src/proto_icmpv4.h

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2009, 2010 Daniel Borkmann.
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #ifndef PROTO_ICMP_H
   9 #define PROTO_ICMP_H
  10
  11 #include <stdio.h>
  12 #include <stdint.h>
  13 #include <netinet/in.h>    /* for ntohs() */
  14
  15 #include "proto_struct.h"
  16 #include "dissector_eth.h"
  17 #include "pkt_buff.h"
  18 #include "built_in.h"
  19
  20 struct icmphdr {
  21         uint8_t type;
  22         uint8_t code;
  23         uint16_t checksum;
  24         union {
  25                 struct {
  26                         uint16_t id;
  27                         uint16_t sequence;
  28                 } echo;
  29                 uint32_t gateway;
  30                 struct {
  31                         uint16_t ____unused;
  32                         uint16_t mtu;
  33                 } frag;
  34         } un;
  35 } __packed;
  36
  37 static inline void icmp(struct pkt_buff *pkt)
  38 {
  39         struct icmphdr *icmp = (struct icmphdr *) pkt_pull(pkt, sizeof(*icmp));
  40
  41         if (icmp == NULL)
  42                 return;
  43
  44         tprintf(" [ ICMP ");
  45         tprintf("Type (%u), ", icmp->type);
  46         tprintf("Code (%u), ", icmp->code);
  47         tprintf("CSum (0x%.4x)", ntohs(icmp->checksum));
  48         tprintf(" ]\n");
  49 }
  50
  51 static inline void icmp_less(struct pkt_buff *pkt)
  52 {
  53         struct icmphdr *icmp = (struct icmphdr *) pkt_pull(pkt, sizeof(*icmp));
  54
  55         if (icmp == NULL)
  56                 return;
  57
  58         tprintf(" Type %u Code %u", icmp->type, icmp->code);
  59 }
  60
  61 struct protocol icmp_ops = {
  62         .key = 0x01,
  63         .print_full = icmp,
  64         .print_less = icmp_less,
  65 };
  66
  67 #endif /* PROTO_ICMP_H */