/
rulechecker.go
181 lines (163 loc) · 5.1 KB
/
rulechecker.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
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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
package nsg
// Copyright (c) Microsoft Corporation.
// Licensed under the Apache License 2.0.
import (
"fmt"
"net/netip"
"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/network/armnetwork/v2"
"github.com/sirupsen/logrus"
)
const (
virtualNetwork = "VirtualNetwork"
wildcard = "*"
)
type ruleChecker struct {
log *logrus.Entry
master []netip.Prefix
workers []netip.Prefix
rule *armnetwork.SecurityRule
sourceStrings, destinationStrings []string
}
func newRuleChecker(log *logrus.Entry, master []netip.Prefix, workers []netip.Prefix, rule *armnetwork.SecurityRule) ruleChecker {
var sourceStrings, destinationStrings []string
if rule.Properties.SourceAddressPrefix != nil {
sourceStrings = append(sourceStrings, *rule.Properties.SourceAddressPrefix)
}
srcPrefixes := rule.Properties.SourceAddressPrefixes
for i := range srcPrefixes {
sourceStrings = append(sourceStrings, *srcPrefixes[i])
}
if rule.Properties.DestinationAddressPrefix != nil {
destinationStrings = append(destinationStrings, *rule.Properties.DestinationAddressPrefix)
}
destPrefixes := rule.Properties.DestinationAddressPrefixes
for i := range destPrefixes {
destinationStrings = append(destinationStrings, *destPrefixes[i])
}
return ruleChecker{
log: log,
master: master,
workers: workers,
rule: rule,
sourceStrings: sourceStrings,
destinationStrings: destinationStrings,
}
}
// For storing evaluation results
type properties struct {
isMaster bool
isWorker bool
isAny bool
isVirtualNetwork bool
}
func (p properties) isNothing() bool {
return !p.isMaster && !p.isWorker && !p.isAny && !p.isVirtualNetwork
}
func (c ruleChecker) newProperties(addresses []string) properties {
return properties{
isMaster: c.isMaster(addresses),
isWorker: c.isWorker(addresses),
isAny: isAny(addresses),
isVirtualNetwork: isVirtualNetwork(addresses),
}
}
func (c ruleChecker) isInvalidDenyRule() bool {
source := c.newProperties(c.sourceStrings)
destination := c.newProperties(c.destinationStrings)
switch {
case source.isNothing() && destination.isNothing():
return false
case source.isMaster && destination.isMaster:
return true
case source.isMaster && destination.isWorker:
return true
case source.isWorker && destination.isMaster:
return true
case source.isMaster && destination.isAny:
return true
case source.isAny && destination.isMaster:
return true
case source.isWorker && destination.isAny:
return true
case source.isAny && destination.isWorker:
return true
case source.isAny && destination.isAny:
return true
case source.isMaster && destination.isVirtualNetwork:
return true
case source.isVirtualNetwork && destination.isMaster:
return true
case source.isWorker && destination.isVirtualNetwork:
return true
case source.isVirtualNetwork && destination.isWorker:
return true
case source.isVirtualNetwork && destination.isAny:
return true
case source.isAny && destination.isVirtualNetwork:
return true
case source.isVirtualNetwork && destination.isVirtualNetwork:
return true
}
return false
}
func (c ruleChecker) isMaster(addresses []string) bool {
prefixes := toPrefixes(c.log, addresses)
return overlaps(prefixes, c.master)
}
func (c ruleChecker) isWorker(addresses []string) bool {
prefixes := toPrefixes(c.log, addresses)
return overlaps(prefixes, c.workers)
}
func overlaps(prefixes []netip.Prefix, subnet []netip.Prefix) bool {
for _, subnetcidr := range subnet {
for _, p := range prefixes {
if subnetcidr.Overlaps(p) {
return true
}
}
}
return false
}
func isAny(addresses []string) bool {
for _, address := range addresses {
if address == wildcard {
return true
}
}
return false
}
func isVirtualNetwork(addresses []string) bool {
for _, address := range addresses {
if address == virtualNetwork {
return true
}
}
return false
}
// toPrefix converts a string value of an IP address or a CIDR range into a prefix
func toPrefix(value string) (netip.Prefix, error) {
if addr, err := netip.ParseAddr(value); err == nil {
return netip.PrefixFrom(addr, 32), nil
}
if prefix, err := netip.ParsePrefix(value); err == nil {
return prefix, nil
}
return netip.Prefix{}, fmt.Errorf("invalid IP address or CIDR range: %s", value)
}
// toPrefixes converts a slice of addresses into a slice of Prefixes
func toPrefixes(log *logrus.Entry, addresses []string) []netip.Prefix {
prefixes := make([]netip.Prefix, 0, len(addresses))
for _, address := range addresses {
prefix, err := toPrefix(address)
if err != nil {
// can be continued safely to the next one because:
// 1. The strings always come directly from Azure, which has been validated.
// 2. Even if the value is wrong, it won't be neither master or worker.
// 3. We should also skip other service tags (VirtualNetwork, Internet, Any etc)
log.Debugf("Error while parsing %s. Full error %s.", address, err)
continue
}
prefixes = append(prefixes, prefix)
}
return prefixes
}