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https://github.com/torvalds/linux
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fa23e0d4b7
Sven Auhagen reports transaction failures with following error: ./main.nft:13:1-26: Error: Could not process rule: Cannot allocate memory percpu: allocation failed, size=16 align=8 atomic=1, atomic alloc failed, no space left This points to failing pcpu allocation with GFP_ATOMIC flag. However, transactions happen from user context and are allowed to sleep. One case where we can call into percpu allocator with GFP_ATOMIC is nft_counter expression. Normally this happens from control plane, so this could use GFP_KERNEL instead. But one use case, element insertion from packet path, needs to use GFP_ATOMIC allocations (nft_dynset expression). At this time, .clone callbacks always use GFP_ATOMIC for this reason. Add gfp_t argument to the .clone function and pass GFP_KERNEL or GFP_ATOMIC flag depending on context, this allows all clone memory allocations to sleep for the normal (transaction) case. Cc: Sven Auhagen <sven.auhagen@voleatech.de> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
139 lines
3.2 KiB
C
139 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.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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struct nft_last {
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unsigned long jiffies;
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unsigned int set;
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};
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struct nft_last_priv {
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struct nft_last *last;
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};
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static const struct nla_policy nft_last_policy[NFTA_LAST_MAX + 1] = {
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[NFTA_LAST_SET] = { .type = NLA_U32 },
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[NFTA_LAST_MSECS] = { .type = NLA_U64 },
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};
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static int nft_last_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_last_priv *priv = nft_expr_priv(expr);
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struct nft_last *last;
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u64 last_jiffies;
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int err;
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last = kzalloc(sizeof(*last), GFP_KERNEL_ACCOUNT);
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if (!last)
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return -ENOMEM;
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if (tb[NFTA_LAST_SET])
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last->set = ntohl(nla_get_be32(tb[NFTA_LAST_SET]));
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if (last->set && tb[NFTA_LAST_MSECS]) {
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err = nf_msecs_to_jiffies64(tb[NFTA_LAST_MSECS], &last_jiffies);
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if (err < 0)
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goto err;
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last->jiffies = jiffies - (unsigned long)last_jiffies;
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}
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priv->last = last;
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return 0;
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err:
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kfree(last);
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return err;
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}
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static void nft_last_eval(const struct nft_expr *expr,
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struct nft_regs *regs, const struct nft_pktinfo *pkt)
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{
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struct nft_last_priv *priv = nft_expr_priv(expr);
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struct nft_last *last = priv->last;
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if (READ_ONCE(last->jiffies) != jiffies)
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WRITE_ONCE(last->jiffies, jiffies);
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if (READ_ONCE(last->set) == 0)
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WRITE_ONCE(last->set, 1);
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}
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static int nft_last_dump(struct sk_buff *skb,
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const struct nft_expr *expr, bool reset)
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{
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struct nft_last_priv *priv = nft_expr_priv(expr);
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struct nft_last *last = priv->last;
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unsigned long last_jiffies = READ_ONCE(last->jiffies);
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u32 last_set = READ_ONCE(last->set);
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__be64 msecs;
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if (time_before(jiffies, last_jiffies)) {
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WRITE_ONCE(last->set, 0);
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last_set = 0;
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}
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if (last_set)
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msecs = nf_jiffies64_to_msecs(jiffies - last_jiffies);
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else
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msecs = 0;
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if (nla_put_be32(skb, NFTA_LAST_SET, htonl(last_set)) ||
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nla_put_be64(skb, NFTA_LAST_MSECS, msecs, NFTA_LAST_PAD))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static void nft_last_destroy(const struct nft_ctx *ctx,
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const struct nft_expr *expr)
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{
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struct nft_last_priv *priv = nft_expr_priv(expr);
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kfree(priv->last);
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}
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static int nft_last_clone(struct nft_expr *dst, const struct nft_expr *src, gfp_t gfp)
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{
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struct nft_last_priv *priv_dst = nft_expr_priv(dst);
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struct nft_last_priv *priv_src = nft_expr_priv(src);
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priv_dst->last = kzalloc(sizeof(*priv_dst->last), gfp);
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if (!priv_dst->last)
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return -ENOMEM;
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priv_dst->last->set = priv_src->last->set;
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priv_dst->last->jiffies = priv_src->last->jiffies;
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return 0;
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}
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static const struct nft_expr_ops nft_last_ops = {
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.type = &nft_last_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_last_priv)),
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.eval = nft_last_eval,
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.init = nft_last_init,
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.destroy = nft_last_destroy,
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.clone = nft_last_clone,
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.dump = nft_last_dump,
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.reduce = NFT_REDUCE_READONLY,
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};
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struct nft_expr_type nft_last_type __read_mostly = {
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.name = "last",
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.ops = &nft_last_ops,
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.policy = nft_last_policy,
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.maxattr = NFTA_LAST_MAX,
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.flags = NFT_EXPR_STATEFUL,
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.owner = THIS_MODULE,
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};
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