[LTP] [PATCH] icmp_rate_limit01: Fix rate limit change on older kernels

[Andrea Cervesato]

Hi Martin,

> The icmp_msgs_burst sysfile was added to non-root namespaces in kernel
> v6.12. Older kernels allow changing the value only from the root
> namespace. Set the global limit first, then change the test namespace
> limit as well if needed.
> 
> Fixes: 3c4c712f1f9b ("cve: icmp_rate_limit: set icmp_msgs_burst within network namespace")
> Signed-off-by: Martin Doucha <mdoucha@suse.cz>
> ---
>  testcases/cve/icmp_rate_limit01.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/testcases/cve/icmp_rate_limit01.c b/testcases/cve/icmp_rate_limit01.c
> index 5193c5dfd..37bc71cb8 100644
> --- a/testcases/cve/icmp_rate_limit01.c
> +++ b/testcases/cve/icmp_rate_limit01.c
> @@ -62,7 +62,12 @@ static void setup(void)
>  	/* Do NOT close this FD, or both interfaces will be destroyed */
>  	childns = SAFE_OPEN("/proc/self/ns/net", O_RDONLY);
>  
> -	SAFE_FILE_PRINTF("/proc/sys/net/ipv4/icmp_msgs_burst", "50");
> +	/*
> +	 * Set namespace local rate limit if needed. The global limit might
> +	 * be ignored otherwise.
> +	 */
> +	if (!access("/proc/sys/net/ipv4/icmp_msgs_burst", F_OK))
> +		SAFE_FILE_PRINTF("/proc/sys/net/ipv4/icmp_msgs_burst", "50");
>  
>  	/* Configure child namespace */
>  	CREATE_VETH_PAIR("ltp_veth1", "ltp_veth2");
> @@ -257,6 +262,7 @@ static struct tst_test test = {
>  	},
>  	.save_restore = (const struct tst_path_val[]) {
>  		{"/proc/sys/user/max_user_namespaces", "1024", TST_SR_SKIP},
> +		{"/proc/sys/net/ipv4/icmp_msgs_burst", "50", TST_SR_TBROK},

Shouldn't we use TST_SR_SKIP_MISSING here instead of TBROK?

Regards,
--
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com