[src/trunk]: src/lib/libc/net Enforce that getpeereid only returns success on...

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

details:   https://anonhg.NetBSD.org/src/rev/2f9c205ed4f7
branches:  trunk
changeset: 829899:2f9c205ed4f7
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Feb 16 19:21:49 2018 +0000

description:
Enforce that getpeereid only returns success on AF_LOCAL sockets, instead
of returning garbage for other socket types.

diffstat:

 lib/libc/net/getpeereid.c |  33 ++++++++++++++++++++++-----------
 1 files changed, 22 insertions(+), 11 deletions(-)

diffs (58 lines):

diff -r e7fdc28f7ba5 -r 2f9c205ed4f7 lib/libc/net/getpeereid.c
--- a/lib/libc/net/getpeereid.c Fri Feb 16 18:13:47 2018 +0000
+++ b/lib/libc/net/getpeereid.c Fri Feb 16 19:21:49 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: getpeereid.c,v 1.2 2008/04/29 06:53:01 martin Exp $ */
+/* $NetBSD: getpeereid.c,v 1.3 2018/02/16 19:21:49 christos Exp $ */
 
 /*-
  * Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -31,27 +31,38 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: getpeereid.c,v 1.2 2008/04/29 06:53:01 martin Exp $");
+__RCSID("$NetBSD: getpeereid.c,v 1.3 2018/02/16 19:21:49 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/types.h>
-#include <unistd.h>
 #include <sys/un.h>
 #include <sys/socket.h>
+#include <unistd.h>
+#include <errno.h>
 
 
 int
 getpeereid(int s, uid_t *euid, gid_t *egid)
 {
        struct unpcbid cred;
-       socklen_t len = sizeof(cred);
-       if (getsockopt(s, 0, LOCAL_PEEREID, &cred, &len) < 0) {
+       struct sockaddr_storage ss;
+       socklen_t len;
+
+       len = sizeof(ss);
+       if (getsockname(s, (void *)&ss, &len) == -1)
+               return -1;
+       if (ss.ss_family != AF_LOCAL) {
+               errno = EOPNOTSUPP;
                return -1;
-       } else {
-               if (euid != NULL)
-                       *euid = cred.unp_euid;
-               if (egid != NULL)
-                       *egid = cred.unp_egid;
-               return 0;
        }
+
+       len = sizeof(cred);
+       if (getsockopt(s, 0, LOCAL_PEEREID, &cred, &len) == -1)
+               return -1;
+
+       if (euid != NULL)
+               *euid = cred.unp_euid;
+       if (egid != NULL)
+               *egid = cred.unp_egid;
+       return 0;
 }