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Merge pull request #129 from jmillan/rtp_rtcp_dissection 

rtp: properly dissect RTP and RTCP packets
This commit is contained in:
Kaian 2016-07-13 09:13:40 +02:00 committed by GitHub
parent 789c85aa40 9e8dc05960
commit 7baa0a0c44
2 changed files with 58 additions and 11 deletions
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47
src/rtp.c
View File

@ -176,16 +176,7 @@ rtp_check_packet(packet_t *packet)
src = packet->src;
dst = packet->dst;
// Check if we have at least RTP type
if ((int32_t) size < 2)
return NULL;
// Check RTP version
if (RTP_VERSION(*payload) != RTP_VERSION_RFC1889)
return NULL;
// RTP: even, RTCP: odd
if (((packet->dst.port % 2) == 0)) {
if (data_is_rtp(payload, size) == 0) {
// Get RTP payload type
format = RTP_PAYLOAD_TYPE(*(payload + 1));
@ -221,7 +212,7 @@ rtp_check_packet(packet_t *packet)
// Add packet to stream
stream_add_packet(stream, packet);
} else {
} else if (data_is_rtcp(payload, size) == 0) {
// Find the matching stream
if ((stream = rtp_find_stream(src, dst))) {
@ -294,6 +285,8 @@ rtp_check_packet(packet_t *packet)
stream_complete(stream, src);
stream_add_packet(stream, packet);
}
} else {
return NULL;
}
return stream;
@ -428,3 +421,35 @@ stream_is_complete(rtp_stream_t *stream)
{
return (stream->pktcnt != 0);
}
int
data_is_rtp(u_char *data, uint32_t len)
{
u_char pt = RTP_PAYLOAD_TYPE(*(data + 1));
if ((len >= RTP_HDR_LENGTH) &&
(RTP_VERSION(*data) == RTP_VERSION_RFC1889) &&
(data[0] > 127 && data[0] < 192) &&
(pt <= 64 || pt >= 96)) {
return 0;
}
// Not a RTP packet
return 1;
}
int
data_is_rtcp(u_char *data, uint32_t len)
{
struct rtcp_hdr_generic *hdr = (struct rtcp_hdr_generic*) data;
if ((len >= RTCP_HDR_LENGTH) &&
(RTP_VERSION(*data) == RTP_VERSION_RFC1889) &&
(data[0] > 127 && data[0] < 192) &&
(hdr->type >= 192 && hdr->type <= 223)) {
return 0;
}
// Not a RTCP packet
return 1;
}

22
src/rtp.h
View File

@ -44,6 +44,12 @@
// Handled RTP versions
#define RTP_VERSION_RFC1889 2
// RTP header length
#define RTP_HDR_LENGTH 12
// RTCP common header length
#define RTCP_HDR_LENGTH 4
// RTCP header types
//! http://www.iana.org/assignments/rtp-parameters/rtp-parameters.xhtml
enum rtcp_header_types
@ -312,4 +318,20 @@ stream_is_older(rtp_stream_t *one, rtp_stream_t *two);
int
stream_is_complete(rtp_stream_t *stream);
/**
* @brief Check if the data is a RTP packet
* RFC 5761 Section 4. Distinguishable RTP and RTCP Packets
* RFC 5764 Section 5.1.2. Reception (packet demultiplexing)
*/
int
data_is_rtp(u_char *data, uint32_t len);
/**
* @brief Check if the data is a RTCP packet
* RFC 5761 Section 4. Distinguishable RTP and RTCP Packets
* RFC 5764 Section 5.1.2. Reception (packet demultiplexing)
*/
int
data_is_rtcp(u_char *data, uint32_t len);
#endif /* __SNGREP_RTP_H */