From d3d40f237480abf3268956daf18cdc56edd32834 Mon Sep 17 00:00:00 2001 From: Mark Tomlinson Date: Mon, 8 Mar 2021 14:24:12 +1300 Subject: Revert "netfilter: x_tables: Switch synchronization to RCU" This reverts commit cc00bcaa589914096edef7fb87ca5cee4a166b5c. This (and the preceding) patch basically re-implemented the RCU mechanisms of patch 784544739a25. That patch was replaced because of the performance problems that it created when replacing tables. Now, we have the same issue: the call to synchronize_rcu() makes replacing tables slower by as much as an order of magnitude. Prior to using RCU a script calling "iptables" approx. 200 times was taking 1.16s. With RCU this increased to 11.59s. Revert these patches and fix the issue in a different way. Signed-off-by: Mark Tomlinson Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 8ebb64193757..5deb099d156d 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -227,7 +227,7 @@ struct xt_table { unsigned int valid_hooks; /* Man behind the curtain... */ - struct xt_table_info __rcu *private; + struct xt_table_info *private; /* Set this to THIS_MODULE if you are a module, otherwise NULL */ struct module *me; @@ -448,9 +448,6 @@ xt_get_per_cpu_counter(struct xt_counters *cnt, unsigned int cpu) struct nf_hook_ops *xt_hook_ops_alloc(const struct xt_table *, nf_hookfn *); -struct xt_table_info -*xt_table_get_private_protected(const struct xt_table *table); - #ifdef CONFIG_COMPAT #include -- cgit v1.2.3-70-g09d2 From 175e476b8cdf2a4de7432583b49c871345e4f8a1 Mon Sep 17 00:00:00 2001 From: Mark Tomlinson Date: Mon, 8 Mar 2021 14:24:13 +1300 Subject: netfilter: x_tables: Use correct memory barriers. When a new table value was assigned, it was followed by a write memory barrier. This ensured that all writes before this point would complete before any writes after this point. However, to determine whether the rules are unused, the sequence counter is read. To ensure that all writes have been done before these reads, a full memory barrier is needed, not just a write memory barrier. The same argument applies when incrementing the counter, before the rules are read. Changing to using smp_mb() instead of smp_wmb() fixes the kernel panic reported in cc00bcaa5899 (which is still present), while still maintaining the same speed of replacing tables. The smb_mb() barriers potentially slow the packet path, however testing has shown no measurable change in performance on a 4-core MIPS64 platform. Fixes: 7f5c6d4f665b ("netfilter: get rid of atomic ops in fast path") Signed-off-by: Mark Tomlinson Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/x_tables.h | 2 +- net/netfilter/x_tables.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 5deb099d156d..8ec48466410a 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -376,7 +376,7 @@ static inline unsigned int xt_write_recseq_begin(void) * since addend is most likely 1 */ __this_cpu_add(xt_recseq.sequence, addend); - smp_wmb(); + smp_mb(); return addend; } diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 7df3aef39c5c..6bd31a7a27fc 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -1389,7 +1389,7 @@ xt_replace_table(struct xt_table *table, table->private = newinfo; /* make sure all cpus see new ->private value */ - smp_wmb(); + smp_mb(); /* * Even though table entries have now been swapped, other CPU's -- cgit v1.2.3-70-g09d2 From 7b35582cd04ace2fd1807c1b624934e465cc939d Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 17 Mar 2021 12:54:57 +0100 Subject: netfilter: nftables: allow to update flowtable flags Honor flowtable flags from the control update path. Disallow disabling to toggle hardware offload support though. Fixes: 8bb69f3b2918 ("netfilter: nf_tables: add flowtable offload control plane") Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 3 +++ net/netfilter/nf_tables_api.c | 15 +++++++++++++++ 2 files changed, 18 insertions(+) (limited to 'include') diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index fdec57d862b7..5aaced6bf13e 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1536,6 +1536,7 @@ struct nft_trans_flowtable { struct nft_flowtable *flowtable; bool update; struct list_head hook_list; + u32 flags; }; #define nft_trans_flowtable(trans) \ @@ -1544,6 +1545,8 @@ struct nft_trans_flowtable { (((struct nft_trans_flowtable *)trans->data)->update) #define nft_trans_flowtable_hooks(trans) \ (((struct nft_trans_flowtable *)trans->data)->hook_list) +#define nft_trans_flowtable_flags(trans) \ + (((struct nft_trans_flowtable *)trans->data)->flags) int __init nft_chain_filter_init(void); void nft_chain_filter_fini(void); diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 0d034f895b7b..4fcd07f1e925 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -6842,6 +6842,7 @@ static int nft_flowtable_update(struct nft_ctx *ctx, const struct nlmsghdr *nlh, struct nft_hook *hook, *next; struct nft_trans *trans; bool unregister = false; + u32 flags; int err; err = nft_flowtable_parse_hook(ctx, nla[NFTA_FLOWTABLE_HOOK], @@ -6856,6 +6857,17 @@ static int nft_flowtable_update(struct nft_ctx *ctx, const struct nlmsghdr *nlh, } } + if (nla[NFTA_FLOWTABLE_FLAGS]) { + flags = ntohl(nla_get_be32(nla[NFTA_FLOWTABLE_FLAGS])); + if (flags & ~NFT_FLOWTABLE_MASK) + return -EOPNOTSUPP; + if ((flowtable->data.flags & NFT_FLOWTABLE_HW_OFFLOAD) ^ + (flags & NFT_FLOWTABLE_HW_OFFLOAD)) + return -EOPNOTSUPP; + } else { + flags = flowtable->data.flags; + } + err = nft_register_flowtable_net_hooks(ctx->net, ctx->table, &flowtable_hook.list, flowtable); if (err < 0) @@ -6869,6 +6881,7 @@ static int nft_flowtable_update(struct nft_ctx *ctx, const struct nlmsghdr *nlh, goto err_flowtable_update_hook; } + nft_trans_flowtable_flags(trans) = flags; nft_trans_flowtable(trans) = flowtable; nft_trans_flowtable_update(trans) = true; INIT_LIST_HEAD(&nft_trans_flowtable_hooks(trans)); @@ -8178,6 +8191,8 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) break; case NFT_MSG_NEWFLOWTABLE: if (nft_trans_flowtable_update(trans)) { + nft_trans_flowtable(trans)->data.flags = + nft_trans_flowtable_flags(trans); nf_tables_flowtable_notify(&trans->ctx, nft_trans_flowtable(trans), &nft_trans_flowtable_hooks(trans), -- cgit v1.2.3-70-g09d2