// this is called for each ice candidate. if candidate is null, no additional candidates could be found.
void WebRTCOnIceCandidate(ILibWrapper_WebRTC_Connection webRTCConnection, struct sockaddr_in6* candidate) {
assert(webRTCConnection != NULL);
void* user_data = NULL;
libwebrtc_context* ctx = NULL;
libwebrtc_connection* conn = (libwebrtc_connection*)webRTCConnection;
ILibWrapper_WebRTC_Connection_GetUserData(webRTCConnection, (void**)&ctx, NULL, &user_data);
// no additional candidates found.
if( candidate == NULL )
return;
char* offer = ILibWrapper_WebRTC_Connection_AddServerReflexiveCandidateToLocalSDP( webRTCConnection, candidate );
if( offer == NULL ) {
ctx->callback(ctx, conn, NULL, LWRTC_CALLBACK_ERROR, user_data, NULL, 0 );
LOG("Offer failed, closing socket\n");
return;
}
free(offer);
char address[225];
ILibInet_ntop2((struct sockaddr*)candidate, address, 255);
const char* candidateFormat = "candidate:%d %d UDP %d %s %u typ host";
char buf[255] = {0};
snprintf(buf, sizeof(buf), candidateFormat, 0, 1, 2128609535-1, address, ntohs(candidate->sin6_port));
buf[sizeof(buf)-1] = 0;
ctx->callback(ctx, conn, NULL, LWRTC_CALLBACK_ICE_CANDIDATE, user_data, buf, strlen(buf) );
}
char* ILibWrapper_WebRTC_Connection_AddServerReflexiveCandidateToLocalSDP(ILibWrapper_WebRTC_Connection connection, struct sockaddr_in6* candidate)
{
ILibWrapper_WebRTC_ConnectionStruct *obj = (ILibWrapper_WebRTC_ConnectionStruct*) connection;
char *sdp;
char *username;
char *password;
char address[255];
if(candidate!=NULL)
{
ILibInet_ntop2((struct sockaddr*)candidate, address, 255);
ILibWrapper_BlockToSDPEx(obj->offerBlock, obj->offerBlockLen, &username, &password, &sdp, address, ntohs(candidate->sin6_port));
}
else
{
ILibWrapper_BlockToSDPEx(obj->offerBlock, obj->offerBlockLen, &username, &password, &sdp, NULL, 0);
}
free(username);
free(password);
return(sdp);
}
//
// IPAddress Helper
//
__declspec(dllexport) char* ILibWrapper_SockAddr_GetAddressString(struct sockaddr* addr, char* buffer, int bufferLength)
{
return(ILibInet_ntop2(addr, buffer, bufferLength));
}
int ILibWrapper_BlockToSDPEx(char* block, int blockLen, char** username, char** password, char **sdp, char* serverReflexiveCandidateAddress, unsigned short serverReflexiveCandidatePort)
{
char* sdpTemplate1 = "v=0\r\no=MeshAgent %u 0 IN IP4 0.0.0.0\r\ns=SIP Call\r\nt=0 0\r\na=ice-ufrag:%s\r\na=ice-pwd:%s\r\na=fingerprint:sha-256 %s\r\nm=application 1 DTLS/SCTP 5000\r\nc=IN IP4 0.0.0.0\r\na=sctpmap:5000 webrtc-datachannel 16\r\na=setup:%s\r\n";
char* sdpTemplateRelay = "a=candidate:%d %d UDP %d %s %d typ relay raddr %u.%u.%u.%u %d\r\n";
char* sdpTemplateLocalCand = "a=candidate:%d %d UDP %d %u.%u.%u.%u %u typ host\r\n";
char* sdpTemplateSrflxCand = "a=candidate:%d %d UDP %d %s %u typ srflx raddr %u.%u.%u.%u rport %u\r\n";
int sdpLen;
int c,x,i,ptr;
char junk[4];
struct sockaddr_in6 *relayEndPoint = NULL;
char relayAddressString[128];
unsigned short relayAddressPort = 0;
// Decode the block
//This value is commented out to prevent a compiler warning for unused variables, but I left it here to show how to fetch it
//
//short blockversion = ILibWrapper_ReadShort(block, 0);
//
int blockflags = ILibWrapper_ReadInt(block, 2);
int isActive = (blockflags & ILibWebRTC_SDP_Flags_DTLS_SERVER) == ILibWebRTC_SDP_Flags_DTLS_SERVER ? 0:1;
int usernamelen = (int)block[6];
int passwordlen = (int)block[7 + usernamelen];
int dtlshashlen = (int)block[8 + usernamelen + passwordlen];
int candidatecount = (int)block[9 + usernamelen + passwordlen + dtlshashlen];
char dtlshash[128];
int rlen = 10 + usernamelen + passwordlen + dtlshashlen + (candidatecount * 6);
char* candidates = block + 10 + usernamelen + passwordlen + dtlshashlen;
*username = ILibWrapper_ReadString(block, 7, usernamelen);
*password = ILibWrapper_ReadString(block, 8 + usernamelen, passwordlen);
util_tohex2(block + 9 + usernamelen + passwordlen, dtlshashlen, dtlshash);
if (rlen < blockLen)
{
relayEndPoint = (struct sockaddr_in6*)(block+rlen+1);
ILibInet_ntop2((struct sockaddr*)relayEndPoint, relayAddressString, 128);
switch(((struct sockaddr_in*)relayEndPoint)->sin_family)
{
case AF_INET:
relayAddressPort = ntohs(((struct sockaddr_in*)relayEndPoint)->sin_port);
break;
case AF_INET6:
relayAddressPort = ntohs(relayEndPoint->sin6_port);
break;
}
}
// Build the sdp
sdpLen = 2 + strlen(sdpTemplate1) + usernamelen + passwordlen + 7 + (dtlshashlen*3) + 7 + (2 * (candidatecount * (12 + 21 + strlen(sdpTemplateLocalCand))) );
if(serverReflexiveCandidateAddress!=NULL)
{
sdpLen += (2* (12 + 21 + strlen(sdpTemplateSrflxCand)));
}
if(relayEndPoint!=NULL)
{
sdpLen += (2* (12 + 21 + strlen(sdpTemplateRelay)));
}
if((*sdp = (char*)malloc(sdpLen))==NULL){ILIBCRITICALEXIT(254);}
util_random(4, junk);
x = snprintf(*sdp, sdpLen, sdpTemplate1, ((unsigned int*)junk)[0]%1000000, *username, *password, dtlshash, isActive==0?"passive":"actpass");
for(c = 1; c <= 2; ++c)
{
for (i = 0; i < candidatecount; i++)
{
ptr = i*6;
x += snprintf(*sdp+x, sdpLen-x, sdpTemplateLocalCand, i, c, 2128609535-i, (unsigned char)candidates[ptr], (unsigned char)candidates[ptr+1], (unsigned char)candidates[ptr+2], (unsigned char)candidates[ptr+3], ntohs(((unsigned short*)(candidates+ptr+4))[0]));
}
if(serverReflexiveCandidateAddress!=NULL)
{
x += snprintf(*sdp+x, sdpLen-x, sdpTemplateSrflxCand, i, c, 2128609535-i, serverReflexiveCandidateAddress, serverReflexiveCandidatePort, (unsigned char)candidates[0], (unsigned char)candidates[1], (unsigned char)candidates[2], (unsigned char)candidates[3], ntohs(((unsigned short*)(candidates+4))[0]));
++i;
}
if(relayEndPoint!=NULL)
{
x += snprintf(*sdp+x, sdpLen-x, sdpTemplateRelay, i, c, 2128609535-i, relayAddressString, relayAddressPort, (unsigned char)candidates[0], (unsigned char)candidates[1], (unsigned char)candidates[2], (unsigned char)candidates[3]);
}
}
return(x);
}
