[PATCH 4.9.y v2] netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable" hash to rhashtable"

[PATCH 4.9.y v2] netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable" hash to rhashtable"

[Florian Westphal]

commit e1bf1687740ce1a3598a1c5e452b852ff2190682 upstream.

This reverts commit 870190a9ec9075205c0fa795a09fa931694a3ff1.

It was not a good idea. The custom hash table was a much better
fit for this purpose.

A fast lookup is not essential, in fact for most cases there is no lookup
at all because original tuple is not taken and can be used as-is.
What needs to be fast is insertion and deletion.

rhlist removal however requires a rhlist walk.
We can have thousands of entries in such a list if source port/addresses
are reused for multiple flows, if this happens removal requests are so
expensive that deletions of a few thousand flows can take several
seconds(!).

The advantages that we got from rhashtable are:
1) table auto-sizing
2) multiple locks

1) would be nice to have, but it is not essential as we have at
most one lookup per new flow, so even a million flows in the bysource
table are not a problem compared to current deletion cost.
2) is easy to add to custom hash table.

I tried to add hlist_node to rhlist to speed up rhltable_remove but this
isn't doable without changing semantics.  rhltable_remove_fast will
check that the to-be-deleted object is part of the table and that
requires a list walk that we want to avoid.

Furthermore, using hlist_node increases size of struct rhlist_head, which
in turn increases nf_conn size.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196821
Reported-by: Ivan Babrou <ibobrik@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 Hi Greg,

 this is a 4.9.y backport of the same revert that already went into 4.13.y;
 please consider applying this.

 Note: you need to 'git cherry-pick 6e699867f84c0f358fed233fe6162173aca28e04'
 first, else this won't apply (and cause crash if newly allocated conntrack is
 dropped right away).

 include/net/netfilter/nf_conntrack.h |   3 +-
 include/net/netfilter/nf_nat.h       |   1 -
 net/netfilter/nf_nat_core.c          | 134 +++++++++++++++--------------------
 3 files changed, 57 insertions(+), 81 deletions(-)

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index d9d52c020a70..9ae819e27940 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -17,7 +17,6 @@
 #include <linux/bitops.h>
 #include <linux/compiler.h>
 #include <linux/atomic.h>
-#include <linux/rhashtable.h>
 
 #include <linux/netfilter/nf_conntrack_tcp.h>
 #include <linux/netfilter/nf_conntrack_dccp.h>
@@ -101,7 +100,7 @@ struct nf_conn {
 	possible_net_t ct_net;
 
 #if IS_ENABLED(CONFIG_NF_NAT)
-	struct rhlist_head nat_bysource;
+	struct hlist_node	nat_bysource;
 #endif
 	/* all members below initialized via memset */
 	u8 __nfct_init_offset[0];
diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h
index c327a431a6f3..02515f7ed4cc 100644
--- a/include/net/netfilter/nf_nat.h
+++ b/include/net/netfilter/nf_nat.h
@@ -1,6 +1,5 @@
 #ifndef _NF_NAT_H
 #define _NF_NAT_H
-#include <linux/rhashtable.h>
 #include <linux/netfilter_ipv4.h>
 #include <linux/netfilter/nf_nat.h>
 #include <net/netfilter/nf_conntrack_tuple.h>
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index e9fcb58d4eba..624d6e4dcd5c 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -30,19 +30,17 @@
 #include <net/netfilter/nf_conntrack_zones.h>
 #include <linux/netfilter/nf_nat.h>
 
+static DEFINE_SPINLOCK(nf_nat_lock);
+
 static DEFINE_MUTEX(nf_nat_proto_mutex);
 static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
 						__read_mostly;
 static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
 						__read_mostly;
 
-struct nf_nat_conn_key {
-	const struct net *net;
-	const struct nf_conntrack_tuple *tuple;
-	const struct nf_conntrack_zone *zone;
-};
-
-static struct rhltable nf_nat_bysource_table;
+static struct hlist_head *nf_nat_bysource __read_mostly;
+static unsigned int nf_nat_htable_size __read_mostly;
+static unsigned int nf_nat_hash_rnd __read_mostly;
 
 inline const struct nf_nat_l3proto *
 __nf_nat_l3proto_find(u8 family)
@@ -121,17 +119,19 @@ int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
 EXPORT_SYMBOL(nf_xfrm_me_harder);
 #endif /* CONFIG_XFRM */
 
-static u32 nf_nat_bysource_hash(const void *data, u32 len, u32 seed)
+/* We keep an extra hash for each conntrack, for fast searching. */
+static inline unsigned int
+hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
 {
-	const struct nf_conntrack_tuple *t;
-	const struct nf_conn *ct = data;
+	unsigned int hash;
+
+	get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
 
-	t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
 	/* Original src, to ensure we map it consistently if poss. */
+	hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
+		      tuple->dst.protonum ^ nf_nat_hash_rnd ^ net_hash_mix(n));
 
-	seed ^= net_hash_mix(nf_ct_net(ct));
-	return jhash2((const u32 *)&t->src, sizeof(t->src) / sizeof(u32),
-		      t->dst.protonum ^ seed);
+	return reciprocal_scale(hash, nf_nat_htable_size);
 }
 
 /* Is this tuple already taken? (not by us) */
@@ -187,28 +187,6 @@ same_src(const struct nf_conn *ct,
 		t->src.u.all == tuple->src.u.all);
 }
 
-static int nf_nat_bysource_cmp(struct rhashtable_compare_arg *arg,
-			       const void *obj)
-{
-	const struct nf_nat_conn_key *key = arg->key;
-	const struct nf_conn *ct = obj;
-
-	if (!same_src(ct, key->tuple) ||
-	    !net_eq(nf_ct_net(ct), key->net) ||
-	    !nf_ct_zone_equal(ct, key->zone, IP_CT_DIR_ORIGINAL))
-		return 1;
-
-	return 0;
-}
-
-static struct rhashtable_params nf_nat_bysource_params = {
-	.head_offset = offsetof(struct nf_conn, nat_bysource),
-	.obj_hashfn = nf_nat_bysource_hash,
-	.obj_cmpfn = nf_nat_bysource_cmp,
-	.nelem_hint = 256,
-	.min_size = 1024,
-};
-
 /* Only called for SRC manip */
 static int
 find_appropriate_src(struct net *net,
@@ -219,26 +197,22 @@ find_appropriate_src(struct net *net,
 		     struct nf_conntrack_tuple *result,
 		     const struct nf_nat_range *range)
 {
+	unsigned int h = hash_by_src(net, tuple);
 	const struct nf_conn *ct;
-	struct nf_nat_conn_key key = {
-		.net = net,
-		.tuple = tuple,
-		.zone = zone
-	};
-	struct rhlist_head *hl, *h;
-
-	hl = rhltable_lookup(&nf_nat_bysource_table, &key,
-			     nf_nat_bysource_params);
 
-	rhl_for_each_entry_rcu(ct, h, hl, nat_bysource) {
-		nf_ct_invert_tuplepr(result,
-				     &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
-		result->dst = tuple->dst;
-
-		if (in_range(l3proto, l4proto, result, range))
-			return 1;
+	hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) {
+		if (same_src(ct, tuple) &&
+		    net_eq(net, nf_ct_net(ct)) &&
+		    nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
+			/* Copy source part from reply tuple. */
+			nf_ct_invert_tuplepr(result,
+				       &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+			result->dst = tuple->dst;
+
+			if (in_range(l3proto, l4proto, result, range))
+				return 1;
+		}
 	}
-
 	return 0;
 }
 
@@ -411,6 +385,7 @@ nf_nat_setup_info(struct nf_conn *ct,
 		  const struct nf_nat_range *range,
 		  enum nf_nat_manip_type maniptype)
 {
+	struct net *net = nf_ct_net(ct);
 	struct nf_conntrack_tuple curr_tuple, new_tuple;
 	struct nf_conn_nat *nat;
 
@@ -452,19 +427,16 @@ nf_nat_setup_info(struct nf_conn *ct,
 	}
 
 	if (maniptype == NF_NAT_MANIP_SRC) {
-		struct nf_nat_conn_key key = {
-			.net = nf_ct_net(ct),
-			.tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
-			.zone = nf_ct_zone(ct),
-		};
-		int err;
-
-		err = rhltable_insert_key(&nf_nat_bysource_table,
-					  &key,
-					  &ct->nat_bysource,
-					  nf_nat_bysource_params);
-		if (err)
-			return NF_DROP;
+		unsigned int srchash;
+
+		srchash = hash_by_src(net,
+				      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+		spin_lock_bh(&nf_nat_lock);
+		/* nf_conntrack_alter_reply might re-allocate extension aera */
+		nat = nfct_nat(ct);
+		hlist_add_head_rcu(&ct->nat_bysource,
+				   &nf_nat_bysource[srchash]);
+		spin_unlock_bh(&nf_nat_lock);
 	}
 
 	/* It's done. */
@@ -572,9 +544,10 @@ static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
 	 * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
 	 * will delete entry from already-freed table.
 	 */
+	spin_lock_bh(&nf_nat_lock);
+	hlist_del_rcu(&ct->nat_bysource);
 	ct->status &= ~IPS_NAT_DONE_MASK;
-	rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
-			nf_nat_bysource_params);
+	spin_unlock_bh(&nf_nat_lock);
 
 	/* don't delete conntrack.  Although that would make things a lot
 	 * simpler, we'd end up flushing all conntracks on nat rmmod.
@@ -699,9 +672,11 @@ EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
 /* No one using conntrack by the time this called. */
 static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
 {
-	if (ct->status & IPS_SRC_NAT_DONE)
-		rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
-				nf_nat_bysource_params);
+	if (ct->status & IPS_SRC_NAT_DONE) {
+		spin_lock_bh(&nf_nat_lock);
+		hlist_del_rcu(&ct->nat_bysource);
+		spin_unlock_bh(&nf_nat_lock);
+	}
 }
 
 static struct nf_ct_ext_type nat_extend __read_mostly = {
@@ -836,13 +811,16 @@ static int __init nf_nat_init(void)
 {
 	int ret;
 
-	ret = rhltable_init(&nf_nat_bysource_table, &nf_nat_bysource_params);
-	if (ret)
-		return ret;
+	/* Leave them the same for the moment. */
+	nf_nat_htable_size = nf_conntrack_htable_size;
+
+	nf_nat_bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size, 0);
+	if (!nf_nat_bysource)
+		return -ENOMEM;
 
 	ret = nf_ct_extend_register(&nat_extend);
 	if (ret < 0) {
-		rhltable_destroy(&nf_nat_bysource_table);
+		nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
 		printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
 		return ret;
 	}
@@ -866,7 +844,7 @@ static int __init nf_nat_init(void)
 	return 0;
 
  cleanup_extend:
-	rhltable_destroy(&nf_nat_bysource_table);
+	nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
 	nf_ct_extend_unregister(&nat_extend);
 	return ret;
 }
@@ -886,8 +864,8 @@ static void __exit nf_nat_cleanup(void)
 
 	for (i = 0; i < NFPROTO_NUMPROTO; i++)
 		kfree(nf_nat_l4protos[i]);
-
-	rhltable_destroy(&nf_nat_bysource_table);
+	synchronize_net();
+	nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
 }
 
 MODULE_LICENSE("GPL");
-- 
2.13.6

Re: [PATCH 4.9.y v2] netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable" hash to rhashtable"

[Sebastian Gottschall]

your patch is not clean

patching file net/netfilter/nf_nat_core.c
Hunk #7 succeeded at 550 (offset 6 lines).
Hunk #8 FAILED at 672.
Hunk #9 succeeded at 819 (offset 10 lines).
Hunk #10 succeeded at 852 (offset 10 lines).
Hunk #11 succeeded at 872 (offset 10 lines).

nf_nat_cleanup_conntrack is wrong

your patch

@@ -672,9 +645,11 @@ EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
  /* No one using conntrack by the time this called. */
  static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
  {
-       if (ct->status & IPS_SRC_NAT_DONE)
-               rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
-                               nf_nat_bysource_params);
+       if (ct->status & IPS_SRC_NAT_DONE) {
+               spin_lock_bh(&nf_nat_lock);
+               hlist_del_rcu(&ct->nat_bysource);
+               spin_unlock_bh(&nf_nat_lock);
+       }
  }



original function

/* No one using conntrack by the time this called. */
static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
{
         struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT);

         if (!nat)
                 return;

         rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
                         nf_nat_bysource_params);
}



Am 15.11.2017 um 11:15 schrieb Florian Westphal:
> commit e1bf1687740ce1a3598a1c5e452b852ff2190682 upstream.
>
> This reverts commit 870190a9ec9075205c0fa795a09fa931694a3ff1.
>
> It was not a good idea. The custom hash table was a much better
> fit for this purpose.
>
> A fast lookup is not essential, in fact for most cases there is no lookup
> at all because original tuple is not taken and can be used as-is.
> What needs to be fast is insertion and deletion.
>
> rhlist removal however requires a rhlist walk.
> We can have thousands of entries in such a list if source port/addresses
> are reused for multiple flows, if this happens removal requests are so
> expensive that deletions of a few thousand flows can take several
> seconds(!).
>
> The advantages that we got from rhashtable are:
> 1) table auto-sizing
> 2) multiple locks
>
> 1) would be nice to have, but it is not essential as we have at
> most one lookup per new flow, so even a million flows in the bysource
> table are not a problem compared to current deletion cost.
> 2) is easy to add to custom hash table.
>
> I tried to add hlist_node to rhlist to speed up rhltable_remove but this
> isn't doable without changing semantics.  rhltable_remove_fast will
> check that the to-be-deleted object is part of the table and that
> requires a list walk that we want to avoid.
>
> Furthermore, using hlist_node increases size of struct rhlist_head, which
> in turn increases nf_conn size.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=196821
> Reported-by: Ivan Babrou <ibobrik@gmail.com>
> Signed-off-by: Florian Westphal <fw@strlen.de>
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> ---
>   Hi Greg,
>
>   this is a 4.9.y backport of the same revert that already went into 4.13.y;
>   please consider applying this.
>
>   Note: you need to 'git cherry-pick 6e699867f84c0f358fed233fe6162173aca28e04'
>   first, else this won't apply (and cause crash if newly allocated conntrack is
>   dropped right away).
>
>   include/net/netfilter/nf_conntrack.h |   3 +-
>   include/net/netfilter/nf_nat.h       |   1 -
>   net/netfilter/nf_nat_core.c          | 134 +++++++++++++++--------------------
>   3 files changed, 57 insertions(+), 81 deletions(-)
>
> diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
> index d9d52c020a70..9ae819e27940 100644
> --- a/include/net/netfilter/nf_conntrack.h
> +++ b/include/net/netfilter/nf_conntrack.h
> @@ -17,7 +17,6 @@
>   #include <linux/bitops.h>
>   #include <linux/compiler.h>
>   #include <linux/atomic.h>
> -#include <linux/rhashtable.h>
>   
>   #include <linux/netfilter/nf_conntrack_tcp.h>
>   #include <linux/netfilter/nf_conntrack_dccp.h>
> @@ -101,7 +100,7 @@ struct nf_conn {
>   	possible_net_t ct_net;
>   
>   #if IS_ENABLED(CONFIG_NF_NAT)
> -	struct rhlist_head nat_bysource;
> +	struct hlist_node	nat_bysource;
>   #endif
>   	/* all members below initialized via memset */
>   	u8 __nfct_init_offset[0];
> diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h
> index c327a431a6f3..02515f7ed4cc 100644
> --- a/include/net/netfilter/nf_nat.h
> +++ b/include/net/netfilter/nf_nat.h
> @@ -1,6 +1,5 @@
>   #ifndef _NF_NAT_H
>   #define _NF_NAT_H
> -#include <linux/rhashtable.h>
>   #include <linux/netfilter_ipv4.h>
>   #include <linux/netfilter/nf_nat.h>
>   #include <net/netfilter/nf_conntrack_tuple.h>
> diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
> index e9fcb58d4eba..624d6e4dcd5c 100644
> --- a/net/netfilter/nf_nat_core.c
> +++ b/net/netfilter/nf_nat_core.c
> @@ -30,19 +30,17 @@
>   #include <net/netfilter/nf_conntrack_zones.h>
>   #include <linux/netfilter/nf_nat.h>
>   
> +static DEFINE_SPINLOCK(nf_nat_lock);
> +
>   static DEFINE_MUTEX(nf_nat_proto_mutex);
>   static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
>   						__read_mostly;
>   static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
>   						__read_mostly;
>   
> -struct nf_nat_conn_key {
> -	const struct net *net;
> -	const struct nf_conntrack_tuple *tuple;
> -	const struct nf_conntrack_zone *zone;
> -};
> -
> -static struct rhltable nf_nat_bysource_table;
> +static struct hlist_head *nf_nat_bysource __read_mostly;
> +static unsigned int nf_nat_htable_size __read_mostly;
> +static unsigned int nf_nat_hash_rnd __read_mostly;
>   
>   inline const struct nf_nat_l3proto *
>   __nf_nat_l3proto_find(u8 family)
> @@ -121,17 +119,19 @@ int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
>   EXPORT_SYMBOL(nf_xfrm_me_harder);
>   #endif /* CONFIG_XFRM */
>   
> -static u32 nf_nat_bysource_hash(const void *data, u32 len, u32 seed)
> +/* We keep an extra hash for each conntrack, for fast searching. */
> +static inline unsigned int
> +hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
>   {
> -	const struct nf_conntrack_tuple *t;
> -	const struct nf_conn *ct = data;
> +	unsigned int hash;
> +
> +	get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
>   
> -	t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
>   	/* Original src, to ensure we map it consistently if poss. */
> +	hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
> +		      tuple->dst.protonum ^ nf_nat_hash_rnd ^ net_hash_mix(n));
>   
> -	seed ^= net_hash_mix(nf_ct_net(ct));
> -	return jhash2((const u32 *)&t->src, sizeof(t->src) / sizeof(u32),
> -		      t->dst.protonum ^ seed);
> +	return reciprocal_scale(hash, nf_nat_htable_size);
>   }
>   
>   /* Is this tuple already taken? (not by us) */
> @@ -187,28 +187,6 @@ same_src(const struct nf_conn *ct,
>   		t->src.u.all == tuple->src.u.all);
>   }
>   
> -static int nf_nat_bysource_cmp(struct rhashtable_compare_arg *arg,
> -			       const void *obj)
> -{
> -	const struct nf_nat_conn_key *key = arg->key;
> -	const struct nf_conn *ct = obj;
> -
> -	if (!same_src(ct, key->tuple) ||
> -	    !net_eq(nf_ct_net(ct), key->net) ||
> -	    !nf_ct_zone_equal(ct, key->zone, IP_CT_DIR_ORIGINAL))
> -		return 1;
> -
> -	return 0;
> -}
> -
> -static struct rhashtable_params nf_nat_bysource_params = {
> -	.head_offset = offsetof(struct nf_conn, nat_bysource),
> -	.obj_hashfn = nf_nat_bysource_hash,
> -	.obj_cmpfn = nf_nat_bysource_cmp,
> -	.nelem_hint = 256,
> -	.min_size = 1024,
> -};
> -
>   /* Only called for SRC manip */
>   static int
>   find_appropriate_src(struct net *net,
> @@ -219,26 +197,22 @@ find_appropriate_src(struct net *net,
>   		     struct nf_conntrack_tuple *result,
>   		     const struct nf_nat_range *range)
>   {
> +	unsigned int h = hash_by_src(net, tuple);
>   	const struct nf_conn *ct;
> -	struct nf_nat_conn_key key = {
> -		.net = net,
> -		.tuple = tuple,
> -		.zone = zone
> -	};
> -	struct rhlist_head *hl, *h;
> -
> -	hl = rhltable_lookup(&nf_nat_bysource_table, &key,
> -			     nf_nat_bysource_params);
>   
> -	rhl_for_each_entry_rcu(ct, h, hl, nat_bysource) {
> -		nf_ct_invert_tuplepr(result,
> -				     &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
> -		result->dst = tuple->dst;
> -
> -		if (in_range(l3proto, l4proto, result, range))
> -			return 1;
> +	hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) {
> +		if (same_src(ct, tuple) &&
> +		    net_eq(net, nf_ct_net(ct)) &&
> +		    nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
> +			/* Copy source part from reply tuple. */
> +			nf_ct_invert_tuplepr(result,
> +				       &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
> +			result->dst = tuple->dst;
> +
> +			if (in_range(l3proto, l4proto, result, range))
> +				return 1;
> +		}
>   	}
> -
>   	return 0;
>   }
>   
> @@ -411,6 +385,7 @@ nf_nat_setup_info(struct nf_conn *ct,
>   		  const struct nf_nat_range *range,
>   		  enum nf_nat_manip_type maniptype)
>   {
> +	struct net *net = nf_ct_net(ct);
>   	struct nf_conntrack_tuple curr_tuple, new_tuple;
>   	struct nf_conn_nat *nat;
>   
> @@ -452,19 +427,16 @@ nf_nat_setup_info(struct nf_conn *ct,
>   	}
>   
>   	if (maniptype == NF_NAT_MANIP_SRC) {
> -		struct nf_nat_conn_key key = {
> -			.net = nf_ct_net(ct),
> -			.tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
> -			.zone = nf_ct_zone(ct),
> -		};
> -		int err;
> -
> -		err = rhltable_insert_key(&nf_nat_bysource_table,
> -					  &key,
> -					  &ct->nat_bysource,
> -					  nf_nat_bysource_params);
> -		if (err)
> -			return NF_DROP;
> +		unsigned int srchash;
> +
> +		srchash = hash_by_src(net,
> +				      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
> +		spin_lock_bh(&nf_nat_lock);
> +		/* nf_conntrack_alter_reply might re-allocate extension aera */
> +		nat = nfct_nat(ct);
> +		hlist_add_head_rcu(&ct->nat_bysource,
> +				   &nf_nat_bysource[srchash]);
> +		spin_unlock_bh(&nf_nat_lock);
>   	}
>   
>   	/* It's done. */
> @@ -572,9 +544,10 @@ static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
>   	 * Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
>   	 * will delete entry from already-freed table.
>   	 */
> +	spin_lock_bh(&nf_nat_lock);
> +	hlist_del_rcu(&ct->nat_bysource);
>   	ct->status &= ~IPS_NAT_DONE_MASK;
> -	rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
> -			nf_nat_bysource_params);
> +	spin_unlock_bh(&nf_nat_lock);
>   
>   	/* don't delete conntrack.  Although that would make things a lot
>   	 * simpler, we'd end up flushing all conntracks on nat rmmod.
> @@ -699,9 +672,11 @@ EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
>   /* No one using conntrack by the time this called. */
>   static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
>   {
> -	if (ct->status & IPS_SRC_NAT_DONE)
> -		rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
> -				nf_nat_bysource_params);
> +	if (ct->status & IPS_SRC_NAT_DONE) {
> +		spin_lock_bh(&nf_nat_lock);
> +		hlist_del_rcu(&ct->nat_bysource);
> +		spin_unlock_bh(&nf_nat_lock);
> +	}
>   }
>   
>   static struct nf_ct_ext_type nat_extend __read_mostly = {
> @@ -836,13 +811,16 @@ static int __init nf_nat_init(void)
>   {
>   	int ret;
>   
> -	ret = rhltable_init(&nf_nat_bysource_table, &nf_nat_bysource_params);
> -	if (ret)
> -		return ret;
> +	/* Leave them the same for the moment. */
> +	nf_nat_htable_size = nf_conntrack_htable_size;
> +
> +	nf_nat_bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size, 0);
> +	if (!nf_nat_bysource)
> +		return -ENOMEM;
>   
>   	ret = nf_ct_extend_register(&nat_extend);
>   	if (ret < 0) {
> -		rhltable_destroy(&nf_nat_bysource_table);
> +		nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
>   		printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
>   		return ret;
>   	}
> @@ -866,7 +844,7 @@ static int __init nf_nat_init(void)
>   	return 0;
>   
>    cleanup_extend:
> -	rhltable_destroy(&nf_nat_bysource_table);
> +	nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
>   	nf_ct_extend_unregister(&nat_extend);
>   	return ret;
>   }
> @@ -886,8 +864,8 @@ static void __exit nf_nat_cleanup(void)
>   
>   	for (i = 0; i < NFPROTO_NUMPROTO; i++)
>   		kfree(nf_nat_l4protos[i]);
> -
> -	rhltable_destroy(&nf_nat_bysource_table);
> +	synchronize_net();
> +	nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
>   }
>   
>   MODULE_LICENSE("GPL");


-- 
Mit freundlichen Grüssen / Regards

Sebastian Gottschall / CTO

NewMedia-NET GmbH - DD-WRT
Firmensitz:  Stubenwaldallee 21a, 64625 Bensheim
Registergericht: Amtsgericht Darmstadt, HRB 25473
Geschäftsführer: Peter Steinhäuser, Christian Scheele
http://www.dd-wrt.com
email: s.gottschall@dd-wrt.com
Tel.: +496251-582650 / Fax: +496251-5826565

Re: [PATCH 4.9.y v2] netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable" hash to rhashtable"

[Florian Westphal]

Sebastian Gottschall <s.gottschall@dd-wrt.com> wrote:
> your patch is not clean

Please stop top-posting.

> patching file net/netfilter/nf_nat_core.c
> Hunk #7 succeeded at 550 (offset 6 lines).
> Hunk #8 FAILED at 672.
> Hunk #9 succeeded at 819 (offset 10 lines).
> Hunk #10 succeeded at 852 (offset 10 lines).
> Hunk #11 succeeded at 872 (offset 10 lines).
> 
> nf_nat_cleanup_conntrack is wrong
> 
> your patch
> 
> @@ -672,9 +645,11 @@ EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
> ￜ/* No one using conntrack by the time this called. */
> ï¿œstatic void nf_nat_cleanup_conntrack(struct nf_conn *ct)
> ￜ{
> -ￜￜￜￜￜￜ if (ct->status & IPS_SRC_NAT_DONE)
> -ￜￜￜￜￜￜￜￜￜￜￜￜￜￜ rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
> -ￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜￜ nf_nat_bysource_params);
> +ￜￜￜￜￜￜ if (ct->status & IPS_SRC_NAT_DONE) {
> +ￜￜￜￜￜￜￜￜￜￜￜￜￜￜ spin_lock_bh(&nf_nat_lock);
> +ￜￜￜￜￜￜￜￜￜￜￜￜￜￜ hlist_del_rcu(&ct->nat_bysource);
> +ￜￜￜￜￜￜￜￜￜￜￜￜￜￜ spin_unlock_bh(&nf_nat_lock);
> +ￜￜￜￜￜￜ }
> ￜ}

It assumes
git cherry-pick 6e699867f84c0f358fed233fe6162173aca28e04

to get the IPS_SRC_NAT_DONE test.

Re: [PATCH 4.9.y v2] netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable" hash to rhashtable"

[Greg KH]

On Wed, Nov 15, 2017 at 12:30:11PM +0100, Florian Westphal wrote:
> Sebastian Gottschall <s.gottschall@dd-wrt.com> wrote:
> > your patch is not clean
> 
> Please stop top-posting.
> 
> > patching file net/netfilter/nf_nat_core.c
> > Hunk #7 succeeded at 550 (offset 6 lines).
> > Hunk #8 FAILED at 672.
> > Hunk #9 succeeded at 819 (offset 10 lines).
> > Hunk #10 succeeded at 852 (offset 10 lines).
> > Hunk #11 succeeded at 872 (offset 10 lines).
> > 
> > nf_nat_cleanup_conntrack is wrong
> > 
> > your patch
> > 
> > @@ -672,9 +645,11 @@ EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
> > �/* No one using conntrack by the time this called. */
> > �static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
> > �{
> > -������ if (ct->status & IPS_SRC_NAT_DONE)
> > -�������������� rhltable_remove(&nf_nat_bysource_table, &ct->nat_bysource,
> > -������������������������������ nf_nat_bysource_params);
> > +������ if (ct->status & IPS_SRC_NAT_DONE) {
> > +�������������� spin_lock_bh(&nf_nat_lock);
> > +�������������� hlist_del_rcu(&ct->nat_bysource);
> > +�������������� spin_unlock_bh(&nf_nat_lock);
> > +������ }
> > �}
> 
> It assumes
> git cherry-pick 6e699867f84c0f358fed233fe6162173aca28e04
> 
> to get the IPS_SRC_NAT_DONE test.

Can you all submit a "clean" patch series against the next 4.9-stable
release I do in an hour?

thanks,

greg k-h