checkpoint semi-working version with routing socket

[unix-history] / usr / src / sys / net / route.c

/*
 * Copyright (c) 1980, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)route.c	7.7 (Berkeley) %G%
 */

#include "param.h"
#include "systm.h"
#include "mbuf.h"
#include "protosw.h"
#include "socket.h"
#include "dir.h"
#include "user.h"
#include "ioctl.h"
#include "errno.h"

#include "if.h"
#include "af.h"
#include "route.h"
#include "radix.h"

#include "radix.c"
#ifdef INET
#include "../netinet/in.h"
#include "../netinet/in_var.h"
#endif

int	rttrash;		/* routes not in table but not freed */
struct	sockaddr wildcard;	/* zero valued cookie for wildcard searches */
int	rthashsize = RTHASHSIZ;	/* for netstat, etc. */

static int rtinits_done = 0;
struct radix_node_head *ns_rnhead, *in_rnhead;
rtinitheads()
{
	if (rtinits_done == 0 &&
	    rn_inithead(&ns_rnhead, 16, AF_NS) &&
	    rn_inithead(&in_rnhead, 32, AF_INET))
		rtinits_done = 1;
}

/*
 * Packet routing routines.
 */
rtalloc(ro)
	register struct route *ro;
{
	register struct radix_node_head *rnh;
	register struct radix_node *rn;
	register struct rtentry *rt = 0;
	u_char af = ro->ro_dst.sa_family;
	int  s;

	if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP))
		return;				 /* XXX */
	s = splnet();
	for (rnh = radix_node_head; rnh && (af != rnh->rnh_af); )
		rnh = rnh->rnh_next;
	if (rnh && rnh->rnh_treetop &&
	    (rn = rn_match((char *)&(ro->ro_dst), rnh->rnh_treetop)) &&
	    ((rn->rn_flags & RNF_ROOT) == 0)) {
		rt = &(((struct nrtentry *)rn)->nrt_rt);
		rt->rt_refcnt++;
	} else
		rtstat.rts_unreach++;
	ro->ro_rt = rt;
	splx(s);
}

rtfree(rt)
	register struct rtentry *rt;
{
	register struct nrtentry *nrt;
	u_char *af;
	if (rt == 0)
		panic("rtfree");
	rt->rt_refcnt--;
	if (rt->rt_refcnt <= 0 && (rt->rt_flags&RTF_UP) == 0) {
		rttrash--;
		nrt = (struct nrtentry *) (((struct radix_node *)rt) - 2);
		if (nrt->nrt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT))
			panic ("rtfree 2");
		free((caddr_t)nrt, M_RTABLE);
	}
}

/*
 * 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
 *
 */
rtredirect(dst, gateway, flags, src)
	struct sockaddr *dst, *gateway, *src;
	int flags;
{
	struct route ro;
	register struct rtentry *rt;

	/* verify the gateway is directly reachable */
	if (ifa_ifwithnet(gateway) == 0) {
		rtstat.rts_badredirect++;
		return;
	}
	ro.ro_dst = *dst;
	ro.ro_rt = 0;
	rtalloc(&ro);
	rt = ro.ro_rt;
#define	equal(a1, a2) \
  (bcmp((caddr_t)(a1), (caddr_t)(a2), ((struct sockaddr *)(a1))->sa_len) == 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.
	 */
	if ((rt && !equal(src, &rt->rt_gateway)) || ifa_ifwithaddr(gateway)) {
		rtstat.rts_badredirect++;
		if (rt)
			rtfree(rt);
		return;
	}
	/*
	 * Old comment:
	 * 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.
	 *
	 * New comment:
	 * If we survived the previous tests, it doesn't matter
	 * what sort of entry we got when we looked it up;
	 * we should just go ahead and free the reference to
	 * the route we created.  rtalloc will not give a
	 * pointer to the root node.  And if we got a pointer
	 * to a default gateway, we should free the reference
	 * in any case.
	if (rt) {
		rtfree(rt);
		rt = 0;
	}
	 */
	if (rt == 0) {
		rtinit(dst, gateway, (int)SIOCADDRT,
		    (flags & RTF_HOST) | RTF_GATEWAY | RTF_DYNAMIC);
		rtstat.rts_dynamic++;
		return;
	}
	/*
	 * 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.
			 */
			rtinit(dst, gateway, (int)SIOCADDRT,
			    flags | RTF_DYNAMIC);
			rtstat.rts_dynamic++;
		} else {
			/*
			 * Smash the current notion of the gateway to
			 * this destination.
			 */
			rt->rt_gateway = *gateway; /*XXX -- size? */
			rt->rt_flags |= RTF_MODIFIED;
			rtstat.rts_newgateway++;
		}
	} else
		rtstat.rts_badredirect++;
	rtfree(rt);
}

/*
 * Routing table ioctl interface.
 */
rtioctl(cmd, data)
	int cmd;
	caddr_t data;
{

	if (cmd != SIOCADDRT && cmd != SIOCDELRT)
		return (EINVAL);
	if (!suser())
		return (u.u_error);
	return (rtrequest(cmd, (struct rtentry *)data));
}
/*
 * This routine will go away soon.
 * Tries to guess which netmask is appropriate for a given net.
 */
static struct sockaddr_in rtgmask = { 8, 0 };

char *
rtgetmask(sa, ifa)
register struct sockaddr *sa;
register struct ifaddr *ifa;
{
	u_long i, net, mask, subnet;

	switch (sa->sa_family) {
#ifdef INET
	register struct in_ifaddr *ia;

	case AF_INET:

		i = ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr);
		if (i == 0) {
			rtgmask.sin_addr.s_addr = 0;
			return ((char *)&rtgmask);
		} else if (IN_CLASSA(i)) {
			net = i & IN_CLASSA_NET;
			mask = IN_CLASSA_NET;
		} else if (IN_CLASSB(i)) {
			net = i & IN_CLASSB_NET;
			mask = IN_CLASSB_NET;
		} else if (IN_CLASSC(i)) {
			net = i & IN_CLASSC_NET;
			mask = IN_CLASSC_NET;
		} else {
			net = i;
			mask = 0xffffffff;
		}

		/*
		 * Check whether network is a subnet;
		 * if so, return subnet number.
		 */
		for (ia = in_ifaddr; ia; ia = ia->ia_next)
			if (net == ia->ia_net) {
				ifa = &ia->ia_ifa;
				break;
			}
		if (ia == 0) {
			rtgmask.sin_addr.s_addr = ntohl(mask);
			return ((char *)&rtgmask);
		}
#endif
	}
	return ((char *)ifa->ifa_netmask);
}

/*
 * Carry out a request to change the routing table.  Called by
 * interfaces at boot time to make their ``local routes'' known,
 * for ioctl's, and as the result of routing redirects.
 */
rtrequest(req, entry)
	int req;
	register struct rtentry *entry;
{
	register struct rtentry *rt;
	int s, error = 0, found;
	u_char af;
	struct ifaddr *ifa;
	struct ifaddr *ifa_ifwithdstaddr();
	register struct nrtentry *nrt;
	register struct radix_node *rn;
	register struct radix_node_head *rnh;
	struct radix_node *head;
	char *netmask;

#ifdef COMPAT_43
#if BYTE_ORDER != BIG_ENDIAN
	s = splnet();
	if (entry->rt_dst.sa_family == 0 && entry->rt_dst.sa_len < 16) {
		entry->rt_dst.sa_family = entry->rt_dst.sa_len;
		entry->rt_dst.sa_len = 16;
	}
	if (entry->rt_gateway.sa_family == 0 && entry->rt_gateway.sa_len < 16) {
		entry->rt_gateway.sa_family = entry->rt_gateway.sa_len;
		entry->rt_gateway.sa_len = 16;
	}
#else
	if (entry->rt_dst.sa_len == 0)
		entry->rt_dst.sa_len = 16;
	if (entry->rt_gateway.sa_len == 0)
		entry->rt_gateway.sa_len = 16;
#endif
#endif
	if (rtinits_done == 0)
		rtinitheads();
	af = entry->rt_dst.sa_family;
	for (rnh = radix_node_head; rnh && (af != rnh->rnh_af); )
		rnh = rnh->rnh_next;
	if (rnh == 0) {
		error = ESRCH;
		goto bad;
	}
	head = rnh->rnh_treetop;
	if ((entry->rt_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 (entry->rt_flags & RTF_HOST) 
			ifa = ifa_ifwithdstaddr(&entry->rt_dst);
		if (ifa == 0)
			ifa = ifa_ifwithaddr(&entry->rt_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(&entry->rt_gateway);
	}
	if (ifa == 0) {
		ifa = ifa_ifwithnet(&entry->rt_gateway);
		if (ifa == 0 && req == SIOCADDRT) {
			error = ENETUNREACH;
			goto bad;
		}
	}
	if (entry->rt_flags & RTF_HOST)
		netmask = 0;
	else
		netmask = rtgetmask(&entry->rt_dst, ifa);
	switch (req) {

	case SIOCDELRT:
		if ((rn = rn_delete((char *)&entry->rt_dst,
					netmask, head)) == 0) {
			error = ESRCH;
			goto bad;
		}
		if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT))
			panic ("rtrequest delete");
		nrt = (struct nrtentry *)rn;
		nrt->nrt_rt.rt_flags &= ~RTF_UP;
		if (nrt->nrt_rt.rt_refcnt > 0)
			rttrash++;
		else 
			free((caddr_t)nrt, M_RTABLE);
		break;

	case SIOCADDRT:
		Malloc(nrt, struct nrtentry *, sizeof *nrt);
		if (nrt == 0) {
			error = ENOBUFS;
			goto bad;
		}
		Bzero(nrt, sizeof *nrt);
		rn = rn_addroute((char *)&entry->rt_dst, netmask,
						    head, nrt->nrt_nodes);
		if (rn == 0) {
			free((caddr_t)nrt, M_RTABLE);
			error = EEXIST;
			goto bad;
		}
		rt = &nrt->nrt_rt;
		rn->rn_key = (char *)&(nrt->nrt_rt.rt_dst);
		rt->rt_dst = entry->rt_dst;
		rt->rt_gateway = entry->rt_gateway;
		rt->rt_flags = RTF_UP |
		    (entry->rt_flags & (RTF_HOST|RTF_GATEWAY|RTF_DYNAMIC));
		rt->rt_use = 0;
		rt->rt_refcnt = 0;
		rt->rt_ifp = ifa->ifa_ifp;
		break;
	}
bad:
	splx(s);
	return (error);
}

/*
 * Set up a routing table entry, normally
 * for an interface.
 */
rtinit(dst, gateway, cmd, flags)
	struct sockaddr *dst, *gateway;
	int cmd, flags;
{
	struct rtentry route;

	bzero((caddr_t)&route, sizeof (route));
	route.rt_dst = *dst;
	route.rt_gateway = *gateway;
	route.rt_flags = flags;
	(void) rtrequest(cmd, &route);
}