Initial commit

internal/imap/server.go

@@ -0,0 +1,62 @@
+package imap
+
+import (
+	"context"
+	"io"
+	"log"
+
+	imapbackend "github.com/emersion/go-imap/backend"
+	imapserver "github.com/emersion/go-imap/server"
+
+	"ur.gs/crockery/internal/store"
+)
+
+type Server interface {
+	Run()
+
+	io.Closer
+}
+
+func NewServer(cancel context.CancelFunc, datastore store.Interface, starttls bool) Server {
+	out := &concrete{
+		cancel: cancel,
+		store:  datastore,
+	}
+
+	out.server = imapserver.New(out)
+
+	if starttls {
+		out.server.Addr = ":143"
+	} else {
+		out.server.Addr = ":993"
+	}
+
+	return out
+}
+
+type concrete struct {
+	cancel context.CancelFunc
+	store  store.Interface
+	server *imapserver.Server
+}
+
+func (c *concrete) Run() {
+	if err := c.server.ListenAndServe(); err != nil {
+		log.Printf("Error serving IMAP %s: %v", c.server.Addr, err)
+	} else {
+		log.Printf("Stopped listening on IMAP %s", c.server.Addr)
+	}
+
+	c.cancel()
+}
+
+// backend implementation for go-smtp
+func (c *concrete) Login(string, string) (imapbackend.User, error) {
+	return nil, nil
+}
+
+func (c *concrete) Close() error {
+	c.cancel()  // FIXME: this doesn't touch the server
+
+	return nil
+}

internal/services/services.go

@@ -0,0 +1,69 @@
+package services
+
+import (
+	"context"
+	"io"
+	"log"
+
+	"ur.gs/crockery/internal/imap"
+	"ur.gs/crockery/internal/smtp"
+	"ur.gs/crockery/internal/store"
+)
+
+type Interface interface {
+	Run() // Run the services
+}
+
+func New(ctx context.Context, datastore store.Interface) (Interface, error) {
+	ctx, cancelFunc := context.WithCancel(ctx)
+
+	return &concrete{
+		ctx:    ctx,
+		cancel: cancelFunc,
+		store:  datastore,
+	}, nil
+}
+
+type genServer interface {
+	Run()
+
+	io.Closer
+}
+
+type concrete struct {
+	ctx    context.Context
+	cancel context.CancelFunc
+	store  store.Interface
+
+	// This is only mutated in the Run() method
+	servers []genServer
+}
+
+// For now, bind unconditionally to these ports, on IPv4 + IPv6:
+// 25  - incoming SMTP (STARTTLS)
+// 587 - outgoing SMTP (STARTTLS)
+// 143 - IMAP (STARTTLS)
+// 993 - IMAP (TLS)
+//
+// Each listener gets incoming connections serviced against the passed-in store.
+func (c *concrete) Run() {
+	c.servers = []genServer{
+		smtp.NewServer(c.cancel, c.store, false),
+		smtp.NewServer(c.cancel, c.store, true),
+
+		imap.NewServer(c.cancel, c.store, false),
+		imap.NewServer(c.cancel, c.store, true),
+	}
+
+	log.Print("Running all services")
+	for _, srv := range c.servers {
+		go srv.Run()
+	}
+
+	<-c.ctx.Done()
+
+	log.Print("Closing all services")
+	for _, srv := range c.servers {
+		srv.Close()
+	}
+}

internal/smtp/server.go

@@ -0,0 +1,62 @@
+package smtp
+
+import (
+	"context"
+	"io"
+	"log"
+
+	"github.com/emersion/go-smtp"
+
+	"ur.gs/crockery/internal/store"
+)
+
+type Server interface {
+	Run()
+
+	io.Closer
+}
+
+func NewServer(cancel context.CancelFunc, datastore store.Interface, submission bool) Server {
+	out := &concrete{
+		cancel: cancel,
+		store:  datastore,
+	}
+
+	out.server = smtp.NewServer(out)
+	out.server.Domain = datastore.Domain()
+
+	if submission {
+		out.server.Addr = ":587"
+	} else {
+		out.server.Addr = ":25"
+	}
+
+	return out
+}
+
+type concrete struct {
+	cancel context.CancelFunc
+	store  store.Interface
+	server *smtp.Server
+}
+
+func (c *concrete) Run() {
+	if err := c.server.ListenAndServe(); err != nil {
+		log.Printf("Error serving SMTP %s: %v", c.server.Addr, err)
+	} else {
+		log.Printf("Stopped listening on SMTP %s", c.server.Addr)
+	}
+
+	c.cancel()
+}
+
+// backend implementation for go-smtp
+func (c *concrete) Login(string, string) (smtp.User, error) {
+	return nil, nil
+}
+
+func (c *concrete) Close() error {
+	c.cancel() // FIXME: this doesn't touch the server
+
+	return nil
+}

internal/store/store.go

@@ -0,0 +1,21 @@
+package store
+
+import (
+	"context"
+)
+
+type Interface interface {
+	Domain() string
+}
+
+func New(ctx context.Context, filename string) (Interface, error) {
+	return &concrete{domain: "example.com"}, nil
+}
+
+type concrete struct {
+	domain string
+}
+
+func (c *concrete) Domain() string {
+	return c.domain
+}