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() and "struct in6_addr" */
  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 #ifndef FNTTYPE_PRINT_NORM
  22 #define FNTTYPE_PRINT_NORM      0
  23 #endif
  24 #ifndef FNTTYPE_PRINT_LESS
  25 #define FNTTYPE_PRINT_LESS      1
  26 #endif
  27
  28 #define ROUTING_HEADER_TYPE_0   0x00
  29
  30 struct routinghdr {
  31         uint8_t h_next_header;
  32         uint8_t h_hdr_ext_len;
  33         uint8_t h_routing_type;
  34         uint8_t h_segments_left;
  35 } __packed;
  36
  37 struct routinghdr_0 {
  38         uint32_t reserved;
  39         uint32_t addresses[0];
  40 } __packed;
  41
  42
  43 static inline void dissect_routinghdr_type_0(struct pkt_buff *pkt,
  44                                              uint8_t *data_len, int less)
  45 {
  46         uint8_t num_addr;
  47         char address[INET6_ADDRSTRLEN];
  48         struct in6_addr *addr;
  49         struct routinghdr_0 *routing_0;
  50
  51         routing_0 = (struct routinghdr_0 *) pkt_pull(pkt, sizeof(*routing_0));
  52         *data_len -= sizeof(*routing_0);
  53         if (routing_0 == NULL || *data_len > pkt_len(pkt))
  54                 return;
  55
  56         if (less) {
  57                 tprintf("Addresses (%u)", *data_len / sizeof(struct in6_addr));
  58                 return;
  59         }
  60
  61         tprintf("Res (0x%x)", routing_0->reserved);
  62
  63         num_addr = *data_len / sizeof(*addr);
  64
  65         while (num_addr--) {
  66                 addr = (struct in6_addr *) pkt_pull(pkt, sizeof(*addr));
  67                 *data_len -= sizeof(*addr);
  68                 if (addr == NULL || *data_len > pkt_len(pkt))
  69                         return;
  70
  71                 tprintf("\n\t   Address: %s",
  72                         inet_ntop(AF_INET6, addr, address,
  73                                   sizeof(address)));
  74         }
  75 }
  76
  77 static inline void routing(struct pkt_buff *pkt)
  78 {
  79         uint8_t hdr_ext_len, data_len;
  80         struct routinghdr *routing;
  81
  82         routing = (struct routinghdr *) pkt_pull(pkt, sizeof(*routing));
  83
  84         /* Total Header Length in Bytes */
  85         hdr_ext_len = (routing->h_hdr_ext_len + 1) * 8;
  86         /* Data length in Bytes */
  87         data_len = hdr_ext_len - sizeof(*routing);
  88         if (routing == NULL || data_len > pkt_len(pkt))
  89                 return;
  90
  91         tprintf("\t [ Routing ");
  92         tprintf("NextHdr (%u), ", routing->h_next_header);
  93         tprintf("HdrExtLen (%u, %u Bytes), ", routing->h_hdr_ext_len,
  94                 hdr_ext_len);
  95         tprintf("Type (%u), ", routing->h_routing_type);
  96         tprintf("Left (%u), ", routing->h_segments_left);
  97
  98         switch (routing->h_routing_type) {
  99         case ROUTING_HEADER_TYPE_0:
 100                 dissect_routinghdr_type_0(pkt, &data_len, FNTTYPE_PRINT_NORM);
 101                 break;
 102         default:
 103                 tprintf("Type %u is unknown", routing->h_routing_type);
 104         }
 105
 106         tprintf(" ]\n");
 107
 108         pkt_pull(pkt, data_len);
 109         pkt_set_proto(pkt, &eth_lay3, routing->h_next_header);
 110 }
 111
 112 static inline void routing_less(struct pkt_buff *pkt)
 113 {
 114         uint8_t hdr_ext_len, data_len;
 115         struct routinghdr *routing;
 116
 117         routing = (struct routinghdr *) pkt_pull(pkt, sizeof(*routing));
 118
 119         /* Total Header Length in Bytes */
 120         hdr_ext_len = (routing->h_hdr_ext_len + 1) * 8;
 121         /* Data length in Bytes */
 122         data_len = hdr_ext_len - sizeof(*routing);
 123         if (routing == NULL || data_len > pkt_len(pkt))
 124                 return;
 125
 126         tprintf(" Routing ");
 127
 128         switch (routing->h_routing_type) {
 129         case ROUTING_HEADER_TYPE_0:
 130                 dissect_routinghdr_type_0(pkt, &data_len, FNTTYPE_PRINT_LESS);
 131                 break;
 132         default:
 133                 tprintf("Type %u is unknown", routing->h_routing_type);
 134         }
 135
 136         pkt_pull(pkt, data_len);
 137         pkt_set_proto(pkt, &eth_lay3, routing->h_next_header);
 138 }
 139
 140 struct protocol ipv6_routing_ops = {
 141         .key = 0x2B,
 142         .print_full = routing,
 143         .print_less = routing_less,
 144 };
 145
 146 #endif /* PROTO_IPV6_ROUTING_H */