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 1.23 2005/07/10 15:17:00 joerg 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>
30 #include <sys/filio.h>
31 #include <sys/sockio.h>
32 #include <sys/thread2.h>
33 #include <sys/ttycom.h>
35 #include <sys/signalvar.h>
36 #include <sys/filedesc.h>
37 #include <sys/kernel.h>
38 #include <sys/sysctl.h>
41 #include <sys/vnode.h>
42 #include <sys/malloc.h>
45 #include <net/if_types.h>
46 #include <net/ifq_var.h>
47 #include <net/netisr.h>
48 #include <net/route.h>
51 #include <netinet/in.h>
56 #include "if_tunvar.h"
59 static MALLOC_DEFINE(M_TUN, "tun", "Tunnel Interface");
61 static void tunattach (void *);
62 PSEUDO_SET(tunattach, if_tun);
64 static void tuncreate (dev_t dev);
66 #define TUNDEBUG if (tundebug) if_printf
67 static int tundebug = 0;
68 SYSCTL_INT(_debug, OID_AUTO, if_tun_debug, CTLFLAG_RW, &tundebug, 0, "");
70 static int tunoutput (struct ifnet *, struct mbuf *, struct sockaddr *,
72 static int tunifioctl (struct ifnet *, u_long, caddr_t, struct ucred *);
73 static int tuninit (struct ifnet *);
74 static void tunstart(struct ifnet *);
76 static d_open_t tunopen;
77 static d_close_t tunclose;
78 static d_read_t tunread;
79 static d_write_t tunwrite;
80 static d_ioctl_t tunioctl;
81 static d_poll_t tunpoll;
84 static struct cdevsw tun_cdevsw = {
98 /* strategy */ nostrategy,
104 tunattach(void *dummy)
106 cdevsw_add(&tun_cdevsw, 0, 0);
113 struct tun_softc *sc;
116 dev = make_dev(&tun_cdevsw, minor(dev),
117 UID_UUCP, GID_DIALER, 0600, "tun%d", lminor(dev));
119 MALLOC(sc, struct tun_softc *, sizeof(*sc), M_TUN, M_WAITOK);
120 bzero(sc, sizeof *sc);
121 sc->tun_flags = TUN_INITED;
124 if_initname(ifp, "tun", lminor(dev));
125 ifp->if_mtu = TUNMTU;
126 ifp->if_ioctl = tunifioctl;
127 ifp->if_output = tunoutput;
128 ifp->if_start = tunstart;
129 ifp->if_flags = IFF_POINTOPOINT | IFF_MULTICAST;
130 ifp->if_type = IFT_PPP;
131 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
132 ifq_set_ready(&ifp->if_snd);
135 bpfattach(ifp, DLT_NULL, sizeof(u_int));
140 * tunnel open - must be superuser & the device must be
144 tunopen(dev_t dev, int flag, int mode, struct thread *td)
147 struct tun_softc *tp;
150 KKASSERT(td->td_proc);
151 if ((error = suser(td)) != NULL)
159 if (tp->tun_flags & TUN_OPEN)
161 tp->tun_pid = td->td_proc->p_pid;
163 tp->tun_flags |= TUN_OPEN;
164 TUNDEBUG(ifp, "open\n");
169 * tunclose - close the device - mark i/f down & delete
173 tunclose(dev_t dev, int foo, int bar, struct thread *td)
175 struct tun_softc *tp;
181 tp->tun_flags &= ~TUN_OPEN;
184 /* Junk all pending output. */
186 ifq_purge(&ifp->if_snd);
189 if (ifp->if_flags & IFF_UP) {
195 if (ifp->if_flags & IFF_RUNNING) {
199 /* find internet addresses and delete routes */
200 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
201 if (ifa->ifa_addr->sa_family == AF_INET)
202 rtinit(ifa, (int)RTM_DELETE,
203 tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0);
204 ifp->if_flags &= ~IFF_RUNNING;
208 funsetown(tp->tun_sigio);
209 selwakeup(&tp->tun_rsel);
211 TUNDEBUG(ifp, "closed\n");
219 struct tun_softc *tp = ifp->if_softc;
223 TUNDEBUG(ifp, "tuninit\n");
225 ifp->if_flags |= IFF_UP | IFF_RUNNING;
226 getmicrotime(&ifp->if_lastchange);
228 for (ifa = TAILQ_FIRST(&ifp->if_addrhead); ifa;
229 ifa = TAILQ_NEXT(ifa, ifa_link)) {
230 if (ifa->ifa_addr == NULL)
232 /* XXX: Should maybe return straight off? */
235 if (ifa->ifa_addr->sa_family == AF_INET) {
236 struct sockaddr_in *si;
238 si = (struct sockaddr_in *)ifa->ifa_addr;
239 if (si->sin_addr.s_addr)
240 tp->tun_flags |= TUN_IASET;
242 si = (struct sockaddr_in *)ifa->ifa_dstaddr;
243 if (si && si->sin_addr.s_addr)
244 tp->tun_flags |= TUN_DSTADDR;
253 * Process an ioctl request.
256 tunifioctl(ifp, cmd, data, cr)
262 struct ifreq *ifr = (struct ifreq *)data;
263 struct tun_softc *tp = ifp->if_softc;
271 ifs = (struct ifstat *)data;
273 sprintf(ifs->ascii + strlen(ifs->ascii),
274 "\tOpened by PID %d\n", tp->tun_pid);
277 error = tuninit(ifp);
278 TUNDEBUG(ifp, "address set, error=%d\n", error);
281 error = tuninit(ifp);
282 TUNDEBUG(ifp, "destination address set, error=%d\n", error);
285 ifp->if_mtu = ifr->ifr_mtu;
286 TUNDEBUG(ifp, "mtu set\n");
301 * tunoutput - queue packets from higher level ready to put out.
304 tunoutput(ifp, m0, dst, rt)
307 struct sockaddr *dst;
310 struct tun_softc *tp = ifp->if_softc;
312 struct altq_pktattr pktattr;
314 TUNDEBUG(ifp, "tunoutput\n");
316 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
317 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags);
323 * if the queueing discipline needs packet classification,
324 * do it before prepending link headers.
326 ifq_classify(&ifp->if_snd, m0, dst->sa_family, &pktattr);
328 /* BPF write needs to be handled specially */
329 if (dst->sa_family == AF_UNSPEC) {
330 dst->sa_family = *(mtod(m0, int *));
331 m0->m_len -= sizeof(int);
332 m0->m_pkthdr.len -= sizeof(int);
333 m0->m_data += sizeof(int);
338 * We need to prepend the address family as
341 uint32_t af = dst->sa_family;
343 bpf_ptap(ifp->if_bpf, m0, &af, sizeof(af));
346 /* prepend sockaddr? this may abort if the mbuf allocation fails */
347 if (tp->tun_flags & TUN_LMODE) {
348 /* allocate space for sockaddr */
349 M_PREPEND(m0, dst->sa_len, MB_DONTWAIT);
351 /* if allocation failed drop packet */
354 IF_DROP(&ifp->if_snd);
359 bcopy(dst, m0->m_data, dst->sa_len);
363 if (tp->tun_flags & TUN_IFHEAD) {
364 /* Prepend the address family */
365 M_PREPEND(m0, 4, MB_DONTWAIT);
367 /* if allocation failed drop packet */
370 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;
395 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
396 pgsigio(tp->tun_sigio, SIGIO, 0);
397 selwakeup(&tp->tun_rsel);
403 * the cdevsw interface is now pretty minimal.
406 tunioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
408 struct tun_softc *tp = dev->si_drv1;
409 struct tuninfo *tunp;
413 tunp = (struct tuninfo *)data;
414 if (tunp->mtu < IF_MINMTU)
416 tp->tun_if.if_mtu = tunp->mtu;
417 tp->tun_if.if_type = tunp->type;
418 tp->tun_if.if_baudrate = tunp->baudrate;
421 tunp = (struct tuninfo *)data;
422 tunp->mtu = tp->tun_if.if_mtu;
423 tunp->type = tp->tun_if.if_type;
424 tunp->baudrate = tp->tun_if.if_baudrate;
427 tundebug = *(int *)data;
430 *(int *)data = tundebug;
434 tp->tun_flags |= TUN_LMODE;
435 tp->tun_flags &= ~TUN_IFHEAD;
437 tp->tun_flags &= ~TUN_LMODE;
441 tp->tun_flags |= TUN_IFHEAD;
442 tp->tun_flags &= ~TUN_LMODE;
444 tp->tun_flags &= ~TUN_IFHEAD;
447 *(int *)data = (tp->tun_flags & TUN_IFHEAD) ? 1 : 0;
450 /* deny this if UP */
451 if (tp->tun_if.if_flags & IFF_UP)
454 switch (*(int *)data & ~IFF_MULTICAST) {
455 case IFF_POINTOPOINT:
457 tp->tun_if.if_flags &= ~(IFF_BROADCAST|IFF_POINTOPOINT);
458 tp->tun_if.if_flags |= *(int *)data;
465 tp->tun_pid = curproc->p_pid;
471 tp->tun_flags |= TUN_ASYNC;
473 tp->tun_flags &= ~TUN_ASYNC;
478 if (!ifq_is_empty(&tp->tun_if.if_snd)) {
481 mb = ifq_poll(&tp->tun_if.if_snd);
482 for( *(int *)data = 0; mb != 0; mb = mb->m_next)
483 *(int *)data += mb->m_len;
490 return (fsetown(*(int *)data, &tp->tun_sigio));
493 *(int *)data = fgetown(tp->tun_sigio);
496 /* This is deprecated, FIOSETOWN should be used instead. */
498 return (fsetown(-(*(int *)data), &tp->tun_sigio));
500 /* This is deprecated, FIOGETOWN should be used instead. */
502 *(int *)data = -fgetown(tp->tun_sigio);
512 * The cdevsw read interface - reads a packet at a time, or at
513 * least as much of a packet as can be read.
516 tunread(dev, uio, flag)
521 struct tun_softc *tp = dev->si_drv1;
522 struct ifnet *ifp = &tp->tun_if;
526 TUNDEBUG(ifp, "read\n");
527 if ((tp->tun_flags & TUN_READY) != TUN_READY) {
528 TUNDEBUG(ifp, "not ready 0%o\n", tp->tun_flags);
532 tp->tun_flags &= ~TUN_RWAIT;
536 while ((m0 = ifq_dequeue(&ifp->if_snd)) == NULL) {
537 if (flag & IO_NDELAY) {
541 tp->tun_flags |= TUN_RWAIT;
542 if ((error = tsleep(tp, PCATCH, "tunread", 0)) != 0) {
550 while (m0 && uio->uio_resid > 0 && error == 0) {
551 len = min(uio->uio_resid, m0->m_len);
553 error = uiomove(mtod(m0, caddr_t), len, uio);
558 TUNDEBUG(ifp, "Dropping mbuf\n");
565 * the cdevsw write interface - an atomic write is a packet - or else!
568 tunwrite(dev, uio, flag)
573 struct tun_softc *tp = dev->si_drv1;
574 struct ifnet *ifp = &tp->tun_if;
575 struct mbuf *top, **mp, *m;
576 int error=0, tlen, mlen;
580 TUNDEBUG(ifp, "tunwrite\n");
582 if (uio->uio_resid == 0)
585 if (uio->uio_resid < 0 || uio->uio_resid > TUNMRU) {
586 TUNDEBUG(ifp, "len=%d!\n", uio->uio_resid);
589 tlen = uio->uio_resid;
591 /* get a header mbuf */
592 MGETHDR(m, MB_DONTWAIT, MT_DATA);
599 while (error == 0 && uio->uio_resid > 0) {
600 m->m_len = min(mlen, uio->uio_resid);
601 error = uiomove(mtod (m, caddr_t), m->m_len, uio);
604 if (uio->uio_resid > 0) {
605 MGET (m, MB_DONTWAIT, MT_DATA);
620 top->m_pkthdr.len = tlen;
621 top->m_pkthdr.rcvif = ifp;
624 if (tp->tun_flags & TUN_IFHEAD) {
626 * Conveniently, we already have a 4-byte address
627 * family prepended to our packet !
628 * Inconveniently, it's in the wrong byte order !
630 if ((top = m_pullup(top, sizeof(family))) == NULL)
632 *mtod(top, u_int32_t *) =
633 ntohl(*mtod(top, u_int32_t *));
634 bpf_mtap(ifp->if_bpf, top);
635 *mtod(top, u_int32_t *) =
636 htonl(*mtod(top, u_int32_t *));
639 * We need to prepend the address family as
642 static const uint32_t af = AF_INET;
644 bpf_ptap(ifp->if_bpf, top, &af, sizeof(af));
648 if (tp->tun_flags & TUN_IFHEAD) {
649 if (top->m_len < sizeof(family) &&
650 (top = m_pullup(top, sizeof(family))) == NULL)
652 family = ntohl(*mtod(top, u_int32_t *));
653 m_adj(top, sizeof(family));
657 ifp->if_ibytes += top->m_pkthdr.len;
683 return (EAFNOSUPPORT);
686 netisr_dispatch(isr, top);
691 * tunpoll - the poll interface, this is only useful on reads
692 * really. The write detect always returns true, write never blocks
693 * anyway, it either accepts the packet or drops it.
696 tunpoll(dev_t dev, int events, struct thread *td)
698 struct tun_softc *tp = dev->si_drv1;
699 struct ifnet *ifp = &tp->tun_if;
702 TUNDEBUG(ifp, "tunpoll\n");
706 if (events & (POLLIN | POLLRDNORM)) {
707 if (!ifq_is_empty(&ifp->if_snd)) {
708 TUNDEBUG(ifp, "tunpoll q=%d\n", ifp->if_snd.ifq_len);
709 revents |= events & (POLLIN | POLLRDNORM);
711 TUNDEBUG(ifp, "tunpoll waiting\n");
712 selrecord(td, &tp->tun_rsel);
715 if (events & (POLLOUT | POLLWRNORM))
716 revents |= events & (POLLOUT | POLLWRNORM);
724 * Start packet transmission on the interface.
725 * when the interface queue is rate-limited by ALTQ,
726 * if_start is needed to drain packets from the queue in order
727 * to notify readers when outgoing packets become ready.
730 tunstart(struct ifnet *ifp)
732 struct tun_softc *tp = ifp->if_softc;
735 if (!ifq_is_enabled(&ifp->if_snd))
738 m = ifq_poll(&ifp->if_snd);
740 if (tp->tun_flags & TUN_RWAIT) {
741 tp->tun_flags &= ~TUN_RWAIT;
744 if (tp->tun_flags & TUN_ASYNC && tp->tun_sigio)
745 pgsigio(tp->tun_sigio, SIGIO, 0);
746 selwakeup(&tp->tun_rsel);