/* $NetBSD: udp6_usrreq.c,v 1.156 2024/10/08 02:30:05 riastradh Exp $ */

/* $NetBSD: udp6_usrreq.c,v 1.156 2024/10/08 02:30:05 riastradh Exp $ */
/* $KAME: udp6_usrreq.c,v 1.86 2001/05/27 17:33:00 itojun Exp $ */
/* $KAME: udp6_output.c,v 1.43 2001/10/15 09:19:52 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, 1989, 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.
*
* @(#)udp_var.h 8.1 (Berkeley) 6/10/93
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: udp6_usrreq.c,v 1.156 2024/10/08 02:30:05 riastradh Exp $");

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

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/syslog.h>
#include <sys/domain.h>
#include <sys/sysctl.h>

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

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/in_offload.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/in_pcb.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/udp_private.h>

#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/ip6_private.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/udp6_var.h>
#include <netinet6/udp6_private.h>
#include <netinet6/ip6protosw.h>
#include <netinet6/scope6_var.h>

#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/esp.h>
#ifdef INET6
#include <netipsec/ipsec6.h>
#endif
#endif

#include "faith.h"
#if defined(NFAITH) && NFAITH > 0
#include <net/if_faith.h>
#endif

/*
* UDP protocol implementation.
* Per RFC 768, August, 1980.
*/

extern struct inpcbtable udbtable;

percpu_t *udp6stat_percpu;

/* UDP on IP6 parameters */
static int udp6_sendspace = 9216; /* really max datagram size */
static int udp6_recvspace = 40 * (1024 + sizeof(struct sockaddr_in6));
/* 40 1K datagrams */

static void udp6_notify(struct inpcb *, int);
static void sysctl_net_inet6_udp6_setup(struct sysctllog **);
#ifdef IPSEC
static int udp6_espinudp(struct mbuf **, int);
#endif

#ifdef UDP_CSUM_COUNTERS
#include <sys/device.h>
struct evcnt udp6_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
NULL, "udp6", "hwcsum bad");
struct evcnt udp6_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
NULL, "udp6", "hwcsum ok");
struct evcnt udp6_hwcsum_data = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
NULL, "udp6", "hwcsum data");
struct evcnt udp6_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
NULL, "udp6", "swcsum");

EVCNT_ATTACH_STATIC(udp6_hwcsum_bad);
EVCNT_ATTACH_STATIC(udp6_hwcsum_ok);
EVCNT_ATTACH_STATIC(udp6_hwcsum_data);
EVCNT_ATTACH_STATIC(udp6_swcsum);

#define UDP_CSUM_COUNTER_INCR(ev) (ev)->ev_count++
#else
#define UDP_CSUM_COUNTER_INCR(ev) /* nothing */
#endif

void
udp6_init(void)
{
sysctl_net_inet6_udp6_setup(NULL);
udp6stat_percpu = percpu_alloc(sizeof(uint64_t) * UDP6_NSTATS);

udp_init_common();
}

/*
* Notify a udp user of an asynchronous error;
* just wake up so that he can collect error status.
*/
static void
udp6_notify(struct inpcb *inp, int errno)
{
inp->inp_socket->so_error = errno;
sorwakeup(inp->inp_socket);
sowwakeup(inp->inp_socket);
}

void *
udp6_ctlinput(int cmd, const struct sockaddr *sa, void *d)
{
struct udphdr uh;
struct ip6_hdr *ip6;
const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *)sa;
struct mbuf *m;
int off;
void *cmdarg;
struct ip6ctlparam *ip6cp = NULL;
const struct sockaddr_in6 *sa6_src = NULL;
void (*notify)(struct inpcb *, int) = udp6_notify;
struct udp_portonly {
u_int16_t uh_sport;
u_int16_t uh_dport;
} *uhp;

if (sa->sa_family != AF_INET6 ||
sa->sa_len != sizeof(struct sockaddr_in6))
return NULL;

if ((unsigned)cmd >= PRC_NCMDS)
return NULL;
if (PRC_IS_REDIRECT(cmd))
notify = in6pcb_rtchange, d = NULL;
else if (cmd == PRC_HOSTDEAD)
d = NULL;
else if (cmd == PRC_MSGSIZE) {
/* special code is present, see below */
notify = in6pcb_rtchange;
}
else if (inet6ctlerrmap[cmd] == 0)
return NULL;

/* if the parameter is from icmp6, decode it. */
if (d != NULL) {
ip6cp = (struct ip6ctlparam *)d;
m = ip6cp->ip6c_m;
ip6 = ip6cp->ip6c_ip6;
off = ip6cp->ip6c_off;
cmdarg = ip6cp->ip6c_cmdarg;
sa6_src = ip6cp->ip6c_src;
} else {
m = NULL;
ip6 = NULL;
cmdarg = NULL;
sa6_src = &sa6_any;
off = 0;
}

if (ip6) {
/* check if we can safely examine src and dst ports */
if (m->m_pkthdr.len < off + sizeof(*uhp)) {
if (cmd == PRC_MSGSIZE)
icmp6_mtudisc_update((struct ip6ctlparam *)d, 0);
return NULL;
}

memset(&uh, 0, sizeof(uh));
m_copydata(m, off, sizeof(*uhp), (void *)&uh);

if (cmd == PRC_MSGSIZE) {
int valid = 0;

/*
* Check to see if we have a valid UDP socket
* corresponding to the address in the ICMPv6 message
* payload.
*/
if (in6pcb_lookup(&udbtable, &sa6->sin6_addr,
uh.uh_dport, (const struct in6_addr *)&sa6_src->sin6_addr,
uh.uh_sport, 0, 0))
valid++;
#if 0
/*
* As the use of sendto(2) is fairly popular,
* we may want to allow non-connected pcb too.
* But it could be too weak against attacks...
* We should at least check if the local address (= s)
* is really ours.
*/
else if (in6pcb_lookup_bound(&udbtable, &sa6->sin6_addr,
uh.uh_dport, 0))
valid++;
#endif

/*
* Depending on the value of "valid" and routing table
* size (mtudisc_{hi,lo}wat), we will:
* - recalculate the new MTU and create the
* corresponding routing entry, or
* - ignore the MTU change notification.
*/
icmp6_mtudisc_update((struct ip6ctlparam *)d, valid);

/*
* regardless of if we called
* icmp6_mtudisc_update(), we need to call
* in6pcb_notify(), to notify path MTU change
* to the userland (RFC3542), because some
* unconnected sockets may share the same
* destination and want to know the path MTU.
*/
}

(void)in6pcb_notify(&udbtable, sa, uh.uh_dport,
sin6tocsa(sa6_src), uh.uh_sport, cmd, cmdarg,
notify);
} else {
(void)in6pcb_notify(&udbtable, sa, 0,
sin6tocsa(sa6_src), 0, cmd, cmdarg, notify);
}
return NULL;
}

int
udp6_ctloutput(int op, struct socket *so, struct sockopt *sopt)
{
int s;
int error = 0;
struct inpcb *inp;
int family;
int optval;

family = so->so_proto->pr_domain->dom_family;

s = splsoftnet();
switch (family) {
#ifdef INET
case PF_INET:
if (sopt->sopt_level != IPPROTO_UDP) {
error = ip_ctloutput(op, so, sopt);
goto end;
}
break;
#endif
#ifdef INET6
case PF_INET6:
if (sopt->sopt_level != IPPROTO_UDP) {
error = ip6_ctloutput(op, so, sopt);
goto end;
}
break;
#endif
default:
error = EAFNOSUPPORT;
goto end;
}

switch (op) {
case PRCO_SETOPT:
inp = sotoinpcb(so);

switch (sopt->sopt_name) {
case UDP_ENCAP:
error = sockopt_getint(sopt, &optval);
if (error)
break;

switch(optval) {
case 0:
inp->inp_flags &= ~IN6P_ESPINUDP;
break;

case UDP_ENCAP_ESPINUDP:
inp->inp_flags |= IN6P_ESPINUDP;
break;

default:
error = EINVAL;
break;
}
break;

default:
error = ENOPROTOOPT;
break;
}
break;

default:
error = EINVAL;
break;
}

end:
splx(s);
return error;
}

static void
udp6_sendup(struct mbuf *m, int off /* offset of data portion */,
struct sockaddr *src, struct socket *so)
{
struct mbuf *opts = NULL;
struct mbuf *n;
struct inpcb *inp;

KASSERT(so != NULL);
KASSERT(so->so_proto->pr_domain->dom_family == AF_INET6);
inp = sotoinpcb(so);
KASSERT(inp != NULL);

#if defined(IPSEC)
if (ipsec_used && ipsec_in_reject(m, inp)) {
if ((n = m_copypacket(m, M_DONTWAIT)) != NULL)
icmp6_error(n, ICMP6_DST_UNREACH,
ICMP6_DST_UNREACH_ADMIN, 0);
return;
}
#endif

if ((n = m_copypacket(m, M_DONTWAIT)) != NULL) {
if (inp->inp_flags & IN6P_CONTROLOPTS ||
SOOPT_TIMESTAMP(inp->inp_socket->so_options)) {
struct ip6_hdr *ip6 = mtod(n, struct ip6_hdr *);
ip6_savecontrol(inp, &opts, ip6, n);
}

m_adj(n, off);
if (sbappendaddr(&so->so_rcv, src, n, opts) == 0) {
m_freem(n);
m_freem(opts);
UDP6_STATINC(UDP6_STAT_FULLSOCK);
soroverflow(so);
} else
sorwakeup(so);
}
}

int
udp6_realinput(int af, struct sockaddr_in6 *src, struct sockaddr_in6 *dst,
struct mbuf **mp, int off)
{
u_int16_t sport, dport;
int rcvcnt;
struct in6_addr src6, *dst6;
const struct in_addr *dst4;
struct inpcb *inp;
struct mbuf *m = *mp;

rcvcnt = 0;
off += sizeof(struct udphdr); /* now, offset of payload */

if (af != AF_INET && af != AF_INET6)
goto bad;
if (src->sin6_family != AF_INET6 || dst->sin6_family != AF_INET6)
goto bad;

src6 = src->sin6_addr;
if (sa6_recoverscope(src) != 0) {
/* XXX: should be impossible. */
goto bad;
}
sport = src->sin6_port;

dport = dst->sin6_port;
dst4 = (struct in_addr *)&dst->sin6_addr.s6_addr[12];
dst6 = &dst->sin6_addr;

if (IN6_IS_ADDR_MULTICAST(dst6) ||
(af == AF_INET && IN_MULTICAST(dst4->s_addr))) {
/*
* Deliver a multicast or broadcast datagram to *all* sockets
* for which the local and remote addresses and ports match
* those of the incoming datagram. This allows more than
* one process to receive multi/broadcasts on the same port.
* (This really ought to be done for unicast datagrams as
* well, but that would cause problems with existing
* applications that open both address-specific sockets and
* a wildcard socket listening to the same port -- they would
* end up receiving duplicates of every unicast datagram.
* Those applications open the multiple sockets to overcome an
* inadequacy of the UDP socket interface, but for backwards
* compatibility we avoid the problem here rather than
* fixing the interface. Maybe 4.5BSD will remedy this?)
*/

/*
* KAME note: traditionally we dropped udpiphdr from mbuf here.
* we need udpiphdr for IPsec processing so we do that later.
*/
/*
* Locate pcb(s) for datagram.
*/
TAILQ_FOREACH(inp, &udbtable.inpt_queue, inp_queue) {
if (inp->inp_af != AF_INET6)
continue;

if (inp->inp_lport != dport)
continue;
if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp))) {
if (!IN6_ARE_ADDR_EQUAL(&in6p_laddr(inp),
dst6))
continue;
} else {
if (IN6_IS_ADDR_V4MAPPED(dst6) &&
(inp->inp_flags & IN6P_IPV6_V6ONLY))
continue;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp))) {
if (!IN6_ARE_ADDR_EQUAL(&in6p_faddr(inp),
&src6) || inp->inp_fport != sport)
continue;
} else {
if (IN6_IS_ADDR_V4MAPPED(&src6) &&
(inp->inp_flags & IN6P_IPV6_V6ONLY))
continue;
}

udp6_sendup(m, off, sin6tosa(src), inp->inp_socket);
rcvcnt++;

/*
* Don't look for additional matches if this one does
* not have either the SO_REUSEPORT or SO_REUSEADDR
* socket options set. This heuristic avoids searching
* through all pcbs in the common case of a non-shared
* port. It assumes that an application will never
* clear these options after setting them.
*/
if ((inp->inp_socket->so_options &
(SO_REUSEPORT|SO_REUSEADDR)) == 0)
break;
}
} else {
/*
* Locate pcb for datagram.
*/
inp = in6pcb_lookup(&udbtable, &src6, sport, dst6,
dport, 0, 0);
if (inp == NULL) {
UDP_STATINC(UDP_STAT_PCBHASHMISS);
inp = in6pcb_lookup_bound(&udbtable, dst6, dport, 0);
if (inp == NULL)
return rcvcnt;
}

#ifdef IPSEC
/* Handle ESP over UDP */
if (inp->inp_flags & IN6P_ESPINUDP) {
switch (udp6_espinudp(mp, off)) {
case -1: /* Error, m was freed */
KASSERT(*mp == NULL);
rcvcnt = -1;
goto bad;

case 1: /* ESP over UDP */
KASSERT(*mp == NULL);
rcvcnt++;
goto bad;

case 0: /* plain UDP */
default: /* Unexpected */
/*
* Normal UDP processing will take place,
* m may have changed.
*/
m = *mp;
break;
}
}
#endif

if (inp->inp_overudp_cb != NULL) {
int ret;
ret = inp->inp_overudp_cb(mp, off, inp->inp_socket,
sin6tosa(src), inp->inp_overudp_arg);
switch (ret) {
case -1: /* Error, m was freed */
KASSERT(*mp == NULL);
rcvcnt = -1;
goto bad;

case 1: /* Foo over UDP */
KASSERT(*mp == NULL);
rcvcnt++;
goto bad;

case 0: /* plain UDP */
default: /* Unexpected */
/*
* Normal UDP processing will take place,
* m may have changed.
*/
m = *mp;
break;
}
}

udp6_sendup(m, off, sin6tosa(src), inp->inp_socket);
rcvcnt++;
}

bad:
return rcvcnt;
}

int
udp6_input_checksum(struct mbuf *m, const struct udphdr *uh, int off, int len)
{

/*
* XXX it's better to record and check if this mbuf is
* already checked.
*/

if (__predict_false((m->m_flags & M_LOOP) && !udp_do_loopback_cksum)) {
goto good;
}
if (uh->uh_sum == 0) {
UDP6_STATINC(UDP6_STAT_NOSUM);
goto bad;
}

switch (m->m_pkthdr.csum_flags &
((m_get_rcvif_NOMPSAFE(m)->if_csum_flags_rx & M_CSUM_UDPv6) |
M_CSUM_TCP_UDP_BAD | M_CSUM_DATA)) {
case M_CSUM_UDPv6|M_CSUM_TCP_UDP_BAD:
UDP_CSUM_COUNTER_INCR(&udp6_hwcsum_bad);
UDP6_STATINC(UDP6_STAT_BADSUM);
goto bad;

#if 0 /* notyet */
case M_CSUM_UDPv6|M_CSUM_DATA:
#endif

case M_CSUM_UDPv6:
/* Checksum was okay. */
UDP_CSUM_COUNTER_INCR(&udp6_hwcsum_ok);
break;

default:
/*
* Need to compute it ourselves. Maybe skip checksum
* on loopback interfaces.
*/
UDP_CSUM_COUNTER_INCR(&udp6_swcsum);
if (in6_cksum(m, IPPROTO_UDP, off, len) != 0) {
UDP6_STATINC(UDP6_STAT_BADSUM);
goto bad;
}
}

good:
return 0;
bad:
return -1;
}

int
udp6_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m = *mp;
int off = *offp;
struct sockaddr_in6 src, dst;
struct ip6_hdr *ip6;
struct udphdr *uh;
u_int32_t plen, ulen;

ip6 = mtod(m, struct ip6_hdr *);

#if defined(NFAITH) && 0 < NFAITH
if (faithprefix(&ip6->ip6_dst)) {
/* send icmp6 host unreach? */
m_freem(m);
return IPPROTO_DONE;
}
#endif

UDP6_STATINC(UDP6_STAT_IPACKETS);

/* Check for jumbogram is done in ip6_input. We can trust pkthdr.len. */
plen = m->m_pkthdr.len - off;
IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(struct udphdr));
if (uh == NULL) {
IP6_STATINC(IP6_STAT_TOOSHORT);
return IPPROTO_DONE;
}

/*
* Enforce alignment requirements that are violated in
* some cases, see kern/50766 for details.
*/
if (ACCESSIBLE_POINTER(uh, struct udphdr) == 0) {
m = m_copyup(m, off + sizeof(struct udphdr), 0);
if (m == NULL) {
IP6_STATINC(IP6_STAT_TOOSHORT);
return IPPROTO_DONE;
}
ip6 = mtod(m, struct ip6_hdr *);
uh = (struct udphdr *)(mtod(m, char *) + off);
}
KASSERT(ACCESSIBLE_POINTER(uh, struct udphdr));
ulen = ntohs((u_short)uh->uh_ulen);

/*
* RFC2675 section 4: jumbograms will have 0 in the UDP header field,
* iff payload length > 0xffff.
*/
if (ulen == 0 && plen > 0xffff)
ulen = plen;

if (plen != ulen) {
UDP6_STATINC(UDP6_STAT_BADLEN);
goto bad;
}

/* destination port of 0 is illegal, based on RFC768. */
if (uh->uh_dport == 0)
goto bad;

/*
* Checksum extended UDP header and data. Maybe skip checksum
* on loopback interfaces.
*/
if (udp6_input_checksum(m, uh, off, ulen))
goto bad;

/*
* Construct source and dst sockaddrs.
*/
memset(&src, 0, sizeof(src));
src.sin6_family = AF_INET6;
src.sin6_len = sizeof(struct sockaddr_in6);
src.sin6_addr = ip6->ip6_src;
src.sin6_port = uh->uh_sport;
memset(&dst, 0, sizeof(dst));
dst.sin6_family = AF_INET6;
dst.sin6_len = sizeof(struct sockaddr_in6);
dst.sin6_addr = ip6->ip6_dst;
dst.sin6_port = uh->uh_dport;

if (udp6_realinput(AF_INET6, &src, &dst, &m, off) == 0) {
if (m->m_flags & M_MCAST) {
UDP6_STATINC(UDP6_STAT_NOPORTMCAST);
goto bad;
}
UDP6_STATINC(UDP6_STAT_NOPORT);
icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
m = NULL;
}

bad:
m_freem(m);
return IPPROTO_DONE;
}

int
udp6_output(struct inpcb * const inp, struct mbuf *m,
struct sockaddr_in6 * const addr6, struct mbuf * const control,
struct lwp * const l)
{
u_int32_t ulen = m->m_pkthdr.len;
u_int32_t plen = sizeof(struct udphdr) + ulen;
struct ip6_hdr *ip6;
struct udphdr *udp6;
struct in6_addr _laddr, *laddr, *faddr;
struct in6_addr laddr_mapped; /* XXX ugly */
struct sockaddr_in6 *sin6 = NULL;
struct ifnet *oifp = NULL;
int scope_ambiguous = 0;
u_int16_t fport;
int error = 0;
struct ip6_pktopts *optp = NULL;
struct ip6_pktopts opt;
int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
#ifdef INET
struct ip *ip;
struct udpiphdr *ui;
int flags = 0;
#endif
struct sockaddr_in6 tmp;

if (addr6) {
sin6 = addr6;
if (sin6->sin6_len != sizeof(*sin6)) {
error = EINVAL;
goto release;
}
if (sin6->sin6_family != AF_INET6) {
error = EAFNOSUPPORT;
goto release;
}

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

/*
* Application should provide a proper zone ID or the use of
* default zone IDs should be enabled. Unfortunately, some
* applications do not behave as it should, so we need a
* workaround. Even if an appropriate ID is not determined,
* we'll see if we can determine the outgoing interface. If we
* can, determine the zone ID based on the interface below.
*/
if (sin6->sin6_scope_id == 0 && !ip6_use_defzone)
scope_ambiguous = 1;
if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
goto release;
}

if (control) {
if (__predict_false(l == NULL)) {
panic("%s: control but no lwp", __func__);
}
if ((error = ip6_setpktopts(control, &opt,
in6p_outputopts(inp), l->l_cred, IPPROTO_UDP)) != 0)
goto release;
optp = &opt;
} else
optp = in6p_outputopts(inp);

if (sin6) {
/*
* Slightly different than v4 version in that we call
* in6_selectsrc and in6pcb_set_port to fill in the local
* address and port rather than inpcb_connect. inpcb_connect
* sets inp_faddr which causes EISCONN below to be hit on
* subsequent sendto.
*/
if (sin6->sin6_port == 0) {
error = EADDRNOTAVAIL;
goto release;
}

if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp))) {
/* how about ::ffff:0.0.0.0 case? */
error = EISCONN;
goto release;
}

faddr = &sin6->sin6_addr;
fport = sin6->sin6_port; /* allow 0 port */

if (IN6_IS_ADDR_V4MAPPED(faddr)) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
/*
* I believe we should explicitly discard the
* packet when mapped addresses are disabled,
* rather than send the packet as an IPv6 one.
* If we chose the latter approach, the packet
* might be sent out on the wire based on the
* default route, the situation which we'd
* probably want to avoid.
* (20010421 [email protected])
*/
error = EINVAL;
goto release;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp)) &&
!IN6_IS_ADDR_V4MAPPED(&in6p_laddr(inp))) {
/*
* when remote addr is an IPv4-mapped address,
* local addr should not be an IPv6 address,
* since you cannot determine how to map IPv6
* source address to IPv4.
*/
error = EINVAL;
goto release;
}

af = AF_INET;
}

if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
struct psref psref;
int bound = curlwp_bind();

error = in6_selectsrc(sin6, optp,
in6p_moptions(inp),
&inp->inp_route,
&in6p_laddr(inp), &oifp, &psref, &_laddr);
if (error)
laddr = NULL;
else
laddr = &_laddr;
if (oifp && scope_ambiguous &&
(error = in6_setscope(&sin6->sin6_addr,
oifp, NULL))) {
if_put(oifp, &psref);
curlwp_bindx(bound);
goto release;
}
if_put(oifp, &psref);
curlwp_bindx(bound);
} else {
/*
* XXX: freebsd[34] does not have in_selectsrc, but
* we can omit the whole part because freebsd4 calls
* udp_output() directly in this case, and thus we'll
* never see this path.
*/
if (IN6_IS_ADDR_UNSPECIFIED(&in6p_laddr(inp))) {
struct sockaddr_in sin_dst;
struct in_addr ina;
struct in_ifaddr *ia4;
struct psref _psref;
int bound;

memcpy(&ina, &faddr->s6_addr[12], sizeof(ina));
sockaddr_in_init(&sin_dst, &ina, 0);
bound = curlwp_bind();
ia4 = in_selectsrc(&sin_dst, &inp->inp_route,
inp->inp_socket->so_options, NULL,
&error, &_psref);
if (ia4 == NULL) {
curlwp_bindx(bound);
if (error == 0)
error = EADDRNOTAVAIL;
goto release;
}
memset(&laddr_mapped, 0, sizeof(laddr_mapped));
laddr_mapped.s6_addr16[5] = 0xffff; /* ugly */
memcpy(&laddr_mapped.s6_addr[12],
&IA_SIN(ia4)->sin_addr,
sizeof(IA_SIN(ia4)->sin_addr));
ia4_release(ia4, &_psref);
curlwp_bindx(bound);
laddr = &laddr_mapped;
} else
{
laddr = &in6p_laddr(inp); /* XXX */
}
}
if (laddr == NULL) {
if (error == 0)
error = EADDRNOTAVAIL;
goto release;
}
if (inp->inp_lport == 0) {
/*
* Craft a sockaddr_in6 for the local endpoint. Use the
* "any" as a base, set the address, and recover the
* scope.
*/
struct sockaddr_in6 lsin6 =
*((const struct sockaddr_in6 *)inp->inp_socket->so_proto->pr_domain->dom_sa_any);
lsin6.sin6_addr = *laddr;
error = sa6_recoverscope(&lsin6);
if (error)
goto release;

error = in6pcb_set_port(&lsin6, inp, l);

if (error) {
in6p_laddr(inp) = in6addr_any;
goto release;
}
}
} else {
if (IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp))) {
error = ENOTCONN;
goto release;
}
if (IN6_IS_ADDR_V4MAPPED(&in6p_faddr(inp))) {
if ((inp->inp_flags & IN6P_IPV6_V6ONLY))
{
/*
* XXX: this case would happen when the
* application sets the V6ONLY flag after
* connecting the foreign address.
* Such applications should be fixed,
* so we bark here.
*/
log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
"option was set for a connected socket\n");
error = EINVAL;
goto release;
} else
af = AF_INET;
}
laddr = &in6p_laddr(inp);
faddr = &in6p_faddr(inp);
fport = inp->inp_fport;
}

if (af == AF_INET)
hlen = sizeof(struct ip);

/*
* Calculate data length and get a mbuf
* for UDP and IP6 headers.
*/
M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
if (m == NULL) {
error = ENOBUFS;
goto release;
}

/*
* Stuff checksum and output datagram.
*/
udp6 = (struct udphdr *)(mtod(m, char *) + hlen);
udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
udp6->uh_dport = fport;
if (plen <= 0xffff)
udp6->uh_ulen = htons((u_int16_t)plen);
else
udp6->uh_ulen = 0;
udp6->uh_sum = 0;

switch (af) {
case AF_INET6:
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = in6p_flowinfo(inp) & IPV6_FLOWINFO_MASK;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
#if 0 /* ip6_plen will be filled in ip6_output. */
ip6->ip6_plen = htons((u_int16_t)plen);
#endif
ip6->ip6_nxt = IPPROTO_UDP;
ip6->ip6_hlim = in6pcb_selecthlim_rt(inp);
ip6->ip6_src = *laddr;
ip6->ip6_dst = *faddr;

udp6->uh_sum = in6_cksum_phdr(laddr, faddr,
htonl(plen), htonl(IPPROTO_UDP));
m->m_pkthdr.csum_flags = M_CSUM_UDPv6;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);

UDP6_STATINC(UDP6_STAT_OPACKETS);
error = ip6_output(m, optp, &inp->inp_route, 0,
in6p_moptions(inp), inp, NULL);
break;
case AF_INET:
#ifdef INET
/* can't transmit jumbogram over IPv4 */
if (plen > 0xffff) {
error = EMSGSIZE;
goto release;
}

ip = mtod(m, struct ip *);
ui = (struct udpiphdr *)ip;
memset(ui->ui_x1, 0, sizeof(ui->ui_x1));
ui->ui_pr = IPPROTO_UDP;
ui->ui_len = htons(plen);
memcpy(&ui->ui_src, &laddr->s6_addr[12], sizeof(ui->ui_src));
ui->ui_ulen = ui->ui_len;

flags = (inp->inp_socket->so_options &
(SO_DONTROUTE | SO_BROADCAST));
memcpy(&ui->ui_dst, &faddr->s6_addr[12], sizeof(ui->ui_dst));

udp6->uh_sum = in_cksum(m, hlen + plen);
if (udp6->uh_sum == 0)
udp6->uh_sum = 0xffff;

ip->ip_len = htons(hlen + plen);
ip->ip_ttl = in6pcb_selecthlim(inp, NULL); /* XXX */
ip->ip_tos = 0; /* XXX */

UDP_STATINC(UDP_STAT_OPACKETS);
error = ip_output(m, NULL, &inp->inp_route, flags /* XXX */,
inp->inp_moptions, NULL);
break;
#else
error = EAFNOSUPPORT;
goto release;
#endif
}
goto releaseopt;

release:
m_freem(m);

releaseopt:
if (control) {
if (optp == &opt)
ip6_clearpktopts(&opt, -1);
m_freem(control);
}
return (error);
}

static int
udp6_attach(struct socket *so, int proto)
{
struct inpcb *inp;
int s, error;

KASSERT(sotoinpcb(so) == NULL);
sosetlock(so);

error = soreserve(so, udp6_sendspace, udp6_recvspace);
if (error) {
return error;
}

/*
* MAPPED_ADDR implementation spec:
* Always attach for IPv6, and only when necessary for IPv4.
*/
s = splsoftnet();
error = inpcb_create(so, &udbtable);
splx(s);
if (error) {
return error;
}

inp = sotoinpcb(so);
in6p_cksum(inp) = -1; /* just to be sure */

KASSERT(solocked(so));
return 0;
}

static void
udp6_detach(struct socket *so)
{
struct inpcb *inp = sotoinpcb(so);
int s;

KASSERT(solocked(so));
KASSERT(inp != NULL);

s = splsoftnet();
inpcb_destroy(inp);
splx(s);
}

static int
udp6_accept(struct socket *so, struct sockaddr *nam)
{
KASSERT(solocked(so));

return EOPNOTSUPP;
}

static int
udp6_bind(struct socket *so, struct sockaddr *nam, struct lwp *l)
{
struct inpcb *inp = sotoinpcb(so);
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
int error = 0;
int s;

KASSERT(solocked(so));
KASSERT(inp != NULL);

s = splsoftnet();
error = in6pcb_bind(inp, sin6, l);
splx(s);
return error;
}

static int
udp6_listen(struct socket *so, struct lwp *l)
{
KASSERT(solocked(so));

return EOPNOTSUPP;
}

static int
udp6_connect(struct socket *so, struct sockaddr *nam, struct lwp *l)
{
struct inpcb *inp = sotoinpcb(so);
int error = 0;
int s;

KASSERT(solocked(so));
KASSERT(inp != NULL);

if (!IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp)))
return EISCONN;
s = splsoftnet();
error = in6pcb_connect(inp, (struct sockaddr_in6 *)nam, l);
splx(s);
if (error == 0)
soisconnected(so);

return error;
}

static int
udp6_connect2(struct socket *so, struct socket *so2)
{
KASSERT(solocked(so));

return EOPNOTSUPP;
}

static int
udp6_disconnect(struct socket *so)
{
struct inpcb *inp = sotoinpcb(so);
int s;

KASSERT(solocked(so));
KASSERT(inp != NULL);

if (IN6_IS_ADDR_UNSPECIFIED(&in6p_faddr(inp)))
return ENOTCONN;

s = splsoftnet();
in6pcb_disconnect(inp);
memset((void *)&in6p_laddr(inp), 0, sizeof(in6p_laddr(inp)));
splx(s);

so->so_state &= ~SS_ISCONNECTED; /* XXX */
in6pcb_set_state(inp, INP_BOUND); /* XXX */
return 0;
}

static int
udp6_shutdown(struct socket *so)
{
int s;

s = splsoftnet();
socantsendmore(so);
splx(s);

return 0;
}

static int
udp6_abort(struct socket *so)
{
int s;

KASSERT(solocked(so));
KASSERT(sotoinpcb(so) != NULL);

s = splsoftnet();
soisdisconnected(so);
inpcb_destroy(sotoinpcb(so));
splx(s);

return 0;
}

static int
udp6_ioctl(struct socket *so, u_long cmd, void *addr6, struct ifnet *ifp)
{
/*
* MAPPED_ADDR implementation info:
* Mapped addr support for PRU_CONTROL is not necessary.
* Because typical user of PRU_CONTROL is such as ifconfig,
* and they don't associate any addr to their socket. Then
* socket family is only hint about the PRU_CONTROL'ed address
* family, especially when getting addrs from kernel.
* So AF_INET socket need to be used to control AF_INET addrs,
* and AF_INET6 socket for AF_INET6 addrs.
*/
return in6_control(so, cmd, addr6, ifp);
}

static int
udp6_stat(struct socket *so, struct stat *ub)
{
KASSERT(solocked(so));

/* stat: don't bother with a blocksize */
return 0;
}

static int
udp6_peeraddr(struct socket *so, struct sockaddr *nam)
{
KASSERT(solocked(so));
KASSERT(sotoinpcb(so) != NULL);
KASSERT(nam != NULL);

in6pcb_fetch_peeraddr(sotoinpcb(so), (struct sockaddr_in6 *)nam);
return 0;
}

static int
udp6_sockaddr(struct socket *so, struct sockaddr *nam)
{
KASSERT(solocked(so));
KASSERT(sotoinpcb(so) != NULL);
KASSERT(nam != NULL);

in6pcb_fetch_sockaddr(sotoinpcb(so), (struct sockaddr_in6 *)nam);
return 0;
}

static int
udp6_rcvd(struct socket *so, int flags, struct lwp *l)
{
KASSERT(solocked(so));

return EOPNOTSUPP;
}

static int
udp6_recvoob(struct socket *so, struct mbuf *m, int flags)
{
KASSERT(solocked(so));

return EOPNOTSUPP;
}

static int
udp6_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
struct mbuf *control, struct lwp *l)
{
struct inpcb *inp = sotoinpcb(so);
int error = 0;
int s;

KASSERT(solocked(so));
KASSERT(inp != NULL);
KASSERT(m != NULL);

s = splsoftnet();
error = udp6_output(inp, m, (struct sockaddr_in6 *)nam, control, l);
splx(s);

return error;
}

static int
udp6_sendoob(struct socket *so, struct mbuf *m, struct mbuf *control)
{
KASSERT(solocked(so));

m_freem(m);
m_freem(control);

return EOPNOTSUPP;
}

static int
udp6_purgeif(struct socket *so, struct ifnet *ifp)
{

mutex_enter(softnet_lock);
in6pcb_purgeif0(&udbtable, ifp);
#ifdef NET_MPSAFE
mutex_exit(softnet_lock);
#endif
in6_purgeif(ifp);
#ifdef NET_MPSAFE
mutex_enter(softnet_lock);
#endif
in6pcb_purgeif(&udbtable, ifp);
mutex_exit(softnet_lock);

return 0;
}

static int
sysctl_net_inet6_udp6_stats(SYSCTLFN_ARGS)
{

return (NETSTAT_SYSCTL(udp6stat_percpu, UDP6_NSTATS));
}

static void
sysctl_net_inet6_udp6_setup(struct sysctllog **clog)
{

sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "inet6", NULL,
NULL, 0, NULL, 0,
CTL_NET, PF_INET6, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "udp6",
SYSCTL_DESCR("UDPv6 related settings"),
NULL, 0, NULL, 0,
CTL_NET, PF_INET6, IPPROTO_UDP, CTL_EOL);

sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_INT, "sendspace",
SYSCTL_DESCR("Default UDP send buffer size"),
NULL, 0, &udp6_sendspace, 0,
CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_SENDSPACE,
CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_INT, "recvspace",
SYSCTL_DESCR("Default UDP receive buffer size"),
NULL, 0, &udp6_recvspace, 0,
CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_RECVSPACE,
CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_INT, "do_loopback_cksum",
SYSCTL_DESCR("Perform UDP checksum on loopback"),
NULL, 0, &udp_do_loopback_cksum, 0,
CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_LOOPBACKCKSUM,
CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRUCT, "pcblist",
SYSCTL_DESCR("UDP protocol control block list"),
sysctl_inpcblist, 0, &udbtable, 0,
CTL_NET, PF_INET6, IPPROTO_UDP, CTL_CREATE,
CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_STRUCT, "stats",
SYSCTL_DESCR("UDPv6 statistics"),
sysctl_net_inet6_udp6_stats, 0, NULL, 0,
CTL_NET, PF_INET6, IPPROTO_UDP, UDP6CTL_STATS,
CTL_EOL);
}

void
udp6_statinc(u_int stat)
{

KASSERT(stat < UDP6_NSTATS);
UDP6_STATINC(stat);
}

#ifdef IPSEC
/*
* Returns:
* 1 if the packet was processed
* 0 if normal UDP processing should take place
* -1 if an error occurred and m was freed
*/
static int
udp6_espinudp(struct mbuf **mp, int off)
{
const size_t skip = sizeof(struct udphdr);
size_t len;
void *data;
size_t minlen;
int ip6hdrlen;
struct ip6_hdr *ip6;
struct m_tag *tag;
struct udphdr *udphdr;
u_int16_t sport, dport;
struct mbuf *m = *mp;
uint32_t *marker;

/*
* Collapse the mbuf chain if the first mbuf is too short
* The longest case is: UDP + non ESP marker + ESP
*/
minlen = off + sizeof(u_int64_t) + sizeof(struct esp);
if (minlen > m->m_pkthdr.len)
minlen = m->m_pkthdr.len;

if (m->m_len < minlen) {
if ((*mp = m_pullup(m, minlen)) == NULL) {
return -1; /* dropped */
}
m = *mp;
}

len = m->m_len - off;
data = mtod(m, char *) + off;

/* Ignore keepalive packets */
if ((len == 1) && (*(unsigned char *)data == 0xff)) {
m_freem(m);
*mp = NULL; /* avoid any further processing by caller ... */
return 1; /* consumed */
}

/* Handle Non-ESP marker (32bit). If zero, then IKE. */
marker = (uint32_t *)data;
if (len <= sizeof(uint32_t))
return 0; /* passthrough */
if (marker[0] == 0)
return 0; /* passthrough */

/*
* Get the UDP ports. They are handled in network
* order everywhere in IPSEC_NAT_T code.
*/
udphdr = (struct udphdr *)((char *)data - skip);
sport = udphdr->uh_sport;
dport = udphdr->uh_dport;

/*
* Remove the UDP header (and possibly the non ESP marker)
* IPv6 header length is ip6hdrlen
* Before:
* <---- off --->
* +-----+------+-----+
* | IP6 | UDP | ESP |
* +-----+------+-----+
* <-skip->
* After:
* +-----+-----+
* | IP6 | ESP |
* +-----+-----+
* <-skip->
*/
ip6hdrlen = off - sizeof(struct udphdr);
memmove(mtod(m, char *) + skip, mtod(m, void *), ip6hdrlen);
m_adj(m, skip);

ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - skip);
ip6->ip6_nxt = IPPROTO_ESP;

/*
* We have modified the packet - it is now ESP, so we should not
* return to UDP processing ...
*
* Add a PACKET_TAG_IPSEC_NAT_T_PORT tag to remember
* the source UDP port. This is required if we want
* to select the right SPD for multiple hosts behind
* same NAT
*/
if ((tag = m_tag_get(PACKET_TAG_IPSEC_NAT_T_PORTS,
sizeof(sport) + sizeof(dport), M_DONTWAIT)) == NULL) {
m_freem(m);
*mp = NULL;
return -1; /* dropped */
}
((u_int16_t *)(tag + 1))[0] = sport;
((u_int16_t *)(tag + 1))[1] = dport;
m_tag_prepend(m, tag);

if (ipsec_used)
ipsec6_common_input(&m, &ip6hdrlen, IPPROTO_ESP);
else
m_freem(m);

/* We handled it, it shouldn't be handled by UDP */
*mp = NULL; /* avoid free by caller ... */
return 1; /* consumed */
}
#endif /* IPSEC */

PR_WRAP_USRREQS(udp6)
#define udp6_attach udp6_attach_wrapper
#define udp6_detach udp6_detach_wrapper
#define udp6_accept udp6_accept_wrapper
#define udp6_bind udp6_bind_wrapper
#define udp6_listen udp6_listen_wrapper
#define udp6_connect udp6_connect_wrapper
#define udp6_connect2 udp6_connect2_wrapper
#define udp6_disconnect udp6_disconnect_wrapper
#define udp6_shutdown udp6_shutdown_wrapper
#define udp6_abort udp6_abort_wrapper
#define udp6_ioctl udp6_ioctl_wrapper
#define udp6_stat udp6_stat_wrapper
#define udp6_peeraddr udp6_peeraddr_wrapper
#define udp6_sockaddr udp6_sockaddr_wrapper
#define udp6_rcvd udp6_rcvd_wrapper
#define udp6_recvoob udp6_recvoob_wrapper
#define udp6_send udp6_send_wrapper
#define udp6_sendoob udp6_sendoob_wrapper
#define udp6_purgeif udp6_purgeif_wrapper

const struct pr_usrreqs udp6_usrreqs = {
.pr_attach = udp6_attach,
.pr_detach = udp6_detach,
.pr_accept = udp6_accept,
.pr_bind = udp6_bind,
.pr_listen = udp6_listen,
.pr_connect = udp6_connect,
.pr_connect2 = udp6_connect2,
.pr_disconnect = udp6_disconnect,
.pr_shutdown = udp6_shutdown,
.pr_abort = udp6_abort,
.pr_ioctl = udp6_ioctl,
.pr_stat = udp6_stat,
.pr_peeraddr = udp6_peeraddr,
.pr_sockaddr = udp6_sockaddr,
.pr_rcvd = udp6_rcvd,
.pr_recvoob = udp6_recvoob,
.pr_send = udp6_send,
.pr_sendoob = udp6_sendoob,
.pr_purgeif = udp6_purgeif,
};