diff --git a/go.mod b/go.mod index 29e81c1..c844f19 100644 --- a/go.mod +++ b/go.mod @@ -18,6 +18,7 @@ require ( gitlab.com/etke.cc/go/logger v1.1.0 gitlab.com/etke.cc/go/mxidwc v1.0.0 gitlab.com/etke.cc/go/secgen v1.1.1 + gitlab.com/etke.cc/go/trysmtp v1.0.0 gitlab.com/etke.cc/linkpearl v0.0.0-20221002171411-bb783f7e50f0 golang.org/x/net v0.0.0-20221002022538-bcab6841153b maunium.net/go/mautrix v0.12.1 diff --git a/go.sum b/go.sum index b0b8a8a..60bf3c6 100644 --- a/go.sum +++ b/go.sum @@ -95,6 +95,8 @@ gitlab.com/etke.cc/go/mxidwc v1.0.0 h1:6EAlJXvs3nU4RaMegYq6iFlyVvLw7JZYnZmNCGMYQ gitlab.com/etke.cc/go/mxidwc v1.0.0/go.mod h1:E/0kh45SAN9+ntTG0cwkAEKdaPxzvxVmnjwivm9nmz8= gitlab.com/etke.cc/go/secgen v1.1.1 h1:RmKOki725HIhWJHzPtAc9X4YvBneczndchpMgoDkE8w= gitlab.com/etke.cc/go/secgen v1.1.1/go.mod h1:3pJqRGeWApzx7qXjABqz2o2SMCNpKSZao/gXVdasqE8= +gitlab.com/etke.cc/go/trysmtp v1.0.0 h1:f/7gSmzohKniVeLSLevI+ZsySYcPUGkT9cRlOTwjOr8= +gitlab.com/etke.cc/go/trysmtp v1.0.0/go.mod h1:KqRuIB2IPElEEbAxXmFyKtm7S5YiuEb4lxwWthccqyE= gitlab.com/etke.cc/linkpearl v0.0.0-20221002171411-bb783f7e50f0 h1:B5YV62XKsLb9sCu9jW4Pnc5HDNRzdR1FswtRBMw1sR0= gitlab.com/etke.cc/linkpearl v0.0.0-20221002171411-bb783f7e50f0/go.mod h1:hjn0SVswej+Jo3+MycLm+lTsAVFy047Df+adX6MoXoE= golang.org/x/crypto v0.0.0-20220518034528-6f7dac969898/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4= diff --git a/smtp/mta.go b/smtp/mta.go index dcf6475..a8647cb 100644 --- a/smtp/mta.go +++ b/smtp/mta.go @@ -2,14 +2,11 @@ package smtp import ( "context" - "crypto/tls" - "fmt" "io" - "net" - "net/smtp" "strings" "gitlab.com/etke.cc/go/logger" + "gitlab.com/etke.cc/go/trysmtp" "maunium.net/go/mautrix/id" "gitlab.com/etke.cc/postmoogle/utils" @@ -28,9 +25,6 @@ type mta struct { log *logger.Logger } -// SMTPAddrs priority list -var SMTPAddrs = []string{":25", ":587", ":465"} - func NewMTA(loglevel string) utils.MTA { return &mta{ log: logger.New("smtp/mta.", loglevel), @@ -39,22 +33,12 @@ func NewMTA(loglevel string) utils.MTA { func (m *mta) Send(from, to, data string) error { m.log.Debug("Sending email from %s to %s", from, to) - conn, err := m.connect(from, to) + conn, err := trysmtp.Connect(from, to) if err != nil { m.log.Error("cannot connect to SMTP server of %s: %v", to, err) return err } defer conn.Close() - err = conn.Mail(from) - if err != nil { - m.log.Error("cannot call MAIL command: %v", err) - return err - } - err = conn.Rcpt(to) - if err != nil { - m.log.Error("cannot send RCPT command: %v", err) - return err - } var w io.WriteCloser w, err = conn.Data() @@ -73,61 +57,3 @@ func (m *mta) Send(from, to, data string) error { m.log.Debug("email has been sent") return nil } - -func (m *mta) tryServer(localname, mxhost, addr string) *smtp.Client { - m.log.Debug("trying SMTP connection to %s%s", mxhost, addr) - conn, err := smtp.Dial(mxhost + addr) - if err != nil { - m.log.Warn("cannot connect to the %s%s: %v", mxhost, addr, err) - return nil - } - err = conn.Hello(localname) - if err != nil { - m.log.Warn("cannot call HELLO command of the %s%s: %v", mxhost, addr, err) - return nil - } - if ok, _ := conn.Extension("STARTTLS"); ok { - m.log.Debug("%s supports STARTTLS", mxhost) - config := &tls.Config{ServerName: mxhost} - err = conn.StartTLS(config) - if err != nil { - m.log.Warn("STARTTLS connection to the %s failed: %v", mxhost, err) - } - } - - return conn -} - -func (m *mta) connect(from, to string) (*smtp.Client, error) { - localname := strings.SplitN(from, "@", 2)[1] - hostname := strings.SplitN(to, "@", 2)[1] - - m.log.Debug("performing MX lookup of %s", hostname) - mxs, err := net.LookupMX(hostname) - if err != nil { - m.log.Error("cannot perform MX lookup: %v", err) - return nil, err - } - - for _, mx := range mxs { - for _, addr := range SMTPAddrs { - client := m.tryServer(localname, strings.TrimSuffix(mx.Host, "."), addr) - if client != nil { - return client, nil - } - } - } - - // If there are no MX records, according to https://datatracker.ietf.org/doc/html/rfc5321#section-5.1, - // we're supposed to try talking directly to the host. - if len(mxs) == 0 { - for _, addr := range SMTPAddrs { - client := m.tryServer(localname, hostname, addr) - if client != nil { - return client, nil - } - } - } - - return nil, fmt.Errorf("target SMTP server not found") -}