xref: /freebsd/sys/netinet/ip_output.c (revision 8b25e8410533a6e69cceff910546b2dc485a5059)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_inet.h"
36 #include "opt_ratelimit.h"
37 #include "opt_ipsec.h"
38 #include "opt_mbuf_stress_test.h"
39 #include "opt_mpath.h"
40 #include "opt_route.h"
41 #include "opt_sctp.h"
42 #include "opt_rss.h"
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/lock.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/priv.h>
51 #include <sys/proc.h>
52 #include <sys/protosw.h>
53 #include <sys/rmlock.h>
54 #include <sys/sdt.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
57 #include <sys/sysctl.h>
58 #include <sys/ucred.h>
59 
60 #include <net/if.h>
61 #include <net/if_var.h>
62 #include <net/if_llatbl.h>
63 #include <net/netisr.h>
64 #include <net/pfil.h>
65 #include <net/route.h>
66 #include <net/flowtable.h>
67 #ifdef RADIX_MPATH
68 #include <net/radix_mpath.h>
69 #endif
70 #include <net/rss_config.h>
71 #include <net/vnet.h>
72 
73 #include <netinet/in.h>
74 #include <netinet/in_kdtrace.h>
75 #include <netinet/in_systm.h>
76 #include <netinet/ip.h>
77 #include <netinet/in_pcb.h>
78 #include <netinet/in_rss.h>
79 #include <netinet/in_var.h>
80 #include <netinet/ip_var.h>
81 #include <netinet/ip_options.h>
82 #ifdef SCTP
83 #include <netinet/sctp.h>
84 #include <netinet/sctp_crc32.h>
85 #endif
86 
87 #ifdef IPSEC
88 #include <netinet/ip_ipsec.h>
89 #include <netipsec/ipsec.h>
90 #endif /* IPSEC*/
91 
92 #include <machine/in_cksum.h>
93 
94 #include <security/mac/mac_framework.h>
95 
96 #ifdef MBUF_STRESS_TEST
97 static int mbuf_frag_size = 0;
98 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
99 	&mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
100 #endif
101 
102 static void	ip_mloopback(struct ifnet *, const struct mbuf *, int);
103 
104 
105 extern int in_mcast_loop;
106 extern	struct protosw inetsw[];
107 
108 static inline int
109 ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, struct inpcb *inp,
110     struct sockaddr_in *dst, int *fibnum, int *error)
111 {
112 	struct m_tag *fwd_tag = NULL;
113 	struct mbuf *m;
114 	struct in_addr odst;
115 	struct ip *ip;
116 
117 	m = *mp;
118 	ip = mtod(m, struct ip *);
119 
120 	/* Run through list of hooks for output packets. */
121 	odst.s_addr = ip->ip_dst.s_addr;
122 	*error = pfil_run_hooks(&V_inet_pfil_hook, mp, ifp, PFIL_OUT, inp);
123 	m = *mp;
124 	if ((*error) != 0 || m == NULL)
125 		return 1; /* Finished */
126 
127 	ip = mtod(m, struct ip *);
128 
129 	/* See if destination IP address was changed by packet filter. */
130 	if (odst.s_addr != ip->ip_dst.s_addr) {
131 		m->m_flags |= M_SKIP_FIREWALL;
132 		/* If destination is now ourself drop to ip_input(). */
133 		if (in_localip(ip->ip_dst)) {
134 			m->m_flags |= M_FASTFWD_OURS;
135 			if (m->m_pkthdr.rcvif == NULL)
136 				m->m_pkthdr.rcvif = V_loif;
137 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
138 				m->m_pkthdr.csum_flags |=
139 					CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
140 				m->m_pkthdr.csum_data = 0xffff;
141 			}
142 			m->m_pkthdr.csum_flags |=
143 				CSUM_IP_CHECKED | CSUM_IP_VALID;
144 #ifdef SCTP
145 			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
146 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
147 #endif
148 			*error = netisr_queue(NETISR_IP, m);
149 			return 1; /* Finished */
150 		}
151 
152 		bzero(dst, sizeof(*dst));
153 		dst->sin_family = AF_INET;
154 		dst->sin_len = sizeof(*dst);
155 		dst->sin_addr = ip->ip_dst;
156 
157 		return -1; /* Reloop */
158 	}
159 	/* See if fib was changed by packet filter. */
160 	if ((*fibnum) != M_GETFIB(m)) {
161 		m->m_flags |= M_SKIP_FIREWALL;
162 		*fibnum = M_GETFIB(m);
163 		return -1; /* Reloop for FIB change */
164 	}
165 
166 	/* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
167 	if (m->m_flags & M_FASTFWD_OURS) {
168 		if (m->m_pkthdr.rcvif == NULL)
169 			m->m_pkthdr.rcvif = V_loif;
170 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
171 			m->m_pkthdr.csum_flags |=
172 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
173 			m->m_pkthdr.csum_data = 0xffff;
174 		}
175 #ifdef SCTP
176 		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
177 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
178 #endif
179 		m->m_pkthdr.csum_flags |=
180 			CSUM_IP_CHECKED | CSUM_IP_VALID;
181 
182 		*error = netisr_queue(NETISR_IP, m);
183 		return 1; /* Finished */
184 	}
185 	/* Or forward to some other address? */
186 	if ((m->m_flags & M_IP_NEXTHOP) &&
187 	    ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
188 		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
189 		m->m_flags |= M_SKIP_FIREWALL;
190 		m->m_flags &= ~M_IP_NEXTHOP;
191 		m_tag_delete(m, fwd_tag);
192 
193 		return -1; /* Reloop for CHANGE of dst */
194 	}
195 
196 	return 0;
197 }
198 
199 /*
200  * IP output.  The packet in mbuf chain m contains a skeletal IP
201  * header (with len, off, ttl, proto, tos, src, dst).
202  * The mbuf chain containing the packet will be freed.
203  * The mbuf opt, if present, will not be freed.
204  * If route ro is present and has ro_rt initialized, route lookup would be
205  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
206  * then result of route lookup is stored in ro->ro_rt.
207  *
208  * In the IP forwarding case, the packet will arrive with options already
209  * inserted, so must have a NULL opt pointer.
210  */
211 int
212 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
213     struct ip_moptions *imo, struct inpcb *inp)
214 {
215 	struct rm_priotracker in_ifa_tracker;
216 	struct ip *ip;
217 	struct ifnet *ifp = NULL;	/* keep compiler happy */
218 	struct mbuf *m0;
219 	int hlen = sizeof (struct ip);
220 	int mtu;
221 	int error = 0;
222 	struct sockaddr_in *dst;
223 	const struct sockaddr_in *gw;
224 	struct in_ifaddr *ia;
225 	int isbroadcast;
226 	uint16_t ip_len, ip_off;
227 	struct route iproute;
228 	struct rtentry *rte;	/* cache for ro->ro_rt */
229 	uint32_t fibnum;
230 	int have_ia_ref;
231 #ifdef IPSEC
232 	int no_route_but_check_spd = 0;
233 #endif
234 	M_ASSERTPKTHDR(m);
235 
236 	if (inp != NULL) {
237 		INP_LOCK_ASSERT(inp);
238 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
239 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
240 			m->m_pkthdr.flowid = inp->inp_flowid;
241 			M_HASHTYPE_SET(m, inp->inp_flowtype);
242 		}
243 	}
244 
245 	if (ro == NULL) {
246 		ro = &iproute;
247 		bzero(ro, sizeof (*ro));
248 	} else
249 		ro->ro_flags |= RT_LLE_CACHE;
250 
251 #ifdef FLOWTABLE
252 	if (ro->ro_rt == NULL)
253 		(void )flowtable_lookup(AF_INET, m, ro);
254 #endif
255 
256 	if (opt) {
257 		int len = 0;
258 		m = ip_insertoptions(m, opt, &len);
259 		if (len != 0)
260 			hlen = len; /* ip->ip_hl is updated above */
261 	}
262 	ip = mtod(m, struct ip *);
263 	ip_len = ntohs(ip->ip_len);
264 	ip_off = ntohs(ip->ip_off);
265 
266 	if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
267 		ip->ip_v = IPVERSION;
268 		ip->ip_hl = hlen >> 2;
269 		ip_fillid(ip);
270 		IPSTAT_INC(ips_localout);
271 	} else {
272 		/* Header already set, fetch hlen from there */
273 		hlen = ip->ip_hl << 2;
274 	}
275 
276 	/*
277 	 * dst/gw handling:
278 	 *
279 	 * dst can be rewritten but always points to &ro->ro_dst.
280 	 * gw is readonly but can point either to dst OR rt_gateway,
281 	 * therefore we need restore gw if we're redoing lookup.
282 	 */
283 	gw = dst = (struct sockaddr_in *)&ro->ro_dst;
284 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
285 	rte = ro->ro_rt;
286 	if (rte == NULL) {
287 		bzero(dst, sizeof(*dst));
288 		dst->sin_family = AF_INET;
289 		dst->sin_len = sizeof(*dst);
290 		dst->sin_addr = ip->ip_dst;
291 	}
292 again:
293 	/*
294 	 * Validate route against routing table additions;
295 	 * a better/more specific route might have been added.
296 	 */
297 	if (inp)
298 		RT_VALIDATE(ro, &inp->inp_rt_cookie, fibnum);
299 	/*
300 	 * If there is a cached route,
301 	 * check that it is to the same destination
302 	 * and is still up.  If not, free it and try again.
303 	 * The address family should also be checked in case of sharing the
304 	 * cache with IPv6.
305 	 * Also check whether routing cache needs invalidation.
306 	 */
307 	rte = ro->ro_rt;
308 	if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
309 		    rte->rt_ifp == NULL ||
310 		    !RT_LINK_IS_UP(rte->rt_ifp) ||
311 			  dst->sin_family != AF_INET ||
312 			  dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
313 		RTFREE(rte);
314 		rte = ro->ro_rt = (struct rtentry *)NULL;
315 		if (ro->ro_lle)
316 			LLE_FREE(ro->ro_lle);	/* zeros ro_lle */
317 		ro->ro_lle = (struct llentry *)NULL;
318 	}
319 	ia = NULL;
320 	have_ia_ref = 0;
321 	/*
322 	 * If routing to interface only, short circuit routing lookup.
323 	 * The use of an all-ones broadcast address implies this; an
324 	 * interface is specified by the broadcast address of an interface,
325 	 * or the destination address of a ptp interface.
326 	 */
327 	if (flags & IP_SENDONES) {
328 		if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
329 						      M_GETFIB(m)))) == NULL &&
330 		    (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
331 						    M_GETFIB(m)))) == NULL) {
332 			IPSTAT_INC(ips_noroute);
333 			error = ENETUNREACH;
334 			goto bad;
335 		}
336 		have_ia_ref = 1;
337 		ip->ip_dst.s_addr = INADDR_BROADCAST;
338 		dst->sin_addr = ip->ip_dst;
339 		ifp = ia->ia_ifp;
340 		ip->ip_ttl = 1;
341 		isbroadcast = 1;
342 	} else if (flags & IP_ROUTETOIF) {
343 		if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
344 						    M_GETFIB(m)))) == NULL &&
345 		    (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
346 						M_GETFIB(m)))) == NULL) {
347 			IPSTAT_INC(ips_noroute);
348 			error = ENETUNREACH;
349 			goto bad;
350 		}
351 		have_ia_ref = 1;
352 		ifp = ia->ia_ifp;
353 		ip->ip_ttl = 1;
354 		isbroadcast = ifp->if_flags & IFF_BROADCAST ?
355 		    in_ifaddr_broadcast(dst->sin_addr, ia) : 0;
356 	} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
357 	    imo != NULL && imo->imo_multicast_ifp != NULL) {
358 		/*
359 		 * Bypass the normal routing lookup for multicast
360 		 * packets if the interface is specified.
361 		 */
362 		ifp = imo->imo_multicast_ifp;
363 		IFP_TO_IA(ifp, ia, &in_ifa_tracker);
364 		if (ia)
365 			have_ia_ref = 1;
366 		isbroadcast = 0;	/* fool gcc */
367 	} else {
368 		/*
369 		 * We want to do any cloning requested by the link layer,
370 		 * as this is probably required in all cases for correct
371 		 * operation (as it is for ARP).
372 		 */
373 		if (rte == NULL) {
374 #ifdef RADIX_MPATH
375 			rtalloc_mpath_fib(ro,
376 			    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
377 			    fibnum);
378 #else
379 			in_rtalloc_ign(ro, 0, fibnum);
380 #endif
381 			rte = ro->ro_rt;
382 		}
383 		if (rte == NULL ||
384 		    (rte->rt_flags & RTF_UP) == 0 ||
385 		    rte->rt_ifp == NULL ||
386 		    !RT_LINK_IS_UP(rte->rt_ifp)) {
387 #ifdef IPSEC
388 			/*
389 			 * There is no route for this packet, but it is
390 			 * possible that a matching SPD entry exists.
391 			 */
392 			no_route_but_check_spd = 1;
393 			mtu = 0; /* Silence GCC warning. */
394 			goto sendit;
395 #endif
396 			IPSTAT_INC(ips_noroute);
397 			error = EHOSTUNREACH;
398 			goto bad;
399 		}
400 		ia = ifatoia(rte->rt_ifa);
401 		ifp = rte->rt_ifp;
402 		counter_u64_add(rte->rt_pksent, 1);
403 		rt_update_ro_flags(ro);
404 		if (rte->rt_flags & RTF_GATEWAY)
405 			gw = (struct sockaddr_in *)rte->rt_gateway;
406 		if (rte->rt_flags & RTF_HOST)
407 			isbroadcast = (rte->rt_flags & RTF_BROADCAST);
408 		else if (ifp->if_flags & IFF_BROADCAST)
409 			isbroadcast = in_ifaddr_broadcast(gw->sin_addr, ia);
410 		else
411 			isbroadcast = 0;
412 	}
413 
414 	/*
415 	 * Calculate MTU.  If we have a route that is up, use that,
416 	 * otherwise use the interface's MTU.
417 	 */
418 	if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST)))
419 		mtu = rte->rt_mtu;
420 	else
421 		mtu = ifp->if_mtu;
422 	/* Catch a possible divide by zero later. */
423 	KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
424 	    __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
425 
426 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
427 		m->m_flags |= M_MCAST;
428 		/*
429 		 * IP destination address is multicast.  Make sure "gw"
430 		 * still points to the address in "ro".  (It may have been
431 		 * changed to point to a gateway address, above.)
432 		 */
433 		gw = dst;
434 		/*
435 		 * See if the caller provided any multicast options
436 		 */
437 		if (imo != NULL) {
438 			ip->ip_ttl = imo->imo_multicast_ttl;
439 			if (imo->imo_multicast_vif != -1)
440 				ip->ip_src.s_addr =
441 				    ip_mcast_src ?
442 				    ip_mcast_src(imo->imo_multicast_vif) :
443 				    INADDR_ANY;
444 		} else
445 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
446 		/*
447 		 * Confirm that the outgoing interface supports multicast.
448 		 */
449 		if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
450 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
451 				IPSTAT_INC(ips_noroute);
452 				error = ENETUNREACH;
453 				goto bad;
454 			}
455 		}
456 		/*
457 		 * If source address not specified yet, use address
458 		 * of outgoing interface.
459 		 */
460 		if (ip->ip_src.s_addr == INADDR_ANY) {
461 			/* Interface may have no addresses. */
462 			if (ia != NULL)
463 				ip->ip_src = IA_SIN(ia)->sin_addr;
464 		}
465 
466 		if ((imo == NULL && in_mcast_loop) ||
467 		    (imo && imo->imo_multicast_loop)) {
468 			/*
469 			 * Loop back multicast datagram if not expressly
470 			 * forbidden to do so, even if we are not a member
471 			 * of the group; ip_input() will filter it later,
472 			 * thus deferring a hash lookup and mutex acquisition
473 			 * at the expense of a cheap copy using m_copym().
474 			 */
475 			ip_mloopback(ifp, m, hlen);
476 		} else {
477 			/*
478 			 * If we are acting as a multicast router, perform
479 			 * multicast forwarding as if the packet had just
480 			 * arrived on the interface to which we are about
481 			 * to send.  The multicast forwarding function
482 			 * recursively calls this function, using the
483 			 * IP_FORWARDING flag to prevent infinite recursion.
484 			 *
485 			 * Multicasts that are looped back by ip_mloopback(),
486 			 * above, will be forwarded by the ip_input() routine,
487 			 * if necessary.
488 			 */
489 			if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
490 				/*
491 				 * If rsvp daemon is not running, do not
492 				 * set ip_moptions. This ensures that the packet
493 				 * is multicast and not just sent down one link
494 				 * as prescribed by rsvpd.
495 				 */
496 				if (!V_rsvp_on)
497 					imo = NULL;
498 				if (ip_mforward &&
499 				    ip_mforward(ip, ifp, m, imo) != 0) {
500 					m_freem(m);
501 					goto done;
502 				}
503 			}
504 		}
505 
506 		/*
507 		 * Multicasts with a time-to-live of zero may be looped-
508 		 * back, above, but must not be transmitted on a network.
509 		 * Also, multicasts addressed to the loopback interface
510 		 * are not sent -- the above call to ip_mloopback() will
511 		 * loop back a copy. ip_input() will drop the copy if
512 		 * this host does not belong to the destination group on
513 		 * the loopback interface.
514 		 */
515 		if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
516 			m_freem(m);
517 			goto done;
518 		}
519 
520 		goto sendit;
521 	}
522 
523 	/*
524 	 * If the source address is not specified yet, use the address
525 	 * of the outoing interface.
526 	 */
527 	if (ip->ip_src.s_addr == INADDR_ANY) {
528 		/* Interface may have no addresses. */
529 		if (ia != NULL) {
530 			ip->ip_src = IA_SIN(ia)->sin_addr;
531 		}
532 	}
533 
534 	/*
535 	 * Look for broadcast address and
536 	 * verify user is allowed to send
537 	 * such a packet.
538 	 */
539 	if (isbroadcast) {
540 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
541 			error = EADDRNOTAVAIL;
542 			goto bad;
543 		}
544 		if ((flags & IP_ALLOWBROADCAST) == 0) {
545 			error = EACCES;
546 			goto bad;
547 		}
548 		/* don't allow broadcast messages to be fragmented */
549 		if (ip_len > mtu) {
550 			error = EMSGSIZE;
551 			goto bad;
552 		}
553 		m->m_flags |= M_BCAST;
554 	} else {
555 		m->m_flags &= ~M_BCAST;
556 	}
557 
558 sendit:
559 #ifdef IPSEC
560 	switch(ip_ipsec_output(&m, inp, &error)) {
561 	case 1:
562 		goto bad;
563 	case -1:
564 		goto done;
565 	case 0:
566 	default:
567 		break;	/* Continue with packet processing. */
568 	}
569 	/*
570 	 * Check if there was a route for this packet; return error if not.
571 	 */
572 	if (no_route_but_check_spd) {
573 		IPSTAT_INC(ips_noroute);
574 		error = EHOSTUNREACH;
575 		goto bad;
576 	}
577 	/* Update variables that are affected by ipsec4_output(). */
578 	ip = mtod(m, struct ip *);
579 	hlen = ip->ip_hl << 2;
580 #endif /* IPSEC */
581 
582 	/* Jump over all PFIL processing if hooks are not active. */
583 	if (PFIL_HOOKED(&V_inet_pfil_hook)) {
584 		switch (ip_output_pfil(&m, ifp, inp, dst, &fibnum, &error)) {
585 		case 1: /* Finished */
586 			goto done;
587 
588 		case 0: /* Continue normally */
589 			ip = mtod(m, struct ip *);
590 			break;
591 
592 		case -1: /* Need to try again */
593 			/* Reset everything for a new round */
594 			RO_RTFREE(ro);
595 			if (have_ia_ref)
596 				ifa_free(&ia->ia_ifa);
597 			ro->ro_prepend = NULL;
598 			rte = NULL;
599 			gw = dst;
600 			ip = mtod(m, struct ip *);
601 			goto again;
602 
603 		}
604 	}
605 
606 	/* 127/8 must not appear on wire - RFC1122. */
607 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
608 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
609 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
610 			IPSTAT_INC(ips_badaddr);
611 			error = EADDRNOTAVAIL;
612 			goto bad;
613 		}
614 	}
615 
616 	m->m_pkthdr.csum_flags |= CSUM_IP;
617 	if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
618 		in_delayed_cksum(m);
619 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
620 	}
621 #ifdef SCTP
622 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
623 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
624 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
625 	}
626 #endif
627 
628 	/*
629 	 * If small enough for interface, or the interface will take
630 	 * care of the fragmentation for us, we can just send directly.
631 	 */
632 	if (ip_len <= mtu ||
633 	    (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) {
634 		ip->ip_sum = 0;
635 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
636 			ip->ip_sum = in_cksum(m, hlen);
637 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
638 		}
639 
640 		/*
641 		 * Record statistics for this interface address.
642 		 * With CSUM_TSO the byte/packet count will be slightly
643 		 * incorrect because we count the IP+TCP headers only
644 		 * once instead of for every generated packet.
645 		 */
646 		if (!(flags & IP_FORWARDING) && ia) {
647 			if (m->m_pkthdr.csum_flags & CSUM_TSO)
648 				counter_u64_add(ia->ia_ifa.ifa_opackets,
649 				    m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
650 			else
651 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
652 
653 			counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
654 		}
655 #ifdef MBUF_STRESS_TEST
656 		if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
657 			m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
658 #endif
659 		/*
660 		 * Reset layer specific mbuf flags
661 		 * to avoid confusing lower layers.
662 		 */
663 		m_clrprotoflags(m);
664 		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
665 #ifdef RATELIMIT
666 		if (inp != NULL) {
667 			if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
668 				in_pcboutput_txrtlmt(inp, ifp, m);
669 			/* stamp send tag on mbuf */
670 			m->m_pkthdr.snd_tag = inp->inp_snd_tag;
671 		} else {
672 			m->m_pkthdr.snd_tag = NULL;
673 		}
674 #endif
675 		error = (*ifp->if_output)(ifp, m,
676 		    (const struct sockaddr *)gw, ro);
677 #ifdef RATELIMIT
678 		/* check for route change */
679 		if (error == EAGAIN)
680 			in_pcboutput_eagain(inp);
681 #endif
682 		goto done;
683 	}
684 
685 	/* Balk when DF bit is set or the interface didn't support TSO. */
686 	if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
687 		error = EMSGSIZE;
688 		IPSTAT_INC(ips_cantfrag);
689 		goto bad;
690 	}
691 
692 	/*
693 	 * Too large for interface; fragment if possible. If successful,
694 	 * on return, m will point to a list of packets to be sent.
695 	 */
696 	error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
697 	if (error)
698 		goto bad;
699 	for (; m; m = m0) {
700 		m0 = m->m_nextpkt;
701 		m->m_nextpkt = 0;
702 		if (error == 0) {
703 			/* Record statistics for this interface address. */
704 			if (ia != NULL) {
705 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
706 				counter_u64_add(ia->ia_ifa.ifa_obytes,
707 				    m->m_pkthdr.len);
708 			}
709 			/*
710 			 * Reset layer specific mbuf flags
711 			 * to avoid confusing upper layers.
712 			 */
713 			m_clrprotoflags(m);
714 
715 			IP_PROBE(send, NULL, NULL, mtod(m, struct ip *), ifp,
716 			    mtod(m, struct ip *), NULL);
717 #ifdef RATELIMIT
718 			if (inp != NULL) {
719 				if (inp->inp_flags2 & INP_RATE_LIMIT_CHANGED)
720 					in_pcboutput_txrtlmt(inp, ifp, m);
721 				/* stamp send tag on mbuf */
722 				m->m_pkthdr.snd_tag = inp->inp_snd_tag;
723 			} else {
724 				m->m_pkthdr.snd_tag = NULL;
725 			}
726 #endif
727 			error = (*ifp->if_output)(ifp, m,
728 			    (const struct sockaddr *)gw, ro);
729 #ifdef RATELIMIT
730 			/* check for route change */
731 			if (error == EAGAIN)
732 				in_pcboutput_eagain(inp);
733 #endif
734 		} else
735 			m_freem(m);
736 	}
737 
738 	if (error == 0)
739 		IPSTAT_INC(ips_fragmented);
740 
741 done:
742 	if (ro == &iproute)
743 		RO_RTFREE(ro);
744 	else if (rte == NULL)
745 		/*
746 		 * If the caller supplied a route but somehow the reference
747 		 * to it has been released need to prevent the caller
748 		 * calling RTFREE on it again.
749 		 */
750 		ro->ro_rt = NULL;
751 	if (have_ia_ref)
752 		ifa_free(&ia->ia_ifa);
753 	return (error);
754 bad:
755 	m_freem(m);
756 	goto done;
757 }
758 
759 /*
760  * Create a chain of fragments which fit the given mtu. m_frag points to the
761  * mbuf to be fragmented; on return it points to the chain with the fragments.
762  * Return 0 if no error. If error, m_frag may contain a partially built
763  * chain of fragments that should be freed by the caller.
764  *
765  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
766  */
767 int
768 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
769     u_long if_hwassist_flags)
770 {
771 	int error = 0;
772 	int hlen = ip->ip_hl << 2;
773 	int len = (mtu - hlen) & ~7;	/* size of payload in each fragment */
774 	int off;
775 	struct mbuf *m0 = *m_frag;	/* the original packet		*/
776 	int firstlen;
777 	struct mbuf **mnext;
778 	int nfrags;
779 	uint16_t ip_len, ip_off;
780 
781 	ip_len = ntohs(ip->ip_len);
782 	ip_off = ntohs(ip->ip_off);
783 
784 	if (ip_off & IP_DF) {	/* Fragmentation not allowed */
785 		IPSTAT_INC(ips_cantfrag);
786 		return EMSGSIZE;
787 	}
788 
789 	/*
790 	 * Must be able to put at least 8 bytes per fragment.
791 	 */
792 	if (len < 8)
793 		return EMSGSIZE;
794 
795 	/*
796 	 * If the interface will not calculate checksums on
797 	 * fragmented packets, then do it here.
798 	 */
799 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
800 		in_delayed_cksum(m0);
801 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
802 	}
803 #ifdef SCTP
804 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
805 		sctp_delayed_cksum(m0, hlen);
806 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
807 	}
808 #endif
809 	if (len > PAGE_SIZE) {
810 		/*
811 		 * Fragment large datagrams such that each segment
812 		 * contains a multiple of PAGE_SIZE amount of data,
813 		 * plus headers. This enables a receiver to perform
814 		 * page-flipping zero-copy optimizations.
815 		 *
816 		 * XXX When does this help given that sender and receiver
817 		 * could have different page sizes, and also mtu could
818 		 * be less than the receiver's page size ?
819 		 */
820 		int newlen;
821 
822 		off = MIN(mtu, m0->m_pkthdr.len);
823 
824 		/*
825 		 * firstlen (off - hlen) must be aligned on an
826 		 * 8-byte boundary
827 		 */
828 		if (off < hlen)
829 			goto smart_frag_failure;
830 		off = ((off - hlen) & ~7) + hlen;
831 		newlen = (~PAGE_MASK) & mtu;
832 		if ((newlen + sizeof (struct ip)) > mtu) {
833 			/* we failed, go back the default */
834 smart_frag_failure:
835 			newlen = len;
836 			off = hlen + len;
837 		}
838 		len = newlen;
839 
840 	} else {
841 		off = hlen + len;
842 	}
843 
844 	firstlen = off - hlen;
845 	mnext = &m0->m_nextpkt;		/* pointer to next packet */
846 
847 	/*
848 	 * Loop through length of segment after first fragment,
849 	 * make new header and copy data of each part and link onto chain.
850 	 * Here, m0 is the original packet, m is the fragment being created.
851 	 * The fragments are linked off the m_nextpkt of the original
852 	 * packet, which after processing serves as the first fragment.
853 	 */
854 	for (nfrags = 1; off < ip_len; off += len, nfrags++) {
855 		struct ip *mhip;	/* ip header on the fragment */
856 		struct mbuf *m;
857 		int mhlen = sizeof (struct ip);
858 
859 		m = m_gethdr(M_NOWAIT, MT_DATA);
860 		if (m == NULL) {
861 			error = ENOBUFS;
862 			IPSTAT_INC(ips_odropped);
863 			goto done;
864 		}
865 		/*
866 		 * Make sure the complete packet header gets copied
867 		 * from the originating mbuf to the newly created
868 		 * mbuf. This also ensures that existing firewall
869 		 * classification(s), VLAN tags and so on get copied
870 		 * to the resulting fragmented packet(s):
871 		 */
872 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
873 			m_free(m);
874 			error = ENOBUFS;
875 			IPSTAT_INC(ips_odropped);
876 			goto done;
877 		}
878 		/*
879 		 * In the first mbuf, leave room for the link header, then
880 		 * copy the original IP header including options. The payload
881 		 * goes into an additional mbuf chain returned by m_copym().
882 		 */
883 		m->m_data += max_linkhdr;
884 		mhip = mtod(m, struct ip *);
885 		*mhip = *ip;
886 		if (hlen > sizeof (struct ip)) {
887 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
888 			mhip->ip_v = IPVERSION;
889 			mhip->ip_hl = mhlen >> 2;
890 		}
891 		m->m_len = mhlen;
892 		/* XXX do we need to add ip_off below ? */
893 		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
894 		if (off + len >= ip_len)
895 			len = ip_len - off;
896 		else
897 			mhip->ip_off |= IP_MF;
898 		mhip->ip_len = htons((u_short)(len + mhlen));
899 		m->m_next = m_copym(m0, off, len, M_NOWAIT);
900 		if (m->m_next == NULL) {	/* copy failed */
901 			m_free(m);
902 			error = ENOBUFS;	/* ??? */
903 			IPSTAT_INC(ips_odropped);
904 			goto done;
905 		}
906 		m->m_pkthdr.len = mhlen + len;
907 #ifdef MAC
908 		mac_netinet_fragment(m0, m);
909 #endif
910 		mhip->ip_off = htons(mhip->ip_off);
911 		mhip->ip_sum = 0;
912 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
913 			mhip->ip_sum = in_cksum(m, mhlen);
914 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
915 		}
916 		*mnext = m;
917 		mnext = &m->m_nextpkt;
918 	}
919 	IPSTAT_ADD(ips_ofragments, nfrags);
920 
921 	/*
922 	 * Update first fragment by trimming what's been copied out
923 	 * and updating header.
924 	 */
925 	m_adj(m0, hlen + firstlen - ip_len);
926 	m0->m_pkthdr.len = hlen + firstlen;
927 	ip->ip_len = htons((u_short)m0->m_pkthdr.len);
928 	ip->ip_off = htons(ip_off | IP_MF);
929 	ip->ip_sum = 0;
930 	if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
931 		ip->ip_sum = in_cksum(m0, hlen);
932 		m0->m_pkthdr.csum_flags &= ~CSUM_IP;
933 	}
934 
935 done:
936 	*m_frag = m0;
937 	return error;
938 }
939 
940 void
941 in_delayed_cksum(struct mbuf *m)
942 {
943 	struct ip *ip;
944 	uint16_t csum, offset, ip_len;
945 
946 	ip = mtod(m, struct ip *);
947 	offset = ip->ip_hl << 2 ;
948 	ip_len = ntohs(ip->ip_len);
949 	csum = in_cksum_skip(m, ip_len, offset);
950 	if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
951 		csum = 0xffff;
952 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
953 
954 	/* find the mbuf in the chain where the checksum starts*/
955 	while ((m != NULL) && (offset >= m->m_len)) {
956 		offset -= m->m_len;
957 		m = m->m_next;
958 	}
959 	KASSERT(m != NULL, ("in_delayed_cksum: checksum outside mbuf chain."));
960 	KASSERT(offset + sizeof(u_short) <= m->m_len, ("in_delayed_cksum: checksum split between mbufs."));
961 	*(u_short *)(m->m_data + offset) = csum;
962 }
963 
964 /*
965  * IP socket option processing.
966  */
967 int
968 ip_ctloutput(struct socket *so, struct sockopt *sopt)
969 {
970 	struct	inpcb *inp = sotoinpcb(so);
971 	int	error, optval;
972 #ifdef	RSS
973 	uint32_t rss_bucket;
974 	int retval;
975 #endif
976 
977 	error = optval = 0;
978 	if (sopt->sopt_level != IPPROTO_IP) {
979 		error = EINVAL;
980 
981 		if (sopt->sopt_level == SOL_SOCKET &&
982 		    sopt->sopt_dir == SOPT_SET) {
983 			switch (sopt->sopt_name) {
984 			case SO_REUSEADDR:
985 				INP_WLOCK(inp);
986 				if ((so->so_options & SO_REUSEADDR) != 0)
987 					inp->inp_flags2 |= INP_REUSEADDR;
988 				else
989 					inp->inp_flags2 &= ~INP_REUSEADDR;
990 				INP_WUNLOCK(inp);
991 				error = 0;
992 				break;
993 			case SO_REUSEPORT:
994 				INP_WLOCK(inp);
995 				if ((so->so_options & SO_REUSEPORT) != 0)
996 					inp->inp_flags2 |= INP_REUSEPORT;
997 				else
998 					inp->inp_flags2 &= ~INP_REUSEPORT;
999 				INP_WUNLOCK(inp);
1000 				error = 0;
1001 				break;
1002 			case SO_SETFIB:
1003 				INP_WLOCK(inp);
1004 				inp->inp_inc.inc_fibnum = so->so_fibnum;
1005 				INP_WUNLOCK(inp);
1006 				error = 0;
1007 				break;
1008 			case SO_MAX_PACING_RATE:
1009 #ifdef RATELIMIT
1010 				INP_WLOCK(inp);
1011 				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1012 				INP_WUNLOCK(inp);
1013 				error = 0;
1014 #else
1015 				error = EOPNOTSUPP;
1016 #endif
1017 				break;
1018 			default:
1019 				break;
1020 			}
1021 		}
1022 		return (error);
1023 	}
1024 
1025 	switch (sopt->sopt_dir) {
1026 	case SOPT_SET:
1027 		switch (sopt->sopt_name) {
1028 		case IP_OPTIONS:
1029 #ifdef notyet
1030 		case IP_RETOPTS:
1031 #endif
1032 		{
1033 			struct mbuf *m;
1034 			if (sopt->sopt_valsize > MLEN) {
1035 				error = EMSGSIZE;
1036 				break;
1037 			}
1038 			m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
1039 			if (m == NULL) {
1040 				error = ENOBUFS;
1041 				break;
1042 			}
1043 			m->m_len = sopt->sopt_valsize;
1044 			error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1045 					    m->m_len);
1046 			if (error) {
1047 				m_free(m);
1048 				break;
1049 			}
1050 			INP_WLOCK(inp);
1051 			error = ip_pcbopts(inp, sopt->sopt_name, m);
1052 			INP_WUNLOCK(inp);
1053 			return (error);
1054 		}
1055 
1056 		case IP_BINDANY:
1057 			if (sopt->sopt_td != NULL) {
1058 				error = priv_check(sopt->sopt_td,
1059 				    PRIV_NETINET_BINDANY);
1060 				if (error)
1061 					break;
1062 			}
1063 			/* FALLTHROUGH */
1064 		case IP_BINDMULTI:
1065 #ifdef	RSS
1066 		case IP_RSS_LISTEN_BUCKET:
1067 #endif
1068 		case IP_TOS:
1069 		case IP_TTL:
1070 		case IP_MINTTL:
1071 		case IP_RECVOPTS:
1072 		case IP_RECVRETOPTS:
1073 		case IP_RECVDSTADDR:
1074 		case IP_RECVTTL:
1075 		case IP_RECVIF:
1076 		case IP_ONESBCAST:
1077 		case IP_DONTFRAG:
1078 		case IP_RECVTOS:
1079 		case IP_RECVFLOWID:
1080 #ifdef	RSS
1081 		case IP_RECVRSSBUCKETID:
1082 #endif
1083 			error = sooptcopyin(sopt, &optval, sizeof optval,
1084 					    sizeof optval);
1085 			if (error)
1086 				break;
1087 
1088 			switch (sopt->sopt_name) {
1089 			case IP_TOS:
1090 				inp->inp_ip_tos = optval;
1091 				break;
1092 
1093 			case IP_TTL:
1094 				inp->inp_ip_ttl = optval;
1095 				break;
1096 
1097 			case IP_MINTTL:
1098 				if (optval >= 0 && optval <= MAXTTL)
1099 					inp->inp_ip_minttl = optval;
1100 				else
1101 					error = EINVAL;
1102 				break;
1103 
1104 #define	OPTSET(bit) do {						\
1105 	INP_WLOCK(inp);							\
1106 	if (optval)							\
1107 		inp->inp_flags |= bit;					\
1108 	else								\
1109 		inp->inp_flags &= ~bit;					\
1110 	INP_WUNLOCK(inp);						\
1111 } while (0)
1112 
1113 #define	OPTSET2(bit, val) do {						\
1114 	INP_WLOCK(inp);							\
1115 	if (val)							\
1116 		inp->inp_flags2 |= bit;					\
1117 	else								\
1118 		inp->inp_flags2 &= ~bit;				\
1119 	INP_WUNLOCK(inp);						\
1120 } while (0)
1121 
1122 			case IP_RECVOPTS:
1123 				OPTSET(INP_RECVOPTS);
1124 				break;
1125 
1126 			case IP_RECVRETOPTS:
1127 				OPTSET(INP_RECVRETOPTS);
1128 				break;
1129 
1130 			case IP_RECVDSTADDR:
1131 				OPTSET(INP_RECVDSTADDR);
1132 				break;
1133 
1134 			case IP_RECVTTL:
1135 				OPTSET(INP_RECVTTL);
1136 				break;
1137 
1138 			case IP_RECVIF:
1139 				OPTSET(INP_RECVIF);
1140 				break;
1141 
1142 			case IP_ONESBCAST:
1143 				OPTSET(INP_ONESBCAST);
1144 				break;
1145 			case IP_DONTFRAG:
1146 				OPTSET(INP_DONTFRAG);
1147 				break;
1148 			case IP_BINDANY:
1149 				OPTSET(INP_BINDANY);
1150 				break;
1151 			case IP_RECVTOS:
1152 				OPTSET(INP_RECVTOS);
1153 				break;
1154 			case IP_BINDMULTI:
1155 				OPTSET2(INP_BINDMULTI, optval);
1156 				break;
1157 			case IP_RECVFLOWID:
1158 				OPTSET2(INP_RECVFLOWID, optval);
1159 				break;
1160 #ifdef	RSS
1161 			case IP_RSS_LISTEN_BUCKET:
1162 				if ((optval >= 0) &&
1163 				    (optval < rss_getnumbuckets())) {
1164 					inp->inp_rss_listen_bucket = optval;
1165 					OPTSET2(INP_RSS_BUCKET_SET, 1);
1166 				} else {
1167 					error = EINVAL;
1168 				}
1169 				break;
1170 			case IP_RECVRSSBUCKETID:
1171 				OPTSET2(INP_RECVRSSBUCKETID, optval);
1172 				break;
1173 #endif
1174 			}
1175 			break;
1176 #undef OPTSET
1177 #undef OPTSET2
1178 
1179 		/*
1180 		 * Multicast socket options are processed by the in_mcast
1181 		 * module.
1182 		 */
1183 		case IP_MULTICAST_IF:
1184 		case IP_MULTICAST_VIF:
1185 		case IP_MULTICAST_TTL:
1186 		case IP_MULTICAST_LOOP:
1187 		case IP_ADD_MEMBERSHIP:
1188 		case IP_DROP_MEMBERSHIP:
1189 		case IP_ADD_SOURCE_MEMBERSHIP:
1190 		case IP_DROP_SOURCE_MEMBERSHIP:
1191 		case IP_BLOCK_SOURCE:
1192 		case IP_UNBLOCK_SOURCE:
1193 		case IP_MSFILTER:
1194 		case MCAST_JOIN_GROUP:
1195 		case MCAST_LEAVE_GROUP:
1196 		case MCAST_JOIN_SOURCE_GROUP:
1197 		case MCAST_LEAVE_SOURCE_GROUP:
1198 		case MCAST_BLOCK_SOURCE:
1199 		case MCAST_UNBLOCK_SOURCE:
1200 			error = inp_setmoptions(inp, sopt);
1201 			break;
1202 
1203 		case IP_PORTRANGE:
1204 			error = sooptcopyin(sopt, &optval, sizeof optval,
1205 					    sizeof optval);
1206 			if (error)
1207 				break;
1208 
1209 			INP_WLOCK(inp);
1210 			switch (optval) {
1211 			case IP_PORTRANGE_DEFAULT:
1212 				inp->inp_flags &= ~(INP_LOWPORT);
1213 				inp->inp_flags &= ~(INP_HIGHPORT);
1214 				break;
1215 
1216 			case IP_PORTRANGE_HIGH:
1217 				inp->inp_flags &= ~(INP_LOWPORT);
1218 				inp->inp_flags |= INP_HIGHPORT;
1219 				break;
1220 
1221 			case IP_PORTRANGE_LOW:
1222 				inp->inp_flags &= ~(INP_HIGHPORT);
1223 				inp->inp_flags |= INP_LOWPORT;
1224 				break;
1225 
1226 			default:
1227 				error = EINVAL;
1228 				break;
1229 			}
1230 			INP_WUNLOCK(inp);
1231 			break;
1232 
1233 #ifdef IPSEC
1234 		case IP_IPSEC_POLICY:
1235 		{
1236 			caddr_t req;
1237 			struct mbuf *m;
1238 
1239 			if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1240 				break;
1241 			if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1242 				break;
1243 			req = mtod(m, caddr_t);
1244 			error = ipsec_set_policy(inp, sopt->sopt_name, req,
1245 			    m->m_len, (sopt->sopt_td != NULL) ?
1246 			    sopt->sopt_td->td_ucred : NULL);
1247 			m_freem(m);
1248 			break;
1249 		}
1250 #endif /* IPSEC */
1251 
1252 		default:
1253 			error = ENOPROTOOPT;
1254 			break;
1255 		}
1256 		break;
1257 
1258 	case SOPT_GET:
1259 		switch (sopt->sopt_name) {
1260 		case IP_OPTIONS:
1261 		case IP_RETOPTS:
1262 			if (inp->inp_options)
1263 				error = sooptcopyout(sopt,
1264 						     mtod(inp->inp_options,
1265 							  char *),
1266 						     inp->inp_options->m_len);
1267 			else
1268 				sopt->sopt_valsize = 0;
1269 			break;
1270 
1271 		case IP_TOS:
1272 		case IP_TTL:
1273 		case IP_MINTTL:
1274 		case IP_RECVOPTS:
1275 		case IP_RECVRETOPTS:
1276 		case IP_RECVDSTADDR:
1277 		case IP_RECVTTL:
1278 		case IP_RECVIF:
1279 		case IP_PORTRANGE:
1280 		case IP_ONESBCAST:
1281 		case IP_DONTFRAG:
1282 		case IP_BINDANY:
1283 		case IP_RECVTOS:
1284 		case IP_BINDMULTI:
1285 		case IP_FLOWID:
1286 		case IP_FLOWTYPE:
1287 		case IP_RECVFLOWID:
1288 #ifdef	RSS
1289 		case IP_RSSBUCKETID:
1290 		case IP_RECVRSSBUCKETID:
1291 #endif
1292 			switch (sopt->sopt_name) {
1293 
1294 			case IP_TOS:
1295 				optval = inp->inp_ip_tos;
1296 				break;
1297 
1298 			case IP_TTL:
1299 				optval = inp->inp_ip_ttl;
1300 				break;
1301 
1302 			case IP_MINTTL:
1303 				optval = inp->inp_ip_minttl;
1304 				break;
1305 
1306 #define	OPTBIT(bit)	(inp->inp_flags & bit ? 1 : 0)
1307 #define	OPTBIT2(bit)	(inp->inp_flags2 & bit ? 1 : 0)
1308 
1309 			case IP_RECVOPTS:
1310 				optval = OPTBIT(INP_RECVOPTS);
1311 				break;
1312 
1313 			case IP_RECVRETOPTS:
1314 				optval = OPTBIT(INP_RECVRETOPTS);
1315 				break;
1316 
1317 			case IP_RECVDSTADDR:
1318 				optval = OPTBIT(INP_RECVDSTADDR);
1319 				break;
1320 
1321 			case IP_RECVTTL:
1322 				optval = OPTBIT(INP_RECVTTL);
1323 				break;
1324 
1325 			case IP_RECVIF:
1326 				optval = OPTBIT(INP_RECVIF);
1327 				break;
1328 
1329 			case IP_PORTRANGE:
1330 				if (inp->inp_flags & INP_HIGHPORT)
1331 					optval = IP_PORTRANGE_HIGH;
1332 				else if (inp->inp_flags & INP_LOWPORT)
1333 					optval = IP_PORTRANGE_LOW;
1334 				else
1335 					optval = 0;
1336 				break;
1337 
1338 			case IP_ONESBCAST:
1339 				optval = OPTBIT(INP_ONESBCAST);
1340 				break;
1341 			case IP_DONTFRAG:
1342 				optval = OPTBIT(INP_DONTFRAG);
1343 				break;
1344 			case IP_BINDANY:
1345 				optval = OPTBIT(INP_BINDANY);
1346 				break;
1347 			case IP_RECVTOS:
1348 				optval = OPTBIT(INP_RECVTOS);
1349 				break;
1350 			case IP_FLOWID:
1351 				optval = inp->inp_flowid;
1352 				break;
1353 			case IP_FLOWTYPE:
1354 				optval = inp->inp_flowtype;
1355 				break;
1356 			case IP_RECVFLOWID:
1357 				optval = OPTBIT2(INP_RECVFLOWID);
1358 				break;
1359 #ifdef	RSS
1360 			case IP_RSSBUCKETID:
1361 				retval = rss_hash2bucket(inp->inp_flowid,
1362 				    inp->inp_flowtype,
1363 				    &rss_bucket);
1364 				if (retval == 0)
1365 					optval = rss_bucket;
1366 				else
1367 					error = EINVAL;
1368 				break;
1369 			case IP_RECVRSSBUCKETID:
1370 				optval = OPTBIT2(INP_RECVRSSBUCKETID);
1371 				break;
1372 #endif
1373 			case IP_BINDMULTI:
1374 				optval = OPTBIT2(INP_BINDMULTI);
1375 				break;
1376 			}
1377 			error = sooptcopyout(sopt, &optval, sizeof optval);
1378 			break;
1379 
1380 		/*
1381 		 * Multicast socket options are processed by the in_mcast
1382 		 * module.
1383 		 */
1384 		case IP_MULTICAST_IF:
1385 		case IP_MULTICAST_VIF:
1386 		case IP_MULTICAST_TTL:
1387 		case IP_MULTICAST_LOOP:
1388 		case IP_MSFILTER:
1389 			error = inp_getmoptions(inp, sopt);
1390 			break;
1391 
1392 #ifdef IPSEC
1393 		case IP_IPSEC_POLICY:
1394 		{
1395 			struct mbuf *m = NULL;
1396 			caddr_t req = NULL;
1397 			size_t len = 0;
1398 
1399 			if (m != NULL) {
1400 				req = mtod(m, caddr_t);
1401 				len = m->m_len;
1402 			}
1403 			error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1404 			if (error == 0)
1405 				error = soopt_mcopyout(sopt, m); /* XXX */
1406 			if (error == 0)
1407 				m_freem(m);
1408 			break;
1409 		}
1410 #endif /* IPSEC */
1411 
1412 		default:
1413 			error = ENOPROTOOPT;
1414 			break;
1415 		}
1416 		break;
1417 	}
1418 	return (error);
1419 }
1420 
1421 /*
1422  * Routine called from ip_output() to loop back a copy of an IP multicast
1423  * packet to the input queue of a specified interface.  Note that this
1424  * calls the output routine of the loopback "driver", but with an interface
1425  * pointer that might NOT be a loopback interface -- evil, but easier than
1426  * replicating that code here.
1427  */
1428 static void
1429 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1430 {
1431 	struct ip *ip;
1432 	struct mbuf *copym;
1433 
1434 	/*
1435 	 * Make a deep copy of the packet because we're going to
1436 	 * modify the pack in order to generate checksums.
1437 	 */
1438 	copym = m_dup(m, M_NOWAIT);
1439 	if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1440 		copym = m_pullup(copym, hlen);
1441 	if (copym != NULL) {
1442 		/* If needed, compute the checksum and mark it as valid. */
1443 		if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1444 			in_delayed_cksum(copym);
1445 			copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1446 			copym->m_pkthdr.csum_flags |=
1447 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1448 			copym->m_pkthdr.csum_data = 0xffff;
1449 		}
1450 		/*
1451 		 * We don't bother to fragment if the IP length is greater
1452 		 * than the interface's MTU.  Can this possibly matter?
1453 		 */
1454 		ip = mtod(copym, struct ip *);
1455 		ip->ip_sum = 0;
1456 		ip->ip_sum = in_cksum(copym, hlen);
1457 		if_simloop(ifp, copym, AF_INET, 0);
1458 	}
1459 }
1460