res_rtp_asterisk: Revert DTLS negotiation changes.

Due to locking issues within pjnath these changes are being
reverted until pjnath can be changed.

ASTERISK-25645

Revert "res_rtp_asterisk.c: Fix DTLS negotiation delays."

This reverts commit 24ae124e4f.

Change-Id: I2986cfb2c43dc14455c1bcaf92c3804f9da49705

Revert "res_rtp_asterisk: Resolve further timing issues with DTLS negotiation"

This reverts commit 965a0eee46.

Change-Id: Ie68fafde27dad4b03cb7a1e27ce2a8502c3f7bbe

res/res_rtp_asterisk.c

@@ -444,7 +444,6 @@ static int ast_rtp_sendcng(struct ast_rtp_instance *instance, int level);
 #ifdef HAVE_OPENSSL_SRTP
 static int ast_rtp_activate(struct ast_rtp_instance *instance);
 static void dtls_srtp_check_pending(struct ast_rtp_instance *instance, struct ast_rtp *rtp, int rtcp);
-static void dtls_srtp_flush_pending(struct ast_rtp_instance *instance, struct ast_rtp *rtp);
 static void dtls_srtp_start_timeout_timer(struct ast_rtp_instance *instance, struct ast_rtp *rtp, int rtcp);
 static void dtls_srtp_stop_timeout_timer(struct ast_rtp_instance *instance, struct ast_rtp *rtp, int rtcp);
 #endif
@@ -1684,20 +1683,15 @@ static void ast_rtp_on_ice_complete(pj_ice_sess *ice, pj_status_t status)
 		if (rtp->rtcp) {
 			update_address_with_ice_candidate(rtp, AST_RTP_ICE_COMPONENT_RTCP, &rtp->rtcp->them);
 		}
-
-#ifdef HAVE_OPENSSL_SRTP
-		if (rtp->dtls.dtls_setup != AST_RTP_DTLS_SETUP_PASSIVE) {
-			dtls_perform_handshake(instance, &rtp->dtls, 0);
-		}
-		else {
-			dtls_srtp_flush_pending(instance, rtp); /* this flushes pending BIO for both rtp & rtcp as needed. */
-		}
-
-		if (rtp->rtcp && rtp->rtcp->dtls.dtls_setup != AST_RTP_DTLS_SETUP_PASSIVE) {
-			dtls_perform_handshake(instance, &rtp->rtcp->dtls, 1);
-		}
-#endif
 	}
+ 
+#ifdef HAVE_OPENSSL_SRTP
+	dtls_perform_handshake(instance, &rtp->dtls, 0);
+
+	if (rtp->rtcp) {
+		dtls_perform_handshake(instance, &rtp->rtcp->dtls, 1);
+	}
+#endif
 
 	if (!strictrtp) {
 		return;
@@ -1892,23 +1886,6 @@ static void dtls_srtp_stop_timeout_timer(struct ast_rtp_instance *instance, stru
 	AST_SCHED_DEL_UNREF(rtp->sched, dtls->timeout_timer, ao2_ref(instance, -1));
 }
 
-static void dtls_srtp_flush_pending(struct ast_rtp_instance *instance, struct ast_rtp *rtp)
-{
-	struct dtls_details *dtls;
-
-	dtls = &rtp->dtls;
-	ast_mutex_lock(&dtls->lock);
-	dtls_srtp_check_pending(instance, rtp, 0);
-	ast_mutex_unlock(&dtls->lock);
-
-	if (rtp->rtcp) {
-		dtls = &rtp->rtcp->dtls;
-		ast_mutex_lock(&dtls->lock);
-		dtls_srtp_check_pending(instance, rtp, 1);
-		ast_mutex_unlock(&dtls->lock);
-	}
-}
-
 static void dtls_srtp_check_pending(struct ast_rtp_instance *instance, struct ast_rtp *rtp, int rtcp)
 {
 	struct dtls_details *dtls = !rtcp ? &rtp->dtls : &rtp->rtcp->dtls;
@@ -2141,8 +2118,6 @@ static int __rtp_recvfrom(struct ast_rtp_instance *instance, void *buf, size_t s
 			SSL_set_accept_state(dtls->ssl);
 		}
 
-		ast_mutex_lock(&dtls->lock);
-
 		dtls_srtp_check_pending(instance, rtp, rtcp);
 
 		BIO_write(dtls->read_bio, buf, len);
@@ -2153,7 +2128,6 @@ static int __rtp_recvfrom(struct ast_rtp_instance *instance, void *buf, size_t s
 			unsigned long error = ERR_get_error();
 			ast_log(LOG_ERROR, "DTLS failure occurred on RTP instance '%p' due to reason '%s', terminating\n",
 				instance, ERR_reason_error_string(error));
-			ast_mutex_unlock(&dtls->lock);
 			return -1;
 		}
 
@@ -2171,8 +2145,6 @@ static int __rtp_recvfrom(struct ast_rtp_instance *instance, void *buf, size_t s
 			dtls_srtp_start_timeout_timer(instance, rtp, rtcp);
 		}
 
-		ast_mutex_unlock(&dtls->lock);
-
 		return res;
 	}
 #endif
@@ -4861,20 +4833,7 @@ static void ast_rtp_remote_address_set(struct ast_rtp_instance *instance, struct
 		rtp_learning_seq_init(&rtp->rtp_source_learn, rtp->seqno);
 	}
 
-#ifdef HAVE_OPENSSL_SRTP
+	return;
-	/* Trigger pending outbound DTLS packets received before the address was set.  Avoid unnecessary locking
-	 * by checking if we're passive. Without this, we only send the pending packets once a new SSL packet is
-	 * received in __rtp_recvfrom.  If rtp->ice, this is instead done on_ice_complete
-	 */
-#ifdef HAVE_PJPROJECT
-	if (rtp->ice) {
-		return;
-	}
-#endif
-	if (rtp->dtls.dtls_setup == AST_RTP_DTLS_SETUP_PASSIVE) {
-		dtls_srtp_flush_pending(instance, rtp);
-	}
-#endif
 }
 
 /*! \brief Write t140 redundacy frame