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 <fcntl.h>
  45
  46 #include "asterisk/zapata.h"
  47
  48 #include "asterisk/lock.h"
  49 #include "asterisk/file.h"
  50 #include "asterisk/channel.h"
  51 #include "asterisk/pbx.h"
  52 #include "asterisk/module.h"
  53 #include "asterisk/app.h"
  54
  55 static char *app = "ZapRAS";
  56
  57 static char *synopsis = "Executes Zaptel ISDN RAS application";
  58
  59 static char *descrip =
  60 "  ZapRAS(args): Executes a RAS server using pppd on the given channel.\n"
  61 "The channel must be a clear channel (i.e. PRI source) and a Zaptel\n"
  62 "channel to be able to use this function (No modem emulation is included).\n"
  63 "Your pppd must be patched to be zaptel aware. Arguments should be\n"
  64 "separated by , characters.\n";
  65
  66
  67 #define PPP_MAX_ARGS    32
  68 #define PPP_EXEC        "/usr/sbin/pppd"
  69
  70 static pid_t spawn_ras(struct ast_channel *chan, char *args)
  71 {
  72         pid_t pid;
  73         char *c;
  74
  75         char *argv[PPP_MAX_ARGS];
  76         int argc = 0;
  77         char *stringp=NULL;
  78
  79         /* Start by forking */
  80         pid = ast_safe_fork(1);
  81         if (pid) {
  82                 return pid;
  83         }
  84
  85         /* Execute RAS on File handles */
  86         dup2(chan->fds[0], STDIN_FILENO);
  87
  88         /* Drop high priority */
  89         if (ast_opt_high_priority)
  90                 ast_set_priority(0);
  91
  92         /* Close other file descriptors */
  93         ast_close_fds_above_n(STDERR_FILENO);
  94
  95         /* Reset all arguments */
  96         memset(argv, 0, sizeof(argv));
  97
  98         /* First argument is executable, followed by standard
  99            arguments for zaptel PPP */
 100         argv[argc++] = PPP_EXEC;
 101         argv[argc++] = "nodetach";
 102
 103         /* And all the other arguments */
 104         stringp=args;
 105         c = strsep(&stringp, ",");
 106         while(c && strlen(c) && (argc < (PPP_MAX_ARGS - 4))) {
 107                 argv[argc++] = c;
 108                 c = strsep(&stringp, ",");
 109         }
 110
 111         argv[argc++] = "plugin";
 112         argv[argc++] = "zaptel.so";
 113         argv[argc++] = "stdin";
 114
 115         /* Finally launch PPP */
 116         execv(PPP_EXEC, argv);
 117         fprintf(stderr, "Failed to exec PPPD!\n");
 118         exit(1);
 119 }
 120
 121 static void run_ras(struct ast_channel *chan, char *args)
 122 {
 123         pid_t pid;
 124         int status;
 125         int res;
 126         int signalled = 0;
 127         struct zt_bufferinfo savebi;
 128         int x;
 129
 130         res = ioctl(chan->fds[0], ZT_GET_BUFINFO, &savebi);
 131         if(res) {
 132                 ast_log(LOG_WARNING, "Unable to check buffer policy on channel %s\n", chan->name);
 133                 return;
 134         }
 135
 136         pid = spawn_ras(chan, args);
 137         if (pid < 0) {
 138                 ast_log(LOG_WARNING, "Failed to spawn RAS\n");
 139         } else {
 140                 for (;;) {
 141                         res = wait4(pid, &status, WNOHANG, NULL);
 142                         if (!res) {
 143                                 /* Check for hangup */
 144                                 if (ast_check_hangup(chan) && !signalled) {
 145                                         ast_debug(1, "Channel '%s' hungup.  Signalling RAS at %d to die...\n", chan->name, pid);
 146                                         kill(pid, SIGTERM);
 147                                         signalled=1;
 148                                 }
 149                                 /* Try again */
 150                                 sleep(1);
 151                                 continue;
 152                         }
 153                         if (res < 0) {
 154                                 ast_log(LOG_WARNING, "wait4 returned %d: %s\n", res, strerror(errno));
 155                         }
 156                         if (WIFEXITED(status)) {
 157                                 ast_verb(3, "RAS on %s terminated with status %d\n", chan->name, WEXITSTATUS(status));
 158                         } else if (WIFSIGNALED(status)) {
 159                                 ast_verb(3, "RAS on %s terminated with signal %d\n",
 160                                          chan->name, WTERMSIG(status));
 161                         } else {
 162                                 ast_verb(3, "RAS on %s terminated weirdly.\n", chan->name);
 163                         }
 164                         /* Throw back into audio mode */
 165                         x = 1;
 166                         ioctl(chan->fds[0], ZT_AUDIOMODE, &x);
 167
 168                         /* Restore saved values */
 169                         res = ioctl(chan->fds[0], ZT_SET_BUFINFO, &savebi);
 170                         if (res < 0) {
 171                                 ast_log(LOG_WARNING, "Unable to set buffer policy on channel %s\n", chan->name);
 172                         }
 173                         break;
 174                 }
 175         }
 176         ast_safe_fork_cleanup();
 177 }
 178
 179 static int zapras_exec(struct ast_channel *chan, void *data)
 180 {
 181         int res=-1;
 182         char *args;
 183         ZT_PARAMS ztp;
 184
 185         if (!data)
 186                 data = "";
 187
 188         args = ast_strdupa(data);
 189
 190         /* Answer the channel if it's not up */
 191         if (chan->_state != AST_STATE_UP)
 192                 ast_answer(chan);
 193         if (strcasecmp(chan->tech->type, "Zap")) {
 194                 /* If it's not a zap channel, we're done.  Wait a couple of
 195                    seconds and then hangup... */
 196                 ast_verb(2, "Channel %s is not a Zap channel\n", chan->name);
 197                 sleep(2);
 198         } else {
 199                 memset(&ztp, 0, sizeof(ztp));
 200                 if (ioctl(chan->fds[0], ZT_GET_PARAMS, &ztp)) {
 201                         ast_log(LOG_WARNING, "Unable to get zaptel parameters\n");
 202                 } else if (ztp.sigtype != ZT_SIG_CLEAR) {
 203                         ast_verb(2, "Channel %s is not a clear channel\n", chan->name);
 204                 } else {
 205                         /* Everything should be okay.  Run PPP. */
 206                         ast_verb(3, "Starting RAS on %s\n", chan->name);
 207                         /* Execute RAS */
 208                         run_ras(chan, args);
 209                 }
 210         }
 211         return res;
 212 }
 213
 214 static int unload_module(void)
 215 {
 216         return ast_unregister_application(app);
 217 }
 218
 219 static int load_module(void)
 220 {
 221         return ((ast_register_application(app, zapras_exec, synopsis, descrip)) ? AST_MODULE_LOAD_FAILURE : AST_MODULE_LOAD_SUCCESS);
 222 }
 223
 224 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Zaptel ISDN Remote Access Server");
 225