char *
sdp_message_a_att_value_get (sdp_message_t * sdp, int pos_media, int pos)
{
sdp_attribute_t *attr = sdp_message_attribute_get (sdp, pos_media, pos);
if (attr == NULL)
return NULL;
return attr->a_att_value;
}
/* return the value of attr "field" */
static const char *sdp_message_a_attr_value_get(sdp_message_t *sdp,int pos,const char *field)
{
int i;
sdp_attribute_t *attr;
for (i=0;(attr=sdp_message_attribute_get(sdp,pos,i))!=NULL;i++){
if (keywordcmp(field,attr->a_att_field)==0 && attr->a_att_value!=NULL){
return attr->a_att_value;
}
}
return NULL;
}
static int _sdp_message_get_a_ptime(sdp_message_t *sdp, int mline){
int i,ret;
sdp_attribute_t *attr;
for (i=0;(attr=sdp_message_attribute_get(sdp,mline,i))!=NULL;i++){
if (keywordcmp("ptime",attr->a_att_field)==0){
int nb = sscanf(attr->a_att_value,"%i",&ret);
/* the return value may depend on how %n is interpreted by the libc: see manpage*/
if (nb == 1){
return ret;
}else ms_warning("sdp has a strange a=ptime line (%s) ",attr->a_att_value);
}
}
return 0;
}
static int _sdp_message_get_mline_dir(sdp_message_t *sdp, int mline){
int i;
sdp_attribute_t *attr;
for (i=0;(attr=sdp_message_attribute_get(sdp,mline,i))!=NULL;i++){
if (keywordcmp("sendrecv",attr->a_att_field)==0){
return SalStreamSendRecv;
}else if (keywordcmp("sendonly",attr->a_att_field)==0){
return SalStreamSendOnly;
}else if (keywordcmp("recvonly",attr->a_att_field)==0){
return SalStreamSendOnly;
}else if (keywordcmp("inactive",attr->a_att_field)==0){
return SalStreamInactive;
}
}
return SalStreamSendRecv;
}
/* return the value of attr "field" for payload pt at line pos (field=rtpmap,fmtp...)*/
static const char *sdp_message_a_attr_value_get_with_pt(sdp_message_t *sdp,int pos,int pt,const char *field)
{
int i,tmppt=0,scanned=0;
char *tmp;
sdp_attribute_t *attr;
for (i=0;(attr=sdp_message_attribute_get(sdp,pos,i))!=NULL;i++){
if (keywordcmp(field,attr->a_att_field)==0 && attr->a_att_value!=NULL){
int nb = sscanf(attr->a_att_value,"%i %n",&tmppt,&scanned);
/* the return value may depend on how %n is interpreted by the libc: see manpage*/
if (nb == 1 || nb==2 ){
if (pt==tmppt){
tmp=attr->a_att_value+scanned;
if (strlen(tmp)>0)
return tmp;
}
}else ms_warning("sdp has a strange a= line (%s) nb=%i",attr->a_att_value,nb);
}
}
return NULL;
}
/*--------------------------------------------------------------------*/
static int sdp_filter_codec(sdp_message_t *sdp) {
int sts;
int i;
char *sdp_media;
int media_stream_no;
// SDP payload list processing
char *payload;
int payload_mediatype;
int payload_no;
// SDP attribute list processing
sdp_attribute_t *sdp_attr;
int attr_mediatype;
int media_attr_no;
int skip_media_attr_inc=0;
//
// loop through all media descriptions (normal phone call has 1 stream, a video call
// may have multiple streams)
//
media_stream_no=0;
while ((sdp_media=sdp_message_m_media_get(sdp, media_stream_no))) {
//
// loop through all media attributes of this media stream
//
media_attr_no=0;
while ((sdp_attr=sdp_message_attribute_get(sdp, media_stream_no, media_attr_no))) {
DEBUGC(DBCLASS_PLUGIN, " +--Attr m:%i, a=%i", media_stream_no, media_attr_no);
// check if attribute field and value exist
if (sdp_attr->a_att_field && sdp_attr->a_att_value) {
// fetch the media type value (first number field in value)
attr_mediatype=0;
sts=sscanf(sdp_attr->a_att_value, "%i", &attr_mediatype);
DEBUGC(DBCLASS_PLUGIN, " +--Attr field=%s, val=%s [MT=%i]",
sdp_attr->a_att_field, sdp_attr->a_att_value, attr_mediatype);
//
// loop through all configured "blacklisted" media strings
// and look for a match
//
for (i=0; i<plugin_cfg.codec_blacklist.used; i++) {
// do an *case-insensitive* *substring* match
if (strcasestr(sdp_attr->a_att_value, plugin_cfg.codec_blacklist.string[i])) {
// match, need to remove this codec
DEBUGC(DBCLASS_PLUGIN, "%s: blacklisted - removing media attr [%s] at attrpos=%i", name,
sdp_attr->a_att_value, media_attr_no);
//
// remove media attribute (a)
//
// libosip bug?? -> the following coda causes an infinite loop inside libosip2.
//if (sdp_message_a_attribute_del_at_index(sdp, media_stream_no, sdp_attr->a_att_field, media_attr_no) != OSIP_SUCCESS) {
// ERROR("%s: sdp_message_a_attribute_del() failed", name);
//}
// #&%+!@ -> So it manually...
{
sdp_media_t *med;
sdp_attribute_t *attr;
med = (sdp_media_t *) osip_list_get(&sdp->m_medias, media_stream_no);
if ((attr = osip_list_get(&med->a_attributes, media_attr_no)) != NULL) {
osip_list_remove(&med->a_attributes, media_attr_no);
sdp_attribute_free(attr);
attr=NULL;
// as I have removed the current attribute, all other
// attributes are shifted one down, so for the next iteration
// I must not increment the index or I will skip one attribute
skip_media_attr_inc=1;
}
}
//
// find corresponding (m) payload and remove it as well$
//
// loop through all payloads of the current media description
payload_no=0;
while ((payload=sdp_message_m_payload_get(sdp, media_stream_no, payload_no))) {
// extract the media type from the payload
payload_mediatype=0;
sts=sscanf(payload, "%i", &payload_mediatype);
DEBUGC(DBCLASS_PLUGIN, " +-- payload:%s MT=%i", payload, payload_mediatype);
// medfia type matches?
if (payload_mediatype == attr_mediatype) {
DEBUGC(DBCLASS_PLUGIN, "%s: blacklisted - removing media format %i at stream=%i, pos=%i", name,
payload_mediatype, media_stream_no, payload_no);
// remove (m) playload in media description
if (sdp_message_m_payload_del(sdp, media_stream_no, payload_no) != OSIP_SUCCESS) {
ERROR("%s: sdp_message_a_attribute_del() failed", name);
}
} else {
// increment index only if the current payload has not been removed
// as all other medias would have shifted down.
payload_no++;
}
} /* while playload */
} /* if match with config blacklist */
} /* for codec_blacklist */
} /* if attribute field and value exist */
// increment index only of the current media attribute has not been deleted
if (skip_media_attr_inc == 0) {
media_attr_no++;
} else {
skip_media_attr_inc=0;
}
} /* while sdp_message_attribute_get */
media_stream_no++;
} /* while sdp_message_m_media_get */
return STS_SUCCESS;
}
