source: libpacketdump/eth_2048.c @ 120540d

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include "libpacketdump.h"
#ifndef WIN32
        #include <netinet/in_systm.h>
#endif
#include <arpa/inet.h>
#include <netdb.h>

#define DISPLAY_EXP(x,fmt,exp) \
        if ((unsigned int)len>=((char*)&ip->x-(char*)ip+sizeof(ip->x))) \
                printf(fmt,exp); \
        else \
                return; 

#define DISPLAY(x,fmt) DISPLAY_EXP(x,fmt,ip->x)

#define DISPLAYS(x,fmt) DISPLAY_EXP(x,fmt,htons(ip->x))
#define DISPLAYIP(x,fmt) DISPLAY_EXP(x,fmt,inet_ntoa(*(struct in_addr*)&ip->x))

void decode(int link_type,char *packet,int len)
{
        libtrace_ip_t *ip = (libtrace_ip_t*)packet;
        if (len>=1) {
                printf(" IP: Header Len %i",ip->ip_hl*4);
                printf(" Ver %i",ip->ip_v);
        }
        //DISPLAY(ip_tos," TOS %02x")
        DISPLAY_EXP(ip_tos," DSCP %02x",ip->ip_tos >> 2)
        DISPLAY_EXP(ip_tos," ECN %x",ip->ip_tos & 0x2)
        DISPLAYS(ip_len," Total Length %i")
        printf("\n IP:");
        DISPLAY(ip_id," Id %u");
        
        if ((unsigned int)len >= ((char *)&ip->ip_ttl - (char *)ip - 2)) {
                printf(" Fragoff %i", ip->ip_off);
                if (ip->ip_mf) printf(" MORE_FRAG");
                if (ip->ip_df) printf(" DONT_FRAG");
                if (ip->ip_rf) printf(" RESV_FRAG");
        }
        //printf("\n IP:");
        DISPLAY(ip_ttl,"\n IP: TTL %i");
        if ((unsigned int)len>=((char*)&ip->ip_p-(char*)ip+sizeof(ip->ip_p))) {
                struct protoent *ent=getprotobynumber(ip->ip_p);
                if (ent) {
                        printf(" Proto %i (%s)",ip->ip_p,ent->p_name);
                }
                else {
                        printf(" Proto %i",ip->ip_p);
                }
        } else {
                printf("\n");
                return;
        }
        DISPLAYS(ip_sum," Checksum %i\n");
        DISPLAYIP(ip_src," IP: Source %s ");
        DISPLAYIP(ip_dst,"Destination %s\n");
        decode_next(packet+sizeof(*ip),len-sizeof(*ip),"ip",ip->ip_p);
        return;
}