1 /* 2 * 802_3 3 * 4 * Author: 5 * Chris Vitale csv@bluetail.com 6 * 7 * May 2003 8 * 9 */ 10 #include <linux/module.h> 11 #include <linux/netfilter/x_tables.h> 12 #include <linux/netfilter_bridge/ebtables.h> 13 #include <linux/netfilter_bridge/ebt_802_3.h> 14 15 static bool 16 ebt_802_3_mt(const struct sk_buff *skb, struct xt_action_param *par) 17 { 18 const struct ebt_802_3_info *info = par->matchinfo; 19 const struct ebt_802_3_hdr *hdr = ebt_802_3_hdr(skb); 20 __be16 type = hdr->llc.ui.ctrl & IS_UI ? hdr->llc.ui.type : hdr->llc.ni.type; 21 22 if (info->bitmask & EBT_802_3_SAP) { 23 if (NF_INVF(info, EBT_802_3_SAP, info->sap != hdr->llc.ui.ssap)) 24 return false; 25 if (NF_INVF(info, EBT_802_3_SAP, info->sap != hdr->llc.ui.dsap)) 26 return false; 27 } 28 29 if (info->bitmask & EBT_802_3_TYPE) { 30 if (!(hdr->llc.ui.dsap == CHECK_TYPE && hdr->llc.ui.ssap == CHECK_TYPE)) 31 return false; 32 if (NF_INVF(info, EBT_802_3_TYPE, info->type != type)) 33 return false; 34 } 35 36 return true; 37 } 38 39 static int ebt_802_3_mt_check(const struct xt_mtchk_param *par) 40 { 41 const struct ebt_802_3_info *info = par->matchinfo; 42 43 if (info->bitmask & ~EBT_802_3_MASK || info->invflags & ~EBT_802_3_MASK) 44 return -EINVAL; 45 46 return 0; 47 } 48 49 static struct xt_match ebt_802_3_mt_reg __read_mostly = { 50 .name = "802_3", 51 .revision = 0, 52 .family = NFPROTO_BRIDGE, 53 .match = ebt_802_3_mt, 54 .checkentry = ebt_802_3_mt_check, 55 .matchsize = sizeof(struct ebt_802_3_info), 56 .me = THIS_MODULE, 57 }; 58 59 static int __init ebt_802_3_init(void) 60 { 61 return xt_register_match(&ebt_802_3_mt_reg); 62 } 63 64 static void __exit ebt_802_3_fini(void) 65 { 66 xt_unregister_match(&ebt_802_3_mt_reg); 67 } 68 69 module_init(ebt_802_3_init); 70 module_exit(ebt_802_3_fini); 71 MODULE_DESCRIPTION("Ebtables: DSAP/SSAP field and SNAP type matching"); 72 MODULE_LICENSE("GPL"); 73