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https://github.com/vel21ripn/nDPI.git
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Initial import from SVN
This commit is contained in:
Luca Deri
parent
7fa4694dad
commit
2e5ceac844
204 changed files with 47689 additions and 1 deletions
325
src/lib/protocols/rtp.c
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325
src/lib/protocols/rtp.c
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/*
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* rtp.c
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*
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* Copyright (C) 2009-2011 by ipoque GmbH
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* Copyright (C) 2011-15 - ntop.org
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*
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* This file is part of nDPI, an open source deep packet inspection
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* library based on the OpenDPI and PACE technology by ipoque GmbH
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*
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* nDPI is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* nDPI is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with nDPI. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "ndpi_api.h"
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#ifdef NDPI_PROTOCOL_RTP
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static void ndpi_rtp_search(struct ndpi_detection_module_struct *ndpi_struct,
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struct ndpi_flow_struct *flow,
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const u_int8_t * payload, const u_int16_t payload_len)
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{
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//struct ndpi_packet_struct *packet = &flow->packet;
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u_int8_t payload_type = payload[1] & 0x7F;
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u_int32_t *ssid = (u_int32_t*)&payload[8];
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/* Check whether this is an RTP flow */
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if((payload_len >= 12)
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&& ((payload[0] & 0xFF) == 0x80) /* RTP magic byte[1] */
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&& ((payload_type < 72) || (payload_type > 76))
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&& (payload_type < 128 /* http://anonsvn.wireshark.org/wireshark/trunk/epan/dissectors/packet-rtp.c */)
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&& (*ssid != 0)
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) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "Found rtp.\n");
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ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_RTP, NDPI_REAL_PROTOCOL);
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} else {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "exclude rtp.\n");
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NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_RTP);
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}
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}
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void ndpi_search_rtp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
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{
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struct ndpi_packet_struct *packet = &flow->packet;
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if((packet->udp != NULL)
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&& (ntohs(packet->udp->source) > 1023)
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&& (ntohs(packet->udp->dest) > 1023))
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ndpi_rtp_search(ndpi_struct, flow, packet->payload, packet->payload_packet_len);
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}
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#if 0
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/* Original (messy) OpenDPI code */
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#define RTP_MAX_OUT_OF_ORDER 11
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static void ndpi_int_rtp_add_connection(struct ndpi_detection_module_struct
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*ndpi_struct, struct ndpi_flow_struct *flow)
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{
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ndpi_int_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_RTP, NDPI_REAL_PROTOCOL);
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}
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/*
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* maintenance of current highest sequence number, cycle count, packet counter
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* adapted from RFC3550 Appendix A.1
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*
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* In their formulation, it is not possible to represent "no packets sent yet". This is fixed here by defining
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* baseseq to be the sequence number of the first packet minus 1 (in other words, the sequence number of the
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* zeroth packet).
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*
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* Note: As described in the RFC, the number of packets received includes retransmitted packets.
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* This means the "packets lost" count (seq_num-isn+1)-received can become negative.
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*
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* include_current_packet should be
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* 1, if the current packet should count towards the total, or
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* 0, if it it regarded as belonging to the previous reporting interval
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*/
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#if !defined(WIN32)
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static inline
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#else
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__forceinline static
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#endif
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void init_seq(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow,
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u_int8_t direction, u_int16_t seq, u_int8_t include_current_packet)
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{
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flow->rtp_seqnum[direction] = seq;
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "rtp_seqnum[%u] = %u\n", direction, seq);
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}
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/* returns difference between old and new highest sequence number */
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#if !defined(WIN32)
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static inline
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#else
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__forceinline static
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#endif
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u_int16_t update_seq(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow,
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u_int8_t direction, u_int16_t seq)
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{
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u_int16_t delta = seq - flow->rtp_seqnum[direction];
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if (delta < RTP_MAX_OUT_OF_ORDER) { /* in order, with permissible gap */
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flow->rtp_seqnum[direction] = seq;
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "rtp_seqnum[%u] = %u (increased by %u)\n",
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direction, seq, delta);
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return delta;
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} else {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "retransmission (dir %u, seqnum %u)\n",
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direction, seq);
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return 0;
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}
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}
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static void ndpi_rtp_search(struct ndpi_detection_module_struct *ndpi_struct,
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struct ndpi_flow_struct *flow,
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const u_int8_t * payload, const u_int16_t payload_len)
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{
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struct ndpi_packet_struct *packet = &flow->packet;
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u_int8_t stage;
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u_int16_t seqnum = ntohs(get_u_int16_t(payload, 2));
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "search rtp.\n");
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if (payload_len == 4 && get_u_int32_t(packet->payload, 0) == 0 && flow->packet_counter < 8) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "need next packet, maybe ClearSea out calls.\n");
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return;
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}
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if (payload_len == 5 && memcmp(payload, "hello", 5) == 0) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG,
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"need next packet, initial hello packet of SIP out calls.\n");
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return;
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}
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if (payload_len == 1 && payload[0] == 0) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG,
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"need next packet, payload_packet_len == 1 && payload[0] == 0.\n");
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return;
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}
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if (payload_len == 3 && memcmp(payload, "png", 3) == 0) {
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/* weird packet found in Ninja GlobalIP trace */
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "skipping packet with len = 3 and png payload.\n");
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return;
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}
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if (payload_len < 12) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "minimal packet size for rtp packets: 12.\n");
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goto exclude_rtp;
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}
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if (payload_len == 12 && get_u_int32_t(payload, 0) == 0 && get_u_int32_t(payload, 4) == 0 && get_u_int32_t(payload, 8) == 0) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "skipping packet with len = 12 and only 0-bytes.\n");
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return;
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}
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if ((payload[0] & 0xc0) == 0xc0 || (payload[0] & 0xc0) == 0x40 || (payload[0] & 0xc0) == 0x00) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "version = 3 || 1 || 0, maybe first rtp packet.\n");
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return;
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}
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if ((payload[0] & 0xc0) != 0x80) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct,
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NDPI_LOG_DEBUG, "rtp version must be 2, first two bits of a packets must be 10.\n");
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goto exclude_rtp;
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}
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/* rtp_payload_type are the last seven bits of the second byte */
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if (flow->rtp_payload_type[packet->packet_direction] != (payload[1] & 0x7F)) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "payload_type has changed, reset stages.\n");
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packet->packet_direction == 0 ? (flow->rtp_stage1 = 0) : (flow->rtp_stage2 = 0);
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}
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/* first bit of first byte is not part of payload_type */
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flow->rtp_payload_type[packet->packet_direction] = payload[1] & 0x7F;
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stage = (packet->packet_direction == 0 ? flow->rtp_stage1 : flow->rtp_stage2);
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if (stage > 0) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct,
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NDPI_LOG_DEBUG, "stage = %u.\n", packet->packet_direction == 0 ? flow->rtp_stage1 : flow->rtp_stage2);
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if (flow->rtp_ssid[packet->packet_direction] != get_u_int32_t(payload, 8)) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "ssid has changed, goto exclude rtp.\n");
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goto exclude_rtp;
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}
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if (seqnum == flow->rtp_seqnum[packet->packet_direction]) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "maybe \"retransmission\", need next packet.\n");
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return;
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} else if ((u_int16_t) (seqnum - flow->rtp_seqnum[packet->packet_direction]) < RTP_MAX_OUT_OF_ORDER) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG,
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"new packet has larger sequence number (within valid range)\n");
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update_seq(ndpi_struct, flow, packet->packet_direction, seqnum);
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} else if ((u_int16_t) (flow->rtp_seqnum[packet->packet_direction] - seqnum) < RTP_MAX_OUT_OF_ORDER) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG,
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"new packet has smaller sequence number (within valid range)\n");
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init_seq(ndpi_struct, flow, packet->packet_direction, seqnum, 1);
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} else {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG,
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"sequence number diff is too big, goto exclude rtp.\n");
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goto exclude_rtp;
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}
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} else {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct,
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NDPI_LOG_DEBUG, "rtp_ssid[%u] = %u.\n", packet->packet_direction,
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flow->rtp_ssid[packet->packet_direction]);
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flow->rtp_ssid[packet->packet_direction] = get_u_int32_t(payload, 8);
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if (flow->packet_counter < 3) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "packet_counter < 3, need next packet.\n");
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}
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init_seq(ndpi_struct, flow, packet->packet_direction, seqnum, 1);
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}
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if (seqnum <= 3) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct,
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NDPI_LOG_DEBUG, "sequence_number = %u, too small, need next packet, return.\n", seqnum);
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return;
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}
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if (stage == 3) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "add connection I.\n");
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ndpi_int_rtp_add_connection(ndpi_struct, flow);
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} else {
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packet->packet_direction == 0 ? flow->rtp_stage1++ : flow->rtp_stage2++;
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "stage[%u]++; need next packet.\n",
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packet->packet_direction);
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}
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return;
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exclude_rtp:
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#ifdef NDPI_PROTOCOL_STUN
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if (packet->detected_protocol_stack[0] == NDPI_PROTOCOL_STUN
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|| packet->real_protocol_read_only == NDPI_PROTOCOL_STUN) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "STUN: is detected, need next packet.\n");
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return;
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}
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#endif /* NDPI_PROTOCOL_STUN */
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "exclude rtp.\n");
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NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_RTP);
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}
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void ndpi_search_rtp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
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{
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struct ndpi_packet_struct *packet = &flow->packet;
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if (packet->udp) {
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ndpi_rtp_search(ndpi_struct, flow, packet->payload, packet->payload_packet_len);
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} else if (packet->tcp) {
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/* skip special packets seen at yahoo traces */
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if (packet->payload_packet_len >= 20 && ntohs(get_u_int16_t(packet->payload, 2)) + 20 == packet->payload_packet_len &&
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packet->payload[0] == 0x90 && packet->payload[1] >= 0x01 && packet->payload[1] <= 0x07) {
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if (flow->packet_counter == 2)
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flow->l4.tcp.rtp_special_packets_seen = 1;
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG,
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"skipping STUN-like, special yahoo packets with payload[0] == 0x90.\n");
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return;
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}
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#ifdef NDPI_PROTOCOL_STUN
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/* TODO the rtp detection sometimes doesn't exclude rtp
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* so for TCP flows only run the detection if STUN has been
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* detected (or RTP is already detected)
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* If flows will be seen which start directly with RTP
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* we can remove this restriction
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*/
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if (packet->detected_protocol_stack[0] == NDPI_PROTOCOL_STUN
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|| packet->detected_protocol_stack[0] == NDPI_PROTOCOL_RTP) {
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/* RTP may be encapsulated in TCP packets */
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if (packet->payload_packet_len >= 2 && ntohs(get_u_int16_t(packet->payload, 0)) + 2 == packet->payload_packet_len) {
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/* TODO there could be several RTP packets in a single TCP packet so maybe the detection could be
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* improved by checking only the RTP packet of given length */
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ndpi_rtp_search(ndpi_struct, flow, packet->payload + 2, packet->payload_packet_len - 2);
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return;
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}
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}
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if (packet->detected_protocol_stack[0] == NDPI_PROTOCOL_UNKNOWN && flow->l4.tcp.rtp_special_packets_seen == 1) {
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if (packet->payload_packet_len >= 4 && ntohl(get_u_int32_t(packet->payload, 0)) + 4 == packet->payload_packet_len) {
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/* TODO there could be several RTP packets in a single TCP packet so maybe the detection could be
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* improved by checking only the RTP packet of given length */
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ndpi_rtp_search(ndpi_struct, flow, packet->payload + 4, packet->payload_packet_len - 4);
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return;
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}
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}
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if (NDPI_FLOW_PROTOCOL_EXCLUDED(ndpi_struct, flow, NDPI_PROTOCOL_STUN)) {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "exclude rtp.\n");
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NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_RTP);
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} else {
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "STUN not yet excluded, need next packet.\n");
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}
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#else
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NDPI_LOG(NDPI_PROTOCOL_RTP, ndpi_struct, NDPI_LOG_DEBUG, "exclude rtp.\n");
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NDPI_ADD_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_RTP);
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#endif
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}
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}
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#endif
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#endif /* NDPI_PROTOCOL_RTP */
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