* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.

/* $NetBSD: in6_pcb.c,v 1.177 2022/11/04 09:04:27 ozaki-r Exp $ */
/* $KAME: in6_pcb.c,v 1.84 2001/02/08 18:02:08 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. 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in6_pcb.c,v 1.177 2022/11/04 09:04:27 ozaki-r Exp $");

#ifdef _KERNEL_OPT
#include "opt_inet.h"
#include "opt_ipsec.h"
#endif

#include <sys/param.h>
#include <sys/systm.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 <sys/kauth.h>
#include <sys/domain.h>
#include <sys/once.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 <netinet/ip6.h>
#include <netinet/portalgo.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/scope6_var.h>

#include "faith.h"

#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#include <netipsec/key.h>
#endif /* IPSEC */

#include <netinet/tcp_vtw.h>

const struct in6_addr zeroin6_addr;

#define IN6PCBHASH_PORT(table, lport) \
&(table)->inpt_porthashtbl[ntohs(lport) & (table)->inpt_porthash]
#define IN6PCBHASH_BIND(table, laddr, lport) \
&(table)->inpt_bindhashtbl[ \
(((laddr)->s6_addr32[0] ^ (laddr)->s6_addr32[1] ^ \
(laddr)->s6_addr32[2] ^ (laddr)->s6_addr32[3]) + ntohs(lport)) & \
(table)->inpt_bindhash]
#define IN6PCBHASH_CONNECT(table, faddr, fport, laddr, lport) \
&(table)->inpt_bindhashtbl[ \
((((faddr)->s6_addr32[0] ^ (faddr)->s6_addr32[1] ^ \
(faddr)->s6_addr32[2] ^ (faddr)->s6_addr32[3]) + ntohs(fport)) + \
(((laddr)->s6_addr32[0] ^ (laddr)->s6_addr32[1] ^ \
(laddr)->s6_addr32[2] ^ (laddr)->s6_addr32[3]) + \
ntohs(lport))) & (table)->inpt_bindhash]

int ip6_anonportmin = IPV6PORT_ANONMIN;
int ip6_anonportmax = IPV6PORT_ANONMAX;
int ip6_lowportmin = IPV6PORT_RESERVEDMIN;
int ip6_lowportmax = IPV6PORT_RESERVEDMAX;

void
in6pcb_init(struct inpcbtable *table, int bindhashsize, int connecthashsize)
{

inpcb_init(table, bindhashsize, connecthashsize);
table->inpt_lastport = (in_port_t)ip6_anonportmax;
}

/*
* Bind address from sin6 to inp.
*/
static int
in6pcb_bind_addr(struct inpcb *inp, struct sockaddr_in6 *sin6, struct lwp *l)
{
int error;
int s;

/*
* We should check the family, but old programs
* incorrectly fail to initialize it.
*/
if (sin6->sin6_family != AF_INET6)
return EAFNOSUPPORT;

#ifndef INET
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
return EADDRNOTAVAIL;
#endif

if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
return error;

s = pserialize_read_enter();
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
error = EINVAL;
goto out;
}
if (sin6->sin6_addr.s6_addr32[3]) {
struct sockaddr_in sin;

memset(&sin, 0, sizeof(sin));
sin.sin_len = sizeof(sin);
sin.sin_family = AF_INET;
bcopy(&sin6->sin6_addr.s6_addr32[3],
&sin.sin_addr, sizeof(sin.sin_addr));
if (!IN_MULTICAST(sin.sin_addr.s_addr)) {
struct ifaddr *ifa;
ifa = ifa_ifwithaddr((struct sockaddr *)&sin);
if (ifa == NULL &&
(inp->inp_flags & IN6P_BINDANY) == 0) {
error = EADDRNOTAVAIL;
goto out;
}
}
}
} else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
// succeed
} else if (!IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
struct ifaddr *ifa = NULL;

if ((inp->inp_flags & IN6P_FAITH) == 0) {
ifa = ifa_ifwithaddr(sin6tosa(sin6));
if (ifa == NULL &&
(inp->inp_flags & IN6P_BINDANY) == 0) {
error = EADDRNOTAVAIL;
goto out;
}
}

/*
* bind to an anycast address might accidentally
* cause sending a packet with an anycast source
* address, so we forbid it.
*
* We should allow to bind to a deprecated address,
* since the application dare to use it.
* But, can we assume that they are careful enough
* to check if the address is deprecated or not?
* Maybe, as a safeguard, we should have a setsockopt
* flag to control the bind(2) behavior against
* deprecated addresses (default: forbid bind(2)).
*/
if (ifa &&
ifatoia6(ifa)->ia6_flags &
(IN6_IFF_ANYCAST | IN6_IFF_DUPLICATED)) {
error = EADDRNOTAVAIL;
goto out;
}
}
in6p_laddr(inp) = sin6->sin6_addr;
error = 0;
out:
pserialize_read_exit(s);
return error;
}

/*
* Bind port from sin6 to inp.
*/
static int
in6pcb_bind_port(struct inpcb *inp, struct sockaddr_in6 *sin6, struct lwp *l)
{
struct inpcbtable *table = inp->inp_table;
struct socket *so = inp->inp_socket;
int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
int error;

if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
(so->so_options & SO_ACCEPTCONN) == 0))
wild = 1;

if (sin6->sin6_port != 0) {
enum kauth_network_req req;

#ifndef IPNOPRIVPORTS
if (ntohs(sin6->sin6_port) < IPV6PORT_RESERVED)
req = KAUTH_REQ_NETWORK_BIND_PRIVPORT;
else
#endif /* IPNOPRIVPORTS */
req = KAUTH_REQ_NETWORK_BIND_PORT;

error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_BIND,
req, so, sin6, NULL);
if (error)
return EACCES;
}

if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
/*
* Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
* allow compepte duplication of binding if
* SO_REUSEPORT is set, or if SO_REUSEADDR is set
* and a multicast address is bound on both
* new and duplicated sockets.
*/
if (so->so_options & (SO_REUSEADDR | SO_REUSEPORT))
reuseport = SO_REUSEADDR|SO_REUSEPORT;
}

if (sin6->sin6_port != 0) {
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
#ifdef INET
struct inpcb *t;
struct vestigial_inpcb vestige;

t = inpcb_lookup_local(table,
*(struct in_addr *)&sin6->sin6_addr.s6_addr32[3],
sin6->sin6_port, wild, &vestige);
if (t && (reuseport & t->inp_socket->so_options) == 0)
return EADDRINUSE;
if (!t
&& vestige.valid
&& !(reuseport && vestige.reuse_port))
return EADDRINUSE;
#else
return EADDRNOTAVAIL;
#endif
}

{
struct inpcb *t;
struct vestigial_inpcb vestige;

t = in6pcb_lookup_local(table, &sin6->sin6_addr,
sin6->sin6_port, wild, &vestige);
if (t && (reuseport & t->inp_socket->so_options) == 0)
return EADDRINUSE;
if (!t
&& vestige.valid
&& !(reuseport && vestige.reuse_port))
return EADDRINUSE;
}
}

if (sin6->sin6_port == 0) {
int e;
e = in6pcb_set_port(sin6, inp, l);
if (e != 0)
return e;
} else {
inp->inp_lport = sin6->sin6_port;
inpcb_set_state(inp, INP_BOUND);
}

LIST_REMOVE(inp, inp_lhash);
LIST_INSERT_HEAD(IN6PCBHASH_PORT(table, inp->inp_lport),
inp, inp_lhash);

return 0;
}

int
in6pcb_bind(void *v, struct sockaddr_in6 *sin6, struct lwp *l)
{
struct inpcb *inp = v;
struct sockaddr_in6 lsin6;
int error;

if (inp->inp_af != AF_INET6)
return EINVAL;

/*
* If we already have a local port or a local address it means we're
* bounded.
*/
if (inp->inp_lport || !(IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)) ||
(IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp)) &&
in6p_laddr(inp).s6_addr32[3] == 0)))
return EINVAL;

if (NULL != sin6) {
/* We were provided a sockaddr_in6 to use. */
if (sin6->sin6_len != sizeof(*sin6))
return EINVAL;
} else {
/* We always bind to *something*, even if it's "anything". */
lsin6 = *((const struct sockaddr_in6 *)
inp->inp_socket->so_proto->pr_domain->dom_sa_any);
sin6 = &lsin6;
}

/* Bind address. */
error = in6pcb_bind_addr(inp, sin6, l);
if (error)
return error;

/* Bind port. */
error = in6pcb_bind_port(inp, sin6, l);
if (error) {
/*
* Reset the address here to "any" so we don't "leak" the
* inpcb.
*/
in6p_laddr(inp) = in6addr_any;

return error;
}

#if 0
in6p_flowinfo(inp) = 0; /* XXX */
#endif
return 0;
}

/*
* Connect from a socket to a specified address.
* Both address and port must be specified in argument sin6.
* If don't have a local address for this socket yet,
* then pick one.
*/
int
in6pcb_connect(void *v, struct sockaddr_in6 *sin6, struct lwp *l)
{
struct inpcb *inp = v;
struct in6_addr *in6a = NULL;
struct in6_addr ia6;
struct ifnet *ifp = NULL; /* outgoing interface */
int error = 0;
int scope_ambiguous = 0;
#ifdef INET
struct in6_addr mapped;
#endif
struct sockaddr_in6 tmp;
struct vestigial_inpcb vestige;
struct psref psref;
int bound;

(void)&in6a; /* XXX fool gcc */

if (inp->inp_af != AF_INET6)
return EINVAL;

if (sin6->sin6_len != sizeof(*sin6))
return EINVAL;
if (sin6->sin6_family != AF_INET6)
return EAFNOSUPPORT;
if (sin6->sin6_port == 0)
return EADDRNOTAVAIL;

if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr) &&
inp->inp_socket->so_type == SOCK_STREAM)
return EADDRNOTAVAIL;

if (sin6->sin6_scope_id == 0 && !ip6_use_defzone)
scope_ambiguous = 1;
if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
return error;

/* sanity check for mapped address case */
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
return EINVAL;
if (IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)))
in6p_laddr(inp).s6_addr16[5] = htons(0xffff);
if (!IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp)))
return EINVAL;
} else
{
if (IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp)))
return EINVAL;
}

/* protect *sin6 from overwrites */
tmp = *sin6;
sin6 = &tmp;

bound = curlwp_bind();
/* Source address selection. */
if (IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp)) &&
in6p_laddr(inp).s6_addr32[3] == 0) {
#ifdef INET
struct sockaddr_in sin;
struct in_ifaddr *ia4;
struct psref _psref;

memset(&sin, 0, sizeof(sin));
sin.sin_len = sizeof(sin);
sin.sin_family = AF_INET;
memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr32[3],
sizeof(sin.sin_addr));
ia4 = in_selectsrc(&sin, &inp->inp_route,
inp->inp_socket->so_options, NULL, &error, &_psref);
if (ia4 == NULL) {
if (error == 0)
error = EADDRNOTAVAIL;
curlwp_bindx(bound);
return error;
}
memset(&mapped, 0, sizeof(mapped));
mapped.s6_addr16[5] = htons(0xffff);
memcpy(&mapped.s6_addr32[3], &IA_SIN(ia4)->sin_addr,
sizeof(IA_SIN(ia4)->sin_addr));
ia4_release(ia4, &_psref);
in6a = &mapped;
#else
curlwp_bindx(bound);
return EADDRNOTAVAIL;
#endif
} else {
/*
* XXX: in6_selectsrc might replace the bound local address
* with the address specified by setsockopt(IPV6_PKTINFO).
* Is it the intended behavior?
*/
error = in6_selectsrc(sin6, in6p_outputopts(inp),
in6p_moptions(inp), &inp->inp_route, &in6p_laddr(inp),
&ifp, &psref, &ia6);
if (error == 0)
in6a = &ia6;
if (ifp && scope_ambiguous &&
(error = in6_setscope(&sin6->sin6_addr, ifp, NULL)) != 0) {
if_put(ifp, &psref);
curlwp_bindx(bound);
return error;
}

if (in6a == NULL) {
if_put(ifp, &psref);
curlwp_bindx(bound);
if (error == 0)
error = EADDRNOTAVAIL;
return error;
}
}

if (ifp != NULL) {
in6p_ip6(inp).ip6_hlim = (u_int8_t)in6pcb_selecthlim(inp, ifp);
if_put(ifp, &psref);
} else
in6p_ip6(inp).ip6_hlim = (u_int8_t)in6pcb_selecthlim_rt(inp);
curlwp_bindx(bound);

if (in6pcb_lookup(inp->inp_table, &sin6->sin6_addr,
sin6->sin6_port,
IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)) ? in6a : &in6p_laddr(inp),
inp->inp_lport, 0, &vestige)
|| vestige.valid)
return EADDRINUSE;
if (IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)) ||
(IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp)) &&
in6p_laddr(inp).s6_addr32[3] == 0))
{
if (inp->inp_lport == 0) {
error = in6pcb_bind(inp, NULL, l);
if (error != 0)
return error;
}
in6p_laddr(inp) = *in6a;
}
in6p_faddr(inp) = sin6->sin6_addr;
inp->inp_fport = sin6->sin6_port;

/* Late bind, if needed */
if (inp->inp_bindportonsend) {
struct sockaddr_in6 lsin = *((const struct sockaddr_in6 *)
inp->inp_socket->so_proto->pr_domain->dom_sa_any);
lsin.sin6_addr = in6p_laddr(inp);
lsin.sin6_port = 0;

if ((error = in6pcb_bind_port(inp, &lsin, l)) != 0)
return error;
}

inpcb_set_state(inp, INP_CONNECTED);
in6p_flowinfo(inp) &= ~IPV6_FLOWLABEL_MASK;
if (ip6_auto_flowlabel)
in6p_flowinfo(inp) |=
(htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
#if defined(IPSEC)
if (ipsec_enabled && inp->inp_socket->so_type == SOCK_STREAM)
ipsec_pcbconn(inp->inp_sp);
#endif
return 0;
}

void
in6pcb_disconnect(struct inpcb *inp)
{
memset((void *)&in6p_faddr(inp), 0, sizeof(in6p_faddr(inp)));
inp->inp_fport = 0;
inpcb_set_state(inp, INP_BOUND);
in6p_flowinfo(inp) &= ~IPV6_FLOWLABEL_MASK;
#if defined(IPSEC)
if (ipsec_enabled)
ipsec_pcbdisconn(inp->inp_sp);
#endif
if (inp->inp_socket->so_state & SS_NOFDREF)
inpcb_destroy(inp);
}

void
in6pcb_fetch_sockaddr(struct inpcb *inp, struct sockaddr_in6 *sin6)
{

if (inp->inp_af != AF_INET6)
return;

sockaddr_in6_init(sin6, &in6p_laddr(inp), inp->inp_lport, 0, 0);
(void)sa6_recoverscope(sin6); /* XXX: should catch errors */
}

void
in6pcb_fetch_peeraddr(struct inpcb *inp, struct sockaddr_in6 *sin6)
{

if (inp->inp_af != AF_INET6)
return;

sockaddr_in6_init(sin6, &in6p_faddr(inp), inp->inp_fport, 0, 0);
(void)sa6_recoverscope(sin6); /* XXX: should catch errors */
}

/*
* Pass some notification to all connections of a protocol
* associated with address dst. The local address and/or port numbers
* may be specified to limit the search. The "usual action" will be
* taken, depending on the ctlinput cmd. The caller must filter any
* cmds that are uninteresting (e.g., no error in the map).
* Call the protocol specific routine (if any) to report
* any errors for each matching socket.
*
* Must be called at splsoftnet.
*
* Note: src (4th arg) carries the flowlabel value on the original IPv6
* header, in sin6_flowinfo member.
*/
int
in6pcb_notify(struct inpcbtable *table, const struct sockaddr *dst,
u_int fport_arg, const struct sockaddr *src, u_int lport_arg, int cmd,
void *cmdarg, void (*notify)(struct inpcb *, int))
{
struct inpcb *inp;
struct sockaddr_in6 sa6_src;
const struct sockaddr_in6 *sa6_dst;
in_port_t fport = fport_arg, lport = lport_arg;
int errno;
int nmatch = 0;
u_int32_t flowinfo;

if ((unsigned)cmd >= PRC_NCMDS || dst->sa_family != AF_INET6)
return 0;

sa6_dst = (const struct sockaddr_in6 *)dst;
if (IN6_IS_ADDR_UNSPECIFIED(&sa6_dst->sin6_addr))
return 0;

/*
* note that src can be NULL when we get notify by local fragmentation.
*/
sa6_src = (src == NULL) ? sa6_any : *(const struct sockaddr_in6 *)src;
flowinfo = sa6_src.sin6_flowinfo;

/*
* Redirects go to all references to the destination,
* and use in6pcb_rtchange to invalidate the route cache.
* Dead host indications: also use in6pcb_rtchange to invalidate
* the cache, and deliver the error to all the sockets.
* Otherwise, if we have knowledge of the local port and address,
* deliver only to that socket.
*/
if (PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) {
fport = 0;
lport = 0;
memset((void *)&sa6_src.sin6_addr, 0, sizeof(sa6_src.sin6_addr));

if (cmd != PRC_HOSTDEAD)
notify = in6pcb_rtchange;
}

errno = inet6ctlerrmap[cmd];
TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
struct rtentry *rt = NULL;

if (inp->inp_af != AF_INET6)
continue;

/*
* Under the following condition, notify of redirects
* to the pcb, without making address matches against inpcb.
* - redirect notification is arrived.
* - the inpcb is unconnected.
* - the inpcb is caching !RTF_HOST routing entry.
* - the ICMPv6 notification is from the gateway cached in the
* inpcb. i.e. ICMPv6 notification is from nexthop gateway
* the inpcb used very recently.
*
* This is to improve interaction between netbsd/openbsd
* redirect handling code, and inpcb route cache code.
* without the clause, !RTF_HOST routing entry (which carries
* gateway used by inpcb right before the ICMPv6 redirect)
* will be cached forever in unconnected inpcb.
*
* There still is a question regarding to what is TRT:
* - On bsdi/freebsd, RTF_HOST (cloned) routing entry will be
* generated on packet output. inpcb will always cache
* RTF_HOST routing entry so there's no need for the clause
* (ICMPv6 redirect will update RTF_HOST routing entry,
* and inpcb is caching it already).
* However, bsdi/freebsd are vulnerable to local DoS attacks
* due to the cloned routing entries.
* - Specwise, "destination cache" is mentioned in RFC2461.
* Jinmei says that it implies bsdi/freebsd behavior, itojun
* is not really convinced.
* - Having hiwat/lowat on # of cloned host route (redirect/
* pmtud) may be a good idea. netbsd/openbsd has it. see
* icmp6_mtudisc_update().
*/
if ((PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) &&
IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)) &&
(rt = rtcache_validate(&inp->inp_route)) != NULL &&
!(rt->rt_flags & RTF_HOST)) {
const struct sockaddr_in6 *dst6;

dst6 = (const struct sockaddr_in6 *)
rtcache_getdst(&inp->inp_route);
if (dst6 == NULL)
;
else if (IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr,
&sa6_dst->sin6_addr)) {
rtcache_unref(rt, &inp->inp_route);
goto do_notify;
}
}
rtcache_unref(rt, &inp->inp_route);

/*
* If the error designates a new path MTU for a destination
* and the application (associated with this socket) wanted to
* know the value, notify. Note that we notify for all
* disconnected sockets if the corresponding application
* wanted. This is because some UDP applications keep sending
* sockets disconnected.
* XXX: should we avoid to notify the value to TCP sockets?
*/
if (cmd == PRC_MSGSIZE && (inp->inp_flags & IN6P_MTU) != 0 &&
(IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp)) ||
IN6_ARE_ADDR_EQUAL(&in6p_faddr(inp), &sa6_dst->sin6_addr))) {
ip6_notify_pmtu(inp, (const struct sockaddr_in6 *)dst,
(u_int32_t *)cmdarg);
}

/*
* Detect if we should notify the error. If no source and
* destination ports are specified, but non-zero flowinfo and
* local address match, notify the error. This is the case
* when the error is delivered with an encrypted buffer
* by ESP. Otherwise, just compare addresses and ports
* as usual.
*/
if (lport == 0 && fport == 0 && flowinfo &&
inp->inp_socket != NULL &&
flowinfo == (in6p_flowinfo(inp) & IPV6_FLOWLABEL_MASK) &&
IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp), &sa6_src.sin6_addr))
goto do_notify;
else if (!IN6_ARE_ADDR_EQUAL(&in6p_faddr(inp),
&sa6_dst->sin6_addr) ||
inp->inp_socket == NULL ||
(lport && inp->inp_lport != lport) ||
(!IN6_IS_ADDR_UNSPECIFIED(&sa6_src.sin6_addr) &&
!IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp),
&sa6_src.sin6_addr)) ||
(fport && inp->inp_fport != fport))
continue;

do_notify:
if (notify)
(*notify)(inp, errno);
nmatch++;
}
return nmatch;
}

void
in6pcb_purgeif0(struct inpcbtable *table, struct ifnet *ifp)
{
struct inpcb *inp;
struct ip6_moptions *im6o;
struct in6_multi_mship *imm, *nimm;

KASSERT(ifp != NULL);

TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
bool need_unlock = false;
if (inp->inp_af != AF_INET6)
continue;

/* The caller holds either one of inps' lock */
if (!inp_locked(inp)) {
inp_lock(inp);
need_unlock = true;
}
im6o = in6p_moptions(inp);
if (im6o) {
/*
* Unselect the outgoing interface if it is being
* detached.
*/
if (im6o->im6o_multicast_if_index == ifp->if_index)
im6o->im6o_multicast_if_index = 0;

/*
* Drop multicast group membership if we joined
* through the interface being detached.
* XXX controversial - is it really legal for kernel
* to force this?
*/
LIST_FOREACH_SAFE(imm, &im6o->im6o_memberships,
i6mm_chain, nimm) {
if (imm->i6mm_maddr->in6m_ifp == ifp) {
LIST_REMOVE(imm, i6mm_chain);
in6_leavegroup(imm);
}
}
}

in_purgeifmcast(inp->inp_moptions, ifp);

if (need_unlock)
inp_unlock(inp);
}
}

void
in6pcb_purgeif(struct inpcbtable *table, struct ifnet *ifp)
{
struct rtentry *rt;
struct inpcb *inp;

TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
if (inp->inp_af != AF_INET6)
continue;
if ((rt = rtcache_validate(&inp->inp_route)) != NULL &&
rt->rt_ifp == ifp) {
rtcache_unref(rt, &inp->inp_route);
in6pcb_rtchange(inp, 0);
} else
rtcache_unref(rt, &inp->inp_route);
}
}

/*
* After a routing change, flush old routing. A new route can be
* allocated the next time output is attempted.
*/
void
in6pcb_rtchange(struct inpcb *inp, int errno)
{
if (inp->inp_af != AF_INET6)
return;

rtcache_free(&inp->inp_route);
/*
* A new route can be allocated the next time
* output is attempted.
*/
}

struct inpcb *
in6pcb_lookup_local(struct inpcbtable *table, struct in6_addr *laddr6,
u_int lport_arg, int lookup_wildcard, struct vestigial_inpcb *vp)
{
struct inpcbhead *head;
struct inpcb *inp, *match = NULL;
int matchwild = 3, wildcard;
in_port_t lport = lport_arg;

if (vp)
vp->valid = 0;

head = IN6PCBHASH_PORT(table, lport);
LIST_FOREACH(inp, head, inp_lhash) {
if (inp->inp_af != AF_INET6)
continue;

if (inp->inp_lport != lport)
continue;
wildcard = 0;
if (IN6_IS_ADDR_V4MAPPED(&in6p_faddr(inp))) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp)))
wildcard++;
if (IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp))) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
if (!IN6_IS_ADDR_V4MAPPED(laddr6))
continue;

/* duplicate of IPv4 logic */
wildcard = 0;
if (IN6_IS_ADDR_V4MAPPED(&in6p_faddr(inp)) &&
in6p_faddr(inp).s6_addr32[3])
wildcard++;
if (!in6p_laddr(inp).s6_addr32[3]) {
if (laddr6->s6_addr32[3])
wildcard++;
} else {
if (!laddr6->s6_addr32[3])
wildcard++;
else {
if (in6p_laddr(inp).s6_addr32[3] !=
laddr6->s6_addr32[3])
continue;
}
}
} else if (IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp))) {
if (IN6_IS_ADDR_V4MAPPED(laddr6)) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
}
if (!IN6_IS_ADDR_UNSPECIFIED(laddr6))
wildcard++;
} else {
if (IN6_IS_ADDR_V4MAPPED(laddr6)) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
}
if (IN6_IS_ADDR_UNSPECIFIED(laddr6))
wildcard++;
else {
if (!IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp),
laddr6))
continue;
}
}
if (wildcard && !lookup_wildcard)
continue;
if (wildcard < matchwild) {
match = inp;
matchwild = wildcard;
if (matchwild == 0)
break;
}
}
if (match && matchwild == 0)
return match;

if (vp && table->vestige && table->vestige->init_ports6) {
struct vestigial_inpcb better;
bool has_better = false;
void *state;

state = (*table->vestige->init_ports6)(laddr6,
lport_arg,
lookup_wildcard);
while (table->vestige
&& (*table->vestige->next_port6)(state, vp)) {

if (vp->lport != lport)
continue;
wildcard = 0;
if (!IN6_IS_ADDR_UNSPECIFIED(&vp->faddr.v6))
wildcard++;
if (IN6_IS_ADDR_UNSPECIFIED(&vp->laddr.v6)) {
if (!IN6_IS_ADDR_UNSPECIFIED(laddr6))
wildcard++;
} else {
if (IN6_IS_ADDR_V4MAPPED(laddr6)) {
if (vp->v6only)
continue;
}
if (IN6_IS_ADDR_UNSPECIFIED(laddr6))
wildcard++;
else {
if (!IN6_ARE_ADDR_EQUAL(&vp->laddr.v6, laddr6))
continue;
}
}
if (wildcard && !lookup_wildcard)
continue;
if (wildcard < matchwild) {
better = *vp;
has_better = true;

matchwild = wildcard;
if (matchwild == 0)
break;
}
}

if (has_better) {
*vp = better;
return 0;
}
}
return match;
}

/*
* WARNING: return value (rtentry) could be IPv4 one if inpcb is connected to
* IPv4 mapped address.
*/
struct rtentry *
in6pcb_rtentry(struct inpcb *inp)
{
struct rtentry *rt;
struct route *ro;
union {
const struct sockaddr *sa;
const struct sockaddr_in6 *sa6;
#ifdef INET
const struct sockaddr_in *sa4;
#endif
} cdst;

ro = &inp->inp_route;

if (inp->inp_af != AF_INET6)
return NULL;

cdst.sa = rtcache_getdst(ro);
if (cdst.sa == NULL)
;
#ifdef INET
else if (cdst.sa->sa_family == AF_INET) {
KASSERT(IN6_IS_ADDR_V4MAPPED(&in6p_faddr(inp)));
if (cdst.sa4->sin_addr.s_addr != in6p_faddr(inp).s6_addr32[3])
rtcache_free(ro);
}
#endif
else {
if (!IN6_ARE_ADDR_EQUAL(&cdst.sa6->sin6_addr,
&in6p_faddr(inp)))
rtcache_free(ro);
}
if ((rt = rtcache_validate(ro)) == NULL)
rt = rtcache_update(ro, 1);
#ifdef INET
if (rt == NULL && IN6_IS_ADDR_V4MAPPED(&in6p_faddr(inp))) {
union {
struct sockaddr dst;
struct sockaddr_in dst4;
} u;
struct in_addr addr;

addr.s_addr = in6p_faddr(inp).s6_addr32[3];

sockaddr_in_init(&u.dst4, &addr, 0);
if (rtcache_setdst(ro, &u.dst) != 0)
return NULL;

rt = rtcache_init(ro);
} else
#endif
if (rt == NULL && !IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp))) {
union {
struct sockaddr dst;
struct sockaddr_in6 dst6;
} u;

sockaddr_in6_init(&u.dst6, &in6p_faddr(inp), 0, 0, 0);
if (rtcache_setdst(ro, &u.dst) != 0)
return NULL;

rt = rtcache_init(ro);
}
return rt;
}

void
in6pcb_rtentry_unref(struct rtentry *rt, struct inpcb *inp)
{

rtcache_unref(rt, &inp->inp_route);
}

struct inpcb *
in6pcb_lookup(struct inpcbtable *table, const struct in6_addr *faddr6,
u_int fport_arg, const struct in6_addr *laddr6, u_int lport_arg,
int faith,
struct vestigial_inpcb *vp)
{
struct inpcbhead *head;
struct inpcb *inp;
in_port_t fport = fport_arg, lport = lport_arg;

if (vp)
vp->valid = 0;

head = IN6PCBHASH_CONNECT(table, faddr6, fport, laddr6, lport);
LIST_FOREACH(inp, head, inp_hash) {
if (inp->inp_af != AF_INET6)
continue;

/* find exact match on both source and dest */
if (inp->inp_fport != fport)
continue;
if (inp->inp_lport != lport)
continue;
if (IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp)))
continue;
if (!IN6_ARE_ADDR_EQUAL(&in6p_faddr(inp), faddr6))
continue;
if (IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)))
continue;
if (!IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp), laddr6))
continue;
if ((IN6_IS_ADDR_V4MAPPED(laddr6) ||
IN6_IS_ADDR_V4MAPPED(faddr6)) &&
(inp->inp_flags & IN6P_IPV6_V6ONLY))
continue;
return inp;
}
if (vp && table->vestige) {
if ((*table->vestige->lookup6)(faddr6, fport_arg,
laddr6, lport_arg, vp))
return NULL;
}

return NULL;
}

struct inpcb *
in6pcb_lookup_bound(struct inpcbtable *table, const struct in6_addr *laddr6,
u_int lport_arg, int faith)
{
struct inpcbhead *head;
struct inpcb *inp;
in_port_t lport = lport_arg;
#ifdef INET
struct in6_addr zero_mapped;
#endif

head = IN6PCBHASH_BIND(table, laddr6, lport);
LIST_FOREACH(inp, head, inp_hash) {
if (inp->inp_af != AF_INET6)
continue;

if (faith && (inp->inp_flags & IN6P_FAITH) == 0)
continue;
if (inp->inp_fport != 0)
continue;
if (inp->inp_lport != lport)
continue;
if (IN6_IS_ADDR_V4MAPPED(laddr6) &&
(inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
if (IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp), laddr6))
goto out;
}
#ifdef INET
if (IN6_IS_ADDR_V4MAPPED(laddr6)) {
memset(&zero_mapped, 0, sizeof(zero_mapped));
zero_mapped.s6_addr16[5] = 0xffff;
head = IN6PCBHASH_BIND(table, &zero_mapped, lport);
LIST_FOREACH(inp, head, inp_hash) {
if (inp->inp_af != AF_INET6)
continue;

if (faith && (inp->inp_flags & IN6P_FAITH) == 0)
continue;
if (inp->inp_fport != 0)
continue;
if (inp->inp_lport != lport)
continue;
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
if (IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp), &zero_mapped))
goto out;
}
}
#endif
head = IN6PCBHASH_BIND(table, &zeroin6_addr, lport);
LIST_FOREACH(inp, head, inp_hash) {
if (inp->inp_af != AF_INET6)
continue;

if (faith && (inp->inp_flags & IN6P_FAITH) == 0)
continue;
if (inp->inp_fport != 0)
continue;
if (inp->inp_lport != lport)
continue;
if (IN6_IS_ADDR_V4MAPPED(laddr6) &&
(inp->inp_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
if (IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp), &zeroin6_addr))
goto out;
}
return NULL;

out:
if (inp != LIST_FIRST(head)) {
LIST_REMOVE(inp, inp_hash);
LIST_INSERT_HEAD(head, inp, inp_hash);
}
return inp;
}

void
in6pcb_set_state(struct inpcb *inp, int state)
{

if (inp->inp_af != AF_INET6)
return;

if (inp->inp_state > INP_ATTACHED)
LIST_REMOVE(inp, inp_hash);

switch (state) {
case INP_BOUND:
LIST_INSERT_HEAD(IN6PCBHASH_BIND(inp->inp_table,
&in6p_laddr(inp), inp->inp_lport), inp,
inp_hash);
break;
case INP_CONNECTED:
LIST_INSERT_HEAD(IN6PCBHASH_CONNECT(inp->inp_table,
&in6p_faddr(inp), inp->inp_fport,
&in6p_laddr(inp), inp->inp_lport), inp,
inp_hash);
break;
}

inp->inp_state = state;
}