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- /*
- * Asterisk -- An open source telephony toolkit.
- *
- * Copyright (C) 2013, Digium, Inc.
- *
- * Joshua Colp <jcolp@digium.com>
- *
- * See http://www.asterisk.org for more information about
- * the Asterisk project. Please do not directly contact
- * any of the maintainers of this project for assistance;
- * the project provides a web site, mailing lists and IRC
- * channels for your use.
- *
- * This program is free software, distributed under the terms of
- * the GNU General Public License Version 2. See the LICENSE file
- * at the top of the source tree.
- */
- /*! \file
- *
- * \author Joshua Colp <jcolp@digium.com>
- *
- * \brief SIP T.38 handling
- */
- /*** MODULEINFO
- <depend>pjproject</depend>
- <depend>res_pjsip</depend>
- <depend>res_pjsip_session</depend>
- <support_level>core</support_level>
- ***/
- #include "asterisk.h"
- #include <pjsip.h>
- #include <pjsip_ua.h>
- #include <pjmedia.h>
- #include <pjlib.h>
- ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
- #include "asterisk/module.h"
- #include "asterisk/udptl.h"
- #include "asterisk/netsock2.h"
- #include "asterisk/channel.h"
- #include "asterisk/acl.h"
- #include "asterisk/utils.h"
- #include "asterisk/res_pjsip.h"
- #include "asterisk/res_pjsip_session.h"
- /*! \brief The number of seconds after receiving a T.38 re-invite before automatically rejecting it */
- #define T38_AUTOMATIC_REJECTION_SECONDS 5
- /*! \brief Address for UDPTL */
- static struct ast_sockaddr address;
- /*! \brief T.38 state information */
- struct t38_state {
- /*! \brief Current state */
- enum ast_sip_session_t38state state;
- /*! \brief Our T.38 parameters */
- struct ast_control_t38_parameters our_parms;
- /*! \brief Their T.38 parameters */
- struct ast_control_t38_parameters their_parms;
- /*! \brief Timer entry for automatically rejecting an inbound re-invite */
- pj_timer_entry timer;
- };
- /*! \brief Destructor for T.38 state information */
- static void t38_state_destroy(void *obj)
- {
- ast_free(obj);
- }
- /*! \brief Datastore for attaching T.38 state information */
- static const struct ast_datastore_info t38_datastore = {
- .type = "t38",
- .destroy = t38_state_destroy,
- };
- static void session_media_dec(void *obj)
- {
- ao2_cleanup(obj);
- }
- /*! \brief Datastore for T.38 session_media information */
- static const struct ast_datastore_info session_media_datastore = {
- .type = "t38_session_media",
- .destroy = session_media_dec,
- };
- /*! \brief Structure for T.38 parameters task data */
- struct t38_parameters_task_data {
- /*! \brief Session itself */
- struct ast_sip_session *session;
- /*! \brief T.38 control frame */
- struct ast_frame *frame;
- };
- /*! \brief Destructor for T.38 data */
- static void t38_parameters_task_data_destroy(void *obj)
- {
- struct t38_parameters_task_data *data = obj;
- ao2_cleanup(data->session);
- if (data->frame) {
- ast_frfree(data->frame);
- }
- }
- /*! \brief Allocator for T.38 data */
- static struct t38_parameters_task_data *t38_parameters_task_data_alloc(struct ast_sip_session *session,
- struct ast_frame *frame)
- {
- 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;
- }
- /*! \brief Helper function which retrieves a T.38 session_media from datastore */
- static struct ast_sip_session_media *session_media_from_datastore_addref(struct ast_sip_session *session)
- {
- struct ast_datastore *datastore = NULL;
- struct ast_sip_session_media *session_media = NULL;
- if ((datastore = ast_sip_session_get_datastore(session, "t38_session_media"))) {
- session_media = datastore->data;
- ao2_ref(session_media, +1);
- ao2_ref(datastore, -1);
- }
- return session_media;
- }
- /*! \brief Helper function which allocates datastore with a session media */
- static int create_datastore_session_media(struct ast_sip_session *session, struct ast_sip_session_media *session_media)
- {
- struct ast_datastore *datastore = NULL;
- if (!(datastore = ast_sip_session_alloc_datastore(&session_media_datastore, "t38_session_media"))) {
- return -1;
- }
- if (ast_sip_session_add_datastore(session, datastore)) {
- ao2_ref(datastore, -1);
- return -1;
- }
- datastore->data = session_media;
- ao2_bump(session_media);
- ao2_ref(datastore, -1);
- return 0;
- }
- /*! \brief Helper function for changing the T.38 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)
- {
- 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, ¶meters, sizeof(parameters));
- }
- }
- /*! \brief Task function which rejects a T.38 re-invite and resumes handling it */
- static int t38_automatic_reject(void *obj)
- {
- 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);
- RAII_VAR(struct ast_sip_session_media *, session_media, session_media_from_datastore_addref(session), 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, session_media, datastore->data, T38_REJECTED);
- ast_sip_session_resume_reinvite(session);
- return 0;
- }
- /*! \brief Timer entry callback which queues a task to reject a T.38 re-invite and resume handling it */
- static void t38_automatic_reject_timer_cb(pj_timer_heap_t *timer_heap, struct pj_timer_entry *entry)
- {
- struct ast_sip_session *session = entry->user_data;
- if (ast_sip_push_task(session->serializer, t38_automatic_reject, session)) {
- ao2_ref(session, -1);
- }
- }
- /*! \brief Helper function which retrieves or allocates a T.38 state information datastore */
- static struct t38_state *t38_state_get_or_alloc(struct ast_sip_session *session)
- {
- 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;
- }
- /*! \brief Initializes UDPTL support on a session, only done when actually needed */
- static int t38_initialize_session(struct ast_sip_session *session, struct ast_sip_session_media *session_media)
- {
- if (session_media->udptl) {
- return 0;
- }
- if (create_datastore_session_media(session, session_media)) {
- return -1;
- }
- if (!(session_media->udptl = ast_udptl_new_with_bindaddr(NULL, NULL, 0, &address))) {
- return -1;
- }
- ast_channel_set_fd(session->channel, 5, ast_udptl_fd(session_media->udptl));
- 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;
- }
- /*! \brief Callback for when T.38 reinvite SDP is created */
- static int t38_reinvite_sdp_cb(struct ast_sip_session *session, pjmedia_sdp_session *sdp)
- {
- int stream;
- /* Move the image media stream to the front and have it as the only stream, pjmedia will fill in
- * dummy streams for the rest
- */
- for (stream = 0; stream < sdp->media_count; ++stream) {
- if (!pj_strcmp2(&sdp->media[stream]->desc.media, "image")) {
- sdp->media[0] = sdp->media[stream];
- sdp->media_count = 1;
- break;
- }
- }
- return 0;
- }
- /*! \brief Callback for when a response is received for a T.38 re-invite */
- static int t38_reinvite_response_cb(struct ast_sip_session *session, pjsip_rx_data *rdata)
- {
- struct pjsip_status_line status = rdata->msg_info.msg->line.status;
- struct t38_state *state;
- RAII_VAR(struct ast_sip_session_media *, session_media,
- session_media_from_datastore_addref(session), ao2_cleanup);
- if (status.code / 100 <= 1) {
- /* Ignore any non-final responses (1xx) */
- return 0;
- }
- if (!session->channel || !(state = t38_state_get_or_alloc(session)) ||
- !session_media) {
- 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;
- }
- /* Accept any 2xx response as successfully negotiated */
- t38_change_state(session, session_media, state,
- (status.code / 100 == 2) ? T38_ENABLED : T38_REJECTED);
- return 0;
- }
- /*! \brief Task for reacting to T.38 control frame */
- static int t38_interpret_parameters(void *obj)
- {
- 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);
- RAII_VAR(struct ast_sip_session_media *, session_media, ao2_find(data->session->media, "image", OBJ_KEY), ao2_cleanup);
- /* Without session media or state we can't interpret parameters */
- if (!session_media || !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, session_media, state, T38_REJECTED);
- ast_sip_session_resume_reinvite(data->session);
- } else if (data->session->t38state == T38_ENABLED) {
- t38_change_state(data->session, session_media, state, T38_DISABLED);
- ast_sip_session_refresh(data->session, NULL, NULL, NULL,
- AST_SIP_SESSION_REFRESH_METHOD_INVITE, 1);
- }
- 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;
- 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))) {
- if (t38_initialize_session(data->session, session_media)) {
- break;
- }
- state->our_parms = *parameters;
- ast_udptl_set_local_max_ifp(session_media->udptl, state->our_parms.max_ifp);
- t38_change_state(data->session, session_media, 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);
- }
- 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, session_media, state, T38_REJECTED);
- ast_sip_session_resume_reinvite(data->session);
- } else if (data->session->t38state == T38_ENABLED) {
- t38_change_state(data->session, session_media, state, T38_DISABLED);
- ast_sip_session_refresh(data->session, NULL, NULL, NULL, AST_SIP_SESSION_REFRESH_METHOD_INVITE, 1);
- }
- 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) {
- 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, ¶meters, sizeof(parameters));
- }
- break;
- }
- default:
- break;
- }
- return 0;
- }
- /*! \brief Frame hook callback for writing */
- static struct ast_frame *t38_framehook_write(struct ast_channel *chan,
- struct ast_sip_session *session, struct ast_frame *f)
- {
- if (f->frametype == AST_FRAME_CONTROL
- && f->subclass.integer == AST_CONTROL_T38_PARAMETERS) {
- if (session->endpoint->media.t38.enabled) {
- struct t38_parameters_task_data *data;
- data = t38_parameters_task_data_alloc(session, f);
- if (data
- && ast_sip_push_task(session->serializer,
- t38_interpret_parameters, data)) {
- ao2_ref(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;
- }
- }
- } else if (f->frametype == AST_FRAME_MODEM) {
- struct ast_sip_session_media *session_media;
- session_media = session_media_from_datastore_addref(session);
- if (session_media && session_media->udptl) {
- ast_udptl_write(session_media->udptl, f);
- }
- ao2_cleanup(session_media);
- }
- return f;
- }
- /*! \brief Frame hook callback for reading */
- static struct ast_frame *t38_framehook_read(struct ast_channel *chan,
- struct ast_sip_session *session, struct ast_frame *f)
- {
- if (ast_channel_fdno(session->channel) == 5) {
- struct ast_sip_session_media *session_media;
- session_media = session_media_from_datastore_addref(session);
- if (session_media && session_media->udptl) {
- f = ast_udptl_read(session_media->udptl);
- }
- ao2_cleanup(session_media);
- }
- return f;
- }
- /*! \brief Frame hook callback for T.38 related stuff */
- static struct ast_frame *t38_framehook(struct ast_channel *chan, struct ast_frame *f,
- enum ast_framehook_event event, void *data)
- {
- struct ast_sip_channel_pvt *channel = ast_channel_tech_pvt(chan);
- if (event == AST_FRAMEHOOK_EVENT_READ) {
- f = t38_framehook_read(chan, channel->session, f);
- } else if (event == AST_FRAMEHOOK_EVENT_WRITE) {
- f = t38_framehook_write(chan, channel->session, f);
- }
- return f;
- }
- static void t38_masq(void *data, int framehook_id,
- struct ast_channel *old_chan, struct ast_channel *new_chan)
- {
- 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);
- }
- static int t38_consume(void *data, enum ast_frame_type type)
- {
- return 0;
- }
- static const struct ast_datastore_info t38_framehook_datastore = {
- .type = "T38 framehook",
- };
- /*! \brief Function called to attach T.38 framehook to channel when appropriate */
- static void t38_attach_framehook(struct ast_sip_session *session)
- {
- 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);
- }
- /*! \brief Function called when an INVITE arrives */
- static int t38_incoming_invite_request(struct ast_sip_session *session, struct pjsip_rx_data *rdata)
- {
- t38_attach_framehook(session);
- return 0;
- }
- /*! \brief Function called when an INVITE is sent */
- static void t38_outgoing_invite_request(struct ast_sip_session *session, struct pjsip_tx_data *tdata)
- {
- t38_attach_framehook(session);
- }
- /*! \brief Get Max T.38 Transmission rate from T38 capabilities */
- static unsigned int t38_get_rate(enum ast_control_t38_rate rate)
- {
- 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;
- }
- }
- /*! \brief Supplement for adding framehook to session channel */
- static struct ast_sip_session_supplement t38_supplement = {
- .method = "INVITE",
- .priority = AST_SIP_SUPPLEMENT_PRIORITY_CHANNEL + 1,
- .incoming_request = t38_incoming_invite_request,
- .outgoing_request = t38_outgoing_invite_request,
- };
- /*! \brief Parse a T.38 image stream and store the attribute information */
- 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)
- {
- 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 (!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);
- }
- }
- }
- }
- /*! \brief Function which defers an incoming media 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)
- {
- 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;
- }
- /*! \brief Function which negotiates an incoming media 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, const struct pjmedia_sdp_media *stream)
- {
- struct t38_state *state;
- char host[NI_MAXHOST];
- 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, session_media, 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_INET) <= 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;
- }
- /*! \brief Function which creates an outgoing stream */
- static int create_outgoing_sdp_stream(struct ast_sip_session *session, struct ast_sip_session_media *session_media,
- struct pjmedia_sdp_session *sdp)
- {
- 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;
- }
- media->desc.media = pj_str(session_media->stream_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;
- }
- /*! \brief Function which applies a negotiated 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_media *local_stream,
- const struct pjmedia_sdp_session *remote, const struct pjmedia_sdp_media *remote_stream)
- {
- RAII_VAR(struct ast_sockaddr *, addrs, NULL, ast_free);
- 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);
- return 0;
- }
- /*! \brief Function which updates the media stream with external media address, if applicable */
- static void change_outgoing_sdp_stream_media_address(pjsip_tx_data *tdata, struct pjmedia_sdp_media *stream, struct ast_sip_transport *transport)
- {
- 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_host(&transport_state->external_media_address));
- pj_strdup2(tdata->pool, &stream->conn->addr, ast_sockaddr_stringify_host(&transport_state->external_media_address));
- }
- /*! \brief Function which destroys the UDPTL instance when session ends */
- static void stream_destroy(struct ast_sip_session_media *session_media)
- {
- if (session_media->udptl) {
- ast_udptl_destroy(session_media->udptl);
- }
- session_media->udptl = NULL;
- }
- /*! \brief SDP handler for 'image' media stream */
- static struct ast_sip_session_sdp_handler image_sdp_handler = {
- .id = "image",
- .defer_incoming_sdp_stream = defer_incoming_sdp_stream,
- .negotiate_incoming_sdp_stream = negotiate_incoming_sdp_stream,
- .create_outgoing_sdp_stream = create_outgoing_sdp_stream,
- .apply_negotiated_sdp_stream = apply_negotiated_sdp_stream,
- .change_outgoing_sdp_stream_media_address = change_outgoing_sdp_stream_media_address,
- .stream_destroy = stream_destroy,
- };
- /*! \brief Unloads the SIP T.38 module from Asterisk */
- static int unload_module(void)
- {
- ast_sip_session_unregister_sdp_handler(&image_sdp_handler, "image");
- ast_sip_session_unregister_supplement(&t38_supplement);
- return 0;
- }
- /*!
- * \brief 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.
- */
- static int load_module(void)
- {
- CHECK_PJSIP_SESSION_MODULE_LOADED();
- if (ast_check_ipv6()) {
- ast_sockaddr_parse(&address, "::", 0);
- } else {
- ast_sockaddr_parse(&address, "0.0.0.0", 0);
- }
- if (ast_sip_session_register_supplement(&t38_supplement)) {
- ast_log(LOG_ERROR, "Unable to register T.38 session supplement\n");
- goto end;
- }
- 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;
- }
- AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PJSIP T.38 UDPTL Support",
- .support_level = AST_MODULE_SUPPORT_CORE,
- .load = load_module,
- .unload = unload_module,
- .load_pri = AST_MODPRI_CHANNEL_DRIVER,
- );
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