xref: /freebsd/sys/netinet/ip_output.c (revision 8c784bb8cf36911b828652f0bf7e88f443abec50)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)ip_output.c	8.3 (Berkeley) 1/21/94
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_inet.h"
38 #include "opt_ipsec.h"
39 #include "opt_kern_tls.h"
40 #include "opt_mbuf_stress_test.h"
41 #include "opt_ratelimit.h"
42 #include "opt_route.h"
43 #include "opt_rss.h"
44 #include "opt_sctp.h"
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/ktls.h>
50 #include <sys/lock.h>
51 #include <sys/malloc.h>
52 #include <sys/mbuf.h>
53 #include <sys/priv.h>
54 #include <sys/proc.h>
55 #include <sys/protosw.h>
56 #include <sys/sdt.h>
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
59 #include <sys/sysctl.h>
60 #include <sys/ucred.h>
61 
62 #include <net/if.h>
63 #include <net/if_var.h>
64 #include <net/if_private.h>
65 #include <net/if_vlan_var.h>
66 #include <net/if_llatbl.h>
67 #include <net/ethernet.h>
68 #include <net/netisr.h>
69 #include <net/pfil.h>
70 #include <net/route.h>
71 #include <net/route/nhop.h>
72 #include <net/rss_config.h>
73 #include <net/vnet.h>
74 
75 #include <netinet/in.h>
76 #include <netinet/in_fib.h>
77 #include <netinet/in_kdtrace.h>
78 #include <netinet/in_systm.h>
79 #include <netinet/ip.h>
80 #include <netinet/in_fib.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/in_rss.h>
83 #include <netinet/in_var.h>
84 #include <netinet/ip_var.h>
85 #include <netinet/ip_options.h>
86 
87 #include <netinet/udp.h>
88 #include <netinet/udp_var.h>
89 
90 #if defined(SCTP) || defined(SCTP_SUPPORT)
91 #include <netinet/sctp.h>
92 #include <netinet/sctp_crc32.h>
93 #endif
94 
95 #include <netipsec/ipsec_support.h>
96 
97 #include <machine/in_cksum.h>
98 
99 #include <security/mac/mac_framework.h>
100 
101 #ifdef MBUF_STRESS_TEST
102 static int mbuf_frag_size = 0;
103 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
104 	&mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
105 #endif
106 
107 static void	ip_mloopback(struct ifnet *, const struct mbuf *, int);
108 
109 extern int in_mcast_loop;
110 
111 static inline int
112 ip_output_pfil(struct mbuf **mp, struct ifnet *ifp, int flags,
113     struct inpcb *inp, struct sockaddr_in *dst, int *fibnum, int *error)
114 {
115 	struct m_tag *fwd_tag = NULL;
116 	struct mbuf *m;
117 	struct in_addr odst;
118 	struct ip *ip;
119 	int pflags = PFIL_OUT;
120 
121 	m = *mp;
122 	ip = mtod(m, struct ip *);
123 
124 	/* Run through list of hooks for output packets. */
125 	odst.s_addr = ip->ip_dst.s_addr;
126 	switch (pfil_run_hooks(V_inet_pfil_head, mp, ifp, pflags, inp)) {
127 	case PFIL_DROPPED:
128 		*error = EACCES;
129 		/* FALLTHROUGH */
130 	case PFIL_CONSUMED:
131 		return 1; /* Finished */
132 	case PFIL_PASS:
133 		*error = 0;
134 	}
135 	m = *mp;
136 	ip = mtod(m, struct ip *);
137 
138 	/* See if destination IP address was changed by packet filter. */
139 	if (odst.s_addr != ip->ip_dst.s_addr) {
140 		m->m_flags |= M_SKIP_FIREWALL;
141 		/* If destination is now ourself drop to ip_input(). */
142 		if (in_localip(ip->ip_dst)) {
143 			m->m_flags |= M_FASTFWD_OURS;
144 			if (m->m_pkthdr.rcvif == NULL)
145 				m->m_pkthdr.rcvif = V_loif;
146 			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
147 				m->m_pkthdr.csum_flags |=
148 					CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
149 				m->m_pkthdr.csum_data = 0xffff;
150 			}
151 			m->m_pkthdr.csum_flags |=
152 				CSUM_IP_CHECKED | CSUM_IP_VALID;
153 #if defined(SCTP) || defined(SCTP_SUPPORT)
154 			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
155 				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
156 #endif
157 			*error = netisr_queue(NETISR_IP, m);
158 			return 1; /* Finished */
159 		}
160 
161 		bzero(dst, sizeof(*dst));
162 		dst->sin_family = AF_INET;
163 		dst->sin_len = sizeof(*dst);
164 		dst->sin_addr = ip->ip_dst;
165 
166 		return -1; /* Reloop */
167 	}
168 	/* See if fib was changed by packet filter. */
169 	if ((*fibnum) != M_GETFIB(m)) {
170 		m->m_flags |= M_SKIP_FIREWALL;
171 		*fibnum = M_GETFIB(m);
172 		return -1; /* Reloop for FIB change */
173 	}
174 
175 	/* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
176 	if (m->m_flags & M_FASTFWD_OURS) {
177 		if (m->m_pkthdr.rcvif == NULL)
178 			m->m_pkthdr.rcvif = V_loif;
179 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
180 			m->m_pkthdr.csum_flags |=
181 				CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
182 			m->m_pkthdr.csum_data = 0xffff;
183 		}
184 #if defined(SCTP) || defined(SCTP_SUPPORT)
185 		if (m->m_pkthdr.csum_flags & CSUM_SCTP)
186 			m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
187 #endif
188 		m->m_pkthdr.csum_flags |=
189 			CSUM_IP_CHECKED | CSUM_IP_VALID;
190 
191 		*error = netisr_queue(NETISR_IP, m);
192 		return 1; /* Finished */
193 	}
194 	/* Or forward to some other address? */
195 	if ((m->m_flags & M_IP_NEXTHOP) &&
196 	    ((fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL)) {
197 		bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
198 		m->m_flags |= M_SKIP_FIREWALL;
199 		m->m_flags &= ~M_IP_NEXTHOP;
200 		m_tag_delete(m, fwd_tag);
201 
202 		return -1; /* Reloop for CHANGE of dst */
203 	}
204 
205 	return 0;
206 }
207 
208 static int
209 ip_output_send(struct inpcb *inp, struct ifnet *ifp, struct mbuf *m,
210     const struct sockaddr *gw, struct route *ro, bool stamp_tag)
211 {
212 #ifdef KERN_TLS
213 	struct ktls_session *tls = NULL;
214 #endif
215 	struct m_snd_tag *mst;
216 	int error;
217 
218 	MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
219 	mst = NULL;
220 
221 #ifdef KERN_TLS
222 	/*
223 	 * If this is an unencrypted TLS record, save a reference to
224 	 * the record.  This local reference is used to call
225 	 * ktls_output_eagain after the mbuf has been freed (thus
226 	 * dropping the mbuf's reference) in if_output.
227 	 */
228 	if (m->m_next != NULL && mbuf_has_tls_session(m->m_next)) {
229 		tls = ktls_hold(m->m_next->m_epg_tls);
230 		mst = tls->snd_tag;
231 
232 		/*
233 		 * If a TLS session doesn't have a valid tag, it must
234 		 * have had an earlier ifp mismatch, so drop this
235 		 * packet.
236 		 */
237 		if (mst == NULL) {
238 			m_freem(m);
239 			error = EAGAIN;
240 			goto done;
241 		}
242 		/*
243 		 * Always stamp tags that include NIC ktls.
244 		 */
245 		stamp_tag = true;
246 	}
247 #endif
248 #ifdef RATELIMIT
249 	if (inp != NULL && mst == NULL) {
250 		if ((inp->inp_flags2 & INP_RATE_LIMIT_CHANGED) != 0 ||
251 		    (inp->inp_snd_tag != NULL &&
252 		    inp->inp_snd_tag->ifp != ifp))
253 			in_pcboutput_txrtlmt(inp, ifp, m);
254 
255 		if (inp->inp_snd_tag != NULL)
256 			mst = inp->inp_snd_tag;
257 	}
258 #endif
259 	if (stamp_tag && mst != NULL) {
260 		KASSERT(m->m_pkthdr.rcvif == NULL,
261 		    ("trying to add a send tag to a forwarded packet"));
262 		if (mst->ifp != ifp) {
263 			m_freem(m);
264 			error = EAGAIN;
265 			goto done;
266 		}
267 
268 		/* stamp send tag on mbuf */
269 		m->m_pkthdr.snd_tag = m_snd_tag_ref(mst);
270 		m->m_pkthdr.csum_flags |= CSUM_SND_TAG;
271 	}
272 
273 	error = (*ifp->if_output)(ifp, m, gw, ro);
274 
275 done:
276 	/* Check for route change invalidating send tags. */
277 #ifdef KERN_TLS
278 	if (tls != NULL) {
279 		if (error == EAGAIN)
280 			error = ktls_output_eagain(inp, tls);
281 		ktls_free(tls);
282 	}
283 #endif
284 #ifdef RATELIMIT
285 	if (error == EAGAIN)
286 		in_pcboutput_eagain(inp);
287 #endif
288 	return (error);
289 }
290 
291 /* rte<>ro_flags translation */
292 static inline void
293 rt_update_ro_flags(struct route *ro, const struct nhop_object *nh)
294 {
295 	int nh_flags = nh->nh_flags;
296 
297 	ro->ro_flags &= ~ (RT_REJECT|RT_BLACKHOLE|RT_HAS_GW);
298 
299 	ro->ro_flags |= (nh_flags & NHF_REJECT) ? RT_REJECT : 0;
300 	ro->ro_flags |= (nh_flags & NHF_BLACKHOLE) ? RT_BLACKHOLE : 0;
301 	ro->ro_flags |= (nh_flags & NHF_GATEWAY) ? RT_HAS_GW : 0;
302 }
303 
304 /*
305  * IP output.  The packet in mbuf chain m contains a skeletal IP
306  * header (with len, off, ttl, proto, tos, src, dst).
307  * The mbuf chain containing the packet will be freed.
308  * The mbuf opt, if present, will not be freed.
309  * If route ro is present and has ro_rt initialized, route lookup would be
310  * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
311  * then result of route lookup is stored in ro->ro_rt.
312  *
313  * In the IP forwarding case, the packet will arrive with options already
314  * inserted, so must have a NULL opt pointer.
315  */
316 int
317 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
318     struct ip_moptions *imo, struct inpcb *inp)
319 {
320 	struct ip *ip;
321 	struct ifnet *ifp = NULL;	/* keep compiler happy */
322 	struct mbuf *m0;
323 	int hlen = sizeof (struct ip);
324 	int mtu = 0;
325 	int error = 0;
326 	int vlan_pcp = -1;
327 	struct sockaddr_in *dst;
328 	const struct sockaddr *gw;
329 	struct in_ifaddr *ia = NULL;
330 	struct in_addr src;
331 	int isbroadcast;
332 	uint16_t ip_len, ip_off;
333 	struct route iproute;
334 	uint32_t fibnum;
335 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
336 	int no_route_but_check_spd = 0;
337 #endif
338 
339 	M_ASSERTPKTHDR(m);
340 	NET_EPOCH_ASSERT();
341 
342 	if (inp != NULL) {
343 		INP_LOCK_ASSERT(inp);
344 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
345 		if ((flags & IP_NODEFAULTFLOWID) == 0) {
346 			m->m_pkthdr.flowid = inp->inp_flowid;
347 			M_HASHTYPE_SET(m, inp->inp_flowtype);
348 		}
349 		if ((inp->inp_flags2 & INP_2PCP_SET) != 0)
350 			vlan_pcp = (inp->inp_flags2 & INP_2PCP_MASK) >>
351 			    INP_2PCP_SHIFT;
352 #ifdef NUMA
353 		m->m_pkthdr.numa_domain = inp->inp_numa_domain;
354 #endif
355 	}
356 
357 	if (opt) {
358 		int len = 0;
359 		m = ip_insertoptions(m, opt, &len);
360 		if (len != 0)
361 			hlen = len; /* ip->ip_hl is updated above */
362 	}
363 	ip = mtod(m, struct ip *);
364 	ip_len = ntohs(ip->ip_len);
365 	ip_off = ntohs(ip->ip_off);
366 
367 	if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
368 		ip->ip_v = IPVERSION;
369 		ip->ip_hl = hlen >> 2;
370 		ip_fillid(ip);
371 	} else {
372 		/* Header already set, fetch hlen from there */
373 		hlen = ip->ip_hl << 2;
374 	}
375 	if ((flags & IP_FORWARDING) == 0)
376 		IPSTAT_INC(ips_localout);
377 
378 	/*
379 	 * dst/gw handling:
380 	 *
381 	 * gw is readonly but can point either to dst OR rt_gateway,
382 	 * therefore we need restore gw if we're redoing lookup.
383 	 */
384 	fibnum = (inp != NULL) ? inp->inp_inc.inc_fibnum : M_GETFIB(m);
385 	if (ro == NULL) {
386 		ro = &iproute;
387 		bzero(ro, sizeof (*ro));
388 	}
389 	dst = (struct sockaddr_in *)&ro->ro_dst;
390 	if (ro->ro_nh == NULL) {
391 		dst->sin_family = AF_INET;
392 		dst->sin_len = sizeof(*dst);
393 		dst->sin_addr = ip->ip_dst;
394 	}
395 	gw = (const struct sockaddr *)dst;
396 again:
397 	/*
398 	 * Validate route against routing table additions;
399 	 * a better/more specific route might have been added.
400 	 */
401 	if (inp != NULL && ro->ro_nh != NULL)
402 		NH_VALIDATE(ro, &inp->inp_rt_cookie, fibnum);
403 	/*
404 	 * If there is a cached route,
405 	 * check that it is to the same destination
406 	 * and is still up.  If not, free it and try again.
407 	 * The address family should also be checked in case of sharing the
408 	 * cache with IPv6.
409 	 * Also check whether routing cache needs invalidation.
410 	 */
411 	if (ro->ro_nh != NULL &&
412 	    ((!NH_IS_VALID(ro->ro_nh)) || dst->sin_family != AF_INET ||
413 	    dst->sin_addr.s_addr != ip->ip_dst.s_addr))
414 		RO_INVALIDATE_CACHE(ro);
415 	ia = NULL;
416 	/*
417 	 * If routing to interface only, short circuit routing lookup.
418 	 * The use of an all-ones broadcast address implies this; an
419 	 * interface is specified by the broadcast address of an interface,
420 	 * or the destination address of a ptp interface.
421 	 */
422 	if (flags & IP_SENDONES) {
423 		if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst),
424 						      M_GETFIB(m)))) == NULL &&
425 		    (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
426 						    M_GETFIB(m)))) == NULL) {
427 			IPSTAT_INC(ips_noroute);
428 			error = ENETUNREACH;
429 			goto bad;
430 		}
431 		ip->ip_dst.s_addr = INADDR_BROADCAST;
432 		dst->sin_addr = ip->ip_dst;
433 		ifp = ia->ia_ifp;
434 		mtu = ifp->if_mtu;
435 		ip->ip_ttl = 1;
436 		isbroadcast = 1;
437 		src = IA_SIN(ia)->sin_addr;
438 	} else if (flags & IP_ROUTETOIF) {
439 		if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst),
440 						    M_GETFIB(m)))) == NULL &&
441 		    (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0,
442 						M_GETFIB(m)))) == NULL) {
443 			IPSTAT_INC(ips_noroute);
444 			error = ENETUNREACH;
445 			goto bad;
446 		}
447 		ifp = ia->ia_ifp;
448 		mtu = ifp->if_mtu;
449 		ip->ip_ttl = 1;
450 		isbroadcast = ifp->if_flags & IFF_BROADCAST ?
451 		    in_ifaddr_broadcast(dst->sin_addr, ia) : 0;
452 		src = IA_SIN(ia)->sin_addr;
453 	} else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
454 	    imo != NULL && imo->imo_multicast_ifp != NULL) {
455 		/*
456 		 * Bypass the normal routing lookup for multicast
457 		 * packets if the interface is specified.
458 		 */
459 		ifp = imo->imo_multicast_ifp;
460 		mtu = ifp->if_mtu;
461 		IFP_TO_IA(ifp, ia);
462 		isbroadcast = 0;	/* fool gcc */
463 		/* Interface may have no addresses. */
464 		if (ia != NULL)
465 			src = IA_SIN(ia)->sin_addr;
466 		else
467 			src.s_addr = INADDR_ANY;
468 	} else if (ro != &iproute) {
469 		if (ro->ro_nh == NULL) {
470 			/*
471 			 * We want to do any cloning requested by the link
472 			 * layer, as this is probably required in all cases
473 			 * for correct operation (as it is for ARP).
474 			 */
475 			uint32_t flowid;
476 			flowid = m->m_pkthdr.flowid;
477 			ro->ro_nh = fib4_lookup(fibnum, dst->sin_addr, 0,
478 			    NHR_REF, flowid);
479 
480 			if (ro->ro_nh == NULL || (!NH_IS_VALID(ro->ro_nh))) {
481 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
482 				/*
483 				 * There is no route for this packet, but it is
484 				 * possible that a matching SPD entry exists.
485 				 */
486 				no_route_but_check_spd = 1;
487 				goto sendit;
488 #endif
489 				IPSTAT_INC(ips_noroute);
490 				error = EHOSTUNREACH;
491 				goto bad;
492 			}
493 		}
494 		struct nhop_object *nh = ro->ro_nh;
495 
496 		ia = ifatoia(nh->nh_ifa);
497 		ifp = nh->nh_ifp;
498 		counter_u64_add(nh->nh_pksent, 1);
499 		rt_update_ro_flags(ro, nh);
500 		if (nh->nh_flags & NHF_GATEWAY)
501 			gw = &nh->gw_sa;
502 		if (nh->nh_flags & NHF_HOST)
503 			isbroadcast = (nh->nh_flags & NHF_BROADCAST);
504 		else if ((ifp->if_flags & IFF_BROADCAST) && (gw->sa_family == AF_INET))
505 			isbroadcast = in_ifaddr_broadcast(((const struct sockaddr_in *)gw)->sin_addr, ia);
506 		else
507 			isbroadcast = 0;
508 		mtu = nh->nh_mtu;
509 		src = IA_SIN(ia)->sin_addr;
510 	} else {
511 		struct nhop_object *nh;
512 
513 		nh = fib4_lookup(M_GETFIB(m), dst->sin_addr, 0, NHR_NONE,
514 		    m->m_pkthdr.flowid);
515 		if (nh == NULL) {
516 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
517 			/*
518 			 * There is no route for this packet, but it is
519 			 * possible that a matching SPD entry exists.
520 			 */
521 			no_route_but_check_spd = 1;
522 			goto sendit;
523 #endif
524 			IPSTAT_INC(ips_noroute);
525 			error = EHOSTUNREACH;
526 			goto bad;
527 		}
528 		ifp = nh->nh_ifp;
529 		mtu = nh->nh_mtu;
530 		rt_update_ro_flags(ro, nh);
531 		if (nh->nh_flags & NHF_GATEWAY)
532 			gw = &nh->gw_sa;
533 		ia = ifatoia(nh->nh_ifa);
534 		src = IA_SIN(ia)->sin_addr;
535 		isbroadcast = (((nh->nh_flags & (NHF_HOST | NHF_BROADCAST)) ==
536 		    (NHF_HOST | NHF_BROADCAST)) ||
537 		    ((ifp->if_flags & IFF_BROADCAST) &&
538 		    (gw->sa_family == AF_INET) &&
539 		    in_ifaddr_broadcast(((const struct sockaddr_in *)gw)->sin_addr, ia)));
540 	}
541 
542 	/* Catch a possible divide by zero later. */
543 	KASSERT(mtu > 0, ("%s: mtu %d <= 0, ro=%p (nh_flags=0x%08x) ifp=%p",
544 	    __func__, mtu, ro,
545 	    (ro != NULL && ro->ro_nh != NULL) ? ro->ro_nh->nh_flags : 0, ifp));
546 
547 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
548 		m->m_flags |= M_MCAST;
549 		/*
550 		 * IP destination address is multicast.  Make sure "gw"
551 		 * still points to the address in "ro".  (It may have been
552 		 * changed to point to a gateway address, above.)
553 		 */
554 		gw = (const struct sockaddr *)dst;
555 		/*
556 		 * See if the caller provided any multicast options
557 		 */
558 		if (imo != NULL) {
559 			ip->ip_ttl = imo->imo_multicast_ttl;
560 			if (imo->imo_multicast_vif != -1)
561 				ip->ip_src.s_addr =
562 				    ip_mcast_src ?
563 				    ip_mcast_src(imo->imo_multicast_vif) :
564 				    INADDR_ANY;
565 		} else
566 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
567 		/*
568 		 * Confirm that the outgoing interface supports multicast.
569 		 */
570 		if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
571 			if ((ifp->if_flags & IFF_MULTICAST) == 0) {
572 				IPSTAT_INC(ips_noroute);
573 				error = ENETUNREACH;
574 				goto bad;
575 			}
576 		}
577 		/*
578 		 * If source address not specified yet, use address
579 		 * of outgoing interface.
580 		 */
581 		if (ip->ip_src.s_addr == INADDR_ANY)
582 			ip->ip_src = src;
583 
584 		if ((imo == NULL && in_mcast_loop) ||
585 		    (imo && imo->imo_multicast_loop)) {
586 			/*
587 			 * Loop back multicast datagram if not expressly
588 			 * forbidden to do so, even if we are not a member
589 			 * of the group; ip_input() will filter it later,
590 			 * thus deferring a hash lookup and mutex acquisition
591 			 * at the expense of a cheap copy using m_copym().
592 			 */
593 			ip_mloopback(ifp, m, hlen);
594 		} else {
595 			/*
596 			 * If we are acting as a multicast router, perform
597 			 * multicast forwarding as if the packet had just
598 			 * arrived on the interface to which we are about
599 			 * to send.  The multicast forwarding function
600 			 * recursively calls this function, using the
601 			 * IP_FORWARDING flag to prevent infinite recursion.
602 			 *
603 			 * Multicasts that are looped back by ip_mloopback(),
604 			 * above, will be forwarded by the ip_input() routine,
605 			 * if necessary.
606 			 */
607 			if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
608 				/*
609 				 * If rsvp daemon is not running, do not
610 				 * set ip_moptions. This ensures that the packet
611 				 * is multicast and not just sent down one link
612 				 * as prescribed by rsvpd.
613 				 */
614 				if (!V_rsvp_on)
615 					imo = NULL;
616 				if (ip_mforward &&
617 				    ip_mforward(ip, ifp, m, imo) != 0) {
618 					m_freem(m);
619 					goto done;
620 				}
621 			}
622 		}
623 
624 		/*
625 		 * Multicasts with a time-to-live of zero may be looped-
626 		 * back, above, but must not be transmitted on a network.
627 		 * Also, multicasts addressed to the loopback interface
628 		 * are not sent -- the above call to ip_mloopback() will
629 		 * loop back a copy. ip_input() will drop the copy if
630 		 * this host does not belong to the destination group on
631 		 * the loopback interface.
632 		 */
633 		if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
634 			m_freem(m);
635 			goto done;
636 		}
637 
638 		goto sendit;
639 	}
640 
641 	/*
642 	 * If the source address is not specified yet, use the address
643 	 * of the outoing interface.
644 	 */
645 	if (ip->ip_src.s_addr == INADDR_ANY)
646 		ip->ip_src = src;
647 
648 	/*
649 	 * Look for broadcast address and
650 	 * verify user is allowed to send
651 	 * such a packet.
652 	 */
653 	if (isbroadcast) {
654 		if ((ifp->if_flags & IFF_BROADCAST) == 0) {
655 			error = EADDRNOTAVAIL;
656 			goto bad;
657 		}
658 		if ((flags & IP_ALLOWBROADCAST) == 0) {
659 			error = EACCES;
660 			goto bad;
661 		}
662 		/* don't allow broadcast messages to be fragmented */
663 		if (ip_len > mtu) {
664 			error = EMSGSIZE;
665 			goto bad;
666 		}
667 		m->m_flags |= M_BCAST;
668 	} else {
669 		m->m_flags &= ~M_BCAST;
670 	}
671 
672 sendit:
673 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
674 	if (IPSEC_ENABLED(ipv4)) {
675 		if ((error = IPSEC_OUTPUT(ipv4, m, inp)) != 0) {
676 			if (error == EINPROGRESS)
677 				error = 0;
678 			goto done;
679 		}
680 	}
681 	/*
682 	 * Check if there was a route for this packet; return error if not.
683 	 */
684 	if (no_route_but_check_spd) {
685 		IPSTAT_INC(ips_noroute);
686 		error = EHOSTUNREACH;
687 		goto bad;
688 	}
689 	/* Update variables that are affected by ipsec4_output(). */
690 	ip = mtod(m, struct ip *);
691 	hlen = ip->ip_hl << 2;
692 #endif /* IPSEC */
693 
694 	/* Jump over all PFIL processing if hooks are not active. */
695 	if (PFIL_HOOKED_OUT(V_inet_pfil_head)) {
696 		switch (ip_output_pfil(&m, ifp, flags, inp, dst, &fibnum,
697 		    &error)) {
698 		case 1: /* Finished */
699 			goto done;
700 
701 		case 0: /* Continue normally */
702 			ip = mtod(m, struct ip *);
703 			break;
704 
705 		case -1: /* Need to try again */
706 			/* Reset everything for a new round */
707 			if (ro != NULL) {
708 				RO_NHFREE(ro);
709 				ro->ro_prepend = NULL;
710 			}
711 			gw = (const struct sockaddr *)dst;
712 			ip = mtod(m, struct ip *);
713 			goto again;
714 		}
715 	}
716 
717 	if (vlan_pcp > -1)
718 		EVL_APPLY_PRI(m, vlan_pcp);
719 
720 	/* IN_LOOPBACK must not appear on the wire - RFC1122. */
721 	if (IN_LOOPBACK(ntohl(ip->ip_dst.s_addr)) ||
722 	    IN_LOOPBACK(ntohl(ip->ip_src.s_addr))) {
723 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
724 			IPSTAT_INC(ips_badaddr);
725 			error = EADDRNOTAVAIL;
726 			goto bad;
727 		}
728 	}
729 
730 	/* Ensure the packet data is mapped if the interface requires it. */
731 	if ((ifp->if_capenable & IFCAP_MEXTPG) == 0) {
732 		m = mb_unmapped_to_ext(m);
733 		if (m == NULL) {
734 			IPSTAT_INC(ips_odropped);
735 			error = ENOBUFS;
736 			goto bad;
737 		}
738 	}
739 
740 	m->m_pkthdr.csum_flags |= CSUM_IP;
741 	if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
742 		in_delayed_cksum(m);
743 		m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
744 	}
745 #if defined(SCTP) || defined(SCTP_SUPPORT)
746 	if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
747 		sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
748 		m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
749 	}
750 #endif
751 
752 	/*
753 	 * If small enough for interface, or the interface will take
754 	 * care of the fragmentation for us, we can just send directly.
755 	 * Note that if_vxlan could have requested TSO even though the outer
756 	 * frame is UDP.  It is correct to not fragment such datagrams and
757 	 * instead just pass them on to the driver.
758 	 */
759 	if (ip_len <= mtu ||
760 	    (m->m_pkthdr.csum_flags & ifp->if_hwassist &
761 	    (CSUM_TSO | CSUM_INNER_TSO)) != 0) {
762 		ip->ip_sum = 0;
763 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
764 			ip->ip_sum = in_cksum(m, hlen);
765 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
766 		}
767 
768 		/*
769 		 * Record statistics for this interface address.
770 		 * With CSUM_TSO the byte/packet count will be slightly
771 		 * incorrect because we count the IP+TCP headers only
772 		 * once instead of for every generated packet.
773 		 */
774 		if (!(flags & IP_FORWARDING) && ia) {
775 			if (m->m_pkthdr.csum_flags &
776 			    (CSUM_TSO | CSUM_INNER_TSO))
777 				counter_u64_add(ia->ia_ifa.ifa_opackets,
778 				    m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
779 			else
780 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
781 
782 			counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
783 		}
784 #ifdef MBUF_STRESS_TEST
785 		if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
786 			m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
787 #endif
788 		/*
789 		 * Reset layer specific mbuf flags
790 		 * to avoid confusing lower layers.
791 		 */
792 		m_clrprotoflags(m);
793 		IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
794 		error = ip_output_send(inp, ifp, m, gw, ro,
795 		    (flags & IP_NO_SND_TAG_RL) ? false : true);
796 		goto done;
797 	}
798 
799 	/* Balk when DF bit is set or the interface didn't support TSO. */
800 	if ((ip_off & IP_DF) ||
801 	    (m->m_pkthdr.csum_flags & (CSUM_TSO | CSUM_INNER_TSO))) {
802 		error = EMSGSIZE;
803 		IPSTAT_INC(ips_cantfrag);
804 		goto bad;
805 	}
806 
807 	/*
808 	 * Too large for interface; fragment if possible. If successful,
809 	 * on return, m will point to a list of packets to be sent.
810 	 */
811 	error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
812 	if (error)
813 		goto bad;
814 	for (; m; m = m0) {
815 		m0 = m->m_nextpkt;
816 		m->m_nextpkt = 0;
817 		if (error == 0) {
818 			/* Record statistics for this interface address. */
819 			if (ia != NULL) {
820 				counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
821 				counter_u64_add(ia->ia_ifa.ifa_obytes,
822 				    m->m_pkthdr.len);
823 			}
824 			/*
825 			 * Reset layer specific mbuf flags
826 			 * to avoid confusing upper layers.
827 			 */
828 			m_clrprotoflags(m);
829 
830 			IP_PROBE(send, NULL, NULL, mtod(m, struct ip *), ifp,
831 			    mtod(m, struct ip *), NULL);
832 			error = ip_output_send(inp, ifp, m, gw, ro, true);
833 		} else
834 			m_freem(m);
835 	}
836 
837 	if (error == 0)
838 		IPSTAT_INC(ips_fragmented);
839 
840 done:
841 	return (error);
842  bad:
843 	m_freem(m);
844 	goto done;
845 }
846 
847 /*
848  * Create a chain of fragments which fit the given mtu. m_frag points to the
849  * mbuf to be fragmented; on return it points to the chain with the fragments.
850  * Return 0 if no error. If error, m_frag may contain a partially built
851  * chain of fragments that should be freed by the caller.
852  *
853  * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
854  */
855 int
856 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
857     u_long if_hwassist_flags)
858 {
859 	int error = 0;
860 	int hlen = ip->ip_hl << 2;
861 	int len = (mtu - hlen) & ~7;	/* size of payload in each fragment */
862 	int off;
863 	struct mbuf *m0 = *m_frag;	/* the original packet		*/
864 	int firstlen;
865 	struct mbuf **mnext;
866 	int nfrags;
867 	uint16_t ip_len, ip_off;
868 
869 	ip_len = ntohs(ip->ip_len);
870 	ip_off = ntohs(ip->ip_off);
871 
872 	/*
873 	 * Packet shall not have "Don't Fragment" flag and have at least 8
874 	 * bytes of payload.
875 	 */
876 	if (__predict_false((ip_off & IP_DF) || len < 8)) {
877 		IPSTAT_INC(ips_cantfrag);
878 		return (EMSGSIZE);
879 	}
880 
881 	/*
882 	 * If the interface will not calculate checksums on
883 	 * fragmented packets, then do it here.
884 	 */
885 	if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
886 		in_delayed_cksum(m0);
887 		m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
888 	}
889 #if defined(SCTP) || defined(SCTP_SUPPORT)
890 	if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
891 		sctp_delayed_cksum(m0, hlen);
892 		m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
893 	}
894 #endif
895 	if (len > PAGE_SIZE) {
896 		/*
897 		 * Fragment large datagrams such that each segment
898 		 * contains a multiple of PAGE_SIZE amount of data,
899 		 * plus headers. This enables a receiver to perform
900 		 * page-flipping zero-copy optimizations.
901 		 *
902 		 * XXX When does this help given that sender and receiver
903 		 * could have different page sizes, and also mtu could
904 		 * be less than the receiver's page size ?
905 		 */
906 		int newlen;
907 
908 		off = MIN(mtu, m0->m_pkthdr.len);
909 
910 		/*
911 		 * firstlen (off - hlen) must be aligned on an
912 		 * 8-byte boundary
913 		 */
914 		if (off < hlen)
915 			goto smart_frag_failure;
916 		off = ((off - hlen) & ~7) + hlen;
917 		newlen = (~PAGE_MASK) & mtu;
918 		if ((newlen + sizeof (struct ip)) > mtu) {
919 			/* we failed, go back the default */
920 smart_frag_failure:
921 			newlen = len;
922 			off = hlen + len;
923 		}
924 		len = newlen;
925 
926 	} else {
927 		off = hlen + len;
928 	}
929 
930 	firstlen = off - hlen;
931 	mnext = &m0->m_nextpkt;		/* pointer to next packet */
932 
933 	/*
934 	 * Loop through length of segment after first fragment,
935 	 * make new header and copy data of each part and link onto chain.
936 	 * Here, m0 is the original packet, m is the fragment being created.
937 	 * The fragments are linked off the m_nextpkt of the original
938 	 * packet, which after processing serves as the first fragment.
939 	 */
940 	for (nfrags = 1; off < ip_len; off += len, nfrags++) {
941 		struct ip *mhip;	/* ip header on the fragment */
942 		struct mbuf *m;
943 		int mhlen = sizeof (struct ip);
944 
945 		m = m_gethdr(M_NOWAIT, MT_DATA);
946 		if (m == NULL) {
947 			error = ENOBUFS;
948 			IPSTAT_INC(ips_odropped);
949 			goto done;
950 		}
951 		/*
952 		 * Make sure the complete packet header gets copied
953 		 * from the originating mbuf to the newly created
954 		 * mbuf. This also ensures that existing firewall
955 		 * classification(s), VLAN tags and so on get copied
956 		 * to the resulting fragmented packet(s):
957 		 */
958 		if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
959 			m_free(m);
960 			error = ENOBUFS;
961 			IPSTAT_INC(ips_odropped);
962 			goto done;
963 		}
964 		/*
965 		 * In the first mbuf, leave room for the link header, then
966 		 * copy the original IP header including options. The payload
967 		 * goes into an additional mbuf chain returned by m_copym().
968 		 */
969 		m->m_data += max_linkhdr;
970 		mhip = mtod(m, struct ip *);
971 		*mhip = *ip;
972 		if (hlen > sizeof (struct ip)) {
973 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
974 			mhip->ip_v = IPVERSION;
975 			mhip->ip_hl = mhlen >> 2;
976 		}
977 		m->m_len = mhlen;
978 		/* XXX do we need to add ip_off below ? */
979 		mhip->ip_off = ((off - hlen) >> 3) + ip_off;
980 		if (off + len >= ip_len)
981 			len = ip_len - off;
982 		else
983 			mhip->ip_off |= IP_MF;
984 		mhip->ip_len = htons((u_short)(len + mhlen));
985 		m->m_next = m_copym(m0, off, len, M_NOWAIT);
986 		if (m->m_next == NULL) {	/* copy failed */
987 			m_free(m);
988 			error = ENOBUFS;	/* ??? */
989 			IPSTAT_INC(ips_odropped);
990 			goto done;
991 		}
992 		m->m_pkthdr.len = mhlen + len;
993 #ifdef MAC
994 		mac_netinet_fragment(m0, m);
995 #endif
996 		mhip->ip_off = htons(mhip->ip_off);
997 		mhip->ip_sum = 0;
998 		if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
999 			mhip->ip_sum = in_cksum(m, mhlen);
1000 			m->m_pkthdr.csum_flags &= ~CSUM_IP;
1001 		}
1002 		*mnext = m;
1003 		mnext = &m->m_nextpkt;
1004 	}
1005 	IPSTAT_ADD(ips_ofragments, nfrags);
1006 
1007 	/*
1008 	 * Update first fragment by trimming what's been copied out
1009 	 * and updating header.
1010 	 */
1011 	m_adj(m0, hlen + firstlen - ip_len);
1012 	m0->m_pkthdr.len = hlen + firstlen;
1013 	ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1014 	ip->ip_off = htons(ip_off | IP_MF);
1015 	ip->ip_sum = 0;
1016 	if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
1017 		ip->ip_sum = in_cksum(m0, hlen);
1018 		m0->m_pkthdr.csum_flags &= ~CSUM_IP;
1019 	}
1020 
1021 done:
1022 	*m_frag = m0;
1023 	return error;
1024 }
1025 
1026 void
1027 in_delayed_cksum(struct mbuf *m)
1028 {
1029 	struct ip *ip;
1030 	struct udphdr *uh;
1031 	uint16_t cklen, csum, offset;
1032 
1033 	ip = mtod(m, struct ip *);
1034 	offset = ip->ip_hl << 2 ;
1035 
1036 	if (m->m_pkthdr.csum_flags & CSUM_UDP) {
1037 		/* if udp header is not in the first mbuf copy udplen */
1038 		if (offset + sizeof(struct udphdr) > m->m_len) {
1039 			m_copydata(m, offset + offsetof(struct udphdr,
1040 			    uh_ulen), sizeof(cklen), (caddr_t)&cklen);
1041 			cklen = ntohs(cklen);
1042 		} else {
1043 			uh = (struct udphdr *)mtodo(m, offset);
1044 			cklen = ntohs(uh->uh_ulen);
1045 		}
1046 		csum = in_cksum_skip(m, cklen + offset, offset);
1047 		if (csum == 0)
1048 			csum = 0xffff;
1049 	} else {
1050 		cklen = ntohs(ip->ip_len);
1051 		csum = in_cksum_skip(m, cklen, offset);
1052 	}
1053 	offset += m->m_pkthdr.csum_data;	/* checksum offset */
1054 
1055 	if (offset + sizeof(csum) > m->m_len)
1056 		m_copyback(m, offset, sizeof(csum), (caddr_t)&csum);
1057 	else
1058 		*(u_short *)mtodo(m, offset) = csum;
1059 }
1060 
1061 /*
1062  * IP socket option processing.
1063  */
1064 int
1065 ip_ctloutput(struct socket *so, struct sockopt *sopt)
1066 {
1067 	struct inpcb *inp = sotoinpcb(so);
1068 	int	error, optval;
1069 #ifdef	RSS
1070 	uint32_t rss_bucket;
1071 	int retval;
1072 #endif
1073 
1074 	error = optval = 0;
1075 	if (sopt->sopt_level != IPPROTO_IP) {
1076 		error = EINVAL;
1077 
1078 		if (sopt->sopt_level == SOL_SOCKET &&
1079 		    sopt->sopt_dir == SOPT_SET) {
1080 			switch (sopt->sopt_name) {
1081 			case SO_REUSEADDR:
1082 				INP_WLOCK(inp);
1083 				if ((so->so_options & SO_REUSEADDR) != 0)
1084 					inp->inp_flags2 |= INP_REUSEADDR;
1085 				else
1086 					inp->inp_flags2 &= ~INP_REUSEADDR;
1087 				INP_WUNLOCK(inp);
1088 				error = 0;
1089 				break;
1090 			case SO_REUSEPORT:
1091 				INP_WLOCK(inp);
1092 				if ((so->so_options & SO_REUSEPORT) != 0)
1093 					inp->inp_flags2 |= INP_REUSEPORT;
1094 				else
1095 					inp->inp_flags2 &= ~INP_REUSEPORT;
1096 				INP_WUNLOCK(inp);
1097 				error = 0;
1098 				break;
1099 			case SO_REUSEPORT_LB:
1100 				INP_WLOCK(inp);
1101 				if ((so->so_options & SO_REUSEPORT_LB) != 0)
1102 					inp->inp_flags2 |= INP_REUSEPORT_LB;
1103 				else
1104 					inp->inp_flags2 &= ~INP_REUSEPORT_LB;
1105 				INP_WUNLOCK(inp);
1106 				error = 0;
1107 				break;
1108 			case SO_SETFIB:
1109 				INP_WLOCK(inp);
1110 				inp->inp_inc.inc_fibnum = so->so_fibnum;
1111 				INP_WUNLOCK(inp);
1112 				error = 0;
1113 				break;
1114 			case SO_MAX_PACING_RATE:
1115 #ifdef RATELIMIT
1116 				INP_WLOCK(inp);
1117 				inp->inp_flags2 |= INP_RATE_LIMIT_CHANGED;
1118 				INP_WUNLOCK(inp);
1119 				error = 0;
1120 #else
1121 				error = EOPNOTSUPP;
1122 #endif
1123 				break;
1124 			default:
1125 				break;
1126 			}
1127 		}
1128 		return (error);
1129 	}
1130 
1131 	switch (sopt->sopt_dir) {
1132 	case SOPT_SET:
1133 		switch (sopt->sopt_name) {
1134 		case IP_OPTIONS:
1135 #ifdef notyet
1136 		case IP_RETOPTS:
1137 #endif
1138 		{
1139 			struct mbuf *m;
1140 			if (sopt->sopt_valsize > MLEN) {
1141 				error = EMSGSIZE;
1142 				break;
1143 			}
1144 			m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
1145 			if (m == NULL) {
1146 				error = ENOBUFS;
1147 				break;
1148 			}
1149 			m->m_len = sopt->sopt_valsize;
1150 			error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1151 					    m->m_len);
1152 			if (error) {
1153 				m_free(m);
1154 				break;
1155 			}
1156 			INP_WLOCK(inp);
1157 			error = ip_pcbopts(inp, sopt->sopt_name, m);
1158 			INP_WUNLOCK(inp);
1159 			return (error);
1160 		}
1161 
1162 		case IP_BINDANY:
1163 			if (sopt->sopt_td != NULL) {
1164 				error = priv_check(sopt->sopt_td,
1165 				    PRIV_NETINET_BINDANY);
1166 				if (error)
1167 					break;
1168 			}
1169 			/* FALLTHROUGH */
1170 		case IP_BINDMULTI:
1171 #ifdef	RSS
1172 		case IP_RSS_LISTEN_BUCKET:
1173 #endif
1174 		case IP_TOS:
1175 		case IP_TTL:
1176 		case IP_MINTTL:
1177 		case IP_RECVOPTS:
1178 		case IP_RECVRETOPTS:
1179 		case IP_ORIGDSTADDR:
1180 		case IP_RECVDSTADDR:
1181 		case IP_RECVTTL:
1182 		case IP_RECVIF:
1183 		case IP_ONESBCAST:
1184 		case IP_DONTFRAG:
1185 		case IP_RECVTOS:
1186 		case IP_RECVFLOWID:
1187 #ifdef	RSS
1188 		case IP_RECVRSSBUCKETID:
1189 #endif
1190 		case IP_VLAN_PCP:
1191 			error = sooptcopyin(sopt, &optval, sizeof optval,
1192 					    sizeof optval);
1193 			if (error)
1194 				break;
1195 
1196 			switch (sopt->sopt_name) {
1197 			case IP_TOS:
1198 				inp->inp_ip_tos = optval;
1199 				break;
1200 
1201 			case IP_TTL:
1202 				inp->inp_ip_ttl = optval;
1203 				break;
1204 
1205 			case IP_MINTTL:
1206 				if (optval >= 0 && optval <= MAXTTL)
1207 					inp->inp_ip_minttl = optval;
1208 				else
1209 					error = EINVAL;
1210 				break;
1211 
1212 #define	OPTSET(bit) do {						\
1213 	INP_WLOCK(inp);							\
1214 	if (optval)							\
1215 		inp->inp_flags |= bit;					\
1216 	else								\
1217 		inp->inp_flags &= ~bit;					\
1218 	INP_WUNLOCK(inp);						\
1219 } while (0)
1220 
1221 #define	OPTSET2(bit, val) do {						\
1222 	INP_WLOCK(inp);							\
1223 	if (val)							\
1224 		inp->inp_flags2 |= bit;					\
1225 	else								\
1226 		inp->inp_flags2 &= ~bit;				\
1227 	INP_WUNLOCK(inp);						\
1228 } while (0)
1229 
1230 			case IP_RECVOPTS:
1231 				OPTSET(INP_RECVOPTS);
1232 				break;
1233 
1234 			case IP_RECVRETOPTS:
1235 				OPTSET(INP_RECVRETOPTS);
1236 				break;
1237 
1238 			case IP_RECVDSTADDR:
1239 				OPTSET(INP_RECVDSTADDR);
1240 				break;
1241 
1242 			case IP_ORIGDSTADDR:
1243 				OPTSET2(INP_ORIGDSTADDR, optval);
1244 				break;
1245 
1246 			case IP_RECVTTL:
1247 				OPTSET(INP_RECVTTL);
1248 				break;
1249 
1250 			case IP_RECVIF:
1251 				OPTSET(INP_RECVIF);
1252 				break;
1253 
1254 			case IP_ONESBCAST:
1255 				OPTSET(INP_ONESBCAST);
1256 				break;
1257 			case IP_DONTFRAG:
1258 				OPTSET(INP_DONTFRAG);
1259 				break;
1260 			case IP_BINDANY:
1261 				OPTSET(INP_BINDANY);
1262 				break;
1263 			case IP_RECVTOS:
1264 				OPTSET(INP_RECVTOS);
1265 				break;
1266 			case IP_BINDMULTI:
1267 				OPTSET2(INP_BINDMULTI, optval);
1268 				break;
1269 			case IP_RECVFLOWID:
1270 				OPTSET2(INP_RECVFLOWID, optval);
1271 				break;
1272 #ifdef	RSS
1273 			case IP_RSS_LISTEN_BUCKET:
1274 				if ((optval >= 0) &&
1275 				    (optval < rss_getnumbuckets())) {
1276 					inp->inp_rss_listen_bucket = optval;
1277 					OPTSET2(INP_RSS_BUCKET_SET, 1);
1278 				} else {
1279 					error = EINVAL;
1280 				}
1281 				break;
1282 			case IP_RECVRSSBUCKETID:
1283 				OPTSET2(INP_RECVRSSBUCKETID, optval);
1284 				break;
1285 #endif
1286 			case IP_VLAN_PCP:
1287 				if ((optval >= -1) && (optval <=
1288 				    (INP_2PCP_MASK >> INP_2PCP_SHIFT))) {
1289 					if (optval == -1) {
1290 						INP_WLOCK(inp);
1291 						inp->inp_flags2 &=
1292 						    ~(INP_2PCP_SET |
1293 						      INP_2PCP_MASK);
1294 						INP_WUNLOCK(inp);
1295 					} else {
1296 						INP_WLOCK(inp);
1297 						inp->inp_flags2 |=
1298 						    INP_2PCP_SET;
1299 						inp->inp_flags2 &=
1300 						    ~INP_2PCP_MASK;
1301 						inp->inp_flags2 |=
1302 						    optval << INP_2PCP_SHIFT;
1303 						INP_WUNLOCK(inp);
1304 					}
1305 				} else
1306 					error = EINVAL;
1307 				break;
1308 			}
1309 			break;
1310 #undef OPTSET
1311 #undef OPTSET2
1312 
1313 		/*
1314 		 * Multicast socket options are processed by the in_mcast
1315 		 * module.
1316 		 */
1317 		case IP_MULTICAST_IF:
1318 		case IP_MULTICAST_VIF:
1319 		case IP_MULTICAST_TTL:
1320 		case IP_MULTICAST_LOOP:
1321 		case IP_ADD_MEMBERSHIP:
1322 		case IP_DROP_MEMBERSHIP:
1323 		case IP_ADD_SOURCE_MEMBERSHIP:
1324 		case IP_DROP_SOURCE_MEMBERSHIP:
1325 		case IP_BLOCK_SOURCE:
1326 		case IP_UNBLOCK_SOURCE:
1327 		case IP_MSFILTER:
1328 		case MCAST_JOIN_GROUP:
1329 		case MCAST_LEAVE_GROUP:
1330 		case MCAST_JOIN_SOURCE_GROUP:
1331 		case MCAST_LEAVE_SOURCE_GROUP:
1332 		case MCAST_BLOCK_SOURCE:
1333 		case MCAST_UNBLOCK_SOURCE:
1334 			error = inp_setmoptions(inp, sopt);
1335 			break;
1336 
1337 		case IP_PORTRANGE:
1338 			error = sooptcopyin(sopt, &optval, sizeof optval,
1339 					    sizeof optval);
1340 			if (error)
1341 				break;
1342 
1343 			INP_WLOCK(inp);
1344 			switch (optval) {
1345 			case IP_PORTRANGE_DEFAULT:
1346 				inp->inp_flags &= ~(INP_LOWPORT);
1347 				inp->inp_flags &= ~(INP_HIGHPORT);
1348 				break;
1349 
1350 			case IP_PORTRANGE_HIGH:
1351 				inp->inp_flags &= ~(INP_LOWPORT);
1352 				inp->inp_flags |= INP_HIGHPORT;
1353 				break;
1354 
1355 			case IP_PORTRANGE_LOW:
1356 				inp->inp_flags &= ~(INP_HIGHPORT);
1357 				inp->inp_flags |= INP_LOWPORT;
1358 				break;
1359 
1360 			default:
1361 				error = EINVAL;
1362 				break;
1363 			}
1364 			INP_WUNLOCK(inp);
1365 			break;
1366 
1367 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1368 		case IP_IPSEC_POLICY:
1369 			if (IPSEC_ENABLED(ipv4)) {
1370 				error = IPSEC_PCBCTL(ipv4, inp, sopt);
1371 				break;
1372 			}
1373 			/* FALLTHROUGH */
1374 #endif /* IPSEC */
1375 
1376 		default:
1377 			error = ENOPROTOOPT;
1378 			break;
1379 		}
1380 		break;
1381 
1382 	case SOPT_GET:
1383 		switch (sopt->sopt_name) {
1384 		case IP_OPTIONS:
1385 		case IP_RETOPTS:
1386 			INP_RLOCK(inp);
1387 			if (inp->inp_options) {
1388 				struct mbuf *options;
1389 
1390 				options = m_copym(inp->inp_options, 0,
1391 				    M_COPYALL, M_NOWAIT);
1392 				INP_RUNLOCK(inp);
1393 				if (options != NULL) {
1394 					error = sooptcopyout(sopt,
1395 							     mtod(options, char *),
1396 							     options->m_len);
1397 					m_freem(options);
1398 				} else
1399 					error = ENOMEM;
1400 			} else {
1401 				INP_RUNLOCK(inp);
1402 				sopt->sopt_valsize = 0;
1403 			}
1404 			break;
1405 
1406 		case IP_TOS:
1407 		case IP_TTL:
1408 		case IP_MINTTL:
1409 		case IP_RECVOPTS:
1410 		case IP_RECVRETOPTS:
1411 		case IP_ORIGDSTADDR:
1412 		case IP_RECVDSTADDR:
1413 		case IP_RECVTTL:
1414 		case IP_RECVIF:
1415 		case IP_PORTRANGE:
1416 		case IP_ONESBCAST:
1417 		case IP_DONTFRAG:
1418 		case IP_BINDANY:
1419 		case IP_RECVTOS:
1420 		case IP_BINDMULTI:
1421 		case IP_FLOWID:
1422 		case IP_FLOWTYPE:
1423 		case IP_RECVFLOWID:
1424 #ifdef	RSS
1425 		case IP_RSSBUCKETID:
1426 		case IP_RECVRSSBUCKETID:
1427 #endif
1428 		case IP_VLAN_PCP:
1429 			switch (sopt->sopt_name) {
1430 			case IP_TOS:
1431 				optval = inp->inp_ip_tos;
1432 				break;
1433 
1434 			case IP_TTL:
1435 				optval = inp->inp_ip_ttl;
1436 				break;
1437 
1438 			case IP_MINTTL:
1439 				optval = inp->inp_ip_minttl;
1440 				break;
1441 
1442 #define	OPTBIT(bit)	(inp->inp_flags & bit ? 1 : 0)
1443 #define	OPTBIT2(bit)	(inp->inp_flags2 & bit ? 1 : 0)
1444 
1445 			case IP_RECVOPTS:
1446 				optval = OPTBIT(INP_RECVOPTS);
1447 				break;
1448 
1449 			case IP_RECVRETOPTS:
1450 				optval = OPTBIT(INP_RECVRETOPTS);
1451 				break;
1452 
1453 			case IP_RECVDSTADDR:
1454 				optval = OPTBIT(INP_RECVDSTADDR);
1455 				break;
1456 
1457 			case IP_ORIGDSTADDR:
1458 				optval = OPTBIT2(INP_ORIGDSTADDR);
1459 				break;
1460 
1461 			case IP_RECVTTL:
1462 				optval = OPTBIT(INP_RECVTTL);
1463 				break;
1464 
1465 			case IP_RECVIF:
1466 				optval = OPTBIT(INP_RECVIF);
1467 				break;
1468 
1469 			case IP_PORTRANGE:
1470 				if (inp->inp_flags & INP_HIGHPORT)
1471 					optval = IP_PORTRANGE_HIGH;
1472 				else if (inp->inp_flags & INP_LOWPORT)
1473 					optval = IP_PORTRANGE_LOW;
1474 				else
1475 					optval = 0;
1476 				break;
1477 
1478 			case IP_ONESBCAST:
1479 				optval = OPTBIT(INP_ONESBCAST);
1480 				break;
1481 			case IP_DONTFRAG:
1482 				optval = OPTBIT(INP_DONTFRAG);
1483 				break;
1484 			case IP_BINDANY:
1485 				optval = OPTBIT(INP_BINDANY);
1486 				break;
1487 			case IP_RECVTOS:
1488 				optval = OPTBIT(INP_RECVTOS);
1489 				break;
1490 			case IP_FLOWID:
1491 				optval = inp->inp_flowid;
1492 				break;
1493 			case IP_FLOWTYPE:
1494 				optval = inp->inp_flowtype;
1495 				break;
1496 			case IP_RECVFLOWID:
1497 				optval = OPTBIT2(INP_RECVFLOWID);
1498 				break;
1499 #ifdef	RSS
1500 			case IP_RSSBUCKETID:
1501 				retval = rss_hash2bucket(inp->inp_flowid,
1502 				    inp->inp_flowtype,
1503 				    &rss_bucket);
1504 				if (retval == 0)
1505 					optval = rss_bucket;
1506 				else
1507 					error = EINVAL;
1508 				break;
1509 			case IP_RECVRSSBUCKETID:
1510 				optval = OPTBIT2(INP_RECVRSSBUCKETID);
1511 				break;
1512 #endif
1513 			case IP_BINDMULTI:
1514 				optval = OPTBIT2(INP_BINDMULTI);
1515 				break;
1516 			case IP_VLAN_PCP:
1517 				if (OPTBIT2(INP_2PCP_SET)) {
1518 					optval = (inp->inp_flags2 &
1519 					    INP_2PCP_MASK) >> INP_2PCP_SHIFT;
1520 				} else {
1521 					optval = -1;
1522 				}
1523 				break;
1524 			}
1525 			error = sooptcopyout(sopt, &optval, sizeof optval);
1526 			break;
1527 
1528 		/*
1529 		 * Multicast socket options are processed by the in_mcast
1530 		 * module.
1531 		 */
1532 		case IP_MULTICAST_IF:
1533 		case IP_MULTICAST_VIF:
1534 		case IP_MULTICAST_TTL:
1535 		case IP_MULTICAST_LOOP:
1536 		case IP_MSFILTER:
1537 			error = inp_getmoptions(inp, sopt);
1538 			break;
1539 
1540 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1541 		case IP_IPSEC_POLICY:
1542 			if (IPSEC_ENABLED(ipv4)) {
1543 				error = IPSEC_PCBCTL(ipv4, inp, sopt);
1544 				break;
1545 			}
1546 			/* FALLTHROUGH */
1547 #endif /* IPSEC */
1548 
1549 		default:
1550 			error = ENOPROTOOPT;
1551 			break;
1552 		}
1553 		break;
1554 	}
1555 	return (error);
1556 }
1557 
1558 /*
1559  * Routine called from ip_output() to loop back a copy of an IP multicast
1560  * packet to the input queue of a specified interface.  Note that this
1561  * calls the output routine of the loopback "driver", but with an interface
1562  * pointer that might NOT be a loopback interface -- evil, but easier than
1563  * replicating that code here.
1564  */
1565 static void
1566 ip_mloopback(struct ifnet *ifp, const struct mbuf *m, int hlen)
1567 {
1568 	struct ip *ip;
1569 	struct mbuf *copym;
1570 
1571 	/*
1572 	 * Make a deep copy of the packet because we're going to
1573 	 * modify the pack in order to generate checksums.
1574 	 */
1575 	copym = m_dup(m, M_NOWAIT);
1576 	if (copym != NULL && (!M_WRITABLE(copym) || copym->m_len < hlen))
1577 		copym = m_pullup(copym, hlen);
1578 	if (copym != NULL) {
1579 		/* If needed, compute the checksum and mark it as valid. */
1580 		if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1581 			in_delayed_cksum(copym);
1582 			copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1583 			copym->m_pkthdr.csum_flags |=
1584 			    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1585 			copym->m_pkthdr.csum_data = 0xffff;
1586 		}
1587 		/*
1588 		 * We don't bother to fragment if the IP length is greater
1589 		 * than the interface's MTU.  Can this possibly matter?
1590 		 */
1591 		ip = mtod(copym, struct ip *);
1592 		ip->ip_sum = 0;
1593 		ip->ip_sum = in_cksum(copym, hlen);
1594 		if_simloop(ifp, copym, AF_INET, 0);
1595 	}
1596 }
1597