summaryrefslogtreecommitdiffstats
path: root/modules/hostmatcher/hostmatcher.go
blob: 81c4202fcd98c609bea5cf749c2042099daed582 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
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 {
	if hl == nil {
		return false
	}

	hostname, _, err := net.SplitHostPort(host)
	if err != nil {
		hostname = host
	}
	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)
}