dissector.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2009, 2010, 2011, 2012 Daniel Borkmann.
   4  * Subject to the GPL, version 2.
   5  */
   6
   7 #include <stdint.h>
   8 #include <stdlib.h>
   9 #include <unistd.h>
  10
  11 #include "built_in.h"
  12 #include "tprintf.h"
  13 #include "pkt_buff.h"
  14 #include "proto.h"
  15 #include "dissector.h"
  16 #include "dissector_eth.h"
  17 #include "dissector_80211.h"
  18 #include "dissector_netlink.h"
  19 #include "linktype.h"
  20
  21 int dissector_set_print_type(void *ptr, int type)
  22 {
  23         struct protocol *proto;
  24
  25         for (proto = ptr; proto; proto = proto->next) {
  26                 switch (type) {
  27                 case PRINT_NORM:
  28                         proto->process = proto->print_full;
  29                         break;
  30                 case PRINT_LESS:
  31                         proto->process = proto->print_less;
  32                         break;
  33                 default:
  34                         proto->process = NULL;
  35                         break;
  36                 }
  37         }
  38
  39         return 0;
  40 }
  41
  42 static void dissector_main(struct pkt_buff *pkt, struct protocol *start,
  43                            struct protocol *end)
  44 {
  45         struct protocol *dissector;
  46
  47         if (!start)
  48                 return;
  49
  50         for (pkt->dissector = start; pkt->dissector; ) {
  51                 if (unlikely(!pkt->dissector->process))
  52                         break;
  53
  54                 dissector = pkt->dissector;
  55                 pkt->dissector = NULL;
  56                 dissector->process(pkt);
  57         }
  58
  59         if (end && likely(end->process))
  60                 end->process(pkt);
  61 }
  62
  63 void dissector_entry_point(uint8_t *packet, size_t len, int linktype, int mode,
  64                            uint16_t proto)
  65 {
  66         struct protocol *proto_start, *proto_end;
  67         struct pkt_buff *pkt;
  68
  69         if (mode == PRINT_NONE)
  70                 return;
  71
  72         pkt = pkt_alloc(packet, len);
  73         pkt->link_type = linktype;
  74         pkt->proto = proto;
  75
  76         switch (linktype) {
  77         case LINKTYPE_EN10MB:
  78         case ___constant_swab32(LINKTYPE_EN10MB):
  79                 proto_start = dissector_get_ethernet_entry_point();
  80                 proto_end = dissector_get_ethernet_exit_point();
  81                 break;
  82         case LINKTYPE_IEEE802_11_RADIOTAP:
  83         case ___constant_swab32(LINKTYPE_IEEE802_11_RADIOTAP):
  84         case LINKTYPE_IEEE802_11:
  85         case ___constant_swab32(LINKTYPE_IEEE802_11):
  86                 proto_start = dissector_get_ieee80211_entry_point();
  87                 proto_end = dissector_get_ieee80211_exit_point();
  88                 break;
  89         case LINKTYPE_NETLINK:
  90         case ___constant_swab32(LINKTYPE_NETLINK):
  91                 proto_start = dissector_get_netlink_entry_point();
  92                 proto_end = dissector_get_netlink_exit_point();
  93                 break;
  94         default:
  95                 proto_start = &none_ops;
  96                 proto_end = NULL;
  97                 break;
  98         };
  99
 100         dissector_main(pkt, proto_start, proto_end);
 101
 102         switch (mode) {
 103         case PRINT_HEX:
 104                 hex(pkt);
 105                 break;
 106         case PRINT_ASCII:
 107                 ascii(pkt);
 108                 break;
 109         case PRINT_HEX_ASCII:
 110                 hex_ascii(pkt);
 111                 break;
 112         }
 113
 114         tprintf_flush();
 115         pkt_free(pkt);
 116 }
 117
 118 void dissector_init_all(int fnttype)
 119 {
 120         dissector_init_ethernet(fnttype);
 121         dissector_init_ieee80211(fnttype);
 122         dissector_init_netlink(fnttype);
 123 }
 124
 125 void dissector_cleanup_all(void)
 126 {
 127         dissector_cleanup_ethernet();
 128         dissector_cleanup_ieee80211();
 129         dissector_cleanup_netlink();
 130 }