+++ /dev/null
-/*-*- 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 <sys/capability.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"
-
-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 ? username : pw->pw_name;
-
- 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) {
-
-#ifdef ENABLE_KDBUS
- _cleanup_free_ char *s = NULL;
- int r;
-
- /* skip export if kdbus is not active */
- if (access("/dev/kdbus", F_OK) < 0)
- return PAM_SUCCESS;
-
- if (asprintf(&s, KERNEL_USER_BUS_FMT ";" UNIX_USER_BUS_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;
- }
-#endif
- 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_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))
- 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 %d 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) &&
- !streq_ptr(remote_host, "localhost") &&
- !streq_ptr(remote_host, "localhost.localdomain");
-
- /* 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=%u pid=%u service=%s type=%s class=%s desktop=%s seat=%s vtnr=%u 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_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;
-}
~ianmdlvl / elogind.git / blobdiff