2 * Copyright (C) 2010-2011 Robert Ancell.
3 * Author: Robert Ancell <robert.ancell@canonical.com>
5 * This program is free software: you can redistribute it and/or modify it under
6 * the terms of the GNU General Public License as published by the Free Software
7 * Foundation, either version 3 of the License, or (at your option) any later
8 * version. See http://www.gnu.org/copyleft/gpl.html the full text of the
19 #include "ldm-marshal.h"
27 static guint signals[LAST_SIGNAL] = { 0 };
31 /* Session running on */
34 /* Buffer for data read from greeter */
38 /* Hints for the greeter */
41 /* Default session to use */
42 gchar *default_session;
44 /* Sequence number of current PAM session */
45 guint32 authentication_sequence_number;
47 /* PAM session being constructed by the greeter */
48 PAMSession *authentication;
50 /* TRUE if can log into guest accounts */
53 /* TRUE if logging into guest session */
54 gboolean guest_account_authenticated;
56 /* Communication channels to communicate with */
57 GIOChannel *to_greeter_channel;
58 GIOChannel *from_greeter_channel;
61 G_DEFINE_TYPE (Greeter, greeter, G_TYPE_OBJECT);
63 /* Messages from the greeter to the server */
66 GREETER_MESSAGE_CONNECT = 0,
67 GREETER_MESSAGE_AUTHENTICATE,
68 GREETER_MESSAGE_AUTHENTICATE_AS_GUEST,
69 GREETER_MESSAGE_CONTINUE_AUTHENTICATION,
70 GREETER_MESSAGE_START_SESSION,
71 GREETER_MESSAGE_CANCEL_AUTHENTICATION,
72 GREETER_MESSAGE_SET_LANGUAGE
75 /* Messages from the server to the greeter */
78 SERVER_MESSAGE_CONNECTED = 0,
79 SERVER_MESSAGE_PROMPT_AUTHENTICATION,
80 SERVER_MESSAGE_END_AUTHENTICATION,
81 SERVER_MESSAGE_SESSION_RESULT
85 greeter_new (Session *session)
87 Greeter *greeter = g_object_new (GREETER_TYPE, NULL);
89 greeter->priv->session = g_object_ref (session);
95 greeter_set_allow_guest (Greeter *greeter, gboolean allow_guest)
97 greeter->priv->allow_guest = allow_guest;
101 greeter_set_hint (Greeter *greeter, const gchar *name, const gchar *value)
103 g_hash_table_insert (greeter->priv->hints, g_strdup (name), g_strdup (value));
112 #define HEADER_SIZE (sizeof (guint32) * 2)
113 #define MAX_MESSAGE_LENGTH 1024
116 write_message (Greeter *greeter, guint8 *message, gsize message_length)
119 GError *error = NULL;
121 status = g_io_channel_write_chars (greeter->priv->to_greeter_channel, (gchar *) message, message_length, NULL, &error);
123 g_warning ("Error writing to greeter: %s", error->message);
124 g_clear_error (&error);
125 if (status == G_IO_STATUS_NORMAL)
126 g_debug ("Wrote %zi bytes to greeter", message_length);
127 g_io_channel_flush (greeter->priv->to_greeter_channel, NULL);
131 write_int (guint8 *buffer, gint buffer_length, guint32 value, gsize *offset)
133 if (*offset + 4 >= buffer_length)
135 buffer[*offset] = value >> 24;
136 buffer[*offset+1] = (value >> 16) & 0xFF;
137 buffer[*offset+2] = (value >> 8) & 0xFF;
138 buffer[*offset+3] = value & 0xFF;
143 write_string (guint8 *buffer, gint buffer_length, const gchar *value, gsize *offset)
148 length = strlen (value);
151 write_int (buffer, buffer_length, length, offset);
152 if (*offset + length >= buffer_length)
156 memcpy (buffer + *offset, value, length);
162 write_header (guint8 *buffer, gint buffer_length, guint32 id, guint32 length, gsize *offset)
164 write_int (buffer, buffer_length, id, offset);
165 write_int (buffer, buffer_length, length, offset);
169 string_length (const gchar *value)
172 return int_length ();
174 return int_length () + strlen (value);
178 handle_connect (Greeter *greeter, const gchar *version)
180 guint8 message[MAX_MESSAGE_LENGTH];
186 g_debug ("Greeter connected version=%s", version);
188 length = string_length (VERSION);
189 g_hash_table_iter_init (&iter, greeter->priv->hints);
190 while (g_hash_table_iter_next (&iter, &key, &value))
191 length += string_length (key) + string_length (value);
193 write_header (message, MAX_MESSAGE_LENGTH, SERVER_MESSAGE_CONNECTED, length, &offset);
194 write_string (message, MAX_MESSAGE_LENGTH, VERSION, &offset);
195 g_hash_table_iter_init (&iter, greeter->priv->hints);
196 while (g_hash_table_iter_next (&iter, &key, &value))
198 write_string (message, MAX_MESSAGE_LENGTH, key, &offset);
199 write_string (message, MAX_MESSAGE_LENGTH, value, &offset);
201 write_message (greeter, message, offset);
203 g_signal_emit (greeter, signals[CONNECTED], 0);
207 pam_messages_cb (PAMSession *authentication, int num_msg, const struct pam_message **msg, Greeter *greeter)
211 guint8 message[MAX_MESSAGE_LENGTH];
215 /* Respond to d-bus query with messages */
216 g_debug ("Prompt greeter with %d message(s)", num_msg);
217 size = int_length () + string_length (pam_session_get_username (authentication)) + int_length ();
218 for (i = 0; i < num_msg; i++)
219 size += int_length () + string_length (msg[i]->msg);
221 write_header (message, MAX_MESSAGE_LENGTH, SERVER_MESSAGE_PROMPT_AUTHENTICATION, size, &offset);
222 write_int (message, MAX_MESSAGE_LENGTH, greeter->priv->authentication_sequence_number, &offset);
223 write_string (message, MAX_MESSAGE_LENGTH, pam_session_get_username (authentication), &offset);
224 write_int (message, MAX_MESSAGE_LENGTH, num_msg, &offset);
225 for (i = 0; i < num_msg; i++)
227 write_int (message, MAX_MESSAGE_LENGTH, msg[i]->msg_style, &offset);
228 write_string (message, MAX_MESSAGE_LENGTH, msg[i]->msg, &offset);
230 if (msg[i]->msg_style == PAM_PROMPT_ECHO_OFF || msg[i]->msg_style == PAM_PROMPT_ECHO_ON)
233 write_message (greeter, message, offset);
235 /* Continue immediately if nothing to respond with */
236 // FIXME: Should probably give the greeter a chance to ack the message
239 struct pam_response *response;
240 response = calloc (num_msg, sizeof (struct pam_response));
241 pam_session_respond (greeter->priv->authentication, response);
246 send_end_authentication (Greeter *greeter, guint32 sequence_number, const gchar *username, int result)
248 guint8 message[MAX_MESSAGE_LENGTH];
251 write_header (message, MAX_MESSAGE_LENGTH, SERVER_MESSAGE_END_AUTHENTICATION, int_length () + string_length (username) + int_length (), &offset);
252 write_int (message, MAX_MESSAGE_LENGTH, sequence_number, &offset);
253 write_string (message, MAX_MESSAGE_LENGTH, username, &offset);
254 write_int (message, MAX_MESSAGE_LENGTH, result, &offset);
255 write_message (greeter, message, offset);
259 authentication_result_cb (PAMSession *authentication, int result, Greeter *greeter)
261 g_debug ("Authenticate result for user %s: %s", pam_session_get_username (authentication), pam_session_strerror (authentication, result));
263 if (result == PAM_SUCCESS)
264 g_debug ("User %s authorized", pam_session_get_username (authentication));
266 send_end_authentication (greeter, greeter->priv->authentication_sequence_number, pam_session_get_username (authentication), result);
270 reset_session (Greeter *greeter)
272 if (greeter->priv->authentication)
274 g_signal_handlers_disconnect_matched (greeter->priv->authentication, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, greeter);
275 pam_session_cancel (greeter->priv->authentication);
276 g_object_unref (greeter->priv->authentication);
277 greeter->priv->authentication = NULL;
280 greeter->priv->guest_account_authenticated = FALSE;
284 handle_login (Greeter *greeter, guint32 sequence_number, const gchar *username)
287 GError *error = NULL;
289 if (username[0] == '\0')
291 g_debug ("Greeter start authentication");
295 g_debug ("Greeter start authentication for %s", username);
297 reset_session (greeter);
299 greeter->priv->authentication_sequence_number = sequence_number;
300 g_signal_emit (greeter, signals[START_AUTHENTICATION], 0, username, &greeter->priv->authentication);
301 if (!greeter->priv->authentication)
303 send_end_authentication (greeter, sequence_number, "", PAM_USER_UNKNOWN);
307 g_signal_connect (G_OBJECT (greeter->priv->authentication), "got-messages", G_CALLBACK (pam_messages_cb), greeter);
308 g_signal_connect (G_OBJECT (greeter->priv->authentication), "authentication-result", G_CALLBACK (authentication_result_cb), greeter);
309 result = pam_session_authenticate (greeter->priv->authentication, &error);
311 g_debug ("Failed to start authentication: %s", error->message);
313 send_end_authentication (greeter, sequence_number, "", PAM_SYSTEM_ERR);
314 g_clear_error (&error);
318 handle_login_as_guest (Greeter *greeter, guint32 sequence_number)
320 g_debug ("Greeter start authentication for guest account");
322 reset_session (greeter);
324 if (!greeter->priv->allow_guest)
326 g_debug ("Guest account is disabled");
327 send_end_authentication (greeter, sequence_number, "", PAM_USER_UNKNOWN);
331 greeter->priv->guest_account_authenticated = TRUE;
332 send_end_authentication (greeter, sequence_number, "", PAM_SUCCESS);
336 handle_continue_authentication (Greeter *greeter, gchar **secrets)
339 const struct pam_message **messages;
340 struct pam_response *response;
341 int i, j, n_prompts = 0;
343 /* Not in authentication */
344 if (greeter->priv->authentication == NULL)
347 num_messages = pam_session_get_num_messages (greeter->priv->authentication);
348 messages = pam_session_get_messages (greeter->priv->authentication);
350 /* Check correct number of responses */
351 for (i = 0; i < num_messages; i++)
353 int msg_style = messages[i]->msg_style;
354 if (msg_style == PAM_PROMPT_ECHO_OFF || msg_style == PAM_PROMPT_ECHO_ON)
357 if (g_strv_length (secrets) != n_prompts)
359 pam_session_cancel (greeter->priv->authentication);
363 g_debug ("Continue authentication");
366 response = calloc (num_messages, sizeof (struct pam_response));
367 for (i = 0, j = 0; i < num_messages; i++)
369 int msg_style = messages[i]->msg_style;
370 if (msg_style == PAM_PROMPT_ECHO_OFF || msg_style == PAM_PROMPT_ECHO_ON)
372 response[i].resp = strdup (secrets[j]); // FIXME: Need to convert from UTF-8
377 pam_session_respond (greeter->priv->authentication, response);
381 handle_cancel_authentication (Greeter *greeter)
383 /* Not in authentication */
384 if (greeter->priv->authentication == NULL)
387 g_debug ("Cancel authentication");
389 pam_session_cancel (greeter->priv->authentication);
393 handle_start_session (Greeter *greeter, const gchar *session)
397 if (strcmp (session, "") == 0)
400 if (greeter->priv->guest_account_authenticated || pam_session_get_is_authenticated (greeter->priv->authentication))
403 g_debug ("Greeter requests session %s", session);
405 g_debug ("Greeter requests default session");
406 g_signal_emit (greeter, signals[START_SESSION], 0, session, &result);
410 g_debug ("Ignoring start session request, user is not authorized");
416 guint8 message[MAX_MESSAGE_LENGTH];
419 write_header (message, MAX_MESSAGE_LENGTH, SERVER_MESSAGE_SESSION_RESULT, int_length (), &offset);
420 write_int (message, MAX_MESSAGE_LENGTH, 1, &offset);
421 write_message (greeter, message, offset);
426 handle_set_language (Greeter *greeter, const gchar *language)
430 if (!greeter->priv->guest_account_authenticated && !pam_session_get_is_authenticated (greeter->priv->authentication))
432 g_debug ("Ignoring set language request, user is not authorized");
436 // FIXME: Could use this
437 if (greeter->priv->guest_account_authenticated)
439 g_debug ("Ignoring set language request for guest user");
443 g_debug ("Greeter sets language %s", language);
444 user = pam_session_get_user (greeter->priv->authentication);
445 user_set_locale (user, language);
449 read_int (Greeter *greeter, gsize *offset)
453 if (greeter->priv->n_read - *offset < sizeof (guint32))
455 g_warning ("Not enough space for int, need %zu, got %zu", sizeof (guint32), greeter->priv->n_read - *offset);
458 buffer = greeter->priv->read_buffer + *offset;
459 value = buffer[0] << 24 | buffer[1] << 16 | buffer[2] << 8 | buffer[3];
460 *offset += int_length ();
465 read_string (Greeter *greeter, gsize *offset)
470 length = read_int (greeter, offset);
471 if (greeter->priv->n_read - *offset < length)
473 g_warning ("Not enough space for string, need %u, got %zu", length, greeter->priv->n_read - *offset);
474 return g_strdup ("");
477 value = g_malloc (sizeof (gchar *) * (length + 1));
478 memcpy (value, greeter->priv->read_buffer + *offset, length);
479 value[length] = '\0';
486 read_cb (GIOChannel *source, GIOCondition condition, gpointer data)
488 Greeter *greeter = data;
489 gsize n_to_read, n_read, offset;
491 int id, n_secrets, i;
492 guint32 sequence_number;
493 gchar *version, *username, *session_name, *language;
495 GError *error = NULL;
497 if (condition == G_IO_HUP)
499 g_debug ("Greeter closed communication channel");
503 n_to_read = HEADER_SIZE;
504 if (greeter->priv->n_read >= HEADER_SIZE)
506 offset = int_length ();
507 n_to_read += read_int (greeter, &offset);
510 status = g_io_channel_read_chars (greeter->priv->from_greeter_channel,
511 (gchar *) greeter->priv->read_buffer + greeter->priv->n_read,
512 n_to_read - greeter->priv->n_read,
516 g_warning ("Error reading from greeter: %s", error->message);
517 g_clear_error (&error);
518 if (status != G_IO_STATUS_NORMAL)
521 g_debug ("Read %zi bytes from greeter", n_read);
522 /*for (i = 0; i < n_read; i++)
523 g_print ("%02X ", greeter->priv->read_buffer[greeter->priv->n_read+i]);
526 greeter->priv->n_read += n_read;
527 if (greeter->priv->n_read != n_to_read)
530 /* If have header, rerun for content */
531 if (greeter->priv->n_read == HEADER_SIZE)
533 gsize offset = int_length ();
534 n_to_read = read_int (greeter, &offset);
537 greeter->priv->read_buffer = g_realloc (greeter->priv->read_buffer, HEADER_SIZE + n_to_read);
538 read_cb (source, condition, greeter);
544 id = read_int (greeter, &offset);
545 read_int (greeter, &offset);
548 case GREETER_MESSAGE_CONNECT:
549 version = read_string (greeter, &offset);
550 handle_connect (greeter, version);
553 case GREETER_MESSAGE_AUTHENTICATE:
554 sequence_number = read_int (greeter, &offset);
555 username = read_string (greeter, &offset);
556 handle_login (greeter, sequence_number, username);
559 case GREETER_MESSAGE_AUTHENTICATE_AS_GUEST:
560 sequence_number = read_int (greeter, &offset);
561 handle_login_as_guest (greeter, sequence_number);
563 case GREETER_MESSAGE_CONTINUE_AUTHENTICATION:
564 n_secrets = read_int (greeter, &offset);
565 secrets = g_malloc (sizeof (gchar *) * (n_secrets + 1));
566 for (i = 0; i < n_secrets; i++)
567 secrets[i] = read_string (greeter, &offset);
569 handle_continue_authentication (greeter, secrets);
570 g_strfreev (secrets);
572 case GREETER_MESSAGE_CANCEL_AUTHENTICATION:
573 handle_cancel_authentication (greeter);
575 case GREETER_MESSAGE_START_SESSION:
576 session_name = read_string (greeter, &offset);
577 handle_start_session (greeter, session_name);
578 g_free (session_name);
580 case GREETER_MESSAGE_SET_LANGUAGE:
581 language = read_string (greeter, &offset);
582 handle_set_language (greeter, language);
586 g_warning ("Unknown message from greeter: %d", id);
590 greeter->priv->n_read = 0;
596 greeter_start (Greeter *greeter)
598 int to_greeter_pipe[2], from_greeter_pipe[2];
602 if (pipe (to_greeter_pipe) != 0 ||
603 pipe (from_greeter_pipe) != 0)
605 g_warning ("Failed to create pipes: %s", strerror (errno));
609 greeter->priv->to_greeter_channel = g_io_channel_unix_new (to_greeter_pipe[1]);
610 g_io_channel_set_encoding (greeter->priv->to_greeter_channel, NULL, NULL);
611 greeter->priv->from_greeter_channel = g_io_channel_unix_new (from_greeter_pipe[0]);
612 g_io_channel_set_encoding (greeter->priv->from_greeter_channel, NULL, NULL);
613 g_io_channel_set_buffered (greeter->priv->from_greeter_channel, FALSE);
614 g_io_add_watch (greeter->priv->from_greeter_channel, G_IO_IN | G_IO_HUP, read_cb, greeter);
616 fd = from_greeter_pipe[1];
617 value = g_strdup_printf ("%d", fd);
618 session_set_env (greeter->priv->session, "LIGHTDM_TO_SERVER_FD", value);
621 fd = to_greeter_pipe[0];
622 value = g_strdup_printf ("%d", fd);
623 session_set_env (greeter->priv->session, "LIGHTDM_FROM_SERVER_FD", value);
630 greeter_get_guest_authenticated (Greeter *greeter)
632 g_return_val_if_fail (greeter != NULL, FALSE);
633 return greeter->priv->guest_account_authenticated;
637 greeter_get_authentication (Greeter *greeter)
639 g_return_val_if_fail (greeter != NULL, NULL);
640 return greeter->priv->authentication;
644 greeter_quit (Greeter *greeter)
646 guint8 message[MAX_MESSAGE_LENGTH];
649 g_return_if_fail (greeter != NULL);
651 write_header (message, MAX_MESSAGE_LENGTH, SERVER_MESSAGE_SESSION_RESULT, int_length (), &offset);
652 write_int (message, MAX_MESSAGE_LENGTH, 0, &offset);
653 write_message (greeter, message, offset);
657 greeter_real_start_authentication (Greeter *greeter, const gchar *username)
663 greeter_real_start_session (Greeter *greeter, const gchar *session, gboolean is_guest)
669 greeter_init (Greeter *greeter)
671 greeter->priv = G_TYPE_INSTANCE_GET_PRIVATE (greeter, GREETER_TYPE, GreeterPrivate);
672 greeter->priv->read_buffer = g_malloc (HEADER_SIZE);
673 greeter->priv->hints = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
677 greeter_finalize (GObject *object)
681 self = GREETER (object);
683 g_object_unref (self->priv->session);
684 g_free (self->priv->read_buffer);
685 g_hash_table_unref (self->priv->hints);
686 if (self->priv->authentication)
688 g_signal_handlers_disconnect_matched (self->priv->authentication, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, self);
689 pam_session_cancel (self->priv->authentication);
690 g_object_unref (self->priv->authentication);
692 if (self->priv->to_greeter_channel)
693 g_io_channel_unref (self->priv->to_greeter_channel);
694 if (self->priv->from_greeter_channel)
695 g_io_channel_unref (self->priv->from_greeter_channel);
697 G_OBJECT_CLASS (greeter_parent_class)->finalize (object);
701 greeter_class_init (GreeterClass *klass)
703 GObjectClass *object_class = G_OBJECT_CLASS (klass);
705 klass->start_authentication = greeter_real_start_authentication;
706 klass->start_session = greeter_real_start_session;
707 object_class->finalize = greeter_finalize;
710 g_signal_new ("connected",
711 G_TYPE_FROM_CLASS (klass),
713 G_STRUCT_OFFSET (GreeterClass, connected),
715 g_cclosure_marshal_VOID__VOID,
718 signals[START_AUTHENTICATION] =
719 g_signal_new ("start-authentication",
720 G_TYPE_FROM_CLASS (klass),
722 G_STRUCT_OFFSET (GreeterClass, start_authentication),
723 g_signal_accumulator_first_wins,
725 ldm_marshal_OBJECT__STRING,
726 PAM_SESSION_TYPE, 1, G_TYPE_STRING);
728 signals[START_SESSION] =
729 g_signal_new ("start-session",
730 G_TYPE_FROM_CLASS (klass),
732 G_STRUCT_OFFSET (GreeterClass, start_session),
733 g_signal_accumulator_true_handled,
735 ldm_marshal_BOOLEAN__STRING,
736 G_TYPE_BOOLEAN, 1, G_TYPE_STRING);
738 g_type_class_add_private (klass, sizeof (GreeterPrivate));