FreeBSD-5.3/sys/net/route.c
/*
* Copyright (c) 1980, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS 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.
*
* @(#)route.c 8.3.1.1 (Berkeley) 2/23/95
* $FreeBSD: src/sys/net/route.c,v 1.106.2.1 2004/09/02 14:49:34 csjp Exp $
*/
#include "opt_inet.h"
#include "opt_mrouting.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/domain.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/ip_mroute.h>
#include <vm/uma.h>
static struct rtstat rtstat;
struct radix_node_head *rt_tables[AF_MAX+1];
static int rttrash; /* routes not in table but not freed */
static void rt_maskedcopy(struct sockaddr *,
struct sockaddr *, struct sockaddr *);
static void rtable_init(void **);
/* compare two sockaddr structures */
#define sa_equal(a1, a2) (bcmp((a1), (a2), (a1)->sa_len) == 0)
/*
* Convert a 'struct radix_node *' to a 'struct rtentry *'.
* The operation can be done safely (in this code) because a
* 'struct rtentry' starts with two 'struct radix_node''s, the first
* one representing leaf nodes in the routing tree, which is
* what the code in radix.c passes us as a 'struct radix_node'.
*
* But because there are a lot of assumptions in this conversion,
* do not cast explicitly, but always use the macro below.
*/
#define RNTORT(p) ((struct rtentry *)(p))
static void
rtable_init(void **table)
{
struct domain *dom;
for (dom = domains; dom; dom = dom->dom_next)
if (dom->dom_rtattach)
dom->dom_rtattach(&table[dom->dom_family],
dom->dom_rtoffset);
}
static uma_zone_t rtzone; /* Routing table UMA zone. */
static void
route_init(void)
{
rtzone = uma_zcreate("rtentry", sizeof(struct rtentry), NULL, NULL,
NULL, NULL, UMA_ALIGN_PTR, 0);
rn_init(); /* initialize all zeroes, all ones, mask table */
rtable_init((void **)rt_tables);
}
/*
* Packet routing routines.
*/
void
rtalloc(struct route *ro)
{
rtalloc_ign(ro, 0UL);
}
void
rtalloc_ign(struct route *ro, u_long ignore)
{
struct rtentry *rt;
if ((rt = ro->ro_rt) != NULL) {
if (rt->rt_ifp != NULL && rt->rt_flags & RTF_UP)
return;
RTFREE(rt);
ro->ro_rt = NULL;
}
ro->ro_rt = rtalloc1(&ro->ro_dst, 1, ignore);
if (ro->ro_rt)
RT_UNLOCK(ro->ro_rt);
}
/*
* Look up the route that matches the address given
* Or, at least try.. Create a cloned route if needed.
*
* The returned route, if any, is locked.
*/
struct rtentry *
rtalloc1(struct sockaddr *dst, int report, u_long ignflags)
{
struct radix_node_head *rnh = rt_tables[dst->sa_family];
struct rtentry *rt;
struct radix_node *rn;
struct rtentry *newrt;
struct rt_addrinfo info;
u_long nflags;
int err = 0, msgtype = RTM_MISS;
newrt = NULL;
bzero(&info, sizeof(info));
/*
* Look up the address in the table for that Address Family
*/
if (rnh == NULL) {
rtstat.rts_unreach++;
goto miss2;
}
RADIX_NODE_HEAD_LOCK(rnh);
if ((rn = rnh->rnh_matchaddr(dst, rnh)) &&
(rn->rn_flags & RNF_ROOT) == 0) {
/*
* If we find it and it's not the root node, then
* get a refernce on the rtentry associated.
*/
newrt = rt = RNTORT(rn);
nflags = rt->rt_flags & ~ignflags;
if (report && (nflags & RTF_CLONING)) {
/*
* We are apparently adding (report = 0 in delete).
* If it requires that it be cloned, do so.
* (This implies it wasn't a HOST route.)
*/
err = rtrequest(RTM_RESOLVE, dst, NULL,
NULL, 0, &newrt);
if (err) {
/*
* If the cloning didn't succeed, maybe
* what we have will do. Return that.
*/
newrt = rt; /* existing route */
RT_LOCK(newrt);
RT_ADDREF(newrt);
goto miss;
}
KASSERT(newrt, ("no route and no error"));
RT_LOCK(newrt);
if (newrt->rt_flags & RTF_XRESOLVE) {
/*
* If the new route specifies it be
* externally resolved, then go do that.
*/
msgtype = RTM_RESOLVE;
goto miss;
}
/* Inform listeners of the new route. */
info.rti_info[RTAX_DST] = rt_key(newrt);
info.rti_info[RTAX_NETMASK] = rt_mask(newrt);
info.rti_info[RTAX_GATEWAY] = newrt->rt_gateway;
if (newrt->rt_ifp != NULL) {
info.rti_info[RTAX_IFP] =
ifaddr_byindex(newrt->rt_ifp->if_index)->ifa_addr;
info.rti_info[RTAX_IFA] = newrt->rt_ifa->ifa_addr;
}
rt_missmsg(RTM_ADD, &info, newrt->rt_flags, 0);
} else {
KASSERT(rt == newrt, ("locking wrong route"));
RT_LOCK(newrt);
RT_ADDREF(newrt);
}
RADIX_NODE_HEAD_UNLOCK(rnh);
} else {
/*
* Either we hit the root or couldn't find any match,
* Which basically means
* "caint get there frm here"
*/
rtstat.rts_unreach++;
miss:
RADIX_NODE_HEAD_UNLOCK(rnh);
miss2: if (report) {
/*
* If required, report the failure to the supervising
* Authorities.
* For a delete, this is not an error. (report == 0)
*/
info.rti_info[RTAX_DST] = dst;
rt_missmsg(msgtype, &info, 0, err);
}
}
if (newrt)
RT_LOCK_ASSERT(newrt);
return (newrt);
}
/*
* Remove a reference count from an rtentry.
* If the count gets low enough, take it out of the routing table
*/
void
rtfree(struct rtentry *rt)
{
struct radix_node_head *rnh;
/* XXX the NULL checks are probably useless */
if (rt == NULL)
panic("rtfree: NULL rt");
rnh = rt_tables[rt_key(rt)->sa_family];
if (rnh == NULL)
panic("rtfree: NULL rnh");
RT_LOCK_ASSERT(rt);
/*
* decrement the reference count by one and if it reaches 0,
* and there is a close function defined, call the close function
*/
RT_REMREF(rt);
if (rt->rt_refcnt > 0)
goto done;
/*
* On last reference give the "close method" a chance
* to cleanup private state. This also permits (for
* IPv4 and IPv6) a chance to decide if the routing table
* entry should be purged immediately or at a later time.
* When an immediate purge is to happen the close routine
* typically calls rtexpunge which clears the RTF_UP flag
* on the entry so that the code below reclaims the storage.
*/
if (rt->rt_refcnt == 0 && rnh->rnh_close)
rnh->rnh_close((struct radix_node *)rt, rnh);
/*
* If we are no longer "up" (and ref == 0)
* then we can free the resources associated
* with the route.
*/
if ((rt->rt_flags & RTF_UP) == 0) {
if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT))
panic ("rtfree 2");
/*
* the rtentry must have been removed from the routing table
* so it is represented in rttrash.. remove that now.
*/
rttrash--;
#ifdef DIAGNOSTIC
if (rt->rt_refcnt < 0) {
printf("rtfree: %p not freed (neg refs)\n", rt);
goto done;
}
#endif
/*
* release references on items we hold them on..
* e.g other routes and ifaddrs.
*/
if (rt->rt_ifa)
IFAFREE(rt->rt_ifa);
rt->rt_parent = NULL; /* NB: no refcnt on parent */
/*
* The key is separatly alloc'd so free it (see rt_setgate()).
* This also frees the gateway, as they are always malloc'd
* together.
*/
Free(rt_key(rt));
/*
* and the rtentry itself of course
*/
RT_LOCK_DESTROY(rt);
uma_zfree(rtzone, rt);
return;
}
done:
RT_UNLOCK(rt);
}
/*
* Force a routing table entry to the specified
* destination to go through the given gateway.
* Normally called as a result of a routing redirect
* message from the network layer.
*/
void
rtredirect(struct sockaddr *dst,
struct sockaddr *gateway,
struct sockaddr *netmask,
int flags,
struct sockaddr *src)
{
struct rtentry *rt;
int error = 0;
short *stat = NULL;
struct rt_addrinfo info;
struct ifaddr *ifa;
/* verify the gateway is directly reachable */
if ((ifa = ifa_ifwithnet(gateway)) == NULL) {
error = ENETUNREACH;
goto out;
}
rt = rtalloc1(dst, 0, 0UL); /* NB: rt is locked */
/*
* If the redirect isn't from our current router for this dst,
* it's either old or wrong. If it redirects us to ourselves,
* we have a routing loop, perhaps as a result of an interface
* going down recently.
*/
if (!(flags & RTF_DONE) && rt &&
(!sa_equal(src, rt->rt_gateway) || rt->rt_ifa != ifa))
error = EINVAL;
else if (ifa_ifwithaddr(gateway))
error = EHOSTUNREACH;
if (error)
goto done;
/*
* Create a new entry if we just got back a wildcard entry
* or the the lookup failed. This is necessary for hosts
* which use routing redirects generated by smart gateways
* to dynamically build the routing tables.
*/
if (rt == NULL || (rt_mask(rt) && rt_mask(rt)->sa_len < 2))
goto create;
/*
* Don't listen to the redirect if it's
* for a route to an interface.
*/
if (rt->rt_flags & RTF_GATEWAY) {
if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) {
/*
* Changing from route to net => route to host.
* Create new route, rather than smashing route to net.
*/
create:
if (rt)
rtfree(rt);
flags |= RTF_GATEWAY | RTF_DYNAMIC;
bzero((caddr_t)&info, sizeof(info));
info.rti_info[RTAX_DST] = dst;
info.rti_info[RTAX_GATEWAY] = gateway;
info.rti_info[RTAX_NETMASK] = netmask;
info.rti_ifa = ifa;
info.rti_flags = flags;
rt = NULL;
error = rtrequest1(RTM_ADD, &info, &rt);
if (rt != NULL) {
RT_LOCK(rt);
flags = rt->rt_flags;
}
stat = &rtstat.rts_dynamic;
} else {
/*
* Smash the current notion of the gateway to
* this destination. Should check about netmask!!!
*/
rt->rt_flags |= RTF_MODIFIED;
flags |= RTF_MODIFIED;
stat = &rtstat.rts_newgateway;
/*
* add the key and gateway (in one malloc'd chunk).
*/
rt_setgate(rt, rt_key(rt), gateway);
}
} else
error = EHOSTUNREACH;
done:
if (rt)
rtfree(rt);
out:
if (error)
rtstat.rts_badredirect++;
else if (stat != NULL)
(*stat)++;
bzero((caddr_t)&info, sizeof(info));
info.rti_info[RTAX_DST] = dst;
info.rti_info[RTAX_GATEWAY] = gateway;
info.rti_info[RTAX_NETMASK] = netmask;
info.rti_info[RTAX_AUTHOR] = src;
rt_missmsg(RTM_REDIRECT, &info, flags, error);
}
/*
* Routing table ioctl interface.
*/
int
rtioctl(u_long req, caddr_t data)
{
/*
* If more ioctl commands are added here, make sure the proper
* super-user checks are being performed because it is possible for
* prison-root to make it this far if raw sockets have been enabled
* in jails.
*/
#ifdef INET
/* Multicast goop, grrr... */
return mrt_ioctl ? mrt_ioctl(req, data) : EOPNOTSUPP;
#else /* INET */
return ENXIO;
#endif /* INET */
}
struct ifaddr *
ifa_ifwithroute(int flags, struct sockaddr *dst, struct sockaddr *gateway)
{
register struct ifaddr *ifa;
if ((flags & RTF_GATEWAY) == 0) {
/*
* If we are adding a route to an interface,
* and the interface is a pt to pt link
* we should search for the destination
* as our clue to the interface. Otherwise
* we can use the local address.
*/
ifa = NULL;
if (flags & RTF_HOST)
ifa = ifa_ifwithdstaddr(dst);
if (ifa == NULL)
ifa = ifa_ifwithaddr(gateway);
} else {
/*
* If we are adding a route to a remote net
* or host, the gateway may still be on the
* other end of a pt to pt link.
*/
ifa = ifa_ifwithdstaddr(gateway);
}
if (ifa == NULL)
ifa = ifa_ifwithnet(gateway);
if (ifa == NULL) {
struct rtentry *rt = rtalloc1(gateway, 0, 0UL);
if (rt == NULL)
return (NULL);
RT_REMREF(rt);
RT_UNLOCK(rt);
if ((ifa = rt->rt_ifa) == NULL)
return (NULL);
}
if (ifa->ifa_addr->sa_family != dst->sa_family) {
struct ifaddr *oifa = ifa;
ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp);
if (ifa == NULL)
ifa = oifa;
}
return (ifa);
}
static walktree_f_t rt_fixdelete;
static walktree_f_t rt_fixchange;
struct rtfc_arg {
struct rtentry *rt0;
struct radix_node_head *rnh;
};
/*
* Do appropriate manipulations of a routing tree given
* all the bits of info needed
*/
int
rtrequest(int req,
struct sockaddr *dst,
struct sockaddr *gateway,
struct sockaddr *netmask,
int flags,
struct rtentry **ret_nrt)
{
struct rt_addrinfo info;
bzero((caddr_t)&info, sizeof(info));
info.rti_flags = flags;
info.rti_info[RTAX_DST] = dst;
info.rti_info[RTAX_GATEWAY] = gateway;
info.rti_info[RTAX_NETMASK] = netmask;
return rtrequest1(req, &info, ret_nrt);
}
/*
* These (questionable) definitions of apparent local variables apply
* to the next two functions. XXXXXX!!!
*/
#define dst info->rti_info[RTAX_DST]
#define gateway info->rti_info[RTAX_GATEWAY]
#define netmask info->rti_info[RTAX_NETMASK]
#define ifaaddr info->rti_info[RTAX_IFA]
#define ifpaddr info->rti_info[RTAX_IFP]
#define flags info->rti_flags
int
rt_getifa(struct rt_addrinfo *info)
{
struct ifaddr *ifa;
int error = 0;
/*
* ifp may be specified by sockaddr_dl
* when protocol address is ambiguous.
*/
if (info->rti_ifp == NULL && ifpaddr != NULL &&
ifpaddr->sa_family == AF_LINK &&
(ifa = ifa_ifwithnet(ifpaddr)) != NULL)
info->rti_ifp = ifa->ifa_ifp;
if (info->rti_ifa == NULL && ifaaddr != NULL)
info->rti_ifa = ifa_ifwithaddr(ifaaddr);
if (info->rti_ifa == NULL) {
struct sockaddr *sa;
sa = ifaaddr != NULL ? ifaaddr :
(gateway != NULL ? gateway : dst);
if (sa != NULL && info->rti_ifp != NULL)
info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp);
else if (dst != NULL && gateway != NULL)
info->rti_ifa = ifa_ifwithroute(flags, dst, gateway);
else if (sa != NULL)
info->rti_ifa = ifa_ifwithroute(flags, sa, sa);
}
if ((ifa = info->rti_ifa) != NULL) {
if (info->rti_ifp == NULL)
info->rti_ifp = ifa->ifa_ifp;
} else
error = ENETUNREACH;
return (error);
}
/*
* Expunges references to a route that's about to be reclaimed.
* The route must be locked.
*/
int
rtexpunge(struct rtentry *rt)
{
struct radix_node *rn;
struct radix_node_head *rnh;
struct ifaddr *ifa;
int error = 0;
RT_LOCK_ASSERT(rt);
#if 0
/*
* We cannot assume anything about the reference count
* because protocols call us in many situations; often
* before unwinding references to the table entry.
*/
KASSERT(rt->rt_refcnt <= 1, ("bogus refcnt %ld", rt->rt_refcnt));
#endif
/*
* Find the correct routing tree to use for this Address Family
*/
rnh = rt_tables[rt_key(rt)->sa_family];
if (rnh == NULL)
return (EAFNOSUPPORT);
RADIX_NODE_HEAD_LOCK(rnh);
/*
* Remove the item from the tree; it should be there,
* but when callers invoke us blindly it may not (sigh).
*/
rn = rnh->rnh_deladdr(rt_key(rt), rt_mask(rt), rnh);
if (rn == NULL) {
error = ESRCH;
goto bad;
}
KASSERT((rn->rn_flags & (RNF_ACTIVE | RNF_ROOT)) == 0,
("unexpected flags 0x%x", rn->rn_flags));
KASSERT(rt == RNTORT(rn),
("lookup mismatch, rt %p rn %p", rt, rn));
rt->rt_flags &= ~RTF_UP;
/*
* Now search what's left of the subtree for any cloned
* routes which might have been formed from this node.
*/
if ((rt->rt_flags & RTF_CLONING) && rt_mask(rt))
rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
rt_fixdelete, rt);
/*
* Remove any external references we may have.
* This might result in another rtentry being freed if
* we held its last reference.
*/
if (rt->rt_gwroute) {
RTFREE(rt->rt_gwroute);
rt->rt_gwroute = NULL;
}
/*
* Give the protocol a chance to keep things in sync.
*/
if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest) {
struct rt_addrinfo info;
bzero((caddr_t)&info, sizeof(info));
info.rti_flags = rt->rt_flags;
info.rti_info[RTAX_DST] = rt_key(rt);
info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
info.rti_info[RTAX_NETMASK] = rt_mask(rt);
ifa->ifa_rtrequest(RTM_DELETE, rt, &info);
}
/*
* one more rtentry floating around that is not
* linked to the routing table.
*/
rttrash++;
bad:
RADIX_NODE_HEAD_UNLOCK(rnh);
return (error);
}
int
rtrequest1(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt)
{
int error = 0;
register struct rtentry *rt;
register struct radix_node *rn;
register struct radix_node_head *rnh;
struct ifaddr *ifa;
struct sockaddr *ndst;
#define senderr(x) { error = x ; goto bad; }
/*
* Find the correct routing tree to use for this Address Family
*/
rnh = rt_tables[dst->sa_family];
if (rnh == NULL)
return (EAFNOSUPPORT);
RADIX_NODE_HEAD_LOCK(rnh);
/*
* If we are adding a host route then we don't want to put
* a netmask in the tree, nor do we want to clone it.
*/
if (flags & RTF_HOST) {
netmask = NULL;
flags &= ~RTF_CLONING;
}
switch (req) {
case RTM_DELETE:
/*
* Remove the item from the tree and return it.
* Complain if it is not there and do no more processing.
*/
rn = rnh->rnh_deladdr(dst, netmask, rnh);
if (rn == NULL)
senderr(ESRCH);
if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
panic ("rtrequest delete");
rt = RNTORT(rn);
RT_LOCK(rt);
RT_ADDREF(rt);
rt->rt_flags &= ~RTF_UP;
/*
* Now search what's left of the subtree for any cloned
* routes which might have been formed from this node.
*/
if ((rt->rt_flags & RTF_CLONING) &&
rt_mask(rt)) {
rnh->rnh_walktree_from(rnh, dst, rt_mask(rt),
rt_fixdelete, rt);
}
/*
* Remove any external references we may have.
* This might result in another rtentry being freed if
* we held its last reference.
*/
if (rt->rt_gwroute) {
RTFREE(rt->rt_gwroute);
rt->rt_gwroute = NULL;
}
/*
* give the protocol a chance to keep things in sync.
*/
if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest)
ifa->ifa_rtrequest(RTM_DELETE, rt, info);
/*
* One more rtentry floating around that is not
* linked to the routing table. rttrash will be decremented
* when RTFREE(rt) is eventually called.
*/
rttrash++;
/*
* If the caller wants it, then it can have it,
* but it's up to it to free the rtentry as we won't be
* doing it.
*/
if (ret_nrt) {
*ret_nrt = rt;
RT_UNLOCK(rt);
} else
RTFREE_LOCKED(rt);
break;
case RTM_RESOLVE:
if (ret_nrt == NULL || (rt = *ret_nrt) == NULL)
senderr(EINVAL);
ifa = rt->rt_ifa;
/* XXX locking? */
flags = rt->rt_flags &
~(RTF_CLONING | RTF_STATIC);
flags |= RTF_WASCLONED;
gateway = rt->rt_gateway;
if ((netmask = rt->rt_genmask) == NULL)
flags |= RTF_HOST;
goto makeroute;
case RTM_ADD:
if ((flags & RTF_GATEWAY) && !gateway)
panic("rtrequest: GATEWAY but no gateway");
if (info->rti_ifa == NULL && (error = rt_getifa(info)))
senderr(error);
ifa = info->rti_ifa;
makeroute:
rt = uma_zalloc(rtzone, M_NOWAIT | M_ZERO);
if (rt == NULL)
senderr(ENOBUFS);
RT_LOCK_INIT(rt);
rt->rt_flags = RTF_UP | flags;
/*
* Add the gateway. Possibly re-malloc-ing the storage for it
* also add the rt_gwroute if possible.
*/
RT_LOCK(rt);
if ((error = rt_setgate(rt, dst, gateway)) != 0) {
RT_LOCK_DESTROY(rt);
uma_zfree(rtzone, rt);
senderr(error);
}
/*
* point to the (possibly newly malloc'd) dest address.
*/
ndst = (struct sockaddr *)rt_key(rt);
/*
* make sure it contains the value we want (masked if needed).
*/
if (netmask) {
rt_maskedcopy(dst, ndst, netmask);
} else
bcopy(dst, ndst, dst->sa_len);
/*
* Note that we now have a reference to the ifa.
* This moved from below so that rnh->rnh_addaddr() can
* examine the ifa and ifa->ifa_ifp if it so desires.
*/
IFAREF(ifa);
rt->rt_ifa = ifa;
rt->rt_ifp = ifa->ifa_ifp;
/* XXX mtu manipulation will be done in rnh_addaddr -- itojun */
rn = rnh->rnh_addaddr(ndst, netmask, rnh, rt->rt_nodes);
if (rn == NULL) {
struct rtentry *rt2;
/*
* Uh-oh, we already have one of these in the tree.
* We do a special hack: if the route that's already
* there was generated by the cloning mechanism
* then we just blow it away and retry the insertion
* of the new one.
*/
rt2 = rtalloc1(dst, 0, 0);
if (rt2 && rt2->rt_parent) {
rtexpunge(rt2);
RT_UNLOCK(rt2);
rn = rnh->rnh_addaddr(ndst, netmask,
rnh, rt->rt_nodes);
} else if (rt2) {
/* undo the extra ref we got */
RTFREE_LOCKED(rt2);
}
}
/*
* If it still failed to go into the tree,
* then un-make it (this should be a function)
*/
if (rn == NULL) {
if (rt->rt_gwroute)
RTFREE(rt->rt_gwroute);
if (rt->rt_ifa)
IFAFREE(rt->rt_ifa);
Free(rt_key(rt));
RT_LOCK_DESTROY(rt);
uma_zfree(rtzone, rt);
senderr(EEXIST);
}
rt->rt_parent = NULL;
/*
* If we got here from RESOLVE, then we are cloning
* so clone the rest, and note that we
* are a clone (and increment the parent's references)
*/
if (req == RTM_RESOLVE) {
KASSERT(ret_nrt && *ret_nrt,
("no route to clone from"));
rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */
rt->rt_rmx.rmx_pksent = 0; /* reset packet counter */
if ((*ret_nrt)->rt_flags & RTF_CLONING) {
/*
* NB: We do not bump the refcnt on the parent
* entry under the assumption that it will
* remain so long as we do. This is
* important when deleting the parent route
* as this operation requires traversing
* the tree to delete all clones and futzing
* with refcnts requires us to double-lock
* parent through this back reference.
*/
rt->rt_parent = *ret_nrt;
}
}
/*
* if this protocol has something to add to this then
* allow it to do that as well.
*/
if (ifa->ifa_rtrequest)
ifa->ifa_rtrequest(req, rt, info);
/*
* We repeat the same procedure from rt_setgate() here because
* it doesn't fire when we call it there because the node
* hasn't been added to the tree yet.
*/
if (req == RTM_ADD &&
!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != NULL) {
struct rtfc_arg arg;
arg.rnh = rnh;
arg.rt0 = rt;
rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
rt_fixchange, &arg);
}
/*
* actually return a resultant rtentry and
* give the caller a single reference.
*/
if (ret_nrt) {
*ret_nrt = rt;
RT_ADDREF(rt);
}
RT_UNLOCK(rt);
break;
default:
error = EOPNOTSUPP;
}
bad:
RADIX_NODE_HEAD_UNLOCK(rnh);
return (error);
#undef senderr
}
#undef dst
#undef gateway
#undef netmask
#undef ifaaddr
#undef ifpaddr
#undef flags
/*
* Called from rtrequest(RTM_DELETE, ...) to fix up the route's ``family''
* (i.e., the routes related to it by the operation of cloning). This
* routine is iterated over all potential former-child-routes by way of
* rnh->rnh_walktree_from() above, and those that actually are children of
* the late parent (passed in as VP here) are themselves deleted.
*/
static int
rt_fixdelete(struct radix_node *rn, void *vp)
{
struct rtentry *rt = RNTORT(rn);
struct rtentry *rt0 = vp;
if (rt->rt_parent == rt0 &&
!(rt->rt_flags & (RTF_PINNED | RTF_CLONING))) {
return rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt),
rt->rt_flags, NULL);
}
return 0;
}
/*
* This routine is called from rt_setgate() to do the analogous thing for
* adds and changes. There is the added complication in this case of a
* middle insert; i.e., insertion of a new network route between an older
* network route and (cloned) host routes. For this reason, a simple check
* of rt->rt_parent is insufficient; each candidate route must be tested
* against the (mask, value) of the new route (passed as before in vp)
* to see if the new route matches it.
*
* XXX - it may be possible to do fixdelete() for changes and reserve this
* routine just for adds. I'm not sure why I thought it was necessary to do
* changes this way.
*/
static int
rt_fixchange(struct radix_node *rn, void *vp)
{
struct rtentry *rt = RNTORT(rn);
struct rtfc_arg *ap = vp;
struct rtentry *rt0 = ap->rt0;
struct radix_node_head *rnh = ap->rnh;
u_char *xk1, *xm1, *xk2, *xmp;
int i, len, mlen;
/* make sure we have a parent, and route is not pinned or cloning */
if (!rt->rt_parent ||
(rt->rt_flags & (RTF_PINNED | RTF_CLONING)))
return 0;
if (rt->rt_parent == rt0) /* parent match */
goto delete_rt;
/*
* There probably is a function somewhere which does this...
* if not, there should be.
*/
len = imin(rt_key(rt0)->sa_len, rt_key(rt)->sa_len);
xk1 = (u_char *)rt_key(rt0);
xm1 = (u_char *)rt_mask(rt0);
xk2 = (u_char *)rt_key(rt);
/* avoid applying a less specific route */
xmp = (u_char *)rt_mask(rt->rt_parent);
mlen = rt_key(rt->rt_parent)->sa_len;
if (mlen > rt_key(rt0)->sa_len) /* less specific route */
return 0;
for (i = rnh->rnh_treetop->rn_offset; i < mlen; i++)
if ((xmp[i] & ~(xmp[i] ^ xm1[i])) != xmp[i])
return 0; /* less specific route */
for (i = rnh->rnh_treetop->rn_offset; i < len; i++)
if ((xk2[i] & xm1[i]) != xk1[i])
return 0; /* no match */
/*
* OK, this node is a clone, and matches the node currently being
* changed/added under the node's mask. So, get rid of it.
*/
delete_rt:
return rtrequest(RTM_DELETE, rt_key(rt), NULL,
rt_mask(rt), rt->rt_flags, NULL);
}
int
rt_setgate(struct rtentry *rt, struct sockaddr *dst, struct sockaddr *gate)
{
/* XXX dst may be overwritten, can we move this to below */
struct radix_node_head *rnh = rt_tables[dst->sa_family];
int dlen = SA_SIZE(dst), glen = SA_SIZE(gate);
RT_LOCK_ASSERT(rt);
/*
* A host route with the destination equal to the gateway
* will interfere with keeping LLINFO in the routing
* table, so disallow it.
*/
if (((rt->rt_flags & (RTF_HOST|RTF_GATEWAY|RTF_LLINFO)) ==
(RTF_HOST|RTF_GATEWAY)) &&
dst->sa_len == gate->sa_len &&
bcmp(dst, gate, dst->sa_len) == 0) {
/*
* The route might already exist if this is an RTM_CHANGE
* or a routing redirect, so try to delete it.
*/
if (rt_key(rt))
rtexpunge(rt);
return EADDRNOTAVAIL;
}
/*
* Prepare to store the gateway in rt->rt_gateway.
* Both dst and gateway are stored one after the other in the same
* malloc'd chunk. If we have room, we can reuse the old buffer,
* rt_gateway already points to the right place.
* Otherwise, malloc a new block and update the 'dst' address.
*/
if (rt->rt_gateway == NULL || glen > SA_SIZE(rt->rt_gateway)) {
caddr_t new;
R_Malloc(new, caddr_t, dlen + glen);
if (new == NULL)
return ENOBUFS;
/*
* XXX note, we copy from *dst and not *rt_key(rt) because
* rt_setgate() can be called to initialize a newly
* allocated route entry, in which case rt_key(rt) == NULL
* (and also rt->rt_gateway == NULL).
* Free()/free() handle a NULL argument just fine.
*/
bcopy(dst, new, dlen);
Free(rt_key(rt)); /* free old block, if any */
rt_key(rt) = (struct sockaddr *)new;
rt->rt_gateway = (struct sockaddr *)(new + dlen);
}
/*
* Copy the new gateway value into the memory chunk.
*/
bcopy(gate, rt->rt_gateway, glen);
/*
* If there is already a gwroute, it's now almost definitly wrong
* so drop it.
*/
if (rt->rt_gwroute != NULL) {
RTFREE(rt->rt_gwroute);
rt->rt_gwroute = NULL;
}
/*
* Cloning loop avoidance:
* In the presence of protocol-cloning and bad configuration,
* it is possible to get stuck in bottomless mutual recursion
* (rtrequest rt_setgate rtalloc1). We avoid this by not allowing
* protocol-cloning to operate for gateways (which is probably the
* correct choice anyway), and avoid the resulting reference loops
* by disallowing any route to run through itself as a gateway.
* This is obviously mandatory when we get rt->rt_output().
* XXX: After removal of PRCLONING this is probably not needed anymore.
*/
if (rt->rt_flags & RTF_GATEWAY) {
struct rtentry *gwrt;
RT_UNLOCK(rt); /* XXX workaround LOR */
gwrt = rtalloc1(gate, 1, 0);
RT_LOCK(rt);
rt->rt_gwroute = gwrt;
if (rt->rt_gwroute == rt) {
RTFREE_LOCKED(rt->rt_gwroute);
rt->rt_gwroute = NULL;
return EDQUOT; /* failure */
}
if (rt->rt_gwroute != NULL)
RT_UNLOCK(rt->rt_gwroute);
}
/*
* This isn't going to do anything useful for host routes, so
* don't bother. Also make sure we have a reasonable mask
* (we don't yet have one during adds).
*/
if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) {
struct rtfc_arg arg;
arg.rnh = rnh;
arg.rt0 = rt;
RT_UNLOCK(rt); /* XXX workaround LOR */
RADIX_NODE_HEAD_LOCK(rnh);
RT_LOCK(rt);
rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
rt_fixchange, &arg);
RADIX_NODE_HEAD_UNLOCK(rnh);
}
return 0;
}
static void
rt_maskedcopy(struct sockaddr *src, struct sockaddr *dst, struct sockaddr *netmask)
{
register u_char *cp1 = (u_char *)src;
register u_char *cp2 = (u_char *)dst;
register u_char *cp3 = (u_char *)netmask;
u_char *cplim = cp2 + *cp3;
u_char *cplim2 = cp2 + *cp1;
*cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */
cp3 += 2;
if (cplim > cplim2)
cplim = cplim2;
while (cp2 < cplim)
*cp2++ = *cp1++ & *cp3++;
if (cp2 < cplim2)
bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2));
}
/*
* Set up a routing table entry, normally
* for an interface.
*/
int
rtinit(struct ifaddr *ifa, int cmd, int flags)
{
struct sockaddr *dst;
struct sockaddr *netmask;
struct mbuf *m = NULL;
struct rtentry *rt = NULL;
struct rt_addrinfo info;
int error;
if (flags & RTF_HOST) {
dst = ifa->ifa_dstaddr;
netmask = NULL;
} else {
dst = ifa->ifa_addr;
netmask = ifa->ifa_netmask;
}
/*
* If it's a delete, check that if it exists, it's on the correct
* interface or we might scrub a route to another ifa which would
* be confusing at best and possibly worse.
*/
if (cmd == RTM_DELETE) {
struct sockaddr *deldst;
struct radix_node_head *rnh;
struct radix_node *rn;
/*
* It's a delete, so it should already exist..
* If it's a net, mask off the host bits
* (Assuming we have a mask)
*/
if (netmask != NULL) {
m = m_get(M_DONTWAIT, MT_SONAME);
if (m == NULL)
return(ENOBUFS);
deldst = mtod(m, struct sockaddr *);
rt_maskedcopy(dst, deldst, netmask);
dst = deldst;
}
/*
* Look up an rtentry that is in the routing tree and
* contains the correct info.
*/
if ((rnh = rt_tables[dst->sa_family]) == NULL)
goto bad;
RADIX_NODE_HEAD_LOCK(rnh);
error = ((rn = rnh->rnh_lookup(dst, netmask, rnh)) == NULL ||
(rn->rn_flags & RNF_ROOT) ||
RNTORT(rn)->rt_ifa != ifa ||
!sa_equal((struct sockaddr *)rn->rn_key, dst));
RADIX_NODE_HEAD_UNLOCK(rnh);
if (error) {
bad:
if (m)
(void) m_free(m);
return (flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
}
}
/*
* Do the actual request
*/
bzero((caddr_t)&info, sizeof(info));
info.rti_ifa = ifa;
info.rti_flags = flags | ifa->ifa_flags;
info.rti_info[RTAX_DST] = dst;
info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr;
info.rti_info[RTAX_NETMASK] = netmask;
error = rtrequest1(cmd, &info, &rt);
if (error == 0 && rt != NULL) {
/*
* notify any listening routing agents of the change
*/
RT_LOCK(rt);
rt_newaddrmsg(cmd, ifa, error, rt);
if (cmd == RTM_DELETE) {
/*
* If we are deleting, and we found an entry, then
* it's been removed from the tree.. now throw it away.
*/
RTFREE_LOCKED(rt);
} else {
if (cmd == RTM_ADD) {
/*
* We just wanted to add it.. we don't actually
* need a reference.
*/
RT_REMREF(rt);
}
RT_UNLOCK(rt);
}
}
if (m)
(void) m_free(m);
return (error);
}
/*
* rt_check() is invoked on each layer 2 output path, prior to
* encapsulating outbound packets.
*
* The function is mostly used to find a routing entry for the gateway,
* which in some protocol families could also point to the link-level
* address for the gateway itself (the side effect of revalidating the
* route to the destination is rather pointless at this stage, we did it
* already a moment before in the pr_output() routine to locate the ifp
* and gateway to use).
*
* When we remove the layer-3 to layer-2 mapping tables from the
* routing table, this function can be removed.
*
* === On input ===
* *dst is the address of the NEXT HOP (which coincides with the
* final destination if directly reachable);
* *lrt0 points to the cached route to the final destination;
* *lrt is not meaningful;
*
* === Operation ===
* If the route is marked down try to find a new route. If the route
* to the gateway is gone, try to setup a new route. Otherwise,
* if the route is marked for packets to be rejected, enforce that.
*
* === On return ===
* *dst is unchanged;
* *lrt0 points to the (possibly new) route to the final destination
* *lrt points to the route to the next hop
*
* Their values are meaningful ONLY if no error is returned.
*/
int
rt_check(struct rtentry **lrt, struct rtentry **lrt0, struct sockaddr *dst)
{
#define senderr(x) { error = x ; goto bad; }
struct rtentry *rt;
struct rtentry *rt0;
int error;
rt0 = *lrt0;
rt = rt0;
if (rt) {
/* NB: the locking here is tortuous... */
RT_LOCK(rt);
if ((rt->rt_flags & RTF_UP) == 0) {
RT_UNLOCK(rt);
rt = rtalloc1(dst, 1, 0UL);
if (rt != NULL) {
RT_REMREF(rt);
/* XXX what about if change? */
} else
senderr(EHOSTUNREACH);
rt0 = rt;
}
/* XXX BSD/OS checks dst->sa_family != AF_NS */
if (rt->rt_flags & RTF_GATEWAY) {
if (rt->rt_gwroute == NULL)
goto lookup;
rt = rt->rt_gwroute;
RT_LOCK(rt); /* NB: gwroute */
if ((rt->rt_flags & RTF_UP) == 0) {
rtfree(rt); /* unlock gwroute */
rt = rt0;
lookup:
RT_UNLOCK(rt0);
rt = rtalloc1(rt->rt_gateway, 1, 0UL);
RT_LOCK(rt0);
rt0->rt_gwroute = rt;
if (rt == NULL) {
RT_UNLOCK(rt0);
senderr(EHOSTUNREACH);
}
}
RT_UNLOCK(rt0);
}
/* XXX why are we inspecting rmx_expire? */
error = (rt->rt_flags & RTF_REJECT) &&
(rt->rt_rmx.rmx_expire == 0 ||
time_second < rt->rt_rmx.rmx_expire);
RT_UNLOCK(rt);
if (error)
senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
}
*lrt = rt; /* NB: return unlocked */
*lrt0 = rt0;
return (0);
bad:
/* NB: lrt and lrt0 should not be interpreted if error is non-zero */
return (error);
#undef senderr
}
/* This must be before ip6_init2(), which is now SI_ORDER_MIDDLE */
SYSINIT(route, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, route_init, 0);