On 1/28/25 1:57 AM, Bastien Curutchet (eBPF Foundation) wrote:
> Some tests can't be run in parallel because they use same namespace
> names or veth names.
>
> Create an helper that appends the thread ID to a given string. 8
> characters are used for it (7 digits + '\0')
>
> Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet@bootlin.com>
> ---
> tools/testing/selftests/bpf/network_helpers.c | 11 +++++++++++
> tools/testing/selftests/bpf/network_helpers.h | 10 ++++++++++
> 2 files changed, 21 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> index 80844a5fb1feef2ff73c2f0293e52495803ab769..d2ff7521aaa696ed04d8f1308394b4c01c1c038b 100644
> --- a/tools/testing/selftests/bpf/network_helpers.c
> +++ b/tools/testing/selftests/bpf/network_helpers.c
> @@ -446,6 +446,17 @@ char *ping_command(int family)
> return "ping";
> }
>
> +int append_tid(char *str, size_t offset)
nit. offset should always be strlen(str) now. The append_tid will be easier to
use if the append_tid always does the strlen() itself to figure out the end of
the str.
It will be useful to replace the "size_t offset" arg with "size_t sz" which
tells the max size of the "char *str" and the append_tid does a check to ensure
there is enough space to append the "%07d" tid.
> +{
> + if (!str)
> + return -1;
> +
> + sprintf(&str[offset], "%07d", gettid());
> + str[offset + 7] = '\0';
> +
> + return 0;
> +}
> +
> int remove_netns(const char *name)
> {
> char *cmd;
> diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
> index ebec8a8d6f81e9d079a3b087127a37885c656856..b2451dd00594190e1dcb58498d70dd80c0e7c51c 100644
> --- a/tools/testing/selftests/bpf/network_helpers.h
> +++ b/tools/testing/selftests/bpf/network_helpers.h
> @@ -98,6 +98,16 @@ int send_recv_data(int lfd, int fd, uint32_t total_bytes);
> int make_netns(const char *name);
> int remove_netns(const char *name);
>
> +/**
> + * append_tid() - Append thread ID to the given string.
> + *
> + * /!\ the appended thread ID is 8 characters long
> + * so the input string must be allocated accordingly
> + *
> + * Returns -1 if input is NULL, 0 otherwise
> + */
> +int append_tid(char *str, size_t offset);
> +
> static __u16 csum_fold(__u32 csum)
> {
> csum = (csum & 0xffff) + (csum >> 16);
>