xref: /freebsd/sys/netinet/ip_output.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
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_ipsec.h"
37 #include "opt_mbuf_stress_test.h"
38 #include "opt_mpath.h"
39 #include "opt_route.h"
40 #include "opt_sctp.h"
41 #include "opt_rss.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/lock.h>
47 #include <sys/malloc.h>
48 #include <sys/mbuf.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/protosw.h>
52 #include <sys/rmlock.h>
53 #include <sys/sdt.h>
54 #include <sys/socket.h>
55 #include <sys/socketvar.h>
56 #include <sys/sysctl.h>
57 #include <sys/ucred.h>
58 
59 #include <net/if.h>
60 #include <net/if_var.h>
61 #include <net/if_llatbl.h>
62 #include <net/netisr.h>
63 #include <net/pfil.h>
64 #include <net/route.h>
65 #include <net/flowtable.h>
66 #ifdef RADIX_MPATH
67 #include <net/radix_mpath.h>
68 #endif
69 #include <net/rss_config.h>
70 #include <net/vnet.h>
71 
72 #include <netinet/in.h>
73 #include <netinet/in_kdtrace.h>
74 #include <netinet/in_systm.h>
75 #include <netinet/ip.h>
76 #include <netinet/in_pcb.h>
77 #include <netinet/in_rss.h>
78 #include <netinet/in_var.h>
79 #include <netinet/ip_var.h>
80 #include <netinet/ip_options.h>
81 #ifdef SCTP
82 #include <netinet/sctp.h>
83 #include <netinet/sctp_crc32.h>
84 #endif
85 
86 #ifdef IPSEC
87 #include <netinet/ip_ipsec.h>
88 #include <netipsec/ipsec.h>
89 #endif /* IPSEC*/
90 
91 #include <machine/in_cksum.h>
92 
93 #include <security/mac/mac_framework.h>
94 
95 #ifdef MBUF_STRESS_TEST
96 static int mbuf_frag_size = 0;
97 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
98 	&mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
99 #endif
100 
101 static void	ip_mloopback(struct ifnet *, const struct mbuf *, int);
102 
103 
104 extern int in_mcast_loop;
105 extern	struct protosw inetsw[];
106 
107 static inline int
108 ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, struct inpcb *inp,
109     struct sockaddr_in *dst, int *fibnum, int *error)
110 {
111 	struct m_tag *fwd_tag = NULL;
112 	struct mbuf *m;
113 	struct in_addr odst;
114 	struct ip *ip;
115 
116 	m = *mp;
117 	ip = mtod(m, struct ip *);
118 
119 	/* Run through list of hooks for output packets. */
120 	odst.s_addr = ip->ip_dst.s_addr;
121 	*error = pfil_run_hooks(&V_inet_pfil_hook, mp, ifp, PFIL_OUT, inp);
122 	m = *mp;
123 	if ((*error) != 0 || m == NULL)
124 		return 1; /* Finished */
125 
126 	ip = mtod(m, struct ip *);
127 
128 	/* See if destination IP address was changed by packet filter. */
129 	if (odst.s_addr != ip->ip_dst.s_addr) {
130 		m->m_flags |= M_SKIP_FIREWALL;
131 		/* If destination is now ourself drop to ip_input(). */
132 		if (in_localip(ip->ip_dst)) {
133 			m->m_flags |= M_FASTFWD_OURS;
134 			if (m->m_pkthdr.rcvif == NULL)
135 				m->m_pkthdr.rcvif = V_loif;
136 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
137 				m->m_pkthdr.csum_flags |=
138 					CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
139 				m->m_pkthdr.csum_data = 0xffff;
140 			}
141 			m->m_pkthdr.csum_flags |=
142 				CSUM_IP_CHECKED | CSUM_IP_VALID;
143 #ifdef SCTP
144 			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
145 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
146 #endif
147 			*error = netisr_queue(NETISR_IP, m);
148 			return 1; /* Finished */
149 		}
150 
151 		bzero(dst, sizeof(*dst));
152 		dst->sin_family = AF_INET;
153 		dst->sin_len = sizeof(*dst);
154 		dst->sin_addr = ip->ip_dst;
155 
156 		return -1; /* Reloop */
157 	}
158 	/* See if fib was changed by packet filter. */
159 	if ((*fibnum) != M_GETFIB(m)) {
160 		m->m_flags |= M_SKIP_FIREWALL;
161 		*fibnum = M_GETFIB(m);
162 		return -1; /* Reloop for FIB change */
163 	}
164 
165 	/* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
166 	if (m->m_flags & M_FASTFWD_OURS) {
167 		if (m->m_pkthdr.rcvif == NULL)
168 			m->m_pkthdr.rcvif = V_loif;
169 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
170 			m->m_pkthdr.csum_flags |=
171 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
172 			m->m_pkthdr.csum_data = 0xffff;
173 		}
174 #ifdef SCTP
175 		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
176 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
177 #endif
178 		m->m_pkthdr.csum_flags |=
179 			CSUM_IP_CHECKED | CSUM_IP_VALID;
180 
181 		*error = netisr_queue(NETISR_IP, m);
182 		return 1; /* Finished */
183 	}
184 	/* Or forward to some other address? */
185 	if ((m->m_flags & M_IP_NEXTHOP) &&
186 	    ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
187 		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
188 		m->m_flags |= M_SKIP_FIREWALL;
189 		m->m_flags &= ~M_IP_NEXTHOP;
190 		m_tag_delete(m, fwd_tag);
191 
192 		return -1; /* Reloop for CHANGE of dst */
193 	}
194 
195 	return 0;
196 }
197 
198 /*
199  * IP output.  The packet in mbuf chain m contains a skeletal IP
200  * header (with len, off, ttl, proto, tos, src, dst).
201  * The mbuf chain containing the packet will be freed.
202  * The mbuf opt, if present, will not be freed.
203  * If route ro is present and has ro_rt initialized, route lookup would be
204  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
205  * then result of route lookup is stored in ro->ro_rt.
206  *
207  * In the IP forwarding case, the packet will arrive with options already
208  * inserted, so must have a NULL opt pointer.
209  */
210 int
211 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
212     struct ip_moptions *imo, struct inpcb *inp)
213 {
214 	struct rm_priotracker in_ifa_tracker;
215 	struct ip *ip;
216 	struct ifnet *ifp = NULL;	/* keep compiler happy */
217 	struct mbuf *m0;
218 	int hlen = sizeof (struct ip);
219 	int mtu;
220 	int error = 0;
221 	struct sockaddr_in *dst;
222 	const struct sockaddr_in *gw;
223 	struct in_ifaddr *ia;
224 	int isbroadcast;
225 	uint16_t ip_len, ip_off;
226 	struct route iproute;
227 	struct rtentry *rte;	/* cache for ro->ro_rt */
228 	uint32_t fibnum;
229 	int have_ia_ref;
230 #ifdef IPSEC
231 	int no_route_but_check_spd = 0;
232 #endif
233 	M_ASSERTPKTHDR(m);
234 
235 	if (inp != NULL) {
236 		INP_LOCK_ASSERT(inp);
237 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
238 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
239 			m->m_pkthdr.flowid = inp->inp_flowid;
240 			M_HASHTYPE_SET(m, inp->inp_flowtype);
241 		}
242 	}
243 
244 	if (ro == NULL) {
245 		ro = &iproute;
246 		bzero(ro, sizeof (*ro));
247 	} else
248 		ro->ro_flags |= RT_LLE_CACHE;
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 		if (ro->ro_lle)
315 			LLE_FREE(ro->ro_lle);	/* zeros ro_lle */
316 		ro->ro_lle = (struct llentry *)NULL;
317 	}
318 	ia = NULL;
319 	have_ia_ref = 0;
320 	/*
321 	 * If routing to interface only, short circuit routing lookup.
322 	 * The use of an all-ones broadcast address implies this; an
323 	 * interface is specified by the broadcast address of an interface,
324 	 * or the destination address of a ptp interface.
325 	 */
326 	if (flags & IP_SENDONES) {
327 		if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
328 						      M_GETFIB(m)))) == NULL &&
329 		    (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
330 						    M_GETFIB(m)))) == NULL) {
331 			IPSTAT_INC(ips_noroute);
332 			error = ENETUNREACH;
333 			goto bad;
334 		}
335 		have_ia_ref = 1;
336 		ip->ip_dst.s_addr = INADDR_BROADCAST;
337 		dst->sin_addr = ip->ip_dst;
338 		ifp = ia->ia_ifp;
339 		ip->ip_ttl = 1;
340 		isbroadcast = 1;
341 	} else if (flags & IP_ROUTETOIF) {
342 		if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
343 						    M_GETFIB(m)))) == NULL &&
344 		    (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
345 						M_GETFIB(m)))) == NULL) {
346 			IPSTAT_INC(ips_noroute);
347 			error = ENETUNREACH;
348 			goto bad;
349 		}
350 		have_ia_ref = 1;
351 		ifp = ia->ia_ifp;
352 		ip->ip_ttl = 1;
353 		isbroadcast = ifp->if_flags & IFF_BROADCAST ?
354 		    in_ifaddr_broadcast(dst->sin_addr, ia) : 0;
355 	} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
356 	    imo != NULL && imo->imo_multicast_ifp != NULL) {
357 		/*
358 		 * Bypass the normal routing lookup for multicast
359 		 * packets if the interface is specified.
360 		 */
361 		ifp = imo->imo_multicast_ifp;
362 		IFP_TO_IA(ifp, ia, &in_ifa_tracker);
363 		if (ia)
364 			have_ia_ref = 1;
365 		isbroadcast = 0;	/* fool gcc */
366 	} else {
367 		/*
368 		 * We want to do any cloning requested by the link layer,
369 		 * as this is probably required in all cases for correct
370 		 * operation (as it is for ARP).
371 		 */
372 		if (rte == NULL) {
373 #ifdef RADIX_MPATH
374 			rtalloc_mpath_fib(ro,
375 			    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
376 			    fibnum);
377 #else
378 			in_rtalloc_ign(ro, 0, fibnum);
379 #endif
380 			rte = ro->ro_rt;
381 		}
382 		if (rte == NULL ||
383 		    (rte->rt_flags & RTF_UP) == 0 ||
384 		    rte->rt_ifp == NULL ||
385 		    !RT_LINK_IS_UP(rte->rt_ifp)) {
386 #ifdef IPSEC
387 			/*
388 			 * There is no route for this packet, but it is
389 			 * possible that a matching SPD entry exists.
390 			 */
391 			no_route_but_check_spd = 1;
392 			mtu = 0; /* Silence GCC warning. */
393 			goto sendit;
394 #endif
395 			IPSTAT_INC(ips_noroute);
396 			error = EHOSTUNREACH;
397 			goto bad;
398 		}
399 		ia = ifatoia(rte->rt_ifa);
400 		ifp = rte->rt_ifp;
401 		counter_u64_add(rte->rt_pksent, 1);
402 		rt_update_ro_flags(ro);
403 		if (rte->rt_flags & RTF_GATEWAY)
404 			gw = (struct sockaddr_in *)rte->rt_gateway;
405 		if (rte->rt_flags & RTF_HOST)
406 			isbroadcast = (rte->rt_flags & RTF_BROADCAST);
407 		else if (ifp->if_flags & IFF_BROADCAST)
408 			isbroadcast = in_ifaddr_broadcast(gw->sin_addr, ia);
409 		else
410 			isbroadcast = 0;
411 	}
412 
413 	/*
414 	 * Calculate MTU.  If we have a route that is up, use that,
415 	 * otherwise use the interface's MTU.
416 	 */
417 	if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST)))
418 		mtu = rte->rt_mtu;
419 	else
420 		mtu = ifp->if_mtu;
421 	/* Catch a possible divide by zero later. */
422 	KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
423 	    __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
424 
425 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
426 		m->m_flags |= M_MCAST;
427 		/*
428 		 * IP destination address is multicast.  Make sure "gw"
429 		 * still points to the address in "ro".  (It may have been
430 		 * changed to point to a gateway address, above.)
431 		 */
432 		gw = dst;
433 		/*
434 		 * See if the caller provided any multicast options
435 		 */
436 		if (imo != NULL) {
437 			ip->ip_ttl = imo->imo_multicast_ttl;
438 			if (imo->imo_multicast_vif != -1)
439 				ip->ip_src.s_addr =
440 				    ip_mcast_src ?
441 				    ip_mcast_src(imo->imo_multicast_vif) :
442 				    INADDR_ANY;
443 		} else
444 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
445 		/*
446 		 * Confirm that the outgoing interface supports multicast.
447 		 */
448 		if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
449 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
450 				IPSTAT_INC(ips_noroute);
451 				error = ENETUNREACH;
452 				goto bad;
453 			}
454 		}
455 		/*
456 		 * If source address not specified yet, use address
457 		 * of outgoing interface.
458 		 */
459 		if (ip->ip_src.s_addr == INADDR_ANY) {
460 			/* Interface may have no addresses. */
461 			if (ia != NULL)
462 				ip->ip_src = IA_SIN(ia)->sin_addr;
463 		}
464 
465 		if ((imo == NULL && in_mcast_loop) ||
466 		    (imo && imo->imo_multicast_loop)) {
467 			/*
468 			 * Loop back multicast datagram if not expressly
469 			 * forbidden to do so, even if we are not a member
470 			 * of the group; ip_input() will filter it later,
471 			 * thus deferring a hash lookup and mutex acquisition
472 			 * at the expense of a cheap copy using m_copym().
473 			 */
474 			ip_mloopback(ifp, m, hlen);
475 		} else {
476 			/*
477 			 * If we are acting as a multicast router, perform
478 			 * multicast forwarding as if the packet had just
479 			 * arrived on the interface to which we are about
480 			 * to send.  The multicast forwarding function
481 			 * recursively calls this function, using the
482 			 * IP_FORWARDING flag to prevent infinite recursion.
483 			 *
484 			 * Multicasts that are looped back by ip_mloopback(),
485 			 * above, will be forwarded by the ip_input() routine,
486 			 * if necessary.
487 			 */
488 			if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
489 				/*
490 				 * If rsvp daemon is not running, do not
491 				 * set ip_moptions. This ensures that the packet
492 				 * is multicast and not just sent down one link
493 				 * as prescribed by rsvpd.
494 				 */
495 				if (!V_rsvp_on)
496 					imo = NULL;
497 				if (ip_mforward &&
498 				    ip_mforward(ip, ifp, m, imo) != 0) {
499 					m_freem(m);
500 					goto done;
501 				}
502 			}
503 		}
504 
505 		/*
506 		 * Multicasts with a time-to-live of zero may be looped-
507 		 * back, above, but must not be transmitted on a network.
508 		 * Also, multicasts addressed to the loopback interface
509 		 * are not sent -- the above call to ip_mloopback() will
510 		 * loop back a copy. ip_input() will drop the copy if
511 		 * this host does not belong to the destination group on
512 		 * the loopback interface.
513 		 */
514 		if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
515 			m_freem(m);
516 			goto done;
517 		}
518 
519 		goto sendit;
520 	}
521 
522 	/*
523 	 * If the source address is not specified yet, use the address
524 	 * of the outoing interface.
525 	 */
526 	if (ip->ip_src.s_addr == INADDR_ANY) {
527 		/* Interface may have no addresses. */
528 		if (ia != NULL) {
529 			ip->ip_src = IA_SIN(ia)->sin_addr;
530 		}
531 	}
532 
533 	/*
534 	 * Look for broadcast address and
535 	 * verify user is allowed to send
536 	 * such a packet.
537 	 */
538 	if (isbroadcast) {
539 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
540 			error = EADDRNOTAVAIL;
541 			goto bad;
542 		}
543 		if ((flags & IP_ALLOWBROADCAST) == 0) {
544 			error = EACCES;
545 			goto bad;
546 		}
547 		/* don't allow broadcast messages to be fragmented */
548 		if (ip_len > mtu) {
549 			error = EMSGSIZE;
550 			goto bad;
551 		}
552 		m->m_flags |= M_BCAST;
553 	} else {
554 		m->m_flags &= ~M_BCAST;
555 	}
556 
557 sendit:
558 #ifdef IPSEC
559 	switch(ip_ipsec_output(&m, inp, &error)) {
560 	case 1:
561 		goto bad;
562 	case -1:
563 		goto done;
564 	case 0:
565 	default:
566 		break;	/* Continue with packet processing. */
567 	}
568 	/*
569 	 * Check if there was a route for this packet; return error if not.
570 	 */
571 	if (no_route_but_check_spd) {
572 		IPSTAT_INC(ips_noroute);
573 		error = EHOSTUNREACH;
574 		goto bad;
575 	}
576 	/* Update variables that are affected by ipsec4_output(). */
577 	ip = mtod(m, struct ip *);
578 	hlen = ip->ip_hl << 2;
579 #endif /* IPSEC */
580 
581 	/* Jump over all PFIL processing if hooks are not active. */
582 	if (PFIL_HOOKED(&V_inet_pfil_hook)) {
583 		switch (ip_output_pfil(&m, ifp, inp, dst, &fibnum, &error)) {
584 		case 1: /* Finished */
585 			goto done;
586 
587 		case 0: /* Continue normally */
588 			ip = mtod(m, struct ip *);
589 			break;
590 
591 		case -1: /* Need to try again */
592 			/* Reset everything for a new round */
593 			RO_RTFREE(ro);
594 			if (have_ia_ref)
595 				ifa_free(&ia->ia_ifa);
596 			ro->ro_prepend = NULL;
597 			rte = NULL;
598 			gw = dst;
599 			ip = mtod(m, struct ip *);
600 			goto again;
601 
602 		}
603 	}
604 
605 	/* 127/8 must not appear on wire - RFC1122. */
606 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
607 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
608 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
609 			IPSTAT_INC(ips_badaddr);
610 			error = EADDRNOTAVAIL;
611 			goto bad;
612 		}
613 	}
614 
615 	m->m_pkthdr.csum_flags |= CSUM_IP;
616 	if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
617 		in_delayed_cksum(m);
618 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
619 	}
620 #ifdef SCTP
621 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
622 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
623 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
624 	}
625 #endif
626 
627 	/*
628 	 * If small enough for interface, or the interface will take
629 	 * care of the fragmentation for us, we can just send directly.
630 	 */
631 	if (ip_len <= mtu ||
632 	    (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) {
633 		ip->ip_sum = 0;
634 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
635 			ip->ip_sum = in_cksum(m, hlen);
636 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
637 		}
638 
639 		/*
640 		 * Record statistics for this interface address.
641 		 * With CSUM_TSO the byte/packet count will be slightly
642 		 * incorrect because we count the IP+TCP headers only
643 		 * once instead of for every generated packet.
644 		 */
645 		if (!(flags & IP_FORWARDING) && ia) {
646 			if (m->m_pkthdr.csum_flags & CSUM_TSO)
647 				counter_u64_add(ia->ia_ifa.ifa_opackets,
648 				    m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
649 			else
650 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
651 
652 			counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
653 		}
654 #ifdef MBUF_STRESS_TEST
655 		if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
656 			m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
657 #endif
658 		/*
659 		 * Reset layer specific mbuf flags
660 		 * to avoid confusing lower layers.
661 		 */
662 		m_clrprotoflags(m);
663 		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
664 		error = (*ifp->if_output)(ifp, m,
665 		    (const struct sockaddr *)gw, ro);
666 		goto done;
667 	}
668 
669 	/* Balk when DF bit is set or the interface didn't support TSO. */
670 	if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
671 		error = EMSGSIZE;
672 		IPSTAT_INC(ips_cantfrag);
673 		goto bad;
674 	}
675 
676 	/*
677 	 * Too large for interface; fragment if possible. If successful,
678 	 * on return, m will point to a list of packets to be sent.
679 	 */
680 	error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
681 	if (error)
682 		goto bad;
683 	for (; m; m = m0) {
684 		m0 = m->m_nextpkt;
685 		m->m_nextpkt = 0;
686 		if (error == 0) {
687 			/* Record statistics for this interface address. */
688 			if (ia != NULL) {
689 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
690 				counter_u64_add(ia->ia_ifa.ifa_obytes,
691 				    m->m_pkthdr.len);
692 			}
693 			/*
694 			 * Reset layer specific mbuf flags
695 			 * to avoid confusing upper layers.
696 			 */
697 			m_clrprotoflags(m);
698 
699 			IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
700 			error = (*ifp->if_output)(ifp, m,
701 			    (const struct sockaddr *)gw, ro);
702 		} else
703 			m_freem(m);
704 	}
705 
706 	if (error == 0)
707 		IPSTAT_INC(ips_fragmented);
708 
709 done:
710 	if (ro == &iproute)
711 		RO_RTFREE(ro);
712 	else if (rte == NULL)
713 		/*
714 		 * If the caller supplied a route but somehow the reference
715 		 * to it has been released need to prevent the caller
716 		 * calling RTFREE on it again.
717 		 */
718 		ro->ro_rt = NULL;
719 	if (have_ia_ref)
720 		ifa_free(&ia->ia_ifa);
721 	return (error);
722 bad:
723 	m_freem(m);
724 	goto done;
725 }
726 
727 /*
728  * Create a chain of fragments which fit the given mtu. m_frag points to the
729  * mbuf to be fragmented; on return it points to the chain with the fragments.
730  * Return 0 if no error. If error, m_frag may contain a partially built
731  * chain of fragments that should be freed by the caller.
732  *
733  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
734  */
735 int
736 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
737     u_long if_hwassist_flags)
738 {
739 	int error = 0;
740 	int hlen = ip->ip_hl << 2;
741 	int len = (mtu - hlen) & ~7;	/* size of payload in each fragment */
742 	int off;
743 	struct mbuf *m0 = *m_frag;	/* the original packet		*/
744 	int firstlen;
745 	struct mbuf **mnext;
746 	int nfrags;
747 	uint16_t ip_len, ip_off;
748 
749 	ip_len = ntohs(ip->ip_len);
750 	ip_off = ntohs(ip->ip_off);
751 
752 	if (ip_off & IP_DF) {	/* Fragmentation not allowed */
753 		IPSTAT_INC(ips_cantfrag);
754 		return EMSGSIZE;
755 	}
756 
757 	/*
758 	 * Must be able to put at least 8 bytes per fragment.
759 	 */
760 	if (len < 8)
761 		return EMSGSIZE;
762 
763 	/*
764 	 * If the interface will not calculate checksums on
765 	 * fragmented packets, then do it here.
766 	 */
767 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
768 		in_delayed_cksum(m0);
769 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
770 	}
771 #ifdef SCTP
772 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
773 		sctp_delayed_cksum(m0, hlen);
774 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
775 	}
776 #endif
777 	if (len > PAGE_SIZE) {
778 		/*
779 		 * Fragment large datagrams such that each segment
780 		 * contains a multiple of PAGE_SIZE amount of data,
781 		 * plus headers. This enables a receiver to perform
782 		 * page-flipping zero-copy optimizations.
783 		 *
784 		 * XXX When does this help given that sender and receiver
785 		 * could have different page sizes, and also mtu could
786 		 * be less than the receiver's page size ?
787 		 */
788 		int newlen;
789 
790 		off = MIN(mtu, m0->m_pkthdr.len);
791 
792 		/*
793 		 * firstlen (off - hlen) must be aligned on an
794 		 * 8-byte boundary
795 		 */
796 		if (off < hlen)
797 			goto smart_frag_failure;
798 		off = ((off - hlen) & ~7) + hlen;
799 		newlen = (~PAGE_MASK) & mtu;
800 		if ((newlen + sizeof (struct ip)) > mtu) {
801 			/* we failed, go back the default */
802 smart_frag_failure:
803 			newlen = len;
804 			off = hlen + len;
805 		}
806 		len = newlen;
807 
808 	} else {
809 		off = hlen + len;
810 	}
811 
812 	firstlen = off - hlen;
813 	mnext = &m0->m_nextpkt;		/* pointer to next packet */
814 
815 	/*
816 	 * Loop through length of segment after first fragment,
817 	 * make new header and copy data of each part and link onto chain.
818 	 * Here, m0 is the original packet, m is the fragment being created.
819 	 * The fragments are linked off the m_nextpkt of the original
820 	 * packet, which after processing serves as the first fragment.
821 	 */
822 	for (nfrags = 1; off < ip_len; off += len, nfrags++) {
823 		struct ip *mhip;	/* ip header on the fragment */
824 		struct mbuf *m;
825 		int mhlen = sizeof (struct ip);
826 
827 		m = m_gethdr(M_NOWAIT, MT_DATA);
828 		if (m == NULL) {
829 			error = ENOBUFS;
830 			IPSTAT_INC(ips_odropped);
831 			goto done;
832 		}
833 		/*
834 		 * Make sure the complete packet header gets copied
835 		 * from the originating mbuf to the newly created
836 		 * mbuf. This also ensures that existing firewall
837 		 * classification(s), VLAN tags and so on get copied
838 		 * to the resulting fragmented packet(s):
839 		 */
840 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
841 			m_free(m);
842 			error = ENOBUFS;
843 			IPSTAT_INC(ips_odropped);
844 			goto done;
845 		}
846 		/*
847 		 * In the first mbuf, leave room for the link header, then
848 		 * copy the original IP header including options. The payload
849 		 * goes into an additional mbuf chain returned by m_copym().
850 		 */
851 		m->m_data += max_linkhdr;
852 		mhip = mtod(m, struct ip *);
853 		*mhip = *ip;
854 		if (hlen > sizeof (struct ip)) {
855 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
856 			mhip->ip_v = IPVERSION;
857 			mhip->ip_hl = mhlen >> 2;
858 		}
859 		m->m_len = mhlen;
860 		/* XXX do we need to add ip_off below ? */
861 		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
862 		if (off + len >= ip_len)
863 			len = ip_len - off;
864 		else
865 			mhip->ip_off |= IP_MF;
866 		mhip->ip_len = htons((u_short)(len + mhlen));
867 		m->m_next = m_copym(m0, off, len, M_NOWAIT);
868 		if (m->m_next == NULL) {	/* copy failed */
869 			m_free(m);
870 			error = ENOBUFS;	/* ??? */
871 			IPSTAT_INC(ips_odropped);
872 			goto done;
873 		}
874 		m->m_pkthdr.len = mhlen + len;
875 #ifdef MAC
876 		mac_netinet_fragment(m0, m);
877 #endif
878 		mhip->ip_off = htons(mhip->ip_off);
879 		mhip->ip_sum = 0;
880 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
881 			mhip->ip_sum = in_cksum(m, mhlen);
882 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
883 		}
884 		*mnext = m;
885 		mnext = &m->m_nextpkt;
886 	}
887 	IPSTAT_ADD(ips_ofragments, nfrags);
888 
889 	/*
890 	 * Update first fragment by trimming what's been copied out
891 	 * and updating header.
892 	 */
893 	m_adj(m0, hlen + firstlen - ip_len);
894 	m0->m_pkthdr.len = hlen + firstlen;
895 	ip->ip_len = htons((u_short)m0->m_pkthdr.len);
896 	ip->ip_off = htons(ip_off | IP_MF);
897 	ip->ip_sum = 0;
898 	if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
899 		ip->ip_sum = in_cksum(m0, hlen);
900 		m0->m_pkthdr.csum_flags &= ~CSUM_IP;
901 	}
902 
903 done:
904 	*m_frag = m0;
905 	return error;
906 }
907 
908 void
909 in_delayed_cksum(struct mbuf *m)
910 {
911 	struct ip *ip;
912 	uint16_t csum, offset, ip_len;
913 
914 	ip = mtod(m, struct ip *);
915 	offset = ip->ip_hl << 2 ;
916 	ip_len = ntohs(ip->ip_len);
917 	csum = in_cksum_skip(m, ip_len, offset);
918 	if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
919 		csum = 0xffff;
920 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
921 
922 	/* find the mbuf in the chain where the checksum starts*/
923 	while ((m != NULL) && (offset >= m->m_len)) {
924 		offset -= m->m_len;
925 		m = m->m_next;
926 	}
927 	KASSERT(m != NULL, ("in_delayed_cksum: checksum outside mbuf chain."));
928 	KASSERT(offset + sizeof(u_short) <= m->m_len, ("in_delayed_cksum: checksum split between mbufs."));
929 	*(u_short *)(m->m_data + offset) = csum;
930 }
931 
932 /*
933  * IP socket option processing.
934  */
935 int
936 ip_ctloutput(struct socket *so, struct sockopt *sopt)
937 {
938 	struct	inpcb *inp = sotoinpcb(so);
939 	int	error, optval;
940 #ifdef	RSS
941 	uint32_t rss_bucket;
942 	int retval;
943 #endif
944 
945 	error = optval = 0;
946 	if (sopt->sopt_level != IPPROTO_IP) {
947 		error = EINVAL;
948 
949 		if (sopt->sopt_level == SOL_SOCKET &&
950 		    sopt->sopt_dir == SOPT_SET) {
951 			switch (sopt->sopt_name) {
952 			case SO_REUSEADDR:
953 				INP_WLOCK(inp);
954 				if ((so->so_options & SO_REUSEADDR) != 0)
955 					inp->inp_flags2 |= INP_REUSEADDR;
956 				else
957 					inp->inp_flags2 &= ~INP_REUSEADDR;
958 				INP_WUNLOCK(inp);
959 				error = 0;
960 				break;
961 			case SO_REUSEPORT:
962 				INP_WLOCK(inp);
963 				if ((so->so_options & SO_REUSEPORT) != 0)
964 					inp->inp_flags2 |= INP_REUSEPORT;
965 				else
966 					inp->inp_flags2 &= ~INP_REUSEPORT;
967 				INP_WUNLOCK(inp);
968 				error = 0;
969 				break;
970 			case SO_SETFIB:
971 				INP_WLOCK(inp);
972 				inp->inp_inc.inc_fibnum = so->so_fibnum;
973 				INP_WUNLOCK(inp);
974 				error = 0;
975 				break;
976 			default:
977 				break;
978 			}
979 		}
980 		return (error);
981 	}
982 
983 	switch (sopt->sopt_dir) {
984 	case SOPT_SET:
985 		switch (sopt->sopt_name) {
986 		case IP_OPTIONS:
987 #ifdef notyet
988 		case IP_RETOPTS:
989 #endif
990 		{
991 			struct mbuf *m;
992 			if (sopt->sopt_valsize > MLEN) {
993 				error = EMSGSIZE;
994 				break;
995 			}
996 			m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
997 			if (m == NULL) {
998 				error = ENOBUFS;
999 				break;
1000 			}
1001 			m->m_len = sopt->sopt_valsize;
1002 			error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1003 					    m->m_len);
1004 			if (error) {
1005 				m_free(m);
1006 				break;
1007 			}
1008 			INP_WLOCK(inp);
1009 			error = ip_pcbopts(inp, sopt->sopt_name, m);
1010 			INP_WUNLOCK(inp);
1011 			return (error);
1012 		}
1013 
1014 		case IP_BINDANY:
1015 			if (sopt->sopt_td != NULL) {
1016 				error = priv_check(sopt->sopt_td,
1017 				    PRIV_NETINET_BINDANY);
1018 				if (error)
1019 					break;
1020 			}
1021 			/* FALLTHROUGH */
1022 		case IP_BINDMULTI:
1023 #ifdef	RSS
1024 		case IP_RSS_LISTEN_BUCKET:
1025 #endif
1026 		case IP_TOS:
1027 		case IP_TTL:
1028 		case IP_MINTTL:
1029 		case IP_RECVOPTS:
1030 		case IP_RECVRETOPTS:
1031 		case IP_RECVDSTADDR:
1032 		case IP_RECVTTL:
1033 		case IP_RECVIF:
1034 		case IP_ONESBCAST:
1035 		case IP_DONTFRAG:
1036 		case IP_RECVTOS:
1037 		case IP_RECVFLOWID:
1038 #ifdef	RSS
1039 		case IP_RECVRSSBUCKETID:
1040 #endif
1041 			error = sooptcopyin(sopt, &optval, sizeof optval,
1042 					    sizeof optval);
1043 			if (error)
1044 				break;
1045 
1046 			switch (sopt->sopt_name) {
1047 			case IP_TOS:
1048 				inp->inp_ip_tos = optval;
1049 				break;
1050 
1051 			case IP_TTL:
1052 				inp->inp_ip_ttl = optval;
1053 				break;
1054 
1055 			case IP_MINTTL:
1056 				if (optval >= 0 && optval <= MAXTTL)
1057 					inp->inp_ip_minttl = optval;
1058 				else
1059 					error = EINVAL;
1060 				break;
1061 
1062 #define	OPTSET(bit) do {						\
1063 	INP_WLOCK(inp);							\
1064 	if (optval)							\
1065 		inp->inp_flags |= bit;					\
1066 	else								\
1067 		inp->inp_flags &= ~bit;					\
1068 	INP_WUNLOCK(inp);						\
1069 } while (0)
1070 
1071 #define	OPTSET2(bit, val) do {						\
1072 	INP_WLOCK(inp);							\
1073 	if (val)							\
1074 		inp->inp_flags2 |= bit;					\
1075 	else								\
1076 		inp->inp_flags2 &= ~bit;				\
1077 	INP_WUNLOCK(inp);						\
1078 } while (0)
1079 
1080 			case IP_RECVOPTS:
1081 				OPTSET(INP_RECVOPTS);
1082 				break;
1083 
1084 			case IP_RECVRETOPTS:
1085 				OPTSET(INP_RECVRETOPTS);
1086 				break;
1087 
1088 			case IP_RECVDSTADDR:
1089 				OPTSET(INP_RECVDSTADDR);
1090 				break;
1091 
1092 			case IP_RECVTTL:
1093 				OPTSET(INP_RECVTTL);
1094 				break;
1095 
1096 			case IP_RECVIF:
1097 				OPTSET(INP_RECVIF);
1098 				break;
1099 
1100 			case IP_ONESBCAST:
1101 				OPTSET(INP_ONESBCAST);
1102 				break;
1103 			case IP_DONTFRAG:
1104 				OPTSET(INP_DONTFRAG);
1105 				break;
1106 			case IP_BINDANY:
1107 				OPTSET(INP_BINDANY);
1108 				break;
1109 			case IP_RECVTOS:
1110 				OPTSET(INP_RECVTOS);
1111 				break;
1112 			case IP_BINDMULTI:
1113 				OPTSET2(INP_BINDMULTI, optval);
1114 				break;
1115 			case IP_RECVFLOWID:
1116 				OPTSET2(INP_RECVFLOWID, optval);
1117 				break;
1118 #ifdef	RSS
1119 			case IP_RSS_LISTEN_BUCKET:
1120 				if ((optval >= 0) &&
1121 				    (optval < rss_getnumbuckets())) {
1122 					inp->inp_rss_listen_bucket = optval;
1123 					OPTSET2(INP_RSS_BUCKET_SET, 1);
1124 				} else {
1125 					error = EINVAL;
1126 				}
1127 				break;
1128 			case IP_RECVRSSBUCKETID:
1129 				OPTSET2(INP_RECVRSSBUCKETID, optval);
1130 				break;
1131 #endif
1132 			}
1133 			break;
1134 #undef OPTSET
1135 #undef OPTSET2
1136 
1137 		/*
1138 		 * Multicast socket options are processed by the in_mcast
1139 		 * module.
1140 		 */
1141 		case IP_MULTICAST_IF:
1142 		case IP_MULTICAST_VIF:
1143 		case IP_MULTICAST_TTL:
1144 		case IP_MULTICAST_LOOP:
1145 		case IP_ADD_MEMBERSHIP:
1146 		case IP_DROP_MEMBERSHIP:
1147 		case IP_ADD_SOURCE_MEMBERSHIP:
1148 		case IP_DROP_SOURCE_MEMBERSHIP:
1149 		case IP_BLOCK_SOURCE:
1150 		case IP_UNBLOCK_SOURCE:
1151 		case IP_MSFILTER:
1152 		case MCAST_JOIN_GROUP:
1153 		case MCAST_LEAVE_GROUP:
1154 		case MCAST_JOIN_SOURCE_GROUP:
1155 		case MCAST_LEAVE_SOURCE_GROUP:
1156 		case MCAST_BLOCK_SOURCE:
1157 		case MCAST_UNBLOCK_SOURCE:
1158 			error = inp_setmoptions(inp, sopt);
1159 			break;
1160 
1161 		case IP_PORTRANGE:
1162 			error = sooptcopyin(sopt, &optval, sizeof optval,
1163 					    sizeof optval);
1164 			if (error)
1165 				break;
1166 
1167 			INP_WLOCK(inp);
1168 			switch (optval) {
1169 			case IP_PORTRANGE_DEFAULT:
1170 				inp->inp_flags &= ~(INP_LOWPORT);
1171 				inp->inp_flags &= ~(INP_HIGHPORT);
1172 				break;
1173 
1174 			case IP_PORTRANGE_HIGH:
1175 				inp->inp_flags &= ~(INP_LOWPORT);
1176 				inp->inp_flags |= INP_HIGHPORT;
1177 				break;
1178 
1179 			case IP_PORTRANGE_LOW:
1180 				inp->inp_flags &= ~(INP_HIGHPORT);
1181 				inp->inp_flags |= INP_LOWPORT;
1182 				break;
1183 
1184 			default:
1185 				error = EINVAL;
1186 				break;
1187 			}
1188 			INP_WUNLOCK(inp);
1189 			break;
1190 
1191 #ifdef IPSEC
1192 		case IP_IPSEC_POLICY:
1193 		{
1194 			caddr_t req;
1195 			struct mbuf *m;
1196 
1197 			if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1198 				break;
1199 			if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1200 				break;
1201 			req = mtod(m, caddr_t);
1202 			error = ipsec_set_policy(inp, sopt->sopt_name, req,
1203 			    m->m_len, (sopt->sopt_td != NULL) ?
1204 			    sopt->sopt_td->td_ucred : NULL);
1205 			m_freem(m);
1206 			break;
1207 		}
1208 #endif /* IPSEC */
1209 
1210 		default:
1211 			error = ENOPROTOOPT;
1212 			break;
1213 		}
1214 		break;
1215 
1216 	case SOPT_GET:
1217 		switch (sopt->sopt_name) {
1218 		case IP_OPTIONS:
1219 		case IP_RETOPTS:
1220 			if (inp->inp_options)
1221 				error = sooptcopyout(sopt,
1222 						     mtod(inp->inp_options,
1223 							  char *),
1224 						     inp->inp_options->m_len);
1225 			else
1226 				sopt->sopt_valsize = 0;
1227 			break;
1228 
1229 		case IP_TOS:
1230 		case IP_TTL:
1231 		case IP_MINTTL:
1232 		case IP_RECVOPTS:
1233 		case IP_RECVRETOPTS:
1234 		case IP_RECVDSTADDR:
1235 		case IP_RECVTTL:
1236 		case IP_RECVIF:
1237 		case IP_PORTRANGE:
1238 		case IP_ONESBCAST:
1239 		case IP_DONTFRAG:
1240 		case IP_BINDANY:
1241 		case IP_RECVTOS:
1242 		case IP_BINDMULTI:
1243 		case IP_FLOWID:
1244 		case IP_FLOWTYPE:
1245 		case IP_RECVFLOWID:
1246 #ifdef	RSS
1247 		case IP_RSSBUCKETID:
1248 		case IP_RECVRSSBUCKETID:
1249 #endif
1250 			switch (sopt->sopt_name) {
1251 
1252 			case IP_TOS:
1253 				optval = inp->inp_ip_tos;
1254 				break;
1255 
1256 			case IP_TTL:
1257 				optval = inp->inp_ip_ttl;
1258 				break;
1259 
1260 			case IP_MINTTL:
1261 				optval = inp->inp_ip_minttl;
1262 				break;
1263 
1264 #define	OPTBIT(bit)	(inp->inp_flags & bit ? 1 : 0)
1265 #define	OPTBIT2(bit)	(inp->inp_flags2 & bit ? 1 : 0)
1266 
1267 			case IP_RECVOPTS:
1268 				optval = OPTBIT(INP_RECVOPTS);
1269 				break;
1270 
1271 			case IP_RECVRETOPTS:
1272 				optval = OPTBIT(INP_RECVRETOPTS);
1273 				break;
1274 
1275 			case IP_RECVDSTADDR:
1276 				optval = OPTBIT(INP_RECVDSTADDR);
1277 				break;
1278 
1279 			case IP_RECVTTL:
1280 				optval = OPTBIT(INP_RECVTTL);
1281 				break;
1282 
1283 			case IP_RECVIF:
1284 				optval = OPTBIT(INP_RECVIF);
1285 				break;
1286 
1287 			case IP_PORTRANGE:
1288 				if (inp->inp_flags & INP_HIGHPORT)
1289 					optval = IP_PORTRANGE_HIGH;
1290 				else if (inp->inp_flags & INP_LOWPORT)
1291 					optval = IP_PORTRANGE_LOW;
1292 				else
1293 					optval = 0;
1294 				break;
1295 
1296 			case IP_ONESBCAST:
1297 				optval = OPTBIT(INP_ONESBCAST);
1298 				break;
1299 			case IP_DONTFRAG:
1300 				optval = OPTBIT(INP_DONTFRAG);
1301 				break;
1302 			case IP_BINDANY:
1303 				optval = OPTBIT(INP_BINDANY);
1304 				break;
1305 			case IP_RECVTOS:
1306 				optval = OPTBIT(INP_RECVTOS);
1307 				break;
1308 			case IP_FLOWID:
1309 				optval = inp->inp_flowid;
1310 				break;
1311 			case IP_FLOWTYPE:
1312 				optval = inp->inp_flowtype;
1313 				break;
1314 			case IP_RECVFLOWID:
1315 				optval = OPTBIT2(INP_RECVFLOWID);
1316 				break;
1317 #ifdef	RSS
1318 			case IP_RSSBUCKETID:
1319 				retval = rss_hash2bucket(inp->inp_flowid,
1320 				    inp->inp_flowtype,
1321 				    &rss_bucket);
1322 				if (retval == 0)
1323 					optval = rss_bucket;
1324 				else
1325 					error = EINVAL;
1326 				break;
1327 			case IP_RECVRSSBUCKETID:
1328 				optval = OPTBIT2(INP_RECVRSSBUCKETID);
1329 				break;
1330 #endif
1331 			case IP_BINDMULTI:
1332 				optval = OPTBIT2(INP_BINDMULTI);
1333 				break;
1334 			}
1335 			error = sooptcopyout(sopt, &optval, sizeof optval);
1336 			break;
1337 
1338 		/*
1339 		 * Multicast socket options are processed by the in_mcast
1340 		 * module.
1341 		 */
1342 		case IP_MULTICAST_IF:
1343 		case IP_MULTICAST_VIF:
1344 		case IP_MULTICAST_TTL:
1345 		case IP_MULTICAST_LOOP:
1346 		case IP_MSFILTER:
1347 			error = inp_getmoptions(inp, sopt);
1348 			break;
1349 
1350 #ifdef IPSEC
1351 		case IP_IPSEC_POLICY:
1352 		{
1353 			struct mbuf *m = NULL;
1354 			caddr_t req = NULL;
1355 			size_t len = 0;
1356 
1357 			if (m != NULL) {
1358 				req = mtod(m, caddr_t);
1359 				len = m->m_len;
1360 			}
1361 			error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1362 			if (error == 0)
1363 				error = soopt_mcopyout(sopt, m); /* XXX */
1364 			if (error == 0)
1365 				m_freem(m);
1366 			break;
1367 		}
1368 #endif /* IPSEC */
1369 
1370 		default:
1371 			error = ENOPROTOOPT;
1372 			break;
1373 		}
1374 		break;
1375 	}
1376 	return (error);
1377 }
1378 
1379 /*
1380  * Routine called from ip_output() to loop back a copy of an IP multicast
1381  * packet to the input queue of a specified interface.  Note that this
1382  * calls the output routine of the loopback "driver", but with an interface
1383  * pointer that might NOT be a loopback interface -- evil, but easier than
1384  * replicating that code here.
1385  */
1386 static void
1387 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1388 {
1389 	struct ip *ip;
1390 	struct mbuf *copym;
1391 
1392 	/*
1393 	 * Make a deep copy of the packet because we're going to
1394 	 * modify the pack in order to generate checksums.
1395 	 */
1396 	copym = m_dup(m, M_NOWAIT);
1397 	if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1398 		copym = m_pullup(copym, hlen);
1399 	if (copym != NULL) {
1400 		/* If needed, compute the checksum and mark it as valid. */
1401 		if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1402 			in_delayed_cksum(copym);
1403 			copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1404 			copym->m_pkthdr.csum_flags |=
1405 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1406 			copym->m_pkthdr.csum_data = 0xffff;
1407 		}
1408 		/*
1409 		 * We don't bother to fragment if the IP length is greater
1410 		 * than the interface's MTU.  Can this possibly matter?
1411 		 */
1412 		ip = mtod(copym, struct ip *);
1413 		ip->ip_sum = 0;
1414 		ip->ip_sum = in_cksum(copym, hlen);
1415 		if_simloop(ifp, copym, AF_INET, 0);
1416 	}
1417 }
1418