mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-24 11:29:10 +00:00
Code Issues Releases Activity
ebfcca3d61
freebsd/sys/net/route.c
Christian S.J. Peron 5090559b7f When a prison is given the ability to create raw sockets (when the 
security.jail.allow_raw_sockets sysctl MIB is set to 1) where privileged
access to jails is given out, it is possible for prison root to manipulate
various network parameters which effect the host environment. This commit
plugs a number of security holes associated with the use of raw sockets
and prisons.

This commit makes the following changes:

- Add a comment to rtioctl warning developers that if they add
  any ioctl commands, they should use super-user checks where necessary,
  as it is possible for PRISON root to make it this far in execution.
- Add super-user checks for the execution of the SIOCGETVIFCNT
  and SIOCGETSGCNT IP multicast ioctl commands.
- Add a super-user check to rip_ctloutput(). If the calling cred
  is PRISON root, make sure the socket option name is IP_HDRINCL,
  otherwise deny the request.

Although this patch corrects a number of security problems associated
with raw sockets and prisons, the warning in jail(8) should still
apply, and by default we should keep the default value of
security.jail.allow_raw_sockets MIB to 0 (or disabled) until
we are certain that we have tracked down all the problems.

Looking forward, we will probably want to eliminate the
references to curthread.

This may be a MFC candidate for RELENG_5.

Reviewed by:	rwatson
Approved by:	bmilekic (mentor)
2004-08-21 17:38:57 +00:00

1317 lines
34 KiB
C
Raw Blame History

/*
* 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
* $FreeBSD$
*/
#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);
Reference in New Issue View Git Blame Copy Permalink