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