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_sll.h"
  18 #include "dissector_80211.h"
  19 #include "dissector_netlink.h"
  20 #include "linktype.h"
  21
  22 int dissector_set_print_type(void *ptr, int type)
  23 {
  24         struct protocol *proto;
  25
  26         for (proto = ptr; proto; proto = proto->next) {
  27                 switch (type) {
  28                 case PRINT_NORM:
  29                         proto->process = proto->print_full;
  30                         break;
  31                 case PRINT_LESS:
  32                         proto->process = proto->print_less;
  33                         break;
  34                 default:
  35                         proto->process = NULL;
  36                         break;
  37                 }
  38         }
  39
  40         return 0;
  41 }
  42
  43 static void dissector_main(struct pkt_buff *pkt, struct protocol *start,
  44                            struct protocol *end)
  45 {
  46         struct protocol *dissector;
  47
  48         if (!start)
  49                 return;
  50
  51         for (pkt->dissector = start; pkt->dissector; ) {
  52                 if (unlikely(!pkt->dissector->process))
  53                         break;
  54
  55                 dissector = pkt->dissector;
  56                 pkt->dissector = NULL;
  57                 dissector->process(pkt);
  58         }
  59
  60         if (end && likely(end->process))
  61                 end->process(pkt);
  62 }
  63
  64 void dissector_entry_point(uint8_t *packet, size_t len, int linktype, int mode,
  65                            struct sockaddr_ll *sll)
  66 {
  67         struct protocol *proto_start, *proto_end;
  68         struct pkt_buff *pkt;
  69
  70         if (mode == PRINT_NONE)
  71                 return;
  72
  73         pkt = pkt_alloc(packet, len);
  74         pkt->link_type = linktype;
  75         pkt->sll = sll;
  76
  77         switch (linktype) {
  78         case LINKTYPE_EN10MB:
  79         case ___constant_swab32(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_RADIOTAP:
  84         case ___constant_swab32(LINKTYPE_IEEE802_11_RADIOTAP):
  85         case LINKTYPE_IEEE802_11:
  86         case ___constant_swab32(LINKTYPE_IEEE802_11):
  87                 proto_start = dissector_get_ieee80211_entry_point();
  88                 proto_end = dissector_get_ieee80211_exit_point();
  89                 break;
  90         case LINKTYPE_NETLINK:
  91         case ___constant_swab32(LINKTYPE_NETLINK):
  92                 proto_start = dissector_get_netlink_entry_point();
  93                 proto_end = dissector_get_netlink_exit_point();
  94                 break;
  95         case LINKTYPE_LINUX_SLL:
  96         case ___constant_swab32(LINKTYPE_LINUX_SLL):
  97                 proto_start = dissector_get_sll_entry_point();
  98                 proto_end = dissector_get_sll_exit_point();
  99                 break;
 100         default:
 101                 proto_start = &none_ops;
 102                 proto_end = NULL;
 103                 break;
 104         };
 105
 106         dissector_main(pkt, proto_start, proto_end);
 107
 108         switch (mode) {
 109         case PRINT_HEX:
 110                 hex(pkt);
 111                 break;
 112         case PRINT_ASCII:
 113                 ascii(pkt);
 114                 break;
 115         case PRINT_HEX_ASCII:
 116                 hex_ascii(pkt);
 117                 break;
 118         }
 119
 120         tprintf_flush();
 121         pkt_free(pkt);
 122 }
 123
 124 void dissector_init_all(int fnttype)
 125 {
 126         dissector_init_ethernet(fnttype);
 127         dissector_init_ieee80211(fnttype);
 128         dissector_init_netlink(fnttype);
 129         dissector_init_sll(fnttype);
 130 }
 131
 132 void dissector_cleanup_all(void)
 133 {
 134         dissector_cleanup_ethernet();
 135         dissector_cleanup_ieee80211();
 136         dissector_cleanup_netlink();
 137         dissector_cleanup_sll();
 138 }