[PATCH 0/7] Netfilter fixes for net

[PATCH 0/7] Netfilter fixes for net

[Pablo Neira Ayuso]

Hi,

The following patchset contains Netfilter fixes for net:

1) A new selftest for nf_queue, from Florian Westphal. This test
   covers two recent fixes: 07f8e4d0fddb ("tcp: also NULL skb->dev
   when copy was needed") and b738a185beaa ("tcp: ensure skb->dev is
   NULL before leaving TCP stack").

2) The fwd action breaks with ifb. For safety in next extensions,
   make sure the fwd action only runs from ingress until it is extended
   to be used from a different hook.

3) The pipapo set type now reports EEXIST in case of subrange overlaps.
   Update the rbtree set to validate range overlaps, so far this
   validation is only done only from userspace. From Stefano Brivio.

You can pull these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git

Thank you.

----------------------------------------------------------------

The following changes since commit 749f6f6843115b424680f1aada3c0dd613ad807c:

  net: phy: dp83867: w/a for fld detect threshold bootstrapping issue (2020-03-21 20:09:57 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git HEAD

for you to fetch changes up to a64d558d8cf98424cc5eb9ae6631782cd8bf789c:

  selftests: netfilter: add nfqueue test case (2020-03-24 20:00:12 +0100)

----------------------------------------------------------------
Florian Westphal (1):
      selftests: netfilter: add nfqueue test case

Pablo Neira Ayuso (3):
      netfilter: nf_tables: Allow set back-ends to report partial overlaps on insertion
      netfilter: nft_fwd_netdev: validate family and chain type
      netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress

Stefano Brivio (3):
      netfilter: nft_set_pipapo: Separate partial and complete overlap cases on insertion
      netfilter: nft_set_rbtree: Introduce and use nft_rbtree_interval_start()
      netfilter: nft_set_rbtree: Detect partial overlaps on insertion

 net/netfilter/nf_tables_api.c                  |   5 +
 net/netfilter/nft_fwd_netdev.c                 |  13 +
 net/netfilter/nft_set_pipapo.c                 |  34 ++-
 net/netfilter/nft_set_rbtree.c                 |  87 +++++-
 tools/testing/selftests/netfilter/Makefile     |   6 +-
 tools/testing/selftests/netfilter/config       |   6 +
 tools/testing/selftests/netfilter/nf-queue.c   | 352 +++++++++++++++++++++++++
 tools/testing/selftests/netfilter/nft_queue.sh | 332 +++++++++++++++++++++++
 8 files changed, 818 insertions(+), 17 deletions(-)
 create mode 100644 tools/testing/selftests/netfilter/nf-queue.c
 create mode 100755 tools/testing/selftests/netfilter/nft_queue.sh

[PATCH 1/7] netfilter: nf_tables: Allow set back-ends to report partial overlaps on insertion

[Pablo Neira Ayuso]

Currently, the -EEXIST return code of ->insert() callbacks is ambiguous: it
might indicate that a given element (including intervals) already exists as
such, or that the new element would clash with existing ones.

If identical elements already exist, the front-end is ignoring this without
returning error, in case NLM_F_EXCL is not set. However, if the new element
can't be inserted due an overlap, we should report this to the user.

To this purpose, allow set back-ends to return -ENOTEMPTY on collision with
existing elements, translate that to -EEXIST, and return that to userspace,
no matter if NLM_F_EXCL was set.

Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 38c680f28f15..d11f1a74d43c 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -5082,6 +5082,11 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 				err = -EBUSY;
 			else if (!(nlmsg_flags & NLM_F_EXCL))
 				err = 0;
+		} else if (err == -ENOTEMPTY) {
+			/* ENOTEMPTY reports overlapping between this element
+			 * and an existing one.
+			 */
+			err = -EEXIST;
 		}
 		goto err_element_clash;
 	}
-- 
2.11.0

[PATCH 2/7] netfilter: nft_set_pipapo: Separate partial and complete overlap cases on insertion

[Pablo Neira Ayuso]

From: Stefano Brivio <sbrivio@redhat.com>

...and return -ENOTEMPTY to the front-end on collision, -EEXIST if
an identical element already exists. Together with the previous patch,
element collision will now be returned to the user as -EEXIST.

Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_pipapo.c | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 4fc0c924ed5d..ef7e8ad2e344 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -1098,21 +1098,41 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	struct nft_pipapo_field *f;
 	int i, bsize_max, err = 0;
 
+	if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END))
+		end = (const u8 *)nft_set_ext_key_end(ext)->data;
+	else
+		end = start;
+
 	dup = pipapo_get(net, set, start, genmask);
-	if (PTR_ERR(dup) == -ENOENT) {
-		if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END)) {
-			end = (const u8 *)nft_set_ext_key_end(ext)->data;
-			dup = pipapo_get(net, set, end, nft_genmask_next(net));
-		} else {
-			end = start;
+	if (!IS_ERR(dup)) {
+		/* Check if we already have the same exact entry */
+		const struct nft_data *dup_key, *dup_end;
+
+		dup_key = nft_set_ext_key(&dup->ext);
+		if (nft_set_ext_exists(&dup->ext, NFT_SET_EXT_KEY_END))
+			dup_end = nft_set_ext_key_end(&dup->ext);
+		else
+			dup_end = dup_key;
+
+		if (!memcmp(start, dup_key->data, sizeof(*dup_key->data)) &&
+		    !memcmp(end, dup_end->data, sizeof(*dup_end->data))) {
+			*ext2 = &dup->ext;
+			return -EEXIST;
 		}
+
+		return -ENOTEMPTY;
+	}
+
+	if (PTR_ERR(dup) == -ENOENT) {
+		/* Look for partially overlapping entries */
+		dup = pipapo_get(net, set, end, nft_genmask_next(net));
 	}
 
 	if (PTR_ERR(dup) != -ENOENT) {
 		if (IS_ERR(dup))
 			return PTR_ERR(dup);
 		*ext2 = &dup->ext;
-		return -EEXIST;
+		return -ENOTEMPTY;
 	}
 
 	/* Validate */
-- 
2.11.0

[PATCH 3/7] netfilter: nft_set_rbtree: Introduce and use nft_rbtree_interval_start()

[Pablo Neira Ayuso]

From: Stefano Brivio <sbrivio@redhat.com>

Replace negations of nft_rbtree_interval_end() with a new helper,
nft_rbtree_interval_start(), wherever this helps to visualise the
problem at hand, that is, for all the occurrences except for the
comparison against given flags in __nft_rbtree_get().

This gets especially useful in the next patch.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_rbtree.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index 5000b938ab1e..85572b2a6051 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -33,6 +33,11 @@ static bool nft_rbtree_interval_end(const struct nft_rbtree_elem *rbe)
 	       (*nft_set_ext_flags(&rbe->ext) & NFT_SET_ELEM_INTERVAL_END);
 }
 
+static bool nft_rbtree_interval_start(const struct nft_rbtree_elem *rbe)
+{
+	return !nft_rbtree_interval_end(rbe);
+}
+
 static bool nft_rbtree_equal(const struct nft_set *set, const void *this,
 			     const struct nft_rbtree_elem *interval)
 {
@@ -64,7 +69,7 @@ static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set
 			if (interval &&
 			    nft_rbtree_equal(set, this, interval) &&
 			    nft_rbtree_interval_end(rbe) &&
-			    !nft_rbtree_interval_end(interval))
+			    nft_rbtree_interval_start(interval))
 				continue;
 			interval = rbe;
 		} else if (d > 0)
@@ -89,7 +94,7 @@ static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set
 
 	if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
 	    nft_set_elem_active(&interval->ext, genmask) &&
-	    !nft_rbtree_interval_end(interval)) {
+	    nft_rbtree_interval_start(interval)) {
 		*ext = &interval->ext;
 		return true;
 	}
@@ -224,9 +229,9 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 			p = &parent->rb_right;
 		else {
 			if (nft_rbtree_interval_end(rbe) &&
-			    !nft_rbtree_interval_end(new)) {
+			    nft_rbtree_interval_start(new)) {
 				p = &parent->rb_left;
-			} else if (!nft_rbtree_interval_end(rbe) &&
+			} else if (nft_rbtree_interval_start(rbe) &&
 				   nft_rbtree_interval_end(new)) {
 				p = &parent->rb_right;
 			} else if (nft_set_elem_active(&rbe->ext, genmask)) {
@@ -317,10 +322,10 @@ static void *nft_rbtree_deactivate(const struct net *net,
 			parent = parent->rb_right;
 		else {
 			if (nft_rbtree_interval_end(rbe) &&
-			    !nft_rbtree_interval_end(this)) {
+			    nft_rbtree_interval_start(this)) {
 				parent = parent->rb_left;
 				continue;
-			} else if (!nft_rbtree_interval_end(rbe) &&
+			} else if (nft_rbtree_interval_start(rbe) &&
 				   nft_rbtree_interval_end(this)) {
 				parent = parent->rb_right;
 				continue;
-- 
2.11.0

[PATCH 4/7] netfilter: nft_set_rbtree: Detect partial overlaps on insertion

[Pablo Neira Ayuso]

From: Stefano Brivio <sbrivio@redhat.com>

...and return -ENOTEMPTY to the front-end in this case, instead of
proceeding. Currently, nft takes care of checking for these cases
and not sending them to the kernel, but if we drop the set_overlap()
call in nft we can end up in situations like:

 # nft add table t
 # nft add set t s '{ type inet_service ; flags interval ; }'
 # nft add element t s '{ 1 - 5 }'
 # nft add element t s '{ 6 - 10 }'
 # nft add element t s '{ 4 - 7 }'
 # nft list set t s
 table ip t {
 	set s {
 		type inet_service
 		flags interval
 		elements = { 1-3, 4-5, 6-7 }
 	}
 }

This change has the primary purpose of making the behaviour
consistent with nft_set_pipapo, but is also functional to avoid
inconsistent behaviour if userspace sends overlapping elements for
any reason.

v2: When we meet the same key data in the tree, as start element while
    inserting an end element, or as end element while inserting a start
    element, actually check that the existing element is active, before
    resetting the overlap flag (Pablo Neira Ayuso)

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_set_rbtree.c | 70 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 67 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index 85572b2a6051..8617fc16a1ed 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -213,8 +213,43 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 	u8 genmask = nft_genmask_next(net);
 	struct nft_rbtree_elem *rbe;
 	struct rb_node *parent, **p;
+	bool overlap = false;
 	int d;
 
+	/* Detect overlaps as we descend the tree. Set the flag in these cases:
+	 *
+	 * a1. |__ _ _?  >|__ _ _  (insert start after existing start)
+	 * a2. _ _ __>|  ?_ _ __|  (insert end before existing end)
+	 * a3. _ _ ___|  ?_ _ _>|  (insert end after existing end)
+	 * a4. >|__ _ _   _ _ __|  (insert start before existing end)
+	 *
+	 * and clear it later on, as we eventually reach the points indicated by
+	 * '?' above, in the cases described below. We'll always meet these
+	 * later, locally, due to tree ordering, and overlaps for the intervals
+	 * that are the closest together are always evaluated last.
+	 *
+	 * b1. |__ _ _!  >|__ _ _  (insert start after existing end)
+	 * b2. _ _ __>|  !_ _ __|  (insert end before existing start)
+	 * b3. !_____>|            (insert end after existing start)
+	 *
+	 * Case a4. resolves to b1.:
+	 * - if the inserted start element is the leftmost, because the '0'
+	 *   element in the tree serves as end element
+	 * - otherwise, if an existing end is found. Note that end elements are
+	 *   always inserted after corresponding start elements.
+	 *
+	 * For a new, rightmost pair of elements, we'll hit cases b1. and b3.,
+	 * in that order.
+	 *
+	 * The flag is also cleared in two special cases:
+	 *
+	 * b4. |__ _ _!|<_ _ _   (insert start right before existing end)
+	 * b5. |__ _ >|!__ _ _   (insert end right after existing start)
+	 *
+	 * which always happen as last step and imply that no further
+	 * overlapping is possible.
+	 */
+
 	parent = NULL;
 	p = &priv->root.rb_node;
 	while (*p != NULL) {
@@ -223,17 +258,42 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 		d = memcmp(nft_set_ext_key(&rbe->ext),
 			   nft_set_ext_key(&new->ext),
 			   set->klen);
-		if (d < 0)
+		if (d < 0) {
 			p = &parent->rb_left;
-		else if (d > 0)
+
+			if (nft_rbtree_interval_start(new)) {
+				overlap = nft_rbtree_interval_start(rbe) &&
+					  nft_set_elem_active(&rbe->ext,
+							      genmask);
+			} else {
+				overlap = nft_rbtree_interval_end(rbe) &&
+					  nft_set_elem_active(&rbe->ext,
+							      genmask);
+			}
+		} else if (d > 0) {
 			p = &parent->rb_right;
-		else {
+
+			if (nft_rbtree_interval_end(new)) {
+				overlap = nft_rbtree_interval_end(rbe) &&
+					  nft_set_elem_active(&rbe->ext,
+							      genmask);
+			} else if (nft_rbtree_interval_end(rbe) &&
+				   nft_set_elem_active(&rbe->ext, genmask)) {
+				overlap = true;
+			}
+		} else {
 			if (nft_rbtree_interval_end(rbe) &&
 			    nft_rbtree_interval_start(new)) {
 				p = &parent->rb_left;
+
+				if (nft_set_elem_active(&rbe->ext, genmask))
+					overlap = false;
 			} else if (nft_rbtree_interval_start(rbe) &&
 				   nft_rbtree_interval_end(new)) {
 				p = &parent->rb_right;
+
+				if (nft_set_elem_active(&rbe->ext, genmask))
+					overlap = false;
 			} else if (nft_set_elem_active(&rbe->ext, genmask)) {
 				*ext = &rbe->ext;
 				return -EEXIST;
@@ -242,6 +302,10 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 			}
 		}
 	}
+
+	if (overlap)
+		return -ENOTEMPTY;
+
 	rb_link_node_rcu(&new->node, parent, p);
 	rb_insert_color(&new->node, &priv->root);
 	return 0;
-- 
2.11.0

[PATCH 5/7] netfilter: nft_fwd_netdev: validate family and chain type

[Pablo Neira Ayuso]

Make sure the forward action is only used from ingress.

Fixes: 39e6dea28adc ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_fwd_netdev.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/netfilter/nft_fwd_netdev.c b/net/netfilter/nft_fwd_netdev.c
index aba11c2333f3..ddd28de810b6 100644
--- a/net/netfilter/nft_fwd_netdev.c
+++ b/net/netfilter/nft_fwd_netdev.c
@@ -190,6 +190,13 @@ static int nft_fwd_neigh_dump(struct sk_buff *skb, const struct nft_expr *expr)
 	return -1;
 }
 
+static int nft_fwd_validate(const struct nft_ctx *ctx,
+			    const struct nft_expr *expr,
+			    const struct nft_data **data)
+{
+	return nft_chain_validate_hooks(ctx->chain, (1 << NF_NETDEV_INGRESS));
+}
+
 static struct nft_expr_type nft_fwd_netdev_type;
 static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = {
 	.type		= &nft_fwd_netdev_type,
@@ -197,6 +204,7 @@ static const struct nft_expr_ops nft_fwd_neigh_netdev_ops = {
 	.eval		= nft_fwd_neigh_eval,
 	.init		= nft_fwd_neigh_init,
 	.dump		= nft_fwd_neigh_dump,
+	.validate	= nft_fwd_validate,
 };
 
 static const struct nft_expr_ops nft_fwd_netdev_ops = {
@@ -205,6 +213,7 @@ static const struct nft_expr_ops nft_fwd_netdev_ops = {
 	.eval		= nft_fwd_netdev_eval,
 	.init		= nft_fwd_netdev_init,
 	.dump		= nft_fwd_netdev_dump,
+	.validate	= nft_fwd_validate,
 	.offload	= nft_fwd_netdev_offload,
 };
 
-- 
2.11.0

[PATCH 6/7] netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress

[Pablo Neira Ayuso]

Set skb->tc_redirected to 1, otherwise the ifb driver drops the packet.
Set skb->tc_from_ingress to 1 to reinject the packet back to the ingress
path after leaving the ifb egress path.

This patch inconditionally sets on these two skb fields that are
meaningful to the ifb driver. The existing forward action is guaranteed
to run from ingress path.

Fixes: 39e6dea28adc ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_fwd_netdev.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/netfilter/nft_fwd_netdev.c b/net/netfilter/nft_fwd_netdev.c
index ddd28de810b6..74f050ba6bad 100644
--- a/net/netfilter/nft_fwd_netdev.c
+++ b/net/netfilter/nft_fwd_netdev.c
@@ -28,6 +28,10 @@ static void nft_fwd_netdev_eval(const struct nft_expr *expr,
 	struct nft_fwd_netdev *priv = nft_expr_priv(expr);
 	int oif = regs->data[priv->sreg_dev];
 
+	/* These are used by ifb only. */
+	pkt->skb->tc_redirected = 1;
+	pkt->skb->tc_from_ingress = 1;
+
 	nf_fwd_netdev_egress(pkt, oif);
 	regs->verdict.code = NF_STOLEN;
 }
-- 
2.11.0

[PATCH 7/7] selftests: netfilter: add nfqueue test case

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

Add a test case to check nf queue infrastructure.
Could be extended in the future to also cover serialization of
conntrack, uid and secctx attributes in nfqueue.

For now, this checks that 'queue bypass' works, that a queue rule with
no bypass option blocks traffic and that userspace receives the expected
number of packets.
For this we add two queues and hook all of
prerouting/input/forward/output/postrouting.

Packets get queued twice with a dummy base chain in between:
This passes with current nf tree, but reverting
commit 946c0d8e6ed4 ("netfilter: nf_queue: fix reinject verdict handling")
makes this trip (it processes 30 instead of expected 20 packets).

v2: update config file with queue and other options missing/needed for
other tests.
v3: also test with tcp, this reveals problem with commit
28f8bfd1ac94 ("netfilter: Support iif matches in POSTROUTING"), due to
skb->dev pointing at another skb in the retransmit rbtree (skb->dev
aliases to rbnode child).

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 tools/testing/selftests/netfilter/Makefile     |   6 +-
 tools/testing/selftests/netfilter/config       |   6 +
 tools/testing/selftests/netfilter/nf-queue.c   | 352 +++++++++++++++++++++++++
 tools/testing/selftests/netfilter/nft_queue.sh | 332 +++++++++++++++++++++++
 4 files changed, 695 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/netfilter/nf-queue.c
 create mode 100755 tools/testing/selftests/netfilter/nft_queue.sh

diff --git a/tools/testing/selftests/netfilter/Makefile b/tools/testing/selftests/netfilter/Makefile
index 08194aa44006..9c0f758310fe 100644
--- a/tools/testing/selftests/netfilter/Makefile
+++ b/tools/testing/selftests/netfilter/Makefile
@@ -3,6 +3,10 @@
 
 TEST_PROGS := nft_trans_stress.sh nft_nat.sh bridge_brouter.sh \
 	conntrack_icmp_related.sh nft_flowtable.sh ipvs.sh \
-	nft_concat_range.sh
+	nft_concat_range.sh \
+	nft_queue.sh
+
+LDLIBS = -lmnl
+TEST_GEN_FILES =  nf-queue
 
 include ../lib.mk
diff --git a/tools/testing/selftests/netfilter/config b/tools/testing/selftests/netfilter/config
index 59caa8f71cd8..4faf2ce021d9 100644
--- a/tools/testing/selftests/netfilter/config
+++ b/tools/testing/selftests/netfilter/config
@@ -1,2 +1,8 @@
 CONFIG_NET_NS=y
 CONFIG_NF_TABLES_INET=y
+CONFIG_NFT_QUEUE=m
+CONFIG_NFT_NAT=m
+CONFIG_NFT_REDIR=m
+CONFIG_NFT_MASQ=m
+CONFIG_NFT_FLOW_OFFLOAD=m
+CONFIG_NF_CT_NETLINK=m
diff --git a/tools/testing/selftests/netfilter/nf-queue.c b/tools/testing/selftests/netfilter/nf-queue.c
new file mode 100644
index 000000000000..29c73bce38fa
--- /dev/null
+++ b/tools/testing/selftests/netfilter/nf-queue.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <time.h>
+#include <arpa/inet.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_queue.h>
+
+struct options {
+	bool count_packets;
+	int verbose;
+	unsigned int queue_num;
+	unsigned int timeout;
+};
+
+static unsigned int queue_stats[5];
+static struct options opts;
+
+static void help(const char *p)
+{
+	printf("Usage: %s [-c|-v [-vv] ] [-t timeout] [-q queue_num]\n", p);
+}
+
+static int parse_attr_cb(const struct nlattr *attr, void *data)
+{
+	const struct nlattr **tb = data;
+	int type = mnl_attr_get_type(attr);
+
+	/* skip unsupported attribute in user-space */
+	if (mnl_attr_type_valid(attr, NFQA_MAX) < 0)
+		return MNL_CB_OK;
+
+	switch (type) {
+	case NFQA_MARK:
+	case NFQA_IFINDEX_INDEV:
+	case NFQA_IFINDEX_OUTDEV:
+	case NFQA_IFINDEX_PHYSINDEV:
+	case NFQA_IFINDEX_PHYSOUTDEV:
+		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
+			perror("mnl_attr_validate");
+			return MNL_CB_ERROR;
+		}
+		break;
+	case NFQA_TIMESTAMP:
+		if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
+		    sizeof(struct nfqnl_msg_packet_timestamp)) < 0) {
+			perror("mnl_attr_validate2");
+			return MNL_CB_ERROR;
+		}
+		break;
+	case NFQA_HWADDR:
+		if (mnl_attr_validate2(attr, MNL_TYPE_UNSPEC,
+		    sizeof(struct nfqnl_msg_packet_hw)) < 0) {
+			perror("mnl_attr_validate2");
+			return MNL_CB_ERROR;
+		}
+		break;
+	case NFQA_PAYLOAD:
+		break;
+	}
+	tb[type] = attr;
+	return MNL_CB_OK;
+}
+
+static int queue_cb(const struct nlmsghdr *nlh, void *data)
+{
+	struct nlattr *tb[NFQA_MAX+1] = { 0 };
+	struct nfqnl_msg_packet_hdr *ph = NULL;
+	uint32_t id = 0;
+
+	(void)data;
+
+	mnl_attr_parse(nlh, sizeof(struct nfgenmsg), parse_attr_cb, tb);
+	if (tb[NFQA_PACKET_HDR]) {
+		ph = mnl_attr_get_payload(tb[NFQA_PACKET_HDR]);
+		id = ntohl(ph->packet_id);
+
+		if (opts.verbose > 0)
+			printf("packet hook=%u, hwproto 0x%x",
+				ntohs(ph->hw_protocol), ph->hook);
+
+		if (ph->hook >= 5) {
+			fprintf(stderr, "Unknown hook %d\n", ph->hook);
+			return MNL_CB_ERROR;
+		}
+
+		if (opts.verbose > 0) {
+			uint32_t skbinfo = 0;
+
+			if (tb[NFQA_SKB_INFO])
+				skbinfo = ntohl(mnl_attr_get_u32(tb[NFQA_SKB_INFO]));
+			if (skbinfo & NFQA_SKB_CSUMNOTREADY)
+				printf(" csumnotready");
+			if (skbinfo & NFQA_SKB_GSO)
+				printf(" gso");
+			if (skbinfo & NFQA_SKB_CSUM_NOTVERIFIED)
+				printf(" csumnotverified");
+			puts("");
+		}
+
+		if (opts.count_packets)
+			queue_stats[ph->hook]++;
+	}
+
+	return MNL_CB_OK + id;
+}
+
+static struct nlmsghdr *
+nfq_build_cfg_request(char *buf, uint8_t command, int queue_num)
+{
+	struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
+	struct nfqnl_msg_config_cmd cmd = {
+		.command = command,
+		.pf = htons(AF_INET),
+	};
+	struct nfgenmsg *nfg;
+
+	nlh->nlmsg_type	= (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_CONFIG;
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+
+	nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
+
+	nfg->nfgen_family = AF_UNSPEC;
+	nfg->version = NFNETLINK_V0;
+	nfg->res_id = htons(queue_num);
+
+	mnl_attr_put(nlh, NFQA_CFG_CMD, sizeof(cmd), &cmd);
+
+	return nlh;
+}
+
+static struct nlmsghdr *
+nfq_build_cfg_params(char *buf, uint8_t mode, int range, int queue_num)
+{
+	struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);
+	struct nfqnl_msg_config_params params = {
+		.copy_range = htonl(range),
+		.copy_mode = mode,
+	};
+	struct nfgenmsg *nfg;
+
+	nlh->nlmsg_type	= (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_CONFIG;
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+
+	nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
+	nfg->nfgen_family = AF_UNSPEC;
+	nfg->version = NFNETLINK_V0;
+	nfg->res_id = htons(queue_num);
+
+	mnl_attr_put(nlh, NFQA_CFG_PARAMS, sizeof(params), &params);
+
+	return nlh;
+}
+
+static struct nlmsghdr *
+nfq_build_verdict(char *buf, int id, int queue_num, int verd)
+{
+	struct nfqnl_msg_verdict_hdr vh = {
+		.verdict = htonl(verd),
+		.id = htonl(id),
+	};
+	struct nlmsghdr *nlh;
+	struct nfgenmsg *nfg;
+
+	nlh = mnl_nlmsg_put_header(buf);
+	nlh->nlmsg_type = (NFNL_SUBSYS_QUEUE << 8) | NFQNL_MSG_VERDICT;
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+	nfg = mnl_nlmsg_put_extra_header(nlh, sizeof(*nfg));
+	nfg->nfgen_family = AF_UNSPEC;
+	nfg->version = NFNETLINK_V0;
+	nfg->res_id = htons(queue_num);
+
+	mnl_attr_put(nlh, NFQA_VERDICT_HDR, sizeof(vh), &vh);
+
+	return nlh;
+}
+
+static void print_stats(void)
+{
+	unsigned int last, total;
+	int i;
+
+	if (!opts.count_packets)
+		return;
+
+	total = 0;
+	last = queue_stats[0];
+
+	for (i = 0; i < 5; i++) {
+		printf("hook %d packets %08u\n", i, queue_stats[i]);
+		last = queue_stats[i];
+		total += last;
+	}
+
+	printf("%u packets total\n", total);
+}
+
+struct mnl_socket *open_queue(void)
+{
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	unsigned int queue_num;
+	struct mnl_socket *nl;
+	struct nlmsghdr *nlh;
+	struct timeval tv;
+	uint32_t flags;
+
+	nl = mnl_socket_open(NETLINK_NETFILTER);
+	if (nl == NULL) {
+		perror("mnl_socket_open");
+		exit(EXIT_FAILURE);
+	}
+
+	if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
+		perror("mnl_socket_bind");
+		exit(EXIT_FAILURE);
+	}
+
+	queue_num = opts.queue_num;
+	nlh = nfq_build_cfg_request(buf, NFQNL_CFG_CMD_BIND, queue_num);
+
+	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+		perror("mnl_socket_sendto");
+		exit(EXIT_FAILURE);
+	}
+
+	nlh = nfq_build_cfg_params(buf, NFQNL_COPY_PACKET, 0xFFFF, queue_num);
+
+	flags = NFQA_CFG_F_GSO | NFQA_CFG_F_UID_GID;
+	mnl_attr_put_u32(nlh, NFQA_CFG_FLAGS, htonl(flags));
+	mnl_attr_put_u32(nlh, NFQA_CFG_MASK, htonl(flags));
+
+	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+		perror("mnl_socket_sendto");
+		exit(EXIT_FAILURE);
+	}
+
+	memset(&tv, 0, sizeof(tv));
+	tv.tv_sec = opts.timeout;
+	if (opts.timeout && setsockopt(mnl_socket_get_fd(nl),
+				       SOL_SOCKET, SO_RCVTIMEO,
+				       &tv, sizeof(tv))) {
+		perror("setsockopt(SO_RCVTIMEO)");
+		exit(EXIT_FAILURE);
+	}
+
+	return nl;
+}
+
+static int mainloop(void)
+{
+	unsigned int buflen = 64 * 1024 + MNL_SOCKET_BUFFER_SIZE;
+	struct mnl_socket *nl;
+	struct nlmsghdr *nlh;
+	unsigned int portid;
+	char *buf;
+	int ret;
+
+	buf = malloc(buflen);
+	if (!buf) {
+		perror("malloc");
+		exit(EXIT_FAILURE);
+	}
+
+	nl = open_queue();
+	portid = mnl_socket_get_portid(nl);
+
+	for (;;) {
+		uint32_t id;
+
+		ret = mnl_socket_recvfrom(nl, buf, buflen);
+		if (ret == -1) {
+			if (errno == ENOBUFS)
+				continue;
+
+			if (errno == EAGAIN) {
+				errno = 0;
+				ret = 0;
+				break;
+			}
+
+			perror("mnl_socket_recvfrom");
+			exit(EXIT_FAILURE);
+		}
+
+		ret = mnl_cb_run(buf, ret, 0, portid, queue_cb, NULL);
+		if (ret < 0) {
+			perror("mnl_cb_run");
+			exit(EXIT_FAILURE);
+		}
+
+		id = ret - MNL_CB_OK;
+		nlh = nfq_build_verdict(buf, id, opts.queue_num, NF_ACCEPT);
+		if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+			perror("mnl_socket_sendto");
+			exit(EXIT_FAILURE);
+		}
+	}
+
+	mnl_socket_close(nl);
+
+	return ret;
+}
+
+static void parse_opts(int argc, char **argv)
+{
+	int c;
+
+	while ((c = getopt(argc, argv, "chvt:q:")) != -1) {
+		switch (c) {
+		case 'c':
+			opts.count_packets = true;
+			break;
+		case 'h':
+			help(argv[0]);
+			exit(0);
+			break;
+		case 'q':
+			opts.queue_num = atoi(optarg);
+			if (opts.queue_num > 0xffff)
+				opts.queue_num = 0;
+			break;
+		case 't':
+			opts.timeout = atoi(optarg);
+			break;
+		case 'v':
+			opts.verbose++;
+			break;
+		}
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	int ret;
+
+	parse_opts(argc, argv);
+
+	ret = mainloop();
+	if (opts.count_packets)
+		print_stats();
+
+	return ret;
+}
diff --git a/tools/testing/selftests/netfilter/nft_queue.sh b/tools/testing/selftests/netfilter/nft_queue.sh
new file mode 100755
index 000000000000..6898448b4266
--- /dev/null
+++ b/tools/testing/selftests/netfilter/nft_queue.sh
@@ -0,0 +1,332 @@
+#!/bin/bash
+#
+# This tests nf_queue:
+# 1. can process packets from all hooks
+# 2. support running nfqueue from more than one base chain
+#
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+ret=0
+
+sfx=$(mktemp -u "XXXXXXXX")
+ns1="ns1-$sfx"
+ns2="ns2-$sfx"
+nsrouter="nsrouter-$sfx"
+
+cleanup()
+{
+	ip netns del ${ns1}
+	ip netns del ${ns2}
+	ip netns del ${nsrouter}
+	rm -f "$TMPFILE0"
+	rm -f "$TMPFILE1"
+}
+
+nft --version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+	echo "SKIP: Could not run test without nft tool"
+	exit $ksft_skip
+fi
+
+ip -Version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+	echo "SKIP: Could not run test without ip tool"
+	exit $ksft_skip
+fi
+
+ip netns add ${nsrouter}
+if [ $? -ne 0 ];then
+	echo "SKIP: Could not create net namespace"
+	exit $ksft_skip
+fi
+
+TMPFILE0=$(mktemp)
+TMPFILE1=$(mktemp)
+trap cleanup EXIT
+
+ip netns add ${ns1}
+ip netns add ${ns2}
+
+ip link add veth0 netns ${nsrouter} type veth peer name eth0 netns ${ns1} > /dev/null 2>&1
+if [ $? -ne 0 ];then
+    echo "SKIP: No virtual ethernet pair device support in kernel"
+    exit $ksft_skip
+fi
+ip link add veth1 netns ${nsrouter} type veth peer name eth0 netns ${ns2}
+
+ip -net ${nsrouter} link set lo up
+ip -net ${nsrouter} link set veth0 up
+ip -net ${nsrouter} addr add 10.0.1.1/24 dev veth0
+ip -net ${nsrouter} addr add dead:1::1/64 dev veth0
+
+ip -net ${nsrouter} link set veth1 up
+ip -net ${nsrouter} addr add 10.0.2.1/24 dev veth1
+ip -net ${nsrouter} addr add dead:2::1/64 dev veth1
+
+ip -net ${ns1} link set lo up
+ip -net ${ns1} link set eth0 up
+
+ip -net ${ns2} link set lo up
+ip -net ${ns2} link set eth0 up
+
+ip -net ${ns1} addr add 10.0.1.99/24 dev eth0
+ip -net ${ns1} addr add dead:1::99/64 dev eth0
+ip -net ${ns1} route add default via 10.0.1.1
+ip -net ${ns1} route add default via dead:1::1
+
+ip -net ${ns2} addr add 10.0.2.99/24 dev eth0
+ip -net ${ns2} addr add dead:2::99/64 dev eth0
+ip -net ${ns2} route add default via 10.0.2.1
+ip -net ${ns2} route add default via dead:2::1
+
+load_ruleset() {
+	local name=$1
+	local prio=$2
+
+ip netns exec ${nsrouter} nft -f - <<EOF
+table inet $name {
+	chain nfq {
+		ip protocol icmp queue bypass
+		icmpv6 type { "echo-request", "echo-reply" } queue num 1 bypass
+	}
+	chain pre {
+		type filter hook prerouting priority $prio; policy accept;
+		jump nfq
+	}
+	chain input {
+		type filter hook input priority $prio; policy accept;
+		jump nfq
+	}
+	chain forward {
+		type filter hook forward priority $prio; policy accept;
+		tcp dport 12345 queue num 2
+		jump nfq
+	}
+	chain output {
+		type filter hook output priority $prio; policy accept;
+		tcp dport 12345 queue num 3
+		jump nfq
+	}
+	chain post {
+		type filter hook postrouting priority $prio; policy accept;
+		jump nfq
+	}
+}
+EOF
+}
+
+load_counter_ruleset() {
+	local prio=$1
+
+ip netns exec ${nsrouter} nft -f - <<EOF
+table inet countrules {
+	chain pre {
+		type filter hook prerouting priority $prio; policy accept;
+		counter
+	}
+	chain input {
+		type filter hook input priority $prio; policy accept;
+		counter
+	}
+	chain forward {
+		type filter hook forward priority $prio; policy accept;
+		counter
+	}
+	chain output {
+		type filter hook output priority $prio; policy accept;
+		counter
+	}
+	chain post {
+		type filter hook postrouting priority $prio; policy accept;
+		counter
+	}
+}
+EOF
+}
+
+test_ping() {
+  ip netns exec ${ns1} ping -c 1 -q 10.0.2.99 > /dev/null
+  if [ $? -ne 0 ];then
+	return 1
+  fi
+
+  ip netns exec ${ns1} ping -c 1 -q dead:2::99 > /dev/null
+  if [ $? -ne 0 ];then
+	return 1
+  fi
+
+  return 0
+}
+
+test_ping_router() {
+  ip netns exec ${ns1} ping -c 1 -q 10.0.2.1 > /dev/null
+  if [ $? -ne 0 ];then
+	return 1
+  fi
+
+  ip netns exec ${ns1} ping -c 1 -q dead:2::1 > /dev/null
+  if [ $? -ne 0 ];then
+	return 1
+  fi
+
+  return 0
+}
+
+test_queue_blackhole() {
+	local proto=$1
+
+ip netns exec ${nsrouter} nft -f - <<EOF
+table $proto blackh {
+	chain forward {
+	type filter hook forward priority 0; policy accept;
+		queue num 600
+	}
+}
+EOF
+	if [ $proto = "ip" ] ;then
+		ip netns exec ${ns1} ping -c 1 -q 10.0.2.99 > /dev/null
+		lret=$?
+	elif [ $proto = "ip6" ]; then
+		ip netns exec ${ns1} ping -c 1 -q dead:2::99 > /dev/null
+		lret=$?
+	else
+		lret=111
+	fi
+
+	# queue without bypass keyword should drop traffic if no listener exists.
+	if [ $lret -eq 0 ];then
+		echo "FAIL: $proto expected failure, got $lret" 1>&2
+		exit 1
+	fi
+
+	ip netns exec ${nsrouter} nft delete table $proto blackh
+	if [ $? -ne 0 ] ;then
+	        echo "FAIL: $proto: Could not delete blackh table"
+	        exit 1
+	fi
+
+        echo "PASS: $proto: statement with no listener results in packet drop"
+}
+
+test_queue()
+{
+	local expected=$1
+	local last=""
+
+	# spawn nf-queue listeners
+	ip netns exec ${nsrouter} ./nf-queue -c -q 0 -t 3 > "$TMPFILE0" &
+	ip netns exec ${nsrouter} ./nf-queue -c -q 1 -t 3 > "$TMPFILE1" &
+	sleep 1
+	test_ping
+	ret=$?
+	if [ $ret -ne 0 ];then
+		echo "FAIL: netns routing/connectivity with active listener on queue $queue: $ret" 1>&2
+		exit $ret
+	fi
+
+	test_ping_router
+	ret=$?
+	if [ $ret -ne 0 ];then
+		echo "FAIL: netns router unreachable listener on queue $queue: $ret" 1>&2
+		exit $ret
+	fi
+
+	wait
+	ret=$?
+
+	for file in $TMPFILE0 $TMPFILE1; do
+		last=$(tail -n1 "$file")
+		if [ x"$last" != x"$expected packets total" ]; then
+			echo "FAIL: Expected $expected packets total, but got $last" 1>&2
+			cat "$file" 1>&2
+
+			ip netns exec ${nsrouter} nft list ruleset
+			exit 1
+		fi
+	done
+
+	echo "PASS: Expected and received $last"
+}
+
+test_tcp_forward()
+{
+	ip netns exec ${nsrouter} ./nf-queue -q 2 -t 10 &
+	local nfqpid=$!
+
+	tmpfile=$(mktemp) || exit 1
+	dd conv=sparse status=none if=/dev/zero bs=1M count=100 of=$tmpfile
+	ip netns exec ${ns2} nc -w 5 -l -p 12345 <"$tmpfile" >/dev/null &
+	local rpid=$!
+
+	sleep 1
+	ip netns exec ${ns1} nc -w 5 10.0.2.99 12345 <"$tmpfile" >/dev/null &
+
+	rm -f "$tmpfile"
+
+	wait $rpid
+	wait $lpid
+	[ $? -eq 0 ] && echo "PASS: tcp and nfqueue in forward chain"
+}
+
+test_tcp_localhost()
+{
+	tc -net "${nsrouter}" qdisc add dev lo root netem loss random 1%
+
+	tmpfile=$(mktemp) || exit 1
+
+	dd conv=sparse status=none if=/dev/zero bs=1M count=900 of=$tmpfile
+	ip netns exec ${nsrouter} nc -w 5 -l -p 12345 <"$tmpfile" >/dev/null &
+	local rpid=$!
+
+	ip netns exec ${nsrouter} ./nf-queue -q 3 -t 30 &
+	local nfqpid=$!
+
+	sleep 1
+	ip netns exec ${nsrouter} nc -w 5 127.0.0.1 12345 <"$tmpfile" > /dev/null
+	rm -f "$tmpfile"
+
+	wait $rpid
+	[ $? -eq 0 ] && echo "PASS: tcp via loopback"
+}
+
+ip netns exec ${nsrouter} sysctl net.ipv6.conf.all.forwarding=1 > /dev/null
+ip netns exec ${nsrouter} sysctl net.ipv4.conf.veth0.forwarding=1 > /dev/null
+ip netns exec ${nsrouter} sysctl net.ipv4.conf.veth1.forwarding=1 > /dev/null
+
+load_ruleset "filter" 0
+
+sleep 3
+
+test_ping
+ret=$?
+if [ $ret -eq 0 ];then
+	# queue bypass works (rules were skipped, no listener)
+	echo "PASS: ${ns1} can reach ${ns2}"
+else
+	echo "FAIL: ${ns1} cannot reach ${ns2}: $ret" 1>&2
+	exit $ret
+fi
+
+test_queue_blackhole ip
+test_queue_blackhole ip6
+
+# dummy ruleset to add base chains between the
+# queueing rules.  We don't want the second reinject
+# to re-execute the old hooks.
+load_counter_ruleset 10
+
+# we are hooking all: prerouting/input/forward/output/postrouting.
+# we ping ${ns2} from ${ns1} via ${nsrouter} using ipv4 and ipv6, so:
+# 1x icmp prerouting,forward,postrouting -> 3 queue events (6 incl. reply).
+# 1x icmp prerouting,input,output postrouting -> 4 queue events incl. reply.
+# so we expect that userspace program receives 10 packets.
+test_queue 10
+
+# same.  We queue to a second program as well.
+load_ruleset "filter2" 20
+test_queue 20
+
+test_tcp_forward
+test_tcp_localhost
+
+exit $ret
-- 
2.11.0

Re: [PATCH 0/7] Netfilter fixes for net

[David Miller]

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Tue, 24 Mar 2020 23:32:13 +0100

> The following patchset contains Netfilter fixes for net:
> 
> 1) A new selftest for nf_queue, from Florian Westphal. This test
>    covers two recent fixes: 07f8e4d0fddb ("tcp: also NULL skb->dev
>    when copy was needed") and b738a185beaa ("tcp: ensure skb->dev is
>    NULL before leaving TCP stack").
> 
> 2) The fwd action breaks with ifb. For safety in next extensions,
>    make sure the fwd action only runs from ingress until it is extended
>    to be used from a different hook.
> 
> 3) The pipapo set type now reports EEXIST in case of subrange overlaps.
>    Update the rbtree set to validate range overlaps, so far this
>    validation is only done only from userspace. From Stefano Brivio.
> 
> You can pull these changes from:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf.git

Pulled, thanks Pablo.