| /* |
| * 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/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> |
| |
| 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_cmp_fast_eval(const struct nft_expr *expr, |
| struct nft_regs *regs) |
| { |
| const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr); |
| u32 mask = nft_cmp_fast_mask(priv->len); |
| |
| if ((regs->data[priv->sreg] & mask) == priv->data) |
| 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_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++; |
| /* fall through */ |
| 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]); |
| } |