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 $
20 #include "opt_atalk.h"
22 #include "opt_inet6.h"
25 #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>
37 #include <sys/signalvar.h>
38 #include <sys/filedesc.h>
39 #include <sys/kernel.h>
40 #include <sys/sysctl.h>
42 #include <sys/vnode.h>
43 #include <sys/malloc.h>
46 #include <net/if_types.h>
47 #include <net/ifq_var.h>
48 #include <net/netisr.h>
49 #include <net/route.h>
52 #include <netinet/in.h>
57 #include "if_tunvar.h"
60 static MALLOC_DEFINE(M_TUN, "tun", "Tunnel Interface");
62 static void tunattach (void *);
63 PSEUDO_SET(tunattach, if_tun);
65 static void tuncreate (cdev_t dev);
67 #define TUNDEBUG if (tundebug) if_printf
68 static int tundebug = 0;
69 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
71 static int tunoutput (struct ifnet *, struct mbuf *, struct sockaddr *,
73 static int tunifioctl (struct ifnet *, u_long, caddr_t, struct ucred *);
74 static int tuninit (struct ifnet *);
75 static void tunstart(struct ifnet *);
77 static d_open_t tunopen;
78 static d_close_t tunclose;
79 static d_read_t tunread;
80 static d_write_t tunwrite;
81 static d_ioctl_t tunioctl;
82 static d_poll_t tunpoll;
85 static struct dev_ops tun_ops = {
86 { "tun", CDEV_MAJOR, 0 },
96 tunattach(void *dummy)
98 dev_ops_add(&tun_ops, 0, 0);
102 tuncreate(cdev_t dev)
104 struct tun_softc *sc;
107 dev = make_dev(&tun_ops, minor(dev),
108 UID_UUCP, GID_DIALER, 0600, "tun%d", lminor(dev));
110 MALLOC(sc, struct tun_softc *, sizeof(*sc), M_TUN, M_WAITOK | M_ZERO);
111 sc->tun_flags = TUN_INITED;
114 if_initname(ifp, "tun", lminor(dev));
115 ifp->if_mtu = TUNMTU;
116 ifp->if_ioctl = tunifioctl;
117 ifp->if_output = tunoutput;
118 ifp->if_start = tunstart;
119 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
120 ifp->if_type = IFT_PPP;
121 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
122 ifq_set_ready(&ifp->if_snd);
124 if_attach(ifp, NULL);
125 bpfattach(ifp, DLT_NULL, sizeof(u_int));
130 * tunnel open - must be superuser & the device must be
134 tunopen(struct dev_open_args *ap)
136 cdev_t dev = ap->a_head.a_dev;
138 struct tun_softc *tp;
141 if ((error = suser_cred(ap->a_cred, 0)) != 0)
149 if (tp->tun_flags & TUN_OPEN)
151 tp->tun_pid = curproc->p_pid;
153 tp->tun_flags |= TUN_OPEN;
154 TUNDEBUG(ifp, "open\n");
159 * tunclose - close the device - mark i/f down & delete
163 tunclose(struct dev_close_args *ap)
165 cdev_t dev = ap->a_head.a_dev;
166 struct tun_softc *tp;
172 tp->tun_flags &= ~TUN_OPEN;
175 /* Junk all pending output. */
176 lwkt_serialize_enter(ifp->if_serializer);
177 ifq_purge(&ifp->if_snd);
178 lwkt_serialize_exit(ifp->if_serializer);
180 if (ifp->if_flags & IFF_UP) {
181 lwkt_serialize_enter(ifp->if_serializer);
183 lwkt_serialize_exit(ifp->if_serializer);
185 ifp->if_flags &= ~IFF_RUNNING;
186 if_purgeaddrs_nolink(ifp);
188 funsetown(tp->tun_sigio);
189 selwakeup(&tp->tun_rsel);
191 TUNDEBUG(ifp, "closed\n");
196 tuninit(struct ifnet *ifp)
198 struct tun_softc *tp = ifp->if_softc;
199 struct ifaddr_container *ifac;
202 TUNDEBUG(ifp, "tuninit\n");
204 ifp->if_flags |= IFF_UP | IFF_RUNNING;
205 getmicrotime(&ifp->if_lastchange);
207 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
208 struct ifaddr *ifa = ifac->ifa;
210 if (ifa->ifa_addr == NULL) {
212 /* XXX: Should maybe return straight off? */
215 if (ifa->ifa_addr->sa_family == AF_INET) {
216 struct sockaddr_in *si;
218 si = (struct sockaddr_in *)ifa->ifa_addr;
219 if (si->sin_addr.s_addr)
220 tp->tun_flags |= TUN_IASET;
229 * Process an ioctl request.
234 tunifioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
236 struct ifreq *ifr = (struct ifreq *)data;
237 struct tun_softc *tp = ifp->if_softc;
243 ifs = (struct ifstat *)data;
245 ksprintf(ifs->ascii + strlen(ifs->ascii),
246 "\tOpened by PID %d\n", tp->tun_pid);
249 error = tuninit(ifp);
250 TUNDEBUG(ifp, "address set, error=%d\n", error);
253 error = tuninit(ifp);
254 TUNDEBUG(ifp, "destination address set, error=%d\n", error);
257 ifp->if_mtu = ifr->ifr_mtu;
258 TUNDEBUG(ifp, "mtu set\n");
271 * tunoutput - queue packets from higher level ready to put out.
276 tunoutput_serialized(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
279 struct tun_softc *tp = ifp->if_softc;
281 struct altq_pktattr pktattr;
283 TUNDEBUG(ifp, "tunoutput\n");
285 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
286 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags);
292 * if the queueing discipline needs packet classification,
293 * do it before prepending link headers.
295 ifq_classify(&ifp->if_snd, m0, dst->sa_family, &pktattr);
297 /* BPF write needs to be handled specially */
298 if (dst->sa_family == AF_UNSPEC) {
299 dst->sa_family = *(mtod(m0, int *));
300 m0->m_len -= sizeof(int);
301 m0->m_pkthdr.len -= sizeof(int);
302 m0->m_data += sizeof(int);
307 * We need to prepend the address family as
310 uint32_t af = dst->sa_family;
312 bpf_ptap(ifp->if_bpf, m0, &af, sizeof(af));
315 /* prepend sockaddr? this may abort if the mbuf allocation fails */
316 if (tp->tun_flags & TUN_LMODE) {
317 /* allocate space for sockaddr */
318 M_PREPEND(m0, dst->sa_len, MB_DONTWAIT);
320 /* if allocation failed drop packet */
322 IF_DROP(&ifp->if_snd);
326 bcopy(dst, m0->m_data, dst->sa_len);
330 if (tp->tun_flags & TUN_IFHEAD) {
331 /* Prepend the address family */
332 M_PREPEND(m0, 4, MB_DONTWAIT);
334 /* if allocation failed drop packet */
336 IF_DROP(&ifp->if_snd);
340 *(u_int32_t *)m0->m_data = htonl(dst->sa_family);
343 if (dst->sa_family != AF_INET)
351 error = ifq_handoff(ifp, m0, &pktattr);
353 ifp->if_collisions++;
356 if (tp->tun_flags & TUN_RWAIT) {
357 tp->tun_flags &= ~TUN_RWAIT;
361 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
362 pgsigio(tp->tun_sigio, SIGIO, 0);
363 selwakeup(&tp->tun_rsel);
370 tunoutput(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
375 lwkt_serialize_enter(ifp->if_serializer);
376 error = tunoutput_serialized(ifp, m0, dst, rt);
377 lwkt_serialize_exit(ifp->if_serializer);
383 * the ops interface is now pretty minimal.
386 tunioctl(struct dev_ioctl_args *ap)
388 cdev_t dev = ap->a_head.a_dev;
389 struct tun_softc *tp = dev->si_drv1;
390 struct tuninfo *tunp;
394 tunp = (struct tuninfo *)ap->a_data;
395 if (tunp->mtu < IF_MINMTU)
397 tp->tun_if.if_mtu = tunp->mtu;
398 tp->tun_if.if_type = tunp->type;
399 tp->tun_if.if_baudrate = tunp->baudrate;
402 tunp = (struct tuninfo *)ap->a_data;
403 tunp->mtu = tp->tun_if.if_mtu;
404 tunp->type = tp->tun_if.if_type;
405 tunp->baudrate = tp->tun_if.if_baudrate;
408 tundebug = *(int *)ap->a_data;
411 *(int *)ap->a_data = tundebug;
414 if (*(int *)ap->a_data) {
415 tp->tun_flags |= TUN_LMODE;
416 tp->tun_flags &= ~TUN_IFHEAD;
418 tp->tun_flags &= ~TUN_LMODE;
421 if (*(int *)ap->a_data) {
422 tp->tun_flags |= TUN_IFHEAD;
423 tp->tun_flags &= ~TUN_LMODE;
425 tp->tun_flags &= ~TUN_IFHEAD;
428 *(int *)ap->a_data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
431 /* deny this if UP */
432 if (tp->tun_if.if_flags & IFF_UP)
435 switch (*(int *)ap->a_data & ~IFF_MULTICAST) {
436 case IFF_POINTOPOINT:
438 tp->tun_if.if_flags &= ~(IFF_BROADCAST|IFF_POINTOPOINT);
439 tp->tun_if.if_flags |= *(int *)ap->a_data;
446 tp->tun_pid = curproc->p_pid;
449 if (*(int *)ap->a_data)
450 tp->tun_flags |= TUN_ASYNC;
452 tp->tun_flags &= ~TUN_ASYNC;
455 lwkt_serialize_enter(tp->tun_if.if_serializer);
456 if (!ifq_is_empty(&tp->tun_if.if_snd)) {
459 mb = ifq_poll(&tp->tun_if.if_snd);
460 for( *(int *)ap->a_data = 0; mb != 0; mb = mb->m_next)
461 *(int *)ap->a_data += mb->m_len;
463 *(int *)ap->a_data = 0;
465 lwkt_serialize_exit(tp->tun_if.if_serializer);
468 return (fsetown(*(int *)ap->a_data, &tp->tun_sigio));
471 *(int *)ap->a_data = fgetown(tp->tun_sigio);
474 /* This is deprecated, FIOSETOWN should be used instead. */
476 return (fsetown(-(*(int *)ap->a_data), &tp->tun_sigio));
478 /* This is deprecated, FIOGETOWN should be used instead. */
480 *(int *)ap->a_data = -fgetown(tp->tun_sigio);
490 * The ops read interface - reads a packet at a time, or at
491 * least as much of a packet as can be read.
494 tunread(struct dev_read_args *ap)
496 cdev_t dev = ap->a_head.a_dev;
497 struct uio *uio = ap->a_uio;
498 struct tun_softc *tp = dev->si_drv1;
499 struct ifnet *ifp = &tp->tun_if;
503 TUNDEBUG(ifp, "read\n");
504 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
505 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags);
509 tp->tun_flags &= ~TUN_RWAIT;
511 lwkt_serialize_enter(ifp->if_serializer);
513 while ((m0 = ifq_dequeue(&ifp->if_snd, NULL)) == NULL) {
514 if (ap->a_ioflag & IO_NDELAY) {
515 lwkt_serialize_exit(ifp->if_serializer);
518 tp->tun_flags |= TUN_RWAIT;
519 lwkt_serialize_exit(ifp->if_serializer);
520 if ((error = tsleep(tp, PCATCH, "tunread", 0)) != 0)
522 lwkt_serialize_enter(ifp->if_serializer);
525 lwkt_serialize_exit(ifp->if_serializer);
527 while (m0 && uio->uio_resid > 0 && error == 0) {
528 len = min(uio->uio_resid, m0->m_len);
530 error = uiomove(mtod(m0, caddr_t), len, uio);
535 TUNDEBUG(ifp, "Dropping mbuf\n");
542 * the ops write interface - an atomic write is a packet - or else!
545 tunwrite(struct dev_write_args *ap)
547 cdev_t dev = ap->a_head.a_dev;
548 struct uio *uio = ap->a_uio;
549 struct tun_softc *tp = dev->si_drv1;
550 struct ifnet *ifp = &tp->tun_if;
551 struct mbuf *top, **mp, *m;
552 int error=0, tlen, mlen;
556 TUNDEBUG(ifp, "tunwrite\n");
558 if (uio->uio_resid == 0)
561 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) {
562 TUNDEBUG(ifp, "len=%d!\n", uio->uio_resid);
565 tlen = uio->uio_resid;
567 /* get a header mbuf */
568 MGETHDR(m, MB_DONTWAIT, MT_DATA);
575 while (error == 0 && uio->uio_resid > 0) {
576 m->m_len = min(mlen, uio->uio_resid);
577 error = uiomove(mtod (m, caddr_t), m->m_len, uio);
580 if (uio->uio_resid > 0) {
581 MGET (m, MB_DONTWAIT, MT_DATA);
596 top->m_pkthdr.len = tlen;
597 top->m_pkthdr.rcvif = ifp;
600 if (tp->tun_flags & TUN_IFHEAD) {
602 * Conveniently, we already have a 4-byte address
603 * family prepended to our packet !
604 * Inconveniently, it's in the wrong byte order !
606 if ((top = m_pullup(top, sizeof(family))) == NULL)
608 *mtod(top, u_int32_t *) =
609 ntohl(*mtod(top, u_int32_t *));
610 bpf_mtap(ifp->if_bpf, top);
611 *mtod(top, u_int32_t *) =
612 htonl(*mtod(top, u_int32_t *));
615 * We need to prepend the address family as
618 static const uint32_t af = AF_INET;
620 bpf_ptap(ifp->if_bpf, top, &af, sizeof(af));
624 if (tp->tun_flags & TUN_IFHEAD) {
625 if (top->m_len < sizeof(family) &&
626 (top = m_pullup(top, sizeof(family))) == NULL)
628 family = ntohl(*mtod(top, u_int32_t *));
629 m_adj(top, sizeof(family));
633 ifp->if_ibytes += top->m_pkthdr.len;
659 return (EAFNOSUPPORT);
662 netisr_dispatch(isr, top);
667 * tunpoll - the poll interface, this is only useful on reads
668 * really. The write detect always returns true, write never blocks
669 * anyway, it either accepts the packet or drops it.
672 tunpoll(struct dev_poll_args *ap)
674 cdev_t dev = ap->a_head.a_dev;
675 struct tun_softc *tp = dev->si_drv1;
676 struct ifnet *ifp = &tp->tun_if;
679 TUNDEBUG(ifp, "tunpoll\n");
681 lwkt_serialize_enter(ifp->if_serializer);
683 if (ap->a_events & (POLLIN | POLLRDNORM)) {
684 if (!ifq_is_empty(&ifp->if_snd)) {
685 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
686 revents |= ap->a_events & (POLLIN | POLLRDNORM);
688 TUNDEBUG(ifp, "tunpoll waiting\n");
689 selrecord(curthread, &tp->tun_rsel);
692 if (ap->a_events & (POLLOUT | POLLWRNORM))
693 revents |= ap->a_events & (POLLOUT | POLLWRNORM);
695 lwkt_serialize_exit(ifp->if_serializer);
696 ap->a_events = revents;
701 * Start packet transmission on the interface.
702 * when the interface queue is rate-limited by ALTQ,
703 * if_start is needed to drain packets from the queue in order
704 * to notify readers when outgoing packets become ready.
707 tunstart(struct ifnet *ifp)
709 struct tun_softc *tp = ifp->if_softc;
712 if (!ifq_is_enabled(&ifp->if_snd))
715 m = ifq_poll(&ifp->if_snd);
717 if (tp->tun_flags & TUN_RWAIT) {
718 tp->tun_flags &= ~TUN_RWAIT;
721 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
722 pgsigio(tp->tun_sigio, SIGIO, 0);
723 selwakeup(&tp->tun_rsel);