udptl.c File Reference

UDPTL support for T.38 faxing. More...

#include "asterisk.h"
#include <sys/time.h>
#include <signal.h>
#include <fcntl.h>
#include "asterisk/module.h"
#include "asterisk/udptl.h"
#include "asterisk/frame.h"
#include "asterisk/channel.h"
#include "asterisk/acl.h"
#include "asterisk/config_options.h"
#include "asterisk/lock.h"
#include "asterisk/utils.h"
#include "asterisk/netsock2.h"
#include "asterisk/cli.h"
#include "asterisk/unaligned.h"

Include dependency graph for udptl.c:

Go to the source code of this file.

Data Structures
struct	ast_udptl
	Structure for an UDPTL session. More...
struct	udptl_config
struct	udptl_fec_rx_buffer_t
struct	udptl_fec_tx_buffer_t
struct	udptl_global_options

Macros
#define	DEFAULT_FAX_MAX_DATAGRAM   400
#define	DEFAULT_UDPTLEND   4999
#define	DEFAULT_UDPTLSTART   4000
#define	FALSE   0
#define	FAX_MAX_DATAGRAM_LIMIT   1400
#define	LOCAL_FAX_MAX_DATAGRAM   1400
#define	LOG_TAG(u)   S_OR(u->tag, "no tag")
#define	MAX_FEC_ENTRIES   5
#define	MAX_FEC_SPAN   5
#define	TRUE   (!FALSE)
#define	UDPTL_BUF_MASK   15
#define	UDPTL_MTU   1200

Functions
static void	__ast_udptl_reload (int reload)
static void	__reg_module (void)
static void	__unreg_module (void)
static	AO2_GLOBAL_OBJ_STATIC (globals)
struct ast_module *	AST_MODULE_SELF_SYM (void)
void	ast_udptl_destroy (struct ast_udptl *udptl)
int	ast_udptl_fd (const struct ast_udptl *udptl)
enum ast_t38_ec_modes	ast_udptl_get_error_correction_scheme (const struct ast_udptl *udptl)
unsigned int	ast_udptl_get_far_max_datagram (const struct ast_udptl *udptl)
unsigned int	ast_udptl_get_far_max_ifp (struct ast_udptl *udptl)
	retrieves far max ifp More...
unsigned int	ast_udptl_get_local_max_datagram (struct ast_udptl *udptl)
	retrieves local_max_datagram. More...
void	ast_udptl_get_peer (const struct ast_udptl *udptl, struct ast_sockaddr *them)
void	ast_udptl_get_us (const struct ast_udptl *udptl, struct ast_sockaddr *us)
struct ast_udptl *	ast_udptl_new_with_bindaddr (struct ast_sched_context *sched, struct io_context *io, int callbackmode, struct ast_sockaddr *addr)
struct ast_frame *	ast_udptl_read (struct ast_udptl *udptl)
void	ast_udptl_set_callback (struct ast_udptl *udptl, ast_udptl_callback callback)
void	ast_udptl_set_data (struct ast_udptl *udptl, void *data)
void	ast_udptl_set_error_correction_scheme (struct ast_udptl *udptl, enum ast_t38_ec_modes ec)
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 value. More...
void	ast_udptl_set_local_max_ifp (struct ast_udptl *udptl, unsigned int max_ifp)
void	ast_udptl_set_peer (struct ast_udptl *udptl, const struct ast_sockaddr *them)
void	ast_udptl_set_tag (struct ast_udptl *udptl, const char *format,...)
	Associates a character string 'tag' with a UDPTL session. More...
void	ast_udptl_setnat (struct ast_udptl *udptl, int nat)
int	ast_udptl_setqos (struct ast_udptl *udptl, unsigned int tos, unsigned int cos)
void	ast_udptl_stop (struct ast_udptl *udptl)
int	ast_udptl_write (struct ast_udptl *s, struct ast_frame *f)
static void	calculate_far_max_ifp (struct ast_udptl *udptl)
static void	calculate_local_max_datagram (struct ast_udptl *udptl)
	CONFIG_INFO_CORE ("udptl", cfg_info, globals, udptl_snapshot_alloc,.files=ACO_FILES(&udptl_conf),.pre_apply_config=udptl_pre_apply_config,)
static int	decode_length (uint8_t *buf, unsigned int limit, unsigned int *len, unsigned int *pvalue)
static int	decode_open_type (uint8_t *buf, unsigned int limit, unsigned int *len, const uint8_t **p_object, unsigned int *p_num_octets)
static unsigned int	encode_length (uint8_t *buf, unsigned int *len, unsigned int value)
static int	encode_open_type (const struct ast_udptl *udptl, uint8_t *buf, unsigned int buflen, unsigned int *len, const uint8_t *data, unsigned int num_octets)
static char *	handle_cli_show_config (struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
static char *	handle_cli_udptl_set_debug (struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
static int	load_module (void)
static int	reload_module (void)
static int	removed_options_handler (const struct aco_option *opt, struct ast_variable *var, void *obj)
static int	udptl_build_packet (struct ast_udptl *s, uint8_t *buf, unsigned int buflen, uint8_t *ifp, unsigned int ifp_len)
static void	udptl_config_destructor (void *obj)
static int	udptl_debug_test_addr (const struct ast_sockaddr *addr)
static int	udptl_pre_apply_config (void)
static int	udptl_rx_packet (struct ast_udptl *s, uint8_t *buf, unsigned int len)
static void *	udptl_snapshot_alloc (void)
static int	udptlread (int *id, int fd, short events, void *cbdata)
static int	unload_module (void)

Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER , .description = "UDPTL" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "30ef0c93b36035ec78c9cfd712d36d9b" , .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .reload = reload_module, .load_pri = AST_MODPRI_CORE, .requires = "extconfig", }
static const struct ast_module_info *	ast_module_info = &__mod_info
static struct ast_cli_entry	cli_udptl []
static struct aco_type	general_option
static struct aco_type *	general_options [] = ACO_TYPES(&general_option)
static struct aco_file	udptl_conf
static int	udptldebug
static struct ast_sockaddr	udptldebugaddr

Detailed Description

UDPTL support for T.38 faxing.

Author

Mark Spencer marks.nosp@m.ter@.nosp@m.digiu.nosp@m.m.co.nosp@m.m

Steve Underwood steve.nosp@m.u@co.nosp@m.ppice.nosp@m..org

Kevin P. Fleming kpfle.nosp@m.ming.nosp@m.@digi.nosp@m.um.c.nosp@m.om

Definition in file udptl.c.

Macro Definition Documentation

DEFAULT_FAX_MAX_DATAGRAM

#define DEFAULT_FAX_MAX_DATAGRAM   400

Definition at line 134 of file udptl.c.

Referenced by ast_udptl_set_far_max_datagram(), and ast_udptl_write().

DEFAULT_UDPTLEND

#define DEFAULT_UDPTLEND   4999

Definition at line 128 of file udptl.c.

Referenced by load_module(), and udptl_pre_apply_config().

DEFAULT_UDPTLSTART

#define DEFAULT_UDPTLSTART   4000

Definition at line 127 of file udptl.c.

Referenced by load_module(), and udptl_pre_apply_config().

FALSE

#define FALSE   0

Definition at line 119 of file udptl.c.

FAX_MAX_DATAGRAM_LIMIT

#define FAX_MAX_DATAGRAM_LIMIT   1400

Definition at line 135 of file udptl.c.

Referenced by ast_udptl_set_far_max_datagram().

LOCAL_FAX_MAX_DATAGRAM

#define LOCAL_FAX_MAX_DATAGRAM   1400

Definition at line 133 of file udptl.c.

Referenced by calculate_local_max_datagram(), udptl_build_packet(), and udptl_rx_packet().

LOG_TAG

#define LOG_TAG

(

u

)

S_OR(u->tag, "no tag")

Definition at line 125 of file udptl.c.

Referenced by ast_udptl_read(), ast_udptl_write(), calculate_far_max_ifp(), calculate_local_max_datagram(), encode_open_type(), and udptl_build_packet().

MAX_FEC_ENTRIES

#define MAX_FEC_ENTRIES   5

Definition at line 136 of file udptl.c.

Referenced by load_module(), and udptl_rx_packet().

MAX_FEC_SPAN

#define MAX_FEC_SPAN   5

Definition at line 137 of file udptl.c.

Referenced by load_module().

TRUE

#define TRUE   (!FALSE)

Definition at line 122 of file udptl.c.

Referenced by udptl_rx_packet().

UDPTL_BUF_MASK

#define UDPTL_BUF_MASK   15

Definition at line 139 of file udptl.c.

Referenced by ast_udptl_new_with_bindaddr(), udptl_build_packet(), and udptl_rx_packet().

UDPTL_MTU

#define UDPTL_MTU   1200

Definition at line 116 of file udptl.c.

Function Documentation

__ast_udptl_reload()

static void __ast_udptl_reload ( int  reload )

static

Definition at line 1327 of file udptl.c.

References aco_process_config(), ACO_PROCESS_ERROR, aco_set_defaults(), ao2_cleanup, ao2_global_obj_replace_unref, ast_log, globals, LOG_ERROR, LOG_NOTICE, RAII_VAR, and udptl_snapshot_alloc().

Referenced by load_module(), and reload_module().

{
   if (aco_process_config(&cfg_info, reload) == ACO_PROCESS_ERROR) {
      if (!reload) {
         RAII_VAR(struct udptl_config *, udptl_cfg, udptl_snapshot_alloc(), ao2_cleanup);

         if (aco_set_defaults(&general_option, "general", udptl_cfg->general)) {
            ast_log(LOG_ERROR, "Failed to load udptl.conf and failed to initialize defaults.\n");
            return;
         }

         ast_log(LOG_NOTICE, "Could not load udptl config; using defaults\n");
         ao2_global_obj_replace_unref(globals, udptl_cfg);
      }
   }
}

__reg_module()

static void __reg_module ( void  )

static

Definition at line 1441 of file udptl.c.

__unreg_module()

static void __unreg_module ( void  )

static

Definition at line 1441 of file udptl.c.

AO2_GLOBAL_OBJ_STATIC()

static AO2_GLOBAL_OBJ_STATIC ( globals  )

static

AST_MODULE_SELF_SYM()

struct ast_module* AST_MODULE_SELF_SYM

(

void

)

Definition at line 1441 of file udptl.c.

ast_udptl_destroy()

void ast_udptl_destroy

(

struct ast_udptl *

udptl

)

Definition at line 1150 of file udptl.c.

References ast_free, ast_io_remove(), ast_udptl::fd, ast_udptl::io, ast_udptl::ioid, and ast_udptl::tag.

Referenced by ooh323_destroy(), sip_pvt_dtor(), and stream_destroy().

{
   if (udptl->ioid)
      ast_io_remove(udptl->io, udptl->ioid);
   if (udptl->fd > -1)
      close(udptl->fd);
   if (udptl->tag)
      ast_free(udptl->tag);
   ast_free(udptl);
}

ast_udptl_fd()

int ast_udptl_fd

(

const struct ast_udptl *

udptl

)

Definition at line 730 of file udptl.c.

References ast_udptl::fd.

Referenced by apply_negotiated_sdp_stream(), configure_local_rtp(), initialize_udptl(), and sip_new().

{
   return udptl->fd;
}

ast_udptl_get_error_correction_scheme()

enum ast_t38_ec_modes ast_udptl_get_error_correction_scheme

(

const struct ast_udptl *

udptl

)

Definition at line 940 of file udptl.c.

References ast_udptl::error_correction_scheme.

Referenced by add_sdp(), and create_outgoing_sdp_stream().

{
   return udptl->error_correction_scheme;
}

ast_udptl_get_far_max_datagram()

unsigned int ast_udptl_get_far_max_datagram

(

const struct ast_udptl *

udptl

)

Definition at line 1008 of file udptl.c.

References ast_udptl::far_max_datagram.

Referenced by process_sdp().

{
   if (udptl->far_max_datagram < 0) {
      return 0;
   }
   return udptl->far_max_datagram;
}

ast_udptl_get_far_max_ifp()

unsigned int ast_udptl_get_far_max_ifp

(

struct ast_udptl *

udptl

)

retrieves far max ifp

Return values

positive	value representing max ifp size
0	if no value is present

Definition at line 1016 of file udptl.c.

References calculate_far_max_ifp(), and ast_udptl::far_max_ifp.

Referenced by change_t38_state(), interpret_t38_parameters(), onModeChanged(), ooh323_indicate(), setup_udptl_connection(), t38_change_state(), and t38_interpret_parameters().

{
   if (udptl->far_max_ifp == -1) {
      calculate_far_max_ifp(udptl);
   }

   if (udptl->far_max_ifp < 0) {
      return 0;
   }
   return udptl->far_max_ifp;
}

ast_udptl_get_local_max_datagram()

unsigned int ast_udptl_get_local_max_datagram

(

struct ast_udptl *

udptl

)

retrieves local_max_datagram.

Return values

positive	value representing max datagram size.
0	if no value is present

Definition at line 984 of file udptl.c.

References calculate_local_max_datagram(), and ast_udptl::local_max_datagram.

Referenced by add_sdp(), and create_outgoing_sdp_stream().

{
   if (udptl->local_max_datagram == -1) {
      calculate_local_max_datagram(udptl);
   }

   /* this function expects a unsigned value in return. */
   if (udptl->local_max_datagram < 0) {
      return 0;
   }
   return udptl->local_max_datagram;
}

ast_udptl_get_peer()

void ast_udptl_get_peer	(	const struct ast_udptl *	udptl,
		struct ast_sockaddr *	them
	)

Definition at line 1135 of file udptl.c.

References ast_sockaddr_copy(), and ast_udptl::them.

{
   ast_sockaddr_copy(them, &udptl->them);
}

ast_udptl_get_us()

void ast_udptl_get_us	(	const struct ast_udptl *	udptl,
		struct ast_sockaddr *	us
	)

Definition at line 1140 of file udptl.c.

References ast_sockaddr_copy(), and ast_udptl::us.

Referenced by add_sdp(), configure_local_rtp(), and create_outgoing_sdp_stream().

{
   ast_sockaddr_copy(us, &udptl->us);
}

ast_udptl_new_with_bindaddr()

struct ast_udptl* ast_udptl_new_with_bindaddr	(	struct ast_sched_context *	sched,
		struct io_context *	io,
		int	callbackmode,
		struct ast_sockaddr *	addr
	)

Definition at line 1028 of file udptl.c.

References ao2_cleanup, ao2_global_obj_ref, ast_bind(), ast_calloc, ast_free, ast_io_add(), AST_IO_IN, ast_log, ast_random(), ast_sockaddr_copy(), ast_sockaddr_is_ipv6(), ast_sockaddr_set_port, ast_socket_nonblock, udptl_fec_tx_buffer_t::buf_len, udptl_fec_rx_buffer_t::buf_len, errno, ast_udptl::error_correction_entries, ast_udptl::error_correction_span, ast_udptl::far_max_datagram, ast_udptl::far_max_ifp, ast_udptl::fd, globals, ast_udptl::io, io, ast_udptl::ioid, ast_udptl::local_max_datagram, ast_udptl::local_max_ifp, LOG_ERROR, LOG_WARNING, NULL, RAII_VAR, ast_udptl::rx, ast_udptl::sched, sched, ast_udptl::tx, UDPTL_BUF_MASK, udptlread(), and ast_udptl::us.

Referenced by configure_local_rtp(), initialize_udptl(), and t38_initialize_session().

{
   struct ast_udptl *udptl;
   int x;
   int startplace;
   int i;
   RAII_VAR(struct udptl_config *, cfg, ao2_global_obj_ref(globals), ao2_cleanup);

   if (!cfg || !cfg->general) {
      ast_log(LOG_ERROR, "Could not access global udptl options!\n");
      return NULL;
   }

   if (!(udptl = ast_calloc(1, sizeof(*udptl)))) {
      return NULL;
   }

   udptl->error_correction_span = cfg->general->fecspan;
   udptl->error_correction_entries = cfg->general->fecentries;

   udptl->far_max_datagram = -1;
   udptl->far_max_ifp = -1;
   udptl->local_max_ifp = -1;
   udptl->local_max_datagram = -1;

   for (i = 0; i <= UDPTL_BUF_MASK; i++) {
      udptl->rx[i].buf_len = -1;
      udptl->tx[i].buf_len = -1;
   }

   if ((udptl->fd = ast_socket_nonblock(ast_sockaddr_is_ipv6(addr) ?
               AF_INET6 : AF_INET, SOCK_DGRAM, 0)) < 0) {
      ast_free(udptl);
      ast_log(LOG_WARNING, "Unable to allocate socket: %s\n", strerror(errno));
      return NULL;
   }

#ifdef SO_NO_CHECK
   if (cfg->general->nochecksums)
      setsockopt(udptl->fd, SOL_SOCKET, SO_NO_CHECK, &cfg->general->nochecksums, sizeof(cfg->general->nochecksums));
#endif

   /* Find us a place */
   x = (cfg->general->start == cfg->general->end) ? cfg->general->start : (ast_random() % (cfg->general->end - cfg->general->start)) + cfg->general->start;
   if (cfg->general->use_even_ports && (x & 1)) {
      ++x;
   }
   startplace = x;
   for (;;) {
      ast_sockaddr_copy(&udptl->us, addr);
      ast_sockaddr_set_port(&udptl->us, x);
      if (ast_bind(udptl->fd, &udptl->us) == 0) {
         break;
      }
      if (errno != EADDRINUSE && errno != EACCES) {
         ast_log(LOG_WARNING, "Unexpected bind error: %s\n", strerror(errno));
         close(udptl->fd);
         ast_free(udptl);
         return NULL;
      }
      if (cfg->general->use_even_ports) {
         x += 2;
      } else {
         ++x;
      }
      if (x > cfg->general->end)
         x = cfg->general->start;
      if (x == startplace) {
         ast_log(LOG_WARNING, "No UDPTL ports remaining\n");
         close(udptl->fd);
         ast_free(udptl);
         return NULL;
      }
   }
   if (io && sched && callbackmode) {
      /* Operate this one in a callback mode */
      udptl->sched = sched;
      udptl->io = io;
      udptl->ioid = ast_io_add(udptl->io, udptl->fd, udptlread, AST_IO_IN, udptl);
   }

   return udptl;
}

ast_udptl_read()

struct ast_frame* ast_udptl_read

(

struct ast_udptl *

udptl

)

Definition at line 762 of file udptl.c.

References ast_assert, ast_debug, AST_FRIENDLY_OFFSET, ast_log, ast_null_frame, ast_recvfrom(), ast_sockaddr_cmp(), ast_sockaddr_copy(), ast_sockaddr_isnull(), ast_sockaddr_stringify(), ast_verb, buf, errno, ast_udptl::f, ast_udptl::fd, LOG_TAG, LOG_WARNING, ast_udptl::nat, NULL, ast_udptl::rawdata, ast_udptl::tag, ast_udptl::them, udptl_debug_test_addr(), and udptl_rx_packet().

Referenced by media_session_udptl_read_callback(), ooh323_rtp_read(), sip_rtp_read(), skinny_rtp_read(), and udptlread().

{
   int res;
   struct ast_sockaddr addr;
   uint8_t *buf;

   buf = udptl->rawdata + AST_FRIENDLY_OFFSET;

   /* Cache where the header will go */
   res = ast_recvfrom(udptl->fd,
         buf,
         sizeof(udptl->rawdata) - AST_FRIENDLY_OFFSET,
         0,
         &addr);
   if (res < 0) {
      if (errno != EAGAIN)
         ast_log(LOG_WARNING, "UDPTL (%s): read error: %s\n",
            LOG_TAG(udptl), strerror(errno));
      ast_assert(errno != EBADF);
      return &ast_null_frame;
   }

   /* Ignore if the other side hasn't been given an address yet. */
   if (ast_sockaddr_isnull(&udptl->them)) {
      return &ast_null_frame;
   }

   /*
    * If early media isn't turned on for the channel driver, it's going to
    * drop this frame.  By that time though, udptl has already incremented
    * the expected sequence number so if the CPE re-sends, the second frame
    * will be dropped as a dup even though the first frame never went through.
    * So we drop the frame here if the channel isn't up. 'tag' is set by the
    * channel drivers on T38_ENABLED or T38_PEER_REINVITE.
    */
   if (udptl->tag == NULL) {
      return &ast_null_frame;
   }

   if (udptl->nat) {
      /* Send to whoever sent to us */
      if (ast_sockaddr_cmp(&udptl->them, &addr)) {
         ast_sockaddr_copy(&udptl->them, &addr);
         ast_debug(1, "UDPTL (%s): NAT, Using address %s\n",
              LOG_TAG(udptl), ast_sockaddr_stringify(&udptl->them));
      }
   }

   if (udptl_debug_test_addr(&addr)) {
      int seq_no;

      /* Decode sequence number just for verbose message. */
      if (res < 2) {
         /* Short packet. */
         seq_no = -1;
      } else {
         seq_no = (buf[0] << 8) | buf[1];
      }

      ast_verb(1, "UDPTL (%s): packet from %s (seq %d, len %d)\n",
         LOG_TAG(udptl), ast_sockaddr_stringify(&addr), seq_no, res);
   }
   if (udptl_rx_packet(udptl, buf, res) < 1) {
      return &ast_null_frame;
   }

   return &udptl->f[0];
}

ast_udptl_set_callback()

void ast_udptl_set_callback	(	struct ast_udptl *	udptl,
		ast_udptl_callback	callback
	)

Definition at line 740 of file udptl.c.

References ast_udptl::callback.

{
   udptl->callback = callback;
}

ast_udptl_set_data()

void ast_udptl_set_data	(	struct ast_udptl *	udptl,
		void *	data
	)

Definition at line 735 of file udptl.c.

References ast_udptl::data.

{
   udptl->data = data;
}

ast_udptl_set_error_correction_scheme()

void ast_udptl_set_error_correction_scheme	(	struct ast_udptl *	udptl,
		enum ast_t38_ec_modes	ec
	)

Definition at line 945 of file udptl.c.

References ast_udptl::error_correction_entries, ast_udptl::error_correction_scheme, ast_udptl::error_correction_span, ast_udptl::far_max_ifp, ast_udptl::local_max_datagram, UDPTL_ERROR_CORRECTION_FEC, and UDPTL_ERROR_CORRECTION_REDUNDANCY.

Referenced by process_sdp(), process_sdp_a_image(), set_t38_capabilities(), t38_initialize_session(), and t38_interpret_sdp().

{
   udptl->error_correction_scheme = ec;
   switch (ec) {
   case UDPTL_ERROR_CORRECTION_FEC:
      udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_FEC;
      if (udptl->error_correction_entries == 0) {
         udptl->error_correction_entries = 3;
      }
      if (udptl->error_correction_span == 0) {
         udptl->error_correction_span = 3;
      }
      break;
   case UDPTL_ERROR_CORRECTION_REDUNDANCY:
      udptl->error_correction_scheme = UDPTL_ERROR_CORRECTION_REDUNDANCY;
      if (udptl->error_correction_entries == 0) {
         udptl->error_correction_entries = 3;
      }
      break;
   default:
      /* nothing to do */
      break;
   };
   /* reset calculated values so they'll be computed again */
   udptl->local_max_datagram = -1;
   udptl->far_max_ifp = -1;
}

ast_udptl_set_far_max_datagram()

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 value.

Definition at line 997 of file udptl.c.

References DEFAULT_FAX_MAX_DATAGRAM, ast_udptl::far_max_datagram, ast_udptl::far_max_ifp, and FAX_MAX_DATAGRAM_LIMIT.

Referenced by configure_local_rtp(), onModeChanged(), process_sdp(), process_sdp_a_image(), t38_initialize_session(), and t38_interpret_sdp().

{
   if (!max_datagram || (max_datagram > FAX_MAX_DATAGRAM_LIMIT)) {
      udptl->far_max_datagram = DEFAULT_FAX_MAX_DATAGRAM;
   } else {
      udptl->far_max_datagram = max_datagram;
   }
   /* reset calculated values so they'll be computed again */
   udptl->far_max_ifp = -1;
}

ast_udptl_set_local_max_ifp()

void ast_udptl_set_local_max_ifp	(	struct ast_udptl *	udptl,
		unsigned int	max_ifp
	)

Definition at line 973 of file udptl.c.

References ast_udptl::local_max_datagram, and ast_udptl::local_max_ifp.

Referenced by interpret_t38_parameters(), and t38_interpret_parameters().

{
   /* make sure max_ifp is a positive value since a cast will take place when
    * when setting local_max_ifp */
   if ((signed int) max_ifp > 0) {
      udptl->local_max_ifp = max_ifp;
      /* reset calculated values so they'll be computed again */
      udptl->local_max_datagram = -1;
   }
}

ast_udptl_set_peer()

void ast_udptl_set_peer	(	struct ast_udptl *	udptl,
		const struct ast_sockaddr *	them
	)

Definition at line 1130 of file udptl.c.

References ast_sockaddr_copy(), and ast_udptl::them.

Referenced by apply_negotiated_sdp_stream(), process_sdp(), and setup_udptl_connection().

{
   ast_sockaddr_copy(&udptl->them, them);
}

ast_udptl_set_tag()

void ast_udptl_set_tag	(	struct ast_udptl *	udptl,
		const char *	format,
			...
	)

Associates a character string 'tag' with a UDPTL session.

Parameters

udptl	The UDPTL session.
format	printf-style format string used to construct the tag

This function formats a tag for the specified UDPTL session, so that any log messages generated by the UDPTL stack related to that session will include the tag and the reader of the messages will be able to identify which endpoint caused them to be generated.

Return values

none

Definition at line 1112 of file udptl.c.

References ast_free, ast_vasprintf, NULL, and ast_udptl::tag.

Referenced by change_t38_state(), setup_udptl_connection(), and t38_change_state().

{
   va_list ap;

   ast_free(udptl->tag);
   udptl->tag = NULL;
   va_start(ap, format);
   if (ast_vasprintf(&udptl->tag, format, ap) == -1) {
      udptl->tag = NULL;
   }
   va_end(ap);
}

ast_udptl_setnat()

void ast_udptl_setnat	(	struct ast_udptl *	udptl,
		int	nat
	)

Definition at line 745 of file udptl.c.

References ast_udptl::nat, and nat.

Referenced by do_setnat(), initialize_udptl(), and t38_initialize_session().

{
   udptl->nat = nat;
}

ast_udptl_setqos()

int ast_udptl_setqos	(	struct ast_udptl *	udptl,
		unsigned int	tos,
		unsigned int	cos
	)

Definition at line 1125 of file udptl.c.

References ast_set_qos(), and ast_udptl::fd.

Referenced by initialize_udptl().

{
   return ast_set_qos(udptl->fd, tos, cos, "UDPTL");
}

ast_udptl_stop()

void ast_udptl_stop

(

struct ast_udptl *

udptl

)

Definition at line 1145 of file udptl.c.

References ast_sockaddr_setnull(), and ast_udptl::them.

Referenced by process_sdp(), and stop_media_flows().

{
   ast_sockaddr_setnull(&udptl->them);
}

ast_udptl_write()

int ast_udptl_write	(	struct ast_udptl *	s,
		struct ast_frame *	f
	)

Definition at line 1161 of file udptl.c.

References AST_FRAME_MODEM, ast_log, AST_MODEM_T38, ast_sendto(), ast_sockaddr_isnull(), ast_sockaddr_stringify(), ast_verb, buf, ast_frame::data, ast_frame::datalen, DEFAULT_FAX_MAX_DATAGRAM, errno, ast_udptl::far_max_datagram, ast_udptl::far_max_ifp, ast_udptl::fd, ast_frame::frametype, ast_frame_subclass::integer, ast_sockaddr::len, LOG_NOTICE, LOG_TAG, LOG_WARNING, ast_frame::ptr, seq, ast_frame::subclass, ast_udptl::them, ast_udptl::tx_seq_no, udptl_build_packet(), and udptl_debug_test_addr().

Referenced by media_session_udptl_write_callback(), ooh323_write(), and sip_write().

{
   unsigned int seq;
   unsigned int len = f->datalen;
   /* if no max datagram size is provided, use default value */
   const int bufsize = (s->far_max_datagram > 0) ? s->far_max_datagram : DEFAULT_FAX_MAX_DATAGRAM;
   uint8_t buf[bufsize];

   memset(buf, 0, sizeof(buf));

   /* If we have no peer, return immediately */
   if (ast_sockaddr_isnull(&s->them)) {
      return 0;
   }

   /* If there is no data length, return immediately */
   if (f->datalen == 0)
      return 0;

   if ((f->frametype != AST_FRAME_MODEM) ||
       (f->subclass.integer != AST_MODEM_T38)) {
      ast_log(LOG_WARNING, "UDPTL (%s): UDPTL can only send T.38 data.\n",
         LOG_TAG(s));
      return -1;
   }

   if (len > s->far_max_ifp) {
      ast_log(LOG_WARNING,
         "UDPTL (%s): UDPTL asked to send %u bytes of IFP when far end only prepared to accept %d bytes; data loss will occur."
         "You may need to override the T38FaxMaxDatagram value for this endpoint in the channel driver configuration.\n",
         LOG_TAG(s), len, s->far_max_ifp);
      len = s->far_max_ifp;
   }

   /* Save seq_no for debug output because udptl_build_packet increments it */
   seq = s->tx_seq_no & 0xFFFF;

   /* Cook up the UDPTL packet, with the relevant EC info. */
   len = udptl_build_packet(s, buf, sizeof(buf), f->data.ptr, len);

   if ((signed int) len > 0 && !ast_sockaddr_isnull(&s->them)) {
      if (ast_sendto(s->fd, buf, len, 0, &s->them) < 0) {
         ast_log(LOG_NOTICE, "UDPTL (%s): Transmission error to %s: %s\n",
            LOG_TAG(s), ast_sockaddr_stringify(&s->them), strerror(errno));
      }
      if (udptl_debug_test_addr(&s->them)) {
         ast_verb(1, "UDPTL (%s): packet to %s (seq %u, len %u)\n",
            LOG_TAG(s), ast_sockaddr_stringify(&s->them), seq, len);
      }
   }

   return 0;
}

calculate_far_max_ifp()

static void calculate_far_max_ifp ( struct ast_udptl *  udptl )

static

Definition at line 872 of file udptl.c.

References ast_log, ast_udptl::error_correction_entries, ast_udptl::error_correction_scheme, ast_udptl::far_max_datagram, ast_udptl::far_max_ifp, LOG_TAG, LOG_WARNING, UDPTL_ERROR_CORRECTION_FEC, UDPTL_ERROR_CORRECTION_NONE, and UDPTL_ERROR_CORRECTION_REDUNDANCY.

Referenced by ast_udptl_get_far_max_ifp().

{
   unsigned new_max = 0;

   if (udptl->far_max_datagram == -1) {
      ast_log(LOG_WARNING, "UDPTL (%s): Cannot calculate far_max_ifp before far_max_datagram has been set.\n",
         LOG_TAG(udptl));
      udptl->far_max_ifp = -1;
      return;
   }

   /* the goal here is to supply the local endpoint (application
    * or bridged channel) a maximum IFP value that will allow it
    * to effectively and efficiently transfer image data at its
    * selected bit rate, taking into account the selected error
    * correction mode, but without overrunning the far endpoint's
    * datagram buffer. this is complicated by the fact that some
    * far endpoints send us bogus (small) max datagram values,
    * which would result in either buffer overrun or no error
    * correction. we try to accomodate those, but if the supplied
    * value is too small to do so, we'll emit warning messages and
    * the user will have to use configuration options to override
    * the max datagram value supplied by the far endpoint.
    */
   switch (udptl->error_correction_scheme) {
   case UDPTL_ERROR_CORRECTION_NONE:
      /* need room for sequence number, length indicator, redundancy
       * indicator and following length indicator
       */
      new_max = udptl->far_max_datagram - 5;
      break;
   case UDPTL_ERROR_CORRECTION_REDUNDANCY:
      /* for this case, we'd like to send as many error correction entries
       * as possible (up to the number we're configured for), but we'll settle
       * for sending fewer if the configured number would cause the
       * calculated max IFP to be too small for effective operation
       *
       * need room for sequence number, length indicators and the
       * configured number of redundant packets
       *
       * note: we purposely don't allow error_correction_entries to drop to
       * zero in this loop; we'd rather send smaller IFPs (and thus reduce
       * the image data transfer rate) than sacrifice redundancy completely
       */
      for (;;) {
         new_max = (udptl->far_max_datagram - 8) / (udptl->error_correction_entries + 1);

         if ((new_max < 80) && (udptl->error_correction_entries > 1)) {
            /* the max ifp is not large enough, subtract an
             * error correction entry and calculate again
             * */
            --udptl->error_correction_entries;
         } else {
            break;
         }
      }
      break;
   case UDPTL_ERROR_CORRECTION_FEC:
      /* need room for sequence number, length indicators and a
       * a single IFP of the maximum size expected
       */
      new_max = (udptl->far_max_datagram - 10) / 2;
      break;
   }
   /* subtract 5% of space for insurance */
   udptl->far_max_ifp = new_max * 0.95;
}

calculate_local_max_datagram()

static void calculate_local_max_datagram ( struct ast_udptl *  udptl )

static

Definition at line 831 of file udptl.c.

References ast_log, ast_udptl::error_correction_scheme, LOCAL_FAX_MAX_DATAGRAM, ast_udptl::local_max_datagram, ast_udptl::local_max_ifp, LOG_TAG, LOG_WARNING, MIN, UDPTL_ERROR_CORRECTION_FEC, UDPTL_ERROR_CORRECTION_NONE, and UDPTL_ERROR_CORRECTION_REDUNDANCY.

Referenced by ast_udptl_get_local_max_datagram().

{
   unsigned int new_max = 0;

   if (udptl->local_max_ifp == -1) {
      ast_log(LOG_WARNING, "UDPTL (%s): Cannot calculate local_max_datagram before local_max_ifp has been set.\n",
         LOG_TAG(udptl));
      udptl->local_max_datagram = -1;
      return;
   }

   /* calculate the amount of space required to receive an IFP
    * of the maximum size supported by the application/endpoint
    * that we are delivering them to (local endpoint), and add
    * the amount of space required to support the selected
    * error correction mode
    */
   switch (udptl->error_correction_scheme) {
   case UDPTL_ERROR_CORRECTION_NONE:
      /* need room for sequence number, length indicator, redundancy
       * indicator and following length indicator
       */
      new_max = 5 + udptl->local_max_ifp;
      break;
   case UDPTL_ERROR_CORRECTION_REDUNDANCY:
      /* need room for sequence number, length indicators, plus
       * room for up to 3 redundancy packets
       */
      new_max = 5 + udptl->local_max_ifp + 2 + (3 * udptl->local_max_ifp);
      break;
   case UDPTL_ERROR_CORRECTION_FEC:
      /* need room for sequence number, length indicators and a
       * a single IFP of the maximum size expected
       */
      new_max = 5 + udptl->local_max_ifp + 4 + udptl->local_max_ifp;
      break;
   }
   /* add 5% extra space for insurance, but no larger than LOCAL_FAX_MAX_DATAGRAM */
   udptl->local_max_datagram = MIN(new_max * 1.05, LOCAL_FAX_MAX_DATAGRAM);
}

CONFIG_INFO_CORE()

CONFIG_INFO_CORE	(	"udptl"	,
		cfg_info	,
		globals	,
		udptl_snapshot_alloc	,
		.	files = ACO_FILES(&udptl_conf),
		.	pre_apply_config = udptl_pre_apply_config
	)

decode_length()

static int decode_length ( uint8_t *  buf, unsigned int  limit, unsigned int *  len, unsigned int *  pvalue  )

static

Definition at line 274 of file udptl.c.

References ast_debug, and ast_sockaddr::len.

Referenced by decode_open_type(), and udptl_rx_packet().

{
   if (*len >= limit)
      return -1;
   if ((buf[*len] & 0x80) == 0) {
      *pvalue = buf[*len];
      (*len)++;
      return 0;
   }
   if ((buf[*len] & 0x40) == 0) {
      if (*len == limit - 1)
         return -1;
      *pvalue = (buf[*len] & 0x3F) << 8;
      (*len)++;
      *pvalue |= buf[*len];
      (*len)++;
      return 0;
   }
   *pvalue = (buf[*len] & 0x3F) << 14;
   (*len)++;
   /* We have a fragment.  Currently we don't process fragments. */
   ast_debug(1, "UDPTL packet with length greater than 16K received, decoding will fail\n");
   return 1;
}

decode_open_type()

static int decode_open_type ( uint8_t *  buf, unsigned int  limit, unsigned int *  len, const uint8_t **  p_object, unsigned int *  p_num_octets  )

static

Definition at line 300 of file udptl.c.

References decode_length(), and ast_sockaddr::len.

Referenced by udptl_rx_packet().

{
   unsigned int octet_cnt = 0;

   if (decode_length(buf, limit, len, &octet_cnt) != 0)
      return -1;

   /* Make sure the buffer contains at least the number of bits requested */
   if ((*len + octet_cnt) > limit) {
      return -1;
   }

   *p_num_octets = octet_cnt;
   *p_object = &buf[*len];
   *len += octet_cnt;

   return 0;
}

encode_length()

static unsigned int encode_length ( uint8_t *  buf, unsigned int *  len, unsigned int  value  )

static

Definition at line 320 of file udptl.c.

References ast_sockaddr::len, and value.

Referenced by encode_open_type(), and udptl_build_packet().

{
   unsigned int multiplier;

   if (value < 0x80) {
      /* 1 octet */
      buf[*len] = value;
      (*len)++;
      return value;
   }
   if (value < 0x4000) {
      /* 2 octets */
      /* Set the first bit of the first octet */
      buf[*len] = ((0x8000 | value) >> 8) & 0xFF;
      (*len)++;
      buf[*len] = value & 0xFF;
      (*len)++;
      return value;
   }
   /* Fragmentation */
   multiplier = (value < 0x10000) ? (value >> 14) : 4;
   /* Set the first 2 bits of the octet */
   buf[*len] = 0xC0 | multiplier;
   (*len)++;
   return multiplier << 14;
}

encode_open_type()

static int encode_open_type ( const struct ast_udptl *  udptl, uint8_t *  buf, unsigned int  buflen, unsigned int *  len, const uint8_t *  data, unsigned int  num_octets  )

static

Definition at line 348 of file udptl.c.

References ast_log, encode_length(), LOG_ERROR, and LOG_TAG.

Referenced by udptl_build_packet().

{
   unsigned int enclen;
   unsigned int octet_idx;
   uint8_t zero_byte;

   /* If open type is of zero length, add a single zero byte (10.1) */
   if (num_octets == 0) {
      zero_byte = 0;
      data = &zero_byte;
      num_octets = 1;
   }
   /* Encode the open type */
   for (octet_idx = 0; ; num_octets -= enclen, octet_idx += enclen) {
      enclen = encode_length(buf, len, num_octets);
      if (enclen + *len > buflen) {
         ast_log(LOG_ERROR, "UDPTL (%s): Buffer overflow detected (%u + %u > %u)\n",
            LOG_TAG(udptl), enclen, *len, buflen);
         return -1;
      }
      if (enclen > 0) {
         memcpy(&buf[*len], &data[octet_idx], enclen);
         *len += enclen;
      }
      if (enclen >= num_octets)
         break;
   }

   return 0;
}

handle_cli_show_config()

static char* handle_cli_show_config ( struct ast_cli_entry *  e, int  cmd, struct ast_cli_args *  a  )

static

Definition at line 1260 of file udptl.c.

References ao2_cleanup, ao2_global_obj_ref, ast_cli(), AST_CLI_YESNO, CLI_FAILURE, CLI_GENERATE, CLI_INIT, CLI_SUCCESS, ast_cli_entry::command, ast_cli_args::fd, globals, NULL, RAII_VAR, and ast_cli_entry::usage.

{
   RAII_VAR(struct udptl_config *, cfg, NULL, ao2_cleanup);

   switch (cmd) {
   case CLI_INIT:
      e->command = "udptl show config";
      e->usage =
         "Usage: udptl show config\n"
         "       Display UDPTL configuration options\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (!(cfg = ao2_global_obj_ref(globals))) {
      return CLI_FAILURE;
   }

   ast_cli(a->fd, "UDPTL Global options\n");
   ast_cli(a->fd, "--------------------\n");
   ast_cli(a->fd, "udptlstart:      %u\n", cfg->general->start);
   ast_cli(a->fd, "udptlend:        %u\n", cfg->general->end);
   ast_cli(a->fd, "udptlfecentries: %u\n", cfg->general->fecentries);
   ast_cli(a->fd, "udptlfecspan:    %u\n", cfg->general->fecspan);
   ast_cli(a->fd, "use_even_ports:  %s\n", AST_CLI_YESNO(cfg->general->use_even_ports));
   ast_cli(a->fd, "udptlchecksums: %s\n", AST_CLI_YESNO(!cfg->general->nochecksums));

   return CLI_SUCCESS;
}

handle_cli_udptl_set_debug()

static char* handle_cli_udptl_set_debug ( struct ast_cli_entry *  e, int  cmd, struct ast_cli_args *  a  )

static

Definition at line 1215 of file udptl.c.

References ast_cli_args::argc, ast_cli_args::argv, ast_cli(), ast_free, ast_sockaddr_copy(), ast_sockaddr_resolve(), ast_sockaddr_stringify(), CLI_GENERATE, CLI_INIT, CLI_SHOWUSAGE, CLI_SUCCESS, ast_cli_entry::command, ast_cli_args::fd, NULL, udptldebug, udptldebugaddr, and ast_cli_entry::usage.

{
   switch (cmd) {
   case CLI_INIT:
      e->command = "udptl set debug {on|off|ip}";
      e->usage =
         "Usage: udptl set debug {on|off|ip host[:port]}\n"
         "       Enable or disable dumping of UDPTL packets.\n"
         "       If ip is specified, limit the dumped packets to those to and from\n"
         "       the specified 'host' with optional port.\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc < 4 || a->argc > 5)
      return CLI_SHOWUSAGE;

   if (a->argc == 4) {
      if (!strncasecmp(a->argv[3], "on", 2)) {
         udptldebug = 1;
         memset(&udptldebugaddr, 0, sizeof(udptldebugaddr));
         ast_cli(a->fd, "UDPTL Debugging Enabled\n");
      } else if (!strncasecmp(a->argv[3], "off", 3)) {
         udptldebug = 0;
         ast_cli(a->fd, "UDPTL Debugging Disabled\n");
      } else {
         return CLI_SHOWUSAGE;
      }
   } else {
      struct ast_sockaddr *addrs;
      if (strncasecmp(a->argv[3], "ip", 2))
         return CLI_SHOWUSAGE;
      if (!ast_sockaddr_resolve(&addrs, a->argv[4], 0, 0)) {
         return CLI_SHOWUSAGE;
      }
      ast_sockaddr_copy(&udptldebugaddr, &addrs[0]);
         ast_cli(a->fd, "UDPTL Debugging Enabled for IP: %s\n", ast_sockaddr_stringify(&udptldebugaddr));
      udptldebug = 1;
      ast_free(addrs);
   }

   return CLI_SUCCESS;
}

load_module()

static int load_module ( void  )

static

Definition at line 1396 of file udptl.c.

References __ast_udptl_reload(), __stringify, ACO_EXACT, aco_info_init(), aco_option_register, aco_option_register_custom, ARRAY_LEN, ast_cli_register_multiple, AST_MODFLAG_GLOBAL_SYMBOLS, AST_MODFLAG_LOAD_ORDER, AST_MODPRI_CORE, AST_MODULE_INFO(), AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_SUCCESS, AST_MODULE_SUPPORT_CORE, ASTERISK_GPL_KEY, DEFAULT_UDPTLEND, DEFAULT_UDPTLSTART, end, FLDSET, MAX_FEC_ENTRIES, MAX_FEC_SPAN, NULL, OPT_BOOL_T, OPT_UINT_T, PARSE_DEFAULT, PARSE_IN_RANGE, PARSE_RANGE_DEFAULTS, reload(), reload_module(), removed_options_handler(), and unload_module().

{
   if (aco_info_init(&cfg_info)) {
      return AST_MODULE_LOAD_FAILURE;
   }

   aco_option_register(&cfg_info, "udptlstart", ACO_EXACT, general_options, __stringify(DEFAULT_UDPTLSTART),
      OPT_UINT_T, PARSE_IN_RANGE | PARSE_DEFAULT,
      FLDSET(struct udptl_global_options, start), DEFAULT_UDPTLSTART, 1024, 65535);

   aco_option_register(&cfg_info, "udptlend", ACO_EXACT, general_options, __stringify(DEFAULT_UDPTLEND),
      OPT_UINT_T, PARSE_IN_RANGE | PARSE_DEFAULT,
      FLDSET(struct udptl_global_options, end), DEFAULT_UDPTLEND, 1024, 65535);

   aco_option_register(&cfg_info, "udptlfecentries", ACO_EXACT, general_options, NULL,
      OPT_UINT_T, PARSE_IN_RANGE | PARSE_RANGE_DEFAULTS,
      FLDSET(struct udptl_global_options, fecentries), 1, MAX_FEC_ENTRIES);

   aco_option_register(&cfg_info, "udptlfecspan", ACO_EXACT, general_options, NULL,
      OPT_UINT_T, PARSE_IN_RANGE | PARSE_RANGE_DEFAULTS,
      FLDSET(struct udptl_global_options, fecspan), 1, MAX_FEC_SPAN);

   aco_option_register(&cfg_info, "udptlchecksums", ACO_EXACT, general_options, "yes",
      OPT_BOOL_T, 0, FLDSET(struct udptl_global_options, nochecksums));

   aco_option_register(&cfg_info, "use_even_ports", ACO_EXACT, general_options, "no",
      OPT_BOOL_T, 1, FLDSET(struct udptl_global_options, use_even_ports));

   aco_option_register_custom(&cfg_info, "t38faxudpec", ACO_EXACT, general_options, NULL, removed_options_handler, 0);
   aco_option_register_custom(&cfg_info, "t38faxmaxdatagram", ACO_EXACT, general_options, NULL, removed_options_handler, 0);

   __ast_udptl_reload(0);

   ast_cli_register_multiple(cli_udptl, ARRAY_LEN(cli_udptl));

   return AST_MODULE_LOAD_SUCCESS;
}

reload_module()

static int reload_module ( void  )

static

Definition at line 1376 of file udptl.c.

References __ast_udptl_reload().

Referenced by load_module().

{
   __ast_udptl_reload(1);

   return 0;
}

removed_options_handler()

static int removed_options_handler ( const struct aco_option *  opt, struct ast_variable *  var, void *  obj  )

static

Definition at line 1317 of file udptl.c.

References ast_log, LOG_WARNING, and ast_variable::name.

Referenced by load_module().

{
   if (!strcasecmp(var->name, "t38faxudpec")) {
      ast_log(LOG_WARNING, "t38faxudpec in udptl.conf is no longer supported; use the t38pt_udptl configuration option in sip.conf instead.\n");
   } else if (!strcasecmp(var->name, "t38faxmaxdatagram")) {
      ast_log(LOG_WARNING, "t38faxmaxdatagram in udptl.conf is no longer supported; value is now supplied by T.38 applications.\n");
   }
   return 0;
}

udptl_build_packet()

static int udptl_build_packet ( struct ast_udptl *  s, uint8_t *  buf, unsigned int  buflen, uint8_t *  ifp, unsigned int  ifp_len  )

static

Definition at line 621 of file udptl.c.

References ast_debug, udptl_fec_tx_buffer_t::buf, udptl_fec_tx_buffer_t::buf_len, encode_length(), encode_open_type(), ast_udptl::error_correction_entries, ast_udptl::error_correction_scheme, ast_udptl::error_correction_span, ast_sockaddr::len, LOCAL_FAX_MAX_DATAGRAM, LOG_TAG, seq, ast_udptl::tx, ast_udptl::tx_seq_no, UDPTL_BUF_MASK, UDPTL_ERROR_CORRECTION_FEC, UDPTL_ERROR_CORRECTION_NONE, and UDPTL_ERROR_CORRECTION_REDUNDANCY.

Referenced by ast_udptl_write().

{
   uint8_t fec[LOCAL_FAX_MAX_DATAGRAM * 2] = { 0, };
   int i;
   int j;
   int seq;
   int entry;
   int entries;
   int span;
   int m;
   unsigned int len;
   int limit;
   int high_tide;

   seq = s->tx_seq_no & 0xFFFF;

   /* Map the sequence number to an entry in the circular buffer */
   entry = seq & UDPTL_BUF_MASK;

   /* We save the message in a circular buffer, for generating FEC or
      redundancy sets later on. */
   s->tx[entry].buf_len = ifp_len;
   memcpy(s->tx[entry].buf, ifp, ifp_len);

   /* Build the UDPTLPacket */

   len = 0;
   /* Encode the sequence number */
   buf[len++] = (seq >> 8) & 0xFF;
   buf[len++] = seq & 0xFF;

   /* Encode the primary IFP packet */
   if (encode_open_type(s, buf, buflen, &len, ifp, ifp_len) < 0)
      return -1;

   /* Encode the appropriate type of error recovery information */
   switch (s->error_correction_scheme)
   {
   case UDPTL_ERROR_CORRECTION_NONE:
      /* Encode the error recovery type */
      buf[len++] = 0x00;
      /* The number of entries will always be zero, so it is pointless allowing
         for the fragmented case here. */
      encode_length(buf, &len, 0);
      break;
   case UDPTL_ERROR_CORRECTION_REDUNDANCY:
      /* Encode the error recovery type */
      buf[len++] = 0x00;
      if (s->tx_seq_no > s->error_correction_entries)
         entries = s->error_correction_entries;
      else
         entries = s->tx_seq_no;
      /* The number of entries will always be small, so it is pointless allowing
         for the fragmented case here. */
      encode_length(buf, &len, entries);
      /* Encode the elements */
      for (i = 0; i < entries; i++) {
         j = (entry - i - 1) & UDPTL_BUF_MASK;
         if (encode_open_type(s, buf, buflen, &len, s->tx[j].buf, s->tx[j].buf_len) < 0) {
            ast_debug(1, "UDPTL (%s): Encoding failed at i=%d, j=%d\n",
                 LOG_TAG(s), i, j);
            return -1;
         }
      }
      break;
   case UDPTL_ERROR_CORRECTION_FEC:
      span = s->error_correction_span;
      entries = s->error_correction_entries;
      if (seq < s->error_correction_span*s->error_correction_entries) {
         /* In the initial stages, wind up the FEC smoothly */
         entries = seq/s->error_correction_span;
         if (seq < s->error_correction_span)
            span = 0;
      }
      /* Encode the error recovery type */
      buf[len++] = 0x80;
      /* Span is defined as an inconstrained integer, which it dumb. It will only
         ever be a small value. Treat it as such. */
      buf[len++] = 1;
      buf[len++] = span;
      /* The number of entries is defined as a length, but will only ever be a small
         value. Treat it as such. */
      buf[len++] = entries;
      for (m = 0; m < entries; m++) {
         /* Make an XOR'ed entry the maximum length */
         limit = (entry + m) & UDPTL_BUF_MASK;
         high_tide = 0;
         for (i = (limit - span*entries) & UDPTL_BUF_MASK; i != limit; i = (i + entries) & UDPTL_BUF_MASK) {
            if (high_tide < s->tx[i].buf_len) {
               for (j = 0; j < high_tide; j++)
                  fec[j] ^= s->tx[i].buf[j];
               for ( ; j < s->tx[i].buf_len; j++)
                  fec[j] = s->tx[i].buf[j];
               high_tide = s->tx[i].buf_len;
            } else {
               for (j = 0; j < s->tx[i].buf_len; j++)
                  fec[j] ^= s->tx[i].buf[j];
            }
         }
         if (encode_open_type(s, buf, buflen, &len, fec, high_tide) < 0)
            return -1;
      }
      break;
   }

   s->tx_seq_no++;
   return len;
}

udptl_config_destructor()

static void udptl_config_destructor ( void *  obj )

static

Definition at line 1296 of file udptl.c.

References ao2_cleanup, and udptl_config::general.

Referenced by udptl_snapshot_alloc().

{
   struct udptl_config *cfg = obj;
   ao2_cleanup(cfg->general);
}

udptl_debug_test_addr()

static int udptl_debug_test_addr ( const struct ast_sockaddr *  addr )

inlinestatic

Definition at line 258 of file udptl.c.

References ast_sockaddr_cmp(), ast_sockaddr_cmp_addr(), ast_sockaddr_isnull(), ast_sockaddr_port, udptldebug, and udptldebugaddr.

Referenced by ast_udptl_read(), and ast_udptl_write().

{
   if (udptldebug == 0)
      return 0;

   if (ast_sockaddr_isnull(&udptldebugaddr)) {
      return 1;
   }

   if (ast_sockaddr_port(&udptldebugaddr)) {
      return !ast_sockaddr_cmp(&udptldebugaddr, addr);
   } else {
      return !ast_sockaddr_cmp_addr(&udptldebugaddr, addr);
   }
}

udptl_pre_apply_config()

static int udptl_pre_apply_config ( void  )

static

Definition at line 1344 of file udptl.c.

References __stringify, aco_pending_config(), ast_log, DEFAULT_UDPTLEND, DEFAULT_UDPTLSTART, udptl_global_options::end, udptl_config::general, LOG_NOTICE, LOG_WARNING, udptl_global_options::nochecksums, udptl_global_options::start, and udptl_global_options::use_even_ports.

                                        {
   struct udptl_config *cfg = aco_pending_config(&cfg_info);

   if (!cfg->general) {
      return -1;
   }

#ifndef SO_NO_CHECK
   if (cfg->general->nochecksums) {
      ast_log(LOG_WARNING, "Disabling UDPTL checksums is not supported on this operating system!\n");
      cfg->general->nochecksums = 0;
   }
#endif

   /* Fix up any global config values that we can handle before replacing the config */
   if (cfg->general->use_even_ports && (cfg->general->start & 1)) {
      ++cfg->general->start;
      ast_log(LOG_NOTICE, "Odd numbered udptlstart specified but use_even_ports enabled. udptlstart is now %u\n", cfg->general->start);
   }
   if (cfg->general->start > cfg->general->end) {
      ast_log(LOG_WARNING, "Unreasonable values for UDPTL start/end ports; defaulting to %s-%s.\n", __stringify(DEFAULT_UDPTLSTART), __stringify(DEFAULT_UDPTLEND));
      cfg->general->start = DEFAULT_UDPTLSTART;
      cfg->general->end = DEFAULT_UDPTLEND;
   }
   if (cfg->general->use_even_ports && (cfg->general->end & 1)) {
      --cfg->general->end;
      ast_log(LOG_NOTICE, "Odd numbered udptlend specified but use_even_ports enabled. udptlend is now %u\n", cfg->general->end);
   }

   return 0;
}

udptl_rx_packet()

static int udptl_rx_packet ( struct ast_udptl *  s, uint8_t *  buf, unsigned int  len  )

static

Definition at line 381 of file udptl.c.

References ARRAY_LEN, ast_debug, AST_FRAME_MODEM, AST_LIST_NEXT, AST_MODEM_T38, udptl_fec_rx_buffer_t::buf, udptl_fec_rx_buffer_t::buf_len, ast_frame::data, ast_frame::datalen, decode_length(), decode_open_type(), ast_udptl::f, udptl_fec_rx_buffer_t::fec, udptl_fec_rx_buffer_t::fec_entries, udptl_fec_rx_buffer_t::fec_len, udptl_fec_rx_buffer_t::fec_span, ast_frame::frametype, ast_frame_subclass::integer, LOCAL_FAX_MAX_DATAGRAM, ast_frame::mallocd, MAX_FEC_ENTRIES, NULL, ast_frame::offset, ast_frame::ptr, ast_udptl::rx, ast_udptl::rx_seq_no, ast_frame::seqno, ast_frame::src, ast_frame::subclass, TRUE, and UDPTL_BUF_MASK.

Referenced by ast_udptl_read().

{
   int stat1;
   int stat2;
   int i;
   unsigned int ptr; /* an index that keeps track of how much of the UDPTL packet has been processed */
   int seq_no;
   const uint8_t *ifp = NULL;
   const uint8_t *data = NULL;
   unsigned int ifp_len = 0;
   int repaired[16];
   const uint8_t *bufs[ARRAY_LEN(s->f) - 1];
   unsigned int lengths[ARRAY_LEN(s->f) - 1];
   int span;
   int entries;
   int ifp_no;

   ptr = 0;
   ifp_no = 0;
   memset(&s->f[0], 0, sizeof(s->f[0]));

   /* Decode seq_number */
   if (ptr + 2 > len)
      return -1;
   seq_no = (buf[0] << 8) | buf[1];
   ptr += 2;

   /* UDPTL sequence numbers are 16 bit so after 0xFFFF comes
      0 which breaks all packet recovery logic.  To fix this
      if we see that next expected packet (rx_seq_no) is close
      to or beyond the wrap around limit & the received packet
      is still near zero, then we 'unwrap' the received seqno
      so it has the value it would have had.  After a 16
      packet grace period (there shouldn't be  more than
      that many recovery packets) we wrap the expected
      sequence number around and things can return back
      to normal */
   if (seq_no < 0x000F && s->rx_seq_no > 0xFFF0) {
      /* received seq_no has wrapped adjust it */
      seq_no += 0x10000;
   } else {
      /* otherwise make sure expected rx_seq_no is properly wrapped */
      s->rx_seq_no &= 0xFFFF;
   }

   /* Break out the primary packet */
   if ((stat1 = decode_open_type(buf, len, &ptr, &ifp, &ifp_len)) != 0)
      return -1;
   /* Decode error_recovery */
   if (ptr + 1 > len)
      return -1;
   if ((buf[ptr++] & 0x80) == 0) {
      /* Secondary packet mode for error recovery */
      if (seq_no > s->rx_seq_no) {
         /* We received a later packet than we expected, so we need to check if we can fill in the gap from the
            secondary packets. */
         int total_count = 0;
         do {
            unsigned int count;
            if ((stat2 = decode_length(buf, len, &ptr, &count)) < 0)
               return -1;
            for (i = 0; i < count && total_count + i < ARRAY_LEN(bufs); i++) {
               if ((stat1 = decode_open_type(buf, len, &ptr, &bufs[total_count + i], &lengths[total_count + i])) != 0) {
                  return -1;
               }
               /* valid secondaries can contain zero-length packets that should be ignored */
               if (!bufs[total_count + i] || !lengths[total_count + i]) {
                  /* drop the count of items to process and reuse the buffers that were just set */
                  i--;
                  count--;
               }
            }
            total_count += i;
         }
         while (stat2 > 0 && total_count < ARRAY_LEN(bufs));
         /* Step through in reverse order, so we go oldest to newest */
         for (i = total_count; i > 0; i--) {
            if (seq_no - i >= s->rx_seq_no) {
               /* This one wasn't seen before */
               /* Decode the secondary IFP packet */
               ast_debug(3, "Recovering lost packet via secondary %d, len %u\n", seq_no - i, lengths[i - 1]);
               s->f[ifp_no].frametype = AST_FRAME_MODEM;
               s->f[ifp_no].subclass.integer = AST_MODEM_T38;

               s->f[ifp_no].mallocd = 0;
               s->f[ifp_no].seqno = seq_no - i;
               s->f[ifp_no].datalen = lengths[i - 1];
               s->f[ifp_no].data.ptr = (uint8_t *) bufs[i - 1];
               s->f[ifp_no].offset = 0;
               s->f[ifp_no].src = "UDPTL";
               if (ifp_no > 0)
                  AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
               AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
               ifp_no++;
            }
         }
      }
   }
   else
   {
      int j;
      int l;
      int x;
      /* FEC mode for error recovery */
      /* Our buffers cannot tolerate overlength IFP packets in FEC mode */
      if (ifp_len > LOCAL_FAX_MAX_DATAGRAM)
         return -1;
      /* Update any missed slots in the buffer */
      for ( ; seq_no > s->rx_seq_no; s->rx_seq_no++) {
         x = s->rx_seq_no & UDPTL_BUF_MASK;
         s->rx[x].buf_len = -1;
         s->rx[x].fec_len[0] = 0;
         s->rx[x].fec_span = 0;
         s->rx[x].fec_entries = 0;
      }

      x = seq_no & UDPTL_BUF_MASK;

      memset(repaired, 0, sizeof(repaired));

      /* Save the new IFP packet */
      memcpy(s->rx[x].buf, ifp, ifp_len);
      s->rx[x].buf_len = ifp_len;
      repaired[x] = TRUE;

      /* Decode the FEC packets */
      /* The span is defined as an unconstrained integer, but will never be more
         than a small value. */
      if (ptr + 2 > len)
         return -1;
      if (buf[ptr++] != 1)
         return -1;
      span = buf[ptr++];
      s->rx[x].fec_span = span;

      /* The number of entries is defined as a length, but will only ever be a small
         value. Treat it as such. */
      if (ptr + 1 > len)
         return -1;
      entries = buf[ptr++];
      if (entries > MAX_FEC_ENTRIES) {
         return -1;
      }
      s->rx[x].fec_entries = entries;

      /* Decode the elements */
      for (i = 0; i < entries; i++) {
         if ((stat1 = decode_open_type(buf, len, &ptr, &data, &s->rx[x].fec_len[i])) != 0)
            return -1;
         if (s->rx[x].fec_len[i] > LOCAL_FAX_MAX_DATAGRAM)
            return -1;

         /* Save the new FEC data */
         memcpy(s->rx[x].fec[i], data, s->rx[x].fec_len[i]);
#if 0
         fprintf(stderr, "FEC: ");
         for (j = 0; j < s->rx[x].fec_len[i]; j++)
            fprintf(stderr, "%02hhX ", data[j]);
         fprintf(stderr, "\n");
#endif
      }

      /* See if we can reconstruct anything which is missing */
      /* TODO: this does not comprehensively hunt back and repair everything that is possible */
      for (l = x; l != ((x - (16 - span*entries)) & UDPTL_BUF_MASK); l = (l - 1) & UDPTL_BUF_MASK) {
         int m;
         if (s->rx[l].fec_len[0] <= 0)
            continue;
         for (m = 0; m < s->rx[l].fec_entries; m++) {
            int k;
            int which;
            int limit = (l + m) & UDPTL_BUF_MASK;

            /* only repair buffers that actually exist! */
            if (seq_no <= (s->rx[l].fec_span * s->rx[l].fec_entries) - m) {
               continue;
            }

            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) {
               if (s->rx[k].buf_len <= 0)
                  which = (which == -1) ? k : -2;
            }
            if (which >= 0) {
               /* Repairable */
               for (j = 0; j < s->rx[l].fec_len[m]; j++) {
                  s->rx[which].buf[j] = s->rx[l].fec[m][j];
                  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)
                     s->rx[which].buf[j] ^= (s->rx[k].buf_len > j) ? s->rx[k].buf[j] : 0;
               }
               s->rx[which].buf_len = s->rx[l].fec_len[m];
               repaired[which] = TRUE;
            }
         }
      }
      /* Now play any new packets forwards in time */
      for (l = (x + 1) & UDPTL_BUF_MASK, j = seq_no - UDPTL_BUF_MASK; l != x; l = (l + 1) & UDPTL_BUF_MASK, j++) {
         if (repaired[l]) {
            //fprintf(stderr, "Fixed packet %d, len %d\n", j, l);
            s->f[ifp_no].frametype = AST_FRAME_MODEM;
            s->f[ifp_no].subclass.integer = AST_MODEM_T38;

            s->f[ifp_no].mallocd = 0;
            s->f[ifp_no].seqno = j;
            s->f[ifp_no].datalen = s->rx[l].buf_len;
            s->f[ifp_no].data.ptr = s->rx[l].buf;
            s->f[ifp_no].offset = 0;
            s->f[ifp_no].src = "UDPTL";
            if (ifp_no > 0)
               AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
            AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;
            ifp_no++;
         }
      }
   }

   /* If packets are received out of sequence, we may have already processed this packet from the error
      recovery information in a packet already received. */
   if (seq_no >= s->rx_seq_no) {
      /* Decode the primary IFP packet */
      s->f[ifp_no].frametype = AST_FRAME_MODEM;
      s->f[ifp_no].subclass.integer = AST_MODEM_T38;

      s->f[ifp_no].mallocd = 0;
      s->f[ifp_no].seqno = seq_no;
      s->f[ifp_no].datalen = ifp_len;
      s->f[ifp_no].data.ptr = (uint8_t *) ifp;
      s->f[ifp_no].offset = 0;
      s->f[ifp_no].src = "UDPTL";
      if (ifp_no > 0)
         AST_LIST_NEXT(&s->f[ifp_no - 1], frame_list) = &s->f[ifp_no];
      AST_LIST_NEXT(&s->f[ifp_no], frame_list) = NULL;

      ifp_no++;
   }

   s->rx_seq_no = seq_no + 1;
   return ifp_no;
}

udptl_snapshot_alloc()

static void * udptl_snapshot_alloc ( void  )

static

Definition at line 1302 of file udptl.c.

References ao2_alloc, ao2_ref, udptl_config::general, NULL, and udptl_config_destructor().

Referenced by __ast_udptl_reload().

{
   struct udptl_config *cfg;

   if (!(cfg = ao2_alloc(sizeof(*cfg), udptl_config_destructor))) {
      return NULL;
   }
   if (!(cfg->general = ao2_alloc(sizeof(*cfg->general), NULL))) {
      ao2_ref(cfg, -1);
      return NULL;
   }

   return cfg;
}

udptlread()

static int udptlread ( int *  id, int  fd, short  events, void *  cbdata  )

static

Definition at line 750 of file udptl.c.

References ast_udptl_read(), ast_udptl::callback, and ast_udptl::data.

Referenced by ast_udptl_new_with_bindaddr().

{
   struct ast_udptl *udptl = cbdata;
   struct ast_frame *f;

   if ((f = ast_udptl_read(udptl))) {
      if (udptl->callback)
         udptl->callback(udptl, f, udptl->data);
   }
   return 1;
}

unload_module()

static int unload_module ( void  )

static

Definition at line 1387 of file udptl.c.

References aco_info_destroy(), ao2_t_global_obj_release, ARRAY_LEN, ast_cli_unregister_multiple(), and globals.

Referenced by load_module().

{
   ast_cli_unregister_multiple(cli_udptl, ARRAY_LEN(cli_udptl));
   ao2_t_global_obj_release(globals, "Unref udptl global container in shutdown");
   aco_info_destroy(&cfg_info);

   return 0;
}

Variable Documentation

__mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER , .description = "UDPTL" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "30ef0c93b36035ec78c9cfd712d36d9b" , .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .reload = reload_module, .load_pri = AST_MODPRI_CORE, .requires = "extconfig", }

static

Definition at line 1441 of file udptl.c.

ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 1441 of file udptl.c.

cli_udptl

struct ast_cli_entry cli_udptl[]

static

Initial value:

= {
   { .handler =  handle_cli_udptl_set_debug , .summary =  "Enable/Disable UDPTL debugging" ,},
   { .handler =  handle_cli_show_config , .summary =  "Show UDPTL config options" ,},
}

Definition at line 1291 of file udptl.c.

general_option

struct aco_type general_option

static

Definition at line 238 of file udptl.c.

general_options

struct aco_type* general_options[] = ACO_TYPES(&general_option)

static

Definition at line 246 of file udptl.c.

udptl_conf

struct aco_file udptl_conf

static

Initial value:

= {
   .filename = "udptl.conf",
   .types = ACO_TYPES(&general_option),
}

Definition at line 248 of file udptl.c.

udptldebug

int udptldebug

static

Are we debugging?

Definition at line 130 of file udptl.c.

Referenced by handle_cli_udptl_set_debug(), and udptl_debug_test_addr().

udptldebugaddr

struct ast_sockaddr udptldebugaddr

static

Debug packets to/from this host

Definition at line 131 of file udptl.c.

Referenced by handle_cli_udptl_set_debug(), and udptl_debug_test_addr().