1 /* $NetBSD: if_tap.c,v 1.70 2013/01/28 15:05:03 yamt Exp $ */ 2 3 /* 4 * Copyright (c) 2003, 2004, 2008, 2009 The NetBSD Foundation. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /* 30 * tap(4) is a virtual Ethernet interface. It appears as a real Ethernet 31 * device to the system, but can also be accessed by userland through a 32 * character device interface, which allows reading and injecting frames. 33 */ 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: if_tap.c,v 1.70 2013/01/28 15:05:03 yamt Exp $"); 37 38 #if defined(_KERNEL_OPT) 39 40 #include "opt_modular.h" 41 #include "opt_compat_netbsd.h" 42 #endif 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/conf.h> 49 #include <sys/cprng.h> 50 #include <sys/device.h> 51 #include <sys/file.h> 52 #include <sys/filedesc.h> 53 #include <sys/ksyms.h> 54 #include <sys/poll.h> 55 #include <sys/proc.h> 56 #include <sys/select.h> 57 #include <sys/sockio.h> 58 #if defined(COMPAT_40) || defined(MODULAR) 59 #include <sys/sysctl.h> 60 #endif 61 #include <sys/kauth.h> 62 #include <sys/mutex.h> 63 #include <sys/simplelock.h> 64 #include <sys/intr.h> 65 #include <sys/stat.h> 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 #include <net/bpf.h> 73 74 #include <compat/sys/sockio.h> 75 76 #if defined(COMPAT_40) || defined(MODULAR) 77 /* 78 * sysctl node management 79 * 80 * It's not really possible to use a SYSCTL_SETUP block with 81 * current module implementation, so it is easier to just define 82 * our own function. 83 * 84 * The handler function is a "helper" in Andrew Brown's sysctl 85 * framework terminology. It is used as a gateway for sysctl 86 * requests over the nodes. 87 * 88 * tap_log allows the module to log creations of nodes and 89 * destroy them all at once using sysctl_teardown. 90 */ 91 static int tap_node; 92 static int tap_sysctl_handler(SYSCTLFN_PROTO); 93 SYSCTL_SETUP_PROTO(sysctl_tap_setup); 94 #endif 95 96 /* 97 * Since we're an Ethernet device, we need the 2 following 98 * components: a struct ethercom and a struct ifmedia 99 * since we don't attach a PHY to ourselves. 100 * We could emulate one, but there's no real point. 101 */ 102 103 struct tap_softc { 104 device_t sc_dev; 105 struct ifmedia sc_im; 106 struct ethercom sc_ec; 107 int sc_flags; 108 #define TAP_INUSE 0x00000001 /* tap device can only be opened once */ 109 #define TAP_ASYNCIO 0x00000002 /* user is using async I/O (SIGIO) on the device */ 110 #define TAP_NBIO 0x00000004 /* user wants calls to avoid blocking */ 111 #define TAP_GOING 0x00000008 /* interface is being destroyed */ 112 struct selinfo sc_rsel; 113 pid_t sc_pgid; /* For async. IO */ 114 kmutex_t sc_rdlock; 115 struct simplelock sc_kqlock; 116 void *sc_sih; 117 struct timespec sc_atime; 118 struct timespec sc_mtime; 119 struct timespec sc_btime; 120 }; 121 122 /* autoconf(9) glue */ 123 124 void tapattach(int); 125 126 static int tap_match(device_t, cfdata_t, void *); 127 static void tap_attach(device_t, device_t, void *); 128 static int tap_detach(device_t, int); 129 130 CFATTACH_DECL_NEW(tap, sizeof(struct tap_softc), 131 tap_match, tap_attach, tap_detach, NULL); 132 extern struct cfdriver tap_cd; 133 134 /* Real device access routines */ 135 static int tap_dev_close(struct tap_softc *); 136 static int tap_dev_read(int, struct uio *, int); 137 static int tap_dev_write(int, struct uio *, int); 138 static int tap_dev_ioctl(int, u_long, void *, struct lwp *); 139 static int tap_dev_poll(int, int, struct lwp *); 140 static int tap_dev_kqfilter(int, struct knote *); 141 142 /* Fileops access routines */ 143 static int tap_fops_close(file_t *); 144 static int tap_fops_read(file_t *, off_t *, struct uio *, 145 kauth_cred_t, int); 146 static int tap_fops_write(file_t *, off_t *, struct uio *, 147 kauth_cred_t, int); 148 static int tap_fops_ioctl(file_t *, u_long, void *); 149 static int tap_fops_poll(file_t *, int); 150 static int tap_fops_stat(file_t *, struct stat *); 151 static int tap_fops_kqfilter(file_t *, struct knote *); 152 153 static const struct fileops tap_fileops = { 154 .fo_read = tap_fops_read, 155 .fo_write = tap_fops_write, 156 .fo_ioctl = tap_fops_ioctl, 157 .fo_fcntl = fnullop_fcntl, 158 .fo_poll = tap_fops_poll, 159 .fo_stat = tap_fops_stat, 160 .fo_close = tap_fops_close, 161 .fo_kqfilter = tap_fops_kqfilter, 162 .fo_restart = fnullop_restart, 163 }; 164 165 /* Helper for cloning open() */ 166 static int tap_dev_cloner(struct lwp *); 167 168 /* Character device routines */ 169 static int tap_cdev_open(dev_t, int, int, struct lwp *); 170 static int tap_cdev_close(dev_t, int, int, struct lwp *); 171 static int tap_cdev_read(dev_t, struct uio *, int); 172 static int tap_cdev_write(dev_t, struct uio *, int); 173 static int tap_cdev_ioctl(dev_t, u_long, void *, int, struct lwp *); 174 static int tap_cdev_poll(dev_t, int, struct lwp *); 175 static int tap_cdev_kqfilter(dev_t, struct knote *); 176 177 const struct cdevsw tap_cdevsw = { 178 tap_cdev_open, tap_cdev_close, 179 tap_cdev_read, tap_cdev_write, 180 tap_cdev_ioctl, nostop, notty, 181 tap_cdev_poll, nommap, 182 tap_cdev_kqfilter, 183 D_OTHER, 184 }; 185 186 #define TAP_CLONER 0xfffff /* Maximal minor value */ 187 188 /* kqueue-related routines */ 189 static void tap_kqdetach(struct knote *); 190 static int tap_kqread(struct knote *, long); 191 192 /* 193 * Those are needed by the if_media interface. 194 */ 195 196 static int tap_mediachange(struct ifnet *); 197 static void tap_mediastatus(struct ifnet *, struct ifmediareq *); 198 199 /* 200 * Those are needed by the ifnet interface, and would typically be 201 * there for any network interface driver. 202 * Some other routines are optional: watchdog and drain. 203 */ 204 205 static void tap_start(struct ifnet *); 206 static void tap_stop(struct ifnet *, int); 207 static int tap_init(struct ifnet *); 208 static int tap_ioctl(struct ifnet *, u_long, void *); 209 210 /* Internal functions */ 211 #if defined(COMPAT_40) || defined(MODULAR) 212 static int tap_lifaddr(struct ifnet *, u_long, struct ifaliasreq *); 213 #endif 214 static void tap_softintr(void *); 215 216 /* 217 * tap is a clonable interface, although it is highly unrealistic for 218 * an Ethernet device. 219 * 220 * Here are the bits needed for a clonable interface. 221 */ 222 static int tap_clone_create(struct if_clone *, int); 223 static int tap_clone_destroy(struct ifnet *); 224 225 struct if_clone tap_cloners = IF_CLONE_INITIALIZER("tap", 226 tap_clone_create, 227 tap_clone_destroy); 228 229 /* Helper functionis shared by the two cloning code paths */ 230 static struct tap_softc * tap_clone_creator(int); 231 int tap_clone_destroyer(device_t); 232 233 void 234 tapattach(int n) 235 { 236 int error; 237 238 error = config_cfattach_attach(tap_cd.cd_name, &tap_ca); 239 if (error) { 240 aprint_error("%s: unable to register cfattach\n", 241 tap_cd.cd_name); 242 (void)config_cfdriver_detach(&tap_cd); 243 return; 244 } 245 246 if_clone_attach(&tap_cloners); 247 } 248 249 /* Pretty much useless for a pseudo-device */ 250 static int 251 tap_match(device_t parent, cfdata_t cfdata, void *arg) 252 { 253 254 return (1); 255 } 256 257 void 258 tap_attach(device_t parent, device_t self, void *aux) 259 { 260 struct tap_softc *sc = device_private(self); 261 struct ifnet *ifp; 262 #if defined(COMPAT_40) || defined(MODULAR) 263 const struct sysctlnode *node; 264 int error; 265 #endif 266 uint8_t enaddr[ETHER_ADDR_LEN] = 267 { 0xf2, 0x0b, 0xa4, 0xff, 0xff, 0xff }; 268 char enaddrstr[3 * ETHER_ADDR_LEN]; 269 270 sc->sc_dev = self; 271 sc->sc_sih = softint_establish(SOFTINT_CLOCK, tap_softintr, sc); 272 getnanotime(&sc->sc_btime); 273 sc->sc_atime = sc->sc_mtime = sc->sc_btime; 274 275 if (!pmf_device_register(self, NULL, NULL)) 276 aprint_error_dev(self, "couldn't establish power handler\n"); 277 278 /* 279 * In order to obtain unique initial Ethernet address on a host, 280 * do some randomisation. It's not meant for anything but avoiding 281 * hard-coding an address. 282 */ 283 cprng_fast(&enaddr[3], 3); 284 285 aprint_verbose_dev(self, "Ethernet address %s\n", 286 ether_snprintf(enaddrstr, sizeof(enaddrstr), enaddr)); 287 288 /* 289 * Why 1000baseT? Why not? You can add more. 290 * 291 * Note that there are 3 steps: init, one or several additions to 292 * list of supported media, and in the end, the selection of one 293 * of them. 294 */ 295 ifmedia_init(&sc->sc_im, 0, tap_mediachange, tap_mediastatus); 296 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_1000_T, 0, NULL); 297 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_1000_T|IFM_FDX, 0, NULL); 298 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_100_TX, 0, NULL); 299 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_100_TX|IFM_FDX, 0, NULL); 300 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_10_T, 0, NULL); 301 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL); 302 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_AUTO, 0, NULL); 303 ifmedia_set(&sc->sc_im, IFM_ETHER|IFM_AUTO); 304 305 /* 306 * One should note that an interface must do multicast in order 307 * to support IPv6. 308 */ 309 ifp = &sc->sc_ec.ec_if; 310 strcpy(ifp->if_xname, device_xname(self)); 311 ifp->if_softc = sc; 312 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 313 ifp->if_ioctl = tap_ioctl; 314 ifp->if_start = tap_start; 315 ifp->if_stop = tap_stop; 316 ifp->if_init = tap_init; 317 IFQ_SET_READY(&ifp->if_snd); 318 319 sc->sc_ec.ec_capabilities = ETHERCAP_VLAN_MTU | ETHERCAP_JUMBO_MTU; 320 321 /* Those steps are mandatory for an Ethernet driver, the fisrt call 322 * being common to all network interface drivers. */ 323 if_attach(ifp); 324 ether_ifattach(ifp, enaddr); 325 326 sc->sc_flags = 0; 327 328 #if defined(COMPAT_40) || defined(MODULAR) 329 /* 330 * Add a sysctl node for that interface. 331 * 332 * The pointer transmitted is not a string, but instead a pointer to 333 * the softc structure, which we can use to build the string value on 334 * the fly in the helper function of the node. See the comments for 335 * tap_sysctl_handler for details. 336 * 337 * Usually sysctl_createv is called with CTL_CREATE as the before-last 338 * component. However, we can allocate a number ourselves, as we are 339 * the only consumer of the net.link.<iface> node. In this case, the 340 * unit number is conveniently used to number the node. CTL_CREATE 341 * would just work, too. 342 */ 343 if ((error = sysctl_createv(NULL, 0, NULL, 344 &node, CTLFLAG_READWRITE, 345 CTLTYPE_STRING, device_xname(self), NULL, 346 tap_sysctl_handler, 0, (void *)sc, 18, 347 CTL_NET, AF_LINK, tap_node, device_unit(sc->sc_dev), 348 CTL_EOL)) != 0) 349 aprint_error_dev(self, "sysctl_createv returned %d, ignoring\n", 350 error); 351 #endif 352 353 /* 354 * Initialize the two locks for the device. 355 * 356 * We need a lock here because even though the tap device can be 357 * opened only once, the file descriptor might be passed to another 358 * process, say a fork(2)ed child. 359 * 360 * The Giant saves us from most of the hassle, but since the read 361 * operation can sleep, we don't want two processes to wake up at 362 * the same moment and both try and dequeue a single packet. 363 * 364 * The queue for event listeners (used by kqueue(9), see below) has 365 * to be protected, too, but we don't need the same level of 366 * complexity for that lock, so a simple spinning lock is fine. 367 */ 368 mutex_init(&sc->sc_rdlock, MUTEX_DEFAULT, IPL_NONE); 369 simple_lock_init(&sc->sc_kqlock); 370 371 selinit(&sc->sc_rsel); 372 } 373 374 /* 375 * When detaching, we do the inverse of what is done in the attach 376 * routine, in reversed order. 377 */ 378 static int 379 tap_detach(device_t self, int flags) 380 { 381 struct tap_softc *sc = device_private(self); 382 struct ifnet *ifp = &sc->sc_ec.ec_if; 383 #if defined(COMPAT_40) || defined(MODULAR) 384 int error; 385 #endif 386 int s; 387 388 sc->sc_flags |= TAP_GOING; 389 s = splnet(); 390 tap_stop(ifp, 1); 391 if_down(ifp); 392 splx(s); 393 394 softint_disestablish(sc->sc_sih); 395 396 #if defined(COMPAT_40) || defined(MODULAR) 397 /* 398 * Destroying a single leaf is a very straightforward operation using 399 * sysctl_destroyv. One should be sure to always end the path with 400 * CTL_EOL. 401 */ 402 if ((error = sysctl_destroyv(NULL, CTL_NET, AF_LINK, tap_node, 403 device_unit(sc->sc_dev), CTL_EOL)) != 0) 404 aprint_error_dev(self, 405 "sysctl_destroyv returned %d, ignoring\n", error); 406 #endif 407 ether_ifdetach(ifp); 408 if_detach(ifp); 409 ifmedia_delete_instance(&sc->sc_im, IFM_INST_ANY); 410 seldestroy(&sc->sc_rsel); 411 mutex_destroy(&sc->sc_rdlock); 412 413 pmf_device_deregister(self); 414 415 return (0); 416 } 417 418 /* 419 * This function is called by the ifmedia layer to notify the driver 420 * that the user requested a media change. A real driver would 421 * reconfigure the hardware. 422 */ 423 static int 424 tap_mediachange(struct ifnet *ifp) 425 { 426 return (0); 427 } 428 429 /* 430 * Here the user asks for the currently used media. 431 */ 432 static void 433 tap_mediastatus(struct ifnet *ifp, struct ifmediareq *imr) 434 { 435 struct tap_softc *sc = (struct tap_softc *)ifp->if_softc; 436 imr->ifm_active = sc->sc_im.ifm_cur->ifm_media; 437 } 438 439 /* 440 * This is the function where we SEND packets. 441 * 442 * There is no 'receive' equivalent. A typical driver will get 443 * interrupts from the hardware, and from there will inject new packets 444 * into the network stack. 445 * 446 * Once handled, a packet must be freed. A real driver might not be able 447 * to fit all the pending packets into the hardware, and is allowed to 448 * return before having sent all the packets. It should then use the 449 * if_flags flag IFF_OACTIVE to notify the upper layer. 450 * 451 * There are also other flags one should check, such as IFF_PAUSE. 452 * 453 * It is our duty to make packets available to BPF listeners. 454 * 455 * You should be aware that this function is called by the Ethernet layer 456 * at splnet(). 457 * 458 * When the device is opened, we have to pass the packet(s) to the 459 * userland. For that we stay in OACTIVE mode while the userland gets 460 * the packets, and we send a signal to the processes waiting to read. 461 * 462 * wakeup(sc) is the counterpart to the tsleep call in 463 * tap_dev_read, while selnotify() is used for kevent(2) and 464 * poll(2) (which includes select(2)) listeners. 465 */ 466 static void 467 tap_start(struct ifnet *ifp) 468 { 469 struct tap_softc *sc = (struct tap_softc *)ifp->if_softc; 470 struct mbuf *m0; 471 472 if ((sc->sc_flags & TAP_INUSE) == 0) { 473 /* Simply drop packets */ 474 for(;;) { 475 IFQ_DEQUEUE(&ifp->if_snd, m0); 476 if (m0 == NULL) 477 return; 478 479 ifp->if_opackets++; 480 bpf_mtap(ifp, m0); 481 482 m_freem(m0); 483 } 484 } else if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 485 ifp->if_flags |= IFF_OACTIVE; 486 wakeup(sc); 487 selnotify(&sc->sc_rsel, 0, 1); 488 if (sc->sc_flags & TAP_ASYNCIO) 489 softint_schedule(sc->sc_sih); 490 } 491 } 492 493 static void 494 tap_softintr(void *cookie) 495 { 496 struct tap_softc *sc; 497 struct ifnet *ifp; 498 int a, b; 499 500 sc = cookie; 501 502 if (sc->sc_flags & TAP_ASYNCIO) { 503 ifp = &sc->sc_ec.ec_if; 504 if (ifp->if_flags & IFF_RUNNING) { 505 a = POLL_IN; 506 b = POLLIN|POLLRDNORM; 507 } else { 508 a = POLL_HUP; 509 b = 0; 510 } 511 fownsignal(sc->sc_pgid, SIGIO, a, b, NULL); 512 } 513 } 514 515 /* 516 * A typical driver will only contain the following handlers for 517 * ioctl calls, except SIOCSIFPHYADDR. 518 * The latter is a hack I used to set the Ethernet address of the 519 * faked device. 520 * 521 * Note that both ifmedia_ioctl() and ether_ioctl() have to be 522 * called under splnet(). 523 */ 524 static int 525 tap_ioctl(struct ifnet *ifp, u_long cmd, void *data) 526 { 527 struct tap_softc *sc = (struct tap_softc *)ifp->if_softc; 528 struct ifreq *ifr = (struct ifreq *)data; 529 int s, error; 530 531 s = splnet(); 532 533 switch (cmd) { 534 #ifdef OSIOCSIFMEDIA 535 case OSIOCSIFMEDIA: 536 #endif 537 case SIOCSIFMEDIA: 538 case SIOCGIFMEDIA: 539 error = ifmedia_ioctl(ifp, ifr, &sc->sc_im, cmd); 540 break; 541 #if defined(COMPAT_40) || defined(MODULAR) 542 case SIOCSIFPHYADDR: 543 error = tap_lifaddr(ifp, cmd, (struct ifaliasreq *)data); 544 break; 545 #endif 546 default: 547 error = ether_ioctl(ifp, cmd, data); 548 if (error == ENETRESET) 549 error = 0; 550 break; 551 } 552 553 splx(s); 554 555 return (error); 556 } 557 558 #if defined(COMPAT_40) || defined(MODULAR) 559 /* 560 * Helper function to set Ethernet address. This has been replaced by 561 * the generic SIOCALIFADDR ioctl on a PF_LINK socket. 562 */ 563 static int 564 tap_lifaddr(struct ifnet *ifp, u_long cmd, struct ifaliasreq *ifra) 565 { 566 const struct sockaddr *sa = &ifra->ifra_addr; 567 568 if (sa->sa_family != AF_LINK) 569 return (EINVAL); 570 571 if_set_sadl(ifp, sa->sa_data, ETHER_ADDR_LEN, false); 572 573 return (0); 574 } 575 #endif 576 577 /* 578 * _init() would typically be called when an interface goes up, 579 * meaning it should configure itself into the state in which it 580 * can send packets. 581 */ 582 static int 583 tap_init(struct ifnet *ifp) 584 { 585 ifp->if_flags |= IFF_RUNNING; 586 587 tap_start(ifp); 588 589 return (0); 590 } 591 592 /* 593 * _stop() is called when an interface goes down. It is our 594 * responsability to validate that state by clearing the 595 * IFF_RUNNING flag. 596 * 597 * We have to wake up all the sleeping processes to have the pending 598 * read requests cancelled. 599 */ 600 static void 601 tap_stop(struct ifnet *ifp, int disable) 602 { 603 struct tap_softc *sc = (struct tap_softc *)ifp->if_softc; 604 605 ifp->if_flags &= ~IFF_RUNNING; 606 wakeup(sc); 607 selnotify(&sc->sc_rsel, 0, 1); 608 if (sc->sc_flags & TAP_ASYNCIO) 609 softint_schedule(sc->sc_sih); 610 } 611 612 /* 613 * The 'create' command of ifconfig can be used to create 614 * any numbered instance of a given device. Thus we have to 615 * make sure we have enough room in cd_devs to create the 616 * user-specified instance. config_attach_pseudo will do this 617 * for us. 618 */ 619 static int 620 tap_clone_create(struct if_clone *ifc, int unit) 621 { 622 if (tap_clone_creator(unit) == NULL) { 623 aprint_error("%s%d: unable to attach an instance\n", 624 tap_cd.cd_name, unit); 625 return (ENXIO); 626 } 627 628 return (0); 629 } 630 631 /* 632 * tap(4) can be cloned by two ways: 633 * using 'ifconfig tap0 create', which will use the network 634 * interface cloning API, and call tap_clone_create above. 635 * opening the cloning device node, whose minor number is TAP_CLONER. 636 * See below for an explanation on how this part work. 637 */ 638 static struct tap_softc * 639 tap_clone_creator(int unit) 640 { 641 struct cfdata *cf; 642 643 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 644 cf->cf_name = tap_cd.cd_name; 645 cf->cf_atname = tap_ca.ca_name; 646 if (unit == -1) { 647 /* let autoconf find the first free one */ 648 cf->cf_unit = 0; 649 cf->cf_fstate = FSTATE_STAR; 650 } else { 651 cf->cf_unit = unit; 652 cf->cf_fstate = FSTATE_NOTFOUND; 653 } 654 655 return device_private(config_attach_pseudo(cf)); 656 } 657 658 /* 659 * The clean design of if_clone and autoconf(9) makes that part 660 * really straightforward. The second argument of config_detach 661 * means neither QUIET nor FORCED. 662 */ 663 static int 664 tap_clone_destroy(struct ifnet *ifp) 665 { 666 struct tap_softc *sc = ifp->if_softc; 667 668 return tap_clone_destroyer(sc->sc_dev); 669 } 670 671 int 672 tap_clone_destroyer(device_t dev) 673 { 674 cfdata_t cf = device_cfdata(dev); 675 int error; 676 677 if ((error = config_detach(dev, 0)) != 0) 678 aprint_error_dev(dev, "unable to detach instance\n"); 679 free(cf, M_DEVBUF); 680 681 return (error); 682 } 683 684 /* 685 * tap(4) is a bit of an hybrid device. It can be used in two different 686 * ways: 687 * 1. ifconfig tapN create, then use /dev/tapN to read/write off it. 688 * 2. open /dev/tap, get a new interface created and read/write off it. 689 * That interface is destroyed when the process that had it created exits. 690 * 691 * The first way is managed by the cdevsw structure, and you access interfaces 692 * through a (major, minor) mapping: tap4 is obtained by the minor number 693 * 4. The entry points for the cdevsw interface are prefixed by tap_cdev_. 694 * 695 * The second way is the so-called "cloning" device. It's a special minor 696 * number (chosen as the maximal number, to allow as much tap devices as 697 * possible). The user first opens the cloner (e.g., /dev/tap), and that 698 * call ends in tap_cdev_open. The actual place where it is handled is 699 * tap_dev_cloner. 700 * 701 * An tap device cannot be opened more than once at a time, so the cdevsw 702 * part of open() does nothing but noting that the interface is being used and 703 * hence ready to actually handle packets. 704 */ 705 706 static int 707 tap_cdev_open(dev_t dev, int flags, int fmt, struct lwp *l) 708 { 709 struct tap_softc *sc; 710 711 if (minor(dev) == TAP_CLONER) 712 return tap_dev_cloner(l); 713 714 sc = device_lookup_private(&tap_cd, minor(dev)); 715 if (sc == NULL) 716 return (ENXIO); 717 718 /* The device can only be opened once */ 719 if (sc->sc_flags & TAP_INUSE) 720 return (EBUSY); 721 sc->sc_flags |= TAP_INUSE; 722 return (0); 723 } 724 725 /* 726 * There are several kinds of cloning devices, and the most simple is the one 727 * tap(4) uses. What it does is change the file descriptor with a new one, 728 * with its own fileops structure (which maps to the various read, write, 729 * ioctl functions). It starts allocating a new file descriptor with falloc, 730 * then actually creates the new tap devices. 731 * 732 * Once those two steps are successful, we can re-wire the existing file 733 * descriptor to its new self. This is done with fdclone(): it fills the fp 734 * structure as needed (notably f_data gets filled with the fifth parameter 735 * passed, the unit of the tap device which will allows us identifying the 736 * device later), and returns EMOVEFD. 737 * 738 * That magic value is interpreted by sys_open() which then replaces the 739 * current file descriptor by the new one (through a magic member of struct 740 * lwp, l_dupfd). 741 * 742 * The tap device is flagged as being busy since it otherwise could be 743 * externally accessed through the corresponding device node with the cdevsw 744 * interface. 745 */ 746 747 static int 748 tap_dev_cloner(struct lwp *l) 749 { 750 struct tap_softc *sc; 751 file_t *fp; 752 int error, fd; 753 754 if ((error = fd_allocfile(&fp, &fd)) != 0) 755 return (error); 756 757 if ((sc = tap_clone_creator(-1)) == NULL) { 758 fd_abort(curproc, fp, fd); 759 return (ENXIO); 760 } 761 762 sc->sc_flags |= TAP_INUSE; 763 764 return fd_clone(fp, fd, FREAD|FWRITE, &tap_fileops, 765 (void *)(intptr_t)device_unit(sc->sc_dev)); 766 } 767 768 /* 769 * While all other operations (read, write, ioctl, poll and kqfilter) are 770 * really the same whether we are in cdevsw or fileops mode, the close() 771 * function is slightly different in the two cases. 772 * 773 * As for the other, the core of it is shared in tap_dev_close. What 774 * it does is sufficient for the cdevsw interface, but the cloning interface 775 * needs another thing: the interface is destroyed when the processes that 776 * created it closes it. 777 */ 778 static int 779 tap_cdev_close(dev_t dev, int flags, int fmt, 780 struct lwp *l) 781 { 782 struct tap_softc *sc = 783 device_lookup_private(&tap_cd, minor(dev)); 784 785 if (sc == NULL) 786 return (ENXIO); 787 788 return tap_dev_close(sc); 789 } 790 791 /* 792 * It might happen that the administrator used ifconfig to externally destroy 793 * the interface. In that case, tap_fops_close will be called while 794 * tap_detach is already happening. If we called it again from here, we 795 * would dead lock. TAP_GOING ensures that this situation doesn't happen. 796 */ 797 static int 798 tap_fops_close(file_t *fp) 799 { 800 int unit = (intptr_t)fp->f_data; 801 struct tap_softc *sc; 802 int error; 803 804 sc = device_lookup_private(&tap_cd, unit); 805 if (sc == NULL) 806 return (ENXIO); 807 808 /* tap_dev_close currently always succeeds, but it might not 809 * always be the case. */ 810 KERNEL_LOCK(1, NULL); 811 if ((error = tap_dev_close(sc)) != 0) { 812 KERNEL_UNLOCK_ONE(NULL); 813 return (error); 814 } 815 816 /* Destroy the device now that it is no longer useful, 817 * unless it's already being destroyed. */ 818 if ((sc->sc_flags & TAP_GOING) != 0) { 819 KERNEL_UNLOCK_ONE(NULL); 820 return (0); 821 } 822 823 error = tap_clone_destroyer(sc->sc_dev); 824 KERNEL_UNLOCK_ONE(NULL); 825 return error; 826 } 827 828 static int 829 tap_dev_close(struct tap_softc *sc) 830 { 831 struct ifnet *ifp; 832 int s; 833 834 s = splnet(); 835 /* Let tap_start handle packets again */ 836 ifp = &sc->sc_ec.ec_if; 837 ifp->if_flags &= ~IFF_OACTIVE; 838 839 /* Purge output queue */ 840 if (!(IFQ_IS_EMPTY(&ifp->if_snd))) { 841 struct mbuf *m; 842 843 for (;;) { 844 IFQ_DEQUEUE(&ifp->if_snd, m); 845 if (m == NULL) 846 break; 847 848 ifp->if_opackets++; 849 bpf_mtap(ifp, m); 850 m_freem(m); 851 } 852 } 853 splx(s); 854 855 sc->sc_flags &= ~(TAP_INUSE | TAP_ASYNCIO); 856 857 return (0); 858 } 859 860 static int 861 tap_cdev_read(dev_t dev, struct uio *uio, int flags) 862 { 863 return tap_dev_read(minor(dev), uio, flags); 864 } 865 866 static int 867 tap_fops_read(file_t *fp, off_t *offp, struct uio *uio, 868 kauth_cred_t cred, int flags) 869 { 870 int error; 871 872 KERNEL_LOCK(1, NULL); 873 error = tap_dev_read((intptr_t)fp->f_data, uio, flags); 874 KERNEL_UNLOCK_ONE(NULL); 875 return error; 876 } 877 878 static int 879 tap_dev_read(int unit, struct uio *uio, int flags) 880 { 881 struct tap_softc *sc = 882 device_lookup_private(&tap_cd, unit); 883 struct ifnet *ifp; 884 struct mbuf *m, *n; 885 int error = 0, s; 886 887 if (sc == NULL) 888 return (ENXIO); 889 890 getnanotime(&sc->sc_atime); 891 892 ifp = &sc->sc_ec.ec_if; 893 if ((ifp->if_flags & IFF_UP) == 0) 894 return (EHOSTDOWN); 895 896 /* 897 * In the TAP_NBIO case, we have to make sure we won't be sleeping 898 */ 899 if ((sc->sc_flags & TAP_NBIO) != 0) { 900 if (!mutex_tryenter(&sc->sc_rdlock)) 901 return (EWOULDBLOCK); 902 } else { 903 mutex_enter(&sc->sc_rdlock); 904 } 905 906 s = splnet(); 907 if (IFQ_IS_EMPTY(&ifp->if_snd)) { 908 ifp->if_flags &= ~IFF_OACTIVE; 909 /* 910 * We must release the lock before sleeping, and re-acquire it 911 * after. 912 */ 913 mutex_exit(&sc->sc_rdlock); 914 if (sc->sc_flags & TAP_NBIO) 915 error = EWOULDBLOCK; 916 else 917 error = tsleep(sc, PSOCK|PCATCH, "tap", 0); 918 splx(s); 919 920 if (error != 0) 921 return (error); 922 /* The device might have been downed */ 923 if ((ifp->if_flags & IFF_UP) == 0) 924 return (EHOSTDOWN); 925 if ((sc->sc_flags & TAP_NBIO)) { 926 if (!mutex_tryenter(&sc->sc_rdlock)) 927 return (EWOULDBLOCK); 928 } else { 929 mutex_enter(&sc->sc_rdlock); 930 } 931 s = splnet(); 932 } 933 934 IFQ_DEQUEUE(&ifp->if_snd, m); 935 ifp->if_flags &= ~IFF_OACTIVE; 936 splx(s); 937 if (m == NULL) { 938 error = 0; 939 goto out; 940 } 941 942 ifp->if_opackets++; 943 bpf_mtap(ifp, m); 944 945 /* 946 * One read is one packet. 947 */ 948 do { 949 error = uiomove(mtod(m, void *), 950 min(m->m_len, uio->uio_resid), uio); 951 MFREE(m, n); 952 m = n; 953 } while (m != NULL && uio->uio_resid > 0 && error == 0); 954 955 if (m != NULL) 956 m_freem(m); 957 958 out: 959 mutex_exit(&sc->sc_rdlock); 960 return (error); 961 } 962 963 static int 964 tap_fops_stat(file_t *fp, struct stat *st) 965 { 966 int error = 0; 967 struct tap_softc *sc; 968 int unit = (uintptr_t)fp->f_data; 969 970 (void)memset(st, 0, sizeof(*st)); 971 972 KERNEL_LOCK(1, NULL); 973 sc = device_lookup_private(&tap_cd, unit); 974 if (sc == NULL) { 975 error = ENXIO; 976 goto out; 977 } 978 979 st->st_dev = makedev(cdevsw_lookup_major(&tap_cdevsw), unit); 980 st->st_atimespec = sc->sc_atime; 981 st->st_mtimespec = sc->sc_mtime; 982 st->st_ctimespec = st->st_birthtimespec = sc->sc_btime; 983 st->st_uid = kauth_cred_geteuid(fp->f_cred); 984 st->st_gid = kauth_cred_getegid(fp->f_cred); 985 out: 986 KERNEL_UNLOCK_ONE(NULL); 987 return error; 988 } 989 990 static int 991 tap_cdev_write(dev_t dev, struct uio *uio, int flags) 992 { 993 return tap_dev_write(minor(dev), uio, flags); 994 } 995 996 static int 997 tap_fops_write(file_t *fp, off_t *offp, struct uio *uio, 998 kauth_cred_t cred, int flags) 999 { 1000 int error; 1001 1002 KERNEL_LOCK(1, NULL); 1003 error = tap_dev_write((intptr_t)fp->f_data, uio, flags); 1004 KERNEL_UNLOCK_ONE(NULL); 1005 return error; 1006 } 1007 1008 static int 1009 tap_dev_write(int unit, struct uio *uio, int flags) 1010 { 1011 struct tap_softc *sc = 1012 device_lookup_private(&tap_cd, unit); 1013 struct ifnet *ifp; 1014 struct mbuf *m, **mp; 1015 int error = 0; 1016 int s; 1017 1018 if (sc == NULL) 1019 return (ENXIO); 1020 1021 getnanotime(&sc->sc_mtime); 1022 ifp = &sc->sc_ec.ec_if; 1023 1024 /* One write, one packet, that's the rule */ 1025 MGETHDR(m, M_DONTWAIT, MT_DATA); 1026 if (m == NULL) { 1027 ifp->if_ierrors++; 1028 return (ENOBUFS); 1029 } 1030 m->m_pkthdr.len = uio->uio_resid; 1031 1032 mp = &m; 1033 while (error == 0 && uio->uio_resid > 0) { 1034 if (*mp != m) { 1035 MGET(*mp, M_DONTWAIT, MT_DATA); 1036 if (*mp == NULL) { 1037 error = ENOBUFS; 1038 break; 1039 } 1040 } 1041 (*mp)->m_len = min(MHLEN, uio->uio_resid); 1042 error = uiomove(mtod(*mp, void *), (*mp)->m_len, uio); 1043 mp = &(*mp)->m_next; 1044 } 1045 if (error) { 1046 ifp->if_ierrors++; 1047 m_freem(m); 1048 return (error); 1049 } 1050 1051 ifp->if_ipackets++; 1052 m->m_pkthdr.rcvif = ifp; 1053 1054 bpf_mtap(ifp, m); 1055 s = splnet(); 1056 (*ifp->if_input)(ifp, m); 1057 splx(s); 1058 1059 return (0); 1060 } 1061 1062 static int 1063 tap_cdev_ioctl(dev_t dev, u_long cmd, void *data, int flags, 1064 struct lwp *l) 1065 { 1066 return tap_dev_ioctl(minor(dev), cmd, data, l); 1067 } 1068 1069 static int 1070 tap_fops_ioctl(file_t *fp, u_long cmd, void *data) 1071 { 1072 return tap_dev_ioctl((intptr_t)fp->f_data, cmd, data, curlwp); 1073 } 1074 1075 static int 1076 tap_dev_ioctl(int unit, u_long cmd, void *data, struct lwp *l) 1077 { 1078 struct tap_softc *sc = device_lookup_private(&tap_cd, unit); 1079 1080 if (sc == NULL) 1081 return ENXIO; 1082 1083 switch (cmd) { 1084 case FIONREAD: 1085 { 1086 struct ifnet *ifp = &sc->sc_ec.ec_if; 1087 struct mbuf *m; 1088 int s; 1089 1090 s = splnet(); 1091 IFQ_POLL(&ifp->if_snd, m); 1092 1093 if (m == NULL) 1094 *(int *)data = 0; 1095 else 1096 *(int *)data = m->m_pkthdr.len; 1097 splx(s); 1098 return 0; 1099 } 1100 case TIOCSPGRP: 1101 case FIOSETOWN: 1102 return fsetown(&sc->sc_pgid, cmd, data); 1103 case TIOCGPGRP: 1104 case FIOGETOWN: 1105 return fgetown(sc->sc_pgid, cmd, data); 1106 case FIOASYNC: 1107 if (*(int *)data) 1108 sc->sc_flags |= TAP_ASYNCIO; 1109 else 1110 sc->sc_flags &= ~TAP_ASYNCIO; 1111 return 0; 1112 case FIONBIO: 1113 if (*(int *)data) 1114 sc->sc_flags |= TAP_NBIO; 1115 else 1116 sc->sc_flags &= ~TAP_NBIO; 1117 return 0; 1118 #ifdef OTAPGIFNAME 1119 case OTAPGIFNAME: 1120 #endif 1121 case TAPGIFNAME: 1122 { 1123 struct ifreq *ifr = (struct ifreq *)data; 1124 struct ifnet *ifp = &sc->sc_ec.ec_if; 1125 1126 strlcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ); 1127 return 0; 1128 } 1129 default: 1130 return ENOTTY; 1131 } 1132 } 1133 1134 static int 1135 tap_cdev_poll(dev_t dev, int events, struct lwp *l) 1136 { 1137 return tap_dev_poll(minor(dev), events, l); 1138 } 1139 1140 static int 1141 tap_fops_poll(file_t *fp, int events) 1142 { 1143 return tap_dev_poll((intptr_t)fp->f_data, events, curlwp); 1144 } 1145 1146 static int 1147 tap_dev_poll(int unit, int events, struct lwp *l) 1148 { 1149 struct tap_softc *sc = 1150 device_lookup_private(&tap_cd, unit); 1151 int revents = 0; 1152 1153 if (sc == NULL) 1154 return POLLERR; 1155 1156 if (events & (POLLIN|POLLRDNORM)) { 1157 struct ifnet *ifp = &sc->sc_ec.ec_if; 1158 struct mbuf *m; 1159 int s; 1160 1161 s = splnet(); 1162 IFQ_POLL(&ifp->if_snd, m); 1163 splx(s); 1164 1165 if (m != NULL) 1166 revents |= events & (POLLIN|POLLRDNORM); 1167 else { 1168 simple_lock(&sc->sc_kqlock); 1169 selrecord(l, &sc->sc_rsel); 1170 simple_unlock(&sc->sc_kqlock); 1171 } 1172 } 1173 revents |= events & (POLLOUT|POLLWRNORM); 1174 1175 return (revents); 1176 } 1177 1178 static struct filterops tap_read_filterops = { 1, NULL, tap_kqdetach, 1179 tap_kqread }; 1180 static struct filterops tap_seltrue_filterops = { 1, NULL, tap_kqdetach, 1181 filt_seltrue }; 1182 1183 static int 1184 tap_cdev_kqfilter(dev_t dev, struct knote *kn) 1185 { 1186 return tap_dev_kqfilter(minor(dev), kn); 1187 } 1188 1189 static int 1190 tap_fops_kqfilter(file_t *fp, struct knote *kn) 1191 { 1192 return tap_dev_kqfilter((intptr_t)fp->f_data, kn); 1193 } 1194 1195 static int 1196 tap_dev_kqfilter(int unit, struct knote *kn) 1197 { 1198 struct tap_softc *sc = 1199 device_lookup_private(&tap_cd, unit); 1200 1201 if (sc == NULL) 1202 return (ENXIO); 1203 1204 KERNEL_LOCK(1, NULL); 1205 switch(kn->kn_filter) { 1206 case EVFILT_READ: 1207 kn->kn_fop = &tap_read_filterops; 1208 break; 1209 case EVFILT_WRITE: 1210 kn->kn_fop = &tap_seltrue_filterops; 1211 break; 1212 default: 1213 KERNEL_UNLOCK_ONE(NULL); 1214 return (EINVAL); 1215 } 1216 1217 kn->kn_hook = sc; 1218 simple_lock(&sc->sc_kqlock); 1219 SLIST_INSERT_HEAD(&sc->sc_rsel.sel_klist, kn, kn_selnext); 1220 simple_unlock(&sc->sc_kqlock); 1221 KERNEL_UNLOCK_ONE(NULL); 1222 return (0); 1223 } 1224 1225 static void 1226 tap_kqdetach(struct knote *kn) 1227 { 1228 struct tap_softc *sc = (struct tap_softc *)kn->kn_hook; 1229 1230 KERNEL_LOCK(1, NULL); 1231 simple_lock(&sc->sc_kqlock); 1232 SLIST_REMOVE(&sc->sc_rsel.sel_klist, kn, knote, kn_selnext); 1233 simple_unlock(&sc->sc_kqlock); 1234 KERNEL_UNLOCK_ONE(NULL); 1235 } 1236 1237 static int 1238 tap_kqread(struct knote *kn, long hint) 1239 { 1240 struct tap_softc *sc = (struct tap_softc *)kn->kn_hook; 1241 struct ifnet *ifp = &sc->sc_ec.ec_if; 1242 struct mbuf *m; 1243 int s, rv; 1244 1245 KERNEL_LOCK(1, NULL); 1246 s = splnet(); 1247 IFQ_POLL(&ifp->if_snd, m); 1248 1249 if (m == NULL) 1250 kn->kn_data = 0; 1251 else 1252 kn->kn_data = m->m_pkthdr.len; 1253 splx(s); 1254 rv = (kn->kn_data != 0 ? 1 : 0); 1255 KERNEL_UNLOCK_ONE(NULL); 1256 return rv; 1257 } 1258 1259 #if defined(COMPAT_40) || defined(MODULAR) 1260 /* 1261 * sysctl management routines 1262 * You can set the address of an interface through: 1263 * net.link.tap.tap<number> 1264 * 1265 * Note the consistent use of tap_log in order to use 1266 * sysctl_teardown at unload time. 1267 * 1268 * In the kernel you will find a lot of SYSCTL_SETUP blocks. Those 1269 * blocks register a function in a special section of the kernel 1270 * (called a link set) which is used at init_sysctl() time to cycle 1271 * through all those functions to create the kernel's sysctl tree. 1272 * 1273 * It is not possible to use link sets in a module, so the 1274 * easiest is to simply call our own setup routine at load time. 1275 * 1276 * In the SYSCTL_SETUP blocks you find in the kernel, nodes have the 1277 * CTLFLAG_PERMANENT flag, meaning they cannot be removed. Once the 1278 * whole kernel sysctl tree is built, it is not possible to add any 1279 * permanent node. 1280 * 1281 * It should be noted that we're not saving the sysctlnode pointer 1282 * we are returned when creating the "tap" node. That structure 1283 * cannot be trusted once out of the calling function, as it might 1284 * get reused. So we just save the MIB number, and always give the 1285 * full path starting from the root for later calls to sysctl_createv 1286 * and sysctl_destroyv. 1287 */ 1288 SYSCTL_SETUP(sysctl_tap_setup, "sysctl net.link.tap subtree setup") 1289 { 1290 const struct sysctlnode *node; 1291 int error = 0; 1292 1293 if ((error = sysctl_createv(clog, 0, NULL, NULL, 1294 CTLFLAG_PERMANENT, 1295 CTLTYPE_NODE, "net", NULL, 1296 NULL, 0, NULL, 0, 1297 CTL_NET, CTL_EOL)) != 0) 1298 return; 1299 1300 if ((error = sysctl_createv(clog, 0, NULL, NULL, 1301 CTLFLAG_PERMANENT, 1302 CTLTYPE_NODE, "link", NULL, 1303 NULL, 0, NULL, 0, 1304 CTL_NET, AF_LINK, CTL_EOL)) != 0) 1305 return; 1306 1307 /* 1308 * The first four parameters of sysctl_createv are for management. 1309 * 1310 * The four that follows, here starting with a '0' for the flags, 1311 * describe the node. 1312 * 1313 * The next series of four set its value, through various possible 1314 * means. 1315 * 1316 * Last but not least, the path to the node is described. That path 1317 * is relative to the given root (third argument). Here we're 1318 * starting from the root. 1319 */ 1320 if ((error = sysctl_createv(clog, 0, NULL, &node, 1321 CTLFLAG_PERMANENT, 1322 CTLTYPE_NODE, "tap", NULL, 1323 NULL, 0, NULL, 0, 1324 CTL_NET, AF_LINK, CTL_CREATE, CTL_EOL)) != 0) 1325 return; 1326 tap_node = node->sysctl_num; 1327 } 1328 1329 /* 1330 * The helper functions make Andrew Brown's interface really 1331 * shine. It makes possible to create value on the fly whether 1332 * the sysctl value is read or written. 1333 * 1334 * As shown as an example in the man page, the first step is to 1335 * create a copy of the node to have sysctl_lookup work on it. 1336 * 1337 * Here, we have more work to do than just a copy, since we have 1338 * to create the string. The first step is to collect the actual 1339 * value of the node, which is a convenient pointer to the softc 1340 * of the interface. From there we create the string and use it 1341 * as the value, but only for the *copy* of the node. 1342 * 1343 * Then we let sysctl_lookup do the magic, which consists in 1344 * setting oldp and newp as required by the operation. When the 1345 * value is read, that means that the string will be copied to 1346 * the user, and when it is written, the new value will be copied 1347 * over in the addr array. 1348 * 1349 * If newp is NULL, the user was reading the value, so we don't 1350 * have anything else to do. If a new value was written, we 1351 * have to check it. 1352 * 1353 * If it is incorrect, we can return an error and leave 'node' as 1354 * it is: since it is a copy of the actual node, the change will 1355 * be forgotten. 1356 * 1357 * Upon a correct input, we commit the change to the ifnet 1358 * structure of our interface. 1359 */ 1360 static int 1361 tap_sysctl_handler(SYSCTLFN_ARGS) 1362 { 1363 struct sysctlnode node; 1364 struct tap_softc *sc; 1365 struct ifnet *ifp; 1366 int error; 1367 size_t len; 1368 char addr[3 * ETHER_ADDR_LEN]; 1369 uint8_t enaddr[ETHER_ADDR_LEN]; 1370 1371 node = *rnode; 1372 sc = node.sysctl_data; 1373 ifp = &sc->sc_ec.ec_if; 1374 (void)ether_snprintf(addr, sizeof(addr), CLLADDR(ifp->if_sadl)); 1375 node.sysctl_data = addr; 1376 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1377 if (error || newp == NULL) 1378 return (error); 1379 1380 len = strlen(addr); 1381 if (len < 11 || len > 17) 1382 return (EINVAL); 1383 1384 /* Commit change */ 1385 if (ether_aton_r(enaddr, sizeof(enaddr), addr) != 0) 1386 return (EINVAL); 1387 if_set_sadl(ifp, enaddr, ETHER_ADDR_LEN, false); 1388 return (error); 1389 } 1390 #endif 1391