Wed Aug 15 01:24:25 2007

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: 49006 $")
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    uint16_t seqno;
00102    struct sched_context *sched;
00103    struct io_context *io;
00104    void *data;
00105    ast_udptl_callback callback;
00106    int udptl_offered_from_local;
00107 
00108    /*! This option indicates the error correction scheme used in transmitted UDPTL
00109        packets. */
00110    int error_correction_scheme;
00111 
00112    /*! This option indicates the number of error correction entries transmitted in
00113        UDPTL packets. */
00114    int error_correction_entries;
00115 
00116    /*! This option indicates the span of the error correction entries in transmitted
00117        UDPTL packets (FEC only). */
00118    int error_correction_span;
00119 
00120    /*! This option indicates the maximum size of a UDPTL packet that can be accepted by
00121        the remote device. */
00122    int far_max_datagram_size;
00123 
00124    /*! This option indicates the maximum size of a UDPTL packet that we are prepared to
00125        accept. */
00126    int local_max_datagram_size;
00127 
00128    int verbose;
00129 
00130    struct sockaddr_in far;
00131 
00132    int tx_seq_no;
00133    int rx_seq_no;
00134    int rx_expected_seq_no;
00135 
00136    udptl_fec_tx_buffer_t tx[UDPTL_BUF_MASK + 1];
00137    udptl_fec_rx_buffer_t rx[UDPTL_BUF_MASK + 1];
00138 };
00139 
00140 static struct ast_udptl_protocol *protos;
00141 
00142 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len);
00143 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, uint8_t *ifp, int ifp_len);
00144 
00145 static inline int udptl_debug_test_addr(struct sockaddr_in *addr)
00146 {
00147    if (udptldebug == 0)
00148       return 0;
00149    if (udptldebugaddr.sin_addr.s_addr) {
00150       if (((ntohs(udptldebugaddr.sin_port) != 0)
00151          && (udptldebugaddr.sin_port != addr->sin_port))
00152          || (udptldebugaddr.sin_addr.s_addr != addr->sin_addr.s_addr))
00153          return 0;
00154    }
00155    return 1;
00156 }
00157 
00158 static int decode_length(uint8_t *buf, int limit, int *len, int *pvalue)
00159 {
00160    if ((buf[*len] & 0x80) == 0) {
00161       if (*len >= limit)
00162          return -1;
00163       *pvalue = buf[*len];
00164       (*len)++;
00165       return 0;
00166    }
00167    if ((buf[*len] & 0x40) == 0) {
00168       if (*len >= limit - 1)
00169          return -1;
00170       *pvalue = (buf[*len] & 0x3F) << 8;
00171       (*len)++;
00172       *pvalue |= buf[*len];
00173       (*len)++;
00174       return 0;
00175    }
00176    if (*len >= limit)
00177       return -1;
00178    *pvalue = (buf[*len] & 0x3F) << 14;
00179    (*len)++;
00180    /* Indicate we have a fragment */
00181    return 1;
00182 }
00183 /*- End of function --------------------------------------------------------*/
00184 
00185 static int decode_open_type(uint8_t *buf, int limit, int *len, const uint8_t **p_object, int *p_num_octets)
00186 {
00187    int octet_cnt;
00188    int octet_idx;
00189    int stat;
00190    int i;
00191    const uint8_t **pbuf;
00192 
00193    for (octet_idx = 0, *p_num_octets = 0; ; octet_idx += octet_cnt) {
00194       if ((stat = decode_length(buf, limit, len, &octet_cnt)) < 0)
00195          return -1;
00196       if (octet_cnt > 0) {
00197          *p_num_octets += octet_cnt;
00198 
00199          pbuf = &p_object[octet_idx];
00200          i = 0;
00201          /* Make sure the buffer contains at least the number of bits requested */
00202          if ((*len + octet_cnt) > limit)
00203             return -1;
00204 
00205          *pbuf = &buf[*len];
00206          *len += octet_cnt;
00207       }
00208       if (stat == 0)
00209          break;
00210    }
00211    return 0;
00212 }
00213 /*- End of function --------------------------------------------------------*/
00214 
00215 static int encode_length(uint8_t *buf, int *len, int value)
00216 {
00217    int multiplier;
00218 
00219    if (value < 0x80) {
00220       /* 1 octet */
00221       buf[*len] = value;
00222       (*len)++;
00223       return value;
00224    }
00225    if (value < 0x4000) {
00226       /* 2 octets */
00227       /* Set the first bit of the first octet */
00228       buf[*len] = ((0x8000 | value) >> 8) & 0xFF;
00229       (*len)++;
00230       buf[*len] = value & 0xFF;
00231       (*len)++;
00232       return value;
00233    }
00234    /* Fragmentation */
00235    multiplier = (value < 0x10000) ? (value >> 14) : 4;
00236    /* Set the first 2 bits of the octet */
00237    buf[*len] = 0xC0 | multiplier;
00238    (*len)++;
00239    return multiplier << 14;
00240 }
00241 /*- End of function --------------------------------------------------------*/
00242 
00243 static int encode_open_type(uint8_t *buf, int *len, const uint8_t *data, int num_octets)
00244 {
00245    int enclen;
00246    int octet_idx;
00247    uint8_t zero_byte;
00248 
00249    /* If open type is of zero length, add a single zero byte (10.1) */
00250    if (num_octets == 0) {
00251       zero_byte = 0;
00252       data = &zero_byte;
00253       num_octets = 1;
00254    }
00255    /* Encode the open type */
00256    for (octet_idx = 0; ; num_octets -= enclen, octet_idx += enclen) {
00257       if ((enclen = encode_length(buf, len, num_octets)) < 0)
00258          return -1;
00259       if (enclen > 0) {
00260          memcpy(&buf[*len], &data[octet_idx], enclen);
00261          *len += enclen;
00262       }
00263       if (enclen >= num_octets)
00264          break;
00265    }
00266 
00267    return 0;
00268 }
00269 /*- End of function --------------------------------------------------------*/
00270 
00271 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len)
00272 {
00273    int stat;
00274    int stat2;
00275    int i;
00276    int j;
00277    int k;
00278    int l;
00279    int m;
00280    int x;
00281    int limit;
00282    int which;
00283    int ptr;
00284    int count;
00285    int total_count;
00286    int seq_no;
00287    const uint8_t *ifp;
00288    const uint8_t *data;
00289    int ifp_len;
00290    int repaired[16];
00291    const uint8_t *bufs[16];
00292    int lengths[16];
00293    int span;
00294    int entries;
00295    int ifp_no;
00296 
00297    ptr = 0;
00298    ifp_no = 0;
00299    memset(&s->f[0], 0, sizeof(s->f[0]));
00300 
00301    /* Decode seq_number */
00302    if (ptr + 2 > len)
00303       return -1;
00304    seq_no = (buf[0] << 8) | buf[1];
00305    ptr += 2;
00306 
00307    /* Break out the primary packet */
00308    if ((stat = decode_open_type(buf, len, &ptr, &ifp, &ifp_len)) != 0)
00309       return -1;
00310    /* Decode error_recovery */
00311    if (ptr + 1 > len)
00312       return -1;
00313    if ((buf[ptr++] & 0x80) == 0) {
00314       /* Secondary packet mode for error recovery */
00315       if (seq_no > s->rx_seq_no) {
00316          /* We received a later packet than we expected, so we need to check if we can fill in the gap from the
00317             secondary packets. */
00318          total_count = 0;
00319          do {
00320             if ((stat2 = decode_length(buf, len, &ptr, &count)) < 0)
00321                return -1;
00322             for (i = 0; i < count; i++) {
00323                if ((stat = decode_open_type(buf, len, &ptr, &bufs[total_count + i], &lengths[total_count + i])) != 0)
00324                   return -1;
00325             }
00326             total_count += count;
00327          }
00328          while (stat2 > 0);
00329          /* Step through in reverse order, so we go oldest to newest */
00330          for (i = total_count; i > 0; i--) {
00331             if (seq_no - i >= s->rx_seq_no) {
00332                /* This one wasn't seen before */
00333                /* Decode the secondary IFP packet */
00334                //fprintf(stderr, "Secondary %d, len %d\n", seq_no - i, lengths[i - 1]);
00335                s->f[ifp_no].frametype = AST_FRAME_MODEM;
00336                s->f[ifp_no].subclass = AST_MODEM_T38;
00337 
00338                s->f[ifp_no].mallocd = 0;
00339                //s->f[ifp_no].???seq_no = seq_no - i;
00340                s->f[ifp_no].datalen = lengths[i - 1];
00341                s->f[ifp_no].data = (uint8_t *) bufs[i - 1];
00342                s->f[ifp_no].offset = 0;
00343                s->f[ifp_no].src = "UDPTL";
00344                if (ifp_no > 0)
00345                   AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00346                AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00347                ifp_no++;
00348             }
00349          }
00350       }
00351       /* If packets are received out of sequence, we may have already processed this packet from the error
00352          recovery information in a packet already received. */
00353       if (seq_no >= s->rx_seq_no) {
00354          /* Decode the primary IFP packet */
00355          s->f[ifp_no].frametype = AST_FRAME_MODEM;
00356          s->f[ifp_no].subclass = AST_MODEM_T38;
00357          
00358          s->f[ifp_no].mallocd = 0;
00359          //s->f[ifp_no].???seq_no = seq_no;
00360          s->f[ifp_no].datalen = ifp_len;
00361          s->f[ifp_no].data = (uint8_t *) ifp;
00362          s->f[ifp_no].offset = 0;
00363          s->f[ifp_no].src = "UDPTL";
00364          if (ifp_no > 0)
00365             AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00366          AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00367       }
00368    }
00369    else
00370    {
00371       /* FEC mode for error recovery */
00372       /* Our buffers cannot tolerate overlength IFP packets in FEC mode */
00373       if (ifp_len > LOCAL_FAX_MAX_DATAGRAM)
00374          return -1;
00375       /* Update any missed slots in the buffer */
00376       for ( ; seq_no > s->rx_seq_no; s->rx_seq_no++) {
00377          x = s->rx_seq_no & UDPTL_BUF_MASK;
00378          s->rx[x].buf_len = -1;
00379          s->rx[x].fec_len[0] = 0;
00380          s->rx[x].fec_span = 0;
00381          s->rx[x].fec_entries = 0;
00382       }
00383 
00384       x = seq_no & UDPTL_BUF_MASK;
00385 
00386       memset(repaired, 0, sizeof(repaired));
00387 
00388       /* Save the new IFP packet */
00389       memcpy(s->rx[x].buf, ifp, ifp_len);
00390       s->rx[x].buf_len = ifp_len;
00391       repaired[x] = TRUE;
00392 
00393       /* Decode the FEC packets */
00394       /* The span is defined as an unconstrained integer, but will never be more
00395          than a small value. */
00396       if (ptr + 2 > len)
00397          return -1;
00398       if (buf[ptr++] != 1)
00399          return -1;
00400       span = buf[ptr++];
00401       s->rx[x].fec_span = span;
00402 
00403       /* The number of entries is defined as a length, but will only ever be a small
00404          value. Treat it as such. */
00405       if (ptr + 1 > len)
00406          return -1;
00407       entries = buf[ptr++];
00408       s->rx[x].fec_entries = entries;
00409 
00410       /* Decode the elements */
00411       for (i = 0; i < entries; i++) {
00412          if ((stat = decode_open_type(buf, len, &ptr, &data, &s->rx[x].fec_len[i])) != 0)
00413             return -1;
00414          if (s->rx[x].fec_len[i] > LOCAL_FAX_MAX_DATAGRAM)
00415             return -1;
00416 
00417          /* Save the new FEC data */
00418          memcpy(s->rx[x].fec[i], data, s->rx[x].fec_len[i]);
00419 #if 0
00420          fprintf(stderr, "FEC: ");
00421          for (j = 0; j < s->rx[x].fec_len[i]; j++)
00422             fprintf(stderr, "%02X ", data[j]);
00423          fprintf(stderr, "\n");
00424 #endif
00425       }
00426 
00427       /* See if we can reconstruct anything which is missing */
00428       /* TODO: this does not comprehensively hunt back and repair everything that is possible */
00429       for (l = x; l != ((x - (16 - span*entries)) & UDPTL_BUF_MASK); l = (l - 1) & UDPTL_BUF_MASK) {
00430          if (s->rx[l].fec_len[0] <= 0)
00431             continue;
00432          for (m = 0; m < s->rx[l].fec_entries; m++) {
00433             limit = (l + m) & UDPTL_BUF_MASK;
00434             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) {
00435                if (s->rx[k].buf_len <= 0)
00436                   which = (which == -1) ? k : -2;
00437             }
00438             if (which >= 0) {
00439                /* Repairable */
00440                for (j = 0; j < s->rx[l].fec_len[m]; j++) {
00441                   s->rx[which].buf[j] = s->rx[l].fec[m][j];
00442                   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)
00443                      s->rx[which].buf[j] ^= (s->rx[k].buf_len > j) ? s->rx[k].buf[j] : 0;
00444                }
00445                s->rx[which].buf_len = s->rx[l].fec_len[m];
00446                repaired[which] = TRUE;
00447             }
00448          }
00449       }
00450       /* Now play any new packets forwards in time */
00451       for (l = (x + 1) & UDPTL_BUF_MASK, j = seq_no - UDPTL_BUF_MASK; l != x; l = (l + 1) & UDPTL_BUF_MASK, j++) {
00452          if (repaired[l]) {
00453             //fprintf(stderr, "Fixed packet %d, len %d\n", j, l);
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].???seq_no = j;
00459             s->f[ifp_no].datalen = s->rx[l].buf_len;
00460             s->f[ifp_no].data = s->rx[l].buf;
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             ifp_no++;
00467          }
00468       }
00469       /* Decode the primary IFP packet */
00470       s->f[ifp_no].frametype = AST_FRAME_MODEM;
00471       s->f[ifp_no].subclass = AST_MODEM_T38;
00472          
00473       s->f[ifp_no].mallocd = 0;
00474       //s->f[ifp_no].???seq_no = j;
00475       s->f[ifp_no].datalen = ifp_len;
00476       s->f[ifp_no].data = (uint8_t *) ifp;
00477       s->f[ifp_no].offset = 0;
00478       s->f[ifp_no].src = "UDPTL";
00479       if (ifp_no > 0)
00480          AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00481       AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00482    }
00483 
00484    s->rx_seq_no = seq_no + 1;
00485    return 0;
00486 }
00487 /*- End of function --------------------------------------------------------*/
00488 
00489 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, uint8_t *ifp, int ifp_len)
00490 {
00491    uint8_t fec[LOCAL_FAX_MAX_DATAGRAM];
00492    int i;
00493    int j;
00494    int seq;
00495    int entry;
00496    int entries;
00497    int span;
00498    int m;
00499    int len;
00500    int limit;
00501    int high_tide;
00502 
00503    seq = s->tx_seq_no & 0xFFFF;
00504 
00505    /* Map the sequence number to an entry in the circular buffer */
00506    entry = seq & UDPTL_BUF_MASK;
00507 
00508    /* We save the message in a circular buffer, for generating FEC or
00509       redundancy sets later on. */
00510    s->tx[entry].buf_len = ifp_len;
00511    memcpy(s->tx[entry].buf, ifp, ifp_len);
00512    
00513    /* Build the UDPTLPacket */
00514 
00515    len = 0;
00516    /* Encode the sequence number */
00517    buf[len++] = (seq >> 8) & 0xFF;
00518    buf[len++] = seq & 0xFF;
00519 
00520    /* Encode the primary IFP packet */
00521    if (encode_open_type(buf, &len, ifp, ifp_len) < 0)
00522       return -1;
00523 
00524    /* Encode the appropriate type of error recovery information */
00525    switch (s->error_correction_scheme)
00526    {
00527    case UDPTL_ERROR_CORRECTION_NONE:
00528       /* Encode the error recovery type */
00529       buf[len++] = 0x00;
00530       /* The number of entries will always be zero, so it is pointless allowing
00531          for the fragmented case here. */
00532       if (encode_length(buf, &len, 0) < 0)
00533          return -1;
00534       break;
00535    case UDPTL_ERROR_CORRECTION_REDUNDANCY:
00536       /* Encode the error recovery type */
00537       buf[len++] = 0x00;
00538       if (s->tx_seq_no > s->error_correction_entries)
00539          entries = s->error_correction_entries;
00540       else
00541          entries = s->tx_seq_no;
00542       /* The number of entries will always be small, so it is pointless allowing
00543          for the fragmented case here. */
00544       if (encode_length(buf, &len, entries) < 0)
00545          return -1;
00546       /* Encode the elements */
00547       for (i = 0; i < entries; i++) {
00548          j = (entry - i - 1) & UDPTL_BUF_MASK;
00549          if (encode_open_type(buf, &len, s->tx[j].buf, s->tx[j].buf_len) < 0)
00550             return -1;
00551       }
00552       break;
00553    case UDPTL_ERROR_CORRECTION_FEC:
00554       span = s->error_correction_span;
00555       entries = s->error_correction_entries;
00556       if (seq < s->error_correction_span*s->error_correction_entries) {
00557          /* In the initial stages, wind up the FEC smoothly */
00558          entries = seq/s->error_correction_span;
00559          if (seq < s->error_correction_span)
00560             span = 0;
00561       }
00562       /* Encode the error recovery type */
00563       buf[len++] = 0x80;
00564       /* Span is defined as an inconstrained integer, which it dumb. It will only
00565          ever be a small value. Treat it as such. */
00566       buf[len++] = 1;
00567       buf[len++] = span;
00568       /* The number of entries is defined as a length, but will only ever be a small
00569          value. Treat it as such. */
00570       buf[len++] = entries;
00571       for (m = 0; m < entries; m++) {
00572          /* Make an XOR'ed entry the maximum length */
00573          limit = (entry + m) & UDPTL_BUF_MASK;
00574          high_tide = 0;
00575          for (i = (limit - span*entries) & UDPTL_BUF_MASK; i != limit; i = (i + entries) & UDPTL_BUF_MASK) {
00576             if (high_tide < s->tx[i].buf_len) {
00577                for (j = 0; j < high_tide; j++)
00578                   fec[j] ^= s->tx[i].buf[j];
00579                for ( ; j < s->tx[i].buf_len; j++)
00580                   fec[j] = s->tx[i].buf[j];
00581                high_tide = s->tx[i].buf_len;
00582             } else {
00583                for (j = 0; j < s->tx[i].buf_len; j++)
00584                   fec[j] ^= s->tx[i].buf[j];
00585             }
00586          }
00587          if (encode_open_type(buf, &len, fec, high_tide) < 0)
00588             return -1;
00589       }
00590       break;
00591    }
00592 
00593    if (s->verbose)
00594       fprintf(stderr, "\n");
00595 
00596    s->tx_seq_no++;
00597    return len;
00598 }
00599 
00600 int ast_udptl_fd(struct ast_udptl *udptl)
00601 {
00602    return udptl->fd;
00603 }
00604 
00605 void ast_udptl_set_data(struct ast_udptl *udptl, void *data)
00606 {
00607    udptl->data = data;
00608 }
00609 
00610 void ast_udptl_set_callback(struct ast_udptl *udptl, ast_udptl_callback callback)
00611 {
00612    udptl->callback = callback;
00613 }
00614 
00615 void ast_udptl_setnat(struct ast_udptl *udptl, int nat)
00616 {
00617    udptl->nat = nat;
00618 }
00619 
00620 static int udptlread(int *id, int fd, short events, void *cbdata)
00621 {
00622    struct ast_udptl *udptl = cbdata;
00623    struct ast_frame *f;
00624 
00625    if ((f = ast_udptl_read(udptl))) {
00626       if (udptl->callback)
00627          udptl->callback(udptl, f, udptl->data);
00628    }
00629    return 1;
00630 }
00631 
00632 struct ast_frame *ast_udptl_read(struct ast_udptl *udptl)
00633 {
00634    int res;
00635    struct sockaddr_in sin;
00636    socklen_t len;
00637    uint16_t seqno = 0;
00638    uint16_t *udptlheader;
00639 
00640    len = sizeof(sin);
00641    
00642    /* Cache where the header will go */
00643    res = recvfrom(udptl->fd,
00644          udptl->rawdata + AST_FRIENDLY_OFFSET,
00645          sizeof(udptl->rawdata) - AST_FRIENDLY_OFFSET,
00646          0,
00647          (struct sockaddr *) &sin,
00648          &len);
00649    udptlheader = (uint16_t *)(udptl->rawdata + AST_FRIENDLY_OFFSET);
00650    if (res < 0) {
00651       if (errno != EAGAIN)
00652          ast_log(LOG_WARNING, "UDPTL read error: %s\n", strerror(errno));
00653       if (errno == EBADF)
00654          CRASH;
00655       return &ast_null_frame;
00656    }
00657 
00658    /* Ignore if the other side hasn't been given an address yet. */
00659    if (!udptl->them.sin_addr.s_addr || !udptl->them.sin_port)
00660       return &ast_null_frame;
00661 
00662    if (udptl->nat) {
00663       /* Send to whoever sent to us */
00664       if ((udptl->them.sin_addr.s_addr != sin.sin_addr.s_addr) ||
00665          (udptl->them.sin_port != sin.sin_port)) {
00666          memcpy(&udptl->them, &sin, sizeof(udptl->them));
00667          ast_log(LOG_DEBUG, "UDPTL NAT: Using address %s:%d\n", ast_inet_ntoa(udptl->them.sin_addr), ntohs(udptl->them.sin_port));
00668       }
00669    }
00670 
00671    if (udptl_debug_test_addr(&sin)) {
00672       ast_verbose("Got UDPTL packet from %s:%d (type %d, seq %d, len %d)\n",
00673          ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), 0, seqno, res);
00674    }
00675 #if 0
00676    printf("Got UDPTL packet from %s:%d (seq %d, len = %d)\n", ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), seqno, res);
00677 #endif
00678    udptl_rx_packet(udptl, udptl->rawdata + AST_FRIENDLY_OFFSET, res);
00679 
00680    return &udptl->f[0];
00681 }
00682 
00683 void ast_udptl_offered_from_local(struct ast_udptl* udptl, int local)
00684 {
00685    if (udptl)
00686       udptl->udptl_offered_from_local = local;
00687    else
00688       ast_log(LOG_WARNING, "udptl structure is null\n");
00689 }
00690 
00691 int ast_udptl_get_error_correction_scheme(struct ast_udptl* udptl)
00692 {
00693    if (udptl)
00694       return udptl->error_correction_scheme;
00695    else {
00696       ast_log(LOG_WARNING, "udptl structure is null\n");
00697       return -1;
00698    }
00699 }
00700 
00701 void ast_udptl_set_error_correction_scheme(struct ast_udptl* udptl, int ec)
00702 {
00703    if (udptl) {
00704       switch (ec) {
00705       case UDPTL_ERROR_CORRECTION_FEC:
00706          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
00707          break;
00708       case UDPTL_ERROR_CORRECTION_REDUNDANCY:
00709          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
00710          break;
00711       case UDPTL_ERROR_CORRECTION_NONE:
00712          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
00713          break;
00714       default:
00715          ast_log(LOG_WARNING, "error correction parameter invalid\n");
00716       };
00717    } else
00718       ast_log(LOG_WARNING, "udptl structure is null\n");
00719 }
00720 
00721 int ast_udptl_get_local_max_datagram(struct ast_udptl* udptl)
00722 {
00723    if (udptl)
00724       return udptl->local_max_datagram_size;
00725    else {
00726       ast_log(LOG_WARNING, "udptl structure is null\n");
00727       return -1;
00728    }
00729 }
00730 
00731 int ast_udptl_get_far_max_datagram(struct ast_udptl* udptl)
00732 {
00733    if (udptl)
00734       return udptl->far_max_datagram_size;
00735    else {
00736       ast_log(LOG_WARNING, "udptl structure is null\n");
00737       return -1;
00738    }
00739 }
00740 
00741 void ast_udptl_set_local_max_datagram(struct ast_udptl* udptl, int max_datagram)
00742 {
00743    if (udptl)
00744       udptl->local_max_datagram_size = max_datagram;
00745    else
00746       ast_log(LOG_WARNING, "udptl structure is null\n");
00747 }
00748 
00749 void ast_udptl_set_far_max_datagram(struct ast_udptl* udptl, int max_datagram)
00750 {
00751    if (udptl)
00752       udptl->far_max_datagram_size = max_datagram;
00753    else
00754       ast_log(LOG_WARNING, "udptl structure is null\n");
00755 }
00756 
00757 struct ast_udptl *ast_udptl_new_with_bindaddr(struct sched_context *sched, struct io_context *io, int callbackmode, struct in_addr addr)
00758 {
00759    struct ast_udptl *udptl;
00760    int x;
00761    int startplace;
00762    int i;
00763    long int flags;
00764 
00765    if (!(udptl = ast_calloc(1, sizeof(*udptl))))
00766       return NULL;
00767 
00768    if (udptlfectype == 2)
00769       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
00770    else if (udptlfectype == 1)
00771       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
00772    else
00773       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
00774    udptl->error_correction_span = udptlfecspan;
00775    udptl->error_correction_entries = udptlfecentries;
00776    
00777    udptl->far_max_datagram_size = udptlmaxdatagram;
00778    udptl->local_max_datagram_size = udptlmaxdatagram;
00779 
00780    memset(&udptl->rx, 0, sizeof(udptl->rx));
00781    memset(&udptl->tx, 0, sizeof(udptl->tx));
00782    for (i = 0; i <= UDPTL_BUF_MASK; i++) {
00783       udptl->rx[i].buf_len = -1;
00784       udptl->tx[i].buf_len = -1;
00785    }
00786 
00787    udptl->seqno = ast_random() & 0xffff;
00788    udptl->them.sin_family = AF_INET;
00789    udptl->us.sin_family = AF_INET;
00790 
00791    if ((udptl->fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
00792       free(udptl);
00793       ast_log(LOG_WARNING, "Unable to allocate socket: %s\n", strerror(errno));
00794       return NULL;
00795    }
00796    flags = fcntl(udptl->fd, F_GETFL);
00797    fcntl(udptl->fd, F_SETFL, flags | O_NONBLOCK);
00798 #ifdef SO_NO_CHECK
00799    if (nochecksums)
00800       setsockopt(udptl->fd, SOL_SOCKET, SO_NO_CHECK, &nochecksums, sizeof(nochecksums));
00801 #endif
00802    /* Find us a place */
00803    x = (ast_random() % (udptlend - udptlstart)) + udptlstart;
00804    startplace = x;
00805    for (;;) {
00806       udptl->us.sin_port = htons(x);
00807       udptl->us.sin_addr = addr;
00808       if (bind(udptl->fd, (struct sockaddr *) &udptl->us, sizeof(udptl->us)) == 0)
00809          break;
00810       if (errno != EADDRINUSE) {
00811          ast_log(LOG_WARNING, "Unexpected bind error: %s\n", strerror(errno));
00812          close(udptl->fd);
00813          free(udptl);
00814          return NULL;
00815       }
00816       if (++x > udptlend)
00817          x = udptlstart;
00818       if (x == startplace) {
00819          ast_log(LOG_WARNING, "No UDPTL ports remaining\n");
00820          close(udptl->fd);
00821          free(udptl);
00822          return NULL;
00823       }
00824    }
00825    if (io && sched && callbackmode) {
00826       /* Operate this one in a callback mode */
00827       udptl->sched = sched;
00828       udptl->io = io;
00829       udptl->ioid = ast_io_add(udptl->io, udptl->fd, udptlread, AST_IO_IN, udptl);
00830    }
00831    return udptl;
00832 }
00833 
00834 struct ast_udptl *ast_udptl_new(struct sched_context *sched, struct io_context *io, int callbackmode)
00835 {
00836    struct in_addr ia;
00837    memset(&ia, 0, sizeof(ia));
00838    return ast_udptl_new_with_bindaddr(sched, io, callbackmode, ia);
00839 }
00840 
00841 int ast_udptl_settos(struct ast_udptl *udptl, int tos)
00842 {
00843    int res;
00844 
00845    if ((res = setsockopt(udptl->fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)))) 
00846       ast_log(LOG_WARNING, "UDPTL unable to set TOS to %d\n", tos);
00847    return res;
00848 }
00849 
00850 void ast_udptl_set_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
00851 {
00852    udptl->them.sin_port = them->sin_port;
00853    udptl->them.sin_addr = them->sin_addr;
00854 }
00855 
00856 void ast_udptl_get_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
00857 {
00858    them->sin_family = AF_INET;
00859    them->sin_port = udptl->them.sin_port;
00860    them->sin_addr = udptl->them.sin_addr;
00861 }
00862 
00863 void ast_udptl_get_us(struct ast_udptl *udptl, struct sockaddr_in *us)
00864 {
00865    memcpy(us, &udptl->us, sizeof(udptl->us));
00866 }
00867 
00868 void ast_udptl_stop(struct ast_udptl *udptl)
00869 {
00870    memset(&udptl->them.sin_addr, 0, sizeof(udptl->them.sin_addr));
00871    memset(&udptl->them.sin_port, 0, sizeof(udptl->them.sin_port));
00872 }
00873 
00874 void ast_udptl_destroy(struct ast_udptl *udptl)
00875 {
00876    if (udptl->ioid)
00877       ast_io_remove(udptl->io, udptl->ioid);
00878    if (udptl->fd > -1)
00879       close(udptl->fd);
00880    free(udptl);
00881 }
00882 
00883 int ast_udptl_write(struct ast_udptl *s, struct ast_frame *f)
00884 {
00885    int len;
00886    int res;
00887    uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
00888 
00889    /* If we have no peer, return immediately */ 
00890    if (s->them.sin_addr.s_addr == INADDR_ANY)
00891       return 0;
00892 
00893    /* If there is no data length, return immediately */
00894    if (f->datalen == 0)
00895       return 0;
00896    
00897    if (f->frametype != AST_FRAME_MODEM) {
00898       ast_log(LOG_WARNING, "UDPTL can only send T.38 data\n");
00899       return -1;
00900    }
00901 
00902    /* Cook up the UDPTL packet, with the relevant EC info. */
00903    len = udptl_build_packet(s, buf, f->data, f->datalen);
00904 
00905    if (len > 0 && s->them.sin_port && s->them.sin_addr.s_addr) {
00906       if ((res = sendto(s->fd, buf, len, 0, (struct sockaddr *) &s->them, sizeof(s->them))) < 0)
00907          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));
00908 #if 0
00909       printf("Sent %d bytes of UDPTL data to %s:%d\n", res, ast_inet_ntoa(udptl->them.sin_addr), ntohs(udptl->them.sin_port));
00910 #endif
00911       if (udptl_debug_test_addr(&s->them))
00912          ast_verbose("Sent UDPTL packet to %s:%d (type %d, seq %d, len %d)\n",
00913                ast_inet_ntoa(s->them.sin_addr),
00914                ntohs(s->them.sin_port), 0, s->seqno, len);
00915    }
00916       
00917    return 0;
00918 }
00919 
00920 void ast_udptl_proto_unregister(struct ast_udptl_protocol *proto)
00921 {
00922    struct ast_udptl_protocol *cur;
00923    struct ast_udptl_protocol *prev;
00924 
00925    cur = protos;
00926    prev = NULL;
00927    while (cur) {
00928       if (cur == proto) {
00929          if (prev)
00930             prev->next = proto->next;
00931          else
00932             protos = proto->next;
00933          return;
00934       }
00935       prev = cur;
00936       cur = cur->next;
00937    }
00938 }
00939 
00940 int ast_udptl_proto_register(struct ast_udptl_protocol *proto)
00941 {
00942    struct ast_udptl_protocol *cur;
00943 
00944    cur = protos;
00945    while (cur) {
00946       if (cur->type == proto->type) {
00947          ast_log(LOG_WARNING, "Tried to register same protocol '%s' twice\n", cur->type);
00948          return -1;
00949       }
00950       cur = cur->next;
00951    }
00952    proto->next = protos;
00953    protos = proto;
00954    return 0;
00955 }
00956 
00957 static struct ast_udptl_protocol *get_proto(struct ast_channel *chan)
00958 {
00959    struct ast_udptl_protocol *cur;
00960 
00961    cur = protos;
00962    while (cur) {
00963       if (cur->type == chan->tech->type)
00964          return cur;
00965       cur = cur->next;
00966    }
00967    return NULL;
00968 }
00969 
00970 int ast_udptl_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc)
00971 {
00972    struct ast_frame *f;
00973    struct ast_channel *who;
00974    struct ast_channel *cs[3];
00975    struct ast_udptl *p0;
00976    struct ast_udptl *p1;
00977    struct ast_udptl_protocol *pr0;
00978    struct ast_udptl_protocol *pr1;
00979    struct sockaddr_in ac0;
00980    struct sockaddr_in ac1;
00981    struct sockaddr_in t0;
00982    struct sockaddr_in t1;
00983    void *pvt0;
00984    void *pvt1;
00985    int to;
00986    
00987    ast_channel_lock(c0);
00988    while (ast_channel_trylock(c1)) {
00989       ast_channel_unlock(c0);
00990       usleep(1);
00991       ast_channel_lock(c0);
00992    }
00993    pr0 = get_proto(c0);
00994    pr1 = get_proto(c1);
00995    if (!pr0) {
00996       ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c0->name);
00997       ast_channel_unlock(c0);
00998       ast_channel_unlock(c1);
00999       return -1;
01000    }
01001    if (!pr1) {
01002       ast_log(LOG_WARNING, "Can't find native functions for channel '%s'\n", c1->name);
01003       ast_channel_unlock(c0);
01004       ast_channel_unlock(c1);
01005       return -1;
01006    }
01007    pvt0 = c0->tech_pvt;
01008    pvt1 = c1->tech_pvt;
01009    p0 = pr0->get_udptl_info(c0);
01010    p1 = pr1->get_udptl_info(c1);
01011    if (!p0 || !p1) {
01012       /* Somebody doesn't want to play... */
01013       ast_channel_unlock(c0);
01014       ast_channel_unlock(c1);
01015       return -2;
01016    }
01017    if (pr0->set_udptl_peer(c0, p1)) {
01018       ast_log(LOG_WARNING, "Channel '%s' failed to talk to '%s'\n", c0->name, c1->name);
01019    } else {
01020       /* Store UDPTL peer */
01021       ast_udptl_get_peer(p1, &ac1);
01022    }
01023    if (pr1->set_udptl_peer(c1, p0))
01024       ast_log(LOG_WARNING, "Channel '%s' failed to talk back to '%s'\n", c1->name, c0->name);
01025    else {
01026       /* Store UDPTL peer */
01027       ast_udptl_get_peer(p0, &ac0);
01028    }
01029    ast_channel_unlock(c0);
01030    ast_channel_unlock(c1);
01031    cs[0] = c0;
01032    cs[1] = c1;
01033    cs[2] = NULL;
01034    for (;;) {
01035       if ((c0->tech_pvt != pvt0) ||
01036          (c1->tech_pvt != pvt1) ||
01037          (c0->masq || c0->masqr || c1->masq || c1->masqr)) {
01038             ast_log(LOG_DEBUG, "Oooh, something is weird, backing out\n");
01039             /* Tell it to try again later */
01040             return -3;
01041       }
01042       to = -1;
01043       ast_udptl_get_peer(p1, &t1);
01044       ast_udptl_get_peer(p0, &t0);
01045       if (inaddrcmp(&t1, &ac1)) {
01046          ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n", 
01047             c1->name, ast_inet_ntoa(t1.sin_addr), ntohs(t1.sin_port));
01048          ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n", 
01049             c1->name, ast_inet_ntoa(ac1.sin_addr), ntohs(ac1.sin_port));
01050          memcpy(&ac1, &t1, sizeof(ac1));
01051       }
01052       if (inaddrcmp(&t0, &ac0)) {
01053          ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n", 
01054             c0->name, ast_inet_ntoa(t0.sin_addr), ntohs(t0.sin_port));
01055          ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n", 
01056             c0->name, ast_inet_ntoa(ac0.sin_addr), ntohs(ac0.sin_port));
01057          memcpy(&ac0, &t0, sizeof(ac0));
01058       }
01059       who = ast_waitfor_n(cs, 2, &to);
01060       if (!who) {
01061          ast_log(LOG_DEBUG, "Ooh, empty read...\n");
01062          /* check for hangup / whentohangup */
01063          if (ast_check_hangup(c0) || ast_check_hangup(c1))
01064             break;
01065          continue;
01066       }
01067       f = ast_read(who);
01068       if (!f) {
01069          *fo = f;
01070          *rc = who;
01071          ast_log(LOG_DEBUG, "Oooh, got a %s\n", f ? "digit" : "hangup");
01072          /* That's all we needed */
01073          return 0;
01074       } else {
01075          if (f->frametype == AST_FRAME_MODEM) {
01076             /* Forward T.38 frames if they happen upon us */
01077             if (who == c0) {
01078                ast_write(c1, f);
01079             } else if (who == c1) {
01080                ast_write(c0, f);
01081             }
01082          }
01083          ast_frfree(f);
01084       }
01085       /* Swap priority. Not that it's a big deal at this point */
01086       cs[2] = cs[0];
01087       cs[0] = cs[1];
01088       cs[1] = cs[2];
01089    }
01090    return -1;
01091 }
01092 
01093 static int udptl_do_debug_ip(int fd, int argc, char *argv[])
01094 {
01095    struct hostent *hp;
01096    struct ast_hostent ahp;
01097    int port;
01098    char *p;
01099    char *arg;
01100 
01101    port = 0;
01102    if (argc != 4)
01103       return RESULT_SHOWUSAGE;
01104    arg = argv[3];
01105    p = strstr(arg, ":");
01106    if (p) {
01107       *p = '\0';
01108       p++;
01109       port = atoi(p);
01110    }
01111    hp = ast_gethostbyname(arg, &ahp);
01112    if (hp == NULL)
01113       return RESULT_SHOWUSAGE;
01114    udptldebugaddr.sin_family = AF_INET;
01115    memcpy(&udptldebugaddr.sin_addr, hp->h_addr, sizeof(udptldebugaddr.sin_addr));
01116    udptldebugaddr.sin_port = htons(port);
01117    if (port == 0)
01118       ast_cli(fd, "UDPTL Debugging Enabled for IP: %s\n", ast_inet_ntoa(udptldebugaddr.sin_addr));
01119    else
01120       ast_cli(fd, "UDPTL Debugging Enabled for IP: %s:%d\n", ast_inet_ntoa(udptldebugaddr.sin_addr), port);
01121    udptldebug = 1;
01122    return RESULT_SUCCESS;
01123 }
01124 
01125 static int udptl_do_debug(int fd, int argc, char *argv[])
01126 {
01127    if (argc != 2) {
01128       if (argc != 4)
01129          return RESULT_SHOWUSAGE;
01130       return udptl_do_debug_ip(fd, argc, argv);
01131    }
01132    udptldebug = 1;
01133    memset(&udptldebugaddr,0,sizeof(udptldebugaddr));
01134    ast_cli(fd, "UDPTL Debugging Enabled\n");
01135    return RESULT_SUCCESS;
01136 }
01137 
01138 static int udptl_nodebug(int fd, int argc, char *argv[])
01139 {
01140    if (argc != 3)
01141       return RESULT_SHOWUSAGE;
01142    udptldebug = 0;
01143    ast_cli(fd,"UDPTL Debugging Disabled\n");
01144    return RESULT_SUCCESS;
01145 }
01146 
01147 static char debug_usage[] =
01148   "Usage: udptl debug [ip host[:port]]\n"
01149   "       Enable dumping of all UDPTL packets to and from host.\n";
01150 
01151 static char nodebug_usage[] =
01152   "Usage: udptl debug off\n"
01153   "       Disable all UDPTL debugging\n";
01154 
01155 static struct ast_cli_entry cli_udptl_no_debug = {
01156    { "udptl", "no", "debug", NULL },
01157    udptl_nodebug, NULL,
01158    NULL };
01159 
01160 static struct ast_cli_entry cli_udptl[] = {
01161    { { "udptl", "debug", NULL },
01162    udptl_do_debug, "Enable UDPTL debugging",
01163    debug_usage },
01164 
01165    { { "udptl", "debug", "ip", NULL },
01166    udptl_do_debug, "Enable UDPTL debugging on IP",
01167    debug_usage },
01168 
01169    { { "udptl", "debug", "off", NULL },
01170    udptl_nodebug, "Disable UDPTL debugging",
01171    nodebug_usage, NULL, &cli_udptl_no_debug },
01172 };
01173 
01174 void ast_udptl_reload(void)
01175 {
01176    struct ast_config *cfg;
01177    const char *s;
01178 
01179    udptlstart = 4500;
01180    udptlend = 4999;
01181    udptlfectype = 0;
01182    udptlfecentries = 0;
01183    udptlfecspan = 0;
01184    udptlmaxdatagram = 0;
01185 
01186    if ((cfg = ast_config_load("udptl.conf"))) {
01187       if ((s = ast_variable_retrieve(cfg, "general", "udptlstart"))) {
01188          udptlstart = atoi(s);
01189          if (udptlstart < 1024)
01190             udptlstart = 1024;
01191          if (udptlstart > 65535)
01192             udptlstart = 65535;
01193       }
01194       if ((s = ast_variable_retrieve(cfg, "general", "udptlend"))) {
01195          udptlend = atoi(s);
01196          if (udptlend < 1024)
01197             udptlend = 1024;
01198          if (udptlend > 65535)
01199             udptlend = 65535;
01200       }
01201       if ((s = ast_variable_retrieve(cfg, "general", "udptlchecksums"))) {
01202 #ifdef SO_NO_CHECK
01203          if (ast_false(s))
01204             nochecksums = 1;
01205          else
01206             nochecksums = 0;
01207 #else
01208          if (ast_false(s))
01209             ast_log(LOG_WARNING, "Disabling UDPTL checksums is not supported on this operating system!\n");
01210 #endif
01211       }
01212       if ((s = ast_variable_retrieve(cfg, "general", "T38FaxUdpEC"))) {
01213          if (strcmp(s, "t38UDPFEC") == 0)
01214             udptlfectype = 2;
01215          else if (strcmp(s, "t38UDPRedundancy") == 0)
01216             udptlfectype = 1;
01217       }
01218       if ((s = ast_variable_retrieve(cfg, "general", "T38FaxMaxDatagram"))) {
01219          udptlmaxdatagram = atoi(s);
01220          if (udptlmaxdatagram < 0)
01221             udptlmaxdatagram = 0;
01222          if (udptlmaxdatagram > LOCAL_FAX_MAX_DATAGRAM)
01223             udptlmaxdatagram = LOCAL_FAX_MAX_DATAGRAM;
01224       }
01225       if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECentries"))) {
01226          udptlfecentries = atoi(s);
01227          if (udptlfecentries < 0)
01228             udptlfecentries = 0;
01229          if (udptlfecentries > MAX_FEC_ENTRIES)
01230             udptlfecentries = MAX_FEC_ENTRIES;
01231       }
01232       if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECspan"))) {
01233          udptlfecspan = atoi(s);
01234          if (udptlfecspan < 0)
01235             udptlfecspan = 0;
01236          if (udptlfecspan > MAX_FEC_SPAN)
01237             udptlfecspan = MAX_FEC_SPAN;
01238       }
01239       ast_config_destroy(cfg);
01240    }
01241    if (udptlstart >= udptlend) {
01242       ast_log(LOG_WARNING, "Unreasonable values for UDPTL start/end\n");
01243       udptlstart = 4500;
01244       udptlend = 4999;
01245    }
01246    if (option_verbose > 1)
01247       ast_verbose(VERBOSE_PREFIX_2 "UDPTL allocating from port range %d -> %d\n", udptlstart, udptlend);
01248 }
01249 
01250 void ast_udptl_init(void)
01251 {
01252    ast_cli_register_multiple(cli_udptl, sizeof(cli_udptl) / sizeof(struct ast_cli_entry));
01253    ast_udptl_reload();
01254 }

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