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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
- *
- * Development of this code funded by Astaro AG (http://www.astaro.com/)
- */
- #include <linux/kernel.h>
- #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/static_key.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>
- #include <net/netfilter/nft_meta.h>
- static noinline void __nft_trace_packet(struct nft_traceinfo *info,
- const struct nft_chain *chain,
- enum nft_trace_types type)
- {
- const struct nft_pktinfo *pkt = info->pkt;
- if (!info->trace || !pkt->skb->nf_trace)
- return;
- info->chain = chain;
- info->type = type;
- nft_trace_notify(info);
- }
- static inline void nft_trace_packet(struct nft_traceinfo *info,
- const struct nft_chain *chain,
- const struct nft_rule *rule,
- enum nft_trace_types type)
- {
- if (static_branch_unlikely(&nft_trace_enabled)) {
- info->rule = rule;
- __nft_trace_packet(info, chain, type);
- }
- }
- static void nft_bitwise_fast_eval(const struct nft_expr *expr,
- struct nft_regs *regs)
- {
- const struct nft_bitwise_fast_expr *priv = nft_expr_priv(expr);
- u32 *src = ®s->data[priv->sreg];
- u32 *dst = ®s->data[priv->dreg];
- *dst = (*src & priv->mask) ^ priv->xor;
- }
- static void nft_cmp_fast_eval(const struct nft_expr *expr,
- struct nft_regs *regs)
- {
- const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
- if (((regs->data[priv->sreg] & priv->mask) == priv->data) ^ priv->inv)
- return;
- regs->verdict.code = NFT_BREAK;
- }
- static bool nft_payload_fast_eval(const struct nft_expr *expr,
- struct nft_regs *regs,
- const struct nft_pktinfo *pkt)
- {
- const struct nft_payload *priv = nft_expr_priv(expr);
- const struct sk_buff *skb = pkt->skb;
- u32 *dest = ®s->data[priv->dreg];
- unsigned char *ptr;
- if (priv->base == NFT_PAYLOAD_NETWORK_HEADER)
- ptr = skb_network_header(skb);
- else {
- if (!pkt->tprot_set)
- return false;
- ptr = skb_network_header(skb) + pkt->xt.thoff;
- }
- ptr += priv->offset;
- if (unlikely(ptr + priv->len > skb_tail_pointer(skb)))
- return false;
- *dest = 0;
- if (priv->len == 2)
- *(u16 *)dest = *(u16 *)ptr;
- else if (priv->len == 4)
- *(u32 *)dest = *(u32 *)ptr;
- else
- *(u8 *)dest = *(u8 *)ptr;
- return true;
- }
- DEFINE_STATIC_KEY_FALSE(nft_counters_enabled);
- static noinline void nft_update_chain_stats(const struct nft_chain *chain,
- const struct nft_pktinfo *pkt)
- {
- struct nft_base_chain *base_chain;
- struct nft_stats __percpu *pstats;
- struct nft_stats *stats;
- base_chain = nft_base_chain(chain);
- rcu_read_lock();
- pstats = READ_ONCE(base_chain->stats);
- if (pstats) {
- local_bh_disable();
- stats = this_cpu_ptr(pstats);
- u64_stats_update_begin(&stats->syncp);
- stats->pkts++;
- stats->bytes += pkt->skb->len;
- u64_stats_update_end(&stats->syncp);
- local_bh_enable();
- }
- rcu_read_unlock();
- }
- struct nft_jumpstack {
- const struct nft_chain *chain;
- struct nft_rule *const *rules;
- };
- static void expr_call_ops_eval(const struct nft_expr *expr,
- struct nft_regs *regs,
- struct nft_pktinfo *pkt)
- {
- #ifdef CONFIG_RETPOLINE
- unsigned long e = (unsigned long)expr->ops->eval;
- #define X(e, fun) \
- do { if ((e) == (unsigned long)(fun)) \
- return fun(expr, regs, pkt); } while (0)
- X(e, nft_payload_eval);
- X(e, nft_cmp_eval);
- X(e, nft_meta_get_eval);
- X(e, nft_lookup_eval);
- X(e, nft_range_eval);
- X(e, nft_immediate_eval);
- X(e, nft_byteorder_eval);
- X(e, nft_dynset_eval);
- X(e, nft_rt_get_eval);
- X(e, nft_bitwise_eval);
- #undef X
- #endif /* CONFIG_RETPOLINE */
- expr->ops->eval(expr, regs, pkt);
- }
- unsigned int
- nft_do_chain(struct nft_pktinfo *pkt, void *priv)
- {
- const struct nft_chain *chain = priv, *basechain = chain;
- const struct net *net = nft_net(pkt);
- struct nft_rule *const *rules;
- const struct nft_rule *rule;
- const struct nft_expr *expr, *last;
- struct nft_regs regs = {};
- unsigned int stackptr = 0;
- struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE];
- bool genbit = READ_ONCE(net->nft.gencursor);
- struct nft_traceinfo info;
- info.trace = false;
- if (static_branch_unlikely(&nft_trace_enabled))
- nft_trace_init(&info, pkt, ®s.verdict, basechain);
- do_chain:
- if (genbit)
- rules = rcu_dereference(chain->rules_gen_1);
- else
- rules = rcu_dereference(chain->rules_gen_0);
- next_rule:
- rule = *rules;
- regs.verdict.code = NFT_CONTINUE;
- for (; *rules ; rules++) {
- rule = *rules;
- nft_rule_for_each_expr(expr, last, rule) {
- if (expr->ops == &nft_cmp_fast_ops)
- nft_cmp_fast_eval(expr, ®s);
- else if (expr->ops == &nft_bitwise_fast_ops)
- nft_bitwise_fast_eval(expr, ®s);
- else if (expr->ops != &nft_payload_fast_ops ||
- !nft_payload_fast_eval(expr, ®s, pkt))
- expr_call_ops_eval(expr, ®s, pkt);
- if (regs.verdict.code != NFT_CONTINUE)
- break;
- }
- switch (regs.verdict.code) {
- case NFT_BREAK:
- regs.verdict.code = NFT_CONTINUE;
- continue;
- case NFT_CONTINUE:
- nft_trace_packet(&info, chain, rule,
- NFT_TRACETYPE_RULE);
- continue;
- }
- break;
- }
- switch (regs.verdict.code & NF_VERDICT_MASK) {
- case NF_ACCEPT:
- case NF_DROP:
- case NF_QUEUE:
- case NF_STOLEN:
- nft_trace_packet(&info, chain, rule,
- NFT_TRACETYPE_RULE);
- return regs.verdict.code;
- }
- switch (regs.verdict.code) {
- case NFT_JUMP:
- if (WARN_ON_ONCE(stackptr >= NFT_JUMP_STACK_SIZE))
- return NF_DROP;
- jumpstack[stackptr].chain = chain;
- jumpstack[stackptr].rules = rules + 1;
- stackptr++;
- fallthrough;
- case NFT_GOTO:
- nft_trace_packet(&info, chain, rule,
- NFT_TRACETYPE_RULE);
- chain = regs.verdict.chain;
- goto do_chain;
- case NFT_CONTINUE:
- case NFT_RETURN:
- nft_trace_packet(&info, chain, rule,
- NFT_TRACETYPE_RETURN);
- break;
- default:
- WARN_ON(1);
- }
- if (stackptr > 0) {
- stackptr--;
- chain = jumpstack[stackptr].chain;
- rules = jumpstack[stackptr].rules;
- goto next_rule;
- }
- nft_trace_packet(&info, basechain, NULL, NFT_TRACETYPE_POLICY);
- if (static_branch_unlikely(&nft_counters_enabled))
- nft_update_chain_stats(basechain, pkt);
- return nft_base_chain(basechain)->policy;
- }
- EXPORT_SYMBOL_GPL(nft_do_chain);
- static struct nft_expr_type *nft_basic_types[] = {
- &nft_imm_type,
- &nft_cmp_type,
- &nft_lookup_type,
- &nft_bitwise_type,
- &nft_byteorder_type,
- &nft_payload_type,
- &nft_dynset_type,
- &nft_range_type,
- &nft_meta_type,
- &nft_rt_type,
- &nft_exthdr_type,
- };
- static struct nft_object_type *nft_basic_objects[] = {
- #ifdef CONFIG_NETWORK_SECMARK
- &nft_secmark_obj_type,
- #endif
- };
- int __init nf_tables_core_module_init(void)
- {
- int err, i, j = 0;
- for (i = 0; i < ARRAY_SIZE(nft_basic_objects); i++) {
- err = nft_register_obj(nft_basic_objects[i]);
- if (err)
- goto err;
- }
- for (j = 0; j < ARRAY_SIZE(nft_basic_types); j++) {
- err = nft_register_expr(nft_basic_types[j]);
- if (err)
- goto err;
- }
- return 0;
- err:
- while (j-- > 0)
- nft_unregister_expr(nft_basic_types[j]);
- while (i-- > 0)
- nft_unregister_obj(nft_basic_objects[i]);
- return err;
- }
- void nf_tables_core_module_exit(void)
- {
- int i;
- i = ARRAY_SIZE(nft_basic_types);
- while (i-- > 0)
- nft_unregister_expr(nft_basic_types[i]);
- i = ARRAY_SIZE(nft_basic_objects);
- while (i-- > 0)
- nft_unregister_obj(nft_basic_objects[i]);
- }
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