chan_lcr.c

   1 /*****************************************************************************\
   2 **                                                                           **
   3 ** Linux Call Router                                                         **
   4 **                                                                           **
   5 **---------------------------------------------------------------------------**
   6 ** Copyright: Andreas Eversberg                                              **
   7 **                                                                           **
   8 ** Asterisk socket client                                                    **
   9 **                                                                           **
  10 \*****************************************************************************/
  11
  12 /*
  13
  14 How does it work:
  15
  16 To connect, open a socket and send a MESSAGE_HELLO to admin socket with
  17 the application name. This name is unique an can be used for routing calls.
  18
  19 To make a call, send a MESSAGE_NEWREF and a new reference is received.
  20 When receiving a call, a new reference is received.
  21 The reference is received with MESSAGE_NEWREF.
  22
  23 Make a MESSAGE_SETUP or receive a MESSAGE_SETUP with the reference.
  24
  25 To release call and reference, send or receive MESSAGE_RELEASE.
  26 From that point on, the ref is not valid, so no other message may be sent
  27 with that reference.
  28
  29 */
  30
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <stdarg.h>
  35 #include <errno.h>
  36 #include <sys/types.h>
  37 #include <time.h>
  38 #include <unistd.h>
  39 #include <fcntl.h>
  40 #include <sys/ioctl.h>
  41 #include <sys/socket.h>
  42 #include <sys/un.h>
  43 #include "extension.h"
  44 #include "message.h"
  45 #include "admin.h"
  46 #include "cause.h"
  47 #include "bchannel.h"
  48 #include "chan_lcr.h"
  49
  50 int sock;
  51
  52 struct admin_list {
  53         struct admin_list *next;
  54         struct admin_msg msg;
  55 } *admin_first = NULL;
  56
  57 /*
  58  * channel and call instances
  59  */
  60 struct chan_call *call_first;
  61
  62 struct chan_call *find_call_ref(unsigned long ref)
  63 {
  64         struct chan_call *call = call_first;
  65
  66         while(call)
  67         {
  68                 if (call->ref == ref)
  69                         break;
  70                 call = call->next;
  71         }
  72         return(call);
  73 }
  74
  75 struct chan_call *find_call_handle(unsigned long handle)
  76 {
  77         struct chan_call *call = call_first;
  78
  79         while(call)
  80         {
  81                 if (call->bchannel_handle == handle)
  82                         break;
  83                 call = call->next;
  84         }
  85         return(call);
  86 }
  87
  88 struct chan_call *alloc_call(void)
  89 {
  90         struct chan_call **callp = &call_first;
  91
  92         while(*callp)
  93                 callp = &((*callp)->next);
  94
  95         *callp = (struct chan_call *)malloc(sizeof(struct chan_call));
  96         return(*callp);
  97 }
  98
  99 void free_call(struct chan_call *call)
 100 {
 101         struct chan_call **temp = &call_first;
 102
 103         while(*temp)
 104         {
 105                 if (*temp == call)
 106                 {
 107                         *temp = (*temp)->next;
 108                         free(call);
 109                         return;
 110                 }
 111                 temp = &((*temp)->next);
 112         }
 113 }
 114
 115
 116 /*
 117  * receive bchannel data
 118  */
 119 void rx_data(struct bchannel *bchannel, unsigned char *data, int len)
 120 {
 121 }
 122
 123 void rx_dtmf(struct bchannel *bchannel, char tone)
 124 {
 125 }
 126
 127 /*
 128  * enque message to LCR
 129  */
 130 int send_message(int message_type, unsigned long ref, union parameter *param)
 131 {
 132         struct admin_list *admin, **adminp;
 133
 134         adminp = &admin_first;
 135         while(*adminp)
 136                 adminp = &((*adminp)->next);
 137         admin = (struct admin_list *)malloc(sizeof(struct admin_list));
 138         *adminp = admin;
 139
 140         admin->msg.type = message_type;
 141         admin->msg.ref = ref;
 142         memcpy(&admin->msg.param, param, sizeof(union parameter));
 143
 144         return(0);
 145 }
 146
 147 /*
 148  * message received from LCR
 149  */
 150 int receive_message(int message_type, unsigned long ref, union parameter *param)
 151 {
 152         union parameter newparam;
 153         struct bchannel *bchannel;
 154         struct chan_call *call;
 155
 156         memset(&newparam, 0, sizeof(union parameter));
 157
 158         /* handle bchannel message*/
 159         if (message_type == MESSAGE_BCHANNEL)
 160         {
 161                 switch(param->bchannel.type)
 162                 {
 163                         case BCHANNEL_ASSIGN:
 164                         if ((bchannel = find_bchannel_handle(param->bchannel.handle)))
 165                         {
 166                                 fprintf(stderr, "error: bchannel handle %x already assigned.\n", param->bchannel.handle);
 167                                 return(-1);
 168                         }
 169                         /* create bchannel */
 170                         bchannel = alloc_bchannel(param->bchannel.handle);
 171                         if (!bchannel)
 172                         {
 173                                 fprintf(stderr, "error: alloc bchannel handle %x failed.\n", param->bchannel.handle);
 174                                 return(-1);
 175                         }
 176
 177                         /* configure channel */
 178                         bchannel->b_tx_gain = param->bchannel.tx_gain;
 179                         bchannel->b_rx_gain = param->bchannel.rx_gain;
 180                         strncpy(bchannel->b_pipeline, param->bchannel.pipeline, sizeof(bchannel->b_pipeline)-1);
 181                         if (param->bchannel.crypt_len)
 182                         {
 183                                 bchannel->b_crypt_len = param->bchannel.crypt_len;
 184                                 bchannel->b_crypt_type = param->bchannel.crypt_type;
 185                                 memcpy(bchannel->b_crypt_key, param->bchannel.crypt, param->bchannel.crypt_len);
 186                         }
 187                         bchannel->b_txdata = 0;
 188                         bchannel->b_dtmf = 1;
 189                         bchannel->b_tx_dejitter = 1;
 190
 191                         /* in case, ref is not set, this bchannel instance must
 192                          * be created until it is removed again by LCR */
 193                         /* link to call */
 194                         if ((call = find_call_ref(ref)))
 195                         {
 196                                 bchannel->ref = ref;
 197                                 call->bchannel_handle = param->bchannel.handle;
 198                         }
 199                         if (bchannel_create(bchannel))
 200                                 bchannel_activate(bchannel, 1);
 201
 202                         /* acknowledge */
 203                         newparam.bchannel.type = BCHANNEL_ASSIGN_ACK;
 204                         newparam.bchannel.handle = param->bchannel.handle;
 205                         send_message(MESSAGE_BCHANNEL, 0, &newparam);
 206                         break;
 207
 208                         case BCHANNEL_REMOVE:
 209                         if (!(bchannel = find_bchannel_handle(param->bchannel.handle)))
 210                         {
 211                                 fprintf(stderr, "error: bchannel handle %x not assigned.\n", param->bchannel.handle);
 212                                 return(-1);
 213                         }
 214                         /* unlink from call */
 215                         if ((call = find_call_ref(bchannel->ref)))
 216                         {
 217                                 call->bchannel_handle = 0;
 218                         }
 219                         /* destroy and remove bchannel */
 220                         free_bchannel(bchannel);
 221
 222                         /* acknowledge */
 223                         newparam.bchannel.type = BCHANNEL_REMOVE_ACK;
 224                         newparam.bchannel.handle = param->bchannel.handle;
 225                         send_message(MESSAGE_BCHANNEL, 0, &newparam);
 226
 227                         break;
 228
 229                         default:
 230                         fprintf(stderr, "received unknown bchannel message %d\n", param->bchannel.type);
 231                 }
 232                 return(0);
 233         }
 234
 235         /* handle new ref */
 236         if (message_type == MESSAGE_NEWREF)
 237         {
 238                 if (param->direction)
 239                 {
 240                         /* new ref from lcr */
 241                         if (!ref || find_call_ref(ref))
 242                         {
 243                                 fprintf(stderr, "illegal new ref %d received\n", ref);
 244                                 return(-1);
 245                         }
 246                         call = alloc_call();
 247                         call->ref = ref;
 248                 } else
 249                 {
 250                         /* new ref, as requested from this remote application */
 251                         call = find_call_ref(0);
 252                         if (!call)
 253                         {
 254                                 /* send release, if ref does not exist */
 255                                 newparam.disconnectinfo.cause = CAUSE_NORMAL;
 256                                 newparam.disconnectinfo.location = LOCATION_PRIVATE_LOCAL;
 257                                 send_message(MESSAGE_RELEASE, ref, &newparam);
 258                                 return(0);
 259                         }
 260                         call->ref = ref;
 261 #warning process call (send setup, if pending)
 262                 }
 263                 return(0);
 264         }
 265
 266         /* check ref */
 267         if (!ref)
 268         {
 269                 fprintf(stderr, "received message %d without ref\n", message_type);
 270                 return(-1);
 271         }
 272         call = find_call_ref(ref);
 273         if (!call)
 274         {
 275                 /* ignore ref that is not used (anymore) */
 276                 return(0);
 277         }
 278
 279         /* handle messages */
 280         switch(message_type)
 281         {
 282 #warning we must see if ref is a reply or a request, do we??
 283                 case MESSAGE_RELEASE:
 284 #warning release call
 285                 free_call(call);
 286                 return(0);
 287
 288                 case MESSAGE_SETUP:
 289 #warning handle incoming setup, send to asterisk
 290                 break;
 291         }
 292         return(0);
 293 }
 294
 295
 296 /* asterisk handler
 297  * warning! not thread safe
 298  * returns -1 for socket error, 0 for no work, 1 for work
 299  */
 300 int handle_socket(void)
 301 {
 302         int work = 0;
 303         int len;
 304         struct admin_message msg;
 305         struct admin_list *admin;
 306
 307         /* read from socket */
 308         len = read(sock, &msg, sizeof(msg));
 309         if (len == 0)
 310         {
 311                 printf("Socket closed\n");
 312                 return(-1); // socket closed
 313         }
 314         if (len > 0)
 315         {
 316                 if (len != sizeof(msg))
 317                 {
 318                         fprintf(stderr, "Socket short read (%d)\n", len);
 319                         return(-1); // socket error
 320                 }
 321                 if (msg.message != ADMIN_MESSAGE)
 322                 {
 323                         fprintf(stderr, "Socket received illegal message %d\n", msg.message);
 324                         return(-1); // socket error
 325                 }
 326                 receive_message(msg.u.msg.type, msg.u.msg.ref, &msg.u.msg.param);
 327                 printf("message received %d\n", msg.u.msg.type);
 328                 work = 1;
 329         } else
 330         {
 331                 if (errno != EWOULDBLOCK)
 332                 {
 333                         fprintf(stderr, "Socket error %d\n", errno);
 334                         return(-1);
 335                 }
 336         }
 337
 338         /* write to socket */
 339         if (!admin_first)
 340                 return(work);
 341         admin = admin_first;
 342         len = write(sock, &admin->msg, sizeof(msg));
 343         if (len == 0)
 344         {
 345                 printf("Socket closed\n");
 346                 return(-1); // socket closed
 347         }
 348         if (len > 0)
 349         {
 350                 if (len != sizeof(msg))
 351                 {
 352                         fprintf(stderr, "Socket short write (%d)\n", len);
 353                         return(-1); // socket error
 354                 }
 355                 /* free head */
 356                 admin_first = admin->next;
 357                 free(admin);
 358
 359                 work = 1;
 360         } else
 361         {
 362                 if (errno != EWOULDBLOCK)
 363                 {
 364                         fprintf(stderr, "Socket error %d\n", errno);
 365                         return(-1);
 366                 }
 367         }
 368
 369         return(work);
 370 }
 371
 372 /*
 373  * main function
 374  */
 375 int main(int argc, char *argv[])
 376 {
 377         char *socket_name = SOCKET_NAME;
 378         int conn;
 379         struct sockaddr_un sock_address;
 380         int ret;
 381         unsigned long on = 1;
 382         union parameter param;
 383         int work;
 384
 385         /* open socket */
 386         if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 387         {
 388                 fprintf(stderr, "Failed to create socket.\n");
 389                 exit(EXIT_FAILURE);
 390         }
 391
 392         /* set socket address and name */
 393         memset(&sock_address, 0, sizeof(sock_address));
 394         sock_address.sun_family = PF_UNIX;
 395         strcpy(sock_address.sun_path, socket_name);
 396
 397         /* connect socket */
 398         if ((conn = connect(sock, (struct sockaddr *)&sock_address, SUN_LEN(&sock_address))) < 0)
 399         {
 400                 close(sock);
 401                 fprintf(stderr, "Failed to connect to socket \"%s\".\nIs LCR running?\n", sock_address.sun_path);
 402                 exit(EXIT_FAILURE);
 403         }
 404
 405         /* set non-blocking io */
 406         if (ioctl(sock, FIONBIO, (unsigned char *)(&on)) < 0)
 407         {
 408                 close(sock);
 409                 fprintf(stderr, "Failed to set socket into non-blocking IO.\n");
 410                 exit(EXIT_FAILURE);
 411         }
 412
 413         /* enque hello message */
 414         memset(&param, 0, sizeof(param));
 415         strcpy(param.hello.application, "asterisk");
 416         send_message(MESSAGE_HELLO, 0, &param);
 417
 418         /* bchannel */
 419         if (!bchannel_initialize())
 420                 goto bchannel_failed;
 421
 422         while(42)
 423         {
 424                 work = 0;
 425
 426                 /* handle socket */
 427                 ret = handle_socket();
 428                 if (ret < 0)
 429                         break;
 430                 if (ret)
 431                         work = 1;
 432
 433                 /* handle mISDN */
 434                 ret = bchannel_handle();
 435                 if (ret)
 436                         work = 1;
 437
 438                 if (!work)
 439                         usleep(30000);
 440         }
 441
 442         bchannel_deinitialize();
 443         bchannel_failed:
 444
 445         /* close socket */
 446         close(sock);
 447         /* now we say good bye */
 448         if (ret)
 449         {
 450                 printf("%s\n", ret);
 451                 exit(EXIT_FAILURE);
 452         }
 453 }
 454
 455
 456
 457
 458