xref: /netbsd-src/sys/net/if_srt.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /* $NetBSD: if_srt.c,v 1.8 2008/06/15 16:37:21 christos Exp $ */
2 /* This file is in the public domain. */
3 
4 #include <sys/cdefs.h>
5 __KERNEL_RCSID(0, "$NetBSD: if_srt.c,v 1.8 2008/06/15 16:37:21 christos 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 (uvm/uvm_param.h, sys/mbuf.h) */
20 #include <netinet/in.h> /* netinet/ip.h */
21 #include <sys/param.h> /* sys/mbuf.h */
22 #include <netinet/in_systm.h> /* netinet/ip.h */
23 
24 #include <sys/conf.h>
25 #include <sys/mbuf.h>
26 #include <sys/errno.h>
27 #include <sys/fcntl.h>
28 #include <sys/param.h>
29 #include <sys/ioctl.h>
30 #include <netinet/ip.h>
31 #include <netinet/ip6.h>
32 #include <net/if_types.h>
33 #include <machine/stdarg.h>
34 
35 #include "if_srt.h"
36 #include "bpfilter.h"
37 
38 /* until we know what to pass to bpfattach.... */
39 #undef NBPFILTER
40 #define NBPFILTER 0
41 
42 typedef struct srt_rt RT;
43 typedef struct softc SOFTC;
44 
45 struct softc {
46   struct ifnet intf;	/* XXX interface botch */
47   int unit;
48   int nrt;
49   RT **rts;
50   unsigned int flags;	/* SSF_* values from if_srt.h */
51 #define SSF_UCHG (SSF_MTULOCK) /* userland-changeable bits */
52   unsigned int kflags;	/* bits private to this file */
53 #define SKF_CDEVOPEN 0x00000001
54   } ;
55 
56 static SOFTC *softcv[SRT_MAXUNIT+1];
57 static unsigned int global_flags;
58 
59 /* Internal routines. */
60 
61 static unsigned int ipv4_masks[33]
62  = { 0x00000000, /* /0 */
63      0x80000000, 0xc0000000, 0xe0000000, 0xf0000000, /* /1 - /4 */
64      0xf8000000, 0xfc000000, 0xfe000000, 0xff000000, /* /5 - /8 */
65      0xff800000, 0xffc00000, 0xffe00000, 0xfff00000, /* /9 - /12 */
66      0xfff80000, 0xfffc0000, 0xfffe0000, 0xffff0000, /* /13 - /16 */
67      0xffff8000, 0xffffc000, 0xffffe000, 0xfffff000, /* /17 - /20 */
68      0xfffff800, 0xfffffc00, 0xfffffe00, 0xffffff00, /* /21 - /24 */
69      0xffffff80, 0xffffffc0, 0xffffffe0, 0xfffffff0, /* /25 - /28 */
70      0xfffffff8, 0xfffffffc, 0xfffffffe, 0xffffffff  /* /29 - /32 */ };
71 
72 static void update_mtu(SOFTC *sc)
73 {
74  int mtu;
75  int i;
76  RT *r;
77 
78  if (sc->flags & SSF_MTULOCK) return;
79  mtu = 65535;
80  for (i=sc->nrt-1;i>=0;i--)
81   { r = sc->rts[i];
82     if (r->u.dstifp->if_mtu < mtu) mtu = r->u.dstifp->if_mtu;
83   }
84  sc->intf.if_mtu = mtu;
85 }
86 
87 static RT *find_rt(SOFTC *sc, int af, ...)
88 {
89  int i;
90  RT *r;
91  struct in_addr ia;
92  struct in6_addr ia6;
93  va_list ap;
94 
95  ia.s_addr = 0; ia6.s6_addr[0] = 0; /* shut up incorrect -Wuninitialized */
96  va_start(ap,af);
97  switch (af)
98   { case AF_INET:
99        ia = va_arg(ap,struct in_addr);
100        break;
101     case AF_INET6:
102        ia6 = va_arg(ap,struct in6_addr);
103        break;
104     default:
105        panic("if_srt find_rt: impossible address family");
106        break;
107   }
108  va_end(ap);
109  for (i=0;i<sc->nrt;i++)
110   { r = sc->rts[i];
111     if (r->af != af) continue;
112     switch (af)
113      { case AF_INET:
114 	  if ((ia.s_addr & ipv4_masks[r->srcmask]) == r->srcmatch.v4.s_addr) return(r);
115 	  break;
116        case AF_INET6:
117 	  if ((r->srcmask >= 8) && bcmp(&ia6,&r->srcmatch.v6,r->srcmask/8)) continue;
118 	  if ( (r->srcmask % 8) &&
119 	       ( ( ia6.s6_addr[r->srcmask/8] ^
120 		   r->srcmatch.v6.s6_addr[r->srcmask/8] ) &
121 		 0xff & (0xff00 >> (r->srcmask%8)) ) ) continue;
122 	  return(r);
123 	  break;
124        default:
125 	  panic("if_srt find_rt: impossible address family 2");
126 	  break;
127      }
128   }
129  return(0);
130 }
131 
132 /* Network device interface. */
133 
134 static int srt_if_ioctl(struct ifnet *intf, u_long cmd, void *data)
135 {
136  struct ifaddr *ifa;
137  int s;
138  int err;
139 
140  err = 0;
141  s = splnet();
142  switch (cmd)
143   { case SIOCSIFADDR:
144     case SIOCSIFDSTADDR:
145        ifa = (void *) data;
146        switch (ifa->ifa_addr->sa_family)
147 	{
148 #ifdef INET
149 	  case AF_INET:
150 #endif
151 #ifdef INET6
152 	  case AF_INET6:
153 #endif
154 	     break;
155 	  default:
156 	     err = EAFNOSUPPORT;
157 	     break;
158 	}
159        /* XXX do we need to do more here for either of these? */
160        break;
161     case SIOCSIFMTU:
162     case SIOCGIFMTU:
163        if ((err = ifioctl_common(intf, cmd, data)) == ENETRESET)
164              err = 0;
165        break;
166     default:
167        err = EINVAL;
168        break;
169   }
170  splx(s);
171  return(err);
172 }
173 
174 static int srt_if_output(
175 	struct ifnet *intf,
176 	struct mbuf *m,
177 	const struct sockaddr *to,
178 	struct rtentry *rtp )
179 {
180  SOFTC *sc;
181  RT *r;
182 
183  sc = intf->if_softc;
184  if (! (intf->if_flags & IFF_UP))
185   { m_freem(m);
186     return(ENETDOWN);
187   }
188  switch (to->sa_family)
189   {
190 #ifdef INET
191     case AF_INET:
192 #endif
193 	{ struct ip *ip;
194 	  ip = mtod(m,struct ip *);
195 	  r = find_rt(sc,AF_INET,ip->ip_src);
196 	}
197        break;
198 #ifdef INET6
199     case AF_INET6:
200 #endif
201 	{ struct ip6_hdr *ip;
202 	  ip = mtod(m,struct ip6_hdr *);
203 	  r = find_rt(sc,AF_INET6,ip->ip6_src);
204 	}
205        break;
206     default:
207        IF_DROP(&intf->if_snd);
208        m_freem(m);
209        return(EAFNOSUPPORT);
210        break;
211   }
212  /* XXX Do we need to bpf_tap?  Or do higher layers now handle that? */
213  /* if_gif.c seems to imply the latter. */
214  intf->if_opackets ++;
215  if (! r)
216   { intf->if_oerrors ++;
217     m_freem(m);
218     return(0);
219   }
220  if (! (m->m_flags & M_PKTHDR))
221   { printf("srt_if_output no PKTHDR\n");
222     m_freem(m);
223     return(0);
224   }
225  intf->if_obytes += m->m_pkthdr.len;
226  if (! (r->u.dstifp->if_flags & IFF_UP))
227   { m_freem(m);
228     return(0); /* XXX ENETDOWN? */
229   }
230  /* XXX is 0 the right last arg here? */
231  return((*r->u.dstifp->if_output)(r->u.dstifp,m,&r->dst.sa,0));
232 }
233 
234 static int srt_clone_create(struct if_clone *cl, int unit)
235 {
236  SOFTC *sc;
237 
238  if ((unit < 0) || (unit > SRT_MAXUNIT)) return(ENXIO);
239  if (softcv[unit]) return(EBUSY);
240  sc = malloc(sizeof(SOFTC),M_DEVBUF,M_WAIT);
241  bzero(&sc->intf,sizeof(sc->intf)); /* XXX */
242  sc->unit = unit;
243  sc->nrt = 0;
244  sc->rts = 0;
245  sc->flags = 0;
246  sc->kflags = 0;
247  if_initname(&sc->intf,cl->ifc_name,unit);
248  sc->intf.if_softc = sc;
249  sc->intf.if_mtu = 65535;
250  sc->intf.if_flags = IFF_POINTOPOINT;
251  sc->intf.if_type = IFT_OTHER;
252  sc->intf.if_ioctl = &srt_if_ioctl;
253  sc->intf.if_output = &srt_if_output;
254  sc->intf.if_dlt = DLT_RAW;
255  if_attach(&sc->intf);
256  if_alloc_sadl(&sc->intf);
257 #if NBPFILTER > 0 /* see comment near top */
258  bpfattach(&sc->intf,0/*???*/,0/*???*/);
259 #endif
260  softcv[unit] = sc;
261  return(0);
262 }
263 
264 static int srt_clone_destroy(struct ifnet *intf)
265 {
266  SOFTC *sc;
267 
268  sc = intf->if_softc;
269  if ((intf->if_flags & IFF_UP) || (sc->kflags & SKF_CDEVOPEN)) return(EBUSY);
270 #if NBPFILTER > 0
271  bpfdetach(intf);
272 #endif
273  if_detach(intf);
274  if ((sc->unit < 0) || (sc->unit > SRT_MAXUNIT))
275   { panic("srt_clone_destroy: impossible unit %d\n",sc->unit);
276   }
277  if (softcv[sc->unit] != sc)
278   { panic("srt_clone_destroy: bad backpointer ([%d]=%p not %p)\n",
279 			sc->unit,(void *)softcv[sc->unit],(void *)sc);
280   }
281  softcv[sc->unit] = 0;
282  free(sc,M_DEVBUF);
283  return(0);
284 }
285 
286 struct if_clone srt_clone =
287     IF_CLONE_INITIALIZER("srt",&srt_clone_create,&srt_clone_destroy);
288 
289 extern void srtattach(void);
290 void srtattach(void)
291 {
292  int i;
293 
294  for (i=SRT_MAXUNIT;i>=0;i--) softcv[i] = 0;
295  global_flags = 0;
296  if_clone_attach(&srt_clone);
297 }
298 
299 /* Special-device interface. */
300 
301 static int srt_open(dev_t dev, int flag, int mode, struct lwp *l)
302 {
303  int unit;
304  SOFTC *sc;
305 
306  unit = minor(dev);
307  if ((unit < 0) || (unit > SRT_MAXUNIT)) return(ENXIO);
308  sc = softcv[unit];
309  if (! sc) return(ENXIO);
310  sc->kflags |= SKF_CDEVOPEN;
311  return(0);
312 }
313 
314 static int srt_close(dev_t dev, int flag, int mode, struct lwp *l)
315 {
316  int unit;
317  SOFTC *sc;
318 
319  unit = minor(dev);
320  if ((unit < 0) || (unit > SRT_MAXUNIT)) return(ENXIO);
321  sc = softcv[unit];
322  if (! sc) return(ENXIO);
323  sc->kflags &= ~SKF_CDEVOPEN;
324  return(0);
325 }
326 
327 static int srt_ioctl(
328 	dev_t dev,
329 	u_long cmd,
330 	void *data,
331 	int flag,
332 	struct lwp *l )
333 {
334  SOFTC *sc;
335  RT *dr;
336  RT *scr;
337  struct ifnet *intf;
338  char nbuf[IFNAMSIZ];
339 
340  sc = softcv[minor(dev)];
341  if (! sc) panic("srt_ioctl: softc disappeared");
342  switch (cmd)
343   { case SRT_GETNRT:
344        if (! (flag & FREAD)) return(EBADF);
345        *(unsigned int *)data = sc->nrt;
346        return(0);
347        break;
348     case SRT_GETRT:
349        if (! (flag & FREAD)) return(EBADF);
350        dr = (RT *) data;
351        if (dr->inx >= sc->nrt) return(EDOM);
352        scr = sc->rts[dr->inx];
353        dr->af = scr->af;
354        dr->srcmatch = scr->srcmatch;
355        dr->srcmask = scr->srcmask;
356        strncpy(&dr->u.dstifn[0],&scr->u.dstifp->if_xname[0],IFNAMSIZ);
357        memcpy(&dr->dst,&scr->dst,scr->dst.sa.sa_len);
358        return(0);
359        break;
360     case SRT_SETRT:
361        if (! (flag & FWRITE)) return(EBADF);
362        dr = (RT *) data;
363        if (dr->inx > sc->nrt) return(EDOM);
364        strncpy(&nbuf[0],&dr->u.dstifn[0],IFNAMSIZ);
365        nbuf[IFNAMSIZ-1] = '\0';
366        if (dr->dst.sa.sa_family != dr->af) return(EIO);
367        switch (dr->af)
368 	{
369 #ifdef INET
370 	  case AF_INET:
371 	     if (dr->dst.sa.sa_len != sizeof(dr->dst.sin)) return(EIO);
372 	     if (dr->srcmask > 32) return(EIO);
373 	     break;
374 #endif
375 #ifdef INET6
376 	  case AF_INET6:
377 	     if (dr->dst.sa.sa_len != sizeof(dr->dst.sin6)) return(EIO);
378 	     if (dr->srcmask > 128) return(EIO);
379 	     break;
380 #endif
381 	     break;
382 	  default:
383 	     return(EAFNOSUPPORT);
384 	     break;
385 	}
386        intf = ifunit(&nbuf[0]);
387        if (intf == 0) return(ENXIO); /* needs translation */
388        if (dr->inx == sc->nrt)
389 	{ RT **tmp;
390 	  tmp = malloc((sc->nrt+1)*sizeof(*tmp),M_DEVBUF,M_WAITOK);
391 	  if (tmp == 0) return(ENOBUFS);
392 	  tmp[sc->nrt] = 0;
393 	  if (sc->nrt > 0)
394 	   { memcpy(tmp,sc->rts,sc->nrt*sizeof(*tmp));
395 	     free(sc->rts,M_DEVBUF);
396 	   }
397 	  sc->rts = tmp;
398 	  sc->nrt ++;
399 	}
400        scr = sc->rts[dr->inx];
401        if (scr == 0)
402 	{ scr = malloc(sizeof(RT),M_DEVBUF,M_WAITOK);
403 	  if (scr == 0) return(ENOBUFS);
404 	  scr->inx = dr->inx;
405 	  scr->af = AF_UNSPEC;
406 	  sc->rts[dr->inx] = scr;
407 	}
408        scr->af = dr->af;
409        scr->srcmatch = dr->srcmatch;
410        scr->srcmask = dr->srcmask;
411        scr->u.dstifp = intf;
412        memcpy(&scr->dst,&dr->dst,dr->dst.sa.sa_len);
413        update_mtu(sc);
414        return(0);
415        break;
416     case SRT_DELRT:
417 	{ unsigned int i;
418 	  if (! (flag & FWRITE)) return(EBADF);
419 	  i = *(unsigned int *)data;
420 	  if (i >= sc->nrt) return(EDOM);
421 	  scr = sc->rts[i];
422 	  sc->rts[i] = 0;
423 	  free(scr,M_DEVBUF);
424 	  sc->nrt --;
425 	  if (i < sc->nrt) memcpy(sc->rts+i,sc->rts+i+1,(sc->nrt-i)*sizeof(*sc->rts));
426 	  if (sc->nrt == 0)
427 	   { free(sc->rts,M_DEVBUF);
428 	     sc->rts = 0;
429 	     sc->intf.if_flags &= ~IFF_UP;
430 	   }
431 	}
432        update_mtu(sc);
433        return(0);
434        break;
435     case SRT_SFLAGS:
436 	{ unsigned int f;
437 	  if (! (flag & FWRITE)) return(EBADF);
438 	  f = *(unsigned int *)data & SSF_UCHG;
439 	  global_flags = (global_flags & ~SSF_UCHG) | (f & SSF_GLOBAL);
440 	  sc->flags = (sc->flags & ~SSF_UCHG) | (f & ~SSF_GLOBAL);
441 	}
442        return(0);
443        break;
444     case SRT_GFLAGS:
445        if (! (flag & FREAD)) return(EBADF);
446        *(unsigned int *)data = sc->flags | global_flags;
447        return(0);
448        break;
449     case SRT_SGFLAGS:
450 	{ unsigned int o;
451 	  unsigned int n;
452 	  if ((flag & (FWRITE|FREAD)) != (FWRITE|FREAD)) return(EBADF);
453 	  o = sc->flags | global_flags;
454 	  n = *(unsigned int *)data & SSF_UCHG;
455 	  global_flags = (global_flags & ~SSF_UCHG) | (n & SSF_GLOBAL);
456 	  sc->flags = (sc->flags & ~SSF_UCHG) | (n & ~SSF_GLOBAL);
457 	  *(unsigned int *)data = o;
458 	}
459        return(0);
460        break;
461     case SRT_DEBUG:
462        return(0);
463        break;
464   }
465  return(ENOTTY);
466 }
467 
468 const struct cdevsw srt_cdevsw
469  = { &srt_open,
470      &srt_close,
471      nullread,
472      nullwrite,
473      &srt_ioctl,
474      nullstop,
475      notty,
476      nullpoll,
477      nommap,
478      nullkqfilter,
479      D_OTHER };
480