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

[Stanislav Fomichev <sdf@google.com>]

On 04/18, 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 | 28 +++++++++++++++++++
>  tools/testing/selftests/bpf/network_helpers.h |  1 +
>  2 files changed, 29 insertions(+)
> 
> diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
> index 596caa176582..7217cac762f0 100644
> --- a/tools/testing/selftests/bpf/network_helpers.c
> +++ b/tools/testing/selftests/bpf/network_helpers.c
> @@ -427,3 +427,31 @@ void close_netns(struct nstoken *token)
>  	close(token->orig_netns_fd);
>  	free(token);
>  }
> +
> +int get_socket_local_port(int family, int sock_fd, __u16 *out_port)
> +{
> +	socklen_t addr_len;
> +	int err;

Sorry for keeping bikeshedding this part, but if you're going to do
another respin, we can also drop the family argument:

int get_socket_local_port(int sock_fd, __be16 *out_port)
/*                                       ^^ maybe also do be16? */
{
	struct sockaddr_storage addr; 
	socklen_t addrlen;

	addrlen = sizeof(addr);
	getsockname(sock_fd, (struct sockaddr *)&addr, &addrlen);

	if (addr.ss_family == AF_INET) {
	} else if () {
	}
}

> +
> +	if (family == AF_INET) {
> +		struct sockaddr_in addr = {};
> +
> +		addr_len = sizeof(addr);
> +		err = getsockname(sock_fd, (struct sockaddr *)&addr, &addr_len);
> +		if (err < 0)
> +			return err;
> +		*out_port = addr.sin_port;
> +		return 0;
> +	} else if (family == AF_INET6) {
> +		struct sockaddr_in6 addr = {};
> +
> +		addr_len = sizeof(addr);
> +		err = getsockname(sock_fd, (struct sockaddr *)&addr, &addr_len);
> +		if (err < 0)
> +			return err;
> +		*out_port = addr.sin6_port;
> +		return 0;
> +	}
> +
> +	return -1;
> +}
> diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
> index f882c691b790..ca4a147b58b8 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_socket_local_port(int family, int sock_fd, __u16 *out_port);
>  
>  struct nstoken;
>  /**
> -- 
> 2.34.1
>