xref: /freebsd/sys/netinet/ip_output.c (revision c94c8223bd444fa38ded3797060110c590f422f4)
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_ipfw.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 	}
249 
250 #ifdef FLOWTABLE
251 	if (ro->ro_rt == NULL)
252 		(void )flowtable_lookup(AF_INET, m, ro);
253 #endif
254 
255 	if (opt) {
256 		int len = 0;
257 		m = ip_insertoptions(m, opt, &len);
258 		if (len != 0)
259 			hlen = len; /* ip->ip_hl is updated above */
260 	}
261 	ip = mtod(m, struct ip *);
262 	ip_len = ntohs(ip->ip_len);
263 	ip_off = ntohs(ip->ip_off);
264 
265 	if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
266 		ip->ip_v = IPVERSION;
267 		ip->ip_hl = hlen >> 2;
268 		ip_fillid(ip);
269 		IPSTAT_INC(ips_localout);
270 	} else {
271 		/* Header already set, fetch hlen from there */
272 		hlen = ip->ip_hl << 2;
273 	}
274 
275 	/*
276 	 * dst/gw handling:
277 	 *
278 	 * dst can be rewritten but always points to &ro->ro_dst.
279 	 * gw is readonly but can point either to dst OR rt_gateway,
280 	 * therefore we need restore gw if we're redoing lookup.
281 	 */
282 	gw = dst = (struct sockaddr_in *)&ro->ro_dst;
283 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
284 	rte = ro->ro_rt;
285 	if (rte == NULL) {
286 		bzero(dst, sizeof(*dst));
287 		dst->sin_family = AF_INET;
288 		dst->sin_len = sizeof(*dst);
289 		dst->sin_addr = ip->ip_dst;
290 	}
291 again:
292 	/*
293 	 * Validate route against routing table additions;
294 	 * a better/more specific route might have been added.
295 	 */
296 	if (inp)
297 		RT_VALIDATE(ro, &inp->inp_rt_cookie, fibnum);
298 	/*
299 	 * If there is a cached route,
300 	 * check that it is to the same destination
301 	 * and is still up.  If not, free it and try again.
302 	 * The address family should also be checked in case of sharing the
303 	 * cache with IPv6.
304 	 * Also check whether routing cache needs invalidation.
305 	 */
306 	rte = ro->ro_rt;
307 	if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
308 		    rte->rt_ifp == NULL ||
309 		    !RT_LINK_IS_UP(rte->rt_ifp) ||
310 			  dst->sin_family != AF_INET ||
311 			  dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
312 		RTFREE(rte);
313 		rte = ro->ro_rt = (struct rtentry *)NULL;
314 	}
315 	ia = NULL;
316 	have_ia_ref = 0;
317 	/*
318 	 * If routing to interface only, short circuit routing lookup.
319 	 * The use of an all-ones broadcast address implies this; an
320 	 * interface is specified by the broadcast address of an interface,
321 	 * or the destination address of a ptp interface.
322 	 */
323 	if (flags & IP_SENDONES) {
324 		if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
325 						      M_GETFIB(m)))) == NULL &&
326 		    (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
327 						    M_GETFIB(m)))) == NULL) {
328 			IPSTAT_INC(ips_noroute);
329 			error = ENETUNREACH;
330 			goto bad;
331 		}
332 		have_ia_ref = 1;
333 		ip->ip_dst.s_addr = INADDR_BROADCAST;
334 		dst->sin_addr = ip->ip_dst;
335 		ifp = ia->ia_ifp;
336 		ip->ip_ttl = 1;
337 		isbroadcast = 1;
338 	} else if (flags & IP_ROUTETOIF) {
339 		if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
340 						    M_GETFIB(m)))) == NULL &&
341 		    (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
342 						M_GETFIB(m)))) == NULL) {
343 			IPSTAT_INC(ips_noroute);
344 			error = ENETUNREACH;
345 			goto bad;
346 		}
347 		have_ia_ref = 1;
348 		ifp = ia->ia_ifp;
349 		ip->ip_ttl = 1;
350 		isbroadcast = in_broadcast(dst->sin_addr, ifp);
351 	} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
352 	    imo != NULL && imo->imo_multicast_ifp != NULL) {
353 		/*
354 		 * Bypass the normal routing lookup for multicast
355 		 * packets if the interface is specified.
356 		 */
357 		ifp = imo->imo_multicast_ifp;
358 		IFP_TO_IA(ifp, ia, &in_ifa_tracker);
359 		if (ia)
360 			have_ia_ref = 1;
361 		isbroadcast = 0;	/* fool gcc */
362 	} else {
363 		/*
364 		 * We want to do any cloning requested by the link layer,
365 		 * as this is probably required in all cases for correct
366 		 * operation (as it is for ARP).
367 		 */
368 		if (rte == NULL) {
369 #ifdef RADIX_MPATH
370 			rtalloc_mpath_fib(ro,
371 			    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
372 			    fibnum);
373 #else
374 			in_rtalloc_ign(ro, 0, fibnum);
375 #endif
376 			rte = ro->ro_rt;
377 		}
378 		if (rte == NULL ||
379 		    (rte->rt_flags & RTF_UP) == 0 ||
380 		    rte->rt_ifp == NULL ||
381 		    !RT_LINK_IS_UP(rte->rt_ifp)) {
382 #ifdef IPSEC
383 			/*
384 			 * There is no route for this packet, but it is
385 			 * possible that a matching SPD entry exists.
386 			 */
387 			no_route_but_check_spd = 1;
388 			mtu = 0; /* Silence GCC warning. */
389 			goto sendit;
390 #endif
391 			IPSTAT_INC(ips_noroute);
392 			error = EHOSTUNREACH;
393 			goto bad;
394 		}
395 		ia = ifatoia(rte->rt_ifa);
396 		ifp = rte->rt_ifp;
397 		counter_u64_add(rte->rt_pksent, 1);
398 		rt_update_ro_flags(ro);
399 		if (rte->rt_flags & RTF_GATEWAY)
400 			gw = (struct sockaddr_in *)rte->rt_gateway;
401 		if (rte->rt_flags & RTF_HOST)
402 			isbroadcast = (rte->rt_flags & RTF_BROADCAST);
403 		else
404 			isbroadcast = in_broadcast(gw->sin_addr, ifp);
405 	}
406 
407 	/*
408 	 * Calculate MTU.  If we have a route that is up, use that,
409 	 * otherwise use the interface's MTU.
410 	 */
411 	if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST)))
412 		mtu = rte->rt_mtu;
413 	else
414 		mtu = ifp->if_mtu;
415 	/* Catch a possible divide by zero later. */
416 	KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
417 	    __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
418 
419 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
420 		m->m_flags |= M_MCAST;
421 		/*
422 		 * IP destination address is multicast.  Make sure "gw"
423 		 * still points to the address in "ro".  (It may have been
424 		 * changed to point to a gateway address, above.)
425 		 */
426 		gw = dst;
427 		/*
428 		 * See if the caller provided any multicast options
429 		 */
430 		if (imo != NULL) {
431 			ip->ip_ttl = imo->imo_multicast_ttl;
432 			if (imo->imo_multicast_vif != -1)
433 				ip->ip_src.s_addr =
434 				    ip_mcast_src ?
435 				    ip_mcast_src(imo->imo_multicast_vif) :
436 				    INADDR_ANY;
437 		} else
438 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
439 		/*
440 		 * Confirm that the outgoing interface supports multicast.
441 		 */
442 		if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
443 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
444 				IPSTAT_INC(ips_noroute);
445 				error = ENETUNREACH;
446 				goto bad;
447 			}
448 		}
449 		/*
450 		 * If source address not specified yet, use address
451 		 * of outgoing interface.
452 		 */
453 		if (ip->ip_src.s_addr == INADDR_ANY) {
454 			/* Interface may have no addresses. */
455 			if (ia != NULL)
456 				ip->ip_src = IA_SIN(ia)->sin_addr;
457 		}
458 
459 		if ((imo == NULL && in_mcast_loop) ||
460 		    (imo && imo->imo_multicast_loop)) {
461 			/*
462 			 * Loop back multicast datagram if not expressly
463 			 * forbidden to do so, even if we are not a member
464 			 * of the group; ip_input() will filter it later,
465 			 * thus deferring a hash lookup and mutex acquisition
466 			 * at the expense of a cheap copy using m_copym().
467 			 */
468 			ip_mloopback(ifp, m, hlen);
469 		} else {
470 			/*
471 			 * If we are acting as a multicast router, perform
472 			 * multicast forwarding as if the packet had just
473 			 * arrived on the interface to which we are about
474 			 * to send.  The multicast forwarding function
475 			 * recursively calls this function, using the
476 			 * IP_FORWARDING flag to prevent infinite recursion.
477 			 *
478 			 * Multicasts that are looped back by ip_mloopback(),
479 			 * above, will be forwarded by the ip_input() routine,
480 			 * if necessary.
481 			 */
482 			if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
483 				/*
484 				 * If rsvp daemon is not running, do not
485 				 * set ip_moptions. This ensures that the packet
486 				 * is multicast and not just sent down one link
487 				 * as prescribed by rsvpd.
488 				 */
489 				if (!V_rsvp_on)
490 					imo = NULL;
491 				if (ip_mforward &&
492 				    ip_mforward(ip, ifp, m, imo) != 0) {
493 					m_freem(m);
494 					goto done;
495 				}
496 			}
497 		}
498 
499 		/*
500 		 * Multicasts with a time-to-live of zero may be looped-
501 		 * back, above, but must not be transmitted on a network.
502 		 * Also, multicasts addressed to the loopback interface
503 		 * are not sent -- the above call to ip_mloopback() will
504 		 * loop back a copy. ip_input() will drop the copy if
505 		 * this host does not belong to the destination group on
506 		 * the loopback interface.
507 		 */
508 		if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
509 			m_freem(m);
510 			goto done;
511 		}
512 
513 		goto sendit;
514 	}
515 
516 	/*
517 	 * If the source address is not specified yet, use the address
518 	 * of the outoing interface.
519 	 */
520 	if (ip->ip_src.s_addr == INADDR_ANY) {
521 		/* Interface may have no addresses. */
522 		if (ia != NULL) {
523 			ip->ip_src = IA_SIN(ia)->sin_addr;
524 		}
525 	}
526 
527 	/*
528 	 * Look for broadcast address and
529 	 * verify user is allowed to send
530 	 * such a packet.
531 	 */
532 	if (isbroadcast) {
533 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
534 			error = EADDRNOTAVAIL;
535 			goto bad;
536 		}
537 		if ((flags & IP_ALLOWBROADCAST) == 0) {
538 			error = EACCES;
539 			goto bad;
540 		}
541 		/* don't allow broadcast messages to be fragmented */
542 		if (ip_len > mtu) {
543 			error = EMSGSIZE;
544 			goto bad;
545 		}
546 		m->m_flags |= M_BCAST;
547 	} else {
548 		m->m_flags &= ~M_BCAST;
549 	}
550 
551 sendit:
552 #ifdef IPSEC
553 	switch(ip_ipsec_output(&m, inp, &error)) {
554 	case 1:
555 		goto bad;
556 	case -1:
557 		goto done;
558 	case 0:
559 	default:
560 		break;	/* Continue with packet processing. */
561 	}
562 	/*
563 	 * Check if there was a route for this packet; return error if not.
564 	 */
565 	if (no_route_but_check_spd) {
566 		IPSTAT_INC(ips_noroute);
567 		error = EHOSTUNREACH;
568 		goto bad;
569 	}
570 	/* Update variables that are affected by ipsec4_output(). */
571 	ip = mtod(m, struct ip *);
572 	hlen = ip->ip_hl << 2;
573 #endif /* IPSEC */
574 
575 	/* Jump over all PFIL processing if hooks are not active. */
576 	if (PFIL_HOOKED(&V_inet_pfil_hook)) {
577 		switch (ip_output_pfil(&m, ifp, inp, dst, &fibnum, &error)) {
578 		case 1: /* Finished */
579 			goto done;
580 
581 		case 0: /* Continue normally */
582 			ip = mtod(m, struct ip *);
583 			break;
584 
585 		case -1: /* Need to try again */
586 			/* Reset everything for a new round */
587 			RO_RTFREE(ro);
588 			if (have_ia_ref)
589 				ifa_free(&ia->ia_ifa);
590 			ro->ro_prepend = NULL;
591 			rte = NULL;
592 			gw = dst;
593 			ip = mtod(m, struct ip *);
594 			goto again;
595 
596 		}
597 	}
598 
599 	/* 127/8 must not appear on wire - RFC1122. */
600 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
601 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
602 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
603 			IPSTAT_INC(ips_badaddr);
604 			error = EADDRNOTAVAIL;
605 			goto bad;
606 		}
607 	}
608 
609 	m->m_pkthdr.csum_flags |= CSUM_IP;
610 	if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
611 		in_delayed_cksum(m);
612 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
613 	}
614 #ifdef SCTP
615 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
616 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
617 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
618 	}
619 #endif
620 
621 	/*
622 	 * If small enough for interface, or the interface will take
623 	 * care of the fragmentation for us, we can just send directly.
624 	 */
625 	if (ip_len <= mtu ||
626 	    (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) {
627 		ip->ip_sum = 0;
628 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
629 			ip->ip_sum = in_cksum(m, hlen);
630 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
631 		}
632 
633 		/*
634 		 * Record statistics for this interface address.
635 		 * With CSUM_TSO the byte/packet count will be slightly
636 		 * incorrect because we count the IP+TCP headers only
637 		 * once instead of for every generated packet.
638 		 */
639 		if (!(flags & IP_FORWARDING) && ia) {
640 			if (m->m_pkthdr.csum_flags & CSUM_TSO)
641 				counter_u64_add(ia->ia_ifa.ifa_opackets,
642 				    m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
643 			else
644 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
645 
646 			counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
647 		}
648 #ifdef MBUF_STRESS_TEST
649 		if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
650 			m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
651 #endif
652 		/*
653 		 * Reset layer specific mbuf flags
654 		 * to avoid confusing lower layers.
655 		 */
656 		m_clrprotoflags(m);
657 		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
658 		error = (*ifp->if_output)(ifp, m,
659 		    (const struct sockaddr *)gw, ro);
660 		goto done;
661 	}
662 
663 	/* Balk when DF bit is set or the interface didn't support TSO. */
664 	if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
665 		error = EMSGSIZE;
666 		IPSTAT_INC(ips_cantfrag);
667 		goto bad;
668 	}
669 
670 	/*
671 	 * Too large for interface; fragment if possible. If successful,
672 	 * on return, m will point to a list of packets to be sent.
673 	 */
674 	error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
675 	if (error)
676 		goto bad;
677 	for (; m; m = m0) {
678 		m0 = m->m_nextpkt;
679 		m->m_nextpkt = 0;
680 		if (error == 0) {
681 			/* Record statistics for this interface address. */
682 			if (ia != NULL) {
683 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
684 				counter_u64_add(ia->ia_ifa.ifa_obytes,
685 				    m->m_pkthdr.len);
686 			}
687 			/*
688 			 * Reset layer specific mbuf flags
689 			 * to avoid confusing upper layers.
690 			 */
691 			m_clrprotoflags(m);
692 
693 			IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
694 			error = (*ifp->if_output)(ifp, m,
695 			    (const struct sockaddr *)gw, ro);
696 		} else
697 			m_freem(m);
698 	}
699 
700 	if (error == 0)
701 		IPSTAT_INC(ips_fragmented);
702 
703 done:
704 	if (ro == &iproute)
705 		RO_RTFREE(ro);
706 	else if (rte == NULL)
707 		/*
708 		 * If the caller supplied a route but somehow the reference
709 		 * to it has been released need to prevent the caller
710 		 * calling RTFREE on it again.
711 		 */
712 		ro->ro_rt = NULL;
713 	if (have_ia_ref)
714 		ifa_free(&ia->ia_ifa);
715 	return (error);
716 bad:
717 	m_freem(m);
718 	goto done;
719 }
720 
721 /*
722  * Create a chain of fragments which fit the given mtu. m_frag points to the
723  * mbuf to be fragmented; on return it points to the chain with the fragments.
724  * Return 0 if no error. If error, m_frag may contain a partially built
725  * chain of fragments that should be freed by the caller.
726  *
727  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
728  */
729 int
730 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
731     u_long if_hwassist_flags)
732 {
733 	int error = 0;
734 	int hlen = ip->ip_hl << 2;
735 	int len = (mtu - hlen) & ~7;	/* size of payload in each fragment */
736 	int off;
737 	struct mbuf *m0 = *m_frag;	/* the original packet		*/
738 	int firstlen;
739 	struct mbuf **mnext;
740 	int nfrags;
741 	uint16_t ip_len, ip_off;
742 
743 	ip_len = ntohs(ip->ip_len);
744 	ip_off = ntohs(ip->ip_off);
745 
746 	if (ip_off & IP_DF) {	/* Fragmentation not allowed */
747 		IPSTAT_INC(ips_cantfrag);
748 		return EMSGSIZE;
749 	}
750 
751 	/*
752 	 * Must be able to put at least 8 bytes per fragment.
753 	 */
754 	if (len < 8)
755 		return EMSGSIZE;
756 
757 	/*
758 	 * If the interface will not calculate checksums on
759 	 * fragmented packets, then do it here.
760 	 */
761 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
762 		in_delayed_cksum(m0);
763 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
764 	}
765 #ifdef SCTP
766 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
767 		sctp_delayed_cksum(m0, hlen);
768 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
769 	}
770 #endif
771 	if (len > PAGE_SIZE) {
772 		/*
773 		 * Fragment large datagrams such that each segment
774 		 * contains a multiple of PAGE_SIZE amount of data,
775 		 * plus headers. This enables a receiver to perform
776 		 * page-flipping zero-copy optimizations.
777 		 *
778 		 * XXX When does this help given that sender and receiver
779 		 * could have different page sizes, and also mtu could
780 		 * be less than the receiver's page size ?
781 		 */
782 		int newlen;
783 
784 		off = MIN(mtu, m0->m_pkthdr.len);
785 
786 		/*
787 		 * firstlen (off - hlen) must be aligned on an
788 		 * 8-byte boundary
789 		 */
790 		if (off < hlen)
791 			goto smart_frag_failure;
792 		off = ((off - hlen) & ~7) + hlen;
793 		newlen = (~PAGE_MASK) & mtu;
794 		if ((newlen + sizeof (struct ip)) > mtu) {
795 			/* we failed, go back the default */
796 smart_frag_failure:
797 			newlen = len;
798 			off = hlen + len;
799 		}
800 		len = newlen;
801 
802 	} else {
803 		off = hlen + len;
804 	}
805 
806 	firstlen = off - hlen;
807 	mnext = &m0->m_nextpkt;		/* pointer to next packet */
808 
809 	/*
810 	 * Loop through length of segment after first fragment,
811 	 * make new header and copy data of each part and link onto chain.
812 	 * Here, m0 is the original packet, m is the fragment being created.
813 	 * The fragments are linked off the m_nextpkt of the original
814 	 * packet, which after processing serves as the first fragment.
815 	 */
816 	for (nfrags = 1; off < ip_len; off += len, nfrags++) {
817 		struct ip *mhip;	/* ip header on the fragment */
818 		struct mbuf *m;
819 		int mhlen = sizeof (struct ip);
820 
821 		m = m_gethdr(M_NOWAIT, MT_DATA);
822 		if (m == NULL) {
823 			error = ENOBUFS;
824 			IPSTAT_INC(ips_odropped);
825 			goto done;
826 		}
827 		/*
828 		 * Make sure the complete packet header gets copied
829 		 * from the originating mbuf to the newly created
830 		 * mbuf. This also ensures that existing firewall
831 		 * classification(s), VLAN tags and so on get copied
832 		 * to the resulting fragmented packet(s):
833 		 */
834 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
835 			m_free(m);
836 			error = ENOBUFS;
837 			IPSTAT_INC(ips_odropped);
838 			goto done;
839 		}
840 		/*
841 		 * In the first mbuf, leave room for the link header, then
842 		 * copy the original IP header including options. The payload
843 		 * goes into an additional mbuf chain returned by m_copym().
844 		 */
845 		m->m_data += max_linkhdr;
846 		mhip = mtod(m, struct ip *);
847 		*mhip = *ip;
848 		if (hlen > sizeof (struct ip)) {
849 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
850 			mhip->ip_v = IPVERSION;
851 			mhip->ip_hl = mhlen >> 2;
852 		}
853 		m->m_len = mhlen;
854 		/* XXX do we need to add ip_off below ? */
855 		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
856 		if (off + len >= ip_len)
857 			len = ip_len - off;
858 		else
859 			mhip->ip_off |= IP_MF;
860 		mhip->ip_len = htons((u_short)(len + mhlen));
861 		m->m_next = m_copym(m0, off, len, M_NOWAIT);
862 		if (m->m_next == NULL) {	/* copy failed */
863 			m_free(m);
864 			error = ENOBUFS;	/* ??? */
865 			IPSTAT_INC(ips_odropped);
866 			goto done;
867 		}
868 		m->m_pkthdr.len = mhlen + len;
869 #ifdef MAC
870 		mac_netinet_fragment(m0, m);
871 #endif
872 		mhip->ip_off = htons(mhip->ip_off);
873 		mhip->ip_sum = 0;
874 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
875 			mhip->ip_sum = in_cksum(m, mhlen);
876 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
877 		}
878 		*mnext = m;
879 		mnext = &m->m_nextpkt;
880 	}
881 	IPSTAT_ADD(ips_ofragments, nfrags);
882 
883 	/*
884 	 * Update first fragment by trimming what's been copied out
885 	 * and updating header.
886 	 */
887 	m_adj(m0, hlen + firstlen - ip_len);
888 	m0->m_pkthdr.len = hlen + firstlen;
889 	ip->ip_len = htons((u_short)m0->m_pkthdr.len);
890 	ip->ip_off = htons(ip_off | IP_MF);
891 	ip->ip_sum = 0;
892 	if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
893 		ip->ip_sum = in_cksum(m0, hlen);
894 		m0->m_pkthdr.csum_flags &= ~CSUM_IP;
895 	}
896 
897 done:
898 	*m_frag = m0;
899 	return error;
900 }
901 
902 void
903 in_delayed_cksum(struct mbuf *m)
904 {
905 	struct ip *ip;
906 	uint16_t csum, offset, ip_len;
907 
908 	ip = mtod(m, struct ip *);
909 	offset = ip->ip_hl << 2 ;
910 	ip_len = ntohs(ip->ip_len);
911 	csum = in_cksum_skip(m, ip_len, offset);
912 	if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
913 		csum = 0xffff;
914 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
915 
916 	/* find the mbuf in the chain where the checksum starts*/
917 	while ((m != NULL) && (offset >= m->m_len)) {
918 		offset -= m->m_len;
919 		m = m->m_next;
920 	}
921 	KASSERT(m != NULL, ("in_delayed_cksum: checksum outside mbuf chain."));
922 	KASSERT(offset + sizeof(u_short) <= m->m_len, ("in_delayed_cksum: checksum split between mbufs."));
923 	*(u_short *)(m->m_data + offset) = csum;
924 }
925 
926 /*
927  * IP socket option processing.
928  */
929 int
930 ip_ctloutput(struct socket *so, struct sockopt *sopt)
931 {
932 	struct	inpcb *inp = sotoinpcb(so);
933 	int	error, optval;
934 #ifdef	RSS
935 	uint32_t rss_bucket;
936 	int retval;
937 #endif
938 
939 	error = optval = 0;
940 	if (sopt->sopt_level != IPPROTO_IP) {
941 		error = EINVAL;
942 
943 		if (sopt->sopt_level == SOL_SOCKET &&
944 		    sopt->sopt_dir == SOPT_SET) {
945 			switch (sopt->sopt_name) {
946 			case SO_REUSEADDR:
947 				INP_WLOCK(inp);
948 				if ((so->so_options & SO_REUSEADDR) != 0)
949 					inp->inp_flags2 |= INP_REUSEADDR;
950 				else
951 					inp->inp_flags2 &= ~INP_REUSEADDR;
952 				INP_WUNLOCK(inp);
953 				error = 0;
954 				break;
955 			case SO_REUSEPORT:
956 				INP_WLOCK(inp);
957 				if ((so->so_options & SO_REUSEPORT) != 0)
958 					inp->inp_flags2 |= INP_REUSEPORT;
959 				else
960 					inp->inp_flags2 &= ~INP_REUSEPORT;
961 				INP_WUNLOCK(inp);
962 				error = 0;
963 				break;
964 			case SO_SETFIB:
965 				INP_WLOCK(inp);
966 				inp->inp_inc.inc_fibnum = so->so_fibnum;
967 				INP_WUNLOCK(inp);
968 				error = 0;
969 				break;
970 			default:
971 				break;
972 			}
973 		}
974 		return (error);
975 	}
976 
977 	switch (sopt->sopt_dir) {
978 	case SOPT_SET:
979 		switch (sopt->sopt_name) {
980 		case IP_OPTIONS:
981 #ifdef notyet
982 		case IP_RETOPTS:
983 #endif
984 		{
985 			struct mbuf *m;
986 			if (sopt->sopt_valsize > MLEN) {
987 				error = EMSGSIZE;
988 				break;
989 			}
990 			m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
991 			if (m == NULL) {
992 				error = ENOBUFS;
993 				break;
994 			}
995 			m->m_len = sopt->sopt_valsize;
996 			error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
997 					    m->m_len);
998 			if (error) {
999 				m_free(m);
1000 				break;
1001 			}
1002 			INP_WLOCK(inp);
1003 			error = ip_pcbopts(inp, sopt->sopt_name, m);
1004 			INP_WUNLOCK(inp);
1005 			return (error);
1006 		}
1007 
1008 		case IP_BINDANY:
1009 			if (sopt->sopt_td != NULL) {
1010 				error = priv_check(sopt->sopt_td,
1011 				    PRIV_NETINET_BINDANY);
1012 				if (error)
1013 					break;
1014 			}
1015 			/* FALLTHROUGH */
1016 		case IP_BINDMULTI:
1017 #ifdef	RSS
1018 		case IP_RSS_LISTEN_BUCKET:
1019 #endif
1020 		case IP_TOS:
1021 		case IP_TTL:
1022 		case IP_MINTTL:
1023 		case IP_RECVOPTS:
1024 		case IP_RECVRETOPTS:
1025 		case IP_RECVDSTADDR:
1026 		case IP_RECVTTL:
1027 		case IP_RECVIF:
1028 		case IP_ONESBCAST:
1029 		case IP_DONTFRAG:
1030 		case IP_RECVTOS:
1031 		case IP_RECVFLOWID:
1032 #ifdef	RSS
1033 		case IP_RECVRSSBUCKETID:
1034 #endif
1035 			error = sooptcopyin(sopt, &optval, sizeof optval,
1036 					    sizeof optval);
1037 			if (error)
1038 				break;
1039 
1040 			switch (sopt->sopt_name) {
1041 			case IP_TOS:
1042 				inp->inp_ip_tos = optval;
1043 				break;
1044 
1045 			case IP_TTL:
1046 				inp->inp_ip_ttl = optval;
1047 				break;
1048 
1049 			case IP_MINTTL:
1050 				if (optval >= 0 && optval <= MAXTTL)
1051 					inp->inp_ip_minttl = optval;
1052 				else
1053 					error = EINVAL;
1054 				break;
1055 
1056 #define	OPTSET(bit) do {						\
1057 	INP_WLOCK(inp);							\
1058 	if (optval)							\
1059 		inp->inp_flags |= bit;					\
1060 	else								\
1061 		inp->inp_flags &= ~bit;					\
1062 	INP_WUNLOCK(inp);						\
1063 } while (0)
1064 
1065 #define	OPTSET2(bit, val) do {						\
1066 	INP_WLOCK(inp);							\
1067 	if (val)							\
1068 		inp->inp_flags2 |= bit;					\
1069 	else								\
1070 		inp->inp_flags2 &= ~bit;				\
1071 	INP_WUNLOCK(inp);						\
1072 } while (0)
1073 
1074 			case IP_RECVOPTS:
1075 				OPTSET(INP_RECVOPTS);
1076 				break;
1077 
1078 			case IP_RECVRETOPTS:
1079 				OPTSET(INP_RECVRETOPTS);
1080 				break;
1081 
1082 			case IP_RECVDSTADDR:
1083 				OPTSET(INP_RECVDSTADDR);
1084 				break;
1085 
1086 			case IP_RECVTTL:
1087 				OPTSET(INP_RECVTTL);
1088 				break;
1089 
1090 			case IP_RECVIF:
1091 				OPTSET(INP_RECVIF);
1092 				break;
1093 
1094 			case IP_ONESBCAST:
1095 				OPTSET(INP_ONESBCAST);
1096 				break;
1097 			case IP_DONTFRAG:
1098 				OPTSET(INP_DONTFRAG);
1099 				break;
1100 			case IP_BINDANY:
1101 				OPTSET(INP_BINDANY);
1102 				break;
1103 			case IP_RECVTOS:
1104 				OPTSET(INP_RECVTOS);
1105 				break;
1106 			case IP_BINDMULTI:
1107 				OPTSET2(INP_BINDMULTI, optval);
1108 				break;
1109 			case IP_RECVFLOWID:
1110 				OPTSET2(INP_RECVFLOWID, optval);
1111 				break;
1112 #ifdef	RSS
1113 			case IP_RSS_LISTEN_BUCKET:
1114 				if ((optval >= 0) &&
1115 				    (optval < rss_getnumbuckets())) {
1116 					inp->inp_rss_listen_bucket = optval;
1117 					OPTSET2(INP_RSS_BUCKET_SET, 1);
1118 				} else {
1119 					error = EINVAL;
1120 				}
1121 				break;
1122 			case IP_RECVRSSBUCKETID:
1123 				OPTSET2(INP_RECVRSSBUCKETID, optval);
1124 				break;
1125 #endif
1126 			}
1127 			break;
1128 #undef OPTSET
1129 #undef OPTSET2
1130 
1131 		/*
1132 		 * Multicast socket options are processed by the in_mcast
1133 		 * module.
1134 		 */
1135 		case IP_MULTICAST_IF:
1136 		case IP_MULTICAST_VIF:
1137 		case IP_MULTICAST_TTL:
1138 		case IP_MULTICAST_LOOP:
1139 		case IP_ADD_MEMBERSHIP:
1140 		case IP_DROP_MEMBERSHIP:
1141 		case IP_ADD_SOURCE_MEMBERSHIP:
1142 		case IP_DROP_SOURCE_MEMBERSHIP:
1143 		case IP_BLOCK_SOURCE:
1144 		case IP_UNBLOCK_SOURCE:
1145 		case IP_MSFILTER:
1146 		case MCAST_JOIN_GROUP:
1147 		case MCAST_LEAVE_GROUP:
1148 		case MCAST_JOIN_SOURCE_GROUP:
1149 		case MCAST_LEAVE_SOURCE_GROUP:
1150 		case MCAST_BLOCK_SOURCE:
1151 		case MCAST_UNBLOCK_SOURCE:
1152 			error = inp_setmoptions(inp, sopt);
1153 			break;
1154 
1155 		case IP_PORTRANGE:
1156 			error = sooptcopyin(sopt, &optval, sizeof optval,
1157 					    sizeof optval);
1158 			if (error)
1159 				break;
1160 
1161 			INP_WLOCK(inp);
1162 			switch (optval) {
1163 			case IP_PORTRANGE_DEFAULT:
1164 				inp->inp_flags &= ~(INP_LOWPORT);
1165 				inp->inp_flags &= ~(INP_HIGHPORT);
1166 				break;
1167 
1168 			case IP_PORTRANGE_HIGH:
1169 				inp->inp_flags &= ~(INP_LOWPORT);
1170 				inp->inp_flags |= INP_HIGHPORT;
1171 				break;
1172 
1173 			case IP_PORTRANGE_LOW:
1174 				inp->inp_flags &= ~(INP_HIGHPORT);
1175 				inp->inp_flags |= INP_LOWPORT;
1176 				break;
1177 
1178 			default:
1179 				error = EINVAL;
1180 				break;
1181 			}
1182 			INP_WUNLOCK(inp);
1183 			break;
1184 
1185 #ifdef IPSEC
1186 		case IP_IPSEC_POLICY:
1187 		{
1188 			caddr_t req;
1189 			struct mbuf *m;
1190 
1191 			if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1192 				break;
1193 			if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1194 				break;
1195 			req = mtod(m, caddr_t);
1196 			error = ipsec_set_policy(inp, sopt->sopt_name, req,
1197 			    m->m_len, (sopt->sopt_td != NULL) ?
1198 			    sopt->sopt_td->td_ucred : NULL);
1199 			m_freem(m);
1200 			break;
1201 		}
1202 #endif /* IPSEC */
1203 
1204 		default:
1205 			error = ENOPROTOOPT;
1206 			break;
1207 		}
1208 		break;
1209 
1210 	case SOPT_GET:
1211 		switch (sopt->sopt_name) {
1212 		case IP_OPTIONS:
1213 		case IP_RETOPTS:
1214 			if (inp->inp_options)
1215 				error = sooptcopyout(sopt,
1216 						     mtod(inp->inp_options,
1217 							  char *),
1218 						     inp->inp_options->m_len);
1219 			else
1220 				sopt->sopt_valsize = 0;
1221 			break;
1222 
1223 		case IP_TOS:
1224 		case IP_TTL:
1225 		case IP_MINTTL:
1226 		case IP_RECVOPTS:
1227 		case IP_RECVRETOPTS:
1228 		case IP_RECVDSTADDR:
1229 		case IP_RECVTTL:
1230 		case IP_RECVIF:
1231 		case IP_PORTRANGE:
1232 		case IP_ONESBCAST:
1233 		case IP_DONTFRAG:
1234 		case IP_BINDANY:
1235 		case IP_RECVTOS:
1236 		case IP_BINDMULTI:
1237 		case IP_FLOWID:
1238 		case IP_FLOWTYPE:
1239 		case IP_RECVFLOWID:
1240 #ifdef	RSS
1241 		case IP_RSSBUCKETID:
1242 		case IP_RECVRSSBUCKETID:
1243 #endif
1244 			switch (sopt->sopt_name) {
1245 
1246 			case IP_TOS:
1247 				optval = inp->inp_ip_tos;
1248 				break;
1249 
1250 			case IP_TTL:
1251 				optval = inp->inp_ip_ttl;
1252 				break;
1253 
1254 			case IP_MINTTL:
1255 				optval = inp->inp_ip_minttl;
1256 				break;
1257 
1258 #define	OPTBIT(bit)	(inp->inp_flags & bit ? 1 : 0)
1259 #define	OPTBIT2(bit)	(inp->inp_flags2 & bit ? 1 : 0)
1260 
1261 			case IP_RECVOPTS:
1262 				optval = OPTBIT(INP_RECVOPTS);
1263 				break;
1264 
1265 			case IP_RECVRETOPTS:
1266 				optval = OPTBIT(INP_RECVRETOPTS);
1267 				break;
1268 
1269 			case IP_RECVDSTADDR:
1270 				optval = OPTBIT(INP_RECVDSTADDR);
1271 				break;
1272 
1273 			case IP_RECVTTL:
1274 				optval = OPTBIT(INP_RECVTTL);
1275 				break;
1276 
1277 			case IP_RECVIF:
1278 				optval = OPTBIT(INP_RECVIF);
1279 				break;
1280 
1281 			case IP_PORTRANGE:
1282 				if (inp->inp_flags & INP_HIGHPORT)
1283 					optval = IP_PORTRANGE_HIGH;
1284 				else if (inp->inp_flags & INP_LOWPORT)
1285 					optval = IP_PORTRANGE_LOW;
1286 				else
1287 					optval = 0;
1288 				break;
1289 
1290 			case IP_ONESBCAST:
1291 				optval = OPTBIT(INP_ONESBCAST);
1292 				break;
1293 			case IP_DONTFRAG:
1294 				optval = OPTBIT(INP_DONTFRAG);
1295 				break;
1296 			case IP_BINDANY:
1297 				optval = OPTBIT(INP_BINDANY);
1298 				break;
1299 			case IP_RECVTOS:
1300 				optval = OPTBIT(INP_RECVTOS);
1301 				break;
1302 			case IP_FLOWID:
1303 				optval = inp->inp_flowid;
1304 				break;
1305 			case IP_FLOWTYPE:
1306 				optval = inp->inp_flowtype;
1307 				break;
1308 			case IP_RECVFLOWID:
1309 				optval = OPTBIT2(INP_RECVFLOWID);
1310 				break;
1311 #ifdef	RSS
1312 			case IP_RSSBUCKETID:
1313 				retval = rss_hash2bucket(inp->inp_flowid,
1314 				    inp->inp_flowtype,
1315 				    &rss_bucket);
1316 				if (retval == 0)
1317 					optval = rss_bucket;
1318 				else
1319 					error = EINVAL;
1320 				break;
1321 			case IP_RECVRSSBUCKETID:
1322 				optval = OPTBIT2(INP_RECVRSSBUCKETID);
1323 				break;
1324 #endif
1325 			case IP_BINDMULTI:
1326 				optval = OPTBIT2(INP_BINDMULTI);
1327 				break;
1328 			}
1329 			error = sooptcopyout(sopt, &optval, sizeof optval);
1330 			break;
1331 
1332 		/*
1333 		 * Multicast socket options are processed by the in_mcast
1334 		 * module.
1335 		 */
1336 		case IP_MULTICAST_IF:
1337 		case IP_MULTICAST_VIF:
1338 		case IP_MULTICAST_TTL:
1339 		case IP_MULTICAST_LOOP:
1340 		case IP_MSFILTER:
1341 			error = inp_getmoptions(inp, sopt);
1342 			break;
1343 
1344 #ifdef IPSEC
1345 		case IP_IPSEC_POLICY:
1346 		{
1347 			struct mbuf *m = NULL;
1348 			caddr_t req = NULL;
1349 			size_t len = 0;
1350 
1351 			if (m != 0) {
1352 				req = mtod(m, caddr_t);
1353 				len = m->m_len;
1354 			}
1355 			error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1356 			if (error == 0)
1357 				error = soopt_mcopyout(sopt, m); /* XXX */
1358 			if (error == 0)
1359 				m_freem(m);
1360 			break;
1361 		}
1362 #endif /* IPSEC */
1363 
1364 		default:
1365 			error = ENOPROTOOPT;
1366 			break;
1367 		}
1368 		break;
1369 	}
1370 	return (error);
1371 }
1372 
1373 /*
1374  * Routine called from ip_output() to loop back a copy of an IP multicast
1375  * packet to the input queue of a specified interface.  Note that this
1376  * calls the output routine of the loopback "driver", but with an interface
1377  * pointer that might NOT be a loopback interface -- evil, but easier than
1378  * replicating that code here.
1379  */
1380 static void
1381 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1382 {
1383 	struct ip *ip;
1384 	struct mbuf *copym;
1385 
1386 	/*
1387 	 * Make a deep copy of the packet because we're going to
1388 	 * modify the pack in order to generate checksums.
1389 	 */
1390 	copym = m_dup(m, M_NOWAIT);
1391 	if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1392 		copym = m_pullup(copym, hlen);
1393 	if (copym != NULL) {
1394 		/* If needed, compute the checksum and mark it as valid. */
1395 		if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1396 			in_delayed_cksum(copym);
1397 			copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1398 			copym->m_pkthdr.csum_flags |=
1399 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1400 			copym->m_pkthdr.csum_data = 0xffff;
1401 		}
1402 		/*
1403 		 * We don't bother to fragment if the IP length is greater
1404 		 * than the interface's MTU.  Can this possibly matter?
1405 		 */
1406 		ip = mtod(copym, struct ip *);
1407 		ip->ip_sum = 0;
1408 		ip->ip_sum = in_cksum(copym, hlen);
1409 		if_simloop(ifp, copym, AF_INET, 0);
1410 	}
1411 }
1412