From 6162865d5a398d96a08adabe216b292ee3bf4afa Mon Sep 17 00:00:00 2001
From: eric <eric@openbsd.org>
Date: Fri, 16 Feb 2018 20:57:30 +0000
Subject: [PATCH] bump max line length to 16K for incoming mail. SMTP commands
 are still limited to LINE_MAX.

ok gilles@
---
 usr.sbin/smtpd/rfc2822.h      |  4 ++--
 usr.sbin/smtpd/smtp_session.c | 18 +++++++++++++-----
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/usr.sbin/smtpd/rfc2822.h b/usr.sbin/smtpd/rfc2822.h
index 48bdf6de495..2132cca61cc 100644
--- a/usr.sbin/smtpd/rfc2822.h
+++ b/usr.sbin/smtpd/rfc2822.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rfc2822.h,v 1.4 2015/11/05 08:55:09 gilles Exp $	*/
+/*	$OpenBSD: rfc2822.h,v 1.5 2018/02/16 20:57:30 eric Exp $	*/
 
 /*
  * Copyright (c) 2014 Gilles Chehade <gilles@poolp.org>
@@ -19,7 +19,7 @@
 #ifndef _RFC2822_H_
 #define	_RFC2822_H_
 
-#define	RFC2822_MAX_LINE_SIZE		4096
+#define	RFC2822_MAX_LINE_SIZE		16384
 
 struct rfc2822_line {
 	TAILQ_ENTRY(rfc2822_line)	next;
diff --git a/usr.sbin/smtpd/smtp_session.c b/usr.sbin/smtpd/smtp_session.c
index 61ed2cac853..ad64f94e4a8 100644
--- a/usr.sbin/smtpd/smtp_session.c
+++ b/usr.sbin/smtpd/smtp_session.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: smtp_session.c,v 1.316 2018/02/09 09:29:03 eric Exp $	*/
+/*	$OpenBSD: smtp_session.c,v 1.317 2018/02/16 20:57:30 eric Exp $	*/
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@poolp.org>
@@ -45,8 +45,9 @@
 #include "log.h"
 #include "ssl.h"
 
+#define	SMTP_LINE_MAX			16384
 #define	DATA_HIWAT			65535
-#define	APPEND_DOMAIN_BUFFER_SIZE	4096
+#define	APPEND_DOMAIN_BUFFER_SIZE	SMTP_LINE_MAX
 
 enum smtp_state {
 	STATE_NEW = 0,
@@ -1007,8 +1008,8 @@ smtp_io(struct io *io, int evt, void *arg)
 	case IO_DATAIN:
 	    nextline:
 		line = io_getline(s->io, &len);
-		if ((line == NULL && io_datalen(s->io) >= LINE_MAX) ||
-		    (line && len >= LINE_MAX)) {
+		if ((line == NULL && io_datalen(s->io) >= SMTP_LINE_MAX) ||
+		    (line && len >= SMTP_LINE_MAX)) {
 			s->flags |= SF_BADINPUT;
 			smtp_reply(s, "500 %s: Line too long",
 			    esc_code(ESC_STATUS_PERMFAIL, ESC_OTHER_STATUS));
@@ -1047,7 +1048,14 @@ smtp_io(struct io *io, int evt, void *arg)
 		}
 
 		/* Must be a command */
-		(void)strlcpy(s->cmd, line, sizeof s->cmd);
+		if (strlcpy(s->cmd, line, sizeof(s->cmd)) >= sizeof(s->cmd)) {
+			s->flags |= SF_BADINPUT;
+			smtp_reply(s, "500 %s: Command line too long",
+			    esc_code(ESC_STATUS_PERMFAIL, ESC_OTHER_STATUS));
+			smtp_enter_state(s, STATE_QUIT);
+			io_set_write(io);
+			return;
+		}
 		io_set_write(io);
 		smtp_command(s, line);
 		break;
-- 
2.20.1