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res_pjsip_session/res_pjsip_sdp_rtp: Be more tolerant of offers

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When an inbound SDP offer is received, Asterisk currently makes a few
incorrection assumptions:

(1) If the offer contains more than a single audio/video stream, Asterisk will
    reject the entire stream with a 488. This is an overly strict response;
    generally, Asterisk should accept the media streams that it can accept and
    decline the others.
(2) If the offer contains a declined media stream, Asterisk will attempt to
    process it anyway. This can result in attempting to match format
    capabilities on a declined media stream, leading to a 488. Asterisk should
    simply ignore declined media streams.
(3) Asterisk will currently attempt to handle offers with AVPF with
    use_avpf=No/AVP with use_avpf=Yes. This mismatch results in invalid SDP
    answers being sent in response. If there is a mismatch between the media
    type being offered and the configuration, Asterisk must reject the offer
    with a 488.

This patch does the following:
* Asterisk will accept SDP offers with at least one media stream that it can
  use. Some WARNING messages have been dropped to NOTICEs as a result.
* Asterisk will not accept an offer with a media type that doesn't match its
  configuration.
* Asterisk will ignore declined media streams properly.

#SIPit31

Review: https://reviewboard.asterisk.org/r/4063/

ASTERISK-24122 #close
Reported by: James Van Vleet

ASTERISK-24381 #close
Reported by: Matt Jordan
........

Merged revisions 425868 from http://svn.asterisk.org/svn/asterisk/branches/12
........

Merged revisions 425879 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@425881 65c4cc65-6c06-0410-ace0-fbb531ad65f3
changes/42/42/1
Matthew Jordan 11 years ago
parent 0d0e38a0e1
commit 8f58592252
3 changed files with 58 additions and 172 deletions
Show Stats Download Patch File Download Diff File

5
res/res_pjsip.c
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@ -386,9 +386,8 @@
decline media offers not using the AVPF or SAVPF profile.
</para><para>
If set to <literal>no</literal>, res_pjsip will use the AVP or SAVP RTP
profile for all media offers on outbound calls and media updates, but will
accept either the AVP/AVPF or SAVP/SAVPF RTP profile for all inbound
media offers.
profile for all media offers on outbound calls and media updates, and will
decline media offers not using the AVP or SAVP profile.
</para></description>
</configOption>
<configOption name="force_avp" default="no">

31
res/res_pjsip_sdp_rtp.c
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@ -247,9 +247,10 @@ static int set_caps(struct ast_sip_session *session, struct ast_sip_session_medi
struct ast_str *thembuf = ast_str_alloca(64);
ast_rtp_codecs_payloads_destroy(&codecs);
ast_log(LOG_WARNING, "No joint capabilities between our configuration(%s) and incoming SDP(%s)\n",
ast_format_cap_get_names(peer, &usbuf),
ast_format_cap_get_names(caps, &thembuf));
ast_log(LOG_NOTICE, "No joint capabilities for '%s' media stream between our configuration(%s) and incoming SDP(%s)\n",
session_media->stream_type,
ast_format_cap_get_names(caps, &usbuf),
ast_format_cap_get_names(peer, &thembuf));
return -1;
}
@ -521,12 +522,11 @@ static enum ast_sip_session_media_encryption check_endpoint_media_transport(
const struct pjmedia_sdp_media *stream)
{
enum ast_sip_session_media_encryption incoming_encryption;
char transport_end = stream->desc.transport.ptr[stream->desc.transport.slen - 1];
if (endpoint->media.rtp.use_avpf) {
char transport_end = stream->desc.transport.ptr[stream->desc.transport.slen - 1];
if (transport_end != 'F') {
return AST_SIP_MEDIA_TRANSPORT_INVALID;
}
if ((transport_end == 'F' && !endpoint->media.rtp.use_avpf)
|| (transport_end != 'F' && endpoint->media.rtp.use_avpf)) {
return AST_SIP_MEDIA_TRANSPORT_INVALID;
}
incoming_encryption = get_media_encryption_type(stream->desc.transport);
@ -727,8 +727,15 @@ static int negotiate_incoming_sdp_stream(struct ast_sip_session *session, struct
RAII_VAR(struct ast_sockaddr *, addrs, NULL, ast_free_ptr);
enum ast_media_type media_type = stream_to_media_type(session_media->stream_type);
/* If port is 0, ignore this media stream */
if (!stream->desc.port) {
ast_debug(3, "Media stream '%s' is already declined\n", session_media->stream_type);
return 0;
}
/* If no type formats have been configured reject this stream */
if (!ast_format_cap_has_type(session->endpoint->media.codecs, media_type)) {
ast_debug(3, "Endpoint has no codecs for media type '%s', declining stream\n", session_media->stream_type);
return 0;
}
@ -760,7 +767,7 @@ static int negotiate_incoming_sdp_stream(struct ast_sip_session *session, struct
}
if (set_caps(session, session_media, stream)) {
return -1;
return 0;
}
return 1;
}
@ -1061,6 +1068,10 @@ static int apply_negotiated_sdp_stream(struct ast_sip_session *session, struct a
return 1;
}
if (!local_stream->desc.port || !remote_stream->desc.port) {
return 1;
}
/* Ensure incoming transport is compatible with the endpoint's configuration */
if (!session->endpoint->media.rtp.use_received_transport &&
check_endpoint_media_transport(session->endpoint, remote_stream) == AST_SIP_MEDIA_TRANSPORT_INVALID) {
@ -1088,7 +1099,7 @@ static int apply_negotiated_sdp_stream(struct ast_sip_session *session, struct a
ast_sockaddr_set_port(addrs, remote_stream->desc.port);
ast_rtp_instance_set_remote_address(session_media->rtp, addrs);
if (set_caps(session, session_media, local_stream)) {
return -1;
return 1;
}
if ((fdno = media_type_to_fdno(media_type)) < 0) {

194
res/res_pjsip_session.c
Unescape View File

@ -186,160 +186,10 @@ void ast_sip_session_unregister_sdp_handler(struct ast_sip_session_sdp_handler *
ao2_callback_data(sdp_handlers, OBJ_KEY | OBJ_UNLINK | OBJ_NODATA, remove_handler, (void *)stream_type, handler);
}
static int validate_port_hash(const void *obj, int flags)
{
const int *port = obj;
return *port;
}
static int validate_port_cmp(void *obj, void *arg, int flags)
{
int *port1 = obj;
int *port2 = arg;
return *port1 == *port2 ? CMP_MATCH | CMP_STOP : 0;
}
struct bundle_assoc {
int port;
char tag[1];
};
static int bundle_assoc_hash(const void *obj, int flags)
{
const struct bundle_assoc *assoc = obj;
const char *tag = flags & OBJ_KEY ? obj : assoc->tag;
return ast_str_hash(tag);
}
static int bundle_assoc_cmp(void *obj, void *arg, int flags)
{
struct bundle_assoc *assoc1 = obj;
struct bundle_assoc *assoc2 = arg;
const char *tag2 = flags & OBJ_KEY ? arg : assoc2->tag;
return strcmp(assoc1->tag, tag2) ? 0 : CMP_MATCH | CMP_STOP;
}
/* return must be ast_freed */
static pjmedia_sdp_attr *media_get_mid(pjmedia_sdp_media *media)
{
pjmedia_sdp_attr *attr = pjmedia_sdp_media_find_attr2(media, "mid", NULL);
if (!attr) {
return NULL;
}
return attr;
}
static int get_bundle_port(const pjmedia_sdp_session *sdp, const char *mid)
{
int i;
for (i = 0; i < sdp->media_count; ++i) {
pjmedia_sdp_attr *mid_attr = media_get_mid(sdp->media[i]);
if (mid_attr && !pj_strcmp2(&mid_attr->value, mid)) {
return sdp->media[i]->desc.port;
}
}
return -1;
}
static int validate_incoming_sdp(const pjmedia_sdp_session *sdp)
{
int i;
RAII_VAR(struct ao2_container *, portlist, ao2_container_alloc(5, validate_port_hash, validate_port_cmp), ao2_cleanup);
RAII_VAR(struct ao2_container *, bundle_assoc_list, ao2_container_alloc(5, bundle_assoc_hash, bundle_assoc_cmp), ao2_cleanup);
/* check for bundles (for websocket RTP multiplexing, there can be more than one) */
for (i = 0; i < sdp->attr_count; ++i) {
char *bundle_list;
int bundle_port = 0;
if (pj_stricmp2(&sdp->attr[i]->name, "group")) {
continue;
}
/* check to see if this group is a bundle */
if (7 >= sdp->attr[i]->value.slen || pj_strnicmp2(&sdp->attr[i]->value, "bundle ", 7)) {
continue;
}
bundle_list = ast_alloca(sdp->attr[i]->value.slen - 6);
strncpy(bundle_list, sdp->attr[i]->value.ptr + 7, sdp->attr[i]->value.slen - 7);
bundle_list[sdp->attr[i]->value.slen - 7] = '\0';
while (bundle_list) {
char *item;
RAII_VAR(struct bundle_assoc *, assoc, NULL, ao2_cleanup);
item = strsep(&bundle_list, " ,");
if (!bundle_port) {
RAII_VAR(int *, port, ao2_alloc(sizeof(int), NULL), ao2_cleanup);
RAII_VAR(int *, port_match, NULL, ao2_cleanup);
bundle_port = get_bundle_port(sdp, item);
if (bundle_port < 0) {
return -1;
}
port_match = ao2_find(portlist, &bundle_port, OBJ_KEY);
if (port_match) {
/* bundle port aready consumed by a different bundle */
return -1;
}
*port = bundle_port;
ao2_link(portlist, port);
}
assoc = ao2_alloc(sizeof(*assoc) + strlen(item), NULL);
if (!assoc) {
return -1;
}
/* safe use of strcpy */
strcpy(assoc->tag, item);
assoc->port = bundle_port;
ao2_link(bundle_assoc_list, assoc);
}
}
/* validate all streams */
for (i = 0; i < sdp->media_count; ++i) {
RAII_VAR(int *, port, ao2_alloc(sizeof(int), NULL), ao2_cleanup);
RAII_VAR(int *, port_match, NULL, ao2_cleanup);
*port = sdp->media[i]->desc.port;
port_match = ao2_find(portlist, port, OBJ_KEY);
if (port_match) {
RAII_VAR(struct bundle_assoc *, assoc, NULL, ao2_cleanup);
pjmedia_sdp_attr *mid = media_get_mid(sdp->media[i]);
char *mid_val;
if (!mid) {
/* not part of a bundle */
return -1;
}
mid_val = ast_alloca(mid->value.slen + 1);
strncpy(mid_val, mid->value.ptr, mid->value.slen);
mid_val[mid->value.slen] = '\0';
assoc = ao2_find(bundle_assoc_list, mid_val, OBJ_KEY);
if (!assoc || assoc->port != *port) {
/* This port already exists elsewhere in the SDP
* and is not an appropriate bundle port, fail
* catastrophically */
return -1;
}
}
ao2_link(portlist, port);
}
return 0;
}
static int handle_incoming_sdp(struct ast_sip_session *session, const pjmedia_sdp_session *sdp)
{
int i;
if (validate_incoming_sdp(sdp)) {
return -1;
}
int handled = 0;
for (i = 0; i < sdp->media_count; ++i) {
/* See if there are registered handlers for this media stream type */
@ -361,14 +211,22 @@ static int handle_incoming_sdp(struct ast_sip_session *session, const pjmedia_sd
if (session_media->handler) {
handler = session_media->handler;
ast_debug(1, "Negotiating incoming SDP media stream '%s' using %s SDP handler\n",
session_media->stream_type,
session_media->handler->id);
res = handler->negotiate_incoming_sdp_stream(session, session_media, sdp,
sdp->media[i]);
if (res <= 0) {
/* Catastrophic failure or ignored by assigned handler. Abort! */
if (res < 0) {
/* Catastrophic failure. Abort! */
return -1;
} else if (res > 0) {
ast_debug(1, "Media stream '%s' handled by %s\n",
session_media->stream_type,
session_media->handler->id);
/* Handled by this handler. Move to the next stream */
handled = 1;
continue;
}
/* Handled by this handler. Move to the next stream */
continue;
}
handler_list = ao2_find(sdp_handlers, media, OBJ_KEY);
@ -377,6 +235,9 @@ static int handle_incoming_sdp(struct ast_sip_session *session, const pjmedia_sd
continue;
}
AST_LIST_TRAVERSE(&handler_list->list, handler, next) {
ast_debug(1, "Negotiating incoming SDP media stream '%s' using %s SDP handler\n",
session_media->stream_type,
handler->id);
res = handler->negotiate_incoming_sdp_stream(session, session_media, sdp,
sdp->media[i]);
if (res < 0) {
@ -384,12 +245,19 @@ static int handle_incoming_sdp(struct ast_sip_session *session, const pjmedia_sd
return -1;
}
if (res > 0) {
ast_debug(1, "Media stream '%s' handled by %s\n",
session_media->stream_type,
handler->id);
/* Handled by this handler. Move to the next stream */
session_media->handler = handler;
handled = 1;
break;
}
}
}
if (!handled) {
return -1;
}
return 0;
}
@ -429,9 +297,15 @@ static int handle_negotiated_sdp_session_media(void *obj, void *arg, int flags)
handler = session_media->handler;
if (handler) {
ast_debug(1, "Applying negotiated SDP media stream '%s' using %s SDP handler\n",
session_media->stream_type,
handler->id);
res = handler->apply_negotiated_sdp_stream(session, session_media, local,
local->media[i], remote, remote->media[i]);
if (res >= 0) {
ast_debug(1, "Applied negotiated SDP media stream '%s' using %s SDP handler\n",
session_media->stream_type,
handler->id);
return CMP_MATCH;
}
return 0;
@ -443,6 +317,9 @@ static int handle_negotiated_sdp_session_media(void *obj, void *arg, int flags)
continue;
}
AST_LIST_TRAVERSE(&handler_list->list, handler, next) {
ast_debug(1, "Applying negotiated SDP media stream '%s' using %s SDP handler\n",
session_media->stream_type,
handler->id);
res = handler->apply_negotiated_sdp_stream(session, session_media, local,
local->media[i], remote, remote->media[i]);
if (res < 0) {
@ -450,6 +327,9 @@ static int handle_negotiated_sdp_session_media(void *obj, void *arg, int flags)
return 0;
}
if (res > 0) {
ast_debug(1, "Applied negotiated SDP media stream '%s' using %s SDP handler\n",
session_media->stream_type,
handler->id);
/* Handled by this handler. Move to the next stream */
session_media->handler = handler;
return CMP_MATCH;
@ -827,10 +707,6 @@ static int sdp_requires_deferral(struct ast_sip_session *session, const pjmedia_
{
int i;
if (validate_incoming_sdp(sdp)) {
return 0;
}
for (i = 0; i < sdp->media_count; ++i) {
/* See if there are registered handlers for this media stream type */
char media[20];

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