xref: /netbsd-src/sys/net/if_srt.c (revision 3816d47b2c42fcd6e549e3407f842a5b1a1d23ad)
1 /* $NetBSD: if_srt.c,v 1.12 2009/12/09 00:44:26 dyoung Exp $ */
2 /* This file is in the public domain. */
3 
4 #include <sys/cdefs.h>
5 __KERNEL_RCSID(0, "$NetBSD: if_srt.c,v 1.12 2009/12/09 00:44:26 dyoung Exp $");
6 
7 #include "opt_inet.h"
8 
9 #if !defined(INET) && !defined(INET6)
10 #error "srt without INET/INET6?"
11 #endif
12 
13 #ifndef SRT_MAXUNIT
14 #define SRT_MAXUNIT 255
15 #endif
16 
17 /* include-file bug workarounds */
18 #include <sys/types.h>		/* sys/conf.h */
19 #include <sys/resource.h>	/* sys/resourcevar.h
20 				 * (uvm/uvm_param.h, sys/mbuf.h)
21 				 */
22 #include <netinet/in.h>		/* netinet/ip.h */
23 #include <sys/param.h>		/* sys/mbuf.h */
24 #include <netinet/in_systm.h>	/* netinet/ip.h */
25 
26 #include <sys/conf.h>
27 #include <sys/mbuf.h>
28 #include <sys/errno.h>
29 #include <sys/fcntl.h>
30 #include <sys/param.h>
31 #include <sys/ioctl.h>
32 #include <netinet/ip.h>
33 #include <netinet/ip6.h>
34 #include <net/if_types.h>
35 #include <machine/stdarg.h>
36 
37 #include "if_srt.h"
38 #include "bpfilter.h"
39 
40 /* until we know what to pass to bpfattach.... */
41 #undef NBPFILTER
42 #define NBPFILTER 0
43 
44 struct srt_softc {
45 	struct ifnet intf;	/* XXX interface botch */
46 	int unit;
47 	int nrt;
48 	struct srt_rt **rts;
49 	unsigned int flags;	/* SSF_* values from if_srt.h */
50 #define SSF_UCHG (SSF_MTULOCK) /* userland-changeable bits */
51 	unsigned int kflags;	/* bits private to this file */
52 #define SKF_CDEVOPEN 0x00000001
53 };
54 
55 void srtattach(void);
56 
57 static struct srt_softc *softcv[SRT_MAXUNIT+1];
58 static unsigned int global_flags;
59 
60 /* Internal routines. */
61 
62 static unsigned int ipv4_masks[33] = {
63 	0x00000000, /* /0 */
64 	0x80000000, 0xc0000000, 0xe0000000, 0xf0000000, /* /1 - /4 */
65 	0xf8000000, 0xfc000000, 0xfe000000, 0xff000000, /* /5 - /8 */
66 	0xff800000, 0xffc00000, 0xffe00000, 0xfff00000, /* /9 - /12 */
67 	0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000, /* /13 - /16 */
68 	0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000, /* /17 - /20 */
69 	0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00, /* /21 - /24 */
70 	0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0, /* /25 - /28 */
71 	0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff  /* /29 - /32 */
72 };
73 
74 static void
75 update_mtu(struct srt_softc *sc)
76 {
77 	int mtu;
78 	int i;
79 	struct srt_rt *r;
80 
81 	if (sc->flags & SSF_MTULOCK)
82 		return;
83 	mtu = 65535;
84 	for (i=sc->nrt-1;i>=0;i--) {
85 		r = sc->rts[i];
86 		if (r->u.dstifp->if_mtu < mtu)
87 			mtu = r->u.dstifp->if_mtu;
88 	}
89 	sc->intf.if_mtu = mtu;
90 }
91 
92 static struct srt_rt *
93 find_rt(struct srt_softc *sc, int af, ...)
94 {
95 	int i;
96 	struct srt_rt *r;
97 	struct in_addr ia;
98 	struct in6_addr ia6;
99 	va_list ap;
100 
101 	ia.s_addr = 0; ia6.s6_addr[0] = 0; /* shut up incorrect -Wuninitialized */
102 	va_start(ap,af);
103 	switch (af) {
104 	case AF_INET:
105 		ia = va_arg(ap,struct in_addr);
106 		break;
107 	case AF_INET6:
108 		ia6 = va_arg(ap,struct in6_addr);
109 		break;
110 	default:
111 		panic("if_srt find_rt: impossible address family");
112 		break;
113 	}
114 	va_end(ap);
115 	for (i=0;i<sc->nrt;i++) {
116 		r = sc->rts[i];
117 		if (r->af != af)
118 			continue;
119 		switch (af) {
120 		case AF_INET:
121 			if ((ia.s_addr & ipv4_masks[r->srcmask]) ==
122 			    r->srcmatch.v4.s_addr)
123 				return r;
124 			break;
125 		case AF_INET6:
126 			if ((r->srcmask >= 8) &&
127 			    memcmp(&ia6,&r->srcmatch.v6,r->srcmask / 8) != 0)
128 				continue;
129 			if ((r->srcmask % 8) &&
130 			    ((ia6.s6_addr[r->srcmask / 8] ^
131 			     r->srcmatch.v6.s6_addr[r->srcmask / 8]) &
132 			     0xff & (0xff00 >> (r->srcmask % 8))))
133 				continue;
134 			return r;
135 		default:
136 			panic("if_srt find_rt: impossible address family 2");
137 			break;
138 		}
139 	}
140 	return 0;
141 }
142 
143 /* Network device interface. */
144 
145 static int
146 srt_if_ioctl(struct ifnet *ifp, u_long cmd, void *data)
147 {
148 	struct ifaddr *ifa;
149 	int s;
150 	int err;
151 
152 	err = 0;
153 	s = splnet();
154 	switch (cmd) {
155 	case SIOCINITIFADDR:
156 	case SIOCSIFDSTADDR:
157 		ifa = (void *) data;
158 		switch (ifa->ifa_addr->sa_family) {
159 #ifdef INET
160 		case AF_INET:
161 			break;
162 #endif
163 #ifdef INET6
164 		case AF_INET6:
165 			break;
166 #endif
167 		default:
168 			err = EAFNOSUPPORT;
169 			break;
170 		}
171 		/* XXX do we need to do more here for either of these? */
172 		break;
173 	default:
174 		if ((err = ifioctl_common(ifp, cmd, data)) == ENETRESET)
175 			err = 0;
176 		break;
177 	}
178 	splx(s);
179 	return err;
180 }
181 
182 static int
183 srt_if_output(
184 	struct ifnet *ifp,
185 	struct mbuf *m,
186 	const struct sockaddr *to,
187 	struct rtentry *rtp)
188 {
189 	struct srt_softc *sc;
190 	struct srt_rt *r;
191 
192 	sc = ifp->if_softc;
193 	if (! (ifp->if_flags & IFF_UP)) {
194 		m_freem(m);
195 		return ENETDOWN;
196 	}
197 	switch (to->sa_family) {
198 #ifdef INET
199 	case AF_INET: {
200 		struct ip *ip;
201 		ip = mtod(m,struct ip *);
202 		r = find_rt(sc,AF_INET,ip->ip_src);
203 		break;
204 	}
205 #endif
206 #ifdef INET6
207 	case AF_INET6: {
208 		struct ip6_hdr *ip;
209 		ip = mtod(m,struct ip6_hdr *);
210 		r = find_rt(sc,AF_INET6,ip->ip6_src);
211 		break;
212 	}
213 #endif
214 	default:
215 		IF_DROP(&ifp->if_snd);
216 		m_freem(m);
217 		return EAFNOSUPPORT;
218 	}
219 	/* XXX Do we need to bpf_tap?  Or do higher layers now handle that? */
220 	/* if_gif.c seems to imply the latter. */
221 	ifp->if_opackets ++;
222 	if (! r) {
223 		ifp->if_oerrors ++;
224 		m_freem(m);
225 		return 0;
226 	}
227 	if (! (m->m_flags & M_PKTHDR)) {
228 		printf("srt_if_output no PKTHDR\n");
229 		m_freem(m);
230 		return 0;
231 	}
232 	ifp->if_obytes += m->m_pkthdr.len;
233 	if (! (r->u.dstifp->if_flags & IFF_UP)) {
234 		m_freem(m);
235 		return 0; /* XXX ENETDOWN? */
236 	}
237 	/* XXX is 0 the right last arg here? */
238 	return (*r->u.dstifp->if_output)(r->u.dstifp,m,&r->dst.sa,0);
239 }
240 
241 static int
242 srt_clone_create(struct if_clone *cl, int unit)
243 {
244 	struct srt_softc *sc;
245 
246 	if (unit < 0 || unit > SRT_MAXUNIT)
247 		return ENXIO;
248 	if (softcv[unit])
249 		return EBUSY;
250 	sc = malloc(sizeof(struct srt_softc), M_DEVBUF, M_WAITOK|M_ZERO);
251 	sc->unit = unit;
252 	sc->nrt = 0;
253 	sc->rts = 0;
254 	sc->flags = 0;
255 	sc->kflags = 0;
256 	if_initname(&sc->intf,cl->ifc_name,unit);
257 	sc->intf.if_softc = sc;
258 	sc->intf.if_mtu = 65535;
259 	sc->intf.if_flags = IFF_POINTOPOINT;
260 	sc->intf.if_type = IFT_OTHER;
261 	sc->intf.if_ioctl = &srt_if_ioctl;
262 	sc->intf.if_output = &srt_if_output;
263 	sc->intf.if_dlt = DLT_RAW;
264 	if_attach(&sc->intf);
265 	if_alloc_sadl(&sc->intf);
266 #if NBPFILTER > 0 /* see comment near top */
267 	bpfattach(&sc->intf,0/*???*/,0/*???*/);
268 #endif
269 	softcv[unit] = sc;
270 	return 0;
271 }
272 
273 static int
274 srt_clone_destroy(struct ifnet *ifp)
275 {
276 	struct srt_softc *sc;
277 
278 	sc = ifp->if_softc;
279 	if ((ifp->if_flags & IFF_UP) || (sc->kflags & SKF_CDEVOPEN))
280 		return EBUSY;
281 #if NBPFILTER > 0
282 	bpfdetach(ifp);
283 #endif
284 	if_detach(ifp);
285 	if (sc->unit < 0 || sc->unit > SRT_MAXUNIT) {
286 		panic("srt_clone_destroy: impossible unit %d\n",sc->unit);
287 	}
288 	if (softcv[sc->unit] != sc) {
289 		panic("srt_clone_destroy: bad backpointer ([%d]=%p not %p)\n",
290 		sc->unit,(void *)softcv[sc->unit],(void *)sc);
291 	}
292 	softcv[sc->unit] = 0;
293 	free(sc,M_DEVBUF);
294 	return 0;
295 }
296 
297 struct if_clone srt_clone =
298     IF_CLONE_INITIALIZER("srt",&srt_clone_create,&srt_clone_destroy);
299 
300 void
301 srtattach(void)
302 {
303 	int i;
304 
305 	for (i=SRT_MAXUNIT;i>=0;i--)
306 		softcv[i] = 0;
307 	global_flags = 0;
308 	if_clone_attach(&srt_clone);
309 }
310 
311 /* Special-device interface. */
312 
313 static int
314 srt_open(dev_t dev, int flag, int mode, struct lwp *l)
315 {
316 	int unit;
317 	struct srt_softc *sc;
318 
319 	unit = minor(dev);
320 	if (unit < 0 || unit > SRT_MAXUNIT)
321 		return ENXIO;
322 	sc = softcv[unit];
323 	if (! sc)
324 		return ENXIO;
325 	sc->kflags |= SKF_CDEVOPEN;
326 	return 0;
327 }
328 
329 static int
330 srt_close(dev_t dev, int flag, int mode, struct lwp *l)
331 {
332 	int unit;
333 	struct srt_softc *sc;
334 
335 	unit = minor(dev);
336 	if (unit < 0 || unit > SRT_MAXUNIT)
337 		return ENXIO;
338 	sc = softcv[unit];
339 	if (! sc)
340 		return ENXIO;
341 	sc->kflags &= ~SKF_CDEVOPEN;
342 	return 0;
343 }
344 
345 static int
346 srt_ioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
347 {
348 	unsigned int f, i, n, o;
349 	struct srt_softc *sc;
350 	struct srt_rt *dr;
351 	struct srt_rt *scr;
352 	struct ifnet *ifp;
353 	char nbuf[IFNAMSIZ];
354 
355 	sc = softcv[minor(dev)];
356 	if (! sc)
357 		panic("srt_ioctl: softc disappeared");
358 	switch (cmd) {
359 	case SRT_GETNRT:
360 		if (! (flag & FREAD))
361 			return EBADF;
362 		*(unsigned int *)data = sc->nrt;
363 		return 0;
364 	case SRT_GETRT:
365 		if (! (flag & FREAD))
366 			return EBADF;
367 		dr = (struct srt_rt *) data;
368 		if (dr->inx >= sc->nrt)
369 			return EDOM;
370 		scr = sc->rts[dr->inx];
371 		dr->af = scr->af;
372 		dr->srcmatch = scr->srcmatch;
373 		dr->srcmask = scr->srcmask;
374 		strncpy(&dr->u.dstifn[0],&scr->u.dstifp->if_xname[0],IFNAMSIZ);
375 		memcpy(&dr->dst,&scr->dst,scr->dst.sa.sa_len);
376 		return 0;
377 	case SRT_SETRT:
378 		if (! (flag & FWRITE))
379 			return EBADF;
380 		dr = (struct srt_rt *) data;
381 		if (dr->inx > sc->nrt)
382 			return EDOM;
383 		strncpy(&nbuf[0],&dr->u.dstifn[0],IFNAMSIZ);
384 		nbuf[IFNAMSIZ-1] = '\0';
385 		if (dr->dst.sa.sa_family != dr->af)
386 			return EIO;
387 		switch (dr->af) {
388 #ifdef INET
389 		case AF_INET:
390 			if (dr->dst.sa.sa_len != sizeof(dr->dst.sin))
391 				return EIO;
392 			if (dr->srcmask > 32)
393 				return EIO;
394 		break;
395 #endif
396 #ifdef INET6
397 		case AF_INET6:
398 			if (dr->dst.sa.sa_len != sizeof(dr->dst.sin6))
399 				return EIO;
400 			if (dr->srcmask > 128)
401 				return EIO;
402 		break;
403 #endif
404 		default:
405 			return EAFNOSUPPORT;
406 		}
407 		ifp = ifunit(&nbuf[0]);
408 		if (ifp == 0)
409 			return ENXIO; /* needs translation */
410 		if (dr->inx == sc->nrt) {
411 			struct srt_rt **tmp;
412 			tmp = malloc((sc->nrt+1)*sizeof(*tmp), M_DEVBUF,
413 			    M_WAITOK);
414 			if (tmp == 0)
415 				return ENOBUFS;
416 			tmp[sc->nrt] = 0;
417 			if (sc->nrt > 0) {
418 				memcpy(tmp, sc->rts, sc->nrt*sizeof(*tmp));
419 				free(sc->rts, M_DEVBUF);
420 			}
421 			sc->rts = tmp;
422 			sc->nrt ++;
423 		}
424 		scr = sc->rts[dr->inx];
425 		if (scr == 0) {
426 			scr = malloc(sizeof(struct srt_rt),M_DEVBUF,M_WAITOK);
427 			if (scr == 0)
428 				return ENOBUFS;
429 			scr->inx = dr->inx;
430 			scr->af = AF_UNSPEC;
431 			sc->rts[dr->inx] = scr;
432 		}
433 		scr->af = dr->af;
434 		scr->srcmatch = dr->srcmatch;
435 		scr->srcmask = dr->srcmask;
436 		scr->u.dstifp = ifp;
437 		memcpy(&scr->dst,&dr->dst,dr->dst.sa.sa_len);
438 		update_mtu(sc);
439 		return 0;
440 	case SRT_DELRT:
441 		if (! (flag & FWRITE))
442 			return EBADF;
443 		i = *(unsigned int *)data;
444 		if (i >= sc->nrt)
445 			return EDOM;
446 		scr = sc->rts[i];
447 		sc->rts[i] = 0;
448 		free(scr, M_DEVBUF);
449 		sc->nrt--;
450 		if (i < sc->nrt) {
451 			memcpy(sc->rts+i, sc->rts+i+1,
452 			    (sc->nrt-i)*sizeof(*sc->rts));
453 		}
454 		if (sc->nrt == 0) {
455 			free(sc->rts, M_DEVBUF);
456 			sc->rts = 0;
457 			sc->intf.if_flags &= ~IFF_UP;
458 		}
459 		update_mtu(sc);
460 		return 0;
461 	case SRT_SFLAGS:
462 		if (! (flag & FWRITE))
463 			return EBADF;
464 		f = *(unsigned int *)data & SSF_UCHG;
465 		global_flags = (global_flags & ~SSF_UCHG) | (f & SSF_GLOBAL);
466 		sc->flags = (sc->flags & ~SSF_UCHG) | (f & ~SSF_GLOBAL);
467 		return 0;
468 	case SRT_GFLAGS:
469 		if (! (flag & FREAD))
470 			return EBADF;
471 		*(unsigned int *)data = sc->flags | global_flags;
472 		return 0;
473 	case SRT_SGFLAGS:
474 		if ((flag & (FWRITE|FREAD)) != (FWRITE|FREAD))
475 			return EBADF;
476 		o = sc->flags | global_flags;
477 		n = *(unsigned int *)data & SSF_UCHG;
478 		global_flags = (global_flags & ~SSF_UCHG) | (n & SSF_GLOBAL);
479 		sc->flags = (sc->flags & ~SSF_UCHG) | (n & ~SSF_GLOBAL);
480 		*(unsigned int *)data = o;
481 		return 0;
482 	case SRT_DEBUG:
483 		return 0;
484 		break;
485 	}
486 	return ENOTTY;
487 }
488 
489 const struct cdevsw srt_cdevsw = {
490 	&srt_open,
491 	&srt_close,
492 	nullread,
493 	nullwrite,
494 	&srt_ioctl,
495 	nullstop,
496 	notty,
497 	nullpoll,
498 	nommap,
499 	nullkqfilter,
500 	D_OTHER
501 };
502