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 $
21 #include "opt_inet6.h"
24 #include <sys/param.h>
27 #include <sys/systm.h>
29 #include <sys/socket.h>
31 #include <sys/device.h>
32 #include <sys/filio.h>
33 #include <sys/sockio.h>
34 #include <sys/thread2.h>
35 #include <sys/ttycom.h>
36 #include <sys/signalvar.h>
37 #include <sys/filedesc.h>
38 #include <sys/kernel.h>
39 #include <sys/sysctl.h>
41 #include <sys/vnode.h>
42 #include <sys/malloc.h>
44 #include <sys/mplock2.h>
47 #include <net/if_types.h>
48 #include <net/ifq_var.h>
49 #include <net/netisr.h>
50 #include <net/route.h>
51 #include <sys/devfs.h>
54 #include <netinet/in.h>
59 #include "if_tunvar.h"
62 static MALLOC_DEFINE(M_TUN, "tun", "Tunnel Interface");
64 static void tunattach (void *);
65 PSEUDO_SET(tunattach, if_tun);
67 static void tuncreate (cdev_t dev);
69 #define TUNDEBUG if (tundebug) if_printf
70 static int tundebug = 0;
71 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0,
72 "Enable debug output");
74 static int tunoutput (struct ifnet *, struct mbuf *, struct sockaddr *,
76 static int tunifioctl (struct ifnet *, u_long, caddr_t, struct ucred *);
77 static int tuninit (struct ifnet *);
78 static void tunstart(struct ifnet *, struct ifaltq_subque *);
79 static void tun_filter_detach(struct knote *);
80 static int tun_filter_read(struct knote *, long);
81 static int tun_filter_write(struct knote *, long);
83 static d_open_t tunopen;
84 static d_close_t tunclose;
85 static d_read_t tunread;
86 static d_write_t tunwrite;
87 static d_ioctl_t tunioctl;
88 static d_kqfilter_t tunkqfilter;
90 static d_clone_t tunclone;
91 DEVFS_DECLARE_CLONE_BITMAP(tun);
94 #define TUN_PREALLOCATED_UNITS 4
96 #define TUN_PREALLOCATED_UNITS NTUN
99 static struct dev_ops tun_ops = {
106 .d_kqfilter = tunkqfilter
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 sc = kmalloc(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_all(&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 KNOTE(&tp->tun_rkq.ki_note, 0);
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)
234 struct tun_softc *tp = ifp->if_softc;
236 struct ifaddr_container *ifac;
239 TUNDEBUG(ifp, "tuninit\n");
241 ifp->if_flags |= IFF_UP | IFF_RUNNING;
242 getmicrotime(&ifp->if_lastchange);
244 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
245 struct ifaddr *ifa = ifac->ifa;
247 if (ifa->ifa_addr == NULL) {
249 /* XXX: Should maybe return straight off? */
252 if (ifa->ifa_addr->sa_family == AF_INET) {
253 struct sockaddr_in *si;
255 si = (struct sockaddr_in *)ifa->ifa_addr;
256 if (si->sin_addr.s_addr)
257 tp->tun_flags |= TUN_IASET;
266 * Process an ioctl request.
271 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
273 struct ifreq *ifr = (struct ifreq *)data;
274 struct tun_softc *tp = ifp->if_softc;
280 ifs = (struct ifstat *)data;
282 ksprintf(ifs->ascii + strlen(ifs->ascii),
283 "\tOpened by PID %d\n", tp->tun_pid);
286 error = tuninit(ifp);
287 TUNDEBUG(ifp, "address set, error=%d\n", error);
290 error = tuninit(ifp);
291 TUNDEBUG(ifp, "destination address set, error=%d\n", error);
294 ifp->if_mtu = ifr->ifr_mtu;
295 TUNDEBUG(ifp, "mtu set\n");
308 * tunoutput - queue packets from higher level ready to put out.
313 tunoutput_serialized(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
316 struct tun_softc *tp = ifp->if_softc;
318 struct altq_pktattr pktattr;
320 TUNDEBUG(ifp, "tunoutput\n");
322 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
323 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags);
329 * if the queueing discipline needs packet classification,
330 * do it before prepending link headers.
332 ifq_classify(&ifp->if_snd, m0, dst->sa_family, &pktattr);
334 /* BPF write needs to be handled specially */
335 if (dst->sa_family == AF_UNSPEC) {
336 dst->sa_family = *(mtod(m0, int *));
337 m0->m_len -= sizeof(int);
338 m0->m_pkthdr.len -= sizeof(int);
339 m0->m_data += sizeof(int);
346 * We need to prepend the address family as
349 uint32_t af = dst->sa_family;
351 bpf_ptap(ifp->if_bpf, m0, &af, sizeof(af));
356 /* prepend sockaddr? this may abort if the mbuf allocation fails */
357 if (tp->tun_flags & TUN_LMODE) {
358 /* allocate space for sockaddr */
359 M_PREPEND(m0, dst->sa_len, MB_DONTWAIT);
361 /* if allocation failed drop packet */
363 IFNET_STAT_INC(ifp, oerrors, 1);
366 bcopy(dst, m0->m_data, dst->sa_len);
370 if (tp->tun_flags & TUN_IFHEAD) {
371 /* Prepend the address family */
372 M_PREPEND(m0, 4, MB_DONTWAIT);
374 /* if allocation failed drop packet */
376 IFNET_STAT_INC(ifp, oerrors, 1);
379 *(u_int32_t *)m0->m_data = htonl(dst->sa_family);
382 if (dst->sa_family != AF_INET)
390 error = ifq_handoff(ifp, m0, &pktattr);
392 IFNET_STAT_INC(ifp, collisions, 1);
394 IFNET_STAT_INC(ifp, opackets, 1);
395 if (tp->tun_flags & TUN_RWAIT) {
396 tp->tun_flags &= ~TUN_RWAIT;
400 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
401 pgsigio(tp->tun_sigio, SIGIO, 0);
403 ifnet_deserialize_all(ifp);
404 KNOTE(&tp->tun_rkq.ki_note, 0);
405 ifnet_serialize_all(ifp);
411 tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
416 ifnet_serialize_all(ifp);
417 error = tunoutput_serialized(ifp, m0, dst, rt);
418 ifnet_deserialize_all(ifp);
424 * the ops interface is now pretty minimal.
427 tunioctl(struct dev_ioctl_args *ap)
429 cdev_t dev = ap->a_head.a_dev;
430 struct tun_softc *tp = dev->si_drv1;
431 struct tuninfo *tunp;
435 tunp = (struct tuninfo *)ap->a_data;
436 if (tunp->mtu < IF_MINMTU)
438 tp->tun_if.if_mtu = tunp->mtu;
439 tp->tun_if.if_type = tunp->type;
440 tp->tun_if.if_baudrate = tunp->baudrate;
443 tunp = (struct tuninfo *)ap->a_data;
444 tunp->mtu = tp->tun_if.if_mtu;
445 tunp->type = tp->tun_if.if_type;
446 tunp->baudrate = tp->tun_if.if_baudrate;
449 tundebug = *(int *)ap->a_data;
452 *(int *)ap->a_data = tundebug;
455 if (*(int *)ap->a_data) {
456 tp->tun_flags |= TUN_LMODE;
457 tp->tun_flags &= ~TUN_IFHEAD;
459 tp->tun_flags &= ~TUN_LMODE;
462 if (*(int *)ap->a_data) {
463 tp->tun_flags |= TUN_IFHEAD;
464 tp->tun_flags &= ~TUN_LMODE;
466 tp->tun_flags &= ~TUN_IFHEAD;
469 *(int *)ap->a_data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
472 /* deny this if UP */
473 if (tp->tun_if.if_flags & IFF_UP)
476 switch (*(int *)ap->a_data & ~IFF_MULTICAST) {
477 case IFF_POINTOPOINT:
479 tp->tun_if.if_flags &= ~(IFF_BROADCAST|IFF_POINTOPOINT);
480 tp->tun_if.if_flags |= *(int *)ap->a_data;
487 tp->tun_pid = curproc->p_pid;
490 if (*(int *)ap->a_data)
491 tp->tun_flags |= TUN_ASYNC;
493 tp->tun_flags &= ~TUN_ASYNC;
496 if (!ifsq_is_empty(ifq_get_subq_default(&tp->tun_if.if_snd))) {
500 ifq_get_subq_default(&tp->tun_if.if_snd));
501 for( *(int *)ap->a_data = 0; mb != NULL; mb = mb->m_next)
502 *(int *)ap->a_data += mb->m_len;
504 *(int *)ap->a_data = 0;
508 return (fsetown(*(int *)ap->a_data, &tp->tun_sigio));
511 *(int *)ap->a_data = fgetown(&tp->tun_sigio);
514 /* This is deprecated, FIOSETOWN should be used instead. */
516 return (fsetown(-(*(int *)ap->a_data), &tp->tun_sigio));
518 /* This is deprecated, FIOGETOWN should be used instead. */
520 *(int *)ap->a_data = -fgetown(&tp->tun_sigio);
530 * The ops read interface - reads a packet at a time, or at
531 * least as much of a packet as can be read.
534 tunread(struct dev_read_args *ap)
536 cdev_t dev = ap->a_head.a_dev;
537 struct uio *uio = ap->a_uio;
538 struct tun_softc *tp = dev->si_drv1;
539 struct ifnet *ifp = &tp->tun_if;
540 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd);
544 TUNDEBUG(ifp, "read\n");
545 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
546 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags);
550 tp->tun_flags &= ~TUN_RWAIT;
552 ifnet_serialize_all(ifp);
554 while ((m0 = ifsq_dequeue(ifsq, NULL)) == NULL) {
555 if (ap->a_ioflag & IO_NDELAY) {
556 ifnet_deserialize_all(ifp);
559 tp->tun_flags |= TUN_RWAIT;
560 ifnet_deserialize_all(ifp);
561 if ((error = tsleep(tp, PCATCH, "tunread", 0)) != 0)
563 ifnet_serialize_all(ifp);
566 ifnet_deserialize_all(ifp);
568 while (m0 && uio->uio_resid > 0 && error == 0) {
569 len = (int)szmin(uio->uio_resid, m0->m_len);
571 error = uiomove(mtod(m0, caddr_t), (size_t)len, uio);
576 TUNDEBUG(ifp, "Dropping mbuf\n");
583 * the ops write interface - an atomic write is a packet - or else!
586 tunwrite(struct dev_write_args *ap)
588 cdev_t dev = ap->a_head.a_dev;
589 struct uio *uio = ap->a_uio;
590 struct tun_softc *tp = dev->si_drv1;
591 struct ifnet *ifp = &tp->tun_if;
592 struct mbuf *top, **mp, *m;
598 TUNDEBUG(ifp, "tunwrite\n");
600 if (uio->uio_resid == 0)
603 if (uio->uio_resid > TUNMRU) {
604 TUNDEBUG(ifp, "len=%zd!\n", uio->uio_resid);
607 tlen = uio->uio_resid;
609 /* get a header mbuf */
610 MGETHDR(m, MB_WAIT, MT_DATA);
617 while (error == 0 && uio->uio_resid > 0) {
618 m->m_len = (int)szmin(mlen, uio->uio_resid);
619 error = uiomove(mtod (m, caddr_t), (size_t)m->m_len, uio);
622 if (uio->uio_resid > 0) {
623 MGET (m, MB_WAIT, MT_DATA);
634 IFNET_STAT_INC(ifp, ierrors, 1);
638 top->m_pkthdr.len = (int)tlen;
639 top->m_pkthdr.rcvif = ifp;
645 if (tp->tun_flags & TUN_IFHEAD) {
647 * Conveniently, we already have a 4-byte
648 * address family prepended to our packet !
649 * Inconveniently, it's in the wrong byte
652 if ((top = m_pullup(top, sizeof(family)))
657 *mtod(top, u_int32_t *) =
658 ntohl(*mtod(top, u_int32_t *));
659 bpf_mtap(ifp->if_bpf, top);
660 *mtod(top, u_int32_t *) =
661 htonl(*mtod(top, u_int32_t *));
664 * We need to prepend the address family as
667 static const uint32_t af = AF_INET;
669 bpf_ptap(ifp->if_bpf, top, &af, sizeof(af));
676 if (tp->tun_flags & TUN_IFHEAD) {
677 if (top->m_len < sizeof(family) &&
678 (top = m_pullup(top, sizeof(family))) == NULL)
680 family = ntohl(*mtod(top, u_int32_t *));
681 m_adj(top, sizeof(family));
685 IFNET_STAT_INC(ifp, ibytes, top->m_pkthdr.len);
686 IFNET_STAT_INC(ifp, ipackets, 1);
706 return (EAFNOSUPPORT);
709 netisr_queue(isr, top);
713 static struct filterops tun_read_filtops =
714 { FILTEROP_ISFD, NULL, tun_filter_detach, tun_filter_read };
715 static struct filterops tun_write_filtops =
716 { FILTEROP_ISFD, NULL, tun_filter_detach, tun_filter_write };
719 tunkqfilter(struct dev_kqfilter_args *ap)
721 cdev_t dev = ap->a_head.a_dev;
722 struct tun_softc *tp = dev->si_drv1;
723 struct knote *kn = ap->a_kn;
727 ifnet_serialize_all(&tp->tun_if);
729 switch (kn->kn_filter) {
731 kn->kn_fop = &tun_read_filtops;
732 kn->kn_hook = (caddr_t)tp;
735 kn->kn_fop = &tun_write_filtops;
736 kn->kn_hook = (caddr_t)tp;
739 ifnet_deserialize_all(&tp->tun_if);
740 ap->a_result = EOPNOTSUPP;
744 klist = &tp->tun_rkq.ki_note;
745 knote_insert(klist, kn);
746 ifnet_deserialize_all(&tp->tun_if);
752 tun_filter_detach(struct knote *kn)
754 struct tun_softc *tp = (struct tun_softc *)kn->kn_hook;
755 struct klist *klist = &tp->tun_rkq.ki_note;
757 knote_remove(klist, kn);
761 tun_filter_write(struct knote *kn, long hint)
763 /* Always ready for a write */
768 tun_filter_read(struct knote *kn, long hint)
770 struct tun_softc *tp = (struct tun_softc *)kn->kn_hook;
773 ifnet_serialize_all(&tp->tun_if);
774 if (!ifsq_is_empty(ifq_get_subq_default(&tp->tun_if.if_snd)))
776 ifnet_deserialize_all(&tp->tun_if);
782 * Start packet transmission on the interface.
783 * when the interface queue is rate-limited by ALTQ,
784 * if_start is needed to drain packets from the queue in order
785 * to notify readers when outgoing packets become ready.
788 tunstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
790 struct tun_softc *tp = ifp->if_softc;
793 ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
795 if (!ifq_is_enabled(&ifp->if_snd))
800 if (tp->tun_flags & TUN_RWAIT) {
801 tp->tun_flags &= ~TUN_RWAIT;
804 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
805 pgsigio(tp->tun_sigio, SIGIO, 0);
806 ifnet_deserialize_tx(ifp, ifsq);
807 KNOTE(&tp->tun_rkq.ki_note, 0);
808 ifnet_serialize_tx(ifp, ifsq);