Annotation of src/sys/net/if_tap.c, Revision 1.21.4.2
1.21.4.2! yamt 1: /* $NetBSD: if_tap.c,v 1.21.4.1 2006/10/22 06:07:25 yamt Exp $ */
1.1 cube 2:
3: /*
4: * Copyright (c) 2003, 2004 The NetBSD Foundation.
5: * All rights reserved.
6: *
7: * This code is derived from software contributed to the NetBSD Foundation
8: * by Quentin Garnier.
1.6 perry 9: *
1.1 cube 10: * Redistribution and use in source and binary forms, with or without
11: * modification, are permitted provided that the following conditions
12: * are met:
13: * 1. Redistributions of source code must retain the above copyright
14: * notice, this list of conditions and the following disclaimer.
15: * 2. Redistributions in binary form must reproduce the above copyright
16: * notice, this list of conditions and the following disclaimer in the
17: * documentation and/or other materials provided with the distribution.
18: * 3. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed by the NetBSD
21: * Foundation, Inc. and its contributors.
22: * 4. Neither the name of The NetBSD Foundation nor the names of its
23: * contributors may be used to endorse or promote products derived
24: * from this software without specific prior written permission.
1.6 perry 25: *
1.1 cube 26: * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28: * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36: * POSSIBILITY OF SUCH DAMAGE.
37: */
38:
39: /*
40: * tap(4) is a virtual Ethernet interface. It appears as a real Ethernet
41: * device to the system, but can also be accessed by userland through a
42: * character device interface, which allows reading and injecting frames.
43: */
44:
45: #include <sys/cdefs.h>
1.21.4.2! yamt 46: __KERNEL_RCSID(0, "$NetBSD: if_tap.c,v 1.21.4.1 2006/10/22 06:07:25 yamt Exp $");
1.1 cube 47:
1.2 cube 48: #if defined(_KERNEL_OPT)
1.1 cube 49: #include "bpfilter.h"
1.2 cube 50: #endif
1.1 cube 51:
52: #include <sys/param.h>
53: #include <sys/systm.h>
54: #include <sys/kernel.h>
55: #include <sys/malloc.h>
56: #include <sys/conf.h>
57: #include <sys/device.h>
58: #include <sys/file.h>
59: #include <sys/filedesc.h>
60: #include <sys/ksyms.h>
61: #include <sys/poll.h>
62: #include <sys/select.h>
63: #include <sys/sockio.h>
64: #include <sys/sysctl.h>
1.17 elad 65: #include <sys/kauth.h>
1.1 cube 66:
67: #include <net/if.h>
68: #include <net/if_dl.h>
69: #include <net/if_ether.h>
70: #include <net/if_media.h>
71: #include <net/if_tap.h>
72: #if NBPFILTER > 0
73: #include <net/bpf.h>
74: #endif
75:
76: /*
77: * sysctl node management
78: *
79: * It's not really possible to use a SYSCTL_SETUP block with
80: * current LKM implementation, so it is easier to just define
81: * our own function.
82: *
83: * The handler function is a "helper" in Andrew Brown's sysctl
84: * framework terminology. It is used as a gateway for sysctl
85: * requests over the nodes.
86: *
87: * tap_log allows the module to log creations of nodes and
88: * destroy them all at once using sysctl_teardown.
89: */
90: static int tap_node;
91: static int tap_sysctl_handler(SYSCTLFN_PROTO);
1.2 cube 92: SYSCTL_SETUP_PROTO(sysctl_tap_setup);
1.1 cube 93:
94: /*
95: * Since we're an Ethernet device, we need the 3 following
96: * components: a leading struct device, a struct ethercom,
97: * and also a struct ifmedia since we don't attach a PHY to
98: * ourselves. We could emulate one, but there's no real
99: * point.
100: */
101:
102: struct tap_softc {
103: struct device sc_dev;
104: struct ifmedia sc_im;
105: struct ethercom sc_ec;
106: int sc_flags;
107: #define TAP_INUSE 0x00000001 /* tap device can only be opened once */
108: #define TAP_ASYNCIO 0x00000002 /* user is using async I/O (SIGIO) on the device */
109: #define TAP_NBIO 0x00000004 /* user wants calls to avoid blocking */
110: #define TAP_GOING 0x00000008 /* interface is being destroyed */
111: struct selinfo sc_rsel;
112: pid_t sc_pgid; /* For async. IO */
113: struct lock sc_rdlock;
114: struct simplelock sc_kqlock;
115: };
116:
117: /* autoconf(9) glue */
118:
119: void tapattach(int);
120:
121: static int tap_match(struct device *, struct cfdata *, void *);
122: static void tap_attach(struct device *, struct device *, void *);
123: static int tap_detach(struct device*, int);
124:
125: CFATTACH_DECL(tap, sizeof(struct tap_softc),
126: tap_match, tap_attach, tap_detach, NULL);
127: extern struct cfdriver tap_cd;
128:
129: /* Real device access routines */
130: static int tap_dev_close(struct tap_softc *);
131: static int tap_dev_read(int, struct uio *, int);
132: static int tap_dev_write(int, struct uio *, int);
1.11 christos 133: static int tap_dev_ioctl(int, u_long, caddr_t, struct lwp *);
134: static int tap_dev_poll(int, int, struct lwp *);
1.1 cube 135: static int tap_dev_kqfilter(int, struct knote *);
136:
137: /* Fileops access routines */
1.11 christos 138: static int tap_fops_close(struct file *, struct lwp *);
1.1 cube 139: static int tap_fops_read(struct file *, off_t *, struct uio *,
1.17 elad 140: kauth_cred_t, int);
1.1 cube 141: static int tap_fops_write(struct file *, off_t *, struct uio *,
1.17 elad 142: kauth_cred_t, int);
1.1 cube 143: static int tap_fops_ioctl(struct file *, u_long, void *,
1.11 christos 144: struct lwp *);
145: static int tap_fops_poll(struct file *, int, struct lwp *);
1.1 cube 146: static int tap_fops_kqfilter(struct file *, struct knote *);
147:
148: static const struct fileops tap_fileops = {
149: tap_fops_read,
150: tap_fops_write,
151: tap_fops_ioctl,
152: fnullop_fcntl,
153: tap_fops_poll,
154: fbadop_stat,
155: tap_fops_close,
156: tap_fops_kqfilter,
157: };
158:
159: /* Helper for cloning open() */
1.11 christos 160: static int tap_dev_cloner(struct lwp *);
1.1 cube 161:
162: /* Character device routines */
1.11 christos 163: static int tap_cdev_open(dev_t, int, int, struct lwp *);
164: static int tap_cdev_close(dev_t, int, int, struct lwp *);
1.1 cube 165: static int tap_cdev_read(dev_t, struct uio *, int);
166: static int tap_cdev_write(dev_t, struct uio *, int);
1.11 christos 167: static int tap_cdev_ioctl(dev_t, u_long, caddr_t, int, struct lwp *);
168: static int tap_cdev_poll(dev_t, int, struct lwp *);
1.1 cube 169: static int tap_cdev_kqfilter(dev_t, struct knote *);
170:
171: const struct cdevsw tap_cdevsw = {
172: tap_cdev_open, tap_cdev_close,
173: tap_cdev_read, tap_cdev_write,
174: tap_cdev_ioctl, nostop, notty,
175: tap_cdev_poll, nommap,
176: tap_cdev_kqfilter,
1.20 christos 177: D_OTHER,
1.1 cube 178: };
179:
180: #define TAP_CLONER 0xfffff /* Maximal minor value */
181:
182: /* kqueue-related routines */
183: static void tap_kqdetach(struct knote *);
184: static int tap_kqread(struct knote *, long);
185:
186: /*
187: * Those are needed by the if_media interface.
188: */
189:
190: static int tap_mediachange(struct ifnet *);
191: static void tap_mediastatus(struct ifnet *, struct ifmediareq *);
192:
193: /*
194: * Those are needed by the ifnet interface, and would typically be
195: * there for any network interface driver.
196: * Some other routines are optional: watchdog and drain.
197: */
198:
199: static void tap_start(struct ifnet *);
200: static void tap_stop(struct ifnet *, int);
201: static int tap_init(struct ifnet *);
202: static int tap_ioctl(struct ifnet *, u_long, caddr_t);
203:
204: /* This is an internal function to keep tap_ioctl readable */
205: static int tap_lifaddr(struct ifnet *, u_long, struct ifaliasreq *);
206:
207: /*
208: * tap is a clonable interface, although it is highly unrealistic for
209: * an Ethernet device.
210: *
211: * Here are the bits needed for a clonable interface.
212: */
213: static int tap_clone_create(struct if_clone *, int);
214: static int tap_clone_destroy(struct ifnet *);
215:
216: struct if_clone tap_cloners = IF_CLONE_INITIALIZER("tap",
217: tap_clone_create,
218: tap_clone_destroy);
219:
220: /* Helper functionis shared by the two cloning code paths */
221: static struct tap_softc * tap_clone_creator(int);
1.12 cube 222: int tap_clone_destroyer(struct device *);
1.1 cube 223:
224: void
1.21.4.2! yamt 225: tapattach(int n)
1.1 cube 226: {
227: int error;
228:
229: error = config_cfattach_attach(tap_cd.cd_name, &tap_ca);
230: if (error) {
231: aprint_error("%s: unable to register cfattach\n",
232: tap_cd.cd_name);
233: (void)config_cfdriver_detach(&tap_cd);
234: return;
235: }
236:
237: if_clone_attach(&tap_cloners);
238: }
239:
240: /* Pretty much useless for a pseudo-device */
241: static int
1.21.4.2! yamt 242: tap_match(struct device *self, struct cfdata *cfdata,
! 243: void *arg)
1.1 cube 244: {
245: return (1);
246: }
247:
248: void
1.21.4.2! yamt 249: tap_attach(struct device *parent, struct device *self,
! 250: void *aux)
1.1 cube 251: {
252: struct tap_softc *sc = (struct tap_softc *)self;
253: struct ifnet *ifp;
1.18 kardel 254: const struct sysctlnode *node;
1.1 cube 255: u_int8_t enaddr[ETHER_ADDR_LEN] =
1.7 cube 256: { 0xf2, 0x0b, 0xa4, 0xff, 0xff, 0xff };
1.14 christos 257: char enaddrstr[3 * ETHER_ADDR_LEN];
1.18 kardel 258: struct timeval tv;
1.1 cube 259: uint32_t ui;
260: int error;
261:
262: aprint_normal("%s: faking Ethernet device\n",
263: self->dv_xname);
264:
265: /*
266: * In order to obtain unique initial Ethernet address on a host,
1.18 kardel 267: * do some randomisation using the current uptime. It's not meant
268: * for anything but avoiding hard-coding an address.
1.1 cube 269: */
1.18 kardel 270: getmicrouptime(&tv);
271: ui = (tv.tv_sec ^ tv.tv_usec) & 0xffffff;
1.1 cube 272: memcpy(enaddr+3, (u_int8_t *)&ui, 3);
273:
274: aprint_normal("%s: Ethernet address %s\n", sc->sc_dev.dv_xname,
1.14 christos 275: ether_snprintf(enaddrstr, sizeof(enaddrstr), enaddr));
1.1 cube 276:
277: /*
278: * Why 1000baseT? Why not? You can add more.
279: *
280: * Note that there are 3 steps: init, one or several additions to
281: * list of supported media, and in the end, the selection of one
282: * of them.
283: */
284: ifmedia_init(&sc->sc_im, 0, tap_mediachange, tap_mediastatus);
285: ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_1000_T, 0, NULL);
286: ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_1000_T|IFM_FDX, 0, NULL);
287: ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_100_TX, 0, NULL);
288: ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_100_TX|IFM_FDX, 0, NULL);
289: ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_10_T, 0, NULL);
290: ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL);
291: ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_AUTO, 0, NULL);
292: ifmedia_set(&sc->sc_im, IFM_ETHER|IFM_AUTO);
293:
294: /*
295: * One should note that an interface must do multicast in order
296: * to support IPv6.
297: */
298: ifp = &sc->sc_ec.ec_if;
299: strcpy(ifp->if_xname, sc->sc_dev.dv_xname);
300: ifp->if_softc = sc;
301: ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
302: ifp->if_ioctl = tap_ioctl;
303: ifp->if_start = tap_start;
304: ifp->if_stop = tap_stop;
305: ifp->if_init = tap_init;
306: IFQ_SET_READY(&ifp->if_snd);
307:
308: sc->sc_ec.ec_capabilities = ETHERCAP_VLAN_MTU | ETHERCAP_JUMBO_MTU;
309:
310: /* Those steps are mandatory for an Ethernet driver, the fisrt call
311: * being common to all network interface drivers. */
312: if_attach(ifp);
313: ether_ifattach(ifp, enaddr);
314:
315: sc->sc_flags = 0;
316:
317: /*
318: * Add a sysctl node for that interface.
319: *
320: * The pointer transmitted is not a string, but instead a pointer to
321: * the softc structure, which we can use to build the string value on
322: * the fly in the helper function of the node. See the comments for
323: * tap_sysctl_handler for details.
1.21 cube 324: *
325: * Usually sysctl_createv is called with CTL_CREATE as the before-last
326: * component. However, we can allocate a number ourselves, as we are
327: * the only consumer of the net.link.<iface> node. In this case, the
328: * unit number is conveniently used to number the node. CTL_CREATE
329: * would just work, too.
1.1 cube 330: */
331: if ((error = sysctl_createv(NULL, 0, NULL,
332: &node, CTLFLAG_READWRITE,
333: CTLTYPE_STRING, sc->sc_dev.dv_xname, NULL,
334: tap_sysctl_handler, 0, sc, 18,
1.15 thorpej 335: CTL_NET, AF_LINK, tap_node, device_unit(&sc->sc_dev),
336: CTL_EOL)) != 0)
1.1 cube 337: aprint_error("%s: sysctl_createv returned %d, ignoring\n",
338: sc->sc_dev.dv_xname, error);
339:
340: /*
341: * Initialize the two locks for the device.
342: *
343: * We need a lock here because even though the tap device can be
344: * opened only once, the file descriptor might be passed to another
345: * process, say a fork(2)ed child.
346: *
347: * The Giant saves us from most of the hassle, but since the read
348: * operation can sleep, we don't want two processes to wake up at
349: * the same moment and both try and dequeue a single packet.
350: *
351: * The queue for event listeners (used by kqueue(9), see below) has
352: * to be protected, too, but we don't need the same level of
353: * complexity for that lock, so a simple spinning lock is fine.
354: */
355: lockinit(&sc->sc_rdlock, PSOCK|PCATCH, "tapl", 0, LK_SLEEPFAIL);
356: simple_lock_init(&sc->sc_kqlock);
357: }
358:
359: /*
360: * When detaching, we do the inverse of what is done in the attach
361: * routine, in reversed order.
362: */
363: static int
1.21.4.2! yamt 364: tap_detach(struct device* self, int flags)
1.1 cube 365: {
366: struct tap_softc *sc = (struct tap_softc *)self;
367: struct ifnet *ifp = &sc->sc_ec.ec_if;
368: int error, s;
369:
370: /*
371: * Some processes might be sleeping on "tap", so we have to make
372: * them release their hold on the device.
373: *
374: * The LK_DRAIN operation will wait for every locked process to
375: * release their hold.
376: */
377: sc->sc_flags |= TAP_GOING;
378: s = splnet();
379: tap_stop(ifp, 1);
380: if_down(ifp);
381: splx(s);
382: lockmgr(&sc->sc_rdlock, LK_DRAIN, NULL);
383:
384: /*
385: * Destroying a single leaf is a very straightforward operation using
386: * sysctl_destroyv. One should be sure to always end the path with
387: * CTL_EOL.
388: */
1.3 cube 389: if ((error = sysctl_destroyv(NULL, CTL_NET, AF_LINK, tap_node,
1.15 thorpej 390: device_unit(&sc->sc_dev), CTL_EOL)) != 0)
1.1 cube 391: aprint_error("%s: sysctl_destroyv returned %d, ignoring\n",
392: sc->sc_dev.dv_xname, error);
393: ether_ifdetach(ifp);
394: if_detach(ifp);
395: ifmedia_delete_instance(&sc->sc_im, IFM_INST_ANY);
396:
397: return (0);
398: }
399:
400: /*
401: * This function is called by the ifmedia layer to notify the driver
402: * that the user requested a media change. A real driver would
403: * reconfigure the hardware.
404: */
405: static int
1.21.4.2! yamt 406: tap_mediachange(struct ifnet *ifp)
1.1 cube 407: {
408: return (0);
409: }
410:
411: /*
412: * Here the user asks for the currently used media.
413: */
414: static void
415: tap_mediastatus(struct ifnet *ifp, struct ifmediareq *imr)
416: {
417: struct tap_softc *sc = (struct tap_softc *)ifp->if_softc;
418: imr->ifm_active = sc->sc_im.ifm_cur->ifm_media;
419: }
420:
421: /*
422: * This is the function where we SEND packets.
423: *
424: * There is no 'receive' equivalent. A typical driver will get
425: * interrupts from the hardware, and from there will inject new packets
426: * into the network stack.
427: *
428: * Once handled, a packet must be freed. A real driver might not be able
429: * to fit all the pending packets into the hardware, and is allowed to
430: * return before having sent all the packets. It should then use the
431: * if_flags flag IFF_OACTIVE to notify the upper layer.
432: *
433: * There are also other flags one should check, such as IFF_PAUSE.
434: *
435: * It is our duty to make packets available to BPF listeners.
436: *
437: * You should be aware that this function is called by the Ethernet layer
438: * at splnet().
439: *
440: * When the device is opened, we have to pass the packet(s) to the
441: * userland. For that we stay in OACTIVE mode while the userland gets
442: * the packets, and we send a signal to the processes waiting to read.
443: *
444: * wakeup(sc) is the counterpart to the tsleep call in
445: * tap_dev_read, while selnotify() is used for kevent(2) and
446: * poll(2) (which includes select(2)) listeners.
447: */
448: static void
449: tap_start(struct ifnet *ifp)
450: {
451: struct tap_softc *sc = (struct tap_softc *)ifp->if_softc;
452: struct mbuf *m0;
453:
454: if ((sc->sc_flags & TAP_INUSE) == 0) {
455: /* Simply drop packets */
456: for(;;) {
457: IFQ_DEQUEUE(&ifp->if_snd, m0);
458: if (m0 == NULL)
459: return;
460:
461: ifp->if_opackets++;
462: #if NBPFILTER > 0
463: if (ifp->if_bpf)
464: bpf_mtap(ifp->if_bpf, m0);
465: #endif
466:
467: m_freem(m0);
468: }
469: } else if (!IFQ_IS_EMPTY(&ifp->if_snd)) {
470: ifp->if_flags |= IFF_OACTIVE;
471: wakeup(sc);
472: selnotify(&sc->sc_rsel, 1);
473: if (sc->sc_flags & TAP_ASYNCIO)
474: fownsignal(sc->sc_pgid, SIGIO, POLL_IN,
475: POLLIN|POLLRDNORM, NULL);
476: }
477: }
478:
479: /*
480: * A typical driver will only contain the following handlers for
481: * ioctl calls, except SIOCSIFPHYADDR.
482: * The latter is a hack I used to set the Ethernet address of the
483: * faked device.
484: *
485: * Note that both ifmedia_ioctl() and ether_ioctl() have to be
486: * called under splnet().
487: */
488: static int
489: tap_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
490: {
491: struct tap_softc *sc = (struct tap_softc *)ifp->if_softc;
492: struct ifreq *ifr = (struct ifreq *)data;
493: int s, error;
494:
495: s = splnet();
496:
497: switch (cmd) {
498: case SIOCSIFMEDIA:
499: case SIOCGIFMEDIA:
500: error = ifmedia_ioctl(ifp, ifr, &sc->sc_im, cmd);
501: break;
502: case SIOCSIFPHYADDR:
503: error = tap_lifaddr(ifp, cmd, (struct ifaliasreq *)data);
504: break;
505: default:
506: error = ether_ioctl(ifp, cmd, data);
507: if (error == ENETRESET)
508: error = 0;
509: break;
510: }
511:
512: splx(s);
513:
514: return (error);
515: }
516:
517: /*
518: * Helper function to set Ethernet address. This shouldn't be done there,
519: * and should actually be available to all Ethernet drivers, real or not.
520: */
521: static int
1.21.4.2! yamt 522: tap_lifaddr(struct ifnet *ifp, u_long cmd, struct ifaliasreq *ifra)
1.1 cube 523: {
524: struct sockaddr *sa = (struct sockaddr *)&ifra->ifra_addr;
525:
526: if (sa->sa_family != AF_LINK)
527: return (EINVAL);
528:
529: memcpy(LLADDR(ifp->if_sadl), sa->sa_data, ETHER_ADDR_LEN);
530:
531: return (0);
532: }
533:
534: /*
535: * _init() would typically be called when an interface goes up,
536: * meaning it should configure itself into the state in which it
537: * can send packets.
538: */
539: static int
540: tap_init(struct ifnet *ifp)
541: {
542: ifp->if_flags |= IFF_RUNNING;
543:
544: tap_start(ifp);
545:
546: return (0);
547: }
548:
549: /*
550: * _stop() is called when an interface goes down. It is our
551: * responsability to validate that state by clearing the
552: * IFF_RUNNING flag.
553: *
554: * We have to wake up all the sleeping processes to have the pending
555: * read requests cancelled.
556: */
557: static void
1.21.4.2! yamt 558: tap_stop(struct ifnet *ifp, int disable)
1.1 cube 559: {
560: struct tap_softc *sc = (struct tap_softc *)ifp->if_softc;
561:
562: ifp->if_flags &= ~IFF_RUNNING;
563: wakeup(sc);
564: selnotify(&sc->sc_rsel, 1);
565: if (sc->sc_flags & TAP_ASYNCIO)
566: fownsignal(sc->sc_pgid, SIGIO, POLL_HUP, 0, NULL);
567: }
568:
569: /*
570: * The 'create' command of ifconfig can be used to create
571: * any numbered instance of a given device. Thus we have to
572: * make sure we have enough room in cd_devs to create the
573: * user-specified instance. config_attach_pseudo will do this
574: * for us.
575: */
576: static int
1.21.4.2! yamt 577: tap_clone_create(struct if_clone *ifc, int unit)
1.1 cube 578: {
579: if (tap_clone_creator(unit) == NULL) {
580: aprint_error("%s%d: unable to attach an instance\n",
581: tap_cd.cd_name, unit);
582: return (ENXIO);
583: }
584:
585: return (0);
586: }
587:
588: /*
589: * tap(4) can be cloned by two ways:
590: * using 'ifconfig tap0 create', which will use the network
591: * interface cloning API, and call tap_clone_create above.
592: * opening the cloning device node, whose minor number is TAP_CLONER.
593: * See below for an explanation on how this part work.
594: *
595: * config_attach_pseudo can be called with unit = DVUNIT_ANY to have
596: * autoconf(9) choose a unit number for us. This is what happens when
597: * the cloner is openend, while the ifcloner interface creates a device
598: * with a specific unit number.
599: */
600: static struct tap_softc *
601: tap_clone_creator(int unit)
602: {
603: struct cfdata *cf;
604:
605: cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
606: cf->cf_name = tap_cd.cd_name;
607: cf->cf_atname = tap_ca.ca_name;
608: cf->cf_unit = unit;
609: cf->cf_fstate = FSTATE_STAR;
610:
611: return (struct tap_softc *)config_attach_pseudo(cf);
612: }
613:
614: /*
615: * The clean design of if_clone and autoconf(9) makes that part
616: * really straightforward. The second argument of config_detach
617: * means neither QUIET nor FORCED.
618: */
619: static int
620: tap_clone_destroy(struct ifnet *ifp)
621: {
622: return tap_clone_destroyer((struct device *)ifp->if_softc);
623: }
624:
1.12 cube 625: int
1.1 cube 626: tap_clone_destroyer(struct device *dev)
627: {
1.16 thorpej 628: struct cfdata *cf = device_cfdata(dev);
1.1 cube 629: int error;
630:
631: if ((error = config_detach(dev, 0)) != 0)
632: aprint_error("%s: unable to detach instance\n",
633: dev->dv_xname);
634: free(cf, M_DEVBUF);
635:
636: return (error);
637: }
638:
639: /*
640: * tap(4) is a bit of an hybrid device. It can be used in two different
641: * ways:
642: * 1. ifconfig tapN create, then use /dev/tapN to read/write off it.
643: * 2. open /dev/tap, get a new interface created and read/write off it.
644: * That interface is destroyed when the process that had it created exits.
645: *
646: * The first way is managed by the cdevsw structure, and you access interfaces
647: * through a (major, minor) mapping: tap4 is obtained by the minor number
648: * 4. The entry points for the cdevsw interface are prefixed by tap_cdev_.
649: *
650: * The second way is the so-called "cloning" device. It's a special minor
651: * number (chosen as the maximal number, to allow as much tap devices as
652: * possible). The user first opens the cloner (e.g., /dev/tap), and that
653: * call ends in tap_cdev_open. The actual place where it is handled is
654: * tap_dev_cloner.
655: *
656: * An tap device cannot be opened more than once at a time, so the cdevsw
657: * part of open() does nothing but noting that the interface is being used and
658: * hence ready to actually handle packets.
659: */
660:
661: static int
1.21.4.2! yamt 662: tap_cdev_open(dev_t dev, int flags, int fmt, struct lwp *l)
1.1 cube 663: {
664: struct tap_softc *sc;
665:
666: if (minor(dev) == TAP_CLONER)
1.11 christos 667: return tap_dev_cloner(l);
1.1 cube 668:
669: sc = (struct tap_softc *)device_lookup(&tap_cd, minor(dev));
670: if (sc == NULL)
671: return (ENXIO);
672:
673: /* The device can only be opened once */
674: if (sc->sc_flags & TAP_INUSE)
675: return (EBUSY);
676: sc->sc_flags |= TAP_INUSE;
677: return (0);
678: }
679:
680: /*
681: * There are several kinds of cloning devices, and the most simple is the one
682: * tap(4) uses. What it does is change the file descriptor with a new one,
683: * with its own fileops structure (which maps to the various read, write,
684: * ioctl functions). It starts allocating a new file descriptor with falloc,
685: * then actually creates the new tap devices.
686: *
687: * Once those two steps are successful, we can re-wire the existing file
688: * descriptor to its new self. This is done with fdclone(): it fills the fp
689: * structure as needed (notably f_data gets filled with the fifth parameter
690: * passed, the unit of the tap device which will allows us identifying the
691: * device later), and returns EMOVEFD.
692: *
693: * That magic value is interpreted by sys_open() which then replaces the
694: * current file descriptor by the new one (through a magic member of struct
1.13 pooka 695: * lwp, l_dupfd).
1.1 cube 696: *
697: * The tap device is flagged as being busy since it otherwise could be
698: * externally accessed through the corresponding device node with the cdevsw
699: * interface.
700: */
701:
702: static int
1.11 christos 703: tap_dev_cloner(struct lwp *l)
1.1 cube 704: {
705: struct tap_softc *sc;
706: struct file *fp;
707: int error, fd;
708:
1.19 ad 709: if ((error = falloc(l, &fp, &fd)) != 0)
1.1 cube 710: return (error);
711:
712: if ((sc = tap_clone_creator(DVUNIT_ANY)) == NULL) {
1.11 christos 713: FILE_UNUSE(fp, l);
1.1 cube 714: ffree(fp);
715: return (ENXIO);
716: }
717:
718: sc->sc_flags |= TAP_INUSE;
719:
1.11 christos 720: return fdclone(l, fp, fd, FREAD|FWRITE, &tap_fileops,
1.15 thorpej 721: (void *)(intptr_t)device_unit(&sc->sc_dev));
1.1 cube 722: }
723:
724: /*
725: * While all other operations (read, write, ioctl, poll and kqfilter) are
726: * really the same whether we are in cdevsw or fileops mode, the close()
727: * function is slightly different in the two cases.
728: *
729: * As for the other, the core of it is shared in tap_dev_close. What
730: * it does is sufficient for the cdevsw interface, but the cloning interface
731: * needs another thing: the interface is destroyed when the processes that
732: * created it closes it.
733: */
734: static int
1.21.4.2! yamt 735: tap_cdev_close(dev_t dev, int flags, int fmt,
! 736: struct lwp *l)
1.1 cube 737: {
738: struct tap_softc *sc =
739: (struct tap_softc *)device_lookup(&tap_cd, minor(dev));
740:
741: if (sc == NULL)
742: return (ENXIO);
743:
744: return tap_dev_close(sc);
745: }
746:
747: /*
748: * It might happen that the administrator used ifconfig to externally destroy
749: * the interface. In that case, tap_fops_close will be called while
750: * tap_detach is already happening. If we called it again from here, we
751: * would dead lock. TAP_GOING ensures that this situation doesn't happen.
752: */
753: static int
1.21.4.2! yamt 754: tap_fops_close(struct file *fp, struct lwp *l)
1.1 cube 755: {
756: int unit = (intptr_t)fp->f_data;
757: struct tap_softc *sc;
758: int error;
759:
760: sc = (struct tap_softc *)device_lookup(&tap_cd, unit);
761: if (sc == NULL)
762: return (ENXIO);
763:
764: /* tap_dev_close currently always succeeds, but it might not
765: * always be the case. */
766: if ((error = tap_dev_close(sc)) != 0)
767: return (error);
768:
769: /* Destroy the device now that it is no longer useful,
770: * unless it's already being destroyed. */
771: if ((sc->sc_flags & TAP_GOING) != 0)
772: return (0);
773:
774: return tap_clone_destroyer((struct device *)sc);
775: }
776:
777: static int
778: tap_dev_close(struct tap_softc *sc)
779: {
780: struct ifnet *ifp;
781: int s;
782:
783: s = splnet();
784: /* Let tap_start handle packets again */
785: ifp = &sc->sc_ec.ec_if;
786: ifp->if_flags &= ~IFF_OACTIVE;
787:
788: /* Purge output queue */
789: if (!(IFQ_IS_EMPTY(&ifp->if_snd))) {
790: struct mbuf *m;
791:
792: for (;;) {
793: IFQ_DEQUEUE(&ifp->if_snd, m);
794: if (m == NULL)
795: break;
796:
797: ifp->if_opackets++;
798: #if NBPFILTER > 0
799: if (ifp->if_bpf)
800: bpf_mtap(ifp->if_bpf, m);
801: #endif
802: }
803: }
804: splx(s);
805:
806: sc->sc_flags &= ~(TAP_INUSE | TAP_ASYNCIO);
807:
808: return (0);
809: }
810:
811: static int
812: tap_cdev_read(dev_t dev, struct uio *uio, int flags)
813: {
814: return tap_dev_read(minor(dev), uio, flags);
815: }
816:
817: static int
1.21.4.2! yamt 818: tap_fops_read(struct file *fp, off_t *offp, struct uio *uio,
! 819: kauth_cred_t cred, int flags)
1.1 cube 820: {
821: return tap_dev_read((intptr_t)fp->f_data, uio, flags);
822: }
823:
824: static int
1.21.4.2! yamt 825: tap_dev_read(int unit, struct uio *uio, int flags)
1.1 cube 826: {
827: struct tap_softc *sc =
828: (struct tap_softc *)device_lookup(&tap_cd, unit);
829: struct ifnet *ifp;
830: struct mbuf *m, *n;
831: int error = 0, s;
832:
833: if (sc == NULL)
834: return (ENXIO);
835:
836: ifp = &sc->sc_ec.ec_if;
837: if ((ifp->if_flags & IFF_UP) == 0)
838: return (EHOSTDOWN);
839:
840: /*
841: * In the TAP_NBIO case, we have to make sure we won't be sleeping
842: */
843: if ((sc->sc_flags & TAP_NBIO) &&
844: lockstatus(&sc->sc_rdlock) == LK_EXCLUSIVE)
845: return (EWOULDBLOCK);
846: error = lockmgr(&sc->sc_rdlock, LK_EXCLUSIVE, NULL);
847: if (error != 0)
848: return (error);
849:
850: s = splnet();
851: if (IFQ_IS_EMPTY(&ifp->if_snd)) {
852: ifp->if_flags &= ~IFF_OACTIVE;
853: splx(s);
854: /*
855: * We must release the lock before sleeping, and re-acquire it
856: * after.
857: */
858: (void)lockmgr(&sc->sc_rdlock, LK_RELEASE, NULL);
859: if (sc->sc_flags & TAP_NBIO)
860: error = EWOULDBLOCK;
861: else
862: error = tsleep(sc, PSOCK|PCATCH, "tap", 0);
863:
864: if (error != 0)
865: return (error);
866: /* The device might have been downed */
867: if ((ifp->if_flags & IFF_UP) == 0)
868: return (EHOSTDOWN);
869: if ((sc->sc_flags & TAP_NBIO) &&
870: lockstatus(&sc->sc_rdlock) == LK_EXCLUSIVE)
871: return (EWOULDBLOCK);
872: error = lockmgr(&sc->sc_rdlock, LK_EXCLUSIVE, NULL);
873: if (error != 0)
874: return (error);
875: s = splnet();
876: }
877:
878: IFQ_DEQUEUE(&ifp->if_snd, m);
879: ifp->if_flags &= ~IFF_OACTIVE;
880: splx(s);
881: if (m == NULL) {
882: error = 0;
883: goto out;
884: }
885:
886: ifp->if_opackets++;
887: #if NBPFILTER > 0
888: if (ifp->if_bpf)
889: bpf_mtap(ifp->if_bpf, m);
890: #endif
891:
892: /*
893: * One read is one packet.
894: */
895: do {
896: error = uiomove(mtod(m, caddr_t),
897: min(m->m_len, uio->uio_resid), uio);
898: MFREE(m, n);
899: m = n;
900: } while (m != NULL && uio->uio_resid > 0 && error == 0);
901:
902: if (m != NULL)
903: m_freem(m);
904:
905: out:
906: (void)lockmgr(&sc->sc_rdlock, LK_RELEASE, NULL);
907: return (error);
908: }
909:
910: static int
911: tap_cdev_write(dev_t dev, struct uio *uio, int flags)
912: {
913: return tap_dev_write(minor(dev), uio, flags);
914: }
915:
916: static int
1.21.4.2! yamt 917: tap_fops_write(struct file *fp, off_t *offp, struct uio *uio,
! 918: kauth_cred_t cred, int flags)
1.1 cube 919: {
920: return tap_dev_write((intptr_t)fp->f_data, uio, flags);
921: }
922:
923: static int
1.21.4.2! yamt 924: tap_dev_write(int unit, struct uio *uio, int flags)
1.1 cube 925: {
926: struct tap_softc *sc =
927: (struct tap_softc *)device_lookup(&tap_cd, unit);
928: struct ifnet *ifp;
929: struct mbuf *m, **mp;
930: int error = 0;
1.9 bouyer 931: int s;
1.1 cube 932:
933: if (sc == NULL)
934: return (ENXIO);
935:
936: ifp = &sc->sc_ec.ec_if;
937:
938: /* One write, one packet, that's the rule */
939: MGETHDR(m, M_DONTWAIT, MT_DATA);
940: if (m == NULL) {
941: ifp->if_ierrors++;
942: return (ENOBUFS);
943: }
944: m->m_pkthdr.len = uio->uio_resid;
945:
946: mp = &m;
947: while (error == 0 && uio->uio_resid > 0) {
948: if (*mp != m) {
949: MGET(*mp, M_DONTWAIT, MT_DATA);
950: if (*mp == NULL) {
951: error = ENOBUFS;
952: break;
953: }
954: }
955: (*mp)->m_len = min(MHLEN, uio->uio_resid);
956: error = uiomove(mtod(*mp, caddr_t), (*mp)->m_len, uio);
957: mp = &(*mp)->m_next;
958: }
959: if (error) {
960: ifp->if_ierrors++;
961: m_freem(m);
962: return (error);
963: }
964:
965: ifp->if_ipackets++;
966: m->m_pkthdr.rcvif = ifp;
967:
968: #if NBPFILTER > 0
969: if (ifp->if_bpf)
970: bpf_mtap(ifp->if_bpf, m);
971: #endif
1.9 bouyer 972: s =splnet();
1.1 cube 973: (*ifp->if_input)(ifp, m);
1.9 bouyer 974: splx(s);
1.1 cube 975:
976: return (0);
977: }
978:
979: static int
1.21.4.2! yamt 980: tap_cdev_ioctl(dev_t dev, u_long cmd, caddr_t data, int flags,
1.11 christos 981: struct lwp *l)
1.1 cube 982: {
1.11 christos 983: return tap_dev_ioctl(minor(dev), cmd, data, l);
1.1 cube 984: }
985:
986: static int
1.11 christos 987: tap_fops_ioctl(struct file *fp, u_long cmd, void *data, struct lwp *l)
1.1 cube 988: {
1.11 christos 989: return tap_dev_ioctl((intptr_t)fp->f_data, cmd, (caddr_t)data, l);
1.1 cube 990: }
991:
992: static int
1.11 christos 993: tap_dev_ioctl(int unit, u_long cmd, caddr_t data, struct lwp *l)
1.1 cube 994: {
995: struct tap_softc *sc =
996: (struct tap_softc *)device_lookup(&tap_cd, unit);
997: int error = 0;
998:
999: if (sc == NULL)
1000: return (ENXIO);
1001:
1002: switch (cmd) {
1003: case FIONREAD:
1004: {
1005: struct ifnet *ifp = &sc->sc_ec.ec_if;
1006: struct mbuf *m;
1007: int s;
1008:
1009: s = splnet();
1010: IFQ_POLL(&ifp->if_snd, m);
1011:
1012: if (m == NULL)
1013: *(int *)data = 0;
1014: else
1015: *(int *)data = m->m_pkthdr.len;
1016: splx(s);
1017: } break;
1018: case TIOCSPGRP:
1019: case FIOSETOWN:
1.11 christos 1020: error = fsetown(l->l_proc, &sc->sc_pgid, cmd, data);
1.1 cube 1021: break;
1022: case TIOCGPGRP:
1023: case FIOGETOWN:
1.11 christos 1024: error = fgetown(l->l_proc, sc->sc_pgid, cmd, data);
1.1 cube 1025: break;
1026: case FIOASYNC:
1027: if (*(int *)data)
1028: sc->sc_flags |= TAP_ASYNCIO;
1029: else
1030: sc->sc_flags &= ~TAP_ASYNCIO;
1031: break;
1032: case FIONBIO:
1033: if (*(int *)data)
1034: sc->sc_flags |= TAP_NBIO;
1035: else
1036: sc->sc_flags &= ~TAP_NBIO;
1037: break;
1038: case TAPGIFNAME:
1039: {
1040: struct ifreq *ifr = (struct ifreq *)data;
1041: struct ifnet *ifp = &sc->sc_ec.ec_if;
1042:
1043: strlcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
1044: } break;
1045: default:
1046: error = ENOTTY;
1047: break;
1048: }
1049:
1050: return (0);
1051: }
1052:
1053: static int
1.11 christos 1054: tap_cdev_poll(dev_t dev, int events, struct lwp *l)
1.1 cube 1055: {
1.11 christos 1056: return tap_dev_poll(minor(dev), events, l);
1.1 cube 1057: }
1058:
1059: static int
1.11 christos 1060: tap_fops_poll(struct file *fp, int events, struct lwp *l)
1.1 cube 1061: {
1.11 christos 1062: return tap_dev_poll((intptr_t)fp->f_data, events, l);
1.1 cube 1063: }
1064:
1065: static int
1.11 christos 1066: tap_dev_poll(int unit, int events, struct lwp *l)
1.1 cube 1067: {
1068: struct tap_softc *sc =
1069: (struct tap_softc *)device_lookup(&tap_cd, unit);
1070: int revents = 0;
1071:
1072: if (sc == NULL)
1073: return (ENXIO);
1074:
1075: if (events & (POLLIN|POLLRDNORM)) {
1076: struct ifnet *ifp = &sc->sc_ec.ec_if;
1077: struct mbuf *m;
1078: int s;
1079:
1080: s = splnet();
1081: IFQ_POLL(&ifp->if_snd, m);
1082: splx(s);
1083:
1084: if (m != NULL)
1085: revents |= events & (POLLIN|POLLRDNORM);
1086: else {
1.4 ragge 1087: simple_lock(&sc->sc_kqlock);
1.11 christos 1088: selrecord(l, &sc->sc_rsel);
1.1 cube 1089: simple_unlock(&sc->sc_kqlock);
1090: }
1091: }
1092: revents |= events & (POLLOUT|POLLWRNORM);
1093:
1094: return (revents);
1095: }
1096:
1097: static struct filterops tap_read_filterops = { 1, NULL, tap_kqdetach,
1098: tap_kqread };
1099: static struct filterops tap_seltrue_filterops = { 1, NULL, tap_kqdetach,
1100: filt_seltrue };
1101:
1102: static int
1103: tap_cdev_kqfilter(dev_t dev, struct knote *kn)
1104: {
1105: return tap_dev_kqfilter(minor(dev), kn);
1106: }
1107:
1108: static int
1109: tap_fops_kqfilter(struct file *fp, struct knote *kn)
1110: {
1111: return tap_dev_kqfilter((intptr_t)fp->f_data, kn);
1112: }
1113:
1114: static int
1115: tap_dev_kqfilter(int unit, struct knote *kn)
1116: {
1117: struct tap_softc *sc =
1118: (struct tap_softc *)device_lookup(&tap_cd, unit);
1119:
1120: if (sc == NULL)
1121: return (ENXIO);
1122:
1123: switch(kn->kn_filter) {
1124: case EVFILT_READ:
1125: kn->kn_fop = &tap_read_filterops;
1126: break;
1127: case EVFILT_WRITE:
1128: kn->kn_fop = &tap_seltrue_filterops;
1129: break;
1130: default:
1131: return (1);
1132: }
1133:
1134: kn->kn_hook = sc;
1.4 ragge 1135: simple_lock(&sc->sc_kqlock);
1.1 cube 1136: SLIST_INSERT_HEAD(&sc->sc_rsel.sel_klist, kn, kn_selnext);
1137: simple_unlock(&sc->sc_kqlock);
1138: return (0);
1139: }
1140:
1141: static void
1142: tap_kqdetach(struct knote *kn)
1143: {
1144: struct tap_softc *sc = (struct tap_softc *)kn->kn_hook;
1145:
1.4 ragge 1146: simple_lock(&sc->sc_kqlock);
1.1 cube 1147: SLIST_REMOVE(&sc->sc_rsel.sel_klist, kn, knote, kn_selnext);
1148: simple_unlock(&sc->sc_kqlock);
1149: }
1150:
1151: static int
1.21.4.2! yamt 1152: tap_kqread(struct knote *kn, long hint)
1.1 cube 1153: {
1154: struct tap_softc *sc = (struct tap_softc *)kn->kn_hook;
1155: struct ifnet *ifp = &sc->sc_ec.ec_if;
1156: struct mbuf *m;
1157: int s;
1158:
1159: s = splnet();
1160: IFQ_POLL(&ifp->if_snd, m);
1161:
1162: if (m == NULL)
1163: kn->kn_data = 0;
1164: else
1165: kn->kn_data = m->m_pkthdr.len;
1166: splx(s);
1167: return (kn->kn_data != 0 ? 1 : 0);
1168: }
1169:
1170: /*
1171: * sysctl management routines
1172: * You can set the address of an interface through:
1173: * net.link.tap.tap<number>
1174: *
1175: * Note the consistent use of tap_log in order to use
1176: * sysctl_teardown at unload time.
1177: *
1178: * In the kernel you will find a lot of SYSCTL_SETUP blocks. Those
1179: * blocks register a function in a special section of the kernel
1180: * (called a link set) which is used at init_sysctl() time to cycle
1181: * through all those functions to create the kernel's sysctl tree.
1182: *
1183: * It is not (currently) possible to use link sets in a LKM, so the
1184: * easiest is to simply call our own setup routine at load time.
1185: *
1186: * In the SYSCTL_SETUP blocks you find in the kernel, nodes have the
1187: * CTLFLAG_PERMANENT flag, meaning they cannot be removed. Once the
1188: * whole kernel sysctl tree is built, it is not possible to add any
1189: * permanent node.
1190: *
1191: * It should be noted that we're not saving the sysctlnode pointer
1192: * we are returned when creating the "tap" node. That structure
1193: * cannot be trusted once out of the calling function, as it might
1194: * get reused. So we just save the MIB number, and always give the
1195: * full path starting from the root for later calls to sysctl_createv
1196: * and sysctl_destroyv.
1197: */
1198: SYSCTL_SETUP(sysctl_tap_setup, "sysctl net.link.tap subtree setup")
1199: {
1.10 atatat 1200: const struct sysctlnode *node;
1.1 cube 1201: int error = 0;
1202:
1203: if ((error = sysctl_createv(clog, 0, NULL, NULL,
1204: CTLFLAG_PERMANENT,
1205: CTLTYPE_NODE, "net", NULL,
1206: NULL, 0, NULL, 0,
1207: CTL_NET, CTL_EOL)) != 0)
1208: return;
1209:
1210: if ((error = sysctl_createv(clog, 0, NULL, NULL,
1211: CTLFLAG_PERMANENT,
1212: CTLTYPE_NODE, "link", NULL,
1213: NULL, 0, NULL, 0,
1.3 cube 1214: CTL_NET, AF_LINK, CTL_EOL)) != 0)
1.1 cube 1215: return;
1216:
1217: /*
1218: * The first four parameters of sysctl_createv are for management.
1219: *
1220: * The four that follows, here starting with a '0' for the flags,
1221: * describe the node.
1222: *
1223: * The next series of four set its value, through various possible
1224: * means.
1225: *
1226: * Last but not least, the path to the node is described. That path
1227: * is relative to the given root (third argument). Here we're
1228: * starting from the root.
1229: */
1230: if ((error = sysctl_createv(clog, 0, NULL, &node,
1231: CTLFLAG_PERMANENT,
1232: CTLTYPE_NODE, "tap", NULL,
1233: NULL, 0, NULL, 0,
1.3 cube 1234: CTL_NET, AF_LINK, CTL_CREATE, CTL_EOL)) != 0)
1.1 cube 1235: return;
1236: tap_node = node->sysctl_num;
1237: }
1238:
1239: /*
1240: * The helper functions make Andrew Brown's interface really
1241: * shine. It makes possible to create value on the fly whether
1242: * the sysctl value is read or written.
1243: *
1244: * As shown as an example in the man page, the first step is to
1245: * create a copy of the node to have sysctl_lookup work on it.
1246: *
1247: * Here, we have more work to do than just a copy, since we have
1248: * to create the string. The first step is to collect the actual
1249: * value of the node, which is a convenient pointer to the softc
1250: * of the interface. From there we create the string and use it
1251: * as the value, but only for the *copy* of the node.
1252: *
1253: * Then we let sysctl_lookup do the magic, which consists in
1254: * setting oldp and newp as required by the operation. When the
1255: * value is read, that means that the string will be copied to
1256: * the user, and when it is written, the new value will be copied
1257: * over in the addr array.
1258: *
1259: * If newp is NULL, the user was reading the value, so we don't
1260: * have anything else to do. If a new value was written, we
1261: * have to check it.
1262: *
1263: * If it is incorrect, we can return an error and leave 'node' as
1264: * it is: since it is a copy of the actual node, the change will
1265: * be forgotten.
1266: *
1267: * Upon a correct input, we commit the change to the ifnet
1268: * structure of our interface.
1269: */
1270: static int
1271: tap_sysctl_handler(SYSCTLFN_ARGS)
1272: {
1273: struct sysctlnode node;
1274: struct tap_softc *sc;
1275: struct ifnet *ifp;
1276: int error;
1277: size_t len;
1.14 christos 1278: char addr[3 * ETHER_ADDR_LEN];
1.1 cube 1279:
1280: node = *rnode;
1281: sc = node.sysctl_data;
1282: ifp = &sc->sc_ec.ec_if;
1.14 christos 1283: (void)ether_snprintf(addr, sizeof(addr), LLADDR(ifp->if_sadl));
1.1 cube 1284: node.sysctl_data = addr;
1285: error = sysctl_lookup(SYSCTLFN_CALL(&node));
1286: if (error || newp == NULL)
1287: return (error);
1288:
1289: len = strlen(addr);
1290: if (len < 11 || len > 17)
1291: return (EINVAL);
1292:
1293: /* Commit change */
1.21.4.2! yamt 1294: if (ether_nonstatic_aton(LLADDR(ifp->if_sadl), addr) != 0)
1.1 cube 1295: return (EINVAL);
1296: return (error);
1297: }
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