2 * Copyright (c) 2014, 2018 Andrey V. Elsukov <ae@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
27 #include <sys/cdefs.h>
28 #include <sys/param.h>
29 #include <sys/systm.h>
31 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/module.h>
38 #include <sys/socket.h>
39 #include <sys/sockio.h>
41 #include <sys/sysctl.h>
42 #include <sys/syslog.h>
45 #include <net/ethernet.h>
47 #include <net/if_var.h>
48 #include <net/if_clone.h>
49 #include <net/if_types.h>
50 #include <net/netisr.h>
52 #include <net/route.h>
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>
61 #include <machine/in_cksum.h>
62 #include <security/mac/mac_framework.h>
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 */
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) */
80 struct in_addr me_src;
81 struct in_addr me_dst;
83 CK_LIST_ENTRY(me_softc) chain;
84 CK_LIST_ENTRY(me_softc) srchash;
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)
95 #define ME_HASH_SIZE (1 << 4)
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)])
106 static struct sx me_ioctl_sx;
107 SX_SYSINIT(me_ioctl_sx, &me_ioctl_sx, "me_ioctl");
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)
115 static void me_reassign(struct ifnet *, struct vnet *, char *);
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 *);
124 static int me_set_tunnel(struct me_softc *, in_addr_t, in_addr_t);
125 static void me_delete_tunnel(struct me_softc *);
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)");
131 #define MAX_ME_NEST 1
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");
140 me_hashval(in_addr_t src, in_addr_t dst)
144 ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT);
145 return (fnv_32_buf(&dst, sizeof(dst), ret));
148 static struct me_list *
151 struct me_list *hash;
154 hash = malloc(sizeof(struct me_list) * ME_HASH_SIZE,
156 for (i = 0; i < ME_HASH_SIZE; i++)
157 CK_LIST_INIT(&hash[i]);
163 vnet_me_init(const void *unused __unused)
166 V_me_cloner = if_clone_simple(mename, me_clone_create,
167 me_clone_destroy, 0);
169 VNET_SYSINIT(vnet_me_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
173 vnet_me_uninit(const void *unused __unused)
176 if (V_me_hashtbl != NULL) {
177 free(V_me_hashtbl, M_IFME);
180 free(V_me_srchashtbl, M_IFME);
182 if_clone_detach(V_me_cloner);
184 VNET_SYSUNINIT(vnet_me_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
185 vnet_me_uninit, NULL);
188 me_clone_create(struct if_clone *ifc, int unit, caddr_t params)
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);
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;
205 ME2IFP(sc)->if_reassign = me_reassign;
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));
216 me_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
217 char *unused __unused)
221 sx_xlock(&me_ioctl_sx);
224 me_delete_tunnel(sc);
225 sx_xunlock(&me_ioctl_sx);
230 me_clone_destroy(struct ifnet *ifp)
234 sx_xlock(&me_ioctl_sx);
236 me_delete_tunnel(sc);
239 ifp->if_softc = NULL;
240 sx_xunlock(&me_ioctl_sx);
248 me_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
250 struct ifreq *ifr = (struct ifreq *)data;
251 struct sockaddr_in *src, *dst;
257 if (ifr->ifr_mtu < 576)
259 ifp->if_mtu = ifr->ifr_mtu;
262 ifp->if_flags |= IFF_UP;
268 sx_xlock(&me_ioctl_sx);
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)) {
286 if (src->sin_addr.s_addr == INADDR_ANY ||
287 dst->sin_addr.s_addr == INADDR_ANY) {
288 error = EADDRNOTAVAIL;
291 error = me_set_tunnel(sc, src->sin_addr.s_addr,
292 dst->sin_addr.s_addr);
295 me_delete_tunnel(sc);
297 case SIOCGIFPSRCADDR:
298 case SIOCGIFPDSTADDR:
300 error = EADDRNOTAVAIL;
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);
308 case SIOCGIFPSRCADDR:
309 src->sin_addr = sc->me_src;
311 case SIOCGIFPDSTADDR:
312 src->sin_addr = sc->me_dst;
315 error = prison_if(curthread->td_ucred, sintosa(src));
317 memset(src, 0, sizeof(*src));
320 ifr->ifr_fib = sc->me_fibnum;
323 if ((error = priv_check(curthread, PRIV_NET_ME)) != 0)
325 if (ifr->ifr_fib >= rt_numfibs)
328 sc->me_fibnum = ifr->ifr_fib;
335 sx_xunlock(&me_ioctl_sx);
340 me_lookup(const struct mbuf *m, int off, int proto, void **arg)
345 if (V_me_hashtbl == NULL)
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)
357 return (ENCAP_DRV_LOOKUP);
364 * Check that ingress address belongs to local host.
367 me_set_running(struct me_softc *sc)
370 if (in_localip(sc->me_src))
371 ME2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
373 ME2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
377 * ifaddr_event handler.
378 * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
379 * source address spoofing.
382 me_srcaddr(void *arg __unused, const struct sockaddr *sa,
385 const struct sockaddr_in *sin;
388 /* Check that VNET is ready */
389 if (V_me_hashtbl == NULL)
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)
402 me_set_tunnel(struct me_softc *sc, in_addr_t src, in_addr_t dst)
404 struct me_softc *tmp;
406 sx_assert(&me_ioctl_sx, SA_XLOCKED);
408 if (V_me_hashtbl == NULL) {
409 V_me_hashtbl = me_hashinit();
410 V_me_srchashtbl = me_hashinit();
413 if (sc->me_src.s_addr == src && sc->me_dst.s_addr == dst)
416 CK_LIST_FOREACH(tmp, &ME_HASH(src, dst), chain) {
419 if (tmp->me_src.s_addr == src &&
420 tmp->me_dst.s_addr == dst)
421 return (EADDRNOTAVAIL);
424 me_delete_tunnel(sc);
425 sc->me_dst.s_addr = dst;
426 sc->me_src.s_addr = src;
427 CK_LIST_INSERT_HEAD(&ME_HASH(src, dst), sc, chain);
428 CK_LIST_INSERT_HEAD(&ME_SRCHASH(src), sc, srchash);
431 if_link_state_change(ME2IFP(sc), LINK_STATE_UP);
436 me_delete_tunnel(struct me_softc *sc)
439 sx_assert(&me_ioctl_sx, SA_XLOCKED);
441 CK_LIST_REMOVE(sc, chain);
442 CK_LIST_REMOVE(sc, srchash);
445 sc->me_src.s_addr = 0;
446 sc->me_dst.s_addr = 0;
447 ME2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
448 if_link_state_change(ME2IFP(sc), LINK_STATE_DOWN);
453 me_in_cksum(uint16_t *p, int nwords)
459 sum = (sum >> 16) + (sum & 0xffff);
465 me_input(struct mbuf *m, int off, int proto, void *arg)
467 struct me_softc *sc = arg;
476 /* checks for short packets */
477 hlen = sizeof(struct mobhdr);
478 if (m->m_pkthdr.len < sizeof(struct ip) + hlen)
479 hlen -= sizeof(struct in_addr);
480 if (m->m_len < sizeof(struct ip) + hlen)
481 m = m_pullup(m, sizeof(struct ip) + hlen);
484 mh = (struct mobhdr *)mtodo(m, sizeof(struct ip));
485 /* check for wrong flags */
486 if (mh->mob_flags & (~MOB_FLAGS_SP)) {
491 if (hlen != sizeof(struct mobhdr)) {
496 hlen = sizeof(struct mobhdr) - sizeof(struct in_addr);
497 /* check mobile header checksum */
498 if (me_in_cksum((uint16_t *)mh, hlen / sizeof(uint16_t)) != 0) {
503 mac_ifnet_create_mbuf(ifp, m);
505 ip = mtod(m, struct ip *);
506 ip->ip_dst = mh->mob_dst;
507 ip->ip_p = mh->mob_proto;
509 ip->ip_len = htons(m->m_pkthdr.len - hlen);
511 ip->ip_src = mh->mob_src;
512 memmove(mtodo(m, hlen), ip, sizeof(struct ip));
515 m->m_pkthdr.rcvif = ifp;
516 m->m_pkthdr.csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID);
517 M_SETFIB(m, ifp->if_fib);
519 BPF_MTAP2(ifp, &hlen, sizeof(hlen), m);
520 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
521 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
522 if ((ifp->if_flags & IFF_MONITOR) != 0)
525 netisr_dispatch(NETISR_IP, m);
526 return (IPPROTO_DONE);
528 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
529 return (IPPROTO_DONE);
533 me_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
538 if (dst->sa_family == AF_UNSPEC)
539 bcopy(dst->sa_data, &af, sizeof(af));
541 af = RO_GET_FAMILY(ro, dst);
542 m->m_pkthdr.csum_data = af;
543 return (ifp->if_transmit(ifp, m));
546 #define MTAG_ME 1414491977
548 me_transmit(struct ifnet *ifp, struct mbuf *m)
555 int error, hlen, plen;
559 error = mac_ifnet_check_transmit(ifp, m);
565 if (sc == NULL || !ME_READY(sc) ||
566 (ifp->if_flags & IFF_MONITOR) != 0 ||
567 (ifp->if_flags & IFF_UP) == 0 ||
568 (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
569 (error = if_tunnel_check_nesting(ifp, m, MTAG_ME,
570 V_max_me_nesting)) != 0) {
574 af = m->m_pkthdr.csum_data;
576 error = EAFNOSUPPORT;
580 if (m->m_len < sizeof(struct ip))
581 m = m_pullup(m, sizeof(struct ip));
586 ip = mtod(m, struct ip *);
587 /* Fragmented datagramms shouldn't be encapsulated */
588 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
593 mh.mob_proto = ip->ip_p;
594 mh.mob_src = ip->ip_src;
595 mh.mob_dst = ip->ip_dst;
596 if (in_hosteq(sc->me_src, ip->ip_src)) {
597 hlen = sizeof(struct mobhdr) - sizeof(struct in_addr);
600 hlen = sizeof(struct mobhdr);
601 mh.mob_flags = MOB_FLAGS_SP;
603 BPF_MTAP2(ifp, &af, sizeof(af), m);
604 plen = m->m_pkthdr.len;
605 ip->ip_src = sc->me_src;
606 ip->ip_dst = sc->me_dst;
607 m->m_flags &= ~(M_BCAST|M_MCAST);
608 M_SETFIB(m, sc->me_fibnum);
609 M_PREPEND(m, hlen, M_NOWAIT);
614 if (m->m_len < sizeof(struct ip) + hlen)
615 m = m_pullup(m, sizeof(struct ip) + hlen);
620 memmove(mtod(m, void *), mtodo(m, hlen), sizeof(struct ip));
621 ip = mtod(m, struct ip *);
622 ip->ip_len = htons(m->m_pkthdr.len);
623 ip->ip_p = IPPROTO_MOBILE;
626 mh.mob_csum = me_in_cksum((uint16_t *)&mh, hlen / sizeof(uint16_t));
627 bcopy(&mh, mtodo(m, sizeof(struct ip)), hlen);
628 error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
631 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
633 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
634 if_inc_counter(ifp, IFCOUNTER_OBYTES, plen);
641 me_qflush(struct ifnet *ifp __unused)
646 static const struct srcaddrtab *me_srcaddrtab = NULL;
647 static const struct encaptab *ecookie = NULL;
648 static const struct encap_config me_encap_cfg = {
649 .proto = IPPROTO_MOBILE,
650 .min_length = sizeof(struct ip) + sizeof(struct mobhdr) -
652 .exact_match = ENCAP_DRV_LOOKUP,
658 memodevent(module_t mod, int type, void *data)
663 me_srcaddrtab = ip_encap_register_srcaddr(me_srcaddr,
665 ecookie = ip_encap_attach(&me_encap_cfg, NULL, M_WAITOK);
668 ip_encap_detach(ecookie);
669 ip_encap_unregister_srcaddr(me_srcaddrtab);
677 static moduledata_t me_mod = {
683 DECLARE_MODULE(if_me, me_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
684 MODULE_VERSION(if_me, 1);