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505125808c
NetBSD/sys/netinet/ip_output.c
enami bae9643b84 Increment stats when packet is dropped since there is no room 
to put all fragments in the interfaces's send queue.  Some large
UDP packets are dropped here and administrator may want to bump ifqmaxlen.
2003-10-17 20:31:12 +00:00

1860 lines
45 KiB
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/* $NetBSD: ip_output.c,v 1.126 2003/10/17 20:31:12 enami 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 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 1.126 2003/10/17 20:31:12 enami Exp $");
#include "opt_pfil_hooks.h"
#include "opt_ipsec.h"
#include "opt_mrouting.h"
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#ifdef FAST_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>
#ifdef MROUTING
#include <netinet/ip_mroute.h>
#endif
#include <machine/stdarg.h>
#ifdef IPSEC
#include <netinet6/ipsec.h>
#include <netkey/key.h>
#include <netkey/key_debug.h>
#endif /*IPSEC*/
#ifdef FAST_IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/key.h>
#include <netipsec/xform.h>
#endif /* FAST_IPSEC*/
static struct mbuf *ip_insertoptions __P((struct mbuf *, struct mbuf *, int *));
static struct ifnet *ip_multicast_if __P((struct in_addr *, int *));
static void ip_mloopback
__P((struct ifnet *, struct mbuf *, struct sockaddr_in *));
#ifdef PFIL_HOOKS
extern struct pfil_head inet_pfil_hook; /* XXX */
#endif
/*
* 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
#if __STDC__
ip_output(struct mbuf *m0, ...)
#else
ip_output(m0, va_alist)
struct mbuf *m0;
va_dcl
#endif
{
struct ip *ip;
struct ifnet *ifp;
struct mbuf *m = m0;
int hlen = sizeof (struct ip);
int len, error = 0;
struct route iproute;
struct sockaddr_in *dst;
struct in_ifaddr *ia;
struct mbuf *opt;
struct route *ro;
int flags, sw_csum;
int *mtu_p;
u_long mtu;
struct ip_moptions *imo;
struct socket *so;
va_list ap;
#ifdef IPSEC
struct secpolicy *sp = NULL;
#endif /*IPSEC*/
#ifdef FAST_IPSEC
struct inpcb *inp;
struct m_tag *mtag;
struct secpolicy *sp = NULL;
struct tdb_ident *tdbi;
int s;
#endif
u_int16_t ip_len;
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 FAST_IPSEC
if (so != NULL && so->so_proto->pr_domain->dom_family == AF_INET)
inp = (struct inpcb *)so->so_pcb;
else
inp = NULL;
#endif /*IPSEC*/
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("ip_output no HDR");
#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 = htons(ip_randomid());
ip->ip_hl = hlen >> 2;
ipstat.ips_localout++;
} else {
hlen = ip->ip_hl << 2;
}
/*
* Route packet.
*/
if (ro == 0) {
ro = &iproute;
bzero((caddr_t)ro, sizeof (*ro));
}
dst = satosin(&ro->ro_dst);
/*
* 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 (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
dst->sin_family != AF_INET ||
!in_hosteq(dst->sin_addr, ip->ip_dst))) {
RTFREE(ro->ro_rt);
ro->ro_rt = (struct rtentry *)0;
}
if (ro->ro_rt == 0) {
bzero(dst, sizeof(*dst));
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = ip->ip_dst;
}
/*
* If routing to interface only,
* short circuit routing lookup.
*/
if (flags & IP_ROUTETOIF) {
if ((ia = ifatoia(ifa_ifwithladdr(sintosa(dst)))) == 0) {
ipstat.ips_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 (ro->ro_rt == 0)
rtalloc(ro);
if (ro->ro_rt == 0) {
ipstat.ips_noroute++;
error = EHOSTUNREACH;
goto bad;
}
ia = ifatoia(ro->ro_rt->rt_ifa);
ifp = ro->ro_rt->rt_ifp;
if ((mtu = ro->ro_rt->rt_rmx.rmx_mtu) == 0)
mtu = ifp->if_mtu;
ro->ro_rt->rt_use++;
if (ro->ro_rt->rt_flags & RTF_GATEWAY)
dst = satosin(ro->ro_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;
/*
* IP destination address is multicast. Make sure "dst"
* still points to the address in "ro". (It may have been
* changed to point to a gateway address, above.)
*/
dst = satosin(&ro->ro_dst);
/*
* 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) {
ipstat.ips_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)) {
ipstat.ips_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 *ia;
IFP_TO_IA(ifp, ia);
if (!ia) {
error = EADDRNOTAVAIL;
goto bad;
}
ip->ip_src = ia->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, dst);
}
#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;
}
#ifndef notdef
/*
* If source address not specified yet, use address
* of outgoing interface.
*/
if (in_nullhost(ip->ip_src))
ip->ip_src = ia->ia_addr.sin_addr;
#endif
/*
* packets with Class-D address as source are not valid per
* RFC 1112
*/
if (IN_MULTICAST(ip->ip_src.s_addr)) {
ipstat.ips_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 we're doing Path MTU Discovery, we need to set DF unless
* the route's MTU is locked.
*/
if ((flags & IP_MTUDISC) != 0 && ro->ro_rt != NULL &&
(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0)
ip->ip_off |= htons(IP_DF);
/* Remember the current ip_len */
ip_len = ntohs(ip->ip_len);
#ifdef IPSEC
/* get SP for this packet */
if (so == NULL)
sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND,
flags, &error);
else
sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
if (sp == NULL) {
ipsecstat.out_inval++;
goto bad;
}
error = 0;
/* check policy */
switch (sp->policy) {
case IPSEC_POLICY_DISCARD:
/*
* This packet is just discarded.
*/
ipsecstat.out_polvio++;
goto bad;
case IPSEC_POLICY_BYPASS:
case IPSEC_POLICY_NONE:
/* no need to do IPsec. */
goto skip_ipsec;
case IPSEC_POLICY_IPSEC:
if (sp->req == NULL) {
/* XXX should be panic ? */
printf("ip_output: No IPsec request specified.\n");
error = EINVAL;
goto bad;
}
break;
case IPSEC_POLICY_ENTRUST:
default:
printf("ip_output: Invalid policy found. %d\n", sp->policy);
}
/*
* ipsec4_output() expects ip_len and ip_off in network
* order. They have been set to network order above.
*/
{
struct ipsec_output_state state;
bzero(&state, sizeof(state));
state.m = m;
if (flags & IP_ROUTETOIF) {
state.ro = &iproute;
bzero(&iproute, sizeof(iproute));
} else
state.ro = ro;
state.dst = (struct sockaddr *)dst;
/*
* We can't defer the checksum of payload data if
* we're about to encrypt/authenticate it.
*
* XXX When we support crypto offloading functions of
* XXX network interfaces, we need to reconsider this,
* XXX since it's likely that they'll support checksumming,
* XXX as well.
*/
if (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);
}
error = ipsec4_output(&state, sp, flags);
m = state.m;
if (flags & IP_ROUTETOIF) {
/*
* if we have tunnel mode SA, we may need to ignore
* IP_ROUTETOIF.
*/
if (state.ro != &iproute || state.ro->ro_rt != NULL) {
flags &= ~IP_ROUTETOIF;
ro = state.ro;
}
} else
ro = state.ro;
dst = (struct sockaddr_in *)state.dst;
if (error) {
/* mbuf is already reclaimed in ipsec4_output. */
m0 = NULL;
switch (error) {
case EHOSTUNREACH:
case ENETUNREACH:
case EMSGSIZE:
case ENOBUFS:
case ENOMEM:
break;
default:
printf("ip4_output (ipsec): error code %d\n", error);
/*fall through*/
case ENOENT:
/* don't show these error codes to the user */
error = 0;
break;
}
goto bad;
}
/* be sure to update variables that are affected by ipsec4_output() */
ip = mtod(m, struct ip *);
hlen = ip->ip_hl << 2;
ip_len = ntohs(ip->ip_len);
if (ro->ro_rt == NULL) {
if ((flags & IP_ROUTETOIF) == 0) {
printf("ip_output: "
"can't update route after IPsec processing\n");
error = EHOSTUNREACH; /*XXX*/
goto bad;
}
} else {
/* nobody uses ia beyond here */
if (state.encap)
ifp = ro->ro_rt->rt_ifp;
}
}
skip_ipsec:
#endif /*IPSEC*/
#ifdef FAST_IPSEC
/*
* Check the security policy (SP) for the packet and, if
* required, do IPsec-related processing. There are two
* cases here; the first time a packet is sent through
* it will be untagged and handled by ipsec4_checkpolicy.
* If the packet is resubmitted to ip_output (e.g. after
* AH, ESP, etc. processing), there will be a tag to bypass
* the lookup and related policy checking.
*/
mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
s = splsoftnet();
if (mtag != NULL) {
tdbi = (struct tdb_ident *)(mtag + 1);
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
if (sp == NULL)
error = -EINVAL; /* force silent drop */
m_tag_delete(m, mtag);
} else {
sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags,
&error, inp);
}
/*
* There are four return cases:
* sp != NULL apply IPsec policy
* sp == NULL, error == 0 no IPsec handling needed
* sp == NULL, error == -EINVAL discard packet w/o error
* sp == NULL, error != 0 discard packet, report error
*/
if (sp != NULL) {
/* Loop detection, check if ipsec processing already done */
IPSEC_ASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
for (mtag = m_tag_first(m); mtag != NULL;
mtag = m_tag_next(m, mtag)) {
#ifdef MTAG_ABI_COMPAT
if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
continue;
#endif
if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
continue;
/*
* Check if policy has an SA associated with it.
* This can happen when an SP has yet to acquire
* an SA; e.g. on first reference. If it occurs,
* then we let ipsec4_process_packet do its thing.
*/
if (sp->req->sav == NULL)
break;
tdbi = (struct tdb_ident *)(mtag + 1);
if (tdbi->spi == sp->req->sav->spi &&
tdbi->proto == sp->req->sav->sah->saidx.proto &&
bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
sizeof (union sockaddr_union)) == 0) {
/*
* No IPsec processing is needed, free
* reference to SP.
*
* NB: null pointer to avoid free at
* done: below.
*/
KEY_FREESP(&sp), sp = NULL;
splx(s);
goto spd_done;
}
}
/*
* Do delayed checksums now because we send before
* this is done in the normal processing path.
*/
if (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);
}
#ifdef __FreeBSD__
ip->ip_len = htons(ip->ip_len);
ip->ip_off = htons(ip->ip_off);
#endif
/* NB: callee frees mbuf */
error = ipsec4_process_packet(m, sp->req, flags, 0);
/*
* Preserve KAME behaviour: ENOENT can be returned
* when an SA acquire is in progress. Don't propagate
* this to user-level; it confuses applications.
*
* XXX this will go away when the SADB is redone.
*/
if (error == ENOENT)
error = 0;
splx(s);
goto done;
} else {
splx(s);
if (error != 0) {
/*
* Hack: -EINVAL is used to signal that a packet
* should be silently discarded. This is typically
* because we asked key management for an SA and
* it was delayed (e.g. kicked up to IKE).
*/
if (error == -EINVAL)
error = 0;
goto bad;
} else {
/* No IPsec processing for this packet. */
}
#ifdef notyet
/*
* If deferred crypto processing is needed, check that
* the interface supports it.
*/
mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) {
/* notify IPsec to do its own crypto */
ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1));
error = EHOSTUNREACH;
goto bad;
}
#endif
}
spd_done:
#endif /* FAST_IPSEC */
#ifdef PFIL_HOOKS
/*
* 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;
#endif /* PFIL_HOOKS */
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, can just send directly.
*/
if (ip_len <= mtu) {
#if IFA_STATS
/*
* search for the source address structure to
* maintain output statistics.
*/
INADDR_TO_IA(ip->ip_src, ia);
if (ia)
ia->ia_ifa.ifa_data.ifad_outbytes += ip_len;
#endif
/*
* Always initialize the sum to 0! Some HW assisted
* checksumming requires this.
*/
ip->ip_sum = 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) {
ip->ip_sum = in_cksum(m, hlen);
m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4;
}
if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) {
in_delayed_cksum(m);
m->m_pkthdr.csum_flags &= ~(M_CSUM_TCPv4|M_CSUM_UDPv4);
}
#ifdef IPSEC
/* clean ipsec history once it goes out of the node */
ipsec_delaux(m);
#endif
error = (*ifp->if_output)(ifp, m, sintosa(dst), ro->ro_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)) {
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;
ipstat.ips_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
/*
* search for the source address structure to
* maintain output statistics.
*/
INADDR_TO_IA(ip->ip_src, ia);
if (ia) {
ia->ia_ifa.ifa_data.ifad_outbytes +=
ntohs(ip->ip_len);
}
#endif
#ifdef IPSEC
/* clean ipsec history once it goes out of the node */
ipsec_delaux(m);
#endif
KASSERT((m->m_pkthdr.csum_flags &
(M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0);
error = (*ifp->if_output)(ifp, m, sintosa(dst),
ro->ro_rt);
} else
m_freem(m);
}
if (error == 0)
ipstat.ips_fragmented++;
done:
if (ro == &iproute && (flags & IP_ROUTETOIF) == 0 && ro->ro_rt) {
RTFREE(ro->ro_rt);
ro->ro_rt = 0;
}
#ifdef IPSEC
if (sp != NULL) {
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP ip_output call free SP:%p\n", sp));
key_freesp(sp);
}
#endif /* IPSEC */
#ifdef FAST_IPSEC
if (sp != NULL)
KEY_FREESP(&sp);
#endif /* FAST_IPSEC */
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;
int fragments = 0;
int s;
int error = 0;
ip = mtod(m, struct ip *);
hlen = ip->ip_hl << 2;
sw_csum = m->m_pkthdr.csum_flags & ~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;
ipstat.ips_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_copy(m0, off, len);
if (m->m_next == 0) {
error = ENOBUFS; /* ??? */
ipstat.ips_odropped++;
goto sendorfree;
}
m->m_pkthdr.len = mhlen + len;
m->m_pkthdr.rcvif = (struct ifnet *)0;
mhip->ip_sum = 0;
if (sw_csum & M_CSUM_IPv4) {
mhip->ip_sum = in_cksum(m, mhlen);
KASSERT((m->m_pkthdr.csum_flags & M_CSUM_IPv4) == 0);
} else {
m->m_pkthdr.csum_flags |= M_CSUM_IPv4;
}
ipstat.ips_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 {
KASSERT(m->m_pkthdr.csum_flags & M_CSUM_IPv4);
}
sendorfree:
/*
* If there is no room for all the fragments, don't queue
* any of them.
*/
s = splnet();
if (ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len < fragments &&
error == 0) {
error = ENOBUFS;
ipstat.ips_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->m_pkthdr.csum_data; /* checksum offset */
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), (caddr_t) &csum);
} else
*(u_int16_t *)(mtod(m, caddr_t) + 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(inp)
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(m, opt, phlen)
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_COPY_PKTHDR(n, m);
m_tag_delete_chain(m, NULL);
m->m_flags &= ~M_PKTHDR;
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((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
} else {
m->m_data -= optlen;
m->m_len += optlen;
memmove(mtod(m, caddr_t), ip, sizeof(struct ip));
}
m->m_pkthdr.len += optlen;
ip = mtod(m, struct ip *);
bcopy((caddr_t)p->ipopt_list, (caddr_t)(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(ip, jp)
struct ip *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((caddr_t)cp, (caddr_t)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(op, so, level, optname, mp)
int op;
struct socket *so;
int level, optname;
struct mbuf **mp;
{
struct inpcb *inp = sotoinpcb(so);
struct mbuf *m = *mp;
int optval = 0;
int error = 0;
#if defined(IPSEC) || defined(FAST_IPSEC)
struct proc *p = curproc; /*XXX*/
#endif
if (level != IPPROTO_IP) {
error = EINVAL;
if (op == PRCO_SETOPT && *mp)
(void) m_free(*mp);
} else switch (op) {
case PRCO_SETOPT:
switch (optname) {
case IP_OPTIONS:
#ifdef notyet
case IP_RETOPTS:
return (ip_pcbopts(optname, &inp->inp_options, m));
#else
return (ip_pcbopts(&inp->inp_options, m));
#endif
case IP_TOS:
case IP_TTL:
case IP_RECVOPTS:
case IP_RECVRETOPTS:
case IP_RECVDSTADDR:
case IP_RECVIF:
if (m == NULL || m->m_len != sizeof(int))
error = EINVAL;
else {
optval = *mtod(m, int *);
switch (optname) {
case IP_TOS:
inp->inp_ip.ip_tos = optval;
break;
case IP_TTL:
inp->inp_ip.ip_ttl = optval;
break;
#define OPTSET(bit) \
if (optval) \
inp->inp_flags |= bit; \
else \
inp->inp_flags &= ~bit;
case IP_RECVOPTS:
OPTSET(INP_RECVOPTS);
break;
case IP_RECVRETOPTS:
OPTSET(INP_RECVRETOPTS);
break;
case IP_RECVDSTADDR:
OPTSET(INP_RECVDSTADDR);
break;
case IP_RECVIF:
OPTSET(INP_RECVIF);
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(optname, &inp->inp_moptions, m);
break;
case IP_PORTRANGE:
if (m == 0 || m->m_len != sizeof(int))
error = EINVAL;
else {
optval = *mtod(m, int *);
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;
}
}
break;
#if defined(IPSEC) || defined(FAST_IPSEC)
case IP_IPSEC_POLICY:
{
caddr_t req = NULL;
size_t len = 0;
int priv = 0;
#ifdef __NetBSD__
if (p == 0 || suser(p->p_ucred, &p->p_acflag))
priv = 0;
else
priv = 1;
#else
priv = (in6p->in6p_socket->so_state & SS_PRIV);
#endif
if (m) {
req = mtod(m, caddr_t);
len = m->m_len;
}
error = ipsec4_set_policy(inp, optname, req, len, priv);
break;
}
#endif /*IPSEC*/
default:
error = ENOPROTOOPT;
break;
}
if (m)
(void)m_free(m);
break;
case PRCO_GETOPT:
switch (optname) {
case IP_OPTIONS:
case IP_RETOPTS:
*mp = m = m_get(M_WAIT, MT_SOOPTS);
MCLAIM(m, so->so_mowner);
if (inp->inp_options) {
m->m_len = inp->inp_options->m_len;
bcopy(mtod(inp->inp_options, caddr_t),
mtod(m, caddr_t), (unsigned)m->m_len);
} else
m->m_len = 0;
break;
case IP_TOS:
case IP_TTL:
case IP_RECVOPTS:
case IP_RECVRETOPTS:
case IP_RECVDSTADDR:
case IP_RECVIF:
case IP_ERRORMTU:
*mp = m = m_get(M_WAIT, MT_SOOPTS);
MCLAIM(m, so->so_mowner);
m->m_len = sizeof(int);
switch (optname) {
case IP_TOS:
optval = inp->inp_ip.ip_tos;
break;
case IP_TTL:
optval = inp->inp_ip.ip_ttl;
break;
case IP_ERRORMTU:
optval = inp->inp_errormtu;
break;
#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
case IP_RECVOPTS:
optval = OPTBIT(INP_RECVOPTS);
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;
}
*mtod(m, int *) = optval;
break;
#if defined(IPSEC) || defined(FAST_IPSEC)
case IP_IPSEC_POLICY:
{
caddr_t req = NULL;
size_t len = 0;
if (m) {
req = mtod(m, caddr_t);
len = m->m_len;
}
error = ipsec4_get_policy(inp, req, len, mp);
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(optname, inp->inp_moptions, mp);
if (*mp)
MCLAIM(*mp, so->so_mowner);
break;
case IP_PORTRANGE:
*mp = m = m_get(M_WAIT, MT_SOOPTS);
MCLAIM(m, so->so_mowner);
m->m_len = sizeof(int);
if (inp->inp_flags & INP_LOWPORT)
optval = IP_PORTRANGE_LOW;
else
optval = IP_PORTRANGE_DEFAULT;
*mtod(m, int *) = 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
#ifdef notyet
ip_pcbopts(optname, pcbopt, m)
int optname;
#else
ip_pcbopts(pcbopt, m)
#endif
struct mbuf **pcbopt;
struct mbuf *m;
{
int cnt, optlen;
u_char *cp;
u_char opt;
/* turn off any old options */
if (*pcbopt)
(void)m_free(*pcbopt);
*pcbopt = 0;
if (m == (struct mbuf *)0 || m->m_len == 0) {
/*
* Only turning off any previous options.
*/
if (m)
(void)m_free(m);
return (0);
}
#ifndef __vax__
if (m->m_len % sizeof(int32_t))
goto bad;
#endif
/*
* IP first-hop destination address will be stored before
* actual options; move other options back
* and clear it when none present.
*/
if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
goto bad;
cnt = m->m_len;
m->m_len += sizeof(struct in_addr);
cp = mtod(m, u_char *) + sizeof(struct in_addr);
memmove(cp, mtod(m, caddr_t), (unsigned)cnt);
bzero(mtod(m, caddr_t), sizeof(struct in_addr));
for (; cnt > 0; cnt -= optlen, cp += optlen) {
opt = cp[IPOPT_OPTVAL];
if (opt == IPOPT_EOL)
break;
if (opt == IPOPT_NOP)
optlen = 1;
else {
if (cnt < IPOPT_OLEN + sizeof(*cp))
goto bad;
optlen = cp[IPOPT_OLEN];
if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt)
goto bad;
}
switch (opt) {
default:
break;
case IPOPT_LSRR:
case 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 (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
goto bad;
m->m_len -= sizeof(struct in_addr);
cnt -= sizeof(struct in_addr);
optlen -= sizeof(struct in_addr);
cp[IPOPT_OLEN] = optlen;
/*
* Move first hop before start of options.
*/
bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
sizeof(struct in_addr));
/*
* Then copy rest of options back
* to close up the deleted entry.
*/
memmove(&cp[IPOPT_OFFSET+1],
(caddr_t)(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)),
(unsigned)cnt + sizeof(struct in_addr));
break;
}
}
if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
goto bad;
*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(a, ifindexp)
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_index < ifindex)
return NULL;
ifp = ifindex2ifnet[ifindex];
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;
}
/*
* Set the IP multicast options in response to user setsockopt().
*/
int
ip_setmoptions(optname, imop, m)
int optname;
struct ip_moptions **imop;
struct mbuf *m;
{
int error = 0;
u_char loop;
int i;
struct in_addr addr;
struct ip_mreq *mreq;
struct ifnet *ifp;
struct ip_moptions *imo = *imop;
struct route ro;
struct sockaddr_in *dst;
int ifindex;
if (imo == NULL) {
/*
* No multicast option buffer attached to the pcb;
* allocate one and initialize to default values.
*/
imo = (struct ip_moptions *)malloc(sizeof(*imo), M_IPMOPTS,
M_WAITOK);
if (imo == NULL)
return (ENOBUFS);
*imop = imo;
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;
}
switch (optname) {
case IP_MULTICAST_IF:
/*
* Select the interface for outgoing multicast packets.
*/
if (m == NULL || m->m_len != sizeof(struct in_addr)) {
error = EINVAL;
break;
}
addr = *(mtod(m, struct in_addr *));
/*
* 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.
*/
if (m == NULL || m->m_len != 1) {
error = EINVAL;
break;
}
imo->imo_multicast_ttl = *(mtod(m, u_char *));
break;
case IP_MULTICAST_LOOP:
/*
* Set the loopback flag for outgoing multicast packets.
* Must be zero or one.
*/
if (m == NULL || m->m_len != 1 ||
(loop = *(mtod(m, u_char *))) > 1) {
error = EINVAL;
break;
}
imo->imo_multicast_loop = loop;
break;
case IP_ADD_MEMBERSHIP:
/*
* Add a multicast group membership.
* Group must be a valid IP multicast address.
*/
if (m == NULL || m->m_len != sizeof(struct ip_mreq)) {
error = EINVAL;
break;
}
mreq = mtod(m, struct ip_mreq *);
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)) {
bzero((caddr_t)&ro, sizeof(ro));
ro.ro_rt = NULL;
dst = satosin(&ro.ro_dst);
dst->sin_len = sizeof(*dst);
dst->sin_family = AF_INET;
dst->sin_addr = mreq->imr_multiaddr;
rtalloc(&ro);
if (ro.ro_rt == NULL) {
error = EADDRNOTAVAIL;
break;
}
ifp = ro.ro_rt->rt_ifp;
rtfree(ro.ro_rt);
} 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.
*/
if (m == NULL || m->m_len != sizeof(struct ip_mreq)) {
error = EINVAL;
break;
}
mreq = mtod(m, struct ip_mreq *);
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) {
free(*imop, M_IPMOPTS);
*imop = NULL;
}
return (error);
}
/*
* Return the IP multicast options in response to user getsockopt().
*/
int
ip_getmoptions(optname, imo, mp)
int optname;
struct ip_moptions *imo;
struct mbuf **mp;
{
u_char *ttl;
u_char *loop;
struct in_addr *addr;
struct in_ifaddr *ia;
*mp = m_get(M_WAIT, MT_SOOPTS);
switch (optname) {
case IP_MULTICAST_IF:
addr = mtod(*mp, struct in_addr *);
(*mp)->m_len = sizeof(struct in_addr);
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;
}
return (0);
case IP_MULTICAST_TTL:
ttl = mtod(*mp, u_char *);
(*mp)->m_len = 1;
*ttl = imo ? imo->imo_multicast_ttl
: IP_DEFAULT_MULTICAST_TTL;
return (0);
case IP_MULTICAST_LOOP:
loop = mtod(*mp, u_char *);
(*mp)->m_len = 1;
*loop = imo ? imo->imo_multicast_loop
: IP_DEFAULT_MULTICAST_LOOP;
return (0);
default:
return (EOPNOTSUPP);
}
}
/*
* Discard the IP multicast options.
*/
void
ip_freemoptions(imo)
struct ip_moptions *imo;
{
int i;
if (imo != NULL) {
for (i = 0; i < imo->imo_num_memberships; ++i)
in_delmulti(imo->imo_membership[i]);
free(imo, M_IPMOPTS);
}
}
/*
* 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 &loif -- easier than replicating that code here.
*/
static void
ip_mloopback(ifp, m, dst)
struct ifnet *ifp;
struct mbuf *m;
struct sockaddr_in *dst;
{
struct ip *ip;
struct mbuf *copym;
copym = m_copy(m, 0, M_COPYALL);
if (copym != NULL
&& (copym->m_flags & M_EXT || copym->m_len < sizeof(struct ip)))
copym = m_pullup(copym, sizeof(struct ip));
if (copym != NULL) {
/*
* 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, sintosa(dst), NULL);
}
}
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