src/bacon-message-connection.c

   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
  31 #include "bacon-message-connection.h"
  32
  33 #ifndef UNIX_PATH_MAX
  34 #define UNIX_PATH_MAX 108
  35 #endif
  36
  37 struct BaconMessageConnection {
  38         /* A server accepts connections */
  39         gboolean is_server;
  40
  41         /* The socket path itself */
  42         char *path;
  43
  44         /* File descriptor of the socket */
  45         int fd;
  46         /* Channel to watch */
  47         GIOChannel *chan;
  48         /* Event id returned by g_io_add_watch() */
  49         int conn_id;
  50
  51         /* Connections accepted by this connection */
  52         GSList *accepted_connections;
  53
  54         /* callback */
  55         void (*func) (const char *message, gpointer user_data);
  56         gpointer data;
  57 };
  58
  59 static gboolean
  60 test_is_socket (const char *path)
  61 {
  62         struct stat s;
  63
  64         if (stat (path, &s) == -1)
  65                 return FALSE;
  66
  67         if (S_ISSOCK (s.st_mode))
  68                 return TRUE;
  69
  70         return FALSE;
  71 }
  72
  73 static gboolean
  74 is_owned_by_user_and_socket (const char *path)
  75 {
  76         struct stat s;
  77
  78         if (stat (path, &s) == -1)
  79                 return FALSE;
  80
  81         if (s.st_uid != geteuid ())
  82                 return FALSE;
  83
  84         if ((s.st_mode & S_IFSOCK) != S_IFSOCK)
  85                 return FALSE;
  86
  87         return TRUE;
  88 }
  89
  90 static gboolean server_cb (GIOChannel *source,
  91                            GIOCondition condition, gpointer data);
  92
  93 static gboolean
  94 setup_connection (BaconMessageConnection *conn)
  95 {
  96         g_return_val_if_fail (conn->chan == NULL, FALSE);
  97
  98         conn->chan = g_io_channel_unix_new (conn->fd);
  99         if (!conn->chan) {
 100                 return FALSE;
 101         }
 102         g_io_channel_set_line_term (conn->chan, "\n", 1);
 103         conn->conn_id = g_io_add_watch (conn->chan, G_IO_IN, server_cb, conn);
 104
 105         return TRUE;
 106 }
 107
 108 static void
 109 accept_new_connection (BaconMessageConnection *server_conn)
 110 {
 111         BaconMessageConnection *conn;
 112         int alen;
 113
 114         g_return_if_fail (server_conn->is_server);
 115
 116         conn = g_new0 (BaconMessageConnection, 1);
 117         conn->is_server = FALSE;
 118         conn->func = server_conn->func;
 119         conn->data = server_conn->data;
 120
 121         conn->fd = accept (server_conn->fd, NULL, (guint *)&alen);
 122
 123         server_conn->accepted_connections =
 124                 g_slist_prepend (server_conn->accepted_connections, conn);
 125
 126         setup_connection (conn);
 127 }
 128
 129 static gboolean
 130 server_cb (GIOChannel *source, GIOCondition condition, gpointer data)
 131 {
 132         BaconMessageConnection *conn = (BaconMessageConnection *)data;
 133         char *message, *subs, buf;
 134         int cd, rc, offset;
 135         gboolean finished;
 136
 137         offset = 0;
 138         if (conn->is_server && conn->fd == g_io_channel_unix_get_fd (source)) {
 139                 accept_new_connection (conn);
 140                 return TRUE;
 141         }
 142         message = g_malloc (1);
 143         cd = conn->fd;
 144         rc = read (cd, &buf, 1);
 145         while (rc > 0 && buf != '\n')
 146         {
 147                 message = g_realloc (message, rc + offset + 1);
 148                 message[offset] = buf;
 149                 offset = offset + rc;
 150                 rc = read (cd, &buf, 1);
 151         }
 152         if (rc <= 0) {
 153                 g_io_channel_shutdown (conn->chan, FALSE, NULL);
 154                 g_io_channel_unref (conn->chan);
 155                 conn->chan = NULL;
 156                 close (conn->fd);
 157                 conn->fd = -1;
 158                 g_free (message);
 159                 conn->conn_id = 0;
 160
 161                 return FALSE;
 162         }
 163         message[offset] = '\0';
 164
 165         subs = message;
 166         finished = FALSE;
 167
 168         while (finished == FALSE && *subs != '\0')
 169         {
 170                 if (conn->func != NULL)
 171                         (*conn->func) (subs, conn->data);
 172
 173                 subs += strlen (subs) + 1;
 174                 if (subs - message >= offset)
 175                         finished = TRUE;
 176         }
 177
 178         g_free (message);
 179
 180         return TRUE;
 181 }
 182
 183 static char *
 184 find_file_with_pattern (const char *dir, const char *pattern)
 185 {
 186         GDir *filedir;
 187         char *found_filename;
 188         const char *filename;
 189         GPatternSpec *pat;
 190
 191         filedir = g_dir_open (dir, 0, NULL);
 192         if (filedir == NULL)
 193                 return NULL;
 194
 195         pat = g_pattern_spec_new (pattern);
 196         if (pat == NULL)
 197         {
 198                 g_dir_close (filedir);
 199                 return NULL;
 200         }
 201
 202         found_filename = NULL;
 203
 204         while ((filename = g_dir_read_name (filedir)))
 205         {
 206                 if (g_pattern_match_string (pat, filename))
 207                 {
 208                         char *tmp = g_build_filename (dir, filename, NULL);
 209                         if (is_owned_by_user_and_socket (tmp))
 210                                 found_filename = g_strdup (filename);
 211                         g_free (tmp);
 212                 }
 213
 214                 if (found_filename != NULL)
 215                         break;
 216         }
 217
 218         g_pattern_spec_free (pat);
 219         g_dir_close (filedir);
 220
 221         return found_filename;
 222 }
 223
 224 static char *
 225 socket_filename (const char *prefix)
 226 {
 227         char *pattern, *newfile, *path, *filename;
 228         const char *tmpdir;
 229
 230         pattern = g_strdup_printf ("%s.%s.*", prefix, g_get_user_name ());
 231         tmpdir = g_get_tmp_dir ();
 232         filename = find_file_with_pattern (tmpdir, pattern);
 233         if (filename == NULL)
 234         {
 235                 newfile = g_strdup_printf ("%s.%s.%u", prefix,
 236                                 g_get_user_name (), g_random_int ());
 237                 path = g_build_filename (tmpdir, newfile, NULL);
 238                 g_free (newfile);
 239         } else {
 240                 path = g_build_filename (tmpdir, filename, NULL);
 241                 g_free (filename);
 242         }
 243
 244         g_free (pattern);
 245         return path;
 246 }
 247
 248 static gboolean
 249 try_server (BaconMessageConnection *conn)
 250 {
 251         struct sockaddr_un uaddr;
 252
 253         uaddr.sun_family = AF_UNIX;
 254         strncpy (uaddr.sun_path, conn->path,
 255                         MIN (strlen(conn->path)+1, UNIX_PATH_MAX));
 256         conn->fd = socket (PF_UNIX, SOCK_STREAM, 0);
 257         if (bind (conn->fd, (struct sockaddr *) &uaddr, sizeof (uaddr)) == -1)
 258         {
 259                 conn->fd = -1;
 260                 return FALSE;
 261         }
 262         listen (conn->fd, 5);
 263
 264         if (!setup_connection (conn))
 265                 return FALSE;
 266         return TRUE;
 267 }
 268
 269 static gboolean
 270 try_client (BaconMessageConnection *conn)
 271 {
 272         struct sockaddr_un uaddr;
 273
 274         uaddr.sun_family = AF_UNIX;
 275         strncpy (uaddr.sun_path, conn->path,
 276                         MIN(strlen(conn->path)+1, UNIX_PATH_MAX));
 277         conn->fd = socket (PF_UNIX, SOCK_STREAM, 0);
 278         if (connect (conn->fd, (struct sockaddr *) &uaddr,
 279                                 sizeof (uaddr)) == -1)
 280         {
 281                 conn->fd = -1;
 282                 return FALSE;
 283         }
 284
 285         return setup_connection (conn);
 286 }
 287
 288 BaconMessageConnection *
 289 bacon_message_connection_new (const char *prefix)
 290 {
 291         BaconMessageConnection *conn;
 292
 293         g_return_val_if_fail (prefix != NULL, NULL);
 294
 295         conn = g_new0 (BaconMessageConnection, 1);
 296         conn->path = socket_filename (prefix);
 297
 298         if (test_is_socket (conn->path) == FALSE)
 299         {
 300                 if (!try_server (conn))
 301                 {
 302                         bacon_message_connection_free (conn);
 303                         return NULL;
 304                 }
 305
 306                 conn->is_server = TRUE;
 307                 return conn;
 308         }
 309
 310         if (try_client (conn) == FALSE)
 311         {
 312                 unlink (conn->path);
 313                 try_server (conn);
 314                 if (conn->fd == -1)
 315                 {
 316                         bacon_message_connection_free (conn);
 317                         return NULL;
 318                 }
 319
 320                 conn->is_server = TRUE;
 321                 return conn;
 322         }
 323
 324         conn->is_server = FALSE;
 325         return conn;
 326 }
 327
 328 void
 329 bacon_message_connection_free (BaconMessageConnection *conn)
 330 {
 331         GSList *child_conn;
 332
 333         g_return_if_fail (conn != NULL);
 334         /* Only servers can accept other connections */
 335         g_return_if_fail (conn->is_server != FALSE ||
 336                           conn->accepted_connections == NULL);
 337
 338         child_conn = conn->accepted_connections;
 339         while (child_conn != NULL) {
 340                 bacon_message_connection_free (child_conn->data);
 341                 child_conn = g_slist_next (child_conn);
 342         }
 343         g_slist_free (conn->accepted_connections);
 344
 345         if (conn->conn_id) {
 346                 g_source_remove (conn->conn_id);
 347                 conn->conn_id = 0;
 348         }
 349         if (conn->chan) {
 350                 g_io_channel_shutdown (conn->chan, FALSE, NULL);
 351                 g_io_channel_unref (conn->chan);
 352         }
 353
 354         if (conn->is_server != FALSE) {
 355                 unlink (conn->path);
 356         }
 357         if (conn->fd != -1) {
 358                 close (conn->fd);
 359         }
 360
 361         g_free (conn->path);
 362         g_free (conn);
 363 }
 364
 365 void
 366 bacon_message_connection_set_callback (BaconMessageConnection *conn,
 367                                        BaconMessageReceivedFunc func,
 368                                        gpointer user_data)
 369 {
 370         g_return_if_fail (conn != NULL);
 371
 372         conn->func = func;
 373         conn->data = user_data;
 374 }
 375
 376 void
 377 bacon_message_connection_send (BaconMessageConnection *conn,
 378                                const char *message)
 379 {
 380         g_return_if_fail (conn != NULL);
 381         g_return_if_fail (message != NULL);
 382
 383         g_io_channel_write_chars (conn->chan, message, strlen (message),
 384                                   NULL, NULL);
 385         g_io_channel_write_chars (conn->chan, "\n", 1, NULL, NULL);
 386         g_io_channel_flush (conn->chan, NULL);
 387 }
 388
 389 gboolean
 390 bacon_message_connection_get_is_server (BaconMessageConnection *conn)
 391 {
 392         g_return_val_if_fail (conn != NULL, FALSE);
 393
 394         return conn->is_server;
 395 }
 396