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 #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 static inline void dissect_routinghdr_type_0(struct pkt_buff *pkt,
  36                                              ssize_t *data_len, int less)
  37 {
  38         uint8_t num_addr;
  39         char address[INET6_ADDRSTRLEN];
  40         struct in6_addr *addr;
  41         struct routinghdr_0 *routing_0;
  42
  43         routing_0 = (struct routinghdr_0 *) pkt_pull(pkt, sizeof(*routing_0));
  44         *data_len -= sizeof(*routing_0);
  45         if (routing_0 == NULL || *data_len > pkt_len(pkt) || *data_len < 0)
  46                 return;
  47
  48         if (less) {
  49                 tprintf("Addresses (%u)", *data_len / sizeof(struct in6_addr));
  50                 return;
  51         }
  52
  53         tprintf("Res (0x%x)", routing_0->reserved);
  54
  55         num_addr = *data_len / sizeof(*addr);
  56
  57         while (num_addr--) {
  58                 addr = (struct in6_addr *) pkt_pull(pkt, sizeof(*addr));
  59                 *data_len -= sizeof(*addr);
  60                 if (addr == NULL || *data_len > pkt_len(pkt) || *data_len < 0)
  61                         return;
  62
  63                 tprintf("\n\t   Address: %s",
  64                         inet_ntop(AF_INET6, addr, address,
  65                                   sizeof(address)));
  66         }
  67 }
  68
  69 static inline void dissect_routinghdr_type_0_norm(struct pkt_buff *pkt,
  70                                                   ssize_t *data_len)
  71 {
  72         dissect_routinghdr_type_0(pkt, data_len, 0);
  73 }
  74
  75 static inline void dissect_routinghdr_type_0_less(struct pkt_buff *pkt,
  76                                                   ssize_t *data_len)
  77 {
  78         dissect_routinghdr_type_0(pkt, data_len, 1);
  79 }
  80
  81 static inline void routing(struct pkt_buff *pkt)
  82 {
  83         uint16_t hdr_ext_len;
  84         ssize_t data_len;
  85         struct routinghdr *routing;
  86
  87         routing = (struct routinghdr *) pkt_pull(pkt, sizeof(*routing));
  88
  89         /* Total Header Length in Bytes */
  90         hdr_ext_len = (routing->h_hdr_ext_len + 1) * 8;
  91         /* Data length in Bytes */
  92         data_len = hdr_ext_len - sizeof(*routing);
  93         if (routing == NULL)
  94                 return;
  95
  96         tprintf("\t [ Routing ");
  97         tprintf("NextHdr (%u), ", routing->h_next_header);
  98         if (data_len > pkt_len(pkt) || data_len < 0){
  99                 tprintf("HdrExtLen (%u, %u Bytes %s), ", routing->h_hdr_ext_len,
 100                       hdr_ext_len, colorize_start_full(black, red)
 101                       "invalid" colorize_end());
 102                       return;
 103         }
 104         tprintf("HdrExtLen (%u, %u Bytes), ", routing->h_hdr_ext_len,
 105                 hdr_ext_len);
 106         tprintf("Type (%u), ", routing->h_routing_type);
 107         tprintf("Left (%u), ", routing->h_segments_left);
 108
 109         switch (routing->h_routing_type) {
 110         case ROUTING_HEADER_TYPE_0:
 111                 dissect_routinghdr_type_0_norm(pkt, &data_len);
 112                 break;
 113         default:
 114                 tprintf("Type %u is unknown", routing->h_routing_type);
 115         }
 116
 117         tprintf(" ]\n");
 118
 119         if (data_len > pkt_len(pkt) || data_len < 0)
 120                 return;
 121
 122         pkt_pull(pkt, data_len);
 123         pkt_set_proto(pkt, &eth_lay3, routing->h_next_header);
 124 }
 125
 126 static inline void routing_less(struct pkt_buff *pkt)
 127 {
 128         uint16_t hdr_ext_len;
 129         ssize_t data_len;
 130         struct routinghdr *routing;
 131
 132         routing = (struct routinghdr *) pkt_pull(pkt, sizeof(*routing));
 133
 134         /* Total Header Length in Bytes */
 135         hdr_ext_len = (routing->h_hdr_ext_len + 1) * 8;
 136         /* Data length in Bytes */
 137         data_len = hdr_ext_len - sizeof(*routing);
 138         if (routing == NULL || data_len > pkt_len(pkt) || data_len < 0)
 139                 return;
 140
 141         tprintf(" Routing ");
 142
 143         switch (routing->h_routing_type) {
 144         case ROUTING_HEADER_TYPE_0:
 145                 dissect_routinghdr_type_0_less(pkt, &data_len);
 146                 break;
 147         default:
 148                 tprintf("Type %u is unknown", routing->h_routing_type);
 149         }
 150
 151         if (data_len > pkt_len(pkt) || data_len < 0)
 152                 return;
 153
 154         pkt_pull(pkt, data_len);
 155         pkt_set_proto(pkt, &eth_lay3, routing->h_next_header);
 156 }
 157
 158 struct protocol ipv6_routing_ops = {
 159         .key = 0x2B,
 160         .print_full = routing,
 161         .print_less = routing_less,
 162 };
 163
 164 #endif /* PROTO_IPV6_ROUTING_H */