1 /*
2 * Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "webrtc/modules/video_coding/main/test/pcap_file_reader.h"
12
13 #ifdef WIN32
14 #include <windows.h>
15 #include <Winsock2.h>
16 #else
17 #include <arpa/inet.h>
18 #endif
19 #include <assert.h>
20 #include <stdio.h>
21
22 #include <map>
23 #include <string>
24 #include <vector>
25
26 #include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
27 #include "webrtc/modules/video_coding/main/test/rtp_player.h"
28 #include "webrtc/system_wrappers/interface/scoped_ptr.h"
29
30 namespace webrtc {
31 namespace rtpplayer {
32
33 enum {
34 kResultFail = -1,
35 kResultSuccess = 0,
36 kResultSkip = 1,
37
38 kPcapVersionMajor = 2,
39 kPcapVersionMinor = 4,
40 kLinktypeNull = 0,
41 kLinktypeEthernet = 1,
42 kBsdNullLoopback1 = 0x00000002,
43 kBsdNullLoopback2 = 0x02000000,
44 kEthernetIIHeaderMacSkip = 12,
45 kEthertypeIp = 0x0800,
46 kIpVersion4 = 4,
47 kMinIpHeaderLength = 20,
48 kFragmentOffsetClear = 0x0000,
49 kFragmentOffsetDoNotFragment = 0x4000,
50 kProtocolTcp = 0x06,
51 kProtocolUdp = 0x11,
52 kUdpHeaderLength = 8,
53 kMaxReadBufferSize = 4096
54 };
55
56 const uint32_t kPcapBOMSwapOrder = 0xd4c3b2a1UL;
57 const uint32_t kPcapBOMNoSwapOrder = 0xa1b2c3d4UL;
58
59 #if 1
60 # define DEBUG_LOG(text)
61 # define DEBUG_LOG1(text, arg)
62 #else
63 # define DEBUG_LOG(text) (printf(text "\n"))
64 # define DEBUG_LOG1(text, arg) (printf(text "\n", arg))
65 #endif
66
67 #define TRY(expr) \
68 do { \
69 int r = (expr); \
70 if (r == kResultFail) { \
71 DEBUG_LOG1("FAIL at " __FILE__ ":%d", __LINE__); \
72 return kResultFail; \
73 } else if (r == kResultSkip) { \
74 return kResultSkip; \
75 } \
76 } while (0)
77
78 // Read RTP packets from file in tcpdump/libpcap format, as documented at:
79 // http://wiki.wireshark.org/Development/LibpcapFileFormat
80 class PcapFileReaderImpl : public RtpPacketSourceInterface {
81 public:
PcapFileReaderImpl()82 PcapFileReaderImpl()
83 : file_(NULL),
84 swap_pcap_byte_order_(false),
85 swap_network_byte_order_(false),
86 read_buffer_(),
87 packets_by_ssrc_(),
88 packets_(),
89 next_packet_it_() {
90 int16_t test = 0x7f00;
91 if (test != htons(test)) {
92 swap_network_byte_order_ = true;
93 }
94 }
95
~PcapFileReaderImpl()96 virtual ~PcapFileReaderImpl() {
97 if (file_ != NULL) {
98 fclose(file_);
99 file_ = NULL;
100 }
101 }
102
Initialize(const std::string & filename)103 int Initialize(const std::string& filename) {
104 file_ = fopen(filename.c_str(), "rb");
105 if (file_ == NULL) {
106 printf("ERROR: Can't open file: %s\n", filename.c_str());
107 return kResultFail;
108 }
109
110 if (ReadGlobalHeader() < 0) {
111 return kResultFail;
112 }
113
114 int total_packet_count = 0;
115 uint32_t stream_start_ms = 0;
116 int32_t next_packet_pos = ftell(file_);
117 for (;;) {
118 TRY(fseek(file_, next_packet_pos, SEEK_SET));
119 int result = ReadPacket(&next_packet_pos, stream_start_ms,
120 ++total_packet_count);
121 if (result == kResultFail) {
122 break;
123 } else if (result == kResultSuccess && packets_.size() == 1) {
124 assert(stream_start_ms == 0);
125 PacketIterator it = packets_.begin();
126 stream_start_ms = it->time_offset_ms;
127 it->time_offset_ms = 0;
128 }
129 }
130
131 if (feof(file_) == 0) {
132 printf("Failed reading file!\n");
133 return kResultFail;
134 }
135
136 printf("Total packets in file: %d\n", total_packet_count);
137 printf("Total RTP/RTCP packets: %d\n", static_cast<int>(packets_.size()));
138
139 for (SsrcMapIterator mit = packets_by_ssrc_.begin();
140 mit != packets_by_ssrc_.end(); ++mit) {
141 uint32_t ssrc = mit->first;
142 const std::vector<uint32_t>& packet_numbers = mit->second;
143 uint8_t pt = packets_[packet_numbers[0]].rtp_header.payloadType;
144 printf("SSRC: %08x, %d packets, pt=%d\n", ssrc,
145 static_cast<int>(packet_numbers.size()), pt);
146 }
147
148 // TODO(solenberg): Better validation of identified SSRC streams.
149 //
150 // Since we're dealing with raw network data here, we will wrongly identify
151 // some packets as RTP. When these packets are consumed by RtpPlayer, they
152 // are unlikely to cause issues as they will ultimately be filtered out by
153 // the RtpRtcp module. However, we should really do better filtering here,
154 // which we can accomplish in a number of ways, e.g.:
155 //
156 // - Verify that the time stamps and sequence numbers for RTP packets are
157 // both increasing/decreasing. If they move in different directions, the
158 // SSRC is likely bogus and can be dropped. (Normally they should be inc-
159 // reasing but we must allow packet reordering).
160 // - If RTP sequence number is not changing, drop the stream.
161 // - Can also use srcip:port->dstip:port pairs, assuming few SSRC collisions
162 // for up/down streams.
163
164 next_packet_it_ = packets_.begin();
165 return kResultSuccess;
166 }
167
NextPacket(uint8_t * data,uint32_t * length,uint32_t * time_ms)168 virtual int NextPacket(uint8_t* data, uint32_t* length, uint32_t* time_ms) {
169 assert(data);
170 assert(length);
171 assert(time_ms);
172
173 if (next_packet_it_ == packets_.end()) {
174 return -1;
175 }
176 if (*length < next_packet_it_->payload_length) {
177 return -1;
178 }
179 TRY(fseek(file_, next_packet_it_->pos_in_file, SEEK_SET));
180 TRY(Read(data, next_packet_it_->payload_length));
181 *length = next_packet_it_->payload_length;
182 *time_ms = next_packet_it_->time_offset_ms;
183 next_packet_it_++;
184
185 return 0;
186 }
187
188 private:
189 // A marker of an RTP packet within the file.
190 struct RtpPacketMarker {
191 uint32_t packet_number; // One-based index (like in WireShark)
192 uint32_t time_offset_ms;
193 uint32_t source_ip;
194 uint32_t dest_ip;
195 uint16_t source_port;
196 uint16_t dest_port;
197 RTPHeader rtp_header;
198 int32_t pos_in_file; // Byte offset of payload from start of file.
199 uint32_t payload_length;
200 };
201
202 typedef std::vector<RtpPacketMarker>::iterator PacketIterator;
203 typedef std::map<uint32_t, std::vector<uint32_t> > SsrcMap;
204 typedef std::map<uint32_t, std::vector<uint32_t> >::iterator SsrcMapIterator;
205
ReadGlobalHeader()206 int ReadGlobalHeader() {
207 uint32_t magic;
208 TRY(Read(&magic, false));
209 if (magic == kPcapBOMSwapOrder) {
210 swap_pcap_byte_order_ = true;
211 } else if (magic == kPcapBOMNoSwapOrder) {
212 swap_pcap_byte_order_ = false;
213 } else {
214 return kResultFail;
215 }
216
217 uint16_t version_major;
218 uint16_t version_minor;
219 TRY(Read(&version_major, false));
220 TRY(Read(&version_minor, false));
221 if (version_major != kPcapVersionMajor ||
222 version_minor != kPcapVersionMinor) {
223 return kResultFail;
224 }
225
226 int32_t this_zone; // GMT to local correction.
227 uint32_t sigfigs; // Accuracy of timestamps.
228 uint32_t snaplen; // Max length of captured packets, in octets.
229 uint32_t network; // Data link type.
230 TRY(Read(&this_zone, false));
231 TRY(Read(&sigfigs, false));
232 TRY(Read(&snaplen, false));
233 TRY(Read(&network, false));
234
235 // Accept only LINKTYPE_NULL and LINKTYPE_ETHERNET.
236 // See: http://www.tcpdump.org/linktypes.html
237 if (network != kLinktypeNull && network != kLinktypeEthernet) {
238 return kResultFail;
239 }
240
241 return kResultSuccess;
242 }
243
ReadPacket(int32_t * next_packet_pos,uint32_t stream_start_ms,uint32_t number)244 int ReadPacket(int32_t* next_packet_pos, uint32_t stream_start_ms,
245 uint32_t number) {
246 assert(next_packet_pos);
247
248 uint32_t ts_sec; // Timestamp seconds.
249 uint32_t ts_usec; // Timestamp microseconds.
250 uint32_t incl_len; // Number of octets of packet saved in file.
251 uint32_t orig_len; // Actual length of packet.
252 TRY(Read(&ts_sec, false));
253 TRY(Read(&ts_usec, false));
254 TRY(Read(&incl_len, false));
255 TRY(Read(&orig_len, false));
256
257 *next_packet_pos = ftell(file_) + incl_len;
258
259 RtpPacketMarker marker = {0};
260 marker.packet_number = number;
261 marker.time_offset_ms = CalcTimeDelta(ts_sec, ts_usec, stream_start_ms);
262 TRY(ReadPacketHeader(&marker));
263 marker.pos_in_file = ftell(file_);
264
265 if (marker.payload_length > sizeof(read_buffer_)) {
266 printf("Packet too large!\n");
267 return kResultFail;
268 }
269 TRY(Read(read_buffer_, marker.payload_length));
270
271 ModuleRTPUtility::RTPHeaderParser rtp_parser(read_buffer_,
272 marker.payload_length);
273 if (rtp_parser.RTCP()) {
274 rtp_parser.ParseRtcp(&marker.rtp_header);
275 packets_.push_back(marker);
276 } else {
277 if (!rtp_parser.Parse(marker.rtp_header, NULL)) {
278 DEBUG_LOG("Not recognized as RTP/RTCP");
279 return kResultSkip;
280 }
281
282 uint32_t ssrc = marker.rtp_header.ssrc;
283 packets_by_ssrc_[ssrc].push_back(marker.packet_number);
284 packets_.push_back(marker);
285 }
286
287 return kResultSuccess;
288 }
289
ReadPacketHeader(RtpPacketMarker * marker)290 int ReadPacketHeader(RtpPacketMarker* marker) {
291 int32_t file_pos = ftell(file_);
292
293 // Check for BSD null/loopback frame header. The header is just 4 bytes in
294 // native byte order, so we check for both versions as we don't care about
295 // the header as such and will likely fail reading the IP header if this is
296 // something else than null/loopback.
297 uint32_t protocol;
298 TRY(Read(&protocol, true));
299 if (protocol == kBsdNullLoopback1 || protocol == kBsdNullLoopback2) {
300 int result = ReadXxpIpHeader(marker);
301 DEBUG_LOG("Recognized loopback frame");
302 if (result != kResultSkip) {
303 return result;
304 }
305 }
306
307 TRY(fseek(file_, file_pos, SEEK_SET));
308
309 // Check for Ethernet II, IP frame header.
310 uint16_t type;
311 TRY(Skip(kEthernetIIHeaderMacSkip)); // Source+destination MAC.
312 TRY(Read(&type, true));
313 if (type == kEthertypeIp) {
314 int result = ReadXxpIpHeader(marker);
315 DEBUG_LOG("Recognized ethernet 2 frame");
316 if (result != kResultSkip) {
317 return result;
318 }
319 }
320
321 return kResultSkip;
322 }
323
CalcTimeDelta(uint32_t ts_sec,uint32_t ts_usec,uint32_t start_ms)324 uint32_t CalcTimeDelta(uint32_t ts_sec, uint32_t ts_usec, uint32_t start_ms) {
325 // Round to nearest ms.
326 uint64_t t2_ms = ((static_cast<uint64_t>(ts_sec) * 1000000) + ts_usec +
327 500) / 1000;
328 uint64_t t1_ms = static_cast<uint64_t>(start_ms);
329 if (t2_ms < t1_ms) {
330 return 0;
331 } else {
332 return t2_ms - t1_ms;
333 }
334 }
335
ReadXxpIpHeader(RtpPacketMarker * marker)336 int ReadXxpIpHeader(RtpPacketMarker* marker) {
337 assert(marker);
338
339 uint16_t version;
340 uint16_t length;
341 uint16_t id;
342 uint16_t fragment;
343 uint16_t protocol;
344 uint16_t checksum;
345 TRY(Read(&version, true));
346 TRY(Read(&length, true));
347 TRY(Read(&id, true));
348 TRY(Read(&fragment, true));
349 TRY(Read(&protocol, true));
350 TRY(Read(&checksum, true));
351 TRY(Read(&marker->source_ip, true));
352 TRY(Read(&marker->dest_ip, true));
353
354 if (((version >> 12) & 0x000f) != kIpVersion4) {
355 DEBUG_LOG("IP header is not IPv4");
356 return kResultSkip;
357 }
358
359 if (fragment != kFragmentOffsetClear &&
360 fragment != kFragmentOffsetDoNotFragment) {
361 DEBUG_LOG("IP fragments cannot be handled");
362 return kResultSkip;
363 }
364
365 // Skip remaining fields of IP header.
366 uint16_t header_length = (version & 0x0f00) >> (8 - 2);
367 assert(header_length >= kMinIpHeaderLength);
368 TRY(Skip(header_length - kMinIpHeaderLength));
369
370 protocol = protocol & 0x00ff;
371 if (protocol == kProtocolTcp) {
372 DEBUG_LOG("TCP packets are not handled");
373 return kResultSkip;
374 } else if (protocol == kProtocolUdp) {
375 uint16_t length;
376 uint16_t checksum;
377 TRY(Read(&marker->source_port, true));
378 TRY(Read(&marker->dest_port, true));
379 TRY(Read(&length, true));
380 TRY(Read(&checksum, true));
381 marker->payload_length = length - kUdpHeaderLength;
382 } else {
383 DEBUG_LOG("Unknown transport (expected UDP or TCP)");
384 return kResultSkip;
385 }
386
387 return kResultSuccess;
388 }
389
Read(uint32_t * out,bool expect_network_order)390 int Read(uint32_t* out, bool expect_network_order) {
391 uint32_t tmp = 0;
392 if (fread(&tmp, 1, sizeof(uint32_t), file_) != sizeof(uint32_t)) {
393 return kResultFail;
394 }
395 if ((!expect_network_order && swap_pcap_byte_order_) ||
396 (expect_network_order && swap_network_byte_order_)) {
397 tmp = ((tmp >> 24) & 0x000000ff) | (tmp << 24) |
398 ((tmp >> 8) & 0x0000ff00) | ((tmp << 8) & 0x00ff0000);
399 }
400 *out = tmp;
401 return kResultSuccess;
402 }
403
Read(uint16_t * out,bool expect_network_order)404 int Read(uint16_t* out, bool expect_network_order) {
405 uint16_t tmp = 0;
406 if (fread(&tmp, 1, sizeof(uint16_t), file_) != sizeof(uint16_t)) {
407 return kResultFail;
408 }
409 if ((!expect_network_order && swap_pcap_byte_order_) ||
410 (expect_network_order && swap_network_byte_order_)) {
411 tmp = ((tmp >> 8) & 0x00ff) | (tmp << 8);
412 }
413 *out = tmp;
414 return kResultSuccess;
415 }
416
Read(uint8_t * out,uint32_t count)417 int Read(uint8_t* out, uint32_t count) {
418 if (fread(out, 1, count, file_) != count) {
419 return kResultFail;
420 }
421 return kResultSuccess;
422 }
423
Read(int32_t * out,bool expect_network_order)424 int Read(int32_t* out, bool expect_network_order) {
425 int32_t tmp = 0;
426 if (fread(&tmp, 1, sizeof(uint32_t), file_) != sizeof(uint32_t)) {
427 return kResultFail;
428 }
429 if ((!expect_network_order && swap_pcap_byte_order_) ||
430 (expect_network_order && swap_network_byte_order_)) {
431 tmp = ((tmp >> 24) & 0x000000ff) | (tmp << 24) |
432 ((tmp >> 8) & 0x0000ff00) | ((tmp << 8) & 0x00ff0000);
433 }
434 *out = tmp;
435 return kResultSuccess;
436 }
437
Skip(uint32_t length)438 int Skip(uint32_t length) {
439 if (fseek(file_, length, SEEK_CUR) != 0) {
440 return kResultFail;
441 }
442 return kResultSuccess;
443 }
444
445 FILE* file_;
446 bool swap_pcap_byte_order_;
447 bool swap_network_byte_order_;
448 uint8_t read_buffer_[kMaxReadBufferSize];
449
450 SsrcMap packets_by_ssrc_;
451 std::vector<RtpPacketMarker> packets_;
452 PacketIterator next_packet_it_;
453
454 DISALLOW_COPY_AND_ASSIGN(PcapFileReaderImpl);
455 };
456
CreatePcapFileReader(const std::string & filename)457 RtpPacketSourceInterface* CreatePcapFileReader(const std::string& filename) {
458 scoped_ptr<PcapFileReaderImpl> impl(new PcapFileReaderImpl());
459 if (impl->Initialize(filename) != 0) {
460 return NULL;
461 }
462 return impl.release();
463 }
464 } // namespace rtpplayer
465 } // namespace webrtc
466