#include <errno.h>

#include <fcntl.h>

#include <getopt.h>

#include <poll.h>

#include <stdbool.h>

#include <stddef.h>

#include <string.h>

#include <sys/inotify.h>

#include <sys/signalfd.h>

#include <sys/socket.h>

#include <sys/un.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 "fd-util.h"

#include "io-util.h"

#include "mkdir.h"

#include "path-util.h"

#include "process-util.h"

#include "signal-util.h"

#include "socket-util.h"

#include "string-util.h"

#include "strv.h"

#include "terminal-util.h"

#include "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 int ask_password_plymouth(

const char *message,

usec_t until,

AskPasswordFlags flags,

const char *flag_file,

char ***ret) {

_cleanup_close_ int fd = -1, notify = -1;

union sockaddr_union sa = PLYMOUTH_SOCKET;

_cleanup_free_ 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(ret);

if (flag_file) {

notify = inotify_init1(IN_CLOEXEC|IN_NONBLOCK);

if (notify < 0)

return -errno;

r = inotify_add_watch(notify, flag_file, IN_ATTRIB); /* for the link count */

if (r < 0)

return -errno;

}

fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);

if (fd < 0)

return -errno;

r = connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + 1 + strlen(sa.un.sun_path+1));

if (r < 0)

return -errno;

if (flags & ASK_PASSWORD_ACCEPT_CACHED) {

packet = strdup("c");

n = 1;

} else if (asprintf(&packet, "*\002%c%s%n", (int) (strlen(message) + 1), message, &n) < 0)

packet = NULL;

if (!packet)

return -ENOMEM;

r = loop_write(fd, packet, n + 1, true);

if (r < 0)

return r;

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 && access(flag_file, F_OK) < 0) {

r = -errno;

goto finish;

}

j = poll(pollfd, notify >= 0 ? 2 : 1, sleep_for);

if (j < 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;

k = read(fd, buffer + p, sizeof(buffer) - p);

if (k < 0) {

if (errno == EINTR || errno == EAGAIN)

continue;

r = -errno;

goto finish;

} else if (k == 0) {

r = -EIO;

goto finish;

}

p += k;

if (p < 1)

continue;

if (buffer[0] == 5) {

if (flags & ASK_PASSWORD_ACCEPT_CACHED) {

/* Hmm, first try with cached

packet = mfree(packet);

if (asprintf(&packet, "*\002%c%s%n", (int) (strlen(message) + 1), message, &n) < 0) {

r = -ENOMEM;

goto finish;

}

r = loop_write(fd, packet, n+1, true);

if (r < 0)

goto finish;

flags &= ~ASK_PASSWORD_ACCEPT_CACHED;

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 or 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;

l = strv_parse_nulstr(buffer + 5, size);

if (!l) {

r = -ENOMEM;

goto finish;

}

*ret = l;

break;

} else {

/* Unknown packet */

r = -EIO;

goto finish;

}

}

r = 0;

finish:

memory_erase(buffer, sizeof(buffer));

return r;

}

static int parse_password(const char *filename, char **wall) {

_cleanup_free_ char *socket_name = NULL, *message = NULL, *packet = NULL;

bool accept_cached = false, echo = false;

size_t packet_length = 0;

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, &not_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 },

{}

};

int r;

assert(filename);

r = config_parse(NULL, filename, NULL,

NULL,

config_item_table_lookup, items,

true, false, true, NULL);

if (r < 0)

return r;

if (!socket_name) {

log_error("Invalid password file %s", filename);

return -EBADMSG;

}

if (not_after > 0 && now(CLOCK_MONOTONIC) > not_after)

return 0;

if (pid > 0 && !pid_is_alive(pid))

return 0;

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!",

strempty(*wall),

*wall ? "\r\n\r\n" : "",

message,

pid) < 0)

return log_oom();

free(*wall);

*wall = _wall;

} else {

union sockaddr_union sa = {};

_cleanup_close_ int socket_fd = -1;

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);

return 0;

}

if (arg_plymouth) {

_cleanup_strv_free_erase_ char **passwords = NULL;

r = ask_password_plymouth(message, not_after, accept_cached ? ASK_PASSWORD_ACCEPT_CACHED : 0, filename, &passwords);

if (r >= 0) {

char **p;

packet_length = 1;

STRV_FOREACH(p, passwords)

packet_length += strlen(*p) + 1;

packet = new(char, packet_length);

if (!packet)

r = -ENOMEM;

else {

char *d = packet + 1;

STRV_FOREACH(p, passwords)

d = stpcpy(d, *p) + 1;

packet[0] = '+';

}

}

} else {

_cleanup_string_free_erase_ char *password = NULL;

int tty_fd = -1;

if (arg_console) {

tty_fd = acquire_terminal("/dev/console", false, false, false, USEC_INFINITY);

if (tty_fd < 0)

return log_error_errno(tty_fd, "Failed to acquire /dev/console: %m");

r = reset_terminal_fd(tty_fd, true);

if (r < 0)

log_warning_errno(r, "Failed to reset terminal, ignoring: %m");

}

r = ask_password_tty(message, NULL, not_after, echo ? ASK_PASSWORD_ECHO : 0, filename, &password);

if (arg_console) {

tty_fd = safe_close(tty_fd);

release_terminal();

}

if (r >= 0) {

packet_length = 1 + strlen(password) + 1;

packet = new(char, packet_length);

if (!packet)

r = -ENOMEM;

else {

packet[0] = '+';

strcpy(packet + 1, password);

}

}

}

if (IN_SET(r, -ETIME, -ENOENT)) {

/* If the query went away, that's OK */

r = 0;

goto finish;

}

if (r < 0) {

log_error_errno(r, "Failed to query password: %m");

goto finish;

}

socket_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0);

if (socket_fd < 0) {

r = log_error_errno(errno, "socket(): %m");

goto finish;

}

sa.un.sun_family = AF_UNIX;

strncpy(sa.un.sun_path, socket_name, sizeof(sa.un.sun_path));

r = sendto(socket_fd, packet, packet_length, MSG_NOSIGNAL, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(socket_name));

memory_erase(packet, packet_length);

if (r < 0)

return log_error_errno(errno, "Failed to send: %m");

}

return 0;

finish:

memory_erase(packet, packet_length);

return r;

}

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();

mkdir_parents_label(p, 0700);

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 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

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 top open the wall pipe: %m");

return 1;

}

/* What, we managed to open the pipe? Then this tty is filtered. */

return 0;

}

static int show_passwords(void) {

_cleanup_closedir_ DIR *d;

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_ALL(de, d, return log_error_errno(errno, "Failed to read directory: %m")) {

_cleanup_free_ char *p = NULL, *wall = NULL;

int q;

/* We only support /dev on tmpfs, hence we can rely on

if (de->d_type != DT_REG)

continue;

if (hidden_file(de->d_name))

continue;

if (!startswith(de->d_name, "ask."))

continue;

p = strappend("/run/systemd/ask-password/", de->d_name);

if (!p)

return log_oom();

q = parse_password(p, &wall);

if (q < 0 && r == 0)

r = q;

if (wall)

(void) utmp_wall(wall, NULL, NULL, wall_tty_match, NULL);

}

return r;

}

static int watch_passwords(void) {

enum {

FD_INOTIFY,

FD_SIGNAL,

_FD_MAX

};

_cleanup_close_ 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();

(void) mkdir_p_label("/run/systemd/ask-password", 0755);

notify = inotify_init1(IN_CLOEXEC);

if (notify < 0)

return log_error_errno(errno, "Failed to allocate directory watch: %m");

if (inotify_add_watch(notify, "/run/systemd/ask-password", IN_CLOSE_WRITE|IN_MOVED_TO) < 0)

return log_error_errno(errno, "Failed to add /run/systemd/ask-password to directory watch: %m");

assert_se(sigemptyset(&mask) >= 0);

assert_se(sigset_add_many(&mask, SIGINT, SIGTERM, -1) >= 0);

assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) >= 0);

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_INOTIFY].fd = notify;

pollfd[FD_INOTIFY].events = POLLIN;

pollfd[FD_SIGNAL].fd = signal_fd;

pollfd[FD_SIGNAL].events = POLLIN;

for (;;) {

r = show_passwords();

if (r < 0)

log_error_errno(r, "Failed to show password: %m");

if (poll(pollfd, _FD_MAX, -1) < 0) {

if (errno == EINTR)

continue;

return -errno;

}

if (pollfd[FD_INOTIFY].revents != 0)

(void) flush_fd(notify);

if (pollfd[FD_SIGNAL].revents != 0)

break;

}

return 0;

}

static void help(void) {

printf("%s [OPTIONS...]\n\n"

"Process system password requests.\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 Ask question on /dev/console instead of current TTY\n",

program_invocation_short_name);

}

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", no_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':

help();

return 0;

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;

break;

case '?':

return -EINVAL;

default:

assert_not_reached("Unhandled option");

}

if (optind != argc) {

log_error("%s takes no arguments.", program_invocation_short_name);

return -EINVAL;

}

return 1;

}

int main(int argc, char *argv[]) {

int r;

log_set_target(LOG_TARGET_AUTO);

log_parse_environment();

log_open();

umask(0022);

r = parse_argv(argc, argv);

if (r <= 0)

goto finish;

if (arg_console) {

(void) setsid();

(void) release_terminal();

}

if (IN_SET(arg_action, ACTION_WATCH, ACTION_WALL))

r = watch_passwords();

else

r = show_passwords();

finish:

return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;

}