#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 "dbus-common.h"

#include "def.h"

#include "socket-util.h"

#include "fileio.h"

static int parse_argv(pam_handle_t *handle,

int argc, const char **argv,

const char **class,

bool *debug) {

unsigned i;

assert(argc >= 0);

assert(argc == 0 || argv);

for (i = 0; i < (unsigned) argc; i++) {

int k;

if (startswith(argv[i], "class=")) {

if (class)

*class = argv[i] + 6;

} else if (startswith(argv[i], "debug=")) {

k = parse_boolean(argv[i] + 6);

if (k < 0) {

pam_syslog(handle, LOG_ERR, "Failed to parse debug= argument.");

return k;

}

if (debug)

*debug = k;

} else {

pam_syslog(handle, LOG_WARNING, "Unknown parameter '%s', ignoring", argv[i]);

return 0;

}

}

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;

uid_t uid;

int r;

assert(handle);

assert(ret_username);

assert(ret_pw);

r = audit_loginuid_from_pid(0, &uid);

if (r >= 0)

pw = pam_modutil_getpwuid(handle, uid);

else {

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) {

_cleanup_free_ char *p = NULL;

int r;

_cleanup_close_ int fd = -1;

union sockaddr_union sa = {

.un.sun_family = AF_UNIX,

};

struct ucred ucred;

socklen_t l;

_cleanup_free_ char *tty = NULL;

int v;

assert(display);

assert(vtnr);

/* We deduce the X11 socket from the display name, then use

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;

l = sizeof(ucred);

r = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &l);

if (r < 0)

return -errno;

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;

}

_public_ PAM_EXTERN int pam_sm_open_session(

pam_handle_t *handle,

int flags,

int argc, const char **argv) {

struct passwd *pw;

bool 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 = NULL, *class = NULL, *class_pam = NULL, *cvtnr = NULL;

DBusError error;

uint32_t uid, pid;

DBusMessageIter iter;

int session_fd = -1;

DBusConnection *bus = NULL;

DBusMessage *m = NULL, *reply = NULL;

dbus_bool_t remote, existing;

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-logind systems */

if (!logind_running())

return PAM_SUCCESS;

if (parse_argv(handle,

argc, argv,

&class_pam,

&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

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;

}

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, "XDG_SEAT");

if (isempty(seat))

seat = getenv("XDG_SEAT");

cvtnr = pam_getenv(handle, "XDG_VTNR");

if (isempty(cvtnr))

cvtnr = getenv("XDG_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,

if (isempty(display))

display = tty;

tty = "";

} else if (streq(tty, "cron")) {

/* cron has been setting PAM_TTY to "cron" for a very

tty = "";

type = "unspecified";

} else if (streq(tty, "ssh")) {

/* ssh has been setting PAM_TTY to "ssh" for a very

tty = "";

type ="tty";

}

/* If this fails vtnr will be 0, that's intended */

if (!isempty(cvtnr))

safe_atou32(cvtnr, &vtnr);

if (!isempty(display) && vtnr <= 0) {

if (isempty(seat))

get_seat_from_display(display, &seat, &vtnr);

else if (streq(seat, "seat0"))

get_seat_from_display(display, NULL, &vtnr);

}

if (!type)

type = !isempty(display) ? "x11" :

!isempty(tty) ? "tty" : "unspecified";

class = pam_getenv(handle, "XDG_SESSION_CLASS");

if (isempty(class))

class = getenv("XDG_SESSION_CLASS");

if (isempty(class))

class = class_pam;

if (isempty(class))

class = streq(type, "unspecified") ? "background" : "user";

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, &class,

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);

if (debug)

pam_syslog(handle, LOG_DEBUG, "Asking logind to create session: "

"uid=%u pid=%u service=%s type=%s class=%s seat=%s vtnr=%u tty=%s display=%s remote=%s remote_user=%s remote_host=%s",

uid, pid, service, type, class, seat, vtnr, tty, display, yes_no(remote), remote_user, remote_host);

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_STRING, &seat,

DBUS_TYPE_UINT32, &vtnr,

DBUS_TYPE_BOOLEAN, &existing,

DBUS_TYPE_INVALID)) {

pam_syslog(handle, LOG_ERR, "Failed to parse message: %s", bus_error_message(&error));

r = PAM_SESSION_ERR;

goto finish;

}

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",

id, object_path, runtime_path, session_fd, seat, vtnr);

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 (!isempty(seat)) {

r = pam_misc_setenv(handle, "XDG_SEAT", seat, 0);

if (r != PAM_SUCCESS) {

pam_syslog(handle, LOG_ERR, "Failed to set seat.");

goto finish;

}

}

if (vtnr > 0) {

char buf[11];

snprintf(buf, sizeof(buf), "%u", vtnr);

char_array_0(buf);

r = pam_misc_setenv(handle, "XDG_VTNR", buf, 0);

if (r != PAM_SUCCESS) {

pam_syslog(handle, LOG_ERR, "Failed to set virtual terminal number.");

goto finish;

}

}

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) {

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:

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, *existing = NULL;

const char *id;

DBusConnection *bus = NULL;

DBusMessage *m = NULL, *reply = NULL;

DBusError error;

int r;

assert(handle);

dbus_error_init(&error);

/* Only release session if it wasn't pre-existing when we

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

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",

"ReleaseSession");

if (!m) {

pam_syslog(handle, LOG_ERR, "Could not allocate release session message.");

r = PAM_BUF_ERR;

goto finish;

}

if (!dbus_message_append_args(m,

DBUS_TYPE_STRING, &id,

DBUS_TYPE_INVALID)) {

pam_syslog(handle, LOG_ERR, "Could not attach parameters 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 release session: %s", bus_error_message(&error));

r = PAM_SESSION_ERR;

goto finish;

}

}

r = PAM_SUCCESS;

finish:

pam_get_data(handle, "systemd.session-fd", &p);

if (p)

close_nointr(PTR_TO_INT(p) - 1);

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);

return r;

}