ref: 801cf888d679a233a5708df92e0424b78c148859
parent: e24c02237fb131393bd04f0d89ab63895371442c
author: Ralph Giles <giles@mozilla.com>
date: Thu Aug 16 13:31:02 EDT 2012
Abstract some of the header parsing on the captured packets.
--- a/src/opusrtp.c
+++ b/src/opusrtp.c
@@ -92,7 +92,7 @@
le32(data + 8, strlen(vendor));
memcpy(data + 12, vendor, strlen(vendor));
le32(data + 12 + strlen(vendor), 0);
-
+
op->packet = data;
op->bytes = size;
op->b_o_s = 0;
@@ -137,7 +137,7 @@
if (!params || !params->stream || !params->out) {return -1;
}
-
+
while (ogg_stream_pageout(params->stream, &page)) {fwrite(page.header, 1, page.header_len, params->out);
fwrite(page.body, 1, page.body_len, params->out);
@@ -154,7 +154,7 @@
if (!params || !params->stream || !params->out) {return -1;
}
-
+
while (ogg_stream_flush(params->stream, &page)) {fwrite(page.header, 1, page.header_len, params->out);
fwrite(page.body, 1, page.body_len, params->out);
@@ -163,16 +163,45 @@
return 0;
}
+typedef struct {+ unsigned char src[6], dst[6]; /* ethernet MACs */
+ int type;
+} eth_header;
+
+typedef struct {+ int version;
+ int header_size;
+ unsigned char src[4], dst[4]; /* ipv4 addrs */
+ int protocol;
+} ip_header;
+
+typedef struct {+ int src, dst; /* ports */
+ int size, checksum;
+} udp_header;
+
+typedef struct {+ int version;
+ int type;
+ int pad, ext, cc, mark;
+ int seq, time;
+ int ssrc;
+ int header_size;
+ int payload_size;
+} rtp_header;
+
/* pcap 'got_packet' callback */
void write_packet(u_char *args, const struct pcap_pkthdr *header,
const u_char *packet)
{state *params = (state *)args;
- int ip_header_size;
- int rtp_header_size;
+ eth_header eth;
+ ip_header ip;
+ udp_header udp;
+ rtp_header rtp;
fprintf(stderr, "Got %d byte packet (%d bytes captured)\n",
- header->len, header->caplen);
+ header->len, header->caplen);
/* eth header is always 14 bytes */
if (header->caplen < 14) {@@ -179,11 +208,17 @@
fprintf(stderr, "Packet too short for eth\n");
return;
}
+ memcpy(eth.src, packet, 6);
+ memcpy(eth.dst, packet + 6, 6);
+ eth.type = packet[12] << 8 | packet[13];
+
fprintf(stderr, " src mac %02x:%02x:%02x:%02x:%02x:%02x\n",
- packet[0], packet[1], packet[2], packet[3], packet[4], packet[5]);
- fprintf(stderr, " dest mac %02x:%02x:%02x:%02x:%02x:%02x\n",
- packet[6], packet[7], packet[8], packet[9], packet[10], packet[11]);
- fprintf(stderr, " eth type 0x%04x\n", packet[12] << 8 | packet[13]);
+ eth.src[0], eth.src[1], eth.src[2],
+ eth.src[3], eth.src[4], eth.src[5]);
+ fprintf(stderr, " dst mac %02x:%02x:%02x:%02x:%02x:%02x\n",
+ eth.dst[0], eth.dst[1], eth.dst[2],
+ eth.dst[3], eth.dst[4], eth.dst[5]);
+ fprintf(stderr, " eth type 0x%04x\n", eth.type);
/* ipv4 header */
if (header->caplen < 14 + 20) {@@ -190,74 +225,104 @@
fprintf(stderr, "Packet too short for ipv4\n");
return;
}
- fprintf(stderr, " IP version %d\n", (packet[14+0] >> 4) & 0x0f);
- ip_header_size = (packet[14+0] & 0x0f) * 4;
- fprintf(stderr, " header length %d\n", ip_header_size);
+ ip.version = (packet[14+0] >> 4) & 0x0f;
+ ip.header_size = 4 * (packet[14+0] & 0x0f);
+ ip.protocol = packet[14 + 9];
+ memcpy(ip.src, packet + 14 + 12, 4);
+ memcpy(ip.dst, packet + 12 + 16, 4);
+
+ fprintf(stderr, " IP version %d\n", ip.version);
+ fprintf(stderr, " header length %d\n", ip.header_size);
fprintf(stderr, " src addr %d.%d.%d.%d\n",
- packet[14+12+0], packet[14+12+1], packet[14+12+2], packet[14+12+3]);
- fprintf(stderr, " dest addr %d.%d.%d.%d\n",
- packet[14+16+0], packet[14+16+1], packet[14+16+2], packet[14+16+3]);
- fprintf(stderr, " protocol %d\n", packet[14+9]);
- if (header->caplen < 14 + ip_header_size) {+ ip.src[0], ip.src[1], ip.src[2], ip.src[3]);
+ fprintf(stderr, " dst addr %d.%d.%d.%d\n",
+ ip.dst[0], ip.dst[1], ip.dst[2], ip.dst[3]);
+ fprintf(stderr, " protocol %d\n", ip.protocol);
+ if (header->caplen < 14 + ip.header_size) {fprintf(stderr, "Packet too short for ipv4 with options\n");
return;
}
- if (header->caplen < 14 + ip_header_size + 8) {+ if (header->caplen < 14 + ip.header_size + 8) {fprintf(stderr, "Packet too short for udp\n");
return;
}
- fprintf(stderr, " src port %d\n", packet[14+ip_header_size] << 8 |
- packet[14+ip_header_size + 1]);
- fprintf(stderr, " dest port %d\n", packet[14+ip_header_size + 2] << 8 |
- packet[14+ip_header_size + 3]);
- fprintf(stderr, " udp length %d\n", packet[14+ip_header_size + 4] << 8 |
- packet[14+ip_header_size + 5]);
+ udp.src = packet[14+ip.header_size] << 8 |
+ packet[14+ip.header_size + 1];
+ udp.dst = packet[14+ip.header_size + 2] << 8 |
+ packet[14+ip.header_size + 3];
+ udp.size = packet[14+ip.header_size + 4] << 8 |
+ packet[14+ip.header_size + 5];
+ udp.checksum = packet[14+ip.header_size + 6] << 8 |
+ packet[14+ip.header_size + 7];
- if (header->caplen < 14 + ip_header_size + 8 + 12) {+ fprintf(stderr, " src port %d\n", udp.src);
+ fprintf(stderr, " dst port %d\n", udp.dst);
+ fprintf(stderr, " udp length %d\n", udp.size);
+ fprintf(stderr, " checksum %d\n", udp.checksum);
+
+ if (header->caplen < 14 + ip.header_size + 8 + 12) {fprintf(stderr, "Packet too short for rtp\n");
return;
}
- fprintf(stderr, " rtp version %d\n",
- (packet[14+ip_header_size + 8 + 0] >> 6) & 3);
- fprintf(stderr, " padding %d\n",
- (packet[14+ip_header_size + 8 + 0] >> 5) & 1);
- fprintf(stderr, " extension %d\n",
- (packet[14+ip_header_size + 8 + 0] >> 4) & 1);
- rtp_header_size = 12 + 4*((packet[14+ip_header_size + 8 + 0]) & 7);
- fprintf(stderr, " CSRC count %d\n",
- (packet[14+ip_header_size + 8 + 0]) & 7);
- fprintf(stderr, " marker %d\n",
- (packet[14+ip_header_size + 8 + 1] >> 7) & 1);
- fprintf(stderr, " payload type %d\n",
- (packet[14+ip_header_size + 8 + 1]) & 127);
- int seq = packet[14+ip_header_size + 8 + 2] << 8 |
- packet[14+ip_header_size + 8 + 3];
- fprintf(stderr, " sequence no %d\n", seq);
+ rtp.version = (packet[14+ip.header_size+8 + 0] >> 6) & 3;
+ rtp.pad = (packet[14+ip.header_size+8] >> 5) & 1;
+ rtp.ext = (packet[14+ip.header_size+8] >> 4) & 1;
+ rtp.cc = packet[14+ip.header_size+8] & 7;
+ rtp.header_size = 12 + 4 * rtp.cc;
+ rtp.payload_size = udp.size - rtp.header_size;
- if (header->caplen < 14 + ip_header_size + 8 + rtp_header_size) {+ rtp.mark = (packet[14+ip.header_size+8 + 1] >> 7) & 1;
+ rtp.type = (packet[14+ip.header_size+8 + 1]) & 127;
+ rtp.seq = packet[14+ip.header_size+8 + 2] << 8 |
+ packet[14+ip.header_size+8 + 3];
+ rtp.time = packet[14+ip.header_size+8 + 4] << 24 |
+ packet[14+ip.header_size+8 + 5] << 16 |
+ packet[14+ip.header_size+8 + 6] << 8 |
+ packet[14+ip.header_size+8 + 7];
+ rtp.ssrc = packet[14+ip.header_size+8 + 8] << 24 |
+ packet[14+ip.header_size+8 + 9] << 16 |
+ packet[14+ip.header_size+8 + 10] << 8 |
+ packet[14+ip.header_size+8 + 11];
+
+ fprintf(stderr, " rtp version %d\n", rtp.version);
+ fprintf(stderr, " payload type %d\n", rtp.type);
+ fprintf(stderr, " SSRC 0x%08x\n", rtp.ssrc);
+ fprintf(stderr, " sequence no %d\n", rtp.seq);
+ fprintf(stderr, " timestamp %d\n", rtp.time);
+ fprintf(stderr, " padding %d\n", rtp.pad);
+ fprintf(stderr, " extension %d\n", rtp.ext);
+ fprintf(stderr, " CSRC count %d\n", rtp.cc);
+ fprintf(stderr, " marker %d\n", rtp.mark);
+
+ if (header->caplen < 14 + ip.header_size + 8 + rtp.header_size) {fprintf(stderr, "skipping short packet\n");
return;
}
- if (seq < params->seq) {+ if (rtp.seq < params->seq) {fprintf(stderr, "skipping out-of-sequence packet\n");
return;
}
- params->seq = seq;
+ params->seq = rtp.seq;
+ if (rtp.type != 109) {+ fprintf(stderr, "skipping non-opus packet\n");
+ return;
+ }
+
/* write the payload to our opus file */
- int size = header->caplen - 14 - ip_header_size - 8 - rtp_header_size;
- unsigned char *data = packet + 14 + ip_header_size + 8 + rtp_header_size;
+ int size = header->caplen - 14 - ip.header_size - 8 - rtp.header_size;
+ unsigned char *data = packet + 14+ip.header_size+8 + rtp.header_size;
fprintf(stderr, " payload data %d bytes\n",
- header->len - 14 - ip_header_size - 8 - rtp_header_size);
- if ( (packet[14+ip_header_size + 8 + 1] & 127) != 109) {+ header->len - 14 - ip.header_size - 8 - rtp.header_size);
+ if ( (packet[14+ip.header_size + 8 + 1] & 127) != 109) {fprintf(stderr, "skipping non-opus packet\n");
return;
}
ogg_packet *op = op_from_pkt(data, size);
- op->granulepos = 960*seq;
- ogg_stream_packetin(params->stream, op);
+ op->granulepos = 960*rtp.seq;
+ ogg_stream_packetin(params->stream, op);
free(op);
ogg_write(params);
}
@@ -270,7 +335,6 @@
int port = 55555;
char errbuf[PCAP_ERRBUF_SIZE];
ogg_packet *op;
- int i;
/* set up */
pcap = pcap_open_live(dev, 9600, 0, 1000, errbuf);
@@ -312,13 +376,6 @@
/* start capture loop */
fprintf(stderr, "Capturing packets\n");
pcap_loop(pcap, 300, write_packet, (u_char *)params);
-
- /* write packets */
- int num_packets = 0;
- unsigned char **packets;
- int *sizes;
- for (i = 0; i < num_packets; i++) {- }
/* write outstanding data */
ogg_flush(params);