| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| /*** |
| Copyright © 2015 Werner Fink |
| ***/ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <getopt.h> |
| #include <stdbool.h> |
| #include <stddef.h> |
| #include <sys/prctl.h> |
| #include <sys/signalfd.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <sys/un.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #include "alloc-util.h" |
| #include "ask-password-api.h" |
| #include "conf-parser.h" |
| #include "def.h" |
| #include "dirent-util.h" |
| #include "exit-status.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "fs-util.h" |
| #include "hashmap.h" |
| #include "io-util.h" |
| #include "macro.h" |
| #include "main-func.h" |
| #include "memory-util.h" |
| #include "mkdir.h" |
| #include "path-util.h" |
| #include "pretty-print.h" |
| #include "process-util.h" |
| #include "set.h" |
| #include "signal-util.h" |
| #include "socket-util.h" |
| #include "string-util.h" |
| #include "strv.h" |
| #include "terminal-util.h" |
| #include "utmp-wtmp.h" |
| |
| static enum { |
| ACTION_LIST, |
| ACTION_QUERY, |
| ACTION_WATCH, |
| ACTION_WALL, |
| } arg_action = ACTION_QUERY; |
| |
| static bool arg_plymouth = false; |
| static bool arg_console = false; |
| static const char *arg_device = NULL; |
| |
| static int send_passwords(const char *socket_name, char **passwords) { |
| _cleanup_(erase_and_freep) char *packet = NULL; |
| _cleanup_close_ int socket_fd = -1; |
| union sockaddr_union sa; |
| socklen_t sa_len; |
| size_t packet_length = 1; |
| char **p, *d; |
| ssize_t n; |
| int r; |
| |
| assert(socket_name); |
| |
| r = sockaddr_un_set_path(&sa.un, socket_name); |
| if (r < 0) |
| return r; |
| sa_len = r; |
| |
| STRV_FOREACH(p, passwords) |
| packet_length += strlen(*p) + 1; |
| |
| packet = new(char, packet_length); |
| if (!packet) |
| return -ENOMEM; |
| |
| packet[0] = '+'; |
| |
| d = packet + 1; |
| STRV_FOREACH(p, passwords) |
| d = stpcpy(d, *p) + 1; |
| |
| socket_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0); |
| if (socket_fd < 0) |
| return log_debug_errno(errno, "socket(): %m"); |
| |
| n = sendto(socket_fd, packet, packet_length, MSG_NOSIGNAL, &sa.sa, sa_len); |
| if (n < 0) |
| return log_debug_errno(errno, "sendto(): %m"); |
| |
| return (int) n; |
| } |
| |
| static bool wall_tty_match(const char *path, void *userdata) { |
| _cleanup_free_ char *p = NULL; |
| _cleanup_close_ int fd = -1; |
| struct stat st; |
| |
| if (!path_is_absolute(path)) |
| path = strjoina("/dev/", path); |
| |
| if (lstat(path, &st) < 0) { |
| log_debug_errno(errno, "Failed to stat %s: %m", path); |
| return true; |
| } |
| |
| if (!S_ISCHR(st.st_mode)) { |
| log_debug("%s is not a character device.", path); |
| return true; |
| } |
| |
| /* We use named pipes to ensure that wall messages suggesting |
| * password entry are not printed over password prompts |
| * already shown. We use the fact here that opening a pipe in |
| * non-blocking mode for write-only will succeed only if |
| * there's some writer behind it. Using pipes has the |
| * advantage that the block will automatically go away if the |
| * process dies. */ |
| |
| if (asprintf(&p, "/run/systemd/ask-password-block/%u:%u", major(st.st_rdev), minor(st.st_rdev)) < 0) { |
| log_oom(); |
| return true; |
| } |
| |
| fd = open(p, O_WRONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); |
| if (fd < 0) { |
| log_debug_errno(errno, "Failed to open the wall pipe: %m"); |
| return 1; |
| } |
| |
| /* What, we managed to open the pipe? Then this tty is filtered. */ |
| return 0; |
| } |
| |
| static int agent_ask_password_tty( |
| const char *message, |
| usec_t until, |
| AskPasswordFlags flags, |
| const char *flag_file, |
| char ***ret) { |
| |
| int tty_fd = -1, r; |
| const char *con = arg_device ?: "/dev/console"; |
| |
| if (arg_console) { |
| tty_fd = acquire_terminal(con, ACQUIRE_TERMINAL_WAIT, USEC_INFINITY); |
| if (tty_fd < 0) |
| return log_error_errno(tty_fd, "Failed to acquire %s: %m", con); |
| |
| r = reset_terminal_fd(tty_fd, true); |
| if (r < 0) |
| log_warning_errno(r, "Failed to reset terminal, ignoring: %m"); |
| |
| log_info("Starting password query on %s.", con); |
| } |
| |
| r = ask_password_tty(tty_fd, message, NULL, until, flags, flag_file, ret); |
| |
| if (arg_console) { |
| tty_fd = safe_close(tty_fd); |
| release_terminal(); |
| |
| if (r >= 0) |
| log_info("Password query on %s finished successfully.", con); |
| } |
| |
| return r; |
| } |
| |
| static int process_one_password_file(const char *filename) { |
| _cleanup_free_ char *socket_name = NULL, *message = NULL; |
| bool accept_cached = false, echo = false, silent = false; |
| uint64_t not_after = 0; |
| unsigned pid = 0; |
| |
| const ConfigTableItem items[] = { |
| { "Ask", "Socket", config_parse_string, 0, &socket_name }, |
| { "Ask", "NotAfter", config_parse_uint64, 0, ¬_after }, |
| { "Ask", "Message", config_parse_string, 0, &message }, |
| { "Ask", "PID", config_parse_unsigned, 0, &pid }, |
| { "Ask", "AcceptCached", config_parse_bool, 0, &accept_cached }, |
| { "Ask", "Echo", config_parse_bool, 0, &echo }, |
| { "Ask", "Silent", config_parse_bool, 0, &silent }, |
| {} |
| }; |
| |
| int r; |
| |
| assert(filename); |
| |
| r = config_parse(NULL, filename, NULL, |
| NULL, |
| config_item_table_lookup, items, |
| CONFIG_PARSE_RELAXED|CONFIG_PARSE_WARN, |
| NULL, |
| NULL); |
| if (r < 0) |
| return r; |
| |
| if (!socket_name) |
| return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), |
| "Invalid password file %s", filename); |
| |
| if (not_after > 0 && now(CLOCK_MONOTONIC) > not_after) |
| return 0; |
| |
| if (pid > 0 && !pid_is_alive(pid)) |
| return 0; |
| |
| switch (arg_action) { |
| case ACTION_LIST: |
| printf("'%s' (PID %u)\n", strna(message), pid); |
| return 0; |
| |
| case ACTION_WALL: { |
| _cleanup_free_ char *wall = NULL; |
| |
| if (asprintf(&wall, |
| "Password entry required for \'%s\' (PID %u).\r\n" |
| "Please enter password with the systemd-tty-ask-password-agent tool.", |
| strna(message), |
| pid) < 0) |
| return log_oom(); |
| |
| (void) utmp_wall(wall, NULL, NULL, wall_tty_match, NULL); |
| return 0; |
| } |
| case ACTION_QUERY: |
| case ACTION_WATCH: { |
| _cleanup_strv_free_erase_ char **passwords = NULL; |
| AskPasswordFlags flags = 0; |
| |
| if (access(socket_name, W_OK) < 0) { |
| if (arg_action == ACTION_QUERY) |
| log_info("Not querying '%s' (PID %u), lacking privileges.", strna(message), pid); |
| |
| return 0; |
| } |
| |
| SET_FLAG(flags, ASK_PASSWORD_ACCEPT_CACHED, accept_cached); |
| SET_FLAG(flags, ASK_PASSWORD_CONSOLE_COLOR, arg_console); |
| SET_FLAG(flags, ASK_PASSWORD_ECHO, echo); |
| SET_FLAG(flags, ASK_PASSWORD_SILENT, silent); |
| |
| if (arg_plymouth) |
| r = ask_password_plymouth(message, not_after, flags, filename, &passwords); |
| else |
| r = agent_ask_password_tty(message, not_after, flags, filename, &passwords); |
| if (r < 0) { |
| /* If the query went away, that's OK */ |
| if (IN_SET(r, -ETIME, -ENOENT)) |
| return 0; |
| |
| return log_error_errno(r, "Failed to query password: %m"); |
| } |
| |
| if (strv_isempty(passwords)) |
| return -ECANCELED; |
| |
| r = send_passwords(socket_name, passwords); |
| if (r < 0) |
| return log_error_errno(r, "Failed to send: %m"); |
| break; |
| }} |
| |
| return 0; |
| } |
| |
| static int wall_tty_block(void) { |
| _cleanup_free_ char *p = NULL; |
| dev_t devnr; |
| int fd, r; |
| |
| r = get_ctty_devnr(0, &devnr); |
| if (r == -ENXIO) /* We have no controlling tty */ |
| return -ENOTTY; |
| if (r < 0) |
| return log_error_errno(r, "Failed to get controlling TTY: %m"); |
| |
| if (asprintf(&p, "/run/systemd/ask-password-block/%u:%u", major(devnr), minor(devnr)) < 0) |
| return log_oom(); |
| |
| (void) mkdir_parents_label(p, 0700); |
| (void) mkfifo(p, 0600); |
| |
| fd = open(p, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); |
| if (fd < 0) |
| return log_debug_errno(errno, "Failed to open %s: %m", p); |
| |
| return fd; |
| } |
| |
| static int process_password_files(void) { |
| _cleanup_closedir_ DIR *d = NULL; |
| struct dirent *de; |
| int r = 0; |
| |
| d = opendir("/run/systemd/ask-password"); |
| if (!d) { |
| if (errno == ENOENT) |
| return 0; |
| |
| return log_error_errno(errno, "Failed to open /run/systemd/ask-password: %m"); |
| } |
| |
| FOREACH_DIRENT(de, d, return log_error_errno(errno, "Failed to read directory: %m")) { |
| _cleanup_free_ char *p = NULL; |
| int q; |
| |
| /* We only support /run on tmpfs, hence we can rely on |
| * d_type to be reliable */ |
| |
| if (de->d_type != DT_REG) |
| continue; |
| |
| if (!startswith(de->d_name, "ask.")) |
| continue; |
| |
| p = path_join("/run/systemd/ask-password", de->d_name); |
| if (!p) |
| return log_oom(); |
| |
| q = process_one_password_file(p); |
| if (q < 0 && r == 0) |
| r = q; |
| } |
| |
| return r; |
| } |
| |
| static int process_and_watch_password_files(bool watch) { |
| enum { |
| FD_SIGNAL, |
| FD_INOTIFY, |
| _FD_MAX |
| }; |
| |
| _unused_ _cleanup_close_ int tty_block_fd = -1; |
| _cleanup_close_ int notify = -1, signal_fd = -1; |
| struct pollfd pollfd[_FD_MAX]; |
| sigset_t mask; |
| int r; |
| |
| tty_block_fd = wall_tty_block(); |
| |
| (void) mkdir_p_label("/run/systemd/ask-password", 0755); |
| |
| assert_se(sigemptyset(&mask) >= 0); |
| assert_se(sigset_add_many(&mask, SIGTERM, -1) >= 0); |
| assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) >= 0); |
| |
| if (watch) { |
| signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC); |
| if (signal_fd < 0) |
| return log_error_errno(errno, "Failed to allocate signal file descriptor: %m"); |
| |
| pollfd[FD_SIGNAL] = (struct pollfd) { .fd = signal_fd, .events = POLLIN }; |
| |
| notify = inotify_init1(IN_CLOEXEC); |
| if (notify < 0) |
| return log_error_errno(errno, "Failed to allocate directory watch: %m"); |
| |
| r = inotify_add_watch_and_warn(notify, "/run/systemd/ask-password", IN_CLOSE_WRITE|IN_MOVED_TO); |
| if (r < 0) |
| return r; |
| |
| pollfd[FD_INOTIFY] = (struct pollfd) { .fd = notify, .events = POLLIN }; |
| } |
| |
| for (;;) { |
| usec_t timeout = USEC_INFINITY; |
| |
| r = process_password_files(); |
| if (r < 0) { |
| if (r == -ECANCELED) |
| /* Disable poll() timeout since at least one password has |
| * been skipped and therefore one file remains and is |
| * unlikely to trigger any events. */ |
| timeout = 0; |
| else |
| /* FIXME: we should do something here since otherwise the service |
| * requesting the password won't notice the error and will wait |
| * indefinitely. */ |
| log_error_errno(r, "Failed to process password: %m"); |
| } |
| |
| if (!watch) |
| break; |
| |
| r = ppoll_usec(pollfd, _FD_MAX, timeout); |
| if (r == -EINTR) |
| continue; |
| if (r < 0) |
| return r; |
| |
| if (pollfd[FD_INOTIFY].revents != 0) |
| (void) flush_fd(notify); |
| |
| if (pollfd[FD_SIGNAL].revents != 0) |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static int help(void) { |
| _cleanup_free_ char *link = NULL; |
| int r; |
| |
| r = terminal_urlify_man("systemd-tty-ask-password-agent", "1", &link); |
| if (r < 0) |
| return log_oom(); |
| |
| printf("%s [OPTIONS...]\n\n" |
| "%sProcess system password requests.%s\n\n" |
| " -h --help Show this help\n" |
| " --version Show package version\n" |
| " --list Show pending password requests\n" |
| " --query Process pending password requests\n" |
| " --watch Continuously process password requests\n" |
| " --wall Continuously forward password requests to wall\n" |
| " --plymouth Ask question with Plymouth instead of on TTY\n" |
| " --console[=DEVICE] Ask question on /dev/console (or DEVICE if specified)\n" |
| " instead of the current TTY\n" |
| "\nSee the %s for details.\n", |
| program_invocation_short_name, |
| ansi_highlight(), |
| ansi_normal(), |
| link); |
| |
| return 0; |
| } |
| |
| static int parse_argv(int argc, char *argv[]) { |
| |
| enum { |
| ARG_LIST = 0x100, |
| ARG_QUERY, |
| ARG_WATCH, |
| ARG_WALL, |
| ARG_PLYMOUTH, |
| ARG_CONSOLE, |
| ARG_VERSION |
| }; |
| |
| static const struct option options[] = { |
| { "help", no_argument, NULL, 'h' }, |
| { "version", no_argument, NULL, ARG_VERSION }, |
| { "list", no_argument, NULL, ARG_LIST }, |
| { "query", no_argument, NULL, ARG_QUERY }, |
| { "watch", no_argument, NULL, ARG_WATCH }, |
| { "wall", no_argument, NULL, ARG_WALL }, |
| { "plymouth", no_argument, NULL, ARG_PLYMOUTH }, |
| { "console", optional_argument, NULL, ARG_CONSOLE }, |
| {} |
| }; |
| |
| int c; |
| |
| assert(argc >= 0); |
| assert(argv); |
| |
| while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) |
| |
| switch (c) { |
| |
| case 'h': |
| return help(); |
| |
| case ARG_VERSION: |
| return version(); |
| |
| case ARG_LIST: |
| arg_action = ACTION_LIST; |
| break; |
| |
| case ARG_QUERY: |
| arg_action = ACTION_QUERY; |
| break; |
| |
| case ARG_WATCH: |
| arg_action = ACTION_WATCH; |
| break; |
| |
| case ARG_WALL: |
| arg_action = ACTION_WALL; |
| break; |
| |
| case ARG_PLYMOUTH: |
| arg_plymouth = true; |
| break; |
| |
| case ARG_CONSOLE: |
| arg_console = true; |
| if (optarg) { |
| |
| if (isempty(optarg)) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Empty console device path is not allowed."); |
| |
| arg_device = optarg; |
| } |
| break; |
| |
| case '?': |
| return -EINVAL; |
| |
| default: |
| assert_not_reached("Unhandled option"); |
| } |
| |
| if (optind != argc) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "%s takes no arguments.", program_invocation_short_name); |
| |
| if (arg_plymouth || arg_console) { |
| |
| if (!IN_SET(arg_action, ACTION_QUERY, ACTION_WATCH)) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Options --query and --watch conflict."); |
| |
| if (arg_plymouth && arg_console) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Options --plymouth and --console conflict."); |
| } |
| |
| return 1; |
| } |
| |
| /* |
| * To be able to ask on all terminal devices of /dev/console the devices are collected. If more than one |
| * device is found, then on each of the terminals an inquiring task is forked. Every task has its own session |
| * and its own controlling terminal. If one of the tasks does handle a password, the remaining tasks will be |
| * terminated. |
| */ |
| static int ask_on_this_console(const char *tty, pid_t *ret_pid, char **arguments) { |
| static const struct sigaction sigchld = { |
| .sa_handler = nop_signal_handler, |
| .sa_flags = SA_NOCLDSTOP | SA_RESTART, |
| }; |
| static const struct sigaction sighup = { |
| .sa_handler = SIG_DFL, |
| .sa_flags = SA_RESTART, |
| }; |
| int r; |
| |
| assert_se(sigaction(SIGCHLD, &sigchld, NULL) >= 0); |
| assert_se(sigaction(SIGHUP, &sighup, NULL) >= 0); |
| assert_se(sigprocmask_many(SIG_UNBLOCK, NULL, SIGHUP, SIGCHLD, -1) >= 0); |
| |
| r = safe_fork("(sd-passwd)", FORK_RESET_SIGNALS|FORK_LOG, ret_pid); |
| if (r < 0) |
| return r; |
| if (r == 0) { |
| char **i; |
| |
| assert_se(prctl(PR_SET_PDEATHSIG, SIGHUP) >= 0); |
| |
| STRV_FOREACH(i, arguments) { |
| char *k; |
| |
| if (!streq(*i, "--console")) |
| continue; |
| |
| k = strjoin("--console=", tty); |
| if (!k) { |
| log_oom(); |
| _exit(EXIT_FAILURE); |
| } |
| |
| free_and_replace(*i, k); |
| } |
| |
| execv(SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH, arguments); |
| _exit(EXIT_FAILURE); |
| } |
| |
| return 0; |
| } |
| |
| static void terminate_agents(Set *pids) { |
| struct timespec ts; |
| siginfo_t status = {}; |
| sigset_t set; |
| void *p; |
| int r, signum; |
| |
| /* |
| * Request termination of the remaining processes as those |
| * are not required anymore. |
| */ |
| SET_FOREACH(p, pids) |
| (void) kill(PTR_TO_PID(p), SIGTERM); |
| |
| /* |
| * Collect the processes which have go away. |
| */ |
| assert_se(sigemptyset(&set) >= 0); |
| assert_se(sigaddset(&set, SIGCHLD) >= 0); |
| timespec_store(&ts, 50 * USEC_PER_MSEC); |
| |
| while (!set_isempty(pids)) { |
| |
| zero(status); |
| r = waitid(P_ALL, 0, &status, WEXITED|WNOHANG); |
| if (r < 0 && errno == EINTR) |
| continue; |
| |
| if (r == 0 && status.si_pid > 0) { |
| set_remove(pids, PID_TO_PTR(status.si_pid)); |
| continue; |
| } |
| |
| signum = sigtimedwait(&set, NULL, &ts); |
| if (signum < 0) { |
| if (errno != EAGAIN) |
| log_error_errno(errno, "sigtimedwait() failed: %m"); |
| break; |
| } |
| assert(signum == SIGCHLD); |
| } |
| |
| /* |
| * Kill hanging processes. |
| */ |
| SET_FOREACH(p, pids) { |
| log_warning("Failed to terminate child %d, killing it", PTR_TO_PID(p)); |
| (void) kill(PTR_TO_PID(p), SIGKILL); |
| } |
| } |
| |
| static int ask_on_consoles(char *argv[]) { |
| _cleanup_set_free_ Set *pids = NULL; |
| _cleanup_strv_free_ char **consoles = NULL, **arguments = NULL; |
| siginfo_t status = {}; |
| char **tty; |
| pid_t pid; |
| int r; |
| |
| r = get_kernel_consoles(&consoles); |
| if (r < 0) |
| return log_error_errno(r, "Failed to determine devices of /dev/console: %m"); |
| |
| pids = set_new(NULL); |
| if (!pids) |
| return log_oom(); |
| |
| arguments = strv_copy(argv); |
| if (!arguments) |
| return log_oom(); |
| |
| /* Start an agent on each console. */ |
| STRV_FOREACH(tty, consoles) { |
| r = ask_on_this_console(*tty, &pid, arguments); |
| if (r < 0) |
| return r; |
| |
| if (set_put(pids, PID_TO_PTR(pid)) < 0) |
| return log_oom(); |
| } |
| |
| /* Wait for an agent to exit. */ |
| for (;;) { |
| zero(status); |
| |
| if (waitid(P_ALL, 0, &status, WEXITED) < 0) { |
| if (errno == EINTR) |
| continue; |
| |
| return log_error_errno(errno, "waitid() failed: %m"); |
| } |
| |
| set_remove(pids, PID_TO_PTR(status.si_pid)); |
| break; |
| } |
| |
| if (!is_clean_exit(status.si_code, status.si_status, EXIT_CLEAN_DAEMON, NULL)) |
| log_error("Password agent failed with: %d", status.si_status); |
| |
| terminate_agents(pids); |
| return 0; |
| } |
| |
| static int run(int argc, char *argv[]) { |
| int r; |
| |
| log_setup(); |
| |
| umask(0022); |
| |
| r = parse_argv(argc, argv); |
| if (r <= 0) |
| return r; |
| |
| if (arg_console && !arg_device) |
| /* |
| * Spawn a separate process for each console device. |
| */ |
| return ask_on_consoles(argv); |
| |
| if (arg_device) { |
| /* |
| * Later on, a controlling terminal will be acquired, |
| * therefore the current process has to become a session |
| * leader and should not have a controlling terminal already. |
| */ |
| (void) setsid(); |
| (void) release_terminal(); |
| } |
| |
| return process_and_watch_password_files(!IN_SET(arg_action, ACTION_QUERY, ACTION_LIST)); |
| } |
| |
| DEFINE_MAIN_FUNCTION(run); |
