FreeCalypso > hg > rtp-debug-utils

comparison rtp-gsmfr-dump.c @ 3:50aa973a91ef

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new program rtp-gsmfr-dump
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 16 Apr 2023 06:43:18 +0000
parents rtp-gsmfr-extr.c@210dfa39f573
children 7c85a7a913f7
comparison
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2:210dfa39f573 3:50aa973a91ef
1 /*
2 * This program is a combination of rtp-gsmfr-extr and gsmrec-dump into
3 * one step: it reads a pcap file, extracts packets belonging to a
4 * particular RTP stream as identified by a source or destination
5 * IP:port, verifies that an unbroken RTP stream is present, which is
6 * expected to be in GSM FR or EFR codec, but instead of writing this
7 * FR/EFR frame stream to a gsmx file, decodes it like gsmrec-dump.
8 *
9 * The advantage of this program over running rtp-gsmfr-extr followed
10 * by gsmrec-dump is that TRAUlike Extension Headers (if present) are
11 * dumped for analysis, rather than discarded.
12 */
13
14 #include <sys/types.h>
15 #include <sys/socket.h>
16 #include <netinet/in.h>
17 #include <arpa/inet.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <string.h>
21 #include <strings.h>
22 #include <pcap/pcap.h>
23 #include <gsm.h>
24 #include <gsm_efr.h>
25
26 static pcap_t *pcap;
27 static in_addr_t match_ip_addr;
28 static u_short match_udp_port;
29 static unsigned iphdr_addr_offset, udphdr_port_offset;
30 static unsigned link_hdr_len, ethertype_offset;
31 static int stream_init_flag;
32 static unsigned last_seq, last_tstamp, stream_ssrc;
33 static gsm dummy_state;
34
35 static void
36 check_dl_type()
37 {
38 int dltype;
39
40 dltype = pcap_datalink(pcap);
41 switch (dltype) {
42 case DLT_EN10MB:
43 link_hdr_len = 14;
44 ethertype_offset = 12;
45 break;
46 case DLT_RAW:
47 link_hdr_len = 0;
48 break;
49 case DLT_LINUX_SLL:
50 link_hdr_len = 16;
51 ethertype_offset = 14;
52 break;
53 default:
54 fprintf(stderr, "error: unsupported data link type %d\n",
55 dltype);
56 exit(1);
57 }
58 }
59
60 static void
61 rtp_stream_logic(rtp_hdr, pkt_idx)
62 u_char *rtp_hdr;
63 unsigned pkt_idx;
64 {
65 unsigned cur_seq, cur_tstamp, cur_ssrc;
66
67 cur_seq = (rtp_hdr[2] << 8) | rtp_hdr[3];
68 cur_tstamp = (rtp_hdr[4] << 24) | (rtp_hdr[5] << 16) |
69 (rtp_hdr[6] << 8) | rtp_hdr[7];
70 cur_ssrc = (rtp_hdr[8] << 24) | (rtp_hdr[9] << 16) |
71 (rtp_hdr[10] << 8) | rtp_hdr[11];
72 if (stream_init_flag) {
73 if (cur_ssrc != stream_ssrc) {
74 fprintf(stderr,
75 "error in packet #%u: SSRC change from 0x%08X to 0x%08X\n",
76 pkt_idx, stream_ssrc, cur_ssrc);
77 exit(1);
78 }
79 if (cur_seq != last_seq + 1 &&
80 (cur_seq != 0 || last_seq != 0xFFFF)) {
81 fprintf(stderr,
82 "error in packet #%u: seq break from 0x%04X to 0x%04X\n",
83 pkt_idx, last_seq, cur_seq);
84 exit(1);
85 }
86 if (cur_tstamp != last_tstamp + 160) {
87 fprintf(stderr,
88 "error in packet #%u: timestamp break from 0x%08X to 0x%08X\n",
89 pkt_idx, last_tstamp, cur_tstamp);
90 exit(1);
91 }
92 } else {
93 stream_init_flag = 1;
94 stream_ssrc = cur_ssrc;
95 }
96 last_seq = cur_seq;
97 last_tstamp = cur_tstamp;
98 }
99
100 static void
101 process_payload(payload, payload_len)
102 u_char *payload;
103 unsigned payload_len;
104 {
105 gsm_signal params[76];
106 int i, j, n;
107
108 printf("seq 0x%04X ts 0x%08X: ", last_seq, last_tstamp);
109 switch (payload_len) {
110 case 0:
111 printf("zero-length payload\n");
112 return;
113 case 1:
114 if ((payload[0] & 0xF6) != 0xE6)
115 break;
116 printf("TEH 0x%02X\n", payload[0]);
117 return;
118 case 2:
119 if (payload[0] != 0xBF)
120 break;
121 printf("old BFI TAF=%u\n", payload[1] & 1);
122 return;
123 case 31:
124 if ((payload[0] & 0xF0) != 0xC0)
125 break;
126 printf("std EFR SID=%d LPC", EFR_sid_classify(payload));
127 EFR_frame2params(payload, params);
128 print_efr:
129 n = 0;
130 for (i = 0; i < 5; i++)
131 printf(" %d", params[n++]);
132 putchar('\n');
133 for (i = 0; i < 4; i++) {
134 putchar(' ');
135 for (j = 0; j < 13; j++)
136 printf(" %d", params[n++]);
137 putchar('\n');
138 }
139 return;
140 case 32:
141 if ((payload[0] & 0xF4) != 0xE0)
142 break;
143 if ((payload[1] & 0xF0) != 0xC0)
144 break;
145 printf("TEH 0x%02X EFR SID=%d LPC", payload[0],
146 EFR_sid_classify(payload+1));
147 EFR_frame2params(payload+1, params);
148 goto print_efr;
149 case 33:
150 if ((payload[0] & 0xF0) != 0xD0)
151 break;
152 fputs("std FR", stdout);
153 gsm_explode(dummy_state, payload, params);
154 print_fr:
155 n = 0;
156 for (i = 0; i < 8; i++)
157 printf(" %d", params[n++]);
158 putchar('\n');
159 for (i = 0; i < 4; i++) {
160 putchar(' ');
161 for (j = 0; j < 17; j++)
162 printf(" %d", params[n++]);
163 putchar('\n');
164 }
165 return;
166 case 34:
167 if ((payload[0] & 0xF4) != 0xE0)
168 break;
169 if ((payload[1] & 0xF0) != 0xD0)
170 break;
171 printf("TEH 0x%02X FR", payload[0]);
172 gsm_explode(dummy_state, payload+1, params);
173 goto print_fr;
174 }
175 printf("unknown payload format, length=%u\n", payload_len);
176 }
177
178 static void
179 process_packet(pkt, caplen, pkt_idx)
180 u_char *pkt;
181 unsigned caplen, pkt_idx;
182 {
183 unsigned udplen, payload_len;
184
185 if (caplen < link_hdr_len + 28)
186 return;
187 if (link_hdr_len) {
188 if (pkt[ethertype_offset] != 0x08)
189 return;
190 if (pkt[ethertype_offset+1] != 0x00)
191 return;
192 pkt += link_hdr_len;
193 caplen -= link_hdr_len;
194 }
195 /* check IP header */
196 if (pkt[0] != 0x45)
197 return;
198 if (pkt[9] != 17) /* UDP */
199 return;
200 if (bcmp(pkt + iphdr_addr_offset, &match_ip_addr, 4))
201 return;
202 /* check UDP header */
203 if (bcmp(pkt + 20 + udphdr_port_offset, &match_udp_port, 2))
204 return;
205 /* it is our target - now scrutinize it */
206 udplen = (pkt[24] << 8) | pkt[25];
207 if (caplen < udplen + 20) {
208 fprintf(stderr,
209 "error: packet #%u is truncated in the capture\n",
210 pkt_idx);
211 exit(1);
212 }
213 if (udplen < 20) {
214 fprintf(stderr,
215 "error in packet #%u: UDP length is too short for RTP header\n",
216 pkt_idx);
217 exit(1);
218 }
219 if (pkt[28] != 0x80) {
220 fprintf(stderr,
221 "error in packet #%u: unsupported RTP header structure\n",
222 pkt_idx);
223 exit(1);
224 }
225 rtp_stream_logic(pkt + 28, pkt_idx);
226 process_payload(pkt + 40, udplen - 20);
227 }
228
229 main(argc, argv)
230 char **argv;
231 {
232 char errbuf[PCAP_ERRBUF_SIZE];
233 u_char *pkt;
234 struct pcap_pkthdr pkthdr;
235 unsigned pkt_idx;
236
237 if (argc != 5) {
238 fprintf(stderr,
239 "usage: %s pcap-file src|dest ip-addr udp-port\n",
240 argv[0]);
241 exit(1);
242 }
243 pcap = pcap_open_offline(argv[1], errbuf);
244 if (!pcap) {
245 fprintf(stderr, "%s: %s\n", argv[1], errbuf);
246 exit(1);
247 }
248 check_dl_type();
249 if (!strcmp(argv[2], "src")) {
250 iphdr_addr_offset = 12;
251 udphdr_port_offset = 0;
252 } else if (!strcmp(argv[2], "dest")) {
253 iphdr_addr_offset = 16;
254 udphdr_port_offset = 2;
255 } else {
256 fprintf(stderr,
257 "error: direction argument must be \"src\" or \"dest\"\n");
258 exit(1);
259 }
260 match_ip_addr = inet_addr(argv[3]);
261 if (match_ip_addr == INADDR_NONE) {
262 fprintf(stderr, "error: IP address argument is invalid\n");
263 exit(1);
264 }
265 match_udp_port = htons(strtoul(argv[4], 0, 0));
266 dummy_state = gsm_create();
267 if (!dummy_state) {
268 fprintf(stderr, "gsm_create() failed!\n");
269 exit(1);
270 }
271 for (pkt_idx = 0; ; pkt_idx++) {
272 pkt = pcap_next(pcap, &pkthdr);
273 if (!pkt)
274 break;
275 process_packet(pkt, (unsigned) pkthdr.caplen, pkt_idx);
276 }
277 if (!stream_init_flag) {
278 fprintf(stderr, "error: specified RTP stream not found\n");
279 exit(1);
280 }
281 exit(0);
282 }