/*
* Copyright (C) 2010-2011 Raphael Coeffic
*
* This file is part of SEMS, a free SIP media server.
*
* SEMS is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version. This program is released under
* the GPL with the additional exemption that compiling, linking,
* and/or using OpenSSL is allowed.
*
* For a license to use the SEMS software under conditions
* other than those described here, or to purchase support for this
* software, please contact iptel.org by e-mail at the following addresses:
* info@iptel.org
*
* SEMS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/** @file AmOfferAnswer.cpp */
#include "AmOfferAnswer.h"
#include "AmSipDialog.h"
#include "AmSipHeaders.h"
#include "log.h"
#include <assert.h>
const char* __dlg_oa_status2str[AmOfferAnswer::__max_OA] = {
"None",
"OfferRecved",
"OfferSent",
"Completed"
};
static const char* getOAStateStr(AmOfferAnswer::OAState st) {
if((st < 0) || (st >= AmOfferAnswer::__max_OA))
return "Invalid";
else
return __dlg_oa_status2str[st];
}
AmOfferAnswer::AmOfferAnswer(AmSipDialog* dlg)
: state(OA_None),
cseq(0),
sdp_remote(),
sdp_local(),
dlg(dlg)
{
}
AmOfferAnswer::OAState AmOfferAnswer::getState()
{
return state;
}
void AmOfferAnswer::setState(AmOfferAnswer::OAState n_st)
{
DBG("setting SIP dialog O/A status: %s->%s\n",
getOAStateStr(state), getOAStateStr(n_st));
state = n_st;
}
const AmSdp& AmOfferAnswer::getLocalSdp()
{
return sdp_local;
}
const AmSdp& AmOfferAnswer::getRemoteSdp()
{
return sdp_remote;
}
/** State maintenance */
void AmOfferAnswer::saveState()
{
saved_state = state;
}
int AmOfferAnswer::checkStateChange()
{
int ret = 0;
if((saved_state != state) &&
(state == OA_Completed)) {
ret = dlg->onSdpCompleted();
}
return ret;
}
void AmOfferAnswer::clear()
{
setState(OA_None);
cseq = 0;
sdp_remote.clear();
sdp_local.clear();
}
void AmOfferAnswer::clearTransitionalState()
{
if(state != OA_Completed){
clear();
}
}
int AmOfferAnswer::onRequestIn(const AmSipRequest& req)
{
saveState();
const char* err_txt = NULL;
int err_code = 0;
if((req.method == SIP_METH_INVITE ||
req.method == SIP_METH_UPDATE ||
req.method == SIP_METH_ACK ||
req.method == SIP_METH_PRACK) &&
!req.body.empty() ) {
const AmMimeBody* sdp_body = req.body.hasContentType(SIP_APPLICATION_SDP);
if(sdp_body)
err_code = onRxSdp(req.cseq,*sdp_body,&err_txt);
}
if(checkStateChange()){
err_code = 500;
err_txt = "internal error";
}
if(err_code){
if( req.method != SIP_METH_ACK ){ // INVITE || UPDATE || PRACK
dlg->reply(req,err_code,err_txt);
}
else { // ACK
// TODO: only if reply to initial INVITE (if re-INV, app should decide)
DBG("error %i with SDP received in ACK request: sending BYE\n",err_code);
dlg->bye();
}
}
if((req.method == SIP_METH_ACK) &&
(req.cseq == cseq)){
// 200 ACK received:
// -> reset OA state
DBG("200 ACK received: resetting OA state");
clearTransitionalState();
}
return err_code ? -1 : 0;
}
int AmOfferAnswer::onReplyIn(const AmSipReply& reply)
{
const char* err_txt = NULL;
int err_code = 0;
if((reply.cseq_method == SIP_METH_INVITE ||
reply.cseq_method == SIP_METH_UPDATE ||
reply.cseq_method == SIP_METH_PRACK) &&
!reply.body.empty() ) {
const AmMimeBody* sdp_body = reply.body.hasContentType(SIP_APPLICATION_SDP);
if(sdp_body) {
if(((state == OA_Completed) ||
(state == OA_OfferRecved)) &&
(reply.cseq == cseq)) {
DBG("ignoring subsequent SDP reply within the same transaction\n");
DBG("this usually happens when 183 and 200 have SDP\n");
/* Make sure that session is started when 200 OK is received */
if (reply.code == 200) dlg->onSdpCompleted();
}
else {
saveState();
err_code = onRxSdp(reply.cseq,reply.body,&err_txt);
checkStateChange();
}
}
}
if( (reply.code >= 300) &&
(reply.cseq == cseq) ) {
// final error reply -> cleanup OA state
DBG("after %u reply to %s: resetting OA state\n",
reply.code, reply.cseq_method.c_str());
clearTransitionalState();
}
if(err_code){
// TODO: only if initial INVITE (if re-INV, app should decide)
DBG("error %i (%s) with SDP received in %i reply: sending ACK+BYE\n",
err_code,err_txt?err_txt:"none",reply.code);
dlg->bye();
}
return 0;
}
int AmOfferAnswer::onRxSdp(unsigned int m_cseq, const AmMimeBody& body, const char** err_txt)
{
DBG("entering onRxSdp(), oa_state=%s\n", getOAStateStr(state));
OAState old_oa_state = state;
int err_code = 0;
assert(err_txt);
const AmMimeBody *sdp = body.hasContentType("application/sdp");
if (sdp == NULL) {
err_code = 400;
*err_txt = "sdp body part not found";
}
if (sdp_remote.parse((const char*)sdp->getPayload())) {
err_code = 400;
*err_txt = "session description parsing failed";
}
else if(sdp_remote.media.empty()){
err_code = 400;
*err_txt = "no media line found in SDP message";
}
if(err_code != 0) {
sdp_remote.clear();
}
if(err_code == 0) {
switch(state) {
case OA_None:
case OA_Completed:
setState(OA_OfferRecved);
cseq = m_cseq;
break;
case OA_OfferSent:
setState(OA_Completed);
break;
case OA_OfferRecved:
err_code = 400;// TODO: check correct error code
*err_txt = "pending SDP offer";
break;
default:
assert(0);
break;
}
}
DBG("oa_state: %s -> %s\n", getOAStateStr(old_oa_state), getOAStateStr(state));
return err_code;
}
int AmOfferAnswer::onTxSdp(unsigned int m_cseq, const AmMimeBody& body)
{
// assume that the payload is ok if it is not empty.
// (do not parse again self-generated SDP)
if(body.empty()){
return -1;
}
switch(state) {
case OA_None:
case OA_Completed:
setState(OA_OfferSent);
cseq = m_cseq;
break;
case OA_OfferRecved:
setState(OA_Completed);
break;
case OA_OfferSent:
// There is already a pending offer!!!
DBG("There is already a pending offer, onTxSdp fails\n");
return -1;
default:
break;
}
return 0;
}
int AmOfferAnswer::onRequestOut(AmSipRequest& req)
{
AmMimeBody* sdp_body = req.body.hasContentType(SIP_APPLICATION_SDP);
bool generate_sdp = sdp_body && !sdp_body->getLen();
bool has_sdp = sdp_body && sdp_body->getLen();
if (!sdp_body &&
((req.method == SIP_METH_PRACK) ||
(req.method == SIP_METH_ACK))) {
generate_sdp = (state == OA_OfferRecved);
sdp_body = req.body.addPart(SIP_APPLICATION_SDP);
}
saveState();
if (generate_sdp) {
string sdp_buf;
if (!getSdpBody(sdp_buf)){
sdp_body->setPayload((const unsigned char*)sdp_buf.c_str(),
sdp_buf.length());
has_sdp = true;
}
else {
return -1;
}
} else if (sdp_body && has_sdp) {
// update local SDP copy
if (sdp_local.parse((const char*)sdp_body->getPayload())) {
ERROR("parser failed on Tx SDP: '%s'\n", (const char*)sdp_body->getPayload());
}
}
if(has_sdp && (onTxSdp(req.cseq,req.body) != 0)){
DBG("onTxSdp() failed\n");
return -1;
}
return 0;
}
int AmOfferAnswer::onReplyOut(AmSipReply& reply)
{
AmMimeBody* sdp_body = reply.body.hasContentType(SIP_APPLICATION_SDP);
bool generate_sdp = sdp_body && !sdp_body->getLen();
bool has_sdp = sdp_body && sdp_body->getLen();
if (!has_sdp && !generate_sdp) {
// let's see whether we should force SDP or not.
if (reply.cseq_method == SIP_METH_INVITE){
if ((reply.code == 183)
|| ((reply.code >= 200) && (reply.code < 300))) {
// either offer received or no offer at all:
// -> force SDP
generate_sdp = (state == OA_OfferRecved)
|| (state == OA_None)
|| (state == OA_Completed);
}
}
else if (reply.cseq_method == SIP_METH_UPDATE) {
if ((reply.code >= 200) &&
(reply.code < 300)) {
// offer received:
// -> force SDP
generate_sdp = (state == OA_OfferRecved);
}
}
}
if (reply.cseq_method == SIP_METH_INVITE && reply.code < 300) {
// ignore SDP repeated in 1xx and 2xx replies (183, 180, ... 2xx)
if (has_sdp &&
(state == OA_Completed || state == OA_OfferSent) &&
reply.cseq == cseq)
{
has_sdp = false;
}
}
saveState();
if (generate_sdp) {
string sdp_buf;
if(getSdpBody(sdp_buf)) {
if (reply.code == 183 && reply.cseq_method == SIP_METH_INVITE) {
// just ignore if no SDP is generated (required for B2B)
}
else return -1;
}
else {
if(!sdp_body){
if( (sdp_body =
reply.body.addPart(SIP_APPLICATION_SDP))
== NULL ) {
DBG("AmMimeBody::addPart() failed\n");
return -1;
}
}
sdp_body->setPayload((const unsigned char*)sdp_buf.c_str(),
sdp_buf.length());
has_sdp = true;
}
} else if (sdp_body && has_sdp) {
// update local SDP copy
if (sdp_local.parse((const char*)sdp_body->getPayload())) {
ERROR("parser failed on Tx SDP: '%s'\n", (const char*)sdp_body->getPayload());
}
}
if (has_sdp && (onTxSdp(reply.cseq,reply.body) != 0)) {
DBG("onTxSdp() failed\n");
return -1;
}
if( (reply.code >= 300) &&
(reply.cseq == cseq) ) {
// final error reply -> cleanup OA state
DBG("after %u reply to %s: resetting OA state\n",
reply.code, reply.cseq_method.c_str());
clearTransitionalState();
}
return 0;
}
int AmOfferAnswer::onRequestSent(const AmSipRequest& req)
{
int ret = checkStateChange();
if((req.method == SIP_METH_ACK) &&
(req.cseq == cseq)) {
// transaction has been removed:
// -> cleanup OA state
DBG("200 ACK sent: resetting OA state\n");
clearTransitionalState();
}
return ret;
}
int AmOfferAnswer::onReplySent(const AmSipReply& reply)
{
int ret = checkStateChange();
// final answer to non-invite req that triggered O/A transaction
if( (reply.code >= 200) &&
(reply.cseq_method != SIP_METH_CANCEL) &&
(reply.cseq == cseq) &&
(reply.cseq_method != SIP_METH_INVITE) ) {
// transaction has been removed:
// -> cleanup OA state
DBG("transaction finished by final reply %u: resetting OA state\n", reply.cseq);
clearTransitionalState();
}
return ret;
}
int AmOfferAnswer::getSdpBody(string& sdp_body)
{
switch(state){
case OA_None:
case OA_Completed:
if(dlg->getSdpOffer(sdp_local)){
sdp_local.print(sdp_body);
}
else {
DBG("No SDP Offer.\n");
return -1;
}
break;
case OA_OfferRecved:
if(dlg->getSdpAnswer(sdp_remote,sdp_local)){
sdp_local.print(sdp_body);
}
else {
DBG("No SDP Answer.\n");
return -1;
}
break;
case OA_OfferSent:
DBG("Still waiting for a reply\n");
return -1;
default:
break;
}
return 0;
}
void AmOfferAnswer::onNoAck(unsigned int ack_cseq)
{
if(ack_cseq == cseq){
DBG("ACK timeout: resetting OA state\n");
clearTransitionalState();
}
}