src/proto_ipv6_fragm.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 Fragmentation Header described in RFC2460
   7  */
   8
   9 #ifndef PROTO_IPV6_FRAGM_H
  10 #define PROTO_IPV6_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 #include "built_in.h"
  19
  20 struct fragmhdr {
  21         uint8_t h_fragm_next_header;
  22         uint8_t h_fragm_reserved;
  23         uint16_t h_fragm_off_res_M;
  24         uint32_t h_fragm_identification;
  25 } __packed;
  26
  27 static inline void fragm(struct pkt_buff *pkt)
  28 {
  29         uint16_t off_res_M;
  30         struct fragmhdr *fragm_ops;
  31
  32         fragm_ops = (struct fragmhdr *) pkt_pull(pkt, sizeof(*fragm_ops));
  33         if (fragm_ops == NULL)
  34                 return;
  35
  36         off_res_M = ntohs(fragm_ops->h_fragm_off_res_M);
  37
  38         tprintf("\t [ Fragment ");
  39         tprintf("NextHdr (%u), ", fragm_ops->h_fragm_next_header);
  40         tprintf("Reserved (%u), ", fragm_ops->h_fragm_reserved);
  41         tprintf("Offset (%u), ", off_res_M >> 3);
  42         tprintf("Res (%u), ", (off_res_M >> 1) & 0x3);
  43         tprintf("M flag (%u), ", off_res_M & 0x1);
  44         tprintf("Identification (%u)",
  45                 ntohl(fragm_ops->h_fragm_identification));
  46         tprintf(" ]\n");
  47
  48         pkt_set_proto(pkt, &eth_lay3, fragm_ops->h_fragm_next_header);
  49 }
  50
  51 static inline void fragm_less(struct pkt_buff *pkt)
  52 {
  53         uint16_t off_res_M;
  54         struct fragmhdr *fragm_ops;
  55
  56         fragm_ops = (struct fragmhdr *) pkt_pull(pkt, sizeof(*fragm_ops));
  57         if (fragm_ops == NULL)
  58                 return;
  59
  60         off_res_M = ntohs(fragm_ops->h_fragm_off_res_M);
  61
  62         tprintf(" FragmOffs %u", off_res_M >> 3);
  63
  64         pkt_set_proto(pkt, &eth_lay3, fragm_ops->h_fragm_next_header);
  65 }
  66
  67 struct protocol ipv6_fragm_ops = {
  68         .key = 0x2C,
  69         .print_full = fragm,
  70         .print_less = fragm_less,
  71 };
  72
  73 #endif /* PROTO_IPV6_FRAGM_H */