1 files changed, 270 insertions, 0 deletions
diff --git a/net/netfilter/nf_tables_core.c b/net/netfilter/nf_tables_core.c
new file mode 100644
index 000000000000..cb9e685caae1
--- /dev/null
+++ b/net/netfilter/nf_tables_core.c
@@ -0,0 +1,270 @@
+/*
+ * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/rculist.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nf_tables.h>
+#include <net/netfilter/nf_tables_core.h>
+#include <net/netfilter/nf_tables.h>
+#include <net/netfilter/nf_log.h>
+
+static void nft_cmp_fast_eval(const struct nft_expr *expr,
+			      struct nft_data data[NFT_REG_MAX + 1])
+{
+	const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
+	u32 mask;
+
+	mask = ~0U >> (sizeof(priv->data) * BITS_PER_BYTE - priv->len);
+	if ((data[priv->sreg].data[0] & mask) == priv->data)
+		return;
+	data[NFT_REG_VERDICT].verdict = NFT_BREAK;
+}
+
+static bool nft_payload_fast_eval(const struct nft_expr *expr,
+				  struct nft_data data[NFT_REG_MAX + 1],
+				  const struct nft_pktinfo *pkt)
+{
+	const struct nft_payload *priv = nft_expr_priv(expr);
+	const struct sk_buff *skb = pkt->skb;
+	struct nft_data *dest = &data[priv->dreg];
+	unsigned char *ptr;
+
+	if (priv->base == NFT_PAYLOAD_NETWORK_HEADER)
+		ptr = skb_network_header(skb);
+	else
+		ptr = skb_network_header(skb) + pkt->xt.thoff;
+
+	ptr += priv->offset;
+
+	if (unlikely(ptr + priv->len >= skb_tail_pointer(skb)))
+		return false;
+
+	if (priv->len == 2)
+		*(u16 *)dest->data = *(u16 *)ptr;
+	else if (priv->len == 4)
+		*(u32 *)dest->data = *(u32 *)ptr;
+	else
+		*(u8 *)dest->data = *(u8 *)ptr;
+	return true;
+}
+
+struct nft_jumpstack {
+	const struct nft_chain	*chain;
+	const struct nft_rule	*rule;
+	int			rulenum;
+};
+
+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();
+}
+
+enum nft_trace {
+	NFT_TRACE_RULE,
+	NFT_TRACE_RETURN,
+	NFT_TRACE_POLICY,
+};
+
+static const char *const comments[] = {
+	[NFT_TRACE_RULE]	= "rule",
+	[NFT_TRACE_RETURN]	= "return",
+	[NFT_TRACE_POLICY]	= "policy",
+};
+
+static struct nf_loginfo trace_loginfo = {
+	.type = NF_LOG_TYPE_LOG,
+	.u = {
+		.log = {
+			.level = 4,
+			.logflags = NF_LOG_MASK,
+	        },
+	},
+};
+
+static inline void nft_trace_packet(const struct nft_pktinfo *pkt,
+				    const struct nft_chain *chain,
+				    int rulenum, enum nft_trace type)
+{
+	struct net *net = dev_net(pkt->in ? pkt->in : pkt->out);
+
+	nf_log_packet(net, pkt->xt.family, pkt->hooknum, pkt->skb, pkt->in,
+		      pkt->out, &trace_loginfo, "TRACE: %s:%s:%s:%u ",
+		      chain->table->name, chain->name, comments[type],
+		      rulenum);
+}
+
+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];
+	unsigned int stackptr = 0;
+	struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE];
+	int rulenum = 0;
+	/*
+	 * Cache cursor to avoid problems in case that the cursor is updated
+	 * while traversing the ruleset.
+	 */
+	unsigned int gencursor = ACCESS_ONCE(chain->net->nft.gencursor);
+
+do_chain:
+	rule = list_entry(&chain->rules, struct nft_rule, list);
+next_rule:
+	data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
+	list_for_each_entry_continue_rcu(rule, &chain->rules, list) {
+
+		/* This rule is not active, skip. */
+		if (unlikely(rule->genmask & (1 << gencursor)))
+			continue;
+
+		rulenum++;
+
+		nft_rule_for_each_expr(expr, last, 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);
+
+			if (data[NFT_REG_VERDICT].verdict != NFT_CONTINUE)
+				break;
+		}
+
+		switch (data[NFT_REG_VERDICT].verdict) {
+		case NFT_BREAK:
+			data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
+			/* fall through */
+		case NFT_CONTINUE:
+			continue;
+		}
+		break;
+	}
+
+	switch (data[NFT_REG_VERDICT].verdict) {
+	case NF_ACCEPT:
+	case NF_DROP:
+	case NF_QUEUE:
+		if (unlikely(pkt->skb->nf_trace))
+			nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RULE);
+
+		return data[NFT_REG_VERDICT].verdict;
+	case NFT_JUMP:
+		if (unlikely(pkt->skb->nf_trace))
+			nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RULE);
+
+		BUG_ON(stackptr >= NFT_JUMP_STACK_SIZE);
+		jumpstack[stackptr].chain = chain;
+		jumpstack[stackptr].rule  = rule;
+		jumpstack[stackptr].rulenum = rulenum;
+		stackptr++;
+		/* fall through */
+	case NFT_GOTO:
+		chain = data[NFT_REG_VERDICT].chain;
+		goto do_chain;
+	case NFT_RETURN:
+		if (unlikely(pkt->skb->nf_trace))
+			nft_trace_packet(pkt, chain, rulenum, NFT_TRACE_RETURN);
+
+		/* fall through */
+	case NFT_CONTINUE:
+		break;
+	default:
+		WARN_ON(1);
+	}
+
+	if (stackptr > 0) {
+		if (unlikely(pkt->skb->nf_trace))
+			nft_trace_packet(pkt, chain, ++rulenum, NFT_TRACE_RETURN);
+
+		stackptr--;
+		chain = jumpstack[stackptr].chain;
+		rule  = jumpstack[stackptr].rule;
+		rulenum = jumpstack[stackptr].rulenum;
+		goto next_rule;
+	}
+	nft_chain_stats(chain, pkt, jumpstack, stackptr);
+
+	if (unlikely(pkt->skb->nf_trace))
+		nft_trace_packet(pkt, chain, ++rulenum, NFT_TRACE_POLICY);
+
+	return nft_base_chain(chain)->policy;
+}
+EXPORT_SYMBOL_GPL(nft_do_chain_pktinfo);
+
+int __init nf_tables_core_module_init(void)
+{
+	int err;
+
+	err = nft_immediate_module_init();
+	if (err < 0)
+		goto err1;
+
+	err = nft_cmp_module_init();
+	if (err < 0)
+		goto err2;
+
+	err = nft_lookup_module_init();
+	if (err < 0)
+		goto err3;
+
+	err = nft_bitwise_module_init();
+	if (err < 0)
+		goto err4;
+
+	err = nft_byteorder_module_init();
+	if (err < 0)
+		goto err5;
+
+	err = nft_payload_module_init();
+	if (err < 0)
+		goto err6;
+
+	return 0;
+
+err6:
+	nft_byteorder_module_exit();
+err5:
+	nft_bitwise_module_exit();
+err4:
+	nft_lookup_module_exit();
+err3:
+	nft_cmp_module_exit();
+err2:
+	nft_immediate_module_exit();
+err1:
+	return err;
+}
+
+void nf_tables_core_module_exit(void)
+{
+	nft_payload_module_exit();
+	nft_byteorder_module_exit();
+	nft_bitwise_module_exit();
+	nft_lookup_module_exit();
+	nft_cmp_module_exit();
+	nft_immediate_module_exit();
+}