4.4BSD/usr/src/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.
* 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 8.1 (Berkeley) 6/11/93
*/
#include <sys/param.h>
#include <sys/systm.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/af.h>
#include <net/route.h>
#include <net/raw_cb.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#ifdef NS
#include <netns/ns.h>
#endif
#define SA(p) ((struct sockaddr *)(p))
int rttrash; /* routes not in table but not freed */
struct sockaddr wildcard; /* zero valued cookie for wildcard searches */
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);
}
struct rtentry *
rtalloc1(dst, report)
register struct sockaddr *dst;
int report;
{
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;
int s = splnet(), err = 0, msgtype = RTM_MISS;
if (rnh && (rn = rnh->rnh_matchaddr((caddr_t)dst, rnh)) &&
((rn->rn_flags & RNF_ROOT) == 0)) {
newrt = rt = (struct rtentry *)rn;
if (report && (rt->rt_flags & RTF_CLONING)) {
err = rtrequest(RTM_RESOLVE, dst, SA(0),
SA(0), 0, &newrt);
if (err) {
newrt = rt;
rt->rt_refcnt++;
goto miss;
}
if ((rt = newrt) && (rt->rt_flags & RTF_XRESOLVE)) {
msgtype = RTM_RESOLVE;
goto miss;
}
} else
rt->rt_refcnt++;
} else {
rtstat.rts_unreach++;
miss: if (report) {
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 ifaddr *ifa;
if (rt == 0)
panic("rtfree");
rt->rt_refcnt--;
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: %x not freed (neg refs)\n", rt);
return;
}
ifa = rt->rt_ifa;
IFAFREE(ifa);
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
*
*/
int
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);
/*
* 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;
{
return (EOPNOTSUPP);
}
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);
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))
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; }
if ((rnh = rt_tables[dst->sa_family]) == 0)
senderr(ESRCH);
if (flags & RTF_HOST)
netmask = 0;
switch (req) {
case RTM_DELETE:
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;
rt->rt_flags &= ~RTF_UP;
if (rt->rt_gwroute) {
rt = rt->rt_gwroute; RTFREE(rt);
(rt = (struct rtentry *)rn)->rt_gwroute = 0;
}
if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest)
ifa->ifa_rtrequest(RTM_DELETE, rt, SA(0));
rttrash++;
if (ret_nrt)
*ret_nrt = rt;
else if (rt->rt_refcnt <= 0) {
rt->rt_refcnt++;
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;
gateway = rt->rt_gateway;
if ((netmask = rt->rt_genmask) == 0)
flags |= RTF_HOST;
goto makeroute;
case RTM_ADD:
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 (rt_setgate(rt, dst, gateway)) {
Free(rt);
senderr(ENOBUFS);
}
ndst = rt_key(rt);
if (netmask) {
rt_maskedcopy(dst, ndst, netmask);
} else
Bcopy(dst, ndst, dst->sa_len);
rn = rnh->rnh_addaddr((caddr_t)ndst, (caddr_t)netmask,
rnh, rt->rt_nodes);
if (rn == 0) {
if (rt->rt_gwroute)
rtfree(rt->rt_gwroute);
Free(rt_key(rt));
Free(rt);
senderr(EEXIST);
}
ifa->ifa_refcnt++;
rt->rt_ifa = ifa;
rt->rt_ifp = ifa->ifa_ifp;
if (req == RTM_RESOLVE)
rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */
if (ifa->ifa_rtrequest)
ifa->ifa_rtrequest(req, rt, SA(ret_nrt ? *ret_nrt : 0));
if (ret_nrt) {
*ret_nrt = rt;
rt->rt_refcnt++;
}
break;
}
bad:
splx(s);
return (error);
}
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;
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 1;
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;
}
if (rt->rt_flags & RTF_GATEWAY) {
rt->rt_gwroute = rtalloc1(gate, 1);
}
return 0;
}
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 (cmd == RTM_DELETE) {
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;
}
if (rt = rtalloc1(dst, 0)) {
rt->rt_refcnt--;
if (rt->rt_ifa != ifa) {
if (m)
(void) m_free(m);
return (flags & RTF_HOST ? EHOSTUNREACH
: ENETUNREACH);
}
}
}
error = rtrequest(cmd, dst, ifa->ifa_addr, ifa->ifa_netmask,
flags | ifa->ifa_flags, &nrt);
if (m)
(void) m_free(m);
if (cmd == RTM_DELETE && error == 0 && (rt = nrt)) {
rt_newaddrmsg(cmd, ifa, error, nrt);
if (rt->rt_refcnt <= 0) {
rt->rt_refcnt++;
rtfree(rt);
}
}
if (cmd == RTM_ADD && error == 0 && (rt = nrt)) {
rt->rt_refcnt--;
if (rt->rt_ifa != ifa) {
printf("rtinit: wrong ifa (%x) was (%x)\n", ifa,
rt->rt_ifa);
if (rt->rt_ifa->ifa_rtrequest)
rt->rt_ifa->ifa_rtrequest(RTM_DELETE, rt, SA(0));
IFAFREE(rt->rt_ifa);
rt->rt_ifa = ifa;
rt->rt_ifp = ifa->ifa_ifp;
ifa->ifa_refcnt++;
if (ifa->ifa_rtrequest)
ifa->ifa_rtrequest(RTM_ADD, rt, SA(0));
}
rt_newaddrmsg(cmd, ifa, error, nrt);
}
return (error);
}