xref: /freebsd/sys/net/if_gif.c (revision 23f282aa31e9b6fceacd449020e936e98d6f2298)
1 /*
2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3  * 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. Neither the name of the project nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 /*
33  * gif.c
34  */
35 
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
46 #include <sys/errno.h>
47 #include <sys/time.h>
48 #include <sys/syslog.h>
49 #include <machine/cpu.h>
50 
51 #include <net/if.h>
52 #include <net/if_types.h>
53 #include <net/netisr.h>
54 #include <net/route.h>
55 #include <net/bpf.h>
56 
57 #ifdef	INET
58 #include <netinet/in.h>
59 #include <netinet/in_systm.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip.h>
62 #include <netinet/in_gif.h>
63 #endif	/* INET */
64 
65 #ifdef INET6
66 #ifndef INET
67 #include <netinet/in.h>
68 #endif
69 #include <netinet6/in6_var.h>
70 #include <netinet/ip6.h>
71 #include <netinet6/ip6_var.h>
72 #include <netinet6/in6_gif.h>
73 #endif /* INET6 */
74 
75 #include <net/if_gif.h>
76 
77 #include "gif.h"
78 
79 #include <net/net_osdep.h>
80 
81 void gifattach __P((void *));
82 
83 /*
84  * gif global variable definitions
85  */
86 int ngif = NGIF + 1;		/* number of interfaces. +1 for stf. */
87 struct gif_softc *gif = 0;
88 
89 void
90 gifattach(dummy)
91 	void *dummy;
92 {
93 	register struct gif_softc *sc;
94 	register int i;
95 
96 	gif = sc = malloc (ngif * sizeof(struct gif_softc), M_DEVBUF, M_WAIT);
97 	bzero(sc, ngif * sizeof(struct gif_softc));
98 	for (i = 0; i < ngif - 1; sc++, i++) {  /* leave last one for stf */
99 		sc->gif_if.if_name = "gif";
100 		sc->gif_if.if_unit = i;
101 		sc->gif_if.if_mtu    = GIF_MTU;
102 		sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
103 		sc->gif_if.if_ioctl  = gif_ioctl;
104 		sc->gif_if.if_output = gif_output;
105 		sc->gif_if.if_type   = IFT_GIF;
106 		sc->gif_if.if_snd.ifq_maxlen = ifqmaxlen;
107 		if_attach(&sc->gif_if);
108 		bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
109 	}
110 	sc->gif_if.if_name = "stf";
111 	sc->gif_if.if_unit = 0;
112 	sc->gif_if.if_mtu    = GIF_MTU;
113 	sc->gif_if.if_flags  = IFF_MULTICAST;
114 	sc->gif_if.if_ioctl  = gif_ioctl;
115 	sc->gif_if.if_output = gif_output;
116 	sc->gif_if.if_type   = IFT_GIF;
117 	sc->gif_if.if_snd.ifq_maxlen = ifqmaxlen;
118 	if_attach(&sc->gif_if);
119 	bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
120 }
121 
122 PSEUDO_SET(gifattach, if_gif);
123 
124 int
125 gif_output(ifp, m, dst, rt)
126 	struct ifnet *ifp;
127 	struct mbuf *m;
128 	struct sockaddr *dst;
129 	struct rtentry *rt;	/* added in net2 */
130 {
131 	register struct gif_softc *sc = (struct gif_softc*)ifp;
132 	int error = 0;
133 	static int called = 0;	/* XXX: MUTEX */
134 	int calllimit = 10;	/* XXX: adhoc */
135 
136 	/*
137 	 * gif may cause infinite recursion calls when misconfigured.
138 	 * We'll prevent this by introducing upper limit.
139 	 * XXX: this mechanism may introduce another problem about
140 	 *      mutual exclusion of the variable CALLED, especially if we
141 	 *      use kernel thread.
142 	 */
143 	if (++called >= calllimit) {
144 		log(LOG_NOTICE,
145 		    "gif_output: recursively called too many times(%d)\n",
146 		    called);
147 		m_freem(m);
148 		error = EIO;	/* is there better errno? */
149 		goto end;
150 	}
151 	getmicrotime(&ifp->if_lastchange);
152 	m->m_flags &= ~(M_BCAST|M_MCAST);
153 	if (!(ifp->if_flags & IFF_UP) ||
154 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
155 		m_freem(m);
156 		error = ENETDOWN;
157 		goto end;
158 	}
159 
160 	if (ifp->if_bpf) {
161 		/*
162 		 * We need to prepend the address family as
163 		 * a four byte field.  Cons up a dummy header
164 		 * to pacify bpf.  This is safe because bpf
165 		 * will only read from the mbuf (i.e., it won't
166 		 * try to free it or keep a pointer a to it).
167 		 */
168 		struct mbuf m0;
169 		u_int af = dst->sa_family;
170 
171 		m0.m_next = m;
172 		m0.m_len = 4;
173 		m0.m_data = (char *)&af;
174 
175 		bpf_mtap(ifp, &m0);
176 	}
177 	ifp->if_opackets++;
178 	ifp->if_obytes += m->m_pkthdr.len;
179 
180 	switch (sc->gif_psrc->sa_family) {
181 #ifdef INET
182 	case AF_INET:
183 		error = in_gif_output(ifp, dst->sa_family, m, rt);
184 		break;
185 #endif
186 #ifdef INET6
187 	case AF_INET6:
188 		error = in6_gif_output(ifp, dst->sa_family, m, rt);
189 		break;
190 #endif
191 	default:
192 		m_freem(m);
193 		error = ENETDOWN;
194 	}
195 
196   end:
197 	called = 0;		/* reset recursion counter */
198 	if (error) ifp->if_oerrors++;
199 	return error;
200 }
201 
202 void
203 gif_input(m, af, gifp)
204 	struct mbuf *m;
205 	int af;
206 	struct ifnet *gifp;
207 {
208 	int s, isr;
209 	register struct ifqueue *ifq = 0;
210 
211 	if (gifp == NULL) {
212 		/* just in case */
213 		m_freem(m);
214 		return;
215 	}
216 
217 	if (m->m_pkthdr.rcvif)
218 		m->m_pkthdr.rcvif = gifp;
219 
220 	if (gifp->if_bpf) {
221 		/*
222 		 * We need to prepend the address family as
223 		 * a four byte field.  Cons up a dummy header
224 		 * to pacify bpf.  This is safe because bpf
225 		 * will only read from the mbuf (i.e., it won't
226 		 * try to free it or keep a pointer a to it).
227 		 */
228 		struct mbuf m0;
229 		u_int af = AF_INET6;
230 
231 		m0.m_next = m;
232 		m0.m_len = 4;
233 		m0.m_data = (char *)&af;
234 
235 		bpf_mtap(gifp, &m0);
236 	}
237 
238 	/*
239 	 * Put the packet to the network layer input queue according to the
240 	 * specified address family.
241 	 * Note: older versions of gif_input directly called network layer
242 	 * input functions, e.g. ip6_input, here. We changed the policy to
243 	 * prevent too many recursive calls of such input functions, which
244 	 * might cause kernel panic. But the change may introduce another
245 	 * problem; if the input queue is full, packets are discarded.
246 	 * We believed it rarely occurs and changed the policy. If we find
247 	 * it occurs more times than we thought, we may change the policy
248 	 * again.
249 	 */
250 	switch (af) {
251 #ifdef INET
252 	case AF_INET:
253 		ifq = &ipintrq;
254 		isr = NETISR_IP;
255 		break;
256 #endif
257 #ifdef INET6
258 	case AF_INET6:
259 		ifq = &ip6intrq;
260 		isr = NETISR_IPV6;
261 		break;
262 #endif
263 	default:
264 		m_freem(m);
265 		return;
266 	}
267 
268 	s = splimp();
269 	if (IF_QFULL(ifq)) {
270 		IF_DROP(ifq);	/* update statistics */
271 		m_freem(m);
272 		splx(s);
273 		return;
274 	}
275 	IF_ENQUEUE(ifq, m);
276 	/* we need schednetisr since the address family may change */
277 	schednetisr(isr);
278 	gifp->if_ipackets++;
279 	gifp->if_ibytes += m->m_pkthdr.len;
280 	splx(s);
281 
282 	return;
283 }
284 
285 
286 int
287 gif_ioctl(ifp, cmd, data)
288 	struct ifnet *ifp;
289 	u_long cmd;
290 	caddr_t data;
291 {
292 	struct gif_softc *sc  = (struct gif_softc*)ifp;
293 	struct ifreq     *ifr = (struct ifreq*)data;
294 	int error = 0, size;
295 	struct sockaddr *sa, *dst, *src;
296 
297 	switch (cmd) {
298 	case SIOCSIFADDR:
299 		break;
300 
301 	case SIOCSIFDSTADDR:
302 		break;
303 
304 	case SIOCADDMULTI:
305 	case SIOCDELMULTI:
306 		break;
307 
308 	case SIOCGIFMTU:
309 		break;
310 	case SIOCSIFMTU:
311 		{
312 			u_long mtu;
313 			mtu = ifr->ifr_mtu;
314 			if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX) {
315 				return (EINVAL);
316 			}
317 			ifp->if_mtu = mtu;
318 		}
319 		break;
320 
321 	case SIOCSIFPHYADDR:
322 #ifdef INET6
323 	case SIOCSIFPHYADDR_IN6:
324 #endif /* INET6 */
325 		switch (ifr->ifr_addr.sa_family) {
326 #ifdef INET
327 		case AF_INET:
328 			src = (struct sockaddr *)
329 				&(((struct in_aliasreq *)data)->ifra_addr);
330 			dst = (struct sockaddr *)
331 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
332 
333 			/* only one gif can have dst = INADDR_ANY */
334 #define	satosaddr(sa) (((struct sockaddr_in *)(sa))->sin_addr.s_addr)
335 
336 #ifdef INET6
337 			if (bcmp(ifp->if_name, "stf", 3) == 0)
338 				satosaddr(dst) = INADDR_BROADCAST;
339 #endif
340 
341 			if (satosaddr(dst) == INADDR_ANY) {
342 				int i;
343 				struct gif_softc *sc2;
344 
345 			  	for (i = 0, sc2 = gif; i < ngif; i++, sc2++) {
346 					if (sc2 == sc) continue;
347 					if (sc2->gif_pdst &&
348 					    satosaddr(sc2->gif_pdst)
349 						== INADDR_ANY) {
350 					    error = EADDRNOTAVAIL;
351 					    goto bad;
352 					}
353 				}
354 			}
355 			size = sizeof(struct sockaddr_in);
356 			break;
357 #endif /* INET */
358 #ifdef INET6
359 		case AF_INET6:
360 			src = (struct sockaddr *)
361 				&(((struct in6_aliasreq *)data)->ifra_addr);
362 			dst = (struct sockaddr *)
363 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
364 
365 			/* only one gif can have dst = in6addr_any */
366 #define	satoin6(sa) (&((struct sockaddr_in6 *)(sa))->sin6_addr)
367 
368 			if (IN6_IS_ADDR_UNSPECIFIED(satoin6(dst))) {
369 				int i;
370 				struct gif_softc *sc2;
371 
372 			  	for (i = 0, sc2 = gif; i < ngif; i++, sc2++) {
373 					if (sc2 == sc) continue;
374 					if (sc2->gif_pdst &&
375 					    IN6_IS_ADDR_UNSPECIFIED(
376 						satoin6(sc2->gif_pdst)
377 								    )) {
378 					    error = EADDRNOTAVAIL;
379 					    goto bad;
380 					}
381 				}
382 			}
383 			size = sizeof(struct sockaddr_in6);
384 			break;
385 #endif /* INET6 */
386 		default:
387 			error = EPROTOTYPE;
388 			goto bad;
389 			break;
390 		}
391 		if (sc->gif_psrc != NULL)
392 			free((caddr_t)sc->gif_psrc, M_IFADDR);
393 		if (sc->gif_pdst != NULL)
394 			free((caddr_t)sc->gif_pdst, M_IFADDR);
395 
396 		sa = (struct sockaddr *)malloc(size, M_IFADDR, M_WAITOK);
397 		bzero((caddr_t)sa, size);
398 		bcopy((caddr_t)src, (caddr_t)sa, size);
399 		sc->gif_psrc = sa;
400 
401 		sa = (struct sockaddr *)malloc(size, M_IFADDR, M_WAITOK);
402 		bzero((caddr_t)sa, size);
403 		bcopy((caddr_t)dst, (caddr_t)sa, size);
404 		sc->gif_pdst = sa;
405 
406 		ifp->if_flags |= (IFF_UP|IFF_RUNNING);
407 		{
408 			int s;
409 
410 			s = splnet();
411 			if_up(ifp);		/* send up RTM_IFINFO */
412 			splx(s);
413 		}
414 
415 		break;
416 
417 	case SIOCGIFPSRCADDR:
418 #ifdef INET6
419 	case SIOCGIFPSRCADDR_IN6:
420 #endif /* INET6 */
421 		if (sc->gif_psrc == NULL) {
422 			error = EADDRNOTAVAIL;
423 			goto bad;
424 		}
425 		src = sc->gif_psrc;
426 		switch (sc->gif_psrc->sa_family) {
427 #ifdef INET
428 		case AF_INET:
429 			dst = &ifr->ifr_addr;
430 			size = sizeof(struct sockaddr_in);
431 			break;
432 #endif /* INET */
433 #ifdef INET6
434 		case AF_INET6:
435 			dst = (struct sockaddr *)
436 				&(((struct in6_ifreq *)data)->ifr_addr);
437 			size = sizeof(struct sockaddr_in6);
438 			break;
439 #endif /* INET6 */
440 		default:
441 			error = EADDRNOTAVAIL;
442 			goto bad;
443 		}
444 		bcopy((caddr_t)src, (caddr_t)dst, size);
445 		break;
446 
447 	case SIOCGIFPDSTADDR:
448 #ifdef INET6
449 	case SIOCGIFPDSTADDR_IN6:
450 #endif /* INET6 */
451 		if (sc->gif_pdst == NULL) {
452 			error = EADDRNOTAVAIL;
453 			goto bad;
454 		}
455 		src = sc->gif_pdst;
456 		switch (sc->gif_pdst->sa_family) {
457 #ifdef INET
458 		case AF_INET:
459 			dst = &ifr->ifr_addr;
460 			size = sizeof(struct sockaddr_in);
461 			break;
462 #endif /* INET */
463 #ifdef INET6
464 		case AF_INET6:
465 			dst = (struct sockaddr *)
466 				&(((struct in6_ifreq *)data)->ifr_addr);
467 			size = sizeof(struct sockaddr_in6);
468 			break;
469 #endif /* INET6 */
470 		default:
471 			error = EADDRNOTAVAIL;
472 			goto bad;
473 		}
474 		bcopy((caddr_t)src, (caddr_t)dst, size);
475 		break;
476 
477 	case SIOCSIFFLAGS:
478 		break;
479 
480 	default:
481 		error = EINVAL;
482 		break;
483 	}
484  bad:
485 	return error;
486 }
487