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NetBSD/sys/netinet/ip_output.c
roy a37502b2b6 Add RTF_BROADCAST to mark routes used for the broadcast address when 
they are created on the fly. This makes it clear what the route is for
and allows an optimisation in ip_output() by avoiding a call to
in_broadcast() because most of the time we do talk to a host.
It also avoids a needless allocation for the storage of llinfo_arp and
thus vanishes from arp(8) - it showed as incomplete anyway so this
is a nice side effect.

Guard against this and routes marked with RTF_BLACKHOLE in
ip_fastforward().
While here, guard against routes marked with RTF_BLACKHOLE in
ip6_fastforward().
RTF_BROADCAST is IPv4 only, so don't bother checking that here.
2015-03-23 18:33:17 +00:00

1727 lines
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/* $NetBSD: ip_output.c,v 1.234 2015/03/23 18:33:17 roy 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) 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Public Access Networks Corporation ("Panix"). It was developed under
* contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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, 1988, 1990, 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.
*
* @(#)ip_output.c 8.3 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.234 2015/03/23 18:33:17 roy Exp $");
#include "opt_inet.h"
#include "opt_ipsec.h"
#include "opt_mrouting.h"
#include <sys/param.h>
#include <sys/kmem.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/kauth.h>
#ifdef IPSEC
#include <sys/domain.h>
#endif
#include <sys/systm.h>
#include <net/if.h>
#include <net/route.h>
#include <net/pfil.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/ip_private.h>
#include <netinet/in_offload.h>
#include <netinet/portalgo.h>
#include <netinet/udp.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#endif
#ifdef MROUTING
#include <netinet/ip_mroute.h>
#endif
#include <netipsec/ipsec.h>
#include <netipsec/key.h>
static int ip_pcbopts(struct inpcb *, const struct sockopt *);
static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
static struct ifnet *ip_multicast_if(struct in_addr *, int *);
static void ip_mloopback(struct ifnet *, struct mbuf *,
const struct sockaddr_in *);
extern pfil_head_t *inet_pfil_hook; /* XXX */
int ip_do_loopback_cksum = 0;
/*
* IP output. The packet in mbuf chain m contains a skeletal IP
* header (with len, off, ttl, proto, tos, src, dst).
* The mbuf chain containing the packet will be freed.
* The mbuf opt, if present, will not be freed.
*/
int
ip_output(struct mbuf *m0, ...)
{
struct rtentry *rt;
struct ip *ip;
struct ifnet *ifp;
struct mbuf *m = m0;
int hlen = sizeof (struct ip);
int len, error = 0;
struct route iproute;
const struct sockaddr_in *dst;
struct in_ifaddr *ia;
int isbroadcast;
struct mbuf *opt;
struct route *ro;
int flags, sw_csum;
u_long mtu;
struct ip_moptions *imo;
struct socket *so;
va_list ap;
#ifdef IPSEC
struct secpolicy *sp = NULL;
#endif
bool natt_frag = false;
bool rtmtu_nolock;
union {
struct sockaddr dst;
struct sockaddr_in dst4;
} u;
struct sockaddr *rdst = &u.dst; /* real IP destination, as opposed
* to the nexthop
*/
len = 0;
va_start(ap, m0);
opt = va_arg(ap, struct mbuf *);
ro = va_arg(ap, struct route *);
flags = va_arg(ap, int);
imo = va_arg(ap, struct ip_moptions *);
so = va_arg(ap, struct socket *);
va_end(ap);
MCLAIM(m, &ip_tx_mowner);
KASSERT((m->m_flags & M_PKTHDR) != 0);
KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) == 0);
KASSERT((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) !=
(M_CSUM_TCPv4|M_CSUM_UDPv4));
if (opt) {
m = ip_insertoptions(m, opt, &len);
if (len >= sizeof(struct ip))
hlen = len;
}
ip = mtod(m, struct ip *);
/*
* Fill in IP header.
*/
if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
ip->ip_v = IPVERSION;
ip->ip_off = htons(0);
/* ip->ip_id filled in after we find out source ia */
ip->ip_hl = hlen >> 2;
IP_STATINC(IP_STAT_LOCALOUT);
} else {
hlen = ip->ip_hl << 2;
}
/*
* Route packet.
*/
if (ro == NULL) {
memset(&iproute, 0, sizeof(iproute));
ro = &iproute;
}
sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
dst = satocsin(rtcache_getdst(ro));
/*
* If there is a cached route, check that it is to the same
* destination and is still up. If not, free it and try again.
* The address family should also be checked in case of sharing
* the cache with IPv6.
*/
if (dst && (dst->sin_family != AF_INET ||
!in_hosteq(dst->sin_addr, ip->ip_dst)))
rtcache_free(ro);
if ((rt = rtcache_validate(ro)) == NULL &&
(rt = rtcache_update(ro, 1)) == NULL) {
dst = &u.dst4;
rtcache_setdst(ro, &u.dst);
}
/*
* If routing to interface only, short circuit routing lookup.
*/
if (flags & IP_ROUTETOIF) {
if ((ia = ifatoia(ifa_ifwithladdr(sintocsa(dst)))) == NULL) {
IP_STATINC(IP_STAT_NOROUTE);
error = ENETUNREACH;
goto bad;
}
ifp = ia->ia_ifp;
mtu = ifp->if_mtu;
ip->ip_ttl = 1;
isbroadcast = in_broadcast(dst->sin_addr, ifp);
} else if ((IN_MULTICAST(ip->ip_dst.s_addr) ||
ip->ip_dst.s_addr == INADDR_BROADCAST) &&
imo != NULL && imo->imo_multicast_ifp != NULL) {
ifp = imo->imo_multicast_ifp;
mtu = ifp->if_mtu;
IFP_TO_IA(ifp, ia);
isbroadcast = 0;
} else {
if (rt == NULL)
rt = rtcache_init(ro);
if (rt == NULL) {
IP_STATINC(IP_STAT_NOROUTE);
error = EHOSTUNREACH;
goto bad;
}
ia = ifatoia(rt->rt_ifa);
ifp = rt->rt_ifp;
if ((mtu = rt->rt_rmx.rmx_mtu) == 0)
mtu = ifp->if_mtu;
rt->rt_use++;
if (rt->rt_flags & RTF_GATEWAY)
dst = satosin(rt->rt_gateway);
if (rt->rt_flags & RTF_HOST)
isbroadcast = rt->rt_flags & RTF_BROADCAST;
else
isbroadcast = in_broadcast(dst->sin_addr, ifp);
}
rtmtu_nolock = rt && (rt->rt_rmx.rmx_locks & RTV_MTU) == 0;
if (IN_MULTICAST(ip->ip_dst.s_addr) ||
(ip->ip_dst.s_addr == INADDR_BROADCAST)) {
bool inmgroup;
m->m_flags |= (ip->ip_dst.s_addr == INADDR_BROADCAST) ?
M_BCAST : M_MCAST;
/*
* See if the caller provided any multicast options
*/
if (imo != NULL)
ip->ip_ttl = imo->imo_multicast_ttl;
else
ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
/*
* if we don't know the outgoing ifp yet, we can't generate
* output
*/
if (!ifp) {
IP_STATINC(IP_STAT_NOROUTE);
error = ENETUNREACH;
goto bad;
}
/*
* If the packet is multicast or broadcast, confirm that
* the outgoing interface can transmit it.
*/
if (((m->m_flags & M_MCAST) &&
(ifp->if_flags & IFF_MULTICAST) == 0) ||
((m->m_flags & M_BCAST) &&
(ifp->if_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0)) {
IP_STATINC(IP_STAT_NOROUTE);
error = ENETUNREACH;
goto bad;
}
/*
* If source address not specified yet, use an address
* of outgoing interface.
*/
if (in_nullhost(ip->ip_src)) {
struct in_ifaddr *xia;
struct ifaddr *xifa;
IFP_TO_IA(ifp, xia);
if (!xia) {
error = EADDRNOTAVAIL;
goto bad;
}
xifa = &xia->ia_ifa;
if (xifa->ifa_getifa != NULL) {
xia = ifatoia((*xifa->ifa_getifa)(xifa, rdst));
}
ip->ip_src = xia->ia_addr.sin_addr;
}
inmgroup = in_multi_group(ip->ip_dst, ifp, flags);
if (inmgroup && (imo == NULL || imo->imo_multicast_loop)) {
/*
* If we belong to the destination multicast group
* on the outgoing interface, and the caller did not
* forbid loopback, loop back a copy.
*/
ip_mloopback(ifp, m, &u.dst4);
}
#ifdef MROUTING
else {
/*
* If we are acting as a multicast router, perform
* multicast forwarding as if the packet had just
* arrived on the interface to which we are about
* to send. The multicast forwarding function
* recursively calls this function, using the
* IP_FORWARDING flag to prevent infinite recursion.
*
* Multicasts that are looped back by ip_mloopback(),
* above, will be forwarded by the ip_input() routine,
* if necessary.
*/
extern struct socket *ip_mrouter;
if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
if (ip_mforward(m, ifp) != 0) {
m_freem(m);
goto done;
}
}
}
#endif
/*
* Multicasts with a time-to-live of zero may be looped-
* back, above, but must not be transmitted on a network.
* Also, multicasts addressed to the loopback interface
* are not sent -- the above call to ip_mloopback() will
* loop back a copy if this host actually belongs to the
* destination group on the loopback interface.
*/
if (ip->ip_ttl == 0 || (ifp->if_flags & IFF_LOOPBACK) != 0) {
m_freem(m);
goto done;
}
goto sendit;
}
/*
* If source address not specified yet, use address
* of outgoing interface.
*/
if (in_nullhost(ip->ip_src)) {
struct ifaddr *xifa;
xifa = &ia->ia_ifa;
if (xifa->ifa_getifa != NULL)
ia = ifatoia((*xifa->ifa_getifa)(xifa, rdst));
ip->ip_src = ia->ia_addr.sin_addr;
}
/*
* packets with Class-D address as source are not valid per
* RFC 1112
*/
if (IN_MULTICAST(ip->ip_src.s_addr)) {
IP_STATINC(IP_STAT_ODROPPED);
error = EADDRNOTAVAIL;
goto bad;
}
/*
* Look for broadcast address and and verify user is allowed to
* send such a packet.
*/
if (isbroadcast) {
if ((ifp->if_flags & IFF_BROADCAST) == 0) {
error = EADDRNOTAVAIL;
goto bad;
}
if ((flags & IP_ALLOWBROADCAST) == 0) {
error = EACCES;
goto bad;
}
/* don't allow broadcast messages to be fragmented */
if (ntohs(ip->ip_len) > ifp->if_mtu) {
error = EMSGSIZE;
goto bad;
}
m->m_flags |= M_BCAST;
} else
m->m_flags &= ~M_BCAST;
sendit:
if ((flags & (IP_FORWARDING|IP_NOIPNEWID)) == 0) {
if (m->m_pkthdr.len < IP_MINFRAGSIZE) {
ip->ip_id = 0;
} else if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) {
ip->ip_id = ip_newid(ia);
} else {
/*
* TSO capable interfaces (typically?) increment
* ip_id for each segment.
* "allocate" enough ids here to increase the chance
* for them to be unique.
*
* note that the following calculation is not
* needed to be precise. wasting some ip_id is fine.
*/
unsigned int segsz = m->m_pkthdr.segsz;
unsigned int datasz = ntohs(ip->ip_len) - hlen;
unsigned int num = howmany(datasz, segsz);
ip->ip_id = ip_newid_range(ia, num);
}
}
/*
* If we're doing Path MTU Discovery, we need to set DF unless
* the route's MTU is locked.
*/
if ((flags & IP_MTUDISC) != 0 && rtmtu_nolock) {
ip->ip_off |= htons(IP_DF);
}
#ifdef IPSEC
if (ipsec_used) {
bool ipsec_done = false;
/* Perform IPsec processing, if any. */
error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag,
&ipsec_done);
if (error || ipsec_done)
goto done;
}
#endif
/*
* Run through list of hooks for output packets.
*/
error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT);
if (error)
goto done;
if (m == NULL)
goto done;
ip = mtod(m, struct ip *);
hlen = ip->ip_hl << 2;
m->m_pkthdr.csum_data |= hlen << 16;
#if IFA_STATS
/*
* search for the source address structure to
* maintain output statistics.
*/
INADDR_TO_IA(ip->ip_src, ia);
#endif
/* Maybe skip checksums on loopback interfaces. */
if (IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4)) {
m->m_pkthdr.csum_flags |= M_CSUM_IPv4;
}
sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx;
/*
* If small enough for mtu of path, or if using TCP segmentation
* offload, can just send directly.
*/
if (ntohs(ip->ip_len) <= mtu ||
(m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) {
const struct sockaddr *sa;
#if IFA_STATS
if (ia)
ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len);
#endif
/*
* Always initialize the sum to 0! Some HW assisted
* checksumming requires this.
*/
ip->ip_sum = 0;
if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) {
/*
* Perform any checksums that the hardware can't do
* for us.
*
* XXX Does any hardware require the {th,uh}_sum
* XXX fields to be 0?
*/
if (sw_csum & M_CSUM_IPv4) {
KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4));
ip->ip_sum = in_cksum(m, hlen);
m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4;
}
if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) {
if (IN_NEED_CHECKSUM(ifp,
sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) {
in_delayed_cksum(m);
}
m->m_pkthdr.csum_flags &=
~(M_CSUM_TCPv4|M_CSUM_UDPv4);
}
}
sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst);
if (__predict_true(
(m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0 ||
(ifp->if_capenable & IFCAP_TSOv4) != 0)) {
KERNEL_LOCK(1, NULL);
error = (*ifp->if_output)(ifp, m, sa, rt);
KERNEL_UNLOCK_ONE(NULL);
} else {
error = ip_tso_output(ifp, m, sa, rt);
}
goto done;
}
/*
* We can't use HW checksumming if we're about to
* to fragment the packet.
*
* XXX Some hardware can do this.
*/
if (m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) {
if (IN_NEED_CHECKSUM(ifp,
m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4))) {
in_delayed_cksum(m);
}
m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4);
}
/*
* Too large for interface; fragment if possible.
* Must be able to put at least 8 bytes per fragment.
*/
if (ntohs(ip->ip_off) & IP_DF) {
if (flags & IP_RETURNMTU) {
struct inpcb *inp;
KASSERT(so && solocked(so));
inp = sotoinpcb(so);
inp->inp_errormtu = mtu;
}
error = EMSGSIZE;
IP_STATINC(IP_STAT_CANTFRAG);
goto bad;
}
error = ip_fragment(m, ifp, mtu);
if (error) {
m = NULL;
goto bad;
}
for (; m; m = m0) {
m0 = m->m_nextpkt;
m->m_nextpkt = 0;
if (error) {
m_freem(m);
continue;
}
#if IFA_STATS
if (ia)
ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len);
#endif
/*
* If we get there, the packet has not been handled by
* IPsec whereas it should have. Now that it has been
* fragmented, re-inject it in ip_output so that IPsec
* processing can occur.
*/
if (natt_frag) {
error = ip_output(m, opt, ro,
flags | IP_RAWOUTPUT | IP_NOIPNEWID,
imo, so);
} else {
KASSERT((m->m_pkthdr.csum_flags &
(M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0);
KERNEL_LOCK(1, NULL);
error = (*ifp->if_output)(ifp, m,
(m->m_flags & M_MCAST) ?
sintocsa(rdst) : sintocsa(dst), rt);
KERNEL_UNLOCK_ONE(NULL);
}
}
if (error == 0) {
IP_STATINC(IP_STAT_FRAGMENTED);
}
done:
if (ro == &iproute) {
rtcache_free(&iproute);
}
#ifdef IPSEC
if (sp) {
KEY_FREESP(&sp);
}
#endif
return error;
bad:
m_freem(m);
goto done;
}
int
ip_fragment(struct mbuf *m, struct ifnet *ifp, u_long mtu)
{
struct ip *ip, *mhip;
struct mbuf *m0;
int len, hlen, off;
int mhlen, firstlen;
struct mbuf **mnext;
int sw_csum = m->m_pkthdr.csum_flags;
int fragments = 0;
int s;
int error = 0;
ip = mtod(m, struct ip *);
hlen = ip->ip_hl << 2;
if (ifp != NULL)
sw_csum &= ~ifp->if_csum_flags_tx;
len = (mtu - hlen) &~ 7;
if (len < 8) {
m_freem(m);
return (EMSGSIZE);
}
firstlen = len;
mnext = &m->m_nextpkt;
/*
* Loop through length of segment after first fragment,
* make new header and copy data of each part and link onto chain.
*/
m0 = m;
mhlen = sizeof (struct ip);
for (off = hlen + len; off < ntohs(ip->ip_len); off += len) {
MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m == 0) {
error = ENOBUFS;
IP_STATINC(IP_STAT_ODROPPED);
goto sendorfree;
}
MCLAIM(m, m0->m_owner);
*mnext = m;
mnext = &m->m_nextpkt;
m->m_data += max_linkhdr;
mhip = mtod(m, struct ip *);
*mhip = *ip;
/* we must inherit MCAST and BCAST flags */
m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST);
if (hlen > sizeof (struct ip)) {
mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
mhip->ip_hl = mhlen >> 2;
}
m->m_len = mhlen;
mhip->ip_off = ((off - hlen) >> 3) +
(ntohs(ip->ip_off) & ~IP_MF);
if (ip->ip_off & htons(IP_MF))
mhip->ip_off |= IP_MF;
if (off + len >= ntohs(ip->ip_len))
len = ntohs(ip->ip_len) - off;
else
mhip->ip_off |= IP_MF;
HTONS(mhip->ip_off);
mhip->ip_len = htons((u_int16_t)(len + mhlen));
m->m_next = m_copym(m0, off, len, M_DONTWAIT);
if (m->m_next == 0) {
error = ENOBUFS; /* ??? */
IP_STATINC(IP_STAT_ODROPPED);
goto sendorfree;
}
m->m_pkthdr.len = mhlen + len;
m->m_pkthdr.rcvif = NULL;
mhip->ip_sum = 0;
KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0);
if (sw_csum & M_CSUM_IPv4) {
mhip->ip_sum = in_cksum(m, mhlen);
} else {
/*
* checksum is hw-offloaded or not necessary.
*/
m->m_pkthdr.csum_flags |=
m0->m_pkthdr.csum_flags & M_CSUM_IPv4;
m->m_pkthdr.csum_data |= mhlen << 16;
KASSERT(!(ifp != NULL &&
IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4))
|| (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0);
}
IP_STATINC(IP_STAT_OFRAGMENTS);
fragments++;
}
/*
* Update first fragment by trimming what's been copied out
* and updating header, then send each fragment (in order).
*/
m = m0;
m_adj(m, hlen + firstlen - ntohs(ip->ip_len));
m->m_pkthdr.len = hlen + firstlen;
ip->ip_len = htons((u_int16_t)m->m_pkthdr.len);
ip->ip_off |= htons(IP_MF);
ip->ip_sum = 0;
if (sw_csum & M_CSUM_IPv4) {
ip->ip_sum = in_cksum(m, hlen);
m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4;
} else {
/*
* checksum is hw-offloaded or not necessary.
*/
KASSERT(!(ifp != NULL && IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4))
|| (m->m_pkthdr.csum_flags & M_CSUM_IPv4) != 0);
KASSERT(M_CSUM_DATA_IPv4_IPHL(m->m_pkthdr.csum_data) >=
sizeof(struct ip));
}
sendorfree:
/*
* If there is no room for all the fragments, don't queue
* any of them.
*/
if (ifp != NULL) {
s = splnet();
if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments &&
error == 0) {
error = ENOBUFS;
IP_STATINC(IP_STAT_ODROPPED);
IFQ_INC_DROPS(&ifp->if_snd);
}
splx(s);
}
if (error) {
for (m = m0; m; m = m0) {
m0 = m->m_nextpkt;
m->m_nextpkt = NULL;
m_freem(m);
}
}
return (error);
}
/*
* Process a delayed payload checksum calculation.
*/
void
in_delayed_cksum(struct mbuf *m)
{
struct ip *ip;
u_int16_t csum, offset;
ip = mtod(m, struct ip *);
offset = ip->ip_hl << 2;
csum = in4_cksum(m, 0, offset, ntohs(ip->ip_len) - offset);
if (csum == 0 && (m->m_pkthdr.csum_flags & M_CSUM_UDPv4) != 0)
csum = 0xffff;
offset += M_CSUM_DATA_IPv4_OFFSET(m->m_pkthdr.csum_data);
if ((offset + sizeof(u_int16_t)) > m->m_len) {
/* This happen when ip options were inserted
printf("in_delayed_cksum: pullup len %d off %d proto %d\n",
m->m_len, offset, ip->ip_p);
*/
m_copyback(m, offset, sizeof(csum), (void *) &csum);
} else
*(u_int16_t *)(mtod(m, char *) + offset) = csum;
}
/*
* Determine the maximum length of the options to be inserted;
* we would far rather allocate too much space rather than too little.
*/
u_int
ip_optlen(struct inpcb *inp)
{
struct mbuf *m = inp->inp_options;
if (m && m->m_len > offsetof(struct ipoption, ipopt_dst)) {
return (m->m_len - offsetof(struct ipoption, ipopt_dst));
}
return 0;
}
/*
* Insert IP options into preformed packet.
* Adjust IP destination as required for IP source routing,
* as indicated by a non-zero in_addr at the start of the options.
*/
static struct mbuf *
ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen)
{
struct ipoption *p = mtod(opt, struct ipoption *);
struct mbuf *n;
struct ip *ip = mtod(m, struct ip *);
unsigned optlen;
optlen = opt->m_len - sizeof(p->ipopt_dst);
if (optlen + ntohs(ip->ip_len) > IP_MAXPACKET)
return (m); /* XXX should fail */
if (!in_nullhost(p->ipopt_dst))
ip->ip_dst = p->ipopt_dst;
if (M_READONLY(m) || M_LEADINGSPACE(m) < optlen) {
MGETHDR(n, M_DONTWAIT, MT_HEADER);
if (n == 0)
return (m);
MCLAIM(n, m->m_owner);
M_MOVE_PKTHDR(n, m);
m->m_len -= sizeof(struct ip);
m->m_data += sizeof(struct ip);
n->m_next = m;
m = n;
m->m_len = optlen + sizeof(struct ip);
m->m_data += max_linkhdr;
bcopy((void *)ip, mtod(m, void *), sizeof(struct ip));
} else {
m->m_data -= optlen;
m->m_len += optlen;
memmove(mtod(m, void *), ip, sizeof(struct ip));
}
m->m_pkthdr.len += optlen;
ip = mtod(m, struct ip *);
bcopy((void *)p->ipopt_list, (void *)(ip + 1), (unsigned)optlen);
*phlen = sizeof(struct ip) + optlen;
ip->ip_len = htons(ntohs(ip->ip_len) + optlen);
return (m);
}
/*
* Copy options from ip to jp,
* omitting those not copied during fragmentation.
*/
int
ip_optcopy(struct ip *ip, struct ip *jp)
{
u_char *cp, *dp;
int opt, optlen, cnt;
cp = (u_char *)(ip + 1);
dp = (u_char *)(jp + 1);
cnt = (ip->ip_hl << 2) - sizeof (struct ip);
for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[0];
if (opt == IPOPT_EOL)
break;
if (opt == IPOPT_NOP) {
/* Preserve for IP mcast tunnel's LSRR alignment. */
*dp++ = IPOPT_NOP;
optlen = 1;
continue;
}
KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp));
optlen = cp[IPOPT_OLEN];
KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen < cnt);
/* Invalid lengths should have been caught by ip_dooptions. */
if (optlen > cnt)
optlen = cnt;
if (IPOPT_COPIED(opt)) {
bcopy((void *)cp, (void *)dp, (unsigned)optlen);
dp += optlen;
}
}
for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
*dp++ = IPOPT_EOL;
return (optlen);
}
/*
* IP socket option processing.
*/
int
ip_ctloutput(int op, struct socket *so, struct sockopt *sopt)
{
struct inpcb *inp = sotoinpcb(so);
struct ip *ip = &inp->inp_ip;
int inpflags = inp->inp_flags;
int optval = 0, error = 0;
if (sopt->sopt_level != IPPROTO_IP) {
if (sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_NOHEADER)
return 0;
return ENOPROTOOPT;
}
switch (op) {
case PRCO_SETOPT:
switch (sopt->sopt_name) {
case IP_OPTIONS:
#ifdef notyet
case IP_RETOPTS:
#endif
error = ip_pcbopts(inp, sopt);
break;
case IP_TOS:
case IP_TTL:
case IP_MINTTL:
case IP_PKTINFO:
case IP_RECVOPTS:
case IP_RECVRETOPTS:
case IP_RECVDSTADDR:
case IP_RECVIF:
case IP_RECVPKTINFO:
case IP_RECVTTL:
error = sockopt_getint(sopt, &optval);
if (error)
break;
switch (sopt->sopt_name) {
case IP_TOS:
ip->ip_tos = optval;
break;
case IP_TTL:
ip->ip_ttl = optval;
break;
case IP_MINTTL:
if (optval > 0 && optval <= MAXTTL)
inp->inp_ip_minttl = optval;
else
error = EINVAL;
break;
#define OPTSET(bit) \
if (optval) \
inpflags |= bit; \
else \
inpflags &= ~bit;
case IP_PKTINFO:
OPTSET(INP_PKTINFO);
break;
case IP_RECVOPTS:
OPTSET(INP_RECVOPTS);
break;
case IP_RECVPKTINFO:
OPTSET(INP_RECVPKTINFO);
break;
case IP_RECVRETOPTS:
OPTSET(INP_RECVRETOPTS);
break;
case IP_RECVDSTADDR:
OPTSET(INP_RECVDSTADDR);
break;
case IP_RECVIF:
OPTSET(INP_RECVIF);
break;
case IP_RECVTTL:
OPTSET(INP_RECVTTL);
break;
}
break;
#undef OPTSET
case IP_MULTICAST_IF:
case IP_MULTICAST_TTL:
case IP_MULTICAST_LOOP:
case IP_ADD_MEMBERSHIP:
case IP_DROP_MEMBERSHIP:
error = ip_setmoptions(&inp->inp_moptions, sopt);
break;
case IP_PORTRANGE:
error = sockopt_getint(sopt, &optval);
if (error)
break;
switch (optval) {
case IP_PORTRANGE_DEFAULT:
case IP_PORTRANGE_HIGH:
inpflags &= ~(INP_LOWPORT);
break;
case IP_PORTRANGE_LOW:
inpflags |= INP_LOWPORT;
break;
default:
error = EINVAL;
break;
}
break;
case IP_PORTALGO:
error = sockopt_getint(sopt, &optval);
if (error)
break;
error = portalgo_algo_index_select(
(struct inpcb_hdr *)inp, optval);
break;
#if defined(IPSEC)
case IP_IPSEC_POLICY:
if (ipsec_enabled) {
error = ipsec4_set_policy(inp, sopt->sopt_name,
sopt->sopt_data, sopt->sopt_size,
curlwp->l_cred);
break;
}
/*FALLTHROUGH*/
#endif /* IPSEC */
default:
error = ENOPROTOOPT;
break;
}
break;
case PRCO_GETOPT:
switch (sopt->sopt_name) {
case IP_OPTIONS:
case IP_RETOPTS: {
struct mbuf *mopts = inp->inp_options;
if (mopts) {
struct mbuf *m;
m = m_copym(mopts, 0, M_COPYALL, M_DONTWAIT);
if (m == NULL) {
error = ENOBUFS;
break;
}
error = sockopt_setmbuf(sopt, m);
}
break;
}
case IP_PKTINFO:
case IP_TOS:
case IP_TTL:
case IP_MINTTL:
case IP_RECVOPTS:
case IP_RECVRETOPTS:
case IP_RECVDSTADDR:
case IP_RECVIF:
case IP_RECVPKTINFO:
case IP_RECVTTL:
case IP_ERRORMTU:
switch (sopt->sopt_name) {
case IP_TOS:
optval = ip->ip_tos;
break;
case IP_TTL:
optval = ip->ip_ttl;
break;
case IP_MINTTL:
optval = inp->inp_ip_minttl;
break;
case IP_ERRORMTU:
optval = inp->inp_errormtu;
break;
#define OPTBIT(bit) (inpflags & bit ? 1 : 0)
case IP_PKTINFO:
optval = OPTBIT(INP_PKTINFO);
break;
case IP_RECVOPTS:
optval = OPTBIT(INP_RECVOPTS);
break;
case IP_RECVPKTINFO:
optval = OPTBIT(INP_RECVPKTINFO);
break;
case IP_RECVRETOPTS:
optval = OPTBIT(INP_RECVRETOPTS);
break;
case IP_RECVDSTADDR:
optval = OPTBIT(INP_RECVDSTADDR);
break;
case IP_RECVIF:
optval = OPTBIT(INP_RECVIF);
break;
case IP_RECVTTL:
optval = OPTBIT(INP_RECVTTL);
break;
}
error = sockopt_setint(sopt, optval);
break;
#if 0 /* defined(IPSEC) */
case IP_IPSEC_POLICY:
{
struct mbuf *m = NULL;
/* XXX this will return EINVAL as sopt is empty */
error = ipsec4_get_policy(inp, sopt->sopt_data,
sopt->sopt_size, &m);
if (error == 0)
error = sockopt_setmbuf(sopt, m);
break;
}
#endif /*IPSEC*/
case IP_MULTICAST_IF:
case IP_MULTICAST_TTL:
case IP_MULTICAST_LOOP:
case IP_ADD_MEMBERSHIP:
case IP_DROP_MEMBERSHIP:
error = ip_getmoptions(inp->inp_moptions, sopt);
break;
case IP_PORTRANGE:
if (inpflags & INP_LOWPORT)
optval = IP_PORTRANGE_LOW;
else
optval = IP_PORTRANGE_DEFAULT;
error = sockopt_setint(sopt, optval);
break;
case IP_PORTALGO:
optval = inp->inp_portalgo;
error = sockopt_setint(sopt, optval);
break;
default:
error = ENOPROTOOPT;
break;
}
break;
}
if (!error) {
inp->inp_flags = inpflags;
}
return error;
}
/*
* Set up IP options in pcb for insertion in output packets.
* Store in mbuf with pointer in pcbopt, adding pseudo-option
* with destination address if source routed.
*/
static int
ip_pcbopts(struct inpcb *inp, const struct sockopt *sopt)
{
struct mbuf *m;
const u_char *cp;
u_char *dp;
int cnt;
/* Turn off any old options. */
if (inp->inp_options) {
m_free(inp->inp_options);
}
inp->inp_options = NULL;
if ((cnt = sopt->sopt_size) == 0) {
/* Only turning off any previous options. */
return 0;
}
cp = sopt->sopt_data;
#ifndef __vax__
if (cnt % sizeof(int32_t))
return (EINVAL);
#endif
m = m_get(M_DONTWAIT, MT_SOOPTS);
if (m == NULL)
return (ENOBUFS);
dp = mtod(m, u_char *);
memset(dp, 0, sizeof(struct in_addr));
dp += sizeof(struct in_addr);
m->m_len = sizeof(struct in_addr);
/*
* IP option list according to RFC791. Each option is of the form
*
* [optval] [olen] [(olen - 2) data bytes]
*
* We validate the list and copy options to an mbuf for prepending
* to data packets. The IP first-hop destination address will be
* stored before actual options and is zero if unset.
*/
while (cnt > 0) {
uint8_t optval, olen, offset;
optval = cp[IPOPT_OPTVAL];
if (optval == IPOPT_EOL || optval == IPOPT_NOP) {
olen = 1;
} else {
if (cnt < IPOPT_OLEN + 1)
goto bad;
olen = cp[IPOPT_OLEN];
if (olen < IPOPT_OLEN + 1 || olen > cnt)
goto bad;
}
if (optval == IPOPT_LSRR || optval == IPOPT_SSRR) {
/*
* user process specifies route as:
* ->A->B->C->D
* D must be our final destination (but we can't
* check that since we may not have connected yet).
* A is first hop destination, which doesn't appear in
* actual IP option, but is stored before the options.
*/
if (olen < IPOPT_OFFSET + 1 + sizeof(struct in_addr))
goto bad;
offset = cp[IPOPT_OFFSET];
memcpy(mtod(m, u_char *), cp + IPOPT_OFFSET + 1,
sizeof(struct in_addr));
cp += sizeof(struct in_addr);
cnt -= sizeof(struct in_addr);
olen -= sizeof(struct in_addr);
if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr))
goto bad;
memcpy(dp, cp, olen);
dp[IPOPT_OPTVAL] = optval;
dp[IPOPT_OLEN] = olen;
dp[IPOPT_OFFSET] = offset;
break;
} else {
if (m->m_len + olen > MAX_IPOPTLEN + sizeof(struct in_addr))
goto bad;
memcpy(dp, cp, olen);
break;
}
dp += olen;
m->m_len += olen;
if (optval == IPOPT_EOL)
break;
cp += olen;
cnt -= olen;
}
inp->inp_options = m;
return 0;
bad:
(void)m_free(m);
return EINVAL;
}
/*
* following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
*/
static struct ifnet *
ip_multicast_if(struct in_addr *a, int *ifindexp)
{
int ifindex;
struct ifnet *ifp = NULL;
struct in_ifaddr *ia;
if (ifindexp)
*ifindexp = 0;
if (ntohl(a->s_addr) >> 24 == 0) {
ifindex = ntohl(a->s_addr) & 0xffffff;
ifp = if_byindex(ifindex);
if (!ifp)
return NULL;
if (ifindexp)
*ifindexp = ifindex;
} else {
LIST_FOREACH(ia, &IN_IFADDR_HASH(a->s_addr), ia_hash) {
if (in_hosteq(ia->ia_addr.sin_addr, *a) &&
(ia->ia_ifp->if_flags & IFF_MULTICAST) != 0) {
ifp = ia->ia_ifp;
break;
}
}
}
return ifp;
}
static int
ip_getoptval(const struct sockopt *sopt, u_int8_t *val, u_int maxval)
{
u_int tval;
u_char cval;
int error;
if (sopt == NULL)
return EINVAL;
switch (sopt->sopt_size) {
case sizeof(u_char):
error = sockopt_get(sopt, &cval, sizeof(u_char));
tval = cval;
break;
case sizeof(u_int):
error = sockopt_get(sopt, &tval, sizeof(u_int));
break;
default:
error = EINVAL;
}
if (error)
return error;
if (tval > maxval)
return EINVAL;
*val = tval;
return 0;
}
static int
ip_get_membership(const struct sockopt *sopt, struct ifnet **ifp,
struct in_addr *ia, bool add)
{
int error;
struct ip_mreq mreq;
error = sockopt_get(sopt, &mreq, sizeof(mreq));
if (error)
return error;
if (!IN_MULTICAST(mreq.imr_multiaddr.s_addr))
return EINVAL;
memcpy(ia, &mreq.imr_multiaddr, sizeof(*ia));
if (in_nullhost(mreq.imr_interface)) {
union {
struct sockaddr dst;
struct sockaddr_in dst4;
} u;
struct route ro;
if (!add) {
*ifp = NULL;
return 0;
}
/*
* If no interface address was provided, use the interface of
* the route to the given multicast address.
*/
struct rtentry *rt;
memset(&ro, 0, sizeof(ro));
sockaddr_in_init(&u.dst4, ia, 0);
rtcache_setdst(&ro, &u.dst);
*ifp = (rt = rtcache_init(&ro)) != NULL ? rt->rt_ifp : NULL;
rtcache_free(&ro);
} else {
*ifp = ip_multicast_if(&mreq.imr_interface, NULL);
if (!add && *ifp == NULL)
return EADDRNOTAVAIL;
}
return 0;
}
/*
* Add a multicast group membership.
* Group must be a valid IP multicast address.
*/
static int
ip_add_membership(struct ip_moptions *imo, const struct sockopt *sopt)
{
struct ifnet *ifp;
struct in_addr ia;
int i, error;
if (sopt->sopt_size == sizeof(struct ip_mreq))
error = ip_get_membership(sopt, &ifp, &ia, true);
else
#ifdef INET6
error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia));
#else
return EINVAL;
#endif
if (error)
return error;
/*
* See if we found an interface, and confirm that it
* supports multicast.
*/
if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0)
return EADDRNOTAVAIL;
/*
* See if the membership already exists or if all the
* membership slots are full.
*/
for (i = 0; i < imo->imo_num_memberships; ++i) {
if (imo->imo_membership[i]->inm_ifp == ifp &&
in_hosteq(imo->imo_membership[i]->inm_addr, ia))
break;
}
if (i < imo->imo_num_memberships)
return EADDRINUSE;
if (i == IP_MAX_MEMBERSHIPS)
return ETOOMANYREFS;
/*
* Everything looks good; add a new record to the multicast
* address list for the given interface.
*/
if ((imo->imo_membership[i] = in_addmulti(&ia, ifp)) == NULL)
return ENOBUFS;
++imo->imo_num_memberships;
return 0;
}
/*
* Drop a multicast group membership.
* Group must be a valid IP multicast address.
*/
static int
ip_drop_membership(struct ip_moptions *imo, const struct sockopt *sopt)
{
struct in_addr ia;
struct ifnet *ifp;
int i, error;
if (sopt->sopt_size == sizeof(struct ip_mreq))
error = ip_get_membership(sopt, &ifp, &ia, false);
else
#ifdef INET6
error = ip6_get_membership(sopt, &ifp, &ia, sizeof(ia));
#else
return EINVAL;
#endif
if (error)
return error;
/*
* Find the membership in the membership array.
*/
for (i = 0; i < imo->imo_num_memberships; ++i) {
if ((ifp == NULL ||
imo->imo_membership[i]->inm_ifp == ifp) &&
in_hosteq(imo->imo_membership[i]->inm_addr, ia))
break;
}
if (i == imo->imo_num_memberships)
return EADDRNOTAVAIL;
/*
* Give up the multicast address record to which the
* membership points.
*/
in_delmulti(imo->imo_membership[i]);
/*
* Remove the gap in the membership array.
*/
for (++i; i < imo->imo_num_memberships; ++i)
imo->imo_membership[i-1] = imo->imo_membership[i];
--imo->imo_num_memberships;
return 0;
}
/*
* Set the IP multicast options in response to user setsockopt().
*/
int
ip_setmoptions(struct ip_moptions **pimo, const struct sockopt *sopt)
{
struct ip_moptions *imo = *pimo;
struct in_addr addr;
struct ifnet *ifp;
int ifindex, error = 0;
if (!imo) {
/*
* No multicast option buffer attached to the pcb;
* allocate one and initialize to default values.
*/
imo = kmem_intr_alloc(sizeof(*imo), KM_NOSLEEP);
if (imo == NULL)
return ENOBUFS;
imo->imo_multicast_ifp = NULL;
imo->imo_multicast_addr.s_addr = INADDR_ANY;
imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
imo->imo_num_memberships = 0;
*pimo = imo;
}
switch (sopt->sopt_name) {
case IP_MULTICAST_IF:
/*
* Select the interface for outgoing multicast packets.
*/
error = sockopt_get(sopt, &addr, sizeof(addr));
if (error)
break;
/*
* INADDR_ANY is used to remove a previous selection.
* When no interface is selected, a default one is
* chosen every time a multicast packet is sent.
*/
if (in_nullhost(addr)) {
imo->imo_multicast_ifp = NULL;
break;
}
/*
* The selected interface is identified by its local
* IP address. Find the interface and confirm that
* it supports multicasting.
*/
ifp = ip_multicast_if(&addr, &ifindex);
if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
error = EADDRNOTAVAIL;
break;
}
imo->imo_multicast_ifp = ifp;
if (ifindex)
imo->imo_multicast_addr = addr;
else
imo->imo_multicast_addr.s_addr = INADDR_ANY;
break;
case IP_MULTICAST_TTL:
/*
* Set the IP time-to-live for outgoing multicast packets.
*/
error = ip_getoptval(sopt, &imo->imo_multicast_ttl, MAXTTL);
break;
case IP_MULTICAST_LOOP:
/*
* Set the loopback flag for outgoing multicast packets.
* Must be zero or one.
*/
error = ip_getoptval(sopt, &imo->imo_multicast_loop, 1);
break;
case IP_ADD_MEMBERSHIP: /* IPV6_JOIN_GROUP */
error = ip_add_membership(imo, sopt);
break;
case IP_DROP_MEMBERSHIP: /* IPV6_LEAVE_GROUP */
error = ip_drop_membership(imo, sopt);
break;
default:
error = EOPNOTSUPP;
break;
}
/*
* If all options have default values, no need to keep the mbuf.
*/
if (imo->imo_multicast_ifp == NULL &&
imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
imo->imo_num_memberships == 0) {
kmem_free(imo, sizeof(*imo));
*pimo = NULL;
}
return error;
}
/*
* Return the IP multicast options in response to user getsockopt().
*/
int
ip_getmoptions(struct ip_moptions *imo, struct sockopt *sopt)
{
struct in_addr addr;
struct in_ifaddr *ia;
uint8_t optval;
int error = 0;
switch (sopt->sopt_name) {
case IP_MULTICAST_IF:
if (imo == NULL || imo->imo_multicast_ifp == NULL)
addr = zeroin_addr;
else if (imo->imo_multicast_addr.s_addr) {
/* return the value user has set */
addr = imo->imo_multicast_addr;
} else {
IFP_TO_IA(imo->imo_multicast_ifp, ia);
addr = ia ? ia->ia_addr.sin_addr : zeroin_addr;
}
error = sockopt_set(sopt, &addr, sizeof(addr));
break;
case IP_MULTICAST_TTL:
optval = imo ? imo->imo_multicast_ttl
: IP_DEFAULT_MULTICAST_TTL;
error = sockopt_set(sopt, &optval, sizeof(optval));
break;
case IP_MULTICAST_LOOP:
optval = imo ? imo->imo_multicast_loop
: IP_DEFAULT_MULTICAST_LOOP;
error = sockopt_set(sopt, &optval, sizeof(optval));
break;
default:
error = EOPNOTSUPP;
}
return error;
}
/*
* Discard the IP multicast options.
*/
void
ip_freemoptions(struct ip_moptions *imo)
{
int i;
if (imo != NULL) {
for (i = 0; i < imo->imo_num_memberships; ++i)
in_delmulti(imo->imo_membership[i]);
kmem_free(imo, sizeof(*imo));
}
}
/*
* Routine called from ip_output() to loop back a copy of an IP multicast
* packet to the input queue of a specified interface. Note that this
* calls the output routine of the loopback "driver", but with an interface
* pointer that might NOT be lo0ifp -- easier than replicating that code here.
*/
static void
ip_mloopback(struct ifnet *ifp, struct mbuf *m, const struct sockaddr_in *dst)
{
struct ip *ip;
struct mbuf *copym;
copym = m_copypacket(m, M_DONTWAIT);
if (copym != NULL
&& (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip)))
copym = m_pullup(copym, sizeof(struct ip));
if (copym == NULL)
return;
/*
* We don't bother to fragment if the IP length is greater
* than the interface's MTU. Can this possibly matter?
*/
ip = mtod(copym, struct ip *);
if (copym->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) {
in_delayed_cksum(copym);
copym->m_pkthdr.csum_flags &=
~(M_CSUM_TCPv4|M_CSUM_UDPv4);
}
ip->ip_sum = 0;
ip->ip_sum = in_cksum(copym, ip->ip_hl << 2);
KERNEL_LOCK(1, NULL);
(void)looutput(ifp, copym, sintocsa(dst), NULL);
KERNEL_UNLOCK_ONE(NULL);
}
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