1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47
48. 48
49. 49
50. 50
51. 51
52. 52
53. 53
54. 54
55. 55
56. 56
57. 57
58. 58
59. 59
60. 60
61. 61
62. 62
63. 63
64. 64
65. 65
66. 66
67. 67
68. 68
69. 69
70. 70
71. 71
72. 72
73. 73
74. 74
75. 75
76. 76
77. 77
78. 78
79. 79
80. 80
81. 81
82. 82
83. 83
84. 84
85. 85
86. 86
87. 87
88. 88
89. 89
90. 90
91. 91
92. 92
93. 93
94. 94
95. 95
96. 96
97. 97
98. 98
99. 99
100. 100
101. 101
102. 102
103. 103
104. 104
105. 105
106. 106
107. 107
108. 108
109. 109
110. 110
111. 111
112. 112
113. 113
114. 114
115. 115
116. 116
117. 117
118. 118
119. 119
120. 120
121. 121
122. 122
123. 123
124. 124
125. 125
126. 126
127. 127
128. 128
129. 129
130. 130
131. 131
132. 132
133. 133
134. 134
135. 135
136. 136
137. 137
138. 138
139. 139
140. 140
141. 141
142. 142
143. 143
144. 144
145. 145
146. 146
147. 147
148. 148
149. 149
150. 150
151. 151
152. 152
153. 153
154. 154
155. 155
156. 156
157. 157

// Copyright 2021 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package hostmatcher

import (
	"net"
	"path/filepath"
	"strings"
)

// HostMatchList is used to check if a host or IP is in a list.
type HostMatchList struct {
	SettingKeyHint string
	SettingValue   string

	// builtins networks
	builtins []string
	// patterns for host names (with wildcard support)
	patterns []string
	// ipNets is the CIDR network list
	ipNets []*net.IPNet
}

// MatchBuiltinExternal A valid non-private unicast IP, all hosts on public internet are matched
const MatchBuiltinExternal = "external"

// MatchBuiltinPrivate RFC 1918 (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) and RFC 4193 (FC00::/7). Also called LAN/Intranet.
const MatchBuiltinPrivate = "private"

// MatchBuiltinLoopback 127.0.0.0/8 for IPv4 and ::1/128 for IPv6, localhost is included.
const MatchBuiltinLoopback = "loopback"

func isBuiltin(s string) bool {
	return s == MatchBuiltinExternal || s == MatchBuiltinPrivate || s == MatchBuiltinLoopback
}

// ParseHostMatchList parses the host list HostMatchList
func ParseHostMatchList(settingKeyHint, hostList string) *HostMatchList {
	hl := &HostMatchList{SettingKeyHint: settingKeyHint, SettingValue: hostList}
	for _, s := range strings.Split(hostList, ",") {
		s = strings.ToLower(strings.TrimSpace(s))
		if s == "" {
			continue
		}
		_, ipNet, err := net.ParseCIDR(s)
		if err == nil {
			hl.ipNets = append(hl.ipNets, ipNet)
		} else if isBuiltin(s) {
			hl.builtins = append(hl.builtins, s)
		} else {
			hl.patterns = append(hl.patterns, s)
		}
	}
	return hl
}

// ParseSimpleMatchList parse a simple matchlist (no built-in networks, no CIDR support, only wildcard pattern match)
func ParseSimpleMatchList(settingKeyHint, matchList string) *HostMatchList {
	hl := &HostMatchList{
		SettingKeyHint: settingKeyHint,
		SettingValue:   matchList,
	}
	for _, s := range strings.Split(matchList, ",") {
		s = strings.ToLower(strings.TrimSpace(s))
		if s == "" {
			continue
		}
		// we keep the same result as old `matchlist`, so no builtin/CIDR support here, we only match wildcard patterns
		hl.patterns = append(hl.patterns, s)
	}
	return hl
}

// AppendBuiltin appends more builtins to match
func (hl *HostMatchList) AppendBuiltin(builtin string) {
	hl.builtins = append(hl.builtins, builtin)
}

// IsEmpty checks if the checklist is empty
func (hl *HostMatchList) IsEmpty() bool {
	return hl == nil || (len(hl.builtins) == 0 && len(hl.patterns) == 0 && len(hl.ipNets) == 0)
}

func (hl *HostMatchList) checkPattern(host string) bool {
	host = strings.ToLower(strings.TrimSpace(host))
	for _, pattern := range hl.patterns {
		if matched, _ := filepath.Match(pattern, host); matched {
			return true
		}
	}
	return false
}

func (hl *HostMatchList) checkIP(ip net.IP) bool {
	for _, pattern := range hl.patterns {
		if pattern == "*" {
			return true
		}
	}
	for _, builtin := range hl.builtins {
		switch builtin {
		case MatchBuiltinExternal:
			if ip.IsGlobalUnicast() && !ip.IsPrivate() {
				return true
			}
		case MatchBuiltinPrivate:
			if ip.IsPrivate() {
				return true
			}
		case MatchBuiltinLoopback:
			if ip.IsLoopback() {
				return true
			}
		}
	}
	for _, ipNet := range hl.ipNets {
		if ipNet.Contains(ip) {
			return true
		}
	}
	return false
}

// MatchHostName checks if the host matches an allow/deny(block) list
func (hl *HostMatchList) MatchHostName(host string) bool {
	hostname, _, err := net.SplitHostPort(host)
	if err != nil {
		hostname = host
	}

	if hl == nil {
		return false
	}
	if hl.checkPattern(hostname) {
		return true
	}
	if ip := net.ParseIP(hostname); ip != nil {
		return hl.checkIP(ip)
	}
	return false
}

// MatchIPAddr checks if the IP matches an allow/deny(block) list, it's safe to pass `nil` to `ip`
func (hl *HostMatchList) MatchIPAddr(ip net.IP) bool {
	if hl == nil {
		return false
	}
	host := ip.String() // nil-safe, we will get "<nil>" if ip is nil
	return hl.checkPattern(host) || hl.checkIP(ip)
}

// MatchHostOrIP checks if the host or IP matches an allow/deny(block) list
func (hl *HostMatchList) MatchHostOrIP(host string, ip net.IP) bool {
	return hl.MatchHostName(host) || hl.MatchIPAddr(ip)
}