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NetBSD/sys/netinet/ip_output.c

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/* $NetBSD: ip_output.c,v 1.224 2013/06/29 21:06:58 rmind 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 1.224 2013/06/29 21:06:58 rmind Exp $");
#include "opt_inet.h"
#include "opt_ipsec.h"
#include "opt_mrouting.h"
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/kmem.h>
#include <sys/mbuf.h>
#include <sys/errno.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 <sys/proc.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 MROUTING
#include <netinet/ip_mroute.h>
#endif
#include <netipsec/ipsec.h>
#include <netipsec/key.h>
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;
struct ifaddr *xifa;
struct mbuf *opt;
struct route *ro;
int flags, sw_csum, *mtu_p;
u_long mtu;
struct ip_moptions *imo;
struct socket *so;
va_list ap;
struct secpolicy *sp = NULL;
bool natt_frag = false;
bool __unused done = false;
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 *);
if (flags & IP_RETURNMTU)
mtu_p = va_arg(ap, int *);
else
mtu_p = NULL;
va_end(ap);
MCLAIM(m, &ip_tx_mowner);
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("ip_output: no HDR");
if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv6|M_CSUM_UDPv6)) != 0) {
panic("ip_output: IPv6 checksum offload flags: %d",
m->m_pkthdr.csum_flags);
}
if ((m->m_pkthdr.csum_flags & (M_CSUM_TCPv4|M_CSUM_UDPv4)) ==
(M_CSUM_TCPv4|M_CSUM_UDPv4)) {
panic("ip_output: conflicting checksum offload flags: %d",
m->m_pkthdr.csum_flags);
}
#endif
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.
*/
memset(&iproute, 0, sizeof(iproute));
if (ro == NULL)
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 == NULL)
;
else if (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;
} 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);
} 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 (IN_MULTICAST(ip->ip_dst.s_addr) ||
(ip->ip_dst.s_addr == INADDR_BROADCAST)) {
struct in_multi *inm;
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;
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;
}
IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm);
if (inm != NULL &&
(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)) {
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 (in_broadcast(dst->sin_addr, ifp)) {
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 && rt != NULL &&
(rt->rt_rmx.rmx_locks & RTV_MTU) == 0)
ip->ip_off |= htons(IP_DF);
#ifdef IPSEC
/* Perform IPsec processing, if any. */
error = ipsec4_output(m, so, flags, &sp, &mtu, &natt_frag, &done);
if (error || done) {
goto done;
}
#endif
/*
* Run through list of hooks for output packets.
*/
if ((error = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_OUT)) != 0)
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) {
#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);
}
}
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,
(m->m_flags & M_MCAST) ?
sintocsa(rdst) : sintocsa(dst),
rt);
KERNEL_UNLOCK_ONE(NULL);
} else {
error =
ip_tso_output(ifp, m,
(m->m_flags & M_MCAST) ?
sintocsa(rdst) : sintocsa(dst),
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)
*mtu_p = 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 == 0) {
#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, mtu_p);
} 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);
}
} else
m_freem(m);
}
if (error == 0)
IP_STATINC(IP_STAT_FRAGMENTED);
done:
rtcache_free(&iproute);
if (sp) {
#ifdef IPSEC
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));
else
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;
}
#ifdef DIAGNOSTIC
if (cnt < IPOPT_OLEN + sizeof(*cp))
panic("malformed IPv4 option passed to ip_optcopy");
#endif
optlen = cp[IPOPT_OLEN];
#ifdef DIAGNOSTIC
if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt)
panic("malformed IPv4 option passed to ip_optcopy");
#endif
/* bogus 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);
int optval = 0;
int error = 0;
#if defined(IPSEC)
struct lwp *l = curlwp; /*XXX*/
#endif
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->inp_options, 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:
inp->inp_ip.ip_tos = optval;
break;
case IP_TTL:
inp->inp_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) \
inp->inp_flags |= bit; \
else \
inp->inp_flags &= ~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;
/* INP_LOCK(inp); */
switch (optval) {
case IP_PORTRANGE_DEFAULT:
case IP_PORTRANGE_HIGH:
inp->inp_flags &= ~(INP_LOWPORT);
break;
case IP_PORTRANGE_LOW:
inp->inp_flags |= INP_LOWPORT;
break;
default:
error = EINVAL;
break;
}
/* INP_UNLOCK(inp); */
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:
error = ipsec4_set_policy(inp, sopt->sopt_name,
sopt->sopt_data, sopt->sopt_size, l->l_cred);
break;
#endif /*IPSEC*/
default:
error = ENOPROTOOPT;
break;
}
break;
case PRCO_GETOPT:
switch (sopt->sopt_name) {
case IP_OPTIONS:
case IP_RETOPTS:
if (inp->inp_options) {
struct mbuf *m;
m = m_copym(inp->inp_options, 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 = inp->inp_ip.ip_tos;
break;
case IP_TTL:
optval = inp->inp_ip.ip_ttl;
break;
case IP_MINTTL:
optval = inp->inp_ip_minttl;
break;
case IP_ERRORMTU:
optval = inp->inp_errormtu;
break;
#define OPTBIT(bit) (inp->inp_flags & 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 (inp->inp_flags & INP_LOWPORT)
optval = IP_PORTRANGE_LOW;
else
optval = IP_PORTRANGE_DEFAULT;
error = sockopt_setint(sopt, optval);
break;
case IP_PORTALGO:
optval = ((struct inpcb_hdr *)inp)->inph_portalgo;
error = sockopt_setint(sopt, optval);
break;
default:
error = ENOPROTOOPT;
break;
}
break;
}
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.
*/
int
ip_pcbopts(struct mbuf **pcbopt, const struct sockopt *sopt)
{
struct mbuf *m;
const u_char *cp;
u_char *dp;
int cnt;
uint8_t optval, olen, offset;
/* turn off any old options */
if (*pcbopt)
(void)m_free(*pcbopt);
*pcbopt = NULL;
cp = sopt->sopt_data;
cnt = sopt->sopt_size;
if (cnt == 0)
return (0); /* Only turning off any previous options */
#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) {
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;
}
*pcbopt = 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;
if (ifindex < 0 || if_indexlim <= ifindex)
return NULL;
ifp = ifindex2ifnet[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;
}
/*
* Set the IP multicast options in response to user setsockopt().
*/
int
ip_setmoptions(struct ip_moptions **imop, const struct sockopt *sopt)
{
struct in_addr addr;
struct ip_mreq lmreq, *mreq;
struct ifnet *ifp;
struct ip_moptions *imo = *imop;
int i, ifindex, error = 0;
if (imo == NULL) {
/*
* 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;
*imop = 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:
/*
* Add a multicast group membership.
* Group must be a valid IP multicast address.
*/
error = sockopt_get(sopt, &lmreq, sizeof(lmreq));
if (error)
break;
mreq = &lmreq;
if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) {
error = EINVAL;
break;
}
/*
* If no interface address was provided, use the interface of
* the route to the given multicast address.
*/
if (in_nullhost(mreq->imr_interface)) {
struct rtentry *rt;
union {
struct sockaddr dst;
struct sockaddr_in dst4;
} u;
struct route ro;
memset(&ro, 0, sizeof(ro));
sockaddr_in_init(&u.dst4, &mreq->imr_multiaddr, 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);
}
/*
* See if we found an interface, and confirm that it
* supports multicast.
*/
if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
error = EADDRNOTAVAIL;
break;
}
/*
* 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,
mreq->imr_multiaddr))
break;
}
if (i < imo->imo_num_memberships) {
error = EADDRINUSE;
break;
}
if (i == IP_MAX_MEMBERSHIPS) {
error = ETOOMANYREFS;
break;
}
/*
* Everything looks good; add a new record to the multicast
* address list for the given interface.
*/
if ((imo->imo_membership[i] =
in_addmulti(&mreq->imr_multiaddr, ifp)) == NULL) {
error = ENOBUFS;
break;
}
++imo->imo_num_memberships;
break;
case IP_DROP_MEMBERSHIP:
/*
* Drop a multicast group membership.
* Group must be a valid IP multicast address.
*/
error = sockopt_get(sopt, &lmreq, sizeof(lmreq));
if (error)
break;
mreq = &lmreq;
if (!IN_MULTICAST(mreq->imr_multiaddr.s_addr)) {
error = EINVAL;
break;
}
/*
* If an interface address was specified, get a pointer
* to its ifnet structure.
*/
if (in_nullhost(mreq->imr_interface))
ifp = NULL;
else {
ifp = ip_multicast_if(&mreq->imr_interface, NULL);
if (ifp == NULL) {
error = EADDRNOTAVAIL;
break;
}
}
/*
* 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,
mreq->imr_multiaddr))
break;
}
if (i == imo->imo_num_memberships) {
error = EADDRNOTAVAIL;
break;
}
/*
* 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;
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));
*imop = 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;
int error;
uint8_t optval;
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);
(void)looutput(ifp, copym, sintocsa(dst), NULL);
}
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