5bb17c7066
This patch updates all build tag constraints to add the new format, alongside the old one, to maintain backwards compatibility. This was done by using `go fmt`. See https://go.dev/doc/go1.17#gofmt and https://golang.org/design/draft-gobuild for more details.
158 lines
3.4 KiB
Go
158 lines
3.4 KiB
Go
// mda-lmtp is a very basic MDA that uses LMTP to do the delivery.
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//
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// See the usage below for details.
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//
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//go:build !coverage
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// +build !coverage
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package main
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import (
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"flag"
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"fmt"
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"io"
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"net"
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"net/textproto"
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"os"
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"strings"
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"golang.org/x/net/idna"
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)
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// Command-line flags
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var (
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fromwhom = flag.String("f", "", "Whom the message is from")
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recipient = flag.String("d", "", "Recipient")
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addrNetwork = flag.String("addr_network", "",
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"Network of the LMTP address (e.g. unix or tcp)")
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addr = flag.String("addr", "", "LMTP server address")
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toPuny = flag.Bool("to_puny", false,
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"Encode addresses using punycode")
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)
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func usage() {
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fmt.Fprintf(os.Stderr, `
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mda-lmtp is a very basic MDA that uses LMTP to do the mail delivery.
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It takes command line arguments similar to maildrop or procmail, reads an
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email via standard input, and sends it over the given LMTP server.
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Supports connecting to LMTP servers over UNIX sockets and TCP.
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It can be used when your mail server does not support LMTP directly.
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Example of use:
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$ mda-lmtp --addr localhost:1234 -f juan@casa -d jose < email
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Flags:
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`)
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flag.PrintDefaults()
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}
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// Exit with EX_TEMPFAIL.
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func tempExit(format string, args ...interface{}) {
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fmt.Printf(format+"\n", args...)
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// 75 = EX_TEMPFAIL "temporary failure" exit code (sysexits.h).
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os.Exit(75)
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}
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func permExit(format string, args ...interface{}) {
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fmt.Printf(format+"\n", args...)
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os.Exit(2)
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}
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func main() {
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var err error
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flag.Usage = usage
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flag.Parse()
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if *addr == "" {
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permExit("No LMTP server address given (use --addr)")
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}
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if *toPuny {
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*fromwhom, err = idna.ToASCII(*fromwhom)
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if err != nil {
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permExit("cannot puny-encode from: %v", err)
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}
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*recipient, err = idna.ToASCII(*recipient)
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if err != nil {
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permExit("cannot puny-encode recipient: %v", err)
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}
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}
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// Try to autodetect the network if it's missing.
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if *addrNetwork == "" {
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*addrNetwork = "tcp"
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if strings.HasPrefix(*addr, "/") {
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*addrNetwork = "unix"
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}
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}
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conn, err := net.Dial(*addrNetwork, *addr)
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if err != nil {
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tempExit("Error connecting to (%s, %s): %v",
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*addrNetwork, *addr, err)
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}
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tc := textproto.NewConn(conn)
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// Expect the hello from the server.
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_, _, err = tc.ReadResponse(220)
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if err != nil {
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tempExit("Server greeting error: %v", err)
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}
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hostname, err := os.Hostname()
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if err != nil {
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tempExit("Could not get hostname: %v", err)
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}
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if *fromwhom == "<>" {
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*fromwhom = ""
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}
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if *recipient == "<>" {
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*recipient = ""
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}
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cmd(tc, 250, "LHLO %s", hostname)
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cmd(tc, 250, "MAIL FROM:<%s>", *fromwhom)
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cmd(tc, 250, "RCPT TO:<%s>", *recipient)
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cmd(tc, 354, "DATA")
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w := tc.DotWriter()
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_, err = io.Copy(w, os.Stdin)
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w.Close()
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if err != nil {
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tempExit("Error writing DATA: %v", err)
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}
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// This differs from SMTP: here we get one reply per recipient, with the
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// result of the delivery. Since we deliver to only one recipient, read
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// one code.
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_, _, err = tc.ReadResponse(250)
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if err != nil {
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tempExit("Delivery failed remotely: %v", err)
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}
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cmd(tc, 221, "QUIT")
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tc.Close()
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}
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// cmd sends a command and checks it matched the expected code.
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func cmd(conn *textproto.Conn, expectCode int, format string, args ...interface{}) {
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id, err := conn.Cmd(format, args...)
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if err != nil {
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tempExit("Sent %q, got %v", fmt.Sprintf(format, args...), err)
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}
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conn.StartResponse(id)
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defer conn.EndResponse(id)
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_, _, err = conn.ReadResponse(expectCode)
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if err != nil {
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tempExit("Sent %q, got %v", fmt.Sprintf(format, args...), err)
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}
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}
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