1 /*-
2 * Copyright (c) 2014, 2018 Andrey V. Elsukov <[email protected]>
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/cdefs.h>
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/jail.h>
31 #include <sys/kernel.h>
32 #include <sys/lock.h>
33 #include <sys/malloc.h>
34 #include <sys/module.h>
35 #include <sys/mbuf.h>
36 #include <sys/priv.h>
37 #include <sys/proc.h>
38 #include <sys/socket.h>
39 #include <sys/sockio.h>
40 #include <sys/sx.h>
41 #include <sys/sysctl.h>
42 #include <sys/syslog.h>
43
44 #include <net/bpf.h>
45 #include <net/ethernet.h>
46 #include <net/if.h>
47 #include <net/if_var.h>
48 #include <net/if_private.h>
49 #include <net/if_clone.h>
50 #include <net/if_types.h>
51 #include <net/netisr.h>
52 #include <net/vnet.h>
53 #include <net/route.h>
54
55 #include <netinet/in.h>
56 #include <netinet/in_systm.h>
57 #include <netinet/in_var.h>
58 #include <netinet/ip.h>
59 #include <netinet/ip_var.h>
60 #include <netinet/ip_encap.h>
61
62 #include <machine/in_cksum.h>
63 #include <security/mac/mac_framework.h>
64
65 #define MEMTU (1500 - sizeof(struct mobhdr))
66 static const char mename[] = "me";
67 static MALLOC_DEFINE(M_IFME, mename, "Minimal Encapsulation for IP");
68 /* Minimal forwarding header RFC 2004 */
69 struct mobhdr {
70 uint8_t mob_proto; /* protocol */
71 uint8_t mob_flags; /* flags */
72 #define MOB_FLAGS_SP 0x80 /* source present */
73 uint16_t mob_csum; /* header checksum */
74 struct in_addr mob_dst; /* original destination address */
75 struct in_addr mob_src; /* original source addr (optional) */
76 } __packed;
77
78 struct me_softc {
79 struct ifnet *me_ifp;
80 u_int me_fibnum;
81 struct in_addr me_src;
82 struct in_addr me_dst;
83
84 CK_LIST_ENTRY(me_softc) chain;
85 CK_LIST_ENTRY(me_softc) srchash;
86 };
87 CK_LIST_HEAD(me_list, me_softc);
88 #define ME2IFP(sc) ((sc)->me_ifp)
89 #define ME_READY(sc) ((sc)->me_src.s_addr != 0)
90 #define ME_RLOCK_TRACKER struct epoch_tracker me_et
91 #define ME_RLOCK() epoch_enter_preempt(net_epoch_preempt, &me_et)
92 #define ME_RUNLOCK() epoch_exit_preempt(net_epoch_preempt, &me_et)
93 #define ME_WAIT() epoch_wait_preempt(net_epoch_preempt)
94
95 #ifndef ME_HASH_SIZE
96 #define ME_HASH_SIZE (1 << 4)
97 #endif
98 VNET_DEFINE_STATIC(struct me_list *, me_hashtbl) = NULL;
99 VNET_DEFINE_STATIC(struct me_list *, me_srchashtbl) = NULL;
100 #define V_me_hashtbl VNET(me_hashtbl)
101 #define V_me_srchashtbl VNET(me_srchashtbl)
102 #define ME_HASH(src, dst) (V_me_hashtbl[\
103 me_hashval((src), (dst)) & (ME_HASH_SIZE - 1)])
104 #define ME_SRCHASH(src) (V_me_srchashtbl[\
105 fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (ME_HASH_SIZE - 1)])
106
107 static struct sx me_ioctl_sx;
108 SX_SYSINIT(me_ioctl_sx, &me_ioctl_sx, "me_ioctl");
109
110 static int me_clone_create(struct if_clone *, int, caddr_t);
111 static void me_clone_destroy(struct ifnet *);
112 VNET_DEFINE_STATIC(struct if_clone *, me_cloner);
113 #define V_me_cloner VNET(me_cloner)
114
115 #ifdef VIMAGE
116 static void me_reassign(struct ifnet *, struct vnet *, char *);
117 #endif
118 static void me_qflush(struct ifnet *);
119 static int me_transmit(struct ifnet *, struct mbuf *);
120 static int me_ioctl(struct ifnet *, u_long, caddr_t);
121 static int me_output(struct ifnet *, struct mbuf *,
122 const struct sockaddr *, struct route *);
123 static int me_input(struct mbuf *, int, int, void *);
124
125 static int me_set_tunnel(struct me_softc *, in_addr_t, in_addr_t);
126 static void me_delete_tunnel(struct me_softc *);
127
128 SYSCTL_DECL(_net_link);
129 static SYSCTL_NODE(_net_link, IFT_TUNNEL, me, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
130 "Minimal Encapsulation for IP (RFC 2004)");
131 #ifndef MAX_ME_NEST
132 #define MAX_ME_NEST 1
133 #endif
134
135 VNET_DEFINE_STATIC(int, max_me_nesting) = MAX_ME_NEST;
136 #define V_max_me_nesting VNET(max_me_nesting)
137 SYSCTL_INT(_net_link_me, OID_AUTO, max_nesting, CTLFLAG_RW | CTLFLAG_VNET,
138 &VNET_NAME(max_me_nesting), 0, "Max nested tunnels");
139
140 static uint32_t
me_hashval(in_addr_t src,in_addr_t dst)141 me_hashval(in_addr_t src, in_addr_t dst)
142 {
143 uint32_t ret;
144
145 ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT);
146 return (fnv_32_buf(&dst, sizeof(dst), ret));
147 }
148
149 static struct me_list *
me_hashinit(void)150 me_hashinit(void)
151 {
152 struct me_list *hash;
153 int i;
154
155 hash = malloc(sizeof(struct me_list) * ME_HASH_SIZE,
156 M_IFME, M_WAITOK);
157 for (i = 0; i < ME_HASH_SIZE; i++)
158 CK_LIST_INIT(&hash[i]);
159
160 return (hash);
161 }
162
163 static void
vnet_me_init(const void * unused __unused)164 vnet_me_init(const void *unused __unused)
165 {
166
167 V_me_cloner = if_clone_simple(mename, me_clone_create,
168 me_clone_destroy, 0);
169 }
170 VNET_SYSINIT(vnet_me_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
171 vnet_me_init, NULL);
172
173 static void
vnet_me_uninit(const void * unused __unused)174 vnet_me_uninit(const void *unused __unused)
175 {
176
177 if (V_me_hashtbl != NULL) {
178 free(V_me_hashtbl, M_IFME);
179 V_me_hashtbl = NULL;
180 ME_WAIT();
181 free(V_me_srchashtbl, M_IFME);
182 }
183 if_clone_detach(V_me_cloner);
184 }
185 VNET_SYSUNINIT(vnet_me_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
186 vnet_me_uninit, NULL);
187
188 static int
me_clone_create(struct if_clone * ifc,int unit,caddr_t params)189 me_clone_create(struct if_clone *ifc, int unit, caddr_t params)
190 {
191 struct me_softc *sc;
192
193 sc = malloc(sizeof(struct me_softc), M_IFME, M_WAITOK | M_ZERO);
194 sc->me_fibnum = curthread->td_proc->p_fibnum;
195 ME2IFP(sc) = if_alloc(IFT_TUNNEL);
196 ME2IFP(sc)->if_softc = sc;
197 if_initname(ME2IFP(sc), mename, unit);
198
199 ME2IFP(sc)->if_mtu = MEMTU;
200 ME2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
201 ME2IFP(sc)->if_output = me_output;
202 ME2IFP(sc)->if_ioctl = me_ioctl;
203 ME2IFP(sc)->if_transmit = me_transmit;
204 ME2IFP(sc)->if_qflush = me_qflush;
205 #ifdef VIMAGE
206 ME2IFP(sc)->if_reassign = me_reassign;
207 #endif
208 ME2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE;
209 ME2IFP(sc)->if_capenable |= IFCAP_LINKSTATE;
210 if_attach(ME2IFP(sc));
211 bpfattach(ME2IFP(sc), DLT_NULL, sizeof(u_int32_t));
212 return (0);
213 }
214
215 #ifdef VIMAGE
216 static void
me_reassign(struct ifnet * ifp,struct vnet * new_vnet __unused,char * unused __unused)217 me_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
218 char *unused __unused)
219 {
220 struct me_softc *sc;
221
222 sx_xlock(&me_ioctl_sx);
223 sc = ifp->if_softc;
224 if (sc != NULL)
225 me_delete_tunnel(sc);
226 sx_xunlock(&me_ioctl_sx);
227 }
228 #endif /* VIMAGE */
229
230 static void
me_clone_destroy(struct ifnet * ifp)231 me_clone_destroy(struct ifnet *ifp)
232 {
233 struct me_softc *sc;
234
235 sx_xlock(&me_ioctl_sx);
236 sc = ifp->if_softc;
237 me_delete_tunnel(sc);
238 bpfdetach(ifp);
239 if_detach(ifp);
240 ifp->if_softc = NULL;
241 sx_xunlock(&me_ioctl_sx);
242
243 ME_WAIT();
244 if_free(ifp);
245 free(sc, M_IFME);
246 }
247
248 static int
me_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)249 me_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
250 {
251 struct ifreq *ifr = (struct ifreq *)data;
252 struct sockaddr_in *src, *dst;
253 struct me_softc *sc;
254 int error;
255
256 switch (cmd) {
257 case SIOCSIFMTU:
258 if (ifr->ifr_mtu < 576)
259 return (EINVAL);
260 ifp->if_mtu = ifr->ifr_mtu;
261 return (0);
262 case SIOCSIFADDR:
263 ifp->if_flags |= IFF_UP;
264 case SIOCSIFFLAGS:
265 case SIOCADDMULTI:
266 case SIOCDELMULTI:
267 return (0);
268 }
269 sx_xlock(&me_ioctl_sx);
270 sc = ifp->if_softc;
271 if (sc == NULL) {
272 error = ENXIO;
273 goto end;
274 }
275 error = 0;
276 switch (cmd) {
277 case SIOCSIFPHYADDR:
278 src = &((struct in_aliasreq *)data)->ifra_addr;
279 dst = &((struct in_aliasreq *)data)->ifra_dstaddr;
280 if (src->sin_family != dst->sin_family ||
281 src->sin_family != AF_INET ||
282 src->sin_len != dst->sin_len ||
283 src->sin_len != sizeof(struct sockaddr_in)) {
284 error = EINVAL;
285 break;
286 }
287 if (src->sin_addr.s_addr == INADDR_ANY ||
288 dst->sin_addr.s_addr == INADDR_ANY) {
289 error = EADDRNOTAVAIL;
290 break;
291 }
292 error = me_set_tunnel(sc, src->sin_addr.s_addr,
293 dst->sin_addr.s_addr);
294 break;
295 case SIOCDIFPHYADDR:
296 me_delete_tunnel(sc);
297 break;
298 case SIOCGIFPSRCADDR:
299 case SIOCGIFPDSTADDR:
300 if (!ME_READY(sc)) {
301 error = EADDRNOTAVAIL;
302 break;
303 }
304 src = (struct sockaddr_in *)&ifr->ifr_addr;
305 memset(src, 0, sizeof(*src));
306 src->sin_family = AF_INET;
307 src->sin_len = sizeof(*src);
308 switch (cmd) {
309 case SIOCGIFPSRCADDR:
310 src->sin_addr = sc->me_src;
311 break;
312 case SIOCGIFPDSTADDR:
313 src->sin_addr = sc->me_dst;
314 break;
315 }
316 error = prison_if(curthread->td_ucred, sintosa(src));
317 if (error != 0)
318 memset(src, 0, sizeof(*src));
319 break;
320 case SIOCGTUNFIB:
321 ifr->ifr_fib = sc->me_fibnum;
322 break;
323 case SIOCSTUNFIB:
324 if ((error = priv_check(curthread, PRIV_NET_ME)) != 0)
325 break;
326 if (ifr->ifr_fib >= rt_numfibs)
327 error = EINVAL;
328 else
329 sc->me_fibnum = ifr->ifr_fib;
330 break;
331 default:
332 error = EINVAL;
333 break;
334 }
335 end:
336 sx_xunlock(&me_ioctl_sx);
337 return (error);
338 }
339
340 static int
me_lookup(const struct mbuf * m,int off,int proto,void ** arg)341 me_lookup(const struct mbuf *m, int off, int proto, void **arg)
342 {
343 const struct ip *ip;
344 struct me_softc *sc;
345
346 if (V_me_hashtbl == NULL)
347 return (0);
348
349 NET_EPOCH_ASSERT();
350 ip = mtod(m, const struct ip *);
351 CK_LIST_FOREACH(sc, &ME_HASH(ip->ip_dst.s_addr,
352 ip->ip_src.s_addr), chain) {
353 if (sc->me_src.s_addr == ip->ip_dst.s_addr &&
354 sc->me_dst.s_addr == ip->ip_src.s_addr) {
355 if ((ME2IFP(sc)->if_flags & IFF_UP) == 0)
356 return (0);
357 *arg = sc;
358 return (ENCAP_DRV_LOOKUP);
359 }
360 }
361 return (0);
362 }
363
364 /*
365 * Check that ingress address belongs to local host.
366 */
367 static void
me_set_running(struct me_softc * sc)368 me_set_running(struct me_softc *sc)
369 {
370
371 if (in_localip(sc->me_src))
372 ME2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
373 else
374 ME2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
375 }
376
377 /*
378 * ifaddr_event handler.
379 * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
380 * source address spoofing.
381 */
382 static void
me_srcaddr(void * arg __unused,const struct sockaddr * sa,int event __unused)383 me_srcaddr(void *arg __unused, const struct sockaddr *sa,
384 int event __unused)
385 {
386 const struct sockaddr_in *sin;
387 struct me_softc *sc;
388
389 /* Check that VNET is ready */
390 if (V_me_hashtbl == NULL)
391 return;
392
393 NET_EPOCH_ASSERT();
394 sin = (const struct sockaddr_in *)sa;
395 CK_LIST_FOREACH(sc, &ME_SRCHASH(sin->sin_addr.s_addr), srchash) {
396 if (sc->me_src.s_addr != sin->sin_addr.s_addr)
397 continue;
398 me_set_running(sc);
399 }
400 }
401
402 static int
me_set_tunnel(struct me_softc * sc,in_addr_t src,in_addr_t dst)403 me_set_tunnel(struct me_softc *sc, in_addr_t src, in_addr_t dst)
404 {
405 struct epoch_tracker et;
406 struct me_softc *tmp;
407
408 sx_assert(&me_ioctl_sx, SA_XLOCKED);
409
410 if (V_me_hashtbl == NULL) {
411 V_me_hashtbl = me_hashinit();
412 V_me_srchashtbl = me_hashinit();
413 }
414
415 if (sc->me_src.s_addr == src && sc->me_dst.s_addr == dst)
416 return (0);
417
418 CK_LIST_FOREACH(tmp, &ME_HASH(src, dst), chain) {
419 if (tmp == sc)
420 continue;
421 if (tmp->me_src.s_addr == src &&
422 tmp->me_dst.s_addr == dst)
423 return (EADDRNOTAVAIL);
424 }
425
426 me_delete_tunnel(sc);
427 sc->me_dst.s_addr = dst;
428 sc->me_src.s_addr = src;
429 CK_LIST_INSERT_HEAD(&ME_HASH(src, dst), sc, chain);
430 CK_LIST_INSERT_HEAD(&ME_SRCHASH(src), sc, srchash);
431
432 NET_EPOCH_ENTER(et);
433 me_set_running(sc);
434 NET_EPOCH_EXIT(et);
435 if_link_state_change(ME2IFP(sc), LINK_STATE_UP);
436 return (0);
437 }
438
439 static void
me_delete_tunnel(struct me_softc * sc)440 me_delete_tunnel(struct me_softc *sc)
441 {
442
443 sx_assert(&me_ioctl_sx, SA_XLOCKED);
444 if (ME_READY(sc)) {
445 CK_LIST_REMOVE(sc, chain);
446 CK_LIST_REMOVE(sc, srchash);
447 ME_WAIT();
448
449 sc->me_src.s_addr = 0;
450 sc->me_dst.s_addr = 0;
451 ME2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
452 if_link_state_change(ME2IFP(sc), LINK_STATE_DOWN);
453 }
454 }
455
456 static uint16_t
me_in_cksum(uint16_t * p,int nwords)457 me_in_cksum(uint16_t *p, int nwords)
458 {
459 uint32_t sum = 0;
460
461 while (nwords-- > 0)
462 sum += *p++;
463 sum = (sum >> 16) + (sum & 0xffff);
464 sum += (sum >> 16);
465 return (~sum);
466 }
467
468 static int
me_input(struct mbuf * m,int off,int proto,void * arg)469 me_input(struct mbuf *m, int off, int proto, void *arg)
470 {
471 struct me_softc *sc = arg;
472 struct mobhdr *mh;
473 struct ifnet *ifp;
474 struct ip *ip;
475 int hlen;
476
477 NET_EPOCH_ASSERT();
478
479 ifp = ME2IFP(sc);
480 /* checks for short packets */
481 hlen = sizeof(struct mobhdr);
482 if (m->m_pkthdr.len < sizeof(struct ip) + hlen)
483 hlen -= sizeof(struct in_addr);
484 if (m->m_len < sizeof(struct ip) + hlen)
485 m = m_pullup(m, sizeof(struct ip) + hlen);
486 if (m == NULL)
487 goto drop;
488 mh = (struct mobhdr *)mtodo(m, sizeof(struct ip));
489 /* check for wrong flags */
490 if (mh->mob_flags & (~MOB_FLAGS_SP)) {
491 m_freem(m);
492 goto drop;
493 }
494 if (mh->mob_flags) {
495 if (hlen != sizeof(struct mobhdr)) {
496 m_freem(m);
497 goto drop;
498 }
499 } else
500 hlen = sizeof(struct mobhdr) - sizeof(struct in_addr);
501 /* check mobile header checksum */
502 if (me_in_cksum((uint16_t *)mh, hlen / sizeof(uint16_t)) != 0) {
503 m_freem(m);
504 goto drop;
505 }
506 #ifdef MAC
507 mac_ifnet_create_mbuf(ifp, m);
508 #endif
509 ip = mtod(m, struct ip *);
510 ip->ip_dst = mh->mob_dst;
511 ip->ip_p = mh->mob_proto;
512 ip->ip_sum = 0;
513 ip->ip_len = htons(m->m_pkthdr.len - hlen);
514 if (mh->mob_flags)
515 ip->ip_src = mh->mob_src;
516 memmove(mtodo(m, hlen), ip, sizeof(struct ip));
517 m_adj(m, hlen);
518 m_clrprotoflags(m);
519 m->m_pkthdr.rcvif = ifp;
520 m->m_pkthdr.csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID);
521 M_SETFIB(m, ifp->if_fib);
522 hlen = AF_INET;
523 BPF_MTAP2(ifp, &hlen, sizeof(hlen), m);
524 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
525 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
526 if ((ifp->if_flags & IFF_MONITOR) != 0)
527 m_freem(m);
528 else
529 netisr_dispatch(NETISR_IP, m);
530 return (IPPROTO_DONE);
531 drop:
532 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
533 return (IPPROTO_DONE);
534 }
535
536 static int
me_output(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * ro)537 me_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
538 struct route *ro)
539 {
540 uint32_t af;
541
542 /* BPF writes need to be handled specially. */
543 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT)
544 bcopy(dst->sa_data, &af, sizeof(af));
545 else
546 af = RO_GET_FAMILY(ro, dst);
547 m->m_pkthdr.csum_data = af;
548 return (ifp->if_transmit(ifp, m));
549 }
550
551 #define MTAG_ME 1414491977
552 static int
me_transmit(struct ifnet * ifp,struct mbuf * m)553 me_transmit(struct ifnet *ifp, struct mbuf *m)
554 {
555 ME_RLOCK_TRACKER;
556 struct mobhdr mh;
557 struct me_softc *sc;
558 struct ip *ip;
559 uint32_t af;
560 int error, hlen, plen;
561
562 ME_RLOCK();
563 #ifdef MAC
564 error = mac_ifnet_check_transmit(ifp, m);
565 if (error != 0)
566 goto drop;
567 #endif
568 error = ENETDOWN;
569 sc = ifp->if_softc;
570 if (sc == NULL || !ME_READY(sc) ||
571 (ifp->if_flags & IFF_MONITOR) != 0 ||
572 (ifp->if_flags & IFF_UP) == 0 ||
573 (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
574 (error = if_tunnel_check_nesting(ifp, m, MTAG_ME,
575 V_max_me_nesting)) != 0) {
576 m_freem(m);
577 goto drop;
578 }
579 af = m->m_pkthdr.csum_data;
580 if (af != AF_INET) {
581 error = EAFNOSUPPORT;
582 m_freem(m);
583 goto drop;
584 }
585 if (m->m_len < sizeof(struct ip))
586 m = m_pullup(m, sizeof(struct ip));
587 if (m == NULL) {
588 error = ENOBUFS;
589 goto drop;
590 }
591 ip = mtod(m, struct ip *);
592 /* Fragmented datagramms shouldn't be encapsulated */
593 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
594 error = EINVAL;
595 m_freem(m);
596 goto drop;
597 }
598 mh.mob_proto = ip->ip_p;
599 mh.mob_src = ip->ip_src;
600 mh.mob_dst = ip->ip_dst;
601 if (in_hosteq(sc->me_src, ip->ip_src)) {
602 hlen = sizeof(struct mobhdr) - sizeof(struct in_addr);
603 mh.mob_flags = 0;
604 } else {
605 hlen = sizeof(struct mobhdr);
606 mh.mob_flags = MOB_FLAGS_SP;
607 }
608 BPF_MTAP2(ifp, &af, sizeof(af), m);
609 plen = m->m_pkthdr.len;
610 ip->ip_src = sc->me_src;
611 ip->ip_dst = sc->me_dst;
612 m->m_flags &= ~(M_BCAST|M_MCAST);
613 M_SETFIB(m, sc->me_fibnum);
614 M_PREPEND(m, hlen, M_NOWAIT);
615 if (m == NULL) {
616 error = ENOBUFS;
617 goto drop;
618 }
619 if (m->m_len < sizeof(struct ip) + hlen)
620 m = m_pullup(m, sizeof(struct ip) + hlen);
621 if (m == NULL) {
622 error = ENOBUFS;
623 goto drop;
624 }
625 memmove(mtod(m, void *), mtodo(m, hlen), sizeof(struct ip));
626 ip = mtod(m, struct ip *);
627 ip->ip_len = htons(m->m_pkthdr.len);
628 ip->ip_p = IPPROTO_MOBILE;
629 ip->ip_sum = 0;
630 mh.mob_csum = 0;
631 mh.mob_csum = me_in_cksum((uint16_t *)&mh, hlen / sizeof(uint16_t));
632 bcopy(&mh, mtodo(m, sizeof(struct ip)), hlen);
633 error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
634 drop:
635 if (error)
636 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
637 else {
638 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
639 if_inc_counter(ifp, IFCOUNTER_OBYTES, plen);
640 }
641 ME_RUNLOCK();
642 return (error);
643 }
644
645 static void
me_qflush(struct ifnet * ifp __unused)646 me_qflush(struct ifnet *ifp __unused)
647 {
648
649 }
650
651 static const struct srcaddrtab *me_srcaddrtab = NULL;
652 static const struct encaptab *ecookie = NULL;
653 static const struct encap_config me_encap_cfg = {
654 .proto = IPPROTO_MOBILE,
655 .min_length = sizeof(struct ip) + sizeof(struct mobhdr) -
656 sizeof(in_addr_t),
657 .exact_match = ENCAP_DRV_LOOKUP,
658 .lookup = me_lookup,
659 .input = me_input
660 };
661
662 static int
memodevent(module_t mod,int type,void * data)663 memodevent(module_t mod, int type, void *data)
664 {
665
666 switch (type) {
667 case MOD_LOAD:
668 me_srcaddrtab = ip_encap_register_srcaddr(me_srcaddr,
669 NULL, M_WAITOK);
670 ecookie = ip_encap_attach(&me_encap_cfg, NULL, M_WAITOK);
671 break;
672 case MOD_UNLOAD:
673 ip_encap_detach(ecookie);
674 ip_encap_unregister_srcaddr(me_srcaddrtab);
675 break;
676 default:
677 return (EOPNOTSUPP);
678 }
679 return (0);
680 }
681
682 static moduledata_t me_mod = {
683 "if_me",
684 memodevent,
685 0
686 };
687
688 DECLARE_MODULE(if_me, me_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
689 MODULE_VERSION(if_me, 1);
690