source: libpacketdump/ip_6.c @ a82a9e8

/*
 *
 * Copyright (c) 2007-2016 The University of Waikato, Hamilton, New Zealand.
 * All rights reserved.
 *
 * This file is part of libtrace.
 *
 * This code has been developed by the University of Waikato WAND
 * research group. For further information please see http://www.wand.net.nz/
 *
 * libtrace is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * libtrace is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 */
#include <stdio.h>
#include <inttypes.h>
#include <dlfcn.h>
#include "libpacketdump.h"
#include <assert.h>
#include <netdb.h>

DLLEXPORT void decode(int link_type UNUSED,const char *packet,unsigned len)
{
        unsigned char *pkt = NULL;
        unsigned char type,optlen,*data;
        int plen, i;
        libtrace_tcp_t *tcp = (libtrace_tcp_t *)packet;
        printf(" TCP:");
        if (SAFE(tcp, source)) {
                struct servent *ent=getservbyport(tcp->source,"tcp");
                if(ent) {
                        printf(" Source %i (%s)",htons(tcp->source),ent->s_name);
                } else {
                        printf(" Source %i",htons(tcp->source));
                }
        }
        else {
                printf("\n");
                return;
        }
        if (SAFE(tcp, dest)) {
                struct servent *ent=getservbyport(tcp->dest,"tcp");
                if(ent) {
                        printf(" Dest %i (%s)",htons(tcp->dest),ent->s_name);
                } else {
                        printf(" Dest %i",htons(tcp->dest));
                }
        }
        else {
                printf("\n");
                return;
        }
        printf("\n TCP:");
        DISPLAYL(tcp, seq," Seq %u");
        printf("\n TCP:");
        DISPLAYL(tcp, ack_seq," Ack %u");
        if ((char*)&tcp->window-(char *)tcp>len) {
                printf("\n");
                return;
        }
        printf("\n TCP:");
        printf(" DOFF %i",tcp->doff);
        printf(" Flags:");
        if (tcp->ecn_ns) printf(" ECN_NS");
        if (tcp->cwr) printf(" CWR");
        if (tcp->ece) printf(" ECE");
        if (tcp->fin) printf(" FIN");
        if (tcp->syn) printf(" SYN");
        if (tcp->rst) printf(" RST");
        if (tcp->psh) printf(" PSH");
        if (tcp->ack) printf(" ACK");
        if (tcp->urg) printf(" URG");
        DISPLAYS(tcp, window," Window %i");
        printf("\n TCP:");
        DISPLAYS(tcp, check," Checksum %i");
        DISPLAYS(tcp, urg_ptr," Urgent %i");
        pkt = (unsigned char*)packet+sizeof(*tcp);
        plen = (len-sizeof *tcp) < (tcp->doff*4-sizeof(*tcp))?(len-sizeof(*tcp)):(tcp->doff*4-sizeof *tcp);
        while(trace_get_next_option(&pkt,&plen,&type,&optlen,&data)) {
                printf("\n TCP: ");
                switch(type) {
                        case 0:
                                printf("End of options");
                                break;
                        case 1:
                                printf("NOP");
                                break;
                        case 2:
                                printf("MSS %i",htons(*(uint32_t *)(data)));
                                break;
                        case 3:
                                printf("Winscale %i",data[0]);
                                break;
                        case 4:
                                printf("SACK");
                                break;
                        case 5:
                                printf("SACK Information");
                                i=0;
                                while(i+8<optlen) {
                                        printf("\n TCP:  %u-%u",
                                                htonl(*(uint32_t*)&data[i]),
                                                htonl(*(uint32_t*)&data[i+4]));
                                        i+=8;
                                }
                                break;
                        case 8:
                                printf("Timestamp %u %u",
                                                htonl(*(uint32_t *)&data[0]),
                                                htonl(*(uint32_t *)&data[4])
                                      );
                                break;
                        default:
                                printf("Unknown option %i",type);
                }
        }
        printf("\n");
        if (htons(tcp->source) < htons(tcp->dest)) 
                decode_next(packet+tcp->doff*4,len-tcp->doff*4,"tcp",htons(tcp->source));
        else
                decode_next(packet+tcp->doff*4,len-tcp->doff*4,"tcp",htons(tcp->dest));
        return;
}