Reserve the highest route priority for kernel-managed routes and prevent

userland from playing with the local and broadcast flags.

ok claudio@

diff --git a/sys/net/route.c b/sys/net/route.c
index 959d143..b965469 100644 (file)
--- a/sys/net/route.c
+++ b/sys/net/route.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: route.c,v 1.166 2014/05/21 14:48:28 mpi Exp $ */
+/*     $OpenBSD: route.c,v 1.167 2014/05/27 09:39:58 mpi Exp $ */
 /*     $NetBSD: route.c,v 1.14 1996/02/13 22:00:46 christos Exp $      */
 
 /*
@@ -784,6 +784,15 @@ rtrequest1(int req, struct rt_addrinfo *info, u_int8_t prio,
                                senderr(ESRCH);
                }
 #endif
+
+               /*
+                * Since RTP_LOCAL cannot be set by userland, make
+                * sure that local routes are only modified by the
+                * kernel.
+                */
+               if (rt->rt_flags & RTF_LOCAL && prio != RTP_LOCAL)
+                       senderr(EINVAL);
+
                if ((rn = rnh->rnh_deladdr(info->rti_info[RTAX_DST],
                    info->rti_info[RTAX_NETMASK], rnh, rn)) == NULL)
                        senderr(ESRCH);

diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 72834b7..e52e350 100644 (file)
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rtsock.c,v 1.144 2014/05/16 08:21:54 mpi Exp $        */
+/*     $OpenBSD: rtsock.c,v 1.145 2014/05/27 09:39:58 mpi Exp $        */
 /*     $NetBSD: rtsock.c,v 1.18 1996/03/29 00:32:10 cgd Exp $  */
 
 /*
@@ -534,13 +534,21 @@ route_output(struct mbuf *m, ...)
                }
        }
 
+
+       /* Do not let userland play with kernel-only flags. */
+       if ((rtm->rtm_flags & (RTF_LOCAL|RTF_BROADCAST)) != 0) {
+               error = EINVAL;
+               goto fail;
+       }
+
        /* make sure that kernel-only bits are not set */
        rtm->rtm_priority &= RTP_MASK;
        rtm->rtm_flags &= ~(RTF_DONE|RTF_CLONED);
        rtm->rtm_fmask &= RTF_FMASK;
 
        if (rtm->rtm_priority != 0) {
-               if (rtm->rtm_priority > RTP_MAX) {
+               if (rtm->rtm_priority > RTP_MAX ||
+                   rtm->rtm_priority == RTP_LOCAL) {
                        error = EINVAL;
                        goto fail;
                }