1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 Copyright 2010 Lennart Poettering
4 Copyright 2015 Werner Fink
15 #include <sys/inotify.h>
16 #include <sys/prctl.h>
17 #include <sys/signalfd.h>
18 #include <sys/socket.h>
23 #include "alloc-util.h"
24 #include "ask-password-api.h"
25 #include "conf-parser.h"
27 #include "dirent-util.h"
28 #include "exit-status.h"
35 #include "path-util.h"
36 #include "process-util.h"
37 #include "signal-util.h"
38 #include "socket-util.h"
39 #include "string-util.h"
41 #include "terminal-util.h"
43 #include "utmp-wtmp.h"
50 } arg_action
= ACTION_QUERY
;
52 static bool arg_plymouth
= false;
53 static bool arg_console
= false;
54 static const char *arg_device
= NULL
;
56 static int ask_password_plymouth(
59 AskPasswordFlags flags
,
60 const char *flag_file
,
63 static const union sockaddr_union sa
= PLYMOUTH_SOCKET
;
64 _cleanup_close_
int fd
= -1, notify
= -1;
65 _cleanup_free_
char *packet
= NULL
;
68 struct pollfd pollfd
[2] = {};
69 char buffer
[LINE_MAX
];
79 notify
= inotify_init1(IN_CLOEXEC
|IN_NONBLOCK
);
83 r
= inotify_add_watch(notify
, flag_file
, IN_ATTRIB
); /* for the link count */
88 fd
= socket(AF_UNIX
, SOCK_STREAM
|SOCK_CLOEXEC
|SOCK_NONBLOCK
, 0);
92 r
= connect(fd
, &sa
.sa
, SOCKADDR_UN_LEN(sa
.un
));
96 if (flags
& ASK_PASSWORD_ACCEPT_CACHED
) {
99 } else if (asprintf(&packet
, "*\002%c%s%n", (int) (strlen(message
) + 1), message
, &n
) < 0)
104 r
= loop_write(fd
, packet
, n
+ 1, true);
108 pollfd
[POLL_SOCKET
].fd
= fd
;
109 pollfd
[POLL_SOCKET
].events
= POLLIN
;
110 pollfd
[POLL_INOTIFY
].fd
= notify
;
111 pollfd
[POLL_INOTIFY
].events
= POLLIN
;
114 int sleep_for
= -1, j
;
119 y
= now(CLOCK_MONOTONIC
);
126 sleep_for
= (int) ((until
- y
) / USEC_PER_MSEC
);
129 if (flag_file
&& access(flag_file
, F_OK
) < 0) {
134 j
= poll(pollfd
, notify
>= 0 ? 2 : 1, sleep_for
);
146 if (notify
>= 0 && pollfd
[POLL_INOTIFY
].revents
!= 0)
147 (void) flush_fd(notify
);
149 if (pollfd
[POLL_SOCKET
].revents
== 0)
152 k
= read(fd
, buffer
+ p
, sizeof(buffer
) - p
);
154 if (IN_SET(errno
, EINTR
, EAGAIN
))
169 if (buffer
[0] == 5) {
171 if (flags
& ASK_PASSWORD_ACCEPT_CACHED
) {
172 /* Hmm, first try with cached
173 * passwords failed, so let's retry
174 * with a normal password request */
175 packet
= mfree(packet
);
177 if (asprintf(&packet
, "*\002%c%s%n", (int) (strlen(message
) + 1), message
, &n
) < 0) {
182 r
= loop_write(fd
, packet
, n
+1, true);
186 flags
&= ~ASK_PASSWORD_ACCEPT_CACHED
;
191 /* No password, because UI not shown */
195 } else if (IN_SET(buffer
[0], 2, 9)) {
199 /* One or more answers */
203 memcpy(&size
, buffer
+1, sizeof(size
));
204 size
= le32toh(size
);
205 if (size
+ 5 > sizeof(buffer
)) {
213 l
= strv_parse_nulstr(buffer
+ 5, size
);
232 explicit_bzero(buffer
, sizeof(buffer
));
236 static int send_passwords(const char *socket_name
, char **passwords
) {
237 _cleanup_free_
char *packet
= NULL
;
238 _cleanup_close_
int socket_fd
= -1;
239 union sockaddr_union sa
= { .un
.sun_family
= AF_UNIX
};
240 size_t packet_length
= 1;
247 STRV_FOREACH(p
, passwords
)
248 packet_length
+= strlen(*p
) + 1;
250 packet
= new(char, packet_length
);
257 STRV_FOREACH(p
, passwords
)
258 d
= stpcpy(d
, *p
) + 1;
260 socket_fd
= socket(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0);
262 r
= log_debug_errno(errno
, "socket(): %m");
266 strncpy(sa
.un
.sun_path
, socket_name
, sizeof(sa
.un
.sun_path
));
268 n
= sendto(socket_fd
, packet
, packet_length
, MSG_NOSIGNAL
, &sa
.sa
, SOCKADDR_UN_LEN(sa
.un
));
270 r
= log_debug_errno(errno
, "sendto(): %m");
277 explicit_bzero(packet
, packet_length
);
281 static int parse_password(const char *filename
, char **wall
) {
282 _cleanup_free_
char *socket_name
= NULL
, *message
= NULL
;
283 bool accept_cached
= false, echo
= false;
284 uint64_t not_after
= 0;
287 const ConfigTableItem items
[] = {
288 { "Ask", "Socket", config_parse_string
, 0, &socket_name
},
289 { "Ask", "NotAfter", config_parse_uint64
, 0, ¬_after
},
290 { "Ask", "Message", config_parse_string
, 0, &message
},
291 { "Ask", "PID", config_parse_unsigned
, 0, &pid
},
292 { "Ask", "AcceptCached", config_parse_bool
, 0, &accept_cached
},
293 { "Ask", "Echo", config_parse_bool
, 0, &echo
},
301 r
= config_parse(NULL
, filename
, NULL
,
303 config_item_table_lookup
, items
,
304 CONFIG_PARSE_RELAXED
|CONFIG_PARSE_WARN
, NULL
);
309 log_error("Invalid password file %s", filename
);
313 if (not_after
> 0 && now(CLOCK_MONOTONIC
) > not_after
)
316 if (pid
> 0 && !pid_is_alive(pid
))
319 if (arg_action
== ACTION_LIST
)
320 printf("'%s' (PID %u)\n", message
, pid
);
322 else if (arg_action
== ACTION_WALL
) {
326 "%s%sPassword entry required for \'%s\' (PID %u).\r\n"
327 "Please enter password with the systemd-tty-ask-password-agent tool!",
329 *wall
? "\r\n\r\n" : "",
338 _cleanup_strv_free_erase_
char **passwords
= NULL
;
340 assert(IN_SET(arg_action
, ACTION_QUERY
, ACTION_WATCH
));
342 if (access(socket_name
, W_OK
) < 0) {
343 if (arg_action
== ACTION_QUERY
)
344 log_info("Not querying '%s' (PID %u), lacking privileges.", message
, pid
);
350 r
= ask_password_plymouth(message
, not_after
, accept_cached
? ASK_PASSWORD_ACCEPT_CACHED
: 0, filename
, &passwords
);
352 char *password
= NULL
;
356 const char *con
= arg_device
?: "/dev/console";
358 tty_fd
= acquire_terminal(con
, ACQUIRE_TERMINAL_WAIT
, USEC_INFINITY
);
360 return log_error_errno(tty_fd
, "Failed to acquire %s: %m", con
);
362 r
= reset_terminal_fd(tty_fd
, true);
364 log_warning_errno(r
, "Failed to reset terminal, ignoring: %m");
367 r
= ask_password_tty(tty_fd
, message
, NULL
, not_after
,
368 (echo
? ASK_PASSWORD_ECHO
: 0) |
369 (arg_console
? ASK_PASSWORD_CONSOLE_COLOR
: 0),
370 filename
, &password
);
373 tty_fd
= safe_close(tty_fd
);
378 r
= strv_push(&passwords
, password
);
381 string_free_erase(password
);
384 /* If the query went away, that's OK */
385 if (IN_SET(r
, -ETIME
, -ENOENT
))
389 return log_error_errno(r
, "Failed to query password: %m");
391 r
= send_passwords(socket_name
, passwords
);
393 return log_error_errno(r
, "Failed to send: %m");
399 static int wall_tty_block(void) {
400 _cleanup_free_
char *p
= NULL
;
404 r
= get_ctty_devnr(0, &devnr
);
405 if (r
== -ENXIO
) /* We have no controlling tty */
408 return log_error_errno(r
, "Failed to get controlling TTY: %m");
410 if (asprintf(&p
, "/run/systemd/ask-password-block/%u:%u", major(devnr
), minor(devnr
)) < 0)
413 (void) mkdir_parents_label(p
, 0700);
414 (void) mkfifo(p
, 0600);
416 fd
= open(p
, O_RDONLY
|O_CLOEXEC
|O_NONBLOCK
|O_NOCTTY
);
418 return log_debug_errno(errno
, "Failed to open %s: %m", p
);
423 static bool wall_tty_match(const char *path
, void *userdata
) {
424 _cleanup_free_
char *p
= NULL
;
425 _cleanup_close_
int fd
= -1;
428 if (!path_is_absolute(path
))
429 path
= strjoina("/dev/", path
);
431 if (lstat(path
, &st
) < 0) {
432 log_debug_errno(errno
, "Failed to stat %s: %m", path
);
436 if (!S_ISCHR(st
.st_mode
)) {
437 log_debug("%s is not a character device.", path
);
441 /* We use named pipes to ensure that wall messages suggesting
442 * password entry are not printed over password prompts
443 * already shown. We use the fact here that opening a pipe in
444 * non-blocking mode for write-only will succeed only if
445 * there's some writer behind it. Using pipes has the
446 * advantage that the block will automatically go away if the
449 if (asprintf(&p
, "/run/systemd/ask-password-block/%u:%u", major(st
.st_rdev
), minor(st
.st_rdev
)) < 0) {
454 fd
= open(p
, O_WRONLY
|O_CLOEXEC
|O_NONBLOCK
|O_NOCTTY
);
456 log_debug_errno(errno
, "Failed to open the wall pipe: %m");
460 /* What, we managed to open the pipe? Then this tty is filtered. */
464 static int show_passwords(void) {
465 _cleanup_closedir_
DIR *d
;
469 d
= opendir("/run/systemd/ask-password");
474 return log_error_errno(errno
, "Failed to open /run/systemd/ask-password: %m");
477 FOREACH_DIRENT_ALL(de
, d
, return log_error_errno(errno
, "Failed to read directory: %m")) {
478 _cleanup_free_
char *p
= NULL
, *wall
= NULL
;
481 /* We only support /dev on tmpfs, hence we can rely on
482 * d_type to be reliable */
484 if (de
->d_type
!= DT_REG
)
487 if (hidden_or_backup_file(de
->d_name
))
490 if (!startswith(de
->d_name
, "ask."))
493 p
= strappend("/run/systemd/ask-password/", de
->d_name
);
497 q
= parse_password(p
, &wall
);
502 (void) utmp_wall(wall
, NULL
, NULL
, wall_tty_match
, NULL
);
508 static int watch_passwords(void) {
515 _cleanup_close_
int notify
= -1, signal_fd
= -1, tty_block_fd
= -1;
516 struct pollfd pollfd
[_FD_MAX
] = {};
520 tty_block_fd
= wall_tty_block();
522 (void) mkdir_p_label("/run/systemd/ask-password", 0755);
524 notify
= inotify_init1(IN_CLOEXEC
);
526 return log_error_errno(errno
, "Failed to allocate directory watch: %m");
528 if (inotify_add_watch(notify
, "/run/systemd/ask-password", IN_CLOSE_WRITE
|IN_MOVED_TO
) < 0)
529 return log_error_errno(errno
, "Failed to add /run/systemd/ask-password to directory watch: %m");
531 assert_se(sigemptyset(&mask
) >= 0);
532 assert_se(sigset_add_many(&mask
, SIGINT
, SIGTERM
, -1) >= 0);
533 assert_se(sigprocmask(SIG_SETMASK
, &mask
, NULL
) >= 0);
535 signal_fd
= signalfd(-1, &mask
, SFD_NONBLOCK
|SFD_CLOEXEC
);
537 return log_error_errno(errno
, "Failed to allocate signal file descriptor: %m");
539 pollfd
[FD_INOTIFY
].fd
= notify
;
540 pollfd
[FD_INOTIFY
].events
= POLLIN
;
541 pollfd
[FD_SIGNAL
].fd
= signal_fd
;
542 pollfd
[FD_SIGNAL
].events
= POLLIN
;
545 r
= show_passwords();
547 log_error_errno(r
, "Failed to show password: %m");
549 if (poll(pollfd
, _FD_MAX
, -1) < 0) {
556 if (pollfd
[FD_INOTIFY
].revents
!= 0)
557 (void) flush_fd(notify
);
559 if (pollfd
[FD_SIGNAL
].revents
!= 0)
566 static void help(void) {
567 printf("%s [OPTIONS...]\n\n"
568 "Process system password requests.\n\n"
569 " -h --help Show this help\n"
570 " --version Show package version\n"
571 " --list Show pending password requests\n"
572 " --query Process pending password requests\n"
573 " --watch Continuously process password requests\n"
574 " --wall Continuously forward password requests to wall\n"
575 " --plymouth Ask question with Plymouth instead of on TTY\n"
576 " --console Ask question on /dev/console instead of current TTY\n",
577 program_invocation_short_name
);
580 static int parse_argv(int argc
, char *argv
[]) {
592 static const struct option options
[] = {
593 { "help", no_argument
, NULL
, 'h' },
594 { "version", no_argument
, NULL
, ARG_VERSION
},
595 { "list", no_argument
, NULL
, ARG_LIST
},
596 { "query", no_argument
, NULL
, ARG_QUERY
},
597 { "watch", no_argument
, NULL
, ARG_WATCH
},
598 { "wall", no_argument
, NULL
, ARG_WALL
},
599 { "plymouth", no_argument
, NULL
, ARG_PLYMOUTH
},
600 { "console", optional_argument
, NULL
, ARG_CONSOLE
},
609 while ((c
= getopt_long(argc
, argv
, "h", options
, NULL
)) >= 0)
621 arg_action
= ACTION_LIST
;
625 arg_action
= ACTION_QUERY
;
629 arg_action
= ACTION_WATCH
;
633 arg_action
= ACTION_WALL
;
644 if (isempty(optarg
)) {
645 log_error("Empty console device path is not allowed.");
657 assert_not_reached("Unhandled option");
660 if (optind
!= argc
) {
661 log_error("%s takes no arguments.", program_invocation_short_name
);
665 if (arg_plymouth
|| arg_console
) {
667 if (!IN_SET(arg_action
, ACTION_QUERY
, ACTION_WATCH
)) {
668 log_error("Options --query and --watch conflict.");
672 if (arg_plymouth
&& arg_console
) {
673 log_error("Options --plymouth and --console conflict.");
682 * To be able to ask on all terminal devices of /dev/console
683 * the devices are collected. If more than one device is found,
684 * then on each of the terminals a inquiring task is forked.
685 * Every task has its own session and its own controlling terminal.
686 * If one of the tasks does handle a password, the remaining tasks
687 * will be terminated.
689 static int ask_on_this_console(const char *tty
, pid_t
*ret_pid
, int argc
, char *argv
[]) {
690 struct sigaction sig
= {
691 .sa_handler
= nop_signal_handler
,
692 .sa_flags
= SA_NOCLDSTOP
| SA_RESTART
,
697 assert_se(sigprocmask_many(SIG_UNBLOCK
, NULL
, SIGHUP
, SIGCHLD
, -1) >= 0);
699 assert_se(sigemptyset(&sig
.sa_mask
) >= 0);
700 assert_se(sigaction(SIGCHLD
, &sig
, NULL
) >= 0);
702 sig
.sa_handler
= SIG_DFL
;
703 assert_se(sigaction(SIGHUP
, &sig
, NULL
) >= 0);
705 r
= safe_fork("(sd-passwd)", FORK_RESET_SIGNALS
|FORK_LOG
, &pid
);
711 assert_se(prctl(PR_SET_PDEATHSIG
, SIGHUP
) >= 0);
713 for (ac
= 0; ac
< argc
; ac
++) {
714 if (streq(argv
[ac
], "--console")) {
715 argv
[ac
] = strjoina("--console=", tty
);
722 execv(SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH
, argv
);
730 static void terminate_agents(Set
*pids
) {
732 siginfo_t status
= {};
739 * Request termination of the remaining processes as those
740 * are not required anymore.
742 SET_FOREACH(p
, pids
, i
)
743 (void) kill(PTR_TO_PID(p
), SIGTERM
);
746 * Collect the processes which have go away.
748 assert_se(sigemptyset(&set
) >= 0);
749 assert_se(sigaddset(&set
, SIGCHLD
) >= 0);
750 timespec_store(&ts
, 50 * USEC_PER_MSEC
);
752 while (!set_isempty(pids
)) {
755 r
= waitid(P_ALL
, 0, &status
, WEXITED
|WNOHANG
);
756 if (r
< 0 && errno
== EINTR
)
759 if (r
== 0 && status
.si_pid
> 0) {
760 set_remove(pids
, PID_TO_PTR(status
.si_pid
));
764 signum
= sigtimedwait(&set
, NULL
, &ts
);
767 log_error_errno(errno
, "sigtimedwait() failed: %m");
770 assert(signum
== SIGCHLD
);
774 * Kill hanging processes.
776 SET_FOREACH(p
, pids
, i
) {
777 log_warning("Failed to terminate child %d, killing it", PTR_TO_PID(p
));
778 (void) kill(PTR_TO_PID(p
), SIGKILL
);
782 static int ask_on_consoles(int argc
, char *argv
[]) {
783 _cleanup_set_free_ Set
*pids
= NULL
;
784 _cleanup_strv_free_
char **consoles
= NULL
;
785 siginfo_t status
= {};
790 r
= get_kernel_consoles(&consoles
);
792 return log_error_errno(r
, "Failed to determine devices of /dev/console: %m");
794 pids
= set_new(NULL
);
798 /* Start an agent on each console. */
799 STRV_FOREACH(tty
, consoles
) {
800 r
= ask_on_this_console(*tty
, &pid
, argc
, argv
);
804 if (set_put(pids
, PID_TO_PTR(pid
)) < 0)
808 /* Wait for an agent to exit. */
812 if (waitid(P_ALL
, 0, &status
, WEXITED
) < 0) {
816 return log_error_errno(errno
, "waitid() failed: %m");
819 set_remove(pids
, PID_TO_PTR(status
.si_pid
));
823 if (!is_clean_exit(status
.si_code
, status
.si_status
, EXIT_CLEAN_DAEMON
, NULL
))
824 log_error("Password agent failed with: %d", status
.si_status
);
826 terminate_agents(pids
);
830 int main(int argc
, char *argv
[]) {
833 log_set_target(LOG_TARGET_AUTO
);
834 log_parse_environment();
839 r
= parse_argv(argc
, argv
);
843 if (arg_console
&& !arg_device
)
845 * Spawn for each console device a separate process.
847 r
= ask_on_consoles(argc
, argv
);
852 * Later on, a controlling terminal will be acquired,
853 * therefore the current process has to become a session
854 * leader and should not have a controlling terminal already.
857 (void) release_terminal();
860 if (IN_SET(arg_action
, ACTION_WATCH
, ACTION_WALL
))
861 r
= watch_passwords();
863 r
= show_passwords();
867 return r
< 0 ? EXIT_FAILURE
: EXIT_SUCCESS
;