apps/app_dahdiras.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 1999 - 2005, Digium, Inc.
   5  *
   6  * Mark Spencer <markster@digium.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief Execute an ISDN RAS
  22  *
  23  * \author Mark Spencer <markster@digium.com>
  24  *
  25  * \ingroup applications
  26  */
  27
  28 /*** MODULEINFO
  29         <depend>dahdi</depend>
  30  ***/
  31
  32 #include "asterisk.h"
  33
  34 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  35
  36 #include <sys/ioctl.h>
  37 #include <sys/wait.h>
  38 #ifdef __linux__
  39 #include <sys/signal.h>
  40 #else
  41 #include <signal.h>
  42 #endif /* __linux__ */
  43
  44 #include <stdlib.h>
  45 #include <unistd.h>
  46 #include <string.h>
  47 #include <stdlib.h>
  48 #include <errno.h>
  49 #include <stdio.h>
  50 #include <fcntl.h>
  51
  52 #include "asterisk/lock.h"
  53 #include "asterisk/file.h"
  54 #include "asterisk/logger.h"
  55 #include "asterisk/channel.h"
  56 #include "asterisk/pbx.h"
  57 #include "asterisk/module.h"
  58 #include "asterisk/options.h"
  59
  60 #include "asterisk/dahdi_compat.h"
  61
  62 static char *dahdi_app = "DAHDIRAS";
  63 static char *zap_app = "ZapRAS";
  64
  65 static char *dahdi_synopsis = "Executes DAHDI ISDN RAS application";
  66 static char *zap_synopsis = "Executes Zaptel ISDN RAS application";
  67
  68 static char *dahdi_descrip =
  69 "  DAHDIRAS(args): Executes a RAS server using pppd on the given channel.\n"
  70 "The channel must be a clear channel (i.e. PRI source) and a DAHDI\n"
  71 "channel to be able to use this function (no modem emulation is included).\n"
  72 "Your pppd must have the DAHDI plugin available. Arguments should be\n"
  73 "separated by | characters.\n";
  74
  75 static char *zap_descrip =
  76 "  ZapRAS(args): Executes a RAS server using pppd on the given channel.\n"
  77 "The channel must be a clear channel (i.e. PRI source) and a Zaptel\n"
  78 "channel to be able to use this function (no modem emulation is included).\n"
  79 "Your pppd must have the Zaptel plugin available. Arguments should be\n"
  80 "separated by | characters.\n";
  81
  82 #define PPP_MAX_ARGS    32
  83 #define PPP_EXEC        "/usr/sbin/pppd"
  84
  85 static pid_t spawn_ras(struct ast_channel *chan, char *args)
  86 {
  87         pid_t pid;
  88         int x;
  89         char *c;
  90
  91         char *argv[PPP_MAX_ARGS];
  92         int argc = 0;
  93         char *stringp=NULL;
  94         sigset_t fullset, oldset;
  95
  96         sigfillset(&fullset);
  97         pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
  98
  99         /* Start by forking */
 100         pid = fork();
 101         if (pid) {
 102                 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 103                 return pid;
 104         }
 105
 106         /* Restore original signal handlers */
 107         for (x=0;x<NSIG;x++)
 108                 signal(x, SIG_DFL);
 109
 110         pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
 111
 112         /* Execute RAS on File handles */
 113         dup2(chan->fds[0], STDIN_FILENO);
 114
 115         /* Drop high priority */
 116         if (ast_opt_high_priority)
 117                 ast_set_priority(0);
 118
 119         /* Close other file descriptors */
 120         for (x=STDERR_FILENO + 1;x<1024;x++)
 121                 close(x);
 122
 123         /* Reset all arguments */
 124         memset(argv, 0, sizeof(argv));
 125
 126         /* First argument is executable, followed by standard
 127            arguments for DAHDI PPP */
 128         argv[argc++] = PPP_EXEC;
 129         argv[argc++] = "nodetach";
 130
 131         /* And all the other arguments */
 132         stringp=args;
 133         c = strsep(&stringp, "|");
 134         while(c && strlen(c) && (argc < (PPP_MAX_ARGS - 4))) {
 135                 argv[argc++] = c;
 136                 c = strsep(&stringp, "|");
 137         }
 138
 139         argv[argc++] = "plugin";
 140 #ifdef HAVE_ZAPTEL
 141         argv[argc++] = "zaptel.so";
 142 #else
 143         argv[argc++] = "dahdi.so";
 144 #endif
 145         argv[argc++] = "stdin";
 146
 147         /* Finally launch PPP */
 148         execv(PPP_EXEC, argv);
 149         fprintf(stderr, "Failed to exec PPPD!\n");
 150         exit(1);
 151 }
 152
 153 static void run_ras(struct ast_channel *chan, char *args)
 154 {
 155         pid_t pid;
 156         int status;
 157         int res;
 158         int signalled = 0;
 159         struct dahdi_bufferinfo savebi;
 160         int x;
 161
 162         res = ioctl(chan->fds[0], DAHDI_GET_BUFINFO, &savebi);
 163         if(res) {
 164                 ast_log(LOG_WARNING, "Unable to check buffer policy on channel %s\n", chan->name);
 165                 return;
 166         }
 167
 168         pid = spawn_ras(chan, args);
 169         if (pid < 0) {
 170                 ast_log(LOG_WARNING, "Failed to spawn RAS\n");
 171         } else {
 172                 for (;;) {
 173                         res = wait4(pid, &status, WNOHANG, NULL);
 174                         if (!res) {
 175                                 /* Check for hangup */
 176                                 if (chan->_softhangup && !signalled) {
 177                                         ast_log(LOG_DEBUG, "Channel '%s' hungup.  Signalling RAS at %d to die...\n", chan->name, pid);
 178                                         kill(pid, SIGTERM);
 179                                         signalled=1;
 180                                 }
 181                                 /* Try again */
 182                                 sleep(1);
 183                                 continue;
 184                         }
 185                         if (res < 0) {
 186                                 ast_log(LOG_WARNING, "wait4 returned %d: %s\n", res, strerror(errno));
 187                         }
 188                         if (option_verbose > 2) {
 189                                 if (WIFEXITED(status)) {
 190                                         ast_verbose(VERBOSE_PREFIX_3 "RAS on %s terminated with status %d\n", chan->name, WEXITSTATUS(status));
 191                                 } else if (WIFSIGNALED(status)) {
 192                                         ast_verbose(VERBOSE_PREFIX_3 "RAS on %s terminated with signal %d\n",
 193                                                  chan->name, WTERMSIG(status));
 194                                 } else {
 195                                         ast_verbose(VERBOSE_PREFIX_3 "RAS on %s terminated weirdly.\n", chan->name);
 196                                 }
 197                         }
 198                         /* Throw back into audio mode */
 199                         x = 1;
 200                         ioctl(chan->fds[0], DAHDI_AUDIOMODE, &x);
 201
 202                         /* Restore saved values */
 203                         res = ioctl(chan->fds[0], DAHDI_SET_BUFINFO, &savebi);
 204                         if (res < 0) {
 205                                 ast_log(LOG_WARNING, "Unable to set buffer policy on channel %s\n", chan->name);
 206                         }
 207                         break;
 208                 }
 209         }
 210 }
 211
 212 static int exec(struct ast_channel *chan, void *data)
 213 {
 214         int res=-1;
 215         char *args;
 216         struct ast_module_user *u;
 217         struct dahdi_params ztp;
 218
 219         if (!data)
 220                 data = "";
 221
 222         u = ast_module_user_add(chan);
 223
 224         args = ast_strdupa(data);
 225
 226         /* Answer the channel if it's not up */
 227         if (chan->_state != AST_STATE_UP)
 228                 ast_answer(chan);
 229         if (strcasecmp(chan->tech->type, dahdi_chan_name)) {
 230                 if (option_verbose > 1)
 231                         ast_verbose(VERBOSE_PREFIX_2 "Channel %s is not a %s channel\n", chan->name, dahdi_chan_name);
 232                 sleep(2);
 233         } else {
 234                 memset(&ztp, 0, sizeof(ztp));
 235                 if (ioctl(chan->fds[0], DAHDI_GET_PARAMS, &ztp)) {
 236                         ast_log(LOG_WARNING, "Unable to get parameters\n");
 237                 } else if (ztp.sigtype != DAHDI_SIG_CLEAR) {
 238                         if (option_verbose > 1)
 239                                 ast_verbose(VERBOSE_PREFIX_2 "Channel %s is not a clear channel\n", chan->name);
 240                 } else {
 241                         /* Everything should be okay.  Run PPP. */
 242                         if (option_verbose > 2)
 243                                 ast_verbose(VERBOSE_PREFIX_3 "Starting RAS on %s\n", chan->name);
 244                         /* Execute RAS */
 245                         run_ras(chan, args);
 246                 }
 247         }
 248         ast_module_user_remove(u);
 249         return res;
 250 }
 251
 252 static int exec_warn(struct ast_channel *chan, void *data)
 253 {
 254         ast_log(LOG_WARNING, "Use of the command %s is deprecated, please use %s instead.\n", zap_app, dahdi_app);
 255
 256         return exec(chan, data);
 257 }
 258
 259 static int unload_module(void)
 260 {
 261         int res = 0;
 262
 263         if (*dahdi_chan_mode == CHAN_DAHDI_PLUS_ZAP_MODE) {
 264                 res |= ast_unregister_application(dahdi_app);
 265         }
 266
 267         res |= ast_unregister_application(zap_app);
 268
 269         ast_module_user_hangup_all();
 270
 271         return res;
 272 }
 273
 274 static int load_module(void)
 275 {
 276         int res = 0;
 277
 278         if (*dahdi_chan_mode == CHAN_DAHDI_PLUS_ZAP_MODE) {
 279                 res |= ast_register_application(dahdi_app, exec, dahdi_synopsis, dahdi_descrip);
 280         }
 281
 282         res |= ast_register_application(zap_app, exec_warn, zap_synopsis, zap_descrip);
 283
 284         return res;
 285 }
 286
 287 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "DAHDI RAS Application");
 288