Re: [PATCH v5 bpf-next 6/7] selftests/bpf: Add helper to get port using getsockname

Stanislav Fomichev
2023-03-30T18:41:59Z

On 03/30, Aditi Ghag wrote:
> The helper will be used to programmatically retrieve,
> and pass ports in userspace and kernel selftest programs.

> Suggested-by: Stanislav Fomichev <sdf@google.com>
> Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com>
> ---
> tools/testing/selftests/bpf/network_helpers.c | 14 ++++++++++++++
> tools/testing/selftests/bpf/network_helpers.h | 1 +
> 2 files changed, 15 insertions(+)

> diff --git a/tools/testing/selftests/bpf/network_helpers.c
> b/tools/testing/selftests/bpf/network_helpers.c
> index 596caa176582..4c1dc7cf7390 100644
> --- a/tools/testing/selftests/bpf/network_helpers.c
> +++ b/tools/testing/selftests/bpf/network_helpers.c
> @@ -427,3 +427,17 @@ void close_netns(struct nstoken *token)
> close(token->orig_netns_fd);
> free(token);
> }
> +
> +int get_sock_port6(int sock_fd, __u16 *out_port)
> +{
> + struct sockaddr_in6 addr = {};
> + socklen_t addr_len = sizeof(addr);
> + int err;
> +
> + err = getsockname(sock_fd, (struct sockaddr *)&addr, &addr_len);
> + if (err < 0)
> + return err;
> + *out_port = addr.sin6_port;

The rest of the helpers don't usually care about v4 vs v6.
Making it work for both v4 and v6 seems trivial, so maybe let's do it?

> +
> + return err;
> +}
> diff --git a/tools/testing/selftests/bpf/network_helpers.h
> b/tools/testing/selftests/bpf/network_helpers.h
> index f882c691b790..2ab3b50de0b7 100644
> --- a/tools/testing/selftests/bpf/network_helpers.h
> +++ b/tools/testing/selftests/bpf/network_helpers.h
> @@ -56,6 +56,7 @@ int fastopen_connect(int server_fd, const char *data,
> unsigned int data_len,
> int make_sockaddr(int family, const char *addr_str, __u16 port,
> struct sockaddr_storage *addr, socklen_t *len);
> char *ping_command(int family);
> +int get_sock_port6(int sock_fd, __u16 *out_port);

> struct nstoken;
> /**
> --
> 2.34.1