src/proto_ipv6.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2009, 2010 Daniel Borkmann.
   5  * Copyright 2010 Emmanuel Roullit.
   6  * Subject to the GPL, version 2.
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdint.h>
  11 #include <netinet/in.h>    /* for ntohs() */
  12 #include <arpa/inet.h>     /* for inet_ntop() */
  13 #include <asm/byteorder.h>
  14
  15 #include "proto.h"
  16 #include "protos.h"
  17 #include "csum.h"
  18 #include "dissector_eth.h"
  19 #include "pkt_buff.h"
  20 #include "built_in.h"
  21
  22 /*
  23  * IPv6 fixed header
  24  *
  25  * BEWARE, it is incorrect. The first 4 bits of flow_lbl
  26  * are glued to priority now, forming "class".
  27  */
  28 struct ipv6hdr {
  29 #if defined(__LITTLE_ENDIAN_BITFIELD)
  30         __extension__ uint8_t priority:4,
  31                               version:4;
  32 #elif defined(__BIG_ENDIAN_BITFIELD)
  33         __extension__ uint8_t version:4,
  34                               priority:4;
  35 #else
  36 # error "Please fix <asm/byteorder.h>"
  37 #endif
  38         uint8_t flow_lbl[3];
  39         uint16_t payload_len;
  40         uint8_t nexthdr;
  41         uint8_t hop_limit;
  42         struct in6_addr saddr;
  43         struct in6_addr daddr;
  44 } __packed;
  45
  46 extern void ipv6(struct pkt_buff *pkt);
  47 extern void ipv6_less(struct pkt_buff *pkt);
  48
  49 void ipv6(struct pkt_buff *pkt)
  50 {
  51         uint8_t traffic_class;
  52         uint32_t flow_label;
  53         char src_ip[INET6_ADDRSTRLEN];
  54         char dst_ip[INET6_ADDRSTRLEN];
  55         struct ipv6hdr *ip = (struct ipv6hdr *) pkt_pull(pkt, sizeof(*ip));
  56
  57         if (ip == NULL)
  58                 return;
  59
  60         traffic_class = (ip->priority << 4) |
  61                         ((ip->flow_lbl[0] & 0xF0) >> 4);
  62         flow_label = ((ip->flow_lbl[0] & 0x0F) << 8) |
  63                      (ip->flow_lbl[1] << 4) | ip->flow_lbl[2];
  64
  65         inet_ntop(AF_INET6, &ip->saddr, src_ip, sizeof(src_ip));
  66         inet_ntop(AF_INET6, &ip->daddr, dst_ip, sizeof(dst_ip));
  67
  68         tprintf(" [ IPv6 ");
  69         tprintf("Addr (%s => %s), ", src_ip, dst_ip);
  70         tprintf("Version (%u), ", ip->version);
  71         tprintf("TrafficClass (%u), ", traffic_class);
  72         tprintf("FlowLabel (%u), ", flow_label);
  73         tprintf("Len (%u), ", ntohs(ip->payload_len));
  74         tprintf("NextHdr (%u), ", ip->nexthdr);
  75         tprintf("HopLimit (%u)", ip->hop_limit);
  76         tprintf(" ]\n");
  77
  78         pkt_set_proto(pkt, &eth_lay3, ip->nexthdr);
  79 }
  80
  81 void ipv6_less(struct pkt_buff *pkt)
  82 {
  83         char src_ip[INET6_ADDRSTRLEN];
  84         char dst_ip[INET6_ADDRSTRLEN];
  85         struct ipv6hdr *ip = (struct ipv6hdr *) pkt_pull(pkt, sizeof(*ip));
  86
  87         if (ip == NULL)
  88                 return;
  89
  90         inet_ntop(AF_INET6, &ip->saddr, src_ip, sizeof(src_ip));
  91         inet_ntop(AF_INET6, &ip->daddr, dst_ip, sizeof(dst_ip));
  92
  93         tprintf(" %s/%s Len %u", src_ip, dst_ip,
  94                 ntohs(ip->payload_len));
  95
  96         pkt_set_proto(pkt, &eth_lay3, ip->nexthdr);
  97 }
  98
  99 struct protocol ipv6_ops = {
 100         .key = 0x86DD,
 101         .print_full = ipv6,
 102         .print_less = ipv6_less,
 103 };
 104
 105 EXPORT_SYMBOL(ipv6_ops);