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- implemented live capture

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- implemented basic capture loop
This commit is contained in:
farrokhi 2014-07-28 17:52:19 +04:30
parent 02726243cd
commit 97b57d0055
1 changed files with 57 additions and 20 deletions
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71
sipcap/sipcap.c
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@ -10,9 +10,20 @@
#define ETHER_TYPE_IP (0x0800)
#define ETHER_TYPE_8021Q (0x8100)
// Global Vars
int pkt_count = 0;
int live_pcap = 0;
int offline_pcap = 0;
int has_expression = 0;
int output_to_file = 0;
int snaplen = 0;
char errbuf[PCAP_ERRBUF_SIZE];
char *capfile, *capdev, *capture_expression, *out_file;
void help(int quit)
{
printf("sipcap - version %.2f\n\n", SIPCAP_VERSION);
printf("Usage: sipcap [-i <interface>|-f <pcapfile>] [-e expression] [-o outfile] \n");
printf(" [-s snaplen] [-h]\n");
@ -21,22 +32,16 @@ void help(int quit)
}
void error(char *msg) {
fprintf(stderr, "Error: %s\n", msg);
exit(1);
}
int main(int argc, char *argv[])
{
pcap_t *pcap;
char errbuf[PCAP_ERRBUF_SIZE];
int opt;
int live_pcap = 0;
int offline_pcap = 0;
int has_expression = 0;
int output_to_file = 0;
int snaplen = 0;
char *pcap_file, *pcap_interface, *capture_expression, *out_file;
void parse_options(int argc, char *argv[]) {
// TODO: Add "-c" option that stops after capturing n packets
int opt;
while ((opt = getopt (argc, argv, "i:f:e:o:s:h")) != -1)
switch (opt) {
case 'h':
@ -46,17 +51,18 @@ int main(int argc, char *argv[])
live_pcap = 1;
if (offline_pcap) error("-i and -f are mutually exclusive");
if (optarg == NULL) help(1);
pcap_interface = optarg;
capdev = optarg;
break;
case 'f':
offline_pcap = 1;
if (live_pcap) error("-i and -f are mutually exclusive");
if (optarg == NULL) help(1);
pcap_file = optarg;
capfile = optarg;
break;
case 'e':
has_expression = 1;
if (optarg == NULL) help(1);
capture_expression = optarg;
break;
case 'o':
output_to_file = 1;
@ -66,19 +72,50 @@ int main(int argc, char *argv[])
case 's':
if (optarg == NULL) help(1);
snaplen = atoi(optarg);
printf("snaplen is %d\n", snaplen);
break;
}
if (!live_pcap && !offline_pcap) help(1);
}
void process_packet(u_char *args, const struct pcap_pkthdr *header, const u_char *packet) {
// we do actual packet processing here
pkt_count++;
}
int main(int argc, char *argv[])
{
pcap_t *pcap;
const u_char *packet;
struct pcap_pkthdr header;
struct bpf_program fp;
bpf_u_int32 devnet, devmask;
parse_options(argc, argv);
if (live_pcap) {
error("live capture not implemented");
if (pcap_lookupnet(capdev, &devnet, &devmask, errbuf) == -1) {
fprintf(stderr, "WARNING: Can't get netmask for device %s\n", capdev);
devnet = 0;
devmask = 0;
}
pcap = pcap_open_live(capdev, BUFSIZ, 1, 1000, errbuf);
} else {
pcap = pcap_open_offline(pcap_file, errbuf);
if (pcap == NULL) error("cannot open capture file");
pcap = pcap_open_offline(capfile, errbuf);
}
if (has_expression) {
if (pcap_compile(pcap, &fp, capture_expression, 0, devnet) == -1) error(pcap_geterr(pcap));
if (pcap_setfilter(pcap, &fp) == -1) error(pcap_geterr(pcap));
}
if (pcap == NULL) error(errbuf);
pcap_loop(pcap, -1, &process_packet, NULL);
printf("finished processing %d packets\n", pkt_count);
pcap_close(pcap);
exit(0);
}