xref: /netbsd-src/sys/net/if_srt.c (revision ca453df649ce9db45b64d73678ba06cbccf9aa11)
1 /* $NetBSD: if_srt.c,v 1.16 2011/07/17 20:54:52 joerg Exp $ */
2 /* This file is in the public domain. */
3 
4 #include <sys/cdefs.h>
5 __KERNEL_RCSID(0, "$NetBSD: if_srt.c,v 1.16 2011/07/17 20:54:52 joerg 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 
36 #include "if_srt.h"
37 
38 /* until we know what to pass to bpfattach.... */
39 /* #define BPFILTER_NOW_AVAILABLE */
40 
41 struct srt_softc {
42 	struct ifnet intf;	/* XXX interface botch */
43 	int unit;
44 	int nrt;
45 	struct srt_rt **rts;
46 	unsigned int flags;	/* SSF_* values from if_srt.h */
47 #define SSF_UCHG (SSF_MTULOCK) /* userland-changeable bits */
48 	unsigned int kflags;	/* bits private to this file */
49 #define SKF_CDEVOPEN 0x00000001
50 };
51 
52 void srtattach(void);
53 
54 static struct srt_softc *softcv[SRT_MAXUNIT+1];
55 static unsigned int global_flags;
56 
57 /* Internal routines. */
58 
59 static unsigned int ipv4_masks[33] = {
60 	0x00000000, /* /0 */
61 	0x80000000, 0xc0000000, 0xe0000000, 0xf0000000, /* /1 - /4 */
62 	0xf8000000, 0xfc000000, 0xfe000000, 0xff000000, /* /5 - /8 */
63 	0xff800000, 0xffc00000, 0xffe00000, 0xfff00000, /* /9 - /12 */
64 	0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000, /* /13 - /16 */
65 	0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000, /* /17 - /20 */
66 	0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00, /* /21 - /24 */
67 	0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0, /* /25 - /28 */
68 	0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff  /* /29 - /32 */
69 };
70 
71 static void
72 update_mtu(struct srt_softc *sc)
73 {
74 	int mtu;
75 	int i;
76 	struct srt_rt *r;
77 
78 	if (sc->flags & SSF_MTULOCK)
79 		return;
80 	mtu = 65535;
81 	for (i=sc->nrt-1;i>=0;i--) {
82 		r = sc->rts[i];
83 		if (r->u.dstifp->if_mtu < mtu)
84 			mtu = r->u.dstifp->if_mtu;
85 	}
86 	sc->intf.if_mtu = mtu;
87 }
88 
89 static struct srt_rt *
90 find_rt(struct srt_softc *sc, int af, ...)
91 {
92 	int i;
93 	struct srt_rt *r;
94 	struct in_addr ia;
95 	struct in6_addr ia6;
96 	va_list ap;
97 
98 	ia.s_addr = 0; ia6.s6_addr[0] = 0; /* shut up incorrect -Wuninitialized */
99 	va_start(ap,af);
100 	switch (af) {
101 	case AF_INET:
102 		ia = va_arg(ap,struct in_addr);
103 		break;
104 	case AF_INET6:
105 		ia6 = va_arg(ap,struct in6_addr);
106 		break;
107 	default:
108 		panic("if_srt find_rt: impossible address family");
109 		break;
110 	}
111 	va_end(ap);
112 	for (i=0; i < sc->nrt; i++) {
113 		r = sc->rts[i];
114 		if (r->af != af)
115 			continue;
116 		switch (af) {
117 		case AF_INET:
118 			if ((ia.s_addr & htonl(ipv4_masks[r->srcmask])) ==
119 			    r->srcmatch.v4.s_addr)
120 				return r;
121 			break;
122 		case AF_INET6:
123 			if ((r->srcmask >= 8) &&
124 			    memcmp(&ia6,&r->srcmatch.v6,r->srcmask / 8) != 0)
125 				continue;
126 			if ((r->srcmask % 8) &&
127 			    ((ia6.s6_addr[r->srcmask / 8] ^
128 			     r->srcmatch.v6.s6_addr[r->srcmask / 8]) &
129 			     0xff & (0xff00 >> (r->srcmask % 8))))
130 				continue;
131 			return r;
132 		default:
133 			panic("if_srt find_rt: impossible address family 2");
134 			break;
135 		}
136 	}
137 	return 0;
138 }
139 
140 /* Network device interface. */
141 
142 static int
143 srt_if_ioctl(struct ifnet *ifp, u_long cmd, void *data)
144 {
145 	struct ifaddr *ifa;
146 	int s;
147 	int err;
148 
149 	err = 0;
150 	s = splnet();
151 	switch (cmd) {
152 	case SIOCINITIFADDR:
153 	case SIOCSIFDSTADDR:
154 		ifa = (void *) data;
155 		switch (ifa->ifa_addr->sa_family) {
156 #ifdef INET
157 		case AF_INET:
158 			break;
159 #endif
160 #ifdef INET6
161 		case AF_INET6:
162 			break;
163 #endif
164 		default:
165 			err = EAFNOSUPPORT;
166 			break;
167 		}
168 		/* XXX do we need to do more here for either of these? */
169 		break;
170 	default:
171 		if ((err = ifioctl_common(ifp, cmd, data)) == ENETRESET)
172 			err = 0;
173 		break;
174 	}
175 	splx(s);
176 	return err;
177 }
178 
179 static int
180 srt_if_output(
181 	struct ifnet *ifp,
182 	struct mbuf *m,
183 	const struct sockaddr *to,
184 	struct rtentry *rtp)
185 {
186 	struct srt_softc *sc;
187 	struct srt_rt *r;
188 
189 	sc = ifp->if_softc;
190 	if (! (ifp->if_flags & IFF_UP)) {
191 		m_freem(m);
192 		return ENETDOWN;
193 	}
194 	switch (to->sa_family) {
195 #ifdef INET
196 	case AF_INET: {
197 		struct ip *ip;
198 		ip = mtod(m,struct ip *);
199 		r = find_rt(sc,AF_INET,ip->ip_src);
200 		break;
201 	}
202 #endif
203 #ifdef INET6
204 	case AF_INET6: {
205 		struct ip6_hdr *ip;
206 		ip = mtod(m,struct ip6_hdr *);
207 		r = find_rt(sc,AF_INET6,ip->ip6_src);
208 		break;
209 	}
210 #endif
211 	default:
212 		IF_DROP(&ifp->if_snd);
213 		m_freem(m);
214 		return EAFNOSUPPORT;
215 	}
216 	/* XXX Do we need to bpf_tap?  Or do higher layers now handle that? */
217 	/* if_gif.c seems to imply the latter. */
218 	ifp->if_opackets ++;
219 	if (! r) {
220 		ifp->if_oerrors ++;
221 		m_freem(m);
222 		return 0;
223 	}
224 	if (! (m->m_flags & M_PKTHDR)) {
225 		printf("srt_if_output no PKTHDR\n");
226 		m_freem(m);
227 		return 0;
228 	}
229 	ifp->if_obytes += m->m_pkthdr.len;
230 	if (! (r->u.dstifp->if_flags & IFF_UP)) {
231 		m_freem(m);
232 		return 0; /* XXX ENETDOWN? */
233 	}
234 	/* XXX is 0 the right last arg here? */
235 	return (*r->u.dstifp->if_output)(r->u.dstifp,m,&r->dst.sa,0);
236 }
237 
238 static int
239 srt_clone_create(struct if_clone *cl, int unit)
240 {
241 	struct srt_softc *sc;
242 
243 	if (unit < 0 || unit > SRT_MAXUNIT)
244 		return ENXIO;
245 	if (softcv[unit])
246 		return EBUSY;
247 	sc = malloc(sizeof(struct srt_softc), M_DEVBUF, M_WAITOK|M_ZERO);
248 	sc->unit = unit;
249 	sc->nrt = 0;
250 	sc->rts = 0;
251 	sc->flags = 0;
252 	sc->kflags = 0;
253 	if_initname(&sc->intf,cl->ifc_name,unit);
254 	sc->intf.if_softc = sc;
255 	sc->intf.if_mtu = 65535;
256 	sc->intf.if_flags = IFF_POINTOPOINT;
257 	sc->intf.if_type = IFT_OTHER;
258 	sc->intf.if_ioctl = &srt_if_ioctl;
259 	sc->intf.if_output = &srt_if_output;
260 	sc->intf.if_dlt = DLT_RAW;
261 	if_attach(&sc->intf);
262 	if_alloc_sadl(&sc->intf);
263 #ifdef BPFILTER_NOW_AVAILABLE
264 	bpf_attach(&sc->intf, 0, 0);
265 #endif
266 	softcv[unit] = sc;
267 	return 0;
268 }
269 
270 static int
271 srt_clone_destroy(struct ifnet *ifp)
272 {
273 	struct srt_softc *sc;
274 
275 	sc = ifp->if_softc;
276 	if ((ifp->if_flags & IFF_UP) || (sc->kflags & SKF_CDEVOPEN))
277 		return EBUSY;
278 #ifdef BPFILTER_NOW_AVAILABLE
279 	bpf_detach(ifp);
280 #endif
281 	if_detach(ifp);
282 	if (sc->unit < 0 || sc->unit > SRT_MAXUNIT) {
283 		panic("srt_clone_destroy: impossible unit %d\n",sc->unit);
284 	}
285 	if (softcv[sc->unit] != sc) {
286 		panic("srt_clone_destroy: bad backpointer ([%d]=%p not %p)\n",
287 		sc->unit,(void *)softcv[sc->unit],(void *)sc);
288 	}
289 	softcv[sc->unit] = 0;
290 	free(sc,M_DEVBUF);
291 	return 0;
292 }
293 
294 struct if_clone srt_clone =
295     IF_CLONE_INITIALIZER("srt",&srt_clone_create,&srt_clone_destroy);
296 
297 void
298 srtattach(void)
299 {
300 	int i;
301 
302 	for (i=SRT_MAXUNIT;i>=0;i--)
303 		softcv[i] = 0;
304 	global_flags = 0;
305 	if_clone_attach(&srt_clone);
306 }
307 
308 /* Special-device interface. */
309 
310 static int
311 srt_open(dev_t dev, int flag, int mode, struct lwp *l)
312 {
313 	int unit;
314 	struct srt_softc *sc;
315 
316 	unit = minor(dev);
317 	if (unit < 0 || unit > SRT_MAXUNIT)
318 		return ENXIO;
319 	sc = softcv[unit];
320 	if (! sc)
321 		return ENXIO;
322 	sc->kflags |= SKF_CDEVOPEN;
323 	return 0;
324 }
325 
326 static int
327 srt_close(dev_t dev, int flag, int mode, struct lwp *l)
328 {
329 	int unit;
330 	struct srt_softc *sc;
331 
332 	unit = minor(dev);
333 	if (unit < 0 || unit > SRT_MAXUNIT)
334 		return ENXIO;
335 	sc = softcv[unit];
336 	if (! sc)
337 		return ENXIO;
338 	sc->kflags &= ~SKF_CDEVOPEN;
339 	return 0;
340 }
341 
342 static int
343 srt_ioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
344 {
345 	unsigned int f, i, n, o;
346 	struct srt_softc *sc;
347 	struct srt_rt *dr;
348 	struct srt_rt *scr;
349 	struct ifnet *ifp;
350 	char nbuf[IFNAMSIZ];
351 
352 	sc = softcv[minor(dev)];
353 	if (! sc)
354 		panic("srt_ioctl: softc disappeared");
355 	switch (cmd) {
356 	case SRT_GETNRT:
357 		if (! (flag & FREAD))
358 			return EBADF;
359 		*(unsigned int *)data = sc->nrt;
360 		return 0;
361 	case SRT_GETRT:
362 		if (! (flag & FREAD))
363 			return EBADF;
364 		dr = (struct srt_rt *) data;
365 		if (dr->inx >= sc->nrt)
366 			return EDOM;
367 		scr = sc->rts[dr->inx];
368 		dr->af = scr->af;
369 		dr->srcmatch = scr->srcmatch;
370 		dr->srcmask = scr->srcmask;
371 		strncpy(&dr->u.dstifn[0],&scr->u.dstifp->if_xname[0],IFNAMSIZ);
372 		memcpy(&dr->dst,&scr->dst,scr->dst.sa.sa_len);
373 		return 0;
374 	case SRT_SETRT:
375 		if (! (flag & FWRITE))
376 			return EBADF;
377 		dr = (struct srt_rt *) data;
378 		if (dr->inx > sc->nrt)
379 			return EDOM;
380 		strncpy(&nbuf[0],&dr->u.dstifn[0],IFNAMSIZ);
381 		nbuf[IFNAMSIZ-1] = '\0';
382 		if (dr->dst.sa.sa_family != dr->af)
383 			return EIO;
384 		switch (dr->af) {
385 #ifdef INET
386 		case AF_INET:
387 			if (dr->dst.sa.sa_len != sizeof(dr->dst.sin))
388 				return EIO;
389 			if (dr->srcmask > 32)
390 				return EIO;
391 		break;
392 #endif
393 #ifdef INET6
394 		case AF_INET6:
395 			if (dr->dst.sa.sa_len != sizeof(dr->dst.sin6))
396 				return EIO;
397 			if (dr->srcmask > 128)
398 				return EIO;
399 		break;
400 #endif
401 		default:
402 			return EAFNOSUPPORT;
403 		}
404 		ifp = ifunit(&nbuf[0]);
405 		if (ifp == 0)
406 			return ENXIO; /* needs translation */
407 		if (dr->inx == sc->nrt) {
408 			struct srt_rt **tmp;
409 			tmp = malloc((sc->nrt+1)*sizeof(*tmp), M_DEVBUF,
410 			    M_WAITOK);
411 			if (tmp == 0)
412 				return ENOBUFS;
413 			tmp[sc->nrt] = 0;
414 			if (sc->nrt > 0) {
415 				memcpy(tmp, sc->rts, sc->nrt*sizeof(*tmp));
416 				free(sc->rts, M_DEVBUF);
417 			}
418 			sc->rts = tmp;
419 			sc->nrt ++;
420 		}
421 		scr = sc->rts[dr->inx];
422 		if (scr == 0) {
423 			scr = malloc(sizeof(struct srt_rt),M_DEVBUF,M_WAITOK);
424 			if (scr == 0)
425 				return ENOBUFS;
426 			scr->inx = dr->inx;
427 			scr->af = AF_UNSPEC;
428 			sc->rts[dr->inx] = scr;
429 		}
430 		scr->af = dr->af;
431 		scr->srcmatch = dr->srcmatch;
432 		scr->srcmask = dr->srcmask;
433 		scr->u.dstifp = ifp;
434 		memcpy(&scr->dst,&dr->dst,dr->dst.sa.sa_len);
435 		update_mtu(sc);
436 		return 0;
437 	case SRT_DELRT:
438 		if (! (flag & FWRITE))
439 			return EBADF;
440 		i = *(unsigned int *)data;
441 		if (i >= sc->nrt)
442 			return EDOM;
443 		scr = sc->rts[i];
444 		sc->rts[i] = 0;
445 		free(scr, M_DEVBUF);
446 		sc->nrt--;
447 		if (i < sc->nrt) {
448 			memcpy(sc->rts+i, sc->rts+i+1,
449 			    (sc->nrt-i)*sizeof(*sc->rts));
450 		}
451 		if (sc->nrt == 0) {
452 			free(sc->rts, M_DEVBUF);
453 			sc->rts = 0;
454 			sc->intf.if_flags &= ~IFF_UP;
455 		}
456 		update_mtu(sc);
457 		return 0;
458 	case SRT_SFLAGS:
459 		if (! (flag & FWRITE))
460 			return EBADF;
461 		f = *(unsigned int *)data & SSF_UCHG;
462 		global_flags = (global_flags & ~SSF_UCHG) | (f & SSF_GLOBAL);
463 		sc->flags = (sc->flags & ~SSF_UCHG) | (f & ~SSF_GLOBAL);
464 		return 0;
465 	case SRT_GFLAGS:
466 		if (! (flag & FREAD))
467 			return EBADF;
468 		*(unsigned int *)data = sc->flags | global_flags;
469 		return 0;
470 	case SRT_SGFLAGS:
471 		if ((flag & (FWRITE|FREAD)) != (FWRITE|FREAD))
472 			return EBADF;
473 		o = sc->flags | global_flags;
474 		n = *(unsigned int *)data & SSF_UCHG;
475 		global_flags = (global_flags & ~SSF_UCHG) | (n & SSF_GLOBAL);
476 		sc->flags = (sc->flags & ~SSF_UCHG) | (n & ~SSF_GLOBAL);
477 		*(unsigned int *)data = o;
478 		return 0;
479 	case SRT_DEBUG:
480 		return 0;
481 		break;
482 	}
483 	return ENOTTY;
484 }
485 
486 const struct cdevsw srt_cdevsw = {
487 	&srt_open,
488 	&srt_close,
489 	nullread,
490 	nullwrite,
491 	&srt_ioctl,
492 	nullstop,
493 	notty,
494 	nullpoll,
495 	nommap,
496 	nullkqfilter,
497 	D_OTHER
498 };
499