/
check_runner.go
351 lines (303 loc) · 9.68 KB
/
check_runner.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
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
/*
Maddy Mail Server - Composable all-in-one email server.
Copyright © 2019-2020 Max Mazurov <fox.cpp@disroot.org>, Maddy Mail Server contributors
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package msgpipeline
import (
"context"
"runtime/debug"
"sync"
"github.com/emersion/go-message/textproto"
"github.com/emersion/go-msgauth/authres"
"github.com/foxcpp/maddy/framework/buffer"
"github.com/foxcpp/maddy/framework/dns"
"github.com/foxcpp/maddy/framework/exterrors"
"github.com/foxcpp/maddy/framework/log"
"github.com/foxcpp/maddy/framework/module"
"github.com/foxcpp/maddy/internal/dmarc"
)
// checkRunner runs groups of checks, collects and merges results.
// It also makes sure that each check gets only one state object created.
type checkRunner struct {
msgMeta *module.MsgMetadata
mailFrom string
mailFromReceived bool
checkedRcpts []string
checkedRcptsPerCheck map[module.CheckState]map[string]struct{}
checkedRcptsLock sync.Mutex
resolver dns.Resolver
doDMARC bool
didDMARCFetch bool
dmarcVerify *dmarc.Verifier
log log.Logger
states map[module.Check]module.CheckState
mergedRes module.CheckResult
}
func newCheckRunner(msgMeta *module.MsgMetadata, log log.Logger, r dns.Resolver) *checkRunner {
return &checkRunner{
msgMeta: msgMeta,
checkedRcptsPerCheck: map[module.CheckState]map[string]struct{}{},
log: log,
resolver: r,
dmarcVerify: dmarc.NewVerifier(r),
states: make(map[module.Check]module.CheckState),
}
}
func (cr *checkRunner) checkStates(ctx context.Context, checks []module.Check) ([]module.CheckState, error) {
states := make([]module.CheckState, 0, len(checks))
newStates := make([]module.CheckState, 0, len(checks))
newStatesMap := make(map[module.Check]module.CheckState, len(checks))
closeStates := func() {
for _, state := range states {
state.Close()
}
}
for _, check := range checks {
state, ok := cr.states[check]
if ok {
states = append(states, state)
continue
}
cr.log.Debugf("initializing state for %v (%p)", objectName(check), check)
state, err := check.CheckStateForMsg(ctx, cr.msgMeta)
if err != nil {
closeStates()
return nil, err
}
states = append(states, state)
newStates = append(newStates, state)
newStatesMap[check] = state
}
if len(newStates) == 0 {
return states, nil
}
// Here we replay previous CheckConnection/CheckSender/CheckRcpt calls
// for any newly initialized checks so they all get change to see all these things.
//
// Done outside of check loop above to make sure we can run these for multiple
// checks in parallel.
if cr.mailFromReceived {
err := cr.runAndMergeResults(newStates, func(s module.CheckState) module.CheckResult {
res := s.CheckConnection(ctx)
return res
})
if err != nil {
closeStates()
return nil, err
}
err = cr.runAndMergeResults(newStates, func(s module.CheckState) module.CheckResult {
res := s.CheckSender(ctx, cr.mailFrom)
return res
})
if err != nil {
closeStates()
return nil, err
}
}
if len(cr.checkedRcpts) != 0 {
for _, rcpt := range cr.checkedRcpts {
rcpt := rcpt
err := cr.runAndMergeResults(states, func(s module.CheckState) module.CheckResult {
// Avoid calling CheckRcpt for the same recipient for the same check
// multiple times, even if requested.
cr.checkedRcptsLock.Lock()
if _, ok := cr.checkedRcptsPerCheck[s][rcpt]; ok {
cr.checkedRcptsLock.Unlock()
return module.CheckResult{}
}
if cr.checkedRcptsPerCheck[s] == nil {
cr.checkedRcptsPerCheck[s] = make(map[string]struct{})
}
cr.checkedRcptsPerCheck[s][rcpt] = struct{}{}
cr.checkedRcptsLock.Unlock()
res := s.CheckRcpt(ctx, rcpt)
return res
})
if err != nil {
closeStates()
return nil, err
}
}
}
// This is done after all actions that can fail so we will not have to remove
// state objects from main map.
for check, state := range newStatesMap {
cr.states[check] = state
}
return states, nil
}
func (cr *checkRunner) runAndMergeResults(states []module.CheckState, runner func(module.CheckState) module.CheckResult) error {
data := struct {
authResLock sync.Mutex
headerLock sync.Mutex
quarantineErr error
quarantineCheck string
setQuarantineErr sync.Once
rejectErr error
rejectCheck string
setRejectErr sync.Once
wg sync.WaitGroup
}{}
for _, state := range states {
state := state
data.wg.Add(1)
go func() {
defer func() {
data.wg.Done()
if err := recover(); err != nil {
stack := debug.Stack()
log.Printf("panic during check execution: %v\n%s", err, stack)
}
}()
subCheckRes := runner(state)
// We check the length because we don't want to take locks
// when it is not necessary.
if len(subCheckRes.AuthResult) != 0 {
data.authResLock.Lock()
cr.mergedRes.AuthResult = append(cr.mergedRes.AuthResult, subCheckRes.AuthResult...)
data.authResLock.Unlock()
}
if subCheckRes.Header.Len() != 0 {
data.headerLock.Lock()
for field := subCheckRes.Header.Fields(); field.Next(); {
formatted, err := field.Raw()
if err != nil {
cr.log.Error("malformed header field added by check", err)
}
cr.mergedRes.Header.AddRaw(formatted)
}
data.headerLock.Unlock()
}
if subCheckRes.Quarantine {
data.setQuarantineErr.Do(func() {
data.quarantineErr = subCheckRes.Reason
})
} else if subCheckRes.Reject {
data.setRejectErr.Do(func() {
data.rejectErr = subCheckRes.Reason
})
} else if subCheckRes.Reason != nil {
// 'action ignore' case. There is Reason, but action.Apply set
// both Reject and Quarantine to false. Log the reason for
// purposes of deployment testing.
cr.log.Error("no check action", subCheckRes.Reason)
}
}()
}
data.wg.Wait()
if data.rejectErr != nil {
return data.rejectErr
}
if data.quarantineErr != nil {
cr.log.Error("quarantined", data.quarantineErr)
cr.mergedRes.Quarantine = true
}
return nil
}
func (cr *checkRunner) checkConnSender(ctx context.Context, checks []module.Check, mailFrom string) error {
cr.mailFrom = mailFrom
cr.mailFromReceived = true
// checkStates will run CheckConnection and CheckSender.
_, err := cr.checkStates(ctx, checks)
return err
}
func (cr *checkRunner) checkRcpt(ctx context.Context, checks []module.Check, rcptTo string) error {
states, err := cr.checkStates(ctx, checks)
if err != nil {
return err
}
err = cr.runAndMergeResults(states, func(s module.CheckState) module.CheckResult {
cr.checkedRcptsLock.Lock()
if _, ok := cr.checkedRcptsPerCheck[s][rcptTo]; ok {
cr.checkedRcptsLock.Unlock()
return module.CheckResult{}
}
if cr.checkedRcptsPerCheck[s] == nil {
cr.checkedRcptsPerCheck[s] = make(map[string]struct{})
}
cr.checkedRcptsPerCheck[s][rcptTo] = struct{}{}
cr.checkedRcptsLock.Unlock()
res := s.CheckRcpt(ctx, rcptTo)
return res
})
cr.checkedRcpts = append(cr.checkedRcpts, rcptTo)
return err
}
func (cr *checkRunner) checkBody(ctx context.Context, checks []module.Check, header textproto.Header, body buffer.Buffer) error {
states, err := cr.checkStates(ctx, checks)
if err != nil {
return err
}
if cr.doDMARC && !cr.didDMARCFetch {
cr.dmarcVerify.FetchRecord(ctx, header)
cr.didDMARCFetch = true
}
return cr.runAndMergeResults(states, func(s module.CheckState) module.CheckResult {
res := s.CheckBody(ctx, header, body)
return res
})
}
func (cr *checkRunner) applyResults(hostname string, header *textproto.Header) error {
if cr.mergedRes.Quarantine {
cr.msgMeta.Quarantine = true
}
if cr.doDMARC {
dmarcRes, policy := cr.dmarcVerify.Apply(cr.mergedRes.AuthResult)
cr.mergedRes.AuthResult = append(cr.mergedRes.AuthResult, &dmarcRes.Authres)
switch policy {
case dmarc.PolicyReject:
code := 550
enchCode := exterrors.EnhancedCode{5, 7, 1}
if dmarcRes.Authres.Value == authres.ResultTempError {
code = 450
enchCode[0] = 4
}
return &exterrors.SMTPError{
Code: code,
EnhancedCode: enchCode,
Message: "DMARC check failed",
CheckName: "dmarc",
Misc: map[string]interface{}{
"reason": dmarcRes.Authres.Reason,
"dkim_res": dmarcRes.DKIMResult.Value,
"dkim_domain": dmarcRes.DKIMResult.Domain,
"spf_res": dmarcRes.SPFResult.Value,
"spf_from": dmarcRes.SPFResult.From,
},
}
case dmarc.PolicyQuarantine:
cr.msgMeta.Quarantine = true
// Mimick the message structure for regular checks.
cr.log.Msg("quarantined", "reason", dmarcRes.Authres.Reason, "check", "dmarc")
}
}
// After results for all checks are checked, authRes will be populated with values
// we should put into Authentication-Results header.
if len(cr.mergedRes.AuthResult) != 0 {
header.Add("Authentication-Results", authres.Format(hostname, cr.mergedRes.AuthResult))
}
for field := cr.mergedRes.Header.Fields(); field.Next(); {
formatted, err := field.Raw()
if err != nil {
cr.log.Error("malformed header field added by check", err)
}
header.AddRaw(formatted)
}
return nil
}
func (cr *checkRunner) close() {
cr.dmarcVerify.Close()
for _, state := range cr.states {
state.Close()
}
}