udptl.c

   1 /*
   2  * Asterisk -- A telephony toolkit for Linux.
   3  *
   4  * UDPTL support for T.38
   5  *
   6  * Copyright (C) 2005, Steve Underwood, partly based on RTP code which is
   7  * Copyright (C) 1999-2006, Digium, Inc.
   8  *
   9  * Steve Underwood <steveu@coppice.org>
  10  *
  11  * This program is free software, distributed under the terms of
  12  * the GNU General Public License
  13  *
  14  * This version is disclaimed to DIGIUM for inclusion in the Asterisk project.
  15  */
  16
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <sys/time.h>
  21 #include <signal.h>
  22 #include <errno.h>
  23 #include <unistd.h>
  24 #include <netinet/in.h>
  25 #include <sys/time.h>
  26 #include <sys/socket.h>
  27 #include <arpa/inet.h>
  28 #include <fcntl.h>
  29
  30 #include "asterisk.h"
  31
  32 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  33
  34 #include "asterisk/udptl.h"
  35 #include "asterisk/frame.h"
  36 #include "asterisk/logger.h"
  37 #include "asterisk/options.h"
  38 #include "asterisk/channel.h"
  39 #include "asterisk/acl.h"
  40 #include "asterisk/channel.h"
  41 #include "asterisk/config.h"
  42 #include "asterisk/lock.h"
  43 #include "asterisk/utils.h"
  44 #include "asterisk/cli.h"
  45 #include "asterisk/unaligned.h"
  46 #include "asterisk/utils.h"
  47
  48 #define UDPTL_MTU               1200
  49
  50 #if !defined(FALSE)
  51 #define FALSE 0
  52 #endif
  53 #if !defined(TRUE)
  54 #define TRUE (!FALSE)
  55 #endif
  56
  57 static int udptlstart = 0;
  58 static int udptlend = 0;
  59 static int udptldebug = 0;                      /* Are we debugging? */
  60 static struct sockaddr_in udptldebugaddr;       /* Debug packets to/from this host */
  61 #ifdef SO_NO_CHECK
  62 static int nochecksums = 0;
  63 #endif
  64 static int udptlfectype = 0;
  65 static int udptlfecentries = 0;
  66 static int udptlfecspan = 0;
  67 static int udptlmaxdatagram = 0;
  68
  69 #define LOCAL_FAX_MAX_DATAGRAM      400
  70 #define MAX_FEC_ENTRIES             5
  71 #define MAX_FEC_SPAN                5
  72
  73 #define UDPTL_BUF_MASK              15
  74
  75 typedef struct {
  76         int buf_len;
  77         uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
  78 } udptl_fec_tx_buffer_t;
  79
  80 typedef struct {
  81         int buf_len;
  82         uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
  83         int fec_len[MAX_FEC_ENTRIES];
  84         uint8_t fec[MAX_FEC_ENTRIES][LOCAL_FAX_MAX_DATAGRAM];
  85         int fec_span;
  86         int fec_entries;
  87 } udptl_fec_rx_buffer_t;
  88
  89 struct ast_udptl {
  90         int fd;
  91         char resp;
  92         struct ast_frame f[16];
  93         unsigned char rawdata[8192 + AST_FRIENDLY_OFFSET];
  94         unsigned int lasteventseqn;
  95         int nat;
  96         int flags;
  97         struct sockaddr_in us;
  98         struct sockaddr_in them;
  99         int *ioid;
 100         uint16_t seqno;
 101         struct sched_context *sched;
 102         struct io_context *io;
 103         void *data;
 104         ast_udptl_callback callback;
 105         int udptl_offered_from_local;
 106
 107         /*! This option indicates the error correction scheme used in transmitted UDPTL
 108             packets. */
 109         int error_correction_scheme;
 110
 111         /*! This option indicates the number of error correction entries transmitted in
 112             UDPTL packets. */
 113         int error_correction_entries;
 114
 115         /*! This option indicates the span of the error correction entries in transmitted
 116             UDPTL packets (FEC only). */
 117         int error_correction_span;
 118
 119         /*! This option indicates the maximum size of a UDPTL packet that can be accepted by
 120             the remote device. */
 121         int far_max_datagram_size;
 122
 123         /*! This option indicates the maximum size of a UDPTL packet that we are prepared to
 124             accept. */
 125         int local_max_datagram_size;
 126
 127         int verbose;
 128
 129         struct sockaddr_in far;
 130
 131         int tx_seq_no;
 132         int rx_seq_no;
 133         int rx_expected_seq_no;
 134
 135         udptl_fec_tx_buffer_t tx[UDPTL_BUF_MASK + 1];
 136         udptl_fec_rx_buffer_t rx[UDPTL_BUF_MASK + 1];
 137 };
 138
 139 static struct ast_udptl_protocol *protos = NULL;
 140
 141 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len);
 142 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, uint8_t *ifp, int ifp_len);
 143
 144 static inline int udptl_debug_test_addr(struct sockaddr_in *addr)
 145 {
 146         if (udptldebug == 0)
 147                 return 0;
 148         if (udptldebugaddr.sin_addr.s_addr) {
 149                 if (((ntohs(udptldebugaddr.sin_port) != 0)
 150                         && (udptldebugaddr.sin_port != addr->sin_port))
 151                         || (udptldebugaddr.sin_addr.s_addr != addr->sin_addr.s_addr))
 152                 return 0;
 153         }
 154         return 1;
 155 }
 156
 157 static int decode_length(uint8_t *buf, int limit, int *len, int *pvalue)
 158 {
 159         if ((buf[*len] & 0x80) == 0) {
 160                 if (*len >= limit)
 161                         return -1;
 162                 *pvalue = buf[*len];
 163                 (*len)++;
 164                 return 0;
 165         }
 166         if ((buf[*len] & 0x40) == 0) {
 167                 if (*len >= limit - 1)
 168                         return -1;
 169                 *pvalue = (buf[*len] & 0x3F) << 8;
 170                 (*len)++;
 171                 *pvalue |= buf[*len];
 172                 (*len)++;
 173                 return 0;
 174         }
 175         if (*len >= limit)
 176                 return -1;
 177         *pvalue = (buf[*len] & 0x3F) << 14;
 178         (*len)++;
 179         /* Indicate we have a fragment */
 180         return 1;
 181 }
 182 /*- End of function --------------------------------------------------------*/
 183
 184 static int decode_open_type(uint8_t *buf, int limit, int *len, const uint8_t **p_object, int *p_num_octets)
 185 {
 186         int octet_cnt;
 187         int octet_idx;
 188         int stat;
 189         int i;
 190         const uint8_t **pbuf;
 191
 192         for (octet_idx = 0, *p_num_octets = 0;  ;  octet_idx += octet_cnt) {
 193                 if ((stat = decode_length(buf, limit, len, &octet_cnt)) < 0)
 194                         return -1;
 195                 if (octet_cnt > 0) {
 196                         *p_num_octets += octet_cnt;
 197
 198                         pbuf = &p_object[octet_idx];
 199                         i = 0;
 200                         /* Make sure the buffer contains at least the number of bits requested */
 201                         if ((*len + octet_cnt) > limit)
 202                                 return -1;
 203
 204                         *pbuf = &buf[*len];
 205                         *len += octet_cnt;
 206                 }
 207                 if (stat == 0)
 208                         break;
 209         }
 210         return 0;
 211 }
 212 /*- End of function --------------------------------------------------------*/
 213
 214 static int encode_length(uint8_t *buf, int *len, int value)
 215 {
 216         int multiplier;
 217
 218         if (value < 0x80) {
 219                 /* 1 octet */
 220                 buf[*len] = value;
 221                 (*len)++;
 222                 return value;
 223         }
 224         if (value < 0x4000) {
 225                 /* 2 octets */
 226                 /* Set the first bit of the first octet */
 227                 buf[*len] = ((0x8000 | value) >> 8) & 0xFF;
 228                 (*len)++;
 229                 buf[*len] = value & 0xFF;
 230                 (*len)++;
 231                 return value;
 232         }
 233         /* Fragmentation */
 234         multiplier = (value < 0x10000)  ?  (value >> 14)  :  4;
 235         /* Set the first 2 bits of the octet */
 236         buf[*len] = 0xC0 | multiplier;
 237         (*len)++;
 238         return multiplier << 14;
 239 }
 240 /*- End of function --------------------------------------------------------*/
 241
 242 static int encode_open_type(uint8_t *buf, int *len, const uint8_t *data, int num_octets)
 243 {
 244         int enclen;
 245         int octet_idx;
 246         uint8_t zero_byte;
 247
 248         /* If open type is of zero length, add a single zero byte (10.1) */
 249         if (num_octets == 0) {
 250                 zero_byte = 0;
 251                 data = &zero_byte;
 252                 num_octets = 1;
 253         }
 254         /* Encode the open type */
 255         for (octet_idx = 0;  ;  num_octets -= enclen, octet_idx += enclen) {
 256                 if ((enclen = encode_length(buf, len, num_octets)) < 0)
 257                         return -1;
 258                 if (enclen > 0) {
 259                         memcpy(&buf[*len], &data[octet_idx], enclen);
 260                         *len += enclen;
 261                 }
 262                 if (enclen >= num_octets)
 263                         break;
 264         }
 265
 266         return 0;
 267 }
 268 /*- End of function --------------------------------------------------------*/
 269
 270 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len)
 271 {
 272         int stat;
 273         int stat2;
 274         int i;
 275         int j;
 276         int k;
 277         int l;
 278         int m;
 279         int x;
 280         int limit;
 281         int which;
 282         int ptr;
 283         int count;
 284         int total_count;
 285         int seq_no;
 286         const uint8_t *ifp;
 287         const uint8_t *data;
 288         int ifp_len;
 289         int repaired[16];
 290         const uint8_t *bufs[16];
 291         int lengths[16];
 292         int span;
 293         int entries;
 294         int ifp_no;
 295
 296         ptr = 0;
 297         ifp_no = 0;
 298         s->f[0].prev = NULL;
 299         s->f[0].next = NULL;
 300
 301         /* Decode seq_number */
 302         if (ptr + 2 > len)
 303                 return -1;
 304         seq_no = (buf[0] << 8) | buf[1];
 305         ptr += 2;
 306
 307         /* Break out the primary packet */
 308         if ((stat = decode_open_type(buf, len, &ptr, &ifp, &ifp_len)) != 0)
 309                 return -1;
 310         /* Decode error_recovery */
 311         if (ptr + 1 > len)
 312                 return -1;
 313         if ((buf[ptr++] & 0x80) == 0) {
 314                 /* Secondary packet mode for error recovery */
 315                 if (seq_no > s->rx_seq_no) {
 316                         /* We received a later packet than we expected, so we need to check if we can fill in the gap from the
 317                            secondary packets. */
 318                         total_count = 0;
 319                         do {
 320                                 if ((stat2 = decode_length(buf, len, &ptr, &count)) < 0)
 321                                         return -1;
 322                                 for (i = 0;  i < count;  i++) {
 323                                         if ((stat = decode_open_type(buf, len, &ptr, &bufs[total_count + i], &lengths[total_count + i])) != 0)
 324                                                 return -1;
 325                                 }
 326                                 total_count += count;
 327                         }
 328                         while (stat2 > 0);
 329                         /* Step through in reverse order, so we go oldest to newest */
 330                         for (i = total_count;  i > 0;  i--) {
 331                                 if (seq_no - i >= s->rx_seq_no) {
 332                                         /* This one wasn't seen before */
 333                                         /* Decode the secondary IFP packet */
 334                                         //fprintf(stderr, "Secondary %d, len %d\n", seq_no - i, lengths[i - 1]);
 335                                         s->f[ifp_no].frametype = AST_FRAME_MODEM;
 336                                         s->f[ifp_no].subclass = AST_MODEM_T38;
 337
 338                                         s->f[ifp_no].mallocd = 0;
 339                                         //s->f[ifp_no].???seq_no = seq_no - i;
 340                                         s->f[ifp_no].datalen = lengths[i - 1];
 341                                         s->f[ifp_no].data = (uint8_t *) bufs[i - 1];
 342                                         s->f[ifp_no].offset = 0;
 343                                         s->f[ifp_no].src = "UDPTL";
 344                                         if (ifp_no > 0) {
 345                                                 s->f[ifp_no].prev = &s->f[ifp_no - 1];
 346                                                 s->f[ifp_no - 1].next = &s->f[ifp_no];
 347                                         }
 348                                         s->f[ifp_no].next = NULL;
 349                                         ifp_no++;
 350                                 }
 351                         }
 352                 }
 353                 /* If packets are received out of sequence, we may have already processed this packet from the error
 354                    recovery information in a packet already received. */
 355                 if (seq_no >= s->rx_seq_no) {
 356                         /* Decode the primary IFP packet */
 357                         s->f[ifp_no].frametype = AST_FRAME_MODEM;
 358                         s->f[ifp_no].subclass = AST_MODEM_T38;
 359
 360                         s->f[ifp_no].mallocd = 0;
 361                         //s->f[ifp_no].???seq_no = seq_no;
 362                         s->f[ifp_no].datalen = ifp_len;
 363                         s->f[ifp_no].data = (uint8_t *) ifp;
 364                         s->f[ifp_no].offset = 0;
 365                         s->f[ifp_no].src = "UDPTL";
 366                         if (ifp_no > 0) {
 367                                 s->f[ifp_no].prev = &s->f[ifp_no - 1];
 368                                 s->f[ifp_no - 1].next = &s->f[ifp_no];
 369                         }
 370                         s->f[ifp_no].next = NULL;
 371                 }
 372         }
 373         else
 374         {
 375                 /* FEC mode for error recovery */
 376                 /* Our buffers cannot tolerate overlength IFP packets in FEC mode */
 377                 if (ifp_len > LOCAL_FAX_MAX_DATAGRAM)
 378                         return -1;
 379                 /* Update any missed slots in the buffer */
 380                 for (  ;  seq_no > s->rx_seq_no;  s->rx_seq_no++) {
 381                         x = s->rx_seq_no & UDPTL_BUF_MASK;
 382                         s->rx[x].buf_len = -1;
 383                         s->rx[x].fec_len[0] = 0;
 384                         s->rx[x].fec_span = 0;
 385                         s->rx[x].fec_entries = 0;
 386                 }
 387
 388                 x = seq_no & UDPTL_BUF_MASK;
 389
 390                 memset(repaired, 0, sizeof(repaired));
 391
 392                 /* Save the new IFP packet */
 393                 memcpy(s->rx[x].buf, ifp, ifp_len);
 394                 s->rx[x].buf_len = ifp_len;
 395                 repaired[x] = TRUE;
 396
 397                 /* Decode the FEC packets */
 398                 /* The span is defined as an unconstrained integer, but will never be more
 399                    than a small value. */
 400                 if (ptr + 2 > len)
 401                         return -1;
 402                 if (buf[ptr++] != 1)
 403                         return -1;
 404                 span = buf[ptr++];
 405                 s->rx[x].fec_span = span;
 406
 407                 /* The number of entries is defined as a length, but will only ever be a small
 408                    value. Treat it as such. */
 409                 if (ptr + 1 > len)
 410                         return -1;
 411                 entries = buf[ptr++];
 412                 s->rx[x].fec_entries = entries;
 413
 414                 /* Decode the elements */
 415                 for (i = 0;  i < entries;  i++) {
 416                         if ((stat = decode_open_type(buf, len, &ptr, &data, &s->rx[x].fec_len[i])) != 0)
 417                                 return -1;
 418                         if (s->rx[x].fec_len[i] > LOCAL_FAX_MAX_DATAGRAM)
 419                                 return -1;
 420
 421                         /* Save the new FEC data */
 422                         memcpy(s->rx[x].fec[i], data, s->rx[x].fec_len[i]);
 423 #if 0
 424                         fprintf(stderr, "FEC: ");
 425                         for (j = 0;  j < s->rx[x].fec_len[i];  j++)
 426                                 fprintf(stderr, "%02X ", data[j]);
 427                         fprintf(stderr, "\n");
 428 #endif
 429            }
 430
 431                 /* See if we can reconstruct anything which is missing */
 432                 /* TODO: this does not comprehensively hunt back and repair everything that is possible */
 433                 for (l = x;  l != ((x - (16 - span*entries)) & UDPTL_BUF_MASK);  l = (l - 1) & UDPTL_BUF_MASK) {
 434                         if (s->rx[l].fec_len[0] <= 0)
 435                                 continue;
 436                         for (m = 0;  m < s->rx[l].fec_entries;  m++) {
 437                                 limit = (l + m) & UDPTL_BUF_MASK;
 438                                 for (which = -1, k = (limit - s->rx[l].fec_span*s->rx[l].fec_entries) & UDPTL_BUF_MASK;  k != limit;  k = (k + s->rx[l].fec_entries) & UDPTL_BUF_MASK) {
 439                                         if (s->rx[k].buf_len <= 0)
 440                                                 which = (which == -1)  ?  k  :  -2;
 441                                 }
 442                                 if (which >= 0) {
 443                                         /* Repairable */
 444                                         for (j = 0;  j < s->rx[l].fec_len[m];  j++) {
 445                                                 s->rx[which].buf[j] = s->rx[l].fec[m][j];
 446                                                 for (k = (limit - s->rx[l].fec_span*s->rx[l].fec_entries) & UDPTL_BUF_MASK;  k != limit;  k = (k + s->rx[l].fec_entries) & UDPTL_BUF_MASK)
 447                                                         s->rx[which].buf[j] ^= (s->rx[k].buf_len > j)  ?  s->rx[k].buf[j]  :  0;
 448                                         }
 449                                         s->rx[which].buf_len = s->rx[l].fec_len[m];
 450                                         repaired[which] = TRUE;
 451                                 }
 452                         }
 453                 }
 454                 /* Now play any new packets forwards in time */
 455                 for (l = (x + 1) & UDPTL_BUF_MASK, j = seq_no - UDPTL_BUF_MASK;  l != x;  l = (l + 1) & UDPTL_BUF_MASK, j++) {
 456                         if (repaired[l]) {
 457                                 //fprintf(stderr, "Fixed packet %d, len %d\n", j, l);
 458                                 s->f[ifp_no].frametype = AST_FRAME_MODEM;
 459                                 s->f[ifp_no].subclass = AST_MODEM_T38;
 460
 461                                 s->f[ifp_no].mallocd = 0;
 462                                 //s->f[ifp_no].???seq_no = j;
 463                                 s->f[ifp_no].datalen = s->rx[l].buf_len;
 464                                 s->f[ifp_no].data = s->rx[l].buf;
 465                                 s->f[ifp_no].offset = 0;
 466                                 s->f[ifp_no].src = "UDPTL";
 467                                 if (ifp_no > 0) {
 468                                         s->f[ifp_no].prev = &s->f[ifp_no - 1];
 469                                         s->f[ifp_no - 1].next = &s->f[ifp_no];
 470                                 }
 471                                 s->f[ifp_no].next = NULL;
 472                                 ifp_no++;
 473                         }
 474                 }
 475                 /* Decode the primary IFP packet */
 476                 s->f[ifp_no].frametype = AST_FRAME_MODEM;
 477                 s->f[ifp_no].subclass = AST_MODEM_T38;
 478
 479                 s->f[ifp_no].mallocd = 0;
 480                 //s->f[ifp_no].???seq_no = j;
 481                 s->f[ifp_no].datalen = ifp_len;
 482                 s->f[ifp_no].data = (uint8_t *) ifp;
 483                 s->f[ifp_no].offset = 0;
 484                 s->f[ifp_no].src = "UDPTL";
 485                 if (ifp_no > 0) {
 486                         s->f[ifp_no].prev = &s->f[ifp_no - 1];
 487                         s->f[ifp_no - 1].next = &s->f[ifp_no];
 488                 }
 489                 s->f[ifp_no].next = NULL;
 490         }
 491
 492         s->rx_seq_no = seq_no + 1;
 493         return 0;
 494 }
 495 /*- End of function --------------------------------------------------------*/
 496
 497 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, uint8_t *ifp, int ifp_len)
 498 {
 499         uint8_t fec[LOCAL_FAX_MAX_DATAGRAM];
 500         int i;
 501         int j;
 502         int seq;
 503         int entry;
 504         int entries;
 505         int span;
 506         int m;
 507         int len;
 508         int limit;
 509         int high_tide;
 510
 511         seq = s->tx_seq_no & 0xFFFF;
 512
 513         /* Map the sequence number to an entry in the circular buffer */
 514         entry = seq & UDPTL_BUF_MASK;
 515
 516         /* We save the message in a circular buffer, for generating FEC or
 517            redundancy sets later on. */
 518         s->tx[entry].buf_len = ifp_len;
 519         memcpy(s->tx[entry].buf, ifp, ifp_len);
 520
 521         /* Build the UDPTLPacket */
 522
 523         len = 0;
 524         /* Encode the sequence number */
 525         buf[len++] = (seq >> 8) & 0xFF;
 526         buf[len++] = seq & 0xFF;
 527
 528         /* Encode the primary IFP packet */
 529         if (encode_open_type(buf, &len, ifp, ifp_len) < 0)
 530                 return -1;
 531
 532         /* Encode the appropriate type of error recovery information */
 533         switch (s->error_correction_scheme)
 534         {
 535         case UDPTL_ERROR_CORRECTION_NONE:
 536                 /* Encode the error recovery type */
 537                 buf[len++] = 0x00;
 538                 /* The number of entries will always be zero, so it is pointless allowing
 539                    for the fragmented case here. */
 540                 if (encode_length(buf, &len, 0) < 0)
 541                         return -1;
 542                 break;
 543         case UDPTL_ERROR_CORRECTION_REDUNDANCY:
 544                 /* Encode the error recovery type */
 545                 buf[len++] = 0x00;
 546                 if (s->tx_seq_no > s->error_correction_entries)
 547                         entries = s->error_correction_entries;
 548                 else
 549                         entries = s->tx_seq_no;
 550                 /* The number of entries will always be small, so it is pointless allowing
 551                    for the fragmented case here. */
 552                 if (encode_length(buf, &len, entries) < 0)
 553                         return -1;
 554                 /* Encode the elements */
 555                 for (i = 0;  i < entries;  i++) {
 556                         j = (entry - i - 1) & UDPTL_BUF_MASK;
 557                         if (encode_open_type(buf, &len, s->tx[j].buf, s->tx[j].buf_len) < 0)
 558                                 return -1;
 559                 }
 560                 break;
 561         case UDPTL_ERROR_CORRECTION_FEC:
 562                 span = s->error_correction_span;
 563                 entries = s->error_correction_entries;
 564                 if (seq < s->error_correction_span*s->error_correction_entries) {
 565                         /* In the initial stages, wind up the FEC smoothly */
 566                         entries = seq/s->error_correction_span;
 567                         if (seq < s->error_correction_span)
 568                                 span = 0;
 569                 }
 570                 /* Encode the error recovery type */
 571                 buf[len++] = 0x80;
 572                 /* Span is defined as an inconstrained integer, which it dumb. It will only
 573                    ever be a small value. Treat it as such. */
 574                 buf[len++] = 1;
 575                 buf[len++] = span;
 576                 /* The number of entries is defined as a length, but will only ever be a small
 577                    value. Treat it as such. */
 578                 buf[len++] = entries;
 579                 for (m = 0;  m < entries;  m++) {
 580                         /* Make an XOR'ed entry the maximum length */
 581                         limit = (entry + m) & UDPTL_BUF_MASK;
 582                         high_tide = 0;
 583                         for (i = (limit - span*entries) & UDPTL_BUF_MASK;  i != limit;  i = (i + entries) & UDPTL_BUF_MASK) {
 584                                 if (high_tide < s->tx[i].buf_len) {
 585                                         for (j = 0;  j < high_tide;  j++)
 586                                                 fec[j] ^= s->tx[i].buf[j];
 587                                         for (  ;  j < s->tx[i].buf_len;  j++)
 588                                                 fec[j] = s->tx[i].buf[j];
 589                                         high_tide = s->tx[i].buf_len;
 590                                 } else {
 591                                         for (j = 0;  j < s->tx[i].buf_len;  j++)
 592                                                 fec[j] ^= s->tx[i].buf[j];
 593                                 }
 594                         }
 595                         if (encode_open_type(buf, &len, fec, high_tide) < 0)
 596                                 return -1;
 597                 }
 598                 break;
 599         }
 600
 601         if (s->verbose)
 602                 fprintf(stderr, "\n");
 603
 604         s->tx_seq_no++;
 605         return len;
 606 }
 607
 608 int ast_udptl_fd(struct ast_udptl *udptl)
 609 {
 610         return udptl->fd;
 611 }
 612
 613 void ast_udptl_set_data(struct ast_udptl *udptl, void *data)
 614 {
 615         udptl->data = data;
 616 }
 617
 618 void ast_udptl_set_callback(struct ast_udptl *udptl, ast_udptl_callback callback)
 619 {
 620         udptl->callback = callback;
 621 }
 622
 623 void ast_udptl_setnat(struct ast_udptl *udptl, int nat)
 624 {
 625         udptl->nat = nat;
 626 }
 627
 628 static int udptlread(int *id, int fd, short events, void *cbdata)
 629 {
 630         struct ast_udptl *udptl = cbdata;
 631         struct ast_frame *f;
 632
 633         if ((f = ast_udptl_read(udptl))) {
 634                 if (udptl->callback)
 635                         udptl->callback(udptl, f, udptl->data);
 636         }
 637         return 1;
 638 }
 639
 640 struct ast_frame *ast_udptl_read(struct ast_udptl *udptl)
 641 {
 642         int res;
 643         struct sockaddr_in sin;
 644         socklen_t len;
 645         uint16_t seqno = 0;
 646         char iabuf[INET_ADDRSTRLEN];
 647         uint16_t *udptlheader;
 648
 649         len = sizeof(sin);
 650
 651         /* Cache where the header will go */
 652         res = recvfrom(udptl->fd,
 653                         udptl->rawdata + AST_FRIENDLY_OFFSET,
 654                         sizeof(udptl->rawdata) - AST_FRIENDLY_OFFSET,
 655                         0,
 656                         (struct sockaddr *) &sin,
 657                         &len);
 658         udptlheader = (uint16_t *)(udptl->rawdata + AST_FRIENDLY_OFFSET);
 659         if (res < 0) {
 660                 if (errno != EAGAIN)
 661                         ast_log(LOG_WARNING, "UDPTL read error: %s\n", strerror(errno));
 662                 if (errno == EBADF)
 663                         CRASH;
 664                 return &ast_null_frame;
 665         }
 666
 667         /* Ignore if the other side hasn't been given an address yet. */
 668         if (!udptl->them.sin_addr.s_addr || !udptl->them.sin_port)
 669                 return &ast_null_frame;
 670
 671         if (udptl->nat) {
 672                 /* Send to whoever sent to us */
 673                 if ((udptl->them.sin_addr.s_addr != sin.sin_addr.s_addr) ||
 674                         (udptl->them.sin_port != sin.sin_port)) {
 675                         memcpy(&udptl->them, &sin, sizeof(udptl->them));
 676                         ast_log(LOG_DEBUG, "UDPTL NAT: Using address %s:%d\n", ast_inet_ntoa(iabuf, sizeof(iabuf), udptl->them.sin_addr), ntohs(udptl->them.sin_port));
 677                 }
 678         }
 679
 680         if (udptl_debug_test_addr(&sin)) {
 681                 ast_verbose("Got UDPTL packet from %s:%d (type %d, seq %d, len %d)\n",
 682                         ast_inet_ntoa(iabuf, sizeof(iabuf), sin.sin_addr), ntohs(sin.sin_port), 0, seqno, res);
 683         }
 684 #if 0
 685         printf("Got UDPTL packet from %s:%d (seq %d, len = %d)\n", ast_inet_ntoa(iabuf, sizeof(iabuf), sin.sin_addr), ntohs(sin.sin_port), seqno, res);
 686 #endif
 687         udptl_rx_packet(udptl, udptl->rawdata + AST_FRIENDLY_OFFSET, res);
 688
 689         return &udptl->f[0];
 690 }
 691
 692 void ast_udptl_offered_from_local(struct ast_udptl* udptl, int local)
 693 {
 694         if (udptl)
 695                 udptl->udptl_offered_from_local = local;
 696         else
 697                 ast_log(LOG_WARNING, "udptl structure is null\n");
 698 }
 699
 700 int ast_udptl_get_error_correction_scheme(struct ast_udptl* udptl)
 701 {
 702     if (udptl)
 703             return udptl->error_correction_scheme;
 704     else {
 705             ast_log(LOG_WARNING, "udptl structure is null\n");
 706             return -1;
 707     }
 708 }
 709
 710 void ast_udptl_set_error_correction_scheme(struct ast_udptl* udptl, int ec)
 711 {
 712     if (udptl) {
 713         switch (ec) {
 714             case UDPTL_ERROR_CORRECTION_FEC:
 715                 udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
 716                 break;
 717             case UDPTL_ERROR_CORRECTION_REDUNDANCY:
 718                 udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
 719                 break;
 720             case UDPTL_ERROR_CORRECTION_NONE:
 721                 udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
 722                 break;
 723             default:
 724                 ast_log(LOG_WARNING, "error correction parameter invalid");
 725         };
 726     } else
 727             ast_log(LOG_WARNING, "udptl structure is null\n");
 728 }
 729
 730 int ast_udptl_get_local_max_datagram(struct ast_udptl* udptl)
 731 {
 732     if (udptl)
 733             return udptl->local_max_datagram_size;
 734     else {
 735             ast_log(LOG_WARNING, "udptl structure is null\n");
 736             return -1;
 737     }
 738 }
 739
 740 int ast_udptl_get_far_max_datagram(struct ast_udptl* udptl)
 741 {
 742     if (udptl)
 743             return udptl->far_max_datagram_size;
 744     else {
 745             ast_log(LOG_WARNING, "udptl structure is null\n");
 746             return -1;
 747     }
 748 }
 749
 750 void ast_udptl_set_local_max_datagram(struct ast_udptl* udptl, int max_datagram)
 751 {
 752     if (udptl)
 753             udptl->local_max_datagram_size = max_datagram;
 754     else
 755             ast_log(LOG_WARNING, "udptl structure is null\n");
 756 }
 757
 758 void ast_udptl_set_far_max_datagram(struct ast_udptl* udptl, int max_datagram)
 759 {
 760     if (udptl)
 761             udptl->far_max_datagram_size = max_datagram;
 762     else
 763             ast_log(LOG_WARNING, "udptl structure is null\n");
 764 }
 765
 766 struct ast_udptl *ast_udptl_new_with_bindaddr(struct sched_context *sched, struct io_context *io, int callbackmode, struct in_addr addr)
 767 {
 768         struct ast_udptl *udptl;
 769         int x;
 770         int startplace;
 771         int i;
 772         long int flags;
 773
 774         if ((udptl = malloc(sizeof(struct ast_udptl))) == NULL)
 775                 return NULL;
 776         memset(udptl, 0, sizeof(struct ast_udptl));
 777
 778         if (udptlfectype == 2)
 779                 udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
 780         else if (udptlfectype == 1)
 781                 udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
 782         else
 783                 udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
 784         udptl->error_correction_span = udptlfecspan;
 785         udptl->error_correction_entries = udptlfecentries;
 786
 787         udptl->far_max_datagram_size = udptlmaxdatagram;
 788         udptl->local_max_datagram_size = udptlmaxdatagram;
 789
 790         memset(&udptl->rx, 0, sizeof(udptl->rx));
 791         memset(&udptl->tx, 0, sizeof(udptl->tx));
 792         for (i = 0;  i <= UDPTL_BUF_MASK;  i++) {
 793                 udptl->rx[i].buf_len = -1;
 794                 udptl->tx[i].buf_len = -1;
 795         }
 796
 797         udptl->seqno = ast_random() & 0xffff;
 798         udptl->them.sin_family = AF_INET;
 799         udptl->us.sin_family = AF_INET;
 800
 801         if ((udptl->fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 802                 free(udptl);
 803                 ast_log(LOG_WARNING, "Unable to allocate socket: %s\n", strerror(errno));
 804                 return NULL;
 805         }
 806         flags = fcntl(udptl->fd, F_GETFL);
 807         fcntl(udptl->fd, F_SETFL, flags | O_NONBLOCK);
 808 #ifdef SO_NO_CHECK
 809         if (nochecksums)
 810                 setsockopt(udptl->fd, SOL_SOCKET, SO_NO_CHECK, &nochecksums, sizeof(nochecksums));
 811 #endif
 812         /* Find us a place */
 813         x = (ast_random() % (udptlend - udptlstart)) + udptlstart;
 814         startplace = x;
 815         for (;;) {
 816                 udptl->us.sin_port = htons(x);
 817                 udptl->us.sin_addr = addr;
 818                 if (bind(udptl->fd, (struct sockaddr *) &udptl->us, sizeof(udptl->us)) == 0)
 819                         break;
 820                 if (errno != EADDRINUSE) {
 821                         ast_log(LOG_WARNING, "Unexpected bind error: %s\n", strerror(errno));
 822                         close(udptl->fd);
 823                         free(udptl);
 824                         return NULL;
 825                 }
 826                 if (++x > udptlend)
 827                         x = udptlstart;
 828                 if (x == startplace) {
 829                         ast_log(LOG_WARNING, "No UDPTL ports remaining\n");
 830                         close(udptl->fd);
 831                         free(udptl);
 832                         return NULL;
 833                 }
 834         }
 835         if (io && sched && callbackmode) {
 836                 /* Operate this one in a callback mode */
 837                 udptl->sched = sched;
 838                 udptl->io = io;
 839                 udptl->ioid = ast_io_add(udptl->io, udptl->fd, udptlread, AST_IO_IN, udptl);
 840         }
 841         return udptl;
 842 }
 843
 844 struct ast_udptl *ast_udptl_new(struct sched_context *sched, struct io_context *io, int callbackmode)
 845 {
 846         struct in_addr ia;
 847         memset(&ia, 0, sizeof(ia));
 848         return ast_udptl_new_with_bindaddr(sched, io, callbackmode, ia);
 849 }
 850
 851 int ast_udptl_settos(struct ast_udptl *udptl, int tos)
 852 {
 853         int res;
 854
 855         if ((res = setsockopt(udptl->fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos))))
 856                 ast_log(LOG_WARNING, "UDPTL unable to set TOS to %d\n", tos);
 857         return res;
 858 }
 859
 860 void ast_udptl_set_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
 861 {
 862         udptl->them.sin_port = them->sin_port;
 863         udptl->them.sin_addr = them->sin_addr;
 864 }
 865
 866 void ast_udptl_get_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
 867 {
 868         them->sin_family = AF_INET;
 869         them->sin_port = udptl->them.sin_port;
 870         them->sin_addr = udptl->them.sin_addr;
 871 }
 872
 873 void ast_udptl_get_us(struct ast_udptl *udptl, struct sockaddr_in *us)
 874 {
 875         memcpy(us, &udptl->us, sizeof(udptl->us));
 876 }
 877
 878 void ast_udptl_stop(struct ast_udptl *udptl)
 879 {
 880         memset(&udptl->them.sin_addr, 0, sizeof(udptl->them.sin_addr));
 881         memset(&udptl->them.sin_port, 0, sizeof(udptl->them.sin_port));
 882 }
 883
 884 void ast_udptl_destroy(struct ast_udptl *udptl)
 885 {
 886         if (udptl->ioid)
 887                 ast_io_remove(udptl->io, udptl->ioid);
 888         if (udptl->fd > -1)
 889                 close(udptl->fd);
 890         free(udptl);
 891 }
 892
 893 int ast_udptl_write(struct ast_udptl *s, struct ast_frame *f)
 894 {
 895         int len;
 896         int res;
 897         uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
 898         char iabuf[INET_ADDRSTRLEN];
 899
 900         /* If we have no peer, return immediately */
 901         if (s->them.sin_addr.s_addr == INADDR_ANY)
 902                 return 0;
 903
 904         /* If there is no data length, return immediately */
 905         if (f->datalen == 0)
 906                 return 0;
 907
 908         if (f->frametype != AST_FRAME_MODEM) {
 909                 ast_log(LOG_WARNING, "UDPTL can only send T.38 data\n");
 910                 return -1;
 911         }
 912
 913         /* Cook up the UDPTL packet, with the relevant EC info. */
 914         len = udptl_build_packet(s, buf, f->data, f->datalen);
 915
 916         if (len > 0  &&  s->them.sin_port && s->them.sin_addr.s_addr) {
 917                 if ((res = sendto(s->fd, buf, len, 0, (struct sockaddr *) &s->them, sizeof(s->them))) < 0)
 918                         ast_log(LOG_NOTICE, "UDPTL Transmission error to %s:%d: %s\n", ast_inet_ntoa(iabuf, sizeof(iabuf), s->them.sin_addr), ntohs(s->them.sin_port), strerror(errno));
 919 #if 0
 920                 printf("Sent %d bytes of UDPTL data to %s:%d\n", res, ast_inet_ntoa(iabuf, sizeof(iabuf), udptl->them.sin_addr), ntohs(udptl->them.sin_port));
 921 #endif
 922                 if (udptl_debug_test_addr(&s->them))
 923                         ast_verbose("Sent UDPTL packet to %s:%d (type %d, seq %d, len %d)\n",
 924                                         ast_inet_ntoa(iabuf, sizeof(iabuf), s->them.sin_addr),
 925                                         ntohs(s->them.sin_port), 0, s->seqno, len);
 926         }
 927
 928         return 0;
 929 }
 930
 931 void ast_udptl_proto_unregister(struct ast_udptl_protocol *proto)
 932 {
 933         struct ast_udptl_protocol *cur;
 934         struct ast_udptl_protocol *prev;
 935
 936         cur = protos;
 937         prev = NULL;
 938         while(cur) {
 939                 if (cur == proto) {
 940                         if (prev)
 941                                 prev->next = proto->next;
 942                         else
 943                                 protos = proto->next;
 944                         return;
 945                 }
 946                 prev = cur;
 947                 cur = cur->next;
 948         }
 949 }
 950
 951 int ast_udptl_proto_register(struct ast_udptl_protocol *proto)
 952 {
 953         struct ast_udptl_protocol *cur;
 954
 955         cur = protos;
 956         while(cur) {
 957                 if (cur->type == proto->type) {
 958                         ast_log(LOG_WARNING, "Tried to register same protocol '%s' twice\n", cur->type);
 959                         return -1;
 960                 }
 961                 cur = cur->next;
 962         }
 963         proto->next = protos;
 964         protos = proto;
 965         return 0;
 966 }
 967
 968 static struct ast_udptl_protocol *get_proto(struct ast_channel *chan)
 969 {
 970         struct ast_udptl_protocol *cur;
 971
 972         cur = protos;
 973         while (cur) {
 974                 if (cur->type == chan->tech->type)
 975                         return cur;
 976                 cur = cur->next;
 977         }
 978         return NULL;
 979 }
 980
 981 int ast_udptl_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
 982 {
 983         struct ast_frame *f;
 984         struct ast_channel *who;
 985         struct ast_channel *cs[3];
 986         struct ast_udptl *p0;
 987         struct ast_udptl *p1;
 988         struct ast_udptl_protocol *pr0;
 989         struct ast_udptl_protocol *pr1;
 990         struct sockaddr_in ac0;
 991         struct sockaddr_in ac1;
 992         struct sockaddr_in t0;
 993         struct sockaddr_in t1;
 994         char iabuf[INET_ADDRSTRLEN];
 995         void *pvt0;
 996         void *pvt1;
 997         int to;
 998
 999         ast_channel_lock(c0);
1000         while (ast_channel_trylock(c1)) {
1001                 ast_channel_unlock(c0);
1002                 usleep(1);
1003                 ast_channel_lock(c0);
1004         }
1005         pr0 = get_proto(c0);
1006         pr1 = get_proto(c1);
1007         if (!pr0) {
1008                 ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c0->name);
1009                 ast_channel_unlock(c0);
1010                 ast_channel_unlock(c1);
1011                 return -1;
1012         }
1013         if (!pr1) {
1014                 ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c1->name);
1015                 ast_channel_unlock(c0);
1016                 ast_channel_unlock(c1);
1017                 return -1;
1018         }
1019         pvt0 = c0->tech_pvt;
1020         pvt1 = c1->tech_pvt;
1021         p0 = pr0->get_udptl_info(c0);
1022         p1 = pr1->get_udptl_info(c1);
1023         if (!p0 || !p1) {
1024                 /* Somebody doesn't want to play... */
1025                 ast_channel_unlock(c0);
1026                 ast_channel_unlock(c1);
1027                 return -2;
1028         }
1029         if (pr0->set_udptl_peer(c0, p1)) {
1030                 ast_log(LOG_WARNING, "Channel '%s' failed to talk to '%s'\n", c0->name, c1->name);
1031         } else {
1032                 /* Store UDPTL peer */
1033                 ast_udptl_get_peer(p1, &ac1);
1034         }
1035         if (pr1->set_udptl_peer(c1, p0))
1036                 ast_log(LOG_WARNING, "Channel '%s' failed to talk back to '%s'\n", c1->name, c0->name);
1037         else {
1038                 /* Store UDPTL peer */
1039                 ast_udptl_get_peer(p0, &ac0);
1040         }
1041         ast_channel_unlock(c0);
1042         ast_channel_unlock(c1);
1043         cs[0] = c0;
1044         cs[1] = c1;
1045         cs[2] = NULL;
1046         for (;;) {
1047                 if ((c0->tech_pvt != pvt0)  ||
1048                         (c1->tech_pvt != pvt1) ||
1049                         (c0->masq || c0->masqr || c1->masq || c1->masqr)) {
1050                                 ast_log(LOG_DEBUG, "Oooh, something is weird, backing out\n");
1051                                 /* Tell it to try again later */
1052                                 return -3;
1053                 }
1054                 to = -1;
1055                 ast_udptl_get_peer(p1, &t1);
1056                 ast_udptl_get_peer(p0, &t0);
1057                 if (inaddrcmp(&t1, &ac1)) {
1058                         ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n",
1059                                 c1->name, ast_inet_ntoa(iabuf, sizeof(iabuf), t1.sin_addr), ntohs(t1.sin_port));
1060                         ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n",
1061                                 c1->name, ast_inet_ntoa(iabuf, sizeof(iabuf), ac1.sin_addr), ntohs(ac1.sin_port));
1062                         memcpy(&ac1, &t1, sizeof(ac1));
1063                 }
1064                 if (inaddrcmp(&t0, &ac0)) {
1065                         ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n",
1066                                 c0->name, ast_inet_ntoa(iabuf, sizeof(iabuf), t0.sin_addr), ntohs(t0.sin_port));
1067                         ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n",
1068                                 c0->name, ast_inet_ntoa(iabuf, sizeof(iabuf), ac0.sin_addr), ntohs(ac0.sin_port));
1069                         memcpy(&ac0, &t0, sizeof(ac0));
1070                 }
1071                 who = ast_waitfor_n(cs, 2, &to);
1072                 if (!who) {
1073                         ast_log(LOG_DEBUG, "Ooh, empty read...\n");
1074                         /* check for hangup / whentohangup */
1075                         if (ast_check_hangup(c0) || ast_check_hangup(c1))
1076                                 break;
1077                         continue;
1078                 }
1079                 f = ast_read(who);
1080                 if (!f) {
1081                         *fo = f;
1082                         *rc = who;
1083                         ast_log(LOG_DEBUG, "Oooh, got a %s\n", f ? "digit" : "hangup");
1084                         /* That's all we needed */
1085                         return 0;
1086                 } else {
1087                         if (f->frametype == AST_FRAME_MODEM) {
1088                                 /* Forward T.38 frames if they happen upon us */
1089                                 if (who == c0) {
1090                                         ast_write(c1, f);
1091                                 } else if (who == c1) {
1092                                         ast_write(c0, f);
1093                                 }
1094                         }
1095                         ast_frfree(f);
1096                 }
1097                 /* Swap priority. Not that it's a big deal at this point */
1098                 cs[2] = cs[0];
1099                 cs[0] = cs[1];
1100                 cs[1] = cs[2];
1101         }
1102         return -1;
1103 }
1104
1105 static int udptl_do_debug_ip(int fd, int argc, char *argv[])
1106 {
1107         struct hostent *hp;
1108         struct ast_hostent ahp;
1109         char iabuf[INET_ADDRSTRLEN];
1110         int port;
1111         char *p;
1112         char *arg;
1113
1114         port = 0;
1115         if (argc != 4)
1116                 return RESULT_SHOWUSAGE;
1117         arg = argv[3];
1118         p = strstr(arg, ":");
1119         if (p) {
1120                 *p = '\0';
1121                 p++;
1122                 port = atoi(p);
1123         }
1124         hp = ast_gethostbyname(arg, &ahp);
1125         if (hp == NULL)
1126                 return RESULT_SHOWUSAGE;
1127         udptldebugaddr.sin_family = AF_INET;
1128         memcpy(&udptldebugaddr.sin_addr, hp->h_addr, sizeof(udptldebugaddr.sin_addr));
1129         udptldebugaddr.sin_port = htons(port);
1130         if (port == 0)
1131                 ast_cli(fd, "UDPTL Debugging Enabled for IP: %s\n", ast_inet_ntoa(iabuf, sizeof(iabuf), udptldebugaddr.sin_addr));
1132         else
1133                 ast_cli(fd, "UDPTL Debugging Enabled for IP: %s:%d\n", ast_inet_ntoa(iabuf, sizeof(iabuf), udptldebugaddr.sin_addr), port);
1134         udptldebug = 1;
1135         return RESULT_SUCCESS;
1136 }
1137
1138 static int udptl_do_debug(int fd, int argc, char *argv[])
1139 {
1140         if (argc != 2) {
1141                 if (argc != 4)
1142                         return RESULT_SHOWUSAGE;
1143                 return udptl_do_debug_ip(fd, argc, argv);
1144         }
1145         udptldebug = 1;
1146         memset(&udptldebugaddr,0,sizeof(udptldebugaddr));
1147         ast_cli(fd, "UDPTL Debugging Enabled\n");
1148         return RESULT_SUCCESS;
1149 }
1150
1151 static int udptl_no_debug(int fd, int argc, char *argv[])
1152 {
1153         if (argc !=3)
1154                 return RESULT_SHOWUSAGE;
1155         udptldebug = 0;
1156         ast_cli(fd,"UDPTL Debugging Disabled\n");
1157         return RESULT_SUCCESS;
1158 }
1159
1160 static char debug_usage[] =
1161   "Usage: udptl debug [ip host[:port]]\n"
1162   "       Enable dumping of all UDPTL packets to and from host.\n";
1163
1164 static char no_debug_usage[] =
1165   "Usage: udptl no debug\n"
1166   "       Disable all UDPTL debugging\n";
1167
1168 static struct ast_cli_entry  cli_debug_ip =
1169 {{ "udptl", "debug", "ip", NULL } , udptl_do_debug, "Enable UDPTL debugging on IP", debug_usage };
1170
1171 static struct ast_cli_entry  cli_debug =
1172 {{ "udptl", "debug", NULL } , udptl_do_debug, "Enable UDPTL debugging", debug_usage };
1173
1174 static struct ast_cli_entry  cli_no_debug =
1175 {{ "udptl", "no", "debug", NULL } , udptl_no_debug, "Disable UDPTL debugging", no_debug_usage };
1176
1177 void ast_udptl_reload(void)
1178 {
1179         struct ast_config *cfg;
1180         char *s;
1181
1182         udptlstart = 4500;
1183         udptlend = 4999;
1184         udptlfectype = 0;
1185         udptlfecentries = 0;
1186         udptlfecspan = 0;
1187         udptlmaxdatagram = 0;
1188
1189         if ((cfg = ast_config_load("udptl.conf"))) {
1190                 if ((s = ast_variable_retrieve(cfg, "general", "udptlstart"))) {
1191                         udptlstart = atoi(s);
1192                         if (udptlstart < 1024)
1193                                 udptlstart = 1024;
1194                         if (udptlstart > 65535)
1195                                 udptlstart = 65535;
1196                 }
1197                 if ((s = ast_variable_retrieve(cfg, "general", "udptlend"))) {
1198                         udptlend = atoi(s);
1199                         if (udptlend < 1024)
1200                                 udptlend = 1024;
1201                         if (udptlend > 65535)
1202                                 udptlend = 65535;
1203                 }
1204                 if ((s = ast_variable_retrieve(cfg, "general", "udptlchecksums"))) {
1205 #ifdef SO_NO_CHECK
1206                         if (ast_false(s))
1207                                 nochecksums = 1;
1208                         else
1209                                 nochecksums = 0;
1210 #else
1211                         if (ast_false(s))
1212                                 ast_log(LOG_WARNING, "Disabling UDPTL checksums is not supported on this operating system!\n");
1213 #endif
1214                 }
1215                 if ((s = ast_variable_retrieve(cfg, "general", "T38FaxUdpEC"))) {
1216                         if (strcmp(s, "t38UDPFEC") == 0)
1217                                 udptlfectype = 2;
1218                         else if (strcmp(s, "t38UDPRedundancy") == 0)
1219                                 udptlfectype = 1;
1220                 }
1221                 if ((s = ast_variable_retrieve(cfg, "general", "T38FaxMaxDatagram"))) {
1222                         udptlmaxdatagram = atoi(s);
1223                         if (udptlmaxdatagram < 0)
1224                                 udptlmaxdatagram = 0;
1225                         if (udptlmaxdatagram > LOCAL_FAX_MAX_DATAGRAM)
1226                                 udptlmaxdatagram = LOCAL_FAX_MAX_DATAGRAM;
1227                 }
1228                 if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECentries"))) {
1229                         udptlfecentries = atoi(s);
1230                         if (udptlfecentries < 0)
1231                                 udptlfecentries = 0;
1232                         if (udptlfecentries > MAX_FEC_ENTRIES)
1233                                 udptlfecentries = MAX_FEC_ENTRIES;
1234                 }
1235                 if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECspan"))) {
1236                         udptlfecspan = atoi(s);
1237                         if (udptlfecspan < 0)
1238                                 udptlfecspan = 0;
1239                         if (udptlfecspan > MAX_FEC_SPAN)
1240                                 udptlfecspan = MAX_FEC_SPAN;
1241                 }
1242                 ast_config_destroy(cfg);
1243         }
1244         if (udptlstart >= udptlend) {
1245                 ast_log(LOG_WARNING, "Unreasonable values for UDPTL start/end\n");
1246                 udptlstart = 4500;
1247                 udptlend = 4999;
1248         }
1249         if (option_verbose > 1)
1250                 ast_verbose(VERBOSE_PREFIX_2 "UDPTL allocating from port range %d -> %d\n", udptlstart, udptlend);
1251 }
1252
1253 void ast_udptl_init(void)
1254 {
1255         ast_cli_register(&cli_debug);
1256         ast_cli_register(&cli_debug_ip);
1257         ast_cli_register(&cli_no_debug);
1258         ast_udptl_reload();
1259 }