/*! \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) {
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 */
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 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) {
return AST_SIP_SESSION_SDP_DEFER_NOT_HANDLED;
}
if (t38_initialize_session(session, session_media)) {
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);
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 -1;
}
if (!(state = t38_state_get_or_alloc(session))) {
return -1;
}
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 -1;
}
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 -1;
}
/* 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 -1;
}
return 1;
}
/*! \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, NULL, ao2_cleanup);
if (status.code == 100) {
return 0;
}
if (!(state = t38_state_get_or_alloc(session)) ||
!(session_media = ao2_find(session->media, "image", OBJ_KEY))) {
ast_log(LOG_WARNING, "Received response to T.38 re-invite on '%s' but state unavailable\n",
ast_channel_name(session->channel));
return 0;
}
t38_change_state(session, session_media, state, (status.code == 200) ? T38_ENABLED : T38_REJECTED);
return 0;
}
/*! \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) {
return 1;
} else if ((session->t38state != T38_LOCAL_REINVITE) && (session->t38state != T38_PEER_REINVITE) &&
(session->t38state != T38_ENABLED)) {
return 1;
} else if (!(state = t38_state_get_or_alloc(session))) {
return -1;
} else if (t38_initialize_session(session, session_media)) {
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)) {
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 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) {
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;
}
