Systemd/src/libsystemd/sd-login/sd-login.c
Zbigniew Jędrzejewski-Szmek a2a5291b3f Reject invalid quoted strings
String which ended in an unfinished quote were accepted, potentially
with bad memory accesses.

Reject anything which ends in a unfished quote, or contains
non-whitespace characters right after the closing quote.

_FOREACH_WORD now returns the invalid character in *state. But this return
value is not checked anywhere yet.

Also, make 'word' and 'state' variables const pointers, and rename 'w'
to 'word' in various places. Things are easier to read if the same name
is used consistently.

mbiebl_> am I correct that something like this doesn't work
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-passwd "Unlock EncFS"'
mbiebl_> systemd seems to strip of the quotes
mbiebl_> systemctl status shows
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-password Unlock EncFS  $RootDir $MountPoint
mbiebl_> which is pretty weird
2014-07-31 04:00:31 -04:00

944 lines
23 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2011 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/inotify.h>
#include <sys/poll.h>
#include "util.h"
#include "cgroup-util.h"
#include "macro.h"
#include "strv.h"
#include "fileio.h"
#include "login-shared.h"
#include "sd-login.h"
_public_ int sd_pid_get_session(pid_t pid, char **session) {
assert_return(pid >= 0, -EINVAL);
assert_return(session, -EINVAL);
return cg_pid_get_session(pid, session);
}
_public_ int sd_pid_get_unit(pid_t pid, char **unit) {
assert_return(pid >= 0, -EINVAL);
assert_return(unit, -EINVAL);
return cg_pid_get_unit(pid, unit);
}
_public_ int sd_pid_get_user_unit(pid_t pid, char **unit) {
assert_return(pid >= 0, -EINVAL);
assert_return(unit, -EINVAL);
return cg_pid_get_user_unit(pid, unit);
}
_public_ int sd_pid_get_machine_name(pid_t pid, char **name) {
assert_return(pid >= 0, -EINVAL);
assert_return(name, -EINVAL);
return cg_pid_get_machine_name(pid, name);
}
_public_ int sd_pid_get_slice(pid_t pid, char **slice) {
assert_return(pid >= 0, -EINVAL);
assert_return(slice, -EINVAL);
return cg_pid_get_slice(pid, slice);
}
_public_ int sd_pid_get_owner_uid(pid_t pid, uid_t *uid) {
assert_return(pid >= 0, -EINVAL);
assert_return(uid, -EINVAL);
return cg_pid_get_owner_uid(pid, uid);
}
_public_ int sd_peer_get_session(int fd, char **session) {
struct ucred ucred;
int r;
assert_return(fd >= 0, -EINVAL);
assert_return(session, -EINVAL);
r = getpeercred(fd, &ucred);
if (r < 0)
return r;
return cg_pid_get_session(ucred.pid, session);
}
_public_ int sd_peer_get_owner_uid(int fd, uid_t *uid) {
struct ucred ucred;
int r;
assert_return(fd >= 0, -EINVAL);
assert_return(uid, -EINVAL);
r = getpeercred(fd, &ucred);
if (r < 0)
return r;
return cg_pid_get_owner_uid(ucred.pid, uid);
}
_public_ int sd_peer_get_unit(int fd, char **unit) {
struct ucred ucred;
int r;
assert_return(fd >= 0, -EINVAL);
assert_return(unit, -EINVAL);
r = getpeercred(fd, &ucred);
if (r < 0)
return r;
return cg_pid_get_unit(ucred.pid, unit);
}
_public_ int sd_peer_get_user_unit(int fd, char **unit) {
struct ucred ucred;
int r;
assert_return(fd >= 0, -EINVAL);
assert_return(unit, -EINVAL);
r = getpeercred(fd, &ucred);
if (r < 0)
return r;
return cg_pid_get_user_unit(ucred.pid, unit);
}
_public_ int sd_peer_get_machine_name(int fd, char **machine) {
struct ucred ucred;
int r;
assert_return(fd >= 0, -EINVAL);
assert_return(machine, -EINVAL);
r = getpeercred(fd, &ucred);
if (r < 0)
return r;
return cg_pid_get_machine_name(ucred.pid, machine);
}
_public_ int sd_peer_get_slice(int fd, char **slice) {
struct ucred ucred;
int r;
assert_return(fd >= 0, -EINVAL);
assert_return(slice, -EINVAL);
r = getpeercred(fd, &ucred);
if (r < 0)
return r;
return cg_pid_get_slice(ucred.pid, slice);
}
static int file_of_uid(uid_t uid, char **p) {
assert(p);
if (asprintf(p, "/run/systemd/users/" UID_FMT, uid) < 0)
return -ENOMEM;
return 0;
}
_public_ int sd_uid_get_state(uid_t uid, char**state) {
_cleanup_free_ char *p = NULL;
char *s = NULL;
int r;
assert_return(state, -EINVAL);
r = file_of_uid(uid, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
if (r == -ENOENT) {
free(s);
s = strdup("offline");
if (!s)
return -ENOMEM;
} else if (r < 0) {
free(s);
return r;
} else if (!s)
return -EIO;
*state = s;
return 0;
}
_public_ int sd_uid_get_display(uid_t uid, char **session) {
_cleanup_free_ char *p = NULL, *s = NULL;
int r;
assert_return(session, -EINVAL);
r = file_of_uid(uid, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE, "DISPLAY", &s, NULL);
if (r < 0)
return r;
if (isempty(s))
return -ENOENT;
*session = s;
s = NULL;
return 0;
}
_public_ int sd_uid_is_on_seat(uid_t uid, int require_active, const char *seat) {
_cleanup_free_ char *t = NULL, *s = NULL, *p = NULL;
size_t l;
int r;
const char *word, *variable, *state;
assert_return(seat, -EINVAL);
variable = require_active ? "ACTIVE_UID" : "UIDS";
p = strappend("/run/systemd/seats/", seat);
if (!p)
return -ENOMEM;
r = parse_env_file(p, NEWLINE, variable, &s, NULL);
if (r < 0)
return r;
if (!s)
return -EIO;
if (asprintf(&t, UID_FMT, uid) < 0)
return -ENOMEM;
FOREACH_WORD(word, l, s, state) {
if (strneq(t, word, l))
return 1;
}
return 0;
}
static int uid_get_array(uid_t uid, const char *variable, char ***array) {
_cleanup_free_ char *p = NULL, *s = NULL;
char **a;
int r;
r = file_of_uid(uid, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE,
variable, &s,
NULL);
if (r < 0) {
if (r == -ENOENT) {
if (array)
*array = NULL;
return 0;
}
return r;
}
if (!s) {
if (array)
*array = NULL;
return 0;
}
a = strv_split(s, " ");
if (!a)
return -ENOMEM;
strv_uniq(a);
r = strv_length(a);
if (array)
*array = a;
else
strv_free(a);
return r;
}
_public_ int sd_uid_get_sessions(uid_t uid, int require_active, char ***sessions) {
return uid_get_array(
uid,
require_active == 0 ? "ONLINE_SESSIONS" :
require_active > 0 ? "ACTIVE_SESSIONS" :
"SESSIONS",
sessions);
}
_public_ int sd_uid_get_seats(uid_t uid, int require_active, char ***seats) {
return uid_get_array(
uid,
require_active == 0 ? "ONLINE_SEATS" :
require_active > 0 ? "ACTIVE_SEATS" :
"SEATS",
seats);
}
static int file_of_session(const char *session, char **_p) {
char *p;
int r;
assert(_p);
if (session) {
if (!session_id_valid(session))
return -EINVAL;
p = strappend("/run/systemd/sessions/", session);
} else {
_cleanup_free_ char *buf = NULL;
r = sd_pid_get_session(0, &buf);
if (r < 0)
return r;
p = strappend("/run/systemd/sessions/", buf);
}
if (!p)
return -ENOMEM;
*_p = p;
return 0;
}
_public_ int sd_session_is_active(const char *session) {
int r;
_cleanup_free_ char *p = NULL, *s = NULL;
r = file_of_session(session, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE, "ACTIVE", &s, NULL);
if (r < 0)
return r;
if (!s)
return -EIO;
return parse_boolean(s);
}
_public_ int sd_session_is_remote(const char *session) {
int r;
_cleanup_free_ char *p = NULL, *s = NULL;
r = file_of_session(session, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE, "REMOTE", &s, NULL);
if (r < 0)
return r;
if (!s)
return -EIO;
return parse_boolean(s);
}
_public_ int sd_session_get_state(const char *session, char **state) {
_cleanup_free_ char *p = NULL, *s = NULL;
int r;
assert_return(state, -EINVAL);
r = file_of_session(session, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
if (r < 0)
return r;
else if (!s)
return -EIO;
*state = s;
s = NULL;
return 0;
}
_public_ int sd_session_get_uid(const char *session, uid_t *uid) {
int r;
_cleanup_free_ char *p = NULL, *s = NULL;
assert_return(uid, -EINVAL);
r = file_of_session(session, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE, "UID", &s, NULL);
if (r < 0)
return r;
if (!s)
return -EIO;
return parse_uid(s, uid);
}
static int session_get_string(const char *session, const char *field, char **value) {
_cleanup_free_ char *p = NULL, *s = NULL;
int r;
assert_return(value, -EINVAL);
r = file_of_session(session, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE, field, &s, NULL);
if (r < 0)
return r;
if (isempty(s))
return -ENOENT;
*value = s;
s = NULL;
return 0;
}
_public_ int sd_session_get_seat(const char *session, char **seat) {
return session_get_string(session, "SEAT", seat);
}
_public_ int sd_session_get_tty(const char *session, char **tty) {
return session_get_string(session, "TTY", tty);
}
_public_ int sd_session_get_vt(const char *session, unsigned *vtnr) {
_cleanup_free_ char *vtnr_string = NULL;
unsigned u;
int r;
r = session_get_string(session, "VTNR", &vtnr_string);
if (r < 0)
return r;
r = safe_atou(vtnr_string, &u);
if (r < 0)
return r;
*vtnr = u;
return 0;
}
_public_ int sd_session_get_service(const char *session, char **service) {
return session_get_string(session, "SERVICE", service);
}
_public_ int sd_session_get_type(const char *session, char **type) {
return session_get_string(session, "TYPE", type);
}
_public_ int sd_session_get_class(const char *session, char **class) {
return session_get_string(session, "CLASS", class);
}
_public_ int sd_session_get_display(const char *session, char **display) {
return session_get_string(session, "DISPLAY", display);
}
_public_ int sd_session_get_remote_user(const char *session, char **remote_user) {
return session_get_string(session, "REMOTE_USER", remote_user);
}
_public_ int sd_session_get_remote_host(const char *session, char **remote_host) {
return session_get_string(session, "REMOTE_HOST", remote_host);
}
static int file_of_seat(const char *seat, char **_p) {
char *p;
int r;
assert(_p);
if (seat)
p = strappend("/run/systemd/seats/", seat);
else {
_cleanup_free_ char *buf = NULL;
r = sd_session_get_seat(NULL, &buf);
if (r < 0)
return r;
p = strappend("/run/systemd/seats/", buf);
}
if (!p)
return -ENOMEM;
*_p = p;
p = NULL;
return 0;
}
_public_ int sd_seat_get_active(const char *seat, char **session, uid_t *uid) {
_cleanup_free_ char *p = NULL, *s = NULL, *t = NULL;
int r;
assert_return(session || uid, -EINVAL);
r = file_of_seat(seat, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE,
"ACTIVE", &s,
"ACTIVE_UID", &t,
NULL);
if (r < 0)
return r;
if (session && !s)
return -ENOENT;
if (uid && !t)
return -ENOENT;
if (uid && t) {
r = parse_uid(t, uid);
if (r < 0)
return r;
}
if (session && s) {
*session = s;
s = NULL;
}
return 0;
}
_public_ int sd_seat_get_sessions(const char *seat, char ***sessions, uid_t **uids, unsigned *n_uids) {
_cleanup_free_ char *p = NULL, *s = NULL, *t = NULL;
_cleanup_strv_free_ char **a = NULL;
_cleanup_free_ uid_t *b = NULL;
unsigned n = 0;
int r;
r = file_of_seat(seat, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE,
"SESSIONS", &s,
"ACTIVE_SESSIONS", &t,
NULL);
if (r < 0)
return r;
if (s) {
a = strv_split(s, " ");
if (!a)
return -ENOMEM;
}
if (uids && t) {
const char *word, *state;
size_t l;
FOREACH_WORD(word, l, t, state)
n++;
if (n > 0) {
unsigned i = 0;
b = new(uid_t, n);
if (!b)
return -ENOMEM;
FOREACH_WORD(word, l, t, state) {
_cleanup_free_ char *k = NULL;
k = strndup(word, l);
if (!k)
return -ENOMEM;
r = parse_uid(k, b + i);
if (r < 0)
continue;
i++;
}
}
}
r = strv_length(a);
if (sessions) {
*sessions = a;
a = NULL;
}
if (uids) {
*uids = b;
b = NULL;
}
if (n_uids)
*n_uids = n;
return r;
}
static int seat_get_can(const char *seat, const char *variable) {
_cleanup_free_ char *p = NULL, *s = NULL;
int r;
assert_return(variable, -EINVAL);
r = file_of_seat(seat, &p);
if (r < 0)
return r;
r = parse_env_file(p, NEWLINE,
variable, &s,
NULL);
if (r < 0)
return r;
if (!s)
return 0;
return parse_boolean(s);
}
_public_ int sd_seat_can_multi_session(const char *seat) {
return seat_get_can(seat, "CAN_MULTI_SESSION");
}
_public_ int sd_seat_can_tty(const char *seat) {
return seat_get_can(seat, "CAN_TTY");
}
_public_ int sd_seat_can_graphical(const char *seat) {
return seat_get_can(seat, "CAN_GRAPHICAL");
}
_public_ int sd_get_seats(char ***seats) {
return get_files_in_directory("/run/systemd/seats/", seats);
}
_public_ int sd_get_sessions(char ***sessions) {
return get_files_in_directory("/run/systemd/sessions/", sessions);
}
_public_ int sd_get_uids(uid_t **users) {
_cleanup_closedir_ DIR *d;
int r = 0;
unsigned n = 0;
_cleanup_free_ uid_t *l = NULL;
d = opendir("/run/systemd/users/");
if (!d)
return -errno;
for (;;) {
struct dirent *de;
int k;
uid_t uid;
errno = 0;
de = readdir(d);
if (!de && errno != 0)
return -errno;
if (!de)
break;
dirent_ensure_type(d, de);
if (!dirent_is_file(de))
continue;
k = parse_uid(de->d_name, &uid);
if (k < 0)
continue;
if (users) {
if ((unsigned) r >= n) {
uid_t *t;
n = MAX(16, 2*r);
t = realloc(l, sizeof(uid_t) * n);
if (!t)
return -ENOMEM;
l = t;
}
assert((unsigned) r < n);
l[r++] = uid;
} else
r++;
}
if (users) {
*users = l;
l = NULL;
}
return r;
}
_public_ int sd_get_machine_names(char ***machines) {
char **l = NULL, **a, **b;
int r;
assert_return(machines, -EINVAL);
r = get_files_in_directory("/run/systemd/machines/", &l);
if (r < 0)
return r;
if (l) {
r = 0;
/* Filter out the unit: symlinks */
for (a = l, b = l; *a; a++) {
if (startswith(*a, "unit:"))
free(*a);
else {
*b = *a;
b++;
r++;
}
}
*b = NULL;
}
*machines = l;
return r;
}
_public_ int sd_machine_get_class(const char *machine, char **class) {
_cleanup_free_ char *c = NULL;
const char *p;
int r;
assert_return(machine_name_is_valid(machine), -EINVAL);
assert_return(class, -EINVAL);
p = strappenda("/run/systemd/machines/", machine);
r = parse_env_file(p, NEWLINE, "CLASS", &c, NULL);
if (r < 0)
return r;
if (!c)
return -EIO;
*class = c;
c = NULL;
return 0;
}
_public_ int sd_machine_get_ifindices(const char *machine, int **ifindices) {
_cleanup_free_ char *netif = NULL;
size_t l, allocated = 0, nr = 0;
int *ni = NULL;
const char *p, *word, *state;
int r;
assert_return(machine_name_is_valid(machine), -EINVAL);
assert_return(ifindices, -EINVAL);
p = strappenda("/run/systemd/machines/", machine);
r = parse_env_file(p, NEWLINE, "NETIF", &netif, NULL);
if (r < 0)
return r;
if (!netif) {
*ifindices = NULL;
return 0;
}
FOREACH_WORD(word, l, netif, state) {
char buf[l+1];
int ifi;
*(char*) (mempcpy(buf, word, l)) = 0;
if (safe_atoi(buf, &ifi) < 0)
continue;
if (ifi <= 0)
continue;
if (!GREEDY_REALLOC(ni, allocated, nr+1)) {
free(ni);
return -ENOMEM;
}
ni[nr++] = ifi;
}
*ifindices = ni;
return nr;
}
static inline int MONITOR_TO_FD(sd_login_monitor *m) {
return (int) (unsigned long) m - 1;
}
static inline sd_login_monitor* FD_TO_MONITOR(int fd) {
return (sd_login_monitor*) (unsigned long) (fd + 1);
}
_public_ int sd_login_monitor_new(const char *category, sd_login_monitor **m) {
int fd, k;
bool good = false;
assert_return(m, -EINVAL);
fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
if (fd < 0)
return -errno;
if (!category || streq(category, "seat")) {
k = inotify_add_watch(fd, "/run/systemd/seats/", IN_MOVED_TO|IN_DELETE);
if (k < 0) {
safe_close(fd);
return -errno;
}
good = true;
}
if (!category || streq(category, "session")) {
k = inotify_add_watch(fd, "/run/systemd/sessions/", IN_MOVED_TO|IN_DELETE);
if (k < 0) {
safe_close(fd);
return -errno;
}
good = true;
}
if (!category || streq(category, "uid")) {
k = inotify_add_watch(fd, "/run/systemd/users/", IN_MOVED_TO|IN_DELETE);
if (k < 0) {
safe_close(fd);
return -errno;
}
good = true;
}
if (!category || streq(category, "machine")) {
k = inotify_add_watch(fd, "/run/systemd/machines/", IN_MOVED_TO|IN_DELETE);
if (k < 0) {
safe_close(fd);
return -errno;
}
good = true;
}
if (!good) {
close_nointr(fd);
return -EINVAL;
}
*m = FD_TO_MONITOR(fd);
return 0;
}
_public_ sd_login_monitor* sd_login_monitor_unref(sd_login_monitor *m) {
int fd;
assert_return(m, NULL);
fd = MONITOR_TO_FD(m);
close_nointr(fd);
return NULL;
}
_public_ int sd_login_monitor_flush(sd_login_monitor *m) {
assert_return(m, -EINVAL);
return flush_fd(MONITOR_TO_FD(m));
}
_public_ int sd_login_monitor_get_fd(sd_login_monitor *m) {
assert_return(m, -EINVAL);
return MONITOR_TO_FD(m);
}
_public_ int sd_login_monitor_get_events(sd_login_monitor *m) {
assert_return(m, -EINVAL);
/* For now we will only return POLLIN here, since we don't
* need anything else ever for inotify. However, let's have
* this API to keep our options open should we later on need
* it. */
return POLLIN;
}
_public_ int sd_login_monitor_get_timeout(sd_login_monitor *m, uint64_t *timeout_usec) {
assert_return(m, -EINVAL);
assert_return(timeout_usec, -EINVAL);
/* For now we will only return (uint64_t) -1, since we don't
* need any timeout. However, let's have this API to keep our
* options open should we later on need it. */
*timeout_usec = (uint64_t) -1;
return 0;
}