Re: [PATCH bpf-next v2 11/14] selftests/bpf: Use start_server_setsockopt in sockopt_inherit

[Martin KaFai Lau <martin.lau@linux.dev>]

On 4/10/24 6:03 PM, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> Include network_helpers.h in prog_tests/sockopt_inherit.c, use public
> helpers make_sockaddr() and start_server_setsockopt() instead of the
> local defined function start_server(). This can avoid duplicate code.
> 
> Add a helper setsockopt_loop() to set SOL_CUSTOM sockopt looply, and
> pass it to start_server_setsockopt().
> 
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> ---
>   .../bpf/prog_tests/sockopt_inherit.c          | 33 ++++++++-----------
>   1 file changed, 14 insertions(+), 19 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt_inherit.c b/tools/testing/selftests/bpf/prog_tests/sockopt_inherit.c
> index 917f486db826..f000d9229765 100644
> --- a/tools/testing/selftests/bpf/prog_tests/sockopt_inherit.c
> +++ b/tools/testing/selftests/bpf/prog_tests/sockopt_inherit.c
> @@ -1,6 +1,7 @@
>   // SPDX-License-Identifier: GPL-2.0
>   #include <test_progs.h>
>   #include "cgroup_helpers.h"
> +#include "network_helpers.h"
>   
>   #include "sockopt_inherit.skel.h"
>   
> @@ -98,23 +99,12 @@ static void *server_thread(void *arg)
>   	return (void *)(long)err;
>   }
>   
> -static int start_server(void)
> +static int setsockopt_loop(int fd, int val)
>   {
> -	struct sockaddr_in addr = {
> -		.sin_family = AF_INET,
> -		.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
> -	};
>   	char buf;
>   	int err;
> -	int fd;
>   	int i;
>   
> -	fd = socket(AF_INET, SOCK_STREAM, 0);
> -	if (fd < 0) {
> -		log_err("Failed to create server socket");
> -		return -1;
> -	}
> -
>   	for (i = CUSTOM_INHERIT1; i <= CUSTOM_LISTENER; i++) {
>   		buf = 0x01;
>   		err = setsockopt(fd, SOL_CUSTOM, i, &buf, 1);
> @@ -125,13 +115,18 @@ static int start_server(void)
>   		}
>   	}
>   
> -	if (bind(fd, (const struct sockaddr *)&addr, sizeof(addr)) < 0) {
> -		log_err("Failed to bind socket");
> -		close(fd);
> -		return -1;
> -	}
> +	return 0;
> +}
>   
> -	return fd;
> +static int start_server_lo(void)
> +{
> +	struct sockaddr_storage addr;
> +	socklen_t addrlen;
> +
> +	if (make_sockaddr(AF_INET, "127.0.0.1", 0, &addr, &addrlen))
> +		return -1;
> +	return start_server_setsockopt((struct sockaddr *)&addr, addrlen,
> +				       SOCK_STREAM, (void *)setsockopt_loop, 0);

The start_server_setsockopt is only limited to integer socket option. It is not 
very flexible. It seems this is the only test that will be useful. Lets drop 
start_server_setsockopt addition from this set for now and discuss it separately.

>   }
>   
>   static void run_test(int cgroup_fd)
> @@ -160,7 +155,7 @@ static void run_test(int cgroup_fd)
>   	if (!ASSERT_OK_PTR(link_setsockopt, "cg-attach-setsockopt"))
>   		goto close_bpf_object;
>   
> -	server_fd = start_server();
> +	server_fd = start_server_lo();
>   	if (!ASSERT_GE(server_fd, 0, "start_server"))
>   		goto close_bpf_object;
>