| 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"); |