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Implemented MaxConnections, corrected examples, removed MailAddress.

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This commit is contained in:
Christian Joergensen 2014-07-15 10:07:58 +02:00
parent c214cd0c15
commit 0e0eb0eda4
5 changed files with 84 additions and 27 deletions
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9
address.go
View file

@ -5,12 +5,9 @@ import (
"strings"
)
// MailAddress holds an e-mail address
type MailAddress string
func parseMailAddress(src string) (MailAddress, error) {
func parseAddress(src string) (string, error) {
if src[0] != '<' || src[len(src)-1] != '>' || strings.Count(src, "@") != 1 {
return MailAddress(""), fmt.Errorf("Ill-formatted e-mail address: %s", src)
return "", fmt.Errorf("Ill-formatted e-mail address: %s", src)
}
return MailAddress(src[1 : len(src)-1]), nil
return src[1 : len(src)-1], nil
}

20
example_test.go
View file

@ -1,32 +1,32 @@
package smtpd
import (
"bitbucket.org/chrj/smtpd"
"errors"
"net"
"net/smtp"
"strings"
)
func ExampleServer() {
var server *Server
// No-op server. Accepts and discards
server := &smtpd.Server{}
server.serve()
server = &Server{}
server.ListenAndServe()
// Relay server. Accepts only from single IP address and forwards using the Gmail smtp
server := &smtpd.Server{
server = &Server{
Addr: "0.0.0.0:10025",
HeloChecker: func(peer smtpd.Peer) error {
HeloChecker: func(peer Peer) error {
if !strings.HasPrefix(peer.Addr.String(), "42.42.42.42:") {
return errors.New("Denied")
}
return nil
},
Handler: func(peer smtpd.Peer, env smtpd.Envelope) error {
Handler: func(peer Peer, env Envelope) error {
return smtp.SendMail(
"smtp.gmail.com:587",
smtp.PlainAuth(
@ -35,14 +35,14 @@ func ExampleServer() {
"password",
"smtp.gmail.com",
),
env.Sender,
env.Recipients,
string(env.Sender),
[]string(env.Recipients),
env.Data,
)
},
}
server.serve()
server.ListenAndServe()
}

4
protocol.go
View file

@ -148,7 +148,7 @@ func (session *session) handleMAIL(cmd command) {
return
}
addr, err := parseMailAddress(cmd.params[1])
addr, err := parseAddress(cmd.params[1])
if err != nil {
session.reply(502, "Ill-formatted e-mail address")
@ -178,7 +178,7 @@ func (session *session) handleRCPT(cmd command) {
return
}
addr, err := parseMailAddress(cmd.params[1])
addr, err := parseAddress(cmd.params[1])
if err != nil {
session.reply(502, "Ill-formatted e-mail address")

44
smtpd.go
View file

@ -19,6 +19,9 @@ type Server struct {
ReadTimeout time.Duration // Socket timeout for read operations (default: 60s)
WriteTimeout time.Duration // Socket timeout for write operations (default: 60s)
MaxMessageSize int // Max message size in bytes (default: 10240000)
MaxConnections int // Max concurrent connections, use -1 to disable (default: 100)
// New e-mails are handed off to this function.
// Can be left empty for a NOOP server.
// If an error is returned, it will be reported in the SMTP session.
@ -28,8 +31,8 @@ type Server struct {
// Can be left empty for no restrictions.
// If an error is returned, it will be reported in the SMTP session.
HeloChecker func(peer Peer) error // Called after HELO/EHLO.
SenderChecker func(peer Peer, addr MailAddress) error // Called after MAIL FROM.
RecipientChecker func(peer Peer, addr MailAddress) error // Called after each RCPT TO.
SenderChecker func(peer Peer, addr string) error // Called after MAIL FROM.
RecipientChecker func(peer Peer, addr string) error // Called after each RCPT TO.
// Enable PLAIN/LOGIN authentication, only available after STARTTLS.
// Can be left empty for no authentication support.
@ -37,8 +40,6 @@ type Server struct {
TLSConfig *tls.Config // Enable STARTTLS support
ForceTLS bool // Force STARTTLS usage
MaxMessageSize int // Max message size in bytes (default: 10240000)
}
// Peer represents the client connecting to the server
@ -51,8 +52,8 @@ type Peer struct {
// Envelope holds a message
type Envelope struct {
Sender MailAddress
Recipients []MailAddress
Sender string
Recipients []string
Data []byte
}
@ -107,6 +108,14 @@ func (srv *Server) Serve(l net.Listener) error {
defer l.Close()
var limiter chan struct{}
if srv.MaxConnections > 0 {
limiter = make(chan struct{}, srv.MaxConnections)
} else {
limiter = nil
}
for {
conn, e := l.Accept()
@ -123,7 +132,19 @@ func (srv *Server) Serve(l net.Listener) error {
continue
}
go session.serve()
if limiter != nil {
go func() {
select {
case limiter <- struct{}{}:
session.serve()
<-limiter
default:
session.reject()
}
}()
} else {
go session.serve()
}
}
@ -135,6 +156,10 @@ func (srv *Server) configureDefaults() {
srv.MaxMessageSize = 10240000
}
if srv.MaxConnections == 0 {
srv.MaxConnections = 100
}
if srv.ReadTimeout == 0 {
srv.ReadTimeout = time.Second * 60
}
@ -177,6 +202,11 @@ func (session *session) serve() {
}
func (session *session) reject() {
session.reply(450, "Too busy. Try again later.")
session.close()
}
func (session *session) reply(code int, message string) {
fmt.Fprintf(session.writer, "%d %s\r\n", code, message)

34
smtpd_test.go
View file

@ -233,7 +233,7 @@ func TestSenderCheck(t *testing.T) {
defer ln.Close()
server := &Server{
SenderChecker: func(peer Peer, addr MailAddress) error { return errors.New("Denied") },
SenderChecker: func(peer Peer, addr string) error { return errors.New("Denied") },
}
go func() {
@ -261,7 +261,7 @@ func TestRecipientCheck(t *testing.T) {
defer ln.Close()
server := &Server{
RecipientChecker: func(peer Peer, addr MailAddress) error { return errors.New("Denied") },
RecipientChecker: func(peer Peer, addr string) error { return errors.New("Denied") },
}
go func() {
@ -398,3 +398,33 @@ func TestHandler(t *testing.T) {
}
}
func TestMaxConnections(t *testing.T) {
ln, err := net.Listen("tcp", "127.0.0.1:0")
if err != nil {
t.Fatalf("Listen failed: %v", err)
}
defer ln.Close()
server := &Server{
MaxConnections: 1,
}
go func() {
server.Serve(ln)
}()
c1, err := smtp.Dial(ln.Addr().String())
if err != nil {
t.Fatalf("Dial failed: %v", err)
}
_, err = smtp.Dial(ln.Addr().String())
if err == nil {
t.Fatal("Dial succeeded despite MaxConnections = 1")
}
c1.Close()
}