Re: [PATCH v2] release/checks/integration: handle partial sends

[Yureka <yuka@yuka.dev>]

On 11/29/25 19:00, Alyssa Ross wrote:
> Sometimes we see a test failure that looks like this:
>
> 	unexpected connection data: qemu-system-aarch64: terminating on signal 15 from pid 184 ()
>
> I think this is because, now that the nc command in the networking
> integration test has a timeout, it's possible for it to time out after
> having opened the connection, but before having written all its input
> to it.  Therefore, ignore connections that send a prefix of the
> expected data (including nothing), and just wait for the next
> connection rather than failing if that happens.
>
> Closes: https://spectrum-os.org/lists/archives/spectrum-devel/875xbl33vw.fsf@alyssa.is/
> Fixes: c61b297 ("release/checks/integration: add nc timeout")
> Signed-off-by: Alyssa Ross <hi@alyssa.is>
> ---
> v2: close connections when finished reading.
> v1: https://spectrum-os.org/lists/archives/spectrum-devel/20251129163521.717709-2-hi@alyssa.is/
>
>   release/checks/integration/networking.c | 50 +++++++++++++++----------
>   1 file changed, 31 insertions(+), 19 deletions(-)
>
> diff --git a/release/checks/integration/networking.c b/release/checks/integration/networking.c
> index 97d7895..df76ec5 100644
> --- a/release/checks/integration/networking.c
> +++ b/release/checks/integration/networking.c
> @@ -57,32 +57,44 @@ static int setup_server(void)
>   
>   static void expect_connection(int listener)
>   {
> -	int conn_fd;
> -	FILE *conn;
> +	int conn, r;
>   	char msg[7];
>   	size_t len;
>   
> -	fputs("waiting for server connection\n", stderr);
> -	if ((conn_fd = accept(listener, nullptr, nullptr)) == -1) {
> -		perror("accept");
> -		exit(EXIT_FAILURE);
> -	}
> -	fputs("accepted connection!\n", stderr);
> -	if (!(conn = fdopen(conn_fd, "r"))) {
> -		perror("fdopen(server connection)");
> -		exit(EXIT_FAILURE);
> -	}
> +	for (;;) {
> +		len = 0;
>   
> -	len = fread(msg, 1, sizeof msg, conn);
> -	if (len != 6 || memcmp("hello\n", msg, 6)) {
> -		if (ferror(conn))
> -			perror("fread(server connection)");
> -		else
> +		fputs("waiting for server connection\n", stderr);
> +		if ((conn = accept(listener, nullptr, nullptr)) == -1) {
> +			perror("accept");
> +			exit(EXIT_FAILURE);
> +		}
> +		fputs("accepted connection!\n", stderr);
> +
> +		for (;;) {
> +			r = read(conn, msg + len, sizeof msg - len);
> +			if (r == -1) {
> +				perror("read");
> +				exit(EXIT_FAILURE);
> +			}
> +			if (r == 0)
> +				break;
> +			len += r;
> +		}
> +		close(conn);
> +
> +		if (memcmp("hello\n", msg, len) || len > 6) {
>   			fprintf(stderr, "unexpected connection data: %.*s",
>   			        (int)len, msg);
> -		exit(EXIT_FAILURE);
> +			exit(EXIT_FAILURE);
> +		}
> +
> +		// If connection was disconnect partway through, try again.
> +		if (len < 6)
> +			continue;
> +
> +		return;
>   	}
> -	fclose(conn);
>   }
>   
>   static void drain_connections(int listener)
>
> base-commit: 067c6a5d50971242f9cb8ac0ac76e20d88a9b5c1
Reviewed-by: Yureka Lilian <yureka@cyberchaos.dev>