Re: [PATCH bpf-next] selftests/bpf: Sanitize traffic monitor log file names

On 8/6/26 2:11 PM, Vineet Gupta wrote:
> The traffic monitor names its capture logs after the test and subtest
> being run, replacing '/' and ' ' so the result is usable as a file name.
> Test names are free form though, and other characters make it through.
> A subtest called "INET4: bpf timestamping" produces
> 
>   /tmp/tmon_pcap/packets-125-15-net_timestamping__INET4:_bpf_timestamping-net_timestamping_ns.log
> 
> CI systems that collect these logs as artifacts reject such names.
> GitHub Actions' upload-artifact fails the upload with
> 
>   Error: The path for one of the files in artifact is not valid:
>   ... Contains the following character:  Colon :
> 
> Replace the whole set of awkward characters in one pass rather than
> adding another strchr() loop per character. Note the loop tests *p
> before calling strchr(), so the terminating NUL is never passed to it.
> 
> This came up as a side error/annoyance when trying to re-enable BPF-GCC
> CI runs [1]. The CI side already has path name normalization and needs
> some tweaking as well, however fixing it at the source also makes sense.
> 
> Fixes: f52403b6bfea ("selftests/bpf: Add traffic monitor functions.")
> Link: https://github.com/kernel-patches/vmtest/actions/runs/30710914503/job/91399011388 [1]
> Signed-off-by: Vineet Gupta <[email protected]>
> ---
>  tools/testing/selftests/bpf/network_helpers.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> index db935a9d9fc1..3818cec354a0 100644
> --- a/tools/testing/selftests/bpf/network_helpers.c
> +++ b/tools/testing/selftests/bpf/network_helpers.c
> @@ -1142,10 +1142,13 @@ static void encode_test_name(char *buf, size_t len, const char *test_name, const
>  		snprintf(buf, len, "%s__%s", test_name, subtest_name);
>  	else
>  		snprintf(buf, len, "%s", test_name);
> -	while ((p = strchr(buf, '/')))
> -		*p = '_';
> -	while ((p = strchr(buf, ' ')))
> -		*p = '_';
> +	/* Test names are free form, so replace anything that is awkward in a
> +	 * file name. Besides the path separator, this covers the characters
> +	 * rejected by CI systems collecting these logs as artifacts.
> +	 */
> +	for (p = buf; *p; p++)
> +		if (strchr("/ \":<>|*?\r\n", *p))

Hi Vineet,

We already do this on the CI side here:
https://github.com/libbpf/ci/blob/main/run-vmtest/normalize-paths-for-github.sh

The problem on the CI side is that the script is not executed
in some corner cases, like a VM timeout.

I don't think this change is necessary upstream: the paths are
technically valid, it's an issue for CI only due to github quirks.

> +			*p = '_';
>  }
>  
>  #define PCAP_DIR "/tmp/tmon_pcap"