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 "protos.h"
  16 #include "dissector.h"
  17 #include "dissector_eth.h"
  18 #include "dissector_80211.h"
  19
  20 int dissector_set_print_type(void *ptr, int type)
  21 {
  22         struct protocol *proto;
  23
  24         for (proto = ptr; proto; proto = proto->next) {
  25                 switch (type) {
  26                 case PRINT_NORM:
  27                         proto->process = proto->print_full;
  28                         break;
  29                 case PRINT_LESS:
  30                         proto->process = proto->print_less;
  31                         break;
  32                 default:
  33                         proto->process = NULL;
  34                         break;
  35                 }
  36         }
  37
  38         return 0;
  39 }
  40
  41 static void dissector_main(struct pkt_buff *pkt, struct protocol *start,
  42                            struct protocol *end)
  43 {
  44         struct protocol *proto;
  45
  46         if (!start)
  47                 return;
  48
  49         for (pkt->proto = start; pkt->proto; ) {
  50                 if (unlikely(!pkt->proto->process))
  51                         break;
  52
  53                 proto = pkt->proto;
  54                 pkt->proto = NULL;
  55                 proto->process(pkt);
  56         }
  57
  58         if (end && likely(end->process))
  59                 end->process(pkt);
  60 }
  61
  62 void dissector_entry_point(uint8_t *packet, size_t len, int linktype, int mode)
  63 {
  64         struct protocol *proto_start, *proto_end;
  65         struct pkt_buff *pkt;
  66
  67         if (mode == PRINT_NONE)
  68                 return;
  69
  70         pkt = pkt_alloc(packet, len);
  71
  72         switch (linktype) {
  73         case LINKTYPE_EN10MB:
  74         case ___constant_swab32(LINKTYPE_EN10MB):
  75                 proto_start = dissector_get_ethernet_entry_point();
  76                 proto_end = dissector_get_ethernet_exit_point();
  77                 break;
  78         case LINKTYPE_IEEE802_11:
  79         case ___constant_swab32(LINKTYPE_IEEE802_11):
  80                 proto_start = dissector_get_ieee80211_entry_point();
  81                 proto_end = dissector_get_ieee80211_exit_point();
  82                 break;
  83         default:
  84                 proto_start = &none_ops;
  85                 proto_end = NULL;
  86                 break;
  87         };
  88
  89         dissector_main(pkt, proto_start, proto_end);
  90
  91         switch (mode) {
  92         case PRINT_HEX:
  93                 hex(pkt);
  94                 break;
  95         case PRINT_ASCII:
  96                 ascii(pkt);
  97                 break;
  98         case PRINT_HEX_ASCII:
  99                 hex_ascii(pkt);
 100                 break;
 101         }
 102
 103         tprintf_flush();
 104         pkt_free(pkt);
 105 }
 106
 107 void dissector_init_all(int fnttype)
 108 {
 109         dissector_init_ethernet(fnttype);
 110         dissector_init_ieee80211(fnttype);
 111 }
 112
 113 void dissector_cleanup_all(void)
 114 {
 115         dissector_cleanup_ethernet();
 116         dissector_cleanup_ieee80211();
 117 }