xref: /freebsd/sys/netinet/ip_output.c (revision f3c5273d315a64826d2149ac453ff8c4583ddbe8)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_inet.h"
38 #include "opt_ratelimit.h"
39 #include "opt_ipsec.h"
40 #include "opt_mbuf_stress_test.h"
41 #include "opt_mpath.h"
42 #include "opt_route.h"
43 #include "opt_sctp.h"
44 #include "opt_rss.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/lock.h>
50 #include <sys/malloc.h>
51 #include <sys/mbuf.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/protosw.h>
55 #include <sys/rmlock.h>
56 #include <sys/sdt.h>
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
59 #include <sys/sysctl.h>
60 #include <sys/ucred.h>
61 
62 #include <net/if.h>
63 #include <net/if_var.h>
64 #include <net/if_llatbl.h>
65 #include <net/netisr.h>
66 #include <net/pfil.h>
67 #include <net/route.h>
68 #ifdef RADIX_MPATH
69 #include <net/radix_mpath.h>
70 #endif
71 #include <net/rss_config.h>
72 #include <net/vnet.h>
73 
74 #include <netinet/in.h>
75 #include <netinet/in_kdtrace.h>
76 #include <netinet/in_systm.h>
77 #include <netinet/ip.h>
78 #include <netinet/in_pcb.h>
79 #include <netinet/in_rss.h>
80 #include <netinet/in_var.h>
81 #include <netinet/ip_var.h>
82 #include <netinet/ip_options.h>
83 
84 #include <netinet/udp.h>
85 #include <netinet/udp_var.h>
86 
87 #ifdef SCTP
88 #include <netinet/sctp.h>
89 #include <netinet/sctp_crc32.h>
90 #endif
91 
92 #include <netipsec/ipsec_support.h>
93 
94 #include <machine/in_cksum.h>
95 
96 #include <security/mac/mac_framework.h>
97 
98 #ifdef MBUF_STRESS_TEST
99 static int mbuf_frag_size = 0;
100 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
101 	&mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
102 #endif
103 
104 static void	ip_mloopback(struct ifnet *, const struct mbuf *, int);
105 
106 
107 extern int in_mcast_loop;
108 extern	struct protosw inetsw[];
109 
110 static inline int
111 ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, struct inpcb *inp,
112     struct sockaddr_in *dst, int *fibnum, int *error)
113 {
114 	struct m_tag *fwd_tag = NULL;
115 	struct mbuf *m;
116 	struct in_addr odst;
117 	struct ip *ip;
118 
119 	m = *mp;
120 	ip = mtod(m, struct ip *);
121 
122 	/* Run through list of hooks for output packets. */
123 	odst.s_addr = ip->ip_dst.s_addr;
124 	switch (pfil_run_hooks(V_inet_pfil_head, mp, ifp, PFIL_OUT, inp)) {
125 	case PFIL_DROPPED:
126 		*error = EPERM;
127 		/* FALLTHROUGH */
128 	case PFIL_CONSUMED:
129 		return 1; /* Finished */
130 	case PFIL_PASS:
131 		*error = 0;
132 	}
133 	m = *mp;
134 	ip = mtod(m, struct ip *);
135 
136 	/* See if destination IP address was changed by packet filter. */
137 	if (odst.s_addr != ip->ip_dst.s_addr) {
138 		m->m_flags |= M_SKIP_FIREWALL;
139 		/* If destination is now ourself drop to ip_input(). */
140 		if (in_localip(ip->ip_dst)) {
141 			m->m_flags |= M_FASTFWD_OURS;
142 			if (m->m_pkthdr.rcvif == NULL)
143 				m->m_pkthdr.rcvif = V_loif;
144 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
145 				m->m_pkthdr.csum_flags |=
146 					CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
147 				m->m_pkthdr.csum_data = 0xffff;
148 			}
149 			m->m_pkthdr.csum_flags |=
150 				CSUM_IP_CHECKED | CSUM_IP_VALID;
151 #ifdef SCTP
152 			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
153 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
154 #endif
155 			*error = netisr_queue(NETISR_IP, m);
156 			return 1; /* Finished */
157 		}
158 
159 		bzero(dst, sizeof(*dst));
160 		dst->sin_family = AF_INET;
161 		dst->sin_len = sizeof(*dst);
162 		dst->sin_addr = ip->ip_dst;
163 
164 		return -1; /* Reloop */
165 	}
166 	/* See if fib was changed by packet filter. */
167 	if ((*fibnum) != M_GETFIB(m)) {
168 		m->m_flags |= M_SKIP_FIREWALL;
169 		*fibnum = M_GETFIB(m);
170 		return -1; /* Reloop for FIB change */
171 	}
172 
173 	/* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
174 	if (m->m_flags & M_FASTFWD_OURS) {
175 		if (m->m_pkthdr.rcvif == NULL)
176 			m->m_pkthdr.rcvif = V_loif;
177 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
178 			m->m_pkthdr.csum_flags |=
179 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
180 			m->m_pkthdr.csum_data = 0xffff;
181 		}
182 #ifdef SCTP
183 		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
184 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
185 #endif
186 		m->m_pkthdr.csum_flags |=
187 			CSUM_IP_CHECKED | CSUM_IP_VALID;
188 
189 		*error = netisr_queue(NETISR_IP, m);
190 		return 1; /* Finished */
191 	}
192 	/* Or forward to some other address? */
193 	if ((m->m_flags & M_IP_NEXTHOP) &&
194 	    ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
195 		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
196 		m->m_flags |= M_SKIP_FIREWALL;
197 		m->m_flags &= ~M_IP_NEXTHOP;
198 		m_tag_delete(m, fwd_tag);
199 
200 		return -1; /* Reloop for CHANGE of dst */
201 	}
202 
203 	return 0;
204 }
205 
206 /*
207  * IP output.  The packet in mbuf chain m contains a skeletal IP
208  * header (with len, off, ttl, proto, tos, src, dst).
209  * The mbuf chain containing the packet will be freed.
210  * The mbuf opt, if present, will not be freed.
211  * If route ro is present and has ro_rt initialized, route lookup would be
212  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
213  * then result of route lookup is stored in ro->ro_rt.
214  *
215  * In the IP forwarding case, the packet will arrive with options already
216  * inserted, so must have a NULL opt pointer.
217  */
218 int
219 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
220     struct ip_moptions *imo, struct inpcb *inp)
221 {
222 	struct rm_priotracker in_ifa_tracker;
223 	struct epoch_tracker et;
224 	struct ip *ip;
225 	struct ifnet *ifp = NULL;	/* keep compiler happy */
226 	struct mbuf *m0;
227 	int hlen = sizeof (struct ip);
228 	int mtu;
229 	int error = 0;
230 	struct sockaddr_in *dst;
231 	const struct sockaddr_in *gw;
232 	struct in_ifaddr *ia;
233 	int isbroadcast;
234 	uint16_t ip_len, ip_off;
235 	struct route iproute;
236 	struct rtentry *rte;	/* cache for ro->ro_rt */
237 	uint32_t fibnum;
238 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
239 	int no_route_but_check_spd = 0;
240 #endif
241 	M_ASSERTPKTHDR(m);
242 
243 	if (inp != NULL) {
244 		INP_LOCK_ASSERT(inp);
245 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
246 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
247 			m->m_pkthdr.flowid = inp->inp_flowid;
248 			M_HASHTYPE_SET(m, inp->inp_flowtype);
249 		}
250 	}
251 
252 	if (ro == NULL) {
253 		ro = &iproute;
254 		bzero(ro, sizeof (*ro));
255 	}
256 
257 	if (opt) {
258 		int len = 0;
259 		m = ip_insertoptions(m, opt, &len);
260 		if (len != 0)
261 			hlen = len; /* ip->ip_hl is updated above */
262 	}
263 	ip = mtod(m, struct ip *);
264 	ip_len = ntohs(ip->ip_len);
265 	ip_off = ntohs(ip->ip_off);
266 
267 	if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
268 		ip->ip_v = IPVERSION;
269 		ip->ip_hl = hlen >> 2;
270 		ip_fillid(ip);
271 	} else {
272 		/* Header already set, fetch hlen from there */
273 		hlen = ip->ip_hl << 2;
274 	}
275 	if ((flags & IP_FORWARDING) == 0)
276 		IPSTAT_INC(ips_localout);
277 
278 	/*
279 	 * dst/gw handling:
280 	 *
281 	 * dst can be rewritten but always points to &ro->ro_dst.
282 	 * gw is readonly but can point either to dst OR rt_gateway,
283 	 * therefore we need restore gw if we're redoing lookup.
284 	 */
285 	gw = dst = (struct sockaddr_in *)&ro->ro_dst;
286 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
287 	rte = ro->ro_rt;
288 	if (rte == NULL) {
289 		bzero(dst, sizeof(*dst));
290 		dst->sin_family = AF_INET;
291 		dst->sin_len = sizeof(*dst);
292 		dst->sin_addr = ip->ip_dst;
293 	}
294 	NET_EPOCH_ENTER(et);
295 again:
296 	/*
297 	 * Validate route against routing table additions;
298 	 * a better/more specific route might have been added.
299 	 */
300 	if (inp)
301 		RT_VALIDATE(ro, &inp->inp_rt_cookie, fibnum);
302 	/*
303 	 * If there is a cached route,
304 	 * check that it is to the same destination
305 	 * and is still up.  If not, free it and try again.
306 	 * The address family should also be checked in case of sharing the
307 	 * cache with IPv6.
308 	 * Also check whether routing cache needs invalidation.
309 	 */
310 	rte = ro->ro_rt;
311 	if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
312 		    rte->rt_ifp == NULL ||
313 		    !RT_LINK_IS_UP(rte->rt_ifp) ||
314 			  dst->sin_family != AF_INET ||
315 			  dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
316 		RO_INVALIDATE_CACHE(ro);
317 		rte = NULL;
318 	}
319 	ia = NULL;
320 	/*
321 	 * If routing to interface only, short circuit routing lookup.
322 	 * The use of an all-ones broadcast address implies this; an
323 	 * interface is specified by the broadcast address of an interface,
324 	 * or the destination address of a ptp interface.
325 	 */
326 	if (flags & IP_SENDONES) {
327 		if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
328 						      M_GETFIB(m)))) == NULL &&
329 		    (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
330 						    M_GETFIB(m)))) == NULL) {
331 			IPSTAT_INC(ips_noroute);
332 			error = ENETUNREACH;
333 			goto bad;
334 		}
335 		ip->ip_dst.s_addr = INADDR_BROADCAST;
336 		dst->sin_addr = ip->ip_dst;
337 		ifp = ia->ia_ifp;
338 		ip->ip_ttl = 1;
339 		isbroadcast = 1;
340 	} else if (flags & IP_ROUTETOIF) {
341 		if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
342 						    M_GETFIB(m)))) == NULL &&
343 		    (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
344 						M_GETFIB(m)))) == NULL) {
345 			IPSTAT_INC(ips_noroute);
346 			error = ENETUNREACH;
347 			goto bad;
348 		}
349 		ifp = ia->ia_ifp;
350 		ip->ip_ttl = 1;
351 		isbroadcast = ifp->if_flags & IFF_BROADCAST ?
352 		    in_ifaddr_broadcast(dst->sin_addr, ia) : 0;
353 	} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
354 	    imo != NULL && imo->imo_multicast_ifp != NULL) {
355 		/*
356 		 * Bypass the normal routing lookup for multicast
357 		 * packets if the interface is specified.
358 		 */
359 		ifp = imo->imo_multicast_ifp;
360 		IFP_TO_IA(ifp, ia, &in_ifa_tracker);
361 		isbroadcast = 0;	/* fool gcc */
362 	} else {
363 		/*
364 		 * We want to do any cloning requested by the link layer,
365 		 * as this is probably required in all cases for correct
366 		 * operation (as it is for ARP).
367 		 */
368 		if (rte == NULL) {
369 #ifdef RADIX_MPATH
370 			rtalloc_mpath_fib(ro,
371 			    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
372 			    fibnum);
373 #else
374 			in_rtalloc_ign(ro, 0, fibnum);
375 #endif
376 			rte = ro->ro_rt;
377 		}
378 		if (rte == NULL ||
379 		    (rte->rt_flags & RTF_UP) == 0 ||
380 		    rte->rt_ifp == NULL ||
381 		    !RT_LINK_IS_UP(rte->rt_ifp)) {
382 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
383 			/*
384 			 * There is no route for this packet, but it is
385 			 * possible that a matching SPD entry exists.
386 			 */
387 			no_route_but_check_spd = 1;
388 			mtu = 0; /* Silence GCC warning. */
389 			goto sendit;
390 #endif
391 			IPSTAT_INC(ips_noroute);
392 			error = EHOSTUNREACH;
393 			goto bad;
394 		}
395 		ia = ifatoia(rte->rt_ifa);
396 		ifp = rte->rt_ifp;
397 		counter_u64_add(rte->rt_pksent, 1);
398 		rt_update_ro_flags(ro);
399 		if (rte->rt_flags & RTF_GATEWAY)
400 			gw = (struct sockaddr_in *)rte->rt_gateway;
401 		if (rte->rt_flags & RTF_HOST)
402 			isbroadcast = (rte->rt_flags & RTF_BROADCAST);
403 		else if (ifp->if_flags & IFF_BROADCAST)
404 			isbroadcast = in_ifaddr_broadcast(gw->sin_addr, ia);
405 		else
406 			isbroadcast = 0;
407 	}
408 
409 	/*
410 	 * Calculate MTU.  If we have a route that is up, use that,
411 	 * otherwise use the interface's MTU.
412 	 */
413 	if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST)))
414 		mtu = rte->rt_mtu;
415 	else
416 		mtu = ifp->if_mtu;
417 	/* Catch a possible divide by zero later. */
418 	KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
419 	    __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
420 
421 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
422 		m->m_flags |= M_MCAST;
423 		/*
424 		 * IP destination address is multicast.  Make sure "gw"
425 		 * still points to the address in "ro".  (It may have been
426 		 * changed to point to a gateway address, above.)
427 		 */
428 		gw = dst;
429 		/*
430 		 * See if the caller provided any multicast options
431 		 */
432 		if (imo != NULL) {
433 			ip->ip_ttl = imo->imo_multicast_ttl;
434 			if (imo->imo_multicast_vif != -1)
435 				ip->ip_src.s_addr =
436 				    ip_mcast_src ?
437 				    ip_mcast_src(imo->imo_multicast_vif) :
438 				    INADDR_ANY;
439 		} else
440 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
441 		/*
442 		 * Confirm that the outgoing interface supports multicast.
443 		 */
444 		if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
445 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
446 				IPSTAT_INC(ips_noroute);
447 				error = ENETUNREACH;
448 				goto bad;
449 			}
450 		}
451 		/*
452 		 * If source address not specified yet, use address
453 		 * of outgoing interface.
454 		 */
455 		if (ip->ip_src.s_addr == INADDR_ANY) {
456 			/* Interface may have no addresses. */
457 			if (ia != NULL)
458 				ip->ip_src = IA_SIN(ia)->sin_addr;
459 		}
460 
461 		if ((imo == NULL && in_mcast_loop) ||
462 		    (imo && imo->imo_multicast_loop)) {
463 			/*
464 			 * Loop back multicast datagram if not expressly
465 			 * forbidden to do so, even if we are not a member
466 			 * of the group; ip_input() will filter it later,
467 			 * thus deferring a hash lookup and mutex acquisition
468 			 * at the expense of a cheap copy using m_copym().
469 			 */
470 			ip_mloopback(ifp, m, hlen);
471 		} else {
472 			/*
473 			 * If we are acting as a multicast router, perform
474 			 * multicast forwarding as if the packet had just
475 			 * arrived on the interface to which we are about
476 			 * to send.  The multicast forwarding function
477 			 * recursively calls this function, using the
478 			 * IP_FORWARDING flag to prevent infinite recursion.
479 			 *
480 			 * Multicasts that are looped back by ip_mloopback(),
481 			 * above, will be forwarded by the ip_input() routine,
482 			 * if necessary.
483 			 */
484 			if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
485 				/*
486 				 * If rsvp daemon is not running, do not
487 				 * set ip_moptions. This ensures that the packet
488 				 * is multicast and not just sent down one link
489 				 * as prescribed by rsvpd.
490 				 */
491 				if (!V_rsvp_on)
492 					imo = NULL;
493 				if (ip_mforward &&
494 				    ip_mforward(ip, ifp, m, imo) != 0) {
495 					m_freem(m);
496 					goto done;
497 				}
498 			}
499 		}
500 
501 		/*
502 		 * Multicasts with a time-to-live of zero may be looped-
503 		 * back, above, but must not be transmitted on a network.
504 		 * Also, multicasts addressed to the loopback interface
505 		 * are not sent -- the above call to ip_mloopback() will
506 		 * loop back a copy. ip_input() will drop the copy if
507 		 * this host does not belong to the destination group on
508 		 * the loopback interface.
509 		 */
510 		if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
511 			m_freem(m);
512 			goto done;
513 		}
514 
515 		goto sendit;
516 	}
517 
518 	/*
519 	 * If the source address is not specified yet, use the address
520 	 * of the outoing interface.
521 	 */
522 	if (ip->ip_src.s_addr == INADDR_ANY) {
523 		/* Interface may have no addresses. */
524 		if (ia != NULL) {
525 			ip->ip_src = IA_SIN(ia)->sin_addr;
526 		}
527 	}
528 
529 	/*
530 	 * Look for broadcast address and
531 	 * verify user is allowed to send
532 	 * such a packet.
533 	 */
534 	if (isbroadcast) {
535 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
536 			error = EADDRNOTAVAIL;
537 			goto bad;
538 		}
539 		if ((flags & IP_ALLOWBROADCAST) == 0) {
540 			error = EACCES;
541 			goto bad;
542 		}
543 		/* don't allow broadcast messages to be fragmented */
544 		if (ip_len > mtu) {
545 			error = EMSGSIZE;
546 			goto bad;
547 		}
548 		m->m_flags |= M_BCAST;
549 	} else {
550 		m->m_flags &= ~M_BCAST;
551 	}
552 
553 sendit:
554 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
555 	if (IPSEC_ENABLED(ipv4)) {
556 		if ((error = IPSEC_OUTPUT(ipv4, m, inp)) != 0) {
557 			if (error == EINPROGRESS)
558 				error = 0;
559 			goto done;
560 		}
561 	}
562 	/*
563 	 * Check if there was a route for this packet; return error if not.
564 	 */
565 	if (no_route_but_check_spd) {
566 		IPSTAT_INC(ips_noroute);
567 		error = EHOSTUNREACH;
568 		goto bad;
569 	}
570 	/* Update variables that are affected by ipsec4_output(). */
571 	ip = mtod(m, struct ip *);
572 	hlen = ip->ip_hl << 2;
573 #endif /* IPSEC */
574 
575 	/* Jump over all PFIL processing if hooks are not active. */
576 	if (PFIL_HOOKED_OUT(V_inet_pfil_head)) {
577 		switch (ip_output_pfil(&m, ifp, inp, dst, &fibnum, &error)) {
578 		case 1: /* Finished */
579 			goto done;
580 
581 		case 0: /* Continue normally */
582 			ip = mtod(m, struct ip *);
583 			break;
584 
585 		case -1: /* Need to try again */
586 			/* Reset everything for a new round */
587 			RO_RTFREE(ro);
588 			ro->ro_prepend = NULL;
589 			rte = NULL;
590 			gw = dst;
591 			ip = mtod(m, struct ip *);
592 			goto again;
593 
594 		}
595 	}
596 
597 	/* 127/8 must not appear on wire - RFC1122. */
598 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
599 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
600 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
601 			IPSTAT_INC(ips_badaddr);
602 			error = EADDRNOTAVAIL;
603 			goto bad;
604 		}
605 	}
606 
607 	m->m_pkthdr.csum_flags |= CSUM_IP;
608 	if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
609 		in_delayed_cksum(m);
610 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
611 	}
612 #ifdef SCTP
613 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
614 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
615 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
616 	}
617 #endif
618 
619 	/*
620 	 * If small enough for interface, or the interface will take
621 	 * care of the fragmentation for us, we can just send directly.
622 	 */
623 	if (ip_len <= mtu ||
624 	    (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) {
625 		ip->ip_sum = 0;
626 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
627 			ip->ip_sum = in_cksum(m, hlen);
628 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
629 		}
630 
631 		/*
632 		 * Record statistics for this interface address.
633 		 * With CSUM_TSO the byte/packet count will be slightly
634 		 * incorrect because we count the IP+TCP headers only
635 		 * once instead of for every generated packet.
636 		 */
637 		if (!(flags & IP_FORWARDING) && ia) {
638 			if (m->m_pkthdr.csum_flags & CSUM_TSO)
639 				counter_u64_add(ia->ia_ifa.ifa_opackets,
640 				    m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
641 			else
642 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
643 
644 			counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
645 		}
646 #ifdef MBUF_STRESS_TEST
647 		if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
648 			m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
649 #endif
650 		/*
651 		 * Reset layer specific mbuf flags
652 		 * to avoid confusing lower layers.
653 		 */
654 		m_clrprotoflags(m);
655 		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
656 #ifdef RATELIMIT
657 		if (inp != NULL) {
658 			if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
659 				in_pcboutput_txrtlmt(inp, ifp, m);
660 			/* stamp send tag on mbuf */
661 			m->m_pkthdr.snd_tag = inp->inp_snd_tag;
662 		} else {
663 			m->m_pkthdr.snd_tag = NULL;
664 		}
665 #endif
666 		error = (*ifp->if_output)(ifp, m,
667 		    (const struct sockaddr *)gw, ro);
668 #ifdef RATELIMIT
669 		/* check for route change */
670 		if (error == EAGAIN)
671 			in_pcboutput_eagain(inp);
672 #endif
673 		goto done;
674 	}
675 
676 	/* Balk when DF bit is set or the interface didn't support TSO. */
677 	if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
678 		error = EMSGSIZE;
679 		IPSTAT_INC(ips_cantfrag);
680 		goto bad;
681 	}
682 
683 	/*
684 	 * Too large for interface; fragment if possible. If successful,
685 	 * on return, m will point to a list of packets to be sent.
686 	 */
687 	error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
688 	if (error)
689 		goto bad;
690 	for (; m; m = m0) {
691 		m0 = m->m_nextpkt;
692 		m->m_nextpkt = 0;
693 		if (error == 0) {
694 			/* Record statistics for this interface address. */
695 			if (ia != NULL) {
696 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
697 				counter_u64_add(ia->ia_ifa.ifa_obytes,
698 				    m->m_pkthdr.len);
699 			}
700 			/*
701 			 * Reset layer specific mbuf flags
702 			 * to avoid confusing upper layers.
703 			 */
704 			m_clrprotoflags(m);
705 
706 			IP_PROBE(send, NULL, NULL, mtod(m, struct ip *), ifp,
707 			    mtod(m, struct ip *), NULL);
708 #ifdef RATELIMIT
709 			if (inp != NULL) {
710 				if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
711 					in_pcboutput_txrtlmt(inp, ifp, m);
712 				/* stamp send tag on mbuf */
713 				m->m_pkthdr.snd_tag = inp->inp_snd_tag;
714 			} else {
715 				m->m_pkthdr.snd_tag = NULL;
716 			}
717 #endif
718 			error = (*ifp->if_output)(ifp, m,
719 			    (const struct sockaddr *)gw, ro);
720 #ifdef RATELIMIT
721 			/* check for route change */
722 			if (error == EAGAIN)
723 				in_pcboutput_eagain(inp);
724 #endif
725 		} else
726 			m_freem(m);
727 	}
728 
729 	if (error == 0)
730 		IPSTAT_INC(ips_fragmented);
731 
732 done:
733 	if (ro == &iproute)
734 		RO_RTFREE(ro);
735 	else if (rte == NULL)
736 		/*
737 		 * If the caller supplied a route but somehow the reference
738 		 * to it has been released need to prevent the caller
739 		 * calling RTFREE on it again.
740 		 */
741 		ro->ro_rt = NULL;
742 	NET_EPOCH_EXIT(et);
743 	return (error);
744  bad:
745 	m_freem(m);
746 	goto done;
747 }
748 
749 /*
750  * Create a chain of fragments which fit the given mtu. m_frag points to the
751  * mbuf to be fragmented; on return it points to the chain with the fragments.
752  * Return 0 if no error. If error, m_frag may contain a partially built
753  * chain of fragments that should be freed by the caller.
754  *
755  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
756  */
757 int
758 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
759     u_long if_hwassist_flags)
760 {
761 	int error = 0;
762 	int hlen = ip->ip_hl << 2;
763 	int len = (mtu - hlen) & ~7;	/* size of payload in each fragment */
764 	int off;
765 	struct mbuf *m0 = *m_frag;	/* the original packet		*/
766 	int firstlen;
767 	struct mbuf **mnext;
768 	int nfrags;
769 	uint16_t ip_len, ip_off;
770 
771 	ip_len = ntohs(ip->ip_len);
772 	ip_off = ntohs(ip->ip_off);
773 
774 	if (ip_off & IP_DF) {	/* Fragmentation not allowed */
775 		IPSTAT_INC(ips_cantfrag);
776 		return EMSGSIZE;
777 	}
778 
779 	/*
780 	 * Must be able to put at least 8 bytes per fragment.
781 	 */
782 	if (len < 8)
783 		return EMSGSIZE;
784 
785 	/*
786 	 * If the interface will not calculate checksums on
787 	 * fragmented packets, then do it here.
788 	 */
789 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
790 		in_delayed_cksum(m0);
791 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
792 	}
793 #ifdef SCTP
794 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
795 		sctp_delayed_cksum(m0, hlen);
796 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
797 	}
798 #endif
799 	if (len > PAGE_SIZE) {
800 		/*
801 		 * Fragment large datagrams such that each segment
802 		 * contains a multiple of PAGE_SIZE amount of data,
803 		 * plus headers. This enables a receiver to perform
804 		 * page-flipping zero-copy optimizations.
805 		 *
806 		 * XXX When does this help given that sender and receiver
807 		 * could have different page sizes, and also mtu could
808 		 * be less than the receiver's page size ?
809 		 */
810 		int newlen;
811 
812 		off = MIN(mtu, m0->m_pkthdr.len);
813 
814 		/*
815 		 * firstlen (off - hlen) must be aligned on an
816 		 * 8-byte boundary
817 		 */
818 		if (off < hlen)
819 			goto smart_frag_failure;
820 		off = ((off - hlen) & ~7) + hlen;
821 		newlen = (~PAGE_MASK) & mtu;
822 		if ((newlen + sizeof (struct ip)) > mtu) {
823 			/* we failed, go back the default */
824 smart_frag_failure:
825 			newlen = len;
826 			off = hlen + len;
827 		}
828 		len = newlen;
829 
830 	} else {
831 		off = hlen + len;
832 	}
833 
834 	firstlen = off - hlen;
835 	mnext = &m0->m_nextpkt;		/* pointer to next packet */
836 
837 	/*
838 	 * Loop through length of segment after first fragment,
839 	 * make new header and copy data of each part and link onto chain.
840 	 * Here, m0 is the original packet, m is the fragment being created.
841 	 * The fragments are linked off the m_nextpkt of the original
842 	 * packet, which after processing serves as the first fragment.
843 	 */
844 	for (nfrags = 1; off < ip_len; off += len, nfrags++) {
845 		struct ip *mhip;	/* ip header on the fragment */
846 		struct mbuf *m;
847 		int mhlen = sizeof (struct ip);
848 
849 		m = m_gethdr(M_NOWAIT, MT_DATA);
850 		if (m == NULL) {
851 			error = ENOBUFS;
852 			IPSTAT_INC(ips_odropped);
853 			goto done;
854 		}
855 		/*
856 		 * Make sure the complete packet header gets copied
857 		 * from the originating mbuf to the newly created
858 		 * mbuf. This also ensures that existing firewall
859 		 * classification(s), VLAN tags and so on get copied
860 		 * to the resulting fragmented packet(s):
861 		 */
862 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
863 			m_free(m);
864 			error = ENOBUFS;
865 			IPSTAT_INC(ips_odropped);
866 			goto done;
867 		}
868 		/*
869 		 * In the first mbuf, leave room for the link header, then
870 		 * copy the original IP header including options. The payload
871 		 * goes into an additional mbuf chain returned by m_copym().
872 		 */
873 		m->m_data += max_linkhdr;
874 		mhip = mtod(m, struct ip *);
875 		*mhip = *ip;
876 		if (hlen > sizeof (struct ip)) {
877 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
878 			mhip->ip_v = IPVERSION;
879 			mhip->ip_hl = mhlen >> 2;
880 		}
881 		m->m_len = mhlen;
882 		/* XXX do we need to add ip_off below ? */
883 		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
884 		if (off + len >= ip_len)
885 			len = ip_len - off;
886 		else
887 			mhip->ip_off |= IP_MF;
888 		mhip->ip_len = htons((u_short)(len + mhlen));
889 		m->m_next = m_copym(m0, off, len, M_NOWAIT);
890 		if (m->m_next == NULL) {	/* copy failed */
891 			m_free(m);
892 			error = ENOBUFS;	/* ??? */
893 			IPSTAT_INC(ips_odropped);
894 			goto done;
895 		}
896 		m->m_pkthdr.len = mhlen + len;
897 #ifdef MAC
898 		mac_netinet_fragment(m0, m);
899 #endif
900 		mhip->ip_off = htons(mhip->ip_off);
901 		mhip->ip_sum = 0;
902 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
903 			mhip->ip_sum = in_cksum(m, mhlen);
904 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
905 		}
906 		*mnext = m;
907 		mnext = &m->m_nextpkt;
908 	}
909 	IPSTAT_ADD(ips_ofragments, nfrags);
910 
911 	/*
912 	 * Update first fragment by trimming what's been copied out
913 	 * and updating header.
914 	 */
915 	m_adj(m0, hlen + firstlen - ip_len);
916 	m0->m_pkthdr.len = hlen + firstlen;
917 	ip->ip_len = htons((u_short)m0->m_pkthdr.len);
918 	ip->ip_off = htons(ip_off | IP_MF);
919 	ip->ip_sum = 0;
920 	if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
921 		ip->ip_sum = in_cksum(m0, hlen);
922 		m0->m_pkthdr.csum_flags &= ~CSUM_IP;
923 	}
924 
925 done:
926 	*m_frag = m0;
927 	return error;
928 }
929 
930 void
931 in_delayed_cksum(struct mbuf *m)
932 {
933 	struct ip *ip;
934 	struct udphdr *uh;
935 	uint16_t cklen, csum, offset;
936 
937 	ip = mtod(m, struct ip *);
938 	offset = ip->ip_hl << 2 ;
939 
940 	if (m->m_pkthdr.csum_flags & CSUM_UDP) {
941 		/* if udp header is not in the first mbuf copy udplen */
942 		if (offset + sizeof(struct udphdr) > m->m_len) {
943 			m_copydata(m, offset + offsetof(struct udphdr,
944 			    uh_ulen), sizeof(cklen), (caddr_t)&cklen);
945 			cklen = ntohs(cklen);
946 		} else {
947 			uh = (struct udphdr *)mtodo(m, offset);
948 			cklen = ntohs(uh->uh_ulen);
949 		}
950 		csum = in_cksum_skip(m, cklen + offset, offset);
951 		if (csum == 0)
952 			csum = 0xffff;
953 	} else {
954 		cklen = ntohs(ip->ip_len);
955 		csum = in_cksum_skip(m, cklen, offset);
956 	}
957 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
958 
959 	if (offset + sizeof(csum) > m->m_len)
960 		m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
961 	else
962 		*(u_short *)mtodo(m, offset) = csum;
963 }
964 
965 /*
966  * IP socket option processing.
967  */
968 int
969 ip_ctloutput(struct socket *so, struct sockopt *sopt)
970 {
971 	struct	inpcb *inp = sotoinpcb(so);
972 	int	error, optval;
973 #ifdef	RSS
974 	uint32_t rss_bucket;
975 	int retval;
976 #endif
977 
978 	error = optval = 0;
979 	if (sopt->sopt_level != IPPROTO_IP) {
980 		error = EINVAL;
981 
982 		if (sopt->sopt_level == SOL_SOCKET &&
983 		    sopt->sopt_dir == SOPT_SET) {
984 			switch (sopt->sopt_name) {
985 			case SO_REUSEADDR:
986 				INP_WLOCK(inp);
987 				if ((so->so_options & SO_REUSEADDR) != 0)
988 					inp->inp_flags2 |= INP_REUSEADDR;
989 				else
990 					inp->inp_flags2 &= ~INP_REUSEADDR;
991 				INP_WUNLOCK(inp);
992 				error = 0;
993 				break;
994 			case SO_REUSEPORT:
995 				INP_WLOCK(inp);
996 				if ((so->so_options & SO_REUSEPORT) != 0)
997 					inp->inp_flags2 |= INP_REUSEPORT;
998 				else
999 					inp->inp_flags2 &= ~INP_REUSEPORT;
1000 				INP_WUNLOCK(inp);
1001 				error = 0;
1002 				break;
1003 			case SO_REUSEPORT_LB:
1004 				INP_WLOCK(inp);
1005 				if ((so->so_options & SO_REUSEPORT_LB) != 0)
1006 					inp->inp_flags2 |= INP_REUSEPORT_LB;
1007 				else
1008 					inp->inp_flags2 &= ~INP_REUSEPORT_LB;
1009 				INP_WUNLOCK(inp);
1010 				error = 0;
1011 				break;
1012 			case SO_SETFIB:
1013 				INP_WLOCK(inp);
1014 				inp->inp_inc.inc_fibnum = so->so_fibnum;
1015 				INP_WUNLOCK(inp);
1016 				error = 0;
1017 				break;
1018 			case SO_MAX_PACING_RATE:
1019 #ifdef RATELIMIT
1020 				INP_WLOCK(inp);
1021 				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1022 				INP_WUNLOCK(inp);
1023 				error = 0;
1024 #else
1025 				error = EOPNOTSUPP;
1026 #endif
1027 				break;
1028 			default:
1029 				break;
1030 			}
1031 		}
1032 		return (error);
1033 	}
1034 
1035 	switch (sopt->sopt_dir) {
1036 	case SOPT_SET:
1037 		switch (sopt->sopt_name) {
1038 		case IP_OPTIONS:
1039 #ifdef notyet
1040 		case IP_RETOPTS:
1041 #endif
1042 		{
1043 			struct mbuf *m;
1044 			if (sopt->sopt_valsize > MLEN) {
1045 				error = EMSGSIZE;
1046 				break;
1047 			}
1048 			m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
1049 			if (m == NULL) {
1050 				error = ENOBUFS;
1051 				break;
1052 			}
1053 			m->m_len = sopt->sopt_valsize;
1054 			error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1055 					    m->m_len);
1056 			if (error) {
1057 				m_free(m);
1058 				break;
1059 			}
1060 			INP_WLOCK(inp);
1061 			error = ip_pcbopts(inp, sopt->sopt_name, m);
1062 			INP_WUNLOCK(inp);
1063 			return (error);
1064 		}
1065 
1066 		case IP_BINDANY:
1067 			if (sopt->sopt_td != NULL) {
1068 				error = priv_check(sopt->sopt_td,
1069 				    PRIV_NETINET_BINDANY);
1070 				if (error)
1071 					break;
1072 			}
1073 			/* FALLTHROUGH */
1074 		case IP_BINDMULTI:
1075 #ifdef	RSS
1076 		case IP_RSS_LISTEN_BUCKET:
1077 #endif
1078 		case IP_TOS:
1079 		case IP_TTL:
1080 		case IP_MINTTL:
1081 		case IP_RECVOPTS:
1082 		case IP_RECVRETOPTS:
1083 		case IP_ORIGDSTADDR:
1084 		case IP_RECVDSTADDR:
1085 		case IP_RECVTTL:
1086 		case IP_RECVIF:
1087 		case IP_ONESBCAST:
1088 		case IP_DONTFRAG:
1089 		case IP_RECVTOS:
1090 		case IP_RECVFLOWID:
1091 #ifdef	RSS
1092 		case IP_RECVRSSBUCKETID:
1093 #endif
1094 			error = sooptcopyin(sopt, &optval, sizeof optval,
1095 					    sizeof optval);
1096 			if (error)
1097 				break;
1098 
1099 			switch (sopt->sopt_name) {
1100 			case IP_TOS:
1101 				inp->inp_ip_tos = optval;
1102 				break;
1103 
1104 			case IP_TTL:
1105 				inp->inp_ip_ttl = optval;
1106 				break;
1107 
1108 			case IP_MINTTL:
1109 				if (optval >= 0 && optval <= MAXTTL)
1110 					inp->inp_ip_minttl = optval;
1111 				else
1112 					error = EINVAL;
1113 				break;
1114 
1115 #define	OPTSET(bit) do {						\
1116 	INP_WLOCK(inp);							\
1117 	if (optval)							\
1118 		inp->inp_flags |= bit;					\
1119 	else								\
1120 		inp->inp_flags &= ~bit;					\
1121 	INP_WUNLOCK(inp);						\
1122 } while (0)
1123 
1124 #define	OPTSET2(bit, val) do {						\
1125 	INP_WLOCK(inp);							\
1126 	if (val)							\
1127 		inp->inp_flags2 |= bit;					\
1128 	else								\
1129 		inp->inp_flags2 &= ~bit;				\
1130 	INP_WUNLOCK(inp);						\
1131 } while (0)
1132 
1133 			case IP_RECVOPTS:
1134 				OPTSET(INP_RECVOPTS);
1135 				break;
1136 
1137 			case IP_RECVRETOPTS:
1138 				OPTSET(INP_RECVRETOPTS);
1139 				break;
1140 
1141 			case IP_RECVDSTADDR:
1142 				OPTSET(INP_RECVDSTADDR);
1143 				break;
1144 
1145 			case IP_ORIGDSTADDR:
1146 				OPTSET2(INP_ORIGDSTADDR, optval);
1147 				break;
1148 
1149 			case IP_RECVTTL:
1150 				OPTSET(INP_RECVTTL);
1151 				break;
1152 
1153 			case IP_RECVIF:
1154 				OPTSET(INP_RECVIF);
1155 				break;
1156 
1157 			case IP_ONESBCAST:
1158 				OPTSET(INP_ONESBCAST);
1159 				break;
1160 			case IP_DONTFRAG:
1161 				OPTSET(INP_DONTFRAG);
1162 				break;
1163 			case IP_BINDANY:
1164 				OPTSET(INP_BINDANY);
1165 				break;
1166 			case IP_RECVTOS:
1167 				OPTSET(INP_RECVTOS);
1168 				break;
1169 			case IP_BINDMULTI:
1170 				OPTSET2(INP_BINDMULTI, optval);
1171 				break;
1172 			case IP_RECVFLOWID:
1173 				OPTSET2(INP_RECVFLOWID, optval);
1174 				break;
1175 #ifdef	RSS
1176 			case IP_RSS_LISTEN_BUCKET:
1177 				if ((optval >= 0) &&
1178 				    (optval < rss_getnumbuckets())) {
1179 					inp->inp_rss_listen_bucket = optval;
1180 					OPTSET2(INP_RSS_BUCKET_SET, 1);
1181 				} else {
1182 					error = EINVAL;
1183 				}
1184 				break;
1185 			case IP_RECVRSSBUCKETID:
1186 				OPTSET2(INP_RECVRSSBUCKETID, optval);
1187 				break;
1188 #endif
1189 			}
1190 			break;
1191 #undef OPTSET
1192 #undef OPTSET2
1193 
1194 		/*
1195 		 * Multicast socket options are processed by the in_mcast
1196 		 * module.
1197 		 */
1198 		case IP_MULTICAST_IF:
1199 		case IP_MULTICAST_VIF:
1200 		case IP_MULTICAST_TTL:
1201 		case IP_MULTICAST_LOOP:
1202 		case IP_ADD_MEMBERSHIP:
1203 		case IP_DROP_MEMBERSHIP:
1204 		case IP_ADD_SOURCE_MEMBERSHIP:
1205 		case IP_DROP_SOURCE_MEMBERSHIP:
1206 		case IP_BLOCK_SOURCE:
1207 		case IP_UNBLOCK_SOURCE:
1208 		case IP_MSFILTER:
1209 		case MCAST_JOIN_GROUP:
1210 		case MCAST_LEAVE_GROUP:
1211 		case MCAST_JOIN_SOURCE_GROUP:
1212 		case MCAST_LEAVE_SOURCE_GROUP:
1213 		case MCAST_BLOCK_SOURCE:
1214 		case MCAST_UNBLOCK_SOURCE:
1215 			error = inp_setmoptions(inp, sopt);
1216 			break;
1217 
1218 		case IP_PORTRANGE:
1219 			error = sooptcopyin(sopt, &optval, sizeof optval,
1220 					    sizeof optval);
1221 			if (error)
1222 				break;
1223 
1224 			INP_WLOCK(inp);
1225 			switch (optval) {
1226 			case IP_PORTRANGE_DEFAULT:
1227 				inp->inp_flags &= ~(INP_LOWPORT);
1228 				inp->inp_flags &= ~(INP_HIGHPORT);
1229 				break;
1230 
1231 			case IP_PORTRANGE_HIGH:
1232 				inp->inp_flags &= ~(INP_LOWPORT);
1233 				inp->inp_flags |= INP_HIGHPORT;
1234 				break;
1235 
1236 			case IP_PORTRANGE_LOW:
1237 				inp->inp_flags &= ~(INP_HIGHPORT);
1238 				inp->inp_flags |= INP_LOWPORT;
1239 				break;
1240 
1241 			default:
1242 				error = EINVAL;
1243 				break;
1244 			}
1245 			INP_WUNLOCK(inp);
1246 			break;
1247 
1248 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1249 		case IP_IPSEC_POLICY:
1250 			if (IPSEC_ENABLED(ipv4)) {
1251 				error = IPSEC_PCBCTL(ipv4, inp, sopt);
1252 				break;
1253 			}
1254 			/* FALLTHROUGH */
1255 #endif /* IPSEC */
1256 
1257 		default:
1258 			error = ENOPROTOOPT;
1259 			break;
1260 		}
1261 		break;
1262 
1263 	case SOPT_GET:
1264 		switch (sopt->sopt_name) {
1265 		case IP_OPTIONS:
1266 		case IP_RETOPTS:
1267 			INP_RLOCK(inp);
1268 			if (inp->inp_options) {
1269 				struct mbuf *options;
1270 
1271 				options = m_copym(inp->inp_options, 0,
1272 				    M_COPYALL, M_NOWAIT);
1273 				INP_RUNLOCK(inp);
1274 				if (options != NULL) {
1275 					error = sooptcopyout(sopt,
1276 							     mtod(options, char *),
1277 							     options->m_len);
1278 					m_freem(options);
1279 				} else
1280 					error = ENOMEM;
1281 			} else {
1282 				INP_RUNLOCK(inp);
1283 				sopt->sopt_valsize = 0;
1284 			}
1285 			break;
1286 
1287 		case IP_TOS:
1288 		case IP_TTL:
1289 		case IP_MINTTL:
1290 		case IP_RECVOPTS:
1291 		case IP_RECVRETOPTS:
1292 		case IP_ORIGDSTADDR:
1293 		case IP_RECVDSTADDR:
1294 		case IP_RECVTTL:
1295 		case IP_RECVIF:
1296 		case IP_PORTRANGE:
1297 		case IP_ONESBCAST:
1298 		case IP_DONTFRAG:
1299 		case IP_BINDANY:
1300 		case IP_RECVTOS:
1301 		case IP_BINDMULTI:
1302 		case IP_FLOWID:
1303 		case IP_FLOWTYPE:
1304 		case IP_RECVFLOWID:
1305 #ifdef	RSS
1306 		case IP_RSSBUCKETID:
1307 		case IP_RECVRSSBUCKETID:
1308 #endif
1309 			switch (sopt->sopt_name) {
1310 
1311 			case IP_TOS:
1312 				optval = inp->inp_ip_tos;
1313 				break;
1314 
1315 			case IP_TTL:
1316 				optval = inp->inp_ip_ttl;
1317 				break;
1318 
1319 			case IP_MINTTL:
1320 				optval = inp->inp_ip_minttl;
1321 				break;
1322 
1323 #define	OPTBIT(bit)	(inp->inp_flags & bit ? 1 : 0)
1324 #define	OPTBIT2(bit)	(inp->inp_flags2 & bit ? 1 : 0)
1325 
1326 			case IP_RECVOPTS:
1327 				optval = OPTBIT(INP_RECVOPTS);
1328 				break;
1329 
1330 			case IP_RECVRETOPTS:
1331 				optval = OPTBIT(INP_RECVRETOPTS);
1332 				break;
1333 
1334 			case IP_RECVDSTADDR:
1335 				optval = OPTBIT(INP_RECVDSTADDR);
1336 				break;
1337 
1338 			case IP_ORIGDSTADDR:
1339 				optval = OPTBIT2(INP_ORIGDSTADDR);
1340 				break;
1341 
1342 			case IP_RECVTTL:
1343 				optval = OPTBIT(INP_RECVTTL);
1344 				break;
1345 
1346 			case IP_RECVIF:
1347 				optval = OPTBIT(INP_RECVIF);
1348 				break;
1349 
1350 			case IP_PORTRANGE:
1351 				if (inp->inp_flags & INP_HIGHPORT)
1352 					optval = IP_PORTRANGE_HIGH;
1353 				else if (inp->inp_flags & INP_LOWPORT)
1354 					optval = IP_PORTRANGE_LOW;
1355 				else
1356 					optval = 0;
1357 				break;
1358 
1359 			case IP_ONESBCAST:
1360 				optval = OPTBIT(INP_ONESBCAST);
1361 				break;
1362 			case IP_DONTFRAG:
1363 				optval = OPTBIT(INP_DONTFRAG);
1364 				break;
1365 			case IP_BINDANY:
1366 				optval = OPTBIT(INP_BINDANY);
1367 				break;
1368 			case IP_RECVTOS:
1369 				optval = OPTBIT(INP_RECVTOS);
1370 				break;
1371 			case IP_FLOWID:
1372 				optval = inp->inp_flowid;
1373 				break;
1374 			case IP_FLOWTYPE:
1375 				optval = inp->inp_flowtype;
1376 				break;
1377 			case IP_RECVFLOWID:
1378 				optval = OPTBIT2(INP_RECVFLOWID);
1379 				break;
1380 #ifdef	RSS
1381 			case IP_RSSBUCKETID:
1382 				retval = rss_hash2bucket(inp->inp_flowid,
1383 				    inp->inp_flowtype,
1384 				    &rss_bucket);
1385 				if (retval == 0)
1386 					optval = rss_bucket;
1387 				else
1388 					error = EINVAL;
1389 				break;
1390 			case IP_RECVRSSBUCKETID:
1391 				optval = OPTBIT2(INP_RECVRSSBUCKETID);
1392 				break;
1393 #endif
1394 			case IP_BINDMULTI:
1395 				optval = OPTBIT2(INP_BINDMULTI);
1396 				break;
1397 			}
1398 			error = sooptcopyout(sopt, &optval, sizeof optval);
1399 			break;
1400 
1401 		/*
1402 		 * Multicast socket options are processed by the in_mcast
1403 		 * module.
1404 		 */
1405 		case IP_MULTICAST_IF:
1406 		case IP_MULTICAST_VIF:
1407 		case IP_MULTICAST_TTL:
1408 		case IP_MULTICAST_LOOP:
1409 		case IP_MSFILTER:
1410 			error = inp_getmoptions(inp, sopt);
1411 			break;
1412 
1413 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1414 		case IP_IPSEC_POLICY:
1415 			if (IPSEC_ENABLED(ipv4)) {
1416 				error = IPSEC_PCBCTL(ipv4, inp, sopt);
1417 				break;
1418 			}
1419 			/* FALLTHROUGH */
1420 #endif /* IPSEC */
1421 
1422 		default:
1423 			error = ENOPROTOOPT;
1424 			break;
1425 		}
1426 		break;
1427 	}
1428 	return (error);
1429 }
1430 
1431 /*
1432  * Routine called from ip_output() to loop back a copy of an IP multicast
1433  * packet to the input queue of a specified interface.  Note that this
1434  * calls the output routine of the loopback "driver", but with an interface
1435  * pointer that might NOT be a loopback interface -- evil, but easier than
1436  * replicating that code here.
1437  */
1438 static void
1439 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1440 {
1441 	struct ip *ip;
1442 	struct mbuf *copym;
1443 
1444 	/*
1445 	 * Make a deep copy of the packet because we're going to
1446 	 * modify the pack in order to generate checksums.
1447 	 */
1448 	copym = m_dup(m, M_NOWAIT);
1449 	if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1450 		copym = m_pullup(copym, hlen);
1451 	if (copym != NULL) {
1452 		/* If needed, compute the checksum and mark it as valid. */
1453 		if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1454 			in_delayed_cksum(copym);
1455 			copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1456 			copym->m_pkthdr.csum_flags |=
1457 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1458 			copym->m_pkthdr.csum_data = 0xffff;
1459 		}
1460 		/*
1461 		 * We don't bother to fragment if the IP length is greater
1462 		 * than the interface's MTU.  Can this possibly matter?
1463 		 */
1464 		ip = mtod(copym, struct ip *);
1465 		ip->ip_sum = 0;
1466 		ip->ip_sum = in_cksum(copym, hlen);
1467 		if_simloop(ifp, copym, AF_INET, 0);
1468 	}
1469 }
1470