Asterisk - The Open Source Telephony Project  21.4.1
udptl.c
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1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * UDPTL support for T.38
5  *
6  * Copyright (C) 2005, Steve Underwood, partly based on RTP code which is
7  * Copyright (C) 1999-2009, Digium, Inc.
8  *
9  * Steve Underwood <steveu@coppice.org>
10  * Kevin P. Fleming <kpfleming@digium.com>
11  *
12  * See http://www.asterisk.org for more information about
13  * the Asterisk project. Please do not directly contact
14  * any of the maintainers of this project for assistance;
15  * the project provides a web site, mailing lists and IRC
16  * channels for your use.
17  *
18  * This program is free software, distributed under the terms of
19  * the GNU General Public License Version 2. See the LICENSE file
20  * at the top of the source tree.
21  *
22  * A license has been granted to Digium (via disclaimer) for the use of
23  * this code.
24  */
25 
26 /*!
27  * \file
28  *
29  * \brief UDPTL support for T.38 faxing
30  *
31  *
32  * \author Mark Spencer <markster@digium.com>
33  * \author Steve Underwood <steveu@coppice.org>
34  * \author Kevin P. Fleming <kpfleming@digium.com>
35  *
36  * \page T38fax_udptl T.38 support :: UDPTL
37  *
38  * Asterisk supports T.38 fax passthrough, origination and termination. It does
39  * not support gateway operation.
40  *
41  * UDPTL is handled very much like RTP. It can be reinvited to go directly between
42  * the endpoints, without involving Asterisk in the media stream.
43  *
44  * \b References:
45  * - udptl.c
46  * - app_fax.c
47  */
48 
49 /*! \li \ref udptl.c uses the configuration file \ref udptl.conf
50  * \addtogroup configuration_file Configuration Files
51  */
52 
53 /*!
54  * \page udptl.conf udptl.conf
55  * \verbinclude udptl.conf.sample
56  */
57 
58 /*** MODULEINFO
59  <support_level>core</support_level>
60  ***/
61 
62 #include "asterisk.h"
63 
64 #include <sys/time.h>
65 #include <signal.h>
66 #include <fcntl.h>
67 
68 #include "asterisk/module.h"
69 #include "asterisk/udptl.h"
70 #include "asterisk/frame.h"
71 #include "asterisk/channel.h"
72 #include "asterisk/acl.h"
74 #include "asterisk/lock.h"
75 #include "asterisk/utils.h"
76 #include "asterisk/netsock2.h"
77 #include "asterisk/cli.h"
78 #include "asterisk/unaligned.h"
79 
80 /*** DOCUMENTATION
81  <configInfo name="udptl" language="en_US">
82  <configFile name="udptl.conf">
83  <configObject name="global">
84  <synopsis>Global options for configuring UDPTL</synopsis>
85  <configOption name="udptlstart">
86  <synopsis>The start of the UDPTL port range</synopsis>
87  </configOption>
88  <configOption name="udptlend">
89  <synopsis>The end of the UDPTL port range</synopsis>
90  </configOption>
91  <configOption name="udptlchecksums">
92  <synopsis>Whether to enable or disable UDP checksums on UDPTL traffic</synopsis>
93  </configOption>
94  <configOption name="udptlfecentries">
95  <synopsis>The number of error correction entries in a UDPTL packet</synopsis>
96  </configOption>
97  <configOption name="udptlfecspan">
98  <synopsis>The span over which parity is calculated for FEC in a UDPTL packet</synopsis>
99  </configOption>
100  <configOption name="use_even_ports">
101  <synopsis>Whether to only use even-numbered UDPTL ports</synopsis>
102  </configOption>
103  <configOption name="t38faxudpec">
104  <synopsis>Removed</synopsis>
105  </configOption>
106  <configOption name="t38faxmaxdatagram">
107  <synopsis>Removed</synopsis>
108  </configOption>
109  </configObject>
110  </configFile>
111  </configInfo>
112 ***/
113 
114 #define UDPTL_MTU 1200
115 
116 #if !defined(FALSE)
117 #define FALSE 0
118 #endif
119 #if !defined(TRUE)
120 #define TRUE (!FALSE)
121 #endif
122 
123 #define LOG_TAG(u) S_OR(u->tag, "no tag")
124 
125 #define DEFAULT_UDPTLSTART 4000
126 #define DEFAULT_UDPTLEND 4999
127 
128 static int udptldebug; /*!< Are we debugging? */
129 static struct ast_sockaddr udptldebugaddr; /*!< Debug packets to/from this host */
130 
131 #define LOCAL_FAX_MAX_DATAGRAM 1400
132 #define DEFAULT_FAX_MAX_DATAGRAM 400
133 #define FAX_MAX_DATAGRAM_LIMIT 1400
134 #define MAX_FEC_ENTRIES 5
135 #define MAX_FEC_SPAN 5
136 
137 #define UDPTL_BUF_MASK 15
138 
139 typedef struct {
140  int buf_len;
141  uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
143 
144 typedef struct {
145  int buf_len;
146  uint8_t buf[LOCAL_FAX_MAX_DATAGRAM];
147  unsigned int fec_len[MAX_FEC_ENTRIES];
148  uint8_t fec[MAX_FEC_ENTRIES][LOCAL_FAX_MAX_DATAGRAM];
149  unsigned int fec_span;
150  unsigned int fec_entries;
152 
153 /*! \brief Structure for an UDPTL session */
154 struct ast_udptl {
155  int fd;
156  char resp;
157  struct ast_frame f[16];
158  unsigned char rawdata[8192 + AST_FRIENDLY_OFFSET];
159  unsigned int lasteventseqn;
160  int nat;
161  int flags;
162  struct ast_sockaddr us;
163  struct ast_sockaddr them;
164  int *ioid;
165  struct ast_sched_context *sched;
166  struct io_context *io;
167  void *data;
168  char *tag;
169  ast_udptl_callback callback;
170 
171  /*! This option indicates the error correction scheme used in transmitted UDPTL
172  * packets and expected in received UDPTL packets.
173  */
174  enum ast_t38_ec_modes error_correction_scheme;
175 
176  /*! This option indicates the number of error correction entries transmitted in
177  * UDPTL packets and expected in received UDPTL packets.
178  */
180 
181  /*! This option indicates the span of the error correction entries in transmitted
182  * UDPTL packets (FEC only).
183  */
184  unsigned int error_correction_span;
185 
186  /*! The maximum size UDPTL packet that can be accepted by
187  * the remote device.
188  */
190 
191  /*! The maximum size UDPTL packet that we are prepared to
192  * accept, or -1 if it hasn't been calculated since the last
193  * changes were applied to the UDPTL structure.
194  */
196 
197  /*! The maximum IFP that can be submitted for sending
198  * to the remote device. Calculated from far_max_datagram,
199  * error_correction_scheme and error_correction_entries,
200  * or -1 if it hasn't been calculated since the last
201  * changes were applied to the UDPTL structure.
202  */
204 
205  /*! The maximum IFP that the local endpoint is prepared
206  * to accept. Along with error_correction_scheme and
207  * error_correction_entries, used to calculate local_max_datagram.
208  */
210 
211  unsigned int tx_seq_no;
212  unsigned int rx_seq_no;
213 
214  udptl_fec_tx_buffer_t tx[UDPTL_BUF_MASK + 1];
215  udptl_fec_rx_buffer_t rx[UDPTL_BUF_MASK + 1];
216 };
217 
219  unsigned int start; /*< The UDPTL start port */
220  unsigned int end; /*< The UDPTL end port */
221  unsigned int fecentries;
222  unsigned int fecspan;
223  unsigned int nochecksums;
224  unsigned int use_even_ports;
225 };
226 
227 static AO2_GLOBAL_OBJ_STATIC(globals);
228 
229 struct udptl_config {
230  struct udptl_global_options *general;
231 };
232 
233 static void *udptl_snapshot_alloc(void);
234 static int udptl_pre_apply_config(void);
235 
236 static struct aco_type general_option = {
237  .type = ACO_GLOBAL,
238  .name = "global",
239  .category_match = ACO_WHITELIST_EXACT,
240  .item_offset = offsetof(struct udptl_config, general),
241  .category = "general",
242 };
243 
244 static struct aco_type *general_options[] = ACO_TYPES(&general_option);
245 
246 static struct aco_file udptl_conf = {
247  .filename = "udptl.conf",
248  .types = ACO_TYPES(&general_option),
249 };
250 
251 CONFIG_INFO_CORE("udptl", cfg_info, globals, udptl_snapshot_alloc,
252  .files = ACO_FILES(&udptl_conf),
253  .pre_apply_config = udptl_pre_apply_config,
254 );
255 
256 static inline int udptl_debug_test_addr(const struct ast_sockaddr *addr)
257 {
258  if (udptldebug == 0)
259  return 0;
260 
262  return 1;
263  }
264 
266  return !ast_sockaddr_cmp(&udptldebugaddr, addr);
267  } else {
268  return !ast_sockaddr_cmp_addr(&udptldebugaddr, addr);
269  }
270 }
271 
272 static int decode_length(uint8_t *buf, unsigned int limit, unsigned int *len, unsigned int *pvalue)
273 {
274  if (*len >= limit)
275  return -1;
276  if ((buf[*len] & 0x80) == 0) {
277  *pvalue = buf[*len];
278  (*len)++;
279  return 0;
280  }
281  if ((buf[*len] & 0x40) == 0) {
282  if (*len == limit - 1)
283  return -1;
284  *pvalue = (buf[*len] & 0x3F) << 8;
285  (*len)++;
286  *pvalue |= buf[*len];
287  (*len)++;
288  return 0;
289  }
290  *pvalue = (buf[*len] & 0x3F) << 14;
291  (*len)++;
292  /* We have a fragment. Currently we don't process fragments. */
293  ast_debug(1, "UDPTL packet with length greater than 16K received, decoding will fail\n");
294  return 1;
295 }
296 /*- End of function --------------------------------------------------------*/
297 
298 static int decode_open_type(uint8_t *buf, unsigned int limit, unsigned int *len, const uint8_t **p_object, unsigned int *p_num_octets)
299 {
300  unsigned int octet_cnt = 0;
301 
302  if (decode_length(buf, limit, len, &octet_cnt) != 0)
303  return -1;
304 
305  /* Make sure the buffer contains at least the number of bits requested */
306  if ((*len + octet_cnt) > limit) {
307  return -1;
308  }
309 
310  *p_num_octets = octet_cnt;
311  *p_object = &buf[*len];
312  *len += octet_cnt;
313 
314  return 0;
315 }
316 /*- End of function --------------------------------------------------------*/
317 
318 static unsigned int encode_length(uint8_t *buf, unsigned int *len, unsigned int value)
319 {
320  unsigned int multiplier;
321 
322  if (value < 0x80) {
323  /* 1 octet */
324  buf[*len] = value;
325  (*len)++;
326  return value;
327  }
328  if (value < 0x4000) {
329  /* 2 octets */
330  /* Set the first bit of the first octet */
331  buf[*len] = ((0x8000 | value) >> 8) & 0xFF;
332  (*len)++;
333  buf[*len] = value & 0xFF;
334  (*len)++;
335  return value;
336  }
337  /* Fragmentation */
338  multiplier = (value < 0x10000) ? (value >> 14) : 4;
339  /* Set the first 2 bits of the octet */
340  buf[*len] = 0xC0 | multiplier;
341  (*len)++;
342  return multiplier << 14;
343 }
344 /*- End of function --------------------------------------------------------*/
345 
346 static int encode_open_type(const struct ast_udptl *udptl, uint8_t *buf, unsigned int buflen,
347  unsigned int *len, const uint8_t *data, unsigned int num_octets)
348 {
349  unsigned int enclen;
350  unsigned int octet_idx;
351  uint8_t zero_byte;
352 
353  /* If open type is of zero length, add a single zero byte (10.1) */
354  if (num_octets == 0) {
355  zero_byte = 0;
356  data = &zero_byte;
357  num_octets = 1;
358  }
359  /* Encode the open type */
360  for (octet_idx = 0; ; num_octets -= enclen, octet_idx += enclen) {
361  enclen = encode_length(buf, len, num_octets);
362  if (enclen + *len > buflen) {
363  ast_log(LOG_ERROR, "UDPTL (%s): Buffer overflow detected (%u + %u > %u)\n",
364  LOG_TAG(udptl), enclen, *len, buflen);
365  return -1;
366  }
367  if (enclen > 0) {
368  memcpy(&buf[*len], &data[octet_idx], enclen);
369  *len += enclen;
370  }
371  if (enclen >= num_octets)
372  break;
373  }
374 
375  return 0;
376 }
377 /*- End of function --------------------------------------------------------*/
378 
379 static int udptl_rx_packet(struct ast_udptl *s, uint8_t *buf, unsigned int len)
380 {
381  int stat1;
382  int stat2;
383  int i;
384  unsigned int ptr; /* an index that keeps track of how much of the UDPTL packet has been processed */
385  int seq_no;
386  const uint8_t *ifp = NULL;
387  const uint8_t *data = NULL;
388  unsigned int ifp_len = 0;
389  int repaired[16];
390  const uint8_t *bufs[ARRAY_LEN(s->f) - 1];
391  unsigned int lengths[ARRAY_LEN(s->f) - 1];
392  int span;
393  int entries;
394  int ifp_no;
395 
396  ptr = 0;
397  ifp_no = 0;
398  memset(&s->f[0], 0, sizeof(s->f[0]));
399 
400  /* Decode seq_number */
401  if (ptr + 2 > len)
402  return -1;
403  seq_no = (buf[0] << 8) | buf[1];
404  ptr += 2;
405 
406  /* UDPTL sequence numbers are 16 bit so after 0xFFFF comes
407  0 which breaks all packet recovery logic. To fix this
408  if we see that next expected packet (rx_seq_no) is close
409  to or beyond the wrap around limit & the received packet
410  is still near zero, then we 'unwrap' the received seqno
411  so it has the value it would have had. After a 16
412  packet grace period (there shouldn't be more than
413  that many recovery packets) we wrap the expected
414  sequence number around and things can return back
415  to normal */
416  if (seq_no < 0x000F && s->rx_seq_no > 0xFFF0) {
417  /* received seq_no has wrapped adjust it */
418  seq_no += 0x10000;
419  } else {
420  /* otherwise make sure expected rx_seq_no is properly wrapped */
421  s->rx_seq_no &= 0xFFFF;
422  }
423 
424  /* Break out the primary packet */
425  if ((stat1 = decode_open_type(buf, len, &ptr, &ifp, &ifp_len)) != 0)
426  return -1;
427  /* Decode error_recovery */
428  if (ptr + 1 > len)
429  return -1;
430  if ((buf[ptr++] & 0x80) == 0) {
431  /* Secondary packet mode for error recovery */
432  if (seq_no > s->rx_seq_no) {
433  /* We received a later packet than we expected, so we need to check if we can fill in the gap from the
434  secondary packets. */
435  int total_count = 0;
436  do {
437  unsigned int count;
438  if ((stat2 = decode_length(buf, len, &ptr, &count)) < 0)
439  return -1;
440  for (i = 0; i < count && total_count + i < ARRAY_LEN(bufs); i++) {
441  if ((stat1 = decode_open_type(buf, len, &ptr, &bufs[total_count + i], &lengths[total_count + i])) != 0) {
442  return -1;
443  }
444  /* valid secondaries can contain zero-length packets that should be ignored */
445  if (!bufs[total_count + i] || !lengths[total_count + i]) {
446  /* drop the count of items to process and reuse the buffers that were just set */
447  i--;
448  count--;
449  }
450  }
451  total_count += i;
452  }
453  while (stat2 > 0 && total_count < ARRAY_LEN(bufs));
454  /* Step through in reverse order, so we go oldest to newest */
455  for (i = total_count; i > 0; i--) {
456  if (seq_no - i >= s->rx_seq_no) {
457  /* This one wasn't seen before */
458  /* Decode the secondary IFP packet */
459  ast_debug(3, "Recovering lost packet via secondary %d, len %u\n", seq_no - i, lengths[i - 1]);
460  s->f[ifp_no].frametype = AST_FRAME_MODEM;
461  s->f[ifp_no].subclass.integer = AST_MODEM_T38;
462 
463  s->f[ifp_no].mallocd = 0;
464  s->f[ifp_no].seqno = seq_no - i;
465  s->f[ifp_no].datalen = lengths[i - 1];
466  s->f[ifp_no].data.ptr = (uint8_t *) bufs[i - 1];
467  s->f[ifp_no].offset = 0;
468  s->f[ifp_no].src = "UDPTL";
469  if (ifp_no > 0)
470  AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
471  AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
472  ifp_no++;
473  }
474  }
475  }
476  }
477  else
478  {
479  int j;
480  int l;
481  int x;
482  /* FEC mode for error recovery */
483  /* Our buffers cannot tolerate overlength IFP packets in FEC mode */
484  if (ifp_len > LOCAL_FAX_MAX_DATAGRAM)
485  return -1;
486  /* Update any missed slots in the buffer */
487  for ( ; seq_no > s->rx_seq_no; s->rx_seq_no++) {
488  x = s->rx_seq_no & UDPTL_BUF_MASK;
489  s->rx[x].buf_len = -1;
490  s->rx[x].fec_len[0] = 0;
491  s->rx[x].fec_span = 0;
492  s->rx[x].fec_entries = 0;
493  }
494 
495  x = seq_no & UDPTL_BUF_MASK;
496 
497  memset(repaired, 0, sizeof(repaired));
498 
499  /* Save the new IFP packet */
500  memcpy(s->rx[x].buf, ifp, ifp_len);
501  s->rx[x].buf_len = ifp_len;
502  repaired[x] = TRUE;
503 
504  /* Decode the FEC packets */
505  /* The span is defined as an unconstrained integer, but will never be more
506  than a small value. */
507  if (ptr + 2 > len)
508  return -1;
509  if (buf[ptr++] != 1)
510  return -1;
511  span = buf[ptr++];
512  s->rx[x].fec_span = span;
513 
514  /* The number of entries is defined as a length, but will only ever be a small
515  value. Treat it as such. */
516  if (ptr + 1 > len)
517  return -1;
518  entries = buf[ptr++];
519  if (entries > MAX_FEC_ENTRIES) {
520  return -1;
521  }
522  s->rx[x].fec_entries = entries;
523 
524  /* Decode the elements */
525  for (i = 0; i < entries; i++) {
526  if ((stat1 = decode_open_type(buf, len, &ptr, &data, &s->rx[x].fec_len[i])) != 0)
527  return -1;
528  if (s->rx[x].fec_len[i] > LOCAL_FAX_MAX_DATAGRAM)
529  return -1;
530 
531  /* Save the new FEC data */
532  memcpy(s->rx[x].fec[i], data, s->rx[x].fec_len[i]);
533 #if 0
534  fprintf(stderr, "FEC: ");
535  for (j = 0; j < s->rx[x].fec_len[i]; j++)
536  fprintf(stderr, "%02hhX ", data[j]);
537  fprintf(stderr, "\n");
538 #endif
539  }
540 
541  /* See if we can reconstruct anything which is missing */
542  /* TODO: this does not comprehensively hunt back and repair everything that is possible */
543  for (l = x; l != ((x - (16 - span*entries)) & UDPTL_BUF_MASK); l = (l - 1) & UDPTL_BUF_MASK) {
544  int m;
545  if (s->rx[l].fec_len[0] <= 0)
546  continue;
547  for (m = 0; m < s->rx[l].fec_entries; m++) {
548  int k;
549  int which;
550  int limit = (l + m) & UDPTL_BUF_MASK;
551 
552  /* only repair buffers that actually exist! */
553  if (seq_no <= (s->rx[l].fec_span * s->rx[l].fec_entries) - m) {
554  continue;
555  }
556 
557  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) {
558  if (s->rx[k].buf_len <= 0)
559  which = (which == -1) ? k : -2;
560  }
561  if (which >= 0) {
562  /* Repairable */
563  for (j = 0; j < s->rx[l].fec_len[m]; j++) {
564  s->rx[which].buf[j] = s->rx[l].fec[m][j];
565  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)
566  s->rx[which].buf[j] ^= (s->rx[k].buf_len > j) ? s->rx[k].buf[j] : 0;
567  }
568  s->rx[which].buf_len = s->rx[l].fec_len[m];
569  repaired[which] = TRUE;
570  }
571  }
572  }
573  /* Now play any new packets forwards in time */
574  for (l = (x + 1) & UDPTL_BUF_MASK, j = seq_no - UDPTL_BUF_MASK; l != x; l = (l + 1) & UDPTL_BUF_MASK, j++) {
575  if (repaired[l]) {
576  //fprintf(stderr, "Fixed packet %d, len %d\n", j, l);
577  s->f[ifp_no].frametype = AST_FRAME_MODEM;
578  s->f[ifp_no].subclass.integer = AST_MODEM_T38;
579 
580  s->f[ifp_no].mallocd = 0;
581  s->f[ifp_no].seqno = j;
582  s->f[ifp_no].datalen = s->rx[l].buf_len;
583  s->f[ifp_no].data.ptr = s->rx[l].buf;
584  s->f[ifp_no].offset = 0;
585  s->f[ifp_no].src = "UDPTL";
586  if (ifp_no > 0)
587  AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
588  AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
589  ifp_no++;
590  }
591  }
592  }
593 
594  /* If packets are received out of sequence, we may have already processed this packet from the error
595  recovery information in a packet already received. */
596  if (seq_no >= s->rx_seq_no) {
597  /* Decode the primary IFP packet */
598  s->f[ifp_no].frametype = AST_FRAME_MODEM;
599  s->f[ifp_no].subclass.integer = AST_MODEM_T38;
600 
601  s->f[ifp_no].mallocd = 0;
602  s->f[ifp_no].seqno = seq_no;
603  s->f[ifp_no].datalen = ifp_len;
604  s->f[ifp_no].data.ptr = (uint8_t *) ifp;
605  s->f[ifp_no].offset = 0;
606  s->f[ifp_no].src = "UDPTL";
607  if (ifp_no > 0)
608  AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
609  AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
610 
611  ifp_no++;
612  }
613 
614  s->rx_seq_no = seq_no + 1;
615  return ifp_no;
616 }
617 /*- End of function --------------------------------------------------------*/
618 
619 static int udptl_build_packet(struct ast_udptl *s, uint8_t *buf, unsigned int buflen, uint8_t *ifp, unsigned int ifp_len)
620 {
621  uint8_t fec[LOCAL_FAX_MAX_DATAGRAM * 2] = { 0, };
622  int i;
623  int j;
624  int seq;
625  int entry;
626  int entries;
627  int span;
628  int m;
629  unsigned int len;
630  int limit;
631  int high_tide;
632 
633  seq = s->tx_seq_no & 0xFFFF;
634 
635  /* Map the sequence number to an entry in the circular buffer */
636  entry = seq & UDPTL_BUF_MASK;
637 
638  /* We save the message in a circular buffer, for generating FEC or
639  redundancy sets later on. */
640  s->tx[entry].buf_len = ifp_len;
641  memcpy(s->tx[entry].buf, ifp, ifp_len);
642 
643  /* Build the UDPTLPacket */
644 
645  len = 0;
646  /* Encode the sequence number */
647  buf[len++] = (seq >> 8) & 0xFF;
648  buf[len++] = seq & 0xFF;
649 
650  /* Encode the primary IFP packet */
651  if (encode_open_type(s, buf, buflen, &len, ifp, ifp_len) < 0)
652  return -1;
653 
654  /* Encode the appropriate type of error recovery information */
655  switch (s->error_correction_scheme)
656  {
657  case UDPTL_ERROR_CORRECTION_NONE:
658  /* Encode the error recovery type */
659  buf[len++] = 0x00;
660  /* The number of entries will always be zero, so it is pointless allowing
661  for the fragmented case here. */
662  encode_length(buf, &len, 0);
663  break;
664  case UDPTL_ERROR_CORRECTION_REDUNDANCY:
665  /* Encode the error recovery type */
666  buf[len++] = 0x00;
667  if (s->tx_seq_no > s->error_correction_entries)
668  entries = s->error_correction_entries;
669  else
670  entries = s->tx_seq_no;
671  /* The number of entries will always be small, so it is pointless allowing
672  for the fragmented case here. */
673  encode_length(buf, &len, entries);
674  /* Encode the elements */
675  for (i = 0; i < entries; i++) {
676  j = (entry - i - 1) & UDPTL_BUF_MASK;
677  if (encode_open_type(s, buf, buflen, &len, s->tx[j].buf, s->tx[j].buf_len) < 0) {
678  ast_debug(1, "UDPTL (%s): Encoding failed at i=%d, j=%d\n",
679  LOG_TAG(s), i, j);
680  return -1;
681  }
682  }
683  break;
684  case UDPTL_ERROR_CORRECTION_FEC:
685  span = s->error_correction_span;
686  entries = s->error_correction_entries;
687  if (seq < s->error_correction_span*s->error_correction_entries) {
688  /* In the initial stages, wind up the FEC smoothly */
689  entries = seq/s->error_correction_span;
690  if (seq < s->error_correction_span)
691  span = 0;
692  }
693  /* Encode the error recovery type */
694  buf[len++] = 0x80;
695  /* Span is defined as an unconstrained integer, which it dumb. It will only
696  ever be a small value. Treat it as such. */
697  buf[len++] = 1;
698  buf[len++] = span;
699  /* The number of entries is defined as a length, but will only ever be a small
700  value. Treat it as such. */
701  buf[len++] = entries;
702  for (m = 0; m < entries; m++) {
703  /* Make an XOR'ed entry the maximum length */
704  limit = (entry + m) & UDPTL_BUF_MASK;
705  high_tide = 0;
706  for (i = (limit - span*entries) & UDPTL_BUF_MASK; i != limit; i = (i + entries) & UDPTL_BUF_MASK) {
707  if (high_tide < s->tx[i].buf_len) {
708  for (j = 0; j < high_tide; j++)
709  fec[j] ^= s->tx[i].buf[j];
710  for ( ; j < s->tx[i].buf_len; j++)
711  fec[j] = s->tx[i].buf[j];
712  high_tide = s->tx[i].buf_len;
713  } else {
714  for (j = 0; j < s->tx[i].buf_len; j++)
715  fec[j] ^= s->tx[i].buf[j];
716  }
717  }
718  if (encode_open_type(s, buf, buflen, &len, fec, high_tide) < 0)
719  return -1;
720  }
721  break;
722  }
723 
724  s->tx_seq_no++;
725  return len;
726 }
727 
728 int ast_udptl_fd(const struct ast_udptl *udptl)
729 {
730  return udptl->fd;
731 }
732 
733 void ast_udptl_set_data(struct ast_udptl *udptl, void *data)
734 {
735  udptl->data = data;
736 }
737 
738 void ast_udptl_set_callback(struct ast_udptl *udptl, ast_udptl_callback callback)
739 {
740  udptl->callback = callback;
741 }
742 
743 void ast_udptl_setnat(struct ast_udptl *udptl, int nat)
744 {
745  udptl->nat = nat;
746 }
747 
748 static int udptlread(int *id, int fd, short events, void *cbdata)
749 {
750  struct ast_udptl *udptl = cbdata;
751  struct ast_frame *f;
752 
753  if ((f = ast_udptl_read(udptl))) {
754  if (udptl->callback)
755  udptl->callback(udptl, f, udptl->data);
756  }
757  return 1;
758 }
759 
760 struct ast_frame *ast_udptl_read(struct ast_udptl *udptl)
761 {
762  int res;
763  struct ast_sockaddr addr;
764  uint8_t *buf;
765 
766  buf = udptl->rawdata + AST_FRIENDLY_OFFSET;
767 
768  /* Cache where the header will go */
769  res = ast_recvfrom(udptl->fd,
770  buf,
771  sizeof(udptl->rawdata) - AST_FRIENDLY_OFFSET,
772  0,
773  &addr);
774  if (res < 0) {
775  if (errno != EAGAIN)
776  ast_log(LOG_WARNING, "UDPTL (%s): read error: %s\n",
777  LOG_TAG(udptl), strerror(errno));
778  ast_assert(errno != EBADF);
779  return &ast_null_frame;
780  }
781 
782  /* Ignore if the other side hasn't been given an address yet. */
783  if (ast_sockaddr_isnull(&udptl->them)) {
784  return &ast_null_frame;
785  }
786 
787  /*
788  * If early media isn't turned on for the channel driver, it's going to
789  * drop this frame. By that time though, udptl has already incremented
790  * the expected sequence number so if the CPE re-sends, the second frame
791  * will be dropped as a dup even though the first frame never went through.
792  * So we drop the frame here if the channel isn't up. 'tag' is set by the
793  * channel drivers on T38_ENABLED or T38_PEER_REINVITE.
794  */
795  if (udptl->tag == NULL) {
796  return &ast_null_frame;
797  }
798 
799  if (udptl->nat) {
800  /* Send to whoever sent to us */
801  if (ast_sockaddr_cmp(&udptl->them, &addr)) {
802  ast_sockaddr_copy(&udptl->them, &addr);
803  ast_debug(1, "UDPTL (%s): NAT, Using address %s\n",
804  LOG_TAG(udptl), ast_sockaddr_stringify(&udptl->them));
805  }
806  }
807 
808  if (udptl_debug_test_addr(&addr)) {
809  int seq_no;
810 
811  /* Decode sequence number just for verbose message. */
812  if (res < 2) {
813  /* Short packet. */
814  seq_no = -1;
815  } else {
816  seq_no = (buf[0] << 8) | buf[1];
817  }
818 
819  ast_verb(1, "UDPTL (%s): packet from %s (seq %d, len %d)\n",
820  LOG_TAG(udptl), ast_sockaddr_stringify(&addr), seq_no, res);
821  }
822  if (udptl_rx_packet(udptl, buf, res) < 1) {
823  return &ast_null_frame;
824  }
825 
826  return &udptl->f[0];
827 }
828 
829 static void calculate_local_max_datagram(struct ast_udptl *udptl)
830 {
831  unsigned int new_max = 0;
832 
833  if (udptl->local_max_ifp == -1) {
834  ast_log(LOG_WARNING, "UDPTL (%s): Cannot calculate local_max_datagram before local_max_ifp has been set.\n",
835  LOG_TAG(udptl));
836  udptl->local_max_datagram = -1;
837  return;
838  }
839 
840  /* calculate the amount of space required to receive an IFP
841  * of the maximum size supported by the application/endpoint
842  * that we are delivering them to (local endpoint), and add
843  * the amount of space required to support the selected
844  * error correction mode
845  */
846  switch (udptl->error_correction_scheme) {
847  case UDPTL_ERROR_CORRECTION_NONE:
848  /* need room for sequence number, length indicator, redundancy
849  * indicator and following length indicator
850  */
851  new_max = 5 + udptl->local_max_ifp;
852  break;
853  case UDPTL_ERROR_CORRECTION_REDUNDANCY:
854  /* need room for sequence number, length indicators, plus
855  * room for up to 3 redundancy packets
856  */
857  new_max = 5 + udptl->local_max_ifp + 2 + (3 * udptl->local_max_ifp);
858  break;
859  case UDPTL_ERROR_CORRECTION_FEC:
860  /* need room for sequence number, length indicators and a
861  * a single IFP of the maximum size expected
862  */
863  new_max = 5 + udptl->local_max_ifp + 4 + udptl->local_max_ifp;
864  break;
865  }
866  /* add 5% extra space for insurance, but no larger than LOCAL_FAX_MAX_DATAGRAM */
867  udptl->local_max_datagram = MIN(new_max * 1.05, LOCAL_FAX_MAX_DATAGRAM);
868 }
869 
870 static void calculate_far_max_ifp(struct ast_udptl *udptl)
871 {
872  unsigned new_max = 0;
873 
874  if (udptl->far_max_datagram == -1) {
875  ast_log(LOG_WARNING, "UDPTL (%s): Cannot calculate far_max_ifp before far_max_datagram has been set.\n",
876  LOG_TAG(udptl));
877  udptl->far_max_ifp = -1;
878  return;
879  }
880 
881  /* the goal here is to supply the local endpoint (application
882  * or bridged channel) a maximum IFP value that will allow it
883  * to effectively and efficiently transfer image data at its
884  * selected bit rate, taking into account the selected error
885  * correction mode, but without overrunning the far endpoint's
886  * datagram buffer. this is complicated by the fact that some
887  * far endpoints send us bogus (small) max datagram values,
888  * which would result in either buffer overrun or no error
889  * correction. we try to accomodate those, but if the supplied
890  * value is too small to do so, we'll emit warning messages and
891  * the user will have to use configuration options to override
892  * the max datagram value supplied by the far endpoint.
893  */
894  switch (udptl->error_correction_scheme) {
895  case UDPTL_ERROR_CORRECTION_NONE:
896  /* need room for sequence number, length indicator, redundancy
897  * indicator and following length indicator
898  */
899  new_max = udptl->far_max_datagram - 5;
900  break;
901  case UDPTL_ERROR_CORRECTION_REDUNDANCY:
902  /* for this case, we'd like to send as many error correction entries
903  * as possible (up to the number we're configured for), but we'll settle
904  * for sending fewer if the configured number would cause the
905  * calculated max IFP to be too small for effective operation
906  *
907  * need room for sequence number, length indicators and the
908  * configured number of redundant packets
909  *
910  * note: we purposely don't allow error_correction_entries to drop to
911  * zero in this loop; we'd rather send smaller IFPs (and thus reduce
912  * the image data transfer rate) than sacrifice redundancy completely
913  */
914  for (;;) {
915  new_max = (udptl->far_max_datagram - 8) / (udptl->error_correction_entries + 1);
916 
917  if ((new_max < 80) && (udptl->error_correction_entries > 1)) {
918  /* the max ifp is not large enough, subtract an
919  * error correction entry and calculate again
920  * */
921  --udptl->error_correction_entries;
922  } else {
923  break;
924  }
925  }
926  break;
927  case UDPTL_ERROR_CORRECTION_FEC:
928  /* need room for sequence number, length indicators and a
929  * a single IFP of the maximum size expected
930  */
931  new_max = (udptl->far_max_datagram - 10) / 2;
932  break;
933  }
934  /* subtract 5% of space for insurance */
935  udptl->far_max_ifp = new_max * 0.95;
936 }
937 
938 enum ast_t38_ec_modes ast_udptl_get_error_correction_scheme(const struct ast_udptl *udptl)
939 {
940  return udptl->error_correction_scheme;
941 }
942 
943 void ast_udptl_set_error_correction_scheme(struct ast_udptl *udptl, enum ast_t38_ec_modes ec)
944 {
945  udptl->error_correction_scheme = ec;
946  switch (ec) {
947  case UDPTL_ERROR_CORRECTION_FEC:
948  udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
949  if (udptl->error_correction_entries == 0) {
950  udptl->error_correction_entries = 3;
951  }
952  if (udptl->error_correction_span == 0) {
953  udptl->error_correction_span = 3;
954  }
955  break;
956  case UDPTL_ERROR_CORRECTION_REDUNDANCY:
957  udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
958  if (udptl->error_correction_entries == 0) {
959  udptl->error_correction_entries = 3;
960  }
961  break;
962  default:
963  /* nothing to do */
964  break;
965  };
966  /* reset calculated values so they'll be computed again */
967  udptl->local_max_datagram = -1;
968  udptl->far_max_ifp = -1;
969 }
970 
971 void ast_udptl_set_local_max_ifp(struct ast_udptl *udptl, unsigned int max_ifp)
972 {
973  /* make sure max_ifp is a positive value since a cast will take place when
974  * when setting local_max_ifp */
975  if ((signed int) max_ifp > 0) {
976  udptl->local_max_ifp = max_ifp;
977  /* reset calculated values so they'll be computed again */
978  udptl->local_max_datagram = -1;
979  }
980 }
981 
982 unsigned int ast_udptl_get_local_max_datagram(struct ast_udptl *udptl)
983 {
984  if (udptl->local_max_datagram == -1) {
985  calculate_local_max_datagram(udptl);
986  }
987 
988  /* this function expects a unsigned value in return. */
989  if (udptl->local_max_datagram < 0) {
990  return 0;
991  }
992  return udptl->local_max_datagram;
993 }
994 
995 void ast_udptl_set_far_max_datagram(struct ast_udptl *udptl, unsigned int max_datagram)
996 {
997  if (!max_datagram || (max_datagram > FAX_MAX_DATAGRAM_LIMIT)) {
998  udptl->far_max_datagram = DEFAULT_FAX_MAX_DATAGRAM;
999  } else {
1000  udptl->far_max_datagram = max_datagram;
1001  }
1002  /* reset calculated values so they'll be computed again */
1003  udptl->far_max_ifp = -1;
1004 }
1005 
1006 unsigned int ast_udptl_get_far_max_datagram(const struct ast_udptl *udptl)
1007 {
1008  if (udptl->far_max_datagram < 0) {
1009  return 0;
1010  }
1011  return udptl->far_max_datagram;
1012 }
1013 
1014 unsigned int ast_udptl_get_far_max_ifp(struct ast_udptl *udptl)
1015 {
1016  if (udptl->far_max_ifp == -1) {
1017  calculate_far_max_ifp(udptl);
1018  }
1019 
1020  if (udptl->far_max_ifp < 0) {
1021  return 0;
1022  }
1023  return udptl->far_max_ifp;
1024 }
1025 
1026 struct ast_udptl *ast_udptl_new_with_bindaddr(struct ast_sched_context *sched, struct io_context *io, int callbackmode, struct ast_sockaddr *addr)
1027 {
1028  struct ast_udptl *udptl;
1029  int x;
1030  int startplace;
1031  int i;
1032  RAII_VAR(struct udptl_config *, cfg, ao2_global_obj_ref(globals), ao2_cleanup);
1033 
1034  if (!cfg || !cfg->general) {
1035  ast_log(LOG_ERROR, "Could not access global udptl options!\n");
1036  return NULL;
1037  }
1038 
1039  if (!(udptl = ast_calloc(1, sizeof(*udptl)))) {
1040  return NULL;
1041  }
1042 
1043  udptl->error_correction_span = cfg->general->fecspan;
1044  udptl->error_correction_entries = cfg->general->fecentries;
1045 
1046  udptl->far_max_datagram = -1;
1047  udptl->far_max_ifp = -1;
1048  udptl->local_max_ifp = -1;
1049  udptl->local_max_datagram = -1;
1050 
1051  for (i = 0; i <= UDPTL_BUF_MASK; i++) {
1052  udptl->rx[i].buf_len = -1;
1053  udptl->tx[i].buf_len = -1;
1054  }
1055 
1056  if ((udptl->fd = ast_socket_nonblock(ast_sockaddr_is_ipv6(addr) ?
1057  AF_INET6 : AF_INET, SOCK_DGRAM, 0)) < 0) {
1058  ast_free(udptl);
1059  ast_log(LOG_WARNING, "Unable to allocate socket: %s\n", strerror(errno));
1060  return NULL;
1061  }
1062 
1063 #ifdef SO_NO_CHECK
1064  if (cfg->general->nochecksums)
1065  setsockopt(udptl->fd, SOL_SOCKET, SO_NO_CHECK, &cfg->general->nochecksums, sizeof(cfg->general->nochecksums));
1066 #endif
1067 
1068  /* Find us a place */
1069  x = (cfg->general->start == cfg->general->end) ? cfg->general->start : (ast_random() % (cfg->general->end - cfg->general->start)) + cfg->general->start;
1070  if (cfg->general->use_even_ports && (x & 1)) {
1071  ++x;
1072  }
1073  startplace = x;
1074  for (;;) {
1075  ast_sockaddr_copy(&udptl->us, addr);
1076  ast_sockaddr_set_port(&udptl->us, x);
1077  if (ast_bind(udptl->fd, &udptl->us) == 0) {
1078  break;
1079  }
1080  if (errno != EADDRINUSE && errno != EACCES) {
1081  ast_log(LOG_WARNING, "Unexpected bind error: %s\n", strerror(errno));
1082  close(udptl->fd);
1083  ast_free(udptl);
1084  return NULL;
1085  }
1086  if (cfg->general->use_even_ports) {
1087  x += 2;
1088  } else {
1089  ++x;
1090  }
1091  if (x > cfg->general->end)
1092  x = cfg->general->start;
1093  if (x == startplace) {
1094  ast_log(LOG_WARNING, "No UDPTL ports remaining\n");
1095  close(udptl->fd);
1096  ast_free(udptl);
1097  return NULL;
1098  }
1099  }
1100  if (io && sched && callbackmode) {
1101  /* Operate this one in a callback mode */
1102  udptl->sched = sched;
1103  udptl->io = io;
1104  udptl->ioid = ast_io_add(udptl->io, udptl->fd, udptlread, AST_IO_IN, udptl);
1105  }
1106 
1107  return udptl;
1108 }
1109 
1110 void ast_udptl_set_tag(struct ast_udptl *udptl, const char *format, ...)
1111 {
1112  va_list ap;
1113 
1114  ast_free(udptl->tag);
1115  udptl->tag = NULL;
1116  va_start(ap, format);
1117  if (ast_vasprintf(&udptl->tag, format, ap) == -1) {
1118  udptl->tag = NULL;
1119  }
1120  va_end(ap);
1121 }
1122 
1123 int ast_udptl_setqos(struct ast_udptl *udptl, unsigned int tos, unsigned int cos)
1124 {
1125  return ast_set_qos(udptl->fd, tos, cos, "UDPTL");
1126 }
1127 
1128 void ast_udptl_set_peer(struct ast_udptl *udptl, const struct ast_sockaddr *them)
1129 {
1130  ast_sockaddr_copy(&udptl->them, them);
1131 }
1132 
1133 void ast_udptl_get_peer(const struct ast_udptl *udptl, struct ast_sockaddr *them)
1134 {
1135  ast_sockaddr_copy(them, &udptl->them);
1136 }
1137 
1138 void ast_udptl_get_us(const struct ast_udptl *udptl, struct ast_sockaddr *us)
1139 {
1140  ast_sockaddr_copy(us, &udptl->us);
1141 }
1142 
1143 void ast_udptl_stop(struct ast_udptl *udptl)
1144 {
1145  ast_sockaddr_setnull(&udptl->them);
1146 }
1147 
1148 void ast_udptl_destroy(struct ast_udptl *udptl)
1149 {
1150  if (udptl->ioid)
1151  ast_io_remove(udptl->io, udptl->ioid);
1152  if (udptl->fd > -1)
1153  close(udptl->fd);
1154  if (udptl->tag)
1155  ast_free(udptl->tag);
1156  ast_free(udptl);
1157 }
1158 
1159 int ast_udptl_write(struct ast_udptl *s, struct ast_frame *f)
1160 {
1161  unsigned int seq;
1162  unsigned int len = f->datalen;
1163  /* if no max datagram size is provided, use default value */
1164  const int bufsize = (s->far_max_datagram > 0) ? s->far_max_datagram : DEFAULT_FAX_MAX_DATAGRAM;
1165  uint8_t buf[bufsize];
1166 
1167  memset(buf, 0, sizeof(buf));
1168 
1169  /* If we have no peer, return immediately */
1170  if (ast_sockaddr_isnull(&s->them)) {
1171  return 0;
1172  }
1173 
1174  /* If there is no data length, return immediately */
1175  if (f->datalen == 0)
1176  return 0;
1177 
1178  if ((f->frametype != AST_FRAME_MODEM) ||
1179  (f->subclass.integer != AST_MODEM_T38)) {
1180  ast_log(LOG_WARNING, "UDPTL (%s): UDPTL can only send T.38 data.\n",
1181  LOG_TAG(s));
1182  return -1;
1183  }
1184 
1185  if (len > s->far_max_ifp) {
1186  ast_log(LOG_WARNING,
1187  "UDPTL (%s): UDPTL asked to send %u bytes of IFP when far end only prepared to accept %d bytes; data loss will occur."
1188  "You may need to override the T38FaxMaxDatagram value for this endpoint in the channel driver configuration.\n",
1189  LOG_TAG(s), len, s->far_max_ifp);
1190  len = s->far_max_ifp;
1191  }
1192 
1193  /* Save seq_no for debug output because udptl_build_packet increments it */
1194  seq = s->tx_seq_no & 0xFFFF;
1195 
1196  /* Cook up the UDPTL packet, with the relevant EC info. */
1197  len = udptl_build_packet(s, buf, sizeof(buf), f->data.ptr, len);
1198 
1199  if ((signed int) len > 0 && !ast_sockaddr_isnull(&s->them)) {
1200  if (ast_sendto(s->fd, buf, len, 0, &s->them) < 0) {
1201  ast_log(LOG_NOTICE, "UDPTL (%s): Transmission error to %s: %s\n",
1202  LOG_TAG(s), ast_sockaddr_stringify(&s->them), strerror(errno));
1203  }
1204  if (udptl_debug_test_addr(&s->them)) {
1205  ast_verb(1, "UDPTL (%s): packet to %s (seq %u, len %u)\n",
1206  LOG_TAG(s), ast_sockaddr_stringify(&s->them), seq, len);
1207  }
1208  }
1209 
1210  return 0;
1211 }
1212 
1213 static char *handle_cli_udptl_set_debug(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
1214 {
1215  switch (cmd) {
1216  case CLI_INIT:
1217  e->command = "udptl set debug {on|off|ip}";
1218  e->usage =
1219  "Usage: udptl set debug {on|off|ip host[:port]}\n"
1220  " Enable or disable dumping of UDPTL packets.\n"
1221  " If ip is specified, limit the dumped packets to those to and from\n"
1222  " the specified 'host' with optional port.\n";
1223  return NULL;
1224  case CLI_GENERATE:
1225  return NULL;
1226  }
1227 
1228  if (a->argc < 4 || a->argc > 5)
1229  return CLI_SHOWUSAGE;
1230 
1231  if (a->argc == 4) {
1232  if (!strncasecmp(a->argv[3], "on", 2)) {
1233  udptldebug = 1;
1234  memset(&udptldebugaddr, 0, sizeof(udptldebugaddr));
1235  ast_cli(a->fd, "UDPTL Debugging Enabled\n");
1236  } else if (!strncasecmp(a->argv[3], "off", 3)) {
1237  udptldebug = 0;
1238  ast_cli(a->fd, "UDPTL Debugging Disabled\n");
1239  } else {
1240  return CLI_SHOWUSAGE;
1241  }
1242  } else {
1243  struct ast_sockaddr *addrs;
1244  if (strncasecmp(a->argv[3], "ip", 2))
1245  return CLI_SHOWUSAGE;
1246  if (!ast_sockaddr_resolve(&addrs, a->argv[4], 0, 0)) {
1247  return CLI_SHOWUSAGE;
1248  }
1249  ast_sockaddr_copy(&udptldebugaddr, &addrs[0]);
1250  ast_cli(a->fd, "UDPTL Debugging Enabled for IP: %s\n", ast_sockaddr_stringify(&udptldebugaddr));
1251  udptldebug = 1;
1252  ast_free(addrs);
1253  }
1254 
1255  return CLI_SUCCESS;
1256 }
1257 
1258 static char *handle_cli_show_config(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
1259 {
1260  RAII_VAR(struct udptl_config *, cfg, NULL, ao2_cleanup);
1261 
1262  switch (cmd) {
1263  case CLI_INIT:
1264  e->command = "udptl show config";
1265  e->usage =
1266  "Usage: udptl show config\n"
1267  " Display UDPTL configuration options\n";
1268  return NULL;
1269  case CLI_GENERATE:
1270  return NULL;
1271  }
1272 
1273  if (!(cfg = ao2_global_obj_ref(globals))) {
1274  return CLI_FAILURE;
1275  }
1276 
1277  ast_cli(a->fd, "UDPTL Global options\n");
1278  ast_cli(a->fd, "--------------------\n");
1279  ast_cli(a->fd, "udptlstart: %u\n", cfg->general->start);
1280  ast_cli(a->fd, "udptlend: %u\n", cfg->general->end);
1281  ast_cli(a->fd, "udptlfecentries: %u\n", cfg->general->fecentries);
1282  ast_cli(a->fd, "udptlfecspan: %u\n", cfg->general->fecspan);
1283  ast_cli(a->fd, "use_even_ports: %s\n", AST_CLI_YESNO(cfg->general->use_even_ports));
1284  ast_cli(a->fd, "udptlchecksums: %s\n", AST_CLI_YESNO(!cfg->general->nochecksums));
1285 
1286  return CLI_SUCCESS;
1287 }
1288 
1289 static struct ast_cli_entry cli_udptl[] = {
1290  AST_CLI_DEFINE(handle_cli_udptl_set_debug, "Enable/Disable UDPTL debugging"),
1291  AST_CLI_DEFINE(handle_cli_show_config, "Show UDPTL config options"),
1292 };
1293 
1294 static void udptl_config_destructor(void *obj)
1295 {
1296  struct udptl_config *cfg = obj;
1297  ao2_cleanup(cfg->general);
1298 }
1299 
1300 static void *udptl_snapshot_alloc(void)
1301 {
1302  struct udptl_config *cfg;
1303 
1304  if (!(cfg = ao2_alloc(sizeof(*cfg), udptl_config_destructor))) {
1305  return NULL;
1306  }
1307  if (!(cfg->general = ao2_alloc(sizeof(*cfg->general), NULL))) {
1308  ao2_ref(cfg, -1);
1309  return NULL;
1310  }
1311 
1312  return cfg;
1313 }
1314 
1315 static int removed_options_handler(const struct aco_option *opt, struct ast_variable *var, void *obj)
1316 {
1317  if (!strcasecmp(var->name, "t38faxudpec")) {
1318  ast_log(LOG_WARNING, "t38faxudpec in udptl.conf is no longer supported.\n");
1319  } else if (!strcasecmp(var->name, "t38faxmaxdatagram")) {
1320  ast_log(LOG_WARNING, "t38faxmaxdatagram in udptl.conf is no longer supported; value is now supplied by T.38 applications.\n");
1321  }
1322  return 0;
1323 }
1324 
1325 static void __ast_udptl_reload(int reload)
1326 {
1327  if (aco_process_config(&cfg_info, reload) == ACO_PROCESS_ERROR) {
1328  if (!reload) {
1329  RAII_VAR(struct udptl_config *, udptl_cfg, udptl_snapshot_alloc(), ao2_cleanup);
1330 
1331  if (aco_set_defaults(&general_option, "general", udptl_cfg->general)) {
1332  ast_log(LOG_ERROR, "Failed to load udptl.conf and failed to initialize defaults.\n");
1333  return;
1334  }
1335 
1336  ast_log(LOG_NOTICE, "Could not load udptl config; using defaults\n");
1337  ao2_global_obj_replace_unref(globals, udptl_cfg);
1338  }
1339  }
1340 }
1341 
1342 static int udptl_pre_apply_config(void) {
1343  struct udptl_config *cfg = aco_pending_config(&cfg_info);
1344 
1345  if (!cfg->general) {
1346  return -1;
1347  }
1348 
1349 #ifndef SO_NO_CHECK
1350  if (cfg->general->nochecksums) {
1351  ast_log(LOG_WARNING, "Disabling UDPTL checksums is not supported on this operating system!\n");
1352  cfg->general->nochecksums = 0;
1353  }
1354 #endif
1355 
1356  /* Fix up any global config values that we can handle before replacing the config */
1357  if (cfg->general->use_even_ports && (cfg->general->start & 1)) {
1358  ++cfg->general->start;
1359  ast_log(LOG_NOTICE, "Odd numbered udptlstart specified but use_even_ports enabled. udptlstart is now %u\n", cfg->general->start);
1360  }
1361  if (cfg->general->start > cfg->general->end) {
1362  ast_log(LOG_WARNING, "Unreasonable values for UDPTL start/end ports; defaulting to %s-%s.\n", __stringify(DEFAULT_UDPTLSTART), __stringify(DEFAULT_UDPTLEND));
1363  cfg->general->start = DEFAULT_UDPTLSTART;
1364  cfg->general->end = DEFAULT_UDPTLEND;
1365  }
1366  if (cfg->general->use_even_ports && (cfg->general->end & 1)) {
1367  --cfg->general->end;
1368  ast_log(LOG_NOTICE, "Odd numbered udptlend specified but use_even_ports enabled. udptlend is now %u\n", cfg->general->end);
1369  }
1370 
1371  return 0;
1372 }
1373 
1374 static int reload_module(void)
1375 {
1376  __ast_udptl_reload(1);
1377 
1378  return 0;
1379 }
1380 
1381 /*!
1382  * \internal
1383  * \brief Clean up resources on Asterisk shutdown
1384  */
1385 static int unload_module(void)
1386 {
1387  ast_cli_unregister_multiple(cli_udptl, ARRAY_LEN(cli_udptl));
1388  ao2_t_global_obj_release(globals, "Unref udptl global container in shutdown");
1389  aco_info_destroy(&cfg_info);
1390 
1391  return 0;
1392 }
1393 
1394 static int load_module(void)
1395 {
1396  if (aco_info_init(&cfg_info)) {
1397  return AST_MODULE_LOAD_FAILURE;
1398  }
1399 
1400  aco_option_register(&cfg_info, "udptlstart", ACO_EXACT, general_options, __stringify(DEFAULT_UDPTLSTART),
1401  OPT_UINT_T, PARSE_IN_RANGE | PARSE_DEFAULT,
1402  FLDSET(struct udptl_global_options, start), DEFAULT_UDPTLSTART, 1024, 65535);
1403 
1404  aco_option_register(&cfg_info, "udptlend", ACO_EXACT, general_options, __stringify(DEFAULT_UDPTLEND),
1405  OPT_UINT_T, PARSE_IN_RANGE | PARSE_DEFAULT,
1406  FLDSET(struct udptl_global_options, end), DEFAULT_UDPTLEND, 1024, 65535);
1407 
1408  aco_option_register(&cfg_info, "udptlfecentries", ACO_EXACT, general_options, NULL,
1409  OPT_UINT_T, PARSE_IN_RANGE | PARSE_RANGE_DEFAULTS,
1410  FLDSET(struct udptl_global_options, fecentries), 1, MAX_FEC_ENTRIES);
1411 
1412  aco_option_register(&cfg_info, "udptlfecspan", ACO_EXACT, general_options, NULL,
1413  OPT_UINT_T, PARSE_IN_RANGE | PARSE_RANGE_DEFAULTS,
1414  FLDSET(struct udptl_global_options, fecspan), 1, MAX_FEC_SPAN);
1415 
1416  aco_option_register(&cfg_info, "udptlchecksums", ACO_EXACT, general_options, "yes",
1417  OPT_BOOL_T, 0, FLDSET(struct udptl_global_options, nochecksums));
1418 
1419  aco_option_register(&cfg_info, "use_even_ports", ACO_EXACT, general_options, "no",
1420  OPT_BOOL_T, 1, FLDSET(struct udptl_global_options, use_even_ports));
1421 
1422  aco_option_register_custom(&cfg_info, "t38faxudpec", ACO_EXACT, general_options, NULL, removed_options_handler, 0);
1423  aco_option_register_custom(&cfg_info, "t38faxmaxdatagram", ACO_EXACT, general_options, NULL, removed_options_handler, 0);
1424 
1425  __ast_udptl_reload(0);
1426 
1427  ast_cli_register_multiple(cli_udptl, ARRAY_LEN(cli_udptl));
1428 
1429  return AST_MODULE_LOAD_SUCCESS;
1430 }
1431 
1432 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "UDPTL",
1433  .support_level = AST_MODULE_SUPPORT_CORE,
1434  .load = load_module,
1435  .unload = unload_module,
1436  .reload = reload_module,
1437  .load_pri = AST_MODPRI_CORE,
1438  .requires = "extconfig",
1439 );
ssize_t ast_sendto(int sockfd, const void *buf, size_t len, int flags, const struct ast_sockaddr *dest_addr)
Wrapper around sendto(2) that uses ast_sockaddr.
Definition: netsock2.c:614
Asterisk locking-related definitions:
Asterisk main include file. File version handling, generic pbx functions.
unsigned int error_correction_span
Definition: udptl.c:184
#define aco_option_register_custom(info, name, matchtype, types, default_val, handler, flags)
Register a config option.
int ast_cli_unregister_multiple(struct ast_cli_entry *e, int len)
Unregister multiple commands.
Definition: clicompat.c:30
int local_max_datagram
Definition: udptl.c:195
static struct ast_sockaddr udptldebugaddr
Definition: udptl.c:129
static void ast_sockaddr_copy(struct ast_sockaddr *dst, const struct ast_sockaddr *src)
Copies the data from one ast_sockaddr to another.
Definition: netsock2.h:167
descriptor for a cli entry.
Definition: cli.h:171
#define ast_socket_nonblock(domain, type, protocol)
Create a non-blocking socket.
Definition: utils.h:1073
#define aco_option_register(info, name, matchtype, types, default_val, opt_type, flags,...)
Register a config option.
Structure for variables, used for configurations and for channel variables.
UDPTL support for T.38.
#define AST_LIST_NEXT(elm, field)
Returns the next entry in the list after the given entry.
Definition: linkedlists.h:439
#define AST_IO_IN
Definition: io.h:34
Definition: sched.c:76
Structure for an UDPTL session.
Definition: udptl.c:154
int * ast_io_add(struct io_context *ioc, int fd, ast_io_cb callback, short events, void *data)
Adds an IO context.
Definition: io.c:162
#define ast_cli_register_multiple(e, len)
Register multiple commands.
Definition: cli.h:265
enum aco_process_status aco_process_config(struct aco_info *info, int reload)
Process a config info via the options registered with an aco_info.
#define ao2_global_obj_ref(holder)
Get a reference to the object stored in the global holder.
Definition: astobj2.h:918
CONFIG_INFO_CORE("stasis", cfg_info, globals, stasis_config_alloc,.files=ACO_FILES(&stasis_conf),)
Register information about the configs being processed by this module.
#define ast_vasprintf(ret, fmt, ap)
A wrapper for vasprintf()
Definition: astmm.h:278
unsigned int error_correction_entries
Definition: udptl.c:179
int ast_sockaddr_cmp(const struct ast_sockaddr *a, const struct ast_sockaddr *b)
Compares two ast_sockaddr structures.
Definition: netsock2.c:388
The representation of a single configuration file to be processed.
enum aco_type_t type
Socket address structure.
Definition: netsock2.h:97
#define ACO_TYPES(...)
A helper macro to ensure that aco_info types always have a sentinel.
int ast_bind(int sockfd, const struct ast_sockaddr *addr)
Wrapper around bind(2) that uses struct ast_sockaddr.
Definition: netsock2.c:590
int ast_sockaddr_cmp_addr(const struct ast_sockaddr *a, const struct ast_sockaddr *b)
Compares the addresses of two ast_sockaddr structures.
Definition: netsock2.c:413
struct ast_frame_subclass subclass
Utility functions.
static void ast_sockaddr_setnull(struct ast_sockaddr *addr)
Sets address addr to null.
Definition: netsock2.h:138
static int ast_sockaddr_isnull(const struct ast_sockaddr *addr)
Checks if the ast_sockaddr is null. "null" in this sense essentially means uninitialized, or having a 0 length.
Definition: netsock2.h:127
#define ast_sockaddr_port(addr)
Get the port number of a socket address.
Definition: netsock2.h:517
Handle unaligned data access.
#define FLDSET(type,...)
Convert a struct and list of fields to an argument list of field offsets.
int aco_info_init(struct aco_info *info)
Initialize an aco_info structure.
General Asterisk PBX channel definitions.
#define AST_FRIENDLY_OFFSET
Offset into a frame's data buffer.
const char * src
void * aco_pending_config(struct aco_info *info)
Get pending config changes.
Type for default option handler for unsigned integers.
int far_max_datagram
Definition: udptl.c:189
Access Control of various sorts.
#define ao2_ref(o, delta)
Reference/unreference an object and return the old refcount.
Definition: astobj2.h:459
Global IO variables are now in a struct in order to be made threadsafe.
Definition: io.c:71
Asterisk internal frame definitions.
static struct stasis_rest_handlers events
REST handler for /api-docs/events.json.
#define ast_debug(level,...)
Log a DEBUG message.
Network socket handling.
Their was an error and no changes were applied.
Configuration option-handling.
#define ast_sockaddr_set_port(addr, port)
Sets the port number of a socket address.
Definition: netsock2.h:532
void ast_udptl_set_tag(struct ast_udptl *udptl, const char *format,...)
Associates a character string 'tag' with a UDPTL session.
Definition: udptl.c:1110
void aco_info_destroy(struct aco_info *info)
Destroy an initialized aco_info struct.
Type for default option handler for bools (ast_true/ast_false)
int ast_set_qos(int sockfd, int tos, int cos, const char *desc)
Set type of service.
Definition: netsock2.c:621
static char * ast_sockaddr_stringify(const struct ast_sockaddr *addr)
Wrapper around ast_sockaddr_stringify_fmt() with default format.
Definition: netsock2.h:256
unsigned int ast_udptl_get_local_max_datagram(struct ast_udptl *udptl)
retrieves local_max_datagram.
Definition: udptl.c:982
ssize_t ast_recvfrom(int sockfd, void *buf, size_t len, int flags, struct ast_sockaddr *src_addr)
Wrapper around recvfrom(2) that uses struct ast_sockaddr.
Definition: netsock2.c:606
union ast_frame::@224 data
char * command
Definition: cli.h:186
#define ast_calloc(num, len)
A wrapper for calloc()
Definition: astmm.h:202
void ast_udptl_set_far_max_datagram(struct ast_udptl *udptl, unsigned int max_datagram)
sets far max datagram size. If max_datagram is = 0, the far max datagram size is set to a default val...
Definition: udptl.c:995
int aco_set_defaults(struct aco_type *type, const char *category, void *obj)
Set all default options of obj.
unsigned int flags
Module could not be loaded properly.
Definition: module.h:102
int far_max_ifp
Definition: udptl.c:203
int ast_io_remove(struct io_context *ioc, int *id)
Removes an IO context.
Definition: io.c:245
const char * usage
Definition: cli.h:177
struct ast_frame ast_null_frame
Definition: main/frame.c:79
#define ao2_global_obj_replace_unref(holder, obj)
Replace an ao2 object in the global holder, throwing away any old object.
Definition: astobj2.h:901
Standard Command Line Interface.
Type information about a category-level configurable object.
const char * filename
int local_max_ifp
Definition: udptl.c:209
#define AST_MODEM_T38
Data structure associated with a single frame of data.
Definition: search.h:40
enum ast_frame_type frametype
#define AST_CLI_YESNO(x)
Return Yes or No depending on the argument.
Definition: cli.h:71
#define AO2_GLOBAL_OBJ_STATIC(name)
Define a global object holder to be used to hold an ao2 object, statically initialized.
Definition: astobj2.h:847
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:46
Asterisk module definitions.
#define RAII_VAR(vartype, varname, initval, dtor)
Declare a variable that will call a destructor function when it goes out of scope.
Definition: utils.h:941
int ast_sockaddr_is_ipv6(const struct ast_sockaddr *addr)
Determine if this is an IPv6 address.
Definition: netsock2.c:524
enum ast_t38_ec_modes error_correction_scheme
Definition: udptl.c:174
unsigned int ast_udptl_get_far_max_ifp(struct ast_udptl *udptl)
retrieves far max ifp
Definition: udptl.c:1014
int ast_sockaddr_resolve(struct ast_sockaddr **addrs, const char *str, int flags, int family)
Parses a string with an IPv4 or IPv6 address and place results into an array.
Definition: netsock2.c:280
static int udptldebug
Definition: udptl.c:128