[PATCH net-next 2/2] vsock/test: cover SO_INQ

[David Carlier <devnexen@gmail.com>]

Check the SCM_INQ value after a partial receive, after draining the
queue and at EOF, that no cmsg is sent while the option is off, and
that out of range values and SOCK_SEQPACKET are rejected.

Signed-off-by: David Carlier <devnexen@gmail.com>
---
 tools/testing/vsock/vsock_test.c | 191 +++++++++++++++++++++++++++++++
 1 file changed, 191 insertions(+)

diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
index b4ff9f946565..00bb68c00c07 100644
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@ -2429,6 +2429,188 @@ static void test_stream_collapse_server(const struct test_opts *opts)
 	close(fd);
 }
 
+#define SO_INQ_BUF_LEN 64
+#define SO_INQ_CHUNK_LEN 16
+
+static int so_inq_set(int fd, int val)
+{
+	return setsockopt(fd, SOL_SOCKET, SO_INQ, &val, sizeof(val));
+}
+
+/* Receive @len bytes and return the SCM_INQ value, or -1 if the kernel did
+ * not attach one.
+ */
+static int so_inq_recv(int fd, size_t len, int expected_ret)
+{
+	char control[CMSG_SPACE(sizeof(int))] = { 0 };
+	unsigned char buf[SO_INQ_BUF_LEN];
+	struct iovec iov = {
+		.iov_base = buf,
+		.iov_len = len,
+	};
+	struct msghdr msg = {
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+		.msg_control = control,
+		.msg_controllen = sizeof(control),
+	};
+	struct cmsghdr *cmsg;
+	ssize_t ret;
+	int inq;
+
+	ret = recvmsg(fd, &msg, 0);
+	if (ret < 0) {
+		perror("recvmsg");
+		exit(EXIT_FAILURE);
+	}
+
+	expect_res(ret, expected_ret, "recvmsg");
+
+	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+		if (cmsg->cmsg_level != SOL_SOCKET ||
+		    cmsg->cmsg_type != SCM_INQ)
+			continue;
+
+		memcpy(&inq, CMSG_DATA(cmsg), sizeof(inq));
+		return inq;
+	}
+
+	return -1;
+}
+
+static void test_stream_so_inq_client(const struct test_opts *opts)
+{
+	int fd;
+
+	fd = vsock_stream_connect(opts->peer_cid, opts->peer_port);
+	if (fd < 0) {
+		perror("connect");
+		exit(EXIT_FAILURE);
+	}
+
+	control_expectln("SENT");
+
+	/* Wait for the whole payload to be queued, so the values below do not
+	 * depend on how the transport delivers it.
+	 */
+	if (!vsock_ioctl_int(fd, SIOCINQ, SO_INQ_BUF_LEN)) {
+		fprintf(stderr, "Test skipped, SIOCINQ not supported.\n");
+		goto out;
+	}
+
+	/* No ancillary data unless the option is enabled. */
+	expect_res(so_inq_recv(fd, SO_INQ_CHUNK_LEN, SO_INQ_CHUNK_LEN), -1,
+		   "SCM_INQ with SO_INQ disabled");
+
+	if (so_inq_set(fd, 1)) {
+		if (errno != ENOPROTOOPT) {
+			perror("setsockopt(SO_INQ)");
+			exit(EXIT_FAILURE);
+		}
+
+		fprintf(stderr, "Test skipped, SO_INQ not supported.\n");
+		goto out;
+	}
+
+	/* Partial read: the rest of the payload is still queued. */
+	expect_res(so_inq_recv(fd, SO_INQ_CHUNK_LEN, SO_INQ_CHUNK_LEN),
+		   SO_INQ_BUF_LEN - 2 * SO_INQ_CHUNK_LEN,
+		   "SCM_INQ after partial receive");
+
+	/* Draining read while the peer stays connected. */
+	expect_res(so_inq_recv(fd, SO_INQ_BUF_LEN - 2 * SO_INQ_CHUNK_LEN,
+			       SO_INQ_BUF_LEN - 2 * SO_INQ_CHUNK_LEN), 0,
+		   "SCM_INQ after draining receive");
+
+	control_writeln("DRAINED");
+	vsock_wait_remote_close(fd);
+
+	/* Nothing is queued once the peer is gone, but 1 is reported so the
+	 * caller keeps reading until it observes EOF, as TCP_INQ does.
+	 */
+	expect_res(so_inq_recv(fd, SO_INQ_CHUNK_LEN, 0), 1, "SCM_INQ at EOF");
+
+	if (so_inq_set(fd, 0)) {
+		perror("setsockopt(SO_INQ)");
+		exit(EXIT_FAILURE);
+	}
+
+	expect_res(so_inq_recv(fd, SO_INQ_CHUNK_LEN, 0), -1,
+		   "SCM_INQ after disabling SO_INQ");
+
+	close(fd);
+	return;
+
+out:
+	control_writeln("DRAINED");
+	close(fd);
+}
+
+static void test_stream_so_inq_server(const struct test_opts *opts)
+{
+	unsigned char buf[SO_INQ_BUF_LEN];
+	int fd;
+
+	fd = vsock_stream_accept(VMADDR_CID_ANY, opts->peer_port, NULL);
+	if (fd < 0) {
+		perror("accept");
+		exit(EXIT_FAILURE);
+	}
+
+	memset(buf, 'A', sizeof(buf));
+	send_buf(fd, buf, sizeof(buf), 0, sizeof(buf));
+	control_writeln("SENT");
+
+	/* Keep the connection open until the peer has drained the queue: an
+	 * early close would turn its last SCM_INQ value into the EOF one.
+	 */
+	control_expectln("DRAINED");
+	close(fd);
+}
+
+static void test_so_inq_validation_client(const struct test_opts *opts)
+{
+	int fd;
+
+	fd = socket(AF_VSOCK, SOCK_STREAM, 0);
+	if (fd < 0) {
+		perror("socket");
+		exit(EXIT_FAILURE);
+	}
+
+	if (so_inq_set(fd, 1)) {
+		if (errno != ENOPROTOOPT) {
+			perror("setsockopt(SO_INQ)");
+			exit(EXIT_FAILURE);
+		}
+
+		fprintf(stderr, "Test skipped, SO_INQ not supported.\n");
+		close(fd);
+		return;
+	}
+
+	if (!so_inq_set(fd, 2) || errno != EINVAL) {
+		fprintf(stderr, "SO_INQ accepted an out of range value\n");
+		exit(EXIT_FAILURE);
+	}
+
+	close(fd);
+
+	/* SCM_INQ counts bytes, which a message based socket cannot report. */
+	fd = socket(AF_VSOCK, SOCK_SEQPACKET, 0);
+	if (fd < 0) {
+		perror("socket");
+		exit(EXIT_FAILURE);
+	}
+
+	if (!so_inq_set(fd, 1) || errno != ENOPROTOOPT) {
+		fprintf(stderr, "SO_INQ not rejected on SOCK_SEQPACKET\n");
+		exit(EXIT_FAILURE);
+	}
+
+	close(fd);
+}
+
 static struct test_case test_cases[] = {
 	{
 		.name = "SOCK_STREAM connection reset",
@@ -2633,6 +2815,15 @@ static struct test_case test_cases[] = {
 		.run_client = test_stream_collapse_client,
 		.run_server = test_stream_collapse_server,
 	},
+	{
+		.name = "SOCK_STREAM SO_INQ functionality",
+		.run_client = test_stream_so_inq_client,
+		.run_server = test_stream_so_inq_server,
+	},
+	{
+		.name = "SO_INQ option validation",
+		.run_client = test_so_inq_validation_client,
+	},
 	{},
 };
 
-- 
2.55.0