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
|
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>
// SPDX-FileCopyrightText: Copyright (c) 2024 Robin Jarry <robin@jarry.cc>
package main
import (
"bytes"
"errors"
"fmt"
"io"
"log/slog"
"net"
"strings"
"time"
"github.com/emersion/go-message"
"github.com/emersion/go-smtp"
)
type lmtpHandler struct{}
type lmtpSession struct {
from string
to []string
}
func (session *lmtpSession) Reset() {
session.from = ""
session.to = nil
}
func (session *lmtpSession) Logout() error {
return nil
}
func (session *lmtpSession) AuthPlain(_, _ string) error {
return nil
}
func (session *lmtpSession) Mail(from string, _ *smtp.MailOptions) error {
session.from = from
return nil
}
func (session *lmtpSession) Rcpt(to string, _ *smtp.RcptOptions) error {
session.to = append(session.to, to)
return nil
}
func (*lmtpHandler) NewSession(_ *smtp.Conn) (smtp.Session, error) {
session := &lmtpSession{}
return session, nil
}
func serveLMTP(listener net.Listener) error {
smtpServer := smtp.NewServer(&lmtpHandler{})
smtpServer.LMTP = true
smtpServer.Domain = config.LMTP.Domain
smtpServer.Addr = config.LMTP.Socket
smtpServer.WriteTimeout = time.Duration(config.LMTP.WriteTimeout) * time.Second
smtpServer.ReadTimeout = time.Duration(config.LMTP.ReadTimeout) * time.Second
smtpServer.EnableSMTPUTF8 = true
return smtpServer.Serve(listener)
}
func (session *lmtpSession) Data(r io.Reader) error {
var (
email *message.Entity
from string
to []string
err error
buf bytes.Buffer
data []byte
n int64
)
n, err = io.CopyN(&buf, r, config.LMTP.MaxSize)
switch {
case n == config.LMTP.MaxSize:
err = errors.New("Message too big.")
// drain whatever is left in the pipe
_, _ = io.Copy(io.Discard, r)
goto end
case errors.Is(err, io.EOF):
// message was smaller than max size
break
case err != nil:
goto end
}
data = buf.Bytes()
email, err = message.Read(bytes.NewReader(data))
if err != nil && message.IsUnknownCharset(err) {
goto end
}
switch strings.ToLower(email.Header.Get("Auto-Submitted")) {
case "auto-generated", "auto-replied":
// Disregard automatic emails like OOO replies.
slog.Info("ignoring automatic message",
"from", session.from,
"to", strings.Join(session.to, ","),
"message-id", email.Header.Get("Message-Id"),
"subject", email.Header.Get("Subject"),
)
goto end
}
slog.Info("message received",
"from", session.from,
"to", strings.Join(session.to, ","),
"message-id", email.Header.Get("Message-Id"),
"subject", email.Header.Get("Subject"),
)
// Make local copies of the values before to ensure the references will
// still be valid when the task is run.
from = session.from
to = session.to
_ = from
for _, to := range to {
if !strings.HasSuffix(to, "@"+config.LMTP.Domain) {
continue
}
localPart := to[:len(to)-len("@"+config.LMTP.Domain)]
segments, err := pathToSegments(localPart)
if err != nil {
// TODO: Should the entire email fail or should we just
// notify them out of band?
err = fmt.Errorf("cannot parse path: %w", err)
goto end
}
sepIndex := -1
for i, part := range segments {
if part == "-" {
sepIndex = i
break
}
}
if segments[len(segments)-1] == "" {
segments = segments[:len(segments)-1] // We don't care about dir or not.
}
if sepIndex == -1 || len(segments) <= sepIndex+2 {
err = errors.New("illegal path")
goto end
}
groupPath := segments[:sepIndex]
moduleType := segments[sepIndex+1]
moduleName := segments[sepIndex+2]
switch moduleType {
case "repos":
err = lmtpHandlePatch(groupPath, moduleName, email)
if err != nil {
goto end
}
default:
err = fmt.Errorf("Emailing any endpoint other than repositories, is not supported yet.") // TODO
goto end
}
}
end:
session.to = nil
session.from = ""
return err
}
|
