1 /* $NetBSD: if_tun.c,v 1.14 1994/06/29 06:36:25 cgd Exp $ */
4 * Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
5 * Nottingham University 1987.
7 * This source may be freely distributed, however I would be interested
8 * in any changes that are made.
10 * This driver takes packets off the IP i/f and hands them up to a
11 * user process to have its wicked way with. This driver has it's
12 * roots in a similar driver written by Phil Cockcroft (formerly) at
13 * UCL. This driver is based much more on read/write/poll mode of
16 * $FreeBSD: src/sys/net/if_tun.c,v 1.74.2.8 2002/02/13 00:43:11 dillon Exp $
17 * $DragonFly: src/sys/net/tun/if_tun.c,v 1.37 2008/06/05 18:06:32 swildner Exp $
21 #include "opt_atalk.h"
23 #include "opt_inet6.h"
26 #include <sys/param.h>
29 #include <sys/systm.h>
31 #include <sys/socket.h>
33 #include <sys/device.h>
34 #include <sys/filio.h>
35 #include <sys/sockio.h>
36 #include <sys/thread2.h>
37 #include <sys/ttycom.h>
39 #include <sys/signalvar.h>
40 #include <sys/filedesc.h>
41 #include <sys/kernel.h>
42 #include <sys/sysctl.h>
44 #include <sys/vnode.h>
45 #include <sys/malloc.h>
47 #include <sys/mplock2.h>
50 #include <net/if_types.h>
51 #include <net/ifq_var.h>
52 #include <net/netisr.h>
53 #include <net/route.h>
54 #include <sys/devfs.h>
57 #include <netinet/in.h>
62 #include "if_tunvar.h"
65 static MALLOC_DEFINE(M_TUN, "tun", "Tunnel Interface");
67 static void tunattach (void *);
68 PSEUDO_SET(tunattach, if_tun);
70 static void tuncreate (cdev_t dev);
72 #define TUNDEBUG if (tundebug) if_printf
73 static int tundebug = 0;
74 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
76 static int tunoutput (struct ifnet *, struct mbuf *, struct sockaddr *,
78 static int tunifioctl (struct ifnet *, u_long, caddr_t, struct ucred *);
79 static int tuninit (struct ifnet *);
80 static void tunstart(struct ifnet *);
82 static d_open_t tunopen;
83 static d_close_t tunclose;
84 static d_read_t tunread;
85 static d_write_t tunwrite;
86 static d_ioctl_t tunioctl;
87 static d_poll_t tunpoll;
89 static d_clone_t tunclone;
90 DEVFS_DECLARE_CLONE_BITMAP(tun);
93 #define TUN_PREALLOCATED_UNITS 4
95 #define TUN_PREALLOCATED_UNITS NTUN
99 static struct dev_ops tun_ops = {
100 { "tun", CDEV_MAJOR, 0 },
110 tunattach(void *dummy)
113 make_autoclone_dev(&tun_ops, &DEVFS_CLONE_BITMAP(tun),
114 tunclone, UID_UUCP, GID_DIALER, 0600, "tun");
115 for (i = 0; i < TUN_PREALLOCATED_UNITS; i++) {
116 make_dev(&tun_ops, i, UID_UUCP, GID_DIALER, 0600, "tun%d", i);
117 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(tun), i);
119 /* Doesn't need uninit because unloading is not possible, see PSEUDO_SET */
123 tunclone(struct dev_clone_args *ap)
127 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(tun), 0);
128 ap->a_dev = make_only_dev(&tun_ops, unit, UID_UUCP, GID_DIALER, 0600,
135 tuncreate(cdev_t dev)
137 struct tun_softc *sc;
141 dev = make_dev(&tun_ops, minor(dev),
142 UID_UUCP, GID_DIALER, 0600, "tun%d", lminor(dev));
145 MALLOC(sc, struct tun_softc *, sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
146 sc->tun_flags = TUN_INITED;
149 if_initname(ifp, "tun", lminor(dev));
150 ifp->if_mtu = TUNMTU;
151 ifp->if_ioctl = tunifioctl;
152 ifp->if_output = tunoutput;
153 ifp->if_start = tunstart;
154 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
155 ifp->if_type = IFT_PPP;
156 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
157 ifq_set_ready(&ifp->if_snd);
159 if_attach(ifp, NULL);
160 bpfattach(ifp, DLT_NULL, sizeof(u_int));
165 * tunnel open - must be superuser & the device must be
169 tunopen(struct dev_open_args *ap)
171 cdev_t dev = ap->a_head.a_dev;
173 struct tun_softc *tp;
176 if ((error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) != 0)
184 if (tp->tun_flags & TUN_OPEN)
186 tp->tun_pid = curproc->p_pid;
188 tp->tun_flags |= TUN_OPEN;
189 TUNDEBUG(ifp, "open\n");
194 * tunclose - close the device - mark i/f down & delete
198 tunclose(struct dev_close_args *ap)
200 cdev_t dev = ap->a_head.a_dev;
201 struct tun_softc *tp;
207 tp->tun_flags &= ~TUN_OPEN;
210 /* Junk all pending output. */
211 ifq_purge(&ifp->if_snd);
213 if (ifp->if_flags & IFF_UP)
215 ifp->if_flags &= ~IFF_RUNNING;
216 if_purgeaddrs_nolink(ifp);
218 funsetown(tp->tun_sigio);
219 selwakeup(&tp->tun_rsel);
221 TUNDEBUG(ifp, "closed\n");
223 if (dev->si_uminor >= TUN_PREALLOCATED_UNITS) {
224 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(tun), dev->si_uminor);
231 tuninit(struct ifnet *ifp)
233 struct tun_softc *tp = ifp->if_softc;
234 struct ifaddr_container *ifac;
237 TUNDEBUG(ifp, "tuninit\n");
239 ifp->if_flags |= IFF_UP | IFF_RUNNING;
240 getmicrotime(&ifp->if_lastchange);
242 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
243 struct ifaddr *ifa = ifac->ifa;
245 if (ifa->ifa_addr == NULL) {
247 /* XXX: Should maybe return straight off? */
250 if (ifa->ifa_addr->sa_family == AF_INET) {
251 struct sockaddr_in *si;
253 si = (struct sockaddr_in *)ifa->ifa_addr;
254 if (si->sin_addr.s_addr)
255 tp->tun_flags |= TUN_IASET;
264 * Process an ioctl request.
269 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
271 struct ifreq *ifr = (struct ifreq *)data;
272 struct tun_softc *tp = ifp->if_softc;
278 ifs = (struct ifstat *)data;
280 ksprintf(ifs->ascii + strlen(ifs->ascii),
281 "\tOpened by PID %d\n", tp->tun_pid);
284 error = tuninit(ifp);
285 TUNDEBUG(ifp, "address set, error=%d\n", error);
288 error = tuninit(ifp);
289 TUNDEBUG(ifp, "destination address set, error=%d\n", error);
292 ifp->if_mtu = ifr->ifr_mtu;
293 TUNDEBUG(ifp, "mtu set\n");
306 * tunoutput - queue packets from higher level ready to put out.
311 tunoutput_serialized(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
314 struct tun_softc *tp = ifp->if_softc;
316 struct altq_pktattr pktattr;
318 TUNDEBUG(ifp, "tunoutput\n");
320 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
321 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags);
327 * if the queueing discipline needs packet classification,
328 * do it before prepending link headers.
330 ifq_classify(&ifp->if_snd, m0, dst->sa_family, &pktattr);
332 /* BPF write needs to be handled specially */
333 if (dst->sa_family == AF_UNSPEC) {
334 dst->sa_family = *(mtod(m0, int *));
335 m0->m_len -= sizeof(int);
336 m0->m_pkthdr.len -= sizeof(int);
337 m0->m_data += sizeof(int);
342 * We need to prepend the address family as
345 uint32_t af = dst->sa_family;
347 bpf_ptap(ifp->if_bpf, m0, &af, sizeof(af));
350 /* prepend sockaddr? this may abort if the mbuf allocation fails */
351 if (tp->tun_flags & TUN_LMODE) {
352 /* allocate space for sockaddr */
353 M_PREPEND(m0, dst->sa_len, MB_DONTWAIT);
355 /* if allocation failed drop packet */
357 IF_DROP(&ifp->if_snd);
361 bcopy(dst, m0->m_data, dst->sa_len);
365 if (tp->tun_flags & TUN_IFHEAD) {
366 /* Prepend the address family */
367 M_PREPEND(m0, 4, MB_DONTWAIT);
369 /* if allocation failed drop packet */
371 IF_DROP(&ifp->if_snd);
375 *(u_int32_t *)m0->m_data = htonl(dst->sa_family);
378 if (dst->sa_family != AF_INET)
386 error = ifq_handoff(ifp, m0, &pktattr);
388 ifp->if_collisions++;
391 if (tp->tun_flags & TUN_RWAIT) {
392 tp->tun_flags &= ~TUN_RWAIT;
396 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
397 pgsigio(tp->tun_sigio, SIGIO, 0);
398 selwakeup(&tp->tun_rsel);
405 tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
410 ifnet_serialize_all(ifp);
411 error = tunoutput_serialized(ifp, m0, dst, rt);
412 ifnet_deserialize_all(ifp);
418 * the ops interface is now pretty minimal.
421 tunioctl(struct dev_ioctl_args *ap)
423 cdev_t dev = ap->a_head.a_dev;
424 struct tun_softc *tp = dev->si_drv1;
425 struct tuninfo *tunp;
429 tunp = (struct tuninfo *)ap->a_data;
430 if (tunp->mtu < IF_MINMTU)
432 tp->tun_if.if_mtu = tunp->mtu;
433 tp->tun_if.if_type = tunp->type;
434 tp->tun_if.if_baudrate = tunp->baudrate;
437 tunp = (struct tuninfo *)ap->a_data;
438 tunp->mtu = tp->tun_if.if_mtu;
439 tunp->type = tp->tun_if.if_type;
440 tunp->baudrate = tp->tun_if.if_baudrate;
443 tundebug = *(int *)ap->a_data;
446 *(int *)ap->a_data = tundebug;
449 if (*(int *)ap->a_data) {
450 tp->tun_flags |= TUN_LMODE;
451 tp->tun_flags &= ~TUN_IFHEAD;
453 tp->tun_flags &= ~TUN_LMODE;
456 if (*(int *)ap->a_data) {
457 tp->tun_flags |= TUN_IFHEAD;
458 tp->tun_flags &= ~TUN_LMODE;
460 tp->tun_flags &= ~TUN_IFHEAD;
463 *(int *)ap->a_data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
466 /* deny this if UP */
467 if (tp->tun_if.if_flags & IFF_UP)
470 switch (*(int *)ap->a_data & ~IFF_MULTICAST) {
471 case IFF_POINTOPOINT:
473 tp->tun_if.if_flags &= ~(IFF_BROADCAST|IFF_POINTOPOINT);
474 tp->tun_if.if_flags |= *(int *)ap->a_data;
481 tp->tun_pid = curproc->p_pid;
484 if (*(int *)ap->a_data)
485 tp->tun_flags |= TUN_ASYNC;
487 tp->tun_flags &= ~TUN_ASYNC;
490 if (!ifq_is_empty(&tp->tun_if.if_snd)) {
493 mb = ifq_poll(&tp->tun_if.if_snd);
494 for( *(int *)ap->a_data = 0; mb != 0; mb = mb->m_next)
495 *(int *)ap->a_data += mb->m_len;
497 *(int *)ap->a_data = 0;
501 return (fsetown(*(int *)ap->a_data, &tp->tun_sigio));
504 *(int *)ap->a_data = fgetown(tp->tun_sigio);
507 /* This is deprecated, FIOSETOWN should be used instead. */
509 return (fsetown(-(*(int *)ap->a_data), &tp->tun_sigio));
511 /* This is deprecated, FIOGETOWN should be used instead. */
513 *(int *)ap->a_data = -fgetown(tp->tun_sigio);
523 * The ops read interface - reads a packet at a time, or at
524 * least as much of a packet as can be read.
527 tunread(struct dev_read_args *ap)
529 cdev_t dev = ap->a_head.a_dev;
530 struct uio *uio = ap->a_uio;
531 struct tun_softc *tp = dev->si_drv1;
532 struct ifnet *ifp = &tp->tun_if;
536 TUNDEBUG(ifp, "read\n");
537 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
538 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags);
542 tp->tun_flags &= ~TUN_RWAIT;
544 ifnet_serialize_all(ifp);
546 while ((m0 = ifq_dequeue(&ifp->if_snd, NULL)) == NULL) {
547 if (ap->a_ioflag & IO_NDELAY) {
548 ifnet_deserialize_all(ifp);
551 tp->tun_flags |= TUN_RWAIT;
552 ifnet_deserialize_all(ifp);
553 if ((error = tsleep(tp, PCATCH, "tunread", 0)) != 0)
555 ifnet_serialize_all(ifp);
558 ifnet_deserialize_all(ifp);
560 while (m0 && uio->uio_resid > 0 && error == 0) {
561 len = (int)szmin(uio->uio_resid, m0->m_len);
563 error = uiomove(mtod(m0, caddr_t), (size_t)len, uio);
568 TUNDEBUG(ifp, "Dropping mbuf\n");
575 * the ops write interface - an atomic write is a packet - or else!
578 tunwrite(struct dev_write_args *ap)
580 cdev_t dev = ap->a_head.a_dev;
581 struct uio *uio = ap->a_uio;
582 struct tun_softc *tp = dev->si_drv1;
583 struct ifnet *ifp = &tp->tun_if;
584 struct mbuf *top, **mp, *m;
590 TUNDEBUG(ifp, "tunwrite\n");
592 if (uio->uio_resid == 0)
595 if (uio->uio_resid > TUNMRU) {
596 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
599 tlen = uio->uio_resid;
601 /* get a header mbuf */
602 MGETHDR(m, MB_DONTWAIT, MT_DATA);
609 while (error == 0 && uio->uio_resid > 0) {
610 m->m_len = (int)szmin(mlen, uio->uio_resid);
611 error = uiomove(mtod (m, caddr_t), (size_t)m->m_len, uio);
614 if (uio->uio_resid > 0) {
615 MGET (m, MB_DONTWAIT, MT_DATA);
630 top->m_pkthdr.len = (int)tlen;
631 top->m_pkthdr.rcvif = ifp;
634 if (tp->tun_flags & TUN_IFHEAD) {
636 * Conveniently, we already have a 4-byte address
637 * family prepended to our packet !
638 * Inconveniently, it's in the wrong byte order !
640 if ((top = m_pullup(top, sizeof(family))) == NULL)
642 *mtod(top, u_int32_t *) =
643 ntohl(*mtod(top, u_int32_t *));
644 bpf_mtap(ifp->if_bpf, top);
645 *mtod(top, u_int32_t *) =
646 htonl(*mtod(top, u_int32_t *));
649 * We need to prepend the address family as
652 static const uint32_t af = AF_INET;
654 bpf_ptap(ifp->if_bpf, top, &af, sizeof(af));
658 if (tp->tun_flags & TUN_IFHEAD) {
659 if (top->m_len < sizeof(family) &&
660 (top = m_pullup(top, sizeof(family))) == NULL)
662 family = ntohl(*mtod(top, u_int32_t *));
663 m_adj(top, sizeof(family));
667 ifp->if_ibytes += top->m_pkthdr.len;
693 return (EAFNOSUPPORT);
696 netisr_dispatch(isr, top);
701 * tunpoll - the poll interface, this is only useful on reads
702 * really. The write detect always returns true, write never blocks
703 * anyway, it either accepts the packet or drops it.
706 tunpoll(struct dev_poll_args *ap)
708 cdev_t dev = ap->a_head.a_dev;
709 struct tun_softc *tp = dev->si_drv1;
710 struct ifnet *ifp = &tp->tun_if;
713 TUNDEBUG(ifp, "tunpoll\n");
715 ifnet_serialize_all(ifp);
717 if (ap->a_events & (POLLIN | POLLRDNORM)) {
718 if (!ifq_is_empty(&ifp->if_snd)) {
719 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
720 revents |= ap->a_events & (POLLIN | POLLRDNORM);
722 TUNDEBUG(ifp, "tunpoll waiting\n");
723 selrecord(curthread, &tp->tun_rsel);
726 if (ap->a_events & (POLLOUT | POLLWRNORM))
727 revents |= ap->a_events & (POLLOUT | POLLWRNORM);
729 ifnet_deserialize_all(ifp);
730 ap->a_events = revents;
735 * Start packet transmission on the interface.
736 * when the interface queue is rate-limited by ALTQ,
737 * if_start is needed to drain packets from the queue in order
738 * to notify readers when outgoing packets become ready.
741 tunstart(struct ifnet *ifp)
743 struct tun_softc *tp = ifp->if_softc;
746 if (!ifq_is_enabled(&ifp->if_snd))
749 m = ifq_poll(&ifp->if_snd);
751 if (tp->tun_flags & TUN_RWAIT) {
752 tp->tun_flags &= ~TUN_RWAIT;
755 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
756 pgsigio(tp->tun_sigio, SIGIO, 0);
757 selwakeup(&tp->tun_rsel);