src/proto_ipv6_hop_by_hop.h

   1 /*
   2  * IPv6 Hop-By-Hop Header described in RFC2460
   3  * programmed by Markus Amend 2012 as a contribution to
   4  * netsniff-ng - the packet sniffing beast
   5  * Copyright 2012 Markus Amend.
   6  * Subject to the GPL, version 2.
   7  */
   8
   9 #ifndef HOP_BY_HOP_H
  10 #define 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
  19 struct hop_by_hophdr {
  20         uint8_t h_next_header;
  21         uint8_t h_hdr_ext_len;
  22         uint8_t h_hdr_option_type;
  23 } __attribute__((packed));
  24
  25 static inline void hop_by_hop(uint8_t *packet, size_t len)
  26 {
  27         uint8_t hdr_ext_len;
  28         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  29
  30         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  31         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  32                 return;
  33
  34         tprintf("\t [ Hop-By-Hop ");
  35         tprintf("NextHdr (%u), ", hop_by_hop->h_next_header);
  36         tprintf("HdrExtLen (%u), ", hdr_ext_len);
  37         tprintf("Opt (%u), ", hop_by_hop->h_hdr_option_type);
  38         tprintf("Appendix 0x");
  39         for (uint8_t i = sizeof(struct hop_by_hophdr); i < hdr_ext_len; i++)
  40                 tprintf("%02x",(uint8_t) packet[i]);
  41         tprintf(" ]\n");
  42 }
  43
  44 static inline void hop_by_hop_less(uint8_t *packet, size_t len)
  45 {
  46         uint8_t hdr_ext_len;
  47         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  48
  49         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  50         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  51                 return;
  52
  53         tprintf(" Hop-By-Hop Opt %u", hop_by_hop->h_hdr_option_type);
  54 }
  55
  56 static inline void hop_by_hop_next(uint8_t *packet, size_t len,
  57                              struct hash_table **table,
  58                              unsigned int *key, size_t *off)
  59 {
  60         uint8_t hdr_ext_len;
  61         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  62
  63         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  64         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  65                 return;
  66
  67         (*off) = hdr_ext_len;
  68         (*key) = hop_by_hop->h_next_header;
  69         (*table) = &eth_lay3;
  70 }
  71
  72 struct protocol ipv6_hop_by_hop_ops = {
  73         .key = 0x0,
  74         .print_full = hop_by_hop,
  75         .print_less = hop_by_hop_less,
  76         .print_pay_ascii = empty,
  77         .print_pay_hex = empty,
  78         .print_pay_none = hop_by_hop,
  79         .print_all_hex = hex,
  80         .proto_next = hop_by_hop_next,
  81 };
  82
  83 #endif /* HOP_BY_HOP_H */