apps/app_zapras.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>zaptel</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 #include <zaptel/zaptel.h>
  52
  53 #include "asterisk/lock.h"
  54 #include "asterisk/file.h"
  55 #include "asterisk/logger.h"
  56 #include "asterisk/channel.h"
  57 #include "asterisk/pbx.h"
  58 #include "asterisk/module.h"
  59 #include "asterisk/options.h"
  60
  61 static char *app = "ZapRAS";
  62
  63 static char *synopsis = "Executes Zaptel ISDN RAS application";
  64
  65 static char *descrip =
  66 "  ZapRAS(args): Executes a RAS server using pppd on the given channel.\n"
  67 "The channel must be a clear channel (i.e. PRI source) and a Zaptel\n"
  68 "channel to be able to use this function (No modem emulation is included).\n"
  69 "Your pppd must be patched to be zaptel aware. Arguments should be\n"
  70 "separated by | characters.\n";
  71
  72
  73 #define PPP_MAX_ARGS    32
  74 #define PPP_EXEC        "/usr/sbin/pppd"
  75
  76 static pid_t spawn_ras(struct ast_channel *chan, char *args)
  77 {
  78         pid_t pid;
  79         int x;
  80         char *c;
  81
  82         char *argv[PPP_MAX_ARGS];
  83         int argc = 0;
  84         char *stringp=NULL;
  85         sigset_t fullset, oldset;
  86
  87         sigfillset(&fullset);
  88         pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
  89
  90         /* Start by forking */
  91         pid = fork();
  92         if (pid) {
  93                 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
  94                 return pid;
  95         }
  96
  97         /* Restore original signal handlers */
  98         for (x=0;x<NSIG;x++)
  99                 signal(x, SIG_DFL);
 100
 101         pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
 102
 103         /* Execute RAS on File handles */
 104         dup2(chan->fds[0], STDIN_FILENO);
 105
 106         /* Drop high priority */
 107         if (ast_opt_high_priority)
 108                 ast_set_priority(0);
 109
 110         /* Close other file descriptors */
 111         for (x=STDERR_FILENO + 1;x<1024;x++)
 112                 close(x);
 113
 114         /* Reset all arguments */
 115         memset(argv, 0, sizeof(argv));
 116
 117         /* First argument is executable, followed by standard
 118            arguments for zaptel PPP */
 119         argv[argc++] = PPP_EXEC;
 120         argv[argc++] = "nodetach";
 121
 122         /* And all the other arguments */
 123         stringp=args;
 124         c = strsep(&stringp, "|");
 125         while(c && strlen(c) && (argc < (PPP_MAX_ARGS - 4))) {
 126                 argv[argc++] = c;
 127                 c = strsep(&stringp, "|");
 128         }
 129
 130         argv[argc++] = "plugin";
 131         argv[argc++] = "zaptel.so";
 132         argv[argc++] = "stdin";
 133
 134         /* Finally launch PPP */
 135         execv(PPP_EXEC, argv);
 136         fprintf(stderr, "Failed to exec PPPD!\n");
 137         exit(1);
 138 }
 139
 140 static void run_ras(struct ast_channel *chan, char *args)
 141 {
 142         pid_t pid;
 143         int status;
 144         int res;
 145         int signalled = 0;
 146         struct zt_bufferinfo savebi;
 147         int x;
 148
 149         res = ioctl(chan->fds[0], ZT_GET_BUFINFO, &savebi);
 150         if(res) {
 151                 ast_log(LOG_WARNING, "Unable to check buffer policy on channel %s\n", chan->name);
 152                 return;
 153         }
 154
 155         pid = spawn_ras(chan, args);
 156         if (pid < 0) {
 157                 ast_log(LOG_WARNING, "Failed to spawn RAS\n");
 158         } else {
 159                 for (;;) {
 160                         res = wait4(pid, &status, WNOHANG, NULL);
 161                         if (!res) {
 162                                 /* Check for hangup */
 163                                 if (chan->_softhangup && !signalled) {
 164                                         ast_log(LOG_DEBUG, "Channel '%s' hungup.  Signalling RAS at %d to die...\n", chan->name, pid);
 165                                         kill(pid, SIGTERM);
 166                                         signalled=1;
 167                                 }
 168                                 /* Try again */
 169                                 sleep(1);
 170                                 continue;
 171                         }
 172                         if (res < 0) {
 173                                 ast_log(LOG_WARNING, "wait4 returned %d: %s\n", res, strerror(errno));
 174                         }
 175                         if (option_verbose > 2) {
 176                                 if (WIFEXITED(status)) {
 177                                         ast_verbose(VERBOSE_PREFIX_3 "RAS on %s terminated with status %d\n", chan->name, WEXITSTATUS(status));
 178                                 } else if (WIFSIGNALED(status)) {
 179                                         ast_verbose(VERBOSE_PREFIX_3 "RAS on %s terminated with signal %d\n",
 180                                                  chan->name, WTERMSIG(status));
 181                                 } else {
 182                                         ast_verbose(VERBOSE_PREFIX_3 "RAS on %s terminated weirdly.\n", chan->name);
 183                                 }
 184                         }
 185                         /* Throw back into audio mode */
 186                         x = 1;
 187                         ioctl(chan->fds[0], ZT_AUDIOMODE, &x);
 188
 189                         /* Restore saved values */
 190                         res = ioctl(chan->fds[0], ZT_SET_BUFINFO, &savebi);
 191                         if (res < 0) {
 192                                 ast_log(LOG_WARNING, "Unable to set buffer policy on channel %s\n", chan->name);
 193                         }
 194                         break;
 195                 }
 196         }
 197 }
 198
 199 static int zapras_exec(struct ast_channel *chan, void *data)
 200 {
 201         int res=-1;
 202         char *args;
 203         struct ast_module_user *u;
 204         ZT_PARAMS ztp;
 205
 206         if (!data)
 207                 data = "";
 208
 209         u = ast_module_user_add(chan);
 210
 211         args = ast_strdupa(data);
 212
 213         /* Answer the channel if it's not up */
 214         if (chan->_state != AST_STATE_UP)
 215                 ast_answer(chan);
 216         if (strcasecmp(chan->tech->type, "Zap")) {
 217                 /* If it's not a zap channel, we're done.  Wait a couple of
 218                    seconds and then hangup... */
 219                 if (option_verbose > 1)
 220                         ast_verbose(VERBOSE_PREFIX_2 "Channel %s is not a Zap channel\n", chan->name);
 221                 sleep(2);
 222         } else {
 223                 memset(&ztp, 0, sizeof(ztp));
 224                 if (ioctl(chan->fds[0], ZT_GET_PARAMS, &ztp)) {
 225                         ast_log(LOG_WARNING, "Unable to get zaptel parameters\n");
 226                 } else if (ztp.sigtype != ZT_SIG_CLEAR) {
 227                         if (option_verbose > 1)
 228                                 ast_verbose(VERBOSE_PREFIX_2 "Channel %s is not a clear channel\n", chan->name);
 229                 } else {
 230                         /* Everything should be okay.  Run PPP. */
 231                         if (option_verbose > 2)
 232                                 ast_verbose(VERBOSE_PREFIX_3 "Starting RAS on %s\n", chan->name);
 233                         /* Execute RAS */
 234                         run_ras(chan, args);
 235                 }
 236         }
 237         ast_module_user_remove(u);
 238         return res;
 239 }
 240
 241 static int unload_module(void)
 242 {
 243         int res;
 244
 245         res = ast_unregister_application(app);
 246
 247         ast_module_user_hangup_all();
 248
 249         return res;
 250 }
 251
 252 static int load_module(void)
 253 {
 254         return ast_register_application(app, zapras_exec, synopsis, descrip);
 255 }
 256
 257 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Zap RAS Application");
 258