adb: change mdns tls service names (RFC 6763).
Even though mdnsresponder seems to allow us to use _adb_secure_connect
and _adb_secure_pairing as service names, these names violate the syntax
outlined in RFC6763, and may not be compatible with other dns-sd
implementations.
Also address some comments from a previous CL.
Bug: 154268895
Test: atest adbd_test
Change-Id: Ia872e976fc4276587b500a827a41d46d9dc755dd
diff --git a/adb/mdns_test.cpp b/adb/mdns_test.cpp
new file mode 100644
index 0000000..1f662c1
--- /dev/null
+++ b/adb/mdns_test.cpp
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+
+#include "adb_mdns.h"
+
+static bool isValidMdnsServiceName(std::string_view name) {
+ // The rules for Service Names [RFC6335] state that they may be no more
+ // than fifteen characters long (not counting the mandatory underscore),
+ // consisting of only letters, digits, and hyphens, must begin and end
+ // with a letter or digit, must not contain consecutive hyphens, and
+ // must contain at least one letter.
+
+ // No more than 15 characters long
+ if (name.empty() || name.size() > 15) {
+ return false;
+ }
+
+ bool hasAtLeastOneLetter = false;
+ bool sawHyphen = false;
+ for (size_t i = 0; i < name.size(); ++i) {
+ // Must contain at least one letter
+ // Only contains letters, digits and hyphens
+ if (name[i] == '-') {
+ // Cannot be at beginning or end
+ if (i == 0 || i == name.size() - 1) {
+ return false;
+ }
+ if (sawHyphen) {
+ // Consecutive hyphen found
+ return false;
+ }
+ sawHyphen = true;
+ continue;
+ }
+
+ sawHyphen = false;
+ if ((name[i] >= 'a' && name[i] <= 'z') || (name[i] >= 'A' && name[i] <= 'Z')) {
+ hasAtLeastOneLetter = true;
+ continue;
+ }
+
+ if (name[i] >= '0' && name[i] <= '9') {
+ continue;
+ }
+
+ // Invalid character
+ return false;
+ }
+
+ return hasAtLeastOneLetter;
+}
+
+TEST(mdns, test_isValidMdnsServiceName) {
+ // Longer than 15 characters
+ EXPECT_FALSE(isValidMdnsServiceName("abcd1234abcd1234"));
+
+ // Contains invalid characters
+ EXPECT_FALSE(isValidMdnsServiceName("a*a"));
+ EXPECT_FALSE(isValidMdnsServiceName("a_a"));
+ EXPECT_FALSE(isValidMdnsServiceName("_a"));
+
+ // Does not begin or end with letter or digit
+ EXPECT_FALSE(isValidMdnsServiceName(""));
+ EXPECT_FALSE(isValidMdnsServiceName("-"));
+ EXPECT_FALSE(isValidMdnsServiceName("-a"));
+ EXPECT_FALSE(isValidMdnsServiceName("-1"));
+ EXPECT_FALSE(isValidMdnsServiceName("a-"));
+ EXPECT_FALSE(isValidMdnsServiceName("1-"));
+
+ // Contains consecutive hyphens
+ EXPECT_FALSE(isValidMdnsServiceName("a--a"));
+
+ // Does not contain at least one letter
+ EXPECT_FALSE(isValidMdnsServiceName("1"));
+ EXPECT_FALSE(isValidMdnsServiceName("12"));
+ EXPECT_FALSE(isValidMdnsServiceName("1-2"));
+
+ // Some valid names
+ EXPECT_TRUE(isValidMdnsServiceName("a"));
+ EXPECT_TRUE(isValidMdnsServiceName("a1"));
+ EXPECT_TRUE(isValidMdnsServiceName("1A"));
+ EXPECT_TRUE(isValidMdnsServiceName("aZ"));
+ EXPECT_TRUE(isValidMdnsServiceName("a-Z"));
+ EXPECT_TRUE(isValidMdnsServiceName("a-b-Z"));
+ EXPECT_TRUE(isValidMdnsServiceName("abc-def-123-456"));
+}
+
+TEST(mdns, ServiceName_RFC6335) {
+ EXPECT_TRUE(isValidMdnsServiceName(ADB_MDNS_SERVICE_TYPE));
+ EXPECT_TRUE(isValidMdnsServiceName(ADB_MDNS_TLS_PAIRING_TYPE));
+ EXPECT_TRUE(isValidMdnsServiceName(ADB_MDNS_TLS_CONNECT_TYPE));
+}