src/dissector.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2009, 2010, 2011, 2012 Daniel Borkmann.
   5  * Subject to the GPL, version 2.
   6  */
   7
   8 #include <stdint.h>
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11
  12 #include "built_in.h"
  13 #include "tprintf.h"
  14 #include "pkt_buff.h"
  15 #include "proto.h"
  16 #include "protos.h"
  17 #include "dissector.h"
  18 #include "dissector_eth.h"
  19 #include "dissector_80211.h"
  20
  21 int dissector_set_print_type(void *ptr, int type)
  22 {
  23         struct protocol *proto;
  24
  25         for (proto = (struct protocol *) ptr; proto; proto = proto->next) {
  26                 switch (type) {
  27                 case FNTTYPE_PRINT_NORM:
  28                         proto->process = proto->print_full;
  29                         break;
  30                 case FNTTYPE_PRINT_LESS:
  31                         proto->process = proto->print_less;
  32                         break;
  33                 case FNTTYPE_PRINT_HEX:
  34                 case FNTTYPE_PRINT_ASCII:
  35                 case FNTTYPE_PRINT_HEX_ASCII:
  36                 case FNTTYPE_PRINT_NONE:
  37                 default:
  38                         proto->process = NULL;
  39                         break;
  40                 }
  41         }
  42
  43         return 0;
  44 }
  45
  46 static void dissector_main(struct pkt_buff *pkt, struct protocol *start,
  47                            struct protocol *end)
  48 {
  49         struct protocol *proto;
  50
  51         if (!start)
  52                 return;
  53
  54         for (pkt->proto = start; pkt->proto; ) {
  55                 if (unlikely(!pkt->proto->process))
  56                         break;
  57
  58                 proto = pkt->proto;
  59                 pkt->proto = NULL;
  60                 proto->process(pkt);
  61         }
  62
  63         if (end && likely(end->process))
  64                 end->process(pkt);
  65 }
  66
  67 void dissector_entry_point(uint8_t *packet, size_t len, int linktype, int mode)
  68 {
  69         struct protocol *proto_start = NULL;
  70         struct protocol *proto_end = NULL;
  71         struct pkt_buff *pkt = NULL;
  72
  73         if (mode == FNTTYPE_PRINT_NONE)
  74                 return;
  75
  76         pkt = pkt_alloc(packet, len);
  77
  78         switch (linktype) {
  79         case LINKTYPE_EN10MB:
  80                 proto_start = dissector_get_ethernet_entry_point();
  81                 proto_end = dissector_get_ethernet_exit_point();
  82                 break;
  83         case LINKTYPE_IEEE802_11:
  84                 proto_start = dissector_get_ieee80211_entry_point();
  85                 proto_end = dissector_get_ieee80211_exit_point();
  86                 break;
  87         default:
  88                 panic("Linktype not supported!\n");
  89         };
  90
  91         dissector_main(pkt, proto_start, proto_end);
  92
  93         switch (mode) {
  94         case FNTTYPE_PRINT_HEX:
  95                 hex(pkt);
  96                 break;
  97         case FNTTYPE_PRINT_ASCII:
  98                 ascii(pkt);
  99                 break;
 100         case FNTTYPE_PRINT_HEX_ASCII:
 101                 hex_ascii(pkt);
 102                 break;
 103         }
 104
 105         tprintf_flush();
 106         pkt_free(pkt);
 107 }
 108
 109 void dissector_init_all(int fnttype)
 110 {
 111         dissector_init_ethernet(fnttype);
 112         dissector_init_ieee80211(fnttype);
 113 }
 114
 115 void dissector_cleanup_all(void)
 116 {
 117         dissector_cleanup_ethernet();
 118         dissector_cleanup_ieee80211();
 119 }