1 /*
2  * Copyright (C) 2020 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <gtest/gtest.h>
18 
19 #include "adb_mdns.h"
20 
21 static bool isValidMdnsServiceName(std::string_view name) {
22     // The rules for Service Names [RFC6335] state that they may be no more
23     // than fifteen characters long (not counting the mandatory underscore),
24     // consisting of only letters, digits, and hyphens, must begin and end
25     // with a letter or digit, must not contain consecutive hyphens, and
26     // must contain at least one letter.
27 
28     // No more than 15 characters long
29     if (name.empty() || name.size() > 15) {
30         return false;
31     }
32 
33     bool hasAtLeastOneLetter = false;
34     bool sawHyphen = false;
35     for (size_t i = 0; i < name.size(); ++i) {
36         // Must contain at least one letter
37         // Only contains letters, digits and hyphens
38         if (name[i] == '-') {
39             // Cannot be at beginning or end
40             if (i == 0 || i == name.size() - 1) {
41                 return false;
42             }
43             if (sawHyphen) {
44                 // Consecutive hyphen found
45                 return false;
46             }
47             sawHyphen = true;
48             continue;
49         }
50 
51         sawHyphen = false;
52         if ((name[i] >= 'a' && name[i] <= 'z') || (name[i] >= 'A' && name[i] <= 'Z')) {
53             hasAtLeastOneLetter = true;
54             continue;
55         }
56 
57         if (name[i] >= '0' && name[i] <= '9') {
58             continue;
59         }
60 
61         // Invalid character
62         return false;
63     }
64 
65     return hasAtLeastOneLetter;
66 }
67 
68 TEST(mdns, test_isValidMdnsServiceName) {
69     // Longer than 15 characters
70     EXPECT_FALSE(isValidMdnsServiceName("abcd1234abcd1234"));
71 
72     // Contains invalid characters
73     EXPECT_FALSE(isValidMdnsServiceName("a*a"));
74     EXPECT_FALSE(isValidMdnsServiceName("a_a"));
75     EXPECT_FALSE(isValidMdnsServiceName("_a"));
76 
77     // Does not begin or end with letter or digit
78     EXPECT_FALSE(isValidMdnsServiceName(""));
79     EXPECT_FALSE(isValidMdnsServiceName("-"));
80     EXPECT_FALSE(isValidMdnsServiceName("-a"));
81     EXPECT_FALSE(isValidMdnsServiceName("-1"));
82     EXPECT_FALSE(isValidMdnsServiceName("a-"));
83     EXPECT_FALSE(isValidMdnsServiceName("1-"));
84 
85     // Contains consecutive hyphens
86     EXPECT_FALSE(isValidMdnsServiceName("a--a"));
87 
88     // Does not contain at least one letter
89     EXPECT_FALSE(isValidMdnsServiceName("1"));
90     EXPECT_FALSE(isValidMdnsServiceName("12"));
91     EXPECT_FALSE(isValidMdnsServiceName("1-2"));
92 
93     // Some valid names
94     EXPECT_TRUE(isValidMdnsServiceName("a"));
95     EXPECT_TRUE(isValidMdnsServiceName("a1"));
96     EXPECT_TRUE(isValidMdnsServiceName("1A"));
97     EXPECT_TRUE(isValidMdnsServiceName("aZ"));
98     EXPECT_TRUE(isValidMdnsServiceName("a-Z"));
99     EXPECT_TRUE(isValidMdnsServiceName("a-b-Z"));
100     EXPECT_TRUE(isValidMdnsServiceName("abc-def-123-456"));
101 }
102 
103 TEST(mdns, ServiceName_RFC6335) {
104     EXPECT_TRUE(isValidMdnsServiceName(ADB_MDNS_SERVICE_TYPE));
105     EXPECT_TRUE(isValidMdnsServiceName(ADB_MDNS_TLS_PAIRING_TYPE));
106     EXPECT_TRUE(isValidMdnsServiceName(ADB_MDNS_TLS_CONNECT_TYPE));
107 }
108