forked from v2ray/v2ray-core
-
Notifications
You must be signed in to change notification settings - Fork 0
/
server.go
161 lines (139 loc) · 3.48 KB
/
server.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
package server
//go:generate go run $GOPATH/src/v2ray.com/core/tools/generrorgen/main.go -pkg server -path App,DNS,Server
import (
"context"
"sync"
"time"
dnsmsg "github.com/miekg/dns"
"v2ray.com/core/app"
"v2ray.com/core/app/dispatcher"
"v2ray.com/core/app/dns"
"v2ray.com/core/app/log"
"v2ray.com/core/common"
"v2ray.com/core/common/net"
)
const (
QueryTimeout = time.Second * 8
)
type DomainRecord struct {
IP []net.IP
Expire time.Time
LastAccess time.Time
}
func (r *DomainRecord) Expired() bool {
return r.Expire.Before(time.Now())
}
func (r *DomainRecord) Inactive() bool {
now := time.Now()
return r.Expire.Before(now) || r.LastAccess.Add(time.Minute*5).Before(now)
}
type CacheServer struct {
sync.Mutex
hosts map[string]net.IP
records map[string]*DomainRecord
servers []NameServer
}
func NewCacheServer(ctx context.Context, config *dns.Config) (*CacheServer, error) {
space := app.SpaceFromContext(ctx)
if space == nil {
return nil, newError("no space in context")
}
server := &CacheServer{
records: make(map[string]*DomainRecord),
servers: make([]NameServer, len(config.NameServers)),
hosts: config.GetInternalHosts(),
}
space.OnInitialize(func() error {
disp := dispatcher.FromSpace(space)
if disp == nil {
return newError("dispatcher is not found in the space")
}
for idx, destPB := range config.NameServers {
address := destPB.Address.AsAddress()
if address.Family().IsDomain() && address.Domain() == "localhost" {
server.servers[idx] = &LocalNameServer{}
} else {
dest := destPB.AsDestination()
if dest.Network == net.Network_Unknown {
dest.Network = net.Network_UDP
}
if dest.Network == net.Network_UDP {
server.servers[idx] = NewUDPNameServer(dest, disp)
}
}
}
if len(config.NameServers) == 0 {
server.servers = append(server.servers, &LocalNameServer{})
}
return nil
})
return server, nil
}
func (*CacheServer) Interface() interface{} {
return (*dns.Server)(nil)
}
func (*CacheServer) Start() error {
return nil
}
func (*CacheServer) Close() {}
func (s *CacheServer) GetCached(domain string) []net.IP {
s.Lock()
defer s.Unlock()
if record, found := s.records[domain]; found && !record.Expired() {
record.LastAccess = time.Now()
return record.IP
}
return nil
}
func (s *CacheServer) tryCleanup() {
s.Lock()
defer s.Unlock()
if len(s.records) > 256 {
domains := make([]string, 0, 256)
for d, r := range s.records {
if r.Expired() {
domains = append(domains, d)
}
}
for _, d := range domains {
delete(s.records, d)
}
}
}
func (s *CacheServer) Get(domain string) []net.IP {
if ip, found := s.hosts[domain]; found {
return []net.IP{ip}
}
domain = dnsmsg.Fqdn(domain)
ips := s.GetCached(domain)
if ips != nil {
return ips
}
s.tryCleanup()
for _, server := range s.servers {
response := server.QueryA(domain)
select {
case a, open := <-response:
if !open || a == nil {
continue
}
s.Lock()
s.records[domain] = &DomainRecord{
IP: a.IPs,
Expire: a.Expire,
LastAccess: time.Now(),
}
s.Unlock()
log.Trace(newError("returning ", len(a.IPs), " IPs for domain ", domain).AtDebug())
return a.IPs
case <-time.After(QueryTimeout):
}
}
log.Trace(newError("returning nil for domain ", domain).AtDebug())
return nil
}
func init() {
common.Must(common.RegisterConfig((*dns.Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
return NewCacheServer(ctx, config.(*dns.Config))
}))
}