Add PostgreSQL mail store support

7 files changed, 74 insertions, 62 deletions

diff --git a/config.go b/config.go
index c58071b..591bcd9 100644
--- a/config.go
+++ b/config.go
@@ -21,6 +21,10 @@ var config struct {
 		Type string `scfg:"type"`
 		Conn string `scfg:"conn"`
 	} `scfg:"db"`
+	MX struct {
+		Net string `scfg:"net"`
+		Addr string `scfg:"addr"`
+	} `scfg:"mx"`
 	_tls_config *tls.Config
 }
 var (
diff --git a/deliver_dir.go b/deliver_dir.go
deleted file mode 100644
index bba9eb4..0000000
--- a/deliver_dir.go
+++ /dev/null
@@ -1,33 +0,0 @@
-package main
-
-import (
-	"os"
-	"time"
-
-	"go.lindenii.runxiyu.org/lindenii-common/clog"
-	"go.lindenii.runxiyu.org/lindenii-common/misc"
-)
-
-func deliver_to_local_directory(envelope_from string, envelope_recipients []string, data []byte, dir_path string) error {
-	clog.Debug(
-		"incoming_mail",
-		"envelope_from", envelope_from,
-		"envelope_recipients", envelope_recipients,
-		"data", string(data),
-	)
-	t := time.Now()
-	dir, err := misc.Open_directory_readonly(dir_path)
-	if err != nil {
-		return misc.Wrap_one_error(err_deliver_write, err)
-	}
-	fd, err := misc.Open_file_at(dir, envelope_from+" "+t.Format(time.RFC3339Nano)+".eml", os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0o600)
-	if err != nil {
-		// TODO: handle fs.ErrExist
-		return misc.Wrap_one_error(err_deliver_write, err)
-	}
-	_, err = fd.Write(data)
-	if err != nil {
-		return misc.Wrap_one_error(err_deliver_write, err)
-	}
-	return nil
-}
diff --git a/deliver_local.go b/deliver_local.go
new file mode 100644
index 0000000..9a29459
--- /dev/null
+++ b/deliver_local.go
@@ -0,0 +1,27 @@
+package main
+
+import (
+	"fmt"
+	"context"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+func deliver_local(ctx context.Context, db *pgxpool.Pool, envelope_from string, envelope_recipients []string, data []byte, addresses []string) error {
+	tx, err := db.Begin(ctx)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback(ctx) // BUG: Potential missed error here, but this will always fail if commit succeeded
+	for _, address := range addresses {
+		_, err = tx.Exec(ctx, "INSERT INTO mail (mailbox_id, data) SELECT a.mailbox_id, $2::bytea FROM addresses a JOIN mailboxes m ON a.mailbox_id = m.id WHERE a.address = $1;", address, data)
+		if err != nil {
+			fmt.Printf("%#v\n", err)
+			return err
+		}
+	}
+	err = tx.Commit(ctx)
+	if err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/errors.go b/errors.go
index b34e3a2..1512b60 100644
--- a/errors.go
+++ b/errors.go
@@ -2,9 +2,16 @@ package main
 
 import (
 	"errors"
+	"fmt"
+	"strings"
 )
 
 var (
-	err_deliver_write             = errors.New("unable to write to filesystem while attempting to deliver message")
-	err_unsupported_database_type = errors.New("unsupported database type; only \"postgres\" is currently supported")
+	err_unsupported_database_type = errors.New("Unsupported database type; only \"postgres\" is currently supported")
 )
+
+type err_local_recipients_not_found_t []string
+
+func (e *err_local_recipients_not_found_t) Error() string {
+	return fmt.Sprintf("Local recipients not found: %s", strings.Join([]string(*e), ", "))
+}
diff --git a/maild.scfg b/maild.scfg
index 3bdb3bd..c26f388 100644
--- a/maild.scfg
+++ b/maild.scfg
@@ -9,3 +9,8 @@ db {
 	type postgres
 	conn postgresql:///lindenii-maild?host=/var/run/postgresql
 }
+
+mx {
+	net tcp
+	addr :1025
+}
diff --git a/main.go b/main.go
index 274e9b7..f1c28ba 100644
--- a/main.go
+++ b/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"errors"
 	"flag"
 	"io"
@@ -20,7 +21,7 @@ func main() {
 		panic(err)
 	}
 
-	listener, err := net.Listen("tcp", ":25")
+	listener, err := net.Listen(config.MX.Net, config.MX.Addr)
 	if err != nil {
 		panic(err)
 	}
@@ -33,7 +34,9 @@ func main() {
 		}
 
 		go func() {
-			err := handle_mx_recv_conn(conn)
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+			err := handle_mx_recv_conn(ctx, conn)
 			if err != nil && !errors.Is(err, io.EOF) {
 				clog.Error("connection handler returned error", "err", err)
 			}
diff --git a/mx_recv.go b/mx_recv.go
index f79ff6e..221d8eb 100644
--- a/mx_recv.go
+++ b/mx_recv.go
@@ -3,7 +3,9 @@ package main
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"crypto/tls"
+	"errors"
 	"net"
 	"slices"
 	"strings"
@@ -32,7 +34,7 @@ type mx_recv_session struct {
 	current_mail_from  string
 	current_rcpt_to    []string
 	server_state       server_state_t
-	// ctx             context.Context
+	ctx                context.Context
 }
 
 func (session *mx_recv_session) handle() error {
@@ -128,14 +130,20 @@ func (session *mx_recv_session) handle() error {
 				_ = session.buf_conn.Flush()
 				break
 			}
-			recipient, _, _ := mailkit.Strip_angle_brackets(param[len("TO:"):])
-			ok := true // XXX: Check routing table
-			if !ok {
-				_, _ = session.buf_conn.WriteString("550 5.1.1 <" + recipient + ">: Recipient address rejected: User unknown in local recipient table\r\n")
+			recipient_address, _, _ := mailkit.Strip_angle_brackets(param[len("TO:"):])
+			var count int
+			err := session.db.QueryRow(session.ctx, "SELECT COUNT (*) FROM addresses WHERE address = $1", recipient_address).Scan(&count)
+			if err != nil {
+				_, _ = session.buf_conn.WriteString("451 Internal error: " + err.Error() + "\r\n")
 				_ = session.buf_conn.Flush()
-				break switch_cmd
+				break
 			}
-			session.current_rcpt_to = append(session.current_rcpt_to, recipient)
+			if count == 0 {
+				_, _ = session.buf_conn.WriteString("550 5.1.1 Recipient address rejected: Local recipients not found: " + recipient_address + "\r\n")
+				_ = session.buf_conn.Flush()
+				break
+			}
+			session.current_rcpt_to = append(session.current_rcpt_to, recipient_address)
 			session.server_state = server_state_rcpt
 			_, _ = session.buf_conn.WriteString("250 2.1.5 Ok\r\n")
 			_ = session.buf_conn.Flush()
@@ -176,24 +184,14 @@ func (session *mx_recv_session) handle() error {
 			if err != nil {
 				return err
 			}
-			{
-				inboxes_to_deliver_to := make(map[string]struct{})
-				for _, recipient := range session.current_rcpt_to {
-					inbox, ok := "/tmp", true // XXX: Check routing table
-					if !ok {
-						_, _ = session.buf_conn.WriteString("550 5.1.1 <" + recipient + ">: Recipient address rejected: User unknown in local recipient table\r\n")
-						break switch_cmd
-					}
-					inboxes_to_deliver_to[inbox] = struct{}{}
-				}
-				for inbox := range inboxes_to_deliver_to {
-					err = deliver_to_local_directory(session.current_mail_from, session.current_rcpt_to, current_data, inbox)
-				}
-			}
-			if err == nil {
-				_, _ = session.buf_conn.WriteString("250 2.0.0 Ok: Accepted\r\n")
-			} else {
+			err = deliver_local(session.ctx, session.db, session.current_mail_from, session.current_rcpt_to, current_data, session.current_rcpt_to)
+			var err_local_recipients_not_found *err_local_recipients_not_found_t
+			if errors.As(err, &err_local_recipients_not_found) {
+				_, _ = session.buf_conn.WriteString("550 5.1.1 Recipient address rejected: " + err_local_recipients_not_found.Error() + "\r\n")
+			} else if err != nil {
 				_, _ = session.buf_conn.WriteString("500 2.0.0 Error: " + err.Error() + "\r\n")
+			} else {
+				_, _ = session.buf_conn.WriteString("250 2.0.0 Ok: Accepted\r\n")
 			}
 			_ = session.buf_conn.Flush()
 			session.server_state = server_state_helo
@@ -217,9 +215,10 @@ func (session *mx_recv_session) handle() error {
 	}
 }
 
-func handle_mx_recv_conn(net_conn net.Conn) error {
+func handle_mx_recv_conn(ctx context.Context, net_conn net.Conn) error {
 	session := mx_recv_session{
 		net_conn: net_conn,
+		ctx:      ctx,
 	}
 	return session.handle()
 }