xref: /freebsd/sys/netinet/ip_output.c (revision e08e9e999091f86081377b7cedc3fd2fe2ab70fc)
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 #ifdef SCTP
84 #include <netinet/sctp.h>
85 #include <netinet/sctp_crc32.h>
86 #endif
87 
88 #include <netipsec/ipsec_support.h>
89 
90 #include <machine/in_cksum.h>
91 
92 #include <security/mac/mac_framework.h>
93 
94 #ifdef MBUF_STRESS_TEST
95 static int mbuf_frag_size = 0;
96 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
97 	&mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
98 #endif
99 
100 static void	ip_mloopback(struct ifnet *, const struct mbuf *, int);
101 
102 
103 extern int in_mcast_loop;
104 extern	struct protosw inetsw[];
105 
106 static inline int
107 ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, struct inpcb *inp,
108     struct sockaddr_in *dst, int *fibnum, int *error)
109 {
110 	struct m_tag *fwd_tag = NULL;
111 	struct mbuf *m;
112 	struct in_addr odst;
113 	struct ip *ip;
114 
115 	m = *mp;
116 	ip = mtod(m, struct ip *);
117 
118 	/* Run through list of hooks for output packets. */
119 	odst.s_addr = ip->ip_dst.s_addr;
120 	*error = pfil_run_hooks(&V_inet_pfil_hook, mp, ifp, PFIL_OUT, 0, inp);
121 	m = *mp;
122 	if ((*error) != 0 || m == NULL)
123 		return 1; /* Finished */
124 
125 	ip = mtod(m, struct ip *);
126 
127 	/* See if destination IP address was changed by packet filter. */
128 	if (odst.s_addr != ip->ip_dst.s_addr) {
129 		m->m_flags |= M_SKIP_FIREWALL;
130 		/* If destination is now ourself drop to ip_input(). */
131 		if (in_localip(ip->ip_dst)) {
132 			m->m_flags |= M_FASTFWD_OURS;
133 			if (m->m_pkthdr.rcvif == NULL)
134 				m->m_pkthdr.rcvif = V_loif;
135 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
136 				m->m_pkthdr.csum_flags |=
137 					CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
138 				m->m_pkthdr.csum_data = 0xffff;
139 			}
140 			m->m_pkthdr.csum_flags |=
141 				CSUM_IP_CHECKED | CSUM_IP_VALID;
142 #ifdef SCTP
143 			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
144 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
145 #endif
146 			*error = netisr_queue(NETISR_IP, m);
147 			return 1; /* Finished */
148 		}
149 
150 		bzero(dst, sizeof(*dst));
151 		dst->sin_family = AF_INET;
152 		dst->sin_len = sizeof(*dst);
153 		dst->sin_addr = ip->ip_dst;
154 
155 		return -1; /* Reloop */
156 	}
157 	/* See if fib was changed by packet filter. */
158 	if ((*fibnum) != M_GETFIB(m)) {
159 		m->m_flags |= M_SKIP_FIREWALL;
160 		*fibnum = M_GETFIB(m);
161 		return -1; /* Reloop for FIB change */
162 	}
163 
164 	/* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
165 	if (m->m_flags & M_FASTFWD_OURS) {
166 		if (m->m_pkthdr.rcvif == NULL)
167 			m->m_pkthdr.rcvif = V_loif;
168 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
169 			m->m_pkthdr.csum_flags |=
170 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
171 			m->m_pkthdr.csum_data = 0xffff;
172 		}
173 #ifdef SCTP
174 		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
175 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
176 #endif
177 		m->m_pkthdr.csum_flags |=
178 			CSUM_IP_CHECKED | CSUM_IP_VALID;
179 
180 		*error = netisr_queue(NETISR_IP, m);
181 		return 1; /* Finished */
182 	}
183 	/* Or forward to some other address? */
184 	if ((m->m_flags & M_IP_NEXTHOP) &&
185 	    ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
186 		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
187 		m->m_flags |= M_SKIP_FIREWALL;
188 		m->m_flags &= ~M_IP_NEXTHOP;
189 		m_tag_delete(m, fwd_tag);
190 
191 		return -1; /* Reloop for CHANGE of dst */
192 	}
193 
194 	return 0;
195 }
196 
197 /*
198  * IP output.  The packet in mbuf chain m contains a skeletal IP
199  * header (with len, off, ttl, proto, tos, src, dst).
200  * The mbuf chain containing the packet will be freed.
201  * The mbuf opt, if present, will not be freed.
202  * If route ro is present and has ro_rt initialized, route lookup would be
203  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
204  * then result of route lookup is stored in ro->ro_rt.
205  *
206  * In the IP forwarding case, the packet will arrive with options already
207  * inserted, so must have a NULL opt pointer.
208  */
209 int
210 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
211     struct ip_moptions *imo, struct inpcb *inp)
212 {
213 	struct rm_priotracker in_ifa_tracker;
214 	struct ip *ip;
215 	struct ifnet *ifp = NULL;	/* keep compiler happy */
216 	struct mbuf *m0;
217 	int hlen = sizeof (struct ip);
218 	int mtu;
219 	int error = 0;
220 	struct sockaddr_in *dst;
221 	const struct sockaddr_in *gw;
222 	struct in_ifaddr *ia;
223 	int isbroadcast;
224 	uint16_t ip_len, ip_off;
225 	struct route iproute;
226 	struct rtentry *rte;	/* cache for ro->ro_rt */
227 	uint32_t fibnum;
228 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
229 	int no_route_but_check_spd = 0;
230 #endif
231 	M_ASSERTPKTHDR(m);
232 
233 	if (inp != NULL) {
234 		INP_LOCK_ASSERT(inp);
235 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
236 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
237 			m->m_pkthdr.flowid = inp->inp_flowid;
238 			M_HASHTYPE_SET(m, inp->inp_flowtype);
239 		}
240 	}
241 
242 	if (ro == NULL) {
243 		ro = &iproute;
244 		bzero(ro, sizeof (*ro));
245 	}
246 
247 	if (opt) {
248 		int len = 0;
249 		m = ip_insertoptions(m, opt, &len);
250 		if (len != 0)
251 			hlen = len; /* ip->ip_hl is updated above */
252 	}
253 	ip = mtod(m, struct ip *);
254 	ip_len = ntohs(ip->ip_len);
255 	ip_off = ntohs(ip->ip_off);
256 
257 	if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
258 		ip->ip_v = IPVERSION;
259 		ip->ip_hl = hlen >> 2;
260 		ip_fillid(ip);
261 		IPSTAT_INC(ips_localout);
262 	} else {
263 		/* Header already set, fetch hlen from there */
264 		hlen = ip->ip_hl << 2;
265 	}
266 
267 	/*
268 	 * dst/gw handling:
269 	 *
270 	 * dst can be rewritten but always points to &ro->ro_dst.
271 	 * gw is readonly but can point either to dst OR rt_gateway,
272 	 * therefore we need restore gw if we're redoing lookup.
273 	 */
274 	gw = dst = (struct sockaddr_in *)&ro->ro_dst;
275 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
276 	rte = ro->ro_rt;
277 	if (rte == NULL) {
278 		bzero(dst, sizeof(*dst));
279 		dst->sin_family = AF_INET;
280 		dst->sin_len = sizeof(*dst);
281 		dst->sin_addr = ip->ip_dst;
282 	}
283 	NET_EPOCH_ENTER();
284 again:
285 	/*
286 	 * Validate route against routing table additions;
287 	 * a better/more specific route might have been added.
288 	 */
289 	if (inp)
290 		RT_VALIDATE(ro, &inp->inp_rt_cookie, fibnum);
291 	/*
292 	 * If there is a cached route,
293 	 * check that it is to the same destination
294 	 * and is still up.  If not, free it and try again.
295 	 * The address family should also be checked in case of sharing the
296 	 * cache with IPv6.
297 	 * Also check whether routing cache needs invalidation.
298 	 */
299 	rte = ro->ro_rt;
300 	if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
301 		    rte->rt_ifp == NULL ||
302 		    !RT_LINK_IS_UP(rte->rt_ifp) ||
303 			  dst->sin_family != AF_INET ||
304 			  dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
305 		RO_INVALIDATE_CACHE(ro);
306 		rte = NULL;
307 	}
308 	ia = NULL;
309 	/*
310 	 * If routing to interface only, short circuit routing lookup.
311 	 * The use of an all-ones broadcast address implies this; an
312 	 * interface is specified by the broadcast address of an interface,
313 	 * or the destination address of a ptp interface.
314 	 */
315 	if (flags & IP_SENDONES) {
316 		if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
317 						      M_GETFIB(m)))) == NULL &&
318 		    (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
319 						    M_GETFIB(m)))) == NULL) {
320 			IPSTAT_INC(ips_noroute);
321 			error = ENETUNREACH;
322 			goto bad;
323 		}
324 		ip->ip_dst.s_addr = INADDR_BROADCAST;
325 		dst->sin_addr = ip->ip_dst;
326 		ifp = ia->ia_ifp;
327 		ip->ip_ttl = 1;
328 		isbroadcast = 1;
329 	} else if (flags & IP_ROUTETOIF) {
330 		if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
331 						    M_GETFIB(m)))) == NULL &&
332 		    (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
333 						M_GETFIB(m)))) == NULL) {
334 			IPSTAT_INC(ips_noroute);
335 			error = ENETUNREACH;
336 			goto bad;
337 		}
338 		ifp = ia->ia_ifp;
339 		ip->ip_ttl = 1;
340 		isbroadcast = ifp->if_flags & IFF_BROADCAST ?
341 		    in_ifaddr_broadcast(dst->sin_addr, ia) : 0;
342 	} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
343 	    imo != NULL && imo->imo_multicast_ifp != NULL) {
344 		/*
345 		 * Bypass the normal routing lookup for multicast
346 		 * packets if the interface is specified.
347 		 */
348 		ifp = imo->imo_multicast_ifp;
349 		IFP_TO_IA(ifp, ia, &in_ifa_tracker);
350 		isbroadcast = 0;	/* fool gcc */
351 	} else {
352 		/*
353 		 * We want to do any cloning requested by the link layer,
354 		 * as this is probably required in all cases for correct
355 		 * operation (as it is for ARP).
356 		 */
357 		if (rte == NULL) {
358 #ifdef RADIX_MPATH
359 			rtalloc_mpath_fib(ro,
360 			    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
361 			    fibnum);
362 #else
363 			in_rtalloc_ign(ro, 0, fibnum);
364 #endif
365 			rte = ro->ro_rt;
366 		}
367 		if (rte == NULL ||
368 		    (rte->rt_flags & RTF_UP) == 0 ||
369 		    rte->rt_ifp == NULL ||
370 		    !RT_LINK_IS_UP(rte->rt_ifp)) {
371 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
372 			/*
373 			 * There is no route for this packet, but it is
374 			 * possible that a matching SPD entry exists.
375 			 */
376 			no_route_but_check_spd = 1;
377 			mtu = 0; /* Silence GCC warning. */
378 			goto sendit;
379 #endif
380 			IPSTAT_INC(ips_noroute);
381 			error = EHOSTUNREACH;
382 			goto bad;
383 		}
384 		ia = ifatoia(rte->rt_ifa);
385 		ifp = rte->rt_ifp;
386 		counter_u64_add(rte->rt_pksent, 1);
387 		rt_update_ro_flags(ro);
388 		if (rte->rt_flags & RTF_GATEWAY)
389 			gw = (struct sockaddr_in *)rte->rt_gateway;
390 		if (rte->rt_flags & RTF_HOST)
391 			isbroadcast = (rte->rt_flags & RTF_BROADCAST);
392 		else if (ifp->if_flags & IFF_BROADCAST)
393 			isbroadcast = in_ifaddr_broadcast(gw->sin_addr, ia);
394 		else
395 			isbroadcast = 0;
396 	}
397 
398 	/*
399 	 * Calculate MTU.  If we have a route that is up, use that,
400 	 * otherwise use the interface's MTU.
401 	 */
402 	if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST)))
403 		mtu = rte->rt_mtu;
404 	else
405 		mtu = ifp->if_mtu;
406 	/* Catch a possible divide by zero later. */
407 	KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
408 	    __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
409 
410 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
411 		m->m_flags |= M_MCAST;
412 		/*
413 		 * IP destination address is multicast.  Make sure "gw"
414 		 * still points to the address in "ro".  (It may have been
415 		 * changed to point to a gateway address, above.)
416 		 */
417 		gw = dst;
418 		/*
419 		 * See if the caller provided any multicast options
420 		 */
421 		if (imo != NULL) {
422 			ip->ip_ttl = imo->imo_multicast_ttl;
423 			if (imo->imo_multicast_vif != -1)
424 				ip->ip_src.s_addr =
425 				    ip_mcast_src ?
426 				    ip_mcast_src(imo->imo_multicast_vif) :
427 				    INADDR_ANY;
428 		} else
429 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
430 		/*
431 		 * Confirm that the outgoing interface supports multicast.
432 		 */
433 		if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
434 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
435 				IPSTAT_INC(ips_noroute);
436 				error = ENETUNREACH;
437 				goto bad;
438 			}
439 		}
440 		/*
441 		 * If source address not specified yet, use address
442 		 * of outgoing interface.
443 		 */
444 		if (ip->ip_src.s_addr == INADDR_ANY) {
445 			/* Interface may have no addresses. */
446 			if (ia != NULL)
447 				ip->ip_src = IA_SIN(ia)->sin_addr;
448 		}
449 
450 		if ((imo == NULL && in_mcast_loop) ||
451 		    (imo && imo->imo_multicast_loop)) {
452 			/*
453 			 * Loop back multicast datagram if not expressly
454 			 * forbidden to do so, even if we are not a member
455 			 * of the group; ip_input() will filter it later,
456 			 * thus deferring a hash lookup and mutex acquisition
457 			 * at the expense of a cheap copy using m_copym().
458 			 */
459 			ip_mloopback(ifp, m, hlen);
460 		} else {
461 			/*
462 			 * If we are acting as a multicast router, perform
463 			 * multicast forwarding as if the packet had just
464 			 * arrived on the interface to which we are about
465 			 * to send.  The multicast forwarding function
466 			 * recursively calls this function, using the
467 			 * IP_FORWARDING flag to prevent infinite recursion.
468 			 *
469 			 * Multicasts that are looped back by ip_mloopback(),
470 			 * above, will be forwarded by the ip_input() routine,
471 			 * if necessary.
472 			 */
473 			if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
474 				/*
475 				 * If rsvp daemon is not running, do not
476 				 * set ip_moptions. This ensures that the packet
477 				 * is multicast and not just sent down one link
478 				 * as prescribed by rsvpd.
479 				 */
480 				if (!V_rsvp_on)
481 					imo = NULL;
482 				if (ip_mforward &&
483 				    ip_mforward(ip, ifp, m, imo) != 0) {
484 					m_freem(m);
485 					goto done;
486 				}
487 			}
488 		}
489 
490 		/*
491 		 * Multicasts with a time-to-live of zero may be looped-
492 		 * back, above, but must not be transmitted on a network.
493 		 * Also, multicasts addressed to the loopback interface
494 		 * are not sent -- the above call to ip_mloopback() will
495 		 * loop back a copy. ip_input() will drop the copy if
496 		 * this host does not belong to the destination group on
497 		 * the loopback interface.
498 		 */
499 		if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
500 			m_freem(m);
501 			goto done;
502 		}
503 
504 		goto sendit;
505 	}
506 
507 	/*
508 	 * If the source address is not specified yet, use the address
509 	 * of the outoing interface.
510 	 */
511 	if (ip->ip_src.s_addr == INADDR_ANY) {
512 		/* Interface may have no addresses. */
513 		if (ia != NULL) {
514 			ip->ip_src = IA_SIN(ia)->sin_addr;
515 		}
516 	}
517 
518 	/*
519 	 * Look for broadcast address and
520 	 * verify user is allowed to send
521 	 * such a packet.
522 	 */
523 	if (isbroadcast) {
524 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
525 			error = EADDRNOTAVAIL;
526 			goto bad;
527 		}
528 		if ((flags & IP_ALLOWBROADCAST) == 0) {
529 			error = EACCES;
530 			goto bad;
531 		}
532 		/* don't allow broadcast messages to be fragmented */
533 		if (ip_len > mtu) {
534 			error = EMSGSIZE;
535 			goto bad;
536 		}
537 		m->m_flags |= M_BCAST;
538 	} else {
539 		m->m_flags &= ~M_BCAST;
540 	}
541 
542 sendit:
543 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
544 	if (IPSEC_ENABLED(ipv4)) {
545 		if ((error = IPSEC_OUTPUT(ipv4, m, inp)) != 0) {
546 			if (error == EINPROGRESS)
547 				error = 0;
548 			goto done;
549 		}
550 	}
551 	/*
552 	 * Check if there was a route for this packet; return error if not.
553 	 */
554 	if (no_route_but_check_spd) {
555 		IPSTAT_INC(ips_noroute);
556 		error = EHOSTUNREACH;
557 		goto bad;
558 	}
559 	/* Update variables that are affected by ipsec4_output(). */
560 	ip = mtod(m, struct ip *);
561 	hlen = ip->ip_hl << 2;
562 #endif /* IPSEC */
563 
564 	/* Jump over all PFIL processing if hooks are not active. */
565 	if (PFIL_HOOKED(&V_inet_pfil_hook)) {
566 		switch (ip_output_pfil(&m, ifp, inp, dst, &fibnum, &error)) {
567 		case 1: /* Finished */
568 			goto done;
569 
570 		case 0: /* Continue normally */
571 			ip = mtod(m, struct ip *);
572 			break;
573 
574 		case -1: /* Need to try again */
575 			/* Reset everything for a new round */
576 			RO_RTFREE(ro);
577 			ro->ro_prepend = NULL;
578 			rte = NULL;
579 			gw = dst;
580 			ip = mtod(m, struct ip *);
581 			goto again;
582 
583 		}
584 	}
585 
586 	/* 127/8 must not appear on wire - RFC1122. */
587 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
588 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
589 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
590 			IPSTAT_INC(ips_badaddr);
591 			error = EADDRNOTAVAIL;
592 			goto bad;
593 		}
594 	}
595 
596 	m->m_pkthdr.csum_flags |= CSUM_IP;
597 	if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
598 		in_delayed_cksum(m);
599 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
600 	}
601 #ifdef SCTP
602 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
603 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
604 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
605 	}
606 #endif
607 
608 	/*
609 	 * If small enough for interface, or the interface will take
610 	 * care of the fragmentation for us, we can just send directly.
611 	 */
612 	if (ip_len <= mtu ||
613 	    (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) {
614 		ip->ip_sum = 0;
615 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
616 			ip->ip_sum = in_cksum(m, hlen);
617 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
618 		}
619 
620 		/*
621 		 * Record statistics for this interface address.
622 		 * With CSUM_TSO the byte/packet count will be slightly
623 		 * incorrect because we count the IP+TCP headers only
624 		 * once instead of for every generated packet.
625 		 */
626 		if (!(flags & IP_FORWARDING) && ia) {
627 			if (m->m_pkthdr.csum_flags & CSUM_TSO)
628 				counter_u64_add(ia->ia_ifa.ifa_opackets,
629 				    m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
630 			else
631 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
632 
633 			counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
634 		}
635 #ifdef MBUF_STRESS_TEST
636 		if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
637 			m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
638 #endif
639 		/*
640 		 * Reset layer specific mbuf flags
641 		 * to avoid confusing lower layers.
642 		 */
643 		m_clrprotoflags(m);
644 		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
645 #ifdef RATELIMIT
646 		if (inp != NULL) {
647 			if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
648 				in_pcboutput_txrtlmt(inp, ifp, m);
649 			/* stamp send tag on mbuf */
650 			m->m_pkthdr.snd_tag = inp->inp_snd_tag;
651 		} else {
652 			m->m_pkthdr.snd_tag = NULL;
653 		}
654 #endif
655 		error = (*ifp->if_output)(ifp, m,
656 		    (const struct sockaddr *)gw, ro);
657 #ifdef RATELIMIT
658 		/* check for route change */
659 		if (error == EAGAIN)
660 			in_pcboutput_eagain(inp);
661 #endif
662 		goto done;
663 	}
664 
665 	/* Balk when DF bit is set or the interface didn't support TSO. */
666 	if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
667 		error = EMSGSIZE;
668 		IPSTAT_INC(ips_cantfrag);
669 		goto bad;
670 	}
671 
672 	/*
673 	 * Too large for interface; fragment if possible. If successful,
674 	 * on return, m will point to a list of packets to be sent.
675 	 */
676 	error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
677 	if (error)
678 		goto bad;
679 	for (; m; m = m0) {
680 		m0 = m->m_nextpkt;
681 		m->m_nextpkt = 0;
682 		if (error == 0) {
683 			/* Record statistics for this interface address. */
684 			if (ia != NULL) {
685 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
686 				counter_u64_add(ia->ia_ifa.ifa_obytes,
687 				    m->m_pkthdr.len);
688 			}
689 			/*
690 			 * Reset layer specific mbuf flags
691 			 * to avoid confusing upper layers.
692 			 */
693 			m_clrprotoflags(m);
694 
695 			IP_PROBE(send, NULL, NULL, mtod(m, struct ip *), ifp,
696 			    mtod(m, struct ip *), NULL);
697 #ifdef RATELIMIT
698 			if (inp != NULL) {
699 				if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
700 					in_pcboutput_txrtlmt(inp, ifp, m);
701 				/* stamp send tag on mbuf */
702 				m->m_pkthdr.snd_tag = inp->inp_snd_tag;
703 			} else {
704 				m->m_pkthdr.snd_tag = NULL;
705 			}
706 #endif
707 			error = (*ifp->if_output)(ifp, m,
708 			    (const struct sockaddr *)gw, ro);
709 #ifdef RATELIMIT
710 			/* check for route change */
711 			if (error == EAGAIN)
712 				in_pcboutput_eagain(inp);
713 #endif
714 		} else
715 			m_freem(m);
716 	}
717 
718 	if (error == 0)
719 		IPSTAT_INC(ips_fragmented);
720 
721 done:
722 	if (ro == &iproute)
723 		RO_RTFREE(ro);
724 	else if (rte == NULL)
725 		/*
726 		 * If the caller supplied a route but somehow the reference
727 		 * to it has been released need to prevent the caller
728 		 * calling RTFREE on it again.
729 		 */
730 		ro->ro_rt = NULL;
731 	NET_EPOCH_EXIT();
732 	return (error);
733  bad:
734 	m_freem(m);
735 	goto done;
736 }
737 
738 /*
739  * Create a chain of fragments which fit the given mtu. m_frag points to the
740  * mbuf to be fragmented; on return it points to the chain with the fragments.
741  * Return 0 if no error. If error, m_frag may contain a partially built
742  * chain of fragments that should be freed by the caller.
743  *
744  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
745  */
746 int
747 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
748     u_long if_hwassist_flags)
749 {
750 	int error = 0;
751 	int hlen = ip->ip_hl << 2;
752 	int len = (mtu - hlen) & ~7;	/* size of payload in each fragment */
753 	int off;
754 	struct mbuf *m0 = *m_frag;	/* the original packet		*/
755 	int firstlen;
756 	struct mbuf **mnext;
757 	int nfrags;
758 	uint16_t ip_len, ip_off;
759 
760 	ip_len = ntohs(ip->ip_len);
761 	ip_off = ntohs(ip->ip_off);
762 
763 	if (ip_off & IP_DF) {	/* Fragmentation not allowed */
764 		IPSTAT_INC(ips_cantfrag);
765 		return EMSGSIZE;
766 	}
767 
768 	/*
769 	 * Must be able to put at least 8 bytes per fragment.
770 	 */
771 	if (len < 8)
772 		return EMSGSIZE;
773 
774 	/*
775 	 * If the interface will not calculate checksums on
776 	 * fragmented packets, then do it here.
777 	 */
778 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
779 		in_delayed_cksum(m0);
780 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
781 	}
782 #ifdef SCTP
783 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
784 		sctp_delayed_cksum(m0, hlen);
785 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
786 	}
787 #endif
788 	if (len > PAGE_SIZE) {
789 		/*
790 		 * Fragment large datagrams such that each segment
791 		 * contains a multiple of PAGE_SIZE amount of data,
792 		 * plus headers. This enables a receiver to perform
793 		 * page-flipping zero-copy optimizations.
794 		 *
795 		 * XXX When does this help given that sender and receiver
796 		 * could have different page sizes, and also mtu could
797 		 * be less than the receiver's page size ?
798 		 */
799 		int newlen;
800 
801 		off = MIN(mtu, m0->m_pkthdr.len);
802 
803 		/*
804 		 * firstlen (off - hlen) must be aligned on an
805 		 * 8-byte boundary
806 		 */
807 		if (off < hlen)
808 			goto smart_frag_failure;
809 		off = ((off - hlen) & ~7) + hlen;
810 		newlen = (~PAGE_MASK) & mtu;
811 		if ((newlen + sizeof (struct ip)) > mtu) {
812 			/* we failed, go back the default */
813 smart_frag_failure:
814 			newlen = len;
815 			off = hlen + len;
816 		}
817 		len = newlen;
818 
819 	} else {
820 		off = hlen + len;
821 	}
822 
823 	firstlen = off - hlen;
824 	mnext = &m0->m_nextpkt;		/* pointer to next packet */
825 
826 	/*
827 	 * Loop through length of segment after first fragment,
828 	 * make new header and copy data of each part and link onto chain.
829 	 * Here, m0 is the original packet, m is the fragment being created.
830 	 * The fragments are linked off the m_nextpkt of the original
831 	 * packet, which after processing serves as the first fragment.
832 	 */
833 	for (nfrags = 1; off < ip_len; off += len, nfrags++) {
834 		struct ip *mhip;	/* ip header on the fragment */
835 		struct mbuf *m;
836 		int mhlen = sizeof (struct ip);
837 
838 		m = m_gethdr(M_NOWAIT, MT_DATA);
839 		if (m == NULL) {
840 			error = ENOBUFS;
841 			IPSTAT_INC(ips_odropped);
842 			goto done;
843 		}
844 		/*
845 		 * Make sure the complete packet header gets copied
846 		 * from the originating mbuf to the newly created
847 		 * mbuf. This also ensures that existing firewall
848 		 * classification(s), VLAN tags and so on get copied
849 		 * to the resulting fragmented packet(s):
850 		 */
851 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
852 			m_free(m);
853 			error = ENOBUFS;
854 			IPSTAT_INC(ips_odropped);
855 			goto done;
856 		}
857 		/*
858 		 * In the first mbuf, leave room for the link header, then
859 		 * copy the original IP header including options. The payload
860 		 * goes into an additional mbuf chain returned by m_copym().
861 		 */
862 		m->m_data += max_linkhdr;
863 		mhip = mtod(m, struct ip *);
864 		*mhip = *ip;
865 		if (hlen > sizeof (struct ip)) {
866 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
867 			mhip->ip_v = IPVERSION;
868 			mhip->ip_hl = mhlen >> 2;
869 		}
870 		m->m_len = mhlen;
871 		/* XXX do we need to add ip_off below ? */
872 		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
873 		if (off + len >= ip_len)
874 			len = ip_len - off;
875 		else
876 			mhip->ip_off |= IP_MF;
877 		mhip->ip_len = htons((u_short)(len + mhlen));
878 		m->m_next = m_copym(m0, off, len, M_NOWAIT);
879 		if (m->m_next == NULL) {	/* copy failed */
880 			m_free(m);
881 			error = ENOBUFS;	/* ??? */
882 			IPSTAT_INC(ips_odropped);
883 			goto done;
884 		}
885 		m->m_pkthdr.len = mhlen + len;
886 #ifdef MAC
887 		mac_netinet_fragment(m0, m);
888 #endif
889 		mhip->ip_off = htons(mhip->ip_off);
890 		mhip->ip_sum = 0;
891 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
892 			mhip->ip_sum = in_cksum(m, mhlen);
893 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
894 		}
895 		*mnext = m;
896 		mnext = &m->m_nextpkt;
897 	}
898 	IPSTAT_ADD(ips_ofragments, nfrags);
899 
900 	/*
901 	 * Update first fragment by trimming what's been copied out
902 	 * and updating header.
903 	 */
904 	m_adj(m0, hlen + firstlen - ip_len);
905 	m0->m_pkthdr.len = hlen + firstlen;
906 	ip->ip_len = htons((u_short)m0->m_pkthdr.len);
907 	ip->ip_off = htons(ip_off | IP_MF);
908 	ip->ip_sum = 0;
909 	if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
910 		ip->ip_sum = in_cksum(m0, hlen);
911 		m0->m_pkthdr.csum_flags &= ~CSUM_IP;
912 	}
913 
914 done:
915 	*m_frag = m0;
916 	return error;
917 }
918 
919 void
920 in_delayed_cksum(struct mbuf *m)
921 {
922 	struct ip *ip;
923 	uint16_t csum, offset, ip_len;
924 
925 	ip = mtod(m, struct ip *);
926 	offset = ip->ip_hl << 2 ;
927 	ip_len = ntohs(ip->ip_len);
928 	csum = in_cksum_skip(m, ip_len, offset);
929 	if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
930 		csum = 0xffff;
931 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
932 
933 	/* find the mbuf in the chain where the checksum starts*/
934 	while ((m != NULL) && (offset >= m->m_len)) {
935 		offset -= m->m_len;
936 		m = m->m_next;
937 	}
938 	KASSERT(m != NULL, ("in_delayed_cksum: checksum outside mbuf chain."));
939 	KASSERT(offset + sizeof(u_short) <= m->m_len, ("in_delayed_cksum: checksum split between mbufs."));
940 	*(u_short *)(m->m_data + offset) = csum;
941 }
942 
943 /*
944  * IP socket option processing.
945  */
946 int
947 ip_ctloutput(struct socket *so, struct sockopt *sopt)
948 {
949 	struct	inpcb *inp = sotoinpcb(so);
950 	int	error, optval;
951 #ifdef	RSS
952 	uint32_t rss_bucket;
953 	int retval;
954 #endif
955 
956 	error = optval = 0;
957 	if (sopt->sopt_level != IPPROTO_IP) {
958 		error = EINVAL;
959 
960 		if (sopt->sopt_level == SOL_SOCKET &&
961 		    sopt->sopt_dir == SOPT_SET) {
962 			switch (sopt->sopt_name) {
963 			case SO_REUSEADDR:
964 				INP_WLOCK(inp);
965 				if ((so->so_options & SO_REUSEADDR) != 0)
966 					inp->inp_flags2 |= INP_REUSEADDR;
967 				else
968 					inp->inp_flags2 &= ~INP_REUSEADDR;
969 				INP_WUNLOCK(inp);
970 				error = 0;
971 				break;
972 			case SO_REUSEPORT:
973 				INP_WLOCK(inp);
974 				if ((so->so_options & SO_REUSEPORT) != 0)
975 					inp->inp_flags2 |= INP_REUSEPORT;
976 				else
977 					inp->inp_flags2 &= ~INP_REUSEPORT;
978 				INP_WUNLOCK(inp);
979 				error = 0;
980 				break;
981 			case SO_SETFIB:
982 				INP_WLOCK(inp);
983 				inp->inp_inc.inc_fibnum = so->so_fibnum;
984 				INP_WUNLOCK(inp);
985 				error = 0;
986 				break;
987 			case SO_MAX_PACING_RATE:
988 #ifdef RATELIMIT
989 				INP_WLOCK(inp);
990 				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
991 				INP_WUNLOCK(inp);
992 				error = 0;
993 #else
994 				error = EOPNOTSUPP;
995 #endif
996 				break;
997 			default:
998 				break;
999 			}
1000 		}
1001 		return (error);
1002 	}
1003 
1004 	switch (sopt->sopt_dir) {
1005 	case SOPT_SET:
1006 		switch (sopt->sopt_name) {
1007 		case IP_OPTIONS:
1008 #ifdef notyet
1009 		case IP_RETOPTS:
1010 #endif
1011 		{
1012 			struct mbuf *m;
1013 			if (sopt->sopt_valsize > MLEN) {
1014 				error = EMSGSIZE;
1015 				break;
1016 			}
1017 			m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
1018 			if (m == NULL) {
1019 				error = ENOBUFS;
1020 				break;
1021 			}
1022 			m->m_len = sopt->sopt_valsize;
1023 			error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1024 					    m->m_len);
1025 			if (error) {
1026 				m_free(m);
1027 				break;
1028 			}
1029 			INP_WLOCK(inp);
1030 			error = ip_pcbopts(inp, sopt->sopt_name, m);
1031 			INP_WUNLOCK(inp);
1032 			return (error);
1033 		}
1034 
1035 		case IP_BINDANY:
1036 			if (sopt->sopt_td != NULL) {
1037 				error = priv_check(sopt->sopt_td,
1038 				    PRIV_NETINET_BINDANY);
1039 				if (error)
1040 					break;
1041 			}
1042 			/* FALLTHROUGH */
1043 		case IP_BINDMULTI:
1044 #ifdef	RSS
1045 		case IP_RSS_LISTEN_BUCKET:
1046 #endif
1047 		case IP_TOS:
1048 		case IP_TTL:
1049 		case IP_MINTTL:
1050 		case IP_RECVOPTS:
1051 		case IP_RECVRETOPTS:
1052 		case IP_ORIGDSTADDR:
1053 		case IP_RECVDSTADDR:
1054 		case IP_RECVTTL:
1055 		case IP_RECVIF:
1056 		case IP_ONESBCAST:
1057 		case IP_DONTFRAG:
1058 		case IP_RECVTOS:
1059 		case IP_RECVFLOWID:
1060 #ifdef	RSS
1061 		case IP_RECVRSSBUCKETID:
1062 #endif
1063 			error = sooptcopyin(sopt, &optval, sizeof optval,
1064 					    sizeof optval);
1065 			if (error)
1066 				break;
1067 
1068 			switch (sopt->sopt_name) {
1069 			case IP_TOS:
1070 				inp->inp_ip_tos = optval;
1071 				break;
1072 
1073 			case IP_TTL:
1074 				inp->inp_ip_ttl = optval;
1075 				break;
1076 
1077 			case IP_MINTTL:
1078 				if (optval >= 0 && optval <= MAXTTL)
1079 					inp->inp_ip_minttl = optval;
1080 				else
1081 					error = EINVAL;
1082 				break;
1083 
1084 #define	OPTSET(bit) do {						\
1085 	INP_WLOCK(inp);							\
1086 	if (optval)							\
1087 		inp->inp_flags |= bit;					\
1088 	else								\
1089 		inp->inp_flags &= ~bit;					\
1090 	INP_WUNLOCK(inp);						\
1091 } while (0)
1092 
1093 #define	OPTSET2(bit, val) do {						\
1094 	INP_WLOCK(inp);							\
1095 	if (val)							\
1096 		inp->inp_flags2 |= bit;					\
1097 	else								\
1098 		inp->inp_flags2 &= ~bit;				\
1099 	INP_WUNLOCK(inp);						\
1100 } while (0)
1101 
1102 			case IP_RECVOPTS:
1103 				OPTSET(INP_RECVOPTS);
1104 				break;
1105 
1106 			case IP_RECVRETOPTS:
1107 				OPTSET(INP_RECVRETOPTS);
1108 				break;
1109 
1110 			case IP_RECVDSTADDR:
1111 				OPTSET(INP_RECVDSTADDR);
1112 				break;
1113 
1114 			case IP_ORIGDSTADDR:
1115 				OPTSET2(INP_ORIGDSTADDR, optval);
1116 				break;
1117 
1118 			case IP_RECVTTL:
1119 				OPTSET(INP_RECVTTL);
1120 				break;
1121 
1122 			case IP_RECVIF:
1123 				OPTSET(INP_RECVIF);
1124 				break;
1125 
1126 			case IP_ONESBCAST:
1127 				OPTSET(INP_ONESBCAST);
1128 				break;
1129 			case IP_DONTFRAG:
1130 				OPTSET(INP_DONTFRAG);
1131 				break;
1132 			case IP_BINDANY:
1133 				OPTSET(INP_BINDANY);
1134 				break;
1135 			case IP_RECVTOS:
1136 				OPTSET(INP_RECVTOS);
1137 				break;
1138 			case IP_BINDMULTI:
1139 				OPTSET2(INP_BINDMULTI, optval);
1140 				break;
1141 			case IP_RECVFLOWID:
1142 				OPTSET2(INP_RECVFLOWID, optval);
1143 				break;
1144 #ifdef	RSS
1145 			case IP_RSS_LISTEN_BUCKET:
1146 				if ((optval >= 0) &&
1147 				    (optval < rss_getnumbuckets())) {
1148 					inp->inp_rss_listen_bucket = optval;
1149 					OPTSET2(INP_RSS_BUCKET_SET, 1);
1150 				} else {
1151 					error = EINVAL;
1152 				}
1153 				break;
1154 			case IP_RECVRSSBUCKETID:
1155 				OPTSET2(INP_RECVRSSBUCKETID, optval);
1156 				break;
1157 #endif
1158 			}
1159 			break;
1160 #undef OPTSET
1161 #undef OPTSET2
1162 
1163 		/*
1164 		 * Multicast socket options are processed by the in_mcast
1165 		 * module.
1166 		 */
1167 		case IP_MULTICAST_IF:
1168 		case IP_MULTICAST_VIF:
1169 		case IP_MULTICAST_TTL:
1170 		case IP_MULTICAST_LOOP:
1171 		case IP_ADD_MEMBERSHIP:
1172 		case IP_DROP_MEMBERSHIP:
1173 		case IP_ADD_SOURCE_MEMBERSHIP:
1174 		case IP_DROP_SOURCE_MEMBERSHIP:
1175 		case IP_BLOCK_SOURCE:
1176 		case IP_UNBLOCK_SOURCE:
1177 		case IP_MSFILTER:
1178 		case MCAST_JOIN_GROUP:
1179 		case MCAST_LEAVE_GROUP:
1180 		case MCAST_JOIN_SOURCE_GROUP:
1181 		case MCAST_LEAVE_SOURCE_GROUP:
1182 		case MCAST_BLOCK_SOURCE:
1183 		case MCAST_UNBLOCK_SOURCE:
1184 			error = inp_setmoptions(inp, sopt);
1185 			break;
1186 
1187 		case IP_PORTRANGE:
1188 			error = sooptcopyin(sopt, &optval, sizeof optval,
1189 					    sizeof optval);
1190 			if (error)
1191 				break;
1192 
1193 			INP_WLOCK(inp);
1194 			switch (optval) {
1195 			case IP_PORTRANGE_DEFAULT:
1196 				inp->inp_flags &= ~(INP_LOWPORT);
1197 				inp->inp_flags &= ~(INP_HIGHPORT);
1198 				break;
1199 
1200 			case IP_PORTRANGE_HIGH:
1201 				inp->inp_flags &= ~(INP_LOWPORT);
1202 				inp->inp_flags |= INP_HIGHPORT;
1203 				break;
1204 
1205 			case IP_PORTRANGE_LOW:
1206 				inp->inp_flags &= ~(INP_HIGHPORT);
1207 				inp->inp_flags |= INP_LOWPORT;
1208 				break;
1209 
1210 			default:
1211 				error = EINVAL;
1212 				break;
1213 			}
1214 			INP_WUNLOCK(inp);
1215 			break;
1216 
1217 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1218 		case IP_IPSEC_POLICY:
1219 			if (IPSEC_ENABLED(ipv4)) {
1220 				error = IPSEC_PCBCTL(ipv4, inp, sopt);
1221 				break;
1222 			}
1223 			/* FALLTHROUGH */
1224 #endif /* IPSEC */
1225 
1226 		default:
1227 			error = ENOPROTOOPT;
1228 			break;
1229 		}
1230 		break;
1231 
1232 	case SOPT_GET:
1233 		switch (sopt->sopt_name) {
1234 		case IP_OPTIONS:
1235 		case IP_RETOPTS:
1236 			if (inp->inp_options)
1237 				error = sooptcopyout(sopt,
1238 						     mtod(inp->inp_options,
1239 							  char *),
1240 						     inp->inp_options->m_len);
1241 			else
1242 				sopt->sopt_valsize = 0;
1243 			break;
1244 
1245 		case IP_TOS:
1246 		case IP_TTL:
1247 		case IP_MINTTL:
1248 		case IP_RECVOPTS:
1249 		case IP_RECVRETOPTS:
1250 		case IP_ORIGDSTADDR:
1251 		case IP_RECVDSTADDR:
1252 		case IP_RECVTTL:
1253 		case IP_RECVIF:
1254 		case IP_PORTRANGE:
1255 		case IP_ONESBCAST:
1256 		case IP_DONTFRAG:
1257 		case IP_BINDANY:
1258 		case IP_RECVTOS:
1259 		case IP_BINDMULTI:
1260 		case IP_FLOWID:
1261 		case IP_FLOWTYPE:
1262 		case IP_RECVFLOWID:
1263 #ifdef	RSS
1264 		case IP_RSSBUCKETID:
1265 		case IP_RECVRSSBUCKETID:
1266 #endif
1267 			switch (sopt->sopt_name) {
1268 
1269 			case IP_TOS:
1270 				optval = inp->inp_ip_tos;
1271 				break;
1272 
1273 			case IP_TTL:
1274 				optval = inp->inp_ip_ttl;
1275 				break;
1276 
1277 			case IP_MINTTL:
1278 				optval = inp->inp_ip_minttl;
1279 				break;
1280 
1281 #define	OPTBIT(bit)	(inp->inp_flags & bit ? 1 : 0)
1282 #define	OPTBIT2(bit)	(inp->inp_flags2 & bit ? 1 : 0)
1283 
1284 			case IP_RECVOPTS:
1285 				optval = OPTBIT(INP_RECVOPTS);
1286 				break;
1287 
1288 			case IP_RECVRETOPTS:
1289 				optval = OPTBIT(INP_RECVRETOPTS);
1290 				break;
1291 
1292 			case IP_RECVDSTADDR:
1293 				optval = OPTBIT(INP_RECVDSTADDR);
1294 				break;
1295 
1296 			case IP_ORIGDSTADDR:
1297 				optval = OPTBIT2(INP_ORIGDSTADDR);
1298 				break;
1299 
1300 			case IP_RECVTTL:
1301 				optval = OPTBIT(INP_RECVTTL);
1302 				break;
1303 
1304 			case IP_RECVIF:
1305 				optval = OPTBIT(INP_RECVIF);
1306 				break;
1307 
1308 			case IP_PORTRANGE:
1309 				if (inp->inp_flags & INP_HIGHPORT)
1310 					optval = IP_PORTRANGE_HIGH;
1311 				else if (inp->inp_flags & INP_LOWPORT)
1312 					optval = IP_PORTRANGE_LOW;
1313 				else
1314 					optval = 0;
1315 				break;
1316 
1317 			case IP_ONESBCAST:
1318 				optval = OPTBIT(INP_ONESBCAST);
1319 				break;
1320 			case IP_DONTFRAG:
1321 				optval = OPTBIT(INP_DONTFRAG);
1322 				break;
1323 			case IP_BINDANY:
1324 				optval = OPTBIT(INP_BINDANY);
1325 				break;
1326 			case IP_RECVTOS:
1327 				optval = OPTBIT(INP_RECVTOS);
1328 				break;
1329 			case IP_FLOWID:
1330 				optval = inp->inp_flowid;
1331 				break;
1332 			case IP_FLOWTYPE:
1333 				optval = inp->inp_flowtype;
1334 				break;
1335 			case IP_RECVFLOWID:
1336 				optval = OPTBIT2(INP_RECVFLOWID);
1337 				break;
1338 #ifdef	RSS
1339 			case IP_RSSBUCKETID:
1340 				retval = rss_hash2bucket(inp->inp_flowid,
1341 				    inp->inp_flowtype,
1342 				    &rss_bucket);
1343 				if (retval == 0)
1344 					optval = rss_bucket;
1345 				else
1346 					error = EINVAL;
1347 				break;
1348 			case IP_RECVRSSBUCKETID:
1349 				optval = OPTBIT2(INP_RECVRSSBUCKETID);
1350 				break;
1351 #endif
1352 			case IP_BINDMULTI:
1353 				optval = OPTBIT2(INP_BINDMULTI);
1354 				break;
1355 			}
1356 			error = sooptcopyout(sopt, &optval, sizeof optval);
1357 			break;
1358 
1359 		/*
1360 		 * Multicast socket options are processed by the in_mcast
1361 		 * module.
1362 		 */
1363 		case IP_MULTICAST_IF:
1364 		case IP_MULTICAST_VIF:
1365 		case IP_MULTICAST_TTL:
1366 		case IP_MULTICAST_LOOP:
1367 		case IP_MSFILTER:
1368 			error = inp_getmoptions(inp, sopt);
1369 			break;
1370 
1371 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1372 		case IP_IPSEC_POLICY:
1373 			if (IPSEC_ENABLED(ipv4)) {
1374 				error = IPSEC_PCBCTL(ipv4, inp, sopt);
1375 				break;
1376 			}
1377 			/* FALLTHROUGH */
1378 #endif /* IPSEC */
1379 
1380 		default:
1381 			error = ENOPROTOOPT;
1382 			break;
1383 		}
1384 		break;
1385 	}
1386 	return (error);
1387 }
1388 
1389 /*
1390  * Routine called from ip_output() to loop back a copy of an IP multicast
1391  * packet to the input queue of a specified interface.  Note that this
1392  * calls the output routine of the loopback "driver", but with an interface
1393  * pointer that might NOT be a loopback interface -- evil, but easier than
1394  * replicating that code here.
1395  */
1396 static void
1397 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1398 {
1399 	struct ip *ip;
1400 	struct mbuf *copym;
1401 
1402 	/*
1403 	 * Make a deep copy of the packet because we're going to
1404 	 * modify the pack in order to generate checksums.
1405 	 */
1406 	copym = m_dup(m, M_NOWAIT);
1407 	if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1408 		copym = m_pullup(copym, hlen);
1409 	if (copym != NULL) {
1410 		/* If needed, compute the checksum and mark it as valid. */
1411 		if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1412 			in_delayed_cksum(copym);
1413 			copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1414 			copym->m_pkthdr.csum_flags |=
1415 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1416 			copym->m_pkthdr.csum_data = 0xffff;
1417 		}
1418 		/*
1419 		 * We don't bother to fragment if the IP length is greater
1420 		 * than the interface's MTU.  Can this possibly matter?
1421 		 */
1422 		ip = mtod(copym, struct ip *);
1423 		ip->ip_sum = 0;
1424 		ip->ip_sum = in_cksum(copym, hlen);
1425 		if_simloop(ifp, copym, AF_INET, 0);
1426 	}
1427 }
1428