-
Notifications
You must be signed in to change notification settings - Fork 0
/
proxy.go
309 lines (283 loc) · 6.32 KB
/
proxy.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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
package fakerpc
import (
"fmt"
"io"
"net"
"net/http"
"net/http/httputil"
"net/url"
"sync"
"sync/atomic"
)
var noopRecord = func(*Transmission) {}
type TCPConn interface {
TCPConn() *net.TCPConn
}
type recConn struct {
net.Conn
t []Transmission
commit func([]Transmission)
rec func(*Transmission)
src *net.TCPAddr
dst *net.TCPAddr
wg *sync.WaitGroup
onc sync.Once
}
func (rc *recConn) TCPConn() *net.TCPConn {
return rc.Conn.(*net.TCPConn)
}
func (rc *recConn) record(p []byte, src, dst *net.TCPAddr) {
if rc.t[len(rc.t)-1].Src != src {
rc.rec(&rc.t[len(rc.t)-1])
rc.t = append(rc.t, Transmission{})
}
if len(p) != 0 {
t := &rc.t[len(rc.t)-1]
if t.Src == nil {
t.Src, t.Dst = src, dst
}
t.Raw = append(t.Raw, p...)
}
}
func (rc *recConn) Read(p []byte) (n int, err error) {
n, err = rc.Conn.Read(p)
rc.record(p[:n], rc.dst, rc.src)
return
}
func (rc *recConn) Write(p []byte) (n int, err error) {
n, err = rc.Conn.Write(p)
rc.record(p[:n], rc.src, rc.dst)
return
}
func (rc *recConn) Close() (err error) {
rc.onc.Do(func() {
err = rc.Conn.Close()
if len(rc.t) > 0 && rc.t[len(rc.t)-1].Src == nil {
rc.t = rc.t[:len(rc.t)-1]
}
rc.rec(&rc.t[len(rc.t)-1])
rc.commit(rc.t)
rc.wg.Done()
})
return
}
type recListener struct {
log Log
wg sync.WaitGroup
m sync.Mutex // protects log and con
lis net.Listener
src *net.TCPAddr
dst *net.TCPAddr
rec func(*Transmission)
con map[io.Closer]struct{}
onc sync.Once
tmp bool
}
// ListenAndRecord announces on the local network address laddr, recording all the communication.
//
// It calls provided callback after each successful transmission.
func ListenAndRecord(network, laddr string, callback func(*Transmission)) (net.Listener, error) {
lis, err := net.Listen(network, laddr)
if err != nil {
return nil, err
}
return Record(lis, callback)
}
// Record records all network communication on the listener.
//
// On failure it closes the listener returning non-nil error.
func Record(lis net.Listener, callback func(*Transmission)) (net.Listener, error) {
src, err := tcpaddr(lis.Addr())
if err != nil {
lis.Close()
return nil, err
}
rl, err := newRecListener(lis, src, callback)
if err != nil {
lis.Close()
return nil, err
}
rl.tmp = true
return rl, nil
}
func newRecListener(lis net.Listener, src *net.TCPAddr, rec func(*Transmission)) (l *recListener, err error) {
networks, err := ipnetaddr(lis.Addr())
if err != nil {
return
}
l = &recListener{
log: Log{
Networks: networks,
Filter: fmt.Sprintf("(ip or ipv6) and ( host %s and port %d )", src.IP, src.Port),
T: make([]Transmission, 0),
},
lis: lis,
src: src,
rec: rec,
con: make(map[io.Closer]struct{}),
}
return
}
func (rl *recListener) Accept() (net.Conn, error) {
c, err := rl.lis.Accept()
if err != nil {
return nil, err
}
dst, err := tcpaddr(c.RemoteAddr())
if err != nil {
c.Close()
return nil, err
}
conn := &recConn{
Conn: c,
t: []Transmission{{
Src: dst,
Dst: rl.src,
Raw: make([]byte, 0),
}},
src: rl.src,
dst: dst,
wg: &rl.wg,
rec: rl.rec,
}
if rl.tmp {
conn.commit = func([]Transmission) {
rl.m.Lock()
delete(rl.con, conn)
rl.m.Unlock()
}
} else {
conn.commit = func(t []Transmission) {
rl.m.Lock()
rl.log.T = append(rl.log.T, t...)
delete(rl.con, conn)
rl.m.Unlock()
}
}
rl.wg.Add(1)
rl.m.Lock()
rl.con[conn] = struct{}{}
rl.m.Unlock()
return conn, nil
}
// A proxytransport preserves original Host header from client's request.
type proxytransport struct {
tr http.RoundTripper
host string
}
func (pt proxytransport) RoundTrip(req *http.Request) (*http.Response, error) {
req.Host = pt.host
return pt.tr.RoundTrip(req)
}
func newProxyTransport(u *url.URL) http.RoundTripper {
return proxytransport{
tr: &http.Transport{},
host: u.Host,
}
}
func newReverseProxy(u *url.URL) *httputil.ReverseProxy {
p := httputil.NewSingleHostReverseProxy(u)
p.Transport = newProxyTransport(u)
return p
}
func (rl *recListener) Wait() {
rl.wg.Wait()
}
func (rl *recListener) Close() (err error) {
rl.onc.Do(func() {
err = rl.lis.Close()
for c := range rl.con {
c.Close()
}
})
return
}
func (rl *recListener) Addr() net.Addr {
return rl.lis.Addr()
}
// A Proxy represents a single host HTTP reverse proxy which records all the
// transmission it handles.
type Proxy struct {
// Record function is called after each transmission is successfully completed.
Record func(*Transmission)
m sync.Mutex
wgr sync.WaitGroup
targ *url.URL
rl *recListener
srv *http.Server
addr string
isrun uint32
}
// NewProxy gives new Proxy for the given target URL and listening on the given
// TCP network address.
func NewProxy(addr, target string) (*Proxy, error) {
u, err := url.Parse(target)
if err != nil {
return nil, err
}
p := &Proxy{
Record: noopRecord,
targ: u,
addr: addr,
srv: &http.Server{Handler: newReverseProxy(u)},
}
p.wgr.Add(1)
return p, nil
}
// ListenAndServe starts listening for connections, recording them and proxying
// to the target URL.
func (p *Proxy) ListenAndServe() (err error) {
if atomic.CompareAndSwapUint32(&p.isrun, 0, 1) {
defer func() {
// Ignore "use of closed network connection" comming from closed
// net.Listener when p was explicitely stopped.
if !atomic.CompareAndSwapUint32(&p.isrun, 1, 0) {
err = nil
}
}()
p.m.Lock()
var l net.Listener
if l, err = net.Listen("tcp", p.addr); err != nil {
p.m.Unlock()
return
}
var src *net.TCPAddr
src, err = urltotcpaddr(p.targ)
if err != nil {
p.m.Unlock()
return
}
if p.rl, err = newRecListener(l, src, p.Record); err != nil {
p.m.Unlock()
return
}
p.wgr.Done()
p.m.Unlock()
err = p.srv.Serve(p.rl)
return
}
return ErrAlreadyRunning
}
// Addr returns the Proxy's network address. It blocks when the p is not running.
func (p *Proxy) Addr() (addr net.Addr) {
p.wgr.Wait()
p.m.Lock()
addr = p.rl.Addr()
p.m.Unlock()
return
}
// Stop stops the Proxy from accepting new connections. It waits for on-going
// connections to finish, ensuring all of them were captured in the l.
func (p *Proxy) Stop() (l *Log, err error) {
err = ErrNotRunning
if atomic.CompareAndSwapUint32(&p.isrun, 1, 0) {
p.wgr.Wait()
p.m.Lock()
l, err = &p.rl.log, p.rl.Close()
p.rl = nil
p.wgr.Add(1)
p.m.Unlock()
return
}
return
}