Fix incorrect parsing in chan_gtalk when xmpp contains extra whitespaces

To drill into the xmpp to find the capabilities between channels, chan_gtalk
calls iks_child() and iks_next(). iks_child() and iks_next() are functions in
the iksemel xml parsing library that traverse xml nodes. The bug here is that
both iks_child() and iks_next() will return the next iks_struct node
*regardless* of type. chan_gtalk expects the next node to be of type IKS_TAG,
which in most cases, it is, but in this case (a call being made from the
Empathy IM client), there exists iks_struct nodes which are not IKS_TAG data
(they are extraneous whitespaces), and chan_gtalk doesn't handle that case,
so capabilities don't match, and a call cannot be made.

iks_first_tag() and iks_next_tag(), on the other hand, will not return the
very next iks_struct, but will check to see if the next iks_struct is of
type IKS_TAG. If it isn't, it will be skipped, and the next struct of type
IKS_TAG it finds will be returned. This assures that chan_gtalk will find
the iks_struct it is looking for.

This fix simply changes all calls to iks_child() and iks_next() to become
calls to iks_first_tag() and iks_next_tag(), which resolves the capability
matching.

The following is a payload listing from Empathy, which, due to the extraneous
whitespace, will not be parsed correctly by iksemel:

<iq from='dbrooksjab@235-22-24-10/Telepathy' to='astjab@235-22-24-10/asterisk' type='set' id='542757715704'> <session xmlns='http://www.google.com/session' initiator='dbrooksjab@235-22-24-10/Telepathy' type='initiate' id='1837267342'> <description xmlns='http://www.google.com/session/phone'> <payload-type clockrate='16000' name='speex' id='96'/>
 <payload-type clockrate='8000' name='PCMA' id='8'/>
 <payload-type clockrate='8000' name='PCMU' id='0'/>
 <payload-type clockrate='90000' name='MPA' id='97'/>
 <payload-type clockrate='16000' name='SIREN' id='98'/>
 <payload-type clockrate='8000' name='telephone-event' id='99'/>
</description>
</session>
</iq>

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@185362 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_gtalk.c b/channels/chan_gtalk.c
index ef5e7acab4c05db7df8e6e8862df92593a89c2c7..32ce3973e06b301eb8fe803b18d2330b28374494 100644 (file)
--- a/channels/chan_gtalk.c
+++ b/channels/chan_gtalk.c
@@ -649,11 +649,11 @@ static int gtalk_is_answered(struct gtalk *client, ikspak *pak)
        }
 
        /* codec points to the first <payload-type/> tag */
-       codec = iks_child(iks_child(iks_child(pak->x)));
+       codec = iks_first_tag(iks_first_tag(iks_first_tag(pak->x)));
        while (codec) {
                ast_rtp_set_m_type(tmp->rtp, atoi(iks_find_attrib(codec, "id")));
                ast_rtp_set_rtpmap_type(tmp->rtp, atoi(iks_find_attrib(codec, "id")), "audio", iks_find_attrib(codec, "name"), 0);
-               codec = iks_next(codec);
+               codec = iks_next_tag(codec);
        }
        
        /* Now gather all of the codecs that we are asked for */
@@ -1224,12 +1224,12 @@ static int gtalk_newcall(struct gtalk *client, ikspak *pak)
        }
 
        /* codec points to the first <payload-type/> tag */     
-       codec = iks_child(iks_child(iks_child(pak->x)));
+       codec = iks_first_tag(iks_first_tag(iks_first_tag(pak->x)));
        
        while (codec) {
                ast_rtp_set_m_type(p->rtp, atoi(iks_find_attrib(codec, "id")));
                ast_rtp_set_rtpmap_type(p->rtp, atoi(iks_find_attrib(codec, "id")), "audio", iks_find_attrib(codec, "name"), 0);
-               codec = iks_next(codec);
+               codec = iks_next_tag(codec);
        }
        
        /* Now gather all of the codecs that we are asked for */
@@ -1343,11 +1343,11 @@ static int gtalk_add_candidate(struct gtalk *client, ikspak *pak)
        traversenodes = pak->query;
        while(traversenodes) {
                if(!strcasecmp(iks_name(traversenodes), "session")) {
-                       traversenodes = iks_child(traversenodes);
+                       traversenodes = iks_first_tag(traversenodes);
                        continue;
                }
                if(!strcasecmp(iks_name(traversenodes), "transport")) {
-                       traversenodes = iks_child(traversenodes);
+                       traversenodes = iks_first_tag(traversenodes);
                        continue;
                }
                if(!strcasecmp(iks_name(traversenodes), "candidate")) {
@@ -1386,7 +1386,7 @@ static int gtalk_add_candidate(struct gtalk *client, ikspak *pak)
                        gtalk_update_stun(p->parent, p);
                        newcandidate = NULL;
                }
-               traversenodes = iks_next(traversenodes);
+               traversenodes = iks_next_tag(traversenodes);
        }
        
        receipt = iks_new("iq");