proto_vlan_q_in_q.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2012 Markus Amend <markus@netsniff-ng.org>, Deutsche Flugsicherung GmbH
   4  * Subject to the GPL, version 2.
   5  *
   6  * http://www.ieee802.org/1/pages/802.1ad.html
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdint.h>
  11 #include <netinet/in.h>    /* for ntohs() */
  12
  13 #include "proto.h"
  14 #include "dissector_eth.h"
  15 #include "built_in.h"
  16 #include "pkt_buff.h"
  17
  18 struct QinQhdr {
  19         uint16_t TCI;
  20         uint16_t TPID;
  21 } __packed;
  22
  23 static void QinQ_full(struct pkt_buff *pkt)
  24 {
  25         uint16_t tci;
  26         struct QinQhdr *QinQ = (struct QinQhdr *) pkt_pull(pkt, sizeof(*QinQ));
  27
  28         if (QinQ == NULL)
  29                 return;
  30
  31         tci = ntohs(QinQ->TCI);
  32
  33         tprintf(" [ VLAN QinQ ");
  34         tprintf("Prio (%d), ", (tci & 0xE000) >> 13);
  35         tprintf("DEI (%d), ", (tci & 0x1000) >> 12);
  36         tprintf("ID (%d), ", (tci & 0x0FFF));
  37         tprintf("Proto (0x%.4x)", ntohs(QinQ->TPID));
  38         tprintf(" ]\n");
  39
  40         pkt_set_dissector(pkt, &eth_lay2, ntohs(QinQ->TPID));
  41 }
  42
  43 static void QinQ_less(struct pkt_buff *pkt)
  44 {
  45         uint16_t tci;
  46         struct QinQhdr *QinQ = (struct QinQhdr *) pkt_pull(pkt, sizeof(*QinQ));
  47
  48         if (QinQ == NULL)
  49                 return;
  50
  51         tci = ntohs(QinQ->TCI);
  52
  53         tprintf(" VLAN%d", (tci & 0x0FFF));
  54
  55         pkt_set_dissector(pkt, &eth_lay2, ntohs(QinQ->TPID));
  56 }
  57
  58 struct protocol QinQ_ops = {
  59         .key = 0x88a8,
  60         .print_full = QinQ_full,
  61         .print_less = QinQ_less,
  62 };