From 0ca743a5599199152a31a7146b83213c786c2eb2 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 14 Oct 2013 00:06:06 +0200 Subject: netfilter: nf_tables: add compatibility layer for x_tables This patch adds the x_tables compatibility layer. This allows you to use existing x_tables matches and targets from nf_tables. This compatibility later allows us to use existing matches/targets for features that are still missing in nf_tables. We can progressively replace them with native nf_tables extensions. It also provides the userspace compatibility software that allows you to express the rule-set using the iptables syntax but using the nf_tables kernel components. In order to get this compatibility layer working, I've done the following things: * add NFNL_SUBSYS_NFT_COMPAT: this new nfnetlink subsystem is used to query the x_tables match/target revision, so we don't need to use the native x_table getsockopt interface. * emulate xt structures: this required extending the struct nft_pktinfo to include the fragment offset, which is already obtained from ip[6]_tables and that is used by some matches/targets. * add support for default policy to base chains, required to emulate x_tables. * add NFTA_CHAIN_USE attribute to obtain the number of references to chains, required by x_tables emulation. * add chain packet/byte counters using per-cpu. * support 32-64 bits compat. For historical reasons, this patch includes the following patches that were posted in the netfilter-devel mailing list. From Pablo Neira Ayuso: * nf_tables: add default policy to base chains * netfilter: nf_tables: add NFTA_CHAIN_USE attribute * nf_tables: nft_compat: private data of target and matches in contiguous area * nf_tables: validate hooks for compat match/target * nf_tables: nft_compat: release cached matches/targets * nf_tables: x_tables support as a compile time option * nf_tables: fix alias for xtables over nftables module * nf_tables: add packet and byte counters per chain * nf_tables: fix per-chain counter stats if no counters are passed * nf_tables: don't bump chain stats * nf_tables: add protocol and flags for xtables over nf_tables * nf_tables: add ip[6]t_entry emulation * nf_tables: move specific layer 3 compat code to nf_tables_ipv[4|6] * nf_tables: support 32bits-64bits x_tables compat * nf_tables: fix compilation if CONFIG_COMPAT is disabled From Patrick McHardy: * nf_tables: move policy to struct nft_base_chain * nf_tables: send notifications for base chain policy changes From Alexander Primak: * nf_tables: remove the duplicate NF_INET_LOCAL_OUT From Nicolas Dichtel: * nf_tables: fix compilation when nf-netlink is a module Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_core.c | 46 +++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 19 deletions(-) (limited to 'net/netfilter/nf_tables_core.c') diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c index 9aede59..e51a45c 100644 --- a/net/netfilter/nf_tables_core.c +++ b/net/netfilter/nf_tables_core.c @@ -60,27 +60,34 @@ static bool nft_payload_fast_eval(const struct nft_expr *expr, return true; } -unsigned int nft_do_chain(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +struct nft_jumpstack { + const struct nft_chain *chain; + const struct nft_rule *rule; +}; + +static inline void +nft_chain_stats(const struct nft_chain *this, const struct nft_pktinfo *pkt, + struct nft_jumpstack *jumpstack, unsigned int stackptr) +{ + struct nft_stats __percpu *stats; + const struct nft_chain *chain = stackptr ? jumpstack[0].chain : this; + + rcu_read_lock_bh(); + stats = rcu_dereference(nft_base_chain(chain)->stats); + __this_cpu_inc(stats->pkts); + __this_cpu_add(stats->bytes, pkt->skb->len); + rcu_read_unlock_bh(); +} + +unsigned int +nft_do_chain_pktinfo(struct nft_pktinfo *pkt, const struct nf_hook_ops *ops) { const struct nft_chain *chain = ops->priv; const struct nft_rule *rule; const struct nft_expr *expr, *last; struct nft_data data[NFT_REG_MAX + 1]; - const struct nft_pktinfo pkt = { - .skb = skb, - .in = in, - .out = out, - .hooknum = ops->hooknum, - }; unsigned int stackptr = 0; - struct { - const struct nft_chain *chain; - const struct nft_rule *rule; - } jumpstack[NFT_JUMP_STACK_SIZE]; + struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE]; do_chain: rule = list_entry(&chain->rules, struct nft_rule, list); @@ -91,8 +98,8 @@ next_rule: if (expr->ops == &nft_cmp_fast_ops) nft_cmp_fast_eval(expr, data); else if (expr->ops != &nft_payload_fast_ops || - !nft_payload_fast_eval(expr, data, &pkt)) - expr->ops->eval(expr, data, &pkt); + !nft_payload_fast_eval(expr, data, pkt)) + expr->ops->eval(expr, data, pkt); if (data[NFT_REG_VERDICT].verdict != NFT_CONTINUE) break; @@ -135,10 +142,11 @@ next_rule: rule = jumpstack[stackptr].rule; goto next_rule; } + nft_chain_stats(chain, pkt, jumpstack, stackptr); - return NF_ACCEPT; + return nft_base_chain(chain)->policy; } -EXPORT_SYMBOL_GPL(nft_do_chain); +EXPORT_SYMBOL_GPL(nft_do_chain_pktinfo); int __init nf_tables_core_module_init(void) { -- cgit v1.1