1 /*-
2 * Copyright (c) 2014, 2018 Andrey V. Elsukov <ae@FreeBSD.org>
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 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/jail.h>
30 #include <sys/kernel.h>
31 #include <sys/lock.h>
32 #include <sys/malloc.h>
33 #include <sys/module.h>
34 #include <sys/mbuf.h>
35 #include <sys/priv.h>
36 #include <sys/proc.h>
37 #include <sys/socket.h>
38 #include <sys/sockio.h>
39 #include <sys/sx.h>
40 #include <sys/sysctl.h>
41 #include <sys/syslog.h>
42
43 #include <net/bpf.h>
44 #include <net/ethernet.h>
45 #include <net/if.h>
46 #include <net/if_var.h>
47 #include <net/if_private.h>
48 #include <net/if_clone.h>
49 #include <net/if_types.h>
50 #include <net/netisr.h>
51 #include <net/vnet.h>
52 #include <net/route.h>
53
54 #include <netinet/in.h>
55 #include <netinet/in_systm.h>
56 #include <netinet/in_var.h>
57 #include <netinet/ip.h>
58 #include <netinet/ip_var.h>
59 #include <netinet/ip_encap.h>
60
61 #include <machine/in_cksum.h>
62 #include <security/mac/mac_framework.h>
63
64 #define MEMTU (1500 - sizeof(struct mobhdr))
65 static const char mename[] = "me";
66 static MALLOC_DEFINE(M_IFME, mename, "Minimal Encapsulation for IP");
67 /* Minimal forwarding header RFC 2004 */
68 struct mobhdr {
69 uint8_t mob_proto; /* protocol */
70 uint8_t mob_flags; /* flags */
71 #define MOB_FLAGS_SP 0x80 /* source present */
72 uint16_t mob_csum; /* header checksum */
73 struct in_addr mob_dst; /* original destination address */
74 struct in_addr mob_src; /* original source addr (optional) */
75 } __packed;
76
77 struct me_softc {
78 struct ifnet *me_ifp;
79 u_int me_fibnum;
80 struct in_addr me_src;
81 struct in_addr me_dst;
82
83 CK_LIST_ENTRY(me_softc) chain;
84 CK_LIST_ENTRY(me_softc) srchash;
85 };
86 CK_LIST_HEAD(me_list, me_softc);
87 #define ME2IFP(sc) ((sc)->me_ifp)
88 #define ME_READY(sc) ((sc)->me_src.s_addr != 0)
89 #define ME_RLOCK_TRACKER struct epoch_tracker me_et
90 #define ME_RLOCK() epoch_enter_preempt(net_epoch_preempt, &me_et)
91 #define ME_RUNLOCK() epoch_exit_preempt(net_epoch_preempt, &me_et)
92 #define ME_WAIT() epoch_wait_preempt(net_epoch_preempt)
93
94 #ifndef ME_HASH_SIZE
95 #define ME_HASH_SIZE (1 << 4)
96 #endif
97 VNET_DEFINE_STATIC(struct me_list *, me_hashtbl) = NULL;
98 VNET_DEFINE_STATIC(struct me_list *, me_srchashtbl) = NULL;
99 #define V_me_hashtbl VNET(me_hashtbl)
100 #define V_me_srchashtbl VNET(me_srchashtbl)
101 #define ME_HASH(src, dst) (V_me_hashtbl[\
102 me_hashval((src), (dst)) & (ME_HASH_SIZE - 1)])
103 #define ME_SRCHASH(src) (V_me_srchashtbl[\
104 fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (ME_HASH_SIZE - 1)])
105
106 static struct sx me_ioctl_sx;
107 SX_SYSINIT(me_ioctl_sx, &me_ioctl_sx, "me_ioctl");
108
109 static int me_clone_create(struct if_clone *, int, caddr_t);
110 static void me_clone_destroy(struct ifnet *);
111 VNET_DEFINE_STATIC(struct if_clone *, me_cloner);
112 #define V_me_cloner VNET(me_cloner)
113
114 #ifdef VIMAGE
115 static void me_reassign(struct ifnet *, struct vnet *, char *);
116 #endif
117 static void me_qflush(struct ifnet *);
118 static int me_transmit(struct ifnet *, struct mbuf *);
119 static int me_ioctl(struct ifnet *, u_long, caddr_t);
120 static int me_output(struct ifnet *, struct mbuf *,
121 const struct sockaddr *, struct route *);
122 static int me_input(struct mbuf *, int, int, void *);
123
124 static int me_set_tunnel(struct me_softc *, in_addr_t, in_addr_t);
125 static void me_delete_tunnel(struct me_softc *);
126
127 SYSCTL_DECL(_net_link);
128 static SYSCTL_NODE(_net_link, IFT_TUNNEL, me, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
129 "Minimal Encapsulation for IP (RFC 2004)");
130 #ifndef MAX_ME_NEST
131 #define MAX_ME_NEST 1
132 #endif
133
134 VNET_DEFINE_STATIC(int, max_me_nesting) = MAX_ME_NEST;
135 #define V_max_me_nesting VNET(max_me_nesting)
136 SYSCTL_INT(_net_link_me, OID_AUTO, max_nesting, CTLFLAG_RW | CTLFLAG_VNET,
137 &VNET_NAME(max_me_nesting), 0, "Max nested tunnels");
138
139 static uint32_t
me_hashval(in_addr_t src,in_addr_t dst)140 me_hashval(in_addr_t src, in_addr_t dst)
141 {
142 uint32_t ret;
143
144 ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT);
145 return (fnv_32_buf(&dst, sizeof(dst), ret));
146 }
147
148 static struct me_list *
me_hashinit(void)149 me_hashinit(void)
150 {
151 struct me_list *hash;
152 int i;
153
154 hash = malloc(sizeof(struct me_list) * ME_HASH_SIZE,
155 M_IFME, M_WAITOK);
156 for (i = 0; i < ME_HASH_SIZE; i++)
157 CK_LIST_INIT(&hash[i]);
158
159 return (hash);
160 }
161
162 static void
vnet_me_init(const void * unused __unused)163 vnet_me_init(const void *unused __unused)
164 {
165
166 V_me_cloner = if_clone_simple(mename, me_clone_create,
167 me_clone_destroy, 0);
168 }
169 VNET_SYSINIT(vnet_me_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
170 vnet_me_init, NULL);
171
172 static void
vnet_me_uninit(const void * unused __unused)173 vnet_me_uninit(const void *unused __unused)
174 {
175
176 if (V_me_hashtbl != NULL) {
177 free(V_me_hashtbl, M_IFME);
178 V_me_hashtbl = NULL;
179 ME_WAIT();
180 free(V_me_srchashtbl, M_IFME);
181 }
182 if_clone_detach(V_me_cloner);
183 }
184 VNET_SYSUNINIT(vnet_me_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
185 vnet_me_uninit, NULL);
186
187 static int
me_clone_create(struct if_clone * ifc,int unit,caddr_t params)188 me_clone_create(struct if_clone *ifc, int unit, caddr_t params)
189 {
190 struct me_softc *sc;
191
192 sc = malloc(sizeof(struct me_softc), M_IFME, M_WAITOK | M_ZERO);
193 sc->me_fibnum = curthread->td_proc->p_fibnum;
194 ME2IFP(sc) = if_alloc(IFT_TUNNEL);
195 ME2IFP(sc)->if_softc = sc;
196 if_initname(ME2IFP(sc), mename, unit);
197
198 ME2IFP(sc)->if_mtu = MEMTU;
199 ME2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
200 ME2IFP(sc)->if_output = me_output;
201 ME2IFP(sc)->if_ioctl = me_ioctl;
202 ME2IFP(sc)->if_transmit = me_transmit;
203 ME2IFP(sc)->if_qflush = me_qflush;
204 #ifdef VIMAGE
205 ME2IFP(sc)->if_reassign = me_reassign;
206 #endif
207 ME2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE;
208 ME2IFP(sc)->if_capenable |= IFCAP_LINKSTATE;
209 if_attach(ME2IFP(sc));
210 bpfattach(ME2IFP(sc), DLT_NULL, sizeof(u_int32_t));
211 return (0);
212 }
213
214 #ifdef VIMAGE
215 static void
me_reassign(struct ifnet * ifp,struct vnet * new_vnet __unused,char * unused __unused)216 me_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
217 char *unused __unused)
218 {
219 struct me_softc *sc;
220
221 sx_xlock(&me_ioctl_sx);
222 sc = ifp->if_softc;
223 if (sc != NULL)
224 me_delete_tunnel(sc);
225 sx_xunlock(&me_ioctl_sx);
226 }
227 #endif /* VIMAGE */
228
229 static void
me_clone_destroy(struct ifnet * ifp)230 me_clone_destroy(struct ifnet *ifp)
231 {
232 struct me_softc *sc;
233
234 sx_xlock(&me_ioctl_sx);
235 sc = ifp->if_softc;
236 me_delete_tunnel(sc);
237 bpfdetach(ifp);
238 if_detach(ifp);
239 ifp->if_softc = NULL;
240 sx_xunlock(&me_ioctl_sx);
241
242 ME_WAIT();
243 if_free(ifp);
244 free(sc, M_IFME);
245 }
246
247 static int
me_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)248 me_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
249 {
250 struct ifreq *ifr = (struct ifreq *)data;
251 struct sockaddr_in *src, *dst;
252 struct me_softc *sc;
253 int error;
254
255 switch (cmd) {
256 case SIOCSIFMTU:
257 if (ifr->ifr_mtu < 576)
258 return (EINVAL);
259 ifp->if_mtu = ifr->ifr_mtu;
260 return (0);
261 case SIOCSIFADDR:
262 ifp->if_flags |= IFF_UP;
263 case SIOCSIFFLAGS:
264 case SIOCADDMULTI:
265 case SIOCDELMULTI:
266 return (0);
267 }
268 sx_xlock(&me_ioctl_sx);
269 sc = ifp->if_softc;
270 if (sc == NULL) {
271 error = ENXIO;
272 goto end;
273 }
274 error = 0;
275 switch (cmd) {
276 case SIOCSIFPHYADDR:
277 src = &((struct in_aliasreq *)data)->ifra_addr;
278 dst = &((struct in_aliasreq *)data)->ifra_dstaddr;
279 if (src->sin_family != dst->sin_family ||
280 src->sin_family != AF_INET ||
281 src->sin_len != dst->sin_len ||
282 src->sin_len != sizeof(struct sockaddr_in)) {
283 error = EINVAL;
284 break;
285 }
286 if (src->sin_addr.s_addr == INADDR_ANY ||
287 dst->sin_addr.s_addr == INADDR_ANY) {
288 error = EADDRNOTAVAIL;
289 break;
290 }
291 error = me_set_tunnel(sc, src->sin_addr.s_addr,
292 dst->sin_addr.s_addr);
293 break;
294 case SIOCDIFPHYADDR:
295 me_delete_tunnel(sc);
296 break;
297 case SIOCGIFPSRCADDR:
298 case SIOCGIFPDSTADDR:
299 if (!ME_READY(sc)) {
300 error = EADDRNOTAVAIL;
301 break;
302 }
303 src = (struct sockaddr_in *)&ifr->ifr_addr;
304 memset(src, 0, sizeof(*src));
305 src->sin_family = AF_INET;
306 src->sin_len = sizeof(*src);
307 switch (cmd) {
308 case SIOCGIFPSRCADDR:
309 src->sin_addr = sc->me_src;
310 break;
311 case SIOCGIFPDSTADDR:
312 src->sin_addr = sc->me_dst;
313 break;
314 }
315 error = prison_if(curthread->td_ucred, sintosa(src));
316 if (error != 0)
317 memset(src, 0, sizeof(*src));
318 break;
319 case SIOCGTUNFIB:
320 ifr->ifr_fib = sc->me_fibnum;
321 break;
322 case SIOCSTUNFIB:
323 if ((error = priv_check(curthread, PRIV_NET_ME)) != 0)
324 break;
325 if (ifr->ifr_fib >= rt_numfibs)
326 error = EINVAL;
327 else
328 sc->me_fibnum = ifr->ifr_fib;
329 break;
330 default:
331 error = EINVAL;
332 break;
333 }
334 end:
335 sx_xunlock(&me_ioctl_sx);
336 return (error);
337 }
338
339 static int
me_lookup(const struct mbuf * m,int off,int proto,void ** arg)340 me_lookup(const struct mbuf *m, int off, int proto, void **arg)
341 {
342 const struct ip *ip;
343 struct me_softc *sc;
344
345 if (V_me_hashtbl == NULL)
346 return (0);
347
348 NET_EPOCH_ASSERT();
349 ip = mtod(m, const struct ip *);
350 CK_LIST_FOREACH(sc, &ME_HASH(ip->ip_dst.s_addr,
351 ip->ip_src.s_addr), chain) {
352 if (sc->me_src.s_addr == ip->ip_dst.s_addr &&
353 sc->me_dst.s_addr == ip->ip_src.s_addr) {
354 if ((ME2IFP(sc)->if_flags & IFF_UP) == 0)
355 return (0);
356 *arg = sc;
357 return (ENCAP_DRV_LOOKUP);
358 }
359 }
360 return (0);
361 }
362
363 /*
364 * Check that ingress address belongs to local host.
365 */
366 static void
me_set_running(struct me_softc * sc)367 me_set_running(struct me_softc *sc)
368 {
369
370 if (in_localip(sc->me_src))
371 ME2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
372 else
373 ME2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
374 }
375
376 /*
377 * ifaddr_event handler.
378 * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
379 * source address spoofing.
380 */
381 static void
me_srcaddr(void * arg __unused,const struct sockaddr * sa,int event __unused)382 me_srcaddr(void *arg __unused, const struct sockaddr *sa,
383 int event __unused)
384 {
385 const struct sockaddr_in *sin;
386 struct me_softc *sc;
387
388 /* Check that VNET is ready */
389 if (V_me_hashtbl == NULL)
390 return;
391
392 NET_EPOCH_ASSERT();
393 sin = (const struct sockaddr_in *)sa;
394 CK_LIST_FOREACH(sc, &ME_SRCHASH(sin->sin_addr.s_addr), srchash) {
395 if (sc->me_src.s_addr != sin->sin_addr.s_addr)
396 continue;
397 me_set_running(sc);
398 }
399 }
400
401 static int
me_set_tunnel(struct me_softc * sc,in_addr_t src,in_addr_t dst)402 me_set_tunnel(struct me_softc *sc, in_addr_t src, in_addr_t dst)
403 {
404 struct epoch_tracker et;
405 struct me_softc *tmp;
406
407 sx_assert(&me_ioctl_sx, SA_XLOCKED);
408
409 if (V_me_hashtbl == NULL) {
410 V_me_hashtbl = me_hashinit();
411 V_me_srchashtbl = me_hashinit();
412 }
413
414 if (sc->me_src.s_addr == src && sc->me_dst.s_addr == dst)
415 return (0);
416
417 CK_LIST_FOREACH(tmp, &ME_HASH(src, dst), chain) {
418 if (tmp == sc)
419 continue;
420 if (tmp->me_src.s_addr == src &&
421 tmp->me_dst.s_addr == dst)
422 return (EADDRNOTAVAIL);
423 }
424
425 me_delete_tunnel(sc);
426 sc->me_dst.s_addr = dst;
427 sc->me_src.s_addr = src;
428 CK_LIST_INSERT_HEAD(&ME_HASH(src, dst), sc, chain);
429 CK_LIST_INSERT_HEAD(&ME_SRCHASH(src), sc, srchash);
430
431 NET_EPOCH_ENTER(et);
432 me_set_running(sc);
433 NET_EPOCH_EXIT(et);
434 if_link_state_change(ME2IFP(sc), LINK_STATE_UP);
435 return (0);
436 }
437
438 static void
me_delete_tunnel(struct me_softc * sc)439 me_delete_tunnel(struct me_softc *sc)
440 {
441
442 sx_assert(&me_ioctl_sx, SA_XLOCKED);
443 if (ME_READY(sc)) {
444 CK_LIST_REMOVE(sc, chain);
445 CK_LIST_REMOVE(sc, srchash);
446 ME_WAIT();
447
448 sc->me_src.s_addr = 0;
449 sc->me_dst.s_addr = 0;
450 ME2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
451 if_link_state_change(ME2IFP(sc), LINK_STATE_DOWN);
452 }
453 }
454
455 static uint16_t
me_in_cksum(uint16_t * p,int nwords)456 me_in_cksum(uint16_t *p, int nwords)
457 {
458 uint32_t sum = 0;
459
460 while (nwords-- > 0)
461 sum += *p++;
462 sum = (sum >> 16) + (sum & 0xffff);
463 sum += (sum >> 16);
464 return (~sum);
465 }
466
467 static int
me_input(struct mbuf * m,int off,int proto,void * arg)468 me_input(struct mbuf *m, int off, int proto, void *arg)
469 {
470 struct me_softc *sc = arg;
471 struct mobhdr *mh;
472 struct ifnet *ifp;
473 struct ip *ip;
474 int hlen;
475
476 NET_EPOCH_ASSERT();
477
478 ifp = ME2IFP(sc);
479 /* checks for short packets */
480 hlen = sizeof(struct mobhdr);
481 if (m->m_pkthdr.len < sizeof(struct ip) + hlen)
482 hlen -= sizeof(struct in_addr);
483 if (m->m_len < sizeof(struct ip) + hlen)
484 m = m_pullup(m, sizeof(struct ip) + hlen);
485 if (m == NULL)
486 goto drop;
487 mh = (struct mobhdr *)mtodo(m, sizeof(struct ip));
488 /* check for wrong flags */
489 if (mh->mob_flags & (~MOB_FLAGS_SP)) {
490 m_freem(m);
491 goto drop;
492 }
493 if (mh->mob_flags) {
494 if (hlen != sizeof(struct mobhdr)) {
495 m_freem(m);
496 goto drop;
497 }
498 } else
499 hlen = sizeof(struct mobhdr) - sizeof(struct in_addr);
500 /* check mobile header checksum */
501 if (me_in_cksum((uint16_t *)mh, hlen / sizeof(uint16_t)) != 0) {
502 m_freem(m);
503 goto drop;
504 }
505 #ifdef MAC
506 mac_ifnet_create_mbuf(ifp, m);
507 #endif
508 ip = mtod(m, struct ip *);
509 ip->ip_dst = mh->mob_dst;
510 ip->ip_p = mh->mob_proto;
511 ip->ip_sum = 0;
512 ip->ip_len = htons(m->m_pkthdr.len - hlen);
513 if (mh->mob_flags)
514 ip->ip_src = mh->mob_src;
515 memmove(mtodo(m, hlen), ip, sizeof(struct ip));
516 m_adj(m, hlen);
517 m_clrprotoflags(m);
518 m->m_pkthdr.rcvif = ifp;
519 m->m_pkthdr.csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID);
520 M_SETFIB(m, ifp->if_fib);
521 hlen = AF_INET;
522 BPF_MTAP2(ifp, &hlen, sizeof(hlen), m);
523 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
524 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
525 if ((ifp->if_flags & IFF_MONITOR) != 0)
526 m_freem(m);
527 else
528 netisr_dispatch(NETISR_IP, m);
529 return (IPPROTO_DONE);
530 drop:
531 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
532 return (IPPROTO_DONE);
533 }
534
535 static int
me_output(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * ro)536 me_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
537 struct route *ro)
538 {
539 uint32_t af;
540
541 /* BPF writes need to be handled specially. */
542 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT)
543 bcopy(dst->sa_data, &af, sizeof(af));
544 else
545 af = RO_GET_FAMILY(ro, dst);
546 m->m_pkthdr.csum_data = af;
547 return (ifp->if_transmit(ifp, m));
548 }
549
550 #define MTAG_ME 1414491977
551 static int
me_transmit(struct ifnet * ifp,struct mbuf * m)552 me_transmit(struct ifnet *ifp, struct mbuf *m)
553 {
554 ME_RLOCK_TRACKER;
555 struct mobhdr mh;
556 struct me_softc *sc;
557 struct ip *ip;
558 uint32_t af;
559 int error, hlen, plen;
560
561 ME_RLOCK();
562 #ifdef MAC
563 error = mac_ifnet_check_transmit(ifp, m);
564 if (error != 0)
565 goto drop;
566 #endif
567 error = ENETDOWN;
568 sc = ifp->if_softc;
569 if (sc == NULL || !ME_READY(sc) ||
570 (ifp->if_flags & IFF_MONITOR) != 0 ||
571 (ifp->if_flags & IFF_UP) == 0 ||
572 (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
573 (error = if_tunnel_check_nesting(ifp, m, MTAG_ME,
574 V_max_me_nesting)) != 0) {
575 m_freem(m);
576 goto drop;
577 }
578 af = m->m_pkthdr.csum_data;
579 if (af != AF_INET) {
580 error = EAFNOSUPPORT;
581 m_freem(m);
582 goto drop;
583 }
584 if (m->m_len < sizeof(struct ip))
585 m = m_pullup(m, sizeof(struct ip));
586 if (m == NULL) {
587 error = ENOBUFS;
588 goto drop;
589 }
590 ip = mtod(m, struct ip *);
591 /* Fragmented datagramms shouldn't be encapsulated */
592 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
593 error = EINVAL;
594 m_freem(m);
595 goto drop;
596 }
597 mh.mob_proto = ip->ip_p;
598 mh.mob_src = ip->ip_src;
599 mh.mob_dst = ip->ip_dst;
600 if (in_hosteq(sc->me_src, ip->ip_src)) {
601 hlen = sizeof(struct mobhdr) - sizeof(struct in_addr);
602 mh.mob_flags = 0;
603 } else {
604 hlen = sizeof(struct mobhdr);
605 mh.mob_flags = MOB_FLAGS_SP;
606 }
607 BPF_MTAP2(ifp, &af, sizeof(af), m);
608 plen = m->m_pkthdr.len;
609 ip->ip_src = sc->me_src;
610 ip->ip_dst = sc->me_dst;
611 m->m_flags &= ~(M_BCAST|M_MCAST);
612 M_SETFIB(m, sc->me_fibnum);
613 M_PREPEND(m, hlen, M_NOWAIT);
614 if (m == NULL) {
615 error = ENOBUFS;
616 goto drop;
617 }
618 if (m->m_len < sizeof(struct ip) + hlen)
619 m = m_pullup(m, sizeof(struct ip) + hlen);
620 if (m == NULL) {
621 error = ENOBUFS;
622 goto drop;
623 }
624 memmove(mtod(m, void *), mtodo(m, hlen), sizeof(struct ip));
625 ip = mtod(m, struct ip *);
626 ip->ip_len = htons(m->m_pkthdr.len);
627 ip->ip_p = IPPROTO_MOBILE;
628 ip->ip_sum = 0;
629 mh.mob_csum = 0;
630 mh.mob_csum = me_in_cksum((uint16_t *)&mh, hlen / sizeof(uint16_t));
631 bcopy(&mh, mtodo(m, sizeof(struct ip)), hlen);
632 error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
633 drop:
634 if (error)
635 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
636 else {
637 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
638 if_inc_counter(ifp, IFCOUNTER_OBYTES, plen);
639 }
640 ME_RUNLOCK();
641 return (error);
642 }
643
644 static void
me_qflush(struct ifnet * ifp __unused)645 me_qflush(struct ifnet *ifp __unused)
646 {
647
648 }
649
650 static const struct srcaddrtab *me_srcaddrtab = NULL;
651 static const struct encaptab *ecookie = NULL;
652 static const struct encap_config me_encap_cfg = {
653 .proto = IPPROTO_MOBILE,
654 .min_length = sizeof(struct ip) + sizeof(struct mobhdr) -
655 sizeof(in_addr_t),
656 .exact_match = ENCAP_DRV_LOOKUP,
657 .lookup = me_lookup,
658 .input = me_input
659 };
660
661 static int
memodevent(module_t mod,int type,void * data)662 memodevent(module_t mod, int type, void *data)
663 {
664
665 switch (type) {
666 case MOD_LOAD:
667 me_srcaddrtab = ip_encap_register_srcaddr(me_srcaddr,
668 NULL, M_WAITOK);
669 ecookie = ip_encap_attach(&me_encap_cfg, NULL, M_WAITOK);
670 break;
671 case MOD_UNLOAD:
672 ip_encap_detach(ecookie);
673 ip_encap_unregister_srcaddr(me_srcaddrtab);
674 break;
675 default:
676 return (EOPNOTSUPP);
677 }
678 return (0);
679 }
680
681 static moduledata_t me_mod = {
682 "if_me",
683 memodevent,
684 0
685 };
686
687 DECLARE_MODULE(if_me, me_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
688 MODULE_VERSION(if_me, 1);
689