[src/trunk]: src/sys/kern - Instead of having accept(2) return a zero-filled ...

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

details:   https://anonhg.NetBSD.org/src/rev/8b9cf274dcc1
branches:  trunk
changeset: 790429:8b9cf274dcc1
user:      christos <christos%NetBSD.org@localhost>
date:      Tue Oct 08 15:09:51 2013 +0000

description:
- Instead of having accept(2) return a zero-filled sockaddr for the case
  where accept(2) was called on a unix socket that called connect(2) and
  then close(2), before the connection was accepted, return the empty
  sockaddr_un.
- Fix the length of the empty sockaddr_un socket so that it reflects reality.

diffstat:

 sys/kern/uipc_usrreq.c |  14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diffs (43 lines):

diff -r f7b01ae8ee47 -r 8b9cf274dcc1 sys/kern/uipc_usrreq.c
--- a/sys/kern/uipc_usrreq.c    Tue Oct 08 14:54:29 2013 +0000
+++ b/sys/kern/uipc_usrreq.c    Tue Oct 08 15:09:51 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uipc_usrreq.c,v 1.144 2013/08/29 17:49:21 rmind Exp $  */
+/*     $NetBSD: uipc_usrreq.c,v 1.145 2013/10/08 15:09:51 christos Exp $       */
 
 /*-
  * Copyright (c) 1998, 2000, 2004, 2008, 2009 The NetBSD Foundation, Inc.
@@ -96,7 +96,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uipc_usrreq.c,v 1.144 2013/08/29 17:49:21 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uipc_usrreq.c,v 1.145 2013/10/08 15:09:51 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -165,7 +165,7 @@
  *   that had referenced it have also been destroyed.
  */
 const struct sockaddr_un sun_noname = {
-       .sun_len = sizeof(sun_noname),
+       .sun_len = offsetof(struct sockaddr_un, sun_path),
        .sun_family = AF_LOCAL,
 };
 ino_t  unp_ino;                        /* prototype for fake inode numbers */
@@ -438,8 +438,14 @@
                 * after it's been accepted.  This prevents a client from
                 * overrunning a server and receiving ECONNREFUSED.
                 */
-               if (unp->unp_conn == NULL)
+               if (unp->unp_conn == NULL) {
+                       /*
+                        * This will use the empty socket and will not
+                        * allocate.
+                        */
+                       unp_setaddr(so, nam, true);
                        break;
+               }
                so2 = unp->unp_conn->unp_socket;
                if (so2->so_state & SS_ISCONNECTING) {
                        KASSERT(solocked2(so, so->so_head));