xref: /freebsd/sys/netinet/ip_output.c (revision d3d381b2b194b4d24853e92eecef55f262688d1a)
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 	*error = pfil_run_hooks(&V_inet_pfil_hook, mp, ifp, PFIL_OUT, 0, inp);
125 	m = *mp;
126 	if ((*error) != 0 || m == NULL)
127 		return 1; /* Finished */
128 
129 	ip = mtod(m, struct ip *);
130 
131 	/* See if destination IP address was changed by packet filter. */
132 	if (odst.s_addr != ip->ip_dst.s_addr) {
133 		m->m_flags |= M_SKIP_FIREWALL;
134 		/* If destination is now ourself drop to ip_input(). */
135 		if (in_localip(ip->ip_dst)) {
136 			m->m_flags |= M_FASTFWD_OURS;
137 			if (m->m_pkthdr.rcvif == NULL)
138 				m->m_pkthdr.rcvif = V_loif;
139 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
140 				m->m_pkthdr.csum_flags |=
141 					CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
142 				m->m_pkthdr.csum_data = 0xffff;
143 			}
144 			m->m_pkthdr.csum_flags |=
145 				CSUM_IP_CHECKED | CSUM_IP_VALID;
146 #ifdef SCTP
147 			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
148 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
149 #endif
150 			*error = netisr_queue(NETISR_IP, m);
151 			return 1; /* Finished */
152 		}
153 
154 		bzero(dst, sizeof(*dst));
155 		dst->sin_family = AF_INET;
156 		dst->sin_len = sizeof(*dst);
157 		dst->sin_addr = ip->ip_dst;
158 
159 		return -1; /* Reloop */
160 	}
161 	/* See if fib was changed by packet filter. */
162 	if ((*fibnum) != M_GETFIB(m)) {
163 		m->m_flags |= M_SKIP_FIREWALL;
164 		*fibnum = M_GETFIB(m);
165 		return -1; /* Reloop for FIB change */
166 	}
167 
168 	/* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
169 	if (m->m_flags & M_FASTFWD_OURS) {
170 		if (m->m_pkthdr.rcvif == NULL)
171 			m->m_pkthdr.rcvif = V_loif;
172 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
173 			m->m_pkthdr.csum_flags |=
174 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
175 			m->m_pkthdr.csum_data = 0xffff;
176 		}
177 #ifdef SCTP
178 		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
179 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
180 #endif
181 		m->m_pkthdr.csum_flags |=
182 			CSUM_IP_CHECKED | CSUM_IP_VALID;
183 
184 		*error = netisr_queue(NETISR_IP, m);
185 		return 1; /* Finished */
186 	}
187 	/* Or forward to some other address? */
188 	if ((m->m_flags & M_IP_NEXTHOP) &&
189 	    ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
190 		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
191 		m->m_flags |= M_SKIP_FIREWALL;
192 		m->m_flags &= ~M_IP_NEXTHOP;
193 		m_tag_delete(m, fwd_tag);
194 
195 		return -1; /* Reloop for CHANGE of dst */
196 	}
197 
198 	return 0;
199 }
200 
201 /*
202  * IP output.  The packet in mbuf chain m contains a skeletal IP
203  * header (with len, off, ttl, proto, tos, src, dst).
204  * The mbuf chain containing the packet will be freed.
205  * The mbuf opt, if present, will not be freed.
206  * If route ro is present and has ro_rt initialized, route lookup would be
207  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
208  * then result of route lookup is stored in ro->ro_rt.
209  *
210  * In the IP forwarding case, the packet will arrive with options already
211  * inserted, so must have a NULL opt pointer.
212  */
213 int
214 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
215     struct ip_moptions *imo, struct inpcb *inp)
216 {
217 	struct rm_priotracker in_ifa_tracker;
218 	struct ip *ip;
219 	struct ifnet *ifp = NULL;	/* keep compiler happy */
220 	struct mbuf *m0;
221 	int hlen = sizeof (struct ip);
222 	int mtu;
223 	int error = 0;
224 	struct sockaddr_in *dst;
225 	const struct sockaddr_in *gw;
226 	struct in_ifaddr *ia;
227 	int isbroadcast;
228 	uint16_t ip_len, ip_off;
229 	struct route iproute;
230 	struct rtentry *rte;	/* cache for ro->ro_rt */
231 	uint32_t fibnum;
232 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
233 	int no_route_but_check_spd = 0;
234 #endif
235 	M_ASSERTPKTHDR(m);
236 
237 	if (inp != NULL) {
238 		INP_LOCK_ASSERT(inp);
239 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
240 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
241 			m->m_pkthdr.flowid = inp->inp_flowid;
242 			M_HASHTYPE_SET(m, inp->inp_flowtype);
243 		}
244 	}
245 
246 	if (ro == NULL) {
247 		ro = &iproute;
248 		bzero(ro, sizeof (*ro));
249 	}
250 
251 	if (opt) {
252 		int len = 0;
253 		m = ip_insertoptions(m, opt, &len);
254 		if (len != 0)
255 			hlen = len; /* ip->ip_hl is updated above */
256 	}
257 	ip = mtod(m, struct ip *);
258 	ip_len = ntohs(ip->ip_len);
259 	ip_off = ntohs(ip->ip_off);
260 
261 	if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
262 		ip->ip_v = IPVERSION;
263 		ip->ip_hl = hlen >> 2;
264 		ip_fillid(ip);
265 		IPSTAT_INC(ips_localout);
266 	} else {
267 		/* Header already set, fetch hlen from there */
268 		hlen = ip->ip_hl << 2;
269 	}
270 
271 	/*
272 	 * dst/gw handling:
273 	 *
274 	 * dst can be rewritten but always points to &ro->ro_dst.
275 	 * gw is readonly but can point either to dst OR rt_gateway,
276 	 * therefore we need restore gw if we're redoing lookup.
277 	 */
278 	gw = dst = (struct sockaddr_in *)&ro->ro_dst;
279 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
280 	rte = ro->ro_rt;
281 	if (rte == NULL) {
282 		bzero(dst, sizeof(*dst));
283 		dst->sin_family = AF_INET;
284 		dst->sin_len = sizeof(*dst);
285 		dst->sin_addr = ip->ip_dst;
286 	}
287 	NET_EPOCH_ENTER();
288 again:
289 	/*
290 	 * Validate route against routing table additions;
291 	 * a better/more specific route might have been added.
292 	 */
293 	if (inp)
294 		RT_VALIDATE(ro, &inp->inp_rt_cookie, fibnum);
295 	/*
296 	 * If there is a cached route,
297 	 * check that it is to the same destination
298 	 * and is still up.  If not, free it and try again.
299 	 * The address family should also be checked in case of sharing the
300 	 * cache with IPv6.
301 	 * Also check whether routing cache needs invalidation.
302 	 */
303 	rte = ro->ro_rt;
304 	if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
305 		    rte->rt_ifp == NULL ||
306 		    !RT_LINK_IS_UP(rte->rt_ifp) ||
307 			  dst->sin_family != AF_INET ||
308 			  dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
309 		RO_INVALIDATE_CACHE(ro);
310 		rte = NULL;
311 	}
312 	ia = NULL;
313 	/*
314 	 * If routing to interface only, short circuit routing lookup.
315 	 * The use of an all-ones broadcast address implies this; an
316 	 * interface is specified by the broadcast address of an interface,
317 	 * or the destination address of a ptp interface.
318 	 */
319 	if (flags & IP_SENDONES) {
320 		if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
321 						      M_GETFIB(m)))) == NULL &&
322 		    (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
323 						    M_GETFIB(m)))) == NULL) {
324 			IPSTAT_INC(ips_noroute);
325 			error = ENETUNREACH;
326 			goto bad;
327 		}
328 		ip->ip_dst.s_addr = INADDR_BROADCAST;
329 		dst->sin_addr = ip->ip_dst;
330 		ifp = ia->ia_ifp;
331 		ip->ip_ttl = 1;
332 		isbroadcast = 1;
333 	} else if (flags & IP_ROUTETOIF) {
334 		if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
335 						    M_GETFIB(m)))) == NULL &&
336 		    (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
337 						M_GETFIB(m)))) == NULL) {
338 			IPSTAT_INC(ips_noroute);
339 			error = ENETUNREACH;
340 			goto bad;
341 		}
342 		ifp = ia->ia_ifp;
343 		ip->ip_ttl = 1;
344 		isbroadcast = ifp->if_flags & IFF_BROADCAST ?
345 		    in_ifaddr_broadcast(dst->sin_addr, ia) : 0;
346 	} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
347 	    imo != NULL && imo->imo_multicast_ifp != NULL) {
348 		/*
349 		 * Bypass the normal routing lookup for multicast
350 		 * packets if the interface is specified.
351 		 */
352 		ifp = imo->imo_multicast_ifp;
353 		IFP_TO_IA(ifp, ia, &in_ifa_tracker);
354 		isbroadcast = 0;	/* fool gcc */
355 	} else {
356 		/*
357 		 * We want to do any cloning requested by the link layer,
358 		 * as this is probably required in all cases for correct
359 		 * operation (as it is for ARP).
360 		 */
361 		if (rte == NULL) {
362 #ifdef RADIX_MPATH
363 			rtalloc_mpath_fib(ro,
364 			    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
365 			    fibnum);
366 #else
367 			in_rtalloc_ign(ro, 0, fibnum);
368 #endif
369 			rte = ro->ro_rt;
370 		}
371 		if (rte == NULL ||
372 		    (rte->rt_flags & RTF_UP) == 0 ||
373 		    rte->rt_ifp == NULL ||
374 		    !RT_LINK_IS_UP(rte->rt_ifp)) {
375 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
376 			/*
377 			 * There is no route for this packet, but it is
378 			 * possible that a matching SPD entry exists.
379 			 */
380 			no_route_but_check_spd = 1;
381 			mtu = 0; /* Silence GCC warning. */
382 			goto sendit;
383 #endif
384 			IPSTAT_INC(ips_noroute);
385 			error = EHOSTUNREACH;
386 			goto bad;
387 		}
388 		ia = ifatoia(rte->rt_ifa);
389 		ifp = rte->rt_ifp;
390 		counter_u64_add(rte->rt_pksent, 1);
391 		rt_update_ro_flags(ro);
392 		if (rte->rt_flags & RTF_GATEWAY)
393 			gw = (struct sockaddr_in *)rte->rt_gateway;
394 		if (rte->rt_flags & RTF_HOST)
395 			isbroadcast = (rte->rt_flags & RTF_BROADCAST);
396 		else if (ifp->if_flags & IFF_BROADCAST)
397 			isbroadcast = in_ifaddr_broadcast(gw->sin_addr, ia);
398 		else
399 			isbroadcast = 0;
400 	}
401 
402 	/*
403 	 * Calculate MTU.  If we have a route that is up, use that,
404 	 * otherwise use the interface's MTU.
405 	 */
406 	if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST)))
407 		mtu = rte->rt_mtu;
408 	else
409 		mtu = ifp->if_mtu;
410 	/* Catch a possible divide by zero later. */
411 	KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
412 	    __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
413 
414 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
415 		m->m_flags |= M_MCAST;
416 		/*
417 		 * IP destination address is multicast.  Make sure "gw"
418 		 * still points to the address in "ro".  (It may have been
419 		 * changed to point to a gateway address, above.)
420 		 */
421 		gw = dst;
422 		/*
423 		 * See if the caller provided any multicast options
424 		 */
425 		if (imo != NULL) {
426 			ip->ip_ttl = imo->imo_multicast_ttl;
427 			if (imo->imo_multicast_vif != -1)
428 				ip->ip_src.s_addr =
429 				    ip_mcast_src ?
430 				    ip_mcast_src(imo->imo_multicast_vif) :
431 				    INADDR_ANY;
432 		} else
433 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
434 		/*
435 		 * Confirm that the outgoing interface supports multicast.
436 		 */
437 		if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
438 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
439 				IPSTAT_INC(ips_noroute);
440 				error = ENETUNREACH;
441 				goto bad;
442 			}
443 		}
444 		/*
445 		 * If source address not specified yet, use address
446 		 * of outgoing interface.
447 		 */
448 		if (ip->ip_src.s_addr == INADDR_ANY) {
449 			/* Interface may have no addresses. */
450 			if (ia != NULL)
451 				ip->ip_src = IA_SIN(ia)->sin_addr;
452 		}
453 
454 		if ((imo == NULL && in_mcast_loop) ||
455 		    (imo && imo->imo_multicast_loop)) {
456 			/*
457 			 * Loop back multicast datagram if not expressly
458 			 * forbidden to do so, even if we are not a member
459 			 * of the group; ip_input() will filter it later,
460 			 * thus deferring a hash lookup and mutex acquisition
461 			 * at the expense of a cheap copy using m_copym().
462 			 */
463 			ip_mloopback(ifp, m, hlen);
464 		} else {
465 			/*
466 			 * If we are acting as a multicast router, perform
467 			 * multicast forwarding as if the packet had just
468 			 * arrived on the interface to which we are about
469 			 * to send.  The multicast forwarding function
470 			 * recursively calls this function, using the
471 			 * IP_FORWARDING flag to prevent infinite recursion.
472 			 *
473 			 * Multicasts that are looped back by ip_mloopback(),
474 			 * above, will be forwarded by the ip_input() routine,
475 			 * if necessary.
476 			 */
477 			if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
478 				/*
479 				 * If rsvp daemon is not running, do not
480 				 * set ip_moptions. This ensures that the packet
481 				 * is multicast and not just sent down one link
482 				 * as prescribed by rsvpd.
483 				 */
484 				if (!V_rsvp_on)
485 					imo = NULL;
486 				if (ip_mforward &&
487 				    ip_mforward(ip, ifp, m, imo) != 0) {
488 					m_freem(m);
489 					goto done;
490 				}
491 			}
492 		}
493 
494 		/*
495 		 * Multicasts with a time-to-live of zero may be looped-
496 		 * back, above, but must not be transmitted on a network.
497 		 * Also, multicasts addressed to the loopback interface
498 		 * are not sent -- the above call to ip_mloopback() will
499 		 * loop back a copy. ip_input() will drop the copy if
500 		 * this host does not belong to the destination group on
501 		 * the loopback interface.
502 		 */
503 		if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
504 			m_freem(m);
505 			goto done;
506 		}
507 
508 		goto sendit;
509 	}
510 
511 	/*
512 	 * If the source address is not specified yet, use the address
513 	 * of the outoing interface.
514 	 */
515 	if (ip->ip_src.s_addr == INADDR_ANY) {
516 		/* Interface may have no addresses. */
517 		if (ia != NULL) {
518 			ip->ip_src = IA_SIN(ia)->sin_addr;
519 		}
520 	}
521 
522 	/*
523 	 * Look for broadcast address and
524 	 * verify user is allowed to send
525 	 * such a packet.
526 	 */
527 	if (isbroadcast) {
528 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
529 			error = EADDRNOTAVAIL;
530 			goto bad;
531 		}
532 		if ((flags & IP_ALLOWBROADCAST) == 0) {
533 			error = EACCES;
534 			goto bad;
535 		}
536 		/* don't allow broadcast messages to be fragmented */
537 		if (ip_len > mtu) {
538 			error = EMSGSIZE;
539 			goto bad;
540 		}
541 		m->m_flags |= M_BCAST;
542 	} else {
543 		m->m_flags &= ~M_BCAST;
544 	}
545 
546 sendit:
547 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
548 	if (IPSEC_ENABLED(ipv4)) {
549 		if ((error = IPSEC_OUTPUT(ipv4, m, inp)) != 0) {
550 			if (error == EINPROGRESS)
551 				error = 0;
552 			goto done;
553 		}
554 	}
555 	/*
556 	 * Check if there was a route for this packet; return error if not.
557 	 */
558 	if (no_route_but_check_spd) {
559 		IPSTAT_INC(ips_noroute);
560 		error = EHOSTUNREACH;
561 		goto bad;
562 	}
563 	/* Update variables that are affected by ipsec4_output(). */
564 	ip = mtod(m, struct ip *);
565 	hlen = ip->ip_hl << 2;
566 #endif /* IPSEC */
567 
568 	/* Jump over all PFIL processing if hooks are not active. */
569 	if (PFIL_HOOKED(&V_inet_pfil_hook)) {
570 		switch (ip_output_pfil(&m, ifp, inp, dst, &fibnum, &error)) {
571 		case 1: /* Finished */
572 			goto done;
573 
574 		case 0: /* Continue normally */
575 			ip = mtod(m, struct ip *);
576 			break;
577 
578 		case -1: /* Need to try again */
579 			/* Reset everything for a new round */
580 			RO_RTFREE(ro);
581 			ro->ro_prepend = NULL;
582 			rte = NULL;
583 			gw = dst;
584 			ip = mtod(m, struct ip *);
585 			goto again;
586 
587 		}
588 	}
589 
590 	/* 127/8 must not appear on wire - RFC1122. */
591 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
592 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
593 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
594 			IPSTAT_INC(ips_badaddr);
595 			error = EADDRNOTAVAIL;
596 			goto bad;
597 		}
598 	}
599 
600 	m->m_pkthdr.csum_flags |= CSUM_IP;
601 	if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
602 		in_delayed_cksum(m);
603 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
604 	}
605 #ifdef SCTP
606 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
607 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
608 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
609 	}
610 #endif
611 
612 	/*
613 	 * If small enough for interface, or the interface will take
614 	 * care of the fragmentation for us, we can just send directly.
615 	 */
616 	if (ip_len <= mtu ||
617 	    (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) {
618 		ip->ip_sum = 0;
619 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
620 			ip->ip_sum = in_cksum(m, hlen);
621 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
622 		}
623 
624 		/*
625 		 * Record statistics for this interface address.
626 		 * With CSUM_TSO the byte/packet count will be slightly
627 		 * incorrect because we count the IP+TCP headers only
628 		 * once instead of for every generated packet.
629 		 */
630 		if (!(flags & IP_FORWARDING) && ia) {
631 			if (m->m_pkthdr.csum_flags & CSUM_TSO)
632 				counter_u64_add(ia->ia_ifa.ifa_opackets,
633 				    m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
634 			else
635 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
636 
637 			counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
638 		}
639 #ifdef MBUF_STRESS_TEST
640 		if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
641 			m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
642 #endif
643 		/*
644 		 * Reset layer specific mbuf flags
645 		 * to avoid confusing lower layers.
646 		 */
647 		m_clrprotoflags(m);
648 		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
649 #ifdef RATELIMIT
650 		if (inp != NULL) {
651 			if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
652 				in_pcboutput_txrtlmt(inp, ifp, m);
653 			/* stamp send tag on mbuf */
654 			m->m_pkthdr.snd_tag = inp->inp_snd_tag;
655 		} else {
656 			m->m_pkthdr.snd_tag = NULL;
657 		}
658 #endif
659 		error = (*ifp->if_output)(ifp, m,
660 		    (const struct sockaddr *)gw, ro);
661 #ifdef RATELIMIT
662 		/* check for route change */
663 		if (error == EAGAIN)
664 			in_pcboutput_eagain(inp);
665 #endif
666 		goto done;
667 	}
668 
669 	/* Balk when DF bit is set or the interface didn't support TSO. */
670 	if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
671 		error = EMSGSIZE;
672 		IPSTAT_INC(ips_cantfrag);
673 		goto bad;
674 	}
675 
676 	/*
677 	 * Too large for interface; fragment if possible. If successful,
678 	 * on return, m will point to a list of packets to be sent.
679 	 */
680 	error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
681 	if (error)
682 		goto bad;
683 	for (; m; m = m0) {
684 		m0 = m->m_nextpkt;
685 		m->m_nextpkt = 0;
686 		if (error == 0) {
687 			/* Record statistics for this interface address. */
688 			if (ia != NULL) {
689 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
690 				counter_u64_add(ia->ia_ifa.ifa_obytes,
691 				    m->m_pkthdr.len);
692 			}
693 			/*
694 			 * Reset layer specific mbuf flags
695 			 * to avoid confusing upper layers.
696 			 */
697 			m_clrprotoflags(m);
698 
699 			IP_PROBE(send, NULL, NULL, mtod(m, struct ip *), ifp,
700 			    mtod(m, struct ip *), NULL);
701 #ifdef RATELIMIT
702 			if (inp != NULL) {
703 				if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
704 					in_pcboutput_txrtlmt(inp, ifp, m);
705 				/* stamp send tag on mbuf */
706 				m->m_pkthdr.snd_tag = inp->inp_snd_tag;
707 			} else {
708 				m->m_pkthdr.snd_tag = NULL;
709 			}
710 #endif
711 			error = (*ifp->if_output)(ifp, m,
712 			    (const struct sockaddr *)gw, ro);
713 #ifdef RATELIMIT
714 			/* check for route change */
715 			if (error == EAGAIN)
716 				in_pcboutput_eagain(inp);
717 #endif
718 		} else
719 			m_freem(m);
720 	}
721 
722 	if (error == 0)
723 		IPSTAT_INC(ips_fragmented);
724 
725 done:
726 	if (ro == &iproute)
727 		RO_RTFREE(ro);
728 	else if (rte == NULL)
729 		/*
730 		 * If the caller supplied a route but somehow the reference
731 		 * to it has been released need to prevent the caller
732 		 * calling RTFREE on it again.
733 		 */
734 		ro->ro_rt = NULL;
735 	NET_EPOCH_EXIT();
736 	return (error);
737  bad:
738 	m_freem(m);
739 	goto done;
740 }
741 
742 /*
743  * Create a chain of fragments which fit the given mtu. m_frag points to the
744  * mbuf to be fragmented; on return it points to the chain with the fragments.
745  * Return 0 if no error. If error, m_frag may contain a partially built
746  * chain of fragments that should be freed by the caller.
747  *
748  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
749  */
750 int
751 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
752     u_long if_hwassist_flags)
753 {
754 	int error = 0;
755 	int hlen = ip->ip_hl << 2;
756 	int len = (mtu - hlen) & ~7;	/* size of payload in each fragment */
757 	int off;
758 	struct mbuf *m0 = *m_frag;	/* the original packet		*/
759 	int firstlen;
760 	struct mbuf **mnext;
761 	int nfrags;
762 	uint16_t ip_len, ip_off;
763 
764 	ip_len = ntohs(ip->ip_len);
765 	ip_off = ntohs(ip->ip_off);
766 
767 	if (ip_off & IP_DF) {	/* Fragmentation not allowed */
768 		IPSTAT_INC(ips_cantfrag);
769 		return EMSGSIZE;
770 	}
771 
772 	/*
773 	 * Must be able to put at least 8 bytes per fragment.
774 	 */
775 	if (len < 8)
776 		return EMSGSIZE;
777 
778 	/*
779 	 * If the interface will not calculate checksums on
780 	 * fragmented packets, then do it here.
781 	 */
782 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
783 		in_delayed_cksum(m0);
784 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
785 	}
786 #ifdef SCTP
787 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
788 		sctp_delayed_cksum(m0, hlen);
789 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
790 	}
791 #endif
792 	if (len > PAGE_SIZE) {
793 		/*
794 		 * Fragment large datagrams such that each segment
795 		 * contains a multiple of PAGE_SIZE amount of data,
796 		 * plus headers. This enables a receiver to perform
797 		 * page-flipping zero-copy optimizations.
798 		 *
799 		 * XXX When does this help given that sender and receiver
800 		 * could have different page sizes, and also mtu could
801 		 * be less than the receiver's page size ?
802 		 */
803 		int newlen;
804 
805 		off = MIN(mtu, m0->m_pkthdr.len);
806 
807 		/*
808 		 * firstlen (off - hlen) must be aligned on an
809 		 * 8-byte boundary
810 		 */
811 		if (off < hlen)
812 			goto smart_frag_failure;
813 		off = ((off - hlen) & ~7) + hlen;
814 		newlen = (~PAGE_MASK) & mtu;
815 		if ((newlen + sizeof (struct ip)) > mtu) {
816 			/* we failed, go back the default */
817 smart_frag_failure:
818 			newlen = len;
819 			off = hlen + len;
820 		}
821 		len = newlen;
822 
823 	} else {
824 		off = hlen + len;
825 	}
826 
827 	firstlen = off - hlen;
828 	mnext = &m0->m_nextpkt;		/* pointer to next packet */
829 
830 	/*
831 	 * Loop through length of segment after first fragment,
832 	 * make new header and copy data of each part and link onto chain.
833 	 * Here, m0 is the original packet, m is the fragment being created.
834 	 * The fragments are linked off the m_nextpkt of the original
835 	 * packet, which after processing serves as the first fragment.
836 	 */
837 	for (nfrags = 1; off < ip_len; off += len, nfrags++) {
838 		struct ip *mhip;	/* ip header on the fragment */
839 		struct mbuf *m;
840 		int mhlen = sizeof (struct ip);
841 
842 		m = m_gethdr(M_NOWAIT, MT_DATA);
843 		if (m == NULL) {
844 			error = ENOBUFS;
845 			IPSTAT_INC(ips_odropped);
846 			goto done;
847 		}
848 		/*
849 		 * Make sure the complete packet header gets copied
850 		 * from the originating mbuf to the newly created
851 		 * mbuf. This also ensures that existing firewall
852 		 * classification(s), VLAN tags and so on get copied
853 		 * to the resulting fragmented packet(s):
854 		 */
855 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
856 			m_free(m);
857 			error = ENOBUFS;
858 			IPSTAT_INC(ips_odropped);
859 			goto done;
860 		}
861 		/*
862 		 * In the first mbuf, leave room for the link header, then
863 		 * copy the original IP header including options. The payload
864 		 * goes into an additional mbuf chain returned by m_copym().
865 		 */
866 		m->m_data += max_linkhdr;
867 		mhip = mtod(m, struct ip *);
868 		*mhip = *ip;
869 		if (hlen > sizeof (struct ip)) {
870 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
871 			mhip->ip_v = IPVERSION;
872 			mhip->ip_hl = mhlen >> 2;
873 		}
874 		m->m_len = mhlen;
875 		/* XXX do we need to add ip_off below ? */
876 		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
877 		if (off + len >= ip_len)
878 			len = ip_len - off;
879 		else
880 			mhip->ip_off |= IP_MF;
881 		mhip->ip_len = htons((u_short)(len + mhlen));
882 		m->m_next = m_copym(m0, off, len, M_NOWAIT);
883 		if (m->m_next == NULL) {	/* copy failed */
884 			m_free(m);
885 			error = ENOBUFS;	/* ??? */
886 			IPSTAT_INC(ips_odropped);
887 			goto done;
888 		}
889 		m->m_pkthdr.len = mhlen + len;
890 #ifdef MAC
891 		mac_netinet_fragment(m0, m);
892 #endif
893 		mhip->ip_off = htons(mhip->ip_off);
894 		mhip->ip_sum = 0;
895 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
896 			mhip->ip_sum = in_cksum(m, mhlen);
897 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
898 		}
899 		*mnext = m;
900 		mnext = &m->m_nextpkt;
901 	}
902 	IPSTAT_ADD(ips_ofragments, nfrags);
903 
904 	/*
905 	 * Update first fragment by trimming what's been copied out
906 	 * and updating header.
907 	 */
908 	m_adj(m0, hlen + firstlen - ip_len);
909 	m0->m_pkthdr.len = hlen + firstlen;
910 	ip->ip_len = htons((u_short)m0->m_pkthdr.len);
911 	ip->ip_off = htons(ip_off | IP_MF);
912 	ip->ip_sum = 0;
913 	if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
914 		ip->ip_sum = in_cksum(m0, hlen);
915 		m0->m_pkthdr.csum_flags &= ~CSUM_IP;
916 	}
917 
918 done:
919 	*m_frag = m0;
920 	return error;
921 }
922 
923 void
924 in_delayed_cksum(struct mbuf *m)
925 {
926 	struct ip *ip;
927 	struct udphdr *uh;
928 	uint16_t cklen, csum, offset;
929 
930 	ip = mtod(m, struct ip *);
931 	offset = ip->ip_hl << 2 ;
932 
933 	if (m->m_pkthdr.csum_flags & CSUM_UDP) {
934 		/* if udp header is not in the first mbuf copy udplen */
935 		if (offset + sizeof(struct udphdr) > m->m_len)
936 			m_copydata(m, offset + offsetof(struct udphdr,
937 			    uh_ulen), sizeof(cklen), (caddr_t)&cklen);
938 		else {
939 			uh = (struct udphdr *)mtodo(m, offset);
940 			cklen = ntohs(uh->uh_ulen);
941 		}
942 		csum = in_cksum_skip(m, cklen + offset, offset);
943 		if (csum == 0)
944 			csum = 0xffff;
945 	} else {
946 		cklen = ntohs(ip->ip_len);
947 		csum = in_cksum_skip(m, cklen, offset);
948 	}
949 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
950 
951 	if (offset + sizeof(csum) > m->m_len)
952 		m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
953 	else
954 		*(u_short *)mtodo(m, offset) = csum;
955 }
956 
957 /*
958  * IP socket option processing.
959  */
960 int
961 ip_ctloutput(struct socket *so, struct sockopt *sopt)
962 {
963 	struct	inpcb *inp = sotoinpcb(so);
964 	int	error, optval;
965 #ifdef	RSS
966 	uint32_t rss_bucket;
967 	int retval;
968 #endif
969 
970 	error = optval = 0;
971 	if (sopt->sopt_level != IPPROTO_IP) {
972 		error = EINVAL;
973 
974 		if (sopt->sopt_level == SOL_SOCKET &&
975 		    sopt->sopt_dir == SOPT_SET) {
976 			switch (sopt->sopt_name) {
977 			case SO_REUSEADDR:
978 				INP_WLOCK(inp);
979 				if ((so->so_options & SO_REUSEADDR) != 0)
980 					inp->inp_flags2 |= INP_REUSEADDR;
981 				else
982 					inp->inp_flags2 &= ~INP_REUSEADDR;
983 				INP_WUNLOCK(inp);
984 				error = 0;
985 				break;
986 			case SO_REUSEPORT:
987 				INP_WLOCK(inp);
988 				if ((so->so_options & SO_REUSEPORT) != 0)
989 					inp->inp_flags2 |= INP_REUSEPORT;
990 				else
991 					inp->inp_flags2 &= ~INP_REUSEPORT;
992 				INP_WUNLOCK(inp);
993 				error = 0;
994 				break;
995 			case SO_REUSEPORT_LB:
996 				INP_WLOCK(inp);
997 				if ((so->so_options & SO_REUSEPORT_LB) != 0)
998 					inp->inp_flags2 |= INP_REUSEPORT_LB;
999 				else
1000 					inp->inp_flags2 &= ~INP_REUSEPORT_LB;
1001 				INP_WUNLOCK(inp);
1002 				error = 0;
1003 				break;
1004 			case SO_SETFIB:
1005 				INP_WLOCK(inp);
1006 				inp->inp_inc.inc_fibnum = so->so_fibnum;
1007 				INP_WUNLOCK(inp);
1008 				error = 0;
1009 				break;
1010 			case SO_MAX_PACING_RATE:
1011 #ifdef RATELIMIT
1012 				INP_WLOCK(inp);
1013 				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1014 				INP_WUNLOCK(inp);
1015 				error = 0;
1016 #else
1017 				error = EOPNOTSUPP;
1018 #endif
1019 				break;
1020 			default:
1021 				break;
1022 			}
1023 		}
1024 		return (error);
1025 	}
1026 
1027 	switch (sopt->sopt_dir) {
1028 	case SOPT_SET:
1029 		switch (sopt->sopt_name) {
1030 		case IP_OPTIONS:
1031 #ifdef notyet
1032 		case IP_RETOPTS:
1033 #endif
1034 		{
1035 			struct mbuf *m;
1036 			if (sopt->sopt_valsize > MLEN) {
1037 				error = EMSGSIZE;
1038 				break;
1039 			}
1040 			m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
1041 			if (m == NULL) {
1042 				error = ENOBUFS;
1043 				break;
1044 			}
1045 			m->m_len = sopt->sopt_valsize;
1046 			error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1047 					    m->m_len);
1048 			if (error) {
1049 				m_free(m);
1050 				break;
1051 			}
1052 			INP_WLOCK(inp);
1053 			error = ip_pcbopts(inp, sopt->sopt_name, m);
1054 			INP_WUNLOCK(inp);
1055 			return (error);
1056 		}
1057 
1058 		case IP_BINDANY:
1059 			if (sopt->sopt_td != NULL) {
1060 				error = priv_check(sopt->sopt_td,
1061 				    PRIV_NETINET_BINDANY);
1062 				if (error)
1063 					break;
1064 			}
1065 			/* FALLTHROUGH */
1066 		case IP_BINDMULTI:
1067 #ifdef	RSS
1068 		case IP_RSS_LISTEN_BUCKET:
1069 #endif
1070 		case IP_TOS:
1071 		case IP_TTL:
1072 		case IP_MINTTL:
1073 		case IP_RECVOPTS:
1074 		case IP_RECVRETOPTS:
1075 		case IP_ORIGDSTADDR:
1076 		case IP_RECVDSTADDR:
1077 		case IP_RECVTTL:
1078 		case IP_RECVIF:
1079 		case IP_ONESBCAST:
1080 		case IP_DONTFRAG:
1081 		case IP_RECVTOS:
1082 		case IP_RECVFLOWID:
1083 #ifdef	RSS
1084 		case IP_RECVRSSBUCKETID:
1085 #endif
1086 			error = sooptcopyin(sopt, &optval, sizeof optval,
1087 					    sizeof optval);
1088 			if (error)
1089 				break;
1090 
1091 			switch (sopt->sopt_name) {
1092 			case IP_TOS:
1093 				inp->inp_ip_tos = optval;
1094 				break;
1095 
1096 			case IP_TTL:
1097 				inp->inp_ip_ttl = optval;
1098 				break;
1099 
1100 			case IP_MINTTL:
1101 				if (optval >= 0 && optval <= MAXTTL)
1102 					inp->inp_ip_minttl = optval;
1103 				else
1104 					error = EINVAL;
1105 				break;
1106 
1107 #define	OPTSET(bit) do {						\
1108 	INP_WLOCK(inp);							\
1109 	if (optval)							\
1110 		inp->inp_flags |= bit;					\
1111 	else								\
1112 		inp->inp_flags &= ~bit;					\
1113 	INP_WUNLOCK(inp);						\
1114 } while (0)
1115 
1116 #define	OPTSET2(bit, val) do {						\
1117 	INP_WLOCK(inp);							\
1118 	if (val)							\
1119 		inp->inp_flags2 |= bit;					\
1120 	else								\
1121 		inp->inp_flags2 &= ~bit;				\
1122 	INP_WUNLOCK(inp);						\
1123 } while (0)
1124 
1125 			case IP_RECVOPTS:
1126 				OPTSET(INP_RECVOPTS);
1127 				break;
1128 
1129 			case IP_RECVRETOPTS:
1130 				OPTSET(INP_RECVRETOPTS);
1131 				break;
1132 
1133 			case IP_RECVDSTADDR:
1134 				OPTSET(INP_RECVDSTADDR);
1135 				break;
1136 
1137 			case IP_ORIGDSTADDR:
1138 				OPTSET2(INP_ORIGDSTADDR, optval);
1139 				break;
1140 
1141 			case IP_RECVTTL:
1142 				OPTSET(INP_RECVTTL);
1143 				break;
1144 
1145 			case IP_RECVIF:
1146 				OPTSET(INP_RECVIF);
1147 				break;
1148 
1149 			case IP_ONESBCAST:
1150 				OPTSET(INP_ONESBCAST);
1151 				break;
1152 			case IP_DONTFRAG:
1153 				OPTSET(INP_DONTFRAG);
1154 				break;
1155 			case IP_BINDANY:
1156 				OPTSET(INP_BINDANY);
1157 				break;
1158 			case IP_RECVTOS:
1159 				OPTSET(INP_RECVTOS);
1160 				break;
1161 			case IP_BINDMULTI:
1162 				OPTSET2(INP_BINDMULTI, optval);
1163 				break;
1164 			case IP_RECVFLOWID:
1165 				OPTSET2(INP_RECVFLOWID, optval);
1166 				break;
1167 #ifdef	RSS
1168 			case IP_RSS_LISTEN_BUCKET:
1169 				if ((optval >= 0) &&
1170 				    (optval < rss_getnumbuckets())) {
1171 					inp->inp_rss_listen_bucket = optval;
1172 					OPTSET2(INP_RSS_BUCKET_SET, 1);
1173 				} else {
1174 					error = EINVAL;
1175 				}
1176 				break;
1177 			case IP_RECVRSSBUCKETID:
1178 				OPTSET2(INP_RECVRSSBUCKETID, optval);
1179 				break;
1180 #endif
1181 			}
1182 			break;
1183 #undef OPTSET
1184 #undef OPTSET2
1185 
1186 		/*
1187 		 * Multicast socket options are processed by the in_mcast
1188 		 * module.
1189 		 */
1190 		case IP_MULTICAST_IF:
1191 		case IP_MULTICAST_VIF:
1192 		case IP_MULTICAST_TTL:
1193 		case IP_MULTICAST_LOOP:
1194 		case IP_ADD_MEMBERSHIP:
1195 		case IP_DROP_MEMBERSHIP:
1196 		case IP_ADD_SOURCE_MEMBERSHIP:
1197 		case IP_DROP_SOURCE_MEMBERSHIP:
1198 		case IP_BLOCK_SOURCE:
1199 		case IP_UNBLOCK_SOURCE:
1200 		case IP_MSFILTER:
1201 		case MCAST_JOIN_GROUP:
1202 		case MCAST_LEAVE_GROUP:
1203 		case MCAST_JOIN_SOURCE_GROUP:
1204 		case MCAST_LEAVE_SOURCE_GROUP:
1205 		case MCAST_BLOCK_SOURCE:
1206 		case MCAST_UNBLOCK_SOURCE:
1207 			error = inp_setmoptions(inp, sopt);
1208 			break;
1209 
1210 		case IP_PORTRANGE:
1211 			error = sooptcopyin(sopt, &optval, sizeof optval,
1212 					    sizeof optval);
1213 			if (error)
1214 				break;
1215 
1216 			INP_WLOCK(inp);
1217 			switch (optval) {
1218 			case IP_PORTRANGE_DEFAULT:
1219 				inp->inp_flags &= ~(INP_LOWPORT);
1220 				inp->inp_flags &= ~(INP_HIGHPORT);
1221 				break;
1222 
1223 			case IP_PORTRANGE_HIGH:
1224 				inp->inp_flags &= ~(INP_LOWPORT);
1225 				inp->inp_flags |= INP_HIGHPORT;
1226 				break;
1227 
1228 			case IP_PORTRANGE_LOW:
1229 				inp->inp_flags &= ~(INP_HIGHPORT);
1230 				inp->inp_flags |= INP_LOWPORT;
1231 				break;
1232 
1233 			default:
1234 				error = EINVAL;
1235 				break;
1236 			}
1237 			INP_WUNLOCK(inp);
1238 			break;
1239 
1240 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1241 		case IP_IPSEC_POLICY:
1242 			if (IPSEC_ENABLED(ipv4)) {
1243 				error = IPSEC_PCBCTL(ipv4, inp, sopt);
1244 				break;
1245 			}
1246 			/* FALLTHROUGH */
1247 #endif /* IPSEC */
1248 
1249 		default:
1250 			error = ENOPROTOOPT;
1251 			break;
1252 		}
1253 		break;
1254 
1255 	case SOPT_GET:
1256 		switch (sopt->sopt_name) {
1257 		case IP_OPTIONS:
1258 		case IP_RETOPTS:
1259 			INP_RLOCK(inp);
1260 			if (inp->inp_options) {
1261 				struct mbuf *options;
1262 
1263 				options = m_dup(inp->inp_options, M_NOWAIT);
1264 				INP_RUNLOCK(inp);
1265 				if (options != NULL) {
1266 					error = sooptcopyout(sopt,
1267 							     mtod(options, char *),
1268 							     options->m_len);
1269 					m_freem(options);
1270 				} else
1271 					error = ENOMEM;
1272 			} else {
1273 				INP_RUNLOCK(inp);
1274 				sopt->sopt_valsize = 0;
1275 			}
1276 			break;
1277 
1278 		case IP_TOS:
1279 		case IP_TTL:
1280 		case IP_MINTTL:
1281 		case IP_RECVOPTS:
1282 		case IP_RECVRETOPTS:
1283 		case IP_ORIGDSTADDR:
1284 		case IP_RECVDSTADDR:
1285 		case IP_RECVTTL:
1286 		case IP_RECVIF:
1287 		case IP_PORTRANGE:
1288 		case IP_ONESBCAST:
1289 		case IP_DONTFRAG:
1290 		case IP_BINDANY:
1291 		case IP_RECVTOS:
1292 		case IP_BINDMULTI:
1293 		case IP_FLOWID:
1294 		case IP_FLOWTYPE:
1295 		case IP_RECVFLOWID:
1296 #ifdef	RSS
1297 		case IP_RSSBUCKETID:
1298 		case IP_RECVRSSBUCKETID:
1299 #endif
1300 			switch (sopt->sopt_name) {
1301 
1302 			case IP_TOS:
1303 				optval = inp->inp_ip_tos;
1304 				break;
1305 
1306 			case IP_TTL:
1307 				optval = inp->inp_ip_ttl;
1308 				break;
1309 
1310 			case IP_MINTTL:
1311 				optval = inp->inp_ip_minttl;
1312 				break;
1313 
1314 #define	OPTBIT(bit)	(inp->inp_flags & bit ? 1 : 0)
1315 #define	OPTBIT2(bit)	(inp->inp_flags2 & bit ? 1 : 0)
1316 
1317 			case IP_RECVOPTS:
1318 				optval = OPTBIT(INP_RECVOPTS);
1319 				break;
1320 
1321 			case IP_RECVRETOPTS:
1322 				optval = OPTBIT(INP_RECVRETOPTS);
1323 				break;
1324 
1325 			case IP_RECVDSTADDR:
1326 				optval = OPTBIT(INP_RECVDSTADDR);
1327 				break;
1328 
1329 			case IP_ORIGDSTADDR:
1330 				optval = OPTBIT2(INP_ORIGDSTADDR);
1331 				break;
1332 
1333 			case IP_RECVTTL:
1334 				optval = OPTBIT(INP_RECVTTL);
1335 				break;
1336 
1337 			case IP_RECVIF:
1338 				optval = OPTBIT(INP_RECVIF);
1339 				break;
1340 
1341 			case IP_PORTRANGE:
1342 				if (inp->inp_flags & INP_HIGHPORT)
1343 					optval = IP_PORTRANGE_HIGH;
1344 				else if (inp->inp_flags & INP_LOWPORT)
1345 					optval = IP_PORTRANGE_LOW;
1346 				else
1347 					optval = 0;
1348 				break;
1349 
1350 			case IP_ONESBCAST:
1351 				optval = OPTBIT(INP_ONESBCAST);
1352 				break;
1353 			case IP_DONTFRAG:
1354 				optval = OPTBIT(INP_DONTFRAG);
1355 				break;
1356 			case IP_BINDANY:
1357 				optval = OPTBIT(INP_BINDANY);
1358 				break;
1359 			case IP_RECVTOS:
1360 				optval = OPTBIT(INP_RECVTOS);
1361 				break;
1362 			case IP_FLOWID:
1363 				optval = inp->inp_flowid;
1364 				break;
1365 			case IP_FLOWTYPE:
1366 				optval = inp->inp_flowtype;
1367 				break;
1368 			case IP_RECVFLOWID:
1369 				optval = OPTBIT2(INP_RECVFLOWID);
1370 				break;
1371 #ifdef	RSS
1372 			case IP_RSSBUCKETID:
1373 				retval = rss_hash2bucket(inp->inp_flowid,
1374 				    inp->inp_flowtype,
1375 				    &rss_bucket);
1376 				if (retval == 0)
1377 					optval = rss_bucket;
1378 				else
1379 					error = EINVAL;
1380 				break;
1381 			case IP_RECVRSSBUCKETID:
1382 				optval = OPTBIT2(INP_RECVRSSBUCKETID);
1383 				break;
1384 #endif
1385 			case IP_BINDMULTI:
1386 				optval = OPTBIT2(INP_BINDMULTI);
1387 				break;
1388 			}
1389 			error = sooptcopyout(sopt, &optval, sizeof optval);
1390 			break;
1391 
1392 		/*
1393 		 * Multicast socket options are processed by the in_mcast
1394 		 * module.
1395 		 */
1396 		case IP_MULTICAST_IF:
1397 		case IP_MULTICAST_VIF:
1398 		case IP_MULTICAST_TTL:
1399 		case IP_MULTICAST_LOOP:
1400 		case IP_MSFILTER:
1401 			error = inp_getmoptions(inp, sopt);
1402 			break;
1403 
1404 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1405 		case IP_IPSEC_POLICY:
1406 			if (IPSEC_ENABLED(ipv4)) {
1407 				error = IPSEC_PCBCTL(ipv4, inp, sopt);
1408 				break;
1409 			}
1410 			/* FALLTHROUGH */
1411 #endif /* IPSEC */
1412 
1413 		default:
1414 			error = ENOPROTOOPT;
1415 			break;
1416 		}
1417 		break;
1418 	}
1419 	return (error);
1420 }
1421 
1422 /*
1423  * Routine called from ip_output() to loop back a copy of an IP multicast
1424  * packet to the input queue of a specified interface.  Note that this
1425  * calls the output routine of the loopback "driver", but with an interface
1426  * pointer that might NOT be a loopback interface -- evil, but easier than
1427  * replicating that code here.
1428  */
1429 static void
1430 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1431 {
1432 	struct ip *ip;
1433 	struct mbuf *copym;
1434 
1435 	/*
1436 	 * Make a deep copy of the packet because we're going to
1437 	 * modify the pack in order to generate checksums.
1438 	 */
1439 	copym = m_dup(m, M_NOWAIT);
1440 	if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1441 		copym = m_pullup(copym, hlen);
1442 	if (copym != NULL) {
1443 		/* If needed, compute the checksum and mark it as valid. */
1444 		if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1445 			in_delayed_cksum(copym);
1446 			copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1447 			copym->m_pkthdr.csum_flags |=
1448 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1449 			copym->m_pkthdr.csum_data = 0xffff;
1450 		}
1451 		/*
1452 		 * We don't bother to fragment if the IP length is greater
1453 		 * than the interface's MTU.  Can this possibly matter?
1454 		 */
1455 		ip = mtod(copym, struct ip *);
1456 		ip->ip_sum = 0;
1457 		ip->ip_sum = in_cksum(copym, hlen);
1458 		if_simloop(ifp, copym, AF_INET, 0);
1459 	}
1460 }
1461