mirror of
https://github.com/torvalds/linux
synced 2024-09-19 18:46:35 +00:00
a9f5e78c40
Check the result of dereferencing base_chain->stats, instead of result
of this_cpu_ptr with NULL.
base_chain->stats maybe be changed to NULL when a chain is updated and a
new NULL counter can be attached.
And we do not need to check returning of this_cpu_ptr since
base_chain->stats is from percpu allocator if it is non-NULL,
this_cpu_ptr returns a valid value.
And fix two sparse error by replacing rcu_access_pointer and
rcu_dereference with READ_ONCE under rcu_read_lock.
Thanks for Eric's help to finish this patch.
Fixes: 009240940e
("netfilter: nf_tables: don't assume chain stats are set when jumplabel is set")
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
310 lines
7.1 KiB
C
310 lines
7.1 KiB
C
/*
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* Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
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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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* Development of this code funded by Astaro AG (http://www.astaro.com/)
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/rculist.h>
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#include <linux/skbuff.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/static_key.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 <net/netfilter/nf_tables_core.h>
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#include <net/netfilter/nf_tables.h>
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#include <net/netfilter/nf_log.h>
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static noinline void __nft_trace_packet(struct nft_traceinfo *info,
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const struct nft_chain *chain,
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enum nft_trace_types type)
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{
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const struct nft_pktinfo *pkt = info->pkt;
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if (!info->trace || !pkt->skb->nf_trace)
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return;
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info->chain = chain;
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info->type = type;
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nft_trace_notify(info);
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}
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static inline void nft_trace_packet(struct nft_traceinfo *info,
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const struct nft_chain *chain,
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const struct nft_rule *rule,
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enum nft_trace_types type)
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{
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if (static_branch_unlikely(&nft_trace_enabled)) {
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info->rule = rule;
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__nft_trace_packet(info, chain, type);
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}
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}
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static void nft_cmp_fast_eval(const struct nft_expr *expr,
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struct nft_regs *regs)
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{
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const struct nft_cmp_fast_expr *priv = nft_expr_priv(expr);
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u32 mask = nft_cmp_fast_mask(priv->len);
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if ((regs->data[priv->sreg] & mask) == priv->data)
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return;
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regs->verdict.code = NFT_BREAK;
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}
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static bool nft_payload_fast_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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const struct nft_payload *priv = nft_expr_priv(expr);
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const struct sk_buff *skb = pkt->skb;
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u32 *dest = ®s->data[priv->dreg];
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unsigned char *ptr;
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if (priv->base == NFT_PAYLOAD_NETWORK_HEADER)
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ptr = skb_network_header(skb);
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else {
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if (!pkt->tprot_set)
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return false;
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ptr = skb_network_header(skb) + pkt->xt.thoff;
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}
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ptr += priv->offset;
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if (unlikely(ptr + priv->len > skb_tail_pointer(skb)))
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return false;
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*dest = 0;
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if (priv->len == 2)
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*(u16 *)dest = *(u16 *)ptr;
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else if (priv->len == 4)
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*(u32 *)dest = *(u32 *)ptr;
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else
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*(u8 *)dest = *(u8 *)ptr;
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return true;
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}
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DEFINE_STATIC_KEY_FALSE(nft_counters_enabled);
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static noinline void nft_update_chain_stats(const struct nft_chain *chain,
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const struct nft_pktinfo *pkt)
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{
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struct nft_base_chain *base_chain;
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struct nft_stats __percpu *pstats;
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struct nft_stats *stats;
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base_chain = nft_base_chain(chain);
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rcu_read_lock();
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pstats = READ_ONCE(base_chain->stats);
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if (pstats) {
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local_bh_disable();
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stats = this_cpu_ptr(pstats);
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u64_stats_update_begin(&stats->syncp);
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stats->pkts++;
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stats->bytes += pkt->skb->len;
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u64_stats_update_end(&stats->syncp);
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local_bh_enable();
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}
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rcu_read_unlock();
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}
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struct nft_jumpstack {
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const struct nft_chain *chain;
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struct nft_rule *const *rules;
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};
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static void expr_call_ops_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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struct nft_pktinfo *pkt)
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{
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#ifdef CONFIG_RETPOLINE
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unsigned long e = (unsigned long)expr->ops->eval;
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#define X(e, fun) \
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do { if ((e) == (unsigned long)(fun)) \
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return fun(expr, regs, pkt); } while (0)
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X(e, nft_payload_eval);
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X(e, nft_cmp_eval);
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X(e, nft_meta_get_eval);
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X(e, nft_lookup_eval);
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X(e, nft_range_eval);
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X(e, nft_immediate_eval);
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X(e, nft_byteorder_eval);
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X(e, nft_dynset_eval);
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X(e, nft_rt_get_eval);
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X(e, nft_bitwise_eval);
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#undef X
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#endif /* CONFIG_RETPOLINE */
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expr->ops->eval(expr, regs, pkt);
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}
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unsigned int
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nft_do_chain(struct nft_pktinfo *pkt, void *priv)
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{
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const struct nft_chain *chain = priv, *basechain = chain;
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const struct net *net = nft_net(pkt);
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struct nft_rule *const *rules;
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const struct nft_rule *rule;
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const struct nft_expr *expr, *last;
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struct nft_regs regs;
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unsigned int stackptr = 0;
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struct nft_jumpstack jumpstack[NFT_JUMP_STACK_SIZE];
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bool genbit = READ_ONCE(net->nft.gencursor);
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struct nft_traceinfo info;
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info.trace = false;
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if (static_branch_unlikely(&nft_trace_enabled))
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nft_trace_init(&info, pkt, ®s.verdict, basechain);
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do_chain:
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if (genbit)
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rules = rcu_dereference(chain->rules_gen_1);
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else
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rules = rcu_dereference(chain->rules_gen_0);
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next_rule:
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rule = *rules;
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regs.verdict.code = NFT_CONTINUE;
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for (; *rules ; rules++) {
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rule = *rules;
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nft_rule_for_each_expr(expr, last, rule) {
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if (expr->ops == &nft_cmp_fast_ops)
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nft_cmp_fast_eval(expr, ®s);
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else if (expr->ops != &nft_payload_fast_ops ||
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!nft_payload_fast_eval(expr, ®s, pkt))
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expr_call_ops_eval(expr, ®s, pkt);
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if (regs.verdict.code != NFT_CONTINUE)
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break;
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}
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switch (regs.verdict.code) {
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case NFT_BREAK:
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regs.verdict.code = NFT_CONTINUE;
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continue;
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case NFT_CONTINUE:
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nft_trace_packet(&info, chain, rule,
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NFT_TRACETYPE_RULE);
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continue;
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}
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break;
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}
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switch (regs.verdict.code & NF_VERDICT_MASK) {
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case NF_ACCEPT:
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case NF_DROP:
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case NF_QUEUE:
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case NF_STOLEN:
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nft_trace_packet(&info, chain, rule,
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NFT_TRACETYPE_RULE);
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return regs.verdict.code;
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}
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switch (regs.verdict.code) {
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case NFT_JUMP:
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if (WARN_ON_ONCE(stackptr >= NFT_JUMP_STACK_SIZE))
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return NF_DROP;
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jumpstack[stackptr].chain = chain;
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jumpstack[stackptr].rules = rules + 1;
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stackptr++;
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/* fall through */
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case NFT_GOTO:
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nft_trace_packet(&info, chain, rule,
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NFT_TRACETYPE_RULE);
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chain = regs.verdict.chain;
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goto do_chain;
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case NFT_CONTINUE:
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case NFT_RETURN:
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nft_trace_packet(&info, chain, rule,
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NFT_TRACETYPE_RETURN);
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break;
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default:
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WARN_ON(1);
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}
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if (stackptr > 0) {
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stackptr--;
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chain = jumpstack[stackptr].chain;
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rules = jumpstack[stackptr].rules;
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goto next_rule;
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}
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nft_trace_packet(&info, basechain, NULL, NFT_TRACETYPE_POLICY);
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if (static_branch_unlikely(&nft_counters_enabled))
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nft_update_chain_stats(basechain, pkt);
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return nft_base_chain(basechain)->policy;
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}
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EXPORT_SYMBOL_GPL(nft_do_chain);
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static struct nft_expr_type *nft_basic_types[] = {
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&nft_imm_type,
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&nft_cmp_type,
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&nft_lookup_type,
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&nft_bitwise_type,
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&nft_byteorder_type,
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&nft_payload_type,
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&nft_dynset_type,
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&nft_range_type,
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&nft_meta_type,
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&nft_rt_type,
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&nft_exthdr_type,
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};
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static struct nft_object_type *nft_basic_objects[] = {
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#ifdef CONFIG_NETWORK_SECMARK
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&nft_secmark_obj_type,
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#endif
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};
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int __init nf_tables_core_module_init(void)
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{
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int err, i, j = 0;
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for (i = 0; i < ARRAY_SIZE(nft_basic_objects); i++) {
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err = nft_register_obj(nft_basic_objects[i]);
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if (err)
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goto err;
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}
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for (j = 0; j < ARRAY_SIZE(nft_basic_types); j++) {
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err = nft_register_expr(nft_basic_types[j]);
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if (err)
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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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while (j-- > 0)
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nft_unregister_expr(nft_basic_types[j]);
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while (i-- > 0)
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nft_unregister_obj(nft_basic_objects[i]);
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return err;
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}
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void nf_tables_core_module_exit(void)
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{
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int i;
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i = ARRAY_SIZE(nft_basic_types);
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while (i-- > 0)
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nft_unregister_expr(nft_basic_types[i]);
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i = ARRAY_SIZE(nft_basic_objects);
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while (i-- > 0)
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nft_unregister_obj(nft_basic_objects[i]);
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}
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