[RFC PATCH v1 3/3] test/vsock: skbuff merging test

[Arseniy Krasnov <avkrasnov@sberdevices.ru>]

This adds test which checks case when data of newly received skbuff is
appended to the last skbuff in the socket's queue.

This test is actual only for virtio transport.

Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
---
 tools/testing/vsock/vsock_test.c | 81 ++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
index 3de10dbb50f5..00216c52d8b6 100644
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@ -968,6 +968,82 @@ static void test_seqpacket_inv_buf_server(const struct test_opts *opts)
 	test_inv_buf_server(opts, false);
 }
 
+static void test_stream_virtio_skb_merge_client(const struct test_opts *opts)
+{
+	ssize_t res;
+	int fd;
+
+	fd = vsock_stream_connect(opts->peer_cid, 1234);
+	if (fd < 0) {
+		perror("connect");
+		exit(EXIT_FAILURE);
+	}
+
+	res = send(fd, "HELLO", strlen("HELLO"), 0);
+	if (res != strlen("HELLO")) {
+		fprintf(stderr, "unexpected send(2) result %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("SEND0");
+	/* Peer reads part of first packet. */
+	control_expectln("REPLY0");
+
+	/* Send second skbuff, it will be merged. */
+	res = send(fd, "WORLD", strlen("WORLD"), 0);
+	if (res != strlen("WORLD")) {
+		fprintf(stderr, "unexpected send(2) result %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("SEND1");
+	/* Peer reads merged skbuff packet. */
+	control_expectln("REPLY1");
+
+	close(fd);
+}
+
+static void test_stream_virtio_skb_merge_server(const struct test_opts *opts)
+{
+	unsigned char buf[64];
+	ssize_t res;
+	int fd;
+
+	fd = vsock_stream_accept(VMADDR_CID_ANY, 1234, NULL);
+	if (fd < 0) {
+		perror("accept");
+		exit(EXIT_FAILURE);
+	}
+
+	control_expectln("SEND0");
+
+	/* Read skbuff partially. */
+	res = recv(fd, buf, 2, 0);
+	if (res != 2) {
+		fprintf(stderr, "expected recv(2) failure, got %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("REPLY0");
+	control_expectln("SEND1");
+
+	res = recv(fd, buf, sizeof(buf), 0);
+	if (res != 8) {
+		fprintf(stderr, "expected recv(2) failure, got %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	res = recv(fd, buf, sizeof(buf), MSG_DONTWAIT);
+	if (res != -1) {
+		fprintf(stderr, "expected recv(2) success, got %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("REPLY1");
+
+	close(fd);
+}
+
 static struct test_case test_cases[] = {
 	{
 		.name = "SOCK_STREAM connection reset",
@@ -1038,6 +1114,11 @@ static struct test_case test_cases[] = {
 		.run_client = test_seqpacket_inv_buf_client,
 		.run_server = test_seqpacket_inv_buf_server,
 	},
+	{
+		.name = "SOCK_STREAM virtio skb merge",
+		.run_client = test_stream_virtio_skb_merge_client,
+		.run_server = test_stream_virtio_skb_merge_server,
+	},
 	{},
 };
 
-- 
2.25.1