#include #include #include "pcap.h" #include "stream.h" #define IPPROTO_TCP 6 #define IPPROTO_UDP 17 #define TH_FIN 0x01 #define TH_SYN 0x02 #define TH_RST 0x04 #define TH_PSH 0x08 #define TH_ACK 0x10 #define TH_URG 0x20 void ip4_addr(char *addr_s, uint32_t addr) { snprintf(addr_s, 16, "%u.%u.%u.%u", (addr >> 24) & 0xff, (addr >> 16) & 0xff, (addr >> 8) & 0xff, (addr >> 0) & 0xff); } void print_payload(struct stream *s) { while (s->len) { printf("%02x", read_uint8(s)); } } void process_tcp(struct stream *s, char *saddr_s, char *daddr_s) { uint16_t sport = read_uint16be(s); uint16_t dport = read_uint16be(s); uint32_t seq = read_uint32be(s); uint32_t ack = read_uint32be(s); uint8_t off = read_uint8(s); uint8_t hlen = (off >> 4) * 4; uint8_t flags = read_uint8(s); uint16_t window = read_uint16be(s); uint16_t chksum = read_uint16be(s); uint16_t urgent = read_uint16be(s); if (hlen < 20) { printf("!"); } printf("TCP4 %s:%u %s:%u ", saddr_s, sport, daddr_s, dport); // shut the compiler up if (false && urgent && chksum && window && flags && ack && seq && false); } void process_udp(struct stream *s, char *saddr_s, char *daddr_s) { uint16_t sport = read_uint16be(s); uint16_t dport = read_uint16be(s); uint16_t len = read_uint16be(s); uint16_t chksum = read_uint16be(s); printf("UDP4 %s:%u %s:%u ", saddr_s, sport, daddr_s, dport); // Now, do some shit! if (false && len && chksum && false); } void process_ip4(struct stream *s) { uint8_t vhl = read_uint8(s); uint8_t ihl = (vhl & 0x0f) * 4; uint8_t tos = read_uint8(s); uint16_t length = read_uint16be(s); uint16_t id = read_uint16be(s); uint16_t off = read_uint16be(s); uint8_t ttl = read_uint8(s); uint8_t proto = read_uint8(s); uint16_t chksum = read_uint16be(s); uint32_t saddr = read_uint32be(s); uint32_t daddr = read_uint32be(s); char saddr_s[20]; char daddr_s[20]; ip4_addr(saddr_s, saddr); ip4_addr(daddr_s, daddr); // Ignore options sskip(s, 20 - ihl); // Force stream length to IP payload length s->len = length - ihl; switch (proto) { case IPPROTO_TCP: process_tcp(s, saddr_s, daddr_s); break; case IPPROTO_UDP: process_udp(s, saddr_s, daddr_s); break; default: printf("P%d %s %s ", proto, saddr_s, daddr_s); break; } print_payload(s); /* * Placate compiler */ if (false && chksum && id && tos && ttl && off && false); } void print_ethernet(struct stream *s) { uint8_t saddr[6]; uint8_t daddr[6]; uint16_t ethertype; sread(s, &saddr, sizeof(saddr)); sread(s, &daddr, sizeof(daddr)); ethertype = read_uint16be(s); if (ethertype == 0x8100) { // VLAN read_uint16be(s); ethertype = read_uint16be(s); } switch (ethertype) { case 0x0800: // IPv4 process_ip4(s); break; } } void print_frame(struct pcap_pkthdr *hdr, char const *frame) { struct stream streambuf; struct stream *s = &streambuf; sinit(s, frame, hdr->caplen); printf("%u,%u ", hdr->ts.tv_sec, hdr->ts.tv_usec); print_ethernet(s); printf("\n"); } void pcat(FILE * f) { struct pcap_file p; if (-1 == pcap_open_in(&p, f)) return; for (;;) { struct pcap_pkthdr hdr; char frame[MAXFRAME]; if (-1 == pcap_read_pkthdr(&p, &hdr)) { break; } if (1 != fread(frame, hdr.caplen, 1, f)) { break; } print_frame(&hdr, frame); } } int main(int argc, char *argv[]) { pcat(stdin); return 0; }