freebsd-dev/sys/net/route.c
Julian Elischer b0a76b8898 No code changes what so ever, but added about 150 lines of comments
Sorry if this makes it harder to merge in lite2 stuff but hey..
At least I can figure out what is going on whenever I end up going through those
files again..

do we have a policy regarding commenting existing code?
1996-09-10 07:10:05 +00:00

960 lines
25 KiB
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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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 8.2 (Berkeley) 11/15/93
* $Id: route.c,v 1.36 1996/09/02 02:49:40 fenner Exp $
*/
#include "opt_mrouting.h"
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/route.h>
#include <net/raw_cb.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip_mroute.h>
#define SA(p) ((struct sockaddr *)(p))
struct route_cb route_cb;
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 __P((struct sockaddr *,
struct sockaddr *, struct sockaddr *));
static void rtable_init __P((void **));
static void
rtable_init(table)
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);
}
void
route_init()
{
rn_init(); /* initialize all zeroes, all ones, mask table */
rtable_init((void **)rt_tables);
}
/*
* Packet routing routines.
*/
void
rtalloc(ro)
register struct route *ro;
{
if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP))
return; /* XXX */
ro->ro_rt = rtalloc1(&ro->ro_dst, 1, 0UL);
}
void
rtalloc_ign(ro, ignore)
register struct route *ro;
u_long ignore;
{
if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP))
return; /* XXX */
ro->ro_rt = rtalloc1(&ro->ro_dst, 1, ignore);
}
/*
* Look up the route that matches the address given
* Or, at least try.. Create a cloned route if needed.
*/
struct rtentry *
rtalloc1(dst, report, ignflags)
register struct sockaddr *dst;
int report;
u_long ignflags;
{
register struct radix_node_head *rnh = rt_tables[dst->sa_family];
register struct rtentry *rt;
register struct radix_node *rn;
struct rtentry *newrt = 0;
struct rt_addrinfo info;
u_long nflags;
int s = splnet(), err = 0, msgtype = RTM_MISS;
/*
* Look up the address in the table for that Address Family
*/
if (rnh && (rn = rnh->rnh_matchaddr((caddr_t)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 = (struct rtentry *)rn;
nflags = rt->rt_flags & ~ignflags;
if (report && (nflags & (RTF_CLONING | RTF_PRCLONING))) {
/*
* 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, SA(0),
SA(0), 0, &newrt);
if (err) {
/*
* If the cloning didn't succeed, maybe
* what we have will do. Return that.
*/
newrt = rt;
rt->rt_refcnt++;
goto miss;
}
if ((rt = newrt) && (rt->rt_flags & RTF_XRESOLVE)) {
/*
* If the new route specifies it be
* externally resolved, then go do that.
*/
msgtype = RTM_RESOLVE;
goto miss;
}
} else
rt->rt_refcnt++;
} else {
/*
* Either we hit the root or couldn't find any match,
* Which basically means
* "caint get there frm here"
*/
rtstat.rts_unreach++;
miss: if (report) {
/*
* If required, report the failure to the supervising
* Authorities.
* For a delete, this is not an error. (report == 0)
*/
bzero((caddr_t)&info, sizeof(info));
info.rti_info[RTAX_DST] = dst;
rt_missmsg(msgtype, &info, 0, err);
}
}
splx(s);
return (newrt);
}
void
rtfree(rt)
register struct rtentry *rt;
{
register struct radix_node_head *rnh =
rt_tables[rt_key(rt)->sa_family];
register struct ifaddr *ifa;
if (rt == 0 || rnh == 0)
panic("rtfree");
rt->rt_refcnt--;
if(rnh->rnh_close && rt->rt_refcnt == 0) {
rnh->rnh_close((struct radix_node *)rt, rnh);
}
if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_UP) == 0) {
if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT))
panic ("rtfree 2");
rttrash--;
if (rt->rt_refcnt < 0) {
printf("rtfree: %p not freed (neg refs)\n", rt);
return;
}
ifa = rt->rt_ifa;
IFAFREE(ifa);
if (rt->rt_parent) {
RTFREE(rt->rt_parent);
}
Free(rt_key(rt));
Free(rt);
}
}
void
ifafree(ifa)
register struct ifaddr *ifa;
{
if (ifa == NULL)
panic("ifafree");
if (ifa->ifa_refcnt == 0)
free(ifa, M_IFADDR);
else
ifa->ifa_refcnt--;
}
/*
* 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.
*
* N.B.: must be called at splnet
*
*/
void
rtredirect(dst, gateway, netmask, flags, src, rtp)
struct sockaddr *dst, *gateway, *netmask, *src;
int flags;
struct rtentry **rtp;
{
register struct rtentry *rt;
int error = 0;
short *stat = 0;
struct rt_addrinfo info;
struct ifaddr *ifa;
/* verify the gateway is directly reachable */
if ((ifa = ifa_ifwithnet(gateway)) == 0) {
error = ENETUNREACH;
goto out;
}
rt = rtalloc1(dst, 0, 0UL);
/*
* 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.
*/
#define equal(a1, a2) (bcmp((caddr_t)(a1), (caddr_t)(a2), (a1)->sa_len) == 0)
if (!(flags & RTF_DONE) && rt &&
(!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 == 0) || (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:
flags |= RTF_GATEWAY | RTF_DYNAMIC;
error = rtrequest((int)RTM_ADD, dst, gateway,
netmask, flags,
(struct rtentry **)0);
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;
rt_setgate(rt, rt_key(rt), gateway);
}
} else
error = EHOSTUNREACH;
done:
if (rt) {
if (rtp && !error)
*rtp = rt;
else
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(req, data, p)
int req;
caddr_t data;
struct proc *p;
{
#ifdef INET
/* Multicast goop, grrr... */
#ifdef MROUTING
return mrt_ioctl(req, data);
#else
return mrt_ioctl(req, data, p);
#endif
#else /* INET */
return ENXIO;
#endif /* INET */
}
struct ifaddr *
ifa_ifwithroute(flags, dst, gateway)
int flags;
struct sockaddr *dst, *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 = 0;
if (flags & RTF_HOST) {
ifa = ifa_ifwithdstaddr(dst);
}
if (ifa == 0)
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 == 0)
ifa = ifa_ifwithnet(gateway);
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;
}
return (ifa);
}
#define ROUNDUP(a) (a>0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
static int rt_fixdelete(struct radix_node *, void *);
static int rt_fixchange(struct radix_node *, void *);
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(req, dst, gateway, netmask, flags, ret_nrt)
int req, flags;
struct sockaddr *dst, *gateway, *netmask;
struct rtentry **ret_nrt;
{
int s = splnet(); 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
*/
if ((rnh = rt_tables[dst->sa_family]) == 0)
senderr(ESRCH);
/*
* If we are adding a host route then we don't want to put
* a netmask in the tree
*/
if (flags & RTF_HOST)
netmask = 0;
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.
*/
if ((rn = rnh->rnh_deladdr(dst, netmask, rnh)) == 0)
senderr(ESRCH);
if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
panic ("rtrequest delete");
rt = (struct rtentry *)rn;
/*
* 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_PRCLONING) && netmask) {
rnh->rnh_walktree_from(rnh, dst, netmask,
rt_fixdelete, rt);
}
/*
* Remove any external references we may have.
* This might result in another rtentry being freed if
* we held it's last reference.
*/
if (rt->rt_gwroute) {
rt = rt->rt_gwroute;
RTFREE(rt);
(rt = (struct rtentry *)rn)->rt_gwroute = 0;
}
/*
* NB: RTF_UP must be set during the search above,
* because we might delete the last ref, causing
* rt to get freed prematurely.
*/
rt->rt_flags &= ~RTF_UP;
/*
* If there is llinfo or similar associated with the
* route, give the interface a chance to deal with it..
*/
if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest)
ifa->ifa_rtrequest(RTM_DELETE, rt, SA(0));
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;
else if (rt->rt_refcnt <= 0) {
rt->rt_refcnt++; /* make a 1->0 transition */
rtfree(rt);
}
break;
case RTM_RESOLVE:
if (ret_nrt == 0 || (rt = *ret_nrt) == 0)
senderr(EINVAL);
ifa = rt->rt_ifa;
flags = rt->rt_flags &
~(RTF_CLONING | RTF_PRCLONING | RTF_STATIC);
flags |= RTF_WASCLONED;
gateway = rt->rt_gateway;
if ((netmask = rt->rt_genmask) == 0)
flags |= RTF_HOST;
goto makeroute;
case RTM_ADD:
if ((flags & RTF_GATEWAY) && !gateway)
panic("rtrequest: GATEWAY but no gateway");
if ((ifa = ifa_ifwithroute(flags, dst, gateway)) == 0)
senderr(ENETUNREACH);
makeroute:
R_Malloc(rt, struct rtentry *, sizeof(*rt));
if (rt == 0)
senderr(ENOBUFS);
Bzero(rt, sizeof(*rt));
rt->rt_flags = RTF_UP | flags;
if (error = rt_setgate(rt, dst, gateway)) {
Free(rt);
senderr(error);
}
ndst = rt_key(rt);
if (netmask) {
rt_maskedcopy(dst, ndst, netmask);
} else
Bcopy(dst, ndst, dst->sa_len);
/*
* This moved from below so that rnh->rnh_addaddr() can
* examine the ifa and ifp if it so desires.
*/
ifa->ifa_refcnt++;
rt->rt_ifa = ifa;
rt->rt_ifp = ifa->ifa_ifp;
rn = rnh->rnh_addaddr((caddr_t)ndst, (caddr_t)netmask,
rnh, rt->rt_nodes);
if (rn == 0) {
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 protocol-cloning
* mechanism, then we just blow it away and retry
* the insertion of the new one.
*/
rt2 = rtalloc1(dst, 0, RTF_PRCLONING);
if (rt2 && rt2->rt_parent) {
rtrequest(RTM_DELETE,
(struct sockaddr *)rt_key(rt2),
rt2->rt_gateway,
rt_mask(rt2), rt2->rt_flags, 0);
RTFREE(rt2);
rn = rnh->rnh_addaddr((caddr_t)ndst,
(caddr_t)netmask,
rnh, rt->rt_nodes);
} else if (rt2) {
RTFREE(rt2);
}
}
if (rn == 0) {
if (rt->rt_gwroute)
rtfree(rt->rt_gwroute);
if (rt->rt_ifa) {
IFAFREE(rt->rt_ifa);
}
Free(rt_key(rt));
Free(rt);
senderr(EEXIST);
}
rt->rt_parent = 0;
if (req == RTM_RESOLVE) {
rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */
if ((*ret_nrt)->rt_flags & RTF_PRCLONING) {
rt->rt_parent = (*ret_nrt);
(*ret_nrt)->rt_refcnt++;
}
}
if (ifa->ifa_rtrequest)
ifa->ifa_rtrequest(req, rt, SA(ret_nrt ? *ret_nrt : 0));
/*
* 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 (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) {
struct rtfc_arg arg;
arg.rnh = rnh;
arg.rt0 = rt;
rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
rt_fixchange, &arg);
}
if (ret_nrt) {
*ret_nrt = rt;
rt->rt_refcnt++;
}
break;
}
bad:
splx(s);
return (error);
}
/*
* 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 = (struct rtentry *)rn;
struct rtentry *rt0 = vp;
if (rt->rt_parent == rt0 && !(rt->rt_flags & RTF_PINNED)) {
return rtrequest(RTM_DELETE, rt_key(rt),
(struct sockaddr *)0, rt_mask(rt),
rt->rt_flags, (struct rtentry **)0);
}
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. Unfortunately, this has the obnoxious
* property of also triggering for insertion /above/ a pre-existing network
* route and clones. Sigh. This may be fixed some day.
*
* 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.
*/
#ifdef DEBUG
int rtfcdebug = 0;
#endif
static int
rt_fixchange(struct radix_node *rn, void *vp)
{
struct rtentry *rt = (struct rtentry *)rn;
struct rtfc_arg *ap = vp;
struct rtentry *rt0 = ap->rt0;
struct radix_node_head *rnh = ap->rnh;
u_char *xk1, *xm1, *xk2;
int i, len;
#ifdef DEBUG
if (rtfcdebug)
printf("rt_fixchange: rt %p, rt0 %p\n", rt, rt0);
#endif
if (!rt->rt_parent || (rt->rt_flags & RTF_PINNED)) {
#ifdef DEBUG
if(rtfcdebug) printf("no parent or pinned\n");
#endif
return 0;
}
if (rt->rt_parent == rt0) {
#ifdef DEBUG
if(rtfcdebug) printf("parent match\n");
#endif
return rtrequest(RTM_DELETE, rt_key(rt),
(struct sockaddr *)0, rt_mask(rt),
rt->rt_flags, (struct rtentry **)0);
}
/*
* There probably is a function somewhere which does this...
* if not, there should be.
*/
len = imin(((struct sockaddr *)rt_key(rt0))->sa_len,
((struct sockaddr *)rt_key(rt))->sa_len);
xk1 = (u_char *)rt_key(rt0);
xm1 = (u_char *)rt_mask(rt0);
xk2 = (u_char *)rt_key(rt);
for (i = rnh->rnh_treetop->rn_off; i < len; i++) {
if ((xk2[i] & xm1[i]) != xk1[i]) {
#ifdef DEBUG
if(rtfcdebug) printf("no match\n");
#endif
return 0;
}
}
/*
* OK, this node is a clone, and matches the node currently being
* changed/added under the node's mask. So, get rid of it.
*/
#ifdef DEBUG
if(rtfcdebug) printf("deleting\n");
#endif
return rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0,
rt_mask(rt), rt->rt_flags, (struct rtentry **)0);
}
int
rt_setgate(rt0, dst, gate)
struct rtentry *rt0;
struct sockaddr *dst, *gate;
{
caddr_t new, old;
int dlen = ROUNDUP(dst->sa_len), glen = ROUNDUP(gate->sa_len);
register struct rtentry *rt = rt0;
struct radix_node_head *rnh = rt_tables[dst->sa_family];
/*
* A host route with the destination equal to the gateway
* will interfere with keeping LLINFO in the routing
* table, so disallow it.
*/
if (((rt0->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(rt0))
rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt0),
rt0->rt_gateway, rt_mask(rt0), rt0->rt_flags, 0);
return EADDRNOTAVAIL;
}
if (rt->rt_gateway == 0 || glen > ROUNDUP(rt->rt_gateway->sa_len)) {
old = (caddr_t)rt_key(rt);
R_Malloc(new, caddr_t, dlen + glen);
if (new == 0)
return ENOBUFS;
rt->rt_nodes->rn_key = new;
} else {
new = rt->rt_nodes->rn_key;
old = 0;
}
Bcopy(gate, (rt->rt_gateway = (struct sockaddr *)(new + dlen)), glen);
if (old) {
Bcopy(dst, new, dlen);
Free(old);
}
if (rt->rt_gwroute) {
rt = rt->rt_gwroute; RTFREE(rt);
rt = rt0; rt->rt_gwroute = 0;
}
/*
* 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 obviuosly mandatory when we get rt->rt_output().
*/
if (rt->rt_flags & RTF_GATEWAY) {
rt->rt_gwroute = rtalloc1(gate, 1, RTF_PRCLONING);
if (rt->rt_gwroute == rt) {
RTFREE(rt->rt_gwroute);
rt->rt_gwroute = 0;
return EDQUOT; /* failure */
}
}
/*
* 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;
rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt),
rt_fixchange, &arg);
}
return 0;
}
static void
rt_maskedcopy(src, dst, netmask)
struct sockaddr *src, *dst, *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(ifa, cmd, flags)
register struct ifaddr *ifa;
int cmd, flags;
{
register struct rtentry *rt;
register struct sockaddr *dst;
register struct sockaddr *deldst;
struct mbuf *m = 0;
struct rtentry *nrt = 0;
int error;
dst = flags & RTF_HOST ? ifa->ifa_dstaddr : ifa->ifa_addr;
/*
* 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) {
/*
* 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 ((flags & RTF_HOST) == 0 && ifa->ifa_netmask) {
m = m_get(M_WAIT, MT_SONAME);
deldst = mtod(m, struct sockaddr *);
rt_maskedcopy(dst, deldst, ifa->ifa_netmask);
dst = deldst;
}
/*
* Get an rtentry that is in the routing tree and
* contains the correct info. (if this fails we can't get there).
* We set "report" to FALSE so that if it doesn't exist,
* it doesn't report an error or clone a route, etc. etc.
*/
rt = rtalloc1(dst, 0, 0UL);
if (rt) {
/*
* Ok so we found the rtentry. it has an extra reference
* for us at this stage. we won't need that so
* lop that off now.
*/
rt->rt_refcnt--;
if (rt->rt_ifa != ifa) {
/*
* If the interface in the rtentry doesn't match
* the interface we are using, then we don't
* want to delete it, so return an error.
* This seems to be the only point of
* this whole RTM_DELETE clause.
*/
if (m)
(void) m_free(m);
return (flags & RTF_HOST ? EHOSTUNREACH
: ENETUNREACH);
}
}
/* XXX */
#if 0
else {
/*
* One would think that as we are deleting, and we know
* it doesn't exist, we could just return at this point
* with an "ELSE" clause, but apparently not..
*/
return (flags & RTF_HOST ? EHOSTUNREACH
: ENETUNREACH);
}
#endif
}
/*
* Do the actual request
*/
error = rtrequest(cmd, dst, ifa->ifa_addr, ifa->ifa_netmask,
flags | ifa->ifa_flags, &nrt);
if (m)
(void) m_free(m);
/*
* If we are deleting, and we found an entry, then
* it's been removed from the tree.. now throw it away.
*/
if (cmd == RTM_DELETE && error == 0 && (rt = nrt)) {
/*
* notify any listenning routing agents of the change
*/
rt_newaddrmsg(cmd, ifa, error, nrt);
if (rt->rt_refcnt <= 0) {
rt->rt_refcnt++; /* need a 1->0 transition to free */
rtfree(rt);
}
}
/*
* We are adding, and we have a returned routing entry.
* We need to sanity check the result.
*/
if (cmd == RTM_ADD && error == 0 && (rt = nrt)) {
/*
* We just wanted to add it.. we don't actually need a reference
*/
rt->rt_refcnt--;
/*
* If it came back with an unexpected interface, then it must
* have already existed or something. (XXX)
*/
if (rt->rt_ifa != ifa) {
printf("rtinit: wrong ifa (%p) was (%p)\n", ifa,
rt->rt_ifa);
/*
* Ask that the route we got back be removed
* from the routing tables as we are trying
* to supersede it.
*/
if (rt->rt_ifa->ifa_rtrequest)
rt->rt_ifa->ifa_rtrequest(RTM_DELETE, rt, SA(0));
/*
* Remove the referenve to the it's ifaddr.
*/
IFAFREE(rt->rt_ifa);
/*
* And substitute in references to the ifaddr
* we are adding.
*/
rt->rt_ifa = ifa;
rt->rt_ifp = ifa->ifa_ifp;
ifa->ifa_refcnt++;
/*
* Now add it to the routing table
* XXX could we have just left it?
* as it might have been in the right place..
*/
if (ifa->ifa_rtrequest)
ifa->ifa_rtrequest(RTM_ADD, rt, SA(0));
}
/*
* notify any listenning routing agents of the change
*/
rt_newaddrmsg(cmd, ifa, error, nrt);
}
return (error);
}