-
Notifications
You must be signed in to change notification settings - Fork 51
/
uriregex.go
96 lines (79 loc) · 2.14 KB
/
uriregex.go
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
package urisearch
import (
"fmt"
"regexp"
"strconv"
"github.com/aporeto-inc/trireme-lib/policy"
)
// APIStore is a database of API rules.
type APIStore struct {
Scopes map[string][]string
RegEx *regexp.Regexp
RegExNames []string
}
// NewAPIStore creates a database of API rules based on the provided list.
func NewAPIStore(rules []*policy.HTTPRule) (*APIStore, error) {
if len(rules) == 0 {
return nil, fmt.Errorf("Empty rules")
}
scopes := make(map[string][]string)
ruleName := "rule" + strconv.Itoa(0)
regexString := ruleString(ruleName, rules[0])
scopes[ruleName] = rules[0].Scopes
for i := 1; i < len(rules); i++ {
ruleName := "rule" + strconv.Itoa(i)
regexString = regexString + "|" + ruleString(ruleName, rules[i])
scopes[ruleName] = rules[i].Scopes
}
re, err := regexp.Compile(regexString)
if err != nil {
return nil, fmt.Errorf("Provided rule is not valid regular expression: %s", err)
}
return &APIStore{
Scopes: scopes,
RegEx: re,
RegExNames: re.SubexpNames(),
}, nil
}
// Find finds an API call in the database.
func (a *APIStore) Find(verb, api string) ([]string, error) {
// index := a.RegEx.FindSubmatchIndex([]byte(verb + api))
match := a.RegEx.FindStringSubmatch(verb + api)
for i, name := range a.RegExNames {
if i == 0 {
continue
}
if i >= len(match) {
return nil, fmt.Errorf("Failed to match")
}
if match[i] != "" {
return a.Scopes[name], nil
}
}
return nil, fmt.Errorf("URI Not found")
}
// ruleString converts the HTTP rule to a regular expressions string.
// It assumes that the URI is a valid Go regular expression.
func ruleString(index string, rule *policy.HTTPRule) string {
var verbs string
if len(rule.Verbs) == 0 {
verbs = "PUT|GET|POST|PATCH|DELETE"
} else {
verbs = rule.Verbs[0]
}
for i := 1; i < len(rule.Verbs); i++ {
verbs = verbs + "|" + rule.Verbs[i]
}
verbs = fmt.Sprintf("(%s)", verbs)
var uris string
if len(rule.URIs) == 0 {
uris = "/"
} else {
uris = rule.URIs[0]
}
for i := 1; i < len(rule.URIs); i++ {
uris = uris + "|" + rule.URIs[i]
}
uris = fmt.Sprintf("(%s)", uris)
return fmt.Sprintf("(?P<%s>%s%s$)", index, verbs, uris)
}