547 lines
19 KiB
C
547 lines
19 KiB
C
/*-*- 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 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 <errno.h>
|
|
#include <fcntl.h>
|
|
#include <sys/file.h>
|
|
#include <pwd.h>
|
|
#include <endian.h>
|
|
|
|
#include <security/pam_modules.h>
|
|
#include <security/_pam_macros.h>
|
|
#include <security/pam_modutil.h>
|
|
#include <security/pam_ext.h>
|
|
#include <security/pam_misc.h>
|
|
|
|
#include "util.h"
|
|
#include "audit.h"
|
|
#include "macro.h"
|
|
#include "strv.h"
|
|
#include "bus-util.h"
|
|
#include "def.h"
|
|
#include "socket-util.h"
|
|
#include "fileio.h"
|
|
#include "bus-error.h"
|
|
#include "formats-util.h"
|
|
#include "terminal-util.h"
|
|
#include "hostname-util.h"
|
|
|
|
static int parse_argv(
|
|
pam_handle_t *handle,
|
|
int argc, const char **argv,
|
|
const char **class,
|
|
const char **type,
|
|
bool *debug) {
|
|
|
|
unsigned i;
|
|
|
|
assert(argc >= 0);
|
|
assert(argc == 0 || argv);
|
|
|
|
for (i = 0; i < (unsigned) argc; i++) {
|
|
if (startswith(argv[i], "class=")) {
|
|
if (class)
|
|
*class = argv[i] + 6;
|
|
|
|
} else if (startswith(argv[i], "type=")) {
|
|
if (type)
|
|
*type = argv[i] + 5;
|
|
|
|
} else if (streq(argv[i], "debug")) {
|
|
if (debug)
|
|
*debug = true;
|
|
|
|
} else if (startswith(argv[i], "debug=")) {
|
|
int k;
|
|
|
|
k = parse_boolean(argv[i] + 6);
|
|
if (k < 0)
|
|
pam_syslog(handle, LOG_WARNING, "Failed to parse debug= argument, ignoring.");
|
|
else if (debug)
|
|
*debug = k;
|
|
|
|
} else
|
|
pam_syslog(handle, LOG_WARNING, "Unknown parameter '%s', ignoring", argv[i]);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int get_user_data(
|
|
pam_handle_t *handle,
|
|
const char **ret_username,
|
|
struct passwd **ret_pw) {
|
|
|
|
const char *username = NULL;
|
|
struct passwd *pw = NULL;
|
|
int r;
|
|
|
|
assert(handle);
|
|
assert(ret_username);
|
|
assert(ret_pw);
|
|
|
|
r = pam_get_user(handle, &username, NULL);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to get user name.");
|
|
return r;
|
|
}
|
|
|
|
if (isempty(username)) {
|
|
pam_syslog(handle, LOG_ERR, "User name not valid.");
|
|
return PAM_AUTH_ERR;
|
|
}
|
|
|
|
pw = pam_modutil_getpwnam(handle, username);
|
|
if (!pw) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to get user data.");
|
|
return PAM_USER_UNKNOWN;
|
|
}
|
|
|
|
*ret_pw = pw;
|
|
*ret_username = username;
|
|
|
|
return PAM_SUCCESS;
|
|
}
|
|
|
|
static int get_seat_from_display(const char *display, const char **seat, uint32_t *vtnr) {
|
|
union sockaddr_union sa = {
|
|
.un.sun_family = AF_UNIX,
|
|
};
|
|
_cleanup_free_ char *p = NULL, *tty = NULL;
|
|
_cleanup_close_ int fd = -1;
|
|
struct ucred ucred;
|
|
int v, r;
|
|
|
|
assert(display);
|
|
assert(vtnr);
|
|
|
|
/* We deduce the X11 socket from the display name, then use
|
|
* SO_PEERCRED to determine the X11 server process, ask for
|
|
* the controlling tty of that and if it's a VC then we know
|
|
* the seat and the virtual terminal. Sounds ugly, is only
|
|
* semi-ugly. */
|
|
|
|
r = socket_from_display(display, &p);
|
|
if (r < 0)
|
|
return r;
|
|
strncpy(sa.un.sun_path, p, sizeof(sa.un.sun_path)-1);
|
|
|
|
fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0)
|
|
return -errno;
|
|
|
|
r = getpeercred(fd, &ucred);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = get_ctty(ucred.pid, NULL, &tty);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
v = vtnr_from_tty(tty);
|
|
if (v < 0)
|
|
return v;
|
|
else if (v == 0)
|
|
return -ENOENT;
|
|
|
|
if (seat)
|
|
*seat = "seat0";
|
|
*vtnr = (uint32_t) v;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int export_legacy_dbus_address(
|
|
pam_handle_t *handle,
|
|
uid_t uid,
|
|
const char *runtime) {
|
|
|
|
_cleanup_free_ char *s = NULL;
|
|
int r;
|
|
|
|
/* skip export if kdbus is not active */
|
|
if (access("/sys/fs/kdbus", F_OK) < 0)
|
|
return PAM_SUCCESS;
|
|
|
|
if (asprintf(&s, KERNEL_USER_BUS_ADDRESS_FMT ";" UNIX_USER_BUS_ADDRESS_FMT, uid, runtime) < 0) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to set bus variable.");
|
|
return PAM_BUF_ERR;
|
|
}
|
|
|
|
r = pam_misc_setenv(handle, "DBUS_SESSION_BUS_ADDRESS", s, 0);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to set bus variable.");
|
|
return r;
|
|
}
|
|
|
|
return PAM_SUCCESS;
|
|
}
|
|
|
|
_public_ PAM_EXTERN int pam_sm_open_session(
|
|
pam_handle_t *handle,
|
|
int flags,
|
|
int argc, const char **argv) {
|
|
|
|
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
|
|
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
|
|
const char
|
|
*username, *id, *object_path, *runtime_path,
|
|
*service = NULL,
|
|
*tty = NULL, *display = NULL,
|
|
*remote_user = NULL, *remote_host = NULL,
|
|
*seat = NULL,
|
|
*type = NULL, *class = NULL,
|
|
*class_pam = NULL, *type_pam = NULL, *cvtnr = NULL, *desktop = NULL;
|
|
_cleanup_bus_close_unref_ sd_bus *bus = NULL;
|
|
int session_fd = -1, existing, r;
|
|
bool debug = false, remote;
|
|
struct passwd *pw;
|
|
uint32_t vtnr = 0;
|
|
uid_t original_uid;
|
|
|
|
assert(handle);
|
|
|
|
/* Make this a NOP on non-logind systems */
|
|
if (!logind_running())
|
|
return PAM_SUCCESS;
|
|
|
|
if (parse_argv(handle,
|
|
argc, argv,
|
|
&class_pam,
|
|
&type_pam,
|
|
&debug) < 0)
|
|
return PAM_SESSION_ERR;
|
|
|
|
if (debug)
|
|
pam_syslog(handle, LOG_DEBUG, "pam-systemd initializing");
|
|
|
|
r = get_user_data(handle, &username, &pw);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to get user data.");
|
|
return r;
|
|
}
|
|
|
|
/* Make sure we don't enter a loop by talking to
|
|
* systemd-logind when it is actually waiting for the
|
|
* background to finish start-up. If the service is
|
|
* "systemd-user" we simply set XDG_RUNTIME_DIR and
|
|
* leave. */
|
|
|
|
pam_get_item(handle, PAM_SERVICE, (const void**) &service);
|
|
if (streq_ptr(service, "systemd-user")) {
|
|
_cleanup_free_ char *p = NULL, *rt = NULL;
|
|
|
|
if (asprintf(&p, "/run/systemd/users/"UID_FMT, pw->pw_uid) < 0)
|
|
return PAM_BUF_ERR;
|
|
|
|
r = parse_env_file(p, NEWLINE,
|
|
"RUNTIME", &rt,
|
|
NULL);
|
|
if (r < 0 && r != -ENOENT)
|
|
return PAM_SESSION_ERR;
|
|
|
|
if (rt) {
|
|
r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", rt, 0);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
|
|
return r;
|
|
}
|
|
|
|
r = export_legacy_dbus_address(handle, pw->pw_uid, rt);
|
|
if (r != PAM_SUCCESS)
|
|
return r;
|
|
}
|
|
|
|
return PAM_SUCCESS;
|
|
}
|
|
|
|
/* Otherwise, we ask logind to create a session for us */
|
|
|
|
pam_get_item(handle, PAM_XDISPLAY, (const void**) &display);
|
|
pam_get_item(handle, PAM_TTY, (const void**) &tty);
|
|
pam_get_item(handle, PAM_RUSER, (const void**) &remote_user);
|
|
pam_get_item(handle, PAM_RHOST, (const void**) &remote_host);
|
|
|
|
seat = pam_getenv(handle, "XDG_SEAT");
|
|
if (isempty(seat))
|
|
seat = getenv("XDG_SEAT");
|
|
|
|
cvtnr = pam_getenv(handle, "XDG_VTNR");
|
|
if (isempty(cvtnr))
|
|
cvtnr = getenv("XDG_VTNR");
|
|
|
|
type = pam_getenv(handle, "XDG_SESSION_TYPE");
|
|
if (isempty(type))
|
|
type = getenv("XDG_SESSION_TYPE");
|
|
if (isempty(type))
|
|
type = type_pam;
|
|
|
|
class = pam_getenv(handle, "XDG_SESSION_CLASS");
|
|
if (isempty(class))
|
|
class = getenv("XDG_SESSION_CLASS");
|
|
if (isempty(class))
|
|
class = class_pam;
|
|
|
|
desktop = pam_getenv(handle, "XDG_SESSION_DESKTOP");
|
|
if (isempty(desktop))
|
|
desktop = getenv("XDG_SESSION_DESKTOP");
|
|
|
|
tty = strempty(tty);
|
|
|
|
if (strchr(tty, ':')) {
|
|
/* A tty with a colon is usually an X11 display,
|
|
* placed there to show up in utmp. We rearrange
|
|
* things and don't pretend that an X display was a
|
|
* tty. */
|
|
|
|
if (isempty(display))
|
|
display = tty;
|
|
tty = NULL;
|
|
} else if (streq(tty, "cron")) {
|
|
/* cron has been setting PAM_TTY to "cron" for a very
|
|
* long time and it probably shouldn't stop doing that
|
|
* for compatibility reasons. */
|
|
type = "unspecified";
|
|
class = "background";
|
|
tty = NULL;
|
|
} else if (streq(tty, "ssh")) {
|
|
/* ssh has been setting PAM_TTY to "ssh" for a very
|
|
* long time and probably shouldn't stop doing that
|
|
* for compatibility reasons. */
|
|
type ="tty";
|
|
class = "user";
|
|
tty = NULL;
|
|
}
|
|
|
|
/* If this fails vtnr will be 0, that's intended */
|
|
if (!isempty(cvtnr))
|
|
(void) safe_atou32(cvtnr, &vtnr);
|
|
|
|
if (!isempty(display) && !vtnr) {
|
|
if (isempty(seat))
|
|
get_seat_from_display(display, &seat, &vtnr);
|
|
else if (streq(seat, "seat0"))
|
|
get_seat_from_display(display, NULL, &vtnr);
|
|
}
|
|
|
|
if (seat && !streq(seat, "seat0") && vtnr != 0) {
|
|
pam_syslog(handle, LOG_DEBUG, "Ignoring vtnr %"PRIu32" for %s which is not seat0", vtnr, seat);
|
|
vtnr = 0;
|
|
}
|
|
|
|
if (isempty(type))
|
|
type = !isempty(display) ? "x11" :
|
|
!isempty(tty) ? "tty" : "unspecified";
|
|
|
|
if (isempty(class))
|
|
class = streq(type, "unspecified") ? "background" : "user";
|
|
|
|
remote = !isempty(remote_host) && !is_localhost(remote_host);
|
|
|
|
/* Talk to logind over the message bus */
|
|
|
|
r = sd_bus_open_system(&bus);
|
|
if (r < 0) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", strerror(-r));
|
|
return PAM_SESSION_ERR;
|
|
}
|
|
|
|
if (debug)
|
|
pam_syslog(handle, LOG_DEBUG, "Asking logind to create session: "
|
|
"uid="UID_FMT" pid="PID_FMT" service=%s type=%s class=%s desktop=%s seat=%s vtnr=%"PRIu32" tty=%s display=%s remote=%s remote_user=%s remote_host=%s",
|
|
pw->pw_uid, getpid(),
|
|
strempty(service),
|
|
type, class, strempty(desktop),
|
|
strempty(seat), vtnr, strempty(tty), strempty(display),
|
|
yes_no(remote), strempty(remote_user), strempty(remote_host));
|
|
|
|
r = sd_bus_call_method(bus,
|
|
"org.freedesktop.login1",
|
|
"/org/freedesktop/login1",
|
|
"org.freedesktop.login1.Manager",
|
|
"CreateSession",
|
|
&error,
|
|
&reply,
|
|
"uusssssussbssa(sv)",
|
|
(uint32_t) pw->pw_uid,
|
|
(uint32_t) getpid(),
|
|
service,
|
|
type,
|
|
class,
|
|
desktop,
|
|
seat,
|
|
vtnr,
|
|
tty,
|
|
display,
|
|
remote,
|
|
remote_user,
|
|
remote_host,
|
|
0);
|
|
if (r < 0) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to create session: %s", bus_error_message(&error, r));
|
|
return PAM_SYSTEM_ERR;
|
|
}
|
|
|
|
r = sd_bus_message_read(reply,
|
|
"soshusub",
|
|
&id,
|
|
&object_path,
|
|
&runtime_path,
|
|
&session_fd,
|
|
&original_uid,
|
|
&seat,
|
|
&vtnr,
|
|
&existing);
|
|
if (r < 0) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to parse message: %s", strerror(-r));
|
|
return PAM_SESSION_ERR;
|
|
}
|
|
|
|
if (debug)
|
|
pam_syslog(handle, LOG_DEBUG, "Reply from logind: "
|
|
"id=%s object_path=%s runtime_path=%s session_fd=%d seat=%s vtnr=%u original_uid=%u",
|
|
id, object_path, runtime_path, session_fd, seat, vtnr, original_uid);
|
|
|
|
r = pam_misc_setenv(handle, "XDG_SESSION_ID", id, 0);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to set session id.");
|
|
return r;
|
|
}
|
|
|
|
if (original_uid == pw->pw_uid) {
|
|
/* Don't set $XDG_RUNTIME_DIR if the user we now
|
|
* authenticated for does not match the original user
|
|
* of the session. We do this in order not to result
|
|
* in privileged apps clobbering the runtime directory
|
|
* unnecessarily. */
|
|
|
|
r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", runtime_path, 0);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to set runtime dir.");
|
|
return r;
|
|
}
|
|
|
|
r = export_legacy_dbus_address(handle, pw->pw_uid, runtime_path);
|
|
if (r != PAM_SUCCESS)
|
|
return r;
|
|
}
|
|
|
|
if (!isempty(seat)) {
|
|
r = pam_misc_setenv(handle, "XDG_SEAT", seat, 0);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to set seat.");
|
|
return r;
|
|
}
|
|
}
|
|
|
|
if (vtnr > 0) {
|
|
char buf[DECIMAL_STR_MAX(vtnr)];
|
|
sprintf(buf, "%u", vtnr);
|
|
|
|
r = pam_misc_setenv(handle, "XDG_VTNR", buf, 0);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to set virtual terminal number.");
|
|
return r;
|
|
}
|
|
}
|
|
|
|
r = pam_set_data(handle, "systemd.existing", INT_TO_PTR(!!existing), NULL);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to install existing flag.");
|
|
return r;
|
|
}
|
|
|
|
if (session_fd >= 0) {
|
|
session_fd = fcntl(session_fd, F_DUPFD_CLOEXEC, 3);
|
|
if (session_fd < 0) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to dup session fd: %m");
|
|
return PAM_SESSION_ERR;
|
|
}
|
|
|
|
r = pam_set_data(handle, "systemd.session-fd", INT_TO_PTR(session_fd+1), NULL);
|
|
if (r != PAM_SUCCESS) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to install session fd.");
|
|
safe_close(session_fd);
|
|
return r;
|
|
}
|
|
}
|
|
|
|
return PAM_SUCCESS;
|
|
}
|
|
|
|
_public_ PAM_EXTERN int pam_sm_close_session(
|
|
pam_handle_t *handle,
|
|
int flags,
|
|
int argc, const char **argv) {
|
|
|
|
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
|
|
_cleanup_bus_close_unref_ sd_bus *bus = NULL;
|
|
const void *existing = NULL;
|
|
const char *id;
|
|
int r;
|
|
|
|
assert(handle);
|
|
|
|
/* Only release session if it wasn't pre-existing when we
|
|
* tried to create it */
|
|
pam_get_data(handle, "systemd.existing", &existing);
|
|
|
|
id = pam_getenv(handle, "XDG_SESSION_ID");
|
|
if (id && !existing) {
|
|
|
|
/* Before we go and close the FIFO we need to tell
|
|
* logind that this is a clean session shutdown, so
|
|
* that it doesn't just go and slaughter us
|
|
* immediately after closing the fd */
|
|
|
|
r = sd_bus_open_system(&bus);
|
|
if (r < 0) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", strerror(-r));
|
|
return PAM_SESSION_ERR;
|
|
}
|
|
|
|
r = sd_bus_call_method(bus,
|
|
"org.freedesktop.login1",
|
|
"/org/freedesktop/login1",
|
|
"org.freedesktop.login1.Manager",
|
|
"ReleaseSession",
|
|
&error,
|
|
NULL,
|
|
"s",
|
|
id);
|
|
if (r < 0) {
|
|
pam_syslog(handle, LOG_ERR, "Failed to release session: %s", bus_error_message(&error, r));
|
|
return PAM_SESSION_ERR;
|
|
}
|
|
}
|
|
|
|
/* Note that we are knowingly leaking the FIFO fd here. This
|
|
* way, logind can watch us die. If we closed it here it would
|
|
* not have any clue when that is completed. Given that one
|
|
* cannot really have multiple PAM sessions open from the same
|
|
* process this means we will leak one FD at max. */
|
|
|
|
return PAM_SUCCESS;
|
|
}
|