Re: [PATCH net-next v3 1/2] af_vsock: SOCK_SEQPACKET receive timeout test

[Stefano Garzarella <sgarzare@redhat.com>]

On Thu, Mar 17, 2022 at 05:26:45AM +0000, Krasnov Arseniy Vladimirovich wrote:
>Test for receive timeout check: connection is established,
>receiver sets timeout, but sender does nothing. Receiver's
>'read()' call must return EAGAIN.
>
>Signed-off-by: Krasnov Arseniy Vladimirovich <AVKrasnov@sberdevices.ru>
>---
> v2 -> v3:
> 1) Use 'fprintf()' instead of 'perror()' where 'errno' variable
>    is not affected.
> 2) Print 'read()' overhead.
>
> tools/testing/vsock/vsock_test.c | 84 ++++++++++++++++++++++++++++++++
> 1 file changed, 84 insertions(+)
>
>diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
>index 2a3638c0a008..f5498de6751d 100644
>--- a/tools/testing/vsock/vsock_test.c
>+++ b/tools/testing/vsock/vsock_test.c
>@@ -16,6 +16,7 @@
> #include <linux/kernel.h>
> #include <sys/types.h>
> #include <sys/socket.h>
>+#include <time.h>
>
> #include "timeout.h"
> #include "control.h"
>@@ -391,6 +392,84 @@ static void test_seqpacket_msg_trunc_server(const struct test_opts *opts)
> 	close(fd);
> }
>
>+static time_t current_nsec(void)
>+{
>+	struct timespec ts;
>+
>+	if (clock_gettime(CLOCK_REALTIME, &ts)) {
>+		perror("clock_gettime(3) failed");
>+		exit(EXIT_FAILURE);
>+	}
>+
>+	return (ts.tv_sec * 1000000000ULL) + ts.tv_nsec;
>+}
>+
>+#define RCVTIMEO_TIMEOUT_SEC 1
>+#define READ_OVERHEAD_NSEC 250000000 /* 0.25 sec */
>+
>+static void test_seqpacket_timeout_client(const struct test_opts *opts)
>+{
>+	int fd;
>+	struct timeval tv;
>+	char dummy;
>+	time_t read_enter_ns;
>+	time_t read_overhead_ns;
>+
>+	fd = vsock_seqpacket_connect(opts->peer_cid, 1234);
>+	if (fd < 0) {
>+		perror("connect");
>+		exit(EXIT_FAILURE);
>+	}
>+
>+	tv.tv_sec = RCVTIMEO_TIMEOUT_SEC;
>+	tv.tv_usec = 0;
>+
>+	if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (void *)&tv, sizeof(tv)) == -1) {
>+		perror("setsockopt 'SO_RCVTIMEO'");
>+		exit(EXIT_FAILURE);
>+	}
>+
>+	read_enter_ns = current_nsec();
>+
>+	if (errno != EAGAIN) {
>+		perror("EAGAIN expected");
>+		exit(EXIT_FAILURE);
>+	}

Should this check go after read()?

Indeed now the test fails on my environment with "EAGAIN expected" 
message.

The rest LGTM :-)

Stefano

>+
>+	if (read(fd, &dummy, sizeof(dummy)) != -1) {
>+		fprintf(stderr,
>+			"expected 'dummy' read(2) failure\n");
>+		exit(EXIT_FAILURE);
>+	}
>+
>+	read_overhead_ns = current_nsec() - read_enter_ns -
>+			1000000000ULL * RCVTIMEO_TIMEOUT_SEC;
>+
>+	if (read_overhead_ns > READ_OVERHEAD_NSEC) {
>+		fprintf(stderr,
>+			"too much time in read(2), %lu > %i ns\n",
>+			read_overhead_ns, READ_OVERHEAD_NSEC);
>+		exit(EXIT_FAILURE);
>+	}
>+
>+	control_writeln("WAITDONE");
>+	close(fd);
>+}
>+
>+static void test_seqpacket_timeout_server(const struct test_opts *opts)
>+{
>+	int fd;
>+
>+	fd = vsock_seqpacket_accept(VMADDR_CID_ANY, 1234, NULL);
>+	if (fd < 0) {
>+		perror("accept");
>+		exit(EXIT_FAILURE);
>+	}
>+
>+	control_expectln("WAITDONE");
>+	close(fd);
>+}
>+
> static struct test_case test_cases[] = {
> 	{
> 		.name = "SOCK_STREAM connection reset",
>@@ -431,6 +510,11 @@ static struct test_case test_cases[] = {
> 		.run_client = test_seqpacket_msg_trunc_client,
> 		.run_server = test_seqpacket_msg_trunc_server,
> 	},
>+	{
>+		.name = "SOCK_SEQPACKET timeout",
>+		.run_client = test_seqpacket_timeout_client,
>+		.run_server = test_seqpacket_timeout_server,
>+	},
> 	{},
> };
>
>-- 
>2.25.1