1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 Copyright 2015 Werner Fink
14 #include <sys/inotify.h>
15 #include <sys/prctl.h>
16 #include <sys/signalfd.h>
17 #include <sys/socket.h>
22 #include "alloc-util.h"
23 #include "ask-password-api.h"
24 #include "conf-parser.h"
26 #include "dirent-util.h"
27 #include "exit-status.h"
34 #include "path-util.h"
35 #include "process-util.h"
36 #include "signal-util.h"
37 #include "socket-util.h"
38 #include "string-util.h"
40 #include "terminal-util.h"
42 #include "utmp-wtmp.h"
49 } arg_action
= ACTION_QUERY
;
51 static bool arg_plymouth
= false;
52 static bool arg_console
= false;
53 static const char *arg_device
= NULL
;
55 static int ask_password_plymouth(
58 AskPasswordFlags flags
,
59 const char *flag_file
,
62 static const union sockaddr_union sa
= PLYMOUTH_SOCKET
;
63 _cleanup_close_
int fd
= -1, notify
= -1;
64 _cleanup_free_
char *packet
= NULL
;
67 struct pollfd pollfd
[2] = {};
68 char buffer
[LINE_MAX
];
78 notify
= inotify_init1(IN_CLOEXEC
|IN_NONBLOCK
);
82 r
= inotify_add_watch(notify
, flag_file
, IN_ATTRIB
); /* for the link count */
87 fd
= socket(AF_UNIX
, SOCK_STREAM
|SOCK_CLOEXEC
|SOCK_NONBLOCK
, 0);
91 r
= connect(fd
, &sa
.sa
, SOCKADDR_UN_LEN(sa
.un
));
95 if (flags
& ASK_PASSWORD_ACCEPT_CACHED
) {
98 } else if (asprintf(&packet
, "*\002%c%s%n", (int) (strlen(message
) + 1), message
, &n
) < 0)
103 r
= loop_write(fd
, packet
, n
+ 1, true);
107 pollfd
[POLL_SOCKET
].fd
= fd
;
108 pollfd
[POLL_SOCKET
].events
= POLLIN
;
109 pollfd
[POLL_INOTIFY
].fd
= notify
;
110 pollfd
[POLL_INOTIFY
].events
= POLLIN
;
113 int sleep_for
= -1, j
;
118 y
= now(CLOCK_MONOTONIC
);
125 sleep_for
= (int) ((until
- y
) / USEC_PER_MSEC
);
128 if (flag_file
&& access(flag_file
, F_OK
) < 0) {
133 j
= poll(pollfd
, notify
>= 0 ? 2 : 1, sleep_for
);
145 if (notify
>= 0 && pollfd
[POLL_INOTIFY
].revents
!= 0)
146 (void) flush_fd(notify
);
148 if (pollfd
[POLL_SOCKET
].revents
== 0)
151 k
= read(fd
, buffer
+ p
, sizeof(buffer
) - p
);
153 if (IN_SET(errno
, EINTR
, EAGAIN
))
168 if (buffer
[0] == 5) {
170 if (flags
& ASK_PASSWORD_ACCEPT_CACHED
) {
171 /* Hmm, first try with cached
172 * passwords failed, so let's retry
173 * with a normal password request */
174 packet
= mfree(packet
);
176 if (asprintf(&packet
, "*\002%c%s%n", (int) (strlen(message
) + 1), message
, &n
) < 0) {
181 r
= loop_write(fd
, packet
, n
+1, true);
185 flags
&= ~ASK_PASSWORD_ACCEPT_CACHED
;
190 /* No password, because UI not shown */
194 } else if (IN_SET(buffer
[0], 2, 9)) {
198 /* One or more answers */
202 memcpy(&size
, buffer
+1, sizeof(size
));
203 size
= le32toh(size
);
204 if (size
+ 5 > sizeof(buffer
)) {
212 l
= strv_parse_nulstr(buffer
+ 5, size
);
231 explicit_bzero(buffer
, sizeof(buffer
));
235 static int send_passwords(const char *socket_name
, char **passwords
) {
236 _cleanup_free_
char *packet
= NULL
;
237 _cleanup_close_
int socket_fd
= -1;
238 union sockaddr_union sa
= { .un
.sun_family
= AF_UNIX
};
239 size_t packet_length
= 1;
246 STRV_FOREACH(p
, passwords
)
247 packet_length
+= strlen(*p
) + 1;
249 packet
= new(char, packet_length
);
256 STRV_FOREACH(p
, passwords
)
257 d
= stpcpy(d
, *p
) + 1;
259 socket_fd
= socket(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0);
261 r
= log_debug_errno(errno
, "socket(): %m");
265 strncpy(sa
.un
.sun_path
, socket_name
, sizeof(sa
.un
.sun_path
));
267 n
= sendto(socket_fd
, packet
, packet_length
, MSG_NOSIGNAL
, &sa
.sa
, SOCKADDR_UN_LEN(sa
.un
));
269 r
= log_debug_errno(errno
, "sendto(): %m");
276 explicit_bzero(packet
, packet_length
);
280 static int parse_password(const char *filename
, char **wall
) {
281 _cleanup_free_
char *socket_name
= NULL
, *message
= NULL
;
282 bool accept_cached
= false, echo
= false;
283 uint64_t not_after
= 0;
286 const ConfigTableItem items
[] = {
287 { "Ask", "Socket", config_parse_string
, 0, &socket_name
},
288 { "Ask", "NotAfter", config_parse_uint64
, 0, ¬_after
},
289 { "Ask", "Message", config_parse_string
, 0, &message
},
290 { "Ask", "PID", config_parse_unsigned
, 0, &pid
},
291 { "Ask", "AcceptCached", config_parse_bool
, 0, &accept_cached
},
292 { "Ask", "Echo", config_parse_bool
, 0, &echo
},
300 r
= config_parse(NULL
, filename
, NULL
,
302 config_item_table_lookup
, items
,
303 CONFIG_PARSE_RELAXED
|CONFIG_PARSE_WARN
, NULL
);
308 log_error("Invalid password file %s", filename
);
312 if (not_after
> 0 && now(CLOCK_MONOTONIC
) > not_after
)
315 if (pid
> 0 && !pid_is_alive(pid
))
318 if (arg_action
== ACTION_LIST
)
319 printf("'%s' (PID %u)\n", message
, pid
);
321 else if (arg_action
== ACTION_WALL
) {
325 "%s%sPassword entry required for \'%s\' (PID %u).\r\n"
326 "Please enter password with the systemd-tty-ask-password-agent tool!",
328 *wall
? "\r\n\r\n" : "",
337 _cleanup_strv_free_erase_
char **passwords
= NULL
;
339 assert(IN_SET(arg_action
, ACTION_QUERY
, ACTION_WATCH
));
341 if (access(socket_name
, W_OK
) < 0) {
342 if (arg_action
== ACTION_QUERY
)
343 log_info("Not querying '%s' (PID %u), lacking privileges.", message
, pid
);
349 r
= ask_password_plymouth(message
, not_after
, accept_cached
? ASK_PASSWORD_ACCEPT_CACHED
: 0, filename
, &passwords
);
351 char *password
= NULL
;
355 const char *con
= arg_device
?: "/dev/console";
357 tty_fd
= acquire_terminal(con
, ACQUIRE_TERMINAL_WAIT
, USEC_INFINITY
);
359 return log_error_errno(tty_fd
, "Failed to acquire %s: %m", con
);
361 r
= reset_terminal_fd(tty_fd
, true);
363 log_warning_errno(r
, "Failed to reset terminal, ignoring: %m");
366 r
= ask_password_tty(tty_fd
, message
, NULL
, not_after
,
367 (echo
? ASK_PASSWORD_ECHO
: 0) |
368 (arg_console
? ASK_PASSWORD_CONSOLE_COLOR
: 0),
369 filename
, &password
);
372 tty_fd
= safe_close(tty_fd
);
377 r
= strv_push(&passwords
, password
);
380 string_free_erase(password
);
383 /* If the query went away, that's OK */
384 if (IN_SET(r
, -ETIME
, -ENOENT
))
388 return log_error_errno(r
, "Failed to query password: %m");
390 r
= send_passwords(socket_name
, passwords
);
392 return log_error_errno(r
, "Failed to send: %m");
398 static int wall_tty_block(void) {
399 _cleanup_free_
char *p
= NULL
;
403 r
= get_ctty_devnr(0, &devnr
);
404 if (r
== -ENXIO
) /* We have no controlling tty */
407 return log_error_errno(r
, "Failed to get controlling TTY: %m");
409 if (asprintf(&p
, "/run/systemd/ask-password-block/%u:%u", major(devnr
), minor(devnr
)) < 0)
412 (void) mkdir_parents_label(p
, 0700);
413 (void) mkfifo(p
, 0600);
415 fd
= open(p
, O_RDONLY
|O_CLOEXEC
|O_NONBLOCK
|O_NOCTTY
);
417 return log_debug_errno(errno
, "Failed to open %s: %m", p
);
422 static bool wall_tty_match(const char *path
, void *userdata
) {
423 _cleanup_free_
char *p
= NULL
;
424 _cleanup_close_
int fd
= -1;
427 if (!path_is_absolute(path
))
428 path
= strjoina("/dev/", path
);
430 if (lstat(path
, &st
) < 0) {
431 log_debug_errno(errno
, "Failed to stat %s: %m", path
);
435 if (!S_ISCHR(st
.st_mode
)) {
436 log_debug("%s is not a character device.", path
);
440 /* We use named pipes to ensure that wall messages suggesting
441 * password entry are not printed over password prompts
442 * already shown. We use the fact here that opening a pipe in
443 * non-blocking mode for write-only will succeed only if
444 * there's some writer behind it. Using pipes has the
445 * advantage that the block will automatically go away if the
448 if (asprintf(&p
, "/run/systemd/ask-password-block/%u:%u", major(st
.st_rdev
), minor(st
.st_rdev
)) < 0) {
453 fd
= open(p
, O_WRONLY
|O_CLOEXEC
|O_NONBLOCK
|O_NOCTTY
);
455 log_debug_errno(errno
, "Failed to open the wall pipe: %m");
459 /* What, we managed to open the pipe? Then this tty is filtered. */
463 static int show_passwords(void) {
464 _cleanup_closedir_
DIR *d
;
468 d
= opendir("/run/systemd/ask-password");
473 return log_error_errno(errno
, "Failed to open /run/systemd/ask-password: %m");
476 FOREACH_DIRENT_ALL(de
, d
, return log_error_errno(errno
, "Failed to read directory: %m")) {
477 _cleanup_free_
char *p
= NULL
, *wall
= NULL
;
480 /* We only support /dev on tmpfs, hence we can rely on
481 * d_type to be reliable */
483 if (de
->d_type
!= DT_REG
)
486 if (hidden_or_backup_file(de
->d_name
))
489 if (!startswith(de
->d_name
, "ask."))
492 p
= strappend("/run/systemd/ask-password/", de
->d_name
);
496 q
= parse_password(p
, &wall
);
501 (void) utmp_wall(wall
, NULL
, NULL
, wall_tty_match
, NULL
);
507 static int watch_passwords(void) {
514 _cleanup_close_
int notify
= -1, signal_fd
= -1, tty_block_fd
= -1;
515 struct pollfd pollfd
[_FD_MAX
] = {};
519 tty_block_fd
= wall_tty_block();
521 (void) mkdir_p_label("/run/systemd/ask-password", 0755);
523 notify
= inotify_init1(IN_CLOEXEC
);
525 return log_error_errno(errno
, "Failed to allocate directory watch: %m");
527 if (inotify_add_watch(notify
, "/run/systemd/ask-password", IN_CLOSE_WRITE
|IN_MOVED_TO
) < 0)
528 return log_error_errno(errno
, "Failed to add /run/systemd/ask-password to directory watch: %m");
530 assert_se(sigemptyset(&mask
) >= 0);
531 assert_se(sigset_add_many(&mask
, SIGINT
, SIGTERM
, -1) >= 0);
532 assert_se(sigprocmask(SIG_SETMASK
, &mask
, NULL
) >= 0);
534 signal_fd
= signalfd(-1, &mask
, SFD_NONBLOCK
|SFD_CLOEXEC
);
536 return log_error_errno(errno
, "Failed to allocate signal file descriptor: %m");
538 pollfd
[FD_INOTIFY
].fd
= notify
;
539 pollfd
[FD_INOTIFY
].events
= POLLIN
;
540 pollfd
[FD_SIGNAL
].fd
= signal_fd
;
541 pollfd
[FD_SIGNAL
].events
= POLLIN
;
544 r
= show_passwords();
546 log_error_errno(r
, "Failed to show password: %m");
548 if (poll(pollfd
, _FD_MAX
, -1) < 0) {
555 if (pollfd
[FD_INOTIFY
].revents
!= 0)
556 (void) flush_fd(notify
);
558 if (pollfd
[FD_SIGNAL
].revents
!= 0)
565 static void help(void) {
566 printf("%s [OPTIONS...]\n\n"
567 "Process system password requests.\n\n"
568 " -h --help Show this help\n"
569 " --version Show package version\n"
570 " --list Show pending password requests\n"
571 " --query Process pending password requests\n"
572 " --watch Continuously process password requests\n"
573 " --wall Continuously forward password requests to wall\n"
574 " --plymouth Ask question with Plymouth instead of on TTY\n"
575 " --console Ask question on /dev/console instead of current TTY\n",
576 program_invocation_short_name
);
579 static int parse_argv(int argc
, char *argv
[]) {
591 static const struct option options
[] = {
592 { "help", no_argument
, NULL
, 'h' },
593 { "version", no_argument
, NULL
, ARG_VERSION
},
594 { "list", no_argument
, NULL
, ARG_LIST
},
595 { "query", no_argument
, NULL
, ARG_QUERY
},
596 { "watch", no_argument
, NULL
, ARG_WATCH
},
597 { "wall", no_argument
, NULL
, ARG_WALL
},
598 { "plymouth", no_argument
, NULL
, ARG_PLYMOUTH
},
599 { "console", optional_argument
, NULL
, ARG_CONSOLE
},
608 while ((c
= getopt_long(argc
, argv
, "h", options
, NULL
)) >= 0)
620 arg_action
= ACTION_LIST
;
624 arg_action
= ACTION_QUERY
;
628 arg_action
= ACTION_WATCH
;
632 arg_action
= ACTION_WALL
;
643 if (isempty(optarg
)) {
644 log_error("Empty console device path is not allowed.");
656 assert_not_reached("Unhandled option");
659 if (optind
!= argc
) {
660 log_error("%s takes no arguments.", program_invocation_short_name
);
664 if (arg_plymouth
|| arg_console
) {
666 if (!IN_SET(arg_action
, ACTION_QUERY
, ACTION_WATCH
)) {
667 log_error("Options --query and --watch conflict.");
671 if (arg_plymouth
&& arg_console
) {
672 log_error("Options --plymouth and --console conflict.");
681 * To be able to ask on all terminal devices of /dev/console
682 * the devices are collected. If more than one device is found,
683 * then on each of the terminals a inquiring task is forked.
684 * Every task has its own session and its own controlling terminal.
685 * If one of the tasks does handle a password, the remaining tasks
686 * will be terminated.
688 static int ask_on_this_console(const char *tty
, pid_t
*ret_pid
, int argc
, char *argv
[]) {
689 struct sigaction sig
= {
690 .sa_handler
= nop_signal_handler
,
691 .sa_flags
= SA_NOCLDSTOP
| SA_RESTART
,
696 assert_se(sigprocmask_many(SIG_UNBLOCK
, NULL
, SIGHUP
, SIGCHLD
, -1) >= 0);
698 assert_se(sigemptyset(&sig
.sa_mask
) >= 0);
699 assert_se(sigaction(SIGCHLD
, &sig
, NULL
) >= 0);
701 sig
.sa_handler
= SIG_DFL
;
702 assert_se(sigaction(SIGHUP
, &sig
, NULL
) >= 0);
704 r
= safe_fork("(sd-passwd)", FORK_RESET_SIGNALS
|FORK_LOG
, &pid
);
710 assert_se(prctl(PR_SET_PDEATHSIG
, SIGHUP
) >= 0);
712 for (ac
= 0; ac
< argc
; ac
++) {
713 if (streq(argv
[ac
], "--console")) {
714 argv
[ac
] = strjoina("--console=", tty
);
721 execv(SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH
, argv
);
729 static void terminate_agents(Set
*pids
) {
731 siginfo_t status
= {};
738 * Request termination of the remaining processes as those
739 * are not required anymore.
741 SET_FOREACH(p
, pids
, i
)
742 (void) kill(PTR_TO_PID(p
), SIGTERM
);
745 * Collect the processes which have go away.
747 assert_se(sigemptyset(&set
) >= 0);
748 assert_se(sigaddset(&set
, SIGCHLD
) >= 0);
749 timespec_store(&ts
, 50 * USEC_PER_MSEC
);
751 while (!set_isempty(pids
)) {
754 r
= waitid(P_ALL
, 0, &status
, WEXITED
|WNOHANG
);
755 if (r
< 0 && errno
== EINTR
)
758 if (r
== 0 && status
.si_pid
> 0) {
759 set_remove(pids
, PID_TO_PTR(status
.si_pid
));
763 signum
= sigtimedwait(&set
, NULL
, &ts
);
766 log_error_errno(errno
, "sigtimedwait() failed: %m");
769 assert(signum
== SIGCHLD
);
773 * Kill hanging processes.
775 SET_FOREACH(p
, pids
, i
) {
776 log_warning("Failed to terminate child %d, killing it", PTR_TO_PID(p
));
777 (void) kill(PTR_TO_PID(p
), SIGKILL
);
781 static int ask_on_consoles(int argc
, char *argv
[]) {
782 _cleanup_set_free_ Set
*pids
= NULL
;
783 _cleanup_strv_free_
char **consoles
= NULL
;
784 siginfo_t status
= {};
789 r
= get_kernel_consoles(&consoles
);
791 return log_error_errno(r
, "Failed to determine devices of /dev/console: %m");
793 pids
= set_new(NULL
);
797 /* Start an agent on each console. */
798 STRV_FOREACH(tty
, consoles
) {
799 r
= ask_on_this_console(*tty
, &pid
, argc
, argv
);
803 if (set_put(pids
, PID_TO_PTR(pid
)) < 0)
807 /* Wait for an agent to exit. */
811 if (waitid(P_ALL
, 0, &status
, WEXITED
) < 0) {
815 return log_error_errno(errno
, "waitid() failed: %m");
818 set_remove(pids
, PID_TO_PTR(status
.si_pid
));
822 if (!is_clean_exit(status
.si_code
, status
.si_status
, EXIT_CLEAN_DAEMON
, NULL
))
823 log_error("Password agent failed with: %d", status
.si_status
);
825 terminate_agents(pids
);
829 int main(int argc
, char *argv
[]) {
832 log_set_target(LOG_TARGET_AUTO
);
833 log_parse_environment();
838 r
= parse_argv(argc
, argv
);
842 if (arg_console
&& !arg_device
)
844 * Spawn for each console device a separate process.
846 r
= ask_on_consoles(argc
, argv
);
851 * Later on, a controlling terminal will be acquired,
852 * therefore the current process has to become a session
853 * leader and should not have a controlling terminal already.
856 (void) release_terminal();
859 if (IN_SET(arg_action
, ACTION_WATCH
, ACTION_WALL
))
860 r
= watch_passwords();
862 r
= show_passwords();
866 return r
< 0 ? EXIT_FAILURE
: EXIT_SUCCESS
;