[apple/xnu.git] / bsd / netinet6 / in6_src.c

/*	$FreeBSD: src/sys/netinet6/in6_src.c,v 1.1.2.2 2001/07/03 11:01:52 ume Exp $	*/
/*	$KAME: in6_src.c,v 1.37 2001/03/29 05:34:31 itojun Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
 */

/*
 * Copyright (c) 1982, 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.
 *
 *	@(#)in_pcb.c	8.2 (Berkeley) 1/4/94
 */


#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/proc.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#if ENABLE_DEFAULT_SCOPE
#include <netinet6/scope6_var.h> 
#endif

#include <net/net_osdep.h>

#include "loop.h"

/*
 * Return an IPv6 address, which is the most appropriate for a given
 * destination and user specified options.
 * If necessary, this function lookups the routing table and returns
 * an entry to the caller for later use.
 */
struct in6_addr *
in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp)
	struct sockaddr_in6 *dstsock;
	struct ip6_pktopts *opts;
	struct ip6_moptions *mopts;
	struct route_in6 *ro;
	struct in6_addr *laddr;
	int *errorp;
{
	struct in6_addr *dst;
	struct in6_ifaddr *ia6 = 0;
	struct in6_pktinfo *pi = NULL;

	dst = &dstsock->sin6_addr;
	*errorp = 0;

	/*
	 * If the source address is explicitly specified by the caller,
	 * use it.
	 */
	if (opts && (pi = opts->ip6po_pktinfo) &&
	    !IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr))
		return(&pi->ipi6_addr);

	/*
	 * If the source address is not specified but the socket(if any)
	 * is already bound, use the bound address.
	 */
	if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
		return(laddr);

	/*
	 * If the caller doesn't specify the source address but
	 * the outgoing interface, use an address associated with
	 * the interface.
	 */
	if (pi && pi->ipi6_ifindex) {
		/* XXX boundary check is assumed to be already done. */
		ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex],
				       dst);
		if (ia6 == 0) {
			*errorp = EADDRNOTAVAIL;
			return(0);
		}
		return(&satosin6(&ia6->ia_addr)->sin6_addr);
	}

	/*
	 * If the destination address is a link-local unicast address or
	 * a multicast address, and if the outgoing interface is specified
	 * by the sin6_scope_id filed, use an address associated with the
	 * interface.
	 * XXX: We're now trying to define more specific semantics of
	 *      sin6_scope_id field, so this part will be rewritten in
	 *      the near future.
	 */
	if ((IN6_IS_ADDR_LINKLOCAL(dst) || IN6_IS_ADDR_MULTICAST(dst)) &&
	    dstsock->sin6_scope_id) {
		/*
		 * I'm not sure if boundary check for scope_id is done
		 * somewhere...
		 */
		if (dstsock->sin6_scope_id < 0 ||
		    if_index < dstsock->sin6_scope_id) {
			*errorp = ENXIO; /* XXX: better error? */
			return(0);
		}
		ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id],
				       dst);
		if (ia6 == 0) {
			*errorp = EADDRNOTAVAIL;
			return(0);
		}
		return(&satosin6(&ia6->ia_addr)->sin6_addr);
	}

	/*
	 * If the destination address is a multicast address and
	 * the outgoing interface for the address is specified
	 * by the caller, use an address associated with the interface.
	 * There is a sanity check here; if the destination has node-local
	 * scope, the outgoing interfacde should be a loopback address.
	 * Even if the outgoing interface is not specified, we also
	 * choose a loopback interface as the outgoing interface.
	 */
	if (IN6_IS_ADDR_MULTICAST(dst)) {
		struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL;

		if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) {
			ifp = &loif[0];
		}

		if (ifp) {
			ia6 = in6_ifawithscope(ifp, dst);
			if (ia6 == 0) {
				*errorp = EADDRNOTAVAIL;
				return(0);
			}
			return(&satosin6(&ia6->ia_addr)->sin6_addr);
		}
	}

	/*
	 * If the next hop address for the packet is specified
	 * by caller, use an address associated with the route
	 * to the next hop.
	 */
	{
		struct sockaddr_in6 *sin6_next;
		struct rtentry *rt;

		if (opts && opts->ip6po_nexthop) {
			sin6_next = satosin6(opts->ip6po_nexthop);
			rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL);
			if (rt) {
				ia6 = in6_ifawithscope(rt->rt_ifp, dst);
				if (ia6 == 0)
					ia6 = ifatoia6(rt->rt_ifa);
			}
			if (ia6 == 0) {
				*errorp = EADDRNOTAVAIL;
				return(0);
			}
			return(&satosin6(&ia6->ia_addr)->sin6_addr);
		}
	}

	/*
	 * If route is known or can be allocated now,
	 * our src addr is taken from the i/f, else punt.
	 */
	if (ro) {
		if (ro->ro_rt &&
		    !IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) {
			rtfree(ro->ro_rt);
			ro->ro_rt = (struct rtentry *)0;
		}
		if (ro->ro_rt == (struct rtentry *)0 ||
		    ro->ro_rt->rt_ifp == (struct ifnet *)0) {
			struct sockaddr_in6 *sa6;

			/* No route yet, so try to acquire one */
			bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
			sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
			sa6->sin6_family = AF_INET6;
			sa6->sin6_len = sizeof(struct sockaddr_in6);
			sa6->sin6_addr = *dst;
			sa6->sin6_scope_id = dstsock->sin6_scope_id;
			if (IN6_IS_ADDR_MULTICAST(dst)) {
				ro->ro_rt = rtalloc1(&((struct route *)ro)
						     ->ro_dst, 0, 0UL);
			} else {
				rtalloc((struct route *)ro);
			}
		}

		/*
		 * in_pcbconnect() checks out IFF_LOOPBACK to skip using
		 * the address. But we don't know why it does so.
		 * It is necessary to ensure the scope even for lo0
		 * so doesn't check out IFF_LOOPBACK.
		 */

		if (ro->ro_rt) {
			ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst);
			if (ia6 == 0) /* xxx scope error ?*/
				ia6 = ifatoia6(ro->ro_rt->rt_ifa);
		}
#if 0
		/*
		 * xxx The followings are necessary? (kazu)
		 * I don't think so.
		 * It's for SO_DONTROUTE option in IPv4.(jinmei)
		 */
		if (ia6 == 0) {
			struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0};

			sin6->sin6_addr = *dst;

			ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6)));
			if (ia6 == 0)
				ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6)));
			if (ia6 == 0)
				return(0);
			return(&satosin6(&ia6->ia_addr)->sin6_addr);
		}
#endif /* 0 */
		if (ia6 == 0) {
			*errorp = EHOSTUNREACH;	/* no route */
			return(0);
		}
		return(&satosin6(&ia6->ia_addr)->sin6_addr);
	}

	*errorp = EADDRNOTAVAIL;
	return(0);
}

/*
 * Default hop limit selection. The precedence is as follows:
 * 1. Hoplimit value specified via ioctl.
 * 2. (If the outgoing interface is detected) the current
 *     hop limit of the interface specified by router advertisement.
 * 3. The system default hoplimit.
*/
int
in6_selecthlim(in6p, ifp)
	struct in6pcb *in6p;
	struct ifnet *ifp;
{
	if (in6p && in6p->in6p_hops >= 0)
		return(in6p->in6p_hops);
	else if (ifp)
		return(nd_ifinfo[ifp->if_index].chlim);
	else
		return(ip6_defhlim);
}

/*
 * XXX: this is borrowed from in6_pcbbind(). If possible, we should
 * share this function by all *bsd*...
 */
int
in6_pcbsetport(laddr, inp, p)
	struct in6_addr *laddr;
	struct inpcb *inp;
	struct proc *p;
{
	struct socket *so = inp->inp_socket;
	u_int16_t lport = 0, first, last, *lastport;
	int count, error = 0, wild = 0;
	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;

	/* XXX: this is redundant when called from in6_pcbbind */
	if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0)
		wild = INPLOOKUP_WILDCARD;

	inp->inp_flags |= INP_ANONPORT;

	if (inp->inp_flags & INP_HIGHPORT) {
		first = ipport_hifirstauto;	/* sysctl */
		last  = ipport_hilastauto;
		lastport = &pcbinfo->lasthi;
	} else if (inp->inp_flags & INP_LOWPORT) {
#ifdef __APPLE__
                if (p && (error = suser(p->p_ucred, &p->p_acflag)))
#else
		if (p && (error = suser(p)))
#endif

			return error;
		first = ipport_lowfirstauto;	/* 1023 */
		last  = ipport_lowlastauto;	/* 600 */
		lastport = &pcbinfo->lastlow;
	} else {
		first = ipport_firstauto;	/* sysctl */
		last  = ipport_lastauto;
		lastport = &pcbinfo->lastport;
	}
	/*
	 * Simple check to ensure all ports are not used up causing
	 * a deadlock here.
	 *
	 * We split the two cases (up and down) so that the direction
	 * is not being tested on each round of the loop.
	 */
	if (first > last) {
		/*
		 * counting down
		 */
		count = first - last;

		do {
			if (count-- < 0) {	/* completely used? */
				/*
				 * Undo any address bind that may have
				 * occurred above.
				 */
				inp->in6p_laddr = in6addr_any;
				return (EAGAIN);
			}
			--*lastport;
			if (*lastport > first || *lastport < last)
				*lastport = first;
			lport = htons(*lastport);
		} while (in6_pcblookup_local(pcbinfo,
					     &inp->in6p_laddr, lport, wild));
	} else {
		/*
			 * counting up
			 */
		count = last - first;

		do {
			if (count-- < 0) {	/* completely used? */
				/*
				 * Undo any address bind that may have
				 * occurred above.
				 */
				inp->in6p_laddr = in6addr_any;
				return (EAGAIN);
			}
			++*lastport;
			if (*lastport < first || *lastport > last)
				*lastport = first;
			lport = htons(*lastport);
		} while (in6_pcblookup_local(pcbinfo,
					     &inp->in6p_laddr, lport, wild));
	}

	inp->inp_lport = lport;
	if (in_pcbinshash(inp) != 0) {
		inp->in6p_laddr = in6addr_any;
		inp->inp_lport = 0;
		return (EAGAIN);
	}

	return(0);
}

/*
 * generate kernel-internal form (scopeid embedded into s6_addr16[1]).
 * If the address scope of is link-local, embed the interface index in the
 * address.  The routine determines our precedence
 * between advanced API scope/interface specification and basic API
 * specification.
 *
 * this function should be nuked in the future, when we get rid of
 * embedded scopeid thing.
 *
 * XXX actually, it is over-specification to return ifp against sin6_scope_id.
 * there can be multiple interfaces that belong to a particular scope zone
 * (in specification, we have 1:N mapping between a scope zone and interfaces).
 * we may want to change the function to return something other than ifp.
 */
int
in6_embedscope(in6, sin6, in6p, ifpp)
	struct in6_addr *in6;
	const struct sockaddr_in6 *sin6;
#ifdef HAVE_NRL_INPCB
	struct inpcb *in6p;
#define in6p_outputopts	inp_outputopts6
#define in6p_moptions	inp_moptions6
#else
	struct in6pcb *in6p;
#endif
	struct ifnet **ifpp;
{
	struct ifnet *ifp = NULL;
	u_int32_t scopeid;

	*in6 = sin6->sin6_addr;
	scopeid = sin6->sin6_scope_id;
	if (ifpp)
		*ifpp = NULL;

	/*
	 * don't try to read sin6->sin6_addr beyond here, since the caller may
	 * ask us to overwrite existing sockaddr_in6
	 */

#ifdef ENABLE_DEFAULT_SCOPE
	if (scopeid == 0)
		scopeid = scope6_addr2default(in6);
#endif

	if (IN6_IS_SCOPE_LINKLOCAL(in6)) {
		struct in6_pktinfo *pi;

		/*
		 * KAME assumption: link id == interface id
		 */

		if (in6p && in6p->in6p_outputopts &&
		    (pi = in6p->in6p_outputopts->ip6po_pktinfo) &&
		    pi->ipi6_ifindex) {
			ifp = ifindex2ifnet[pi->ipi6_ifindex];
			in6->s6_addr16[1] = htons(pi->ipi6_ifindex);
		} else if (in6p && IN6_IS_ADDR_MULTICAST(in6) &&
			   in6p->in6p_moptions &&
			   in6p->in6p_moptions->im6o_multicast_ifp) {
			ifp = in6p->in6p_moptions->im6o_multicast_ifp;
			in6->s6_addr16[1] = htons(ifp->if_index);
		} else if (scopeid) {
			/* boundary check */
			if (scopeid < 0 || if_index < scopeid)
				return ENXIO;  /* XXX EINVAL? */
			ifp = ifindex2ifnet[scopeid];
			/*XXX assignment to 16bit from 32bit variable */
			in6->s6_addr16[1] = htons(scopeid & 0xffff);
		}

		if (ifpp)
			*ifpp = ifp;
	}

	return 0;
}
#if HAVE_NRL_INPCB
#undef in6p_outputopts
#undef in6p_moptions
#endif

/*
 * generate standard sockaddr_in6 from embedded form.
 * touches sin6_addr and sin6_scope_id only.
 *
 * this function should be nuked in the future, when we get rid of
 * embedded scopeid thing.
 */
int
in6_recoverscope(sin6, in6, ifp)
	struct sockaddr_in6 *sin6;
	const struct in6_addr *in6;
	struct ifnet *ifp;
{
	u_int32_t scopeid;

	sin6->sin6_addr = *in6;

	/*
	 * don't try to read *in6 beyond here, since the caller may
	 * ask us to overwrite existing sockaddr_in6
	 */

	sin6->sin6_scope_id = 0;
	if (IN6_IS_SCOPE_LINKLOCAL(in6)) {
		/*
		 * KAME assumption: link id == interface id
		 */
		scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
		if (scopeid) {
			/* sanity check */
			if (scopeid < 0 || if_index < scopeid)
				return ENXIO;
			if (ifp && ifp->if_index != scopeid)
				return ENXIO;
			sin6->sin6_addr.s6_addr16[1] = 0;
			sin6->sin6_scope_id = scopeid;
		}
	}

	return 0;
}

/*
 * just clear the embedded scope identifer.
 * XXX: currently used for bsdi4 only as a supplement function.
 */
void
in6_clearscope(addr)
	struct in6_addr *addr;
{
	if (IN6_IS_SCOPE_LINKLOCAL(addr))
		addr->s6_addr16[1] = 0;
}
Commit	Line	Data
9bccf70c A	1	/* $FreeBSD: src/sys/netinet6/in6_src.c,v 1.1.2.2 2001/07/03 11:01:52 ume Exp $ */
9bccf70c A	2	/* $KAME: in6_src.c,v 1.37 2001/03/29 05:34:31 itojun Exp $ */
1c79356b A	3
	4	/*
	5	* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
	6	* All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. Neither the name of the project nor the names of its contributors
	17	* may be used to endorse or promote products derived from this software
	18	* without specific prior written permission.
	19	*
	20	* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
	21	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
	24	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	* SUCH DAMAGE.
	31	*/
	32
	33	/*
	34	* Copyright (c) 1982, 1986, 1991, 1993
	35	* The Regents of the University of California. All rights reserved.
	36	*
	37	* Redistribution and use in source and binary forms, with or without
	38	* modification, are permitted provided that the following conditions
	39	* are met:
	40	* 1. Redistributions of source code must retain the above copyright
	41	* notice, this list of conditions and the following disclaimer.
	42	* 2. Redistributions in binary form must reproduce the above copyright
	43	* notice, this list of conditions and the following disclaimer in the
	44	* documentation and/or other materials provided with the distribution.
	45	* 3. All advertising materials mentioning features or use of this software
	46	* must display the following acknowledgement:
	47	* This product includes software developed by the University of
	48	* California, Berkeley and its contributors.
	49	* 4. Neither the name of the University nor the names of its contributors
	50	* may be used to endorse or promote products derived from this software
	51	* without specific prior written permission.
	52	*
	53	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	54	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	55	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	56	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	57	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	58	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	59	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	60	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	61	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	62	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	63	* SUCH DAMAGE.
	64	*
	65	* @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
	66	*/
67
1c79356b A	68
	69	#include <sys/param.h>
	70	#include <sys/systm.h>
	71	#include <sys/malloc.h>
	72	#include <sys/mbuf.h>
	73	#include <sys/protosw.h>
	74	#include <sys/socket.h>
	75	#include <sys/socketvar.h>
1c79356b A	76	#include <sys/errno.h>
	77	#include <sys/time.h>
	78	#include <sys/proc.h>
	79
	80	#include <net/if.h>
	81	#include <net/route.h>
	82
	83	#include <netinet/in.h>
	84	#include <netinet/in_var.h>
	85	#include <netinet/in_systm.h>
	86	#include <netinet/ip.h>
	87	#include <netinet/in_pcb.h>
	88	#include <netinet6/in6_var.h>
	89	#include <netinet/ip6.h>
1c79356b	90	#include <netinet6/in6_pcb.h>
1c79356b A	91	#include <netinet6/ip6_var.h>
1c79356b A	92	#include <netinet6/nd6.h>
9bccf70c A	93	#if ENABLE_DEFAULT_SCOPE
	94	#include <netinet6/scope6_var.h>
	95	#endif
1c79356b A	96
	97	#include <net/net_osdep.h>
	98
1c79356b	99	#include "loop.h"
1c79356b A	100
1c79356b A	101	/*
9bccf70c	102	* Return an IPv6 address, which is the most appropriate for a given
1c79356b	103	* destination and user specified options.
9bccf70c	104	* If necessary, this function lookups the routing table and returns
1c79356b A	105	* an entry to the caller for later use.
	106	*/
	107	struct in6_addr *
	108	in6_selectsrc(dstsock, opts, mopts, ro, laddr, errorp)
	109	struct sockaddr_in6 *dstsock;
	110	struct ip6_pktopts *opts;
	111	struct ip6_moptions *mopts;
	112	struct route_in6 *ro;
	113	struct in6_addr *laddr;
	114	int *errorp;
	115	{
	116	struct in6_addr *dst;
	117	struct in6_ifaddr *ia6 = 0;
	118	struct in6_pktinfo *pi = NULL;
	119
	120	dst = &dstsock->sin6_addr;
	121	*errorp = 0;
	122
	123	/*
	124	* If the source address is explicitly specified by the caller,
	125	* use it.
	126	*/
	127	if (opts && (pi = opts->ip6po_pktinfo) &&
	128	!IN6_IS_ADDR_UNSPECIFIED(&pi->ipi6_addr))
	129	return(&pi->ipi6_addr);
	130
	131	/*
	132	* If the source address is not specified but the socket(if any)
	133	* is already bound, use the bound address.
	134	*/
	135	if (laddr && !IN6_IS_ADDR_UNSPECIFIED(laddr))
	136	return(laddr);
	137
	138	/*
	139	* If the caller doesn't specify the source address but
	140	* the outgoing interface, use an address associated with
	141	* the interface.
	142	*/
	143	if (pi && pi->ipi6_ifindex) {
	144	/* XXX boundary check is assumed to be already done. */
	145	ia6 = in6_ifawithscope(ifindex2ifnet[pi->ipi6_ifindex],
	146	dst);
	147	if (ia6 == 0) {
	148	*errorp = EADDRNOTAVAIL;
	149	return(0);
	150	}
	151	return(&satosin6(&ia6->ia_addr)->sin6_addr);
	152	}
	153
	154	/*
	155	* If the destination address is a link-local unicast address or
	156	* a multicast address, and if the outgoing interface is specified
	157	* by the sin6_scope_id filed, use an address associated with the
	158	* interface.
	159	* XXX: We're now trying to define more specific semantics of
	160	* sin6_scope_id field, so this part will be rewritten in
	161	* the near future.
	162	*/
	163	if ((IN6_IS_ADDR_LINKLOCAL(dst) \|\| IN6_IS_ADDR_MULTICAST(dst)) &&
	164	dstsock->sin6_scope_id) {
	165	/*
	166	* I'm not sure if boundary check for scope_id is done
	167	* somewhere...
	168	*/
169	if (dstsock->sin6_scope_id < 0 \|\|
170	if_index < dstsock->sin6_scope_id) {
171	errorp = ENXIO; / XXX: better error? */
172	return(0);
173	}
174	ia6 = in6_ifawithscope(ifindex2ifnet[dstsock->sin6_scope_id],
175	dst);
176	if (ia6 == 0) {
177	*errorp = EADDRNOTAVAIL;
178	return(0);
179	}
180	return(&satosin6(&ia6->ia_addr)->sin6_addr);
181	}
182
183	/*
184	* If the destination address is a multicast address and
185	* the outgoing interface for the address is specified
186	* by the caller, use an address associated with the interface.
187	* There is a sanity check here; if the destination has node-local
188	* scope, the outgoing interfacde should be a loopback address.
189	* Even if the outgoing interface is not specified, we also
190	* choose a loopback interface as the outgoing interface.
191	*/
192	if (IN6_IS_ADDR_MULTICAST(dst)) {
193	struct ifnet *ifp = mopts ? mopts->im6o_multicast_ifp : NULL;
1c79356b A	194
1c79356b A	195	if (ifp == NULL && IN6_IS_ADDR_MC_NODELOCAL(dst)) {
1c79356b	196	ifp = &loif[0];
1c79356b A	197	}
	198
	199	if (ifp) {
	200	ia6 = in6_ifawithscope(ifp, dst);
	201	if (ia6 == 0) {
	202	*errorp = EADDRNOTAVAIL;
	203	return(0);
	204	}
	205	return(&satosin6(&ia6->ia_addr)->sin6_addr);
	206	}
	207	}
	208
	209	/*
	210	* If the next hop address for the packet is specified
	211	* by caller, use an address associated with the route
	212	* to the next hop.
	213	*/
	214	{
	215	struct sockaddr_in6 *sin6_next;
	216	struct rtentry *rt;
	217
	218	if (opts && opts->ip6po_nexthop) {
	219	sin6_next = satosin6(opts->ip6po_nexthop);
	220	rt = nd6_lookup(&sin6_next->sin6_addr, 1, NULL);
	221	if (rt) {
	222	ia6 = in6_ifawithscope(rt->rt_ifp, dst);
	223	if (ia6 == 0)
	224	ia6 = ifatoia6(rt->rt_ifa);
	225	}
	226	if (ia6 == 0) {
	227	*errorp = EADDRNOTAVAIL;
	228	return(0);
	229	}
	230	return(&satosin6(&ia6->ia_addr)->sin6_addr);
	231	}
	232	}
	233
1c79356b A	234	/*
	235	* If route is known or can be allocated now,
	236	* our src addr is taken from the i/f, else punt.
	237	*/
	238	if (ro) {
	239	if (ro->ro_rt &&
	240	!IN6_ARE_ADDR_EQUAL(&satosin6(&ro->ro_dst)->sin6_addr, dst)) {
9bccf70c	241	rtfree(ro->ro_rt);
1c79356b A	242	ro->ro_rt = (struct rtentry *)0;
	243	}
	244	if (ro->ro_rt == (struct rtentry *)0 \|\|
	245	ro->ro_rt->rt_ifp == (struct ifnet *)0) {
9bccf70c A	246	struct sockaddr_in6 *sa6;
9bccf70c A	247
1c79356b A	248	/* No route yet, so try to acquire one */
1c79356b A	249	bzero(&ro->ro_dst, sizeof(struct sockaddr_in6));
9bccf70c A	250	sa6 = (struct sockaddr_in6 *)&ro->ro_dst;
	251	sa6->sin6_family = AF_INET6;
	252	sa6->sin6_len = sizeof(struct sockaddr_in6);
	253	sa6->sin6_addr = *dst;
	254	sa6->sin6_scope_id = dstsock->sin6_scope_id;
1c79356b	255	if (IN6_IS_ADDR_MULTICAST(dst)) {
1c79356b A	256	ro->ro_rt = rtalloc1(&((struct route *)ro)
1c79356b A	257	->ro_dst, 0, 0UL);
1c79356b	258	} else {
1c79356b	259	rtalloc((struct route *)ro);
1c79356b A	260	}
	261	}
	262
	263	/*
	264	* in_pcbconnect() checks out IFF_LOOPBACK to skip using
	265	* the address. But we don't know why it does so.
	266	* It is necessary to ensure the scope even for lo0
	267	* so doesn't check out IFF_LOOPBACK.
	268	*/
	269
	270	if (ro->ro_rt) {
	271	ia6 = in6_ifawithscope(ro->ro_rt->rt_ifa->ifa_ifp, dst);
	272	if (ia6 == 0) /* xxx scope error ?*/
	273	ia6 = ifatoia6(ro->ro_rt->rt_ifa);
	274	}
	275	#if 0
	276	/*
	277	* xxx The followings are necessary? (kazu)
	278	* I don't think so.
	279	* It's for SO_DONTROUTE option in IPv4.(jinmei)
	280	*/
	281	if (ia6 == 0) {
	282	struct sockaddr_in6 sin6 = {sizeof(sin6), AF_INET6, 0};
	283
	284	sin6->sin6_addr = *dst;
	285
	286	ia6 = ifatoia6(ifa_ifwithdstaddr(sin6tosa(&sin6)));
	287	if (ia6 == 0)
	288	ia6 = ifatoia6(ifa_ifwithnet(sin6tosa(&sin6)));
	289	if (ia6 == 0)
	290	return(0);
	291	return(&satosin6(&ia6->ia_addr)->sin6_addr);
	292	}
	293	#endif /* 0 */
	294	if (ia6 == 0) {
	295	errorp = EHOSTUNREACH; / no route */
	296	return(0);
	297	}
	298	return(&satosin6(&ia6->ia_addr)->sin6_addr);
	299	}
	300
	301	*errorp = EADDRNOTAVAIL;
	302	return(0);
	303	}
	304
	305	/*
	306	* Default hop limit selection. The precedence is as follows:
	307	* 1. Hoplimit value specified via ioctl.
	308	* 2. (If the outgoing interface is detected) the current
	309	* hop limit of the interface specified by router advertisement.
	310	* 3. The system default hoplimit.
	311	*/
1c79356b A	312	int
	313	in6_selecthlim(in6p, ifp)
	314	struct in6pcb *in6p;
	315	struct ifnet *ifp;
	316	{
	317	if (in6p && in6p->in6p_hops >= 0)
	318	return(in6p->in6p_hops);
	319	else if (ifp)
	320	return(nd_ifinfo[ifp->if_index].chlim);
	321	else
	322	return(ip6_defhlim);
	323	}
1c79356b	324
1c79356b	325	/*
9bccf70c A	326	* XXX: this is borrowed from in6_pcbbind(). If possible, we should
9bccf70c A	327	* share this function by all bsd...
1c79356b	328	*/
1c79356b	329	int
9bccf70c	330	in6_pcbsetport(laddr, inp, p)
1c79356b	331	struct in6_addr *laddr;
9bccf70c A	332	struct inpcb *inp;
9bccf70c A	333	struct proc *p;
1c79356b	334	{
9bccf70c A	335	struct socket *so = inp->inp_socket;
	336	u_int16_t lport = 0, first, last, *lastport;
	337	int count, error = 0, wild = 0;
	338	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
1c79356b A	339
1c79356b A	340	/* XXX: this is redundant when called from in6_pcbbind */
9bccf70c A	341	if ((so->so_options & (SO_REUSEADDR\|SO_REUSEPORT)) == 0)
	342	wild = INPLOOKUP_WILDCARD;
	343
	344	inp->inp_flags \|= INP_ANONPORT;
	345
	346	if (inp->inp_flags & INP_HIGHPORT) {
	347	first = ipport_hifirstauto; /* sysctl */
	348	last = ipport_hilastauto;
	349	lastport = &pcbinfo->lasthi;
	350	} else if (inp->inp_flags & INP_LOWPORT) {
	351	#ifdef __APPLE__
	352	if (p && (error = suser(p->p_ucred, &p->p_acflag)))
1c79356b	353	#else
9bccf70c	354	if (p && (error = suser(p)))
1c79356b	355	#endif
9bccf70c A	356
	357	return error;
	358	first = ipport_lowfirstauto; /* 1023 */
	359	last = ipport_lowlastauto; /* 600 */
	360	lastport = &pcbinfo->lastlow;
1c79356b	361	} else {
9bccf70c A	362	first = ipport_firstauto; /* sysctl */
	363	last = ipport_lastauto;
	364	lastport = &pcbinfo->lastport;
	365	}
	366	/*
	367	* Simple check to ensure all ports are not used up causing
	368	* a deadlock here.
	369	*
	370	* We split the two cases (up and down) so that the direction
	371	* is not being tested on each round of the loop.
	372	*/
	373	if (first > last) {
	374	/*
	375	* counting down
	376	*/
	377	count = first - last;
	378
	379	do {
	380	if (count-- < 0) { /* completely used? */
	381	/*
	382	* Undo any address bind that may have
	383	* occurred above.
	384	*/
	385	inp->in6p_laddr = in6addr_any;
	386	return (EAGAIN);
	387	}
	388	--*lastport;
	389	if (lastport > first \|\| lastport < last)
	390	*lastport = first;
	391	lport = htons(*lastport);
	392	} while (in6_pcblookup_local(pcbinfo,
	393	&inp->in6p_laddr, lport, wild));
	394	} else {
	395	/*
	396	* counting up
	397	*/
	398	count = last - first;
	399
	400	do {
	401	if (count-- < 0) { /* completely used? */
	402	/*
	403	* Undo any address bind that may have
	404	* occurred above.
	405	*/
	406	inp->in6p_laddr = in6addr_any;
	407	return (EAGAIN);
	408	}
	409	++*lastport;
	410	if (lastport < first \|\| lastport > last)
	411	*lastport = first;
	412	lport = htons(*lastport);
	413	} while (in6_pcblookup_local(pcbinfo,
	414	&inp->in6p_laddr, lport, wild));
1c79356b A	415	}
1c79356b A	416
9bccf70c A	417	inp->inp_lport = lport;
	418	if (in_pcbinshash(inp) != 0) {
	419	inp->in6p_laddr = in6addr_any;
	420	inp->inp_lport = 0;
	421	return (EAGAIN);
	422	}
	423
	424	return(0);
	425	}
	426
	427	/*
	428	* generate kernel-internal form (scopeid embedded into s6_addr16[1]).
	429	* If the address scope of is link-local, embed the interface index in the
	430	* address. The routine determines our precedence
	431	* between advanced API scope/interface specification and basic API
	432	* specification.
	433	*
	434	* this function should be nuked in the future, when we get rid of
	435	* embedded scopeid thing.
	436	*
	437	* XXX actually, it is over-specification to return ifp against sin6_scope_id.
	438	* there can be multiple interfaces that belong to a particular scope zone
	439	* (in specification, we have 1:N mapping between a scope zone and interfaces).
	440	* we may want to change the function to return something other than ifp.
	441	*/
	442	int
	443	in6_embedscope(in6, sin6, in6p, ifpp)
	444	struct in6_addr *in6;
	445	const struct sockaddr_in6 *sin6;
	446	#ifdef HAVE_NRL_INPCB
	447	struct inpcb *in6p;
	448	#define in6p_outputopts inp_outputopts6
	449	#define in6p_moptions inp_moptions6
1c79356b	450	#else
9bccf70c	451	struct in6pcb *in6p;
1c79356b	452	#endif
9bccf70c A	453	struct ifnet **ifpp;
	454	{
	455	struct ifnet *ifp = NULL;
	456	u_int32_t scopeid;
	457
	458	*in6 = sin6->sin6_addr;
	459	scopeid = sin6->sin6_scope_id;
	460	if (ifpp)
	461	*ifpp = NULL;
	462
	463	/*
	464	* don't try to read sin6->sin6_addr beyond here, since the caller may
	465	* ask us to overwrite existing sockaddr_in6
	466	*/
	467
	468	#ifdef ENABLE_DEFAULT_SCOPE
	469	if (scopeid == 0)
	470	scopeid = scope6_addr2default(in6);
1c79356b	471	#endif
9bccf70c A	472
	473	if (IN6_IS_SCOPE_LINKLOCAL(in6)) {
	474	struct in6_pktinfo *pi;
	475
	476	/*
	477	* KAME assumption: link id == interface id
	478	*/
	479
	480	if (in6p && in6p->in6p_outputopts &&
	481	(pi = in6p->in6p_outputopts->ip6po_pktinfo) &&
	482	pi->ipi6_ifindex) {
	483	ifp = ifindex2ifnet[pi->ipi6_ifindex];
	484	in6->s6_addr16[1] = htons(pi->ipi6_ifindex);
	485	} else if (in6p && IN6_IS_ADDR_MULTICAST(in6) &&
	486	in6p->in6p_moptions &&
	487	in6p->in6p_moptions->im6o_multicast_ifp) {
	488	ifp = in6p->in6p_moptions->im6o_multicast_ifp;
	489	in6->s6_addr16[1] = htons(ifp->if_index);
	490	} else if (scopeid) {
	491	/* boundary check */
	492	if (scopeid < 0 \|\| if_index < scopeid)
	493	return ENXIO; /* XXX EINVAL? */
	494	ifp = ifindex2ifnet[scopeid];
	495	/XXX assignment to 16bit from 32bit variable /
	496	in6->s6_addr16[1] = htons(scopeid & 0xffff);
1c79356b	497	}
9bccf70c A	498
	499	if (ifpp)
	500	*ifpp = ifp;
1c79356b A	501	}
1c79356b A	502
9bccf70c	503	return 0;
1c79356b A	504	}
1c79356b A	505	#if HAVE_NRL_INPCB
9bccf70c A	506	#undef in6p_outputopts
9bccf70c A	507	#undef in6p_moptions
1c79356b	508	#endif
9bccf70c A	509
	510	/*
	511	* generate standard sockaddr_in6 from embedded form.
	512	* touches sin6_addr and sin6_scope_id only.
	513	*
	514	* this function should be nuked in the future, when we get rid of
	515	* embedded scopeid thing.
	516	*/
	517	int
	518	in6_recoverscope(sin6, in6, ifp)
	519	struct sockaddr_in6 *sin6;
	520	const struct in6_addr *in6;
	521	struct ifnet *ifp;
	522	{
	523	u_int32_t scopeid;
	524
	525	sin6->sin6_addr = *in6;
	526
	527	/*
	528	* don't try to read *in6 beyond here, since the caller may
	529	* ask us to overwrite existing sockaddr_in6
	530	*/
	531
	532	sin6->sin6_scope_id = 0;
	533	if (IN6_IS_SCOPE_LINKLOCAL(in6)) {
	534	/*
	535	* KAME assumption: link id == interface id
	536	*/
	537	scopeid = ntohs(sin6->sin6_addr.s6_addr16[1]);
	538	if (scopeid) {
	539	/* sanity check */
	540	if (scopeid < 0 \|\| if_index < scopeid)
	541	return ENXIO;
	542	if (ifp && ifp->if_index != scopeid)
	543	return ENXIO;
	544	sin6->sin6_addr.s6_addr16[1] = 0;
	545	sin6->sin6_scope_id = scopeid;
	546	}
	547	}
	548
	549	return 0;
	550	}
	551
	552	/*
	553	* just clear the embedded scope identifer.
	554	* XXX: currently used for bsdi4 only as a supplement function.
	555	*/
	556	void
	557	in6_clearscope(addr)
	558	struct in6_addr *addr;
	559	{
	560	if (IN6_IS_SCOPE_LINKLOCAL(addr))
	561	addr->s6_addr16[1] = 0;
	562	}