Merge branch 'vsock-fix-so_zerocopy-on-accept-ed-vsocks'

Michal Luczaj says:

====================
vsock: Fix SO_ZEROCOPY on accept()ed vsocks

vsock has its own handling of setsockopt(SO_ZEROCOPY). Which works just
fine unless socket comes from a call to accept(). Because
SOCK_CUSTOM_SOCKOPT flag is missing, attempting to set the option always
results in errno EOPNOTSUPP.
====================

Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

net/vmw_vsock/af_vsock.c

···
 		} else {
 			newsock->state = SS_CONNECTED;
 			sock_graft(connected, newsock);
+
+			set_bit(SOCK_CUSTOM_SOCKOPT,
+				&connected->sk_socket->flags);
+
 			if (vsock_msgzerocopy_allow(vconnected->transport))
 				set_bit(SOCK_SUPPORT_ZC,
 					&connected->sk_socket->flags);

tools/testing/vsock/vsock_test.c

···
 	close(fd);
 }
 
+static void test_stream_accepted_setsockopt_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);
+	}
+
+	close(fd);
+}
+
+static void test_stream_accepted_setsockopt_server(const struct test_opts *opts)
+{
+	int fd;
+
+	fd = vsock_stream_accept(VMADDR_CID_ANY, opts->peer_port, NULL);
+	if (fd < 0) {
+		perror("accept");
+		exit(EXIT_FAILURE);
+	}
+
+	enable_so_zerocopy_check(fd);
+	close(fd);
+}
+
 static struct test_case test_cases[] = {
 	{
 		.name = "SOCK_STREAM connection reset",
···
 		.name = "SOCK_SEQPACKET ioctl(SIOCINQ) functionality",
 		.run_client = test_seqpacket_unread_bytes_client,
 		.run_server = test_seqpacket_unread_bytes_server,
+	},
+	{
+		.name = "SOCK_STREAM accept()ed socket custom setsockopt()",
+		.run_client = test_stream_accepted_setsockopt_client,
+		.run_server = test_stream_accepted_setsockopt_server,
 	},
 	{},
 };