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
  19 struct vlanhdr {
  20         uint16_t h_vlan_TCI;
  21         uint16_t h_vlan_encapsulated_proto;
  22 } __attribute__((packed));
  23
  24 static inline void vlan(uint8_t *packet, size_t len)
  25 {
  26         uint16_t tci;
  27         struct vlanhdr *vlan = (struct vlanhdr *) packet;
  28
  29         if (len < sizeof(struct vlanhdr))
  30                 return;
  31
  32         tci = ntohs(vlan->h_vlan_TCI);
  33
  34         tprintf(" [ VLAN ");
  35         tprintf("Prio (%d), ", (tci & 0xE000) >> 13);
  36         tprintf("CFI (%d), ", (tci & 0x1000) >> 12);
  37         tprintf("ID (%d), ", (tci & 0x0FFF));
  38         tprintf("Proto (0x%.4x)", ntohs(vlan->h_vlan_encapsulated_proto));
  39         tprintf(" ]\n");
  40 }
  41
  42 static inline void vlan_less(uint8_t *packet, size_t len)
  43 {
  44         uint16_t tci;
  45         struct vlanhdr *vlan = (struct vlanhdr *) packet;
  46
  47         if (len < sizeof(struct vlanhdr))
  48                 return;
  49
  50         tci = ntohs(vlan->h_vlan_TCI);
  51
  52         tprintf(" VLAN%d", (tci & 0x0FFF));
  53 }
  54
  55 static inline void vlan_next(uint8_t *packet, size_t len,
  56                              struct hash_table **table,
  57                              unsigned int *key, size_t *off)
  58 {
  59         struct vlanhdr *vlan = (struct vlanhdr *) packet;
  60
  61         if (len < sizeof(struct vlanhdr))
  62                 goto invalid;
  63
  64         (*off) = sizeof(struct vlanhdr);
  65         (*key) = ntohs(vlan->h_vlan_encapsulated_proto);
  66         (*table) = &eth_lay2;
  67
  68         return;
  69 invalid:
  70         (*off) = 0;
  71         (*key) = 0;
  72         (*table) = NULL;
  73 }
  74
  75 struct protocol vlan_ops = {
  76         .key = 0x8100,
  77         .offset = sizeof(struct vlanhdr),
  78         .print_full = vlan,
  79         .print_less = vlan_less,
  80         .print_pay_ascii = empty,
  81         .print_pay_hex = empty,
  82         .print_pay_none = vlan,
  83         .print_all_cstyle = __hex2,
  84         .print_all_hex = __hex,
  85         .proto_next = vlan_next,
  86 };
  87
  88 #endif /* VLAN_H */