Thu Oct 11 06:42:10 2012

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: 308721 $")
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 static int use_even_ports;
00070 
00071 #define LOCAL_FAX_MAX_DATAGRAM      1400
00072 #define MAX_FEC_ENTRIES             5
00073 #define MAX_FEC_SPAN                5
00074 
00075 #define UDPTL_BUF_MASK              15
00076 
00077 typedef struct {
00078    int buf_len;
00079    uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
00080 } udptl_fec_tx_buffer_t;
00081 
00082 typedef struct {
00083    int buf_len;
00084    uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
00085    int fec_len[MAX_FEC_ENTRIES];
00086    uint8_t fec[MAX_FEC_ENTRIES][LOCAL_FAX_MAX_DATAGRAM];
00087    int fec_span;
00088    int fec_entries;
00089 } udptl_fec_rx_buffer_t;
00090 
00091 struct ast_udptl {
00092    int fd;
00093    char resp;
00094    struct ast_frame f[16];
00095    unsigned char rawdata[8192 + AST_FRIENDLY_OFFSET];
00096    unsigned int lasteventseqn;
00097    int nat;
00098    int flags;
00099    struct sockaddr_in us;
00100    struct sockaddr_in them;
00101    int *ioid;
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    struct sockaddr_in far;
00129 
00130    int tx_seq_no;
00131    int rx_seq_no;
00132    int rx_expected_seq_no;
00133 
00134    udptl_fec_tx_buffer_t tx[UDPTL_BUF_MASK + 1];
00135    udptl_fec_rx_buffer_t rx[UDPTL_BUF_MASK + 1];
00136 };
00137 
00138 static struct ast_udptl_protocol *protos;
00139 
00140 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len);
00141 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, int buflen, uint8_t *ifp, int ifp_len);
00142 
00143 static inline int udptl_debug_test_addr(struct sockaddr_in *addr)
00144 {
00145    if (udptldebug == 0)
00146       return 0;
00147    if (udptldebugaddr.sin_addr.s_addr) {
00148       if (((ntohs(udptldebugaddr.sin_port) != 0)
00149          && (udptldebugaddr.sin_port != addr->sin_port))
00150          || (udptldebugaddr.sin_addr.s_addr != addr->sin_addr.s_addr))
00151          return 0;
00152    }
00153    return 1;
00154 }
00155 
00156 static int decode_length(uint8_t *buf, int limit, int *len, int *pvalue)
00157 {
00158    if (*len >= limit)
00159       return -1;
00160    if ((buf[*len] & 0x80) == 0) {
00161       *pvalue = buf[*len];
00162       (*len)++;
00163       return 0;
00164    }
00165    if ((buf[*len] & 0x40) == 0) {
00166       if (*len == limit - 1)
00167          return -1;
00168       *pvalue = (buf[*len] & 0x3F) << 8;
00169       (*len)++;
00170       *pvalue |= buf[*len];
00171       (*len)++;
00172       return 0;
00173    }
00174    *pvalue = (buf[*len] & 0x3F) << 14;
00175    (*len)++;
00176    /* We have a fragment.  Currently we don't process fragments. */
00177    if (option_debug) {
00178       ast_log(LOG_DEBUG, "UDPTL packet with length greater than 16K received, decoding will fail\n");
00179    }
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 = 0;
00187 
00188    if (decode_length(buf, limit, len, &octet_cnt) != 0)
00189       return -1;
00190 
00191    if (octet_cnt > 0) {
00192       /* Make sure the buffer contains at least the number of bits requested */
00193       if ((*len + octet_cnt) > limit)
00194          return -1;
00195 
00196       *p_num_octets = octet_cnt;
00197       *p_object = &buf[*len];
00198       *len += octet_cnt;
00199    }
00200 
00201    return 0;
00202 }
00203 /*- End of function --------------------------------------------------------*/
00204 
00205 static int encode_length(uint8_t *buf, int *len, int value)
00206 {
00207    int multiplier;
00208 
00209    if (value < 0x80) {
00210       /* 1 octet */
00211       buf[*len] = value;
00212       (*len)++;
00213       return value;
00214    }
00215    if (value < 0x4000) {
00216       /* 2 octets */
00217       /* Set the first bit of the first octet */
00218       buf[*len] = ((0x8000 | value) >> 8) & 0xFF;
00219       (*len)++;
00220       buf[*len] = value & 0xFF;
00221       (*len)++;
00222       return value;
00223    }
00224    /* Fragmentation */
00225    multiplier = (value < 0x10000) ? (value >> 14) : 4;
00226    /* Set the first 2 bits of the octet */
00227    buf[*len] = 0xC0 | multiplier;
00228    (*len)++;
00229    return multiplier << 14;
00230 }
00231 /*- End of function --------------------------------------------------------*/
00232 
00233 static int encode_open_type(uint8_t *buf, int buflen, int *len, const uint8_t *data, int num_octets)
00234 {
00235    int enclen;
00236    int octet_idx;
00237    uint8_t zero_byte;
00238 
00239    /* If open type is of zero length, add a single zero byte (10.1) */
00240    if (num_octets == 0) {
00241       zero_byte = 0;
00242       data = &zero_byte;
00243       num_octets = 1;
00244    }
00245    /* Encode the open type */
00246    for (octet_idx = 0; ; num_octets -= enclen, octet_idx += enclen) {
00247       if ((enclen = encode_length(buf, len, num_octets)) < 0)
00248          return -1;
00249       if (enclen + *len > buflen) {
00250          ast_log(LOG_ERROR, "Buffer overflow detected (%d + %d > %d)\n", enclen, *len, buflen);
00251          return -1;
00252       }
00253       if (enclen > 0) {
00254          memcpy(&buf[*len], &data[octet_idx], enclen);
00255          *len += enclen;
00256       }
00257       if (enclen >= num_octets)
00258          break;
00259    }
00260 
00261    return 0;
00262 }
00263 /*- End of function --------------------------------------------------------*/
00264 
00265 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, int len)
00266 {
00267    int stat;
00268    int stat2;
00269    int i;
00270    int j;
00271    int k;
00272    int l;
00273    int m;
00274    int x;
00275    int limit;
00276    int which;
00277    int ptr;
00278    int count;
00279    int total_count;
00280    int seq_no;
00281    const uint8_t *ifp = NULL;
00282    const uint8_t *data = NULL;
00283    int ifp_len = 0;
00284    int repaired[16];
00285    const uint8_t *bufs[ARRAY_LEN(s->f) - 1];
00286    int lengths[ARRAY_LEN(s->f) - 1];
00287    int span;
00288    int entries;
00289    int ifp_no;
00290 
00291    ptr = 0;
00292    ifp_no = 0;
00293    memset(&s->f[0], 0, sizeof(s->f[0]));
00294 
00295    /* Decode seq_number */
00296    if (ptr + 2 > len)
00297       return -1;
00298    seq_no = (buf[0] << 8) | buf[1];
00299    ptr += 2;
00300 
00301    /* Break out the primary packet */
00302    if ((stat = decode_open_type(buf, len, &ptr, &ifp, &ifp_len)) != 0)
00303       return -1;
00304    /* Decode error_recovery */
00305    if (ptr + 1 > len)
00306       return -1;
00307    if ((buf[ptr++] & 0x80) == 0) {
00308       /* Secondary packet mode for error recovery */
00309       if (seq_no > s->rx_seq_no) {
00310          /* We received a later packet than we expected, so we need to check if we can fill in the gap from the
00311             secondary packets. */
00312          total_count = 0;
00313          do {
00314             if ((stat2 = decode_length(buf, len, &ptr, &count)) < 0)
00315                return -1;
00316             for (i = 0; i < count && total_count + i < ARRAY_LEN(bufs); i++) {
00317                if ((stat = decode_open_type(buf, len, &ptr, &bufs[total_count + i], &lengths[total_count + i])) != 0)
00318                   return -1;
00319             }
00320             total_count += i;
00321          }
00322          while (stat2 > 0 && total_count < ARRAY_LEN(bufs));
00323          /* Step through in reverse order, so we go oldest to newest */
00324          for (i = total_count; i > 0; i--) {
00325             if (seq_no - i >= s->rx_seq_no) {
00326                /* This one wasn't seen before */
00327                /* Decode the secondary IFP packet */
00328                //fprintf(stderr, "Secondary %d, len %d\n", seq_no - i, lengths[i - 1]);
00329                s->f[ifp_no].frametype = AST_FRAME_MODEM;
00330                s->f[ifp_no].subclass = AST_MODEM_T38;
00331 
00332                s->f[ifp_no].mallocd = 0;
00333                s->f[ifp_no].seqno = seq_no - i;
00334                s->f[ifp_no].datalen = lengths[i - 1];
00335                s->f[ifp_no].data = (uint8_t *) bufs[i - 1];
00336                s->f[ifp_no].offset = 0;
00337                s->f[ifp_no].src = "UDPTL";
00338                if (ifp_no > 0)
00339                   AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00340                AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00341                ifp_no++;
00342             }
00343          }
00344       }
00345    }
00346    else
00347    {
00348       /* FEC mode for error recovery */
00349       /* Our buffers cannot tolerate overlength IFP packets in FEC mode */
00350       if (ifp_len > LOCAL_FAX_MAX_DATAGRAM)
00351          return -1;
00352       /* Update any missed slots in the buffer */
00353       for ( ; seq_no > s->rx_seq_no; s->rx_seq_no++) {
00354          x = s->rx_seq_no & UDPTL_BUF_MASK;
00355          s->rx[x].buf_len = -1;
00356          s->rx[x].fec_len[0] = 0;
00357          s->rx[x].fec_span = 0;
00358          s->rx[x].fec_entries = 0;
00359       }
00360 
00361       x = seq_no & UDPTL_BUF_MASK;
00362 
00363       memset(repaired, 0, sizeof(repaired));
00364 
00365       /* Save the new IFP packet */
00366       memcpy(s->rx[x].buf, ifp, ifp_len);
00367       s->rx[x].buf_len = ifp_len;
00368       repaired[x] = TRUE;
00369 
00370       /* Decode the FEC packets */
00371       /* The span is defined as an unconstrained integer, but will never be more
00372          than a small value. */
00373       if (ptr + 2 > len)
00374          return -1;
00375       if (buf[ptr++] != 1)
00376          return -1;
00377       span = buf[ptr++];
00378       s->rx[x].fec_span = span;
00379 
00380       /* The number of entries is defined as a length, but will only ever be a small
00381          value. Treat it as such. */
00382       if (ptr + 1 > len)
00383          return -1;
00384       entries = buf[ptr++];
00385       if (entries > MAX_FEC_ENTRIES) {
00386          return -1;
00387       }
00388       s->rx[x].fec_entries = entries;
00389 
00390       /* Decode the elements */
00391       for (i = 0; i < entries; i++) {
00392          if ((stat = decode_open_type(buf, len, &ptr, &data, &s->rx[x].fec_len[i])) != 0)
00393             return -1;
00394          if (s->rx[x].fec_len[i] > LOCAL_FAX_MAX_DATAGRAM)
00395             return -1;
00396 
00397          /* Save the new FEC data */
00398          memcpy(s->rx[x].fec[i], data, s->rx[x].fec_len[i]);
00399 #if 0
00400          fprintf(stderr, "FEC: ");
00401          for (j = 0; j < s->rx[x].fec_len[i]; j++)
00402             fprintf(stderr, "%02X ", data[j]);
00403          fprintf(stderr, "\n");
00404 #endif
00405       }
00406 
00407       /* See if we can reconstruct anything which is missing */
00408       /* TODO: this does not comprehensively hunt back and repair everything that is possible */
00409       for (l = x; l != ((x - (16 - span*entries)) & UDPTL_BUF_MASK); l = (l - 1) & UDPTL_BUF_MASK) {
00410          if (s->rx[l].fec_len[0] <= 0)
00411             continue;
00412          for (m = 0; m < s->rx[l].fec_entries; m++) {
00413             limit = (l + m) & UDPTL_BUF_MASK;
00414             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) {
00415                if (s->rx[k].buf_len <= 0)
00416                   which = (which == -1) ? k : -2;
00417             }
00418             if (which >= 0) {
00419                /* Repairable */
00420                for (j = 0; j < s->rx[l].fec_len[m]; j++) {
00421                   s->rx[which].buf[j] = s->rx[l].fec[m][j];
00422                   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)
00423                      s->rx[which].buf[j] ^= (s->rx[k].buf_len > j) ? s->rx[k].buf[j] : 0;
00424                }
00425                s->rx[which].buf_len = s->rx[l].fec_len[m];
00426                repaired[which] = TRUE;
00427             }
00428          }
00429       }
00430       /* Now play any new packets forwards in time */
00431       for (l = (x + 1) & UDPTL_BUF_MASK, j = seq_no - UDPTL_BUF_MASK; l != x; l = (l + 1) & UDPTL_BUF_MASK, j++) {
00432          if (repaired[l]) {
00433             //fprintf(stderr, "Fixed packet %d, len %d\n", j, l);
00434             s->f[ifp_no].frametype = AST_FRAME_MODEM;
00435             s->f[ifp_no].subclass = AST_MODEM_T38;
00436          
00437             s->f[ifp_no].mallocd = 0;
00438             s->f[ifp_no].seqno = j;
00439             s->f[ifp_no].datalen = s->rx[l].buf_len;
00440             s->f[ifp_no].data = s->rx[l].buf;
00441             s->f[ifp_no].offset = 0;
00442             s->f[ifp_no].src = "UDPTL";
00443             if (ifp_no > 0)
00444                AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00445             AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00446             ifp_no++;
00447          }
00448       }
00449    }
00450 
00451    /* If packets are received out of sequence, we may have already processed this packet from the error
00452       recovery information in a packet already received. */
00453    if (seq_no >= s->rx_seq_no) {
00454       /* Decode the primary IFP packet */
00455       s->f[ifp_no].frametype = AST_FRAME_MODEM;
00456       s->f[ifp_no].subclass = AST_MODEM_T38;
00457       
00458       s->f[ifp_no].mallocd = 0;
00459       s->f[ifp_no].seqno = seq_no;
00460       s->f[ifp_no].datalen = ifp_len;
00461       s->f[ifp_no].data = (uint8_t *) ifp;
00462       s->f[ifp_no].offset = 0;
00463       s->f[ifp_no].src = "UDPTL";
00464       if (ifp_no > 0)
00465          AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
00466       AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
00467 
00468       ifp_no++;
00469    }
00470 
00471    s->rx_seq_no = seq_no + 1;
00472    return ifp_no;
00473 }
00474 /*- End of function --------------------------------------------------------*/
00475 
00476 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, int buflen, uint8_t *ifp, int ifp_len)
00477 {
00478    uint8_t fec[LOCAL_FAX_MAX_DATAGRAM * 2];
00479    int i;
00480    int j;
00481    int seq;
00482    int entry;
00483    int entries;
00484    int span;
00485    int m;
00486    int len;
00487    int limit;
00488    int high_tide;
00489 
00490    seq = s->tx_seq_no & 0xFFFF;
00491 
00492    /* Map the sequence number to an entry in the circular buffer */
00493    entry = seq & UDPTL_BUF_MASK;
00494 
00495    /* We save the message in a circular buffer, for generating FEC or
00496       redundancy sets later on. */
00497    s->tx[entry].buf_len = ifp_len;
00498    memcpy(s->tx[entry].buf, ifp, ifp_len);
00499    
00500    /* Build the UDPTLPacket */
00501 
00502    len = 0;
00503    /* Encode the sequence number */
00504    buf[len++] = (seq >> 8) & 0xFF;
00505    buf[len++] = seq & 0xFF;
00506 
00507    /* Encode the primary IFP packet */
00508    if (encode_open_type(buf, buflen, &len, ifp, ifp_len) < 0)
00509       return -1;
00510 
00511    /* Encode the appropriate type of error recovery information */
00512    switch (s->error_correction_scheme)
00513    {
00514    case UDPTL_ERROR_CORRECTION_NONE:
00515       /* Encode the error recovery type */
00516       buf[len++] = 0x00;
00517       /* The number of entries will always be zero, so it is pointless allowing
00518          for the fragmented case here. */
00519       if (encode_length(buf, &len, 0) < 0)
00520          return -1;
00521       break;
00522    case UDPTL_ERROR_CORRECTION_REDUNDANCY:
00523       /* Encode the error recovery type */
00524       buf[len++] = 0x00;
00525       if (s->tx_seq_no > s->error_correction_entries)
00526          entries = s->error_correction_entries;
00527       else
00528          entries = s->tx_seq_no;
00529       /* The number of entries will always be small, so it is pointless allowing
00530          for the fragmented case here. */
00531       if (encode_length(buf, &len, entries) < 0)
00532          return -1;
00533       /* Encode the elements */
00534       for (i = 0; i < entries; i++) {
00535          j = (entry - i - 1) & UDPTL_BUF_MASK;
00536          if (encode_open_type(buf, buflen, &len, s->tx[j].buf, s->tx[j].buf_len) < 0) {
00537             if (option_debug) {
00538                ast_log(LOG_DEBUG, "Encoding failed at i=%d, j=%d\n", i, j);
00539             }
00540             return -1;
00541          }
00542       }
00543       break;
00544    case UDPTL_ERROR_CORRECTION_FEC:
00545       span = s->error_correction_span;
00546       entries = s->error_correction_entries;
00547       if (seq < s->error_correction_span*s->error_correction_entries) {
00548          /* In the initial stages, wind up the FEC smoothly */
00549          entries = seq/s->error_correction_span;
00550          if (seq < s->error_correction_span)
00551             span = 0;
00552       }
00553       /* Encode the error recovery type */
00554       buf[len++] = 0x80;
00555       /* Span is defined as an inconstrained integer, which it dumb. It will only
00556          ever be a small value. Treat it as such. */
00557       buf[len++] = 1;
00558       buf[len++] = span;
00559       /* The number of entries is defined as a length, but will only ever be a small
00560          value. Treat it as such. */
00561       buf[len++] = entries;
00562       for (m = 0; m < entries; m++) {
00563          /* Make an XOR'ed entry the maximum length */
00564          limit = (entry + m) & UDPTL_BUF_MASK;
00565          high_tide = 0;
00566          for (i = (limit - span*entries) & UDPTL_BUF_MASK; i != limit; i = (i + entries) & UDPTL_BUF_MASK) {
00567             if (high_tide < s->tx[i].buf_len) {
00568                for (j = 0; j < high_tide; j++)
00569                   fec[j] ^= s->tx[i].buf[j];
00570                for ( ; j < s->tx[i].buf_len; j++)
00571                   fec[j] = s->tx[i].buf[j];
00572                high_tide = s->tx[i].buf_len;
00573             } else {
00574                for (j = 0; j < s->tx[i].buf_len; j++)
00575                   fec[j] ^= s->tx[i].buf[j];
00576             }
00577          }
00578          if (encode_open_type(buf, buflen, &len, fec, high_tide) < 0)
00579             return -1;
00580       }
00581       break;
00582    }
00583 
00584    s->tx_seq_no++;
00585    return len;
00586 }
00587 
00588 int ast_udptl_fd(struct ast_udptl *udptl)
00589 {
00590    return udptl->fd;
00591 }
00592 
00593 void ast_udptl_set_data(struct ast_udptl *udptl, void *data)
00594 {
00595    udptl->data = data;
00596 }
00597 
00598 void ast_udptl_set_callback(struct ast_udptl *udptl, ast_udptl_callback callback)
00599 {
00600    udptl->callback = callback;
00601 }
00602 
00603 void ast_udptl_setnat(struct ast_udptl *udptl, int nat)
00604 {
00605    udptl->nat = nat;
00606 }
00607 
00608 static int udptlread(int *id, int fd, short events, void *cbdata)
00609 {
00610    struct ast_udptl *udptl = cbdata;
00611    struct ast_frame *f;
00612 
00613    if ((f = ast_udptl_read(udptl))) {
00614       if (udptl->callback)
00615          udptl->callback(udptl, f, udptl->data);
00616    }
00617    return 1;
00618 }
00619 
00620 struct ast_frame *ast_udptl_read(struct ast_udptl *udptl)
00621 {
00622    int res;
00623    struct sockaddr_in sin;
00624    socklen_t len;
00625    uint16_t seqno = 0;
00626    uint16_t *udptlheader;
00627 
00628    len = sizeof(sin);
00629    
00630    /* Cache where the header will go */
00631    res = recvfrom(udptl->fd,
00632          udptl->rawdata + AST_FRIENDLY_OFFSET,
00633          sizeof(udptl->rawdata) - AST_FRIENDLY_OFFSET,
00634          0,
00635          (struct sockaddr *) &sin,
00636          &len);
00637    udptlheader = (uint16_t *)(udptl->rawdata + AST_FRIENDLY_OFFSET);
00638    if (res < 0) {
00639       if (errno != EAGAIN)
00640          ast_log(LOG_WARNING, "UDPTL read error: %s\n", strerror(errno));
00641       ast_assert(errno != EBADF);
00642       return &ast_null_frame;
00643    }
00644 
00645    /* Ignore if the other side hasn't been given an address yet. */
00646    if (!udptl->them.sin_addr.s_addr || !udptl->them.sin_port)
00647       return &ast_null_frame;
00648 
00649    if (udptl->nat) {
00650       /* Send to whoever sent to us */
00651       if ((udptl->them.sin_addr.s_addr != sin.sin_addr.s_addr) ||
00652          (udptl->them.sin_port != sin.sin_port)) {
00653          memcpy(&udptl->them, &sin, sizeof(udptl->them));
00654          ast_log(LOG_DEBUG, "UDPTL NAT: Using address %s:%d\n", ast_inet_ntoa(udptl->them.sin_addr), ntohs(udptl->them.sin_port));
00655       }
00656    }
00657 
00658    if (udptl_debug_test_addr(&sin)) {
00659       ast_verbose("Got UDPTL packet from %s:%d (type %d, seq %d, len %d)\n",
00660          ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), 0, seqno, res);
00661    }
00662 #if 0
00663    printf("Got UDPTL packet from %s:%d (seq %d, len = %d)\n", ast_inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), seqno, res);
00664 #endif
00665    if (udptl_rx_packet(udptl, udptl->rawdata + AST_FRIENDLY_OFFSET, res) < 1)
00666       return &ast_null_frame;
00667 
00668    return &udptl->f[0];
00669 }
00670 
00671 void ast_udptl_offered_from_local(struct ast_udptl* udptl, int local)
00672 {
00673    if (udptl)
00674       udptl->udptl_offered_from_local = local;
00675    else
00676       ast_log(LOG_WARNING, "udptl structure is null\n");
00677 }
00678 
00679 int ast_udptl_get_error_correction_scheme(struct ast_udptl* udptl)
00680 {
00681    if (udptl)
00682       return udptl->error_correction_scheme;
00683    else {
00684       ast_log(LOG_WARNING, "udptl structure is null\n");
00685       return -1;
00686    }
00687 }
00688 
00689 void ast_udptl_set_error_correction_scheme(struct ast_udptl* udptl, int ec)
00690 {
00691    if (udptl) {
00692       switch (ec) {
00693       case UDPTL_ERROR_CORRECTION_FEC:
00694          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
00695          break;
00696       case UDPTL_ERROR_CORRECTION_REDUNDANCY:
00697          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
00698          break;
00699       case UDPTL_ERROR_CORRECTION_NONE:
00700          udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
00701          break;
00702       default:
00703          ast_log(LOG_WARNING, "error correction parameter invalid\n");
00704       };
00705    } else
00706       ast_log(LOG_WARNING, "udptl structure is null\n");
00707 }
00708 
00709 int ast_udptl_get_local_max_datagram(struct ast_udptl* udptl)
00710 {
00711    if (udptl)
00712       return udptl->local_max_datagram_size;
00713    else {
00714       ast_log(LOG_WARNING, "udptl structure is null\n");
00715       return -1;
00716    }
00717 }
00718 
00719 int ast_udptl_get_far_max_datagram(struct ast_udptl* udptl)
00720 {
00721    if (udptl)
00722       return udptl->far_max_datagram_size;
00723    else {
00724       ast_log(LOG_WARNING, "udptl structure is null\n");
00725       return -1;
00726    }
00727 }
00728 
00729 void ast_udptl_set_local_max_datagram(struct ast_udptl* udptl, int max_datagram)
00730 {
00731    if (udptl)
00732       udptl->local_max_datagram_size = max_datagram;
00733    else
00734       ast_log(LOG_WARNING, "udptl structure is null\n");
00735 }
00736 
00737 void ast_udptl_set_far_max_datagram(struct ast_udptl* udptl, int max_datagram)
00738 {
00739    if (udptl)
00740       udptl->far_max_datagram_size = max_datagram;
00741    else
00742       ast_log(LOG_WARNING, "udptl structure is null\n");
00743 }
00744 
00745 struct ast_udptl *ast_udptl_new_with_bindaddr(struct sched_context *sched, struct io_context *io, int callbackmode, struct in_addr addr)
00746 {
00747    struct ast_udptl *udptl;
00748    int x;
00749    int startplace;
00750    int i;
00751    long int flags;
00752 
00753    if (!(udptl = ast_calloc(1, sizeof(*udptl))))
00754       return NULL;
00755 
00756    if (udptlfectype == 2)
00757       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
00758    else if (udptlfectype == 1)
00759       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
00760    else
00761       udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_NONE;
00762    udptl->error_correction_span = udptlfecspan;
00763    udptl->error_correction_entries = udptlfecentries;
00764    
00765    udptl->far_max_datagram_size = udptlmaxdatagram;
00766    udptl->local_max_datagram_size = udptlmaxdatagram;
00767 
00768    memset(&udptl->rx, 0, sizeof(udptl->rx));
00769    memset(&udptl->tx, 0, sizeof(udptl->tx));
00770    for (i = 0; i <= UDPTL_BUF_MASK; i++) {
00771       udptl->rx[i].buf_len = -1;
00772       udptl->tx[i].buf_len = -1;
00773    }
00774 
00775    udptl->them.sin_family = AF_INET;
00776    udptl->us.sin_family = AF_INET;
00777 
00778    if ((udptl->fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
00779       free(udptl);
00780       ast_log(LOG_WARNING, "Unable to allocate socket: %s\n", strerror(errno));
00781       return NULL;
00782    }
00783    flags = fcntl(udptl->fd, F_GETFL);
00784    fcntl(udptl->fd, F_SETFL, flags | O_NONBLOCK);
00785 #ifdef SO_NO_CHECK
00786    if (nochecksums)
00787       setsockopt(udptl->fd, SOL_SOCKET, SO_NO_CHECK, &nochecksums, sizeof(nochecksums));
00788 #endif
00789    /* Find us a place */
00790    x = (ast_random() % (udptlend - udptlstart)) + udptlstart;
00791    if (use_even_ports && (x & 1)) {
00792       ++x;
00793    }
00794    startplace = x;
00795    for (;;) {
00796       udptl->us.sin_port = htons(x);
00797       udptl->us.sin_addr = addr;
00798       if (bind(udptl->fd, (struct sockaddr *) &udptl->us, sizeof(udptl->us)) == 0)
00799          break;
00800       if (errno != EADDRINUSE) {
00801          ast_log(LOG_WARNING, "Unexpected bind error: %s\n", strerror(errno));
00802          close(udptl->fd);
00803          free(udptl);
00804          return NULL;
00805       }
00806       if (use_even_ports) {
00807          x += 2;
00808       } else {
00809          ++x;
00810       }
00811       if (x > udptlend)
00812          x = udptlstart;
00813       if (x == startplace) {
00814          ast_log(LOG_WARNING, "No UDPTL ports remaining\n");
00815          close(udptl->fd);
00816          free(udptl);
00817          return NULL;
00818       }
00819    }
00820    if (io && sched && callbackmode) {
00821       /* Operate this one in a callback mode */
00822       udptl->sched = sched;
00823       udptl->io = io;
00824       udptl->ioid = ast_io_add(udptl->io, udptl->fd, udptlread, AST_IO_IN, udptl);
00825    }
00826    return udptl;
00827 }
00828 
00829 struct ast_udptl *ast_udptl_new(struct sched_context *sched, struct io_context *io, int callbackmode)
00830 {
00831    struct in_addr ia;
00832    memset(&ia, 0, sizeof(ia));
00833    return ast_udptl_new_with_bindaddr(sched, io, callbackmode, ia);
00834 }
00835 
00836 int ast_udptl_settos(struct ast_udptl *udptl, int tos)
00837 {
00838    int res;
00839 
00840    if ((res = setsockopt(udptl->fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)))) 
00841       ast_log(LOG_WARNING, "UDPTL unable to set TOS to %d\n", tos);
00842    return res;
00843 }
00844 
00845 void ast_udptl_set_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
00846 {
00847    udptl->them.sin_port = them->sin_port;
00848    udptl->them.sin_addr = them->sin_addr;
00849 }
00850 
00851 void ast_udptl_get_peer(struct ast_udptl *udptl, struct sockaddr_in *them)
00852 {
00853    memset(them, 0, sizeof(*them));
00854    them->sin_family = AF_INET;
00855    them->sin_port = udptl->them.sin_port;
00856    them->sin_addr = udptl->them.sin_addr;
00857 }
00858 
00859 void ast_udptl_get_us(struct ast_udptl *udptl, struct sockaddr_in *us)
00860 {
00861    memcpy(us, &udptl->us, sizeof(udptl->us));
00862 }
00863 
00864 void ast_udptl_stop(struct ast_udptl *udptl)
00865 {
00866    memset(&udptl->them.sin_addr, 0, sizeof(udptl->them.sin_addr));
00867    memset(&udptl->them.sin_port, 0, sizeof(udptl->them.sin_port));
00868 }
00869 
00870 void ast_udptl_destroy(struct ast_udptl *udptl)
00871 {
00872    if (udptl->ioid)
00873       ast_io_remove(udptl->io, udptl->ioid);
00874    if (udptl->fd > -1)
00875       close(udptl->fd);
00876    free(udptl);
00877 }
00878 
00879 int ast_udptl_write(struct ast_udptl *s, struct ast_frame *f)
00880 {
00881    int seq;
00882    int len;
00883    int res;
00884    uint8_t buf[LOCAL_FAX_MAX_DATAGRAM * 2];
00885 
00886    /* If we have no peer, return immediately */ 
00887    if (s->them.sin_addr.s_addr == INADDR_ANY)
00888       return 0;
00889 
00890    /* If there is no data length, return immediately */
00891    if (f->datalen == 0)
00892       return 0;
00893    
00894    if (f->frametype != AST_FRAME_MODEM) {
00895       ast_log(LOG_WARNING, "UDPTL can only send T.38 data\n");
00896       return -1;
00897    }
00898 
00899    /* Save seq_no for debug output because udptl_build_packet increments it */
00900    seq = s->tx_seq_no & 0xFFFF;
00901 
00902    /* Cook up the UDPTL packet, with the relevant EC info. */
00903    len = udptl_build_packet(s, buf, sizeof(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, seq, 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       memset(&ac1, 0, sizeof(ac1));
01020    } else {
01021       /* Store UDPTL peer */
01022       ast_udptl_get_peer(p1, &ac1);
01023    }
01024    if (pr1->set_udptl_peer(c1, p0)) {
01025       ast_log(LOG_WARNING, "Channel '%s' failed to talk back to '%s'\n", c1->name, c0->name);
01026       memset(&ac0, 0, sizeof(ac0));
01027    } else {
01028       /* Store UDPTL peer */
01029       ast_udptl_get_peer(p0, &ac0);
01030    }
01031    ast_channel_unlock(c0);
01032    ast_channel_unlock(c1);
01033    cs[0] = c0;
01034    cs[1] = c1;
01035    cs[2] = NULL;
01036    for (;;) {
01037       if ((c0->tech_pvt != pvt0) ||
01038          (c1->tech_pvt != pvt1) ||
01039          (c0->masq || c0->masqr || c1->masq || c1->masqr)) {
01040             ast_log(LOG_DEBUG, "Oooh, something is weird, backing out\n");
01041             /* Tell it to try again later */
01042             return -3;
01043       }
01044       to = -1;
01045       ast_udptl_get_peer(p1, &t1);
01046       ast_udptl_get_peer(p0, &t0);
01047       if (inaddrcmp(&t1, &ac1)) {
01048          ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n", 
01049             c1->name, ast_inet_ntoa(t1.sin_addr), ntohs(t1.sin_port));
01050          ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n", 
01051             c1->name, ast_inet_ntoa(ac1.sin_addr), ntohs(ac1.sin_port));
01052          memcpy(&ac1, &t1, sizeof(ac1));
01053       }
01054       if (inaddrcmp(&t0, &ac0)) {
01055          ast_log(LOG_DEBUG, "Oooh, '%s' changed end address to %s:%d\n", 
01056             c0->name, ast_inet_ntoa(t0.sin_addr), ntohs(t0.sin_port));
01057          ast_log(LOG_DEBUG, "Oooh, '%s' was %s:%d\n", 
01058             c0->name, ast_inet_ntoa(ac0.sin_addr), ntohs(ac0.sin_port));
01059          memcpy(&ac0, &t0, sizeof(ac0));
01060       }
01061       who = ast_waitfor_n(cs, 2, &to);
01062       if (!who) {
01063          ast_log(LOG_DEBUG, "Ooh, empty read...\n");
01064          /* check for hangup / whentohangup */
01065          if (ast_check_hangup(c0) || ast_check_hangup(c1))
01066             break;
01067          continue;
01068       }
01069       f = ast_read(who);
01070       if (!f) {
01071          *fo = f;
01072          *rc = who;
01073          ast_log(LOG_DEBUG, "Oooh, got a %s\n", f ? "digit" : "hangup");
01074          /* That's all we needed */
01075          return 0;
01076       } else {
01077          if (f->frametype == AST_FRAME_MODEM) {
01078             /* Forward T.38 frames if they happen upon us */
01079             if (who == c0) {
01080                ast_write(c1, f);
01081             } else if (who == c1) {
01082                ast_write(c0, f);
01083             }
01084          }
01085          ast_frfree(f);
01086       }
01087       /* Swap priority. Not that it's a big deal at this point */
01088       cs[2] = cs[0];
01089       cs[0] = cs[1];
01090       cs[1] = cs[2];
01091    }
01092    return -1;
01093 }
01094 
01095 static int udptl_do_debug_ip(int fd, int argc, char *argv[])
01096 {
01097    struct hostent *hp;
01098    struct ast_hostent ahp;
01099    int port;
01100    char *p;
01101    char *arg;
01102 
01103    port = 0;
01104    if (argc != 4)
01105       return RESULT_SHOWUSAGE;
01106    arg = argv[3];
01107    p = strstr(arg, ":");
01108    if (p) {
01109       *p = '\0';
01110       p++;
01111       port = atoi(p);
01112    }
01113    hp = ast_gethostbyname(arg, &ahp);
01114    if (hp == NULL)
01115       return RESULT_SHOWUSAGE;
01116    udptldebugaddr.sin_family = AF_INET;
01117    memcpy(&udptldebugaddr.sin_addr, hp->h_addr, sizeof(udptldebugaddr.sin_addr));
01118    udptldebugaddr.sin_port = htons(port);
01119    if (port == 0)
01120       ast_cli(fd, "UDPTL Debugging Enabled for IP: %s\n", ast_inet_ntoa(udptldebugaddr.sin_addr));
01121    else
01122       ast_cli(fd, "UDPTL Debugging Enabled for IP: %s:%d\n", ast_inet_ntoa(udptldebugaddr.sin_addr), port);
01123    udptldebug = 1;
01124    return RESULT_SUCCESS;
01125 }
01126 
01127 static int udptl_do_debug(int fd, int argc, char *argv[])
01128 {
01129    if (argc != 2) {
01130       if (argc != 4)
01131          return RESULT_SHOWUSAGE;
01132       return udptl_do_debug_ip(fd, argc, argv);
01133    }
01134    udptldebug = 1;
01135    memset(&udptldebugaddr,0,sizeof(udptldebugaddr));
01136    ast_cli(fd, "UDPTL Debugging Enabled\n");
01137    return RESULT_SUCCESS;
01138 }
01139 
01140 static int udptl_nodebug(int fd, int argc, char *argv[])
01141 {
01142    if (argc != 3)
01143       return RESULT_SHOWUSAGE;
01144    udptldebug = 0;
01145    ast_cli(fd,"UDPTL Debugging Disabled\n");
01146    return RESULT_SUCCESS;
01147 }
01148 
01149 static char debug_usage[] =
01150   "Usage: udptl debug [ip host[:port]]\n"
01151   "       Enable dumping of all UDPTL packets to and from host.\n";
01152 
01153 static char nodebug_usage[] =
01154   "Usage: udptl debug off\n"
01155   "       Disable all UDPTL debugging\n";
01156 
01157 static struct ast_cli_entry cli_udptl_no_debug = {
01158    { "udptl", "no", "debug", NULL },
01159    udptl_nodebug, NULL,
01160    NULL };
01161 
01162 static struct ast_cli_entry cli_udptl[] = {
01163    { { "udptl", "debug", NULL },
01164    udptl_do_debug, "Enable UDPTL debugging",
01165    debug_usage },
01166 
01167    { { "udptl", "debug", "ip", NULL },
01168    udptl_do_debug, "Enable UDPTL debugging on IP",
01169    debug_usage },
01170 
01171    { { "udptl", "debug", "off", NULL },
01172    udptl_nodebug, "Disable UDPTL debugging",
01173    nodebug_usage, NULL, &cli_udptl_no_debug },
01174 };
01175 
01176 void ast_udptl_reload(void)
01177 {
01178    struct ast_config *cfg;
01179    const char *s;
01180 
01181    udptlstart = 4500;
01182    udptlend = 4999;
01183    udptlfectype = 0;
01184    udptlfecentries = 0;
01185    udptlfecspan = 0;
01186    udptlmaxdatagram = 0;
01187    use_even_ports = 0;
01188 
01189    if ((cfg = ast_config_load("udptl.conf"))) {
01190       if ((s = ast_variable_retrieve(cfg, "general", "udptlstart"))) {
01191          udptlstart = atoi(s);
01192          if (udptlstart < 1024) {
01193             ast_log(LOG_WARNING, "Ports under 1024 are not allowed for T.38.\n");
01194             udptlstart = 1024;
01195          }
01196          if (udptlstart > 65535) {
01197             ast_log(LOG_WARNING, "Ports over 65535 are invalid.\n");
01198             udptlstart = 65535;
01199          }
01200       }
01201       if ((s = ast_variable_retrieve(cfg, "general", "udptlend"))) {
01202          udptlend = atoi(s);
01203          if (udptlend < 1024) {
01204             ast_log(LOG_WARNING, "Ports under 1024 are not allowed for T.38.\n");
01205             udptlend = 1024;
01206          }
01207          if (udptlend > 65535) {
01208             ast_log(LOG_WARNING, "Ports over 65535 are invalid.\n");
01209             udptlend = 65535;
01210          }
01211       }
01212       if ((s = ast_variable_retrieve(cfg, "general", "udptlchecksums"))) {
01213 #ifdef SO_NO_CHECK
01214          if (ast_false(s))
01215             nochecksums = 1;
01216          else
01217             nochecksums = 0;
01218 #else
01219          if (ast_false(s))
01220             ast_log(LOG_WARNING, "Disabling UDPTL checksums is not supported on this operating system!\n");
01221 #endif
01222       }
01223       if ((s = ast_variable_retrieve(cfg, "general", "T38FaxUdpEC"))) {
01224          if (strcmp(s, "t38UDPFEC") == 0)
01225             udptlfectype = 2;
01226          else if (strcmp(s, "t38UDPRedundancy") == 0)
01227             udptlfectype = 1;
01228       }
01229       if ((s = ast_variable_retrieve(cfg, "general", "T38FaxMaxDatagram"))) {
01230          udptlmaxdatagram = atoi(s);
01231          if (udptlmaxdatagram < 100) {
01232             ast_log(LOG_WARNING, "Too small T38FaxMaxDatagram size.  Defaulting to 100.\n");
01233             udptlmaxdatagram = 100;
01234          }
01235          if (udptlmaxdatagram > LOCAL_FAX_MAX_DATAGRAM) {
01236             ast_log(LOG_WARNING, "Too large T38FaxMaxDatagram size.  Defaulting to %d.\n", LOCAL_FAX_MAX_DATAGRAM);
01237             udptlmaxdatagram = LOCAL_FAX_MAX_DATAGRAM;
01238          }
01239       }
01240       if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECentries"))) {
01241          udptlfecentries = atoi(s);
01242          if (udptlfecentries < 1) {
01243             ast_log(LOG_WARNING, "Too small UDPTLFECentries value.  Defaulting to 1.\n");
01244             udptlfecentries = 1;
01245          }
01246          if (udptlfecentries > MAX_FEC_ENTRIES) {
01247             ast_log(LOG_WARNING, "Too large UDPTLFECentries value.  Defaulting to %d.\n", MAX_FEC_ENTRIES);
01248             udptlfecentries = MAX_FEC_ENTRIES;
01249          }
01250       }
01251       if ((s = ast_variable_retrieve(cfg, "general", "UDPTLFECspan"))) {
01252          udptlfecspan = atoi(s);
01253          if (udptlfecspan < 1) {
01254             ast_log(LOG_WARNING, "Too small UDPTLFECspan value.  Defaulting to 1.\n");
01255             udptlfecspan = 1;
01256          }
01257          if (udptlfecspan > MAX_FEC_SPAN) {
01258             ast_log(LOG_WARNING, "Too large UDPTLFECspan value.  Defaulting to %d.\n", MAX_FEC_SPAN);
01259             udptlfecspan = MAX_FEC_SPAN;
01260          }
01261       }
01262       if ((s = ast_variable_retrieve(cfg, "general", "use_even_ports"))) {
01263          use_even_ports = ast_true(s);
01264       }
01265       ast_config_destroy(cfg);
01266    }
01267    if (udptlstart >= udptlend) {
01268       ast_log(LOG_WARNING, "Unreasonable values for UDPTL start/end\n");
01269       udptlstart = 4500;
01270       udptlend = 4999;
01271    }
01272    if (use_even_ports && (udptlstart & 1)) {
01273       ++udptlstart;
01274       ast_log(LOG_NOTICE, "Odd numbered udptlstart specified but use_even_ports enabled. udptlstart is now %d\n", udptlstart);
01275    }
01276    if (use_even_ports && (udptlend & 1)) {
01277       --udptlend;
01278       ast_log(LOG_NOTICE, "Odd numbered udptlend specified but use_event_ports enabled. udptlend is now %d\n", udptlend);
01279    }
01280    if (option_verbose > 1)
01281       ast_verbose(VERBOSE_PREFIX_2 "UDPTL allocating from port range %d -> %d\n", udptlstart, udptlend);
01282 }
01283 
01284 void ast_udptl_init(void)
01285 {
01286    ast_cli_register_multiple(cli_udptl, sizeof(cli_udptl) / sizeof(struct ast_cli_entry));
01287    ast_udptl_reload();
01288 }

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