proto_ethernet.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2009, 2010 Daniel Borkmann.
   4  * Copyright 2014 Tobias Klauser
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #include <stdio.h>
   9 #include <stdint.h>
  10 #include <netinet/in.h>
  11 #include <linux/if_ether.h>
  12
  13 #include "proto.h"
  14 #include "dissector_eth.h"
  15 #include "lookup.h"
  16 #include "pkt_buff.h"
  17 #include "oui.h"
  18
  19 static inline bool is_multicast_ether_addr(const uint8_t *mac)
  20 {
  21         return mac[0] & 0x01;
  22 }
  23
  24 static inline bool is_broadcast_ether_addr(const uint8_t *mac)
  25 {
  26         return (mac[0] & mac[1] & mac[2] & mac[3] & mac[4] & mac[5]) == 0xff;
  27 }
  28
  29 static const char *ether_lookup_addr(uint8_t *mac)
  30 {
  31         if (is_multicast_ether_addr(mac)) {
  32                 if (is_broadcast_ether_addr(mac))
  33                         return "Broadcast";
  34                 else
  35                         return "Multicast";
  36         }
  37
  38         /* found no matching address, so look up the vendor from OUI */
  39         return lookup_vendor_str((mac[0] << 16) | (mac[1] << 8) | mac[2]);
  40 }
  41
  42 static void ethernet(struct pkt_buff *pkt)
  43 {
  44         char *type;
  45         uint8_t *src_mac, *dst_mac;
  46         struct ethhdr *eth = (struct ethhdr *) pkt_pull(pkt, sizeof(*eth));
  47
  48         if (eth == NULL)
  49                 return;
  50
  51         src_mac = eth->h_source;
  52         dst_mac = eth->h_dest;
  53
  54         tprintf(" [ Eth ");
  55         tprintf("MAC (%.2x:%.2x:%.2x:%.2x:%.2x:%.2x => ",
  56                 src_mac[0], src_mac[1], src_mac[2],
  57                 src_mac[3], src_mac[4], src_mac[5]);
  58         tprintf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x), ",
  59                 dst_mac[0], dst_mac[1], dst_mac[2],
  60                 dst_mac[3], dst_mac[4], dst_mac[5]);
  61         tprintf("Proto (0x%.4x", ntohs(eth->h_proto));
  62
  63         type = lookup_ether_type(ntohs(eth->h_proto));
  64         if (type)
  65                 tprintf(", %s%s%s", colorize_start(bold), type, colorize_end());
  66
  67         tprintf(") ]\n");
  68         tprintf(" [ Vendor ");
  69         tprintf("(%s => %s)", ether_lookup_addr(src_mac), ether_lookup_addr(dst_mac));
  70         tprintf(" ]\n");
  71
  72         pkt_set_proto(pkt, &eth_lay2, ntohs(eth->h_proto));
  73 }
  74
  75 static void ethernet_less(struct pkt_buff *pkt)
  76 {
  77         uint8_t *src_mac, *dst_mac;
  78         struct ethhdr *eth = (struct ethhdr *) pkt_pull(pkt, sizeof(*eth));
  79
  80         if (eth == NULL)
  81                 return;
  82
  83         src_mac = eth->h_source;
  84         dst_mac = eth->h_dest;
  85         tprintf(" %s => %s ",
  86                 lookup_vendor_str((src_mac[0] << 16) | (src_mac[1] << 8) |
  87                               src_mac[2]),
  88                 lookup_vendor_str((dst_mac[0] << 16) | (dst_mac[1] << 8) |
  89                               dst_mac[2]));
  90         tprintf("%s%s%s", colorize_start(bold),
  91                 lookup_ether_type(ntohs(eth->h_proto)), colorize_end());
  92
  93         pkt_set_proto(pkt, &eth_lay2, ntohs(eth->h_proto));
  94 }
  95
  96 struct protocol ethernet_ops = {
  97         .key = 0,
  98         .print_full = ethernet,
  99         .print_less = ethernet_less,
 100 };