src/proto_vlan.h

   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 #ifndef VLAN_H
  10 #define VLAN_H
  11
  12 #include <stdio.h>
  13 #include <stdint.h>
  14 #include <netinet/in.h>    /* for ntohs() */
  15
  16 #include "proto_struct.h"
  17 #include "dissector_eth.h"
  18 #include "pkt_buff.h"
  19
  20 struct vlanhdr {
  21         uint16_t h_vlan_TCI;
  22         uint16_t h_vlan_encapsulated_proto;
  23 } __attribute__((packed));
  24
  25 static inline void vlan(struct pkt_buff *pkt)
  26 {
  27         uint16_t tci;
  28         struct vlanhdr *vlan = (struct vlanhdr *) pkt_pull(pkt, sizeof(*vlan));
  29
  30         if (vlan == NULL)
  31                 return;
  32
  33         tci = ntohs(vlan->h_vlan_TCI);
  34
  35         tprintf(" [ VLAN ");
  36         tprintf("Prio (%d), ", (tci & 0xE000) >> 13);
  37         tprintf("CFI (%d), ", (tci & 0x1000) >> 12);
  38         tprintf("ID (%d), ", (tci & 0x0FFF));
  39         tprintf("Proto (0x%.4x)", ntohs(vlan->h_vlan_encapsulated_proto));
  40         tprintf(" ]\n");
  41
  42         pkt_set_proto(pkt, &eth_lay2, ntohs(vlan->h_vlan_encapsulated_proto));
  43 }
  44
  45 static inline void vlan_less(struct pkt_buff *pkt)
  46 {
  47         uint16_t tci;
  48         struct vlanhdr *vlan = (struct vlanhdr *) pkt_pull(pkt, sizeof(*vlan));
  49
  50         if (vlan == NULL)
  51                 return;
  52
  53         tci = ntohs(vlan->h_vlan_TCI);
  54
  55         tprintf(" VLAN%d", (tci & 0x0FFF));
  56
  57         pkt_set_proto(pkt, &eth_lay2, ntohs(vlan->h_vlan_encapsulated_proto));
  58 }
  59
  60 struct protocol vlan_ops = {
  61         .key = 0x8100,
  62         .print_full = vlan,
  63         .print_less = vlan_less,
  64 };
  65
  66 #endif /* VLAN_H */