/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <stdbool.h> #include <errno.h> #include <string.h> #include <sys/socket.h> #include <sys/un.h> #include <stddef.h> #include <sys/poll.h> #include <sys/inotify.h> #include <unistd.h> #include <getopt.h> #include <sys/signalfd.h> #include <fcntl.h> #include "util.h" #include "conf-parser.h" #include "utmp-wtmp.h" #include "socket-util.h" #include "ask-password-api.h" #include "strv.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 int ask_password_plymouth( const char *message, usec_t until, const char *flag_file, bool accept_cached, char ***_passphrases) { int fd = -1, notify = -1; union sockaddr_union sa; char *packet = NULL; ssize_t k; int r, n; struct pollfd pollfd[2]; char buffer[LINE_MAX]; size_t p = 0; enum { POLL_SOCKET, POLL_INOTIFY }; assert(_passphrases); if (flag_file) { if ((notify = inotify_init1(IN_CLOEXEC|IN_NONBLOCK)) < 0) { r = -errno; goto finish; } if (inotify_add_watch(notify, flag_file, IN_ATTRIB /* for the link count */) < 0) { r = -errno; goto finish; } } if ((fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) { r = -errno; goto finish; } zero(sa); sa.sa.sa_family = AF_UNIX; strncpy(sa.un.sun_path+1, "/org/freedesktop/plymouthd", sizeof(sa.un.sun_path)-1); if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + 1 + strlen(sa.un.sun_path+1)) < 0) { log_error("Failed to connect to Plymouth: %m"); r = -errno; goto finish; } if (accept_cached) { packet = strdup("c"); n = 1; } else asprintf(&packet, "*\002%c%s%n", (int) (strlen(message) + 1), message, &n); if (!packet) { r = -ENOMEM; goto finish; } if ((k = loop_write(fd, packet, n+1, true)) != n+1) { r = k < 0 ? (int) k : -EIO; goto finish; } zero(pollfd); pollfd[POLL_SOCKET].fd = fd; pollfd[POLL_SOCKET].events = POLLIN; pollfd[POLL_INOTIFY].fd = notify; pollfd[POLL_INOTIFY].events = POLLIN; for (;;) { int sleep_for = -1, j; if (until > 0) { usec_t y; y = now(CLOCK_MONOTONIC); if (y > until) { r = -ETIME; goto finish; } sleep_for = (int) ((until - y) / USEC_PER_MSEC); } if (flag_file) if (access(flag_file, F_OK) < 0) { r = -errno; goto finish; } if ((j = poll(pollfd, notify > 0 ? 2 : 1, sleep_for)) < 0) { if (errno == EINTR) continue; r = -errno; goto finish; } else if (j == 0) { r = -ETIME; goto finish; } if (notify > 0 && pollfd[POLL_INOTIFY].revents != 0) flush_fd(notify); if (pollfd[POLL_SOCKET].revents == 0) continue; if ((k = read(fd, buffer + p, sizeof(buffer) - p)) <= 0) { r = k < 0 ? -errno : -EIO; goto finish; } p += k; if (p < 1) continue; if (buffer[0] == 5) { if (accept_cached) { /* Hmm, first try with cached * passwords failed, so let's retry * with a normal password request */ free(packet); packet = NULL; if (asprintf(&packet, "*\002%c%s%n", (int) (strlen(message) + 1), message, &n) < 0) { r = -ENOMEM; goto finish; } if ((k = loop_write(fd, packet, n+1, true)) != n+1) { r = k < 0 ? (int) k : -EIO; goto finish; } accept_cached = false; p = 0; continue; } /* No password, because UI not shown */ r = -ENOENT; goto finish; } else if (buffer[0] == 2 || buffer[0] == 9) { uint32_t size; char **l; /* One ore more answers */ if (p < 5) continue; memcpy(&size, buffer+1, sizeof(size)); if (size+5 > sizeof(buffer)) { r = -EIO; goto finish; } if (p-5 < size) continue; if (!(l = strv_parse_nulstr(buffer + 5, size))) { r = -ENOMEM; goto finish; } *_passphrases = l; break; } else { /* Unknown packet */ r = -EIO; goto finish; } } r = 0; finish: if (notify >= 0) close_nointr_nofail(notify); if (fd >= 0) close_nointr_nofail(fd); free(packet); return r; } static int parse_password(const char *filename, char **wall) { char *socket_name = NULL, *message = NULL, *packet = NULL; uint64_t not_after = 0; unsigned pid = 0; int socket_fd = -1; bool accept_cached = false; 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 }, { NULL, NULL, NULL, 0, NULL } }; FILE *f; int r; assert(filename); f = fopen(filename, "re"); if (!f) { if (errno == ENOENT) return 0; log_error("open(%s): %m", filename); return -errno; } r = config_parse(filename, f, NULL, config_item_table_lookup, (void*) items, true, NULL); if (r < 0) { log_error("Failed to parse password file %s: %s", filename, strerror(-r)); goto finish; } if (!socket_name) { log_error("Invalid password file %s", filename); r = -EBADMSG; goto finish; } if (not_after > 0) { if (now(CLOCK_MONOTONIC) > not_after) { r = 0; goto finish; } } if (pid > 0 && kill(pid, 0) < 0 && errno == ESRCH) { r = 0; goto finish; } if (arg_action == ACTION_LIST) printf("'%s' (PID %u)\n", message, pid); else if (arg_action == ACTION_WALL) { char *_wall; if (asprintf(&_wall, "%s%sPassword entry required for \'%s\' (PID %u).\r\n" "Please enter password with the systemd-tty-ask-password-agent tool!", *wall ? *wall : "", *wall ? "\r\n\r\n" : "", message, pid) < 0) { log_error("Out of memory"); r = -ENOMEM; goto finish; } free(*wall); *wall = _wall; } else { union { struct sockaddr sa; struct sockaddr_un un; } sa; size_t packet_length = 0; assert(arg_action == ACTION_QUERY || arg_action == ACTION_WATCH); if (access(socket_name, W_OK) < 0) { if (arg_action == ACTION_QUERY) log_info("Not querying '%s' (PID %u), lacking privileges.", message, pid); r = 0; goto finish; } if (arg_plymouth) { char **passwords = NULL; if ((r = ask_password_plymouth(message, not_after, filename, accept_cached, &passwords)) >= 0) { char **p; packet_length = 1; STRV_FOREACH(p, passwords) packet_length += strlen(*p) + 1; if (!(packet = new(char, packet_length))) r = -ENOMEM; else { char *d; packet[0] = '+'; d = packet+1; STRV_FOREACH(p, passwords) d = stpcpy(d, *p) + 1; } } } else { int tty_fd = -1; char *password; if (arg_console) if ((tty_fd = acquire_terminal("/dev/console", false, false, false)) < 0) { r = tty_fd; goto finish; } r = ask_password_tty(message, not_after, filename, &password); if (arg_console) { close_nointr_nofail(tty_fd); release_terminal(); } if (r >= 0) { packet_length = 1+strlen(password)+1; if (!(packet = new(char, packet_length))) r = -ENOMEM; else { packet[0] = '+'; strcpy(packet+1, password); } free(password); } } if (r == -ETIME || r == -ENOENT) { /* If the query went away, that's OK */ r = 0; goto finish; } if (r < 0) { log_error("Failed to query password: %s", strerror(-r)); goto finish; } if ((socket_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0) { log_error("socket(): %m"); r = -errno; goto finish; } zero(sa); sa.un.sun_family = AF_UNIX; strncpy(sa.un.sun_path, socket_name, sizeof(sa.un.sun_path)); if (sendto(socket_fd, packet, packet_length, MSG_NOSIGNAL, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(socket_name)) < 0) { log_error("Failed to send: %m"); r = -errno; goto finish; } } finish: fclose(f); if (socket_fd >= 0) close_nointr_nofail(socket_fd); free(packet); free(socket_name); free(message); return r; } static int wall_tty_block(void) { char *p; int fd, r; dev_t devnr; r = get_ctty_devnr(0, &devnr); if (r < 0) return -r; if (asprintf(&p, "/run/systemd/ask-password-block/%u:%u", major(devnr), minor(devnr)) < 0) return -ENOMEM; mkdir_parents(p, 0700); mkfifo(p, 0600); fd = open(p, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); free(p); if (fd < 0) return -errno; return fd; } static bool wall_tty_match(const char *path) { int fd, k; char *p; struct stat st; if (path_is_absolute(path)) k = lstat(path, &st); else { if (asprintf(&p, "/dev/%s", path) < 0) return true; k = lstat(p, &st); free(p); } if (k < 0) return true; if (!S_ISCHR(st.st_mode)) 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) return true; fd = open(p, O_WRONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); free(p); if (fd < 0) return true; /* What, we managed to open the pipe? Then this tty is filtered. */ close_nointr_nofail(fd); return false; } static int show_passwords(void) { DIR *d; struct dirent *de; int r = 0; if (!(d = opendir("/run/systemd/ask-password"))) { if (errno == ENOENT) return 0; log_error("opendir(): %m"); return -errno; } while ((de = readdir(d))) { char *p; int q; char *wall; /* We only support /dev on tmpfs, hence we can rely on * d_type to be reliable */ if (de->d_type != DT_REG) continue; if (ignore_file(de->d_name)) continue; if (!startswith(de->d_name, "ask.")) continue; if (!(p = strappend("/run/systemd/ask-password/", de->d_name))) { log_error("Out of memory"); r = -ENOMEM; goto finish; } wall = NULL; if ((q = parse_password(p, &wall)) < 0) r = q; free(p); if (wall) { utmp_wall(wall, wall_tty_match); free(wall); } } finish: if (d) closedir(d); return r; } static int watch_passwords(void) { enum { FD_INOTIFY, FD_SIGNAL, _FD_MAX }; int notify = -1, signal_fd = -1, tty_block_fd = -1; struct pollfd pollfd[_FD_MAX]; sigset_t mask; int r; tty_block_fd = wall_tty_block(); mkdir_p("/run/systemd/ask-password", 0755); if ((notify = inotify_init1(IN_CLOEXEC)) < 0) { r = -errno; goto finish; } if (inotify_add_watch(notify, "/run/systemd/ask-password", IN_CLOSE_WRITE|IN_MOVED_TO) < 0) { r = -errno; goto finish; } assert_se(sigemptyset(&mask) == 0); sigset_add_many(&mask, SIGINT, SIGTERM, -1); assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0); if ((signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) { log_error("signalfd(): %m"); r = -errno; goto finish; } zero(pollfd); pollfd[FD_INOTIFY].fd = notify; pollfd[FD_INOTIFY].events = POLLIN; pollfd[FD_SIGNAL].fd = signal_fd; pollfd[FD_SIGNAL].events = POLLIN; for (;;) { if ((r = show_passwords()) < 0) log_error("Failed to show password: %s", strerror(-r)); if (poll(pollfd, _FD_MAX, -1) < 0) { if (errno == EINTR) continue; r = -errno; goto finish; } if (pollfd[FD_INOTIFY].revents != 0) flush_fd(notify); if (pollfd[FD_SIGNAL].revents != 0) break; } r = 0; finish: if (notify >= 0) close_nointr_nofail(notify); if (signal_fd >= 0) close_nointr_nofail(signal_fd); if (tty_block_fd >= 0) close_nointr_nofail(tty_block_fd); return r; } static int help(void) { printf("%s [OPTIONS...]\n\n" "Process system password requests.\n\n" " -h --help Show this help\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 Ask question on /dev/console instead of current TTY\n", program_invocation_short_name); return 0; } static int parse_argv(int argc, char *argv[]) { enum { ARG_LIST = 0x100, ARG_QUERY, ARG_WATCH, ARG_WALL, ARG_PLYMOUTH, ARG_CONSOLE }; static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "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", no_argument, NULL, ARG_CONSOLE }, { NULL, 0, NULL, 0 } }; int c; assert(argc >= 0); assert(argv); while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) { switch (c) { case 'h': help(); return 0; 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; break; case '?': return -EINVAL; default: log_error("Unknown option code %c", c); return -EINVAL; } } if (optind != argc) { help(); return -EINVAL; } return 1; } int main(int argc, char *argv[]) { int r; log_parse_environment(); log_open(); umask(0022); if ((r = parse_argv(argc, argv)) <= 0) goto finish; if (arg_console) { setsid(); release_terminal(); } if (arg_action == ACTION_WATCH || arg_action == ACTION_WALL) r = watch_passwords(); else r = show_passwords(); if (r < 0) log_error("Error: %s", strerror(-r)); finish: return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; }