release/src/router/ebtables/extensions/ebt_802_3.c

   1 /* 802_3
   2  *
   3  * Author:
   4  * Chris Vitale <csv@bluetail.com>
   5  *
   6  * May 2003
   7  */
   8
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <stdlib.h>
  12 #include <getopt.h>
  13 #include "../include/ebtables_u.h"
  14 #include "../include/ethernetdb.h"
  15 #include <linux/netfilter_bridge/ebt_802_3.h>
  16
  17 #define _802_3_SAP '1'
  18 #define _802_3_TYPE '2'
  19
  20 static struct option opts[] =
  21 {
  22         { "802_3-sap"   , required_argument, 0, _802_3_SAP },
  23         { "802_3-type"  , required_argument, 0, _802_3_TYPE },
  24         { 0 }
  25 };
  26
  27 static void print_help()
  28 {
  29         printf(
  30 "802_3 options:\n"
  31 "--802_3-sap [!] protocol       : 802.3 DSAP/SSAP- 1 byte value (hex)\n"
  32 "  DSAP and SSAP are always the same.  One SAP applies to both fields\n"
  33 "--802_3-type [!] protocol      : 802.3 SNAP Type- 2 byte value (hex)\n"
  34 "  Type implies SAP value 0xaa\n");
  35 }
  36
  37 static void init(struct ebt_entry_match *match)
  38 {
  39         struct ebt_802_3_info *info = (struct ebt_802_3_info *)match->data;
  40
  41         info->invflags = 0;
  42         info->bitmask = 0;
  43 }
  44
  45 static int parse(int c, char **argv, int argc, const struct ebt_u_entry *entry,
  46    unsigned int *flags, struct ebt_entry_match **match)
  47 {
  48         struct ebt_802_3_info *info = (struct ebt_802_3_info *) (*match)->data;
  49         unsigned int i;
  50         char *end;
  51
  52         switch (c) {
  53                 case _802_3_SAP:
  54                         ebt_check_option2(flags, _802_3_SAP);
  55                         if (ebt_check_inverse2(optarg))
  56                                 info->invflags |= EBT_802_3_SAP;
  57                         i = strtoul(optarg, &end, 16);
  58                         if (i > 255 || *end != '\0')
  59                                 ebt_print_error2("Problem with specified "
  60                                                 "sap hex value, %x",i);
  61                         info->sap = i; /* one byte, so no byte order worries */
  62                         info->bitmask |= EBT_802_3_SAP;
  63                         break;
  64                 case _802_3_TYPE:
  65                         ebt_check_option2(flags, _802_3_TYPE);
  66                         if (ebt_check_inverse2(optarg))
  67                                 info->invflags |= EBT_802_3_TYPE;
  68                         i = strtoul(optarg, &end, 16);
  69                         if (i > 65535 || *end != '\0') {
  70                                 ebt_print_error2("Problem with the specified "
  71                                                 "type hex value, %x",i);
  72                         }
  73                         info->type = htons(i);
  74                         info->bitmask |= EBT_802_3_TYPE;
  75                         break;
  76                 default:
  77                         return 0;
  78         }
  79         return 1;
  80 }
  81
  82 static void final_check(const struct ebt_u_entry *entry,
  83    const struct ebt_entry_match *match, const char *name,
  84    unsigned int hookmask, unsigned int time)
  85 {
  86         if (!(entry->bitmask & EBT_802_3))
  87                 ebt_print_error("For 802.3 DSAP/SSAP filtering the protocol "
  88                                 "must be LENGTH");
  89 }
  90
  91 static void print(const struct ebt_u_entry *entry,
  92    const struct ebt_entry_match *match)
  93 {
  94         struct ebt_802_3_info *info = (struct ebt_802_3_info *)match->data;
  95
  96         if (info->bitmask & EBT_802_3_SAP) {
  97                 printf("--802_3-sap ");
  98                 if (info->invflags & EBT_802_3_SAP)
  99                         printf("! ");
 100                 printf("0x%.2x ", info->sap);
 101         }
 102         if (info->bitmask & EBT_802_3_TYPE) {
 103                 printf("--802_3-type ");
 104                 if (info->invflags & EBT_802_3_TYPE)
 105                         printf("! ");
 106                 printf("0x%.4x ", ntohs(info->type));
 107         }
 108 }
 109
 110 static int compare(const struct ebt_entry_match *m1,
 111    const struct ebt_entry_match *m2)
 112 {
 113         struct ebt_802_3_info *info1 = (struct ebt_802_3_info *)m1->data;
 114         struct ebt_802_3_info *info2 = (struct ebt_802_3_info *)m2->data;
 115
 116         if (info1->bitmask != info2->bitmask)
 117                 return 0;
 118         if (info1->invflags != info2->invflags)
 119                 return 0;
 120         if (info1->bitmask & EBT_802_3_SAP) {
 121                 if (info1->sap != info2->sap)
 122                         return 0;
 123         }
 124         if (info1->bitmask & EBT_802_3_TYPE) {
 125                 if (info1->type != info2->type)
 126                         return 0;
 127         }
 128         return 1;
 129 }
 130
 131 static struct ebt_u_match _802_3_match =
 132 {
 133         .name           = "802_3",
 134         .size           = sizeof(struct ebt_802_3_info),
 135         .help           = print_help,
 136         .init           = init,
 137         .parse          = parse,
 138         .final_check    = final_check,
 139         .print          = print,
 140         .compare        = compare,
 141         .extra_ops      = opts,
 142 };
 143
 144 void _init(void)
 145 {
 146         ebt_register_match(&_802_3_match);
 147 }