src/proto_ipv6_fragm.h

   1 /*
   2  * IPv6 Fragmentation 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 FRAGM_H
  10 #define FRAGM_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 fragmhdr {
  20         uint8_t h_fragm_next_header;
  21         uint8_t h_fragm_reserved;
  22         uint16_t h_fragm_off_res_M;
  23         uint32_t h_fragm_identification;
  24 } __attribute__((packed));
  25
  26 static inline void fragm(uint8_t *packet, size_t len)
  27 {
  28         uint16_t off_res_M;
  29         struct fragmhdr *fragm = (struct fragmhdr *) packet;
  30
  31         if (len < sizeof(struct fragmhdr))
  32                 return;
  33
  34         off_res_M = ntohs(fragm->h_fragm_off_res_M);
  35
  36         tprintf("\t [ Fragment ");
  37         tprintf("NextHdr (%u), ", fragm->h_fragm_next_header);
  38         tprintf("Reserved (%u), ", fragm->h_fragm_reserved);
  39         tprintf("Offset (%u), ", off_res_M >> 3);
  40         tprintf("Res (%u), ", (off_res_M >> 1) & 0x3);
  41         tprintf("M flag (%u), ", off_res_M & 0x1);
  42         tprintf("Identification (%u) ", ntohs(fragm->h_fragm_identification));
  43         tprintf(" ]\n");
  44 }
  45
  46 static inline void fragm_less(uint8_t *packet, size_t len)
  47 {
  48         uint16_t off_res_M;
  49         struct fragmhdr *fragm = (struct fragmhdr *) packet;
  50
  51         if (len < sizeof(struct fragmhdr))
  52                 return;
  53
  54         off_res_M = ntohs(fragm->h_fragm_off_res_M);
  55
  56         tprintf(" FragmOffs %u", off_res_M >> 3);
  57 }
  58
  59 static inline void fragm_next(uint8_t *packet, size_t len,
  60                              struct hash_table **table,
  61                              unsigned int *key, size_t *off)
  62 {
  63         struct fragmhdr *fragm = (struct fragmhdr *) packet;
  64         if (len < sizeof(struct fragmhdr))
  65                 return;
  66         (*off) = sizeof(struct fragmhdr);
  67         (*key) = fragm->h_fragm_next_header;
  68         (*table) = &eth_lay3;
  69 }
  70
  71 struct protocol ipv6_fragm_ops = {
  72         .key = 0x2C,
  73         .print_full = fragm,
  74         .print_less = fragm_less,
  75         .print_pay_ascii = empty,
  76         .print_pay_hex = empty,
  77         .print_pay_none = fragm,
  78         .print_all_hex = hex,
  79         .proto_next = fragm_next,
  80 };
  81
  82 #endif /* FRAGM_H */