Date: Wed, 21 Mar 2001 13:36:11 +0200 From: Ruslan Ermilov <ru@FreeBSD.org> To: Garrett Wollman <wollman@FreeBSD.org> Cc: net@FreeBSD.org Subject: Indirect routes with indirect gateways, bugfix Message-ID: <20010321133611.A62997@sunbay.com>
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Hi!
The routing code (bogusly?) allows to add an indirect route with
also indirect gateway. This results in some nasty bugs:
: Script started on Wed Mar 21 13:17:47 2001
:
: freebsd# netstat -rn
: Routing tables
:
: Internet:
: Destination Gateway Flags Refs Use Netif Expire
: 127.0.0.1 127.0.0.1 UH 0 0 lo0
: 192.168.1 link#1 UC 0 0 rl0 =>
:
: freebsd# route add -net 10 1.2.3.4
: route: writing to routing socket: Network is unreachable
: add net 10: gateway 1.2.3.4: Network is unreachable
:
: freebsd# route add default 192.168.1.1
: add net default: gateway 192.168.1.1
:
: freebsd# route add -net 10 1.2.3.4
: add net 10: gateway 1.2.3.4
:
: freebsd# ping -c1 10.0.0.1
: PING 10.0.0.1 (10.0.0.1): 56 data bytes
:
: --- 10.0.0.1 ping statistics ---
: 1 packets transmitted, 0 packets received, 100% packet loss
:
: freebsd# dmesg | tail -2
: arplookup 1.2.3.4 failed: host is not on local network
: arpresolve: can't allocate llinfo for 1.2.3.4rt
: freebsd#
:
: Script done on Wed Mar 21 13:19:00 2001
I have searched the CSRG SCCS logs, and found that the relevant code
was added in route.c, version 7.22 (well, 7.22 is actually a part of
7.23 that went into Net/2 release). I have marked the relevant text
from the commit log with circumflexes:
CSRG> D 7.23 91/06/27 18:52:33 sklower 69 68 00059/00029/00452
CSRG> mostly changes to merge arp and routing tables; save space by
CSRG> separately allocated dst and gateway sockaddrs from rest of rtentry;
CSRG> also have routing layer look up route to gateway and cache it when
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
CSRG> installing RTF_GATEWAY type routes.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
CSRG>
CSRG> D 7.22 91/06/27 18:48:09 sklower 68 66 00016/00002/00465
CSRG> fixes from following version for net2 release
CSRG>
CSRG> SCCS/s.route.c: 7.21 vs. 7.22
CSRG> --- /tmp/get.860.7.21 Mon Mar 19 18:46:00 2001
CSRG> +++ /tmp/get.860.7.22 Mon Mar 19 18:46:00 2001
CSRG> @@ -1,5 +1,5 @@
CSRG> /*
CSRG> - * Copyright (c) 1980, 1986 Regents of the University of California.
CSRG> + * Copyright (c) 1980, 1986, 1991 Regents of the University of California.
CSRG> * All rights reserved.
CSRG> *
CSRG> * %sccs.include.redist.c%
CSRG> @@ -275,7 +275,7 @@
CSRG> int flags;
CSRG> struct sockaddr *dst, *gateway;
CSRG> {
CSRG> - struct ifaddr *ifa;
CSRG> + register struct ifaddr *ifa;
CSRG> if ((flags & RTF_GATEWAY) == 0) {
CSRG> /*
CSRG> * If we are adding a route to an interface,
CSRG> @@ -299,6 +299,20 @@
CSRG> }
CSRG> if (ifa == 0)
CSRG> ifa = ifa_ifwithnet(gateway);
CSRG> + if (ifa == 0) {
CSRG> + struct rtentry *rt = rtalloc1(dst, 0);
CSRG> + if (rt == 0)
CSRG> + return (0);
CSRG> + rt->rt_refcnt--;
CSRG> + if ((ifa = rt->rt_ifa) == 0)
CSRG> + return (0);
CSRG> + }
CSRG> + if (ifa->ifa_addr->sa_family != dst->sa_family) {
CSRG> + struct ifaddr *oifa = ifa, *ifaof_ifpforaddr();
CSRG> + ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
CSRG> + if (ifa == 0)
CSRG> + ifa = oifa;
CSRG> + }
CSRG> return (ifa);
CSRG> }
Unless someone has a good motivation for not doing this, I am going
to commit the attached patch that disallows indirect routes with
indirect gateways.
Cheers,
--
Ruslan Ermilov Oracle Developer/DBA,
ru@sunbay.com Sunbay Software AG,
ru@FreeBSD.org FreeBSD committer,
+380.652.512.251 Simferopol, Ukraine
http://www.FreeBSD.org The Power To Serve
http://www.oracle.com Enabling The Information Age
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Index: route.c
===================================================================
RCS file: /home/ncvs/src/sys/net/route.c,v
retrieving revision 1.61
diff -u -p -7 -r1.61 route.c
--- route.c 2001/03/15 14:52:11 1.61
+++ route.c 2001/03/19 16:45:00
@@ -420,28 +420,30 @@ ifa_ifwithroute(flags, dst, gateway)
* or host, the gateway may still be on the
* other end of a pt to pt link.
*/
ifa = ifa_ifwithdstaddr(gateway);
}
if (ifa == 0)
ifa = ifa_ifwithnet(gateway);
+#if 0
if (ifa == 0) {
struct rtentry *rt = rtalloc1(dst, 0, 0UL);
if (rt == 0)
return (0);
rt->rt_refcnt--;
if ((ifa = rt->rt_ifa) == 0)
return (0);
}
if (ifa->ifa_addr->sa_family != dst->sa_family) {
struct ifaddr *oifa = ifa;
ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
if (ifa == 0)
ifa = oifa;
}
+#endif
return (ifa);
}
#define ROUNDUP(a) (a>0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
static int rt_fixdelete __P((struct radix_node *, void *));
static int rt_fixchange __P((struct radix_node *, void *));
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