return true;
+
+ return errno != ESRCH;
+}
+
+bool pid_is_alive(pid_t pid) {
+ int r;
+
+ /* Checks whether a PID is still valid and not a zombie */
+
+ if (pid <= 0)
+ return false;
+
+ r = get_process_state(pid);
+ if (r == -ENOENT || r == 'Z')
+ return false;
+
+ return true;
+}
+
+int getpeercred(int fd, struct ucred *ucred) {
+ socklen_t n = sizeof(struct ucred);
+ struct ucred u;
+ int r;
+
+ assert(fd >= 0);
+ assert(ucred);
+
+ r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &u, &n);
+ if (r < 0)
+ return -errno;
+
+ if (n != sizeof(struct ucred))
+ return -EIO;
+
+ /* Check if the data is actually useful and not suppressed due
+ * to namespacing issues */
+ if (u.pid <= 0)
+ return -ENODATA;
+
+ *ucred = u;
+ return 0;
+}
+
+int getpeersec(int fd, char **ret) {
+ socklen_t n = 64;
+ char *s;
+ int r;
+
+ assert(fd >= 0);
+ assert(ret);
+
+ s = new0(char, n);
+ if (!s)
+ return -ENOMEM;
+
+ r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n);
+ if (r < 0) {
+ free(s);
+
+ if (errno != ERANGE)
+ return -errno;
+
+ s = new0(char, n);
+ if (!s)
+ return -ENOMEM;
+
+ r = getsockopt(fd, SOL_SOCKET, SO_PEERSEC, s, &n);
+ if (r < 0) {
+ free(s);
+ return -errno;
+ }
+ }
+
+ 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;
+}
~ianmdlvl / elogind.git / blobdiff