xref: /freebsd/sys/netinet/ip_output.c (revision 76039bc84fae9915788b54ff28fe0cc4876952d2)
1c398230bSWarner Losh /*-
2df8bae1dSRodney W. Grimes  * Copyright (c) 1982, 1986, 1988, 1990, 1993
3df8bae1dSRodney W. Grimes  *	The Regents of the University of California.  All rights reserved.
4df8bae1dSRodney W. Grimes  *
5df8bae1dSRodney W. Grimes  * Redistribution and use in source and binary forms, with or without
6df8bae1dSRodney W. Grimes  * modification, are permitted provided that the following conditions
7df8bae1dSRodney W. Grimes  * are met:
8df8bae1dSRodney W. Grimes  * 1. Redistributions of source code must retain the above copyright
9df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer.
10df8bae1dSRodney W. Grimes  * 2. Redistributions in binary form must reproduce the above copyright
11df8bae1dSRodney W. Grimes  *    notice, this list of conditions and the following disclaimer in the
12df8bae1dSRodney W. Grimes  *    documentation and/or other materials provided with the distribution.
13df8bae1dSRodney W. Grimes  * 4. Neither the name of the University nor the names of its contributors
14df8bae1dSRodney W. Grimes  *    may be used to endorse or promote products derived from this software
15df8bae1dSRodney W. Grimes  *    without specific prior written permission.
16df8bae1dSRodney W. Grimes  *
17df8bae1dSRodney W. Grimes  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18df8bae1dSRodney W. Grimes  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19df8bae1dSRodney W. Grimes  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20df8bae1dSRodney W. Grimes  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21df8bae1dSRodney W. Grimes  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22df8bae1dSRodney W. Grimes  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23df8bae1dSRodney W. Grimes  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24df8bae1dSRodney W. Grimes  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25df8bae1dSRodney W. Grimes  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26df8bae1dSRodney W. Grimes  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27df8bae1dSRodney W. Grimes  * SUCH DAMAGE.
28df8bae1dSRodney W. Grimes  *
29df8bae1dSRodney W. Grimes  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
30df8bae1dSRodney W. Grimes  */
31df8bae1dSRodney W. Grimes 
324b421e2dSMike Silbersack #include <sys/cdefs.h>
334b421e2dSMike Silbersack __FBSDID("$FreeBSD$");
344b421e2dSMike Silbersack 
351f7e052cSJulian Elischer #include "opt_ipfw.h"
366a800098SYoshinobu Inoue #include "opt_ipsec.h"
3757f60867SMark Johnston #include "opt_kdtrace.h"
3853dcc544SMike Silbersack #include "opt_mbuf_stress_test.h"
39e440aed9SQing Li #include "opt_mpath.h"
4057f60867SMark Johnston #include "opt_route.h"
412f4afd21SRandall Stewart #include "opt_sctp.h"
42fbd1372aSJoerg Wunsch 
43df8bae1dSRodney W. Grimes #include <sys/param.h>
4426f9a767SRodney W. Grimes #include <sys/systm.h>
45f0f6d643SLuigi Rizzo #include <sys/kernel.h>
46df8bae1dSRodney W. Grimes #include <sys/malloc.h>
47df8bae1dSRodney W. Grimes #include <sys/mbuf.h>
48acd3428bSRobert Watson #include <sys/priv.h>
49c26fe973SBjoern A. Zeeb #include <sys/proc.h>
50df8bae1dSRodney W. Grimes #include <sys/protosw.h>
5157f60867SMark Johnston #include <sys/sdt.h>
52df8bae1dSRodney W. Grimes #include <sys/socket.h>
53df8bae1dSRodney W. Grimes #include <sys/socketvar.h>
549d9edc56SMike Silbersack #include <sys/sysctl.h>
55c26fe973SBjoern A. Zeeb #include <sys/ucred.h>
56df8bae1dSRodney W. Grimes 
57df8bae1dSRodney W. Grimes #include <net/if.h>
58*76039bc8SGleb Smirnoff #include <net/if_var.h>
593ef5e21dSQing Li #include <net/if_llatbl.h>
609b932e9eSAndre Oppermann #include <net/netisr.h>
61c21fd232SAndre Oppermann #include <net/pfil.h>
62df8bae1dSRodney W. Grimes #include <net/route.h>
6365111ec7SKip Macy #include <net/flowtable.h>
64e440aed9SQing Li #ifdef RADIX_MPATH
65e440aed9SQing Li #include <net/radix_mpath.h>
66e440aed9SQing Li #endif
674b79449eSBjoern A. Zeeb #include <net/vnet.h>
68df8bae1dSRodney W. Grimes 
69df8bae1dSRodney W. Grimes #include <netinet/in.h>
7057f60867SMark Johnston #include <netinet/in_kdtrace.h>
71df8bae1dSRodney W. Grimes #include <netinet/in_systm.h>
72df8bae1dSRodney W. Grimes #include <netinet/ip.h>
73df8bae1dSRodney W. Grimes #include <netinet/in_pcb.h>
74df8bae1dSRodney W. Grimes #include <netinet/in_var.h>
75df8bae1dSRodney W. Grimes #include <netinet/ip_var.h>
76ef39adf0SAndre Oppermann #include <netinet/ip_options.h>
772f4afd21SRandall Stewart #ifdef SCTP
782f4afd21SRandall Stewart #include <netinet/sctp.h>
792f4afd21SRandall Stewart #include <netinet/sctp_crc32.h>
802f4afd21SRandall Stewart #endif
81df8bae1dSRodney W. Grimes 
82b2630c29SGeorge V. Neville-Neil #ifdef IPSEC
832cb64cb2SGeorge V. Neville-Neil #include <netinet/ip_ipsec.h>
841dfcf0d2SAndre Oppermann #include <netipsec/ipsec.h>
85b2630c29SGeorge V. Neville-Neil #endif /* IPSEC*/
866a800098SYoshinobu Inoue 
871dfcf0d2SAndre Oppermann #include <machine/in_cksum.h>
881dfcf0d2SAndre Oppermann 
89aed55708SRobert Watson #include <security/mac/mac_framework.h>
90aed55708SRobert Watson 
91eddfbb76SRobert Watson VNET_DEFINE(u_short, ip_id);
92f23b4c91SGarrett Wollman 
9353dcc544SMike Silbersack #ifdef MBUF_STRESS_TEST
9405b9d121SBjoern A. Zeeb static int mbuf_frag_size = 0;
959d9edc56SMike Silbersack SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
969d9edc56SMike Silbersack 	&mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
979d9edc56SMike Silbersack #endif
989d9edc56SMike Silbersack 
99df8bae1dSRodney W. Grimes static void	ip_mloopback
1004d77a549SAlfred Perlstein 	(struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
101afed1b49SDarren Reed 
102afed1b49SDarren Reed 
1038b889dbbSBruce M Simpson extern int in_mcast_loop;
10493e0e116SJulian Elischer extern	struct protosw inetsw[];
10593e0e116SJulian Elischer 
106df8bae1dSRodney W. Grimes /*
107df8bae1dSRodney W. Grimes  * IP output.  The packet in mbuf chain m contains a skeletal IP
108df8bae1dSRodney W. Grimes  * header (with len, off, ttl, proto, tos, src, dst).
109df8bae1dSRodney W. Grimes  * The mbuf chain containing the packet will be freed.
110df8bae1dSRodney W. Grimes  * The mbuf opt, if present, will not be freed.
111bf984051SGleb Smirnoff  * If route ro is present and has ro_rt initialized, route lookup would be
112bf984051SGleb Smirnoff  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
113bf984051SGleb Smirnoff  * then result of route lookup is stored in ro->ro_rt.
114bf984051SGleb Smirnoff  *
1153de758d3SRobert Watson  * In the IP forwarding case, the packet will arrive with options already
1163de758d3SRobert Watson  * inserted, so must have a NULL opt pointer.
117df8bae1dSRodney W. Grimes  */
118df8bae1dSRodney W. Grimes int
119f2565d68SRobert Watson ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
120f2565d68SRobert Watson     struct ip_moptions *imo, struct inpcb *inp)
121df8bae1dSRodney W. Grimes {
1221e78ac21SJeffrey Hsu 	struct ip *ip;
123fc74d005SBjoern A. Zeeb 	struct ifnet *ifp = NULL;	/* keep compiler happy */
124ac9d7e26SMax Laier 	struct mbuf *m0;
12523bf9953SPoul-Henning Kamp 	int hlen = sizeof (struct ip);
1263ae2ad08SJohn-Mark Gurney 	int mtu;
127ca8b83b0SLuigi Rizzo 	int n;	/* scratchpad */
128ca8b83b0SLuigi Rizzo 	int error = 0;
129ca8b83b0SLuigi Rizzo 	struct sockaddr_in *dst;
1304c7a6059SGleb Smirnoff 	const struct sockaddr_in *gw;
1313c73180fSGleb Smirnoff 	struct in_ifaddr *ia;
13221d172a3SGleb Smirnoff 	int isbroadcast;
133078468edSGleb Smirnoff 	uint16_t ip_len, ip_off;
134e3f406b3SRuslan Ermilov 	struct route iproute;
135ec396e61SLuigi Rizzo 	struct rtentry *rte;	/* cache for ro->ro_rt */
1369b932e9eSAndre Oppermann 	struct in_addr odst;
1379b932e9eSAndre Oppermann 	struct m_tag *fwd_tag = NULL;
1381a499816SEdward Tomasz Napierala #ifdef IPSEC
1391a499816SEdward Tomasz Napierala 	int no_route_but_check_spd = 0;
1401a499816SEdward Tomasz Napierala #endif
141ac9d7e26SMax Laier 	M_ASSERTPKTHDR(m);
14236e8826fSMax Laier 
143bc97ba51SJulian Elischer 	if (inp != NULL) {
144baa45840SRobert Watson 		INP_LOCK_ASSERT(inp);
14562e1ba83SRobert Watson 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
14680cb9f21SKip Macy 		if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
14780cb9f21SKip Macy 			m->m_pkthdr.flowid = inp->inp_flowid;
14880cb9f21SKip Macy 			m->m_flags |= M_FLOWID;
14980cb9f21SKip Macy 		}
150bc97ba51SJulian Elischer 	}
15162e1ba83SRobert Watson 
15262e1ba83SRobert Watson 	if (ro == NULL) {
15362e1ba83SRobert Watson 		ro = &iproute;
15462e1ba83SRobert Watson 		bzero(ro, sizeof (*ro));
155bf984051SGleb Smirnoff 	}
15662e1ba83SRobert Watson 
15753be8fcaSBjoern A. Zeeb #ifdef FLOWTABLE
158bf984051SGleb Smirnoff 	if (ro->ro_rt == NULL) {
159d4121a02SKip Macy 		struct flentry *fle;
160d4121a02SKip Macy 
16162e1ba83SRobert Watson 		/*
16262e1ba83SRobert Watson 		 * The flow table returns route entries valid for up to 30
16362e1ba83SRobert Watson 		 * seconds; we rely on the remainder of ip_output() taking no
16462e1ba83SRobert Watson 		 * longer than that long for the stability of ro_rt. The
16562e1ba83SRobert Watson 		 * flow ID assignment must have happened before this point.
16662e1ba83SRobert Watson 		 */
167bf984051SGleb Smirnoff 		fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET);
168bf984051SGleb Smirnoff 		if (fle != NULL)
169d4121a02SKip Macy 			flow_to_route(fle, ro);
170d4121a02SKip Macy 	}
17153be8fcaSBjoern A. Zeeb #endif
1722b25acc1SLuigi Rizzo 
173df8bae1dSRodney W. Grimes 	if (opt) {
174ca8b83b0SLuigi Rizzo 		int len = 0;
175df8bae1dSRodney W. Grimes 		m = ip_insertoptions(m, opt, &len);
176cb7641e8SMaxim Konovalov 		if (len != 0)
177ca8b83b0SLuigi Rizzo 			hlen = len; /* ip->ip_hl is updated above */
178df8bae1dSRodney W. Grimes 	}
179df8bae1dSRodney W. Grimes 	ip = mtod(m, struct ip *);
1808f134647SGleb Smirnoff 	ip_len = ntohs(ip->ip_len);
1818f134647SGleb Smirnoff 	ip_off = ntohs(ip->ip_off);
1823efc3014SJulian Elischer 
183df8bae1dSRodney W. Grimes 	/*
1846e49b1feSGarrett Wollman 	 * Fill in IP header.  If we are not allowing fragmentation,
185e0f630eaSAndre Oppermann 	 * then the ip_id field is meaningless, but we don't set it
186e0f630eaSAndre Oppermann 	 * to zero.  Doing so causes various problems when devices along
187e0f630eaSAndre Oppermann 	 * the path (routers, load balancers, firewalls, etc.) illegally
188e0f630eaSAndre Oppermann 	 * disable DF on our packet.  Note that a 16-bit counter
1896e49b1feSGarrett Wollman 	 * will wrap around in less than 10 seconds at 100 Mbit/s on a
1906e49b1feSGarrett Wollman 	 * medium with MTU 1500.  See Steven M. Bellovin, "A Technique
1916e49b1feSGarrett Wollman 	 * for Counting NATted Hosts", Proc. IMW'02, available at
1924d09f5a0SGleb Smirnoff 	 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
193df8bae1dSRodney W. Grimes 	 */
194df8bae1dSRodney W. Grimes 	if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
19553be11f6SPoul-Henning Kamp 		ip->ip_v = IPVERSION;
19653be11f6SPoul-Henning Kamp 		ip->ip_hl = hlen >> 2;
1971f44b0a1SDavid Malone 		ip->ip_id = ip_newid();
19886425c62SRobert Watson 		IPSTAT_INC(ips_localout);
199df8bae1dSRodney W. Grimes 	} else {
200ca8b83b0SLuigi Rizzo 		/* Header already set, fetch hlen from there */
20153be11f6SPoul-Henning Kamp 		hlen = ip->ip_hl << 2;
202df8bae1dSRodney W. Grimes 	}
2039c9137eaSGarrett Wollman 
2044c7a6059SGleb Smirnoff 	gw = dst = (struct sockaddr_in *)&ro->ro_dst;
2059b932e9eSAndre Oppermann again:
2063c73180fSGleb Smirnoff 	ia = NULL;
207df8bae1dSRodney W. Grimes 	/*
208df8bae1dSRodney W. Grimes 	 * If there is a cached route,
209df8bae1dSRodney W. Grimes 	 * check that it is to the same destination
210df8bae1dSRodney W. Grimes 	 * and is still up.  If not, free it and try again.
211a4a6e773SHajimu UMEMOTO 	 * The address family should also be checked in case of sharing the
212a4a6e773SHajimu UMEMOTO 	 * cache with IPv6.
213df8bae1dSRodney W. Grimes 	 */
214ec396e61SLuigi Rizzo 	rte = ro->ro_rt;
215ec396e61SLuigi Rizzo 	if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
216c7ea0aa6SQing Li 		    rte->rt_ifp == NULL ||
217c7ea0aa6SQing Li 		    !RT_LINK_IS_UP(rte->rt_ifp) ||
218a4a6e773SHajimu UMEMOTO 			  dst->sin_family != AF_INET ||
2199b932e9eSAndre Oppermann 			  dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
220bf984051SGleb Smirnoff 		RO_RTFREE(ro);
221bf984051SGleb Smirnoff 		ro->ro_lle = NULL;
222bf984051SGleb Smirnoff 		rte = NULL;
223df8bae1dSRodney W. Grimes 	}
224ec396e61SLuigi Rizzo 	if (rte == NULL && fwd_tag == NULL) {
225a4a6e773SHajimu UMEMOTO 		bzero(dst, sizeof(*dst));
226df8bae1dSRodney W. Grimes 		dst->sin_family = AF_INET;
227df8bae1dSRodney W. Grimes 		dst->sin_len = sizeof(*dst);
2289b932e9eSAndre Oppermann 		dst->sin_addr = ip->ip_dst;
229df8bae1dSRodney W. Grimes 	}
230df8bae1dSRodney W. Grimes 	/*
231a3fd02d8SBruce M Simpson 	 * If routing to interface only, short circuit routing lookup.
232a3fd02d8SBruce M Simpson 	 * The use of an all-ones broadcast address implies this; an
233a3fd02d8SBruce M Simpson 	 * interface is specified by the broadcast address of an interface,
234a3fd02d8SBruce M Simpson 	 * or the destination address of a ptp interface.
235df8bae1dSRodney W. Grimes 	 */
236a3fd02d8SBruce M Simpson 	if (flags & IP_SENDONES) {
237a3fd02d8SBruce M Simpson 		if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
238a3fd02d8SBruce M Simpson 		    (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
23986425c62SRobert Watson 			IPSTAT_INC(ips_noroute);
240a3fd02d8SBruce M Simpson 			error = ENETUNREACH;
241a3fd02d8SBruce M Simpson 			goto bad;
242a3fd02d8SBruce M Simpson 		}
243a3fd02d8SBruce M Simpson 		ip->ip_dst.s_addr = INADDR_BROADCAST;
244a3fd02d8SBruce M Simpson 		dst->sin_addr = ip->ip_dst;
245a3fd02d8SBruce M Simpson 		ifp = ia->ia_ifp;
246a3fd02d8SBruce M Simpson 		ip->ip_ttl = 1;
247a3fd02d8SBruce M Simpson 		isbroadcast = 1;
248a3fd02d8SBruce M Simpson 	} else if (flags & IP_ROUTETOIF) {
2490b17fba7SAndre Oppermann 		if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
2500ed6142bSQing Li 		    (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) {
25186425c62SRobert Watson 			IPSTAT_INC(ips_noroute);
252df8bae1dSRodney W. Grimes 			error = ENETUNREACH;
253df8bae1dSRodney W. Grimes 			goto bad;
254df8bae1dSRodney W. Grimes 		}
255df8bae1dSRodney W. Grimes 		ifp = ia->ia_ifp;
256df8bae1dSRodney W. Grimes 		ip->ip_ttl = 1;
2579f9b3dc4SGarrett Wollman 		isbroadcast = in_broadcast(dst->sin_addr, ifp);
2583afefa39SDaniel C. Sobral 	} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
25938c1bc35SRuslan Ermilov 	    imo != NULL && imo->imo_multicast_ifp != NULL) {
2603afefa39SDaniel C. Sobral 		/*
26138c1bc35SRuslan Ermilov 		 * Bypass the normal routing lookup for multicast
26238c1bc35SRuslan Ermilov 		 * packets if the interface is specified.
2633afefa39SDaniel C. Sobral 		 */
26438c1bc35SRuslan Ermilov 		ifp = imo->imo_multicast_ifp;
26538c1bc35SRuslan Ermilov 		IFP_TO_IA(ifp, ia);
26638c1bc35SRuslan Ermilov 		isbroadcast = 0;	/* fool gcc */
267df8bae1dSRodney W. Grimes 	} else {
2682c17fe93SGarrett Wollman 		/*
26997d8d152SAndre Oppermann 		 * We want to do any cloning requested by the link layer,
27097d8d152SAndre Oppermann 		 * as this is probably required in all cases for correct
27197d8d152SAndre Oppermann 		 * operation (as it is for ARP).
2722c17fe93SGarrett Wollman 		 */
273ec396e61SLuigi Rizzo 		if (rte == NULL) {
274e440aed9SQing Li #ifdef RADIX_MPATH
2758b07e49aSJulian Elischer 			rtalloc_mpath_fib(ro,
2768b07e49aSJulian Elischer 			    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
2778b07e49aSJulian Elischer 			    inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
278e440aed9SQing Li #else
2798b07e49aSJulian Elischer 			in_rtalloc_ign(ro, 0,
2808b07e49aSJulian Elischer 			    inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
281e440aed9SQing Li #endif
282ec396e61SLuigi Rizzo 			rte = ro->ro_rt;
283ec396e61SLuigi Rizzo 		}
284c7ea0aa6SQing Li 		if (rte == NULL ||
285c7ea0aa6SQing Li 		    rte->rt_ifp == NULL ||
286c7ea0aa6SQing Li 		    !RT_LINK_IS_UP(rte->rt_ifp)) {
2871a499816SEdward Tomasz Napierala #ifdef IPSEC
2881a499816SEdward Tomasz Napierala 			/*
2891a499816SEdward Tomasz Napierala 			 * There is no route for this packet, but it is
2901a499816SEdward Tomasz Napierala 			 * possible that a matching SPD entry exists.
2911a499816SEdward Tomasz Napierala 			 */
2921a499816SEdward Tomasz Napierala 			no_route_but_check_spd = 1;
2931a499816SEdward Tomasz Napierala 			mtu = 0; /* Silence GCC warning. */
2941a499816SEdward Tomasz Napierala 			goto sendit;
2951a499816SEdward Tomasz Napierala #endif
29686425c62SRobert Watson 			IPSTAT_INC(ips_noroute);
297df8bae1dSRodney W. Grimes 			error = EHOSTUNREACH;
298df8bae1dSRodney W. Grimes 			goto bad;
299df8bae1dSRodney W. Grimes 		}
300ec396e61SLuigi Rizzo 		ia = ifatoia(rte->rt_ifa);
3018c0fec80SRobert Watson 		ifa_ref(&ia->ia_ifa);
302ec396e61SLuigi Rizzo 		ifp = rte->rt_ifp;
303ec396e61SLuigi Rizzo 		rte->rt_rmx.rmx_pksent++;
304ec396e61SLuigi Rizzo 		if (rte->rt_flags & RTF_GATEWAY)
3054c7a6059SGleb Smirnoff 			gw = (struct sockaddr_in *)rte->rt_gateway;
306ec396e61SLuigi Rizzo 		if (rte->rt_flags & RTF_HOST)
307ec396e61SLuigi Rizzo 			isbroadcast = (rte->rt_flags & RTF_BROADCAST);
3089f9b3dc4SGarrett Wollman 		else
3094c7a6059SGleb Smirnoff 			isbroadcast = in_broadcast(gw->sin_addr, ifp);
310df8bae1dSRodney W. Grimes 	}
3113ae2ad08SJohn-Mark Gurney 	/*
3123ae2ad08SJohn-Mark Gurney 	 * Calculate MTU.  If we have a route that is up, use that,
3133ae2ad08SJohn-Mark Gurney 	 * otherwise use the interface's MTU.
3143ae2ad08SJohn-Mark Gurney 	 */
315ec396e61SLuigi Rizzo 	if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
3163ae2ad08SJohn-Mark Gurney 		/*
3173ae2ad08SJohn-Mark Gurney 		 * This case can happen if the user changed the MTU
3183ae2ad08SJohn-Mark Gurney 		 * of an interface after enabling IP on it.  Because
3193ae2ad08SJohn-Mark Gurney 		 * most netifs don't keep track of routes pointing to
3203ae2ad08SJohn-Mark Gurney 		 * them, there is no way for one to update all its
3213ae2ad08SJohn-Mark Gurney 		 * routes when the MTU is changed.
3223ae2ad08SJohn-Mark Gurney 		 */
323ec396e61SLuigi Rizzo 		if (rte->rt_rmx.rmx_mtu > ifp->if_mtu)
324ec396e61SLuigi Rizzo 			rte->rt_rmx.rmx_mtu = ifp->if_mtu;
325ec396e61SLuigi Rizzo 		mtu = rte->rt_rmx.rmx_mtu;
3263ae2ad08SJohn-Mark Gurney 	} else {
3273ae2ad08SJohn-Mark Gurney 		mtu = ifp->if_mtu;
3283ae2ad08SJohn-Mark Gurney 	}
329c744cde4SBjoern A. Zeeb 	/* Catch a possible divide by zero later. */
330c744cde4SBjoern A. Zeeb 	KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
331c744cde4SBjoern A. Zeeb 	    __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
3329b932e9eSAndre Oppermann 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
333df8bae1dSRodney W. Grimes 		m->m_flags |= M_MCAST;
334df8bae1dSRodney W. Grimes 		/*
335df8bae1dSRodney W. Grimes 		 * See if the caller provided any multicast options
336df8bae1dSRodney W. Grimes 		 */
337df8bae1dSRodney W. Grimes 		if (imo != NULL) {
338df8bae1dSRodney W. Grimes 			ip->ip_ttl = imo->imo_multicast_ttl;
3391c5de19aSGarrett Wollman 			if (imo->imo_multicast_vif != -1)
3401c5de19aSGarrett Wollman 				ip->ip_src.s_addr =
341bbb4330bSLuigi Rizzo 				    ip_mcast_src ?
342bbb4330bSLuigi Rizzo 				    ip_mcast_src(imo->imo_multicast_vif) :
343bbb4330bSLuigi Rizzo 				    INADDR_ANY;
344df8bae1dSRodney W. Grimes 		} else
345df8bae1dSRodney W. Grimes 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
346df8bae1dSRodney W. Grimes 		/*
347df8bae1dSRodney W. Grimes 		 * Confirm that the outgoing interface supports multicast.
348df8bae1dSRodney W. Grimes 		 */
3491c5de19aSGarrett Wollman 		if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
350df8bae1dSRodney W. Grimes 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
35186425c62SRobert Watson 				IPSTAT_INC(ips_noroute);
352df8bae1dSRodney W. Grimes 				error = ENETUNREACH;
353df8bae1dSRodney W. Grimes 				goto bad;
354df8bae1dSRodney W. Grimes 			}
3551c5de19aSGarrett Wollman 		}
356df8bae1dSRodney W. Grimes 		/*
357df8bae1dSRodney W. Grimes 		 * If source address not specified yet, use address
358df8bae1dSRodney W. Grimes 		 * of outgoing interface.
359df8bae1dSRodney W. Grimes 		 */
360df8bae1dSRodney W. Grimes 		if (ip->ip_src.s_addr == INADDR_ANY) {
36138c1bc35SRuslan Ermilov 			/* Interface may have no addresses. */
36238c1bc35SRuslan Ermilov 			if (ia != NULL)
36338c1bc35SRuslan Ermilov 				ip->ip_src = IA_SIN(ia)->sin_addr;
364df8bae1dSRodney W. Grimes 		}
365df8bae1dSRodney W. Grimes 
3668b889dbbSBruce M Simpson 		if ((imo == NULL && in_mcast_loop) ||
3678b889dbbSBruce M Simpson 		    (imo && imo->imo_multicast_loop)) {
368df8bae1dSRodney W. Grimes 			/*
3698b889dbbSBruce M Simpson 			 * Loop back multicast datagram if not expressly
3708b889dbbSBruce M Simpson 			 * forbidden to do so, even if we are not a member
3718b889dbbSBruce M Simpson 			 * of the group; ip_input() will filter it later,
3728b889dbbSBruce M Simpson 			 * thus deferring a hash lookup and mutex acquisition
3738b889dbbSBruce M Simpson 			 * at the expense of a cheap copy using m_copym().
374df8bae1dSRodney W. Grimes 			 */
37586b1d6d2SBill Fenner 			ip_mloopback(ifp, m, dst, hlen);
3768b889dbbSBruce M Simpson 		} else {
377df8bae1dSRodney W. Grimes 			/*
378df8bae1dSRodney W. Grimes 			 * If we are acting as a multicast router, perform
379df8bae1dSRodney W. Grimes 			 * multicast forwarding as if the packet had just
380df8bae1dSRodney W. Grimes 			 * arrived on the interface to which we are about
381df8bae1dSRodney W. Grimes 			 * to send.  The multicast forwarding function
382df8bae1dSRodney W. Grimes 			 * recursively calls this function, using the
383df8bae1dSRodney W. Grimes 			 * IP_FORWARDING flag to prevent infinite recursion.
384df8bae1dSRodney W. Grimes 			 *
385df8bae1dSRodney W. Grimes 			 * Multicasts that are looped back by ip_mloopback(),
386df8bae1dSRodney W. Grimes 			 * above, will be forwarded by the ip_input() routine,
387df8bae1dSRodney W. Grimes 			 * if necessary.
388df8bae1dSRodney W. Grimes 			 */
389603724d3SBjoern A. Zeeb 			if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
390f0068c4aSGarrett Wollman 				/*
391bbb4330bSLuigi Rizzo 				 * If rsvp daemon is not running, do not
392f0068c4aSGarrett Wollman 				 * set ip_moptions. This ensures that the packet
393f0068c4aSGarrett Wollman 				 * is multicast and not just sent down one link
394f0068c4aSGarrett Wollman 				 * as prescribed by rsvpd.
395f0068c4aSGarrett Wollman 				 */
396603724d3SBjoern A. Zeeb 				if (!V_rsvp_on)
397f0068c4aSGarrett Wollman 					imo = NULL;
398bbb4330bSLuigi Rizzo 				if (ip_mforward &&
399bbb4330bSLuigi Rizzo 				    ip_mforward(ip, ifp, m, imo) != 0) {
400df8bae1dSRodney W. Grimes 					m_freem(m);
401df8bae1dSRodney W. Grimes 					goto done;
402df8bae1dSRodney W. Grimes 				}
403df8bae1dSRodney W. Grimes 			}
404df8bae1dSRodney W. Grimes 		}
4055e9ae478SGarrett Wollman 
406df8bae1dSRodney W. Grimes 		/*
407df8bae1dSRodney W. Grimes 		 * Multicasts with a time-to-live of zero may be looped-
408df8bae1dSRodney W. Grimes 		 * back, above, but must not be transmitted on a network.
409df8bae1dSRodney W. Grimes 		 * Also, multicasts addressed to the loopback interface
410df8bae1dSRodney W. Grimes 		 * are not sent -- the above call to ip_mloopback() will
4118b889dbbSBruce M Simpson 		 * loop back a copy. ip_input() will drop the copy if
4128b889dbbSBruce M Simpson 		 * this host does not belong to the destination group on
4138b889dbbSBruce M Simpson 		 * the loopback interface.
414df8bae1dSRodney W. Grimes 		 */
415f5fea3ddSPaul Traina 		if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
416df8bae1dSRodney W. Grimes 			m_freem(m);
417df8bae1dSRodney W. Grimes 			goto done;
418df8bae1dSRodney W. Grimes 		}
419df8bae1dSRodney W. Grimes 
420df8bae1dSRodney W. Grimes 		goto sendit;
421df8bae1dSRodney W. Grimes 	}
4226a7c943cSAndre Oppermann 
423df8bae1dSRodney W. Grimes 	/*
4242b25acc1SLuigi Rizzo 	 * If the source address is not specified yet, use the address
425cb459254SJohn-Mark Gurney 	 * of the outoing interface.
426df8bae1dSRodney W. Grimes 	 */
427f9e354dfSJulian Elischer 	if (ip->ip_src.s_addr == INADDR_ANY) {
42838c1bc35SRuslan Ermilov 		/* Interface may have no addresses. */
42938c1bc35SRuslan Ermilov 		if (ia != NULL) {
430df8bae1dSRodney W. Grimes 			ip->ip_src = IA_SIN(ia)->sin_addr;
431f9e354dfSJulian Elischer 		}
43238c1bc35SRuslan Ermilov 	}
4336a7c943cSAndre Oppermann 
434ca7a789aSMax Laier 	/*
435ca7a789aSMax Laier 	 * Verify that we have any chance at all of being able to queue the
436ca7a789aSMax Laier 	 * packet or packet fragments, unless ALTQ is enabled on the given
437ca7a789aSMax Laier 	 * interface in which case packetdrop should be done by queueing.
438ca7a789aSMax Laier 	 */
4398f134647SGleb Smirnoff 	n = ip_len / mtu + 1; /* how many fragments ? */
440ca8b83b0SLuigi Rizzo 	if (
44102b199f1SMax Laier #ifdef ALTQ
442ca8b83b0SLuigi Rizzo 	    (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
443ca7a789aSMax Laier #endif /* ALTQ */
444ca8b83b0SLuigi Rizzo 	    (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
445b5390296SDavid Greenman 		error = ENOBUFS;
44686425c62SRobert Watson 		IPSTAT_INC(ips_odropped);
447ca8b83b0SLuigi Rizzo 		ifp->if_snd.ifq_drops += n;
448b5390296SDavid Greenman 		goto bad;
449b5390296SDavid Greenman 	}
450b5390296SDavid Greenman 
451b5390296SDavid Greenman 	/*
452df8bae1dSRodney W. Grimes 	 * Look for broadcast address and
4538c3f5566SRuslan Ermilov 	 * verify user is allowed to send
454df8bae1dSRodney W. Grimes 	 * such a packet.
455df8bae1dSRodney W. Grimes 	 */
4569f9b3dc4SGarrett Wollman 	if (isbroadcast) {
457df8bae1dSRodney W. Grimes 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
458df8bae1dSRodney W. Grimes 			error = EADDRNOTAVAIL;
459df8bae1dSRodney W. Grimes 			goto bad;
460df8bae1dSRodney W. Grimes 		}
461df8bae1dSRodney W. Grimes 		if ((flags & IP_ALLOWBROADCAST) == 0) {
462df8bae1dSRodney W. Grimes 			error = EACCES;
463df8bae1dSRodney W. Grimes 			goto bad;
464df8bae1dSRodney W. Grimes 		}
465df8bae1dSRodney W. Grimes 		/* don't allow broadcast messages to be fragmented */
4668f134647SGleb Smirnoff 		if (ip_len > mtu) {
467df8bae1dSRodney W. Grimes 			error = EMSGSIZE;
468df8bae1dSRodney W. Grimes 			goto bad;
469df8bae1dSRodney W. Grimes 		}
470df8bae1dSRodney W. Grimes 		m->m_flags |= M_BCAST;
4719f9b3dc4SGarrett Wollman 	} else {
472df8bae1dSRodney W. Grimes 		m->m_flags &= ~M_BCAST;
4739f9b3dc4SGarrett Wollman 	}
474df8bae1dSRodney W. Grimes 
475f1743588SDarren Reed sendit:
476b2630c29SGeorge V. Neville-Neil #ifdef IPSEC
4774f7418a0SEdward Tomasz Napierala 	switch(ip_ipsec_output(&m, inp, &flags, &error)) {
4781dfcf0d2SAndre Oppermann 	case 1:
47933841545SHajimu UMEMOTO 		goto bad;
4801dfcf0d2SAndre Oppermann 	case -1:
4811dfcf0d2SAndre Oppermann 		goto done;
4821dfcf0d2SAndre Oppermann 	case 0:
48333841545SHajimu UMEMOTO 	default:
4841dfcf0d2SAndre Oppermann 		break;	/* Continue with packet processing. */
48533841545SHajimu UMEMOTO 	}
4861a499816SEdward Tomasz Napierala 	/*
4871a499816SEdward Tomasz Napierala 	 * Check if there was a route for this packet; return error if not.
4881a499816SEdward Tomasz Napierala 	 */
4891a499816SEdward Tomasz Napierala 	if (no_route_but_check_spd) {
4901a499816SEdward Tomasz Napierala 		IPSTAT_INC(ips_noroute);
4911a499816SEdward Tomasz Napierala 		error = EHOSTUNREACH;
4921a499816SEdward Tomasz Napierala 		goto bad;
4931a499816SEdward Tomasz Napierala 	}
4941dfcf0d2SAndre Oppermann 	/* Update variables that are affected by ipsec4_output(). */
49533841545SHajimu UMEMOTO 	ip = mtod(m, struct ip *);
49633841545SHajimu UMEMOTO 	hlen = ip->ip_hl << 2;
497b2630c29SGeorge V. Neville-Neil #endif /* IPSEC */
49833841545SHajimu UMEMOTO 
499c21fd232SAndre Oppermann 	/* Jump over all PFIL processing if hooks are not active. */
5000b4b0b0fSJulian Elischer 	if (!PFIL_HOOKED(&V_inet_pfil_hook))
501c21fd232SAndre Oppermann 		goto passout;
502c21fd232SAndre Oppermann 
503c21fd232SAndre Oppermann 	/* Run through list of hooks for output packets. */
5049b932e9eSAndre Oppermann 	odst.s_addr = ip->ip_dst.s_addr;
5050b4b0b0fSJulian Elischer 	error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
506134ea224SSam Leffler 	if (error != 0 || m == NULL)
507c4ac87eaSDarren Reed 		goto done;
5089b932e9eSAndre Oppermann 
509c4ac87eaSDarren Reed 	ip = mtod(m, struct ip *);
510fed1c7e9SSøren Schmidt 
5119b932e9eSAndre Oppermann 	/* See if destination IP address was changed by packet filter. */
5129b932e9eSAndre Oppermann 	if (odst.s_addr != ip->ip_dst.s_addr) {
5139b932e9eSAndre Oppermann 		m->m_flags |= M_SKIP_FIREWALL;
514f4fca2d8SAndre Oppermann 		/* If destination is now ourself drop to ip_input(). */
5159b932e9eSAndre Oppermann 		if (in_localip(ip->ip_dst)) {
5169b932e9eSAndre Oppermann 			m->m_flags |= M_FASTFWD_OURS;
517f9e354dfSJulian Elischer 			if (m->m_pkthdr.rcvif == NULL)
518603724d3SBjoern A. Zeeb 				m->m_pkthdr.rcvif = V_loif;
51920c822f3SJonathan Lemon 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
52020c822f3SJonathan Lemon 				m->m_pkthdr.csum_flags |=
52120c822f3SJonathan Lemon 				    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
522ac9d7e26SMax Laier 				m->m_pkthdr.csum_data = 0xffff;
52320c822f3SJonathan Lemon 			}
52420c822f3SJonathan Lemon 			m->m_pkthdr.csum_flags |=
52520c822f3SJonathan Lemon 			    CSUM_IP_CHECKED | CSUM_IP_VALID;
5262f4afd21SRandall Stewart #ifdef SCTP
5272f4afd21SRandall Stewart 			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
5282f4afd21SRandall Stewart 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
5292f4afd21SRandall Stewart #endif
5309b932e9eSAndre Oppermann 			error = netisr_queue(NETISR_IP, m);
5319b932e9eSAndre Oppermann 			goto done;
5323c73180fSGleb Smirnoff 		} else {
5333c73180fSGleb Smirnoff 			if (ia != NULL)
5343c73180fSGleb Smirnoff 				ifa_free(&ia->ia_ifa);
535f4fca2d8SAndre Oppermann 			goto again;	/* Redo the routing table lookup. */
5369b932e9eSAndre Oppermann 		}
5373c73180fSGleb Smirnoff 	}
5389b932e9eSAndre Oppermann 
5399b932e9eSAndre Oppermann 	/* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
5409b932e9eSAndre Oppermann 	if (m->m_flags & M_FASTFWD_OURS) {
5419b932e9eSAndre Oppermann 		if (m->m_pkthdr.rcvif == NULL)
542603724d3SBjoern A. Zeeb 			m->m_pkthdr.rcvif = V_loif;
5439b932e9eSAndre Oppermann 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
5449b932e9eSAndre Oppermann 			m->m_pkthdr.csum_flags |=
5459b932e9eSAndre Oppermann 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
5469b932e9eSAndre Oppermann 			m->m_pkthdr.csum_data = 0xffff;
5479b932e9eSAndre Oppermann 		}
5482f4afd21SRandall Stewart #ifdef SCTP
5492f4afd21SRandall Stewart 		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
5502f4afd21SRandall Stewart 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
5512f4afd21SRandall Stewart #endif
5529b932e9eSAndre Oppermann 		m->m_pkthdr.csum_flags |=
5539b932e9eSAndre Oppermann 			    CSUM_IP_CHECKED | CSUM_IP_VALID;
5549b932e9eSAndre Oppermann 
5559b932e9eSAndre Oppermann 		error = netisr_queue(NETISR_IP, m);
556f9e354dfSJulian Elischer 		goto done;
557f9e354dfSJulian Elischer 	}
5589b932e9eSAndre Oppermann 	/* Or forward to some other address? */
559ffdbf9daSAndrey V. Elsukov 	if ((m->m_flags & M_IP_NEXTHOP) &&
560ffdbf9daSAndrey V. Elsukov 	    (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
5619b932e9eSAndre Oppermann 		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
5629b932e9eSAndre Oppermann 		m->m_flags |= M_SKIP_FIREWALL;
563ffdbf9daSAndrey V. Elsukov 		m->m_flags &= ~M_IP_NEXTHOP;
5649b932e9eSAndre Oppermann 		m_tag_delete(m, fwd_tag);
5653c73180fSGleb Smirnoff 		if (ia != NULL)
5663c73180fSGleb Smirnoff 			ifa_free(&ia->ia_ifa);
5679b932e9eSAndre Oppermann 		goto again;
568099dd043SAndre Oppermann 	}
5692b25acc1SLuigi Rizzo 
570c21fd232SAndre Oppermann passout:
57151c8ec4aSRuslan Ermilov 	/* 127/8 must not appear on wire - RFC1122. */
57251c8ec4aSRuslan Ermilov 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
57351c8ec4aSRuslan Ermilov 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
57451c8ec4aSRuslan Ermilov 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
57586425c62SRobert Watson 			IPSTAT_INC(ips_badaddr);
57651c8ec4aSRuslan Ermilov 			error = EADDRNOTAVAIL;
57751c8ec4aSRuslan Ermilov 			goto bad;
57851c8ec4aSRuslan Ermilov 		}
57951c8ec4aSRuslan Ermilov 	}
58051c8ec4aSRuslan Ermilov 
581206a3274SRuslan Ermilov 	m->m_pkthdr.csum_flags |= CSUM_IP;
582078468edSGleb Smirnoff 	if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
583db4f9cc7SJonathan Lemon 		in_delayed_cksum(m);
584078468edSGleb Smirnoff 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
585db4f9cc7SJonathan Lemon 	}
5862f4afd21SRandall Stewart #ifdef SCTP
587078468edSGleb Smirnoff 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
5881966e5b5SRandall Stewart 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
589078468edSGleb Smirnoff 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
5902f4afd21SRandall Stewart 	}
5912f4afd21SRandall Stewart #endif
592db4f9cc7SJonathan Lemon 
593e7319babSPoul-Henning Kamp 	/*
594db4f9cc7SJonathan Lemon 	 * If small enough for interface, or the interface will take
595233dcce1SAndre Oppermann 	 * care of the fragmentation for us, we can just send directly.
596df8bae1dSRodney W. Grimes 	 */
59721d172a3SGleb Smirnoff 	if (ip_len <= mtu ||
598233dcce1SAndre Oppermann 	    (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
59921d172a3SGleb Smirnoff 	    ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
600df8bae1dSRodney W. Grimes 		ip->ip_sum = 0;
601078468edSGleb Smirnoff 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
602df8bae1dSRodney W. Grimes 			ip->ip_sum = in_cksum(m, hlen);
603078468edSGleb Smirnoff 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
604078468edSGleb Smirnoff 		}
6055da9f8faSJosef Karthauser 
606233dcce1SAndre Oppermann 		/*
607233dcce1SAndre Oppermann 		 * Record statistics for this interface address.
608233dcce1SAndre Oppermann 		 * With CSUM_TSO the byte/packet count will be slightly
609233dcce1SAndre Oppermann 		 * incorrect because we count the IP+TCP headers only
610233dcce1SAndre Oppermann 		 * once instead of for every generated packet.
611233dcce1SAndre Oppermann 		 */
61238c1bc35SRuslan Ermilov 		if (!(flags & IP_FORWARDING) && ia) {
613233dcce1SAndre Oppermann 			if (m->m_pkthdr.csum_flags & CSUM_TSO)
6147caf4ab7SGleb Smirnoff 				counter_u64_add(ia->ia_ifa.ifa_opackets,
6157caf4ab7SGleb Smirnoff 				    m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
616233dcce1SAndre Oppermann 			else
6177caf4ab7SGleb Smirnoff 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
6187caf4ab7SGleb Smirnoff 
6197caf4ab7SGleb Smirnoff 			counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
6205da9f8faSJosef Karthauser 		}
62153dcc544SMike Silbersack #ifdef MBUF_STRESS_TEST
6223390d476SMike Silbersack 		if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
623eb1b1807SGleb Smirnoff 			m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
6249d9edc56SMike Silbersack #endif
625147f74d1SAndre Oppermann 		/*
626147f74d1SAndre Oppermann 		 * Reset layer specific mbuf flags
627147f74d1SAndre Oppermann 		 * to avoid confusing lower layers.
628147f74d1SAndre Oppermann 		 */
62986bd0491SAndre Oppermann 		m_clrprotoflags(m);
63057f60867SMark Johnston 		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
63147e8d432SGleb Smirnoff 		error = (*ifp->if_output)(ifp, m,
63247e8d432SGleb Smirnoff 		    (const struct sockaddr *)gw, ro);
633df8bae1dSRodney W. Grimes 		goto done;
634df8bae1dSRodney W. Grimes 	}
6351e78ac21SJeffrey Hsu 
636233dcce1SAndre Oppermann 	/* Balk when DF bit is set or the interface didn't support TSO. */
63721d172a3SGleb Smirnoff 	if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
638df8bae1dSRodney W. Grimes 		error = EMSGSIZE;
63986425c62SRobert Watson 		IPSTAT_INC(ips_cantfrag);
640df8bae1dSRodney W. Grimes 		goto bad;
641df8bae1dSRodney W. Grimes 	}
6421e78ac21SJeffrey Hsu 
6431e78ac21SJeffrey Hsu 	/*
6441e78ac21SJeffrey Hsu 	 * Too large for interface; fragment if possible. If successful,
6451e78ac21SJeffrey Hsu 	 * on return, m will point to a list of packets to be sent.
6461e78ac21SJeffrey Hsu 	 */
647078468edSGleb Smirnoff 	error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
6481e78ac21SJeffrey Hsu 	if (error)
649df8bae1dSRodney W. Grimes 		goto bad;
6501e78ac21SJeffrey Hsu 	for (; m; m = m0) {
651df8bae1dSRodney W. Grimes 		m0 = m->m_nextpkt;
652b375c9ecSLuigi Rizzo 		m->m_nextpkt = 0;
65307203494SDaniel C. Sobral 		if (error == 0) {
654fe937674SJosef Karthauser 			/* Record statistics for this interface address. */
65507203494SDaniel C. Sobral 			if (ia != NULL) {
6567caf4ab7SGleb Smirnoff 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
6577caf4ab7SGleb Smirnoff 				counter_u64_add(ia->ia_ifa.ifa_obytes,
6587caf4ab7SGleb Smirnoff 				    m->m_pkthdr.len);
65907203494SDaniel C. Sobral 			}
660147f74d1SAndre Oppermann 			/*
661147f74d1SAndre Oppermann 			 * Reset layer specific mbuf flags
662147f74d1SAndre Oppermann 			 * to avoid confusing upper layers.
663147f74d1SAndre Oppermann 			 */
66486bd0491SAndre Oppermann 			m_clrprotoflags(m);
665fe937674SJosef Karthauser 
66657f60867SMark Johnston 			IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
667df8bae1dSRodney W. Grimes 			error = (*ifp->if_output)(ifp, m,
66847e8d432SGleb Smirnoff 			    (const struct sockaddr *)gw, ro);
669fe937674SJosef Karthauser 		} else
670df8bae1dSRodney W. Grimes 			m_freem(m);
671df8bae1dSRodney W. Grimes 	}
672df8bae1dSRodney W. Grimes 
673df8bae1dSRodney W. Grimes 	if (error == 0)
67486425c62SRobert Watson 		IPSTAT_INC(ips_fragmented);
6751e78ac21SJeffrey Hsu 
676df8bae1dSRodney W. Grimes done:
677bf984051SGleb Smirnoff 	if (ro == &iproute)
678bf984051SGleb Smirnoff 		RO_RTFREE(ro);
6798c0fec80SRobert Watson 	if (ia != NULL)
6808c0fec80SRobert Watson 		ifa_free(&ia->ia_ifa);
681df8bae1dSRodney W. Grimes 	return (error);
682df8bae1dSRodney W. Grimes bad:
6833528d68fSBill Paul 	m_freem(m);
684df8bae1dSRodney W. Grimes 	goto done;
685df8bae1dSRodney W. Grimes }
686df8bae1dSRodney W. Grimes 
6871e78ac21SJeffrey Hsu /*
6881e78ac21SJeffrey Hsu  * Create a chain of fragments which fit the given mtu. m_frag points to the
6891e78ac21SJeffrey Hsu  * mbuf to be fragmented; on return it points to the chain with the fragments.
6901e78ac21SJeffrey Hsu  * Return 0 if no error. If error, m_frag may contain a partially built
6911e78ac21SJeffrey Hsu  * chain of fragments that should be freed by the caller.
6921e78ac21SJeffrey Hsu  *
6931e78ac21SJeffrey Hsu  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
6941e78ac21SJeffrey Hsu  */
6951e78ac21SJeffrey Hsu int
6961e78ac21SJeffrey Hsu ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
697078468edSGleb Smirnoff     u_long if_hwassist_flags)
6981e78ac21SJeffrey Hsu {
6991e78ac21SJeffrey Hsu 	int error = 0;
7001e78ac21SJeffrey Hsu 	int hlen = ip->ip_hl << 2;
7011e78ac21SJeffrey Hsu 	int len = (mtu - hlen) & ~7;	/* size of payload in each fragment */
7021e78ac21SJeffrey Hsu 	int off;
7031e78ac21SJeffrey Hsu 	struct mbuf *m0 = *m_frag;	/* the original packet		*/
7041e78ac21SJeffrey Hsu 	int firstlen;
7051e78ac21SJeffrey Hsu 	struct mbuf **mnext;
7061e78ac21SJeffrey Hsu 	int nfrags;
70721d172a3SGleb Smirnoff 	uint16_t ip_len, ip_off;
7081e78ac21SJeffrey Hsu 
70921d172a3SGleb Smirnoff 	ip_len = ntohs(ip->ip_len);
71021d172a3SGleb Smirnoff 	ip_off = ntohs(ip->ip_off);
71121d172a3SGleb Smirnoff 
71221d172a3SGleb Smirnoff 	if (ip_off & IP_DF) {	/* Fragmentation not allowed */
71386425c62SRobert Watson 		IPSTAT_INC(ips_cantfrag);
7141e78ac21SJeffrey Hsu 		return EMSGSIZE;
7151e78ac21SJeffrey Hsu 	}
7161e78ac21SJeffrey Hsu 
7171e78ac21SJeffrey Hsu 	/*
7181e78ac21SJeffrey Hsu 	 * Must be able to put at least 8 bytes per fragment.
7191e78ac21SJeffrey Hsu 	 */
7201e78ac21SJeffrey Hsu 	if (len < 8)
7211e78ac21SJeffrey Hsu 		return EMSGSIZE;
7221e78ac21SJeffrey Hsu 
7231e78ac21SJeffrey Hsu 	/*
7241e78ac21SJeffrey Hsu 	 * If the interface will not calculate checksums on
7251e78ac21SJeffrey Hsu 	 * fragmented packets, then do it here.
7261e78ac21SJeffrey Hsu 	 */
727da2299c5SAndre Oppermann 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
7281e78ac21SJeffrey Hsu 		in_delayed_cksum(m0);
7291e78ac21SJeffrey Hsu 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
7301e78ac21SJeffrey Hsu 	}
7312f4afd21SRandall Stewart #ifdef SCTP
732da2299c5SAndre Oppermann 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
7331966e5b5SRandall Stewart 		sctp_delayed_cksum(m0, hlen);
7342f4afd21SRandall Stewart 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
7352f4afd21SRandall Stewart 	}
7362f4afd21SRandall Stewart #endif
7371e78ac21SJeffrey Hsu 	if (len > PAGE_SIZE) {
7381e78ac21SJeffrey Hsu 		/*
7391e78ac21SJeffrey Hsu 		 * Fragment large datagrams such that each segment
7401e78ac21SJeffrey Hsu 		 * contains a multiple of PAGE_SIZE amount of data,
7411e78ac21SJeffrey Hsu 		 * plus headers. This enables a receiver to perform
7421e78ac21SJeffrey Hsu 		 * page-flipping zero-copy optimizations.
7431e78ac21SJeffrey Hsu 		 *
7441e78ac21SJeffrey Hsu 		 * XXX When does this help given that sender and receiver
7451e78ac21SJeffrey Hsu 		 * could have different page sizes, and also mtu could
7461e78ac21SJeffrey Hsu 		 * be less than the receiver's page size ?
7471e78ac21SJeffrey Hsu 		 */
7481e78ac21SJeffrey Hsu 		int newlen;
7491e78ac21SJeffrey Hsu 		struct mbuf *m;
7501e78ac21SJeffrey Hsu 
7511e78ac21SJeffrey Hsu 		for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
7521e78ac21SJeffrey Hsu 			off += m->m_len;
7531e78ac21SJeffrey Hsu 
7541e78ac21SJeffrey Hsu 		/*
7551e78ac21SJeffrey Hsu 		 * firstlen (off - hlen) must be aligned on an
7561e78ac21SJeffrey Hsu 		 * 8-byte boundary
7571e78ac21SJeffrey Hsu 		 */
7581e78ac21SJeffrey Hsu 		if (off < hlen)
7591e78ac21SJeffrey Hsu 			goto smart_frag_failure;
7601e78ac21SJeffrey Hsu 		off = ((off - hlen) & ~7) + hlen;
7611e78ac21SJeffrey Hsu 		newlen = (~PAGE_MASK) & mtu;
7621e78ac21SJeffrey Hsu 		if ((newlen + sizeof (struct ip)) > mtu) {
7631e78ac21SJeffrey Hsu 			/* we failed, go back the default */
7641e78ac21SJeffrey Hsu smart_frag_failure:
7651e78ac21SJeffrey Hsu 			newlen = len;
7661e78ac21SJeffrey Hsu 			off = hlen + len;
7671e78ac21SJeffrey Hsu 		}
7681e78ac21SJeffrey Hsu 		len = newlen;
7691e78ac21SJeffrey Hsu 
7701e78ac21SJeffrey Hsu 	} else {
7711e78ac21SJeffrey Hsu 		off = hlen + len;
7721e78ac21SJeffrey Hsu 	}
7731e78ac21SJeffrey Hsu 
7741e78ac21SJeffrey Hsu 	firstlen = off - hlen;
7751e78ac21SJeffrey Hsu 	mnext = &m0->m_nextpkt;		/* pointer to next packet */
7761e78ac21SJeffrey Hsu 
7771e78ac21SJeffrey Hsu 	/*
7781e78ac21SJeffrey Hsu 	 * Loop through length of segment after first fragment,
7791e78ac21SJeffrey Hsu 	 * make new header and copy data of each part and link onto chain.
7801e78ac21SJeffrey Hsu 	 * Here, m0 is the original packet, m is the fragment being created.
7811e78ac21SJeffrey Hsu 	 * The fragments are linked off the m_nextpkt of the original
7821e78ac21SJeffrey Hsu 	 * packet, which after processing serves as the first fragment.
7831e78ac21SJeffrey Hsu 	 */
78421d172a3SGleb Smirnoff 	for (nfrags = 1; off < ip_len; off += len, nfrags++) {
7851e78ac21SJeffrey Hsu 		struct ip *mhip;	/* ip header on the fragment */
7861e78ac21SJeffrey Hsu 		struct mbuf *m;
7871e78ac21SJeffrey Hsu 		int mhlen = sizeof (struct ip);
7881e78ac21SJeffrey Hsu 
789dc4ad05eSGleb Smirnoff 		m = m_gethdr(M_NOWAIT, MT_DATA);
7900b17fba7SAndre Oppermann 		if (m == NULL) {
7911e78ac21SJeffrey Hsu 			error = ENOBUFS;
79286425c62SRobert Watson 			IPSTAT_INC(ips_odropped);
7931e78ac21SJeffrey Hsu 			goto done;
7941e78ac21SJeffrey Hsu 		}
795fb86dfcdSAndre Oppermann 		m->m_flags |= (m0->m_flags & M_MCAST);
7961e78ac21SJeffrey Hsu 		/*
7971e78ac21SJeffrey Hsu 		 * In the first mbuf, leave room for the link header, then
7981e78ac21SJeffrey Hsu 		 * copy the original IP header including options. The payload
7998b889dbbSBruce M Simpson 		 * goes into an additional mbuf chain returned by m_copym().
8001e78ac21SJeffrey Hsu 		 */
8011e78ac21SJeffrey Hsu 		m->m_data += max_linkhdr;
8021e78ac21SJeffrey Hsu 		mhip = mtod(m, struct ip *);
8031e78ac21SJeffrey Hsu 		*mhip = *ip;
8041e78ac21SJeffrey Hsu 		if (hlen > sizeof (struct ip)) {
8051e78ac21SJeffrey Hsu 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
8061e78ac21SJeffrey Hsu 			mhip->ip_v = IPVERSION;
8071e78ac21SJeffrey Hsu 			mhip->ip_hl = mhlen >> 2;
8081e78ac21SJeffrey Hsu 		}
8091e78ac21SJeffrey Hsu 		m->m_len = mhlen;
81021d172a3SGleb Smirnoff 		/* XXX do we need to add ip_off below ? */
81121d172a3SGleb Smirnoff 		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
812fb86dfcdSAndre Oppermann 		if (off + len >= ip_len)
81321d172a3SGleb Smirnoff 			len = ip_len - off;
814fb86dfcdSAndre Oppermann 		else
8151e78ac21SJeffrey Hsu 			mhip->ip_off |= IP_MF;
8161e78ac21SJeffrey Hsu 		mhip->ip_len = htons((u_short)(len + mhlen));
817eb1b1807SGleb Smirnoff 		m->m_next = m_copym(m0, off, len, M_NOWAIT);
8180b17fba7SAndre Oppermann 		if (m->m_next == NULL) {	/* copy failed */
8191e78ac21SJeffrey Hsu 			m_free(m);
8201e78ac21SJeffrey Hsu 			error = ENOBUFS;	/* ??? */
82186425c62SRobert Watson 			IPSTAT_INC(ips_odropped);
8221e78ac21SJeffrey Hsu 			goto done;
8231e78ac21SJeffrey Hsu 		}
8241e78ac21SJeffrey Hsu 		m->m_pkthdr.len = mhlen + len;
825fc74a9f9SBrooks Davis 		m->m_pkthdr.rcvif = NULL;
8261e78ac21SJeffrey Hsu #ifdef MAC
82730d239bcSRobert Watson 		mac_netinet_fragment(m0, m);
8281e78ac21SJeffrey Hsu #endif
8291e78ac21SJeffrey Hsu 		m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
8301e78ac21SJeffrey Hsu 		mhip->ip_off = htons(mhip->ip_off);
8311e78ac21SJeffrey Hsu 		mhip->ip_sum = 0;
832078468edSGleb Smirnoff 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
8331e78ac21SJeffrey Hsu 			mhip->ip_sum = in_cksum(m, mhlen);
834078468edSGleb Smirnoff 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
835078468edSGleb Smirnoff 		}
8361e78ac21SJeffrey Hsu 		*mnext = m;
8371e78ac21SJeffrey Hsu 		mnext = &m->m_nextpkt;
8381e78ac21SJeffrey Hsu 	}
83986425c62SRobert Watson 	IPSTAT_ADD(ips_ofragments, nfrags);
8401e78ac21SJeffrey Hsu 
8411e78ac21SJeffrey Hsu 	/*
8421e78ac21SJeffrey Hsu 	 * Update first fragment by trimming what's been copied out
8431e78ac21SJeffrey Hsu 	 * and updating header.
8441e78ac21SJeffrey Hsu 	 */
84521d172a3SGleb Smirnoff 	m_adj(m0, hlen + firstlen - ip_len);
8461e78ac21SJeffrey Hsu 	m0->m_pkthdr.len = hlen + firstlen;
8471e78ac21SJeffrey Hsu 	ip->ip_len = htons((u_short)m0->m_pkthdr.len);
84821d172a3SGleb Smirnoff 	ip->ip_off = htons(ip_off | IP_MF);
8491e78ac21SJeffrey Hsu 	ip->ip_sum = 0;
850078468edSGleb Smirnoff 	if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
8511e78ac21SJeffrey Hsu 		ip->ip_sum = in_cksum(m0, hlen);
852078468edSGleb Smirnoff 		m0->m_pkthdr.csum_flags &= ~CSUM_IP;
853078468edSGleb Smirnoff 	}
8541e78ac21SJeffrey Hsu 
8551e78ac21SJeffrey Hsu done:
8561e78ac21SJeffrey Hsu 	*m_frag = m0;
8571e78ac21SJeffrey Hsu 	return error;
8581e78ac21SJeffrey Hsu }
8591e78ac21SJeffrey Hsu 
8601c238475SJonathan Lemon void
861db4f9cc7SJonathan Lemon in_delayed_cksum(struct mbuf *m)
862db4f9cc7SJonathan Lemon {
863db4f9cc7SJonathan Lemon 	struct ip *ip;
86423e9c6dcSGleb Smirnoff 	uint16_t csum, offset, ip_len;
865db4f9cc7SJonathan Lemon 
866db4f9cc7SJonathan Lemon 	ip = mtod(m, struct ip *);
86753be11f6SPoul-Henning Kamp 	offset = ip->ip_hl << 2 ;
86823e9c6dcSGleb Smirnoff 	ip_len = ntohs(ip->ip_len);
86923e9c6dcSGleb Smirnoff 	csum = in_cksum_skip(m, ip_len, offset);
870206a3274SRuslan Ermilov 	if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
871206a3274SRuslan Ermilov 		csum = 0xffff;
872db4f9cc7SJonathan Lemon 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
873db4f9cc7SJonathan Lemon 
874db4f9cc7SJonathan Lemon 	if (offset + sizeof(u_short) > m->m_len) {
875db4f9cc7SJonathan Lemon 		printf("delayed m_pullup, m->len: %d  off: %d  p: %d\n",
876db4f9cc7SJonathan Lemon 		    m->m_len, offset, ip->ip_p);
877db4f9cc7SJonathan Lemon 		/*
878db4f9cc7SJonathan Lemon 		 * XXX
879db4f9cc7SJonathan Lemon 		 * this shouldn't happen, but if it does, the
880db4f9cc7SJonathan Lemon 		 * correct behavior may be to insert the checksum
8818f8d29f6SAndre Oppermann 		 * in the appropriate next mbuf in the chain.
882db4f9cc7SJonathan Lemon 		 */
8838f8d29f6SAndre Oppermann 		return;
884db4f9cc7SJonathan Lemon 	}
885db4f9cc7SJonathan Lemon 	*(u_short *)(m->m_data + offset) = csum;
886db4f9cc7SJonathan Lemon }
887db4f9cc7SJonathan Lemon 
888df8bae1dSRodney W. Grimes /*
889df8bae1dSRodney W. Grimes  * IP socket option processing.
890df8bae1dSRodney W. Grimes  */
891df8bae1dSRodney W. Grimes int
892f2565d68SRobert Watson ip_ctloutput(struct socket *so, struct sockopt *sopt)
893df8bae1dSRodney W. Grimes {
894cfe8b629SGarrett Wollman 	struct	inpcb *inp = sotoinpcb(so);
895cfe8b629SGarrett Wollman 	int	error, optval;
896df8bae1dSRodney W. Grimes 
897cfe8b629SGarrett Wollman 	error = optval = 0;
898cfe8b629SGarrett Wollman 	if (sopt->sopt_level != IPPROTO_IP) {
899fc06cd42SMikolaj Golub 		error = EINVAL;
900fc06cd42SMikolaj Golub 
901fc06cd42SMikolaj Golub 		if (sopt->sopt_level == SOL_SOCKET &&
902fc06cd42SMikolaj Golub 		    sopt->sopt_dir == SOPT_SET) {
903fc06cd42SMikolaj Golub 			switch (sopt->sopt_name) {
904fc06cd42SMikolaj Golub 			case SO_REUSEADDR:
905fc06cd42SMikolaj Golub 				INP_WLOCK(inp);
906efdf104bSMikolaj Golub 				if ((so->so_options & SO_REUSEADDR) != 0)
907efdf104bSMikolaj Golub 					inp->inp_flags2 |= INP_REUSEADDR;
908fc06cd42SMikolaj Golub 				else
909efdf104bSMikolaj Golub 					inp->inp_flags2 &= ~INP_REUSEADDR;
910fc06cd42SMikolaj Golub 				INP_WUNLOCK(inp);
911fc06cd42SMikolaj Golub 				error = 0;
912fc06cd42SMikolaj Golub 				break;
913fc06cd42SMikolaj Golub 			case SO_REUSEPORT:
914fc06cd42SMikolaj Golub 				INP_WLOCK(inp);
915fc06cd42SMikolaj Golub 				if ((so->so_options & SO_REUSEPORT) != 0)
916fc06cd42SMikolaj Golub 					inp->inp_flags2 |= INP_REUSEPORT;
917fc06cd42SMikolaj Golub 				else
918fc06cd42SMikolaj Golub 					inp->inp_flags2 &= ~INP_REUSEPORT;
919fc06cd42SMikolaj Golub 				INP_WUNLOCK(inp);
920fc06cd42SMikolaj Golub 				error = 0;
921fc06cd42SMikolaj Golub 				break;
922fc06cd42SMikolaj Golub 			case SO_SETFIB:
923fc06cd42SMikolaj Golub 				INP_WLOCK(inp);
924fc06cd42SMikolaj Golub 				inp->inp_inc.inc_fibnum = so->so_fibnum;
925fc06cd42SMikolaj Golub 				INP_WUNLOCK(inp);
926fc06cd42SMikolaj Golub 				error = 0;
927fc06cd42SMikolaj Golub 				break;
928fc06cd42SMikolaj Golub 			default:
929fc06cd42SMikolaj Golub 				break;
930fc06cd42SMikolaj Golub 			}
931fc06cd42SMikolaj Golub 		}
932fc06cd42SMikolaj Golub 		return (error);
933cfe8b629SGarrett Wollman 	}
934df8bae1dSRodney W. Grimes 
935cfe8b629SGarrett Wollman 	switch (sopt->sopt_dir) {
936cfe8b629SGarrett Wollman 	case SOPT_SET:
937cfe8b629SGarrett Wollman 		switch (sopt->sopt_name) {
938df8bae1dSRodney W. Grimes 		case IP_OPTIONS:
939df8bae1dSRodney W. Grimes #ifdef notyet
940df8bae1dSRodney W. Grimes 		case IP_RETOPTS:
941df8bae1dSRodney W. Grimes #endif
942cfe8b629SGarrett Wollman 		{
943cfe8b629SGarrett Wollman 			struct mbuf *m;
944cfe8b629SGarrett Wollman 			if (sopt->sopt_valsize > MLEN) {
945cfe8b629SGarrett Wollman 				error = EMSGSIZE;
946cfe8b629SGarrett Wollman 				break;
947cfe8b629SGarrett Wollman 			}
948dc4ad05eSGleb Smirnoff 			m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
9490b17fba7SAndre Oppermann 			if (m == NULL) {
950cfe8b629SGarrett Wollman 				error = ENOBUFS;
951cfe8b629SGarrett Wollman 				break;
952cfe8b629SGarrett Wollman 			}
953cfe8b629SGarrett Wollman 			m->m_len = sopt->sopt_valsize;
954cfe8b629SGarrett Wollman 			error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
955cfe8b629SGarrett Wollman 					    m->m_len);
956635354c4SMaxim Konovalov 			if (error) {
957635354c4SMaxim Konovalov 				m_free(m);
958635354c4SMaxim Konovalov 				break;
959635354c4SMaxim Konovalov 			}
9608501a69cSRobert Watson 			INP_WLOCK(inp);
961993d9505SRobert Watson 			error = ip_pcbopts(inp, sopt->sopt_name, m);
9628501a69cSRobert Watson 			INP_WUNLOCK(inp);
963993d9505SRobert Watson 			return (error);
964cfe8b629SGarrett Wollman 		}
965df8bae1dSRodney W. Grimes 
966f44270e7SPawel Jakub Dawidek 		case IP_BINDANY:
967f44270e7SPawel Jakub Dawidek 			if (sopt->sopt_td != NULL) {
968f44270e7SPawel Jakub Dawidek 				error = priv_check(sopt->sopt_td,
969f44270e7SPawel Jakub Dawidek 				    PRIV_NETINET_BINDANY);
970f44270e7SPawel Jakub Dawidek 				if (error)
971be9347e3SAdrian Chadd 					break;
972be9347e3SAdrian Chadd 			}
973cef27294SAdrian Chadd 			/* FALLTHROUGH */
974df8bae1dSRodney W. Grimes 		case IP_TOS:
975df8bae1dSRodney W. Grimes 		case IP_TTL:
976936cd18dSAndre Oppermann 		case IP_MINTTL:
977df8bae1dSRodney W. Grimes 		case IP_RECVOPTS:
978df8bae1dSRodney W. Grimes 		case IP_RECVRETOPTS:
979df8bae1dSRodney W. Grimes 		case IP_RECVDSTADDR:
9804957466bSMatthew N. Dodd 		case IP_RECVTTL:
98182c23ebaSBill Fenner 		case IP_RECVIF:
9826a800098SYoshinobu Inoue 		case IP_FAITH:
9838afa2304SBruce M Simpson 		case IP_ONESBCAST:
984b2828ad2SAndre Oppermann 		case IP_DONTFRAG:
9853cca425bSMichael Tuexen 		case IP_RECVTOS:
986cfe8b629SGarrett Wollman 			error = sooptcopyin(sopt, &optval, sizeof optval,
987cfe8b629SGarrett Wollman 					    sizeof optval);
988cfe8b629SGarrett Wollman 			if (error)
989cfe8b629SGarrett Wollman 				break;
990df8bae1dSRodney W. Grimes 
991cfe8b629SGarrett Wollman 			switch (sopt->sopt_name) {
992df8bae1dSRodney W. Grimes 			case IP_TOS:
993ca98b82cSDavid Greenman 				inp->inp_ip_tos = optval;
994df8bae1dSRodney W. Grimes 				break;
995df8bae1dSRodney W. Grimes 
996df8bae1dSRodney W. Grimes 			case IP_TTL:
997ca98b82cSDavid Greenman 				inp->inp_ip_ttl = optval;
998df8bae1dSRodney W. Grimes 				break;
999936cd18dSAndre Oppermann 
1000936cd18dSAndre Oppermann 			case IP_MINTTL:
1001a603c811SRobert Watson 				if (optval >= 0 && optval <= MAXTTL)
1002936cd18dSAndre Oppermann 					inp->inp_ip_minttl = optval;
1003936cd18dSAndre Oppermann 				else
1004936cd18dSAndre Oppermann 					error = EINVAL;
1005936cd18dSAndre Oppermann 				break;
1006936cd18dSAndre Oppermann 
1007a138d217SRobert Watson #define	OPTSET(bit) do {						\
10088501a69cSRobert Watson 	INP_WLOCK(inp);							\
1009df8bae1dSRodney W. Grimes 	if (optval)							\
1010df8bae1dSRodney W. Grimes 		inp->inp_flags |= bit;					\
1011df8bae1dSRodney W. Grimes 	else								\
1012a138d217SRobert Watson 		inp->inp_flags &= ~bit;					\
10138501a69cSRobert Watson 	INP_WUNLOCK(inp);						\
1014a138d217SRobert Watson } while (0)
1015df8bae1dSRodney W. Grimes 
1016df8bae1dSRodney W. Grimes 			case IP_RECVOPTS:
1017df8bae1dSRodney W. Grimes 				OPTSET(INP_RECVOPTS);
1018df8bae1dSRodney W. Grimes 				break;
1019df8bae1dSRodney W. Grimes 
1020df8bae1dSRodney W. Grimes 			case IP_RECVRETOPTS:
1021df8bae1dSRodney W. Grimes 				OPTSET(INP_RECVRETOPTS);
1022df8bae1dSRodney W. Grimes 				break;
1023df8bae1dSRodney W. Grimes 
1024df8bae1dSRodney W. Grimes 			case IP_RECVDSTADDR:
1025df8bae1dSRodney W. Grimes 				OPTSET(INP_RECVDSTADDR);
1026df8bae1dSRodney W. Grimes 				break;
102782c23ebaSBill Fenner 
10284957466bSMatthew N. Dodd 			case IP_RECVTTL:
10294957466bSMatthew N. Dodd 				OPTSET(INP_RECVTTL);
10304957466bSMatthew N. Dodd 				break;
10314957466bSMatthew N. Dodd 
103282c23ebaSBill Fenner 			case IP_RECVIF:
103382c23ebaSBill Fenner 				OPTSET(INP_RECVIF);
103482c23ebaSBill Fenner 				break;
10356a800098SYoshinobu Inoue 
10366a800098SYoshinobu Inoue 			case IP_FAITH:
10376a800098SYoshinobu Inoue 				OPTSET(INP_FAITH);
10386a800098SYoshinobu Inoue 				break;
10398afa2304SBruce M Simpson 
10408afa2304SBruce M Simpson 			case IP_ONESBCAST:
10418afa2304SBruce M Simpson 				OPTSET(INP_ONESBCAST);
10428afa2304SBruce M Simpson 				break;
1043b2828ad2SAndre Oppermann 			case IP_DONTFRAG:
1044b2828ad2SAndre Oppermann 				OPTSET(INP_DONTFRAG);
1045b2828ad2SAndre Oppermann 				break;
1046f44270e7SPawel Jakub Dawidek 			case IP_BINDANY:
1047f44270e7SPawel Jakub Dawidek 				OPTSET(INP_BINDANY);
1048be9347e3SAdrian Chadd 				break;
10493cca425bSMichael Tuexen 			case IP_RECVTOS:
10503cca425bSMichael Tuexen 				OPTSET(INP_RECVTOS);
10513cca425bSMichael Tuexen 				break;
1052df8bae1dSRodney W. Grimes 			}
1053df8bae1dSRodney W. Grimes 			break;
1054df8bae1dSRodney W. Grimes #undef OPTSET
1055df8bae1dSRodney W. Grimes 
105671498f30SBruce M Simpson 		/*
105771498f30SBruce M Simpson 		 * Multicast socket options are processed by the in_mcast
105871498f30SBruce M Simpson 		 * module.
105971498f30SBruce M Simpson 		 */
1060df8bae1dSRodney W. Grimes 		case IP_MULTICAST_IF:
1061f0068c4aSGarrett Wollman 		case IP_MULTICAST_VIF:
1062df8bae1dSRodney W. Grimes 		case IP_MULTICAST_TTL:
1063df8bae1dSRodney W. Grimes 		case IP_MULTICAST_LOOP:
1064df8bae1dSRodney W. Grimes 		case IP_ADD_MEMBERSHIP:
1065df8bae1dSRodney W. Grimes 		case IP_DROP_MEMBERSHIP:
106671498f30SBruce M Simpson 		case IP_ADD_SOURCE_MEMBERSHIP:
106771498f30SBruce M Simpson 		case IP_DROP_SOURCE_MEMBERSHIP:
106871498f30SBruce M Simpson 		case IP_BLOCK_SOURCE:
106971498f30SBruce M Simpson 		case IP_UNBLOCK_SOURCE:
107071498f30SBruce M Simpson 		case IP_MSFILTER:
107171498f30SBruce M Simpson 		case MCAST_JOIN_GROUP:
107271498f30SBruce M Simpson 		case MCAST_LEAVE_GROUP:
107371498f30SBruce M Simpson 		case MCAST_JOIN_SOURCE_GROUP:
107471498f30SBruce M Simpson 		case MCAST_LEAVE_SOURCE_GROUP:
107571498f30SBruce M Simpson 		case MCAST_BLOCK_SOURCE:
107671498f30SBruce M Simpson 		case MCAST_UNBLOCK_SOURCE:
107771498f30SBruce M Simpson 			error = inp_setmoptions(inp, sopt);
1078df8bae1dSRodney W. Grimes 			break;
1079df8bae1dSRodney W. Grimes 
108033b3ac06SPeter Wemm 		case IP_PORTRANGE:
1081cfe8b629SGarrett Wollman 			error = sooptcopyin(sopt, &optval, sizeof optval,
1082cfe8b629SGarrett Wollman 					    sizeof optval);
1083cfe8b629SGarrett Wollman 			if (error)
1084cfe8b629SGarrett Wollman 				break;
108533b3ac06SPeter Wemm 
10868501a69cSRobert Watson 			INP_WLOCK(inp);
108733b3ac06SPeter Wemm 			switch (optval) {
108833b3ac06SPeter Wemm 			case IP_PORTRANGE_DEFAULT:
108933b3ac06SPeter Wemm 				inp->inp_flags &= ~(INP_LOWPORT);
109033b3ac06SPeter Wemm 				inp->inp_flags &= ~(INP_HIGHPORT);
109133b3ac06SPeter Wemm 				break;
109233b3ac06SPeter Wemm 
109333b3ac06SPeter Wemm 			case IP_PORTRANGE_HIGH:
109433b3ac06SPeter Wemm 				inp->inp_flags &= ~(INP_LOWPORT);
109533b3ac06SPeter Wemm 				inp->inp_flags |= INP_HIGHPORT;
109633b3ac06SPeter Wemm 				break;
109733b3ac06SPeter Wemm 
109833b3ac06SPeter Wemm 			case IP_PORTRANGE_LOW:
109933b3ac06SPeter Wemm 				inp->inp_flags &= ~(INP_HIGHPORT);
110033b3ac06SPeter Wemm 				inp->inp_flags |= INP_LOWPORT;
110133b3ac06SPeter Wemm 				break;
110233b3ac06SPeter Wemm 
110333b3ac06SPeter Wemm 			default:
110433b3ac06SPeter Wemm 				error = EINVAL;
110533b3ac06SPeter Wemm 				break;
110633b3ac06SPeter Wemm 			}
11078501a69cSRobert Watson 			INP_WUNLOCK(inp);
1108ce8c72b1SPeter Wemm 			break;
110933b3ac06SPeter Wemm 
1110b2630c29SGeorge V. Neville-Neil #ifdef IPSEC
11116a800098SYoshinobu Inoue 		case IP_IPSEC_POLICY:
11126a800098SYoshinobu Inoue 		{
11136a800098SYoshinobu Inoue 			caddr_t req;
11146a800098SYoshinobu Inoue 			struct mbuf *m;
11156a800098SYoshinobu Inoue 
11166a800098SYoshinobu Inoue 			if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
11176a800098SYoshinobu Inoue 				break;
11186a800098SYoshinobu Inoue 			if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
11196a800098SYoshinobu Inoue 				break;
11206a800098SYoshinobu Inoue 			req = mtod(m, caddr_t);
112197aa4a51SBjoern A. Zeeb 			error = ipsec_set_policy(inp, sopt->sopt_name, req,
1122c26fe973SBjoern A. Zeeb 			    m->m_len, (sopt->sopt_td != NULL) ?
1123c26fe973SBjoern A. Zeeb 			    sopt->sopt_td->td_ucred : NULL);
11246a800098SYoshinobu Inoue 			m_freem(m);
11256a800098SYoshinobu Inoue 			break;
11266a800098SYoshinobu Inoue 		}
1127b2630c29SGeorge V. Neville-Neil #endif /* IPSEC */
11286a800098SYoshinobu Inoue 
1129df8bae1dSRodney W. Grimes 		default:
1130df8bae1dSRodney W. Grimes 			error = ENOPROTOOPT;
1131df8bae1dSRodney W. Grimes 			break;
1132df8bae1dSRodney W. Grimes 		}
1133df8bae1dSRodney W. Grimes 		break;
1134df8bae1dSRodney W. Grimes 
1135cfe8b629SGarrett Wollman 	case SOPT_GET:
1136cfe8b629SGarrett Wollman 		switch (sopt->sopt_name) {
1137df8bae1dSRodney W. Grimes 		case IP_OPTIONS:
1138df8bae1dSRodney W. Grimes 		case IP_RETOPTS:
1139cfe8b629SGarrett Wollman 			if (inp->inp_options)
1140cfe8b629SGarrett Wollman 				error = sooptcopyout(sopt,
1141cfe8b629SGarrett Wollman 						     mtod(inp->inp_options,
1142cfe8b629SGarrett Wollman 							  char *),
1143cfe8b629SGarrett Wollman 						     inp->inp_options->m_len);
1144cfe8b629SGarrett Wollman 			else
1145cfe8b629SGarrett Wollman 				sopt->sopt_valsize = 0;
1146df8bae1dSRodney W. Grimes 			break;
1147df8bae1dSRodney W. Grimes 
1148df8bae1dSRodney W. Grimes 		case IP_TOS:
1149df8bae1dSRodney W. Grimes 		case IP_TTL:
1150936cd18dSAndre Oppermann 		case IP_MINTTL:
1151df8bae1dSRodney W. Grimes 		case IP_RECVOPTS:
1152df8bae1dSRodney W. Grimes 		case IP_RECVRETOPTS:
1153df8bae1dSRodney W. Grimes 		case IP_RECVDSTADDR:
11544957466bSMatthew N. Dodd 		case IP_RECVTTL:
115582c23ebaSBill Fenner 		case IP_RECVIF:
1156cfe8b629SGarrett Wollman 		case IP_PORTRANGE:
11576a800098SYoshinobu Inoue 		case IP_FAITH:
11588afa2304SBruce M Simpson 		case IP_ONESBCAST:
1159b2828ad2SAndre Oppermann 		case IP_DONTFRAG:
11605f6bf451SAttilio Rao 		case IP_BINDANY:
11613cca425bSMichael Tuexen 		case IP_RECVTOS:
1162cfe8b629SGarrett Wollman 			switch (sopt->sopt_name) {
1163df8bae1dSRodney W. Grimes 
1164df8bae1dSRodney W. Grimes 			case IP_TOS:
1165ca98b82cSDavid Greenman 				optval = inp->inp_ip_tos;
1166df8bae1dSRodney W. Grimes 				break;
1167df8bae1dSRodney W. Grimes 
1168df8bae1dSRodney W. Grimes 			case IP_TTL:
1169ca98b82cSDavid Greenman 				optval = inp->inp_ip_ttl;
1170df8bae1dSRodney W. Grimes 				break;
1171df8bae1dSRodney W. Grimes 
1172936cd18dSAndre Oppermann 			case IP_MINTTL:
1173936cd18dSAndre Oppermann 				optval = inp->inp_ip_minttl;
1174936cd18dSAndre Oppermann 				break;
1175936cd18dSAndre Oppermann 
1176df8bae1dSRodney W. Grimes #define	OPTBIT(bit)	(inp->inp_flags & bit ? 1 : 0)
1177df8bae1dSRodney W. Grimes 
1178df8bae1dSRodney W. Grimes 			case IP_RECVOPTS:
1179df8bae1dSRodney W. Grimes 				optval = OPTBIT(INP_RECVOPTS);
1180df8bae1dSRodney W. Grimes 				break;
1181df8bae1dSRodney W. Grimes 
1182df8bae1dSRodney W. Grimes 			case IP_RECVRETOPTS:
1183df8bae1dSRodney W. Grimes 				optval = OPTBIT(INP_RECVRETOPTS);
1184df8bae1dSRodney W. Grimes 				break;
1185df8bae1dSRodney W. Grimes 
1186df8bae1dSRodney W. Grimes 			case IP_RECVDSTADDR:
1187df8bae1dSRodney W. Grimes 				optval = OPTBIT(INP_RECVDSTADDR);
1188df8bae1dSRodney W. Grimes 				break;
118982c23ebaSBill Fenner 
11904957466bSMatthew N. Dodd 			case IP_RECVTTL:
11914957466bSMatthew N. Dodd 				optval = OPTBIT(INP_RECVTTL);
11924957466bSMatthew N. Dodd 				break;
11934957466bSMatthew N. Dodd 
119482c23ebaSBill Fenner 			case IP_RECVIF:
119582c23ebaSBill Fenner 				optval = OPTBIT(INP_RECVIF);
119682c23ebaSBill Fenner 				break;
1197cfe8b629SGarrett Wollman 
1198cfe8b629SGarrett Wollman 			case IP_PORTRANGE:
1199cfe8b629SGarrett Wollman 				if (inp->inp_flags & INP_HIGHPORT)
1200cfe8b629SGarrett Wollman 					optval = IP_PORTRANGE_HIGH;
1201cfe8b629SGarrett Wollman 				else if (inp->inp_flags & INP_LOWPORT)
1202cfe8b629SGarrett Wollman 					optval = IP_PORTRANGE_LOW;
1203cfe8b629SGarrett Wollman 				else
1204cfe8b629SGarrett Wollman 					optval = 0;
1205cfe8b629SGarrett Wollman 				break;
12066a800098SYoshinobu Inoue 
12076a800098SYoshinobu Inoue 			case IP_FAITH:
12086a800098SYoshinobu Inoue 				optval = OPTBIT(INP_FAITH);
12096a800098SYoshinobu Inoue 				break;
12108afa2304SBruce M Simpson 
12118afa2304SBruce M Simpson 			case IP_ONESBCAST:
12128afa2304SBruce M Simpson 				optval = OPTBIT(INP_ONESBCAST);
12138afa2304SBruce M Simpson 				break;
1214b2828ad2SAndre Oppermann 			case IP_DONTFRAG:
1215b2828ad2SAndre Oppermann 				optval = OPTBIT(INP_DONTFRAG);
1216b2828ad2SAndre Oppermann 				break;
12175f6bf451SAttilio Rao 			case IP_BINDANY:
12185f6bf451SAttilio Rao 				optval = OPTBIT(INP_BINDANY);
12195f6bf451SAttilio Rao 				break;
12203cca425bSMichael Tuexen 			case IP_RECVTOS:
12213cca425bSMichael Tuexen 				optval = OPTBIT(INP_RECVTOS);
12223cca425bSMichael Tuexen 				break;
1223df8bae1dSRodney W. Grimes 			}
1224cfe8b629SGarrett Wollman 			error = sooptcopyout(sopt, &optval, sizeof optval);
1225df8bae1dSRodney W. Grimes 			break;
1226df8bae1dSRodney W. Grimes 
122771498f30SBruce M Simpson 		/*
122871498f30SBruce M Simpson 		 * Multicast socket options are processed by the in_mcast
122971498f30SBruce M Simpson 		 * module.
123071498f30SBruce M Simpson 		 */
1231df8bae1dSRodney W. Grimes 		case IP_MULTICAST_IF:
1232f0068c4aSGarrett Wollman 		case IP_MULTICAST_VIF:
1233df8bae1dSRodney W. Grimes 		case IP_MULTICAST_TTL:
1234df8bae1dSRodney W. Grimes 		case IP_MULTICAST_LOOP:
123571498f30SBruce M Simpson 		case IP_MSFILTER:
123671498f30SBruce M Simpson 			error = inp_getmoptions(inp, sopt);
123733b3ac06SPeter Wemm 			break;
123833b3ac06SPeter Wemm 
1239b2630c29SGeorge V. Neville-Neil #ifdef IPSEC
12406a800098SYoshinobu Inoue 		case IP_IPSEC_POLICY:
12416a800098SYoshinobu Inoue 		{
1242f63e7634SYoshinobu Inoue 			struct mbuf *m = NULL;
12436a800098SYoshinobu Inoue 			caddr_t req = NULL;
1244686cdd19SJun-ichiro itojun Hagino 			size_t len = 0;
12456a800098SYoshinobu Inoue 
1246686cdd19SJun-ichiro itojun Hagino 			if (m != 0) {
12476a800098SYoshinobu Inoue 				req = mtod(m, caddr_t);
1248686cdd19SJun-ichiro itojun Hagino 				len = m->m_len;
1249686cdd19SJun-ichiro itojun Hagino 			}
125097aa4a51SBjoern A. Zeeb 			error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
12516a800098SYoshinobu Inoue 			if (error == 0)
12526a800098SYoshinobu Inoue 				error = soopt_mcopyout(sopt, m); /* XXX */
1253f63e7634SYoshinobu Inoue 			if (error == 0)
12546a800098SYoshinobu Inoue 				m_freem(m);
12556a800098SYoshinobu Inoue 			break;
12566a800098SYoshinobu Inoue 		}
1257b2630c29SGeorge V. Neville-Neil #endif /* IPSEC */
12586a800098SYoshinobu Inoue 
1259df8bae1dSRodney W. Grimes 		default:
1260df8bae1dSRodney W. Grimes 			error = ENOPROTOOPT;
1261df8bae1dSRodney W. Grimes 			break;
1262df8bae1dSRodney W. Grimes 		}
1263df8bae1dSRodney W. Grimes 		break;
1264df8bae1dSRodney W. Grimes 	}
1265df8bae1dSRodney W. Grimes 	return (error);
1266df8bae1dSRodney W. Grimes }
1267df8bae1dSRodney W. Grimes 
1268df8bae1dSRodney W. Grimes /*
1269df8bae1dSRodney W. Grimes  * Routine called from ip_output() to loop back a copy of an IP multicast
1270df8bae1dSRodney W. Grimes  * packet to the input queue of a specified interface.  Note that this
1271df8bae1dSRodney W. Grimes  * calls the output routine of the loopback "driver", but with an interface
1272f5fea3ddSPaul Traina  * pointer that might NOT be a loopback interface -- evil, but easier than
1273f5fea3ddSPaul Traina  * replicating that code here.
1274df8bae1dSRodney W. Grimes  */
1275df8bae1dSRodney W. Grimes static void
1276f2565d68SRobert Watson ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1277f2565d68SRobert Watson     int hlen)
1278df8bae1dSRodney W. Grimes {
1279b375c9ecSLuigi Rizzo 	register struct ip *ip;
1280df8bae1dSRodney W. Grimes 	struct mbuf *copym;
1281df8bae1dSRodney W. Grimes 
1282e4762f75SGeorge V. Neville-Neil 	/*
1283e4762f75SGeorge V. Neville-Neil 	 * Make a deep copy of the packet because we're going to
1284e4762f75SGeorge V. Neville-Neil 	 * modify the pack in order to generate checksums.
1285e4762f75SGeorge V. Neville-Neil 	 */
1286eb1b1807SGleb Smirnoff 	copym = m_dup(m, M_NOWAIT);
128786b1d6d2SBill Fenner 	if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
128886b1d6d2SBill Fenner 		copym = m_pullup(copym, hlen);
1289df8bae1dSRodney W. Grimes 	if (copym != NULL) {
1290390cdc6aSRuslan Ermilov 		/* If needed, compute the checksum and mark it as valid. */
1291390cdc6aSRuslan Ermilov 		if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1292390cdc6aSRuslan Ermilov 			in_delayed_cksum(copym);
1293390cdc6aSRuslan Ermilov 			copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1294390cdc6aSRuslan Ermilov 			copym->m_pkthdr.csum_flags |=
1295390cdc6aSRuslan Ermilov 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1296390cdc6aSRuslan Ermilov 			copym->m_pkthdr.csum_data = 0xffff;
1297390cdc6aSRuslan Ermilov 		}
1298df8bae1dSRodney W. Grimes 		/*
1299df8bae1dSRodney W. Grimes 		 * We don't bother to fragment if the IP length is greater
1300df8bae1dSRodney W. Grimes 		 * than the interface's MTU.  Can this possibly matter?
1301df8bae1dSRodney W. Grimes 		 */
13028f134647SGleb Smirnoff 		ip = mtod(copym, struct ip *);
1303df8bae1dSRodney W. Grimes 		ip->ip_sum = 0;
130486b1d6d2SBill Fenner 		ip->ip_sum = in_cksum(copym, hlen);
1305201c2527SJulian Elischer #if 1 /* XXX */
1306201c2527SJulian Elischer 		if (dst->sin_family != AF_INET) {
13072b8a366cSJulian Elischer 			printf("ip_mloopback: bad address family %d\n",
1308201c2527SJulian Elischer 						dst->sin_family);
1309201c2527SJulian Elischer 			dst->sin_family = AF_INET;
1310201c2527SJulian Elischer 		}
1311201c2527SJulian Elischer #endif
131206a429a3SArchie Cobbs 		if_simloop(ifp, copym, dst->sin_family, 0);
1313df8bae1dSRodney W. Grimes 	}
1314df8bae1dSRodney W. Grimes }
1315