xref: /freebsd/sys/net/if_gif.c (revision 5129159789cc9d7bc514e4546b88e3427695002d)
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 #if NGIF > 0
82 
83 void gifattach __P((void *));
84 
85 /*
86  * gif global variable definitions
87  */
88 int ngif = NGIF;		/* number of interfaces */
89 struct gif_softc *gif = 0;
90 
91 void
92 gifattach(dummy)
93 	void *dummy;
94 {
95 	register struct gif_softc *sc;
96 	register int i;
97 
98 	gif = sc = malloc (ngif * sizeof(struct gif_softc), M_DEVBUF, M_WAIT);
99 	bzero(sc, ngif * sizeof(struct gif_softc));
100 	for (i = 0; i < ngif; sc++, i++) {
101 		sc->gif_if.if_name = "gif";
102 		sc->gif_if.if_unit = i;
103 		sc->gif_if.if_mtu    = GIF_MTU;
104 		sc->gif_if.if_flags  = IFF_POINTOPOINT | IFF_MULTICAST;
105 		sc->gif_if.if_ioctl  = gif_ioctl;
106 		sc->gif_if.if_output = gif_output;
107 		sc->gif_if.if_type   = IFT_GIF;
108 		sc->gif_if.if_snd.ifq_maxlen = ifqmaxlen;
109 		if_attach(&sc->gif_if);
110 		bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int));
111 	}
112 }
113 
114 PSEUDO_SET(gifattach, if_gif);
115 
116 int
117 gif_output(ifp, m, dst, rt)
118 	struct ifnet *ifp;
119 	struct mbuf *m;
120 	struct sockaddr *dst;
121 	struct rtentry *rt;	/* added in net2 */
122 {
123 	register struct gif_softc *sc = (struct gif_softc*)ifp;
124 	int error = 0;
125 	static int called = 0;	/* XXX: MUTEX */
126 	int calllimit = 10;	/* XXX: adhoc */
127 
128 	/*
129 	 * gif may cause infinite recursion calls when misconfigured.
130 	 * We'll prevent this by introducing upper limit.
131 	 * XXX: this mechanism may introduce another problem about
132 	 *      mutual exclusion of the variable CALLED, especially if we
133 	 *      use kernel thread.
134 	 */
135 	if (++called >= calllimit) {
136 		log(LOG_NOTICE,
137 		    "gif_output: recursively called too many times(%d)\n",
138 		    called);
139 		m_freem(m);
140 		error = EIO;	/* is there better errno? */
141 		goto end;
142 	}
143 	getmicrotime(&ifp->if_lastchange);
144 	m->m_flags &= ~(M_BCAST|M_MCAST);
145 	if (!(ifp->if_flags & IFF_UP) ||
146 	    sc->gif_psrc == NULL || sc->gif_pdst == NULL) {
147 		m_freem(m);
148 		error = ENETDOWN;
149 		goto end;
150 	}
151 
152 	if (ifp->if_bpf) {
153 		/*
154 		 * We need to prepend the address family as
155 		 * a four byte field.  Cons up a dummy header
156 		 * to pacify bpf.  This is safe because bpf
157 		 * will only read from the mbuf (i.e., it won't
158 		 * try to free it or keep a pointer a to it).
159 		 */
160 		struct mbuf m0;
161 		u_int af = dst->sa_family;
162 
163 		m0.m_next = m;
164 		m0.m_len = 4;
165 		m0.m_data = (char *)&af;
166 
167 		bpf_mtap(ifp, &m0);
168 	}
169 	ifp->if_opackets++;
170 	ifp->if_obytes += m->m_pkthdr.len;
171 
172 	switch (sc->gif_psrc->sa_family) {
173 #ifdef INET
174 	case AF_INET:
175 		error = in_gif_output(ifp, dst->sa_family, m, rt);
176 		break;
177 #endif
178 #ifdef INET6
179 	case AF_INET6:
180 		error = in6_gif_output(ifp, dst->sa_family, m, rt);
181 		break;
182 #endif
183 	default:
184 		m_freem(m);
185 		error = ENETDOWN;
186 	}
187 
188   end:
189 	called = 0;		/* reset recursion counter */
190 	if (error) ifp->if_oerrors++;
191 	return error;
192 }
193 
194 void
195 gif_input(m, af, gifp)
196 	struct mbuf *m;
197 	int af;
198 	struct ifnet *gifp;
199 {
200 	int s, isr;
201 	register struct ifqueue *ifq = 0;
202 
203 	if (gifp == NULL) {
204 		/* just in case */
205 		m_freem(m);
206 		return;
207 	}
208 
209 	if (m->m_pkthdr.rcvif)
210 		m->m_pkthdr.rcvif = gifp;
211 
212 	if (gifp->if_bpf) {
213 		/*
214 		 * We need to prepend the address family as
215 		 * a four byte field.  Cons up a dummy header
216 		 * to pacify bpf.  This is safe because bpf
217 		 * will only read from the mbuf (i.e., it won't
218 		 * try to free it or keep a pointer a to it).
219 		 */
220 		struct mbuf m0;
221 		u_int af = AF_INET6;
222 
223 		m0.m_next = m;
224 		m0.m_len = 4;
225 		m0.m_data = (char *)&af;
226 
227 		bpf_mtap(gifp, &m0);
228 	}
229 
230 	/*
231 	 * Put the packet to the network layer input queue according to the
232 	 * specified address family.
233 	 * Note: older versions of gif_input directly called network layer
234 	 * input functions, e.g. ip6_input, here. We changed the policy to
235 	 * prevent too many recursive calls of such input functions, which
236 	 * might cause kernel panic. But the change may introduce another
237 	 * problem; if the input queue is full, packets are discarded.
238 	 * We believed it rarely occurs and changed the policy. If we find
239 	 * it occurs more times than we thought, we may change the policy
240 	 * again.
241 	 */
242 	switch (af) {
243 #ifdef INET
244 	case AF_INET:
245 		ifq = &ipintrq;
246 		isr = NETISR_IP;
247 		break;
248 #endif
249 #ifdef INET6
250 	case AF_INET6:
251 		ifq = &ip6intrq;
252 		isr = NETISR_IPV6;
253 		break;
254 #endif
255 	default:
256 		m_freem(m);
257 		return;
258 	}
259 
260 	s = splimp();
261 	if (IF_QFULL(ifq)) {
262 		IF_DROP(ifq);	/* update statistics */
263 		m_freem(m);
264 		splx(s);
265 		return;
266 	}
267 	IF_ENQUEUE(ifq, m);
268 	/* we need schednetisr since the address family may change */
269 	schednetisr(isr);
270 	gifp->if_ipackets++;
271 	gifp->if_ibytes += m->m_pkthdr.len;
272 	splx(s);
273 
274 	return;
275 }
276 
277 
278 int
279 gif_ioctl(ifp, cmd, data)
280 	struct ifnet *ifp;
281 	u_long cmd;
282 	caddr_t data;
283 {
284 	struct gif_softc *sc  = (struct gif_softc*)ifp;
285 	struct ifreq     *ifr = (struct ifreq*)data;
286 	int error = 0, size;
287 	struct sockaddr *sa, *dst, *src;
288 
289 	switch (cmd) {
290 	case SIOCSIFADDR:
291 		break;
292 
293 	case SIOCSIFDSTADDR:
294 		break;
295 
296 	case SIOCADDMULTI:
297 	case SIOCDELMULTI:
298 		break;
299 
300 	case SIOCGIFMTU:
301 		break;
302 	case SIOCSIFMTU:
303 		{
304 			u_long mtu;
305 			mtu = ifr->ifr_mtu;
306 			if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX) {
307 				return (EINVAL);
308 			}
309 			ifp->if_mtu = mtu;
310 		}
311 		break;
312 
313 	case SIOCSIFPHYADDR:
314 #ifdef INET6
315 	case SIOCSIFPHYADDR_IN6:
316 #endif /* INET6 */
317 		switch (ifr->ifr_addr.sa_family) {
318 #ifdef INET
319 		case AF_INET:
320 			src = (struct sockaddr *)
321 				&(((struct in_aliasreq *)data)->ifra_addr);
322 			dst = (struct sockaddr *)
323 				&(((struct in_aliasreq *)data)->ifra_dstaddr);
324 
325 			/* only one gif can have dst = INADDR_ANY */
326 #define	satosaddr(sa) (((struct sockaddr_in *)(sa))->sin_addr.s_addr)
327 
328 			if (satosaddr(dst) == INADDR_ANY) {
329 				int i;
330 				struct gif_softc *sc2;
331 
332 			  	for (i = 0, sc2 = gif; i < ngif; i++, sc2++) {
333 					if (sc2 == sc) continue;
334 					if (sc2->gif_pdst &&
335 					    satosaddr(sc2->gif_pdst)
336 						== INADDR_ANY) {
337 					    error = EADDRNOTAVAIL;
338 					    goto bad;
339 					}
340 				}
341 			}
342 			size = sizeof(struct sockaddr_in);
343 			break;
344 #endif /* INET */
345 #ifdef INET6
346 		case AF_INET6:
347 			src = (struct sockaddr *)
348 				&(((struct in6_aliasreq *)data)->ifra_addr);
349 			dst = (struct sockaddr *)
350 				&(((struct in6_aliasreq *)data)->ifra_dstaddr);
351 
352 			/* only one gif can have dst = in6addr_any */
353 #define	satoin6(sa) (&((struct sockaddr_in6 *)(sa))->sin6_addr)
354 
355 			if (IN6_IS_ADDR_UNSPECIFIED(satoin6(dst))) {
356 				int i;
357 				struct gif_softc *sc2;
358 
359 			  	for (i = 0, sc2 = gif; i < ngif; i++, sc2++) {
360 					if (sc2 == sc) continue;
361 					if (sc2->gif_pdst &&
362 					    IN6_IS_ADDR_UNSPECIFIED(
363 						satoin6(sc2->gif_pdst)
364 								    )) {
365 					    error = EADDRNOTAVAIL;
366 					    goto bad;
367 					}
368 				}
369 			}
370 			size = sizeof(struct sockaddr_in6);
371 			break;
372 #endif /* INET6 */
373 		default:
374 			error = EPROTOTYPE;
375 			goto bad;
376 			break;
377 		}
378 		if (sc->gif_psrc != NULL)
379 			free((caddr_t)sc->gif_psrc, M_IFADDR);
380 		if (sc->gif_pdst != NULL)
381 			free((caddr_t)sc->gif_pdst, M_IFADDR);
382 
383 		sa = (struct sockaddr *)malloc(size, M_IFADDR, M_WAITOK);
384 		bzero((caddr_t)sa, size);
385 		bcopy((caddr_t)src, (caddr_t)sa, size);
386 		sc->gif_psrc = sa;
387 
388 		sa = (struct sockaddr *)malloc(size, M_IFADDR, M_WAITOK);
389 		bzero((caddr_t)sa, size);
390 		bcopy((caddr_t)dst, (caddr_t)sa, size);
391 		sc->gif_pdst = sa;
392 
393 		ifp->if_flags |= (IFF_UP|IFF_RUNNING);
394 		if_up(ifp);		/* send up RTM_IFINFO */
395 
396 		break;
397 
398 	case SIOCGIFPSRCADDR:
399 #ifdef INET6
400 	case SIOCGIFPSRCADDR_IN6:
401 #endif /* INET6 */
402 		if (sc->gif_psrc == NULL) {
403 			error = EADDRNOTAVAIL;
404 			goto bad;
405 		}
406 		src = sc->gif_psrc;
407 		switch (sc->gif_psrc->sa_family) {
408 #ifdef INET
409 		case AF_INET:
410 			dst = &ifr->ifr_addr;
411 			size = sizeof(struct sockaddr_in);
412 			break;
413 #endif /* INET */
414 #ifdef INET6
415 		case AF_INET6:
416 			dst = (struct sockaddr *)
417 				&(((struct in6_ifreq *)data)->ifr_addr);
418 			size = sizeof(struct sockaddr_in6);
419 			break;
420 #endif /* INET6 */
421 		default:
422 			error = EADDRNOTAVAIL;
423 			goto bad;
424 		}
425 		bcopy((caddr_t)src, (caddr_t)dst, size);
426 		break;
427 
428 	case SIOCGIFPDSTADDR:
429 #ifdef INET6
430 	case SIOCGIFPDSTADDR_IN6:
431 #endif /* INET6 */
432 		if (sc->gif_pdst == NULL) {
433 			error = EADDRNOTAVAIL;
434 			goto bad;
435 		}
436 		src = sc->gif_pdst;
437 		switch (sc->gif_pdst->sa_family) {
438 #ifdef INET
439 		case AF_INET:
440 			dst = &ifr->ifr_addr;
441 			size = sizeof(struct sockaddr_in);
442 			break;
443 #endif /* INET */
444 #ifdef INET6
445 		case AF_INET6:
446 			dst = (struct sockaddr *)
447 				&(((struct in6_ifreq *)data)->ifr_addr);
448 			size = sizeof(struct sockaddr_in6);
449 			break;
450 #endif /* INET6 */
451 		default:
452 			error = EADDRNOTAVAIL;
453 			goto bad;
454 		}
455 		bcopy((caddr_t)src, (caddr_t)dst, size);
456 		break;
457 
458 	case SIOCSIFFLAGS:
459 		break;
460 
461 	default:
462 		error = EINVAL;
463 		break;
464 	}
465  bad:
466 	return error;
467 }
468 #endif /*NGIF > 0*/
469