tolerate offset dtmf payload (zoiper)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@14883 d0543943-73ff-0310-b7d9-9358b9ac24b2

diff --git a/src/switch_rtp.c b/src/switch_rtp.c
index e3bd4df63478c19c21549d7f1ad2ca3406d2d805..96c34f5b0db77014e499a66ef95141431c443e71 100644 (file)
--- a/src/switch_rtp.c
+++ b/src/switch_rtp.c
@@ -2065,18 +2065,42 @@ static int rtp_common_read(switch_rtp_t *rtp_session, switch_payload_t *payload_
                 */
                if (bytes && !switch_test_flag(rtp_session, SWITCH_RTP_FLAG_PROXY_MEDIA) && 
                        !switch_test_flag(rtp_session, SWITCH_RTP_FLAG_PASS_RFC2833) && rtp_session->recv_msg.header.pt == rtp_session->te) {
+                       switch_size_t len = bytes - rtp_header_len;
                        unsigned char *packet = (unsigned char *) rtp_session->recv_msg.body;
-                       int end = packet[1] & 0x80 ? 1 : 0;
-                       uint16_t duration = (packet[2] << 8) + packet[3];
-                       char key = switch_rfc2833_to_char(packet[0]);
-                       uint16_t in_digit_seq = ntohs((uint16_t) rtp_session->recv_msg.header.seq);
-                       uint32_t ts = htonl(rtp_session->recv_msg.header.ts);
+                       int end;
+                       uint16_t duration;
+                       char key;
+                       uint16_t in_digit_seq;
+                       uint32_t ts;
+
+
+                       if (!(packet[0] || packet[1] || packet[2] || packet[3]) && len >= 8) {
+                               packet += 4;
+                               len -= 4;
+                               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "DTMF payload offset by 4 bytes.\n");
+                       }
+
+                       if (!(packet[0] || packet[1] || packet[2] || packet[3])) {
+                               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed DTMF payload check.\n");
+                               rtp_session->dtmf_data.last_digit = 0;
+                               rtp_session->dtmf_data.in_digit_ts = 0;
+                       }
+
+                       end = packet[1] & 0x80 ? 1 : 0;
+                       duration = (packet[2] << 8) + packet[3];
+                       key = switch_rfc2833_to_char(packet[0]);
+                       in_digit_seq = ntohs((uint16_t) rtp_session->recv_msg.header.seq);
+                       ts = htonl(rtp_session->recv_msg.header.ts);
 
                        if (in_digit_seq < rtp_session->dtmf_data.in_digit_seq) {
                                if (rtp_session->dtmf_data.in_digit_seq - in_digit_seq > 100) {
                                        rtp_session->dtmf_data.in_digit_seq = 0;
                                }
                        }
+#ifdef DEBUG_2833                      
+                       printf("packet[%d]: %02x %02x %02x %02x\n", (int) len, (unsigned) packet[0],(unsigned)
+                                  packet[1], (unsigned) packet[2], (unsigned) packet[3]);
+#endif
 
                        if (in_digit_seq > rtp_session->dtmf_data.in_digit_seq) {