selftests: tls: factor out cmsg send/receive

Add helpers for sending and receiving special record types.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/tls.c

@@ -123,6 +123,65 @@ static void ulp_sock_pair(struct __test_metadata *_metadata,
 	ASSERT_EQ(ret, 0);
 }
 
+/* Produce a basic cmsg */
+static int tls_send_cmsg(int fd, unsigned char record_type,
+			 void *data, size_t len, int flags)
+{
+	char cbuf[CMSG_SPACE(sizeof(char))];
+	int cmsg_len = sizeof(char);
+	struct cmsghdr *cmsg;
+	struct msghdr msg;
+	struct iovec vec;
+
+	vec.iov_base = data;
+	vec.iov_len = len;
+	memset(&msg, 0, sizeof(struct msghdr));
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+	msg.msg_control = cbuf;
+	msg.msg_controllen = sizeof(cbuf);
+	cmsg = CMSG_FIRSTHDR(&msg);
+	cmsg->cmsg_level = SOL_TLS;
+	/* test sending non-record types. */
+	cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
+	cmsg->cmsg_len = CMSG_LEN(cmsg_len);
+	*CMSG_DATA(cmsg) = record_type;
+	msg.msg_controllen = cmsg->cmsg_len;
+
+	return sendmsg(fd, &msg, flags);
+}
+
+static int tls_recv_cmsg(struct __test_metadata *_metadata,
+			 int fd, unsigned char record_type,
+			 void *data, size_t len, int flags)
+{
+	char cbuf[CMSG_SPACE(sizeof(char))];
+	struct cmsghdr *cmsg;
+	unsigned char ctype;
+	struct msghdr msg;
+	struct iovec vec;
+	int n;
+
+	vec.iov_base = data;
+	vec.iov_len = len;
+	memset(&msg, 0, sizeof(struct msghdr));
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+	msg.msg_control = cbuf;
+	msg.msg_controllen = sizeof(cbuf);
+
+	n = recvmsg(fd, &msg, flags);
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	EXPECT_NE(cmsg, NULL);
+	EXPECT_EQ(cmsg->cmsg_level, SOL_TLS);
+	EXPECT_EQ(cmsg->cmsg_type, TLS_GET_RECORD_TYPE);
+	ctype = *((unsigned char *)CMSG_DATA(cmsg));
+	EXPECT_EQ(ctype, record_type);
+
+	return n;
+}
+
 FIXTURE(tls_basic)
 {
 	int fd, cfd;
@@ -1160,60 +1219,30 @@ TEST_F(tls, mutliproc_sendpage_writers)
 
 TEST_F(tls, control_msg)
 {
-	if (self->notls)
-		return;
-
-	char cbuf[CMSG_SPACE(sizeof(char))];
-	char const *test_str = "test_read";
-	int cmsg_len = sizeof(char);
+	char *test_str = "test_read";
 	char record_type = 100;
-	struct cmsghdr *cmsg;
-	struct msghdr msg;
 	int send_len = 10;
-	struct iovec vec;
 	char buf[10];
 
-	vec.iov_base = (char *)test_str;
-	vec.iov_len = 10;
-	memset(&msg, 0, sizeof(struct msghdr));
-	msg.msg_iov = &vec;
-	msg.msg_iovlen = 1;
-	msg.msg_control = cbuf;
-	msg.msg_controllen = sizeof(cbuf);
-	cmsg = CMSG_FIRSTHDR(&msg);
-	cmsg->cmsg_level = SOL_TLS;
-	/* test sending non-record types. */
-	cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
-	cmsg->cmsg_len = CMSG_LEN(cmsg_len);
-	*CMSG_DATA(cmsg) = record_type;
-	msg.msg_controllen = cmsg->cmsg_len;
+	if (self->notls)
+		SKIP(return, "no TLS support");
 
-	EXPECT_EQ(sendmsg(self->fd, &msg, 0), send_len);
+	EXPECT_EQ(tls_send_cmsg(self->fd, record_type, test_str, send_len, 0),
+		  send_len);
 	/* Should fail because we didn't provide a control message */
 	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), -1);
 
-	vec.iov_base = buf;
-	EXPECT_EQ(recvmsg(self->cfd, &msg, MSG_WAITALL | MSG_PEEK), send_len);
-
-	cmsg = CMSG_FIRSTHDR(&msg);
-	EXPECT_NE(cmsg, NULL);
-	EXPECT_EQ(cmsg->cmsg_level, SOL_TLS);
-	EXPECT_EQ(cmsg->cmsg_type, TLS_GET_RECORD_TYPE);
-	record_type = *((unsigned char *)CMSG_DATA(cmsg));
-	EXPECT_EQ(record_type, 100);
+	EXPECT_EQ(tls_recv_cmsg(_metadata, self->cfd, record_type,
+				buf, sizeof(buf), MSG_WAITALL | MSG_PEEK),
+		  send_len);
 	EXPECT_EQ(memcmp(buf, test_str, send_len), 0);
 
 	/* Recv the message again without MSG_PEEK */
-	record_type = 0;
 	memset(buf, 0, sizeof(buf));
 
-	EXPECT_EQ(recvmsg(self->cfd, &msg, MSG_WAITALL), send_len);
-	cmsg = CMSG_FIRSTHDR(&msg);
-	EXPECT_NE(cmsg, NULL);
-	EXPECT_EQ(cmsg->cmsg_level, SOL_TLS);
-	EXPECT_EQ(cmsg->cmsg_type, TLS_GET_RECORD_TYPE);
-	record_type = *((unsigned char *)CMSG_DATA(cmsg));
-	EXPECT_EQ(record_type, 100);
+	EXPECT_EQ(tls_recv_cmsg(_metadata, self->cfd, record_type,
+				buf, sizeof(buf), MSG_WAITALL),
+		  send_len);
 	EXPECT_EQ(memcmp(buf, test_str, send_len), 0);
 }