Sun Dec 18 20:55:42 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    /* We have a fragment.  Currently we don't process fragments. */
00180    if (option_debug) {
00181       ast_log(LOG_DEBUG, "UDPTL packet with length greater than 16K received, decoding will fail\n");
00182    }
00183    return 1;
00184 }
00185 /*- End of function --------------------------------------------------------*/
00186 
00187 static int decode_open_type(uint8_t *buf, int limit, int *len, const uint8_t **p_object, int *p_num_octets)
00188 {
00189    int octet_cnt = 0;
00190 
00191    if (decode_length(buf, limit, len, &octet_cnt) != 0)
00192       return -1;
00193 
00194    if (octet_cnt > 0) {
00195       /* Make sure the buffer contains at least the number of bits requested */
00196       if ((*len + octet_cnt) > limit)
00197          return -1;
00198 
00199       *p_num_octets = octet_cnt;
00200       *p_object = &buf[*len];
00201       *len += octet_cnt;
00202    }
00203 
00204    return 0;
00205 }
00206 /*- End of function --------------------------------------------------------*/
00207 
00208 static int encode_length(uint8_t *buf, int *len, int value)
00209 {
00210    int multiplier;
00211 
00212    if (value < 0x80) {
00213       /* 1 octet */
00214       buf[*len] = value;
00215       (*len)++;
00216       return value;
00217    }
00218    if (value < 0x4000) {
00219       /* 2 octets */
00220       /* Set the first bit of the first octet */
00221       buf[*len] = ((0x8000 | value) >> 8) & 0xFF;
00222       (*len)++;
00223       buf[*len] = value & 0xFF;
00224       (*len)++;
00225       return value;
00226    }
00227    /* Fragmentation */
00228    multiplier = (value < 0x10000) ? (value >> 14) : 4;
00229    /* Set the first 2 bits of the octet */
00230    buf[*len] = 0xC0 | multiplier;
00231    (*len)++;
00232    return multiplier << 14;
00233 }
00234 /*- End of function --------------------------------------------------------*/
00235 
00236 static int encode_open_type(uint8_t *buf, int *len, const uint8_t *data, int num_octets)
00237 {
00238    int enclen;
00239    int octet_idx;
00240    uint8_t zero_byte;
00241 
00242    /* If open type is of zero length, add a single zero byte (10.1) */
00243    if (num_octets == 0) {
00244       zero_byte = 0;
00245       data = &zero_byte;
00246       num_octets = 1;
00247    }
00248    /* Encode the open type */
00249    for (octet_idx = 0; ; num_octets -= enclen, octet_idx += enclen) {
00250       if ((enclen = encode_length(buf, len, num_octets)) < 0)
00251          return -1;
00252       if (enclen > 0) {
00253          memcpy(&buf[*len], &data[octet_idx], enclen);
00254          *len += enclen;
00255       }
00256       if (enclen >= num_octets)
00257          break;
00258    }
00259 
00260    return 0;
00261 }
00262 /*- End of function --------------------------------------------------------*/
00263 
00264 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len)
00265 {
00266    int stat;
00267    int stat2;
00268    int i;
00269    int j;
00270    int k;
00271    int l;
00272    int m;
00273    int x;
00274    int limit;
00275    int which;
00276    int ptr;
00277    int count;
00278    int total_count;
00279    int seq_no;
00280    const uint8_t *ifp;
00281    const uint8_t *data;
00282    int ifp_len;
00283    int repaired[16];
00284    const uint8_t *bufs[ARRAY_LEN(s->f) - 1];
00285    int lengths[ARRAY_LEN(s->f) - 1];
00286    int span;
00287    int entries;
00288    int ifp_no;
00289 
00290    ptr = 0;
00291    ifp_no = 0;
00292    memset(&s->f[0], 0, sizeof(s->f[0]));
00293 
00294    /* Decode seq_number */
00295    if (ptr + 2 > len)
00296       return -1;
00297    seq_no = (buf[0] << 8) | buf[1];
00298    ptr += 2;
00299 
00300    /* Break out the primary packet */
00301    if ((stat = decode_open_type(buf, len, &ptr, &ifp, &ifp_len)) != 0)
00302       return -1;
00303    /* Decode error_recovery */
00304    if (ptr + 1 > len)
00305       return -1;
00306    if ((buf[ptr++] & 0x80) == 0) {
00307       /* Secondary packet mode for error recovery */
00308       if (seq_no > s->rx_seq_no) {
00309          /* We received a later packet than we expected, so we need to check if we can fill in the gap from the
00310             secondary packets. */
00311          total_count = 0;
00312          do {
00313             if ((stat2 = decode_length(buf, len, &ptr, &count)) < 0)
00314                return -1;
00315             for (i = 0; i < count && total_count + i < ARRAY_LEN(bufs); i++) {
00316                if ((stat = decode_open_type(buf, len, &ptr, &bufs[total_count + i], &lengths[total_count + i])) != 0)
00317                   return -1;
00318             }
00319             total_count += i;
00320          }
00321          while (stat2 > 0 && total_count < ARRAY_LEN(bufs));
00322          /* Step through in reverse order, so we go oldest to newest */
00323          for (i = total_count; i > 0; i--) {
00324             if (seq_no - i >= s->rx_seq_no) {
00325                /* This one wasn't seen before */
00326                /* Decode the secondary IFP packet */
00327                //fprintf(stderr, "Secondary %d, len %d\n", seq_no - i, lengths[i - 1]);
00328                s->f[ifp_no].frametype = AST_FRAME_MODEM;
00329                s->f[ifp_no].subclass = AST_MODEM_T38;
00330 
00331                s->f[ifp_no].mallocd = 0;
00332                s->f[ifp_no].seqno = seq_no - i;
00333                s->f[ifp_no].datalen = lengths[i - 1];
00334                s->f[ifp_no].data = (uint8_t *) bufs[i - 1];
00335                s->f[ifp_no].offset = 0;
00336                s->f[ifp_no].src = "UDPTL";
00337                if (ifp_no > 0)
00338                   AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00339                AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00340                ifp_no++;
00341             }
00342          }
00343       }
00344    }
00345    else
00346    {
00347       /* FEC mode for error recovery */
00348       /* Our buffers cannot tolerate overlength IFP packets in FEC mode */
00349       if (ifp_len > LOCAL_FAX_MAX_DATAGRAM)
00350          return -1;
00351       /* Update any missed slots in the buffer */
00352       for ( ; seq_no > s->rx_seq_no; s->rx_seq_no++) {
00353          x = s->rx_seq_no & UDPTL_BUF_MASK;
00354          s->rx[x].buf_len = -1;
00355          s->rx[x].fec_len[0] = 0;
00356          s->rx[x].fec_span = 0;
00357          s->rx[x].fec_entries = 0;
00358       }
00359 
00360       x = seq_no & UDPTL_BUF_MASK;
00361 
00362       memset(repaired, 0, sizeof(repaired));
00363 
00364       /* Save the new IFP packet */
00365       memcpy(s->rx[x].buf, ifp, ifp_len);
00366       s->rx[x].buf_len = ifp_len;
00367       repaired[x] = TRUE;
00368 
00369       /* Decode the FEC packets */
00370       /* The span is defined as an unconstrained integer, but will never be more
00371          than a small value. */
00372       if (ptr + 2 > len)
00373          return -1;
00374       if (buf[ptr++] != 1)
00375          return -1;
00376       span = buf[ptr++];
00377       s->rx[x].fec_span = span;
00378 
00379       /* The number of entries is defined as a length, but will only ever be a small
00380          value. Treat it as such. */
00381       if (ptr + 1 > len)
00382          return -1;
00383       entries = buf[ptr++];
00384       if (entries > MAX_FEC_ENTRIES) {
00385          return -1;
00386       }
00387       s->rx[x].fec_entries = entries;
00388 
00389       /* Decode the elements */
00390       for (i = 0; i < entries; i++) {
00391          if ((stat = decode_open_type(buf, len, &ptr, &data, &s->rx[x].fec_len[i])) != 0)
00392             return -1;
00393          if (s->rx[x].fec_len[i] > LOCAL_FAX_MAX_DATAGRAM)
00394             return -1;
00395 
00396          /* Save the new FEC data */
00397          memcpy(s->rx[x].fec[i], data, s->rx[x].fec_len[i]);
00398 #if 0
00399          fprintf(stderr, "FEC: ");
00400          for (j = 0; j < s->rx[x].fec_len[i]; j++)
00401             fprintf(stderr, "%02X ", data[j]);
00402          fprintf(stderr, "\n");
00403 #endif
00404       }
00405 
00406       /* See if we can reconstruct anything which is missing */
00407       /* TODO: this does not comprehensively hunt back and repair everything that is possible */
00408       for (l = x; l != ((x - (16 - span*entries)) & UDPTL_BUF_MASK); l = (l - 1) & UDPTL_BUF_MASK) {
00409          if (s->rx[l].fec_len[0] <= 0)
00410             continue;
00411          for (m = 0; m < s->rx[l].fec_entries; m++) {
00412             limit = (l + m) & UDPTL_BUF_MASK;
00413             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) {
00414                if (s->rx[k].buf_len <= 0)
00415                   which = (which == -1) ? k : -2;
00416             }
00417             if (which >= 0) {
00418                /* Repairable */
00419                for (j = 0; j < s->rx[l].fec_len[m]; j++) {
00420                   s->rx[which].buf[j] = s->rx[l].fec[m][j];
00421                   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)
00422                      s->rx[which].buf[j] ^= (s->rx[k].buf_len > j) ? s->rx[k].buf[j] : 0;
00423                }
00424                s->rx[which].buf_len = s->rx[l].fec_len[m];
00425                repaired[which] = TRUE;
00426             }
00427          }
00428       }
00429       /* Now play any new packets forwards in time */
00430       for (l = (x + 1) & UDPTL_BUF_MASK, j = seq_no - UDPTL_BUF_MASK; l != x; l = (l + 1) & UDPTL_BUF_MASK, j++) {
00431          if (repaired[l]) {
00432             //fprintf(stderr, "Fixed packet %d, len %d\n", j, l);
00433             s->f[ifp_no].frametype = AST_FRAME_MODEM;
00434             s->f[ifp_no].subclass = AST_MODEM_T38;
00435          
00436             s->f[ifp_no].mallocd = 0;
00437             s->f[ifp_no].seqno = j;
00438             s->f[ifp_no].datalen = s->rx[l].buf_len;
00439             s->f[ifp_no].data = s->rx[l].buf;
00440             s->f[ifp_no].offset = 0;
00441             s->f[ifp_no].src = "UDPTL";
00442             if (ifp_no > 0)
00443                AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00444             AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00445             ifp_no++;
00446          }
00447       }
00448    }
00449 
00450    /* If packets are received out of sequence, we may have already processed this packet from the error
00451       recovery information in a packet already received. */
00452    if (seq_no >= s->rx_seq_no) {
00453       /* Decode the primary IFP packet */
00454       s->f[ifp_no].frametype = AST_FRAME_MODEM;
00455       s->f[ifp_no].subclass = AST_MODEM_T38;
00456       
00457       s->f[ifp_no].mallocd = 0;
00458       s->f[ifp_no].seqno = seq_no;
00459       s->f[ifp_no].datalen = ifp_len;
00460       s->f[ifp_no].data = (uint8_t *) ifp;
00461       s->f[ifp_no].offset = 0;
00462       s->f[ifp_no].src = "UDPTL";
00463       if (ifp_no > 0)
00464          AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00465       AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00466 
00467       ifp_no++;
00468    }
00469 
00470    s->rx_seq_no = seq_no + 1;
00471    return ifp_no;
00472 }
00473 /*- End of function --------------------------------------------------------*/
00474 
00475 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, uint8_t *ifp, int ifp_len)
00476 {
00477    uint8_t fec[LOCAL_FAX_MAX_DATAGRAM];
00478    int i;
00479    int j;
00480    int seq;
00481    int entry;
00482    int entries;
00483    int span;
00484    int m;
00485    int len;
00486    int limit;
00487    int high_tide;
00488 
00489    seq = s->tx_seq_no & 0xFFFF;
00490 
00491    /* Map the sequence number to an entry in the circular buffer */
00492    entry = seq & UDPTL_BUF_MASK;
00493 
00494    /* We save the message in a circular buffer, for generating FEC or
00495       redundancy sets later on. */
00496    s->tx[entry].buf_len = ifp_len;
00497    memcpy(s->tx[entry].buf, ifp, ifp_len);
00498    
00499    /* Build the UDPTLPacket */
00500 
00501    len = 0;
00502    /* Encode the sequence number */
00503    buf[len++] = (seq >> 8) & 0xFF;
00504    buf[len++] = seq & 0xFF;
00505 
00506    /* Encode the primary IFP packet */
00507    if (encode_open_type(buf, &len, ifp, ifp_len) < 0)
00508       return -1;
00509 
00510    /* Encode the appropriate type of error recovery information */
00511    switch (s->error_correction_scheme)
00512    {
00513    case UDPTL_ERROR_CORRECTION_NONE:
00514       /* Encode the error recovery type */
00515       buf[len++] = 0x00;
00516       /* The number of entries will always be zero, so it is pointless allowing
00517          for the fragmented case here. */
00518       if (encode_length(buf, &len, 0) < 0)
00519          return -1;
00520       break;
00521    case UDPTL_ERROR_CORRECTION_REDUNDANCY:
00522       /* Encode the error recovery type */
00523       buf[len++] = 0x00;
00524       if (s->tx_seq_no > s->error_correction_entries)
00525          entries = s->error_correction_entries;
00526       else
00527          entries = s->tx_seq_no;
00528       /* The number of entries will always be small, so it is pointless allowing
00529          for the fragmented case here. */
00530       if (encode_length(buf, &len, entries) < 0)
00531          return -1;
00532       /* Encode the elements */
00533       for (i = 0; i < entries; i++) {
00534          j = (entry - i - 1) & UDPTL_BUF_MASK;
00535          if (encode_open_type(buf, &len, s->tx[j].buf, s->tx[j].buf_len) < 0)
00536             return -1;
00537       }
00538       break;
00539    case UDPTL_ERROR_CORRECTION_FEC:
00540       span = s->error_correction_span;
00541       entries = s->error_correction_entries;
00542       if (seq < s->error_correction_span*s->error_correction_entries) {
00543          /* In the initial stages, wind up the FEC smoothly */
00544          entries = seq/s->error_correction_span;
00545          if (seq < s->error_correction_span)
00546             span = 0;
00547       }
00548       /* Encode the error recovery type */
00549       buf[len++] = 0x80;
00550       /* Span is defined as an inconstrained integer, which it dumb. It will only
00551          ever be a small value. Treat it as such. */
00552       buf[len++] = 1;
00553       buf[len++] = span;
00554       /* The number of entries is defined as a length, but will only ever be a small
00555          value. Treat it as such. */
00556       buf[len++] = entries;
00557       for (m = 0; m < entries; m++) {
00558          /* Make an XOR'ed entry the maximum length */
00559          limit = (entry + m) & UDPTL_BUF_MASK;
00560          high_tide = 0;
00561          for (i = (limit - span*entries) & UDPTL_BUF_MASK; i != limit; i = (i + entries) & UDPTL_BUF_MASK) {
00562             if (high_tide < s->tx[i].buf_len) {
00563                for (j = 0; j < high_tide; j++)
00564                   fec[j] ^= s->tx[i].buf[j];
00565                for ( ; j < s->tx[i].buf_len; j++)
00566                   fec[j] = s->tx[i].buf[j];
00567                high_tide = s->tx[i].buf_len;
00568             } else {
00569                for (j = 0; j < s->tx[i].buf_len; j++)
00570                   fec[j] ^= s->tx[i].buf[j];
00571             }
00572          }
00573          if (encode_open_type(buf, &len, fec, high_tide) < 0)
00574             return -1;
00575       }
00576       break;
00577    }
00578 
00579    if (s->verbose)
00580       fprintf(stderr, "\n");
00581 
00582    s->tx_seq_no++;
00583    return len;
00584 }
00585 
00586 int ast_udptl_fd(struct ast_udptl *udptl)
00587 {
00588    return udptl->fd;
00589 }
00590 
00591 void ast_udptl_set_data(struct ast_udptl *udptl, void *data)
00592 {
00593    udptl->data = data;
00594 }
00595 
00596 void ast_udptl_set_callback(struct ast_udptl *udptl, ast_udptl_callback callback)
00597 {
00598    udptl->callback = callback;
00599 }
00600 
00601 void ast_udptl_setnat(struct ast_udptl *udptl, int nat)
00602 {
00603    udptl->nat = nat;
00604 }
00605 
00606 static int udptlread(int *id, int fd, short events, void *cbdata)
00607 {
00608    struct ast_udptl *udptl = cbdata;
00609    struct ast_frame *f;
00610 
00611    if ((f = ast_udptl_read(udptl))) {
00612       if (udptl->callback)
00613          udptl->callback(udptl, f, udptl->data);
00614    }
00615    return 1;
00616 }
00617 
00618 struct ast_frame *ast_udptl_read(struct ast_udptl *udptl)
00619 {
00620    int res;
00621    struct sockaddr_in sin;
00622    socklen_t len;
00623    uint16_t seqno = 0;
00624    uint16_t *udptlheader;
00625 
00626    len = sizeof(sin);
00627    
00628    /* Cache where the header will go */
00629    res = recvfrom(udptl->fd,
00630          udptl->rawdata + AST_FRIENDLY_OFFSET,
00631          sizeof(udptl->rawdata) - AST_FRIENDLY_OFFSET,
00632          0,
00633          (struct sockaddr *) &sin,
00634          &len);
00635    udptlheader = (uint16_t *)(udptl->rawdata + AST_FRIENDLY_OFFSET);
00636    if (res < 0) {
00637       if (errno != EAGAIN)
00638          ast_log(LOG_WARNING, "UDPTL read error: %s\n", strerror(errno));
00639       ast_assert(errno != EBADF);
00640       return &ast_null_frame;
00641    }
00642 
00643    /* Ignore if the other side hasn't been given an address yet. */
00644    if (!udptl->them.sin_addr.s_addr || !udptl->them.sin_port)
00645       return &ast_null_frame;
00646 
00647    if (udptl->nat) {
00648       /* Send to whoever sent to us */
00649       if ((udptl->them.sin_addr.s_addr != sin.sin_addr.s_addr) ||
00650          (udptl->them.sin_port != sin.sin_port)) {
00651          memcpy(&udptl->them, &sin, sizeof(udptl->them));
00652          ast_log(LOG_DEBUG, "UDPTL NAT: Using address %s:%d\n", ast_inet_ntoa(udptl->them.sin_addr), ntohs(udptl->them.sin_port));
00653       }
00654    }
00655 
00656    if (udptl_debug_test_addr(&sin)) {
00657       ast_verbose("Got UDPTL packet from %s:%d (type %d, seq %d, len %d)\n",
00658          ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), 0, seqno, res);
00659    }
00660 #if 0
00661    printf("Got UDPTL packet from %s:%d (seq %d, len = %d)\n", ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), seqno, res);
00662 #endif
00663    if (udptl_rx_packet(udptl, udptl->rawdata + AST_FRIENDLY_OFFSET, res) < 1)
00664       return &ast_null_frame;
00665 
00666    return &udptl->f[0];
00667 }
00668 
00669 void ast_udptl_offered_from_local(struct ast_udptl* udptl, int local)
00670 {
00671    if (udptl)
00672       udptl->udptl_offered_from_local = local;
00673    else
00674       ast_log(LOG_WARNING, "udptl structure is null\n");
00675 }
00676 
00677 int ast_udptl_get_error_correction_scheme(struct ast_udptl* udptl)
00678 {
00679    if (udptl)
00680       return udptl->error_correction_scheme;
00681    else {
00682       ast_log(LOG_WARNING, "udptl structure is null\n");
00683       return -1;
00684    }
00685 }
00686 
00687 void ast_udptl_set_error_correction_scheme(struct ast_udptl* udptl, int ec)
00688 {
00689    if (udptl) {
00690       switch (ec) {
00691       case UDPTL_ERROR_CORRECTION_FEC:
00692          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
00693          break;
00694       case UDPTL_ERROR_CORRECTION_REDUNDANCY:
00695          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
00696          break;
00697       case UDPTL_ERROR_CORRECTION_NONE:
00698          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
00699          break;
00700       default:
00701          ast_log(LOG_WARNING, "error correction parameter invalid\n");
00702       };
00703    } else
00704       ast_log(LOG_WARNING, "udptl structure is null\n");
00705 }
00706 
00707 int ast_udptl_get_local_max_datagram(struct ast_udptl* udptl)
00708 {
00709    if (udptl)
00710       return udptl->local_max_datagram_size;
00711    else {
00712       ast_log(LOG_WARNING, "udptl structure is null\n");
00713       return -1;
00714    }
00715 }
00716 
00717 int ast_udptl_get_far_max_datagram(struct ast_udptl* udptl)
00718 {
00719    if (udptl)
00720       return udptl->far_max_datagram_size;
00721    else {
00722       ast_log(LOG_WARNING, "udptl structure is null\n");
00723       return -1;
00724    }
00725 }
00726 
00727 void ast_udptl_set_local_max_datagram(struct ast_udptl* udptl, int max_datagram)
00728 {
00729    if (udptl)
00730       udptl->local_max_datagram_size = max_datagram;
00731    else
00732       ast_log(LOG_WARNING, "udptl structure is null\n");
00733 }
00734 
00735 void ast_udptl_set_far_max_datagram(struct ast_udptl* udptl, int max_datagram)
00736 {
00737    if (udptl)
00738       udptl->far_max_datagram_size = max_datagram;
00739    else
00740       ast_log(LOG_WARNING, "udptl structure is null\n");
00741 }
00742 
00743 struct ast_udptl *ast_udptl_new_with_bindaddr(struct sched_context *sched, struct io_context *io, int callbackmode, struct in_addr addr)
00744 {
00745    struct ast_udptl *udptl;
00746    int x;
00747    int startplace;
00748    int i;
00749    long int flags;
00750 
00751    if (!(udptl = ast_calloc(1, sizeof(*udptl))))
00752       return NULL;
00753 
00754    if (udptlfectype == 2)
00755       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
00756    else if (udptlfectype == 1)
00757       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
00758    else
00759       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
00760    udptl->error_correction_span = udptlfecspan;
00761    udptl->error_correction_entries = udptlfecentries;
00762    
00763    udptl->far_max_datagram_size = udptlmaxdatagram;
00764    udptl->local_max_datagram_size = udptlmaxdatagram;
00765 
00766    memset(&udptl->rx, 0, sizeof(udptl->rx));
00767    memset(&udptl->tx, 0, sizeof(udptl->tx));
00768    for (i = 0; i <= UDPTL_BUF_MASK; i++) {
00769       udptl->rx[i].buf_len = -1;
00770       udptl->tx[i].buf_len = -1;
00771    }
00772 
00773    udptl->them.sin_family = AF_INET;
00774    udptl->us.sin_family = AF_INET;
00775 
00776    if ((udptl->fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
00777       free(udptl);
00778       ast_log(LOG_WARNING, "Unable to allocate socket: %s\n", strerror(errno));
00779       return NULL;
00780    }
00781    flags = fcntl(udptl->fd, F_GETFL);
00782    fcntl(udptl->fd, F_SETFL, flags | O_NONBLOCK);
00783 #ifdef SO_NO_CHECK
00784    if (nochecksums)
00785       setsockopt(udptl->fd, SOL_SOCKET, SO_NO_CHECK, &nochecksums, sizeof(nochecksums));
00786 #endif
00787    /* Find us a place */
00788    x = (ast_random() % (udptlend - udptlstart)) + udptlstart;
00789    startplace = x;
00790    for (;;) {
00791       udptl->us.sin_port = htons(x);
00792       udptl->us.sin_addr = addr;
00793       if (bind(udptl->fd, (struct sockaddr *) &udptl->us, sizeof(udptl->us)) == 0)
00794          break;
00795       if (errno != EADDRINUSE) {
00796          ast_log(LOG_WARNING, "Unexpected bind error: %s\n", strerror(errno));
00797          close(udptl->fd);
00798          free(udptl);
00799          return NULL;
00800       }
00801       if (++x > udptlend)
00802          x = udptlstart;
00803       if (x == startplace) {
00804          ast_log(LOG_WARNING, "No UDPTL ports remaining\n");
00805          close(udptl->fd);
00806          free(udptl);
00807          return NULL;
00808       }
00809    }
00810    if (io && sched && callbackmode) {
00811       /* Operate this one in a callback mode */
00812       udptl->sched = sched;
00813       udptl->io = io;
00814       udptl->ioid = ast_io_add(udptl->io, udptl->fd, udptlread, AST_IO_IN, udptl);
00815    }
00816    return udptl;
00817 }
00818 
00819 struct ast_udptl *ast_udptl_new(struct sched_context *sched, struct io_context *io, int callbackmode)
00820 {
00821    struct in_addr ia;
00822    memset(&ia, 0, sizeof(ia));
00823    return ast_udptl_new_with_bindaddr(sched, io, callbackmode, ia);
00824 }
00825 
00826 int ast_udptl_settos(struct ast_udptl *udptl, int tos)
00827 {
00828    int res;
00829 
00830    if ((res = setsockopt(udptl->fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)))) 
00831       ast_log(LOG_WARNING, "UDPTL unable to set TOS to %d\n", tos);
00832    return res;
00833 }
00834 
00835 void ast_udptl_set_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
00836 {
00837    udptl->them.sin_port = them->sin_port;
00838    udptl->them.sin_addr = them->sin_addr;
00839 }
00840 
00841 void ast_udptl_get_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
00842 {
00843    memset(them, 0, sizeof(*them));
00844    them->sin_family = AF_INET;
00845    them->sin_port = udptl->them.sin_port;
00846    them->sin_addr = udptl->them.sin_addr;
00847 }
00848 
00849 void ast_udptl_get_us(struct ast_udptl *udptl, struct sockaddr_in *us)
00850 {
00851    memcpy(us, &udptl->us, sizeof(udptl->us));
00852 }
00853 
00854 void ast_udptl_stop(struct ast_udptl *udptl)
00855 {
00856    memset(&udptl->them.sin_addr, 0, sizeof(udptl->them.sin_addr));
00857    memset(&udptl->them.sin_port, 0, sizeof(udptl->them.sin_port));
00858 }
00859 
00860 void ast_udptl_destroy(struct ast_udptl *udptl)
00861 {
00862    if (udptl->ioid)
00863       ast_io_remove(udptl->io, udptl->ioid);
00864    if (udptl->fd > -1)
00865       close(udptl->fd);
00866    free(udptl);
00867 }
00868 
00869 int ast_udptl_write(struct ast_udptl *s, struct ast_frame *f)
00870 {
00871    int seq;
00872    int len;
00873    int res;
00874    uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
00875 
00876    /* If we have no peer, return immediately */ 
00877    if (s->them.sin_addr.s_addr == INADDR_ANY)
00878       return 0;
00879 
00880    /* If there is no data length, return immediately */
00881    if (f->datalen == 0)
00882       return 0;
00883    
00884    if (f->frametype != AST_FRAME_MODEM) {
00885       ast_log(LOG_WARNING, "UDPTL can only send T.38 data\n");
00886       return -1;
00887    }
00888 
00889    /* Save seq_no for debug output because udptl_build_packet increments it */
00890    seq = s->tx_seq_no & 0xFFFF;
00891 
00892    /* Cook up the UDPTL packet, with the relevant EC info. */
00893    len = udptl_build_packet(s, buf, f->data, f->datalen);
00894 
00895    if (len > 0 && s->them.sin_port && s->them.sin_addr.s_addr) {
00896       if ((res = sendto(s->fd, buf, len, 0, (struct sockaddr *) &s->them, sizeof(s->them))) < 0)
00897          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));
00898 #if 0
00899       printf("Sent %d bytes of UDPTL data to %s:%d\n", res, ast_inet_ntoa(udptl->them.sin_addr), ntohs(udptl->them.sin_port));
00900 #endif
00901       if (udptl_debug_test_addr(&s->them))
00902          ast_verbose("Sent UDPTL packet to %s:%d (type %d, seq %d, len %d)\n",
00903                ast_inet_ntoa(s->them.sin_addr),
00904                ntohs(s->them.sin_port), 0, seq, len);
00905    }
00906       
00907    return 0;
00908 }
00909 
00910 void ast_udptl_proto_unregister(struct ast_udptl_protocol *proto)
00911 {
00912    struct ast_udptl_protocol *cur;
00913    struct ast_udptl_protocol *prev;
00914 
00915    cur = protos;
00916    prev = NULL;
00917    while (cur) {
00918       if (cur == proto) {
00919          if (prev)
00920             prev->next = proto->next;
00921          else
00922             protos = proto->next;
00923          return;
00924       }
00925       prev = cur;
00926       cur = cur->next;
00927    }
00928 }
00929 
00930 int ast_udptl_proto_register(struct ast_udptl_protocol *proto)
00931 {
00932    struct ast_udptl_protocol *cur;
00933 
00934    cur = protos;
00935    while (cur) {
00936       if (cur->type == proto->type) {
00937          ast_log(LOG_WARNING, "Tried to register same protocol '%s' twice\n", cur->type);
00938          return -1;
00939       }
00940       cur = cur->next;
00941    }
00942    proto->next = protos;
00943    protos = proto;
00944    return 0;
00945 }
00946 
00947 static struct ast_udptl_protocol *get_proto(struct ast_channel *chan)
00948 {
00949    struct ast_udptl_protocol *cur;
00950 
00951    cur = protos;
00952    while (cur) {
00953       if (cur->type == chan->tech->type)
00954          return cur;
00955       cur = cur->next;
00956    }
00957    return NULL;
00958 }
00959 
00960 int ast_udptl_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
00961 {
00962    struct ast_frame *f;
00963    struct ast_channel *who;
00964    struct ast_channel *cs[3];
00965    struct ast_udptl *p0;
00966    struct ast_udptl *p1;
00967    struct ast_udptl_protocol *pr0;
00968    struct ast_udptl_protocol *pr1;
00969    struct sockaddr_in ac0;
00970    struct sockaddr_in ac1;
00971    struct sockaddr_in t0;
00972    struct sockaddr_in t1;
00973    void *pvt0;
00974    void *pvt1;
00975    int to;
00976    
00977    ast_channel_lock(c0);
00978    while (ast_channel_trylock(c1)) {
00979       ast_channel_unlock(c0);
00980       usleep(1);
00981       ast_channel_lock(c0);
00982    }
00983    pr0 = get_proto(c0);
00984    pr1 = get_proto(c1);
00985    if (!pr0) {
00986       ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c0->name);
00987       ast_channel_unlock(c0);
00988       ast_channel_unlock(c1);
00989       return -1;
00990    }
00991    if (!pr1) {
00992       ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c1->name);
00993       ast_channel_unlock(c0);
00994       ast_channel_unlock(c1);
00995       return -1;
00996    }
00997    pvt0 = c0->tech_pvt;
00998    pvt1 = c1->tech_pvt;
00999    p0 = pr0->get_udptl_info(c0);
01000    p1 = pr1->get_udptl_info(c1);
01001    if (!p0 || !p1) {
01002       /* Somebody doesn't want to play... */
01003       ast_channel_unlock(c0);
01004       ast_channel_unlock(c1);
01005       return -2;
01006    }
01007    if (pr0->set_udptl_peer(c0, p1)) {
01008       ast_log(LOG_WARNING, "Channel '%s' failed to talk to '%s'\n", c0->name, c1->name);
01009       memset(&ac1, 0, sizeof(ac1));
01010    } else {
01011       /* Store UDPTL peer */
01012       ast_udptl_get_peer(p1, &ac1);
01013    }
01014    if (pr1->set_udptl_peer(c1, p0)) {
01015       ast_log(LOG_WARNING, "Channel '%s' failed to talk back to '%s'\n", c1->name, c0->name);
01016       memset(&ac0, 0, sizeof(ac0));
01017    } else {
01018       /* Store UDPTL peer */
01019       ast_udptl_get_peer(p0, &ac0);
01020    }
01021    ast_channel_unlock(c0);
01022    ast_channel_unlock(c1);
01023    cs[0] = c0;
01024    cs[1] = c1;
01025    cs[2] = NULL;
01026    for (;;) {
01027       if ((c0->tech_pvt != pvt0) ||
01028          (c1->tech_pvt != pvt1) ||
01029          (c0->masq || c0->masqr || c1->masq || c1->masqr)) {
01030             ast_log(LOG_DEBUG, "Oooh, something is weird, backing out\n");
01031             /* Tell it to try again later */
01032             return -3;
01033       }
01034       to = -1;
01035       ast_udptl_get_peer(p1, &t1);
01036       ast_udptl_get_peer(p0, &t0);
01037       if (inaddrcmp(&t1, &ac1)) {
01038          ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n", 
01039             c1->name, ast_inet_ntoa(t1.sin_addr), ntohs(t1.sin_port));
01040          ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n", 
01041             c1->name, ast_inet_ntoa(ac1.sin_addr), ntohs(ac1.sin_port));
01042          memcpy(&ac1, &t1, sizeof(ac1));
01043       }
01044       if (inaddrcmp(&t0, &ac0)) {
01045          ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n", 
01046             c0->name, ast_inet_ntoa(t0.sin_addr), ntohs(t0.sin_port));
01047          ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n", 
01048             c0->name, ast_inet_ntoa(ac0.sin_addr), ntohs(ac0.sin_port));
01049          memcpy(&ac0, &t0, sizeof(ac0));
01050       }
01051       who = ast_waitfor_n(cs, 2, &to);
01052       if (!who) {
01053          ast_log(LOG_DEBUG, "Ooh, empty read...\n");
01054          /* check for hangup / whentohangup */
01055          if (ast_check_hangup(c0) || ast_check_hangup(c1))
01056             break;
01057          continue;
01058       }
01059       f = ast_read(who);
01060       if (!f) {
01061          *fo = f;
01062          *rc = who;
01063          ast_log(LOG_DEBUG, "Oooh, got a %s\n", f ? "digit" : "hangup");
01064          /* That's all we needed */
01065          return 0;
01066       } else {
01067          if (f->frametype == AST_FRAME_MODEM) {
01068             /* Forward T.38 frames if they happen upon us */
01069             if (who == c0) {
01070                ast_write(c1, f);
01071             } else if (who == c1) {
01072                ast_write(c0, f);
01073             }
01074          }
01075          ast_frfree(f);
01076       }
01077       /* Swap priority. Not that it's a big deal at this point */
01078       cs[2] = cs[0];
01079       cs[0] = cs[1];
01080       cs[1] = cs[2];
01081    }
01082    return -1;
01083 }
01084 
01085 static int udptl_do_debug_ip(int fd, int argc, char *argv[])
01086 {
01087    struct hostent *hp;
01088    struct ast_hostent ahp;
01089    int port;
01090    char *p;
01091    char *arg;
01092 
01093    port = 0;
01094    if (argc != 4)
01095       return RESULT_SHOWUSAGE;
01096    arg = argv[3];
01097    p = strstr(arg, ":");
01098    if (p) {
01099       *p = '\0';
01100       p++;
01101       port = atoi(p);
01102    }
01103    hp = ast_gethostbyname(arg, &ahp);
01104    if (hp == NULL)
01105       return RESULT_SHOWUSAGE;
01106    udptldebugaddr.sin_family = AF_INET;
01107    memcpy(&udptldebugaddr.sin_addr, hp->h_addr, sizeof(udptldebugaddr.sin_addr));
01108    udptldebugaddr.sin_port = htons(port);
01109    if (port == 0)
01110       ast_cli(fd, "UDPTL Debugging Enabled for IP: %s\n", ast_inet_ntoa(udptldebugaddr.sin_addr));
01111    else
01112       ast_cli(fd, "UDPTL Debugging Enabled for IP: %s:%d\n", ast_inet_ntoa(udptldebugaddr.sin_addr), port);
01113    udptldebug = 1;
01114    return RESULT_SUCCESS;
01115 }
01116 
01117 static int udptl_do_debug(int fd, int argc, char *argv[])
01118 {
01119    if (argc != 2) {
01120       if (argc != 4)
01121          return RESULT_SHOWUSAGE;
01122       return udptl_do_debug_ip(fd, argc, argv);
01123    }
01124    udptldebug = 1;
01125    memset(&udptldebugaddr,0,sizeof(udptldebugaddr));
01126    ast_cli(fd, "UDPTL Debugging Enabled\n");
01127    return RESULT_SUCCESS;
01128 }
01129 
01130 static int udptl_nodebug(int fd, int argc, char *argv[])
01131 {
01132    if (argc != 3)
01133       return RESULT_SHOWUSAGE;
01134    udptldebug = 0;
01135    ast_cli(fd,"UDPTL Debugging Disabled\n");
01136    return RESULT_SUCCESS;
01137 }
01138 
01139 static char debug_usage[] =
01140   "Usage: udptl debug [ip host[:port]]\n"
01141   "       Enable dumping of all UDPTL packets to and from host.\n";
01142 
01143 static char nodebug_usage[] =
01144   "Usage: udptl debug off\n"
01145   "       Disable all UDPTL debugging\n";
01146 
01147 static struct ast_cli_entry cli_udptl_no_debug = {
01148    { "udptl", "no", "debug", NULL },
01149    udptl_nodebug, NULL,
01150    NULL };
01151 
01152 static struct ast_cli_entry cli_udptl[] = {
01153    { { "udptl", "debug", NULL },
01154    udptl_do_debug, "Enable UDPTL debugging",
01155    debug_usage },
01156 
01157    { { "udptl", "debug", "ip", NULL },
01158    udptl_do_debug, "Enable UDPTL debugging on IP",
01159    debug_usage },
01160 
01161    { { "udptl", "debug", "off", NULL },
01162    udptl_nodebug, "Disable UDPTL debugging",
01163    nodebug_usage, NULL, &cli_udptl_no_debug },
01164 };
01165 
01166 void ast_udptl_reload(void)
01167 {
01168    struct ast_config *cfg;
01169    const char *s;
01170 
01171    udptlstart = 4500;
01172    udptlend = 4999;
01173    udptlfectype = 0;
01174    udptlfecentries = 0;
01175    udptlfecspan = 0;
01176    udptlmaxdatagram = 0;
01177 
01178    if ((cfg = ast_config_load("udptl.conf"))) {
01179       if ((s = ast_variable_retrieve(cfg, "general", "udptlstart"))) {
01180          udptlstart = atoi(s);
01181          if (udptlstart < 1024)
01182             udptlstart = 1024;
01183          if (udptlstart > 65535)
01184             udptlstart = 65535;
01185       }
01186       if ((s = ast_variable_retrieve(cfg, "general", "udptlend"))) {
01187          udptlend = atoi(s);
01188          if (udptlend < 1024)
01189             udptlend = 1024;
01190          if (udptlend > 65535)
01191             udptlend = 65535;
01192       }
01193       if ((s = ast_variable_retrieve(cfg, "general", "udptlchecksums"))) {
01194 #ifdef SO_NO_CHECK
01195          if (ast_false(s))
01196             nochecksums = 1;
01197          else
01198             nochecksums = 0;
01199 #else
01200          if (ast_false(s))
01201             ast_log(LOG_WARNING, "Disabling UDPTL checksums is not supported on this operating system!\n");
01202 #endif
01203       }
01204       if ((s = ast_variable_retrieve(cfg, "general", "T38FaxUdpEC"))) {
01205          if (strcmp(s, "t38UDPFEC") == 0)
01206             udptlfectype = 2;
01207          else if (strcmp(s, "t38UDPRedundancy") == 0)
01208             udptlfectype = 1;
01209       }
01210       if ((s = ast_variable_retrieve(cfg, "general", "T38FaxMaxDatagram"))) {
01211          udptlmaxdatagram = atoi(s);
01212          if (udptlmaxdatagram < 0)
01213             udptlmaxdatagram = 0;
01214          if (udptlmaxdatagram > LOCAL_FAX_MAX_DATAGRAM)
01215             udptlmaxdatagram = LOCAL_FAX_MAX_DATAGRAM;
01216       }
01217       if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECentries"))) {
01218          udptlfecentries = atoi(s);
01219          if (udptlfecentries < 0)
01220             udptlfecentries = 0;
01221          if (udptlfecentries > MAX_FEC_ENTRIES)
01222             udptlfecentries = MAX_FEC_ENTRIES;
01223       }
01224       if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECspan"))) {
01225          udptlfecspan = atoi(s);
01226          if (udptlfecspan < 0)
01227             udptlfecspan = 0;
01228          if (udptlfecspan > MAX_FEC_SPAN)
01229             udptlfecspan = MAX_FEC_SPAN;
01230       }
01231       ast_config_destroy(cfg);
01232    }
01233    if (udptlstart >= udptlend) {
01234       ast_log(LOG_WARNING, "Unreasonable values for UDPTL start/end\n");
01235       udptlstart = 4500;
01236       udptlend = 4999;
01237    }
01238    if (option_verbose > 1)
01239       ast_verbose(VERBOSE_PREFIX_2 "UDPTL allocating from port range %d -> %d\n", udptlstart, udptlend);
01240 }
01241 
01242 void ast_udptl_init(void)
01243 {
01244    ast_cli_register_multiple(cli_udptl, sizeof(cli_udptl) / sizeof(struct ast_cli_entry));
01245    ast_udptl_reload();
01246 }

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