src/proto_ipv6_hop_by_hop.h

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2012 Markus Amend <markus@netsniff-ng.org>
   4  * Subject to the GPL, version 2.
   5  *
   6  * IPv6 Hop-By-Hop Header described in RFC2460
   7  */
   8
   9 #ifndef PROTO_IPV6_HOP_BY_HOP_H
  10 #define PROTO_IPV6_HOP_BY_HOP_H
  11
  12 #include <stdio.h>
  13 #include <stdint.h>
  14 #include <netinet/in.h>    /* for ntohs() */
  15
  16 #include "proto_struct.h"
  17 #include "dissector_eth.h"
  18 #include "built_in.h"
  19
  20 struct hop_by_hophdr {
  21         uint8_t h_next_header;
  22         uint8_t h_hdr_ext_len;
  23         uint8_t h_hdr_option_type;
  24 } __packed;
  25
  26 static inline void hop_by_hop(uint8_t *packet, size_t len)
  27 {
  28         uint8_t hdr_ext_len;
  29         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  30
  31         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  32         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  33                 return;
  34
  35         tprintf("\t [ Hop-By-Hop ");
  36         tprintf("NextHdr (%u), ", hop_by_hop->h_next_header);
  37         tprintf("HdrExtLen (%u), ", hdr_ext_len);
  38         tprintf("Opt (%u), ", hop_by_hop->h_hdr_option_type);
  39         tprintf("Appendix 0x");
  40         for (uint8_t i = sizeof(struct hop_by_hophdr); i < hdr_ext_len; i++)
  41                 tprintf("%02x",(uint8_t) packet[i]);
  42         tprintf(" ]\n");
  43 }
  44
  45 static inline void hop_by_hop_less(uint8_t *packet, size_t len)
  46 {
  47         uint8_t hdr_ext_len;
  48         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  49
  50         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  51         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  52                 return;
  53
  54         tprintf(" Hop-By-Hop Opt %u", hop_by_hop->h_hdr_option_type);
  55 }
  56
  57 static inline void hop_by_hop_next(uint8_t *packet, size_t len,
  58                              struct hash_table **table,
  59                              unsigned int *key, size_t *off)
  60 {
  61         uint8_t hdr_ext_len;
  62         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  63
  64         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  65         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  66                 return;
  67
  68         (*off) = hdr_ext_len;
  69         (*key) = hop_by_hop->h_next_header;
  70         (*table) = &eth_lay3;
  71 }
  72
  73 struct protocol ipv6_hop_by_hop_ops = {
  74         .key = 0x0,
  75         .print_full = hop_by_hop,
  76         .print_less = hop_by_hop_less,
  77         .proto_next = hop_by_hop_next,
  78 };
  79
  80 #endif /* PROTO_IPV6_HOP_BY_HOP_H */