mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-06 09:17:25 +00:00
415 lines
12 KiB
C
415 lines
12 KiB
C
/*
|
||
* Copyright 1994, 1995 Massachusetts Institute of Technology
|
||
*
|
||
* Permission to use, copy, modify, and distribute this software and
|
||
* its documentation for any purpose and without fee is hereby
|
||
* granted, provided that both the above copyright notice and this
|
||
* permission notice appear in all copies, that both the above
|
||
* copyright notice and this permission notice appear in all
|
||
* supporting documentation, and that the name of M.I.T. not be used
|
||
* in advertising or publicity pertaining to distribution of the
|
||
* software without specific, written prior permission. M.I.T. makes
|
||
* no representations about the suitability of this software for any
|
||
* purpose. It is provided "as is" without express or implied
|
||
* warranty.
|
||
*
|
||
* THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
|
||
* ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
|
||
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
||
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
|
||
* SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
||
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
||
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
|
||
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
||
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
||
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
|
||
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||
* SUCH DAMAGE.
|
||
*
|
||
* $FreeBSD$
|
||
*/
|
||
|
||
/*
|
||
* This code does two things necessary for the enhanced TCP metrics to
|
||
* function in a useful manner:
|
||
* 1) It marks all non-host routes as `cloning', thus ensuring that
|
||
* every actual reference to such a route actually gets turned
|
||
* into a reference to a host route to the specific destination
|
||
* requested.
|
||
* 2) When such routes lose all their references, it arranges for them
|
||
* to be deleted in some random collection of circumstances, so that
|
||
* a large quantity of stale routing data is not kept in kernel memory
|
||
* indefinitely. See in_rtqtimo() below for the exact mechanism.
|
||
*/
|
||
|
||
#include <sys/param.h>
|
||
#include <sys/systm.h>
|
||
#include <sys/kernel.h>
|
||
#include <sys/sysctl.h>
|
||
#include <sys/socket.h>
|
||
#include <sys/mbuf.h>
|
||
#include <sys/syslog.h>
|
||
|
||
#include <net/if.h>
|
||
#include <net/route.h>
|
||
#include <netinet/in.h>
|
||
#include <netinet/in_var.h>
|
||
|
||
extern int in_inithead __P((void **head, int off));
|
||
|
||
#define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */
|
||
|
||
/*
|
||
* Do what we need to do when inserting a route.
|
||
*/
|
||
static struct radix_node *
|
||
in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
|
||
struct radix_node *treenodes)
|
||
{
|
||
struct rtentry *rt = (struct rtentry *)treenodes;
|
||
struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt);
|
||
struct radix_node *ret;
|
||
|
||
/*
|
||
* For IP, all unicast non-host routes are automatically cloning.
|
||
*/
|
||
if(IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
|
||
rt->rt_flags |= RTF_MULTICAST;
|
||
|
||
if(!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST))) {
|
||
rt->rt_flags |= RTF_PRCLONING;
|
||
}
|
||
|
||
/*
|
||
* A little bit of help for both IP output and input:
|
||
* For host routes, we make sure that RTF_BROADCAST
|
||
* is set for anything that looks like a broadcast address.
|
||
* This way, we can avoid an expensive call to in_broadcast()
|
||
* in ip_output() most of the time (because the route passed
|
||
* to ip_output() is almost always a host route).
|
||
*
|
||
* We also do the same for local addresses, with the thought
|
||
* that this might one day be used to speed up ip_input().
|
||
*
|
||
* We also mark routes to multicast addresses as such, because
|
||
* it's easy to do and might be useful (but this is much more
|
||
* dubious since it's so easy to inspect the address). (This
|
||
* is done above.)
|
||
*/
|
||
if (rt->rt_flags & RTF_HOST) {
|
||
if (in_broadcast(sin->sin_addr, rt->rt_ifp)) {
|
||
rt->rt_flags |= RTF_BROADCAST;
|
||
} else {
|
||
#define satosin(sa) ((struct sockaddr_in *)sa)
|
||
if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr
|
||
== sin->sin_addr.s_addr)
|
||
rt->rt_flags |= RTF_LOCAL;
|
||
#undef satosin
|
||
}
|
||
}
|
||
|
||
if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU)
|
||
&& rt->rt_ifp)
|
||
rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
|
||
|
||
ret = rn_addroute(v_arg, n_arg, head, treenodes);
|
||
if (ret == NULL && rt->rt_flags & RTF_HOST) {
|
||
struct rtentry *rt2;
|
||
/*
|
||
* We are trying to add a host route, but can't.
|
||
* Find out if it is because of an
|
||
* ARP entry and delete it if so.
|
||
*/
|
||
rt2 = rtalloc1((struct sockaddr *)sin, 0,
|
||
RTF_CLONING | RTF_PRCLONING);
|
||
if (rt2) {
|
||
if (rt2->rt_flags & RTF_LLINFO &&
|
||
rt2->rt_flags & RTF_HOST &&
|
||
rt2->rt_gateway &&
|
||
rt2->rt_gateway->sa_family == AF_LINK) {
|
||
rtrequest(RTM_DELETE,
|
||
(struct sockaddr *)rt_key(rt2),
|
||
rt2->rt_gateway,
|
||
rt_mask(rt2), rt2->rt_flags, 0);
|
||
ret = rn_addroute(v_arg, n_arg, head,
|
||
treenodes);
|
||
}
|
||
RTFREE(rt2);
|
||
}
|
||
}
|
||
return ret;
|
||
}
|
||
|
||
/*
|
||
* This code is the inverse of in_clsroute: on first reference, if we
|
||
* were managing the route, stop doing so and set the expiration timer
|
||
* back off again.
|
||
*/
|
||
static struct radix_node *
|
||
in_matroute(void *v_arg, struct radix_node_head *head)
|
||
{
|
||
struct radix_node *rn = rn_match(v_arg, head);
|
||
struct rtentry *rt = (struct rtentry *)rn;
|
||
|
||
if(rt && rt->rt_refcnt == 0) { /* this is first reference */
|
||
if(rt->rt_flags & RTPRF_OURS) {
|
||
rt->rt_flags &= ~RTPRF_OURS;
|
||
rt->rt_rmx.rmx_expire = 0;
|
||
}
|
||
}
|
||
return rn;
|
||
}
|
||
|
||
static int rtq_reallyold = 60*60;
|
||
/* one hour is ``really old'' */
|
||
SYSCTL_INT(_net_inet_ip, IPCTL_RTEXPIRE, rtexpire, CTLFLAG_RW,
|
||
&rtq_reallyold , 0,
|
||
"Default expiration time on dynamically learned routes");
|
||
|
||
static int rtq_minreallyold = 10;
|
||
/* never automatically crank down to less */
|
||
SYSCTL_INT(_net_inet_ip, IPCTL_RTMINEXPIRE, rtminexpire, CTLFLAG_RW,
|
||
&rtq_minreallyold , 0,
|
||
"Minimum time to attempt to hold onto dynamically learned routes");
|
||
|
||
static int rtq_toomany = 128;
|
||
/* 128 cached routes is ``too many'' */
|
||
SYSCTL_INT(_net_inet_ip, IPCTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW,
|
||
&rtq_toomany , 0, "Upper limit on dynamically learned routes");
|
||
|
||
/*
|
||
* On last reference drop, mark the route as belong to us so that it can be
|
||
* timed out.
|
||
*/
|
||
static void
|
||
in_clsroute(struct radix_node *rn, struct radix_node_head *head)
|
||
{
|
||
struct rtentry *rt = (struct rtentry *)rn;
|
||
|
||
if(!(rt->rt_flags & RTF_UP))
|
||
return; /* prophylactic measures */
|
||
|
||
if((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST)
|
||
return;
|
||
|
||
if((rt->rt_flags & (RTF_WASCLONED | RTPRF_OURS))
|
||
!= RTF_WASCLONED)
|
||
return;
|
||
|
||
/*
|
||
* As requested by David Greenman:
|
||
* If rtq_reallyold is 0, just delete the route without
|
||
* waiting for a timeout cycle to kill it.
|
||
*/
|
||
if(rtq_reallyold != 0) {
|
||
rt->rt_flags |= RTPRF_OURS;
|
||
rt->rt_rmx.rmx_expire = time_second + rtq_reallyold;
|
||
} else {
|
||
rtrequest(RTM_DELETE,
|
||
(struct sockaddr *)rt_key(rt),
|
||
rt->rt_gateway, rt_mask(rt),
|
||
rt->rt_flags, 0);
|
||
}
|
||
}
|
||
|
||
struct rtqk_arg {
|
||
struct radix_node_head *rnh;
|
||
int draining;
|
||
int killed;
|
||
int found;
|
||
int updating;
|
||
time_t nextstop;
|
||
};
|
||
|
||
/*
|
||
* Get rid of old routes. When draining, this deletes everything, even when
|
||
* the timeout is not expired yet. When updating, this makes sure that
|
||
* nothing has a timeout longer than the current value of rtq_reallyold.
|
||
*/
|
||
static int
|
||
in_rtqkill(struct radix_node *rn, void *rock)
|
||
{
|
||
struct rtqk_arg *ap = rock;
|
||
struct rtentry *rt = (struct rtentry *)rn;
|
||
int err;
|
||
|
||
if(rt->rt_flags & RTPRF_OURS) {
|
||
ap->found++;
|
||
|
||
if(ap->draining || rt->rt_rmx.rmx_expire <= time_second) {
|
||
if(rt->rt_refcnt > 0)
|
||
panic("rtqkill route really not free");
|
||
|
||
err = rtrequest(RTM_DELETE,
|
||
(struct sockaddr *)rt_key(rt),
|
||
rt->rt_gateway, rt_mask(rt),
|
||
rt->rt_flags, 0);
|
||
if(err) {
|
||
log(LOG_WARNING, "in_rtqkill: error %d\n", err);
|
||
} else {
|
||
ap->killed++;
|
||
}
|
||
} else {
|
||
if(ap->updating
|
||
&& (rt->rt_rmx.rmx_expire - time_second
|
||
> rtq_reallyold)) {
|
||
rt->rt_rmx.rmx_expire = time_second
|
||
+ rtq_reallyold;
|
||
}
|
||
ap->nextstop = lmin(ap->nextstop,
|
||
rt->rt_rmx.rmx_expire);
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
#define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */
|
||
static int rtq_timeout = RTQ_TIMEOUT;
|
||
|
||
static void
|
||
in_rtqtimo(void *rock)
|
||
{
|
||
struct radix_node_head *rnh = rock;
|
||
struct rtqk_arg arg;
|
||
struct timeval atv;
|
||
static time_t last_adjusted_timeout = 0;
|
||
int s;
|
||
|
||
arg.found = arg.killed = 0;
|
||
arg.rnh = rnh;
|
||
arg.nextstop = time_second + rtq_timeout;
|
||
arg.draining = arg.updating = 0;
|
||
s = splnet();
|
||
rnh->rnh_walktree(rnh, in_rtqkill, &arg);
|
||
splx(s);
|
||
|
||
/*
|
||
* Attempt to be somewhat dynamic about this:
|
||
* If there are ``too many'' routes sitting around taking up space,
|
||
* then crank down the timeout, and see if we can't make some more
|
||
* go away. However, we make sure that we will never adjust more
|
||
* than once in rtq_timeout seconds, to keep from cranking down too
|
||
* hard.
|
||
*/
|
||
if((arg.found - arg.killed > rtq_toomany)
|
||
&& (time_second - last_adjusted_timeout >= rtq_timeout)
|
||
&& rtq_reallyold > rtq_minreallyold) {
|
||
rtq_reallyold = 2*rtq_reallyold / 3;
|
||
if(rtq_reallyold < rtq_minreallyold) {
|
||
rtq_reallyold = rtq_minreallyold;
|
||
}
|
||
|
||
last_adjusted_timeout = time_second;
|
||
#ifdef DIAGNOSTIC
|
||
log(LOG_DEBUG, "in_rtqtimo: adjusted rtq_reallyold to %d\n",
|
||
rtq_reallyold);
|
||
#endif
|
||
arg.found = arg.killed = 0;
|
||
arg.updating = 1;
|
||
s = splnet();
|
||
rnh->rnh_walktree(rnh, in_rtqkill, &arg);
|
||
splx(s);
|
||
}
|
||
|
||
atv.tv_usec = 0;
|
||
atv.tv_sec = arg.nextstop - time_second;
|
||
timeout(in_rtqtimo, rock, tvtohz(&atv));
|
||
}
|
||
|
||
void
|
||
in_rtqdrain(void)
|
||
{
|
||
struct radix_node_head *rnh = rt_tables[AF_INET];
|
||
struct rtqk_arg arg;
|
||
int s;
|
||
arg.found = arg.killed = 0;
|
||
arg.rnh = rnh;
|
||
arg.nextstop = 0;
|
||
arg.draining = 1;
|
||
arg.updating = 0;
|
||
s = splnet();
|
||
rnh->rnh_walktree(rnh, in_rtqkill, &arg);
|
||
splx(s);
|
||
}
|
||
|
||
/*
|
||
* Initialize our routing tree.
|
||
*/
|
||
int
|
||
in_inithead(void **head, int off)
|
||
{
|
||
struct radix_node_head *rnh;
|
||
|
||
if(!rn_inithead(head, off))
|
||
return 0;
|
||
|
||
if(head != (void **)&rt_tables[AF_INET]) /* BOGUS! */
|
||
return 1; /* only do this for the real routing table */
|
||
|
||
rnh = *head;
|
||
rnh->rnh_addaddr = in_addroute;
|
||
rnh->rnh_matchaddr = in_matroute;
|
||
rnh->rnh_close = in_clsroute;
|
||
in_rtqtimo(rnh); /* kick off timeout first time */
|
||
return 1;
|
||
}
|
||
|
||
|
||
/*
|
||
* This zaps old routes when the interface goes down.
|
||
* Currently it doesn't delete static routes; there are
|
||
* arguments one could make for both behaviors. For the moment,
|
||
* we will adopt the Principle of Least Surprise and leave them
|
||
* alone (with the knowledge that this will not be enough for some
|
||
* people). The ones we really want to get rid of are things like ARP
|
||
* entries, since the user might down the interface, walk over to a completely
|
||
* different network, and plug back in.
|
||
*/
|
||
struct in_ifadown_arg {
|
||
struct radix_node_head *rnh;
|
||
struct ifaddr *ifa;
|
||
};
|
||
|
||
static int
|
||
in_ifadownkill(struct radix_node *rn, void *xap)
|
||
{
|
||
struct in_ifadown_arg *ap = xap;
|
||
struct rtentry *rt = (struct rtentry *)rn;
|
||
int err;
|
||
|
||
if (rt->rt_ifa == ap->ifa && !(rt->rt_flags & RTF_STATIC)) {
|
||
/*
|
||
* We need to disable the automatic prune that happens
|
||
* in this case in rtrequest() because it will blow
|
||
* away the pointers that rn_walktree() needs in order
|
||
* continue our descent. We will end up deleting all
|
||
* the routes that rtrequest() would have in any case,
|
||
* so that behavior is not needed there.
|
||
*/
|
||
rt->rt_flags &= ~RTF_PRCLONING;
|
||
err = rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt),
|
||
rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
|
||
if (err) {
|
||
log(LOG_WARNING, "in_ifadownkill: error %d\n", err);
|
||
}
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
int
|
||
in_ifadown(struct ifaddr *ifa)
|
||
{
|
||
struct in_ifadown_arg arg;
|
||
struct radix_node_head *rnh;
|
||
|
||
if (ifa->ifa_addr->sa_family != AF_INET)
|
||
return 1;
|
||
|
||
arg.rnh = rnh = rt_tables[AF_INET];
|
||
arg.ifa = ifa;
|
||
rnh->rnh_walktree(rnh, in_ifadownkill, &arg);
|
||
ifa->ifa_flags &= ~IFA_ROUTE;
|
||
return 0;
|
||
}
|