[PATCH net] selftests: forwarding: Fix failing tests with old libnet

[PATCH net] selftests: forwarding: Fix failing tests with old libnet

[Ido Schimmel]

The custom multipath hash tests use mausezahn in order to test how
changes in various packet fields affect the packet distribution across
the available nexthops.

The tool uses the libnet library for various low-level packet
construction and injection. The library started using the
"SO_BINDTODEVICE" socket option for IPv6 sockets in version 1.1.6 and
for IPv4 sockets in version 1.2.

When the option is not set, packets are not routed according to the
table associated with the VRF master device and tests fail.

Fix this by prefixing the command with "ip vrf exec", which will cause
the route lookup to occur in the VRF routing table. This makes the tests
pass regardless of the libnet library version.

Fixes: 511e8db54036 ("selftests: forwarding: Add test for custom multipath hash")
Fixes: 185b0c190bb6 ("selftests: forwarding: Add test for custom multipath hash with IPv4 GRE")
Fixes: b7715acba4d3 ("selftests: forwarding: Add test for custom multipath hash with IPv6 GRE")
Reported-by: Ivan Vecera <ivecera@redhat.com>
Tested-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Amit Cohen <amcohen@nvidia.com>
---
 .../net/forwarding/custom_multipath_hash.sh   | 24 ++++++++++++-------
 .../forwarding/gre_custom_multipath_hash.sh   | 24 ++++++++++++-------
 .../ip6gre_custom_multipath_hash.sh           | 24 ++++++++++++-------
 3 files changed, 48 insertions(+), 24 deletions(-)

diff --git a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
index a15d21dc035a..56eb83d1a3bd 100755
--- a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
+++ b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
@@ -181,37 +181,43 @@ ping_ipv6()
 
 send_src_ipv4()
 {
-	$MZ $h1 -q -p 64 -A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_dst_ipv4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B "203.0.113.2-203.0.113.253" \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B "203.0.113.2-203.0.113.253" \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_src_udp4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B 203.0.113.2 \
 		-d 1msec -t udp "sp=0-32768,dp=30000"
 }
 
 send_dst_udp4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B 203.0.113.2 \
 		-d 1msec -t udp "sp=20000,dp=0-32768"
 }
 
 send_src_ipv6()
 {
-	$MZ -6 $h1 -q -p 64 -A "2001:db8:1::2-2001:db8:1::fd" -B 2001:db8:4::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A "2001:db8:1::2-2001:db8:1::fd" -B 2001:db8:4::2 \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_dst_ipv6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B "2001:db8:4::2-2001:db8:4::fd" \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B "2001:db8:4::2-2001:db8:4::fd" \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
@@ -226,13 +232,15 @@ send_flowlabel()
 
 send_src_udp6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B 2001:db8:4::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B 2001:db8:4::2 \
 		-d 1msec -t udp "sp=0-32768,dp=30000"
 }
 
 send_dst_udp6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B 2001:db8:4::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B 2001:db8:4::2 \
 		-d 1msec -t udp "sp=20000,dp=0-32768"
 }
 
diff --git a/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh
index a73f52efcb6c..0446db9c6f74 100755
--- a/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh
+++ b/tools/testing/selftests/net/forwarding/gre_custom_multipath_hash.sh
@@ -276,37 +276,43 @@ ping_ipv6()
 
 send_src_ipv4()
 {
-	$MZ $h1 -q -p 64 -A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_dst_ipv4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B "203.0.113.2-203.0.113.253" \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B "203.0.113.2-203.0.113.253" \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_src_udp4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B 203.0.113.2 \
 		-d 1msec -t udp "sp=0-32768,dp=30000"
 }
 
 send_dst_udp4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B 203.0.113.2 \
 		-d 1msec -t udp "sp=20000,dp=0-32768"
 }
 
 send_src_ipv6()
 {
-	$MZ -6 $h1 -q -p 64 -A "2001:db8:1::2-2001:db8:1::fd" -B 2001:db8:2::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A "2001:db8:1::2-2001:db8:1::fd" -B 2001:db8:2::2 \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_dst_ipv6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B "2001:db8:2::2-2001:db8:2::fd" \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B "2001:db8:2::2-2001:db8:2::fd" \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
@@ -321,13 +327,15 @@ send_flowlabel()
 
 send_src_udp6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B 2001:db8:2::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B 2001:db8:2::2 \
 		-d 1msec -t udp "sp=0-32768,dp=30000"
 }
 
 send_dst_udp6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B 2001:db8:2::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B 2001:db8:2::2 \
 		-d 1msec -t udp "sp=20000,dp=0-32768"
 }
 
diff --git a/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh
index 8fea2c2e0b25..d40183b4eccc 100755
--- a/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh
+++ b/tools/testing/selftests/net/forwarding/ip6gre_custom_multipath_hash.sh
@@ -278,37 +278,43 @@ ping_ipv6()
 
 send_src_ipv4()
 {
-	$MZ $h1 -q -p 64 -A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_dst_ipv4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B "203.0.113.2-203.0.113.253" \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B "203.0.113.2-203.0.113.253" \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_src_udp4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B 203.0.113.2 \
 		-d 1msec -t udp "sp=0-32768,dp=30000"
 }
 
 send_dst_udp4()
 {
-	$MZ $h1 -q -p 64 -A 198.51.100.2 -B 203.0.113.2 \
+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
+		-A 198.51.100.2 -B 203.0.113.2 \
 		-d 1msec -t udp "sp=20000,dp=0-32768"
 }
 
 send_src_ipv6()
 {
-	$MZ -6 $h1 -q -p 64 -A "2001:db8:1::2-2001:db8:1::fd" -B 2001:db8:2::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A "2001:db8:1::2-2001:db8:1::fd" -B 2001:db8:2::2 \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
 send_dst_ipv6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B "2001:db8:2::2-2001:db8:2::fd" \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B "2001:db8:2::2-2001:db8:2::fd" \
 		-d 1msec -c 50 -t udp "sp=20000,dp=30000"
 }
 
@@ -323,13 +329,15 @@ send_flowlabel()
 
 send_src_udp6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B 2001:db8:2::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B 2001:db8:2::2 \
 		-d 1msec -t udp "sp=0-32768,dp=30000"
 }
 
 send_dst_udp6()
 {
-	$MZ -6 $h1 -q -p 64 -A 2001:db8:1::2 -B 2001:db8:2::2 \
+	ip vrf exec v$h1 $MZ -6 $h1 -q -p 64 \
+		-A 2001:db8:1::2 -B 2001:db8:2::2 \
 		-d 1msec -t udp "sp=20000,dp=0-32768"
 }
 
-- 
2.37.1

Re: [PATCH net] selftests: forwarding: Fix failing tests with old libnet

[Jiri Pirko]

Tue, Aug 09, 2022 at 01:33:20PM CEST, idosch@nvidia.com wrote:
>The custom multipath hash tests use mausezahn in order to test how
>changes in various packet fields affect the packet distribution across
>the available nexthops.
>
>The tool uses the libnet library for various low-level packet
>construction and injection. The library started using the
>"SO_BINDTODEVICE" socket option for IPv6 sockets in version 1.1.6 and
>for IPv4 sockets in version 1.2.
>
>When the option is not set, packets are not routed according to the
>table associated with the VRF master device and tests fail.
>
>Fix this by prefixing the command with "ip vrf exec", which will cause
>the route lookup to occur in the VRF routing table. This makes the tests
>pass regardless of the libnet library version.
>
>Fixes: 511e8db54036 ("selftests: forwarding: Add test for custom multipath hash")
>Fixes: 185b0c190bb6 ("selftests: forwarding: Add test for custom multipath hash with IPv4 GRE")
>Fixes: b7715acba4d3 ("selftests: forwarding: Add test for custom multipath hash with IPv6 GRE")
>Reported-by: Ivan Vecera <ivecera@redhat.com>
>Tested-by: Ivan Vecera <ivecera@redhat.com>
>Signed-off-by: Ido Schimmel <idosch@nvidia.com>
>Reviewed-by: Amit Cohen <amcohen@nvidia.com>
>---
> .../net/forwarding/custom_multipath_hash.sh   | 24 ++++++++++++-------
> .../forwarding/gre_custom_multipath_hash.sh   | 24 ++++++++++++-------
> .../ip6gre_custom_multipath_hash.sh           | 24 ++++++++++++-------
> 3 files changed, 48 insertions(+), 24 deletions(-)
>
>diff --git a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
>index a15d21dc035a..56eb83d1a3bd 100755
>--- a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
>+++ b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
>@@ -181,37 +181,43 @@ ping_ipv6()
> 
> send_src_ipv4()
> {
>-	$MZ $h1 -q -p 64 -A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
>+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \

Not directly related to this, but I was wondering, if it would be
possible to use $IP and allow user to replace the system-wide "ip" for
testing purposes...

Re: [PATCH net] selftests: forwarding: Fix failing tests with old libnet

[Petr Machata]

Jiri Pirko <jiri@nvidia.com> writes:

> Tue, Aug 09, 2022 at 01:33:20PM CEST, idosch@nvidia.com wrote:
>>diff --git a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
>>index a15d21dc035a..56eb83d1a3bd 100755
>>--- a/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
>>+++ b/tools/testing/selftests/net/forwarding/custom_multipath_hash.sh
>>@@ -181,37 +181,43 @@ ping_ipv6()
>> 
>> send_src_ipv4()
>> {
>>-	$MZ $h1 -q -p 64 -A "198.51.100.2-198.51.100.253" -B 203.0.113.2 \
>>+	ip vrf exec v$h1 $MZ $h1 -q -p 64 \
>
> Not directly related to this, but I was wondering, if it would be
> possible to use $IP and allow user to replace the system-wide "ip" for
> testing purposes...

A typical forwarding test builds a whole topology with a number of IP
addresses and assumptions about them. E.g. routes need network address
derived from address of the remote endpoint, directly attached hosts
need addresses from the same network, flower rules etc. might match
pieces of endpoint addresses, the above code fragment actually walks a
range of IPs... So it's not just $IP. At the minimum it's a map of IPs
plus some helpers to derive the rest, and conversion of the selftests to
correctly use the helpers. Doable, sure, but I suspect a fairly messy
deal.

That's why the selftests use reserved ranges: 192.0.2.0/24,
198.51.100.0/24 etc. and 2001:db8::/32. They are not supposed to
conflict with whatever addresses the user uses.

Re: [PATCH net] selftests: forwarding: Fix failing tests with old libnet

[Ido Schimmel]

On Tue, Aug 09, 2022 at 03:10:02PM +0200, Jiri Pirko wrote:
> Not directly related to this, but I was wondering, if it would be
> possible to use $IP and allow user to replace the system-wide "ip" for
> testing purposes...

When testing iproute2 patches (mine or from the ML) I usually do:

export PATH=/home/idosch/code/iproute2/ip/:/home/idosch/code/iproute2/devlink/:/home/idosch/code/iproute2/bridge:$PATH

As part of regression we just compile and install iproute2 from git

Re: [PATCH net] selftests: forwarding: Fix failing tests with old libnet

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Tue,  9 Aug 2022 14:33:20 +0300 you wrote:
> The custom multipath hash tests use mausezahn in order to test how
> changes in various packet fields affect the packet distribution across
> the available nexthops.
> 
> The tool uses the libnet library for various low-level packet
> construction and injection. The library started using the
> "SO_BINDTODEVICE" socket option for IPv6 sockets in version 1.1.6 and
> for IPv4 sockets in version 1.2.
> 
> [...]

Here is the summary with links:
  - [net] selftests: forwarding: Fix failing tests with old libnet
    https://git.kernel.org/netdev/net/c/8bcfb4ae4d97

You are awesome, thank you!
-- 
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