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 2009, 2010 Daniel Borkmann.
   6  * Copyright 2010 Emmanuel Roullit.
   7  * Subject to the GPL, version 2.
   8  */
   9
  10 #ifndef HOP_BY_HOP_H
  11 #define HOP_BY_HOP_H
  12
  13 #include <stdio.h>
  14 #include <stdint.h>
  15 #include <netinet/in.h>    /* for ntohs() */
  16
  17 #include "proto_struct.h"
  18 #include "dissector_eth.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 } __attribute__((packed));
  25
  26 static inline void hop_by_hop(uint8_t *packet, size_t len)
  27 {
  28         uint8_t hdr_ext_len;
  29
  30         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  31
  32         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  33
  34         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  35                 return;
  36
  37         tprintf("\t [ Hop-By-Hop ");
  38         tprintf("NextHdr (%u), ", hop_by_hop->h_next_header);
  39         tprintf("HdrExtLen (%u), ", hdr_ext_len);
  40         tprintf("Opt (%u), ", hop_by_hop->h_hdr_option_type);
  41         tprintf("Appendix 0x");
  42         for (uint8_t i=sizeof(struct hop_by_hophdr);i<hdr_ext_len;i++)
  43           tprintf("%02x",(uint8_t) packet[i]);
  44         tprintf(" ]\n");
  45 }
  46
  47 static inline void hop_by_hop_less(uint8_t *packet, size_t len)
  48 {
  49         uint8_t hdr_ext_len;
  50
  51         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  52
  53         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  54
  55         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  56                 return;
  57
  58         tprintf(" Hop-By-Hop Opt %u", hop_by_hop->h_hdr_option_type);
  59 }
  60
  61 static inline void hop_by_hop_next(uint8_t *packet, size_t len,
  62                              struct hash_table **table,
  63                              unsigned int *key, size_t *off)
  64 {
  65         uint8_t hdr_ext_len;
  66
  67         struct hop_by_hophdr *hop_by_hop = (struct hop_by_hophdr *) packet;
  68
  69         hdr_ext_len = (hop_by_hop->h_hdr_ext_len + 1) * 8;
  70
  71         if (len < hdr_ext_len || len < sizeof(struct hop_by_hophdr))
  72                 goto invalid;
  73
  74         (*off) = hdr_ext_len;
  75         (*key) = hop_by_hop->h_next_header;
  76         (*table) = &eth_lay3;
  77
  78         return;
  79 invalid:
  80         (*off) = 0;
  81         (*key) = 0;
  82         (*table) = NULL;
  83 }
  84
  85 struct protocol ipv6_hop_by_hop_ops = {
  86         .key = 0x0,
  87 //      .offset = sizeof(struct fragmhdr),
  88         .print_full = hop_by_hop,
  89         .print_less = hop_by_hop_less,
  90         .print_pay_ascii = empty,
  91         .print_pay_hex = empty,
  92         .print_pay_none = hop_by_hop,
  93         .print_all_cstyle = __hex2,
  94         .print_all_hex = __hex,
  95         .proto_next = hop_by_hop_next,
  96 };
  97
  98 #endif /* HOP_BY_HOP_H */