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
|
package config
import (
"errors"
"fmt"
"regexp"
)
type Rule string
const (
RuleUnknown Rule = ""
RuleAllow Rule = "ALLOW"
RuleDeny Rule = "DENY"
RuleChallenge Rule = "CHALLENGE"
)
type Algorithm string
const (
AlgorithmUnknown Algorithm = ""
AlgorithmFast Algorithm = "fast"
AlgorithmSlow Algorithm = "slow"
)
type Bot struct {
Name string `json:"name"`
UserAgentRegex *string `json:"user_agent_regex"`
PathRegex *string `json:"path_regex"`
Action Rule `json:"action"`
Challenge *ChallengeRules `json:"challenge,omitempty"`
}
var (
ErrNoBotRulesDefined = errors.New("config: must define at least one (1) bot rule")
ErrBotMustHaveName = errors.New("config.Bot: must set name")
ErrBotMustHaveUserAgentOrPath = errors.New("config.Bot: must set either user_agent_regex, path_regex")
ErrBotMustHaveUserAgentOrPathNotBoth = errors.New("config.Bot: must set either user_agent_regex, path_regex, and not both")
ErrUnknownAction = errors.New("config.Bot: unknown action")
ErrInvalidUserAgentRegex = errors.New("config.Bot: invalid user agent regex")
ErrInvalidPathRegex = errors.New("config.Bot: invalid path regex")
)
func (b Bot) Valid() error {
var errs []error
if b.Name == "" {
errs = append(errs, ErrBotMustHaveName)
}
if b.UserAgentRegex == nil && b.PathRegex == nil {
errs = append(errs, ErrBotMustHaveUserAgentOrPath)
}
if b.UserAgentRegex != nil && b.PathRegex != nil {
errs = append(errs, ErrBotMustHaveUserAgentOrPathNotBoth)
}
if b.UserAgentRegex != nil {
if _, err := regexp.Compile(*b.UserAgentRegex); err != nil {
errs = append(errs, ErrInvalidUserAgentRegex, err)
}
}
if b.PathRegex != nil {
if _, err := regexp.Compile(*b.PathRegex); err != nil {
errs = append(errs, ErrInvalidPathRegex, err)
}
}
switch b.Action {
case RuleAllow, RuleChallenge, RuleDeny:
// okay
default:
errs = append(errs, fmt.Errorf("%w: %q", ErrUnknownAction, b.Action))
}
if b.Action == RuleChallenge && b.Challenge != nil {
if err := b.Challenge.Valid(); err != nil {
errs = append(errs, err)
}
}
if len(errs) != 0 {
return fmt.Errorf("config: bot entry for %q is not valid:\n%w", b.Name, errors.Join(errs...))
}
return nil
}
type ChallengeRules struct {
Difficulty int `json:"difficulty"`
ReportAs int `json:"report_as"`
Algorithm Algorithm `json:"algorithm"`
}
var (
ErrChallengeRuleHasWrongAlgorithm = errors.New("config.Bot.ChallengeRules: algorithm is invalid")
ErrChallengeDifficultyTooLow = errors.New("config.Bot.ChallengeRules: difficulty is too low (must be >= 1)")
ErrChallengeDifficultyTooHigh = errors.New("config.Bot.ChallengeRules: difficulty is too high (must be <= 64)")
)
func (cr ChallengeRules) Valid() error {
var errs []error
if cr.Difficulty < 1 {
errs = append(errs, fmt.Errorf("%w, got: %d", ErrChallengeDifficultyTooLow, cr.Difficulty))
}
if cr.Difficulty > 64 {
errs = append(errs, fmt.Errorf("%w, got: %d", ErrChallengeDifficultyTooHigh, cr.Difficulty))
}
switch cr.Algorithm {
case AlgorithmFast, AlgorithmSlow, AlgorithmUnknown:
// do nothing, it's all good
default:
errs = append(errs, fmt.Errorf("%w: %q", ErrChallengeRuleHasWrongAlgorithm, cr.Algorithm))
}
if len(errs) != 0 {
return fmt.Errorf("config: challenge rules entry is not valid:\n%w", errors.Join(errs...))
}
return nil
}
type Config struct {
Bots []Bot `json:"bots"`
DNSBL bool `json:"dnsbl"`
}
func (c Config) Valid() error {
var errs []error
if len(c.Bots) == 0 {
errs = append(errs, ErrNoBotRulesDefined)
}
for _, b := range c.Bots {
if err := b.Valid(); err != nil {
errs = append(errs, err)
}
}
if len(errs) != 0 {
return fmt.Errorf("config is not valid:\n%w", errors.Join(errs...))
}
return nil
}
|
