[PATCH net 0/6] Netfilter fixes for net

[PATCH net 0/6] Netfilter fixes for net

[Pablo Neira Ayuso]

Hi,

The following patchset contains Netfilter fixes for net:

1) Add selftest for nft_synproxy, from Florian Westphal.

2) xt_socket destroy path incorrectly disables IPv4 defrag for
   IPv6 traffic (typo), from Eric Dumazet.

3) Fix exit value selftest nft_concat_range.sh, from Hangbin Liu.

4) nft_synproxy disables the IPv4 hooks if the IPv6 hooks fail
   to be registered.

5) disable rp_filter on router in selftest nft_fib.sh, also
   from Hangbin Liu.

Please, pull these changes from:

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

Thanks.

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

The following changes since commit 7db788ad627aabff2b74d4f1a3b68516d0fee0d7:

  nfp: flower: fix ida_idx not being released (2022-02-08 21:06:35 -0800)

are available in the Git repository at:

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

for you to fetch changes up to bbe4c0896d25009a7c86285d2ab024eed4374eea:

  selftests: netfilter: disable rp_filter on router (2022-02-11 00:01:04 +0100)

----------------------------------------------------------------
Eric Dumazet (1):
      netfilter: xt_socket: fix a typo in socket_mt_destroy()

Florian Westphal (1):
      selftests: netfilter: add synproxy test

Hangbin Liu (2):
      selftests: netfilter: fix exit value for nft_concat_range
      selftests: netfilter: disable rp_filter on router

Pablo Neira Ayuso (2):
      netfilter: nft_synproxy: unregister hooks on init error path
      selftests: netfilter: synproxy test requires nf_conntrack

 net/netfilter/nft_synproxy.c                       |   4 +-
 net/netfilter/xt_socket.c                          |   2 +-
 tools/testing/selftests/netfilter/Makefile         |   2 +-
 .../selftests/netfilter/nft_concat_range.sh        |   2 +-
 tools/testing/selftests/netfilter/nft_fib.sh       |   1 +
 tools/testing/selftests/netfilter/nft_synproxy.sh  | 117 +++++++++++++++++++++
 6 files changed, 124 insertions(+), 4 deletions(-)
 create mode 100755 tools/testing/selftests/netfilter/nft_synproxy.sh

[PATCH net 1/6] selftests: netfilter: add synproxy test

[Pablo Neira Ayuso]

From: Florian Westphal <fw@strlen.de>

Simple test for synproxy feature, iperf3 should be intercepted
by synproxy netns, but connection should still succeed.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 tools/testing/selftests/netfilter/Makefile    |   2 +-
 .../selftests/netfilter/nft_synproxy.sh       | 115 ++++++++++++++++++
 2 files changed, 116 insertions(+), 1 deletion(-)
 create mode 100755 tools/testing/selftests/netfilter/nft_synproxy.sh

diff --git a/tools/testing/selftests/netfilter/Makefile b/tools/testing/selftests/netfilter/Makefile
index ffca314897c4..e4f845dd942b 100644
--- a/tools/testing/selftests/netfilter/Makefile
+++ b/tools/testing/selftests/netfilter/Makefile
@@ -6,7 +6,7 @@ TEST_PROGS := nft_trans_stress.sh nft_fib.sh nft_nat.sh bridge_brouter.sh \
 	nft_concat_range.sh nft_conntrack_helper.sh \
 	nft_queue.sh nft_meta.sh nf_nat_edemux.sh \
 	ipip-conntrack-mtu.sh conntrack_tcp_unreplied.sh \
-	conntrack_vrf.sh
+	conntrack_vrf.sh nft_synproxy.sh
 
 LDLIBS = -lmnl
 TEST_GEN_FILES =  nf-queue
diff --git a/tools/testing/selftests/netfilter/nft_synproxy.sh b/tools/testing/selftests/netfilter/nft_synproxy.sh
new file mode 100755
index 000000000000..09bb95c87198
--- /dev/null
+++ b/tools/testing/selftests/netfilter/nft_synproxy.sh
@@ -0,0 +1,115 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+ret=0
+
+rnd=$(mktemp -u XXXXXXXX)
+nsr="nsr-$rnd"	# synproxy machine
+ns1="ns1-$rnd"  # iperf client
+ns2="ns2-$rnd"  # iperf server
+
+checktool (){
+	if ! $1 > /dev/null 2>&1; then
+		echo "SKIP: Could not $2"
+		exit $ksft_skip
+	fi
+}
+
+checktool "nft --version" "run test without nft tool"
+checktool "ip -Version" "run test without ip tool"
+checktool "iperf3 --version" "run test without iperf3"
+checktool "ip netns add $nsr" "create net namespace"
+
+ip netns add $ns1
+ip netns add $ns2
+
+cleanup() {
+	ip netns pids $ns1 | xargs kill 2>/dev/null
+	ip netns pids $ns2 | xargs kill 2>/dev/null
+	ip netns del $ns1
+	ip netns del $ns2
+
+	ip netns del $nsr
+}
+
+trap cleanup EXIT
+
+ip link add veth0 netns $nsr type veth peer name eth0 netns $ns1
+ip link add veth1 netns $nsr type veth peer name eth0 netns $ns2
+
+for dev in lo veth0 veth1; do
+ip -net $nsr link set $dev up
+done
+
+ip -net $nsr addr add 10.0.1.1/24 dev veth0
+ip -net $nsr addr add 10.0.2.1/24 dev veth1
+
+ip netns exec $nsr sysctl -q net.ipv4.conf.veth0.forwarding=1
+ip netns exec $nsr sysctl -q net.ipv4.conf.veth1.forwarding=1
+ip netns exec $nsr sysctl -q net.netfilter.nf_conntrack_tcp_loose=0
+
+for n in $ns1 $ns2; do
+  ip -net $n link set lo up
+  ip -net $n link set eth0 up
+done
+ip -net $ns1 addr add 10.0.1.99/24 dev eth0
+ip -net $ns2 addr add 10.0.2.99/24 dev eth0
+ip -net $ns1 route add default via 10.0.1.1
+ip -net $ns2 route add default via 10.0.2.1
+
+# test basic connectivity
+if ! ip netns exec $ns1 ping -c 1 -q 10.0.2.99 > /dev/null; then
+  echo "ERROR: $ns1 cannot reach $ns2" 1>&2
+  exit 1
+fi
+
+if ! ip netns exec $ns2 ping -c 1 -q 10.0.1.99 > /dev/null; then
+  echo "ERROR: $ns2 cannot reach $ns1" 1>&2
+  exit 1
+fi
+
+ip netns exec $ns2 iperf3 -s > /dev/null 2>&1 &
+# ip netns exec $nsr tcpdump -vvv -n -i veth1 tcp | head -n 10 &
+
+sleep 1
+
+ip netns exec $nsr nft -f - <<EOF
+table inet filter {
+   chain prerouting {
+      type filter hook prerouting priority -300; policy accept;
+      meta iif veth0 tcp flags syn counter notrack
+   }
+
+  chain forward {
+      type filter hook forward priority 0; policy accept;
+
+      ct state new,established counter accept
+
+      meta iif veth0 meta l4proto tcp ct state untracked,invalid synproxy mss 1460 sack-perm timestamp
+
+      ct state invalid counter drop
+
+      # make ns2 unreachable w.o. tcp synproxy
+      tcp flags syn counter drop
+   }
+}
+EOF
+if [ $? -ne 0 ]; then
+	echo "SKIP: Cannot add nft synproxy"
+	exit $ksft_skip
+fi
+
+ip netns exec $ns1 timeout 5 iperf3 -c 10.0.2.99 -n $((1 * 1024 * 1024)) > /dev/null
+
+if [ $? -ne 0 ]; then
+	echo "FAIL: iperf3 returned an error" 1>&2
+	ret=$?
+	ip netns exec $nsr nft list ruleset
+else
+	echo "PASS: synproxy connection successful"
+fi
+
+exit $ret
-- 
2.30.2

Re: [PATCH net 1/6] selftests: netfilter: add synproxy test

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (master)
by Pablo Neira Ayuso <pablo@netfilter.org>:

On Fri, 11 Feb 2022 00:10:16 +0100 you wrote:
> From: Florian Westphal <fw@strlen.de>
> 
> Simple test for synproxy feature, iperf3 should be intercepted
> by synproxy netns, but connection should still succeed.
> 
> Signed-off-by: Florian Westphal <fw@strlen.de>
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> 
> [...]

Here is the summary with links:
  - [net,1/6] selftests: netfilter: add synproxy test
    https://git.kernel.org/netdev/net/c/7152303cbec4
  - [net,2/6] netfilter: xt_socket: fix a typo in socket_mt_destroy()
    https://git.kernel.org/netdev/net/c/75063c9294fb
  - [net,3/6] selftests: netfilter: fix exit value for nft_concat_range
    https://git.kernel.org/netdev/net/c/2e71ec1a725a
  - [net,4/6] netfilter: nft_synproxy: unregister hooks on init error path
    https://git.kernel.org/netdev/net/c/2b4e5fb4d377
  - [net,5/6] selftests: netfilter: synproxy test requires nf_conntrack
    https://git.kernel.org/netdev/net/c/249749c88906
  - [net,6/6] selftests: netfilter: disable rp_filter on router
    https://git.kernel.org/netdev/net/c/bbe4c0896d25

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

[PATCH net 2/6] netfilter: xt_socket: fix a typo in socket_mt_destroy()

[Pablo Neira Ayuso]

From: Eric Dumazet <edumazet@google.com>

Calling nf_defrag_ipv4_disable() instead of nf_defrag_ipv6_disable()
was probably not the intent.

I found this by code inspection, while chasing a possible issue in TPROXY.

Fixes: de8c12110a13 ("netfilter: disable defrag once its no longer needed")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_socket.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/xt_socket.c b/net/netfilter/xt_socket.c
index 5e6459e11605..662e5eb1cc39 100644
--- a/net/netfilter/xt_socket.c
+++ b/net/netfilter/xt_socket.c
@@ -221,7 +221,7 @@ static void socket_mt_destroy(const struct xt_mtdtor_param *par)
 	if (par->family == NFPROTO_IPV4)
 		nf_defrag_ipv4_disable(par->net);
 	else if (par->family == NFPROTO_IPV6)
-		nf_defrag_ipv4_disable(par->net);
+		nf_defrag_ipv6_disable(par->net);
 }
 
 static struct xt_match socket_mt_reg[] __read_mostly = {
-- 
2.30.2

[PATCH net 3/6] selftests: netfilter: fix exit value for nft_concat_range

[Pablo Neira Ayuso]

From: Hangbin Liu <liuhangbin@gmail.com>

When the nft_concat_range test failed, it exit 1 in the code
specifically.

But when part of, or all of the test passed, it will failed the
[ ${passed} -eq 0 ] check and thus exit with 1, which is the same
exit value with failure result. Fix it by exit 0 when passed is not 0.

Fixes: 611973c1e06f ("selftests: netfilter: Introduce tests for sets with range concatenation")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 tools/testing/selftests/netfilter/nft_concat_range.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/netfilter/nft_concat_range.sh b/tools/testing/selftests/netfilter/nft_concat_range.sh
index df322e47a54f..b35010cc7f6a 100755
--- a/tools/testing/selftests/netfilter/nft_concat_range.sh
+++ b/tools/testing/selftests/netfilter/nft_concat_range.sh
@@ -1601,4 +1601,4 @@ for name in ${TESTS}; do
 	done
 done
 
-[ ${passed} -eq 0 ] && exit ${KSELFTEST_SKIP}
+[ ${passed} -eq 0 ] && exit ${KSELFTEST_SKIP} || exit 0
-- 
2.30.2

[PATCH net 4/6] netfilter: nft_synproxy: unregister hooks on init error path

[Pablo Neira Ayuso]

Disable the IPv4 hooks if the IPv6 hooks fail to be registered.

Fixes: ad49d86e07a4 ("netfilter: nf_tables: Add synproxy support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_synproxy.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nft_synproxy.c b/net/netfilter/nft_synproxy.c
index a0109fa1e92d..1133e06f3c40 100644
--- a/net/netfilter/nft_synproxy.c
+++ b/net/netfilter/nft_synproxy.c
@@ -191,8 +191,10 @@ static int nft_synproxy_do_init(const struct nft_ctx *ctx,
 		if (err)
 			goto nf_ct_failure;
 		err = nf_synproxy_ipv6_init(snet, ctx->net);
-		if (err)
+		if (err) {
+			nf_synproxy_ipv4_fini(snet, ctx->net);
 			goto nf_ct_failure;
+		}
 		break;
 	}
 
-- 
2.30.2

[PATCH net 5/6] selftests: netfilter: synproxy test requires nf_conntrack

[Pablo Neira Ayuso]

Otherwise, this test does not find the sysctl entry in place:

 sysctl: cannot stat /proc/sys/net/netfilter/nf_conntrack_tcp_loose: No such file or directory
 iperf3: error - unable to send control message: Bad file descriptor
 FAIL: iperf3 returned an error

Fixes: 7152303cbec4 ("selftests: netfilter: add synproxy test")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 tools/testing/selftests/netfilter/nft_synproxy.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/netfilter/nft_synproxy.sh b/tools/testing/selftests/netfilter/nft_synproxy.sh
index 09bb95c87198..b62933b680d6 100755
--- a/tools/testing/selftests/netfilter/nft_synproxy.sh
+++ b/tools/testing/selftests/netfilter/nft_synproxy.sh
@@ -23,6 +23,8 @@ checktool "ip -Version" "run test without ip tool"
 checktool "iperf3 --version" "run test without iperf3"
 checktool "ip netns add $nsr" "create net namespace"
 
+modprobe -q nf_conntrack
+
 ip netns add $ns1
 ip netns add $ns2
 
-- 
2.30.2

[PATCH net 6/6] selftests: netfilter: disable rp_filter on router

[Pablo Neira Ayuso]

From: Hangbin Liu <liuhangbin@gmail.com>

Some distros may enable rp_filter by default. After ns1 change addr to
10.0.2.99 and set default router to 10.0.2.1, while the connected router
address is still 10.0.1.1. The router will not reply the arp request
from ns1. Fix it by setting the router's veth0 rp_filter to 0.

Before the fix:
  # ./nft_fib.sh
  PASS: fib expression did not cause unwanted packet drops
  Netns nsrouter-HQkDORO2 fib counter doesn't match expected packet count of 1 for 1.1.1.1
  table inet filter {
          chain prerouting {
                  type filter hook prerouting priority filter; policy accept;
                  ip daddr 1.1.1.1 fib saddr . iif oif missing counter packets 0 bytes 0 drop
                  ip6 daddr 1c3::c01d fib saddr . iif oif missing counter packets 0 bytes 0 drop
          }
  }

After the fix:
  # ./nft_fib.sh
  PASS: fib expression did not cause unwanted packet drops
  PASS: fib expression did drop packets for 1.1.1.1
  PASS: fib expression did drop packets for 1c3::c01d

Fixes: 82944421243e ("selftests: netfilter: add fib test case")
Signed-off-by: Yi Chen <yiche@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 tools/testing/selftests/netfilter/nft_fib.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/netfilter/nft_fib.sh b/tools/testing/selftests/netfilter/nft_fib.sh
index 6caf6ac8c285..695a1958723f 100755
--- a/tools/testing/selftests/netfilter/nft_fib.sh
+++ b/tools/testing/selftests/netfilter/nft_fib.sh
@@ -174,6 +174,7 @@ test_ping() {
 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
+ip netns exec ${nsrouter} sysctl net.ipv4.conf.veth0.rp_filter=0 > /dev/null
 
 sleep 3
 
-- 
2.30.2