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-rw-r--r--src/tty-ask-password-agent.c753
1 files changed, 753 insertions, 0 deletions
diff --git a/src/tty-ask-password-agent.c b/src/tty-ask-password-agent.c
new file mode 100644
index 000000000..13481b29e
--- /dev/null
+++ b/src/tty-ask-password-agent.c
@@ -0,0 +1,753 @@
+/*-*- 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));
+ size = le32toh(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, &not_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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 03:28:09 +0000