xref: /freebsd/sys/netinet/raw_ip.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /*
2  * Copyright (c) 1982, 1986, 1988, 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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)raw_ip.c	8.7 (Berkeley) 5/15/95
34  * $FreeBSD$
35  */
36 
37 #include "opt_inet6.h"
38 #include "opt_ipsec.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
44 #include <sys/mbuf.h>
45 #include <sys/protosw.h>
46 #include <sys/socket.h>
47 #include <sys/socketvar.h>
48 #include <sys/sysctl.h>
49 
50 #include <vm/vm_zone.h>
51 
52 #include <net/if.h>
53 #include <net/route.h>
54 
55 #define _IP_VHL
56 #include <netinet/in.h>
57 #include <netinet/in_systm.h>
58 #include <netinet/ip.h>
59 #include <netinet/in_pcb.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip_var.h>
62 #include <netinet/ip_mroute.h>
63 
64 #include <netinet/ip_fw.h>
65 
66 #ifdef IPSEC
67 #include <netinet6/ipsec.h>
68 #endif /*IPSEC*/
69 
70 #include "opt_ipdn.h"
71 #ifdef DUMMYNET
72 #include <netinet/ip_dummynet.h>
73 #endif
74 
75 struct	inpcbhead ripcb;
76 struct	inpcbinfo ripcbinfo;
77 
78 /*
79  * Nominal space allocated to a raw ip socket.
80  */
81 #define	RIPSNDQ		8192
82 #define	RIPRCVQ		8192
83 
84 /*
85  * Raw interface to IP protocol.
86  */
87 
88 /*
89  * Initialize raw connection block q.
90  */
91 void
92 rip_init()
93 {
94 	LIST_INIT(&ripcb);
95 	ripcbinfo.listhead = &ripcb;
96 	/*
97 	 * XXX We don't use the hash list for raw IP, but it's easier
98 	 * to allocate a one entry hash list than it is to check all
99 	 * over the place for hashbase == NULL.
100 	 */
101 	ripcbinfo.hashbase = hashinit(1, M_PCB, &ripcbinfo.hashmask);
102 	ripcbinfo.porthashbase = hashinit(1, M_PCB, &ripcbinfo.porthashmask);
103 	ripcbinfo.ipi_zone = zinit("ripcb", sizeof(struct inpcb),
104 				   maxsockets, ZONE_INTERRUPT, 0);
105 }
106 
107 static struct	sockaddr_in ripsrc = { sizeof(ripsrc), AF_INET };
108 /*
109  * Setup generic address and protocol structures
110  * for raw_input routine, then pass them along with
111  * mbuf chain.
112  */
113 void
114 rip_input(m, off, proto)
115 	struct mbuf *m;
116 	int off, proto;
117 {
118 	register struct ip *ip = mtod(m, struct ip *);
119 	register struct inpcb *inp;
120 	struct inpcb *last = 0;
121 	struct mbuf *opts = 0;
122 
123 	ripsrc.sin_addr = ip->ip_src;
124 	LIST_FOREACH(inp, &ripcb, inp_list) {
125 #ifdef INET6
126 		if ((inp->inp_vflag & INP_IPV4) == 0)
127 			continue;
128 #endif
129 		if (inp->inp_ip_p && inp->inp_ip_p != proto)
130 			continue;
131 		if (inp->inp_laddr.s_addr &&
132                   inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
133 			continue;
134 		if (inp->inp_faddr.s_addr &&
135                   inp->inp_faddr.s_addr != ip->ip_src.s_addr)
136 			continue;
137 		if (last) {
138 			struct mbuf *n = m_copy(m, 0, (int)M_COPYALL);
139 			if (n) {
140 				if (last->inp_flags & INP_CONTROLOPTS ||
141 				    last->inp_socket->so_options & SO_TIMESTAMP)
142 				    ip_savecontrol(last, &opts, ip, n);
143 				if (sbappendaddr(&last->inp_socket->so_rcv,
144 				    (struct sockaddr *)&ripsrc, n,
145 				    opts) == 0) {
146 					/* should notify about lost packet */
147 					m_freem(n);
148 					if (opts)
149 					    m_freem(opts);
150 				} else
151 					sorwakeup(last->inp_socket);
152 				opts = 0;
153 			}
154 		}
155 		last = inp;
156 	}
157 	if (last) {
158 		if (last->inp_flags & INP_CONTROLOPTS ||
159 		    last->inp_socket->so_options & SO_TIMESTAMP)
160 			ip_savecontrol(last, &opts, ip, m);
161 		if (sbappendaddr(&last->inp_socket->so_rcv,
162 		    (struct sockaddr *)&ripsrc, m, opts) == 0) {
163 			m_freem(m);
164 			if (opts)
165 			    m_freem(opts);
166 		} else
167 			sorwakeup(last->inp_socket);
168 	} else {
169 		m_freem(m);
170               ipstat.ips_noproto++;
171               ipstat.ips_delivered--;
172       }
173 }
174 
175 /*
176  * Generate IP header and pass packet to ip_output.
177  * Tack on options user may have setup with control call.
178  */
179 int
180 rip_output(m, so, dst)
181 	struct mbuf *m;
182 	struct socket *so;
183 	u_long dst;
184 {
185 	register struct ip *ip;
186 	register struct inpcb *inp = sotoinpcb(so);
187 	int flags = (so->so_options & SO_DONTROUTE) | IP_ALLOWBROADCAST;
188 
189 	/*
190 	 * If the user handed us a complete IP packet, use it.
191 	 * Otherwise, allocate an mbuf for a header and fill it in.
192 	 */
193 	if ((inp->inp_flags & INP_HDRINCL) == 0) {
194 		if (m->m_pkthdr.len + sizeof(struct ip) > IP_MAXPACKET) {
195 			m_freem(m);
196 			return(EMSGSIZE);
197 		}
198 		M_PREPEND(m, sizeof(struct ip), M_WAIT);
199 		ip = mtod(m, struct ip *);
200 		ip->ip_tos = 0;
201 		ip->ip_off = 0;
202 		ip->ip_p = inp->inp_ip_p;
203 		ip->ip_len = m->m_pkthdr.len;
204 		ip->ip_src = inp->inp_laddr;
205 		ip->ip_dst.s_addr = dst;
206 		ip->ip_ttl = MAXTTL;
207 	} else {
208 		if (m->m_pkthdr.len > IP_MAXPACKET) {
209 			m_freem(m);
210 			return(EMSGSIZE);
211 		}
212 		ip = mtod(m, struct ip *);
213 		/* don't allow both user specified and setsockopt options,
214 		   and don't allow packet length sizes that will crash */
215 		if (((IP_VHL_HL(ip->ip_vhl) != (sizeof (*ip) >> 2))
216 		     && inp->inp_options)
217 		    || (ip->ip_len > m->m_pkthdr.len)
218 		    || (ip->ip_len < (IP_VHL_HL(ip->ip_vhl) << 2))) {
219 			m_freem(m);
220 			return EINVAL;
221 		}
222 		if (ip->ip_id == 0)
223 			ip->ip_id = htons(ip_id++);
224 		/* XXX prevent ip_output from overwriting header fields */
225 		flags |= IP_RAWOUTPUT;
226 		ipstat.ips_rawout++;
227 	}
228 
229 #ifdef IPSEC
230 	ipsec_setsocket(m, so);
231 #endif /*IPSEC*/
232 
233 	return (ip_output(m, inp->inp_options, &inp->inp_route, flags,
234 			  inp->inp_moptions));
235 }
236 
237 /*
238  * Raw IP socket option processing.
239  */
240 int
241 rip_ctloutput(so, sopt)
242 	struct socket *so;
243 	struct sockopt *sopt;
244 {
245 	struct	inpcb *inp = sotoinpcb(so);
246 	int	error, optval;
247 
248 	if (sopt->sopt_level != IPPROTO_IP)
249 		return (EINVAL);
250 
251 	error = 0;
252 
253 	switch (sopt->sopt_dir) {
254 	case SOPT_GET:
255 		switch (sopt->sopt_name) {
256 		case IP_HDRINCL:
257 			optval = inp->inp_flags & INP_HDRINCL;
258 			error = sooptcopyout(sopt, &optval, sizeof optval);
259 			break;
260 
261 		case IP_FW_ADD:
262 		case IP_FW_GET:
263 			if (ip_fw_ctl_ptr == 0)
264 				error = ENOPROTOOPT;
265 			else
266 				error = ip_fw_ctl_ptr(sopt);
267 			break;
268 
269 #ifdef DUMMYNET
270 		case IP_DUMMYNET_GET:
271 			if (ip_dn_ctl_ptr == NULL)
272 				error = ENOPROTOOPT ;
273 			else
274 				error = ip_dn_ctl_ptr(sopt);
275 			break ;
276 #endif /* DUMMYNET */
277 
278 		case MRT_INIT:
279 		case MRT_DONE:
280 		case MRT_ADD_VIF:
281 		case MRT_DEL_VIF:
282 		case MRT_ADD_MFC:
283 		case MRT_DEL_MFC:
284 		case MRT_VERSION:
285 		case MRT_ASSERT:
286 			error = ip_mrouter_get(so, sopt);
287 			break;
288 
289 		default:
290 			error = ip_ctloutput(so, sopt);
291 			break;
292 		}
293 		break;
294 
295 	case SOPT_SET:
296 		switch (sopt->sopt_name) {
297 		case IP_HDRINCL:
298 			error = sooptcopyin(sopt, &optval, sizeof optval,
299 					    sizeof optval);
300 			if (error)
301 				break;
302 			if (optval)
303 				inp->inp_flags |= INP_HDRINCL;
304 			else
305 				inp->inp_flags &= ~INP_HDRINCL;
306 			break;
307 
308 		case IP_FW_ADD:
309 		case IP_FW_DEL:
310 		case IP_FW_FLUSH:
311 		case IP_FW_ZERO:
312 		case IP_FW_RESETLOG:
313 			if (ip_fw_ctl_ptr == 0)
314 				error = ENOPROTOOPT;
315 			else
316 				error = ip_fw_ctl_ptr(sopt);
317 			break;
318 
319 #ifdef DUMMYNET
320 		case IP_DUMMYNET_CONFIGURE:
321 		case IP_DUMMYNET_DEL:
322 		case IP_DUMMYNET_FLUSH:
323 			if (ip_dn_ctl_ptr == NULL)
324 				error = ENOPROTOOPT ;
325 			else
326 				error = ip_dn_ctl_ptr(sopt);
327 			break ;
328 #endif
329 
330 		case IP_RSVP_ON:
331 			error = ip_rsvp_init(so);
332 			break;
333 
334 		case IP_RSVP_OFF:
335 			error = ip_rsvp_done();
336 			break;
337 
338 			/* XXX - should be combined */
339 		case IP_RSVP_VIF_ON:
340 			error = ip_rsvp_vif_init(so, sopt);
341 			break;
342 
343 		case IP_RSVP_VIF_OFF:
344 			error = ip_rsvp_vif_done(so, sopt);
345 			break;
346 
347 		case MRT_INIT:
348 		case MRT_DONE:
349 		case MRT_ADD_VIF:
350 		case MRT_DEL_VIF:
351 		case MRT_ADD_MFC:
352 		case MRT_DEL_MFC:
353 		case MRT_VERSION:
354 		case MRT_ASSERT:
355 			error = ip_mrouter_set(so, sopt);
356 			break;
357 
358 		default:
359 			error = ip_ctloutput(so, sopt);
360 			break;
361 		}
362 		break;
363 	}
364 
365 	return (error);
366 }
367 
368 /*
369  * This function exists solely to receive the PRC_IFDOWN messages which
370  * are sent by if_down().  It looks for an ifaddr whose ifa_addr is sa,
371  * and calls in_ifadown() to remove all routes corresponding to that address.
372  * It also receives the PRC_IFUP messages from if_up() and reinstalls the
373  * interface routes.
374  */
375 void
376 rip_ctlinput(cmd, sa, vip)
377 	int cmd;
378 	struct sockaddr *sa;
379 	void *vip;
380 {
381 	struct in_ifaddr *ia;
382 	struct ifnet *ifp;
383 	int err;
384 	int flags;
385 
386 	switch (cmd) {
387 	case PRC_IFDOWN:
388 		for (ia = in_ifaddrhead.tqh_first; ia;
389 		     ia = ia->ia_link.tqe_next) {
390 			if (ia->ia_ifa.ifa_addr == sa
391 			    && (ia->ia_flags & IFA_ROUTE)) {
392 				/*
393 				 * in_ifscrub kills the interface route.
394 				 */
395 				in_ifscrub(ia->ia_ifp, ia);
396 				/*
397 				 * in_ifadown gets rid of all the rest of
398 				 * the routes.  This is not quite the right
399 				 * thing to do, but at least if we are running
400 				 * a routing process they will come back.
401 				 */
402 				in_ifadown(&ia->ia_ifa);
403 				break;
404 			}
405 		}
406 		break;
407 
408 	case PRC_IFUP:
409 		for (ia = in_ifaddrhead.tqh_first; ia;
410 		     ia = ia->ia_link.tqe_next) {
411 			if (ia->ia_ifa.ifa_addr == sa)
412 				break;
413 		}
414 		if (ia == 0 || (ia->ia_flags & IFA_ROUTE))
415 			return;
416 		flags = RTF_UP;
417 		ifp = ia->ia_ifa.ifa_ifp;
418 
419 		if ((ifp->if_flags & IFF_LOOPBACK)
420 		    || (ifp->if_flags & IFF_POINTOPOINT))
421 			flags |= RTF_HOST;
422 
423 		err = rtinit(&ia->ia_ifa, RTM_ADD, flags);
424 		if (err == 0)
425 			ia->ia_flags |= IFA_ROUTE;
426 		break;
427 	}
428 }
429 
430 u_long	rip_sendspace = RIPSNDQ;
431 u_long	rip_recvspace = RIPRCVQ;
432 
433 SYSCTL_INT(_net_inet_raw, OID_AUTO, maxdgram, CTLFLAG_RW,
434     &rip_sendspace, 0, "Maximum outgoing raw IP datagram size");
435 SYSCTL_INT(_net_inet_raw, OID_AUTO, recvspace, CTLFLAG_RW,
436     &rip_recvspace, 0, "Maximum incoming raw IP datagram size");
437 
438 static int
439 rip_attach(struct socket *so, int proto, struct proc *p)
440 {
441 	struct inpcb *inp;
442 	int error, s;
443 
444 	inp = sotoinpcb(so);
445 	if (inp)
446 		panic("rip_attach");
447 	if (p && (error = suser(p)) != 0)
448 		return error;
449 
450 	error = soreserve(so, rip_sendspace, rip_recvspace);
451 	if (error)
452 		return error;
453 	s = splnet();
454 	error = in_pcballoc(so, &ripcbinfo, p);
455 	splx(s);
456 	if (error)
457 		return error;
458 	inp = (struct inpcb *)so->so_pcb;
459 	inp->inp_vflag |= INP_IPV4;
460 	inp->inp_ip_p = proto;
461 #ifdef IPSEC
462 	error = ipsec_init_policy(so, &inp->inp_sp);
463 	if (error != 0) {
464 		in_pcbdetach(inp);
465 		return error;
466 	}
467 #endif /*IPSEC*/
468 	return 0;
469 }
470 
471 static int
472 rip_detach(struct socket *so)
473 {
474 	struct inpcb *inp;
475 
476 	inp = sotoinpcb(so);
477 	if (inp == 0)
478 		panic("rip_detach");
479 	if (so == ip_mrouter)
480 		ip_mrouter_done();
481 	ip_rsvp_force_done(so);
482 	if (so == ip_rsvpd)
483 		ip_rsvp_done();
484 	in_pcbdetach(inp);
485 	return 0;
486 }
487 
488 static int
489 rip_abort(struct socket *so)
490 {
491 	soisdisconnected(so);
492 	return rip_detach(so);
493 }
494 
495 static int
496 rip_disconnect(struct socket *so)
497 {
498 	if ((so->so_state & SS_ISCONNECTED) == 0)
499 		return ENOTCONN;
500 	return rip_abort(so);
501 }
502 
503 static int
504 rip_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
505 {
506 	struct inpcb *inp = sotoinpcb(so);
507 	struct sockaddr_in *addr = (struct sockaddr_in *)nam;
508 
509 	if (nam->sa_len != sizeof(*addr))
510 		return EINVAL;
511 
512 	if (TAILQ_EMPTY(&ifnet) || ((addr->sin_family != AF_INET) &&
513 				    (addr->sin_family != AF_IMPLINK)) ||
514 	    (addr->sin_addr.s_addr &&
515 	     ifa_ifwithaddr((struct sockaddr *)addr) == 0))
516 		return EADDRNOTAVAIL;
517 	inp->inp_laddr = addr->sin_addr;
518 	return 0;
519 }
520 
521 static int
522 rip_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
523 {
524 	struct inpcb *inp = sotoinpcb(so);
525 	struct sockaddr_in *addr = (struct sockaddr_in *)nam;
526 
527 	if (nam->sa_len != sizeof(*addr))
528 		return EINVAL;
529 	if (TAILQ_EMPTY(&ifnet))
530 		return EADDRNOTAVAIL;
531 	if ((addr->sin_family != AF_INET) &&
532 	    (addr->sin_family != AF_IMPLINK))
533 		return EAFNOSUPPORT;
534 	inp->inp_faddr = addr->sin_addr;
535 	soisconnected(so);
536 	return 0;
537 }
538 
539 static int
540 rip_shutdown(struct socket *so)
541 {
542 	socantsendmore(so);
543 	return 0;
544 }
545 
546 static int
547 rip_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
548 	 struct mbuf *control, struct proc *p)
549 {
550 	struct inpcb *inp = sotoinpcb(so);
551 	register u_long dst;
552 
553 	if (so->so_state & SS_ISCONNECTED) {
554 		if (nam) {
555 			m_freem(m);
556 			return EISCONN;
557 		}
558 		dst = inp->inp_faddr.s_addr;
559 	} else {
560 		if (nam == NULL) {
561 			m_freem(m);
562 			return ENOTCONN;
563 		}
564 		dst = ((struct sockaddr_in *)nam)->sin_addr.s_addr;
565 	}
566 	return rip_output(m, so, dst);
567 }
568 
569 static int
570 rip_pcblist(SYSCTL_HANDLER_ARGS)
571 {
572 	int error, i, n, s;
573 	struct inpcb *inp, **inp_list;
574 	inp_gen_t gencnt;
575 	struct xinpgen xig;
576 
577 	/*
578 	 * The process of preparing the TCB list is too time-consuming and
579 	 * resource-intensive to repeat twice on every request.
580 	 */
581 	if (req->oldptr == 0) {
582 		n = ripcbinfo.ipi_count;
583 		req->oldidx = 2 * (sizeof xig)
584 			+ (n + n/8) * sizeof(struct xinpcb);
585 		return 0;
586 	}
587 
588 	if (req->newptr != 0)
589 		return EPERM;
590 
591 	/*
592 	 * OK, now we're committed to doing something.
593 	 */
594 	s = splnet();
595 	gencnt = ripcbinfo.ipi_gencnt;
596 	n = ripcbinfo.ipi_count;
597 	splx(s);
598 
599 	xig.xig_len = sizeof xig;
600 	xig.xig_count = n;
601 	xig.xig_gen = gencnt;
602 	xig.xig_sogen = so_gencnt;
603 	error = SYSCTL_OUT(req, &xig, sizeof xig);
604 	if (error)
605 		return error;
606 
607 	inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
608 	if (inp_list == 0)
609 		return ENOMEM;
610 
611 	s = splnet();
612 	for (inp = ripcbinfo.listhead->lh_first, i = 0; inp && i < n;
613 	     inp = inp->inp_list.le_next) {
614 		if (inp->inp_gencnt <= gencnt)
615 			inp_list[i++] = inp;
616 	}
617 	splx(s);
618 	n = i;
619 
620 	error = 0;
621 	for (i = 0; i < n; i++) {
622 		inp = inp_list[i];
623 		if (inp->inp_gencnt <= gencnt) {
624 			struct xinpcb xi;
625 			xi.xi_len = sizeof xi;
626 			/* XXX should avoid extra copy */
627 			bcopy(inp, &xi.xi_inp, sizeof *inp);
628 			if (inp->inp_socket)
629 				sotoxsocket(inp->inp_socket, &xi.xi_socket);
630 			error = SYSCTL_OUT(req, &xi, sizeof xi);
631 		}
632 	}
633 	if (!error) {
634 		/*
635 		 * Give the user an updated idea of our state.
636 		 * If the generation differs from what we told
637 		 * her before, she knows that something happened
638 		 * while we were processing this request, and it
639 		 * might be necessary to retry.
640 		 */
641 		s = splnet();
642 		xig.xig_gen = ripcbinfo.ipi_gencnt;
643 		xig.xig_sogen = so_gencnt;
644 		xig.xig_count = ripcbinfo.ipi_count;
645 		splx(s);
646 		error = SYSCTL_OUT(req, &xig, sizeof xig);
647 	}
648 	free(inp_list, M_TEMP);
649 	return error;
650 }
651 
652 SYSCTL_PROC(_net_inet_raw, OID_AUTO/*XXX*/, pcblist, CTLFLAG_RD, 0, 0,
653 	    rip_pcblist, "S,xinpcb", "List of active raw IP sockets");
654 
655 struct pr_usrreqs rip_usrreqs = {
656 	rip_abort, pru_accept_notsupp, rip_attach, rip_bind, rip_connect,
657 	pru_connect2_notsupp, in_control, rip_detach, rip_disconnect,
658 	pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp,
659 	pru_rcvoob_notsupp, rip_send, pru_sense_null, rip_shutdown,
660 	in_setsockaddr, sosend, soreceive, sopoll
661 };
662