1 /*
2 * Copyright (C) 2003 Bastien Nocera <hadess@hadess.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 */
19
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <fcntl.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <unistd.h>
26 #include <sys/types.h>
27 #include <sys/socket.h>
28 #include <sys/un.h>
29 #include <errno.h>
30 #include "bacon-message-connection.h"
31
32 #ifndef UNIX_PATH_MAX
33 #define UNIX_PATH_MAX 108
34 #endif
35
36 struct BaconMessageConnection {
37 /* A server accepts connections */
38 gboolean is_server;
39
40 /* The socket path itself */
41 char *path;
42
43 /* File descriptor of the socket */
44 int fd;
45 /* Channel to watch */
46 GIOChannel *chan;
47 /* Event id returned by g_io_add_watch() */
48 int conn_id;
49
50 /* Connections accepted by this connection */
51 GSList *accepted_connections;
52
53 /* callback */
54 void (*func) (const char *message, gpointer user_data);
55 gpointer data;
56 };
57
58 static gboolean
test_is_socket(const char * path)59 test_is_socket (const char *path)
60 {
61 struct stat s;
62
63 if (stat (path, &s) == -1)
64 return FALSE;
65
66 if (S_ISSOCK (s.st_mode))
67 return TRUE;
68
69 return FALSE;
70 }
71
72 static gboolean
is_owned_by_user_and_socket(const char * path)73 is_owned_by_user_and_socket (const char *path)
74 {
75 struct stat s;
76
77 if (stat (path, &s) == -1)
78 return FALSE;
79
80 if (s.st_uid != geteuid ())
81 return FALSE;
82
83 if ((s.st_mode & S_IFSOCK) != S_IFSOCK)
84 return FALSE;
85
86 return TRUE;
87 }
88
89 static gboolean server_cb (GIOChannel *source,
90 GIOCondition condition, gpointer data);
91
92 static gboolean
setup_connection(BaconMessageConnection * conn)93 setup_connection (BaconMessageConnection *conn)
94 {
95 g_return_val_if_fail (conn->chan == NULL, FALSE);
96
97 conn->chan = g_io_channel_unix_new (conn->fd);
98 if (!conn->chan) {
99 return FALSE;
100 }
101 g_io_channel_set_line_term (conn->chan, "\n", 1);
102 conn->conn_id = g_io_add_watch (conn->chan, G_IO_IN, server_cb, conn);
103
104 return TRUE;
105 }
106
107 static void
accept_new_connection(BaconMessageConnection * server_conn)108 accept_new_connection (BaconMessageConnection *server_conn)
109 {
110 BaconMessageConnection *conn;
111 int alen;
112
113 g_return_if_fail (server_conn->is_server);
114
115 conn = g_new0 (BaconMessageConnection, 1);
116 conn->is_server = FALSE;
117 conn->func = server_conn->func;
118 conn->data = server_conn->data;
119
120 conn->fd = accept (server_conn->fd, NULL, (guint *)&alen);
121
122 server_conn->accepted_connections =
123 g_slist_prepend (server_conn->accepted_connections, conn);
124
125 setup_connection (conn);
126 }
127
128 static gboolean
server_cb(GIOChannel * source,GIOCondition condition,gpointer data)129 server_cb (GIOChannel *source, GIOCondition condition, gpointer data)
130 {
131 BaconMessageConnection *conn = (BaconMessageConnection *)data;
132 char *message, *subs, buf;
133 int cd, rc, offset;
134 gboolean finished;
135
136 offset = 0;
137 if (conn->is_server && conn->fd == g_io_channel_unix_get_fd (source)) {
138 accept_new_connection (conn);
139 return TRUE;
140 }
141 message = g_malloc (1);
142 cd = conn->fd;
143 rc = read (cd, &buf, 1);
144 while (rc > 0 && buf != '\n')
145 {
146 message = g_realloc (message, rc + offset + 1);
147 message[offset] = buf;
148 offset = offset + rc;
149 rc = read (cd, &buf, 1);
150 }
151 if (rc <= 0) {
152 g_io_channel_shutdown (conn->chan, FALSE, NULL);
153 g_io_channel_unref (conn->chan);
154 conn->chan = NULL;
155 close (conn->fd);
156 conn->fd = -1;
157 g_free (message);
158 conn->conn_id = 0;
159
160 return FALSE;
161 }
162 message[offset] = '\0';
163
164 subs = message;
165 finished = FALSE;
166
167 while (finished == FALSE && *subs != '\0')
168 {
169 if (conn->func)
170 (*conn->func) (subs, conn->data);
171
172 subs += strlen (subs) + 1;
173 if (subs - message >= offset)
174 finished = TRUE;
175 }
176
177 g_free (message);
178
179 return TRUE;
180 }
181
182 static char *
find_file_with_pattern(const char * dir,const char * pattern)183 find_file_with_pattern (const char *dir, const char *pattern)
184 {
185 GDir *filedir;
186 char *found_filename;
187 const char *filename;
188 GPatternSpec *pat;
189
190 filedir = g_dir_open (dir, 0, NULL);
191 if (!filedir)
192 return NULL;
193
194 pat = g_pattern_spec_new (pattern);
195 if (!pat)
196 {
197 g_dir_close (filedir);
198 return NULL;
199 }
200
201 found_filename = NULL;
202
203 while ((filename = g_dir_read_name (filedir)))
204 {
205 if (g_pattern_match_string (pat, filename))
206 {
207 char *tmp = g_build_filename (dir, filename, NULL);
208 if (is_owned_by_user_and_socket (tmp))
209 found_filename = g_strdup (filename);
210 g_free (tmp);
211 }
212
213 if (found_filename)
214 break;
215 }
216
217 g_pattern_spec_free (pat);
218 g_dir_close (filedir);
219
220 return found_filename;
221 }
222
223 static char *
socket_filename(const char * prefix)224 socket_filename (const char *prefix)
225 {
226 char *pattern, *newfile, *path, *filename;
227 const char *tmpdir;
228
229 pattern = g_strdup_printf ("%s.%s.*", prefix, g_get_user_name ());
230 tmpdir = g_get_tmp_dir ();
231 filename = find_file_with_pattern (tmpdir, pattern);
232 if (!filename)
233 {
234 newfile = g_strdup_printf ("%s.%s.%u", prefix,
235 g_get_user_name (), g_random_int ());
236 path = g_build_filename (tmpdir, newfile, NULL);
237 g_free (newfile);
238 } else {
239 path = g_build_filename (tmpdir, filename, NULL);
240 g_free (filename);
241 }
242
243 g_free (pattern);
244 return path;
245 }
246
247 static gboolean
try_server(BaconMessageConnection * conn)248 try_server (BaconMessageConnection *conn)
249 {
250 struct sockaddr_un uaddr;
251
252 uaddr.sun_family = AF_UNIX;
253 strncpy (uaddr.sun_path, conn->path,
254 MIN (strlen(conn->path)+1, UNIX_PATH_MAX));
255 conn->fd = socket (PF_UNIX, SOCK_STREAM, 0);
256 if (bind (conn->fd, (struct sockaddr *) &uaddr, sizeof (uaddr)) == -1)
257 {
258 conn->fd = -1;
259 return FALSE;
260 }
261 listen (conn->fd, 5);
262
263 if (!setup_connection (conn))
264 return FALSE;
265 return TRUE;
266 }
267
268 static gboolean
try_client(BaconMessageConnection * conn)269 try_client (BaconMessageConnection *conn)
270 {
271 struct sockaddr_un uaddr;
272
273 uaddr.sun_family = AF_UNIX;
274 strncpy (uaddr.sun_path, conn->path,
275 MIN(strlen(conn->path)+1, UNIX_PATH_MAX));
276 conn->fd = socket (PF_UNIX, SOCK_STREAM, 0);
277 if (connect (conn->fd, (struct sockaddr *) &uaddr,
278 sizeof (uaddr)) == -1)
279 {
280 conn->fd = -1;
281 return FALSE;
282 }
283
284 return setup_connection (conn);
285 }
286
287 BaconMessageConnection *
bacon_message_connection_new(const char * prefix)288 bacon_message_connection_new (const char *prefix)
289 {
290 BaconMessageConnection *conn;
291
292 g_return_val_if_fail (prefix != NULL, NULL);
293
294 conn = g_new0 (BaconMessageConnection, 1);
295 conn->path = socket_filename (prefix);
296
297 if (test_is_socket (conn->path) == FALSE)
298 {
299 if (!try_server (conn))
300 {
301 bacon_message_connection_free (conn);
302 return NULL;
303 }
304
305 conn->is_server = TRUE;
306 return conn;
307 }
308
309 if (try_client (conn) == FALSE)
310 {
311 unlink (conn->path);
312 try_server (conn);
313 if (conn->fd == -1)
314 {
315 bacon_message_connection_free (conn);
316 return NULL;
317 }
318
319 conn->is_server = TRUE;
320 return conn;
321 }
322
323 conn->is_server = FALSE;
324 return conn;
325 }
326
327 void
bacon_message_connection_free(BaconMessageConnection * conn)328 bacon_message_connection_free (BaconMessageConnection *conn)
329 {
330 GSList *child_conn;
331
332 g_return_if_fail (conn != NULL);
333 /* Only servers can accept other connections */
334 g_return_if_fail (conn->is_server != FALSE || !conn->accepted_connections);
335
336 child_conn = conn->accepted_connections;
337 while (child_conn) {
338 bacon_message_connection_free (child_conn->data);
339 child_conn = g_slist_next (child_conn);
340 }
341 g_slist_free (conn->accepted_connections);
342
343 if (conn->conn_id) {
344 g_source_remove (conn->conn_id);
345 conn->conn_id = 0;
346 }
347 if (conn->chan) {
348 g_io_channel_shutdown (conn->chan, FALSE, NULL);
349 g_io_channel_unref (conn->chan);
350 }
351
352 if (conn->is_server != FALSE) {
353 unlink (conn->path);
354 }
355 if (conn->fd != -1) {
356 close (conn->fd);
357 }
358
359 g_free (conn->path);
360 g_free (conn);
361 }
362
363 void
bacon_message_connection_set_callback(BaconMessageConnection * conn,BaconMessageReceivedFunc func,gpointer user_data)364 bacon_message_connection_set_callback (BaconMessageConnection *conn,
365 BaconMessageReceivedFunc func,
366 gpointer user_data)
367 {
368 g_return_if_fail (conn != NULL);
369
370 conn->func = func;
371 conn->data = user_data;
372 }
373
374 void
bacon_message_connection_send(BaconMessageConnection * conn,const char * message)375 bacon_message_connection_send (BaconMessageConnection *conn,
376 const char *message)
377 {
378 g_return_if_fail (conn != NULL);
379 g_return_if_fail (message != NULL);
380
381 g_io_channel_write_chars (conn->chan, message, strlen (message),
382 NULL, NULL);
383 g_io_channel_write_chars (conn->chan, "\n", 1, NULL, NULL);
384 g_io_channel_flush (conn->chan, NULL);
385 }
386
387 gboolean
bacon_message_connection_get_is_server(BaconMessageConnection * conn)388 bacon_message_connection_get_is_server (BaconMessageConnection *conn)
389 {
390 g_return_val_if_fail (conn != NULL, FALSE);
391
392 return conn->is_server;
393 }
394
395