Ticket #544: Fixed SRTP on hold+reinvite scenario

git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@2064 74dad513-b988-da41-8d7b-12977e46ad98

6 files changed, 58 insertions, 14 deletions

diff --git a/pjmedia/include/pjmedia/config.h b/pjmedia/include/pjmedia/config.h
index 7deae256..f6bf3707 100644
--- a/pjmedia/include/pjmedia/config.h
+++ b/pjmedia/include/pjmedia/config.h
@@ -609,7 +609,7 @@
  * Maximum size in bytes of storage buffer of a transport specific info.
  */
 #ifndef PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXSIZE
-#   define PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXSIZE  (12*sizeof(long))
+#   define PJMEDIA_TRANSPORT_SPECIFIC_INFO_MAXSIZE  (16*sizeof(long))
 #endif
 
 
diff --git a/pjmedia/include/pjmedia/transport_srtp.h b/pjmedia/include/pjmedia/transport_srtp.h
index d622a0a7..d94d9a23 100644
--- a/pjmedia/include/pjmedia/transport_srtp.h
+++ b/pjmedia/include/pjmedia/transport_srtp.h
@@ -138,7 +138,7 @@ typedef struct pjmedia_srtp_setting
     /**
      * Specify the usage policy. Default is PJMEDIA_SRTP_OPTIONAL.
      */
-    pjmedia_srtp_use use;
+    pjmedia_srtp_use		use;
 
     /**
      * Specify whether the SRTP transport should close the member transport 
@@ -180,6 +180,16 @@ typedef struct pjmedia_srtp_info
      */
     pjmedia_srtp_crypto		tx_policy;
 
+    /**
+     * Specify the usage policy.
+     */
+    pjmedia_srtp_use		use;
+
+    /**
+     * Specify the peer's usage policy.
+     */
+    pjmedia_srtp_use		peer_use;
+
 } pjmedia_srtp_info;
 
 
diff --git a/pjmedia/src/pjmedia/transport_srtp.c b/pjmedia/src/pjmedia/transport_srtp.c
index ff18aedf..acb777f7 100644
--- a/pjmedia/src/pjmedia/transport_srtp.c
+++ b/pjmedia/src/pjmedia/transport_srtp.c
@@ -111,13 +111,12 @@ typedef struct transport_srtp
     /* Transport information */
     pjmedia_transport	*member_tp; /**< Underlying transport.       */
 
-    /* When in SRTP optional mode, instead of always offering RTP/AVP,
-     * we should create offer based on remote preference. At the first time,
-     * remote preference is unknown, it is known after media_start() called.
-     * So next time the same session need to create an offer, it will create
-     * SDP with transport type based on remote preference.
+    /* SRTP usage policy of peer. This field is updated when media is starting.
+     * This is useful when SRTP is in optional mode and peer is using mandatory
+     * mode, so when local is about to reinvite/update, it should offer 
+     * RTP/SAVP instead of offering RTP/AVP.
      */
-    pj_bool_t		 remote_prefer_rtp_savp;
+    pjmedia_srtp_use	 peer_use;
 
 } transport_srtp;
 
@@ -348,7 +347,7 @@ PJ_DEF(pj_status_t) pjmedia_transport_srtp_create(
     srtp->pool = pool;
     srtp->session_inited = PJ_FALSE;
     srtp->bypass_srtp = PJ_FALSE;
-    srtp->remote_prefer_rtp_savp = PJ_FALSE;
+    srtp->peer_use = opt->use;
 
     if (opt) {
 	srtp->setting = *opt;
@@ -586,6 +585,8 @@ static pj_status_t transport_get_info(pjmedia_transport *tp,
     srtp_info.active = srtp->session_inited;
     srtp_info.rx_policy = srtp->rx_policy;
     srtp_info.tx_policy = srtp->tx_policy;
+    srtp_info.use = srtp->setting.use;
+    srtp_info.peer_use = srtp->peer_use;
 
     spc_info_idx = info->specific_info_cnt++;
     info->spc_info[spc_info_idx].type = PJMEDIA_TRANSPORT_TYPE_SRTP;
@@ -1076,8 +1077,9 @@ static pj_status_t transport_encode_sdp(pjmedia_transport *tp,
 	    case PJMEDIA_SRTP_DISABLED:
 		goto BYPASS_SRTP;
 	    case PJMEDIA_SRTP_OPTIONAL:
-		m_loc->desc.transport = srtp->remote_prefer_rtp_savp?
-					ID_RTP_SAVP : ID_RTP_AVP;
+		m_loc->desc.transport = 
+				(srtp->peer_use == PJMEDIA_SRTP_MANDATORY)?
+				ID_RTP_SAVP : ID_RTP_AVP;
 		break;
 	    case PJMEDIA_SRTP_MANDATORY:
 		m_loc->desc.transport = ID_RTP_SAVP;
@@ -1283,8 +1285,10 @@ static pj_status_t transport_media_start(pjmedia_transport *tp,
     m_rem = sdp_remote->media[media_index];
     m_loc = sdp_local->media[media_index];
 
-    srtp->remote_prefer_rtp_savp = (pj_stricmp(&m_rem->desc.transport, 
-				   &ID_RTP_SAVP) == 0);
+    if (pj_stricmp(&m_rem->desc.transport, &ID_RTP_SAVP) == 0)
+	srtp->peer_use = PJMEDIA_SRTP_MANDATORY;
+    else
+	srtp->peer_use = PJMEDIA_SRTP_OPTIONAL;
 
     /* For answerer side, this function will just have to start SRTP */
 
@@ -1382,6 +1386,7 @@ static pj_status_t transport_media_start(pjmedia_transport *tp,
 
 BYPASS_SRTP:
     srtp->bypass_srtp = PJ_TRUE;
+    srtp->peer_use = PJMEDIA_SRTP_DISABLED;
 
 PROPAGATE_MEDIA_START:
     return pjmedia_transport_media_start(srtp->member_tp, pool, 
diff --git a/pjsip/include/pjsua-lib/pjsua_internal.h b/pjsip/include/pjsua-lib/pjsua_internal.h
index 02ba5979..6865344d 100644
--- a/pjsip/include/pjsua-lib/pjsua_internal.h
+++ b/pjsip/include/pjsua-lib/pjsua_internal.h
@@ -74,6 +74,7 @@ typedef struct pjsua_call
     pj_timer_entry	 refresh_tm;/**< Timer to send re-INVITE.	    */
     pj_timer_entry	 hangup_tm; /**< Timer to hangup call.		    */
     pj_stun_nat_type	 rem_nat_type; /**< NAT type of remote endpoint.    */
+    pjmedia_srtp_use	 rem_srtp_use; /**< Remote's SRTP usage policy.	    */
 
     char    last_text_buf_[128];    /**< Buffer for last_text.		    */
 
diff --git a/pjsip/src/pjsua-lib/pjsua_call.c b/pjsip/src/pjsua-lib/pjsua_call.c
index b5482957..d12ea9d2 100644
--- a/pjsip/src/pjsua-lib/pjsua_call.c
+++ b/pjsip/src/pjsua-lib/pjsua_call.c
@@ -115,6 +115,7 @@ static void reset_call(pjsua_call_id id)
     call->res_time.sec = 0;
     call->res_time.msec = 0;
     call->rem_nat_type = PJ_STUN_NAT_TYPE_UNKNOWN;
+    call->rem_srtp_use = PJMEDIA_SRTP_DISABLED;
 }
 
 
diff --git a/pjsip/src/pjsua-lib/pjsua_media.c b/pjsip/src/pjsua-lib/pjsua_media.c
index 7d2742f6..84b85101 100644
--- a/pjsip/src/pjsua-lib/pjsua_media.c
+++ b/pjsip/src/pjsua-lib/pjsua_media.c
@@ -888,7 +888,14 @@ pj_status_t pjsua_media_channel_init(pjsua_call_id call_id,
 	/* Always create SRTP adapter */
 	pjmedia_srtp_setting_default(&srtp_opt);
 	srtp_opt.close_member_tp = PJ_FALSE;
-	srtp_opt.use = acc->cfg.use_srtp;
+	/* If media session has been ever established, let's use remote's 
+	 * preference in SRTP usage policy, especially when it is stricter.
+	 */
+	if (call->rem_srtp_use > acc->cfg.use_srtp)
+	    srtp_opt.use = call->rem_srtp_use;
+	else
+	    srtp_opt.use = acc->cfg.use_srtp;
+
 	status = pjmedia_transport_srtp_create(pjsua_var.med_endpt, 
 					       call->med_tp,
 					       &srtp_opt, &srtp);
@@ -1143,6 +1150,9 @@ pj_status_t pjsua_media_channel_update(pjsua_call_id call_id,
 	}
 
     } else {
+	pjmedia_srtp_info srtp_info;
+	pjmedia_transport_info tp_info;
+
 	/* Start/restart media transport */
 	status = pjmedia_transport_media_start(call->med_tp, 
 					       call->inv->pool,
@@ -1152,6 +1162,23 @@ pj_status_t pjsua_media_channel_update(pjsua_call_id call_id,
 
 	call->med_tp_st = PJSUA_MED_TP_RUNNING;
 
+	/* Get remote SRTP usage policy */
+	pjmedia_transport_info_init(&tp_info);
+	pjmedia_transport_get_info(call->med_tp, &tp_info);
+	if (tp_info.specific_info_cnt > 0) {
+	    int i;
+	    for (i = 0; i < tp_info.specific_info_cnt; ++i) {
+		if (tp_info.spc_info[i].type == PJMEDIA_TRANSPORT_TYPE_SRTP) 
+		{
+		    pjmedia_srtp_info *srtp_info = 
+				(pjmedia_srtp_info*) tp_info.spc_info[i].buffer;
+
+		    call->rem_srtp_use = srtp_info->peer_use;
+		    break;
+		}
+	    }
+	}
+
 	/* Override ptime, if this option is specified. */
 	if (pjsua_var.media_cfg.ptime != 0) {
 	    si->param->setting.frm_per_pkt = (pj_uint8_t)