Sun Jun 12 16:37:48 2011

Asterisk developer's documentation


udptl.c

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00001 /*
00002  * Asterisk -- A telephony toolkit for Linux.
00003  *
00004  * UDPTL support for T.38
00005  * 
00006  * Copyright (C) 2005, Steve Underwood, partly based on RTP code which is
00007  * Copyright (C) 1999-2006, Digium, Inc.
00008  *
00009  * Steve Underwood <steveu@coppice.org>
00010  *
00011  * This program is free software, distributed under the terms of
00012  * the GNU General Public License
00013  *
00014  * A license has been granted to Digium (via disclaimer) for the use of
00015  * this code.
00016  */
00017 
00018 #include "asterisk.h"
00019 
00020 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 116463 $")
00021 
00022 #include <stdio.h>
00023 #include <stdlib.h>
00024 #include <string.h>
00025 #include <sys/time.h>
00026 #include <signal.h>
00027 #include <errno.h>
00028 #include <unistd.h>
00029 #include <netinet/in.h>
00030 #include <sys/time.h>
00031 #include <sys/socket.h>
00032 #include <arpa/inet.h>
00033 #include <fcntl.h>
00034 
00035 #include "asterisk/udptl.h"
00036 #include "asterisk/frame.h"
00037 #include "asterisk/logger.h"
00038 #include "asterisk/options.h"
00039 #include "asterisk/channel.h"
00040 #include "asterisk/acl.h"
00041 #include "asterisk/channel.h"
00042 #include "asterisk/config.h"
00043 #include "asterisk/lock.h"
00044 #include "asterisk/utils.h"
00045 #include "asterisk/cli.h"
00046 #include "asterisk/unaligned.h"
00047 #include "asterisk/utils.h"
00048 
00049 #define UDPTL_MTU    1200
00050 
00051 #if !defined(FALSE)
00052 #define FALSE 0
00053 #endif
00054 #if !defined(TRUE)
00055 #define TRUE (!FALSE)
00056 #endif
00057 
00058 static int udptlstart;
00059 static int udptlend;
00060 static int udptldebug;                    /* Are we debugging? */
00061 static struct sockaddr_in udptldebugaddr;   /* Debug packets to/from this host */
00062 #ifdef SO_NO_CHECK
00063 static int nochecksums;
00064 #endif
00065 static int udptlfectype;
00066 static int udptlfecentries;
00067 static int udptlfecspan;
00068 static int udptlmaxdatagram;
00069 
00070 #define LOCAL_FAX_MAX_DATAGRAM      400
00071 #define MAX_FEC_ENTRIES             5
00072 #define MAX_FEC_SPAN                5
00073 
00074 #define UDPTL_BUF_MASK              15
00075 
00076 typedef struct {
00077    int buf_len;
00078    uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
00079 } udptl_fec_tx_buffer_t;
00080 
00081 typedef struct {
00082    int buf_len;
00083    uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
00084    int fec_len[MAX_FEC_ENTRIES];
00085    uint8_t fec[MAX_FEC_ENTRIES][LOCAL_FAX_MAX_DATAGRAM];
00086    int fec_span;
00087    int fec_entries;
00088 } udptl_fec_rx_buffer_t;
00089 
00090 struct ast_udptl {
00091    int fd;
00092    char resp;
00093    struct ast_frame f[16];
00094    unsigned char rawdata[8192 + AST_FRIENDLY_OFFSET];
00095    unsigned int lasteventseqn;
00096    int nat;
00097    int flags;
00098    struct sockaddr_in us;
00099    struct sockaddr_in them;
00100    int *ioid;
00101    struct sched_context *sched;
00102    struct io_context *io;
00103    void *data;
00104    ast_udptl_callback callback;
00105    int udptl_offered_from_local;
00106 
00107    /*! This option indicates the error correction scheme used in transmitted UDPTL
00108        packets. */
00109    int error_correction_scheme;
00110 
00111    /*! This option indicates the number of error correction entries transmitted in
00112        UDPTL packets. */
00113    int error_correction_entries;
00114 
00115    /*! This option indicates the span of the error correction entries in transmitted
00116        UDPTL packets (FEC only). */
00117    int error_correction_span;
00118 
00119    /*! This option indicates the maximum size of a UDPTL packet that can be accepted by
00120        the remote device. */
00121    int far_max_datagram_size;
00122 
00123    /*! This option indicates the maximum size of a UDPTL packet that we are prepared to
00124        accept. */
00125    int local_max_datagram_size;
00126 
00127    int verbose;
00128 
00129    struct sockaddr_in far;
00130 
00131    int tx_seq_no;
00132    int rx_seq_no;
00133    int rx_expected_seq_no;
00134 
00135    udptl_fec_tx_buffer_t tx[UDPTL_BUF_MASK + 1];
00136    udptl_fec_rx_buffer_t rx[UDPTL_BUF_MASK + 1];
00137 };
00138 
00139 static struct ast_udptl_protocol *protos;
00140 
00141 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len);
00142 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, uint8_t *ifp, int ifp_len);
00143 
00144 static inline int udptl_debug_test_addr(struct sockaddr_in *addr)
00145 {
00146    if (udptldebug == 0)
00147       return 0;
00148    if (udptldebugaddr.sin_addr.s_addr) {
00149       if (((ntohs(udptldebugaddr.sin_port) != 0)
00150          && (udptldebugaddr.sin_port != addr->sin_port))
00151          || (udptldebugaddr.sin_addr.s_addr != addr->sin_addr.s_addr))
00152          return 0;
00153    }
00154    return 1;
00155 }
00156 
00157 static int decode_length(uint8_t *buf, int limit, int *len, int *pvalue)
00158 {
00159    if ((buf[*len] & 0x80) == 0) {
00160       if (*len >= limit)
00161          return -1;
00162       *pvalue = buf[*len];
00163       (*len)++;
00164       return 0;
00165    }
00166    if ((buf[*len] & 0x40) == 0) {
00167       if (*len >= limit - 1)
00168          return -1;
00169       *pvalue = (buf[*len] & 0x3F) << 8;
00170       (*len)++;
00171       *pvalue |= buf[*len];
00172       (*len)++;
00173       return 0;
00174    }
00175    if (*len >= limit)
00176       return -1;
00177    *pvalue = (buf[*len] & 0x3F) << 14;
00178    (*len)++;
00179    /* Indicate we have a fragment */
00180    return 1;
00181 }
00182 /*- End of function --------------------------------------------------------*/
00183 
00184 static int decode_open_type(uint8_t *buf, int limit, int *len, const uint8_t **p_object, int *p_num_octets)
00185 {
00186    int octet_cnt;
00187    int octet_idx;
00188    int stat;
00189    int i;
00190    const uint8_t **pbuf;
00191 
00192    for (octet_idx = 0, *p_num_octets = 0; ; octet_idx += octet_cnt) {
00193       if ((stat = decode_length(buf, limit, len, &octet_cnt)) < 0)
00194          return -1;
00195       if (octet_cnt > 0) {
00196          *p_num_octets += octet_cnt;
00197 
00198          pbuf = &p_object[octet_idx];
00199          i = 0;
00200          /* Make sure the buffer contains at least the number of bits requested */
00201          if ((*len + octet_cnt) > limit)
00202             return -1;
00203 
00204          *pbuf = &buf[*len];
00205          *len += octet_cnt;
00206       }
00207       if (stat == 0)
00208          break;
00209    }
00210    return 0;
00211 }
00212 /*- End of function --------------------------------------------------------*/
00213 
00214 static int encode_length(uint8_t *buf, int *len, int value)
00215 {
00216    int multiplier;
00217 
00218    if (value < 0x80) {
00219       /* 1 octet */
00220       buf[*len] = value;
00221       (*len)++;
00222       return value;
00223    }
00224    if (value < 0x4000) {
00225       /* 2 octets */
00226       /* Set the first bit of the first octet */
00227       buf[*len] = ((0x8000 | value) >> 8) & 0xFF;
00228       (*len)++;
00229       buf[*len] = value & 0xFF;
00230       (*len)++;
00231       return value;
00232    }
00233    /* Fragmentation */
00234    multiplier = (value < 0x10000) ? (value >> 14) : 4;
00235    /* Set the first 2 bits of the octet */
00236    buf[*len] = 0xC0 | multiplier;
00237    (*len)++;
00238    return multiplier << 14;
00239 }
00240 /*- End of function --------------------------------------------------------*/
00241 
00242 static int encode_open_type(uint8_t *buf, int *len, const uint8_t *data, int num_octets)
00243 {
00244    int enclen;
00245    int octet_idx;
00246    uint8_t zero_byte;
00247 
00248    /* If open type is of zero length, add a single zero byte (10.1) */
00249    if (num_octets == 0) {
00250       zero_byte = 0;
00251       data = &zero_byte;
00252       num_octets = 1;
00253    }
00254    /* Encode the open type */
00255    for (octet_idx = 0; ; num_octets -= enclen, octet_idx += enclen) {
00256       if ((enclen = encode_length(buf, len, num_octets)) < 0)
00257          return -1;
00258       if (enclen > 0) {
00259          memcpy(&buf[*len], &data[octet_idx], enclen);
00260          *len += enclen;
00261       }
00262       if (enclen >= num_octets)
00263          break;
00264    }
00265 
00266    return 0;
00267 }
00268 /*- End of function --------------------------------------------------------*/
00269 
00270 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len)
00271 {
00272    int stat;
00273    int stat2;
00274    int i;
00275    int j;
00276    int k;
00277    int l;
00278    int m;
00279    int x;
00280    int limit;
00281    int which;
00282    int ptr;
00283    int count;
00284    int total_count;
00285    int seq_no;
00286    const uint8_t *ifp;
00287    const uint8_t *data;
00288    int ifp_len;
00289    int repaired[16];
00290    const uint8_t *bufs[16];
00291    int lengths[16];
00292    int span;
00293    int entries;
00294    int ifp_no;
00295 
00296    ptr = 0;
00297    ifp_no = 0;
00298    memset(&s->f[0], 0, sizeof(s->f[0]));
00299 
00300    /* Decode seq_number */
00301    if (ptr + 2 > len)
00302       return -1;
00303    seq_no = (buf[0] << 8) | buf[1];
00304    ptr += 2;
00305 
00306    /* Break out the primary packet */
00307    if ((stat = decode_open_type(buf, len, &ptr, &ifp, &ifp_len)) != 0)
00308       return -1;
00309    /* Decode error_recovery */
00310    if (ptr + 1 > len)
00311       return -1;
00312    if ((buf[ptr++] & 0x80) == 0) {
00313       /* Secondary packet mode for error recovery */
00314       if (seq_no > s->rx_seq_no) {
00315          /* We received a later packet than we expected, so we need to check if we can fill in the gap from the
00316             secondary packets. */
00317          total_count = 0;
00318          do {
00319             if ((stat2 = decode_length(buf, len, &ptr, &count)) < 0)
00320                return -1;
00321             for (i = 0; i < count; i++) {
00322                if ((stat = decode_open_type(buf, len, &ptr, &bufs[total_count + i], &lengths[total_count + i])) != 0)
00323                   return -1;
00324             }
00325             total_count += count;
00326          }
00327          while (stat2 > 0);
00328          /* Step through in reverse order, so we go oldest to newest */
00329          for (i = total_count; i > 0; i--) {
00330             if (seq_no - i >= s->rx_seq_no) {
00331                /* This one wasn't seen before */
00332                /* Decode the secondary IFP packet */
00333                //fprintf(stderr, "Secondary %d, len %d\n", seq_no - i, lengths[i - 1]);
00334                s->f[ifp_no].frametype = AST_FRAME_MODEM;
00335                s->f[ifp_no].subclass = AST_MODEM_T38;
00336 
00337                s->f[ifp_no].mallocd = 0;
00338                s->f[ifp_no].seqno = seq_no - i;
00339                s->f[ifp_no].datalen = lengths[i - 1];
00340                s->f[ifp_no].data = (uint8_t *) bufs[i - 1];
00341                s->f[ifp_no].offset = 0;
00342                s->f[ifp_no].src = "UDPTL";
00343                if (ifp_no > 0)
00344                   AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00345                AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00346                ifp_no++;
00347             }
00348          }
00349       }
00350    }
00351    else
00352    {
00353       /* FEC mode for error recovery */
00354       /* Our buffers cannot tolerate overlength IFP packets in FEC mode */
00355       if (ifp_len > LOCAL_FAX_MAX_DATAGRAM)
00356          return -1;
00357       /* Update any missed slots in the buffer */
00358       for ( ; seq_no > s->rx_seq_no; s->rx_seq_no++) {
00359          x = s->rx_seq_no & UDPTL_BUF_MASK;
00360          s->rx[x].buf_len = -1;
00361          s->rx[x].fec_len[0] = 0;
00362          s->rx[x].fec_span = 0;
00363          s->rx[x].fec_entries = 0;
00364       }
00365 
00366       x = seq_no & UDPTL_BUF_MASK;
00367 
00368       memset(repaired, 0, sizeof(repaired));
00369 
00370       /* Save the new IFP packet */
00371       memcpy(s->rx[x].buf, ifp, ifp_len);
00372       s->rx[x].buf_len = ifp_len;
00373       repaired[x] = TRUE;
00374 
00375       /* Decode the FEC packets */
00376       /* The span is defined as an unconstrained integer, but will never be more
00377          than a small value. */
00378       if (ptr + 2 > len)
00379          return -1;
00380       if (buf[ptr++] != 1)
00381          return -1;
00382       span = buf[ptr++];
00383       s->rx[x].fec_span = span;
00384 
00385       /* The number of entries is defined as a length, but will only ever be a small
00386          value. Treat it as such. */
00387       if (ptr + 1 > len)
00388          return -1;
00389       entries = buf[ptr++];
00390       s->rx[x].fec_entries = entries;
00391 
00392       /* Decode the elements */
00393       for (i = 0; i < entries; i++) {
00394          if ((stat = decode_open_type(buf, len, &ptr, &data, &s->rx[x].fec_len[i])) != 0)
00395             return -1;
00396          if (s->rx[x].fec_len[i] > LOCAL_FAX_MAX_DATAGRAM)
00397             return -1;
00398 
00399          /* Save the new FEC data */
00400          memcpy(s->rx[x].fec[i], data, s->rx[x].fec_len[i]);
00401 #if 0
00402          fprintf(stderr, "FEC: ");
00403          for (j = 0; j < s->rx[x].fec_len[i]; j++)
00404             fprintf(stderr, "%02X ", data[j]);
00405          fprintf(stderr, "\n");
00406 #endif
00407       }
00408 
00409       /* See if we can reconstruct anything which is missing */
00410       /* TODO: this does not comprehensively hunt back and repair everything that is possible */
00411       for (l = x; l != ((x - (16 - span*entries)) & UDPTL_BUF_MASK); l = (l - 1) & UDPTL_BUF_MASK) {
00412          if (s->rx[l].fec_len[0] <= 0)
00413             continue;
00414          for (m = 0; m < s->rx[l].fec_entries; m++) {
00415             limit = (l + m) & UDPTL_BUF_MASK;
00416             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) {
00417                if (s->rx[k].buf_len <= 0)
00418                   which = (which == -1) ? k : -2;
00419             }
00420             if (which >= 0) {
00421                /* Repairable */
00422                for (j = 0; j < s->rx[l].fec_len[m]; j++) {
00423                   s->rx[which].buf[j] = s->rx[l].fec[m][j];
00424                   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)
00425                      s->rx[which].buf[j] ^= (s->rx[k].buf_len > j) ? s->rx[k].buf[j] : 0;
00426                }
00427                s->rx[which].buf_len = s->rx[l].fec_len[m];
00428                repaired[which] = TRUE;
00429             }
00430          }
00431       }
00432       /* Now play any new packets forwards in time */
00433       for (l = (x + 1) & UDPTL_BUF_MASK, j = seq_no - UDPTL_BUF_MASK; l != x; l = (l + 1) & UDPTL_BUF_MASK, j++) {
00434          if (repaired[l]) {
00435             //fprintf(stderr, "Fixed packet %d, len %d\n", j, l);
00436             s->f[ifp_no].frametype = AST_FRAME_MODEM;
00437             s->f[ifp_no].subclass = AST_MODEM_T38;
00438          
00439             s->f[ifp_no].mallocd = 0;
00440             s->f[ifp_no].seqno = j;
00441             s->f[ifp_no].datalen = s->rx[l].buf_len;
00442             s->f[ifp_no].data = s->rx[l].buf;
00443             s->f[ifp_no].offset = 0;
00444             s->f[ifp_no].src = "UDPTL";
00445             if (ifp_no > 0)
00446                AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00447             AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00448             ifp_no++;
00449          }
00450       }
00451    }
00452 
00453    /* If packets are received out of sequence, we may have already processed this packet from the error
00454       recovery information in a packet already received. */
00455    if (seq_no >= s->rx_seq_no) {
00456       /* Decode the primary IFP packet */
00457       s->f[ifp_no].frametype = AST_FRAME_MODEM;
00458       s->f[ifp_no].subclass = AST_MODEM_T38;
00459       
00460       s->f[ifp_no].mallocd = 0;
00461       s->f[ifp_no].seqno = seq_no;
00462       s->f[ifp_no].datalen = ifp_len;
00463       s->f[ifp_no].data = (uint8_t *) ifp;
00464       s->f[ifp_no].offset = 0;
00465       s->f[ifp_no].src = "UDPTL";
00466       if (ifp_no > 0)
00467          AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00468       AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00469 
00470       ifp_no++;
00471    }
00472 
00473    s->rx_seq_no = seq_no + 1;
00474    return ifp_no;
00475 }
00476 /*- End of function --------------------------------------------------------*/
00477 
00478 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, uint8_t *ifp, int ifp_len)
00479 {
00480    uint8_t fec[LOCAL_FAX_MAX_DATAGRAM];
00481    int i;
00482    int j;
00483    int seq;
00484    int entry;
00485    int entries;
00486    int span;
00487    int m;
00488    int len;
00489    int limit;
00490    int high_tide;
00491 
00492    seq = s->tx_seq_no & 0xFFFF;
00493 
00494    /* Map the sequence number to an entry in the circular buffer */
00495    entry = seq & UDPTL_BUF_MASK;
00496 
00497    /* We save the message in a circular buffer, for generating FEC or
00498       redundancy sets later on. */
00499    s->tx[entry].buf_len = ifp_len;
00500    memcpy(s->tx[entry].buf, ifp, ifp_len);
00501    
00502    /* Build the UDPTLPacket */
00503 
00504    len = 0;
00505    /* Encode the sequence number */
00506    buf[len++] = (seq >> 8) & 0xFF;
00507    buf[len++] = seq & 0xFF;
00508 
00509    /* Encode the primary IFP packet */
00510    if (encode_open_type(buf, &len, ifp, ifp_len) < 0)
00511       return -1;
00512 
00513    /* Encode the appropriate type of error recovery information */
00514    switch (s->error_correction_scheme)
00515    {
00516    case UDPTL_ERROR_CORRECTION_NONE:
00517       /* Encode the error recovery type */
00518       buf[len++] = 0x00;
00519       /* The number of entries will always be zero, so it is pointless allowing
00520          for the fragmented case here. */
00521       if (encode_length(buf, &len, 0) < 0)
00522          return -1;
00523       break;
00524    case UDPTL_ERROR_CORRECTION_REDUNDANCY:
00525       /* Encode the error recovery type */
00526       buf[len++] = 0x00;
00527       if (s->tx_seq_no > s->error_correction_entries)
00528          entries = s->error_correction_entries;
00529       else
00530          entries = s->tx_seq_no;
00531       /* The number of entries will always be small, so it is pointless allowing
00532          for the fragmented case here. */
00533       if (encode_length(buf, &len, entries) < 0)
00534          return -1;
00535       /* Encode the elements */
00536       for (i = 0; i < entries; i++) {
00537          j = (entry - i - 1) & UDPTL_BUF_MASK;
00538          if (encode_open_type(buf, &len, s->tx[j].buf, s->tx[j].buf_len) < 0)
00539             return -1;
00540       }
00541       break;
00542    case UDPTL_ERROR_CORRECTION_FEC:
00543       span = s->error_correction_span;
00544       entries = s->error_correction_entries;
00545       if (seq < s->error_correction_span*s->error_correction_entries) {
00546          /* In the initial stages, wind up the FEC smoothly */
00547          entries = seq/s->error_correction_span;
00548          if (seq < s->error_correction_span)
00549             span = 0;
00550       }
00551       /* Encode the error recovery type */
00552       buf[len++] = 0x80;
00553       /* Span is defined as an inconstrained integer, which it dumb. It will only
00554          ever be a small value. Treat it as such. */
00555       buf[len++] = 1;
00556       buf[len++] = span;
00557       /* The number of entries is defined as a length, but will only ever be a small
00558          value. Treat it as such. */
00559       buf[len++] = entries;
00560       for (m = 0; m < entries; m++) {
00561          /* Make an XOR'ed entry the maximum length */
00562          limit = (entry + m) & UDPTL_BUF_MASK;
00563          high_tide = 0;
00564          for (i = (limit - span*entries) & UDPTL_BUF_MASK; i != limit; i = (i + entries) & UDPTL_BUF_MASK) {
00565             if (high_tide < s->tx[i].buf_len) {
00566                for (j = 0; j < high_tide; j++)
00567                   fec[j] ^= s->tx[i].buf[j];
00568                for ( ; j < s->tx[i].buf_len; j++)
00569                   fec[j] = s->tx[i].buf[j];
00570                high_tide = s->tx[i].buf_len;
00571             } else {
00572                for (j = 0; j < s->tx[i].buf_len; j++)
00573                   fec[j] ^= s->tx[i].buf[j];
00574             }
00575          }
00576          if (encode_open_type(buf, &len, fec, high_tide) < 0)
00577             return -1;
00578       }
00579       break;
00580    }
00581 
00582    if (s->verbose)
00583       fprintf(stderr, "\n");
00584 
00585    s->tx_seq_no++;
00586    return len;
00587 }
00588 
00589 int ast_udptl_fd(struct ast_udptl *udptl)
00590 {
00591    return udptl->fd;
00592 }
00593 
00594 void ast_udptl_set_data(struct ast_udptl *udptl, void *data)
00595 {
00596    udptl->data = data;
00597 }
00598 
00599 void ast_udptl_set_callback(struct ast_udptl *udptl, ast_udptl_callback callback)
00600 {
00601    udptl->callback = callback;
00602 }
00603 
00604 void ast_udptl_setnat(struct ast_udptl *udptl, int nat)
00605 {
00606    udptl->nat = nat;
00607 }
00608 
00609 static int udptlread(int *id, int fd, short events, void *cbdata)
00610 {
00611    struct ast_udptl *udptl = cbdata;
00612    struct ast_frame *f;
00613 
00614    if ((f = ast_udptl_read(udptl))) {
00615       if (udptl->callback)
00616          udptl->callback(udptl, f, udptl->data);
00617    }
00618    return 1;
00619 }
00620 
00621 struct ast_frame *ast_udptl_read(struct ast_udptl *udptl)
00622 {
00623    int res;
00624    struct sockaddr_in sin;
00625    socklen_t len;
00626    uint16_t seqno = 0;
00627    uint16_t *udptlheader;
00628 
00629    len = sizeof(sin);
00630    
00631    /* Cache where the header will go */
00632    res = recvfrom(udptl->fd,
00633          udptl->rawdata + AST_FRIENDLY_OFFSET,
00634          sizeof(udptl->rawdata) - AST_FRIENDLY_OFFSET,
00635          0,
00636          (struct sockaddr *) &sin,
00637          &len);
00638    udptlheader = (uint16_t *)(udptl->rawdata + AST_FRIENDLY_OFFSET);
00639    if (res < 0) {
00640       if (errno != EAGAIN)
00641          ast_log(LOG_WARNING, "UDPTL read error: %s\n", strerror(errno));
00642       ast_assert(errno != EBADF);
00643       return &ast_null_frame;
00644    }
00645 
00646    /* Ignore if the other side hasn't been given an address yet. */
00647    if (!udptl->them.sin_addr.s_addr || !udptl->them.sin_port)
00648       return &ast_null_frame;
00649 
00650    if (udptl->nat) {
00651       /* Send to whoever sent to us */
00652       if ((udptl->them.sin_addr.s_addr != sin.sin_addr.s_addr) ||
00653          (udptl->them.sin_port != sin.sin_port)) {
00654          memcpy(&udptl->them, &sin, sizeof(udptl->them));
00655          ast_log(LOG_DEBUG, "UDPTL NAT: Using address %s:%d\n", ast_inet_ntoa(udptl->them.sin_addr), ntohs(udptl->them.sin_port));
00656       }
00657    }
00658 
00659    if (udptl_debug_test_addr(&sin)) {
00660       ast_verbose("Got UDPTL packet from %s:%d (type %d, seq %d, len %d)\n",
00661          ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), 0, seqno, res);
00662    }
00663 #if 0
00664    printf("Got UDPTL packet from %s:%d (seq %d, len = %d)\n", ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), seqno, res);
00665 #endif
00666    if (udptl_rx_packet(udptl, udptl->rawdata + AST_FRIENDLY_OFFSET, res) < 1)
00667       return &ast_null_frame;
00668 
00669    return &udptl->f[0];
00670 }
00671 
00672 void ast_udptl_offered_from_local(struct ast_udptl* udptl, int local)
00673 {
00674    if (udptl)
00675       udptl->udptl_offered_from_local = local;
00676    else
00677       ast_log(LOG_WARNING, "udptl structure is null\n");
00678 }
00679 
00680 int ast_udptl_get_error_correction_scheme(struct ast_udptl* udptl)
00681 {
00682    if (udptl)
00683       return udptl->error_correction_scheme;
00684    else {
00685       ast_log(LOG_WARNING, "udptl structure is null\n");
00686       return -1;
00687    }
00688 }
00689 
00690 void ast_udptl_set_error_correction_scheme(struct ast_udptl* udptl, int ec)
00691 {
00692    if (udptl) {
00693       switch (ec) {
00694       case UDPTL_ERROR_CORRECTION_FEC:
00695          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
00696          break;
00697       case UDPTL_ERROR_CORRECTION_REDUNDANCY:
00698          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
00699          break;
00700       case UDPTL_ERROR_CORRECTION_NONE:
00701          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
00702          break;
00703       default:
00704          ast_log(LOG_WARNING, "error correction parameter invalid\n");
00705       };
00706    } else
00707       ast_log(LOG_WARNING, "udptl structure is null\n");
00708 }
00709 
00710 int ast_udptl_get_local_max_datagram(struct ast_udptl* udptl)
00711 {
00712    if (udptl)
00713       return udptl->local_max_datagram_size;
00714    else {
00715       ast_log(LOG_WARNING, "udptl structure is null\n");
00716       return -1;
00717    }
00718 }
00719 
00720 int ast_udptl_get_far_max_datagram(struct ast_udptl* udptl)
00721 {
00722    if (udptl)
00723       return udptl->far_max_datagram_size;
00724    else {
00725       ast_log(LOG_WARNING, "udptl structure is null\n");
00726       return -1;
00727    }
00728 }
00729 
00730 void ast_udptl_set_local_max_datagram(struct ast_udptl* udptl, int max_datagram)
00731 {
00732    if (udptl)
00733       udptl->local_max_datagram_size = max_datagram;
00734    else
00735       ast_log(LOG_WARNING, "udptl structure is null\n");
00736 }
00737 
00738 void ast_udptl_set_far_max_datagram(struct ast_udptl* udptl, int max_datagram)
00739 {
00740    if (udptl)
00741       udptl->far_max_datagram_size = max_datagram;
00742    else
00743       ast_log(LOG_WARNING, "udptl structure is null\n");
00744 }
00745 
00746 struct ast_udptl *ast_udptl_new_with_bindaddr(struct sched_context *sched, struct io_context *io, int callbackmode, struct in_addr addr)
00747 {
00748    struct ast_udptl *udptl;
00749    int x;
00750    int startplace;
00751    int i;
00752    long int flags;
00753 
00754    if (!(udptl = ast_calloc(1, sizeof(*udptl))))
00755       return NULL;
00756 
00757    if (udptlfectype == 2)
00758       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
00759    else if (udptlfectype == 1)
00760       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
00761    else
00762       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
00763    udptl->error_correction_span = udptlfecspan;
00764    udptl->error_correction_entries = udptlfecentries;
00765    
00766    udptl->far_max_datagram_size = udptlmaxdatagram;
00767    udptl->local_max_datagram_size = udptlmaxdatagram;
00768 
00769    memset(&udptl->rx, 0, sizeof(udptl->rx));
00770    memset(&udptl->tx, 0, sizeof(udptl->tx));
00771    for (i = 0; i <= UDPTL_BUF_MASK; i++) {
00772       udptl->rx[i].buf_len = -1;
00773       udptl->tx[i].buf_len = -1;
00774    }
00775 
00776    udptl->them.sin_family = AF_INET;
00777    udptl->us.sin_family = AF_INET;
00778 
00779    if ((udptl->fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
00780       free(udptl);
00781       ast_log(LOG_WARNING, "Unable to allocate socket: %s\n", strerror(errno));
00782       return NULL;
00783    }
00784    flags = fcntl(udptl->fd, F_GETFL);
00785    fcntl(udptl->fd, F_SETFL, flags | O_NONBLOCK);
00786 #ifdef SO_NO_CHECK
00787    if (nochecksums)
00788       setsockopt(udptl->fd, SOL_SOCKET, SO_NO_CHECK, &nochecksums, sizeof(nochecksums));
00789 #endif
00790    /* Find us a place */
00791    x = (ast_random() % (udptlend - udptlstart)) + udptlstart;
00792    startplace = x;
00793    for (;;) {
00794       udptl->us.sin_port = htons(x);
00795       udptl->us.sin_addr = addr;
00796       if (bind(udptl->fd, (struct sockaddr *) &udptl->us, sizeof(udptl->us)) == 0)
00797          break;
00798       if (errno != EADDRINUSE) {
00799          ast_log(LOG_WARNING, "Unexpected bind error: %s\n", strerror(errno));
00800          close(udptl->fd);
00801          free(udptl);
00802          return NULL;
00803       }
00804       if (++x > udptlend)
00805          x = udptlstart;
00806       if (x == startplace) {
00807          ast_log(LOG_WARNING, "No UDPTL ports remaining\n");
00808          close(udptl->fd);
00809          free(udptl);
00810          return NULL;
00811       }
00812    }
00813    if (io && sched && callbackmode) {
00814       /* Operate this one in a callback mode */
00815       udptl->sched = sched;
00816       udptl->io = io;
00817       udptl->ioid = ast_io_add(udptl->io, udptl->fd, udptlread, AST_IO_IN, udptl);
00818    }
00819    return udptl;
00820 }
00821 
00822 struct ast_udptl *ast_udptl_new(struct sched_context *sched, struct io_context *io, int callbackmode)
00823 {
00824    struct in_addr ia;
00825    memset(&ia, 0, sizeof(ia));
00826    return ast_udptl_new_with_bindaddr(sched, io, callbackmode, ia);
00827 }
00828 
00829 int ast_udptl_settos(struct ast_udptl *udptl, int tos)
00830 {
00831    int res;
00832 
00833    if ((res = setsockopt(udptl->fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)))) 
00834       ast_log(LOG_WARNING, "UDPTL unable to set TOS to %d\n", tos);
00835    return res;
00836 }
00837 
00838 void ast_udptl_set_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
00839 {
00840    udptl->them.sin_port = them->sin_port;
00841    udptl->them.sin_addr = them->sin_addr;
00842 }
00843 
00844 void ast_udptl_get_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
00845 {
00846    memset(them, 0, sizeof(*them));
00847    them->sin_family = AF_INET;
00848    them->sin_port = udptl->them.sin_port;
00849    them->sin_addr = udptl->them.sin_addr;
00850 }
00851 
00852 void ast_udptl_get_us(struct ast_udptl *udptl, struct sockaddr_in *us)
00853 {
00854    memcpy(us, &udptl->us, sizeof(udptl->us));
00855 }
00856 
00857 void ast_udptl_stop(struct ast_udptl *udptl)
00858 {
00859    memset(&udptl->them.sin_addr, 0, sizeof(udptl->them.sin_addr));
00860    memset(&udptl->them.sin_port, 0, sizeof(udptl->them.sin_port));
00861 }
00862 
00863 void ast_udptl_destroy(struct ast_udptl *udptl)
00864 {
00865    if (udptl->ioid)
00866       ast_io_remove(udptl->io, udptl->ioid);
00867    if (udptl->fd > -1)
00868       close(udptl->fd);
00869    free(udptl);
00870 }
00871 
00872 int ast_udptl_write(struct ast_udptl *s, struct ast_frame *f)
00873 {
00874    int seq;
00875    int len;
00876    int res;
00877    uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
00878 
00879    /* If we have no peer, return immediately */ 
00880    if (s->them.sin_addr.s_addr == INADDR_ANY)
00881       return 0;
00882 
00883    /* If there is no data length, return immediately */
00884    if (f->datalen == 0)
00885       return 0;
00886    
00887    if (f->frametype != AST_FRAME_MODEM) {
00888       ast_log(LOG_WARNING, "UDPTL can only send T.38 data\n");
00889       return -1;
00890    }
00891 
00892    /* Save seq_no for debug output because udptl_build_packet increments it */
00893    seq = s->tx_seq_no & 0xFFFF;
00894 
00895    /* Cook up the UDPTL packet, with the relevant EC info. */
00896    len = udptl_build_packet(s, buf, f->data, f->datalen);
00897 
00898    if (len > 0 && s->them.sin_port && s->them.sin_addr.s_addr) {
00899       if ((res = sendto(s->fd, buf, len, 0, (struct sockaddr *) &s->them, sizeof(s->them))) < 0)
00900          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));
00901 #if 0
00902       printf("Sent %d bytes of UDPTL data to %s:%d\n", res, ast_inet_ntoa(udptl->them.sin_addr), ntohs(udptl->them.sin_port));
00903 #endif
00904       if (udptl_debug_test_addr(&s->them))
00905          ast_verbose("Sent UDPTL packet to %s:%d (type %d, seq %d, len %d)\n",
00906                ast_inet_ntoa(s->them.sin_addr),
00907                ntohs(s->them.sin_port), 0, seq, len);
00908    }
00909       
00910    return 0;
00911 }
00912 
00913 void ast_udptl_proto_unregister(struct ast_udptl_protocol *proto)
00914 {
00915    struct ast_udptl_protocol *cur;
00916    struct ast_udptl_protocol *prev;
00917 
00918    cur = protos;
00919    prev = NULL;
00920    while (cur) {
00921       if (cur == proto) {
00922          if (prev)
00923             prev->next = proto->next;
00924          else
00925             protos = proto->next;
00926          return;
00927       }
00928       prev = cur;
00929       cur = cur->next;
00930    }
00931 }
00932 
00933 int ast_udptl_proto_register(struct ast_udptl_protocol *proto)
00934 {
00935    struct ast_udptl_protocol *cur;
00936 
00937    cur = protos;
00938    while (cur) {
00939       if (cur->type == proto->type) {
00940          ast_log(LOG_WARNING, "Tried to register same protocol '%s' twice\n", cur->type);
00941          return -1;
00942       }
00943       cur = cur->next;
00944    }
00945    proto->next = protos;
00946    protos = proto;
00947    return 0;
00948 }
00949 
00950 static struct ast_udptl_protocol *get_proto(struct ast_channel *chan)
00951 {
00952    struct ast_udptl_protocol *cur;
00953 
00954    cur = protos;
00955    while (cur) {
00956       if (cur->type == chan->tech->type)
00957          return cur;
00958       cur = cur->next;
00959    }
00960    return NULL;
00961 }
00962 
00963 int ast_udptl_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
00964 {
00965    struct ast_frame *f;
00966    struct ast_channel *who;
00967    struct ast_channel *cs[3];
00968    struct ast_udptl *p0;
00969    struct ast_udptl *p1;
00970    struct ast_udptl_protocol *pr0;
00971    struct ast_udptl_protocol *pr1;
00972    struct sockaddr_in ac0;
00973    struct sockaddr_in ac1;
00974    struct sockaddr_in t0;
00975    struct sockaddr_in t1;
00976    void *pvt0;
00977    void *pvt1;
00978    int to;
00979    
00980    ast_channel_lock(c0);
00981    while (ast_channel_trylock(c1)) {
00982       ast_channel_unlock(c0);
00983       usleep(1);
00984       ast_channel_lock(c0);
00985    }
00986    pr0 = get_proto(c0);
00987    pr1 = get_proto(c1);
00988    if (!pr0) {
00989       ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c0->name);
00990       ast_channel_unlock(c0);
00991       ast_channel_unlock(c1);
00992       return -1;
00993    }
00994    if (!pr1) {
00995       ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c1->name);
00996       ast_channel_unlock(c0);
00997       ast_channel_unlock(c1);
00998       return -1;
00999    }
01000    pvt0 = c0->tech_pvt;
01001    pvt1 = c1->tech_pvt;
01002    p0 = pr0->get_udptl_info(c0);
01003    p1 = pr1->get_udptl_info(c1);
01004    if (!p0 || !p1) {
01005       /* Somebody doesn't want to play... */
01006       ast_channel_unlock(c0);
01007       ast_channel_unlock(c1);
01008       return -2;
01009    }
01010    if (pr0->set_udptl_peer(c0, p1)) {
01011       ast_log(LOG_WARNING, "Channel '%s' failed to talk to '%s'\n", c0->name, c1->name);
01012       memset(&ac1, 0, sizeof(ac1));
01013    } else {
01014       /* Store UDPTL peer */
01015       ast_udptl_get_peer(p1, &ac1);
01016    }
01017    if (pr1->set_udptl_peer(c1, p0)) {
01018       ast_log(LOG_WARNING, "Channel '%s' failed to talk back to '%s'\n", c1->name, c0->name);
01019       memset(&ac0, 0, sizeof(ac0));
01020    } else {
01021       /* Store UDPTL peer */
01022       ast_udptl_get_peer(p0, &ac0);
01023    }
01024    ast_channel_unlock(c0);
01025    ast_channel_unlock(c1);
01026    cs[0] = c0;
01027    cs[1] = c1;
01028    cs[2] = NULL;
01029    for (;;) {
01030       if ((c0->tech_pvt != pvt0) ||
01031          (c1->tech_pvt != pvt1) ||
01032          (c0->masq || c0->masqr || c1->masq || c1->masqr)) {
01033             ast_log(LOG_DEBUG, "Oooh, something is weird, backing out\n");
01034             /* Tell it to try again later */
01035             return -3;
01036       }
01037       to = -1;
01038       ast_udptl_get_peer(p1, &t1);
01039       ast_udptl_get_peer(p0, &t0);
01040       if (inaddrcmp(&t1, &ac1)) {
01041          ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n", 
01042             c1->name, ast_inet_ntoa(t1.sin_addr), ntohs(t1.sin_port));
01043          ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n", 
01044             c1->name, ast_inet_ntoa(ac1.sin_addr), ntohs(ac1.sin_port));
01045          memcpy(&ac1, &t1, sizeof(ac1));
01046       }
01047       if (inaddrcmp(&t0, &ac0)) {
01048          ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n", 
01049             c0->name, ast_inet_ntoa(t0.sin_addr), ntohs(t0.sin_port));
01050          ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n", 
01051             c0->name, ast_inet_ntoa(ac0.sin_addr), ntohs(ac0.sin_port));
01052          memcpy(&ac0, &t0, sizeof(ac0));
01053       }
01054       who = ast_waitfor_n(cs, 2, &to);
01055       if (!who) {
01056          ast_log(LOG_DEBUG, "Ooh, empty read...\n");
01057          /* check for hangup / whentohangup */
01058          if (ast_check_hangup(c0) || ast_check_hangup(c1))
01059             break;
01060          continue;
01061       }
01062       f = ast_read(who);
01063       if (!f) {
01064          *fo = f;
01065          *rc = who;
01066          ast_log(LOG_DEBUG, "Oooh, got a %s\n", f ? "digit" : "hangup");
01067          /* That's all we needed */
01068          return 0;
01069       } else {
01070          if (f->frametype == AST_FRAME_MODEM) {
01071             /* Forward T.38 frames if they happen upon us */
01072             if (who == c0) {
01073                ast_write(c1, f);
01074             } else if (who == c1) {
01075                ast_write(c0, f);
01076             }
01077          }
01078          ast_frfree(f);
01079       }
01080       /* Swap priority. Not that it's a big deal at this point */
01081       cs[2] = cs[0];
01082       cs[0] = cs[1];
01083       cs[1] = cs[2];
01084    }
01085    return -1;
01086 }
01087 
01088 static int udptl_do_debug_ip(int fd, int argc, char *argv[])
01089 {
01090    struct hostent *hp;
01091    struct ast_hostent ahp;
01092    int port;
01093    char *p;
01094    char *arg;
01095 
01096    port = 0;
01097    if (argc != 4)
01098       return RESULT_SHOWUSAGE;
01099    arg = argv[3];
01100    p = strstr(arg, ":");
01101    if (p) {
01102       *p = '\0';
01103       p++;
01104       port = atoi(p);
01105    }
01106    hp = ast_gethostbyname(arg, &ahp);
01107    if (hp == NULL)
01108       return RESULT_SHOWUSAGE;
01109    udptldebugaddr.sin_family = AF_INET;
01110    memcpy(&udptldebugaddr.sin_addr, hp->h_addr, sizeof(udptldebugaddr.sin_addr));
01111    udptldebugaddr.sin_port = htons(port);
01112    if (port == 0)
01113       ast_cli(fd, "UDPTL Debugging Enabled for IP: %s\n", ast_inet_ntoa(udptldebugaddr.sin_addr));
01114    else
01115       ast_cli(fd, "UDPTL Debugging Enabled for IP: %s:%d\n", ast_inet_ntoa(udptldebugaddr.sin_addr), port);
01116    udptldebug = 1;
01117    return RESULT_SUCCESS;
01118 }
01119 
01120 static int udptl_do_debug(int fd, int argc, char *argv[])
01121 {
01122    if (argc != 2) {
01123       if (argc != 4)
01124          return RESULT_SHOWUSAGE;
01125       return udptl_do_debug_ip(fd, argc, argv);
01126    }
01127    udptldebug = 1;
01128    memset(&udptldebugaddr,0,sizeof(udptldebugaddr));
01129    ast_cli(fd, "UDPTL Debugging Enabled\n");
01130    return RESULT_SUCCESS;
01131 }
01132 
01133 static int udptl_nodebug(int fd, int argc, char *argv[])
01134 {
01135    if (argc != 3)
01136       return RESULT_SHOWUSAGE;
01137    udptldebug = 0;
01138    ast_cli(fd,"UDPTL Debugging Disabled\n");
01139    return RESULT_SUCCESS;
01140 }
01141 
01142 static char debug_usage[] =
01143   "Usage: udptl debug [ip host[:port]]\n"
01144   "       Enable dumping of all UDPTL packets to and from host.\n";
01145 
01146 static char nodebug_usage[] =
01147   "Usage: udptl debug off\n"
01148   "       Disable all UDPTL debugging\n";
01149 
01150 static struct ast_cli_entry cli_udptl_no_debug = {
01151    { "udptl", "no", "debug", NULL },
01152    udptl_nodebug, NULL,
01153    NULL };
01154 
01155 static struct ast_cli_entry cli_udptl[] = {
01156    { { "udptl", "debug", NULL },
01157    udptl_do_debug, "Enable UDPTL debugging",
01158    debug_usage },
01159 
01160    { { "udptl", "debug", "ip", NULL },
01161    udptl_do_debug, "Enable UDPTL debugging on IP",
01162    debug_usage },
01163 
01164    { { "udptl", "debug", "off", NULL },
01165    udptl_nodebug, "Disable UDPTL debugging",
01166    nodebug_usage, NULL, &cli_udptl_no_debug },
01167 };
01168 
01169 void ast_udptl_reload(void)
01170 {
01171    struct ast_config *cfg;
01172    const char *s;
01173 
01174    udptlstart = 4500;
01175    udptlend = 4999;
01176    udptlfectype = 0;
01177    udptlfecentries = 0;
01178    udptlfecspan = 0;
01179    udptlmaxdatagram = 0;
01180 
01181    if ((cfg = ast_config_load("udptl.conf"))) {
01182       if ((s = ast_variable_retrieve(cfg, "general", "udptlstart"))) {
01183          udptlstart = atoi(s);
01184          if (udptlstart < 1024)
01185             udptlstart = 1024;
01186          if (udptlstart > 65535)
01187             udptlstart = 65535;
01188       }
01189       if ((s = ast_variable_retrieve(cfg, "general", "udptlend"))) {
01190          udptlend = atoi(s);
01191          if (udptlend < 1024)
01192             udptlend = 1024;
01193          if (udptlend > 65535)
01194             udptlend = 65535;
01195       }
01196       if ((s = ast_variable_retrieve(cfg, "general", "udptlchecksums"))) {
01197 #ifdef SO_NO_CHECK
01198          if (ast_false(s))
01199             nochecksums = 1;
01200          else
01201             nochecksums = 0;
01202 #else
01203          if (ast_false(s))
01204             ast_log(LOG_WARNING, "Disabling UDPTL checksums is not supported on this operating system!\n");
01205 #endif
01206       }
01207       if ((s = ast_variable_retrieve(cfg, "general", "T38FaxUdpEC"))) {
01208          if (strcmp(s, "t38UDPFEC") == 0)
01209             udptlfectype = 2;
01210          else if (strcmp(s, "t38UDPRedundancy") == 0)
01211             udptlfectype = 1;
01212       }
01213       if ((s = ast_variable_retrieve(cfg, "general", "T38FaxMaxDatagram"))) {
01214          udptlmaxdatagram = atoi(s);
01215          if (udptlmaxdatagram < 0)
01216             udptlmaxdatagram = 0;
01217          if (udptlmaxdatagram > LOCAL_FAX_MAX_DATAGRAM)
01218             udptlmaxdatagram = LOCAL_FAX_MAX_DATAGRAM;
01219       }
01220       if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECentries"))) {
01221          udptlfecentries = atoi(s);
01222          if (udptlfecentries < 0)
01223             udptlfecentries = 0;
01224          if (udptlfecentries > MAX_FEC_ENTRIES)
01225             udptlfecentries = MAX_FEC_ENTRIES;
01226       }
01227       if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECspan"))) {
01228          udptlfecspan = atoi(s);
01229          if (udptlfecspan < 0)
01230             udptlfecspan = 0;
01231          if (udptlfecspan > MAX_FEC_SPAN)
01232             udptlfecspan = MAX_FEC_SPAN;
01233       }
01234       ast_config_destroy(cfg);
01235    }
01236    if (udptlstart >= udptlend) {
01237       ast_log(LOG_WARNING, "Unreasonable values for UDPTL start/end\n");
01238       udptlstart = 4500;
01239       udptlend = 4999;
01240    }
01241    if (option_verbose > 1)
01242       ast_verbose(VERBOSE_PREFIX_2 "UDPTL allocating from port range %d -> %d\n", udptlstart, udptlend);
01243 }
01244 
01245 void ast_udptl_init(void)
01246 {
01247    ast_cli_register_multiple(cli_udptl, sizeof(cli_udptl) / sizeof(struct ast_cli_entry));
01248    ast_udptl_reload();
01249 }

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