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bird/sysdep/unix/krt-set.c
Ondrej Zajicek 1567edea8d Bugfix for routing table breaking bug.
Here is a patch fixing a bug that causes breakage of a local routing
table during shutdown of Bird. The problem was caused by shutdown
of 'device' protocol before shutdown of 'kernel' protocol.  When
'device' protocol went down, the route (with local network prefix)
From different protocol (BGP or OSPF) became preferred and installed
to the kernel routing table. Such routes were broken (like
192.168.1.0/24 via 192.168.1.2). I think it is also the cause
of problem reported by Martin Kraus.

The patch disables updating of kernel routing table during shutdown of
Bird. I am not sure whether this is the best way to fix it, I would
prefer to forbid 'kernel' protocol to overwrite routes with
'proto kernel'.

The patch also fixes a problem that during shutdown sometimes routes
created by Bird remained in the kernel routing table.
2008-10-26 23:09:46 +01:00

112 lines
2.2 KiB
C

/*
* BIRD -- Unix Routing Table Syncing
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <net/route.h>
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "lib/unix.h"
#include "lib/krt.h"
#include "lib/string.h"
int
krt_capable(rte *e)
{
rta *a = e->attrs;
#ifdef CONFIG_AUTO_ROUTES
if (a->source == RTS_DEVICE)
return 0;
#endif
return
a->cast == RTC_UNICAST &&
(a->dest == RTD_ROUTER
|| a->dest == RTD_DEVICE
#ifdef RTF_REJECT
|| a->dest == RTD_UNREACHABLE
#endif
);
}
static void
krt_ioctl(int ioc, rte *e, char *name)
{
net *net = e->net;
struct rtentry re;
rta *a = e->attrs;
bzero(&re, sizeof(re));
fill_in_sockaddr((struct sockaddr_in *) &re.rt_dst, net->n.prefix, 0);
fill_in_sockaddr((struct sockaddr_in *) &re.rt_genmask, ipa_mkmask(net->n.pxlen), 0);
re.rt_flags = RTF_UP;
if (net->n.pxlen == 32)
re.rt_flags |= RTF_HOST;
switch (a->dest)
{
case RTD_ROUTER:
fill_in_sockaddr((struct sockaddr_in *) &re.rt_gateway, a->gw, 0);
re.rt_flags |= RTF_GATEWAY;
break;
case RTD_DEVICE:
if (!a->iface)
return;
re.rt_dev = a->iface->name;
break;
#ifdef RTF_REJECT
case RTD_UNREACHABLE:
re.rt_flags |= RTF_REJECT;
break;
#endif
default:
bug("krt set: unknown flags, but not filtered");
}
if (ioctl(if_scan_sock, ioc, &re) < 0)
log(L_ERR "%s(%I/%d): %m", name, net->n.prefix, net->n.pxlen);
}
void
krt_set_notify(struct krt_proto *p, net *net, rte *new, rte *old)
{
if (old)
{
DBG("krt_remove_route(%I/%d)\n", net->n.prefix, net->n.pxlen);
krt_ioctl(SIOCDELRT, old, "SIOCDELRT");
}
if (new)
{
DBG("krt_add_route(%I/%d)\n", net->n.prefix, net->n.pxlen);
krt_ioctl(SIOCADDRT, new, "SIOCADDRT");
}
}
void
krt_set_start(struct krt_proto *x, int first)
{
if (if_scan_sock < 0)
bug("krt set: missing socket");
}
void
krt_set_construct(struct krt_config *c)
{
}
void
krt_set_shutdown(struct krt_proto *x, int last)
{
}