xref: /openbsd-src/sys/netinet/raw_ip.c (revision c0dd97bfcad3dab6c31ec12b9de1274fd2d2f993)
1 /*	$OpenBSD: raw_ip.c,v 1.104 2017/10/06 21:14:55 bluhm Exp $	*/
2 /*	$NetBSD: raw_ip.c,v 1.25 1996/02/18 18:58:33 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1988, 1993
6  *	The Regents of the University of California.  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  *	@(#)COPYRIGHT	1.1 (NRL) 17 January 1995
33  *
34  * NRL grants permission for redistribution and use in source and binary
35  * forms, with or without modification, of the software and documentation
36  * created at NRL provided that the following conditions are met:
37  *
38  * 1. Redistributions of source code must retain the above copyright
39  *    notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice, this list of conditions and the following disclaimer in the
42  *    documentation and/or other materials provided with the distribution.
43  * 3. All advertising materials mentioning features or use of this software
44  *    must display the following acknowledgements:
45  *	This product includes software developed by the University of
46  *	California, Berkeley and its contributors.
47  *	This product includes software developed at the Information
48  *	Technology Division, US Naval Research Laboratory.
49  * 4. Neither the name of the NRL nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS
54  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
55  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
56  * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL NRL OR
57  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
58  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
59  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
60  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
61  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
62  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
63  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64  *
65  * The views and conclusions contained in the software and documentation
66  * are those of the authors and should not be interpreted as representing
67  * official policies, either expressed or implied, of the US Naval
68  * Research Laboratory (NRL).
69  */
70 
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/mbuf.h>
74 #include <sys/socket.h>
75 #include <sys/protosw.h>
76 #include <sys/socketvar.h>
77 
78 #include <net/if.h>
79 #include <net/if_var.h>
80 #include <net/route.h>
81 
82 #include <netinet/in.h>
83 #include <netinet/ip.h>
84 #include <netinet/ip_mroute.h>
85 #include <netinet/ip_var.h>
86 #include <netinet/in_pcb.h>
87 #include <netinet/in_var.h>
88 #include <netinet/ip_icmp.h>
89 
90 #include <net/pfvar.h>
91 
92 #include "pf.h"
93 
94 struct inpcbtable rawcbtable;
95 
96 /*
97  * Nominal space allocated to a raw ip socket.
98  */
99 #define	RIPSNDQ		8192
100 #define	RIPRCVQ		8192
101 
102 /*
103  * Raw interface to IP protocol.
104  */
105 
106 /*
107  * Initialize raw connection block q.
108  */
109 void
110 rip_init(void)
111 {
112 
113 	in_pcbinit(&rawcbtable, 1);
114 }
115 
116 struct sockaddr_in ripsrc = { sizeof(ripsrc), AF_INET };
117 
118 int
119 rip_input(struct mbuf **mp, int *offp, int proto, int af)
120 {
121 	struct mbuf *m = *mp;
122 	struct ip *ip = mtod(m, struct ip *);
123 	struct inpcb *inp, *last = NULL;
124 	struct mbuf *opts = NULL;
125 	struct counters_ref ref;
126 	uint64_t *counters;
127 
128 	KASSERT(af == AF_INET);
129 
130 	ripsrc.sin_addr = ip->ip_src;
131 	TAILQ_FOREACH(inp, &rawcbtable.inpt_queue, inp_queue) {
132 		if (inp->inp_socket->so_state & SS_CANTRCVMORE)
133 			continue;
134 #ifdef INET6
135 		if (inp->inp_flags & INP_IPV6)
136 			continue;
137 #endif
138 		if (rtable_l2(inp->inp_rtableid) !=
139 		    rtable_l2(m->m_pkthdr.ph_rtableid))
140 			continue;
141 
142 		if (inp->inp_ip.ip_p && inp->inp_ip.ip_p != ip->ip_p)
143 			continue;
144 #if NPF > 0
145 		if (m->m_pkthdr.pf.flags & PF_TAG_DIVERTED) {
146 			struct pf_divert *divert;
147 
148 			/* XXX rdomain support */
149 			if ((divert = pf_find_divert(m)) == NULL)
150 				continue;
151 			if (!divert->addr.v4.s_addr)
152 				goto divert_reply;
153 			if (inp->inp_laddr.s_addr != divert->addr.v4.s_addr)
154 				continue;
155 		} else
156  divert_reply:
157 #endif
158 		if (inp->inp_laddr.s_addr &&
159 		    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
160 			continue;
161 		if (inp->inp_faddr.s_addr &&
162 		    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
163 			continue;
164 		if (last) {
165 			struct mbuf *n;
166 
167 			if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
168 				if (last->inp_flags & INP_CONTROLOPTS ||
169 				    last->inp_socket->so_options & SO_TIMESTAMP)
170 					ip_savecontrol(last, &opts, ip, n);
171 				if (sbappendaddr(last->inp_socket,
172 				    &last->inp_socket->so_rcv,
173 				    sintosa(&ripsrc), n, opts) == 0) {
174 					/* should notify about lost packet */
175 					m_freem(n);
176 					m_freem(opts);
177 				} else
178 					sorwakeup(last->inp_socket);
179 				opts = NULL;
180 			}
181 		}
182 		last = inp;
183 	}
184 	if (last) {
185 		if (last->inp_flags & INP_CONTROLOPTS ||
186 		    last->inp_socket->so_options & SO_TIMESTAMP)
187 			ip_savecontrol(last, &opts, ip, m);
188 		if (sbappendaddr(last->inp_socket, &last->inp_socket->so_rcv,
189 		    sintosa(&ripsrc), m, opts) == 0) {
190 			m_freem(m);
191 			m_freem(opts);
192 		} else
193 			sorwakeup(last->inp_socket);
194 	} else {
195 		if (ip->ip_p != IPPROTO_ICMP)
196 			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PROTOCOL, 0, 0);
197 		else
198 			m_freem(m);
199 
200 		counters = counters_enter(&ref, ipcounters);
201 		counters[ips_noproto]++;
202 		counters[ips_delivered]--;
203 		counters_leave(&ref, ipcounters);
204 	}
205 	return IPPROTO_DONE;
206 }
207 
208 /*
209  * Generate IP header and pass packet to ip_output.
210  * Tack on options user may have setup with control call.
211  */
212 int
213 rip_output(struct mbuf *m, struct socket *so, struct sockaddr *dstaddr,
214     struct mbuf *control)
215 {
216 	struct ip *ip;
217 	struct inpcb *inp;
218 	int flags, error;
219 
220 	inp = sotoinpcb(so);
221 	flags = IP_ALLOWBROADCAST;
222 
223 	/*
224 	 * If the user handed us a complete IP packet, use it.
225 	 * Otherwise, allocate an mbuf for a header and fill it in.
226 	 */
227 	if ((inp->inp_flags & INP_HDRINCL) == 0) {
228 		if ((m->m_pkthdr.len + sizeof(struct ip)) > IP_MAXPACKET) {
229 			m_freem(m);
230 			return (EMSGSIZE);
231 		}
232 		M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
233 		if (!m)
234 			return (ENOBUFS);
235 		ip = mtod(m, struct ip *);
236 		ip->ip_tos = inp->inp_ip.ip_tos;
237 		ip->ip_off = htons(0);
238 		ip->ip_p = inp->inp_ip.ip_p;
239 		ip->ip_len = htons(m->m_pkthdr.len);
240 		ip->ip_src = inp->inp_laddr;
241 		ip->ip_dst = satosin(dstaddr)->sin_addr;
242 		ip->ip_ttl = inp->inp_ip.ip_ttl ? inp->inp_ip.ip_ttl : MAXTTL;
243 	} else {
244 		if (m->m_pkthdr.len > IP_MAXPACKET) {
245 			m_freem(m);
246 			return (EMSGSIZE);
247 		}
248 		if (m->m_pkthdr.len < sizeof(struct ip)) {
249 			m_freem(m);
250 			return (EINVAL);
251 		}
252 		ip = mtod(m, struct ip *);
253 		/*
254 		 * don't allow both user specified and setsockopt options,
255 		 * and don't allow packet length sizes that will crash
256 		 */
257 		if ((ip->ip_hl != (sizeof (*ip) >> 2) && inp->inp_options) ||
258 		    ntohs(ip->ip_len) > m->m_pkthdr.len ||
259 		    ntohs(ip->ip_len) < ip->ip_hl << 2) {
260 			m_freem(m);
261 			return (EINVAL);
262 		}
263 		if (ip->ip_id == 0) {
264 			ip->ip_id = htons(ip_randomid());
265 		}
266 		/* XXX prevent ip_output from overwriting header fields */
267 		flags |= IP_RAWOUTPUT;
268 		ipstat_inc(ips_rawout);
269 	}
270 #ifdef INET6
271 	/*
272 	 * A thought:  Even though raw IP shouldn't be able to set IPv6
273 	 *             multicast options, if it does, the last parameter to
274 	 *             ip_output should be guarded against v6/v4 problems.
275 	 */
276 #endif
277 	/* force routing table */
278 	m->m_pkthdr.ph_rtableid = inp->inp_rtableid;
279 
280 #if NPF > 0
281 	if (inp->inp_socket->so_state & SS_ISCONNECTED &&
282 	    ip->ip_p != IPPROTO_ICMP)
283 		m->m_pkthdr.pf.inp = inp;
284 #endif
285 
286 	error = ip_output(m, inp->inp_options, &inp->inp_route, flags,
287 	    inp->inp_moptions, inp, 0);
288 	if (error == EACCES)	/* translate pf(4) error for userland */
289 		error = EHOSTUNREACH;
290 	return (error);
291 }
292 
293 /*
294  * Raw IP socket option processing.
295  */
296 int
297 rip_ctloutput(int op, struct socket *so, int level, int optname,
298     struct mbuf *m)
299 {
300 	struct inpcb *inp = sotoinpcb(so);
301 	int error;
302 
303 	if (level != IPPROTO_IP)
304 		return (EINVAL);
305 
306 	switch (optname) {
307 
308 	case IP_HDRINCL:
309 		error = 0;
310 		if (op == PRCO_SETOPT) {
311 			if (m == NULL || m->m_len < sizeof (int))
312 				error = EINVAL;
313 			else if (*mtod(m, int *))
314 				inp->inp_flags |= INP_HDRINCL;
315 			else
316 				inp->inp_flags &= ~INP_HDRINCL;
317 		} else {
318 			m->m_len = sizeof(int);
319 			*mtod(m, int *) = inp->inp_flags & INP_HDRINCL;
320 		}
321 		return (error);
322 
323 	case MRT_INIT:
324 	case MRT_DONE:
325 	case MRT_ADD_VIF:
326 	case MRT_DEL_VIF:
327 	case MRT_ADD_MFC:
328 	case MRT_DEL_MFC:
329 	case MRT_VERSION:
330 	case MRT_ASSERT:
331 	case MRT_API_SUPPORT:
332 	case MRT_API_CONFIG:
333 #ifdef MROUTING
334 		switch (op) {
335 		case PRCO_SETOPT:
336 			error = ip_mrouter_set(so, optname, m);
337 			break;
338 		case PRCO_GETOPT:
339 			error = ip_mrouter_get(so, optname, m);
340 			break;
341 		default:
342 			error = EINVAL;
343 			break;
344 		}
345 		return (error);
346 #else
347 		return (EOPNOTSUPP);
348 #endif
349 	}
350 	return (ip_ctloutput(op, so, level, optname, m));
351 }
352 
353 u_long	rip_sendspace = RIPSNDQ;
354 u_long	rip_recvspace = RIPRCVQ;
355 
356 /*ARGSUSED*/
357 int
358 rip_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
359     struct mbuf *control, struct proc *p)
360 {
361 	struct inpcb *inp = sotoinpcb(so);
362 	int error = 0;
363 
364 	soassertlocked(so);
365 
366 	if (req == PRU_CONTROL)
367 		return (in_control(so, (u_long)m, (caddr_t)nam,
368 		    (struct ifnet *)control));
369 
370 	if (inp == NULL) {
371 		error = EINVAL;
372 		goto release;
373 	}
374 
375 	switch (req) {
376 
377 	case PRU_DISCONNECT:
378 		if ((so->so_state & SS_ISCONNECTED) == 0) {
379 			error = ENOTCONN;
380 			break;
381 		}
382 		/* FALLTHROUGH */
383 	case PRU_ABORT:
384 		soisdisconnected(so);
385 		/* FALLTHROUGH */
386 	case PRU_DETACH:
387 		if (inp == NULL)
388 			panic("rip_detach");
389 #ifdef MROUTING
390 		if (so == ip_mrouter[inp->inp_rtableid])
391 			ip_mrouter_done(so);
392 #endif
393 		in_pcbdetach(inp);
394 		break;
395 
396 	case PRU_BIND:
397 	    {
398 		struct sockaddr_in *addr;
399 
400 		if ((error = in_nam2sin(nam, &addr)))
401 			break;
402 		if (!((so->so_options & SO_BINDANY) ||
403 		    addr->sin_addr.s_addr == INADDR_ANY ||
404 		    addr->sin_addr.s_addr == INADDR_BROADCAST ||
405 		    in_broadcast(addr->sin_addr, inp->inp_rtableid) ||
406 		    ifa_ifwithaddr(sintosa(addr), inp->inp_rtableid))) {
407 			error = EADDRNOTAVAIL;
408 			break;
409 		}
410 		inp->inp_laddr = addr->sin_addr;
411 		break;
412 	    }
413 	case PRU_CONNECT:
414 	    {
415 		struct sockaddr_in *addr;
416 
417 		if ((error = in_nam2sin(nam, &addr)))
418 			break;
419 		inp->inp_faddr = addr->sin_addr;
420 		soisconnected(so);
421 		break;
422 	    }
423 
424 	case PRU_CONNECT2:
425 		error = EOPNOTSUPP;
426 		break;
427 
428 	/*
429 	 * Mark the connection as being incapable of further input.
430 	 */
431 	case PRU_SHUTDOWN:
432 		socantsendmore(so);
433 		break;
434 
435 	/*
436 	 * Ship a packet out.  The appropriate raw output
437 	 * routine handles any massaging necessary.
438 	 */
439 	case PRU_SEND:
440 	    {
441 		struct sockaddr_in dst;
442 
443 		memset(&dst, 0, sizeof(dst));
444 		dst.sin_family = AF_INET;
445 		dst.sin_len = sizeof(dst);
446 		if (so->so_state & SS_ISCONNECTED) {
447 			if (nam) {
448 				error = EISCONN;
449 				break;
450 			}
451 			dst.sin_addr = inp->inp_faddr;
452 		} else {
453 			struct sockaddr_in *addr;
454 
455 			if (nam == NULL) {
456 				error = ENOTCONN;
457 				break;
458 			}
459 			if ((error = in_nam2sin(nam, &addr)))
460 				break;
461 			dst.sin_addr = addr->sin_addr;
462 		}
463 #ifdef IPSEC
464 		/* XXX Find an IPsec TDB */
465 #endif
466 		error = rip_output(m, so, sintosa(&dst), NULL);
467 		m = NULL;
468 		break;
469 	    }
470 
471 	case PRU_SENSE:
472 		/*
473 		 * stat: don't bother with a blocksize.
474 		 */
475 		return (0);
476 
477 	/*
478 	 * Not supported.
479 	 */
480 	case PRU_RCVOOB:
481 	case PRU_RCVD:
482 	case PRU_LISTEN:
483 	case PRU_ACCEPT:
484 	case PRU_SENDOOB:
485 		error = EOPNOTSUPP;
486 		break;
487 
488 	case PRU_SOCKADDR:
489 		in_setsockaddr(inp, nam);
490 		break;
491 
492 	case PRU_PEERADDR:
493 		in_setpeeraddr(inp, nam);
494 		break;
495 
496 	default:
497 		panic("rip_usrreq");
498 	}
499 release:
500 	m_freem(m);
501 	return (error);
502 }
503 
504 int
505 rip_attach(struct socket *so, int proto)
506 {
507 	struct inpcb *inp;
508 	int error;
509 
510 	if (so->so_pcb)
511 		panic("rip_attach");
512 	if ((so->so_state & SS_PRIV) == 0)
513 		return EACCES;
514 	if (proto < 0 || proto >= IPPROTO_MAX)
515 		return EPROTONOSUPPORT;
516 
517 	if ((error = soreserve(so, rip_sendspace, rip_recvspace)) ||
518 	    (error = in_pcballoc(so, &rawcbtable))) {
519 		return error;
520 	}
521 	inp = sotoinpcb(so);
522 	inp->inp_ip.ip_p = proto;
523 	return 0;
524 }
525