xref: /netbsd-src/sys/net/if_srt.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /* $NetBSD: if_srt.c,v 1.15 2010/09/09 03:24:57 tls Exp $ */
2 /* This file is in the public domain. */
3 
4 #include <sys/cdefs.h>
5 __KERNEL_RCSID(0, "$NetBSD: if_srt.c,v 1.15 2010/09/09 03:24:57 tls 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 
39 /* until we know what to pass to bpfattach.... */
40 /* #define BPFILTER_NOW_AVAILABLE */
41 
42 struct srt_softc {
43 	struct ifnet intf;	/* XXX interface botch */
44 	int unit;
45 	int nrt;
46 	struct srt_rt **rts;
47 	unsigned int flags;	/* SSF_* values from if_srt.h */
48 #define SSF_UCHG (SSF_MTULOCK) /* userland-changeable bits */
49 	unsigned int kflags;	/* bits private to this file */
50 #define SKF_CDEVOPEN 0x00000001
51 };
52 
53 void srtattach(void);
54 
55 static struct srt_softc *softcv[SRT_MAXUNIT+1];
56 static unsigned int global_flags;
57 
58 /* Internal routines. */
59 
60 static unsigned int ipv4_masks[33] = {
61 	0x00000000, /* /0 */
62 	0x80000000, 0xc0000000, 0xe0000000, 0xf0000000, /* /1 - /4 */
63 	0xf8000000, 0xfc000000, 0xfe000000, 0xff000000, /* /5 - /8 */
64 	0xff800000, 0xffc00000, 0xffe00000, 0xfff00000, /* /9 - /12 */
65 	0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000, /* /13 - /16 */
66 	0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000, /* /17 - /20 */
67 	0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00, /* /21 - /24 */
68 	0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0, /* /25 - /28 */
69 	0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff  /* /29 - /32 */
70 };
71 
72 static void
73 update_mtu(struct srt_softc *sc)
74 {
75 	int mtu;
76 	int i;
77 	struct srt_rt *r;
78 
79 	if (sc->flags & SSF_MTULOCK)
80 		return;
81 	mtu = 65535;
82 	for (i=sc->nrt-1;i>=0;i--) {
83 		r = sc->rts[i];
84 		if (r->u.dstifp->if_mtu < mtu)
85 			mtu = r->u.dstifp->if_mtu;
86 	}
87 	sc->intf.if_mtu = mtu;
88 }
89 
90 static struct srt_rt *
91 find_rt(struct srt_softc *sc, int af, ...)
92 {
93 	int i;
94 	struct srt_rt *r;
95 	struct in_addr ia;
96 	struct in6_addr ia6;
97 	va_list ap;
98 
99 	ia.s_addr = 0; ia6.s6_addr[0] = 0; /* shut up incorrect -Wuninitialized */
100 	va_start(ap,af);
101 	switch (af) {
102 	case AF_INET:
103 		ia = va_arg(ap,struct in_addr);
104 		break;
105 	case AF_INET6:
106 		ia6 = va_arg(ap,struct in6_addr);
107 		break;
108 	default:
109 		panic("if_srt find_rt: impossible address family");
110 		break;
111 	}
112 	va_end(ap);
113 	for (i=0; i < sc->nrt; i++) {
114 		r = sc->rts[i];
115 		if (r->af != af)
116 			continue;
117 		switch (af) {
118 		case AF_INET:
119 			if ((ia.s_addr & htonl(ipv4_masks[r->srcmask])) ==
120 			    r->srcmatch.v4.s_addr)
121 				return r;
122 			break;
123 		case AF_INET6:
124 			if ((r->srcmask >= 8) &&
125 			    memcmp(&ia6,&r->srcmatch.v6,r->srcmask / 8) != 0)
126 				continue;
127 			if ((r->srcmask % 8) &&
128 			    ((ia6.s6_addr[r->srcmask / 8] ^
129 			     r->srcmatch.v6.s6_addr[r->srcmask / 8]) &
130 			     0xff & (0xff00 >> (r->srcmask % 8))))
131 				continue;
132 			return r;
133 		default:
134 			panic("if_srt find_rt: impossible address family 2");
135 			break;
136 		}
137 	}
138 	return 0;
139 }
140 
141 /* Network device interface. */
142 
143 static int
144 srt_if_ioctl(struct ifnet *ifp, u_long cmd, void *data)
145 {
146 	struct ifaddr *ifa;
147 	int s;
148 	int err;
149 
150 	err = 0;
151 	s = splnet();
152 	switch (cmd) {
153 	case SIOCINITIFADDR:
154 	case SIOCSIFDSTADDR:
155 		ifa = (void *) data;
156 		switch (ifa->ifa_addr->sa_family) {
157 #ifdef INET
158 		case AF_INET:
159 			break;
160 #endif
161 #ifdef INET6
162 		case AF_INET6:
163 			break;
164 #endif
165 		default:
166 			err = EAFNOSUPPORT;
167 			break;
168 		}
169 		/* XXX do we need to do more here for either of these? */
170 		break;
171 	default:
172 		if ((err = ifioctl_common(ifp, cmd, data)) == ENETRESET)
173 			err = 0;
174 		break;
175 	}
176 	splx(s);
177 	return err;
178 }
179 
180 static int
181 srt_if_output(
182 	struct ifnet *ifp,
183 	struct mbuf *m,
184 	const struct sockaddr *to,
185 	struct rtentry *rtp)
186 {
187 	struct srt_softc *sc;
188 	struct srt_rt *r;
189 
190 	sc = ifp->if_softc;
191 	if (! (ifp->if_flags & IFF_UP)) {
192 		m_freem(m);
193 		return ENETDOWN;
194 	}
195 	switch (to->sa_family) {
196 #ifdef INET
197 	case AF_INET: {
198 		struct ip *ip;
199 		ip = mtod(m,struct ip *);
200 		r = find_rt(sc,AF_INET,ip->ip_src);
201 		break;
202 	}
203 #endif
204 #ifdef INET6
205 	case AF_INET6: {
206 		struct ip6_hdr *ip;
207 		ip = mtod(m,struct ip6_hdr *);
208 		r = find_rt(sc,AF_INET6,ip->ip6_src);
209 		break;
210 	}
211 #endif
212 	default:
213 		IF_DROP(&ifp->if_snd);
214 		m_freem(m);
215 		return EAFNOSUPPORT;
216 	}
217 	/* XXX Do we need to bpf_tap?  Or do higher layers now handle that? */
218 	/* if_gif.c seems to imply the latter. */
219 	ifp->if_opackets ++;
220 	if (! r) {
221 		ifp->if_oerrors ++;
222 		m_freem(m);
223 		return 0;
224 	}
225 	if (! (m->m_flags & M_PKTHDR)) {
226 		printf("srt_if_output no PKTHDR\n");
227 		m_freem(m);
228 		return 0;
229 	}
230 	ifp->if_obytes += m->m_pkthdr.len;
231 	if (! (r->u.dstifp->if_flags & IFF_UP)) {
232 		m_freem(m);
233 		return 0; /* XXX ENETDOWN? */
234 	}
235 	/* XXX is 0 the right last arg here? */
236 	return (*r->u.dstifp->if_output)(r->u.dstifp,m,&r->dst.sa,0);
237 }
238 
239 static int
240 srt_clone_create(struct if_clone *cl, int unit)
241 {
242 	struct srt_softc *sc;
243 
244 	if (unit < 0 || unit > SRT_MAXUNIT)
245 		return ENXIO;
246 	if (softcv[unit])
247 		return EBUSY;
248 	sc = malloc(sizeof(struct srt_softc), M_DEVBUF, M_WAITOK|M_ZERO);
249 	sc->unit = unit;
250 	sc->nrt = 0;
251 	sc->rts = 0;
252 	sc->flags = 0;
253 	sc->kflags = 0;
254 	if_initname(&sc->intf,cl->ifc_name,unit);
255 	sc->intf.if_softc = sc;
256 	sc->intf.if_mtu = 65535;
257 	sc->intf.if_flags = IFF_POINTOPOINT;
258 	sc->intf.if_type = IFT_OTHER;
259 	sc->intf.if_ioctl = &srt_if_ioctl;
260 	sc->intf.if_output = &srt_if_output;
261 	sc->intf.if_dlt = DLT_RAW;
262 	if_attach(&sc->intf);
263 	if_alloc_sadl(&sc->intf);
264 #ifdef BPFILTER_NOW_AVAILABLE
265 	bpf_attach(&sc->intf, 0, 0);
266 #endif
267 	softcv[unit] = sc;
268 	return 0;
269 }
270 
271 static int
272 srt_clone_destroy(struct ifnet *ifp)
273 {
274 	struct srt_softc *sc;
275 
276 	sc = ifp->if_softc;
277 	if ((ifp->if_flags & IFF_UP) || (sc->kflags & SKF_CDEVOPEN))
278 		return EBUSY;
279 #ifdef BPFILTER_NOW_AVAILABLE
280 	bpf_detach(ifp);
281 #endif
282 	if_detach(ifp);
283 	if (sc->unit < 0 || sc->unit > SRT_MAXUNIT) {
284 		panic("srt_clone_destroy: impossible unit %d\n",sc->unit);
285 	}
286 	if (softcv[sc->unit] != sc) {
287 		panic("srt_clone_destroy: bad backpointer ([%d]=%p not %p)\n",
288 		sc->unit,(void *)softcv[sc->unit],(void *)sc);
289 	}
290 	softcv[sc->unit] = 0;
291 	free(sc,M_DEVBUF);
292 	return 0;
293 }
294 
295 struct if_clone srt_clone =
296     IF_CLONE_INITIALIZER("srt",&srt_clone_create,&srt_clone_destroy);
297 
298 void
299 srtattach(void)
300 {
301 	int i;
302 
303 	for (i=SRT_MAXUNIT;i>=0;i--)
304 		softcv[i] = 0;
305 	global_flags = 0;
306 	if_clone_attach(&srt_clone);
307 }
308 
309 /* Special-device interface. */
310 
311 static int
312 srt_open(dev_t dev, int flag, int mode, struct lwp *l)
313 {
314 	int unit;
315 	struct srt_softc *sc;
316 
317 	unit = minor(dev);
318 	if (unit < 0 || unit > SRT_MAXUNIT)
319 		return ENXIO;
320 	sc = softcv[unit];
321 	if (! sc)
322 		return ENXIO;
323 	sc->kflags |= SKF_CDEVOPEN;
324 	return 0;
325 }
326 
327 static int
328 srt_close(dev_t dev, int flag, int mode, struct lwp *l)
329 {
330 	int unit;
331 	struct srt_softc *sc;
332 
333 	unit = minor(dev);
334 	if (unit < 0 || unit > SRT_MAXUNIT)
335 		return ENXIO;
336 	sc = softcv[unit];
337 	if (! sc)
338 		return ENXIO;
339 	sc->kflags &= ~SKF_CDEVOPEN;
340 	return 0;
341 }
342 
343 static int
344 srt_ioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
345 {
346 	unsigned int f, i, n, o;
347 	struct srt_softc *sc;
348 	struct srt_rt *dr;
349 	struct srt_rt *scr;
350 	struct ifnet *ifp;
351 	char nbuf[IFNAMSIZ];
352 
353 	sc = softcv[minor(dev)];
354 	if (! sc)
355 		panic("srt_ioctl: softc disappeared");
356 	switch (cmd) {
357 	case SRT_GETNRT:
358 		if (! (flag & FREAD))
359 			return EBADF;
360 		*(unsigned int *)data = sc->nrt;
361 		return 0;
362 	case SRT_GETRT:
363 		if (! (flag & FREAD))
364 			return EBADF;
365 		dr = (struct srt_rt *) data;
366 		if (dr->inx >= sc->nrt)
367 			return EDOM;
368 		scr = sc->rts[dr->inx];
369 		dr->af = scr->af;
370 		dr->srcmatch = scr->srcmatch;
371 		dr->srcmask = scr->srcmask;
372 		strncpy(&dr->u.dstifn[0],&scr->u.dstifp->if_xname[0],IFNAMSIZ);
373 		memcpy(&dr->dst,&scr->dst,scr->dst.sa.sa_len);
374 		return 0;
375 	case SRT_SETRT:
376 		if (! (flag & FWRITE))
377 			return EBADF;
378 		dr = (struct srt_rt *) data;
379 		if (dr->inx > sc->nrt)
380 			return EDOM;
381 		strncpy(&nbuf[0],&dr->u.dstifn[0],IFNAMSIZ);
382 		nbuf[IFNAMSIZ-1] = '\0';
383 		if (dr->dst.sa.sa_family != dr->af)
384 			return EIO;
385 		switch (dr->af) {
386 #ifdef INET
387 		case AF_INET:
388 			if (dr->dst.sa.sa_len != sizeof(dr->dst.sin))
389 				return EIO;
390 			if (dr->srcmask > 32)
391 				return EIO;
392 		break;
393 #endif
394 #ifdef INET6
395 		case AF_INET6:
396 			if (dr->dst.sa.sa_len != sizeof(dr->dst.sin6))
397 				return EIO;
398 			if (dr->srcmask > 128)
399 				return EIO;
400 		break;
401 #endif
402 		default:
403 			return EAFNOSUPPORT;
404 		}
405 		ifp = ifunit(&nbuf[0]);
406 		if (ifp == 0)
407 			return ENXIO; /* needs translation */
408 		if (dr->inx == sc->nrt) {
409 			struct srt_rt **tmp;
410 			tmp = malloc((sc->nrt+1)*sizeof(*tmp), M_DEVBUF,
411 			    M_WAITOK);
412 			if (tmp == 0)
413 				return ENOBUFS;
414 			tmp[sc->nrt] = 0;
415 			if (sc->nrt > 0) {
416 				memcpy(tmp, sc->rts, sc->nrt*sizeof(*tmp));
417 				free(sc->rts, M_DEVBUF);
418 			}
419 			sc->rts = tmp;
420 			sc->nrt ++;
421 		}
422 		scr = sc->rts[dr->inx];
423 		if (scr == 0) {
424 			scr = malloc(sizeof(struct srt_rt),M_DEVBUF,M_WAITOK);
425 			if (scr == 0)
426 				return ENOBUFS;
427 			scr->inx = dr->inx;
428 			scr->af = AF_UNSPEC;
429 			sc->rts[dr->inx] = scr;
430 		}
431 		scr->af = dr->af;
432 		scr->srcmatch = dr->srcmatch;
433 		scr->srcmask = dr->srcmask;
434 		scr->u.dstifp = ifp;
435 		memcpy(&scr->dst,&dr->dst,dr->dst.sa.sa_len);
436 		update_mtu(sc);
437 		return 0;
438 	case SRT_DELRT:
439 		if (! (flag & FWRITE))
440 			return EBADF;
441 		i = *(unsigned int *)data;
442 		if (i >= sc->nrt)
443 			return EDOM;
444 		scr = sc->rts[i];
445 		sc->rts[i] = 0;
446 		free(scr, M_DEVBUF);
447 		sc->nrt--;
448 		if (i < sc->nrt) {
449 			memcpy(sc->rts+i, sc->rts+i+1,
450 			    (sc->nrt-i)*sizeof(*sc->rts));
451 		}
452 		if (sc->nrt == 0) {
453 			free(sc->rts, M_DEVBUF);
454 			sc->rts = 0;
455 			sc->intf.if_flags &= ~IFF_UP;
456 		}
457 		update_mtu(sc);
458 		return 0;
459 	case SRT_SFLAGS:
460 		if (! (flag & FWRITE))
461 			return EBADF;
462 		f = *(unsigned int *)data & SSF_UCHG;
463 		global_flags = (global_flags & ~SSF_UCHG) | (f & SSF_GLOBAL);
464 		sc->flags = (sc->flags & ~SSF_UCHG) | (f & ~SSF_GLOBAL);
465 		return 0;
466 	case SRT_GFLAGS:
467 		if (! (flag & FREAD))
468 			return EBADF;
469 		*(unsigned int *)data = sc->flags | global_flags;
470 		return 0;
471 	case SRT_SGFLAGS:
472 		if ((flag & (FWRITE|FREAD)) != (FWRITE|FREAD))
473 			return EBADF;
474 		o = sc->flags | global_flags;
475 		n = *(unsigned int *)data & SSF_UCHG;
476 		global_flags = (global_flags & ~SSF_UCHG) | (n & SSF_GLOBAL);
477 		sc->flags = (sc->flags & ~SSF_UCHG) | (n & ~SSF_GLOBAL);
478 		*(unsigned int *)data = o;
479 		return 0;
480 	case SRT_DEBUG:
481 		return 0;
482 		break;
483 	}
484 	return ENOTTY;
485 }
486 
487 const struct cdevsw srt_cdevsw = {
488 	&srt_open,
489 	&srt_close,
490 	nullread,
491 	nullwrite,
492 	&srt_ioctl,
493 	nullstop,
494 	notty,
495 	nullpoll,
496 	nommap,
497 	nullkqfilter,
498 	D_OTHER
499 };
500