Refactor mx stuff

1 files changed, 0 insertions, 231 deletions

diff --git a/mx_recv.go b/mx_recv.go
deleted file mode 100644
index 33b4012..0000000
--- a/mx_recv.go
+++ /dev/null
@@ -1,231 +0,0 @@
-package main
-
-import (
-	"bufio"
-	"bytes"
-	"context"
-	"crypto/tls"
-	"errors"
-	"io"
-	"net"
-	"slices"
-	"strings"
-
-	"github.com/jackc/pgx/v5/pgxpool"
-	"go.lindenii.runxiyu.org/lindenii-common/mailkit"
-)
-
-type server_state_t uint
-
-const (
-	server_state_begin server_state_t = iota
-	server_state_helo
-	server_state_mail
-	server_state_rcpt
-)
-
-type mx_recv_session struct {
-	buf_conn           *bufio.ReadWriter
-	net_conn           net.Conn
-	tls_conn           *tls.Conn
-	my_server_name     string
-	tls_config         *tls.Config
-	db                 *pgxpool.Pool
-	remote_server_name string
-	current_mail_from  string
-	current_rcpt_to    []string
-	server_state       server_state_t
-}
-
-func (session *mx_recv_session) handle(ctx context.Context) error {
-	session.buf_conn = bufio.NewReadWriter(bufio.NewReader(session.net_conn), bufio.NewWriter(session.net_conn))
-	config_consistent_run(func() {
-		session.my_server_name = config.Server_name
-		session.tls_config = config._tls_config
-		session.db = global_db
-	})
-	_, _ = session.buf_conn.WriteString("220 " + session.my_server_name + " " + VERSION + "\r\n")
-	_ = session.buf_conn.Flush()
-	session.server_state = server_state_begin
-	for {
-		line, err := session.buf_conn.ReadString('\n')
-		if err != nil {
-			if err == io.EOF {
-				return err_connection_handler_eof
-			}
-			return err
-		}
-		line = strings.TrimSuffix(line, "\n")
-		line = strings.TrimSuffix(line, "\r")
-		cmd_end := strings.IndexByte(line, ' ')
-		var param_start int
-		if cmd_end == -1 {
-			cmd_end = len(line)
-			param_start = len(line)
-		} else {
-			param_start = cmd_end + 1
-		}
-		cmd := strings.ToUpper(line[:cmd_end])
-		param := line[param_start:]
-	switch_cmd:
-		switch cmd {
-		case "STARTTLS":
-			if param != "" {
-				_, _ = session.buf_conn.WriteString("501 5.5.4 Syntax error (no parameters allowed)\r\n")
-				_ = session.buf_conn.Flush()
-				break
-			}
-			if session.tls_conn != nil {
-				_, _ = session.buf_conn.WriteString("554 5.5.1 Error: TLS already active\r\n")
-				_ = session.buf_conn.Flush()
-				break
-			}
-			_, _ = session.buf_conn.WriteString("220 2.0.0 Ready to start TLS\r\n")
-			_ = session.buf_conn.Flush()
-			session.tls_conn = tls.Server(session.net_conn, session.tls_config)
-			session.buf_conn = bufio.NewReadWriter(bufio.NewReader(session.tls_conn), bufio.NewWriter(session.tls_conn))
-			session.server_state = server_state_begin
-			session.current_mail_from = ""
-			session.current_rcpt_to = []string{""}
-		case "HELO":
-			if param == "" { // TODO: actually validate the hostname
-				_, _ = session.buf_conn.WriteString("501 Syntax: HELO hostname\r\n")
-				_ = session.buf_conn.Flush()
-				break
-			}
-			session.remote_server_name = param
-			_ = session.remote_server_name // TODO
-			session.server_state = server_state_helo
-			_, _ = session.buf_conn.WriteString("250 " + session.my_server_name + "\r\n")
-			_ = session.buf_conn.Flush()
-		case "MAIL":
-			switch session.server_state {
-			case server_state_begin:
-				_, _ = session.buf_conn.WriteString("503 5.5.1 Error: send HELO/EHLO first\r\n")
-				_ = session.buf_conn.Flush()
-				break switch_cmd
-			case server_state_helo:
-				break
-			case server_state_mail:
-				_, _ = session.buf_conn.WriteString("503 5.5.1 Error: nested MAIL command\r\n")
-				_ = session.buf_conn.Flush()
-				break switch_cmd
-			}
-			if len(param) <= len("FROM:") || strings.ToUpper(param[:len("FROM:")]) != "FROM:" {
-				_, _ = session.buf_conn.WriteString("501 5.5.4 Syntax: MAIL FROM:<address>\r\n")
-				_ = session.buf_conn.Flush()
-				break
-			}
-			session.current_mail_from = param[len("FROM:"):]
-			session.current_rcpt_to = []string{}
-			session.server_state = server_state_mail
-			_, _ = session.buf_conn.WriteString("250 2.1.0 Ok\r\n")
-			_ = session.buf_conn.Flush()
-			// TODO: Address validation
-		case "RCPT":
-			if session.server_state != server_state_mail && session.server_state != server_state_rcpt {
-				_, _ = session.buf_conn.WriteString("503 5.5.1 Error: need MAIL command\r\n")
-				_ = session.buf_conn.Flush()
-				break
-			}
-			if len(param) <= len("TO:") || strings.ToUpper(param[:len("TO:")]) != "TO:" {
-				_, _ = session.buf_conn.WriteString("501 5.5.4 Syntax: RCPT TO:<address>\r\n")
-				_ = session.buf_conn.Flush()
-				break
-			}
-			recipient_address, _, _ := mailkit.Strip_angle_brackets(param[len("TO:"):])
-			var count int
-			err := session.db.QueryRow(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
-			}
-			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()
-		case "DATA":
-			if session.server_state != server_state_rcpt {
-				_, _ = session.buf_conn.WriteString("503 5.5.1 Error: need RCPT command\r\n")
-				_ = session.buf_conn.Flush()
-				break
-			}
-			_, _ = session.buf_conn.WriteString("354 End data with <CR><LF>.<CR><LF>\r\n")
-			_ = session.buf_conn.Flush()
-			var current_data []byte
-			for {
-				tmp, err := session.buf_conn.ReadSlice('\r')
-				if err != nil {
-					return err
-				}
-
-				// session.buf_conn.ReadSlice returns an internal buffer that gets
-				// overwritten on the next reader operation. So we must
-				// make a copy; also we have to allocate data_part to
-				// the correct length because [[builtin.copy]] copies
-				// min(len(dst), len(src)) items.
-				data_part := make([]byte, len(tmp))
-				copy(data_part, tmp)
-
-				next_four, err := session.buf_conn.Peek(4)
-				if err != nil {
-					return err
-				}
-				if bytes.Equal(next_four, []byte{'\n', '.', '\r', '\n'}) {
-					current_data = slices.Concat(current_data, data_part[:len(data_part)-1])
-					break
-				}
-				current_data = slices.Concat(current_data, data_part)
-			}
-			_, err := session.buf_conn.Discard(4)
-			if err != nil {
-				return err
-			}
-			err = deliver_local(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
-			switch {
-			case 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")
-			case err != nil:
-				_, _ = session.buf_conn.WriteString("500 2.0.0 Error: " + err.Error() + "\r\n")
-			default:
-				_, _ = session.buf_conn.WriteString("250 2.0.0 Ok: Accepted\r\n")
-			}
-			_ = session.buf_conn.Flush()
-			session.server_state = server_state_helo
-		case "QUIT":
-			_, _ = session.buf_conn.WriteString("221 2.0.0 Bye\r\n")
-			_ = session.buf_conn.Flush()
-			if session.tls_conn != nil {
-				session.tls_conn.Close()
-			}
-			session.net_conn.Close()
-			return nil
-		case "NOOP":
-			_, _ = session.buf_conn.WriteString("250 2.0.0 Ok\r\n")
-			_ = session.buf_conn.Flush()
-		case "RSET":
-			if session.server_state != server_state_begin {
-				session.server_state = server_state_helo
-			}
-			_, _ = session.buf_conn.WriteString("250 2.0.0 Ok\r\n")
-			_ = session.buf_conn.Flush()
-		default:
-			_, _ = session.buf_conn.WriteString("500 5.5.2 Error: command not recognized\r\n")
-			_ = session.buf_conn.Flush()
-		}
-	}
-}
-
-func handle_mx_recv_conn(ctx context.Context, net_conn net.Conn) error {
-	session := mx_recv_session{
-		net_conn: net_conn,
-	}
-	return session.handle(ctx)
-}