![Pablo Neira Ayuso](/assets/img/avatar_default.png)
Currently, we have four xtables extensions that cannot be used from the xt over nft compat layer. The problem is that they need real access to the full blown xt_entry to validate that the rule comes with the right dependencies. This check was introduced to overcome the lack of sufficient userspace dependency validation in iptables. To resolve this problem, this patch introduces a new field to the xt_tgchk_param structure that tell us if the extension is run from nft_compat context. The three affected extensions are: 1) CLUSTERIP, this target has been superseded by xt_cluster. So just bail out by returning -EINVAL. 2) TCPMSS. Relax the checking when used from nft_compat. If used with the wrong configuration, it will corrupt !syn packets by adding TCP MSS option. 3) ebt_stp. Relax the check to make sure it uses the reserved destination MAC address for STP. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Tested-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
817 lines
20 KiB
C
817 lines
20 KiB
C
/*
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* (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This software has been sponsored by Sophos Astaro <http://www.sophos.com>
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nf_tables.h>
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#include <linux/netfilter/nf_tables_compat.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv6/ip6_tables.h>
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#include <linux/netfilter_bridge/ebtables.h>
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#include <linux/netfilter_arp/arp_tables.h>
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#include <net/netfilter/nf_tables.h>
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static int nft_compat_chain_validate_dependency(const char *tablename,
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const struct nft_chain *chain)
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{
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const struct nft_base_chain *basechain;
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if (!tablename || !(chain->flags & NFT_BASE_CHAIN))
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return 0;
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basechain = nft_base_chain(chain);
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if (strcmp(tablename, "nat") == 0 &&
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basechain->type->type != NFT_CHAIN_T_NAT)
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return -EINVAL;
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return 0;
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}
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union nft_entry {
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struct ipt_entry e4;
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struct ip6t_entry e6;
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struct ebt_entry ebt;
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struct arpt_entry arp;
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};
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static inline void
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nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info)
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{
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par->target = xt;
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par->targinfo = xt_info;
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par->hotdrop = false;
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}
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static void nft_target_eval_xt(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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void *info = nft_expr_priv(expr);
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struct xt_target *target = expr->ops->data;
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struct sk_buff *skb = pkt->skb;
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int ret;
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nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
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ret = target->target(skb, &pkt->xt);
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if (pkt->xt.hotdrop)
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ret = NF_DROP;
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switch (ret) {
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case XT_CONTINUE:
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regs->verdict.code = NFT_CONTINUE;
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break;
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default:
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regs->verdict.code = ret;
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break;
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}
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}
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static void nft_target_eval_bridge(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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void *info = nft_expr_priv(expr);
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struct xt_target *target = expr->ops->data;
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struct sk_buff *skb = pkt->skb;
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int ret;
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nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info);
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ret = target->target(skb, &pkt->xt);
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if (pkt->xt.hotdrop)
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ret = NF_DROP;
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switch (ret) {
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case EBT_ACCEPT:
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regs->verdict.code = NF_ACCEPT;
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break;
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case EBT_DROP:
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regs->verdict.code = NF_DROP;
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break;
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case EBT_CONTINUE:
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regs->verdict.code = NFT_CONTINUE;
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break;
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case EBT_RETURN:
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regs->verdict.code = NFT_RETURN;
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break;
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default:
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regs->verdict.code = ret;
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break;
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}
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}
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static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = {
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[NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING },
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[NFTA_TARGET_REV] = { .type = NLA_U32 },
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[NFTA_TARGET_INFO] = { .type = NLA_BINARY },
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};
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static void
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nft_target_set_tgchk_param(struct xt_tgchk_param *par,
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const struct nft_ctx *ctx,
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struct xt_target *target, void *info,
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union nft_entry *entry, u16 proto, bool inv)
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{
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par->net = ctx->net;
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par->table = ctx->table->name;
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switch (ctx->afi->family) {
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case AF_INET:
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entry->e4.ip.proto = proto;
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entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
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break;
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case AF_INET6:
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if (proto)
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entry->e6.ipv6.flags |= IP6T_F_PROTO;
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entry->e6.ipv6.proto = proto;
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entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
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break;
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case NFPROTO_BRIDGE:
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entry->ebt.ethproto = (__force __be16)proto;
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entry->ebt.invflags = inv ? EBT_IPROTO : 0;
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break;
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case NFPROTO_ARP:
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break;
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}
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par->entryinfo = entry;
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par->target = target;
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par->targinfo = info;
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if (ctx->chain->flags & NFT_BASE_CHAIN) {
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const struct nft_base_chain *basechain =
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nft_base_chain(ctx->chain);
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const struct nf_hook_ops *ops = &basechain->ops[0];
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par->hook_mask = 1 << ops->hooknum;
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} else {
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par->hook_mask = 0;
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}
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par->family = ctx->afi->family;
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par->nft_compat = true;
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}
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static void target_compat_from_user(struct xt_target *t, void *in, void *out)
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{
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int pad;
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memcpy(out, in, t->targetsize);
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pad = XT_ALIGN(t->targetsize) - t->targetsize;
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if (pad > 0)
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memset(out + t->targetsize, 0, pad);
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}
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static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = {
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[NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 },
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[NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 },
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};
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static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv)
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{
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struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1];
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u32 flags;
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int err;
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err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr,
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nft_rule_compat_policy);
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if (err < 0)
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return err;
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if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS])
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return -EINVAL;
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flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS]));
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if (flags & ~NFT_RULE_COMPAT_F_MASK)
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return -EINVAL;
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if (flags & NFT_RULE_COMPAT_F_INV)
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*inv = true;
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*proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
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return 0;
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}
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static int
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nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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void *info = nft_expr_priv(expr);
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struct xt_target *target = expr->ops->data;
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struct xt_tgchk_param par;
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size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
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u16 proto = 0;
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bool inv = false;
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union nft_entry e = {};
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int ret;
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ret = nft_compat_chain_validate_dependency(target->table, ctx->chain);
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if (ret < 0)
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goto err;
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target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
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if (ctx->nla[NFTA_RULE_COMPAT]) {
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ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
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if (ret < 0)
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goto err;
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}
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nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
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ret = xt_check_target(&par, size, proto, inv);
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if (ret < 0)
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goto err;
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/* The standard target cannot be used */
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if (target->target == NULL) {
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ret = -EINVAL;
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goto err;
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}
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return 0;
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err:
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module_put(target->me);
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return ret;
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}
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static void
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nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
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{
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struct xt_target *target = expr->ops->data;
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void *info = nft_expr_priv(expr);
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struct xt_tgdtor_param par;
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par.net = ctx->net;
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par.target = target;
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par.targinfo = info;
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par.family = ctx->afi->family;
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if (par.target->destroy != NULL)
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par.target->destroy(&par);
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module_put(target->me);
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}
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static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct xt_target *target = expr->ops->data;
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void *info = nft_expr_priv(expr);
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if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
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nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
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nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(target->targetsize), info))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static int nft_target_validate(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nft_data **data)
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{
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struct xt_target *target = expr->ops->data;
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unsigned int hook_mask = 0;
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int ret;
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if (ctx->chain->flags & NFT_BASE_CHAIN) {
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const struct nft_base_chain *basechain =
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nft_base_chain(ctx->chain);
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const struct nf_hook_ops *ops = &basechain->ops[0];
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hook_mask = 1 << ops->hooknum;
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if (!(hook_mask & target->hooks))
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return -EINVAL;
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ret = nft_compat_chain_validate_dependency(target->table,
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ctx->chain);
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if (ret < 0)
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return ret;
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}
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return 0;
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}
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static void nft_match_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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void *info = nft_expr_priv(expr);
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struct xt_match *match = expr->ops->data;
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struct sk_buff *skb = pkt->skb;
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bool ret;
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nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
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ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
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if (pkt->xt.hotdrop) {
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regs->verdict.code = NF_DROP;
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return;
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}
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switch (ret ? 1 : 0) {
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case 1:
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regs->verdict.code = NFT_CONTINUE;
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break;
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case 0:
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regs->verdict.code = NFT_BREAK;
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break;
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}
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}
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static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
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[NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
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[NFTA_MATCH_REV] = { .type = NLA_U32 },
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[NFTA_MATCH_INFO] = { .type = NLA_BINARY },
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};
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/* struct xt_mtchk_param and xt_tgchk_param look very similar */
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static void
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nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
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struct xt_match *match, void *info,
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union nft_entry *entry, u16 proto, bool inv)
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{
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par->net = ctx->net;
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par->table = ctx->table->name;
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switch (ctx->afi->family) {
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case AF_INET:
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entry->e4.ip.proto = proto;
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entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
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break;
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case AF_INET6:
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if (proto)
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entry->e6.ipv6.flags |= IP6T_F_PROTO;
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entry->e6.ipv6.proto = proto;
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entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
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break;
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case NFPROTO_BRIDGE:
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entry->ebt.ethproto = (__force __be16)proto;
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entry->ebt.invflags = inv ? EBT_IPROTO : 0;
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break;
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case NFPROTO_ARP:
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break;
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}
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par->entryinfo = entry;
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par->match = match;
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par->matchinfo = info;
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if (ctx->chain->flags & NFT_BASE_CHAIN) {
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const struct nft_base_chain *basechain =
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nft_base_chain(ctx->chain);
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const struct nf_hook_ops *ops = &basechain->ops[0];
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par->hook_mask = 1 << ops->hooknum;
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} else {
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par->hook_mask = 0;
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}
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par->family = ctx->afi->family;
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par->nft_compat = true;
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}
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static void match_compat_from_user(struct xt_match *m, void *in, void *out)
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{
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int pad;
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memcpy(out, in, m->matchsize);
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pad = XT_ALIGN(m->matchsize) - m->matchsize;
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if (pad > 0)
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memset(out + m->matchsize, 0, pad);
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}
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static int
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nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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void *info = nft_expr_priv(expr);
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struct xt_match *match = expr->ops->data;
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struct xt_mtchk_param par;
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size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
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u16 proto = 0;
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bool inv = false;
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union nft_entry e = {};
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int ret;
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ret = nft_compat_chain_validate_dependency(match->table, ctx->chain);
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if (ret < 0)
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goto err;
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match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
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if (ctx->nla[NFTA_RULE_COMPAT]) {
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ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
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if (ret < 0)
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goto err;
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}
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nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
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ret = xt_check_match(&par, size, proto, inv);
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if (ret < 0)
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goto err;
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return 0;
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err:
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module_put(match->me);
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return ret;
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}
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static void
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nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
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{
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struct xt_match *match = expr->ops->data;
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void *info = nft_expr_priv(expr);
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struct xt_mtdtor_param par;
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par.net = ctx->net;
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par.match = match;
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par.matchinfo = info;
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par.family = ctx->afi->family;
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if (par.match->destroy != NULL)
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par.match->destroy(&par);
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module_put(match->me);
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}
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static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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void *info = nft_expr_priv(expr);
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struct xt_match *match = expr->ops->data;
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if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
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nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
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nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(match->matchsize), info))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static int nft_match_validate(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nft_data **data)
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{
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struct xt_match *match = expr->ops->data;
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unsigned int hook_mask = 0;
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int ret;
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if (ctx->chain->flags & NFT_BASE_CHAIN) {
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const struct nft_base_chain *basechain =
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nft_base_chain(ctx->chain);
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const struct nf_hook_ops *ops = &basechain->ops[0];
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hook_mask = 1 << ops->hooknum;
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if (!(hook_mask & match->hooks))
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return -EINVAL;
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ret = nft_compat_chain_validate_dependency(match->table,
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ctx->chain);
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if (ret < 0)
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return ret;
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}
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return 0;
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}
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static int
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nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
|
|
int event, u16 family, const char *name,
|
|
int rev, int target)
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
struct nfgenmsg *nfmsg;
|
|
unsigned int flags = portid ? NLM_F_MULTI : 0;
|
|
|
|
event |= NFNL_SUBSYS_NFT_COMPAT << 8;
|
|
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
|
|
if (nlh == NULL)
|
|
goto nlmsg_failure;
|
|
|
|
nfmsg = nlmsg_data(nlh);
|
|
nfmsg->nfgen_family = family;
|
|
nfmsg->version = NFNETLINK_V0;
|
|
nfmsg->res_id = 0;
|
|
|
|
if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
|
|
nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
|
|
nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
|
|
goto nla_put_failure;
|
|
|
|
nlmsg_end(skb, nlh);
|
|
return skb->len;
|
|
|
|
nlmsg_failure:
|
|
nla_put_failure:
|
|
nlmsg_cancel(skb, nlh);
|
|
return -1;
|
|
}
|
|
|
|
static int
|
|
nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb,
|
|
const struct nlmsghdr *nlh, const struct nlattr * const tb[])
|
|
{
|
|
int ret = 0, target;
|
|
struct nfgenmsg *nfmsg;
|
|
const char *fmt;
|
|
const char *name;
|
|
u32 rev;
|
|
struct sk_buff *skb2;
|
|
|
|
if (tb[NFTA_COMPAT_NAME] == NULL ||
|
|
tb[NFTA_COMPAT_REV] == NULL ||
|
|
tb[NFTA_COMPAT_TYPE] == NULL)
|
|
return -EINVAL;
|
|
|
|
name = nla_data(tb[NFTA_COMPAT_NAME]);
|
|
rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
|
|
target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
|
|
|
|
nfmsg = nlmsg_data(nlh);
|
|
|
|
switch(nfmsg->nfgen_family) {
|
|
case AF_INET:
|
|
fmt = "ipt_%s";
|
|
break;
|
|
case AF_INET6:
|
|
fmt = "ip6t_%s";
|
|
break;
|
|
case NFPROTO_BRIDGE:
|
|
fmt = "ebt_%s";
|
|
break;
|
|
case NFPROTO_ARP:
|
|
fmt = "arpt_%s";
|
|
break;
|
|
default:
|
|
pr_err("nft_compat: unsupported protocol %d\n",
|
|
nfmsg->nfgen_family);
|
|
return -EINVAL;
|
|
}
|
|
|
|
try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
|
|
rev, target, &ret),
|
|
fmt, name);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
|
|
if (skb2 == NULL)
|
|
return -ENOMEM;
|
|
|
|
/* include the best revision for this extension in the message */
|
|
if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
|
|
nlh->nlmsg_seq,
|
|
NFNL_MSG_TYPE(nlh->nlmsg_type),
|
|
NFNL_MSG_COMPAT_GET,
|
|
nfmsg->nfgen_family,
|
|
name, ret, target) <= 0) {
|
|
kfree_skb(skb2);
|
|
return -ENOSPC;
|
|
}
|
|
|
|
ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
|
|
MSG_DONTWAIT);
|
|
if (ret > 0)
|
|
ret = 0;
|
|
|
|
return ret == -EAGAIN ? -ENOBUFS : ret;
|
|
}
|
|
|
|
static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
|
|
[NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
|
|
.len = NFT_COMPAT_NAME_MAX-1 },
|
|
[NFTA_COMPAT_REV] = { .type = NLA_U32 },
|
|
[NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
|
|
};
|
|
|
|
static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
|
|
[NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
|
|
.attr_count = NFTA_COMPAT_MAX,
|
|
.policy = nfnl_compat_policy_get },
|
|
};
|
|
|
|
static const struct nfnetlink_subsystem nfnl_compat_subsys = {
|
|
.name = "nft-compat",
|
|
.subsys_id = NFNL_SUBSYS_NFT_COMPAT,
|
|
.cb_count = NFNL_MSG_COMPAT_MAX,
|
|
.cb = nfnl_nft_compat_cb,
|
|
};
|
|
|
|
static LIST_HEAD(nft_match_list);
|
|
|
|
struct nft_xt {
|
|
struct list_head head;
|
|
struct nft_expr_ops ops;
|
|
};
|
|
|
|
static struct nft_expr_type nft_match_type;
|
|
|
|
static const struct nft_expr_ops *
|
|
nft_match_select_ops(const struct nft_ctx *ctx,
|
|
const struct nlattr * const tb[])
|
|
{
|
|
struct nft_xt *nft_match;
|
|
struct xt_match *match;
|
|
char *mt_name;
|
|
__u32 rev, family;
|
|
|
|
if (tb[NFTA_MATCH_NAME] == NULL ||
|
|
tb[NFTA_MATCH_REV] == NULL ||
|
|
tb[NFTA_MATCH_INFO] == NULL)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
mt_name = nla_data(tb[NFTA_MATCH_NAME]);
|
|
rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
|
|
family = ctx->afi->family;
|
|
|
|
/* Re-use the existing match if it's already loaded. */
|
|
list_for_each_entry(nft_match, &nft_match_list, head) {
|
|
struct xt_match *match = nft_match->ops.data;
|
|
|
|
if (strcmp(match->name, mt_name) == 0 &&
|
|
match->revision == rev && match->family == family) {
|
|
if (!try_module_get(match->me))
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
return &nft_match->ops;
|
|
}
|
|
}
|
|
|
|
match = xt_request_find_match(family, mt_name, rev);
|
|
if (IS_ERR(match))
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
/* This is the first time we use this match, allocate operations */
|
|
nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
|
|
if (nft_match == NULL)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
nft_match->ops.type = &nft_match_type;
|
|
nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize));
|
|
nft_match->ops.eval = nft_match_eval;
|
|
nft_match->ops.init = nft_match_init;
|
|
nft_match->ops.destroy = nft_match_destroy;
|
|
nft_match->ops.dump = nft_match_dump;
|
|
nft_match->ops.validate = nft_match_validate;
|
|
nft_match->ops.data = match;
|
|
|
|
list_add(&nft_match->head, &nft_match_list);
|
|
|
|
return &nft_match->ops;
|
|
}
|
|
|
|
static void nft_match_release(void)
|
|
{
|
|
struct nft_xt *nft_match, *tmp;
|
|
|
|
list_for_each_entry_safe(nft_match, tmp, &nft_match_list, head)
|
|
kfree(nft_match);
|
|
}
|
|
|
|
static struct nft_expr_type nft_match_type __read_mostly = {
|
|
.name = "match",
|
|
.select_ops = nft_match_select_ops,
|
|
.policy = nft_match_policy,
|
|
.maxattr = NFTA_MATCH_MAX,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static LIST_HEAD(nft_target_list);
|
|
|
|
static struct nft_expr_type nft_target_type;
|
|
|
|
static const struct nft_expr_ops *
|
|
nft_target_select_ops(const struct nft_ctx *ctx,
|
|
const struct nlattr * const tb[])
|
|
{
|
|
struct nft_xt *nft_target;
|
|
struct xt_target *target;
|
|
char *tg_name;
|
|
__u32 rev, family;
|
|
|
|
if (tb[NFTA_TARGET_NAME] == NULL ||
|
|
tb[NFTA_TARGET_REV] == NULL ||
|
|
tb[NFTA_TARGET_INFO] == NULL)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
tg_name = nla_data(tb[NFTA_TARGET_NAME]);
|
|
rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
|
|
family = ctx->afi->family;
|
|
|
|
/* Re-use the existing target if it's already loaded. */
|
|
list_for_each_entry(nft_target, &nft_target_list, head) {
|
|
struct xt_target *target = nft_target->ops.data;
|
|
|
|
if (strcmp(target->name, tg_name) == 0 &&
|
|
target->revision == rev && target->family == family) {
|
|
if (!try_module_get(target->me))
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
return &nft_target->ops;
|
|
}
|
|
}
|
|
|
|
target = xt_request_find_target(family, tg_name, rev);
|
|
if (IS_ERR(target))
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
/* This is the first time we use this target, allocate operations */
|
|
nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
|
|
if (nft_target == NULL)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
nft_target->ops.type = &nft_target_type;
|
|
nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize));
|
|
nft_target->ops.init = nft_target_init;
|
|
nft_target->ops.destroy = nft_target_destroy;
|
|
nft_target->ops.dump = nft_target_dump;
|
|
nft_target->ops.validate = nft_target_validate;
|
|
nft_target->ops.data = target;
|
|
|
|
if (family == NFPROTO_BRIDGE)
|
|
nft_target->ops.eval = nft_target_eval_bridge;
|
|
else
|
|
nft_target->ops.eval = nft_target_eval_xt;
|
|
|
|
list_add(&nft_target->head, &nft_target_list);
|
|
|
|
return &nft_target->ops;
|
|
}
|
|
|
|
static void nft_target_release(void)
|
|
{
|
|
struct nft_xt *nft_target, *tmp;
|
|
|
|
list_for_each_entry_safe(nft_target, tmp, &nft_target_list, head)
|
|
kfree(nft_target);
|
|
}
|
|
|
|
static struct nft_expr_type nft_target_type __read_mostly = {
|
|
.name = "target",
|
|
.select_ops = nft_target_select_ops,
|
|
.policy = nft_target_policy,
|
|
.maxattr = NFTA_TARGET_MAX,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
static int __init nft_compat_module_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = nft_register_expr(&nft_match_type);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = nft_register_expr(&nft_target_type);
|
|
if (ret < 0)
|
|
goto err_match;
|
|
|
|
ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
|
|
if (ret < 0) {
|
|
pr_err("nft_compat: cannot register with nfnetlink.\n");
|
|
goto err_target;
|
|
}
|
|
|
|
pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n");
|
|
|
|
return ret;
|
|
|
|
err_target:
|
|
nft_unregister_expr(&nft_target_type);
|
|
err_match:
|
|
nft_unregister_expr(&nft_match_type);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit nft_compat_module_exit(void)
|
|
{
|
|
nfnetlink_subsys_unregister(&nfnl_compat_subsys);
|
|
nft_unregister_expr(&nft_target_type);
|
|
nft_unregister_expr(&nft_match_type);
|
|
nft_match_release();
|
|
nft_target_release();
|
|
}
|
|
|
|
MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
|
|
|
|
module_init(nft_compat_module_init);
|
|
module_exit(nft_compat_module_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
|
|
MODULE_ALIAS_NFT_EXPR("match");
|
|
MODULE_ALIAS_NFT_EXPR("target");
|