SIP T.38 handling. More...

#include "asterisk.h"
#include <pjsip.h>
#include <pjsip_ua.h>
#include <pjmedia.h>
#include <pjlib.h>
#include "asterisk/utils.h"
#include "asterisk/module.h"
#include "asterisk/udptl.h"
#include "asterisk/netsock2.h"
#include "asterisk/channel.h"
#include "asterisk/acl.h"
#include "asterisk/stream.h"
#include "asterisk/format_cache.h"
#include "asterisk/res_pjsip.h"
#include "asterisk/res_pjsip_session.h"

Include dependency graph for res_pjsip_t38.c:

Go to the source code of this file.

Data Structures
struct	t38_parameters_task_data
	Structure for T.38 parameters task data. More...

struct	t38_state
	T.38 state information. More...

Macros
#define	T38_AUTOMATIC_REJECTION_SECONDS 5
	The number of seconds after receiving a T.38 re-invite before automatically rejecting it. More...

Functions
static void	__reg_module (void)

static void	__unreg_module (void)

static int	apply_negotiated_sdp_stream (struct ast_sip_session session, struct ast_sip_session_media session_media, const struct pjmedia_sdp_session local, const struct pjmedia_sdp_session remote, int index, struct ast_stream *asterisk_stream)
	Function which applies a negotiated stream. More...

struct ast_module *	AST_MODULE_SELF_SYM (void)

static void	change_outgoing_sdp_stream_media_address (pjsip_tx_data tdata, struct pjmedia_sdp_media stream, struct ast_sip_transport *transport)
	Function which updates the media stream with external media address, if applicable. More...

static int	create_outgoing_sdp_stream (struct ast_sip_session session, struct ast_sip_session_media session_media, struct pjmedia_sdp_session sdp, const struct pjmedia_sdp_session remote, struct ast_stream *stream)
	Function which creates an outgoing stream. More...

static enum ast_sip_session_sdp_stream_defer	defer_incoming_sdp_stream (struct ast_sip_session session, struct ast_sip_session_media session_media, const struct pjmedia_sdp_session sdp, const struct pjmedia_sdp_media stream)
	Function which defers an incoming media stream. More...

static int	load_module (void)
	Load the module. More...

static struct ast_frame *	media_session_udptl_read_callback (struct ast_sip_session session, struct ast_sip_session_media session_media)

static int	media_session_udptl_write_callback (struct ast_sip_session session, struct ast_sip_session_media session_media, struct ast_frame *frame)

static int	negotiate_incoming_sdp_stream (struct ast_sip_session session, struct ast_sip_session_media session_media, const struct pjmedia_sdp_session sdp, int index, struct ast_stream asterisk_stream)
	Function which negotiates an incoming media stream. More...

static void	stream_destroy (struct ast_sip_session_media *session_media)
	Function which destroys the UDPTL instance when session ends. More...

static void	t38_attach_framehook (struct ast_sip_session *session)
	Function called to attach T.38 framehook to channel when appropriate. More...

static int	t38_automatic_reject (void *obj)
	Task function which rejects a T.38 re-invite and resumes handling it. More...

static void	t38_automatic_reject_timer_cb (pj_timer_heap_t timer_heap, struct pj_timer_entry entry)
	Timer entry callback which queues a task to reject a T.38 re-invite and resume handling it. More...

static void	t38_change_state (struct ast_sip_session session, struct ast_sip_session_media session_media, struct t38_state *state, enum ast_sip_session_t38state new_state)
	Helper function for changing the T.38 state. More...

static int	t38_consume (void *data, enum ast_frame_type type)

static struct ast_sip_session_media_state *	t38_create_media_state (struct ast_sip_session *session)
	Helper function which creates a media state for strictly T.38. More...

static struct ast_frame *	t38_framehook (struct ast_channel chan, struct ast_frame f, enum ast_framehook_event event, void *data)
	Frame hook callback for T.38 related stuff. More...

static unsigned int	t38_get_rate (enum ast_control_t38_rate rate)
	Get Max T.38 Transmission rate from T38 capabilities. More...

static int	t38_incoming_invite_request (struct ast_sip_session session, struct pjsip_rx_data rdata)
	Function called when an INVITE arrives. More...

static int	t38_initialize_session (struct ast_sip_session session, struct ast_sip_session_media session_media)
	Initializes UDPTL support on a session, only done when actually needed. More...

static int	t38_interpret_parameters (void *obj)
	Task for reacting to T.38 control frame. More...

static void	t38_interpret_sdp (struct t38_state state, struct ast_sip_session session, struct ast_sip_session_media session_media, const struct pjmedia_sdp_media stream)
	Parse a T.38 image stream and store the attribute information. More...

static void	t38_masq (void data, int framehook_id, struct ast_channel old_chan, struct ast_channel *new_chan)

static void	t38_outgoing_invite_request (struct ast_sip_session session, struct pjsip_tx_data tdata)
	Function called when an INVITE is sent. More...

static struct t38_parameters_task_data *	t38_parameters_task_data_alloc (struct ast_sip_session session, struct ast_frame frame)
	Allocator for T.38 data. More...

static void	t38_parameters_task_data_destroy (void *obj)
	Destructor for T.38 data. More...

static int	t38_reinvite_response_cb (struct ast_sip_session session, pjsip_rx_data rdata)
	Callback for when a response is received for a T.38 re-invite. More...

static int	t38_reinvite_sdp_cb (struct ast_sip_session session, pjmedia_sdp_session sdp)
	Callback for when T.38 reinvite SDP is created. More...

static void	t38_state_destroy (void *obj)
	Destructor for T.38 state information. More...

static struct t38_state *	t38_state_get_or_alloc (struct ast_sip_session *session)
	Helper function which retrieves or allocates a T.38 state information datastore. More...

static int	unload_module (void)
	Unloads the SIP T.38 module from Asterisk. More...

Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "PJSIP T.38 UDPTL Support" , .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 = AST_BUILDOPT_SUM, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_CHANNEL_DRIVER, .requires = "res_pjsip,res_pjsip_session,udptl", }

static struct ast_sockaddr	address
	Address for UDPTL. More...

static const struct ast_module_info *	ast_module_info = &__mod_info

static struct ast_sip_session_sdp_handler	image_sdp_handler
	SDP handler for 'image' media stream. More...

static const struct ast_datastore_info	t38_datastore
	Datastore for attaching T.38 state information. More...

static const struct ast_datastore_info	t38_framehook_datastore

static struct ast_sip_session_supplement	t38_supplement
	Supplement for adding framehook to session channel. More...

Detailed Description

SIP T.38 handling.

Author: Joshua Colp jcolp.nosp@m.@dig.nosp@m.ium.c.nosp@m.om

Definition in file res_pjsip_t38.c.

Macro Definition Documentation

◆ T38_AUTOMATIC_REJECTION_SECONDS

#define T38_AUTOMATIC_REJECTION_SECONDS 5

The number of seconds after receiving a T.38 re-invite before automatically rejecting it.

Definition at line 53 of file res_pjsip_t38.c.

Function Documentation

◆ __reg_module()

static void __reg_module ( void )

static

Definition at line 1171 of file res_pjsip_t38.c.

◆ __unreg_module()

static void __unreg_module ( void )

static

Definition at line 1171 of file res_pjsip_t38.c.

◆ apply_negotiated_sdp_stream()

static int apply_negotiated_sdp_stream	(	struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media,
		const struct pjmedia_sdp_session *	local,
		const struct pjmedia_sdp_session *	remote,
		int	index,
		struct ast_stream *	asterisk_stream
	)

static

Function which applies a negotiated stream.

Definition at line 1039 of file res_pjsip_t38.c.

{
    RAII_VAR(struct ast_sockaddr *, addrs, NULL, ast_free);
    pjmedia_sdp_media *remote_stream = remote->media[index];
    char host[NI_MAXHOST];
    struct t38_state *state;
 
    if (!session_media->udptl) {
        ast_debug(3, "Not applying negotiated SDP stream: no UDTPL session\n");
        return 0;
    }
 
    if (!(state = t38_state_get_or_alloc(session))) {
        return -1;
    }
 
    ast_copy_pj_str(host, remote_stream->conn ? &remote_stream->conn->addr : &remote->conn->addr, sizeof(host));
 
    /* Ensure that the address provided is valid */
    if (ast_sockaddr_resolve(&addrs, host, PARSE_PORT_FORBID, AST_AF_UNSPEC) <= 0) {
        /* The provided host was actually invalid so we error out this negotiation */
        ast_debug(3, "Not applying negotiated SDP stream: failed to resolve remote stream host\n");
        return -1;
    }
 
    ast_sockaddr_set_port(addrs, remote_stream->desc.port);
    ast_udptl_set_peer(session_media->udptl, addrs);
 
    t38_interpret_sdp(state, session, session_media, remote_stream);
 
    ast_sip_session_media_set_write_callback(session, session_media, media_session_udptl_write_callback);
    ast_sip_session_media_add_read_callback(session, session_media, ast_udptl_fd(session_media->udptl),
        media_session_udptl_read_callback);
 
    return 0;
}

References AST_AF_UNSPEC, ast_copy_pj_str(), ast_debug, ast_free, ast_sip_session_media_add_read_callback(), ast_sip_session_media_set_write_callback(), ast_sockaddr_resolve(), ast_sockaddr_set_port, ast_udptl_fd(), ast_udptl_set_peer(), media_session_udptl_read_callback(), media_session_udptl_write_callback(), NULL, PARSE_PORT_FORBID, RAII_VAR, session, state, t38_interpret_sdp(), t38_state_get_or_alloc(), and ast_sip_session_media::udptl.

◆ AST_MODULE_SELF_SYM()

struct ast_module * AST_MODULE_SELF_SYM ( void )

Definition at line 1171 of file res_pjsip_t38.c.

◆ change_outgoing_sdp_stream_media_address()

static void change_outgoing_sdp_stream_media_address	(	pjsip_tx_data *	tdata,
		struct pjmedia_sdp_media *	stream,
		struct ast_sip_transport *	transport
	)

static

Function which updates the media stream with external media address, if applicable.

Definition at line 1079 of file res_pjsip_t38.c.

{
    RAII_VAR(struct ast_sip_transport_state *, transport_state, ast_sip_get_transport_state(ast_sorcery_object_get_id(transport)), ao2_cleanup);
    char host[NI_MAXHOST];
    struct ast_sockaddr our_sdp_addr = { { 0, } };
 
    /* If the stream has been rejected there will be no connection line */
    if (!stream->conn || !transport_state) {
        return;
    }
 
    ast_copy_pj_str(host, &stream->conn->addr, sizeof(host));
    ast_sockaddr_parse(&our_sdp_addr, host, PARSE_PORT_FORBID);
 
    /* Reversed check here. We don't check the remote endpoint being
     * in our local net, but whether our outgoing session IP is
     * local. If it is not, we won't do rewriting. No localnet
     * configured? Always rewrite. */
    if (ast_sip_transport_is_nonlocal(transport_state, &our_sdp_addr) && transport_state->localnet) {
        return;
    }
    ast_debug(5, "Setting media address to %s\n", ast_sockaddr_stringify_addr_remote(&transport_state->external_media_address));
    pj_strdup2(tdata->pool, &stream->conn->addr, ast_sockaddr_stringify_addr_remote(&transport_state->external_media_address));
}

References ao2_cleanup, ast_copy_pj_str(), ast_debug, ast_sip_get_transport_state(), ast_sip_transport_is_nonlocal, ast_sockaddr_parse(), ast_sockaddr_stringify_addr_remote(), ast_sorcery_object_get_id(), PARSE_PORT_FORBID, and RAII_VAR.

◆ create_outgoing_sdp_stream()

static int create_outgoing_sdp_stream	(	struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media,
		struct pjmedia_sdp_session *	sdp,
		const struct pjmedia_sdp_session *	remote,
		struct ast_stream *	stream
	)

static

Function which creates an outgoing stream.

Definition at line 904 of file res_pjsip_t38.c.

{
    pj_pool_t *pool = session->inv_session->pool_prov;
    static const pj_str_t STR_IN = { "IN", 2 };
    static const pj_str_t STR_IP4 = { "IP4", 3};
    static const pj_str_t STR_IP6 = { "IP6", 3};
    static const pj_str_t STR_UDPTL = { "udptl", 5 };
    static const pj_str_t STR_T38 = { "t38", 3 };
    static const pj_str_t STR_TRANSFERREDTCF = { "transferredTCF", 14 };
    static const pj_str_t STR_LOCALTCF = { "localTCF", 8 };
    static const pj_str_t STR_T38UDPFEC = { "t38UDPFEC", 9 };
    static const pj_str_t STR_T38UDPREDUNDANCY = { "t38UDPRedundancy", 16 };
    struct t38_state *state;
    pjmedia_sdp_media *media;
    const char *hostip = NULL;
    struct ast_sockaddr addr;
    char tmp[512];
    pj_str_t stmp;
 
    if (!session->endpoint->media.t38.enabled) {
        ast_debug(3, "Not creating outgoing SDP stream: T.38 not enabled\n");
        return 1;
    } else if ((session->t38state != T38_LOCAL_REINVITE) && (session->t38state != T38_PEER_REINVITE) &&
        (session->t38state != T38_ENABLED)) {
        ast_debug(3, "Not creating outgoing SDP stream: T.38 not enabled\n");
        return 1;
    } else if (!(state = t38_state_get_or_alloc(session))) {
        return -1;
    } else if (t38_initialize_session(session, session_media)) {
        ast_debug(3, "Not creating outgoing SDP stream: Failed to initialize T.38 session\n");
        return -1;
    }
 
    if (!(media = pj_pool_zalloc(pool, sizeof(struct pjmedia_sdp_media))) ||
        !(media->conn = pj_pool_zalloc(pool, sizeof(struct pjmedia_sdp_conn)))) {
        return -1;
    }
 
    pj_strdup2(pool, &media->desc.media, ast_codec_media_type2str(session_media->type));
    media->desc.transport = STR_UDPTL;
 
    if (ast_strlen_zero(session->endpoint->media.address)) {
        hostip = ast_sip_get_host_ip_string(session->endpoint->media.t38.ipv6 ? pj_AF_INET6() : pj_AF_INET());
    } else {
        hostip = session->endpoint->media.address;
    }
 
    if (ast_strlen_zero(hostip)) {
        ast_debug(3, "Not creating outgoing SDP stream: no known host IP\n");
        return -1;
    }
 
    media->conn->net_type = STR_IN;
    media->conn->addr_type = session->endpoint->media.t38.ipv6 ? STR_IP6 : STR_IP4;
    pj_strdup2(pool, &media->conn->addr, hostip);
    ast_udptl_get_us(session_media->udptl, &addr);
    media->desc.port = (pj_uint16_t) ast_sockaddr_port(&addr);
    media->desc.port_count = 1;
    media->desc.fmt[media->desc.fmt_count++] = STR_T38;
 
    snprintf(tmp, sizeof(tmp), "%u", state->our_parms.version);
    media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxVersion", pj_cstr(&stmp, tmp));
 
    snprintf(tmp, sizeof(tmp), "%u", t38_get_rate(state->our_parms.rate));
    media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38MaxBitRate", pj_cstr(&stmp, tmp));
 
    if (state->our_parms.fill_bit_removal) {
        media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxFillBitRemoval", NULL);
    }
 
    if (state->our_parms.transcoding_mmr) {
        media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxTranscodingMMR", NULL);
    }
 
    if (state->our_parms.transcoding_jbig) {
        media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxTranscodingJBIG", NULL);
    }
 
    switch (state->our_parms.rate_management) {
    case AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF:
        media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxRateManagement", &STR_TRANSFERREDTCF);
        break;
    case AST_T38_RATE_MANAGEMENT_LOCAL_TCF:
        media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxRateManagement", &STR_LOCALTCF);
        break;
    }
 
    snprintf(tmp, sizeof(tmp), "%u", ast_udptl_get_local_max_datagram(session_media->udptl));
    media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxMaxDatagram", pj_cstr(&stmp, tmp));
 
    switch (ast_udptl_get_error_correction_scheme(session_media->udptl)) {
    case UDPTL_ERROR_CORRECTION_NONE:
        break;
    case UDPTL_ERROR_CORRECTION_FEC:
        media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxUdpEC", &STR_T38UDPFEC);
        break;
    case UDPTL_ERROR_CORRECTION_REDUNDANCY:
        media->attr[media->attr_count++] = pjmedia_sdp_attr_create(pool, "T38FaxUdpEC", &STR_T38UDPREDUNDANCY);
        break;
    }
 
    sdp->media[sdp->media_count++] = media;
 
    return 1;
}

References ast_codec_media_type2str(), ast_debug, ast_sip_get_host_ip_string(), ast_sockaddr_port, ast_strlen_zero(), AST_T38_RATE_MANAGEMENT_LOCAL_TCF, AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF, ast_udptl_get_error_correction_scheme(), ast_udptl_get_local_max_datagram(), ast_udptl_get_us(), NULL, session, state, T38_ENABLED, t38_get_rate(), t38_initialize_session(), T38_LOCAL_REINVITE, T38_PEER_REINVITE, t38_state_get_or_alloc(), tmp(), ast_sip_session_media::type, ast_sip_session_media::udptl, UDPTL_ERROR_CORRECTION_FEC, UDPTL_ERROR_CORRECTION_NONE, and UDPTL_ERROR_CORRECTION_REDUNDANCY.

◆ defer_incoming_sdp_stream()

static enum ast_sip_session_sdp_stream_defer defer_incoming_sdp_stream	(	struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media,
		const struct pjmedia_sdp_session *	sdp,
		const struct pjmedia_sdp_media *	stream
	)

static

Function which defers an incoming media stream.

Definition at line 826 of file res_pjsip_t38.c.

{
    struct t38_state *state;
 
    if (!session->endpoint->media.t38.enabled) {
        ast_debug(3, "Not deferring incoming SDP stream: T.38 not enabled on %s\n", ast_channel_name(session->channel));
        return AST_SIP_SESSION_SDP_DEFER_NOT_HANDLED;
    }
 
    if (t38_initialize_session(session, session_media)) {
        ast_debug(3, "Not deferring incoming SDP stream: Failed to initialize UDPTL on %s\n", ast_channel_name(session->channel));
        return AST_SIP_SESSION_SDP_DEFER_ERROR;
    }
 
    if (!(state = t38_state_get_or_alloc(session))) {
        return AST_SIP_SESSION_SDP_DEFER_ERROR;
    }
 
    t38_interpret_sdp(state, session, session_media, stream);
 
    /* If they are initiating the re-invite we need to defer responding until later */
    if (session->t38state == T38_DISABLED) {
        t38_change_state(session, session_media, state, T38_PEER_REINVITE);
        ast_debug(3, "Deferring incoming SDP stream on %s for peer re-invite\n", ast_channel_name(session->channel));
        return AST_SIP_SESSION_SDP_DEFER_NEEDED;
    }
 
    return AST_SIP_SESSION_SDP_DEFER_NOT_NEEDED;
}

References ast_channel_name(), ast_debug, AST_SIP_SESSION_SDP_DEFER_ERROR, AST_SIP_SESSION_SDP_DEFER_NEEDED, AST_SIP_SESSION_SDP_DEFER_NOT_HANDLED, AST_SIP_SESSION_SDP_DEFER_NOT_NEEDED, session, state, t38_change_state(), T38_DISABLED, t38_initialize_session(), t38_interpret_sdp(), T38_PEER_REINVITE, and t38_state_get_or_alloc().

◆ load_module()

static int load_module ( void )

static

Load the module.

Module loading including tests for configuration or dependencies. This function can return AST_MODULE_LOAD_FAILURE, AST_MODULE_LOAD_DECLINE, or AST_MODULE_LOAD_SUCCESS. If a dependency or environment variable fails tests return AST_MODULE_LOAD_FAILURE. If the module can not load the configuration file or other non-critical problem return AST_MODULE_LOAD_DECLINE. On success return AST_MODULE_LOAD_SUCCESS.

Definition at line 1143 of file res_pjsip_t38.c.

{
    if (ast_check_ipv6()) {
        ast_sockaddr_parse(&address, "::", 0);
    } else {
        ast_sockaddr_parse(&address, "0.0.0.0", 0);
    }
 
    ast_sip_session_register_supplement(&t38_supplement);
 
    if (ast_sip_session_register_sdp_handler(&image_sdp_handler, "image")) {
        ast_log(LOG_ERROR, "Unable to register SDP handler for image stream type\n");
        goto end;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
end:
    unload_module();
 
    return AST_MODULE_LOAD_DECLINE;
}

References ast_check_ipv6(), ast_log, AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, ast_sip_session_register_sdp_handler(), ast_sip_session_register_supplement, ast_sockaddr_parse(), end, image_sdp_handler, LOG_ERROR, t38_supplement, and unload_module().

◆ media_session_udptl_read_callback()

static struct ast_frame * media_session_udptl_read_callback	(	struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media
	)

static

Definition at line 1011 of file res_pjsip_t38.c.

{
    struct ast_frame *frame;
 
    if (!session_media->udptl) {
        return &ast_null_frame;
    }
 
    frame = ast_udptl_read(session_media->udptl);
    if (!frame) {
        return NULL;
    }
 
    frame->stream_num = session_media->stream_num;
 
    return frame;
}

References ast_null_frame, ast_udptl_read(), NULL, ast_frame::stream_num, ast_sip_session_media::stream_num, and ast_sip_session_media::udptl.

Referenced by apply_negotiated_sdp_stream().

◆ media_session_udptl_write_callback()

static int media_session_udptl_write_callback	(	struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media,
		struct ast_frame *	frame
	)

static

Definition at line 1029 of file res_pjsip_t38.c.

{
    if (!session_media->udptl) {
        return 0;
    }
 
    return ast_udptl_write(session_media->udptl, frame);
}

References ast_udptl_write(), and ast_sip_session_media::udptl.

Referenced by apply_negotiated_sdp_stream().

◆ negotiate_incoming_sdp_stream()

static int negotiate_incoming_sdp_stream	(	struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media,
		const struct pjmedia_sdp_session *	sdp,
		int	index,
		struct ast_stream *	asterisk_stream
	)

static

Function which negotiates an incoming media stream.

Definition at line 859 of file res_pjsip_t38.c.

{
    struct t38_state *state;
    char host[NI_MAXHOST];
    pjmedia_sdp_media *stream = sdp->media[index];
    RAII_VAR(struct ast_sockaddr *, addrs, NULL, ast_free);
 
    if (!session->endpoint->media.t38.enabled) {
        ast_debug(3, "Declining; T.38 not enabled on session\n");
        return 0;
    }
 
    if (!(state = t38_state_get_or_alloc(session))) {
        return 0;
    }
 
    if ((session->t38state == T38_REJECTED) || (session->t38state == T38_DISABLED)) {
        ast_debug(3, "Declining; T.38 state is rejected or declined\n");
        t38_change_state(session, NULL, state, T38_DISABLED);
        return 0;
    }
 
    ast_copy_pj_str(host, stream->conn ? &stream->conn->addr : &sdp->conn->addr, sizeof(host));
 
    /* Ensure that the address provided is valid */
    if (ast_sockaddr_resolve(&addrs, host, PARSE_PORT_FORBID, AST_AF_UNSPEC) <= 0) {
        /* The provided host was actually invalid so we error out this negotiation */
        ast_debug(3, "Declining; provided host is invalid\n");
        return 0;
    }
 
    /* Check the address family to make sure it matches configured */
    if ((ast_sockaddr_is_ipv6(addrs) && !session->endpoint->media.t38.ipv6) ||
        (ast_sockaddr_is_ipv4(addrs) && session->endpoint->media.t38.ipv6)) {
        /* The address does not match configured */
        ast_debug(3, "Declining, provided host does not match configured address family\n");
        return 0;
    }
 
    return 1;
}

References AST_AF_UNSPEC, ast_copy_pj_str(), ast_debug, ast_free, ast_sockaddr_is_ipv4(), ast_sockaddr_is_ipv6(), ast_sockaddr_resolve(), NULL, PARSE_PORT_FORBID, RAII_VAR, session, state, t38_change_state(), T38_DISABLED, T38_REJECTED, and t38_state_get_or_alloc().

◆ stream_destroy()

static void stream_destroy ( struct ast_sip_session_media * session_media )

static

Function which destroys the UDPTL instance when session ends.

Definition at line 1105 of file res_pjsip_t38.c.

{
    if (session_media->udptl) {
        ast_udptl_destroy(session_media->udptl);
    }
    session_media->udptl = NULL;
}

References ast_udptl_destroy(), NULL, and ast_sip_session_media::udptl.

◆ t38_attach_framehook()

static void t38_attach_framehook ( struct ast_sip_session * session )

static

Function called to attach T.38 framehook to channel when appropriate.

Definition at line 650 of file res_pjsip_t38.c.

{
    int framehook_id;
    struct ast_datastore *datastore = NULL;
    static struct ast_framehook_interface hook = {
        .version = AST_FRAMEHOOK_INTERFACE_VERSION,
        .event_cb = t38_framehook,
        .consume_cb = t38_consume,
        .chan_fixup_cb = t38_masq,
        .chan_breakdown_cb = t38_masq,
    };
 
    /* If the channel's already gone, bail */
    if (!session->channel) {
        return;
    }
 
    /* Always attach the framehook so we can quickly reject */
 
    ast_channel_lock(session->channel);
 
    /* Skip attaching the framehook if the T.38 datastore already exists for the channel */
    datastore = ast_channel_datastore_find(session->channel, &t38_framehook_datastore,
        NULL);
    if (datastore) {
        ast_channel_unlock(session->channel);
        return;
    }
 
    framehook_id = ast_framehook_attach(session->channel, &hook);
    if (framehook_id < 0) {
        ast_log(LOG_WARNING, "Could not attach T.38 Frame hook, T.38 will be unavailable on '%s'\n",
            ast_channel_name(session->channel));
        ast_channel_unlock(session->channel);
        return;
    }
 
    datastore = ast_datastore_alloc(&t38_framehook_datastore, NULL);
    if (!datastore) {
        ast_log(LOG_ERROR, "Could not alloc T.38 Frame hook datastore, T.38 will be unavailable on '%s'\n",
            ast_channel_name(session->channel));
        ast_framehook_detach(session->channel, framehook_id);
        ast_channel_unlock(session->channel);
        return;
    }
 
    ast_channel_datastore_add(session->channel, datastore);
    ast_channel_unlock(session->channel);
}

References ast_channel_datastore_add(), ast_channel_datastore_find(), ast_channel_lock, ast_channel_name(), ast_channel_unlock, ast_datastore_alloc, ast_framehook_attach(), ast_framehook_detach(), AST_FRAMEHOOK_INTERFACE_VERSION, ast_log, LOG_ERROR, LOG_WARNING, NULL, session, t38_consume(), t38_framehook(), t38_framehook_datastore, t38_masq(), and ast_framehook_interface::version.

Referenced by t38_incoming_invite_request(), and t38_outgoing_invite_request().

◆ t38_automatic_reject()

static int t38_automatic_reject ( void * obj )

static

Task function which rejects a T.38 re-invite and resumes handling it.

Definition at line 202 of file res_pjsip_t38.c.

{
    RAII_VAR(struct ast_sip_session *, session, obj, ao2_cleanup);
    RAII_VAR(struct ast_datastore *, datastore, ast_sip_session_get_datastore(session, "t38"), ao2_cleanup);
 
    if (!datastore) {
        return 0;
    }
 
    ast_debug(2, "Automatically rejecting T.38 request on channel '%s'\n",
        session->channel ? ast_channel_name(session->channel) : "<gone>");
 
    t38_change_state(session, NULL, datastore->data, T38_REJECTED);
    ast_sip_session_resume_reinvite(session);
 
    return 0;
}

References ao2_cleanup, ast_channel_name(), ast_debug, ast_sip_session_get_datastore(), ast_sip_session_resume_reinvite(), NULL, RAII_VAR, session, t38_change_state(), and T38_REJECTED.

Referenced by t38_automatic_reject_timer_cb().

◆ t38_automatic_reject_timer_cb()

static void t38_automatic_reject_timer_cb	(	pj_timer_heap_t *	timer_heap,
		struct pj_timer_entry *	entry
	)

static

Timer entry callback which queues a task to reject a T.38 re-invite and resume handling it.

Definition at line 221 of file res_pjsip_t38.c.

{
    struct ast_sip_session *session = entry->user_data;
 
    if (ast_sip_push_task(session->serializer, t38_automatic_reject, session)) {
        ao2_ref(session, -1);
    }
}

References ao2_ref, ast_sip_push_task(), session, and t38_automatic_reject().

Referenced by t38_state_get_or_alloc().

◆ t38_change_state()

static void t38_change_state	(	struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media,
		struct t38_state *	state,
		enum ast_sip_session_t38state	new_state
	)

static

Helper function for changing the T.38 state.

Definition at line 129 of file res_pjsip_t38.c.

{
    enum ast_sip_session_t38state old_state = session->t38state;
    struct ast_control_t38_parameters parameters = { .request_response = 0, };
    pj_time_val delay = { .sec = T38_AUTOMATIC_REJECTION_SECONDS };
 
    if (old_state == new_state) {
        return;
    }
 
    session->t38state = new_state;
    ast_debug(2, "T.38 state changed to '%u' from '%u' on channel '%s'\n",
        new_state, old_state,
        session->channel ? ast_channel_name(session->channel) : "<gone>");
 
    if (pj_timer_heap_cancel_if_active(pjsip_endpt_get_timer_heap(ast_sip_get_pjsip_endpoint()),
        &state->timer, 0)) {
        ast_debug(2, "Automatic T.38 rejection on channel '%s' terminated\n",
            session->channel ? ast_channel_name(session->channel) : "<gone>");
        ao2_ref(session, -1);
    }
 
    if (!session->channel) {
        return;
    }
 
    switch (new_state) {
    case T38_PEER_REINVITE:
        ao2_ref(session, +1);
        if (pjsip_endpt_schedule_timer(ast_sip_get_pjsip_endpoint(), &state->timer, &delay) != PJ_SUCCESS) {
            ast_log(LOG_WARNING, "Scheduling of automatic T.38 rejection for channel '%s' failed\n",
                ast_channel_name(session->channel));
            ao2_ref(session, -1);
        }
        parameters = state->their_parms;
        parameters.max_ifp = ast_udptl_get_far_max_ifp(session_media->udptl);
        parameters.request_response = AST_T38_REQUEST_NEGOTIATE;
        ast_udptl_set_tag(session_media->udptl, "%s", ast_channel_name(session->channel));
 
        /* Inform the bridge the channel is in that it needs to be reconfigured */
        ast_channel_set_unbridged(session->channel, 1);
        break;
    case T38_ENABLED:
        parameters = state->their_parms;
        parameters.max_ifp = ast_udptl_get_far_max_ifp(session_media->udptl);
        parameters.request_response = AST_T38_NEGOTIATED;
        ast_udptl_set_tag(session_media->udptl, "%s", ast_channel_name(session->channel));
        break;
    case T38_REJECTED:
    case T38_DISABLED:
        if (old_state == T38_ENABLED) {
            parameters.request_response = AST_T38_TERMINATED;
        } else if (old_state == T38_LOCAL_REINVITE) {
            parameters.request_response = AST_T38_REFUSED;
        }
        break;
    case T38_LOCAL_REINVITE:
        /* Inform the bridge the channel is in that it needs to be reconfigured */
        ast_channel_set_unbridged(session->channel, 1);
        break;
    case T38_MAX_ENUM:
        /* Well, that shouldn't happen */
        ast_assert(0);
        break;
    }
 
    if (parameters.request_response) {
        ast_queue_control_data(session->channel, AST_CONTROL_T38_PARAMETERS, &parameters, sizeof(parameters));
    }
}

References ao2_ref, ast_assert, ast_channel_name(), ast_channel_set_unbridged(), AST_CONTROL_T38_PARAMETERS, ast_debug, ast_log, ast_queue_control_data(), ast_sip_get_pjsip_endpoint(), AST_T38_NEGOTIATED, AST_T38_REFUSED, AST_T38_REQUEST_NEGOTIATE, AST_T38_TERMINATED, ast_udptl_get_far_max_ifp(), ast_udptl_set_tag(), LOG_WARNING, ast_control_t38_parameters::max_ifp, ast_control_t38_parameters::request_response, session, T38_AUTOMATIC_REJECTION_SECONDS, T38_DISABLED, T38_ENABLED, T38_LOCAL_REINVITE, T38_MAX_ENUM, T38_PEER_REINVITE, T38_REJECTED, and ast_sip_session_media::udptl.

Referenced by defer_incoming_sdp_stream(), negotiate_incoming_sdp_stream(), t38_automatic_reject(), t38_interpret_parameters(), and t38_reinvite_response_cb().

◆ t38_consume()

static int t38_consume	(	void *	data,
		enum ast_frame_type	type
	)

static

Definition at line 640 of file res_pjsip_t38.c.

{
    return (type == AST_FRAME_CONTROL) ? 1 : 0;
}

References AST_FRAME_CONTROL, and type.

Referenced by t38_attach_framehook().

◆ t38_create_media_state()

static struct ast_sip_session_media_state * t38_create_media_state ( struct ast_sip_session * session )

static

Helper function which creates a media state for strictly T.38.

Definition at line 408 of file res_pjsip_t38.c.

{
    struct ast_sip_session_media_state *media_state;
    struct ast_stream *stream;
    struct ast_format_cap *caps;
    struct ast_sip_session_media *session_media;
 
    media_state = ast_sip_session_media_state_alloc();
    if (!media_state) {
        return NULL;
    }
 
    media_state->topology = ast_stream_topology_alloc();
    if (!media_state->topology) {
        ast_sip_session_media_state_free(media_state);
        return NULL;
    }
 
    stream = ast_stream_alloc("t38", AST_MEDIA_TYPE_IMAGE);
    if (!stream) {
        ast_sip_session_media_state_free(media_state);
        return NULL;
    }
 
    ast_stream_set_state(stream, AST_STREAM_STATE_SENDRECV);
    if (ast_stream_topology_set_stream(media_state->topology, 0, stream)) {
        ast_stream_free(stream);
        ast_sip_session_media_state_free(media_state);
        return NULL;
    }
 
    caps = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
    if (!caps) {
        ast_sip_session_media_state_free(media_state);
        return NULL;
    }
 
    ast_stream_set_formats(stream, caps);
    /* stream holds a reference to cap, release the local reference
     * now so we don't have to deal with it in the error condition. */
    ao2_ref(caps, -1);
    if (ast_format_cap_append(caps, ast_format_t38, 0)) {
        ast_sip_session_media_state_free(media_state);
        return NULL;
    }
 
    session_media = ast_sip_session_media_state_add(session, media_state, AST_MEDIA_TYPE_IMAGE, 0);
    if (!session_media) {
        ast_sip_session_media_state_free(media_state);
        return NULL;
    }
 
    if (t38_initialize_session(session, session_media)) {
        ast_sip_session_media_state_free(media_state);
        return NULL;
    }
 
    return media_state;
}

References ao2_ref, ast_format_cap_alloc, ast_format_cap_append, AST_FORMAT_CAP_FLAG_DEFAULT, ast_format_t38, AST_MEDIA_TYPE_IMAGE, ast_sip_session_media_state_add(), ast_sip_session_media_state_alloc(), ast_sip_session_media_state_free(), ast_stream_alloc(), ast_stream_free(), ast_stream_set_formats(), ast_stream_set_state(), AST_STREAM_STATE_SENDRECV, ast_stream_topology_alloc(), ast_stream_topology_set_stream(), NULL, session, t38_initialize_session(), and ast_sip_session_media_state::topology.

Referenced by t38_interpret_parameters().

◆ t38_framehook()

static struct ast_frame * t38_framehook	(	struct ast_channel *	chan,
		struct ast_frame *	f,
		enum ast_framehook_event	event,
		void *	data
	)

static

Frame hook callback for T.38 related stuff.

Definition at line 578 of file res_pjsip_t38.c.

{
    struct ast_sip_channel_pvt *channel = ast_channel_tech_pvt(chan);
 
    if (event != AST_FRAMEHOOK_EVENT_WRITE) {
        return f;
    }
 
    if (f->frametype == AST_FRAME_CONTROL
        && f->subclass.integer == AST_CONTROL_T38_PARAMETERS) {
        if (channel->session->endpoint->media.t38.enabled) {
            struct t38_parameters_task_data *task_data;
 
            task_data = t38_parameters_task_data_alloc(channel->session, f);
            if (task_data
                && ast_sip_push_task(channel->session->serializer,
                    t38_interpret_parameters, task_data)) {
                ao2_ref(task_data, -1);
            }
        } else {
            static const struct ast_control_t38_parameters rsp_refused = {
                .request_response = AST_T38_REFUSED,
            };
            static const struct ast_control_t38_parameters rsp_terminated = {
                .request_response = AST_T38_TERMINATED,
            };
            const struct ast_control_t38_parameters *parameters = f->data.ptr;
 
            switch (parameters->request_response) {
            case AST_T38_REQUEST_NEGOTIATE:
                ast_debug(2, "T.38 support not enabled on %s, refusing T.38 negotiation\n",
                    ast_channel_name(chan));
                ast_queue_control_data(chan, AST_CONTROL_T38_PARAMETERS,
                    &rsp_refused, sizeof(rsp_refused));
                break;
            case AST_T38_REQUEST_TERMINATE:
                ast_debug(2, "T.38 support not enabled on %s, 'terminating' T.38 session\n",
                    ast_channel_name(chan));
                ast_queue_control_data(chan, AST_CONTROL_T38_PARAMETERS,
                    &rsp_terminated, sizeof(rsp_terminated));
                break;
            default:
                break;
            }
        }
    }
 
    return f;
}

References ao2_ref, ast_channel_name(), ast_channel_tech_pvt(), AST_CONTROL_T38_PARAMETERS, ast_debug, AST_FRAME_CONTROL, AST_FRAMEHOOK_EVENT_WRITE, ast_queue_control_data(), ast_sip_push_task(), AST_T38_REFUSED, AST_T38_REQUEST_NEGOTIATE, AST_T38_REQUEST_TERMINATE, AST_T38_TERMINATED, ast_frame::data, ast_sip_t38_configuration::enabled, ast_sip_session::endpoint, ast_frame::frametype, ast_frame_subclass::integer, ast_sip_endpoint::media, ast_frame::ptr, ast_control_t38_parameters::request_response, ast_sip_session::serializer, ast_sip_channel_pvt::session, ast_frame::subclass, ast_sip_endpoint_media_configuration::t38, t38_interpret_parameters(), and t38_parameters_task_data_alloc().

Referenced by t38_attach_framehook().

◆ t38_get_rate()

static unsigned int t38_get_rate ( enum ast_control_t38_rate rate )

static

Get Max T.38 Transmission rate from T38 capabilities.

Definition at line 714 of file res_pjsip_t38.c.

{
    switch (rate) {
    case AST_T38_RATE_2400:
        return 2400;
    case AST_T38_RATE_4800:
        return 4800;
    case AST_T38_RATE_7200:
        return 7200;
    case AST_T38_RATE_9600:
        return 9600;
    case AST_T38_RATE_12000:
        return 12000;
    case AST_T38_RATE_14400:
        return 14400;
    default:
        return 0;
    }
}

References AST_T38_RATE_12000, AST_T38_RATE_14400, AST_T38_RATE_2400, AST_T38_RATE_4800, AST_T38_RATE_7200, and AST_T38_RATE_9600.

Referenced by create_outgoing_sdp_stream().

◆ t38_incoming_invite_request()

static int t38_incoming_invite_request	(	struct ast_sip_session *	session,
		struct pjsip_rx_data *	rdata
	)

static

Function called when an INVITE arrives.

Definition at line 701 of file res_pjsip_t38.c.

{
    t38_attach_framehook(session);
    return 0;
}

References session, and t38_attach_framehook().

◆ t38_initialize_session()

static int t38_initialize_session	(	struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media
	)

static

Initializes UDPTL support on a session, only done when actually needed.

Definition at line 256 of file res_pjsip_t38.c.

{
    struct ast_sockaddr temp_media_address;
    struct ast_sockaddr *media_address = &address;
 
    if (session_media->udptl) {
        return 0;
    }
 
    if (session->endpoint->media.t38.bind_udptl_to_media_address && !ast_strlen_zero(session->endpoint->media.address)) {
        if (ast_sockaddr_parse(&temp_media_address, session->endpoint->media.address, 0)) {
            ast_debug(5, "Endpoint %s: Binding UDPTL media to %s\n",
                ast_sorcery_object_get_id(session->endpoint),
                session->endpoint->media.address);
            media_address = &temp_media_address;
        } else {
            ast_debug(5, "Endpoint %s: UDPTL media address invalid: %s\n",
                ast_sorcery_object_get_id(session->endpoint),
                session->endpoint->media.address);
        }
    } else {
        struct ast_sip_transport *transport;
 
        transport = ast_sorcery_retrieve_by_id(ast_sip_get_sorcery(), "transport",
                session->endpoint->transport);
        if (transport) {
            struct ast_sip_transport_state *trans_state;
 
            trans_state = ast_sip_get_transport_state(ast_sorcery_object_get_id(transport));
            if (trans_state) {
                char hoststr[PJ_INET6_ADDRSTRLEN];
 
                pj_sockaddr_print(&trans_state->host, hoststr, sizeof(hoststr), 0);
                if (ast_sockaddr_parse(&temp_media_address, hoststr, 0)) {
                    ast_debug(5, "Transport %s bound to %s: Using it for UDPTL media.\n",
                        session->endpoint->transport, hoststr);
                    media_address = &temp_media_address;
                } else {
                    ast_debug(5, "Transport %s bound to %s: Invalid for UDPTL media.\n",
                        session->endpoint->transport, hoststr);
                }
                ao2_ref(trans_state, -1);
            }
            ao2_ref(transport, -1);
        }
    }
 
    if (!(session_media->udptl = ast_udptl_new_with_bindaddr(NULL, NULL, 0, media_address))) {
        return -1;
    }
 
    ast_udptl_set_error_correction_scheme(session_media->udptl, session->endpoint->media.t38.error_correction);
    ast_udptl_setnat(session_media->udptl, session->endpoint->media.t38.nat);
    ast_udptl_set_far_max_datagram(session_media->udptl, session->endpoint->media.t38.maxdatagram);
    ast_debug(3, "UDPTL initialized on session for %s\n", ast_channel_name(session->channel));
 
    return 0;
}

References address, ao2_ref, ast_channel_name(), ast_debug, ast_sip_get_sorcery(), ast_sip_get_transport_state(), ast_sockaddr_parse(), ast_sorcery_object_get_id(), ast_sorcery_retrieve_by_id(), ast_strlen_zero(), ast_udptl_new_with_bindaddr(), ast_udptl_set_error_correction_scheme(), ast_udptl_set_far_max_datagram(), ast_udptl_setnat(), ast_sip_transport_state::host, NULL, session, ast_sip_transport_state::transport, and ast_sip_session_media::udptl.

Referenced by create_outgoing_sdp_stream(), defer_incoming_sdp_stream(), and t38_create_media_state().

◆ t38_interpret_parameters()

static int t38_interpret_parameters ( void * obj )

static

Task for reacting to T.38 control frame.

Definition at line 469 of file res_pjsip_t38.c.

{
    RAII_VAR(struct t38_parameters_task_data *, data, obj, ao2_cleanup);
    const struct ast_control_t38_parameters *parameters = data->frame->data.ptr;
    struct t38_state *state = t38_state_get_or_alloc(data->session);
    struct ast_sip_session_media *session_media = NULL;
 
    if (!state) {
        return 0;
    }
 
    switch (parameters->request_response) {
    case AST_T38_NEGOTIATED:
    case AST_T38_REQUEST_NEGOTIATE:         /* Request T38 */
        /* Negotiation can not take place without a valid max_ifp value. */
        if (!parameters->max_ifp) {
            if (data->session->t38state == T38_PEER_REINVITE) {
                t38_change_state(data->session, NULL, state, T38_REJECTED);
                ast_sip_session_resume_reinvite(data->session);
            } else if (data->session->t38state == T38_ENABLED) {
                t38_change_state(data->session, NULL, state, T38_DISABLED);
                ast_sip_session_refresh(data->session, NULL, NULL, NULL,
                    AST_SIP_SESSION_REFRESH_METHOD_INVITE, 1, state->media_state);
                state->media_state = NULL;
            }
            break;
        } else if (data->session->t38state == T38_PEER_REINVITE) {
            state->our_parms = *parameters;
            /* modify our parameters to conform to the peer's parameters,
             * based on the rules in the ITU T.38 recommendation
             */
            if (!state->their_parms.fill_bit_removal) {
                state->our_parms.fill_bit_removal = 0;
            }
            if (!state->their_parms.transcoding_mmr) {
                state->our_parms.transcoding_mmr = 0;
            }
            if (!state->their_parms.transcoding_jbig) {
                state->our_parms.transcoding_jbig = 0;
            }
            state->our_parms.version = MIN(state->our_parms.version, state->their_parms.version);
            state->our_parms.rate_management = state->their_parms.rate_management;
            session_media = data->session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
            if (!session_media) {
                ast_log(LOG_ERROR, "Failed to negotiate parameters for reinvite on channel '%s' (No pending session media).\n",
                    data->session->channel ? ast_channel_name(data->session->channel) : "unknown channel");
                break;
            }
            ast_udptl_set_local_max_ifp(session_media->udptl, state->our_parms.max_ifp);
            t38_change_state(data->session, session_media, state, T38_ENABLED);
            ast_sip_session_resume_reinvite(data->session);
        } else if ((data->session->t38state != T38_ENABLED) ||
                ((data->session->t38state == T38_ENABLED) &&
                                (parameters->request_response == AST_T38_REQUEST_NEGOTIATE))) {
            struct ast_sip_session_media_state *media_state;
 
            media_state = t38_create_media_state(data->session);
            if (!media_state) {
                break;
            }
            state->our_parms = *parameters;
            session_media = media_state->default_session[AST_MEDIA_TYPE_IMAGE];
            if (!session_media) {
                ast_log(LOG_ERROR, "Failed to negotiate parameters on channel '%s' (No default session media).\n",
                    data->session->channel ? ast_channel_name(data->session->channel) : "unknown channel");
                break;
            }
            ast_udptl_set_local_max_ifp(session_media->udptl, state->our_parms.max_ifp);
            t38_change_state(data->session, NULL, state, T38_LOCAL_REINVITE);
            ast_sip_session_refresh(data->session, NULL, t38_reinvite_sdp_cb, t38_reinvite_response_cb,
                AST_SIP_SESSION_REFRESH_METHOD_INVITE, 1, media_state);
        }
        break;
    case AST_T38_TERMINATED:
    case AST_T38_REFUSED:
    case AST_T38_REQUEST_TERMINATE:         /* Shutdown T38 */
        if (data->session->t38state == T38_PEER_REINVITE) {
            t38_change_state(data->session, NULL, state, T38_REJECTED);
            ast_sip_session_resume_reinvite(data->session);
        } else if (data->session->t38state == T38_ENABLED) {
            t38_change_state(data->session, NULL, state, T38_DISABLED);
            ast_sip_session_refresh(data->session, NULL, NULL, NULL, AST_SIP_SESSION_REFRESH_METHOD_INVITE, 1, state->media_state);
            state->media_state = NULL;
        }
        break;
    case AST_T38_REQUEST_PARMS: {       /* Application wants remote's parameters re-sent */
        struct ast_control_t38_parameters parameters = state->their_parms;
 
        if (data->session->t38state == T38_PEER_REINVITE) {
            session_media = data->session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
            if (!session_media) {
                ast_log(LOG_ERROR, "Failed to request parameters for reinvite on channel '%s' (No pending session media).\n",
                    data->session->channel ? ast_channel_name(data->session->channel) : "unknown channel");
                break;
            }
            parameters.max_ifp = ast_udptl_get_far_max_ifp(session_media->udptl);
            parameters.request_response = AST_T38_REQUEST_NEGOTIATE;
            ast_queue_control_data(data->session->channel, AST_CONTROL_T38_PARAMETERS, &parameters, sizeof(parameters));
        }
        break;
    }
    default:
        break;
    }
 
    return 0;
}

References ao2_cleanup, ast_channel_name(), AST_CONTROL_T38_PARAMETERS, ast_log, AST_MEDIA_TYPE_IMAGE, ast_queue_control_data(), ast_sip_session_refresh(), AST_SIP_SESSION_REFRESH_METHOD_INVITE, ast_sip_session_resume_reinvite(), AST_T38_NEGOTIATED, AST_T38_REFUSED, AST_T38_REQUEST_NEGOTIATE, AST_T38_REQUEST_PARMS, AST_T38_REQUEST_TERMINATE, AST_T38_TERMINATED, ast_udptl_get_far_max_ifp(), ast_udptl_set_local_max_ifp(), ast_sip_session_media_state::default_session, LOG_ERROR, ast_control_t38_parameters::max_ifp, MIN, NULL, RAII_VAR, ast_control_t38_parameters::request_response, t38_change_state(), t38_create_media_state(), T38_DISABLED, T38_ENABLED, T38_LOCAL_REINVITE, T38_PEER_REINVITE, t38_reinvite_response_cb(), t38_reinvite_sdp_cb(), T38_REJECTED, t38_state_get_or_alloc(), and ast_sip_session_media::udptl.

Referenced by t38_framehook().

◆ t38_interpret_sdp()

static void t38_interpret_sdp	(	struct t38_state *	state,
		struct ast_sip_session *	session,
		struct ast_sip_session_media *	session_media,
		const struct pjmedia_sdp_media *	stream
	)

static

Parse a T.38 image stream and store the attribute information.

Definition at line 743 of file res_pjsip_t38.c.

{
    unsigned int attr_i;
 
    for (attr_i = 0; attr_i < stream->attr_count; attr_i++) {
        pjmedia_sdp_attr *attr = stream->attr[attr_i];
 
        if (!pj_stricmp2(&attr->name, "t38faxmaxbuffer")) {
            /* This is purposely left empty, it is unused */
        } else if (!pj_stricmp2(&attr->name, "t38maxbitrate") || !pj_stricmp2(&attr->name, "t38faxmaxrate")) {
            switch (pj_strtoul(&attr->value)) {
            case 14400:
                state->their_parms.rate = AST_T38_RATE_14400;
                break;
            case 12000:
                state->their_parms.rate = AST_T38_RATE_12000;
                break;
            case 9600:
                state->their_parms.rate = AST_T38_RATE_9600;
                break;
            case 7200:
                state->their_parms.rate = AST_T38_RATE_7200;
                break;
            case 4800:
                state->their_parms.rate = AST_T38_RATE_4800;
                break;
            case 2400:
                state->their_parms.rate = AST_T38_RATE_2400;
                break;
            }
        } else if (!pj_stricmp2(&attr->name, "t38faxversion")) {
            state->their_parms.version = pj_strtoul(&attr->value);
        } else if (!pj_stricmp2(&attr->name, "t38faxmaxdatagram") || !pj_stricmp2(&attr->name, "t38maxdatagram")) {
            if (!session->endpoint->media.t38.maxdatagram) {
                ast_udptl_set_far_max_datagram(session_media->udptl, pj_strtoul(&attr->value));
            }
        } else if (!pj_stricmp2(&attr->name, "t38faxfillbitremoval")) {
            state->their_parms.fill_bit_removal = 1;
        } else if (!pj_stricmp2(&attr->name, "t38faxtranscodingmmr")) {
            state->their_parms.transcoding_mmr = 1;
        } else if (!pj_stricmp2(&attr->name, "t38faxtranscodingjbig")) {
            state->their_parms.transcoding_jbig = 1;
        } else if (!pj_stricmp2(&attr->name, "t38faxratemanagement")) {
            if (!pj_stricmp2(&attr->value, "localTCF")) {
                state->their_parms.rate_management = AST_T38_RATE_MANAGEMENT_LOCAL_TCF;
            } else if (!pj_stricmp2(&attr->value, "transferredTCF")) {
                state->their_parms.rate_management = AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF;
            }
        } else if (!pj_stricmp2(&attr->name, "t38faxudpec")) {
            if (session->t38state == T38_LOCAL_REINVITE) {
                if (session->endpoint->media.t38.error_correction == UDPTL_ERROR_CORRECTION_FEC) {
                    if (!pj_stricmp2(&attr->value, "t38UDPFEC")) {
                        ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_FEC);
                    } else if (!pj_stricmp2(&attr->value, "t38UDPRedundancy")) {
                        ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_REDUNDANCY);
                    } else {
                        ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_NONE);
                    }
                } else if (session->endpoint->media.t38.error_correction == UDPTL_ERROR_CORRECTION_REDUNDANCY) {
                    if (!pj_stricmp2(&attr->value, "t38UDPRedundancy")) {
                        ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_REDUNDANCY);
                    } else {
                        ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_NONE);
                    }
                } else {
                    ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_NONE);
                }
            } else {
                if (!pj_stricmp2(&attr->value, "t38UDPRedundancy")) {
                    ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_REDUNDANCY);
                } else if (!pj_stricmp2(&attr->value, "t38UDPFEC")) {
                    ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_FEC);
                } else {
                    ast_udptl_set_error_correction_scheme(session_media->udptl, UDPTL_ERROR_CORRECTION_NONE);
                }
            }
        }
 
    }
}

References AST_T38_RATE_12000, AST_T38_RATE_14400, AST_T38_RATE_2400, AST_T38_RATE_4800, AST_T38_RATE_7200, AST_T38_RATE_9600, AST_T38_RATE_MANAGEMENT_LOCAL_TCF, AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF, ast_udptl_set_error_correction_scheme(), ast_udptl_set_far_max_datagram(), session, T38_LOCAL_REINVITE, ast_sip_session_media::udptl, UDPTL_ERROR_CORRECTION_FEC, UDPTL_ERROR_CORRECTION_NONE, and UDPTL_ERROR_CORRECTION_REDUNDANCY.

Referenced by apply_negotiated_sdp_stream(), and defer_incoming_sdp_stream().

◆ t38_masq()

static void t38_masq	(	void *	data,
		int	framehook_id,
		struct ast_channel *	old_chan,
		struct ast_channel *	new_chan
	)

static

Definition at line 629 of file res_pjsip_t38.c.

{
    if (ast_channel_tech(old_chan) == ast_channel_tech(new_chan)) {
        return;
    }
 
    /* This framehook is only applicable to PJSIP channels */
    ast_framehook_detach(new_chan, framehook_id);
}

References ast_channel_tech(), and ast_framehook_detach().

Referenced by t38_attach_framehook().

◆ t38_outgoing_invite_request()

static void t38_outgoing_invite_request	(	struct ast_sip_session *	session,
		struct pjsip_tx_data *	tdata
	)

static

Function called when an INVITE is sent.

Definition at line 708 of file res_pjsip_t38.c.

{
    t38_attach_framehook(session);
}

References session, and t38_attach_framehook().

◆ t38_parameters_task_data_alloc()

static struct t38_parameters_task_data * t38_parameters_task_data_alloc	(	struct ast_sip_session *	session,
		struct ast_frame *	frame
	)

static

Allocator for T.38 data.

Definition at line 108 of file res_pjsip_t38.c.

{
    struct t38_parameters_task_data *data = ao2_alloc(sizeof(*data), t38_parameters_task_data_destroy);
 
    if (!data) {
        return NULL;
    }
 
    data->session = session;
    ao2_ref(session, +1);
    data->frame = ast_frdup(frame);
    if (!data->frame) {
        ao2_ref(data, -1);
        data = NULL;
    }
 
    return data;
}

References ao2_alloc, ao2_ref, ast_frdup, t38_parameters_task_data::frame, NULL, t38_parameters_task_data::session, session, and t38_parameters_task_data_destroy().

Referenced by t38_framehook().

◆ t38_parameters_task_data_destroy()

static void t38_parameters_task_data_destroy ( void * obj )

static

Destructor for T.38 data.

Definition at line 96 of file res_pjsip_t38.c.

{
    struct t38_parameters_task_data *data = obj;
 
    ao2_cleanup(data->session);
 
    if (data->frame) {
        ast_frfree(data->frame);
    }
}

References ao2_cleanup, ast_frfree, t38_parameters_task_data::frame, and t38_parameters_task_data::session.

Referenced by t38_parameters_task_data_alloc().

◆ t38_reinvite_response_cb()

static int t38_reinvite_response_cb	(	struct ast_sip_session *	session,
		pjsip_rx_data *	rdata
	)

static

Callback for when a response is received for a T.38 re-invite.

Definition at line 331 of file res_pjsip_t38.c.

{
    struct pjsip_status_line status = rdata->msg_info.msg->line.status;
    struct t38_state *state;
    struct ast_sip_session_media *session_media = NULL;
 
    if (status.code / 100 <= 1) {
        /* Ignore any non-final responses (1xx) */
        return 0;
    }
 
    if (session->t38state != T38_LOCAL_REINVITE) {
        /* Do nothing.  We have already processed a final response. */
        ast_debug(3, "Received %d response to T.38 re-invite on '%s' but already had a final response (T.38 state:%d)\n",
            status.code,
            session->channel ? ast_channel_name(session->channel) : "unknown channel",
            session->t38state);
        return 0;
    }
 
    state = t38_state_get_or_alloc(session);
    if (!session->channel || !state) {
        ast_log(LOG_WARNING, "Received %d response to T.38 re-invite on '%s' but state unavailable\n",
            status.code,
            session->channel ? ast_channel_name(session->channel) : "unknown channel");
        return 0;
    }
 
    if (status.code / 100 == 2) {
        /* Accept any 2xx response as successfully negotiated */
        int index;
 
        session_media = session->active_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
 
        /*
         * If there is a session_media object, but no udptl object available
         * then it's assumed the stream was declined.
         */
        if (session_media && !session_media->udptl) {
            session_media = NULL;
        }
 
        if (!session_media) {
            ast_log(LOG_WARNING, "Received %d response to T.38 re-invite on '%s' but no active session media\n",
                    status.code, session->channel ? ast_channel_name(session->channel) : "unknown channel");
        } else {
            t38_change_state(session, session_media, state, T38_ENABLED);
 
            /* Stop all the streams in the stored away active state, they'll go back to being active once
             * we reinvite back.
             */
            for (index = 0; index < AST_VECTOR_SIZE(&state->media_state->sessions); ++index) {
                struct ast_sip_session_media *session_media = AST_VECTOR_GET(&state->media_state->sessions, index);
 
                if (session_media && session_media->handler && session_media->handler->stream_stop) {
                    session_media->handler->stream_stop(session_media);
                }
            }
 
            return 0;
        }
    } else {
        session_media = session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
    }
 
    /* If no session_media then response contained a declined stream, so disable */
    t38_change_state(session, NULL, state, session_media ? T38_REJECTED : T38_DISABLED);
 
    /* Abort this attempt at switching to T.38 by resetting the pending state and freeing our stored away active state */
    ast_sip_session_media_state_free(state->media_state);
    state->media_state = NULL;
    ast_sip_session_media_state_reset(session->pending_media_state);
 
    return 0;
}

References ast_channel_name(), ast_debug, ast_log, AST_MEDIA_TYPE_IMAGE, ast_sip_session_media_state_free(), ast_sip_session_media_state_reset(), AST_VECTOR_GET, AST_VECTOR_SIZE, ast_sip_session_media::handler, LOG_WARNING, NULL, session, state, status, ast_sip_session_sdp_handler::stream_stop, t38_change_state(), T38_DISABLED, T38_ENABLED, T38_LOCAL_REINVITE, T38_REJECTED, t38_state_get_or_alloc(), and ast_sip_session_media::udptl.

Referenced by t38_interpret_parameters().

◆ t38_reinvite_sdp_cb()

static int t38_reinvite_sdp_cb	(	struct ast_sip_session *	session,
		pjmedia_sdp_session *	sdp
	)

static

Callback for when T.38 reinvite SDP is created.

Definition at line 316 of file res_pjsip_t38.c.

{
    struct t38_state *state;
 
    state = t38_state_get_or_alloc(session);
    if (!state) {
        return -1;
    }
 
    state->media_state = ast_sip_session_media_state_clone(session->active_media_state);
 
    return 0;
}

References ast_sip_session_media_state_clone(), session, state, and t38_state_get_or_alloc().

Referenced by t38_interpret_parameters().

◆ t38_state_destroy()

static void t38_state_destroy ( void * obj )

static

Destructor for T.38 state information.

Definition at line 73 of file res_pjsip_t38.c.

{
    struct t38_state *state = obj;
 
    ast_sip_session_media_state_free(state->media_state);
    ast_free(obj);
}

References ast_free, and ast_sip_session_media_state_free().

◆ t38_state_get_or_alloc()

static struct t38_state * t38_state_get_or_alloc ( struct ast_sip_session * session )

static

Helper function which retrieves or allocates a T.38 state information datastore.

Definition at line 231 of file res_pjsip_t38.c.

{
    RAII_VAR(struct ast_datastore *, datastore, ast_sip_session_get_datastore(session, "t38"), ao2_cleanup);
    struct t38_state *state;
 
    /* While the datastore refcount is decremented this is operating in the serializer so it will remain valid regardless */
    if (datastore) {
        return datastore->data;
    }
 
    if (!(datastore = ast_sip_session_alloc_datastore(&t38_datastore, "t38"))
        || !(datastore->data = ast_calloc(1, sizeof(struct t38_state)))
        || ast_sip_session_add_datastore(session, datastore)) {
        return NULL;
    }
 
    state = datastore->data;
 
    /* This will get bumped up before scheduling */
    pj_timer_entry_init(&state->timer, 0, session, t38_automatic_reject_timer_cb);
 
    return state;
}

References ao2_cleanup, ast_calloc, ast_sip_session_add_datastore(), ast_sip_session_alloc_datastore(), ast_sip_session_get_datastore(), NULL, RAII_VAR, session, state, t38_automatic_reject_timer_cb(), and t38_datastore.

Referenced by apply_negotiated_sdp_stream(), create_outgoing_sdp_stream(), defer_incoming_sdp_stream(), negotiate_incoming_sdp_stream(), t38_interpret_parameters(), t38_reinvite_response_cb(), and t38_reinvite_sdp_cb().

◆ unload_module()

static int unload_module ( void )

static

Unloads the SIP T.38 module from Asterisk.

Definition at line 1125 of file res_pjsip_t38.c.

{
    ast_sip_session_unregister_sdp_handler(&image_sdp_handler, "image");
    ast_sip_session_unregister_supplement(&t38_supplement);
 
    return 0;
}

References ast_sip_session_unregister_sdp_handler(), ast_sip_session_unregister_supplement(), image_sdp_handler, and t38_supplement.

Referenced by load_module().

Variable Documentation

◆ __mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_LOAD_ORDER , .description = "PJSIP T.38 UDPTL Support" , .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 = AST_BUILDOPT_SUM, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .load_pri = AST_MODPRI_CHANNEL_DRIVER, .requires = "res_pjsip,res_pjsip_session,udptl", }

static

Definition at line 1171 of file res_pjsip_t38.c.

◆ address

struct ast_sockaddr address

static

Address for UDPTL.

Definition at line 56 of file res_pjsip_t38.c.

Referenced by t38_initialize_session().

◆ ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 1171 of file res_pjsip_t38.c.

◆ image_sdp_handler

struct ast_sip_session_sdp_handler image_sdp_handler

static

SDP handler for 'image' media stream.

Definition at line 1114 of file res_pjsip_t38.c.

Referenced by load_module(), and unload_module().

◆ t38_datastore

const struct ast_datastore_info t38_datastore

static

Initial value:

= {
    .type = "t38",
    .destroy = t38_state_destroy,
}

Datastore for attaching T.38 state information.

Definition at line 82 of file res_pjsip_t38.c.

Referenced by t38_state_get_or_alloc().

◆ t38_framehook_datastore

const struct ast_datastore_info t38_framehook_datastore

static

Initial value:

= {
    .type = "T38 framehook",
}

Definition at line 645 of file res_pjsip_t38.c.

Referenced by t38_attach_framehook().

◆ t38_supplement

struct ast_sip_session_supplement t38_supplement

static

Supplement for adding framehook to session channel.

Definition at line 735 of file res_pjsip_t38.c.

Referenced by load_module(), and unload_module().

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ T38_AUTOMATIC_REJECTION_SECONDS

Function Documentation

◆ __reg_module()

◆ __unreg_module()

◆ apply_negotiated_sdp_stream()

◆ AST_MODULE_SELF_SYM()

◆ change_outgoing_sdp_stream_media_address()

◆ create_outgoing_sdp_stream()

◆ defer_incoming_sdp_stream()

◆ load_module()

◆ media_session_udptl_read_callback()

◆ media_session_udptl_write_callback()

◆ negotiate_incoming_sdp_stream()

◆ stream_destroy()

◆ t38_attach_framehook()

◆ t38_automatic_reject()

◆ t38_automatic_reject_timer_cb()

◆ t38_change_state()

◆ t38_consume()

◆ t38_create_media_state()

◆ t38_framehook()

◆ t38_get_rate()

◆ t38_incoming_invite_request()

◆ t38_initialize_session()

◆ t38_interpret_parameters()

◆ t38_interpret_sdp()

◆ t38_masq()

◆ t38_outgoing_invite_request()

◆ t38_parameters_task_data_alloc()

◆ t38_parameters_task_data_destroy()

◆ t38_reinvite_response_cb()

◆ t38_reinvite_sdp_cb()

◆ t38_state_destroy()

◆ t38_state_get_or_alloc()

◆ unload_module()

Variable Documentation

◆ __mod_info

◆ address

◆ ast_module_info

◆ image_sdp_handler

◆ t38_datastore

◆ t38_framehook_datastore

◆ t38_supplement