src/proto_ipv6_routing.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 Routing Header described in RFC2460
   7  */
   8
   9 #ifndef PROTO_IPV6_ROUTING_H
  10 #define PROTO_IPV6_ROUTING_H
  11
  12 #include <stdio.h>
  13 #include <stdint.h>
  14 #include <netinet/in.h>    /* for ntohs() */
  15 #include <arpa/inet.h>     /* for inet_ntop() */
  16
  17 #include "proto_struct.h"
  18 #include "dissector_eth.h"
  19 #include "built_in.h"
  20
  21 #define ROUTING_HEADER_TYPE_0   0x00
  22
  23 struct routinghdr {
  24         uint8_t h_next_header;
  25         uint8_t h_hdr_ext_len;
  26         uint8_t h_routing_type;
  27         uint8_t h_segments_left;
  28 } __packed;
  29
  30 struct routinghdr_0 {
  31         uint32_t reserved;
  32         uint32_t addresses[0];
  33 } __packed;
  34
  35 struct ipv6_adrr {
  36         uint32_t first_block;
  37         uint32_t second_block;
  38         uint32_t third_block;
  39         uint32_t fourth_block;
  40 } __packed;
  41
  42 static inline void dissect_routinghdr_type_0(struct pkt_buff *pkt,
  43                                              uint8_t *hdr_ext_len)
  44 {
  45         uint8_t num_addr;
  46         char address[INET6_ADDRSTRLEN];
  47         struct ipv6_adrr *addr;
  48         struct routinghdr_0 *routing_0;
  49
  50         routing_0 = (struct routinghdr_0 *) pkt_pull(pkt, sizeof(*routing_0));
  51         if (routing_0 == NULL)
  52                 return;
  53
  54         tprintf("Res (0x%x)", routing_0->reserved);
  55
  56         num_addr = *hdr_ext_len * 8 / sizeof(*addr);
  57         while (num_addr--) {
  58                 addr = (struct ipv6_adrr *) pkt_pull(pkt, sizeof(*addr));
  59                 if (addr == NULL)
  60                         return;
  61
  62                 tprintf("\n\t   Address: %s",
  63                         inet_ntop(AF_INET6, addr, address,
  64                                   sizeof(address)));
  65         }
  66 }
  67
  68 static inline void routing(struct pkt_buff *pkt)
  69 {
  70         uint8_t hdr_ext_len;
  71         struct routinghdr *routing;
  72
  73         routing = (struct routinghdr *) pkt_pull(pkt, sizeof(*routing));
  74
  75         /* Total Header Length in Bytes */
  76         hdr_ext_len = (routing->h_hdr_ext_len + 1) * 8;
  77         if (routing == NULL)
  78                 return;
  79
  80         tprintf("\t [ Routing ");
  81         tprintf("NextHdr (%u), ", routing->h_next_header);
  82         tprintf("HdrExtLen (%u, %u Bytes), ", routing->h_hdr_ext_len,
  83                 hdr_ext_len);
  84         tprintf("Type (%u), ", routing->h_routing_type);
  85         tprintf("Left (%u), ", routing->h_segments_left);
  86
  87         switch (routing->h_routing_type) {
  88         case ROUTING_HEADER_TYPE_0:
  89                 dissect_routinghdr_type_0(pkt, &routing->h_hdr_ext_len);
  90                 break;
  91         default:
  92                 tprintf("Type %u is unknown", routing->h_routing_type);
  93         }
  94
  95         tprintf(" ]\n");
  96
  97         pkt_set_proto(pkt, &eth_lay3, routing->h_next_header);
  98 }
  99
 100 static inline void routing_less(struct pkt_buff *pkt)
 101 {
 102         struct routinghdr *routing;
 103
 104         routing = (struct routinghdr *) pkt_pull(pkt, sizeof(*routing));
 105         if (routing == NULL)
 106                 return;
 107
 108         tprintf(" Routing ");
 109         tprintf("Addresses (%u)",
 110                 routing->h_hdr_ext_len * 8 / sizeof(struct ipv6_adrr));
 111
 112         pkt_set_proto(pkt, &eth_lay3, routing->h_next_header);
 113 }
 114
 115 struct protocol ipv6_routing_ops = {
 116         .key = 0x2B,
 117         .print_full = routing,
 118         .print_less = routing_less,
 119 };
 120
 121 #endif /* PROTO_IPV6_ROUTING_H */