| /*-*- 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 General Public License as published by |
| the Free Software Foundation; either version 2 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 |
| General Public License for more details. |
| |
| You should have received a copy of the GNU 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 "macro.h" |
| #include "sd-daemon.h" |
| #include "strv.h" |
| #include "dbus-common.h" |
| #include "def.h" |
| #include "socket-util.h" |
| |
| static int parse_argv(pam_handle_t *handle, |
| int argc, const char **argv, |
| char ***controllers, |
| char ***reset_controllers, |
| bool *kill_processes, |
| char ***kill_only_users, |
| char ***kill_exclude_users, |
| bool *debug) { |
| |
| unsigned i; |
| |
| assert(argc >= 0); |
| assert(argc == 0 || argv); |
| |
| for (i = 0; i < (unsigned) argc; i++) { |
| int k; |
| |
| if (startswith(argv[i], "kill-session-processes=")) { |
| if ((k = parse_boolean(argv[i] + 23)) < 0) { |
| pam_syslog(handle, LOG_ERR, "Failed to parse kill-session-processes= argument."); |
| return k; |
| } |
| |
| if (kill_processes) |
| *kill_processes = k; |
| |
| } else if (startswith(argv[i], "kill-session=")) { |
| /* As compatibility for old versions */ |
| |
| if ((k = parse_boolean(argv[i] + 13)) < 0) { |
| pam_syslog(handle, LOG_ERR, "Failed to parse kill-session= argument."); |
| return k; |
| } |
| |
| if (kill_processes) |
| *kill_processes = k; |
| |
| } else if (startswith(argv[i], "controllers=")) { |
| |
| if (controllers) { |
| char **l; |
| |
| if (!(l = strv_split(argv[i] + 12, ","))) { |
| pam_syslog(handle, LOG_ERR, "Out of memory."); |
| return -ENOMEM; |
| } |
| |
| strv_free(*controllers); |
| *controllers = l; |
| } |
| |
| } else if (startswith(argv[i], "reset-controllers=")) { |
| |
| if (reset_controllers) { |
| char **l; |
| |
| if (!(l = strv_split(argv[i] + 18, ","))) { |
| pam_syslog(handle, LOG_ERR, "Out of memory."); |
| return -ENOMEM; |
| } |
| |
| strv_free(*reset_controllers); |
| *reset_controllers = l; |
| } |
| |
| } else if (startswith(argv[i], "kill-only-users=")) { |
| |
| if (kill_only_users) { |
| char **l; |
| |
| if (!(l = strv_split(argv[i] + 16, ","))) { |
| pam_syslog(handle, LOG_ERR, "Out of memory."); |
| return -ENOMEM; |
| } |
| |
| strv_free(*kill_only_users); |
| *kill_only_users = l; |
| } |
| |
| } else if (startswith(argv[i], "kill-exclude-users=")) { |
| |
| if (kill_exclude_users) { |
| char **l; |
| |
| if (!(l = strv_split(argv[i] + 19, ","))) { |
| pam_syslog(handle, LOG_ERR, "Out of memory."); |
| return -ENOMEM; |
| } |
| |
| strv_free(*kill_exclude_users); |
| *kill_exclude_users = l; |
| } |
| |
| } else if (startswith(argv[i], "debug=")) { |
| if ((k = parse_boolean(argv[i] + 6)) < 0) { |
| pam_syslog(handle, LOG_ERR, "Failed to parse debug= argument."); |
| return k; |
| } |
| |
| if (debug) |
| *debug = k; |
| |
| } else if (startswith(argv[i], "create-session=") || |
| startswith(argv[i], "kill-user=")) { |
| |
| pam_syslog(handle, LOG_WARNING, "Option %s not supported anymore, ignoring.", argv[i]); |
| |
| } else { |
| pam_syslog(handle, LOG_ERR, "Unknown parameter '%s'.", argv[i]); |
| return -EINVAL; |
| } |
| } |
| |
| 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; |
| bool have_loginuid = false; |
| char *s; |
| |
| assert(handle); |
| assert(ret_username); |
| assert(ret_pw); |
| |
| if (have_effective_cap(CAP_AUDIT_CONTROL) > 0) { |
| /* Only use audit login uid if we are executed with |
| * sufficient capabilities so that pam_loginuid could |
| * do its job. If we are lacking the CAP_AUDIT_CONTROL |
| * capabality we most likely are being run in a |
| * container and /proc/self/loginuid is useless since |
| * it probably contains a uid of the host system. */ |
| |
| if (read_one_line_file("/proc/self/loginuid", &s) >= 0) { |
| uint32_t u; |
| |
| r = safe_atou32(s, &u); |
| free(s); |
| |
| if (r >= 0 && u != (uint32_t) -1 && u > 0) { |
| have_loginuid = true; |
| pw = pam_modutil_getpwuid(handle, u); |
| } |
| } |
| } |
| |
| if (!have_loginuid) { |
| if ((r = pam_get_user(handle, &username, NULL)) != PAM_SUCCESS) { |
| pam_syslog(handle, LOG_ERR, "Failed to get user name."); |
| return r; |
| } |
| |
| if (!username || !*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 bool check_user_lists( |
| pam_handle_t *handle, |
| uid_t uid, |
| char **kill_only_users, |
| char **kill_exclude_users) { |
| |
| const char *name = NULL; |
| char **l; |
| |
| assert(handle); |
| |
| if (uid == 0) |
| name = "root"; /* Avoid obvious NSS requests, to suppress network traffic */ |
| else { |
| struct passwd *pw; |
| |
| pw = pam_modutil_getpwuid(handle, uid); |
| if (pw) |
| name = pw->pw_name; |
| } |
| |
| STRV_FOREACH(l, kill_exclude_users) { |
| uint32_t id; |
| |
| if (safe_atou32(*l, &id) >= 0) |
| if ((uid_t) id == uid) |
| return false; |
| |
| if (name && streq(name, *l)) |
| return false; |
| } |
| |
| if (strv_isempty(kill_only_users)) |
| return true; |
| |
| STRV_FOREACH(l, kill_only_users) { |
| uint32_t id; |
| |
| if (safe_atou32(*l, &id) >= 0) |
| if ((uid_t) id == uid) |
| return true; |
| |
| if (name && streq(name, *l)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static int get_seat_from_display(const char *display, const char **seat, uint32_t *vtnr) { |
| char *p = NULL; |
| int r; |
| int fd; |
| union sockaddr_union sa; |
| struct ucred ucred; |
| socklen_t l; |
| char *tty; |
| int v; |
| |
| assert(display); |
| assert(seat); |
| 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; |
| |
| fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0); |
| if (fd < 0) { |
| free(p); |
| return -errno; |
| } |
| |
| zero(sa); |
| sa.un.sun_family = AF_UNIX; |
| strncpy(sa.un.sun_path, p, sizeof(sa.un.sun_path)-1); |
| free(p); |
| |
| if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) { |
| close_nointr_nofail(fd); |
| return -errno; |
| } |
| |
| l = sizeof(ucred); |
| r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &l); |
| close_nointr_nofail(fd); |
| |
| if (r < 0) |
| return -errno; |
| |
| r = get_ctty(ucred.pid, NULL, &tty); |
| if (r < 0) |
| return r; |
| |
| v = vtnr_from_tty(tty); |
| free(tty); |
| |
| if (v < 0) |
| return v; |
| else if (v == 0) |
| return -ENOENT; |
| |
| *seat = "seat0"; |
| *vtnr = (uint32_t) v; |
| |
| return 0; |
| } |
| |
| _public_ PAM_EXTERN int pam_sm_open_session( |
| pam_handle_t *handle, |
| int flags, |
| int argc, const char **argv) { |
| |
| struct passwd *pw; |
| bool kill_processes = false, debug = false; |
| const char *username, *id, *object_path, *runtime_path, *service = NULL, *tty = NULL, *display = NULL, *remote_user = NULL, *remote_host = NULL, *seat = NULL, *type, *cvtnr = NULL; |
| char **controllers = NULL, **reset_controllers = NULL, **kill_only_users = NULL, **kill_exclude_users = NULL; |
| DBusError error; |
| uint32_t uid, pid; |
| DBusMessageIter iter; |
| dbus_bool_t kp; |
| int session_fd = -1; |
| DBusConnection *bus = NULL; |
| DBusMessage *m = NULL, *reply = NULL; |
| dbus_bool_t remote; |
| int r; |
| uint32_t vtnr = 0; |
| |
| assert(handle); |
| |
| dbus_error_init(&error); |
| |
| /* pam_syslog(handle, LOG_INFO, "pam-systemd initializing"); */ |
| |
| /* Make this a NOP on non-systemd systems */ |
| if (sd_booted() <= 0) |
| return PAM_SUCCESS; |
| |
| if (parse_argv(handle, |
| argc, argv, |
| &controllers, &reset_controllers, |
| &kill_processes, &kill_only_users, &kill_exclude_users, |
| &debug) < 0) { |
| r = PAM_SESSION_ERR; |
| goto finish; |
| } |
| |
| r = get_user_data(handle, &username, &pw); |
| if (r != PAM_SUCCESS) |
| goto finish; |
| |
| /* 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-shared" we simply set XDG_RUNTIME_DIR and |
| * leave. */ |
| |
| pam_get_item(handle, PAM_SERVICE, (const void**) &service); |
| if (streq_ptr(service, "systemd-shared")) { |
| char *p, *rt = NULL; |
| |
| if (asprintf(&p, "/run/systemd/users/%lu", (unsigned long) pw->pw_uid) < 0) { |
| r = PAM_BUF_ERR; |
| goto finish; |
| } |
| |
| r = parse_env_file(p, NEWLINE, |
| "RUNTIME", &rt, |
| NULL); |
| free(p); |
| |
| if (r < 0 && r != -ENOENT) { |
| r = PAM_SESSION_ERR; |
| free(rt); |
| goto finish; |
| } |
| |
| if (rt) { |
| r = pam_misc_setenv(handle, "XDG_RUNTIME_DIR", rt, 0); |
| free(rt); |
| |
| if (r != PAM_SUCCESS) { |
| pam_syslog(handle, LOG_ERR, "Failed to set runtime dir."); |
| goto finish; |
| } |
| } |
| |
| r = PAM_SUCCESS; |
| goto finish; |
| } |
| |
| if (kill_processes) |
| kill_processes = check_user_lists(handle, pw->pw_uid, kill_only_users, kill_exclude_users); |
| |
| dbus_connection_set_change_sigpipe(FALSE); |
| |
| bus = dbus_bus_get_private(DBUS_BUS_SYSTEM, &error); |
| if (!bus) { |
| pam_syslog(handle, LOG_ERR, "Failed to connect to system bus: %s", bus_error_message(&error)); |
| r = PAM_SESSION_ERR; |
| goto finish; |
| } |
| |
| m = dbus_message_new_method_call( |
| "org.freedesktop.login1", |
| "/org/freedesktop/login1", |
| "org.freedesktop.login1.Manager", |
| "CreateSession"); |
| |
| if (!m) { |
| pam_syslog(handle, LOG_ERR, "Could not allocate create session message."); |
| r = PAM_BUF_ERR; |
| goto finish; |
| } |
| |
| uid = pw->pw_uid; |
| pid = getpid(); |
| |
| 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, "LOGIN_SEAT"); |
| cvtnr = pam_getenv(handle, "LOGIN_VTNR"); |
| |
| service = strempty(service); |
| tty = strempty(tty); |
| display = strempty(display); |
| remote_user = strempty(remote_user); |
| remote_host = strempty(remote_host); |
| seat = strempty(seat); |
| |
| if (strchr(tty, ':')) { |
| /* A tty with a colon is usually an X11 display, place |
| * 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 = ""; |
| } |
| |
| if (!isempty(cvtnr)) |
| safe_atou32(cvtnr, &vtnr); |
| |
| if (!isempty(display) && isempty(seat) && vtnr <= 0) |
| get_seat_from_display(display, &seat, &vtnr); |
| |
| type = !isempty(display) ? "x11" : |
| !isempty(tty) ? "tty" : "other"; |
| |
| remote = !isempty(remote_host) && !streq(remote_host, "localhost") && !streq(remote_host, "localhost.localdomain"); |
| |
| if (!dbus_message_append_args(m, |
| DBUS_TYPE_UINT32, &uid, |
| DBUS_TYPE_UINT32, &pid, |
| DBUS_TYPE_STRING, &service, |
| DBUS_TYPE_STRING, &type, |
| DBUS_TYPE_STRING, &seat, |
| DBUS_TYPE_UINT32, &vtnr, |
| DBUS_TYPE_STRING, &tty, |
| DBUS_TYPE_STRING, &display, |
| DBUS_TYPE_BOOLEAN, &remote, |
| DBUS_TYPE_STRING, &remote_user, |
| DBUS_TYPE_STRING, &remote_host, |
| DBUS_TYPE_INVALID)) { |
| pam_syslog(handle, LOG_ERR, "Could not attach parameters to message."); |
| r = PAM_BUF_ERR; |
| goto finish; |
| } |
| |
| dbus_message_iter_init_append(m, &iter); |
| |
| r = bus_append_strv_iter(&iter, controllers); |
| if (r < 0) { |
| pam_syslog(handle, LOG_ERR, "Could not attach parameter to message."); |
| r = PAM_BUF_ERR; |
| goto finish; |
| } |
| |
| r = bus_append_strv_iter(&iter, reset_controllers); |
| if (r < 0) { |
| pam_syslog(handle, LOG_ERR, "Could not attach parameter to message."); |
| r = PAM_BUF_ERR; |
| goto finish; |
| } |
| |
| kp = kill_processes; |
| if (!dbus_message_iter_append_basic(&iter, DBUS_TYPE_BOOLEAN, &kp)) { |
| pam_syslog(handle, LOG_ERR, "Could not attach parameter to message."); |
| r = PAM_BUF_ERR; |
| goto finish; |
| } |
| |
| reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error); |
| if (!reply) { |
| pam_syslog(handle, LOG_ERR, "Failed to create session: %s", bus_error_message(&error)); |
| r = PAM_SESSION_ERR; |
| goto finish; |
| } |
| |
| if (!dbus_message_get_args(reply, &error, |
| DBUS_TYPE_STRING, &id, |
| DBUS_TYPE_OBJECT_PATH, &object_path, |
| DBUS_TYPE_STRING, &runtime_path, |
| DBUS_TYPE_UNIX_FD, &session_fd, |
| DBUS_TYPE_INVALID)) { |
| pam_syslog(handle, LOG_ERR, "Failed to parse message: %s", bus_error_message(&error)); |
| r = PAM_SESSION_ERR; |
| goto finish; |
| } |
| |
| r = pam_misc_setenv(handle, "XDG_SESSION_ID", id, 0); |
| if (r != PAM_SUCCESS) { |
| pam_syslog(handle, LOG_ERR, "Failed to set session id."); |
| goto finish; |
| } |
| |
| 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."); |
| goto finish; |
| } |
| |
| if (session_fd >= 0) { |
| 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."); |
| return r; |
| } |
| } |
| |
| session_fd = -1; |
| |
| r = PAM_SUCCESS; |
| |
| finish: |
| strv_free(controllers); |
| strv_free(reset_controllers); |
| strv_free(kill_only_users); |
| strv_free(kill_exclude_users); |
| |
| dbus_error_free(&error); |
| |
| if (bus) { |
| dbus_connection_close(bus); |
| dbus_connection_unref(bus); |
| } |
| |
| if (m) |
| dbus_message_unref(m); |
| |
| if (reply) |
| dbus_message_unref(reply); |
| |
| if (session_fd >= 0) |
| close_nointr_nofail(session_fd); |
| |
| return r; |
| } |
| |
| _public_ PAM_EXTERN int pam_sm_close_session( |
| pam_handle_t *handle, |
| int flags, |
| int argc, const char **argv) { |
| |
| const void *p = NULL; |
| |
| pam_get_data(handle, "systemd.session-fd", &p); |
| |
| if (p) |
| close_nointr(PTR_TO_INT(p) - 1); |
| |
| return PAM_SUCCESS; |
| } |