xref: /freebsd/sys/netinet/raw_ip.c (revision 8ea2d22e6d54d492b6b169014841eb27d4617459)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1993
5  *	The Regents of the University of California.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)raw_ip.c	8.7 (Berkeley) 5/15/95
33  */
34 
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include "opt_inet.h"
39 #include "opt_inet6.h"
40 #include "opt_ipsec.h"
41 #include "opt_route.h"
42 
43 #include <sys/param.h>
44 #include <sys/jail.h>
45 #include <sys/kernel.h>
46 #include <sys/eventhandler.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/rwlock.h>
54 #include <sys/signalvar.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
57 #include <sys/sx.h>
58 #include <sys/sysctl.h>
59 #include <sys/systm.h>
60 
61 #include <vm/uma.h>
62 
63 #include <net/if.h>
64 #include <net/if_var.h>
65 #include <net/route.h>
66 #include <net/route/route_ctl.h>
67 #include <net/vnet.h>
68 
69 #include <netinet/in.h>
70 #include <netinet/in_systm.h>
71 #include <netinet/in_fib.h>
72 #include <netinet/in_pcb.h>
73 #include <netinet/in_var.h>
74 #include <netinet/if_ether.h>
75 #include <netinet/ip.h>
76 #include <netinet/ip_var.h>
77 #include <netinet/ip_mroute.h>
78 #include <netinet/ip_icmp.h>
79 
80 #include <netipsec/ipsec_support.h>
81 
82 #include <machine/stdarg.h>
83 #include <security/mac/mac_framework.h>
84 
85 VNET_DEFINE(int, ip_defttl) = IPDEFTTL;
86 SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_VNET | CTLFLAG_RW,
87     &VNET_NAME(ip_defttl), 0,
88     "Maximum TTL on IP packets");
89 
90 VNET_DEFINE(struct inpcbinfo, ripcbinfo);
91 #define	V_ripcbinfo		VNET(ripcbinfo)
92 
93 /*
94  * Control and data hooks for ipfw, dummynet, divert and so on.
95  * The data hooks are not used here but it is convenient
96  * to keep them all in one place.
97  */
98 VNET_DEFINE(ip_fw_chk_ptr_t, ip_fw_chk_ptr) = NULL;
99 VNET_DEFINE(ip_fw_ctl_ptr_t, ip_fw_ctl_ptr) = NULL;
100 
101 int	(*ip_dn_ctl_ptr)(struct sockopt *);
102 int	(*ip_dn_io_ptr)(struct mbuf **, struct ip_fw_args *);
103 void	(*ip_divert_ptr)(struct mbuf *, bool);
104 int	(*ng_ipfw_input_p)(struct mbuf **, struct ip_fw_args *, bool);
105 
106 #ifdef INET
107 /*
108  * Hooks for multicast routing. They all default to NULL, so leave them not
109  * initialized and rely on BSS being set to 0.
110  */
111 
112 /*
113  * The socket used to communicate with the multicast routing daemon.
114  */
115 VNET_DEFINE(struct socket *, ip_mrouter);
116 
117 /*
118  * The various mrouter and rsvp functions.
119  */
120 int (*ip_mrouter_set)(struct socket *, struct sockopt *);
121 int (*ip_mrouter_get)(struct socket *, struct sockopt *);
122 int (*ip_mrouter_done)(void);
123 int ip_mrouter_critical_section_cnt;
124 int (*ip_mforward)(struct ip *, struct ifnet *, struct mbuf *,
125 		   struct ip_moptions *);
126 int (*mrt_ioctl)(u_long, caddr_t, int);
127 int (*legal_vif_num)(int);
128 u_long (*ip_mcast_src)(int);
129 
130 int (*rsvp_input_p)(struct mbuf **, int *, int);
131 int (*ip_rsvp_vif)(struct socket *, struct sockopt *);
132 void (*ip_rsvp_force_done)(struct socket *);
133 #endif /* INET */
134 
135 extern	struct protosw inetsw[];
136 
137 u_long	rip_sendspace = 9216;
138 SYSCTL_ULONG(_net_inet_raw, OID_AUTO, maxdgram, CTLFLAG_RW,
139     &rip_sendspace, 0, "Maximum outgoing raw IP datagram size");
140 
141 u_long	rip_recvspace = 9216;
142 SYSCTL_ULONG(_net_inet_raw, OID_AUTO, recvspace, CTLFLAG_RW,
143     &rip_recvspace, 0, "Maximum space for incoming raw IP datagrams");
144 
145 /*
146  * Hash functions
147  */
148 
149 #define INP_PCBHASH_RAW_SIZE	256
150 #define INP_PCBHASH_RAW(proto, laddr, faddr, mask) \
151         (((proto) + (laddr) + (faddr)) % (mask) + 1)
152 
153 #ifdef INET
154 static void
155 rip_inshash(struct inpcb *inp)
156 {
157 	struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
158 	struct inpcbhead *pcbhash;
159 	int hash;
160 
161 	INP_HASH_WLOCK_ASSERT(pcbinfo);
162 	INP_WLOCK_ASSERT(inp);
163 
164 	if (inp->inp_ip_p != 0 &&
165 	    inp->inp_laddr.s_addr != INADDR_ANY &&
166 	    inp->inp_faddr.s_addr != INADDR_ANY) {
167 		hash = INP_PCBHASH_RAW(inp->inp_ip_p, inp->inp_laddr.s_addr,
168 		    inp->inp_faddr.s_addr, pcbinfo->ipi_hashmask);
169 	} else
170 		hash = 0;
171 	pcbhash = &pcbinfo->ipi_hashbase[hash];
172 	CK_LIST_INSERT_HEAD(pcbhash, inp, inp_hash);
173 }
174 
175 static void
176 rip_delhash(struct inpcb *inp)
177 {
178 
179 	INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
180 	INP_WLOCK_ASSERT(inp);
181 
182 	CK_LIST_REMOVE(inp, inp_hash);
183 }
184 #endif /* INET */
185 
186 INPCBSTORAGE_DEFINE(ripcbstor, "rawinp", "ripcb", "rip", "riphash");
187 
188 static void
189 rip_init(void *arg __unused)
190 {
191 
192 	in_pcbinfo_init(&V_ripcbinfo, &ripcbstor, INP_PCBHASH_RAW_SIZE, 1);
193 }
194 VNET_SYSINIT(rip_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, rip_init, NULL);
195 
196 #ifdef VIMAGE
197 static void
198 rip_destroy(void *unused __unused)
199 {
200 
201 	in_pcbinfo_destroy(&V_ripcbinfo);
202 }
203 VNET_SYSUNINIT(raw_ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, rip_destroy, NULL);
204 #endif
205 
206 #ifdef INET
207 static int
208 rip_append(struct inpcb *inp, struct ip *ip, struct mbuf *m,
209     struct sockaddr_in *ripsrc)
210 {
211 	struct socket *so = inp->inp_socket;
212 	struct mbuf *n, *opts = NULL;
213 
214 	INP_LOCK_ASSERT(inp);
215 
216 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
217 	/* check AH/ESP integrity. */
218 	if (IPSEC_ENABLED(ipv4) && IPSEC_CHECK_POLICY(ipv4, m, inp) != 0)
219 		return (0);
220 #endif /* IPSEC */
221 #ifdef MAC
222 	if (mac_inpcb_check_deliver(inp, m) != 0)
223 		return (0);
224 #endif
225 	/* Check the minimum TTL for socket. */
226 	if (inp->inp_ip_minttl && inp->inp_ip_minttl > ip->ip_ttl)
227 		return (0);
228 
229 	if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL)
230 		return (0);
231 
232 	if ((inp->inp_flags & INP_CONTROLOPTS) ||
233 	    (so->so_options & (SO_TIMESTAMP | SO_BINTIME)))
234 		ip_savecontrol(inp, &opts, ip, n);
235 	SOCKBUF_LOCK(&so->so_rcv);
236 	if (sbappendaddr_locked(&so->so_rcv,
237 	    (struct sockaddr *)ripsrc, n, opts) == 0) {
238 		soroverflow_locked(so);
239 		m_freem(n);
240 		if (opts)
241 			m_freem(opts);
242 		return (0);
243 	}
244 	sorwakeup_locked(so);
245 
246 	return (1);
247 }
248 
249 struct rip_inp_match_ctx {
250 	struct ip *ip;
251 	int proto;
252 };
253 
254 static bool
255 rip_inp_match1(const struct inpcb *inp, void *v)
256 {
257 	struct rip_inp_match_ctx *ctx = v;
258 
259 	if (inp->inp_ip_p != ctx->proto)
260 		return (false);
261 #ifdef INET6
262 	/* XXX inp locking */
263 	if ((inp->inp_vflag & INP_IPV4) == 0)
264 		return (false);
265 #endif
266 	if (inp->inp_laddr.s_addr != ctx->ip->ip_dst.s_addr)
267 		return (false);
268 	if (inp->inp_faddr.s_addr != ctx->ip->ip_src.s_addr)
269 		return (false);
270 	return (true);
271 }
272 
273 static bool
274 rip_inp_match2(const struct inpcb *inp, void *v)
275 {
276 	struct rip_inp_match_ctx *ctx = v;
277 
278 	if (inp->inp_ip_p && inp->inp_ip_p != ctx->proto)
279 		return (false);
280 #ifdef INET6
281 	/* XXX inp locking */
282 	if ((inp->inp_vflag & INP_IPV4) == 0)
283 		return (false);
284 #endif
285 	if (!in_nullhost(inp->inp_laddr) &&
286 	    !in_hosteq(inp->inp_laddr, ctx->ip->ip_dst))
287 		return (false);
288 	if (!in_nullhost(inp->inp_faddr) &&
289 	    !in_hosteq(inp->inp_faddr, ctx->ip->ip_src))
290 		return (false);
291 	return (true);
292 }
293 
294 /*
295  * Setup generic address and protocol structures for raw_input routine, then
296  * pass them along with mbuf chain.
297  */
298 int
299 rip_input(struct mbuf **mp, int *offp, int proto)
300 {
301 	struct rip_inp_match_ctx ctx = {
302 		.ip = mtod(*mp, struct ip *),
303 		.proto = proto,
304 	};
305 	struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo,
306 	    INPLOOKUP_RLOCKPCB, rip_inp_match1, &ctx);
307 	struct ifnet *ifp;
308 	struct mbuf *m = *mp;
309 	struct inpcb *inp;
310 	struct sockaddr_in ripsrc;
311 	int appended;
312 
313 	*mp = NULL;
314 	appended = 0;
315 
316 	bzero(&ripsrc, sizeof(ripsrc));
317 	ripsrc.sin_len = sizeof(ripsrc);
318 	ripsrc.sin_family = AF_INET;
319 	ripsrc.sin_addr = ctx.ip->ip_src;
320 
321 	ifp = m->m_pkthdr.rcvif;
322 
323 	inpi.hash = INP_PCBHASH_RAW(proto, ctx.ip->ip_src.s_addr,
324 	    ctx.ip->ip_dst.s_addr, V_ripcbinfo.ipi_hashmask);
325 	while ((inp = inp_next(&inpi)) != NULL) {
326 		INP_RLOCK_ASSERT(inp);
327 		if (jailed_without_vnet(inp->inp_cred) &&
328 		    prison_check_ip4(inp->inp_cred, &ctx.ip->ip_dst) != 0) {
329 			/*
330 			 * XXX: If faddr was bound to multicast group,
331 			 * jailed raw socket will drop datagram.
332 			 */
333 			continue;
334 		}
335 		appended += rip_append(inp, ctx.ip, m, &ripsrc);
336 	}
337 
338 	inpi.hash = 0;
339 	inpi.match = rip_inp_match2;
340 	MPASS(inpi.inp == NULL);
341 	while ((inp = inp_next(&inpi)) != NULL) {
342 		INP_RLOCK_ASSERT(inp);
343 		if (jailed_without_vnet(inp->inp_cred) &&
344 		    !IN_MULTICAST(ntohl(ctx.ip->ip_dst.s_addr)) &&
345 		    prison_check_ip4(inp->inp_cred, &ctx.ip->ip_dst) != 0)
346 			/*
347 			 * Allow raw socket in jail to receive multicast;
348 			 * assume process had PRIV_NETINET_RAW at attach,
349 			 * and fall through into normal filter path if so.
350 			 */
351 			continue;
352 		/*
353 		 * If this raw socket has multicast state, and we
354 		 * have received a multicast, check if this socket
355 		 * should receive it, as multicast filtering is now
356 		 * the responsibility of the transport layer.
357 		 */
358 		if (inp->inp_moptions != NULL &&
359 		    IN_MULTICAST(ntohl(ctx.ip->ip_dst.s_addr))) {
360 			/*
361 			 * If the incoming datagram is for IGMP, allow it
362 			 * through unconditionally to the raw socket.
363 			 *
364 			 * In the case of IGMPv2, we may not have explicitly
365 			 * joined the group, and may have set IFF_ALLMULTI
366 			 * on the interface. imo_multi_filter() may discard
367 			 * control traffic we actually need to see.
368 			 *
369 			 * Userland multicast routing daemons should continue
370 			 * filter the control traffic appropriately.
371 			 */
372 			int blocked;
373 
374 			blocked = MCAST_PASS;
375 			if (proto != IPPROTO_IGMP) {
376 				struct sockaddr_in group;
377 
378 				bzero(&group, sizeof(struct sockaddr_in));
379 				group.sin_len = sizeof(struct sockaddr_in);
380 				group.sin_family = AF_INET;
381 				group.sin_addr = ctx.ip->ip_dst;
382 
383 				blocked = imo_multi_filter(inp->inp_moptions,
384 				    ifp,
385 				    (struct sockaddr *)&group,
386 				    (struct sockaddr *)&ripsrc);
387 			}
388 
389 			if (blocked != MCAST_PASS) {
390 				IPSTAT_INC(ips_notmember);
391 				continue;
392 			}
393 		}
394 		appended += rip_append(inp, ctx.ip, m, &ripsrc);
395 	}
396 	if (appended == 0 &&
397 	    inetsw[ip_protox[ctx.ip->ip_p]].pr_input == rip_input) {
398 		IPSTAT_INC(ips_noproto);
399 		IPSTAT_DEC(ips_delivered);
400 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PROTOCOL, 0, 0);
401 	} else
402 		m_freem(m);
403 	return (IPPROTO_DONE);
404 }
405 
406 /*
407  * Generate IP header and pass packet to ip_output.  Tack on options user may
408  * have setup with control call.
409  */
410 int
411 rip_output(struct mbuf *m, struct socket *so, ...)
412 {
413 	struct epoch_tracker et;
414 	struct ip *ip;
415 	int error;
416 	struct inpcb *inp = sotoinpcb(so);
417 	va_list ap;
418 	u_long dst;
419 	int flags = ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0) |
420 	    IP_ALLOWBROADCAST;
421 	int cnt, hlen;
422 	u_char opttype, optlen, *cp;
423 
424 	va_start(ap, so);
425 	dst = va_arg(ap, u_long);
426 	va_end(ap);
427 
428 	/*
429 	 * If the user handed us a complete IP packet, use it.  Otherwise,
430 	 * allocate an mbuf for a header and fill it in.
431 	 */
432 	if ((inp->inp_flags & INP_HDRINCL) == 0) {
433 		if (m->m_pkthdr.len + sizeof(struct ip) > IP_MAXPACKET) {
434 			m_freem(m);
435 			return(EMSGSIZE);
436 		}
437 		M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
438 		if (m == NULL)
439 			return(ENOBUFS);
440 
441 		INP_RLOCK(inp);
442 		ip = mtod(m, struct ip *);
443 		ip->ip_tos = inp->inp_ip_tos;
444 		if (inp->inp_flags & INP_DONTFRAG)
445 			ip->ip_off = htons(IP_DF);
446 		else
447 			ip->ip_off = htons(0);
448 		ip->ip_p = inp->inp_ip_p;
449 		ip->ip_len = htons(m->m_pkthdr.len);
450 		ip->ip_src = inp->inp_laddr;
451 		ip->ip_dst.s_addr = dst;
452 #ifdef ROUTE_MPATH
453 		if (CALC_FLOWID_OUTBOUND) {
454 			uint32_t hash_type, hash_val;
455 
456 			hash_val = fib4_calc_software_hash(ip->ip_src,
457 			    ip->ip_dst, 0, 0, ip->ip_p, &hash_type);
458 			m->m_pkthdr.flowid = hash_val;
459 			M_HASHTYPE_SET(m, hash_type);
460 			flags |= IP_NODEFAULTFLOWID;
461 		}
462 #endif
463 		if (jailed(inp->inp_cred)) {
464 			/*
465 			 * prison_local_ip4() would be good enough but would
466 			 * let a source of INADDR_ANY pass, which we do not
467 			 * want to see from jails.
468 			 */
469 			if (ip->ip_src.s_addr == INADDR_ANY) {
470 				NET_EPOCH_ENTER(et);
471 				error = in_pcbladdr(inp, &ip->ip_dst,
472 				    &ip->ip_src, inp->inp_cred);
473 				NET_EPOCH_EXIT(et);
474 			} else {
475 				error = prison_local_ip4(inp->inp_cred,
476 				    &ip->ip_src);
477 			}
478 			if (error != 0) {
479 				INP_RUNLOCK(inp);
480 				m_freem(m);
481 				return (error);
482 			}
483 		}
484 		ip->ip_ttl = inp->inp_ip_ttl;
485 	} else {
486 		if (m->m_pkthdr.len > IP_MAXPACKET) {
487 			m_freem(m);
488 			return (EMSGSIZE);
489 		}
490 		if (m->m_pkthdr.len < sizeof(*ip)) {
491 			m_freem(m);
492 			return (EINVAL);
493 		}
494 		m = m_pullup(m, sizeof(*ip));
495 		if (m == NULL)
496 			return (ENOMEM);
497 		ip = mtod(m, struct ip *);
498 		hlen = ip->ip_hl << 2;
499 		if (m->m_len < hlen) {
500 			m = m_pullup(m, hlen);
501 			if (m == NULL)
502 				return (EINVAL);
503 			ip = mtod(m, struct ip *);
504 		}
505 #ifdef ROUTE_MPATH
506 		if (CALC_FLOWID_OUTBOUND) {
507 			uint32_t hash_type, hash_val;
508 
509 			hash_val = fib4_calc_software_hash(ip->ip_dst,
510 			    ip->ip_src, 0, 0, ip->ip_p, &hash_type);
511 			m->m_pkthdr.flowid = hash_val;
512 			M_HASHTYPE_SET(m, hash_type);
513 			flags |= IP_NODEFAULTFLOWID;
514 		}
515 #endif
516 		INP_RLOCK(inp);
517 		/*
518 		 * Don't allow both user specified and setsockopt options,
519 		 * and don't allow packet length sizes that will crash.
520 		 */
521 		if ((hlen < sizeof (*ip))
522 		    || ((hlen > sizeof (*ip)) && inp->inp_options)
523 		    || (ntohs(ip->ip_len) != m->m_pkthdr.len)) {
524 			INP_RUNLOCK(inp);
525 			m_freem(m);
526 			return (EINVAL);
527 		}
528 		error = prison_check_ip4(inp->inp_cred, &ip->ip_src);
529 		if (error != 0) {
530 			INP_RUNLOCK(inp);
531 			m_freem(m);
532 			return (error);
533 		}
534 		/*
535 		 * Don't allow IP options which do not have the required
536 		 * structure as specified in section 3.1 of RFC 791 on
537 		 * pages 15-23.
538 		 */
539 		cp = (u_char *)(ip + 1);
540 		cnt = hlen - sizeof (struct ip);
541 		for (; cnt > 0; cnt -= optlen, cp += optlen) {
542 			opttype = cp[IPOPT_OPTVAL];
543 			if (opttype == IPOPT_EOL)
544 				break;
545 			if (opttype == IPOPT_NOP) {
546 				optlen = 1;
547 				continue;
548 			}
549 			if (cnt < IPOPT_OLEN + sizeof(u_char)) {
550 				INP_RUNLOCK(inp);
551 				m_freem(m);
552 				return (EINVAL);
553 			}
554 			optlen = cp[IPOPT_OLEN];
555 			if (optlen < IPOPT_OLEN + sizeof(u_char) ||
556 			    optlen > cnt) {
557 				INP_RUNLOCK(inp);
558 				m_freem(m);
559 				return (EINVAL);
560 			}
561 		}
562 		/*
563 		 * This doesn't allow application to specify ID of zero,
564 		 * but we got this limitation from the beginning of history.
565 		 */
566 		if (ip->ip_id == 0)
567 			ip_fillid(ip);
568 
569 		/*
570 		 * XXX prevent ip_output from overwriting header fields.
571 		 */
572 		flags |= IP_RAWOUTPUT;
573 		IPSTAT_INC(ips_rawout);
574 	}
575 
576 	if (inp->inp_flags & INP_ONESBCAST)
577 		flags |= IP_SENDONES;
578 
579 #ifdef MAC
580 	mac_inpcb_create_mbuf(inp, m);
581 #endif
582 
583 	NET_EPOCH_ENTER(et);
584 	error = ip_output(m, inp->inp_options, NULL, flags,
585 	    inp->inp_moptions, inp);
586 	NET_EPOCH_EXIT(et);
587 	INP_RUNLOCK(inp);
588 	return (error);
589 }
590 
591 /*
592  * Raw IP socket option processing.
593  *
594  * IMPORTANT NOTE regarding access control: Traditionally, raw sockets could
595  * only be created by a privileged process, and as such, socket option
596  * operations to manage system properties on any raw socket were allowed to
597  * take place without explicit additional access control checks.  However,
598  * raw sockets can now also be created in jail(), and therefore explicit
599  * checks are now required.  Likewise, raw sockets can be used by a process
600  * after it gives up privilege, so some caution is required.  For options
601  * passed down to the IP layer via ip_ctloutput(), checks are assumed to be
602  * performed in ip_ctloutput() and therefore no check occurs here.
603  * Unilaterally checking priv_check() here breaks normal IP socket option
604  * operations on raw sockets.
605  *
606  * When adding new socket options here, make sure to add access control
607  * checks here as necessary.
608  *
609  * XXX-BZ inp locking?
610  */
611 int
612 rip_ctloutput(struct socket *so, struct sockopt *sopt)
613 {
614 	struct	inpcb *inp = sotoinpcb(so);
615 	int	error, optval;
616 
617 	if (sopt->sopt_level != IPPROTO_IP) {
618 		if ((sopt->sopt_level == SOL_SOCKET) &&
619 		    (sopt->sopt_name == SO_SETFIB)) {
620 			inp->inp_inc.inc_fibnum = so->so_fibnum;
621 			return (0);
622 		}
623 		return (EINVAL);
624 	}
625 
626 	error = 0;
627 	switch (sopt->sopt_dir) {
628 	case SOPT_GET:
629 		switch (sopt->sopt_name) {
630 		case IP_HDRINCL:
631 			optval = inp->inp_flags & INP_HDRINCL;
632 			error = sooptcopyout(sopt, &optval, sizeof optval);
633 			break;
634 
635 		case IP_FW3:	/* generic ipfw v.3 functions */
636 		case IP_FW_ADD:	/* ADD actually returns the body... */
637 		case IP_FW_GET:
638 		case IP_FW_TABLE_GETSIZE:
639 		case IP_FW_TABLE_LIST:
640 		case IP_FW_NAT_GET_CONFIG:
641 		case IP_FW_NAT_GET_LOG:
642 			if (V_ip_fw_ctl_ptr != NULL)
643 				error = V_ip_fw_ctl_ptr(sopt);
644 			else
645 				error = ENOPROTOOPT;
646 			break;
647 
648 		case IP_DUMMYNET3:	/* generic dummynet v.3 functions */
649 		case IP_DUMMYNET_GET:
650 			if (ip_dn_ctl_ptr != NULL)
651 				error = ip_dn_ctl_ptr(sopt);
652 			else
653 				error = ENOPROTOOPT;
654 			break ;
655 
656 		case MRT_INIT:
657 		case MRT_DONE:
658 		case MRT_ADD_VIF:
659 		case MRT_DEL_VIF:
660 		case MRT_ADD_MFC:
661 		case MRT_DEL_MFC:
662 		case MRT_VERSION:
663 		case MRT_ASSERT:
664 		case MRT_API_SUPPORT:
665 		case MRT_API_CONFIG:
666 		case MRT_ADD_BW_UPCALL:
667 		case MRT_DEL_BW_UPCALL:
668 			error = priv_check(curthread, PRIV_NETINET_MROUTE);
669 			if (error != 0)
670 				return (error);
671 			error = ip_mrouter_get ? ip_mrouter_get(so, sopt) :
672 				EOPNOTSUPP;
673 			break;
674 
675 		default:
676 			error = ip_ctloutput(so, sopt);
677 			break;
678 		}
679 		break;
680 
681 	case SOPT_SET:
682 		switch (sopt->sopt_name) {
683 		case IP_HDRINCL:
684 			error = sooptcopyin(sopt, &optval, sizeof optval,
685 					    sizeof optval);
686 			if (error)
687 				break;
688 			if (optval)
689 				inp->inp_flags |= INP_HDRINCL;
690 			else
691 				inp->inp_flags &= ~INP_HDRINCL;
692 			break;
693 
694 		case IP_FW3:	/* generic ipfw v.3 functions */
695 		case IP_FW_ADD:
696 		case IP_FW_DEL:
697 		case IP_FW_FLUSH:
698 		case IP_FW_ZERO:
699 		case IP_FW_RESETLOG:
700 		case IP_FW_TABLE_ADD:
701 		case IP_FW_TABLE_DEL:
702 		case IP_FW_TABLE_FLUSH:
703 		case IP_FW_NAT_CFG:
704 		case IP_FW_NAT_DEL:
705 			if (V_ip_fw_ctl_ptr != NULL)
706 				error = V_ip_fw_ctl_ptr(sopt);
707 			else
708 				error = ENOPROTOOPT;
709 			break;
710 
711 		case IP_DUMMYNET3:	/* generic dummynet v.3 functions */
712 		case IP_DUMMYNET_CONFIGURE:
713 		case IP_DUMMYNET_DEL:
714 		case IP_DUMMYNET_FLUSH:
715 			if (ip_dn_ctl_ptr != NULL)
716 				error = ip_dn_ctl_ptr(sopt);
717 			else
718 				error = ENOPROTOOPT ;
719 			break ;
720 
721 		case IP_RSVP_ON:
722 			error = priv_check(curthread, PRIV_NETINET_MROUTE);
723 			if (error != 0)
724 				return (error);
725 			error = ip_rsvp_init(so);
726 			break;
727 
728 		case IP_RSVP_OFF:
729 			error = priv_check(curthread, PRIV_NETINET_MROUTE);
730 			if (error != 0)
731 				return (error);
732 			error = ip_rsvp_done();
733 			break;
734 
735 		case IP_RSVP_VIF_ON:
736 		case IP_RSVP_VIF_OFF:
737 			error = priv_check(curthread, PRIV_NETINET_MROUTE);
738 			if (error != 0)
739 				return (error);
740 			error = ip_rsvp_vif ?
741 				ip_rsvp_vif(so, sopt) : EINVAL;
742 			break;
743 
744 		case MRT_INIT:
745 		case MRT_DONE:
746 		case MRT_ADD_VIF:
747 		case MRT_DEL_VIF:
748 		case MRT_ADD_MFC:
749 		case MRT_DEL_MFC:
750 		case MRT_VERSION:
751 		case MRT_ASSERT:
752 		case MRT_API_SUPPORT:
753 		case MRT_API_CONFIG:
754 		case MRT_ADD_BW_UPCALL:
755 		case MRT_DEL_BW_UPCALL:
756 			error = priv_check(curthread, PRIV_NETINET_MROUTE);
757 			if (error != 0)
758 				return (error);
759 			error = ip_mrouter_set ? ip_mrouter_set(so, sopt) :
760 					EOPNOTSUPP;
761 			break;
762 
763 		default:
764 			error = ip_ctloutput(so, sopt);
765 			break;
766 		}
767 		break;
768 	}
769 
770 	return (error);
771 }
772 
773 /*
774  * This function exists solely to receive the PRC_IFDOWN messages which are
775  * sent by if_down().  It looks for an ifaddr whose ifa_addr is sa, and calls
776  * in_ifadown() to remove all routes corresponding to that address.  It also
777  * receives the PRC_IFUP messages from if_up() and reinstalls the interface
778  * routes.
779  */
780 void
781 rip_ctlinput(int cmd, struct sockaddr *sa, void *vip)
782 {
783 	struct in_ifaddr *ia;
784 	struct ifnet *ifp;
785 	int err;
786 	int flags;
787 
788 	NET_EPOCH_ASSERT();
789 
790 	switch (cmd) {
791 	case PRC_IFDOWN:
792 		CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
793 			if (ia->ia_ifa.ifa_addr == sa
794 			    && (ia->ia_flags & IFA_ROUTE)) {
795 				ifa_ref(&ia->ia_ifa);
796 				/*
797 				 * in_scrubprefix() kills the interface route.
798 				 */
799 				in_scrubprefix(ia, 0);
800 				/*
801 				 * in_ifadown gets rid of all the rest of the
802 				 * routes.  This is not quite the right thing
803 				 * to do, but at least if we are running a
804 				 * routing process they will come back.
805 				 */
806 				in_ifadown(&ia->ia_ifa, 0);
807 				ifa_free(&ia->ia_ifa);
808 				break;
809 			}
810 		}
811 		break;
812 
813 	case PRC_IFUP:
814 		CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
815 			if (ia->ia_ifa.ifa_addr == sa)
816 				break;
817 		}
818 		if (ia == NULL || (ia->ia_flags & IFA_ROUTE))
819 			return;
820 		ifa_ref(&ia->ia_ifa);
821 		flags = RTF_UP;
822 		ifp = ia->ia_ifa.ifa_ifp;
823 
824 		if ((ifp->if_flags & IFF_LOOPBACK)
825 		    || (ifp->if_flags & IFF_POINTOPOINT))
826 			flags |= RTF_HOST;
827 
828 		err = ifa_del_loopback_route((struct ifaddr *)ia, sa);
829 
830 		rt_addrmsg(RTM_ADD, &ia->ia_ifa, ia->ia_ifp->if_fib);
831 		err = in_handle_ifaddr_route(RTM_ADD, ia);
832 		if (err == 0)
833 			ia->ia_flags |= IFA_ROUTE;
834 
835 		err = ifa_add_loopback_route((struct ifaddr *)ia, sa);
836 
837 		ifa_free(&ia->ia_ifa);
838 		break;
839 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
840 	case PRC_MSGSIZE:
841 		if (IPSEC_ENABLED(ipv4))
842 			IPSEC_CTLINPUT(ipv4, cmd, sa, vip);
843 		break;
844 #endif
845 	}
846 }
847 
848 static int
849 rip_attach(struct socket *so, int proto, struct thread *td)
850 {
851 	struct inpcb *inp;
852 	int error;
853 
854 	inp = sotoinpcb(so);
855 	KASSERT(inp == NULL, ("rip_attach: inp != NULL"));
856 
857 	error = priv_check(td, PRIV_NETINET_RAW);
858 	if (error)
859 		return (error);
860 	if (proto >= IPPROTO_MAX || proto < 0)
861 		return EPROTONOSUPPORT;
862 	error = soreserve(so, rip_sendspace, rip_recvspace);
863 	if (error)
864 		return (error);
865 	error = in_pcballoc(so, &V_ripcbinfo);
866 	if (error)
867 		return (error);
868 	inp = (struct inpcb *)so->so_pcb;
869 	inp->inp_vflag |= INP_IPV4;
870 	inp->inp_ip_p = proto;
871 	inp->inp_ip_ttl = V_ip_defttl;
872 	INP_HASH_WLOCK(&V_ripcbinfo);
873 	rip_inshash(inp);
874 	INP_HASH_WUNLOCK(&V_ripcbinfo);
875 	INP_WUNLOCK(inp);
876 	return (0);
877 }
878 
879 static void
880 rip_detach(struct socket *so)
881 {
882 	struct inpcb *inp;
883 
884 	inp = sotoinpcb(so);
885 	KASSERT(inp != NULL, ("rip_detach: inp == NULL"));
886 	KASSERT(inp->inp_faddr.s_addr == INADDR_ANY,
887 	    ("rip_detach: not closed"));
888 
889 	INP_WLOCK(inp);
890 	INP_HASH_WLOCK(&V_ripcbinfo);
891 	rip_delhash(inp);
892 	INP_HASH_WUNLOCK(&V_ripcbinfo);
893 	if (so == V_ip_mrouter && ip_mrouter_done)
894 		ip_mrouter_done();
895 	if (ip_rsvp_force_done)
896 		ip_rsvp_force_done(so);
897 	if (so == V_ip_rsvpd)
898 		ip_rsvp_done();
899 	in_pcbdetach(inp);
900 	in_pcbfree(inp);
901 }
902 
903 static void
904 rip_dodisconnect(struct socket *so, struct inpcb *inp)
905 {
906 	struct inpcbinfo *pcbinfo;
907 
908 	pcbinfo = inp->inp_pcbinfo;
909 	INP_WLOCK(inp);
910 	INP_HASH_WLOCK(pcbinfo);
911 	rip_delhash(inp);
912 	inp->inp_faddr.s_addr = INADDR_ANY;
913 	rip_inshash(inp);
914 	INP_HASH_WUNLOCK(pcbinfo);
915 	SOCK_LOCK(so);
916 	so->so_state &= ~SS_ISCONNECTED;
917 	SOCK_UNLOCK(so);
918 	INP_WUNLOCK(inp);
919 }
920 
921 static void
922 rip_abort(struct socket *so)
923 {
924 	struct inpcb *inp;
925 
926 	inp = sotoinpcb(so);
927 	KASSERT(inp != NULL, ("rip_abort: inp == NULL"));
928 
929 	rip_dodisconnect(so, inp);
930 }
931 
932 static void
933 rip_close(struct socket *so)
934 {
935 	struct inpcb *inp;
936 
937 	inp = sotoinpcb(so);
938 	KASSERT(inp != NULL, ("rip_close: inp == NULL"));
939 
940 	rip_dodisconnect(so, inp);
941 }
942 
943 static int
944 rip_disconnect(struct socket *so)
945 {
946 	struct inpcb *inp;
947 
948 	if ((so->so_state & SS_ISCONNECTED) == 0)
949 		return (ENOTCONN);
950 
951 	inp = sotoinpcb(so);
952 	KASSERT(inp != NULL, ("rip_disconnect: inp == NULL"));
953 
954 	rip_dodisconnect(so, inp);
955 	return (0);
956 }
957 
958 static int
959 rip_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
960 {
961 	struct sockaddr_in *addr = (struct sockaddr_in *)nam;
962 	struct inpcb *inp;
963 	int error;
964 
965 	if (nam->sa_family != AF_INET)
966 		return (EAFNOSUPPORT);
967 	if (nam->sa_len != sizeof(*addr))
968 		return (EINVAL);
969 
970 	error = prison_check_ip4(td->td_ucred, &addr->sin_addr);
971 	if (error != 0)
972 		return (error);
973 
974 	inp = sotoinpcb(so);
975 	KASSERT(inp != NULL, ("rip_bind: inp == NULL"));
976 
977 	if (CK_STAILQ_EMPTY(&V_ifnet) ||
978 	    (addr->sin_family != AF_INET && addr->sin_family != AF_IMPLINK) ||
979 	    (addr->sin_addr.s_addr &&
980 	     (inp->inp_flags & INP_BINDANY) == 0 &&
981 	     ifa_ifwithaddr_check((struct sockaddr *)addr) == 0))
982 		return (EADDRNOTAVAIL);
983 
984 	INP_WLOCK(inp);
985 	INP_HASH_WLOCK(&V_ripcbinfo);
986 	rip_delhash(inp);
987 	inp->inp_laddr = addr->sin_addr;
988 	rip_inshash(inp);
989 	INP_HASH_WUNLOCK(&V_ripcbinfo);
990 	INP_WUNLOCK(inp);
991 	return (0);
992 }
993 
994 static int
995 rip_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
996 {
997 	struct sockaddr_in *addr = (struct sockaddr_in *)nam;
998 	struct inpcb *inp;
999 
1000 	if (nam->sa_len != sizeof(*addr))
1001 		return (EINVAL);
1002 	if (CK_STAILQ_EMPTY(&V_ifnet))
1003 		return (EADDRNOTAVAIL);
1004 	if (addr->sin_family != AF_INET && addr->sin_family != AF_IMPLINK)
1005 		return (EAFNOSUPPORT);
1006 
1007 	inp = sotoinpcb(so);
1008 	KASSERT(inp != NULL, ("rip_connect: inp == NULL"));
1009 
1010 	INP_WLOCK(inp);
1011 	INP_HASH_WLOCK(&V_ripcbinfo);
1012 	rip_delhash(inp);
1013 	inp->inp_faddr = addr->sin_addr;
1014 	rip_inshash(inp);
1015 	INP_HASH_WUNLOCK(&V_ripcbinfo);
1016 	soisconnected(so);
1017 	INP_WUNLOCK(inp);
1018 	return (0);
1019 }
1020 
1021 static int
1022 rip_shutdown(struct socket *so)
1023 {
1024 	struct inpcb *inp;
1025 
1026 	inp = sotoinpcb(so);
1027 	KASSERT(inp != NULL, ("rip_shutdown: inp == NULL"));
1028 
1029 	INP_WLOCK(inp);
1030 	socantsendmore(so);
1031 	INP_WUNLOCK(inp);
1032 	return (0);
1033 }
1034 
1035 static int
1036 rip_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
1037     struct mbuf *control, struct thread *td)
1038 {
1039 	struct inpcb *inp;
1040 	u_long dst;
1041 	int error;
1042 
1043 	inp = sotoinpcb(so);
1044 	KASSERT(inp != NULL, ("rip_send: inp == NULL"));
1045 
1046 	if (control != NULL) {
1047 		m_freem(control);
1048 		control = NULL;
1049 	}
1050 
1051 	/*
1052 	 * Note: 'dst' reads below are unlocked.
1053 	 */
1054 	if (so->so_state & SS_ISCONNECTED) {
1055 		if (nam) {
1056 			error = EISCONN;
1057 			goto release;
1058 		}
1059 		dst = inp->inp_faddr.s_addr;	/* Unlocked read. */
1060 	} else {
1061 		error = 0;
1062 		if (nam == NULL)
1063 			error = ENOTCONN;
1064 		else if (nam->sa_family != AF_INET)
1065 			error = EAFNOSUPPORT;
1066 		else if (nam->sa_len != sizeof(struct sockaddr_in))
1067 			error = EINVAL;
1068 		if (error != 0)
1069 			goto release;
1070 		dst = ((struct sockaddr_in *)nam)->sin_addr.s_addr;
1071 	}
1072 	return (rip_output(m, so, dst));
1073 
1074 release:
1075 	m_freem(m);
1076 	return (error);
1077 }
1078 #endif /* INET */
1079 
1080 static int
1081 rip_pcblist(SYSCTL_HANDLER_ARGS)
1082 {
1083 	struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_ripcbinfo,
1084 	    INPLOOKUP_RLOCKPCB);
1085 	struct xinpgen xig;
1086 	struct inpcb *inp;
1087 	int error;
1088 
1089 	if (req->newptr != 0)
1090 		return (EPERM);
1091 
1092 	if (req->oldptr == 0) {
1093 		int n;
1094 
1095 		n = V_ripcbinfo.ipi_count;
1096 		n += imax(n / 8, 10);
1097 		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
1098 		return (0);
1099 	}
1100 
1101 	if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
1102 		return (error);
1103 
1104 	bzero(&xig, sizeof(xig));
1105 	xig.xig_len = sizeof xig;
1106 	xig.xig_count = V_ripcbinfo.ipi_count;
1107 	xig.xig_gen = V_ripcbinfo.ipi_gencnt;
1108 	xig.xig_sogen = so_gencnt;
1109 	error = SYSCTL_OUT(req, &xig, sizeof xig);
1110 	if (error)
1111 		return (error);
1112 
1113 	while ((inp = inp_next(&inpi)) != NULL) {
1114 		if (inp->inp_gencnt <= xig.xig_gen &&
1115 		    cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
1116 			struct xinpcb xi;
1117 
1118 			in_pcbtoxinpcb(inp, &xi);
1119 			error = SYSCTL_OUT(req, &xi, sizeof xi);
1120 			if (error) {
1121 				INP_RUNLOCK(inp);
1122 				break;
1123 			}
1124 		}
1125 	}
1126 
1127 	if (!error) {
1128 		/*
1129 		 * Give the user an updated idea of our state.  If the
1130 		 * generation differs from what we told her before, she knows
1131 		 * that something happened while we were processing this
1132 		 * request, and it might be necessary to retry.
1133 		 */
1134 		xig.xig_gen = V_ripcbinfo.ipi_gencnt;
1135 		xig.xig_sogen = so_gencnt;
1136 		xig.xig_count = V_ripcbinfo.ipi_count;
1137 		error = SYSCTL_OUT(req, &xig, sizeof xig);
1138 	}
1139 
1140 	return (error);
1141 }
1142 
1143 SYSCTL_PROC(_net_inet_raw, OID_AUTO/*XXX*/, pcblist,
1144     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
1145     rip_pcblist, "S,xinpcb",
1146     "List of active raw IP sockets");
1147 
1148 #ifdef INET
1149 struct pr_usrreqs rip_usrreqs = {
1150 	.pru_abort =		rip_abort,
1151 	.pru_attach =		rip_attach,
1152 	.pru_bind =		rip_bind,
1153 	.pru_connect =		rip_connect,
1154 	.pru_control =		in_control,
1155 	.pru_detach =		rip_detach,
1156 	.pru_disconnect =	rip_disconnect,
1157 	.pru_peeraddr =		in_getpeeraddr,
1158 	.pru_send =		rip_send,
1159 	.pru_shutdown =		rip_shutdown,
1160 	.pru_sockaddr =		in_getsockaddr,
1161 	.pru_sosetlabel =	in_pcbsosetlabel,
1162 	.pru_close =		rip_close,
1163 };
1164 #endif /* INET */
1165