NetBSD/sys/netinet6/in6_src.c

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/* $NetBSD: in6_src.c,v 1.15 2002/09/11 02:46:45 itojun Exp $ */
/* $KAME: in6_src.c,v 1.36 2001/02/06 04:08:17 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
*/
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#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in6_src.c,v 1.15 2002/09/11 02:46:45 itojun Exp $");
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#include "opt_inet.h"
#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/ioctl.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>
#ifdef ENABLE_DEFAULT_SCOPE
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#include <netinet6/scope6_var.h>
#endif
#include <net/net_osdep.h>
#include "loop.h"
extern struct ifnet loif[NLOOP];
/*
* 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.
* Note that we should check the address family of the
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* cached destination, in case of sharing the cache with IPv4.
*/
if (ro) {
if (ro->ro_rt &&
(ro->ro_dst.sin6_family != AF_INET6 ||
!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);
} 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)->chlim);
else
return (ip6_defhlim);
}
/*
* Find an empty port and set it to the specified PCB.
*/
int
in6_pcbsetport(laddr, in6p, p)
struct in6_addr *laddr;
struct in6pcb *in6p;
struct proc *p;
{
struct socket *so = in6p->in6p_socket;
struct in6pcb *head = in6p->in6p_head;
u_int16_t last_port, lport = 0;
int wild = 0;
void *t;
u_int16_t min, max;
/* XXX: this is redundant when called from in6_pcbbind */
if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
(so->so_options & SO_ACCEPTCONN) == 0))
wild = IN6PLOOKUP_WILDCARD;
if (in6p->in6p_flags & IN6P_LOWPORT) {
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#ifndef IPNOPRIVPORTS
if (p == 0 || (suser(p->p_ucred, &p->p_acflag) != 0))
return (EACCES);
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#endif
min = ip6_lowportmin;
max = ip6_lowportmax;
} else {
min = ip6_anonportmin;
max = ip6_anonportmax;
}
/* value out of range */
if (head->in6p_lport < min)
head->in6p_lport = min;
else if (head->in6p_lport > max)
head->in6p_lport = min;
last_port = head->in6p_lport;
goto startover; /*to randomize*/
for (;;) {
lport = htons(head->in6p_lport);
if (IN6_IS_ADDR_V4MAPPED(laddr)) {
#if 0
t = in_pcblookup_bind(&tcbtable,
(struct in_addr *)&in6p->in6p_laddr.s6_addr32[3],
lport);
#else
t = NULL;
#endif
} else {
t = in6_pcblookup(head, &zeroin6_addr, 0, laddr,
lport, wild);
}
if (t == 0)
break;
startover:
if (head->in6p_lport >= max)
head->in6p_lport = min;
else
head->in6p_lport++;
if (head->in6p_lport == last_port)
return (EADDRINUSE);
}
in6p->in6p_lport = lport;
return (0); /* success */
}
/*
* 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;
struct in6pcb *in6p;
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];
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/* XXX assignment to 16bit from 32bit variable */
in6->s6_addr16[1] = htons(scopeid & 0xffff);
}
if (ifpp)
*ifpp = ifp;
}
return 0;
}
/*
* 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.
*/
void
in6_clearscope(addr)
struct in6_addr *addr;
{
if (IN6_IS_SCOPE_LINKLOCAL(addr))
addr->s6_addr16[1] = 0;
}