[src/trunk]: src/sys/netinet Revert rev1.183 (2003).

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/134ccfee1362
branches:  trunk
changeset: 830220:134ccfee1362
user:      maxv <maxv%NetBSD.org@localhost>
date:      Thu Mar 01 06:08:43 2018 +0000

description:
Revert rev1.183 (2003).

It was intended as an optimization, but it increases the attack surface:
the IPsec policy is not enforced on RST packets when the socket is in the
LISTEN state, and an (unauthenticated) attacker could jam the connection
between two IPsec hosts by sending RST packets between the client's SYN
and ACK packets.

Discussed with ozaki-r@.

diffstat:

 sys/netinet/tcp_input.c |  45 +++++----------------------------------------
 1 files changed, 5 insertions(+), 40 deletions(-)

diffs (83 lines):

diff -r 296e36e14689 -r 134ccfee1362 sys/netinet/tcp_input.c
--- a/sys/netinet/tcp_input.c   Thu Mar 01 06:00:49 2018 +0000
+++ b/sys/netinet/tcp_input.c   Thu Mar 01 06:08:43 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tcp_input.c,v 1.382 2018/02/28 11:23:24 maxv Exp $     */
+/*     $NetBSD: tcp_input.c,v 1.383 2018/03/01 06:08:43 maxv Exp $     */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -148,7 +148,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_input.c,v 1.382 2018/02/28 11:23:24 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_input.c,v 1.383 2018/03/01 06:08:43 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -1457,15 +1457,11 @@
                }
 #if defined(IPSEC)
                if (ipsec_used) {
-                       if (inp &&
-                           (inp->inp_socket->so_options & SO_ACCEPTCONN) == 0
-                           && ipsec_in_reject(m, inp)) {
+                       if (inp && ipsec_in_reject(m, inp)) {
                                goto drop;
                        }
 #ifdef INET6
-                       else if (in6p &&
-                           (in6p->in6p_socket->so_options & SO_ACCEPTCONN) == 0
-                           && ipsec_in_reject(m, in6p)) {
+                       else if (in6p && ipsec_in_reject(m, in6p)) {
                                goto drop;
                        }
 #endif
@@ -1500,9 +1496,7 @@
                        goto dropwithreset_ratelim;
                }
 #if defined(IPSEC)
-               if (ipsec_used && in6p &&
-                   (in6p->in6p_socket->so_options & SO_ACCEPTCONN) == 0 &&
-                   ipsec_in_reject(m, in6p)) {
+               if (ipsec_used && in6p && ipsec_in_reject(m, in6p)) {
                        goto drop;
                }
 #endif /*IPSEC*/
@@ -1769,35 +1763,6 @@
                        }
 #endif
 
-#if defined(IPSEC)
-                       if (ipsec_used) {
-                               switch (af) {
-#ifdef INET
-                               case AF_INET:
-                                       /*
-                                        * inp can be NULL when receiving an
-                                        * IPv4 packet on an IPv4-mapped IPv6
-                                        * address.
-                                        */
-                                       KASSERT(inp == NULL ||
-                                           sotoinpcb(so) == inp);
-                                       if (!ipsec_in_reject(m, inp))
-                                               break;
-                                       tp = NULL;
-                                       goto dropwithreset;
-#endif
-#ifdef INET6
-                               case AF_INET6:
-                                       KASSERT(sotoin6pcb(so) == in6p);
-                                       if (!ipsec_in_reject(m, in6p))
-                                               break;
-                                       tp = NULL;
-                                       goto dropwithreset;
-#endif /*INET6*/
-                               }
-                       }
-#endif /*IPSEC*/
-
                        /*
                         * LISTEN socket received a SYN from itself? This
                         * can't possibly be valid; drop the packet.