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[PATCH net 2/2] selftests: mptcp: explicitly trigger the listener diag code-path

Paolo Abeni posted 2 patches 1 year, 11 months ago
There is a newer version of this series
[PATCH net 2/2] selftests: mptcp: explicitly trigger the listener diag code-path
Posted by Paolo Abeni 1 year, 11 months ago 
The mptcp diag interface already experienced a few locking bugs
that lockdep and appropriate coverage have detected in advance.

Let's add a test-case triggering the relevant code path, to prevent
similar issues in the future.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 tools/testing/selftests/net/mptcp/diag.sh | 30 +++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
index 60a7009ce1b5..3ab584b38566 100755
--- a/tools/testing/selftests/net/mptcp/diag.sh
+++ b/tools/testing/selftests/net/mptcp/diag.sh
@@ -81,6 +81,21 @@ chk_msk_nr()
 	__chk_msk_nr "grep -c token:" "$@"
 }
 
+chk_listener_nr()
+{
+	local expected=$1
+	local msg="$2"
+
+	if [ $expected -gt 0 ] && \
+	   ! mptcp_lib_kallsyms_has "mptcp_diag_dump_listeners"; then
+		printf "%-50s%s\n" "$msg - mptcp" "[ skip ]"
+		mptcp_lib_result_skip "many listener sockets"
+	else
+		__chk_nr "ss -inmlHMON $ns | wc -l" "$expected" "$msg - mptcp"
+	fi
+	__chk_nr "ss -inmlHtON $ns | wc -l" "$expected" "$msg - subflows"
+}
+
 wait_msk_nr()
 {
 	local condition="grep -c token:"
@@ -279,5 +294,20 @@ flush_pids
 chk_msk_inuse 0 "many->0"
 chk_msk_cestab 0 "many->0"
 
+chk_listener_nr 0 "no listener sockets"
+NR_SERVERS=100
+for I in $(seq 1 $NR_SERVERS); do
+	ip netns exec $ns ./mptcp_connect -p $((I + 20001)) -l 0.0.0.0 2>&1 >/dev/null &
+	mptcp_lib_wait_local_port_listen $ns $((I + 20001))
+done
+
+chk_listener_nr $NR_SERVERS "many listener sockets"
+
+# gracefull termination
+for I in $(seq 1 $NR_SERVERS); do
+	echo a | ip netns exec $ns ./mptcp_connect -p $((I + 20001)) 127.0.0.1 2>&1 >/dev/null
+done
+flush_pids
+
 mptcp_lib_result_print_all_tap
 exit $ret
-- 
2.43.0
Re: [PATCH net 2/2] selftests: mptcp: explicitly trigger the listener diag code-path
Posted by Simon Horman 1 year, 11 months ago 
On Wed, Feb 22, 2024 at 12:46:59PM +0100, Paolo Abeni wrote:
>l The mptcp diag interface already experienced a few locking bugs
> that lockdep and appropriate coverage have detected in advance.
> 
> Let's add a test-case triggering the relevant code path, to prevent
> similar issues in the future.
> 
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
>  tools/testing/selftests/net/mptcp/diag.sh | 30 +++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
> index 60a7009ce1b5..3ab584b38566 100755
> --- a/tools/testing/selftests/net/mptcp/diag.sh
> +++ b/tools/testing/selftests/net/mptcp/diag.sh
> @@ -81,6 +81,21 @@ chk_msk_nr()
>  	__chk_msk_nr "grep -c token:" "$@"
>  }
>  
> +chk_listener_nr()
> +{
> +	local expected=$1
> +	local msg="$2"
> +
> +	if [ $expected -gt 0 ] && \
> +	   ! mptcp_lib_kallsyms_has "mptcp_diag_dump_listeners"; then
> +		printf "%-50s%s\n" "$msg - mptcp" "[ skip ]"
> +		mptcp_lib_result_skip "many listener sockets"
> +	else
> +		__chk_nr "ss -inmlHMON $ns | wc -l" "$expected" "$msg - mptcp"
> +	fi
> +	__chk_nr "ss -inmlHtON $ns | wc -l" "$expected" "$msg - subflows"
> +}
> +
>  wait_msk_nr()
>  {
>  	local condition="grep -c token:"
> @@ -279,5 +294,20 @@ flush_pids
>  chk_msk_inuse 0 "many->0"
>  chk_msk_cestab 0 "many->0"
>  
> +chk_listener_nr 0 "no listener sockets"
> +NR_SERVERS=100
> +for I in $(seq 1 $NR_SERVERS); do
> +	ip netns exec $ns ./mptcp_connect -p $((I + 20001)) -l 0.0.0.0 2>&1 >/dev/null &
> +	mptcp_lib_wait_local_port_listen $ns $((I + 20001))
> +done
> +
> +chk_listener_nr $NR_SERVERS "many listener sockets"
> +
> +# gracefull termination

nit, as you plan to re-spin anyway: graceful

> +for I in $(seq 1 $NR_SERVERS); do
> +	echo a | ip netns exec $ns ./mptcp_connect -p $((I + 20001)) 127.0.0.1 2>&1 >/dev/null

I'm not sure of the validity of this but shellcheck complains that:

  SC2069 (warning): To redirect stdout+stderr, 2>&1 must be last (or use '{ cmd > file; } 2>&1' to clarify).

Also for the same constriction slightly earlier in this patch.

> +done
> +flush_pids
> +
>  mptcp_lib_result_print_all_tap
>  exit $ret
> -- 
> 2.43.0
> 
>
Re: [PATCH net 2/2] selftests: mptcp: explicitly trigger the listener diag code-path
Posted by Matthieu Baerts 1 year, 11 months ago 
Hi Simon,

Thank you for the review!

On 22/02/2024 2:13 pm, Simon Horman wrote:
> On Wed, Feb 22, 2024 at 12:46:59PM +0100, Paolo Abeni wrote:
>> l The mptcp diag interface already experienced a few locking bugs
>> that lockdep and appropriate coverage have detected in advance.
>>
>> Let's add a test-case triggering the relevant code path, to prevent
>> similar issues in the future.
>>
>> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
>> ---
>>  tools/testing/selftests/net/mptcp/diag.sh | 30 +++++++++++++++++++++++
>>  1 file changed, 30 insertions(+)
>>
>> diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
>> index 60a7009ce1b5..3ab584b38566 100755
>> --- a/tools/testing/selftests/net/mptcp/diag.sh
>> +++ b/tools/testing/selftests/net/mptcp/diag.sh
>> @@ -81,6 +81,21 @@ chk_msk_nr()
>>  	__chk_msk_nr "grep -c token:" "$@"
>>  }
>>  
>> +chk_listener_nr()
>> +{
>> +	local expected=$1
>> +	local msg="$2"
>> +
>> +	if [ $expected -gt 0 ] && \
>> +	   ! mptcp_lib_kallsyms_has "mptcp_diag_dump_listeners"; then
>> +		printf "%-50s%s\n" "$msg - mptcp" "[ skip ]"
>> +		mptcp_lib_result_skip "many listener sockets"
>> +	else
>> +		__chk_nr "ss -inmlHMON $ns | wc -l" "$expected" "$msg - mptcp"
>> +	fi
>> +	__chk_nr "ss -inmlHtON $ns | wc -l" "$expected" "$msg - subflows"
>> +}
>> +
>>  wait_msk_nr()
>>  {
>>  	local condition="grep -c token:"
>> @@ -279,5 +294,20 @@ flush_pids
>>  chk_msk_inuse 0 "many->0"
>>  chk_msk_cestab 0 "many->0"
>>  
>> +chk_listener_nr 0 "no listener sockets"
>> +NR_SERVERS=100
>> +for I in $(seq 1 $NR_SERVERS); do
>> +	ip netns exec $ns ./mptcp_connect -p $((I + 20001)) -l 0.0.0.0 2>&1 >/dev/null &
>> +	mptcp_lib_wait_local_port_listen $ns $((I + 20001))
>> +done
>> +
>> +chk_listener_nr $NR_SERVERS "many listener sockets"
>> +
>> +# gracefull termination
> 
> nit, as you plan to re-spin anyway: graceful

Paolo sent a new version on MPTCP ML only. When applying the new
version, I fixed this:

https://lore.kernel.org/mptcp/e98b8b07-558c-498a-97fb-dd5cab11e439@kernel.org/

>> +for I in $(seq 1 $NR_SERVERS); do
>> +	echo a | ip netns exec $ns ./mptcp_connect -p $((I + 20001)) 127.0.0.1 2>&1 >/dev/null
> 
> I'm not sure of the validity of this but shellcheck complains that:
> 
>   SC2069 (warning): To redirect stdout+stderr, 2>&1 must be last (or use '{ cmd > file; } 2>&1' to clarify).
> 
> Also for the same constriction slightly earlier in this patch.

Good catch!

I should add shellcheck support in our CI to catch that :)

I just applied the suggested modification in our tree [1]. The new
version that will be sent to netdev will no longer have this issue.

https://github.com/multipath-tcp/mptcp_net-next/commit/31f1460d552c

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.
Re: [PATCH net 2/2] selftests: mptcp: explicitly trigger the listener diag code-path
Posted by Simon Horman 1 year, 11 months ago 
On Thu, Feb 22, 2024 at 03:49:44PM +0100, Matthieu Baerts wrote:
> Hi Simon,
> 
> Thank you for the review!
> 
> On 22/02/2024 2:13 pm, Simon Horman wrote:
> > On Wed, Feb 22, 2024 at 12:46:59PM +0100, Paolo Abeni wrote:
> >> l The mptcp diag interface already experienced a few locking bugs
> >> that lockdep and appropriate coverage have detected in advance.
> >>
> >> Let's add a test-case triggering the relevant code path, to prevent
> >> similar issues in the future.
> >>
> >> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> >> ---
> >>  tools/testing/selftests/net/mptcp/diag.sh | 30 +++++++++++++++++++++++
> >>  1 file changed, 30 insertions(+)
> >>
> >> diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
> >> index 60a7009ce1b5..3ab584b38566 100755
> >> --- a/tools/testing/selftests/net/mptcp/diag.sh
> >> +++ b/tools/testing/selftests/net/mptcp/diag.sh
> >> @@ -81,6 +81,21 @@ chk_msk_nr()
> >>  	__chk_msk_nr "grep -c token:" "$@"
> >>  }
> >>  
> >> +chk_listener_nr()
> >> +{
> >> +	local expected=$1
> >> +	local msg="$2"
> >> +
> >> +	if [ $expected -gt 0 ] && \
> >> +	   ! mptcp_lib_kallsyms_has "mptcp_diag_dump_listeners"; then
> >> +		printf "%-50s%s\n" "$msg - mptcp" "[ skip ]"
> >> +		mptcp_lib_result_skip "many listener sockets"
> >> +	else
> >> +		__chk_nr "ss -inmlHMON $ns | wc -l" "$expected" "$msg - mptcp"
> >> +	fi
> >> +	__chk_nr "ss -inmlHtON $ns | wc -l" "$expected" "$msg - subflows"
> >> +}
> >> +
> >>  wait_msk_nr()
> >>  {
> >>  	local condition="grep -c token:"
> >> @@ -279,5 +294,20 @@ flush_pids
> >>  chk_msk_inuse 0 "many->0"
> >>  chk_msk_cestab 0 "many->0"
> >>  
> >> +chk_listener_nr 0 "no listener sockets"
> >> +NR_SERVERS=100
> >> +for I in $(seq 1 $NR_SERVERS); do
> >> +	ip netns exec $ns ./mptcp_connect -p $((I + 20001)) -l 0.0.0.0 2>&1 >/dev/null &
> >> +	mptcp_lib_wait_local_port_listen $ns $((I + 20001))
> >> +done
> >> +
> >> +chk_listener_nr $NR_SERVERS "many listener sockets"
> >> +
> >> +# gracefull termination
> > 
> > nit, as you plan to re-spin anyway: graceful
> 
> Paolo sent a new version on MPTCP ML only. When applying the new
> version, I fixed this:
> 
> https://lore.kernel.org/mptcp/e98b8b07-558c-498a-97fb-dd5cab11e439@kernel.org/
> 
> >> +for I in $(seq 1 $NR_SERVERS); do
> >> +	echo a | ip netns exec $ns ./mptcp_connect -p $((I + 20001)) 127.0.0.1 2>&1 >/dev/null
> > 
> > I'm not sure of the validity of this but shellcheck complains that:
> > 
> >   SC2069 (warning): To redirect stdout+stderr, 2>&1 must be last (or use '{ cmd > file; } 2>&1' to clarify).
> > 
> > Also for the same constriction slightly earlier in this patch.
> 
> Good catch!
> 
> I should add shellcheck support in our CI to catch that :)
> 
> I just applied the suggested modification in our tree [1]. The new
> version that will be sent to netdev will no longer have this issue.
> 
> https://github.com/multipath-tcp/mptcp_net-next/commit/31f1460d552c

Thanks Matt,

much appreciated.
Re: [PATCH net 2/2] selftests: mptcp: explicitly trigger the listener diag code-path
Posted by Paolo Abeni 1 year, 11 months ago 
On Wed, 2024-02-21 at 12:46 +0100, Paolo Abeni wrote:
> The mptcp diag interface already experienced a few locking bugs
> that lockdep and appropriate coverage have detected in advance.
> 
> Let's add a test-case triggering the relevant code path, to prevent
> similar issues in the future.
> 
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
>  tools/testing/selftests/net/mptcp/diag.sh | 30 +++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
> index 60a7009ce1b5..3ab584b38566 100755
> --- a/tools/testing/selftests/net/mptcp/diag.sh
> +++ b/tools/testing/selftests/net/mptcp/diag.sh
> @@ -81,6 +81,21 @@ chk_msk_nr()
>  	__chk_msk_nr "grep -c token:" "$@"
>  }
>  
> +chk_listener_nr()
> +{
> +	local expected=$1
> +	local msg="$2"
> +
> +	if [ $expected -gt 0 ] && \
> +	   ! mptcp_lib_kallsyms_has "mptcp_diag_dump_listeners"; then
> +		printf "%-50s%s\n" "$msg - mptcp" "[ skip ]"
> +		mptcp_lib_result_skip "many listener sockets"

I was too hasty and this is too fragile/requires debug. A v2 with
something more reliable is needed. Given this is not going to land into
this week PR, we will probably send it with a burst with other fixes.

Thanks,

Paolo

Patchew 2.1-devel-b67e4c2

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