From 84b1a0c0140a9a92ea108576c0002210f224ce59 Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue, 5 Mar 2024 09:35:48 +0100
Subject: [PATCH 01/17] netfilter: nf_tables: skip transaction if update object
 is not implemented

Turn update into noop as a follow up for:

  9fedd894b4e1 ("netfilter: nf_tables: fix unexpected EOPNOTSUPP error")

instead of adding a transaction object which is simply discarded at a
later stage of the commit protocol.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 167074283ea91d..a7f54eb68d9a00 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -7776,6 +7776,9 @@ static int nf_tables_newobj(struct sk_buff *skb, const struct nfnl_info *info,
 		if (WARN_ON_ONCE(!type))
 			return -ENOENT;
 
+		if (!obj->ops->update)
+			return 0;
+
 		nft_ctx_init(&ctx, net, skb, info->nlh, family, table, NULL, nla);
 
 		return nf_tables_updobj(&ctx, type, nla[NFTA_OBJ_DATA], obj);
@@ -9467,9 +9470,10 @@ static void nft_obj_commit_update(struct nft_trans *trans)
 	obj = nft_trans_obj(trans);
 	newobj = nft_trans_obj_newobj(trans);
 
-	if (obj->ops->update)
-		obj->ops->update(obj, newobj);
+	if (WARN_ON_ONCE(!obj->ops->update))
+		return;
 
+	obj->ops->update(obj, newobj);
 	nft_obj_destroy(&trans->ctx, newobj);
 }
 

From 6e20eef413d5aa8ea0b19165e40efc8d47c681db Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue, 5 Mar 2024 09:38:04 +0100
Subject: [PATCH 02/17] netfilter: nf_tables: remove NETDEV_CHANGENAME from
 netdev chain event handler

Originally, device name used to be stored in the basechain, but it is
not the case anymore. Remove check for NETDEV_CHANGENAME.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_chain_filter.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c
index d170758a1eb5d0..7010541fcca66f 100644
--- a/net/netfilter/nft_chain_filter.c
+++ b/net/netfilter/nft_chain_filter.c
@@ -325,9 +325,6 @@ static void nft_netdev_event(unsigned long event, struct net_device *dev,
 	struct nft_hook *hook, *found = NULL;
 	int n = 0;
 
-	if (event != NETDEV_UNREGISTER)
-		return;
-
 	list_for_each_entry(hook, &basechain->hook_list, list) {
 		if (hook->ops.dev == dev)
 			found = hook;
@@ -367,8 +364,7 @@ static int nf_tables_netdev_event(struct notifier_block *this,
 		.net	= dev_net(dev),
 	};
 
-	if (event != NETDEV_UNREGISTER &&
-	    event != NETDEV_CHANGENAME)
+	if (event != NETDEV_UNREGISTER)
 		return NOTIFY_DONE;
 
 	nft_net = nft_pernet(ctx.net);

From 4a3540a8bf3c13dc3955f0c0895332b9c653be3f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@c0d3.blue>
Date: Wed, 6 Mar 2024 15:18:04 +0100
Subject: [PATCH 03/17] netfilter: conntrack: fix ct-state for ICMPv6 Multicast
 Router Discovery
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

So far Multicast Router Advertisements and Multicast Router
Solicitations from the Multicast Router Discovery protocol (RFC4286)
would be marked as INVALID for IPv6, even if they are in fact intact
and adhering to RFC4286.

This broke MRA reception and by that multicast reception on
IPv6 multicast routers in a Proxmox managed setup, where Proxmox
would install a rule like "-m conntrack --ctstate INVALID -j DROP"
at the top of the FORWARD chain with br-nf-call-ip6tables enabled
by default.

Similar to as it's done for MLDv1, MLDv2 and IPv6 Neighbor Discovery
already, fix this issue by excluding MRD from connection tracking
handling as MRD always uses predefined multicast destinations
for its messages, too. This changes the ct-state for ICMPv6 MRD messages
from INVALID to UNTRACKED.

This issue was found and fixed with the help of the mrdisc tool
(https://github.com/troglobit/mrdisc).

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/uapi/linux/icmpv6.h               | 1 +
 net/netfilter/nf_conntrack_proto_icmpv6.c | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/icmpv6.h b/include/uapi/linux/icmpv6.h
index ecaece3af38df3..4eaab89e2856d3 100644
--- a/include/uapi/linux/icmpv6.h
+++ b/include/uapi/linux/icmpv6.h
@@ -112,6 +112,7 @@ struct icmp6hdr {
 #define ICMPV6_MOBILE_PREFIX_ADV	147
 
 #define ICMPV6_MRDISC_ADV		151
+#define ICMPV6_MRDISC_SOL		152
 
 #define ICMPV6_MSG_MAX          255
 
diff --git a/net/netfilter/nf_conntrack_proto_icmpv6.c b/net/netfilter/nf_conntrack_proto_icmpv6.c
index 1020d67600a959..327b8059025dad 100644
--- a/net/netfilter/nf_conntrack_proto_icmpv6.c
+++ b/net/netfilter/nf_conntrack_proto_icmpv6.c
@@ -62,7 +62,9 @@ static const u_int8_t noct_valid_new[] = {
 	[NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
 	[NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
 	[NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
-	[ICMPV6_MLD2_REPORT - 130] = 1
+	[ICMPV6_MLD2_REPORT - 130] = 1,
+	[ICMPV6_MRDISC_ADV - 130] = 1,
+	[ICMPV6_MRDISC_SOL - 130] = 1
 };
 
 bool nf_conntrack_invert_icmpv6_tuple(struct nf_conntrack_tuple *tuple,

From 40616789ec462df0e97ee1d5aa4e4fed4249cae0 Mon Sep 17 00:00:00 2001
From: Jason Xing <kernelxing@tencent.com>
Date: Mon, 25 Mar 2024 10:59:38 +0800
Subject: [PATCH 04/17] netfilter: conntrack: dccp: try not to drop skb in
 conntrack

It would be better not to drop skb in conntrack unless we have good
alternatives. So we can treat the result of testing skb's header
pointer as nf_conntrack_tcp_packet() does.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_proto_dccp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_conntrack_proto_dccp.c b/net/netfilter/nf_conntrack_proto_dccp.c
index e2db1f4ec2df93..ebc4f733bb2e69 100644
--- a/net/netfilter/nf_conntrack_proto_dccp.c
+++ b/net/netfilter/nf_conntrack_proto_dccp.c
@@ -525,7 +525,7 @@ int nf_conntrack_dccp_packet(struct nf_conn *ct, struct sk_buff *skb,
 
 	dh = skb_header_pointer(skb, dataoff, sizeof(*dh), &_dh.dh);
 	if (!dh)
-		return NF_DROP;
+		return -NF_ACCEPT;
 
 	if (dccp_error(dh, skb, dataoff, state))
 		return -NF_ACCEPT;
@@ -533,7 +533,7 @@ int nf_conntrack_dccp_packet(struct nf_conn *ct, struct sk_buff *skb,
 	/* pull again, including possible 48 bit sequences and subtype header */
 	dh = dccp_header_pointer(skb, dataoff, dh, &_dh);
 	if (!dh)
-		return NF_DROP;
+		return -NF_ACCEPT;
 
 	type = dh->dccph_type;
 	if (!nf_ct_is_confirmed(ct) && !dccp_new(ct, skb, dh, state))

From 8edc27fc4f220179189932cb5f537f2e90a32b87 Mon Sep 17 00:00:00 2001
From: Jason Xing <kernelxing@tencent.com>
Date: Mon, 25 Mar 2024 20:36:14 +0800
Subject: [PATCH 05/17] netfilter: use NF_DROP instead of -NF_DROP

At the beginning in 2009 one patch [1] introduced collecting drop
counter in nf_conntrack_in() by returning -NF_DROP. Later, another
patch [2] changed the return value of tcp_packet() which now is
renamed to nf_conntrack_tcp_packet() from -NF_DROP to NF_DROP. As
we can see, that -NF_DROP should be corrected.

Similarly, there are other two points where the -NF_DROP is used.

Well, as NF_DROP is equal to 0, inverting NF_DROP makes no sense
as patch [2] said many years ago.

[1]
commit 7d1e04598e5e ("netfilter: nf_conntrack: account packets drop by tcp_packet()")
[2]
commit ec8d540969da ("netfilter: conntrack: fix dropping packet after l4proto->packet()")

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/netfilter/iptable_filter.c  | 2 +-
 net/ipv6/netfilter/ip6table_filter.c | 2 +-
 net/netfilter/nf_conntrack_core.c    | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c
index b9062f4552ace5..3ab908b7479517 100644
--- a/net/ipv4/netfilter/iptable_filter.c
+++ b/net/ipv4/netfilter/iptable_filter.c
@@ -44,7 +44,7 @@ static int iptable_filter_table_init(struct net *net)
 		return -ENOMEM;
 	/* Entry 1 is the FORWARD hook */
 	((struct ipt_standard *)repl->entries)[1].target.verdict =
-		forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
+		forward ? -NF_ACCEPT - 1 : NF_DROP - 1;
 
 	err = ipt_register_table(net, &packet_filter, repl, filter_ops);
 	kfree(repl);
diff --git a/net/ipv6/netfilter/ip6table_filter.c b/net/ipv6/netfilter/ip6table_filter.c
index df785ebda0ca43..e8992693e14a04 100644
--- a/net/ipv6/netfilter/ip6table_filter.c
+++ b/net/ipv6/netfilter/ip6table_filter.c
@@ -43,7 +43,7 @@ static int ip6table_filter_table_init(struct net *net)
 		return -ENOMEM;
 	/* Entry 1 is the FORWARD hook */
 	((struct ip6t_standard *)repl->entries)[1].target.verdict =
-		forward ? -NF_ACCEPT - 1 : -NF_DROP - 1;
+		forward ? -NF_ACCEPT - 1 : NF_DROP - 1;
 
 	err = ip6t_register_table(net, &packet_filter, repl, filter_ops);
 	kfree(repl);
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index c63868666bd9e5..6102dc09cdd3ef 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -2024,7 +2024,7 @@ nf_conntrack_in(struct sk_buff *skb, const struct nf_hook_state *state)
 			goto repeat;
 
 		NF_CT_STAT_INC_ATOMIC(state->net, invalid);
-		if (ret == -NF_DROP)
+		if (ret == NF_DROP)
 			NF_CT_STAT_INC_ATOMIC(state->net, drop);
 
 		ret = -ret;

From f9a6e7fb521cb6e1ff1a654a2a7f9331611f8140 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Fri, 19 Apr 2024 13:39:31 +0200
Subject: [PATCH 06/17] netfilter: conntrack: documentation: remove reference
 to non-existent sysctl

The referenced sysctl doesn't exist anymore.

Fixes: 4592ee7f525c ("netfilter: conntrack: remove offload_pickup sysctl again")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 Documentation/networking/nf_conntrack-sysctl.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/networking/nf_conntrack-sysctl.rst b/Documentation/networking/nf_conntrack-sysctl.rst
index c383a394c66569..238b66d0e05942 100644
--- a/Documentation/networking/nf_conntrack-sysctl.rst
+++ b/Documentation/networking/nf_conntrack-sysctl.rst
@@ -222,11 +222,11 @@ nf_flowtable_tcp_timeout - INTEGER (seconds)
 
         Control offload timeout for tcp connections.
         TCP connections may be offloaded from nf conntrack to nf flow table.
-        Once aged, the connection is returned to nf conntrack with tcp pickup timeout.
+        Once aged, the connection is returned to nf conntrack.
 
 nf_flowtable_udp_timeout - INTEGER (seconds)
         default 30
 
         Control offload timeout for udp connections.
         UDP connections may be offloaded from nf conntrack to nf flow table.
-        Once aged, the connection is returned to nf conntrack with udp pickup timeout.
+        Once aged, the connection is returned to nf conntrack.

From 119c790a271de02dadb36ba0c1fc31a7d5d4c62b Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Tue, 23 Apr 2024 15:44:28 +0200
Subject: [PATCH 07/17] netfilter: conntrack: remove flowtable early-drop test

Not sure why this special case exists.  Early drop logic
(which kicks in when conntrack table is full) should be independent
of flowtable offload and only consider assured bit (i.e., two-way
traffic was seen).

flowtable entries hold a reference to the conntrack entry (struct
nf_conn) that has been offloaded. The conntrack use count is not
decremented until after the entry is free'd.

This change therefore will not result in exceeding the conntrack table
limit.  It does allow early-drop of tcp flows even when they've been
offloaded, but only if they have been offloaded before syn-ack was
received or after at least one peer has sent a fin.

Currently 'fin' packet reception already stops offloading, so this
should not impact offloading either.

Cc: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_conntrack_core.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 6102dc09cdd3ef..7ac20750c127b5 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1440,8 +1440,6 @@ static bool gc_worker_can_early_drop(const struct nf_conn *ct)
 	const struct nf_conntrack_l4proto *l4proto;
 	u8 protonum = nf_ct_protonum(ct);
 
-	if (test_bit(IPS_OFFLOAD_BIT, &ct->status) && protonum != IPPROTO_UDP)
-		return false;
 	if (!test_bit(IPS_ASSURED_BIT, &ct->status))
 		return true;
 

From a590f4760922acaa2d2b55a88004a38eecdd6412 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Thu, 25 Apr 2024 14:06:40 +0200
Subject: [PATCH 08/17] netfilter: nft_set_pipapo: move prove_locking helper
 around

Preparation patch, the helper will soon get called from insert
function too.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 187138afac45d4..b8205d961ba4f8 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -1247,6 +1247,17 @@ static int pipapo_realloc_scratch(struct nft_pipapo_match *clone,
 	return 0;
 }
 
+static bool nft_pipapo_transaction_mutex_held(const struct nft_set *set)
+{
+#ifdef CONFIG_PROVE_LOCKING
+	const struct net *net = read_pnet(&set->net);
+
+	return lockdep_is_held(&nft_pernet(net)->commit_mutex);
+#else
+	return true;
+#endif
+}
+
 /**
  * nft_pipapo_insert() - Validate and insert ranged elements
  * @net:	Network namespace
@@ -1799,17 +1810,6 @@ static void nft_pipapo_commit(struct nft_set *set)
 	priv->clone = new_clone;
 }
 
-static bool nft_pipapo_transaction_mutex_held(const struct nft_set *set)
-{
-#ifdef CONFIG_PROVE_LOCKING
-	const struct net *net = read_pnet(&set->net);
-
-	return lockdep_is_held(&nft_pernet(net)->commit_mutex);
-#else
-	return true;
-#endif
-}
-
 static void nft_pipapo_abort(const struct nft_set *set)
 {
 	struct nft_pipapo *priv = nft_set_priv(set);

From 80efd2997fb9343a0283cf3cac5524a4595c8ff4 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Thu, 25 Apr 2024 14:06:41 +0200
Subject: [PATCH 09/17] netfilter: nft_set_pipapo: make pipapo_clone helper
 return NULL

Currently it returns an error pointer, but the only possible failure
is ENOMEM.

After a followup patch, we'd need to discard the errno code, i.e.

x = pipapo_clone()
if (IS_ERR(x))
	return NULL

or make more changes to fix up callers to expect IS_ERR() code
from set->ops->deactivate().

So simplify this and make it return ptr-or-null.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index b8205d961ba4f8..7b6d5d2d0d5409 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -1395,7 +1395,7 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
  * pipapo_clone() - Clone matching data to create new working copy
  * @old:	Existing matching data
  *
- * Return: copy of matching data passed as 'old', error pointer on failure
+ * Return: copy of matching data passed as 'old' or NULL.
  */
 static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old)
 {
@@ -1405,7 +1405,7 @@ static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old)
 
 	new = kmalloc(struct_size(new, f, old->field_count), GFP_KERNEL);
 	if (!new)
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 
 	new->field_count = old->field_count;
 	new->bsize_max = old->bsize_max;
@@ -1477,7 +1477,7 @@ static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old)
 	free_percpu(new->scratch);
 	kfree(new);
 
-	return ERR_PTR(-ENOMEM);
+	return NULL;
 }
 
 /**
@@ -1797,7 +1797,7 @@ static void nft_pipapo_commit(struct nft_set *set)
 		return;
 
 	new_clone = pipapo_clone(priv->clone);
-	if (IS_ERR(new_clone))
+	if (!new_clone)
 		return;
 
 	priv->dirty = false;
@@ -1821,7 +1821,7 @@ static void nft_pipapo_abort(const struct nft_set *set)
 	m = rcu_dereference_protected(priv->match, nft_pipapo_transaction_mutex_held(set));
 
 	new_clone = pipapo_clone(m);
-	if (IS_ERR(new_clone))
+	if (!new_clone)
 		return;
 
 	priv->dirty = false;
@@ -2269,8 +2269,8 @@ static int nft_pipapo_init(const struct nft_set *set,
 
 	/* Create an initial clone of matching data for next insertion */
 	priv->clone = pipapo_clone(m);
-	if (IS_ERR(priv->clone)) {
-		err = PTR_ERR(priv->clone);
+	if (!priv->clone) {
+		err = -ENOMEM;
 		goto out_free;
 	}
 

From 8b8a2417558c632f249abebde97adf8c46540de2 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Thu, 25 Apr 2024 14:06:42 +0200
Subject: [PATCH 10/17] netfilter: nft_set_pipapo: prepare destroy function for
 on-demand clone

Once priv->clone can be NULL in case no insertions/removals occurred
in the last transaction we need to drop set elements from priv->match
if priv->clone is NULL.

While at it, condense this function by reusing the pipapo_free_match
helper instead of open-coded version.

The rcu_barrier() is removed, its not needed: old call_rcu instances
for pipapo_reclaim_match do not access struct nft_set.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 27 ++++++---------------------
 1 file changed, 6 insertions(+), 21 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 7b6d5d2d0d5409..459e2dd5050c59 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -2326,33 +2326,18 @@ static void nft_pipapo_destroy(const struct nft_ctx *ctx,
 {
 	struct nft_pipapo *priv = nft_set_priv(set);
 	struct nft_pipapo_match *m;
-	int cpu;
 
 	m = rcu_dereference_protected(priv->match, true);
-	if (m) {
-		rcu_barrier();
-
-		for_each_possible_cpu(cpu)
-			pipapo_free_scratch(m, cpu);
-		free_percpu(m->scratch);
-		pipapo_free_fields(m);
-		kfree(m);
-		priv->match = NULL;
-	}
 
 	if (priv->clone) {
-		m = priv->clone;
-
-		nft_set_pipapo_match_destroy(ctx, set, m);
-
-		for_each_possible_cpu(cpu)
-			pipapo_free_scratch(priv->clone, cpu);
-		free_percpu(priv->clone->scratch);
-
-		pipapo_free_fields(priv->clone);
-		kfree(priv->clone);
+		nft_set_pipapo_match_destroy(ctx, set, priv->clone);
+		pipapo_free_match(priv->clone);
 		priv->clone = NULL;
+	} else {
+		nft_set_pipapo_match_destroy(ctx, set, m);
 	}
+
+	pipapo_free_match(m);
 }
 
 /**

From 6c108d9bee448a850b03e682836bfe91fca645cb Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Thu, 25 Apr 2024 14:06:43 +0200
Subject: [PATCH 11/17] netfilter: nft_set_pipapo: prepare walk function for
 on-demand clone

The existing code uses iter->type to figure out what data is needed, the
live copy (READ) or clone (UPDATE).

Without pending updates, priv->clone and priv->match will point to
different memory locations, but they have identical content.

Future patch will make priv->clone == NULL if there are no pending changes,
in this case we must copy the live data for the UPDATE case.

Currently this would require GFP_ATOMIC allocation.  Split the walk
function in two parts: one that does the walk and one that decides which
data is needed.

In the UPDATE case, callers hold the transaction mutex so we do not need
the rcu read lock.  This allows to use GFP_KERNEL allocation while
cloning.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 60 ++++++++++++++++++++++------------
 1 file changed, 39 insertions(+), 21 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 459e2dd5050c59..543d6cf01de61c 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -2106,35 +2106,23 @@ static void nft_pipapo_remove(const struct net *net, const struct nft_set *set,
 }
 
 /**
- * nft_pipapo_walk() - Walk over elements
+ * nft_pipapo_do_walk() - Walk over elements in m
  * @ctx:	nftables API context
  * @set:	nftables API set representation
+ * @m:		matching data pointing to key mapping array
  * @iter:	Iterator
  *
  * As elements are referenced in the mapping array for the last field, directly
  * scan that array: there's no need to follow rule mappings from the first
- * field.
+ * field. @m is protected either by RCU read lock or by transaction mutex.
  */
-static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set,
-			    struct nft_set_iter *iter)
+static void nft_pipapo_do_walk(const struct nft_ctx *ctx, struct nft_set *set,
+			       const struct nft_pipapo_match *m,
+			       struct nft_set_iter *iter)
 {
-	struct nft_pipapo *priv = nft_set_priv(set);
-	const struct nft_pipapo_match *m;
 	const struct nft_pipapo_field *f;
 	unsigned int i, r;
 
-	WARN_ON_ONCE(iter->type != NFT_ITER_READ &&
-		     iter->type != NFT_ITER_UPDATE);
-
-	rcu_read_lock();
-	if (iter->type == NFT_ITER_READ)
-		m = rcu_dereference(priv->match);
-	else
-		m = priv->clone;
-
-	if (unlikely(!m))
-		goto out;
-
 	for (i = 0, f = m->f; i < m->field_count - 1; i++, f++)
 		;
 
@@ -2151,14 +2139,44 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set,
 
 		iter->err = iter->fn(ctx, set, iter, &e->priv);
 		if (iter->err < 0)
-			goto out;
+			return;
 
 cont:
 		iter->count++;
 	}
+}
 
-out:
-	rcu_read_unlock();
+/**
+ * nft_pipapo_walk() - Walk over elements
+ * @ctx:	nftables API context
+ * @set:	nftables API set representation
+ * @iter:	Iterator
+ *
+ * Test if destructive action is needed or not, clone active backend if needed
+ * and call the real function to work on the data.
+ */
+static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set,
+			    struct nft_set_iter *iter)
+{
+	struct nft_pipapo *priv = nft_set_priv(set);
+	const struct nft_pipapo_match *m;
+
+	switch (iter->type) {
+	case NFT_ITER_UPDATE:
+		m = priv->clone;
+		nft_pipapo_do_walk(ctx, set, m, iter);
+		break;
+	case NFT_ITER_READ:
+		rcu_read_lock();
+		m = rcu_dereference(priv->match);
+		nft_pipapo_do_walk(ctx, set, m, iter);
+		rcu_read_unlock();
+		break;
+	default:
+		iter->err = -EINVAL;
+		WARN_ON_ONCE(1);
+		break;
+	}
 }
 
 /**

From c5444786d0ea2417a5e2cee7bd67137fc8bad687 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Thu, 25 Apr 2024 14:06:44 +0200
Subject: [PATCH 12/17] netfilter: nft_set_pipapo: merge deactivate helper into
 caller

Its the only remaining call site so there is no need for this to
be separated anymore.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 39 ++++++++--------------------------
 1 file changed, 9 insertions(+), 30 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 543d6cf01de61c..7c11f568069cec 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -1851,52 +1851,31 @@ static void nft_pipapo_activate(const struct net *net,
 }
 
 /**
- * pipapo_deactivate() - Check that element is in set, mark as inactive
+ * nft_pipapo_deactivate() - Search for element and make it inactive
  * @net:	Network namespace
  * @set:	nftables API set representation
- * @data:	Input key data
- * @ext:	nftables API extension pointer, used to check for end element
- *
- * This is a convenience function that can be called from both
- * nft_pipapo_deactivate() and nft_pipapo_flush(), as they are in fact the same
- * operation.
+ * @elem:	nftables API element representation containing key data
  *
  * Return: deactivated element if found, NULL otherwise.
  */
-static void *pipapo_deactivate(const struct net *net, const struct nft_set *set,
-			       const u8 *data, const struct nft_set_ext *ext)
+static struct nft_elem_priv *
+nft_pipapo_deactivate(const struct net *net, const struct nft_set *set,
+		      const struct nft_set_elem *elem)
 {
 	struct nft_pipapo_elem *e;
 
-	e = pipapo_get(net, set, data, nft_genmask_next(net),
-		       nft_net_tstamp(net), GFP_KERNEL);
+	e = pipapo_get(net, set, (const u8 *)elem->key.val.data,
+		       nft_genmask_next(net), nft_net_tstamp(net), GFP_KERNEL);
 	if (IS_ERR(e))
 		return NULL;
 
 	nft_set_elem_change_active(net, set, &e->ext);
 
-	return e;
-}
-
-/**
- * nft_pipapo_deactivate() - Call pipapo_deactivate() to make element inactive
- * @net:	Network namespace
- * @set:	nftables API set representation
- * @elem:	nftables API element representation containing key data
- *
- * Return: deactivated element if found, NULL otherwise.
- */
-static struct nft_elem_priv *
-nft_pipapo_deactivate(const struct net *net, const struct nft_set *set,
-		      const struct nft_set_elem *elem)
-{
-	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
-
-	return pipapo_deactivate(net, set, (const u8 *)elem->key.val.data, ext);
+	return &e->priv;
 }
 
 /**
- * nft_pipapo_flush() - Call pipapo_deactivate() to make element inactive
+ * nft_pipapo_flush() - make element inactive
  * @net:	Network namespace
  * @set:	nftables API set representation
  * @elem_priv:	nftables API element representation containing key data

From a238106703ab4ae1090b86eba128815b8626d8f1 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Thu, 25 Apr 2024 14:06:45 +0200
Subject: [PATCH 13/17] netfilter: nft_set_pipapo: prepare pipapo_get helper
 for on-demand clone

The helper uses priv->clone unconditionally which will fail once we do
the clone conditionally on first insert or removal.

'nft get element' from userspace needs to use priv->match since this
runs from rcu read side lock section.

Prepare for this by passing the match backend data as argument.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 7c11f568069cec..6657aa34f4d71c 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -504,6 +504,7 @@ bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
  * pipapo_get() - Get matching element reference given key data
  * @net:	Network namespace
  * @set:	nftables API set representation
+ * @m:		storage containing active/existing elements
  * @data:	Key data to be matched against existing elements
  * @genmask:	If set, check that element is active in given genmask
  * @tstamp:	timestamp to check for expired elements
@@ -517,17 +518,15 @@ bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
  */
 static struct nft_pipapo_elem *pipapo_get(const struct net *net,
 					  const struct nft_set *set,
+					  const struct nft_pipapo_match *m,
 					  const u8 *data, u8 genmask,
 					  u64 tstamp, gfp_t gfp)
 {
 	struct nft_pipapo_elem *ret = ERR_PTR(-ENOENT);
-	struct nft_pipapo *priv = nft_set_priv(set);
 	unsigned long *res_map, *fill_map = NULL;
-	const struct nft_pipapo_match *m;
 	const struct nft_pipapo_field *f;
 	int i;
 
-	m = priv->clone;
 	if (m->bsize_max == 0)
 		return ret;
 
@@ -612,9 +611,11 @@ static struct nft_elem_priv *
 nft_pipapo_get(const struct net *net, const struct nft_set *set,
 	       const struct nft_set_elem *elem, unsigned int flags)
 {
+	struct nft_pipapo *priv = nft_set_priv(set);
+	struct nft_pipapo_match *m = rcu_dereference(priv->match);
 	struct nft_pipapo_elem *e;
 
-	e = pipapo_get(net, set, (const u8 *)elem->key.val.data,
+	e = pipapo_get(net, set, m, (const u8 *)elem->key.val.data,
 		       nft_genmask_cur(net), get_jiffies_64(),
 		       GFP_ATOMIC);
 	if (IS_ERR(e))
@@ -1288,7 +1289,7 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	else
 		end = start;
 
-	dup = pipapo_get(net, set, start, genmask, tstamp, GFP_KERNEL);
+	dup = pipapo_get(net, set, m, start, genmask, tstamp, GFP_KERNEL);
 	if (!IS_ERR(dup)) {
 		/* Check if we already have the same exact entry */
 		const struct nft_data *dup_key, *dup_end;
@@ -1310,7 +1311,7 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 
 	if (PTR_ERR(dup) == -ENOENT) {
 		/* Look for partially overlapping entries */
-		dup = pipapo_get(net, set, end, nft_genmask_next(net), tstamp,
+		dup = pipapo_get(net, set, m, end, nft_genmask_next(net), tstamp,
 				 GFP_KERNEL);
 	}
 
@@ -1862,9 +1863,11 @@ static struct nft_elem_priv *
 nft_pipapo_deactivate(const struct net *net, const struct nft_set *set,
 		      const struct nft_set_elem *elem)
 {
+	const struct nft_pipapo *priv = nft_set_priv(set);
+	struct nft_pipapo_match *m = priv->clone;
 	struct nft_pipapo_elem *e;
 
-	e = pipapo_get(net, set, (const u8 *)elem->key.val.data,
+	e = pipapo_get(net, set, m, (const u8 *)elem->key.val.data,
 		       nft_genmask_next(net), nft_net_tstamp(net), GFP_KERNEL);
 	if (IS_ERR(e))
 		return NULL;

From 3f1d886cc7c3525d4dbeee24bfa9bb3fe0d48ddc Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Thu, 25 Apr 2024 14:06:46 +0200
Subject: [PATCH 14/17] netfilter: nft_set_pipapo: move cloning of match info
 to insert/removal path

This set type keeps two copies of the sets' content,
   priv->match (live version, used to match from packet path)
   priv->clone (work-in-progress version of the 'future' priv->match).

All additions and removals are done on priv->clone.  When transaction
completes, priv->clone becomes priv->match and a new clone is allocated
for use by next transaction.

Problem is that the cloning requires GFP_KERNEL allocations but we
cannot fail at either commit or abort time.

This patch defers the clone until we get an insertion or removal
request.  This allows us to handle OOM situations correctly.

This also allows to remove ->dirty in a followup change:

If ->clone exists, ->dirty is always true
If ->clone is NULL, ->dirty is always false, no elements were added
or removed (except catchall elements which are external to the specific
set backend).

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 70 ++++++++++++++++++++++++----------
 1 file changed, 49 insertions(+), 21 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 6657aa34f4d71c..dd9696120ea433 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -1259,6 +1259,29 @@ static bool nft_pipapo_transaction_mutex_held(const struct nft_set *set)
 #endif
 }
 
+static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old);
+
+/**
+ * pipapo_maybe_clone() - Build clone for pending data changes, if not existing
+ * @set:	nftables API set representation
+ *
+ * Return: newly created or existing clone, if any. NULL on allocation failure
+ */
+static struct nft_pipapo_match *pipapo_maybe_clone(const struct nft_set *set)
+{
+	struct nft_pipapo *priv = nft_set_priv(set);
+	struct nft_pipapo_match *m;
+
+	if (priv->clone)
+		return priv->clone;
+
+	m = rcu_dereference_protected(priv->match,
+				      nft_pipapo_transaction_mutex_held(set));
+	priv->clone = pipapo_clone(m);
+
+	return priv->clone;
+}
+
 /**
  * nft_pipapo_insert() - Validate and insert ranged elements
  * @net:	Network namespace
@@ -1275,8 +1298,8 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
 	union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS];
 	const u8 *start = (const u8 *)elem->key.val.data, *end;
+	struct nft_pipapo_match *m = pipapo_maybe_clone(set);
 	struct nft_pipapo *priv = nft_set_priv(set);
-	struct nft_pipapo_match *m = priv->clone;
 	u8 genmask = nft_genmask_next(net);
 	struct nft_pipapo_elem *e, *dup;
 	u64 tstamp = nft_net_tstamp(net);
@@ -1284,6 +1307,9 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	const u8 *start_p, *end_p;
 	int i, bsize_max, err = 0;
 
+	if (!m)
+		return -ENOMEM;
+
 	if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END))
 		end = (const u8 *)nft_set_ext_key_end(ext)->data;
 	else
@@ -1789,7 +1815,10 @@ static void pipapo_reclaim_match(struct rcu_head *rcu)
 static void nft_pipapo_commit(struct nft_set *set)
 {
 	struct nft_pipapo *priv = nft_set_priv(set);
-	struct nft_pipapo_match *new_clone, *old;
+	struct nft_pipapo_match *old;
+
+	if (!priv->clone)
+		return;
 
 	if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set)))
 		pipapo_gc(set, priv->clone);
@@ -1797,38 +1826,27 @@ static void nft_pipapo_commit(struct nft_set *set)
 	if (!priv->dirty)
 		return;
 
-	new_clone = pipapo_clone(priv->clone);
-	if (!new_clone)
-		return;
-
+	old = rcu_replace_pointer(priv->match, priv->clone,
+				  nft_pipapo_transaction_mutex_held(set));
+	priv->clone = NULL;
 	priv->dirty = false;
 
-	old = rcu_access_pointer(priv->match);
-	rcu_assign_pointer(priv->match, priv->clone);
 	if (old)
 		call_rcu(&old->rcu, pipapo_reclaim_match);
-
-	priv->clone = new_clone;
 }
 
 static void nft_pipapo_abort(const struct nft_set *set)
 {
 	struct nft_pipapo *priv = nft_set_priv(set);
-	struct nft_pipapo_match *new_clone, *m;
 
 	if (!priv->dirty)
 		return;
 
-	m = rcu_dereference_protected(priv->match, nft_pipapo_transaction_mutex_held(set));
-
-	new_clone = pipapo_clone(m);
-	if (!new_clone)
+	if (!priv->clone)
 		return;
-
 	priv->dirty = false;
-
 	pipapo_free_match(priv->clone);
-	priv->clone = new_clone;
+	priv->clone = NULL;
 }
 
 /**
@@ -1863,10 +1881,15 @@ static struct nft_elem_priv *
 nft_pipapo_deactivate(const struct net *net, const struct nft_set *set,
 		      const struct nft_set_elem *elem)
 {
-	const struct nft_pipapo *priv = nft_set_priv(set);
-	struct nft_pipapo_match *m = priv->clone;
+	struct nft_pipapo_match *m = pipapo_maybe_clone(set);
 	struct nft_pipapo_elem *e;
 
+	/* removal must occur on priv->clone, if we are low on memory
+	 * we have no choice and must fail the removal request.
+	 */
+	if (!m)
+		return NULL;
+
 	e = pipapo_get(net, set, m, (const u8 *)elem->key.val.data,
 		       nft_genmask_next(net), nft_net_tstamp(net), GFP_KERNEL);
 	if (IS_ERR(e))
@@ -2145,7 +2168,12 @@ static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set,
 
 	switch (iter->type) {
 	case NFT_ITER_UPDATE:
-		m = priv->clone;
+		m = pipapo_maybe_clone(set);
+		if (!m) {
+			iter->err = -ENOMEM;
+			return;
+		}
+
 		nft_pipapo_do_walk(ctx, set, m, iter);
 		break;
 	case NFT_ITER_READ:

From 532aec7e878b527fcee8877350ab5c5341789626 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Thu, 25 Apr 2024 14:06:47 +0200
Subject: [PATCH 15/17] netfilter: nft_set_pipapo: remove dirty flag

After previous change:
 ->clone exists: ->dirty is always true
 ->clone == NULL ->dirty is always false

So remove this flag.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 25 -------------------------
 net/netfilter/nft_set_pipapo.h |  2 --
 2 files changed, 27 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index dd9696120ea433..15a236bebb46a0 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -1299,7 +1299,6 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS];
 	const u8 *start = (const u8 *)elem->key.val.data, *end;
 	struct nft_pipapo_match *m = pipapo_maybe_clone(set);
-	struct nft_pipapo *priv = nft_set_priv(set);
 	u8 genmask = nft_genmask_next(net);
 	struct nft_pipapo_elem *e, *dup;
 	u64 tstamp = nft_net_tstamp(net);
@@ -1370,8 +1369,6 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	}
 
 	/* Insert */
-	priv->dirty = true;
-
 	bsize_max = m->bsize_max;
 
 	nft_pipapo_for_each_field(f, i, m) {
@@ -1736,8 +1733,6 @@ static void pipapo_gc(struct nft_set *set, struct nft_pipapo_match *m)
 		 * NFT_SET_ELEM_DEAD_BIT.
 		 */
 		if (__nft_set_elem_expired(&e->ext, tstamp)) {
-			priv->dirty = true;
-
 			gc = nft_trans_gc_queue_sync(gc, GFP_KERNEL);
 			if (!gc)
 				return;
@@ -1823,13 +1818,9 @@ static void nft_pipapo_commit(struct nft_set *set)
 	if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set)))
 		pipapo_gc(set, priv->clone);
 
-	if (!priv->dirty)
-		return;
-
 	old = rcu_replace_pointer(priv->match, priv->clone,
 				  nft_pipapo_transaction_mutex_held(set));
 	priv->clone = NULL;
-	priv->dirty = false;
 
 	if (old)
 		call_rcu(&old->rcu, pipapo_reclaim_match);
@@ -1839,12 +1830,8 @@ static void nft_pipapo_abort(const struct nft_set *set)
 {
 	struct nft_pipapo *priv = nft_set_priv(set);
 
-	if (!priv->dirty)
-		return;
-
 	if (!priv->clone)
 		return;
-	priv->dirty = false;
 	pipapo_free_match(priv->clone);
 	priv->clone = NULL;
 }
@@ -2098,7 +2085,6 @@ static void nft_pipapo_remove(const struct net *net, const struct nft_set *set,
 			match_end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
 
 			if (last && f->mt[rulemap[i].to].e == e) {
-				priv->dirty = true;
 				pipapo_drop(m, rulemap);
 				return;
 			}
@@ -2295,21 +2281,10 @@ static int nft_pipapo_init(const struct nft_set *set,
 		f->mt = NULL;
 	}
 
-	/* Create an initial clone of matching data for next insertion */
-	priv->clone = pipapo_clone(m);
-	if (!priv->clone) {
-		err = -ENOMEM;
-		goto out_free;
-	}
-
-	priv->dirty = false;
-
 	rcu_assign_pointer(priv->match, m);
 
 	return 0;
 
-out_free:
-	free_percpu(m->scratch);
 out_scratch:
 	kfree(m);
 
diff --git a/net/netfilter/nft_set_pipapo.h b/net/netfilter/nft_set_pipapo.h
index 24cd1ff73f981a..0d2e40e10f7f57 100644
--- a/net/netfilter/nft_set_pipapo.h
+++ b/net/netfilter/nft_set_pipapo.h
@@ -155,14 +155,12 @@ struct nft_pipapo_match {
  * @match:	Currently in-use matching data
  * @clone:	Copy where pending insertions and deletions are kept
  * @width:	Total bytes to be matched for one packet, including padding
- * @dirty:	Working copy has pending insertions or deletions
  * @last_gc:	Timestamp of last garbage collection run, jiffies
  */
 struct nft_pipapo {
 	struct nft_pipapo_match __rcu *match;
 	struct nft_pipapo_match *clone;
 	int width;
-	bool dirty;
 	unsigned long last_gc;
 };
 

From a8a388c2aae490c08d59a6c15d15a968fea5089a Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Tue, 7 May 2024 13:02:10 +0200
Subject: [PATCH 16/17] selftests: netfilter: add packetdrill based conntrack
 tests

Add a new test script that uses packetdrill tool to exercise conntrack
state machine.

Needs ip/ip6tables and conntrack tool (to check if we have an entry in
the expected state).

Test cases added here cover following scenarios:
1. already-acked (retransmitted) packets are not tagged as INVALID
2. RST packet coming when conntrack is already closing (FIN/CLOSE_WAIT)
  transitions conntrack to CLOSE even if the RST is not an exact match
3. RST packets with out-of-window sequence numbers are marked as INVALID
4. SYN+Challenge ACK: check that challenge ack is allowed to pass
5. Old SYN/ACK: check conntrack handles the case where SYN is answered
  with SYN/ACK for an old, previous connection attempt
6. Check SYN reception while in ESTABLISHED state generates a challenge
   ack, RST response clears 'outdated' state + next SYN retransmit gets
   us into 'SYN_RECV' conntrack state.

Tests get run twice, once with ipv4 and once with ipv6.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 .../testing/selftests/net/netfilter/Makefile  |   2 +
 tools/testing/selftests/net/netfilter/config  |   1 +
 .../net/netfilter/nf_conntrack_packetdrill.sh |  71 +++++++++++
 .../net/netfilter/packetdrill/common.sh       |  33 +++++
 .../packetdrill/conntrack_ack_loss_stall.pkt  | 118 ++++++++++++++++++
 .../packetdrill/conntrack_inexact_rst.pkt     |  62 +++++++++
 .../packetdrill/conntrack_rst_invalid.pkt     |  59 +++++++++
 .../conntrack_syn_challenge_ack.pkt           |  44 +++++++
 .../packetdrill/conntrack_synack_old.pkt      |  51 ++++++++
 .../packetdrill/conntrack_synack_reuse.pkt    |  34 +++++
 10 files changed, 475 insertions(+)
 create mode 100755 tools/testing/selftests/net/netfilter/nf_conntrack_packetdrill.sh
 create mode 100755 tools/testing/selftests/net/netfilter/packetdrill/common.sh
 create mode 100644 tools/testing/selftests/net/netfilter/packetdrill/conntrack_ack_loss_stall.pkt
 create mode 100644 tools/testing/selftests/net/netfilter/packetdrill/conntrack_inexact_rst.pkt
 create mode 100644 tools/testing/selftests/net/netfilter/packetdrill/conntrack_rst_invalid.pkt
 create mode 100644 tools/testing/selftests/net/netfilter/packetdrill/conntrack_syn_challenge_ack.pkt
 create mode 100644 tools/testing/selftests/net/netfilter/packetdrill/conntrack_synack_old.pkt
 create mode 100644 tools/testing/selftests/net/netfilter/packetdrill/conntrack_synack_reuse.pkt

diff --git a/tools/testing/selftests/net/netfilter/Makefile b/tools/testing/selftests/net/netfilter/Makefile
index e9a6c702b8c99f..47945b2b3f9258 100644
--- a/tools/testing/selftests/net/netfilter/Makefile
+++ b/tools/testing/selftests/net/netfilter/Makefile
@@ -13,6 +13,7 @@ TEST_PROGS += conntrack_tcp_unreplied.sh
 TEST_PROGS += conntrack_sctp_collision.sh
 TEST_PROGS += conntrack_vrf.sh
 TEST_PROGS += ipvs.sh
+TEST_PROGS += nf_conntrack_packetdrill.sh
 TEST_PROGS += nf_nat_edemux.sh
 TEST_PROGS += nft_audit.sh
 TEST_PROGS += nft_concat_range.sh
@@ -45,6 +46,7 @@ $(OUTPUT)/conntrack_dump_flush: CFLAGS += $(MNL_CFLAGS)
 $(OUTPUT)/conntrack_dump_flush: LDLIBS += $(MNL_LDLIBS)
 
 TEST_FILES := lib.sh
+TEST_FILES += packetdrill
 
 TEST_INCLUDES := \
 	../lib.sh
diff --git a/tools/testing/selftests/net/netfilter/config b/tools/testing/selftests/net/netfilter/config
index 5b5b764f6cd084..63ef80ef47a42c 100644
--- a/tools/testing/selftests/net/netfilter/config
+++ b/tools/testing/selftests/net/netfilter/config
@@ -86,3 +86,4 @@ CONFIG_VLAN_8021Q=m
 CONFIG_XFRM_USER=m
 CONFIG_XFRM_STATISTICS=y
 CONFIG_NET_PKTGEN=m
+CONFIG_TUN=m
diff --git a/tools/testing/selftests/net/netfilter/nf_conntrack_packetdrill.sh b/tools/testing/selftests/net/netfilter/nf_conntrack_packetdrill.sh
new file mode 100755
index 00000000000000..c6fdd2079f4db3
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/nf_conntrack_packetdrill.sh
@@ -0,0 +1,71 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+source lib.sh
+
+checktool "conntrack --version" "run test without conntrack"
+checktool "iptables --version" "run test without iptables"
+checktool "ip6tables --version" "run test without ip6tables"
+
+modprobe -q tun
+modprobe -q nf_conntrack
+# echo 1 > /proc/sys/net/netfilter/nf_log_all_netns
+
+PDRILL_TIMEOUT=10
+
+files="
+conntrack_ack_loss_stall.pkt
+conntrack_inexact_rst.pkt
+conntrack_syn_challenge_ack.pkt
+conntrack_synack_old.pkt
+conntrack_synack_reuse.pkt
+conntrack_rst_invalid.pkt
+"
+
+if ! packetdrill --dry_run --verbose "packetdrill/conntrack_ack_loss_stall.pkt";then
+	echo "SKIP: packetdrill not installed"
+	exit ${ksft_skip}
+fi
+
+ret=0
+
+run_packetdrill()
+{
+	filename="$1"
+	ipver="$2"
+	local mtu=1500
+
+	export NFCT_IP_VERSION="$ipver"
+
+	if [ "$ipver" = "ipv4" ];then
+		export xtables="iptables"
+	elif [ "$ipver" = "ipv6" ];then
+		export xtables="ip6tables"
+		mtu=1520
+	fi
+
+	timeout "$PDRILL_TIMEOUT" unshare -n packetdrill --ip_version="$ipver" --mtu=$mtu \
+		--tolerance_usecs=1000000 --non_fatal packet "$filename"
+}
+
+run_one_test_file()
+{
+	filename="$1"
+
+	for v in ipv4 ipv6;do
+		printf "%-50s(%s)%-20s" "$filename" "$v" ""
+		if run_packetdrill packetdrill/"$f" "$v";then
+			echo OK
+		else
+			echo FAIL
+			ret=1
+		fi
+	done
+}
+
+echo "Replaying packetdrill test cases:"
+for f in $files;do
+	run_one_test_file packetdrill/"$f"
+done
+
+exit $ret
diff --git a/tools/testing/selftests/net/netfilter/packetdrill/common.sh b/tools/testing/selftests/net/netfilter/packetdrill/common.sh
new file mode 100755
index 00000000000000..ed36d535196d0a
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/packetdrill/common.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# for debugging set net.netfilter.nf_log_all_netns=1 in init_net
+# or do not use net namespaces.
+modprobe -q nf_conntrack
+sysctl -q net.netfilter.nf_conntrack_log_invalid=6
+
+# Flush old cached data (fastopen cookies).
+ip tcp_metrics flush all > /dev/null 2>&1
+
+# TCP min, default, and max receive and send buffer sizes.
+sysctl -q net.ipv4.tcp_rmem="4096 540000 $((15*1024*1024))"
+sysctl -q net.ipv4.tcp_wmem="4096 $((256*1024)) 4194304"
+
+# TCP congestion control.
+sysctl -q net.ipv4.tcp_congestion_control=cubic
+
+# TCP slow start after idle.
+sysctl -q net.ipv4.tcp_slow_start_after_idle=0
+
+# TCP Explicit Congestion Notification (ECN)
+sysctl -q net.ipv4.tcp_ecn=0
+
+sysctl -q net.ipv4.tcp_notsent_lowat=4294967295 > /dev/null 2>&1
+
+# Override the default qdisc on the tun device.
+# Many tests fail with timing errors if the default
+# is FQ and that paces their flows.
+tc qdisc add dev tun0 root pfifo
+
+# Enable conntrack
+$xtables -A INPUT -m conntrack --ctstate NEW -p tcp --syn
diff --git a/tools/testing/selftests/net/netfilter/packetdrill/conntrack_ack_loss_stall.pkt b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_ack_loss_stall.pkt
new file mode 100644
index 00000000000000..d755bd64c54f15
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_ack_loss_stall.pkt
@@ -0,0 +1,118 @@
+// check that already-acked (retransmitted) packet is let through rather
+// than tagged as INVALID.
+
+`packetdrill/common.sh`
+
+// should set -P DROP but it disconnects VM w.o. extra netns
++0 `$xtables -A INPUT -m conntrack --ctstate INVALID -j DROP`
+
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
++0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
++0 bind(3, ..., ...) = 0
++0 listen(3, 10) = 0
+
++0 < S 0:0(0) win 32792 <mss 1000>
++0 > S. 0:0(0) ack 1 <mss 1460>
++.01 < . 1:1(0) ack 1 win 65535
++0 accept(3, ..., ...) = 4
+
++0.0001 < P. 1:1461(1460) ack 1 win 257
++.0 > . 1:1(0) ack 1461 win 65535
++0.0001 < P. 1461:2921(1460) ack 1 win 257
++.0 > . 1:1(0) ack 2921 win 65535
++0.0001 < P. 2921:4381(1460) ack 1 win 257
++.0 > . 1:1(0) ack 4381 win 65535
++0.0001 < P. 4381:5841(1460) ack 1 win 257
++.0 > . 1:1(0) ack 5841 win 65535
++0.0001 < P. 5841:7301(1460) ack 1 win 257
++.0 > . 1:1(0) ack 7301 win 65535
++0.0001 < P. 7301:8761(1460) ack 1 win 257
++.0 > . 1:1(0) ack 8761 win 65535
++0.0001 < P. 8761:10221(1460) ack 1 win 257
++.0 > . 1:1(0) ack 10221 win 65535
++0.0001 < P. 10221:11681(1460) ack 1 win 257
++.0 > . 1:1(0) ack 11681 win 65535
++0.0001 < P. 11681:13141(1460) ack 1 win 257
++.0 > . 1:1(0) ack 13141 win 65535
++0.0001 < P. 13141:14601(1460) ack 1 win 257
++.0 > . 1:1(0) ack 14601 win 65535
++0.0001 < P. 14601:16061(1460) ack 1 win 257
++.0 > . 1:1(0) ack 16061 win 65535
++0.0001 < P. 16061:17521(1460) ack 1 win 257
++.0 > . 1:1(0) ack 17521 win 65535
++0.0001 < P. 17521:18981(1460) ack 1 win 257
++.0 > . 1:1(0) ack 18981 win 65535
++0.0001 < P. 18981:20441(1460) ack 1 win 257
++.0 > . 1:1(0) ack 20441 win 65535
++0.0001 < P. 20441:21901(1460) ack 1 win 257
++.0 > . 1:1(0) ack 21901 win 65535
++0.0001 < P. 21901:23361(1460) ack 1 win 257
++.0 > . 1:1(0) ack 23361 win 65535
++0.0001 < P. 23361:24821(1460) ack 1 win 257
+0.055 > . 1:1(0) ack 24821 win 65535
++0.0001 < P. 24821:26281(1460) ack 1 win 257
++.0 > . 1:1(0) ack 26281 win 65535
++0.0001 < P. 26281:27741(1460) ack 1 win 257
++.0 > . 1:1(0) ack 27741 win 65535
++0.0001 < P. 27741:29201(1460) ack 1 win 257
++.0 > . 1:1(0) ack 29201 win 65535
++0.0001 < P. 29201:30661(1460) ack 1 win 257
++.0 > . 1:1(0) ack 30661 win 65535
++0.0001 < P. 30661:32121(1460) ack 1 win 257
++.0 > . 1:1(0) ack 32121 win 65535
++0.0001 < P. 32121:33581(1460) ack 1 win 257
++.0 > . 1:1(0) ack 33581 win 65535
++0.0001 < P. 33581:35041(1460) ack 1 win 257
++.0 > . 1:1(0) ack 35041 win 65535
++0.0001 < P. 35041:36501(1460) ack 1 win 257
++.0 > . 1:1(0) ack 36501 win 65535
++0.0001 < P. 36501:37961(1460) ack 1 win 257
++.0 > . 1:1(0) ack 37961 win 65535
++0.0001 < P. 37961:39421(1460) ack 1 win 257
++.0 > . 1:1(0) ack 39421 win 65535
++0.0001 < P. 39421:40881(1460) ack 1 win 257
++.0 > . 1:1(0) ack 40881 win 65535
++0.0001 < P. 40881:42341(1460) ack 1 win 257
++.0 > . 1:1(0) ack 42341 win 65535
++0.0001 < P. 42341:43801(1460) ack 1 win 257
++.0 > . 1:1(0) ack 43801 win 65535
++0.0001 < P. 43801:45261(1460) ack 1 win 257
++.0 > . 1:1(0) ack 45261 win 65535
++0.0001 < P. 45261:46721(1460) ack 1 win 257
++.0 > . 1:1(0) ack 46721 win 65535
++0.0001 < P. 46721:48181(1460) ack 1 win 257
++.0 > . 1:1(0) ack 48181 win 65535
++0.0001 < P. 48181:49641(1460) ack 1 win 257
++.0 > . 1:1(0) ack 49641 win 65535
++0.0001 < P. 49641:51101(1460) ack 1 win 257
++.0 > . 1:1(0) ack 51101 win 65535
++0.0001 < P. 51101:52561(1460) ack 1 win 257
++.0 > . 1:1(0) ack 52561 win 65535
++0.0001 < P. 52561:54021(1460) ack 1 win 257
++.0 > . 1:1(0) ack 54021 win 65535
++0.0001 < P. 54021:55481(1460) ack 1 win 257
++.0 > . 1:1(0) ack 55481 win 65535
++0.0001 < P. 55481:56941(1460) ack 1 win 257
++.0 > . 1:1(0) ack 56941 win 65535
++0.0001 < P. 56941:58401(1460) ack 1 win 257
++.0 > . 1:1(0) ack 58401 win 65535
++0.0001 < P. 58401:59861(1460) ack 1 win 257
++.0 > . 1:1(0) ack 59861 win 65535
++0.0001 < P. 59861:61321(1460) ack 1 win 257
++.0 > . 1:1(0) ack 61321 win 65535
++0.0001 < P. 61321:62781(1460) ack 1 win 257
++.0 > . 1:1(0) ack 62781 win 65535
++0.0001 < P. 62781:64241(1460) ack 1 win 257
++.0 > . 1:1(0) ack 64241 win 65535
++0.0001 < P. 64241:65701(1460) ack 1 win 257
++.0 > . 1:1(0) ack 65701 win 65535
++0.0001 < P. 65701:67161(1460) ack 1 win 257
++.0 > . 1:1(0) ack 67161 win 65535
+
+// nf_ct_proto_6: SEQ is under the lower bound (already ACKed data retransmitted) IN=tun0 OUT= MAC= SRC=192.0.2.1 DST=192.168.24.72 LEN=1500 TOS=0x00 PREC=0x00 TTL=255 ID=0 PROTO=TCP SPT=34375 DPT=8080 SEQ=1 ACK=4162510439 WINDOW=257 RES=0x00 ACK PSH URGP=0
++0.0001 < P. 1:1461(1460) ack 1 win 257
+
+// only sent if above packet isn't flagged as invalid
++.0 > . 1:1(0) ack 67161 win 65535
+
++0 `$xtables -D INPUT -m conntrack --ctstate INVALID -j DROP`
diff --git a/tools/testing/selftests/net/netfilter/packetdrill/conntrack_inexact_rst.pkt b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_inexact_rst.pkt
new file mode 100644
index 00000000000000..dccdd4c009c69d
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_inexact_rst.pkt
@@ -0,0 +1,62 @@
+// check RST packet that doesn't exactly match expected next sequence
+// number still transitions conntrack state to CLOSE iff its already in
+// FIN/CLOSE_WAIT.
+
+`packetdrill/common.sh`
+
+//  5.771921 server_ip > client_ip TLSv1.2 337 [Packet size limited during capture]
+//  5.771994 server_ip > client_ip TLSv1.2 337 [Packet size limited during capture]
+//  5.772212 client_ip > server_ip TCP 66 45020 > 443 [ACK] Seq=1905874048 Ack=781810658 Win=36352 Len=0 TSval=3317842872 TSecr=675936334
+//  5.787924 server_ip > client_ip TLSv1.2 1300 [Packet size limited during capture]
+//  5.788126 server_ip > client_ip TLSv1.2 90 Application Data
+//  5.788207 server_ip > client_ip TCP 66 443 > 45020 [FIN, ACK] Seq=781811916 Ack=1905874048 Win=31104 Len=0 TSval=675936350 TSecr=3317842872
+//  5.788447 client_ip > server_ip TLSv1.2 90 Application Data
+//  5.788479 client_ip > server_ip TCP 66 45020 > 443 [RST, ACK] Seq=1905874072 Ack=781811917 Win=39040 Len=0 TSval=3317842889 TSecr=675936350
+//  5.788581 server_ip > client_ip TCP 54 8443 > 45020 [RST] Seq=781811892 Win=0 Len=0
+
++0 `iptables -A INPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
++0 `iptables -A OUTPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
+
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
++0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+
+0.1 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress)
+
+0.1 > S 0:0(0) win 65535 <mss 1460,sackOK,TS val 1 ecr 0,nop,wscale 8>
+
++0.1 < S. 1:1(0) ack 1 win 65535 <mss 1460>
+
++0 > . 1:1(0) ack 1 win 65535
++0 < . 1:1001(1000) ack 1 win 65535
++0 < . 1001:2001(1000) ack 1 win 65535
++0 < . 2001:3001(1000) ack 1 win 65535
+
++0 > . 1:1(0) ack 1001 win 65535
++0 > . 1:1(0) ack 2001 win 65535
++0 > . 1:1(0) ack 3001 win 65535
+
++0 write(3, ..., 1000) = 1000
+
++0.0 > P. 1:1001(1000) ack 3001 win 65535
+
++0.1 read(3, ..., 1000) = 1000
+
+// Conntrack should move to FIN_WAIT, then CLOSE_WAIT.
++0 < F. 3001:3001(0) ack 1001 win 65535
++0 >  . 1001:1001(0) ack 3002 win 65535
+
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null |grep -q CLOSE_WAIT`
+
++1 close(3) = 0
+// RST: unread data. FIN was seen, hence ack + 1
++0 > R. 1001:1001(0) ack 3002 win 65535
+// ... and then, CLOSE.
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null |grep -q CLOSE\ `
+
+// Spurious RST from peer -- no sk state.  Should NOT get
+// marked INVALID, because conntrack is already closing.
++0.1 < R 2001:2001(0) win 0
+
+// No packets should have been marked INVALID
++0 `iptables -v -S INPUT  | grep INVALID | grep -q -- "-c 0 0"`
++0 `iptables -v -S OUTPUT | grep INVALID | grep -q -- "-c 0 0"`
diff --git a/tools/testing/selftests/net/netfilter/packetdrill/conntrack_rst_invalid.pkt b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_rst_invalid.pkt
new file mode 100644
index 00000000000000..686f18a3d9ef5f
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_rst_invalid.pkt
@@ -0,0 +1,59 @@
+// check that out of window resets are marked as INVALID and conntrack remains
+// in ESTABLISHED state.
+
+`packetdrill/common.sh`
+
++0 `$xtables -A INPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
++0 `$xtables -A OUTPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
+
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
++0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+
+0.1 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress)
+
+0.1 > S 0:0(0) win 65535 <mss 1460,sackOK,TS val 1 ecr 0,nop,wscale 8>
+
++0.1 < S. 1:1(0) ack 1 win 65535 <mss 1460>
+
++0 > . 1:1(0) ack 1 win 65535
++0 < . 1:1001(1000) ack 1 win 65535
++0 < . 1001:2001(1000) ack 1 win 65535
++0 < . 2001:3001(1000) ack 1 win 65535
+
++0 > . 1:1(0) ack 1001 win 65535
++0 > . 1:1(0) ack 2001 win 65535
++0 > . 1:1(0) ack 3001 win 65535
+
++0 write(3, ..., 1000) = 1000
+
+// out of window
++0.0 < R	0:0(0)	win 0
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null |grep -q ESTABLISHED`
+
+// out of window
++0.0 < R	1000000:1000000(0)	win 0
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null |grep -q ESTABLISHED`
+
+// in-window but not exact match
++0.0 < R	42:42(0)	win 0
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null |grep -q ESTABLISHED`
+
++0.0 > P. 1:1001(1000) ack 3001 win 65535
+
++0.1 read(3, ..., 1000) = 1000
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null |grep -q ESTABLISHED`
+
++0 < . 3001:3001(0) ack 1001 win 65535
+
++0.0 < R. 3000:3000(0) ack 1001 win 0
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null |grep -q ESTABLISHED`
+
+// exact next sequence
++0.0 < R. 3001:3001(0) ack 1001 win 0
+// Conntrack should move to CLOSE
+
+// Expect four invalid RSTs
++0 `$xtables -v -S INPUT  | grep INVALID | grep -q -- "-c 4 "`
++0 `$xtables -v -S OUTPUT | grep INVALID | grep -q -- "-c 0 0"`
+
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null |grep -q CLOSE\ `
diff --git a/tools/testing/selftests/net/netfilter/packetdrill/conntrack_syn_challenge_ack.pkt b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_syn_challenge_ack.pkt
new file mode 100644
index 00000000000000..3442cd29bc9320
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_syn_challenge_ack.pkt
@@ -0,0 +1,44 @@
+// Check connection re-use, i.e. peer that receives the SYN answers with
+// a challenge-ACK.
+// Check that conntrack lets all packets pass, including the challenge ack,
+// and that a new connection is established.
+
+`packetdrill/common.sh`
+
+// S  >
+//  . < (challnge-ack)
+// R. >
+// S  >
+// S. <
+// Expected outcome: established connection.
+
++0 `$xtables -A INPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
++0 `$xtables -A OUTPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
+
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
++0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+
+0.1 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress)
+0.1 > S 0:0(0) win 65535 <mss 1460,sackOK,TS val 1 ecr 0,nop,wscale 8>
+
+// Challenge ACK, old incarnation.
+0.1 < . 145824453:145824453(0) ack 643160523 win 240 <mss 1460,nop,nop,TS val 1 ecr 1,nop,wscale 0>
+
++0.01 > R 643160523:643160523(0) win 0
+
++0.01 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null | grep UNREPLIED | grep -q SYN_SENT`
+
+// Must go through.
++0.01 > S 0:0(0) win 65535 <mss 1460,sackOK,TS val 1 ecr 0,nop,wscale 8>
+
+// correct synack
++0.1 < S. 0:0(0) ack 1 win 250 <mss 1460,nop,nop,TS val 1 ecr 1,nop,wscale 0>
+
+// 3whs completes.
++0.01 > . 1:1(0) ack 1 win 256 <nop,nop,TS val 1 ecr 1>
+
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null | grep ESTABLISHED | grep -q ASSURED`
+
+// No packets should have been marked INVALID
++0 `$xtables -v -S INPUT  | grep INVALID | grep -q -- "-c 0 0"`
++0 `$xtables -v -S OUTPUT | grep INVALID | grep -q -- "-c 0 0"`
diff --git a/tools/testing/selftests/net/netfilter/packetdrill/conntrack_synack_old.pkt b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_synack_old.pkt
new file mode 100644
index 00000000000000..3047160c4bf3f8
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_synack_old.pkt
@@ -0,0 +1,51 @@
+// Check conntrack copes with syn/ack reply for a previous, old incarnation.
+
+// tcpdump with buggy sequence
+// 10.176.25.8.829 > 10.192.171.30.2049: Flags [S], seq 2375731741, win 29200, options [mss 1460,sackOK,TS val 2083107423 ecr 0,nop,wscale 7], length 0
+// OLD synack, for old/previous S
+// 10.192.171.30.2049 > 10.176.25.8.829: Flags [S.], seq 145824453, ack 643160523, win 65535, options [mss 8952,nop,wscale 5,TS val 3215437785 ecr 2082921663,nop,nop], length 0
+// This reset never makes it to the endpoint, elided in the packetdrill script
+// 10.192.171.30.2049 > 10.176.25.8.829: Flags [R.], seq 1, ack 1, win 65535, options [mss 8952,nop,wscale 5,TS val 3215443451 ecr 2082921663,nop,nop], length 0
+// Syn retransmit, no change
+// 10.176.25.8.829 > 10.192.171.30.2049: Flags [S], seq 2375731741, win 29200, options [mss 1460,sackOK,TS val 2083115583 ecr 0,nop,wscale 7], length 0
+// CORRECT synack, should be accepted, but conntrack classified this as INVALID:
+// SEQ is over the upper bound (over the window of the receiver) IN=tun0 OUT= MAC= SRC=192.0.2.1 DST=192.168.37.78 LEN=40 TOS=0x00 PREC=0x00 TTL=255 ID=0 PROTO=TCP SPT=8080 DPT=34500 SEQ=162602411 ACK=2124350315 ..
+// 10.192.171.30.2049 > 10.176.25.8.829: Flags [S.], seq 162602410, ack 2375731742, win 65535, options [mss 8952,nop,wscale 5,TS val 3215445754 ecr 2083115583,nop,nop], length 0
+
+`packetdrill/common.sh`
+
++0 `$xtables -A INPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
++0 `$xtables -A OUTPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
+
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
++0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+
+0.1 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress)
+0.1 > S 0:0(0) win 65535 <mss 1460,sackOK,TS val 1 ecr 0,nop,wscale 8>
+
+// bogus/outdated synack, invalid ack value
+0.1 < S. 145824453:145824453(0) ack 643160523 win 240 <mss 1440,nop,nop,TS val 1 ecr 1,nop,wscale 0>
+
+// syn retransmitted
+1.01 > S 0:0(0) win 65535 <mss 1460,sackOK,TS val 1015 ecr 0,nop,wscale 8>
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null | grep UNREPLIED | grep -q SYN_SENT`
+
+// correct synack
++0 < S. 145758918:145758918(0) ack 1 win 250 <mss 1460,nop,nop,TS val 1 ecr 1,nop,wscale 0>
++0 write(3, ..., 1) = 1
+
+// with buggy conntrack above packet is dropped, so SYN rtx is seen:
+// script packet:  1.054007 . 1:1(0) ack 16777958 win 256 <nop,nop,TS val 1033 ecr 1>
+// actual packet:  3.010000 S 0:0(0) win 65535 <mss 1460,sackOK,TS val 1015 ecr 0,nop,wscale 8>
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null | grep ESTABLISHED | grep -q ASSURED`
+
++0 > P. 1:2(1) ack 4294901762 win 256 <nop,nop,TS val 1067 ecr 1>
+
++0 `conntrack -f $NFCT_IP_VERSION -L -p tcp --dport 8080 2>/dev/null | grep ASSURED | grep -q ESTABLISHED`
+
+// No packets should have been marked INVALID in OUTPUT direction, 1 in INPUT
++0 `$xtables -v -S OUTPUT | grep INVALID | grep -q -- "-c 0 0"`
++0 `$xtables -v -S INPUT  | grep INVALID | grep -q -- "-c 1 "`
+
++0 `$xtables -D INPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
++0 `$xtables -D OUTPUT -p tcp -m conntrack --ctstate INVALID -j DROP`
diff --git a/tools/testing/selftests/net/netfilter/packetdrill/conntrack_synack_reuse.pkt b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_synack_reuse.pkt
new file mode 100644
index 00000000000000..21e1bb6395e4eb
--- /dev/null
+++ b/tools/testing/selftests/net/netfilter/packetdrill/conntrack_synack_reuse.pkt
@@ -0,0 +1,34 @@
+// Check reception of another SYN while we have an established conntrack state.
+// Challenge ACK is supposed to pass through, RST reply should clear conntrack
+// state and SYN retransmit should give us new 'SYN_RECV' connection state.
+
+`packetdrill/common.sh`
+
+// should show a match if bug is present:
++0 `iptables -A INPUT -m conntrack --ctstate INVALID -p tcp --tcp-flags SYN,ACK SYN,ACK`
+
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
++0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
++0 bind(3, ..., ...) = 0
++0 listen(3, 10) = 0
+
++0 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7, TS val 1 ecr 0,nop,nop>
++0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,TS val 100 ecr 1,nop,wscale 8>
++.01 < . 1:1(0) ack 1 win 257 <TS val 1 ecr 100,nop,nop>
++0 accept(3, ..., ...) = 4
+
++0 < P. 1:101(100) ack 1 win 257 <TS val 2 ecr 100,nop,nop>
++.001 > . 1:1(0) ack 101 win 256 <nop,nop,TS val 110 ecr 2>
++0 read(4, ..., 101) = 100
+
+1.0 < S 2000:2000(0) win 32792 <mss 1000,nop,wscale 7, TS val 233 ecr 0,nop,nop>
+// Won't expect this: challenge ack.
+
++0 > . 1:1(0) ack 101 win 256 <nop,nop,TS val 112 ecr 2>
++0 < R. 101:101(0) ack 1 win 257
++0 close(4) = 0
+
+1.5 < S 2000:2000(0) win 32792 <mss 1000,nop,wscale 0, TS val 233 ecr 0,nop,nop>
+
++0 `conntrack -L -p tcp --dport 8080 2>/dev/null | grep -q SYN_RECV`
++0 `iptables -v -S INPUT | grep INVALID | grep -q -- "-c 0 0"`

From fa23e0d4b756d25829e124d6b670a4c6bbd4bf7e Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Wed, 8 May 2024 14:52:47 +0200
Subject: [PATCH 17/17] netfilter: nf_tables: allow clone callbacks to sleep

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>
---
 include/net/netfilter/nf_tables.h |  4 ++--
 net/netfilter/nf_tables_api.c     |  8 ++++----
 net/netfilter/nft_connlimit.c     |  4 ++--
 net/netfilter/nft_counter.c       |  4 ++--
 net/netfilter/nft_dynset.c        |  2 +-
 net/netfilter/nft_last.c          |  4 ++--
 net/netfilter/nft_limit.c         | 14 ++++++++------
 net/netfilter/nft_quota.c         |  4 ++--
 8 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 3f1ed467f951f6..2796153b03dad3 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -416,7 +416,7 @@ struct nft_expr_info;
 
 int nft_expr_inner_parse(const struct nft_ctx *ctx, const struct nlattr *nla,
 			 struct nft_expr_info *info);
-int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src);
+int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src, gfp_t gfp);
 void nft_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr);
 int nft_expr_dump(struct sk_buff *skb, unsigned int attr,
 		  const struct nft_expr *expr, bool reset);
@@ -935,7 +935,7 @@ struct nft_expr_ops {
 						struct nft_regs *regs,
 						const struct nft_pktinfo *pkt);
 	int				(*clone)(struct nft_expr *dst,
-						 const struct nft_expr *src);
+						 const struct nft_expr *src, gfp_t gfp);
 	unsigned int			size;
 
 	int				(*init)(const struct nft_ctx *ctx,
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index a7f54eb68d9a00..be3b4c90d2eda1 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3333,7 +3333,7 @@ static struct nft_expr *nft_expr_init(const struct nft_ctx *ctx,
 	return ERR_PTR(err);
 }
 
-int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
+int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src, gfp_t gfp)
 {
 	int err;
 
@@ -3341,7 +3341,7 @@ int nft_expr_clone(struct nft_expr *dst, struct nft_expr *src)
 		return -EINVAL;
 
 	dst->ops = src->ops;
-	err = src->ops->clone(dst, src);
+	err = src->ops->clone(dst, src, gfp);
 	if (err < 0)
 		return err;
 
@@ -6525,7 +6525,7 @@ int nft_set_elem_expr_clone(const struct nft_ctx *ctx, struct nft_set *set,
 		if (!expr)
 			goto err_expr;
 
-		err = nft_expr_clone(expr, set->exprs[i]);
+		err = nft_expr_clone(expr, set->exprs[i], GFP_KERNEL_ACCOUNT);
 		if (err < 0) {
 			kfree(expr);
 			goto err_expr;
@@ -6564,7 +6564,7 @@ static int nft_set_elem_expr_setup(struct nft_ctx *ctx,
 
 	for (i = 0; i < num_exprs; i++) {
 		expr = nft_setelem_expr_at(elem_expr, elem_expr->size);
-		err = nft_expr_clone(expr, expr_array[i]);
+		err = nft_expr_clone(expr, expr_array[i], GFP_KERNEL_ACCOUNT);
 		if (err < 0)
 			goto err_elem_expr_setup;
 
diff --git a/net/netfilter/nft_connlimit.c b/net/netfilter/nft_connlimit.c
index de9d1980df6964..92b984fa8175c2 100644
--- a/net/netfilter/nft_connlimit.c
+++ b/net/netfilter/nft_connlimit.c
@@ -210,12 +210,12 @@ static void nft_connlimit_destroy(const struct nft_ctx *ctx,
 	nft_connlimit_do_destroy(ctx, priv);
 }
 
-static int nft_connlimit_clone(struct nft_expr *dst, const struct nft_expr *src)
+static int nft_connlimit_clone(struct nft_expr *dst, const struct nft_expr *src, gfp_t gfp)
 {
 	struct nft_connlimit *priv_dst = nft_expr_priv(dst);
 	struct nft_connlimit *priv_src = nft_expr_priv(src);
 
-	priv_dst->list = kmalloc(sizeof(*priv_dst->list), GFP_ATOMIC);
+	priv_dst->list = kmalloc(sizeof(*priv_dst->list), gfp);
 	if (!priv_dst->list)
 		return -ENOMEM;
 
diff --git a/net/netfilter/nft_counter.c b/net/netfilter/nft_counter.c
index dccc68a5135add..291ed2026367ec 100644
--- a/net/netfilter/nft_counter.c
+++ b/net/netfilter/nft_counter.c
@@ -226,7 +226,7 @@ static void nft_counter_destroy(const struct nft_ctx *ctx,
 	nft_counter_do_destroy(priv);
 }
 
-static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
+static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src, gfp_t gfp)
 {
 	struct nft_counter_percpu_priv *priv = nft_expr_priv(src);
 	struct nft_counter_percpu_priv *priv_clone = nft_expr_priv(dst);
@@ -236,7 +236,7 @@ static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src)
 
 	nft_counter_fetch(priv, &total);
 
-	cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_ATOMIC);
+	cpu_stats = alloc_percpu_gfp(struct nft_counter, gfp);
 	if (cpu_stats == NULL)
 		return -ENOMEM;
 
diff --git a/net/netfilter/nft_dynset.c b/net/netfilter/nft_dynset.c
index c09dba57354c17..b4ada3ab21679b 100644
--- a/net/netfilter/nft_dynset.c
+++ b/net/netfilter/nft_dynset.c
@@ -35,7 +35,7 @@ static int nft_dynset_expr_setup(const struct nft_dynset *priv,
 
 	for (i = 0; i < priv->num_exprs; i++) {
 		expr = nft_setelem_expr_at(elem_expr, elem_expr->size);
-		if (nft_expr_clone(expr, priv->expr_array[i]) < 0)
+		if (nft_expr_clone(expr, priv->expr_array[i], GFP_ATOMIC) < 0)
 			return -1;
 
 		elem_expr->size += priv->expr_array[i]->ops->size;
diff --git a/net/netfilter/nft_last.c b/net/netfilter/nft_last.c
index 8e6d7eaf9dc8b5..de1b6066bfa856 100644
--- a/net/netfilter/nft_last.c
+++ b/net/netfilter/nft_last.c
@@ -102,12 +102,12 @@ static void nft_last_destroy(const struct nft_ctx *ctx,
 	kfree(priv->last);
 }
 
-static int nft_last_clone(struct nft_expr *dst, const struct nft_expr *src)
+static int nft_last_clone(struct nft_expr *dst, const struct nft_expr *src, gfp_t gfp)
 {
 	struct nft_last_priv *priv_dst = nft_expr_priv(dst);
 	struct nft_last_priv *priv_src = nft_expr_priv(src);
 
-	priv_dst->last = kzalloc(sizeof(*priv_dst->last), GFP_ATOMIC);
+	priv_dst->last = kzalloc(sizeof(*priv_dst->last), gfp);
 	if (!priv_dst->last)
 		return -ENOMEM;
 
diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c
index cefa25e0dbb0a2..21d26b79b46072 100644
--- a/net/netfilter/nft_limit.c
+++ b/net/netfilter/nft_limit.c
@@ -150,7 +150,7 @@ static void nft_limit_destroy(const struct nft_ctx *ctx,
 }
 
 static int nft_limit_clone(struct nft_limit_priv *priv_dst,
-			   const struct nft_limit_priv *priv_src)
+			   const struct nft_limit_priv *priv_src, gfp_t gfp)
 {
 	priv_dst->tokens_max = priv_src->tokens_max;
 	priv_dst->rate = priv_src->rate;
@@ -158,7 +158,7 @@ static int nft_limit_clone(struct nft_limit_priv *priv_dst,
 	priv_dst->burst = priv_src->burst;
 	priv_dst->invert = priv_src->invert;
 
-	priv_dst->limit = kmalloc(sizeof(*priv_dst->limit), GFP_ATOMIC);
+	priv_dst->limit = kmalloc(sizeof(*priv_dst->limit), gfp);
 	if (!priv_dst->limit)
 		return -ENOMEM;
 
@@ -223,14 +223,15 @@ static void nft_limit_pkts_destroy(const struct nft_ctx *ctx,
 	nft_limit_destroy(ctx, &priv->limit);
 }
 
-static int nft_limit_pkts_clone(struct nft_expr *dst, const struct nft_expr *src)
+static int nft_limit_pkts_clone(struct nft_expr *dst, const struct nft_expr *src,
+				gfp_t gfp)
 {
 	struct nft_limit_priv_pkts *priv_dst = nft_expr_priv(dst);
 	struct nft_limit_priv_pkts *priv_src = nft_expr_priv(src);
 
 	priv_dst->cost = priv_src->cost;
 
-	return nft_limit_clone(&priv_dst->limit, &priv_src->limit);
+	return nft_limit_clone(&priv_dst->limit, &priv_src->limit, gfp);
 }
 
 static struct nft_expr_type nft_limit_type;
@@ -281,12 +282,13 @@ static void nft_limit_bytes_destroy(const struct nft_ctx *ctx,
 	nft_limit_destroy(ctx, priv);
 }
 
-static int nft_limit_bytes_clone(struct nft_expr *dst, const struct nft_expr *src)
+static int nft_limit_bytes_clone(struct nft_expr *dst, const struct nft_expr *src,
+				 gfp_t gfp)
 {
 	struct nft_limit_priv *priv_dst = nft_expr_priv(dst);
 	struct nft_limit_priv *priv_src = nft_expr_priv(src);
 
-	return nft_limit_clone(priv_dst, priv_src);
+	return nft_limit_clone(priv_dst, priv_src, gfp);
 }
 
 static const struct nft_expr_ops nft_limit_bytes_ops = {
diff --git a/net/netfilter/nft_quota.c b/net/netfilter/nft_quota.c
index 3ba12a7471b0f6..9b2d7463d3d326 100644
--- a/net/netfilter/nft_quota.c
+++ b/net/netfilter/nft_quota.c
@@ -233,7 +233,7 @@ static void nft_quota_destroy(const struct nft_ctx *ctx,
 	return nft_quota_do_destroy(ctx, priv);
 }
 
-static int nft_quota_clone(struct nft_expr *dst, const struct nft_expr *src)
+static int nft_quota_clone(struct nft_expr *dst, const struct nft_expr *src, gfp_t gfp)
 {
 	struct nft_quota *priv_dst = nft_expr_priv(dst);
 	struct nft_quota *priv_src = nft_expr_priv(src);
@@ -241,7 +241,7 @@ static int nft_quota_clone(struct nft_expr *dst, const struct nft_expr *src)
 	priv_dst->quota = priv_src->quota;
 	priv_dst->flags = priv_src->flags;
 
-	priv_dst->consumed = kmalloc(sizeof(*priv_dst->consumed), GFP_ATOMIC);
+	priv_dst->consumed = kmalloc(sizeof(*priv_dst->consumed), gfp);
 	if (!priv_dst->consumed)
 		return -ENOMEM;