1 /* $NetBSD: if_tap.c,v 1.82 2015/08/20 14:40:19 christos 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 1.82 2015/08/20 14:40:19 christos 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/poll.h> 54 #include <sys/proc.h> 55 #include <sys/select.h> 56 #include <sys/sockio.h> 57 #if defined(COMPAT_40) || defined(MODULAR) 58 #include <sys/sysctl.h> 59 #endif 60 #include <sys/kauth.h> 61 #include <sys/mutex.h> 62 #include <sys/intr.h> 63 #include <sys/stat.h> 64 65 #include <net/if.h> 66 #include <net/if_dl.h> 67 #include <net/if_ether.h> 68 #include <net/if_media.h> 69 #include <net/if_tap.h> 70 #include <net/bpf.h> 71 72 #include <compat/sys/sockio.h> 73 74 #include "ioconf.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 kmutex_t 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 static int tap_match(device_t, cfdata_t, void *); 125 static void tap_attach(device_t, device_t, void *); 126 static int tap_detach(device_t, int); 127 128 CFATTACH_DECL_NEW(tap, sizeof(struct tap_softc), 129 tap_match, tap_attach, tap_detach, NULL); 130 extern struct cfdriver tap_cd; 131 132 /* Real device access routines */ 133 static int tap_dev_close(struct tap_softc *); 134 static int tap_dev_read(int, struct uio *, int); 135 static int tap_dev_write(int, struct uio *, int); 136 static int tap_dev_ioctl(int, u_long, void *, struct lwp *); 137 static int tap_dev_poll(int, int, struct lwp *); 138 static int tap_dev_kqfilter(int, struct knote *); 139 140 /* Fileops access routines */ 141 static int tap_fops_close(file_t *); 142 static int tap_fops_read(file_t *, off_t *, struct uio *, 143 kauth_cred_t, int); 144 static int tap_fops_write(file_t *, off_t *, struct uio *, 145 kauth_cred_t, int); 146 static int tap_fops_ioctl(file_t *, u_long, void *); 147 static int tap_fops_poll(file_t *, int); 148 static int tap_fops_stat(file_t *, struct stat *); 149 static int tap_fops_kqfilter(file_t *, struct knote *); 150 151 static const struct fileops tap_fileops = { 152 .fo_read = tap_fops_read, 153 .fo_write = tap_fops_write, 154 .fo_ioctl = tap_fops_ioctl, 155 .fo_fcntl = fnullop_fcntl, 156 .fo_poll = tap_fops_poll, 157 .fo_stat = tap_fops_stat, 158 .fo_close = tap_fops_close, 159 .fo_kqfilter = tap_fops_kqfilter, 160 .fo_restart = fnullop_restart, 161 }; 162 163 /* Helper for cloning open() */ 164 static int tap_dev_cloner(struct lwp *); 165 166 /* Character device routines */ 167 static int tap_cdev_open(dev_t, int, int, struct lwp *); 168 static int tap_cdev_close(dev_t, int, int, struct lwp *); 169 static int tap_cdev_read(dev_t, struct uio *, int); 170 static int tap_cdev_write(dev_t, struct uio *, int); 171 static int tap_cdev_ioctl(dev_t, u_long, void *, int, struct lwp *); 172 static int tap_cdev_poll(dev_t, int, struct lwp *); 173 static int tap_cdev_kqfilter(dev_t, struct knote *); 174 175 const struct cdevsw tap_cdevsw = { 176 .d_open = tap_cdev_open, 177 .d_close = tap_cdev_close, 178 .d_read = tap_cdev_read, 179 .d_write = tap_cdev_write, 180 .d_ioctl = tap_cdev_ioctl, 181 .d_stop = nostop, 182 .d_tty = notty, 183 .d_poll = tap_cdev_poll, 184 .d_mmap = nommap, 185 .d_kqfilter = tap_cdev_kqfilter, 186 .d_discard = nodiscard, 187 .d_flag = D_OTHER 188 }; 189 190 #define TAP_CLONER 0xfffff /* Maximal minor value */ 191 192 /* kqueue-related routines */ 193 static void tap_kqdetach(struct knote *); 194 static int tap_kqread(struct knote *, long); 195 196 /* 197 * Those are needed by the if_media interface. 198 */ 199 200 static int tap_mediachange(struct ifnet *); 201 static void tap_mediastatus(struct ifnet *, struct ifmediareq *); 202 203 /* 204 * Those are needed by the ifnet interface, and would typically be 205 * there for any network interface driver. 206 * Some other routines are optional: watchdog and drain. 207 */ 208 209 static void tap_start(struct ifnet *); 210 static void tap_stop(struct ifnet *, int); 211 static int tap_init(struct ifnet *); 212 static int tap_ioctl(struct ifnet *, u_long, void *); 213 214 /* Internal functions */ 215 #if defined(COMPAT_40) || defined(MODULAR) 216 static int tap_lifaddr(struct ifnet *, u_long, struct ifaliasreq *); 217 #endif 218 static void tap_softintr(void *); 219 220 /* 221 * tap is a clonable interface, although it is highly unrealistic for 222 * an Ethernet device. 223 * 224 * Here are the bits needed for a clonable interface. 225 */ 226 static int tap_clone_create(struct if_clone *, int); 227 static int tap_clone_destroy(struct ifnet *); 228 229 struct if_clone tap_cloners = IF_CLONE_INITIALIZER("tap", 230 tap_clone_create, 231 tap_clone_destroy); 232 233 /* Helper functionis shared by the two cloning code paths */ 234 static struct tap_softc * tap_clone_creator(int); 235 int tap_clone_destroyer(device_t); 236 237 void 238 tapattach(int n) 239 { 240 int error; 241 242 error = config_cfattach_attach(tap_cd.cd_name, &tap_ca); 243 if (error) { 244 aprint_error("%s: unable to register cfattach\n", 245 tap_cd.cd_name); 246 (void)config_cfdriver_detach(&tap_cd); 247 return; 248 } 249 250 if_clone_attach(&tap_cloners); 251 } 252 253 /* Pretty much useless for a pseudo-device */ 254 static int 255 tap_match(device_t parent, cfdata_t cfdata, void *arg) 256 { 257 258 return (1); 259 } 260 261 void 262 tap_attach(device_t parent, device_t self, void *aux) 263 { 264 struct tap_softc *sc = device_private(self); 265 struct ifnet *ifp; 266 #if defined(COMPAT_40) || defined(MODULAR) 267 const struct sysctlnode *node; 268 int error; 269 #endif 270 uint8_t enaddr[ETHER_ADDR_LEN] = 271 { 0xf2, 0x0b, 0xa4, 0xff, 0xff, 0xff }; 272 char enaddrstr[3 * ETHER_ADDR_LEN]; 273 274 sc->sc_dev = self; 275 sc->sc_sih = NULL; 276 getnanotime(&sc->sc_btime); 277 sc->sc_atime = sc->sc_mtime = sc->sc_btime; 278 sc->sc_flags = 0; 279 selinit(&sc->sc_rsel); 280 281 /* 282 * Initialize the two locks for the device. 283 * 284 * We need a lock here because even though the tap device can be 285 * opened only once, the file descriptor might be passed to another 286 * process, say a fork(2)ed child. 287 * 288 * The Giant saves us from most of the hassle, but since the read 289 * operation can sleep, we don't want two processes to wake up at 290 * the same moment and both try and dequeue a single packet. 291 * 292 * The queue for event listeners (used by kqueue(9), see below) has 293 * to be protected too, so use a spin lock. 294 */ 295 mutex_init(&sc->sc_rdlock, MUTEX_DEFAULT, IPL_NONE); 296 mutex_init(&sc->sc_kqlock, MUTEX_DEFAULT, IPL_VM); 297 298 if (!pmf_device_register(self, NULL, NULL)) 299 aprint_error_dev(self, "couldn't establish power handler\n"); 300 301 /* 302 * In order to obtain unique initial Ethernet address on a host, 303 * do some randomisation. It's not meant for anything but avoiding 304 * hard-coding an address. 305 */ 306 cprng_fast(&enaddr[3], 3); 307 308 aprint_verbose_dev(self, "Ethernet address %s\n", 309 ether_snprintf(enaddrstr, sizeof(enaddrstr), enaddr)); 310 311 /* 312 * Why 1000baseT? Why not? You can add more. 313 * 314 * Note that there are 3 steps: init, one or several additions to 315 * list of supported media, and in the end, the selection of one 316 * of them. 317 */ 318 ifmedia_init(&sc->sc_im, 0, tap_mediachange, tap_mediastatus); 319 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_1000_T, 0, NULL); 320 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_1000_T|IFM_FDX, 0, NULL); 321 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_100_TX, 0, NULL); 322 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_100_TX|IFM_FDX, 0, NULL); 323 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_10_T, 0, NULL); 324 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_10_T|IFM_FDX, 0, NULL); 325 ifmedia_add(&sc->sc_im, IFM_ETHER|IFM_AUTO, 0, NULL); 326 ifmedia_set(&sc->sc_im, IFM_ETHER|IFM_AUTO); 327 328 /* 329 * One should note that an interface must do multicast in order 330 * to support IPv6. 331 */ 332 ifp = &sc->sc_ec.ec_if; 333 strcpy(ifp->if_xname, device_xname(self)); 334 ifp->if_softc = sc; 335 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 336 ifp->if_ioctl = tap_ioctl; 337 ifp->if_start = tap_start; 338 ifp->if_stop = tap_stop; 339 ifp->if_init = tap_init; 340 IFQ_SET_READY(&ifp->if_snd); 341 342 sc->sc_ec.ec_capabilities = ETHERCAP_VLAN_MTU | ETHERCAP_JUMBO_MTU; 343 344 /* Those steps are mandatory for an Ethernet driver. */ 345 if_initialize(ifp); 346 ether_ifattach(ifp, enaddr); 347 if_register(ifp); 348 349 #if defined(COMPAT_40) || defined(MODULAR) 350 /* 351 * Add a sysctl node for that interface. 352 * 353 * The pointer transmitted is not a string, but instead a pointer to 354 * the softc structure, which we can use to build the string value on 355 * the fly in the helper function of the node. See the comments for 356 * tap_sysctl_handler for details. 357 * 358 * Usually sysctl_createv is called with CTL_CREATE as the before-last 359 * component. However, we can allocate a number ourselves, as we are 360 * the only consumer of the net.link.<iface> node. In this case, the 361 * unit number is conveniently used to number the node. CTL_CREATE 362 * would just work, too. 363 */ 364 if ((error = sysctl_createv(NULL, 0, NULL, 365 &node, CTLFLAG_READWRITE, 366 CTLTYPE_STRING, device_xname(self), NULL, 367 tap_sysctl_handler, 0, (void *)sc, 18, 368 CTL_NET, AF_LINK, tap_node, device_unit(sc->sc_dev), 369 CTL_EOL)) != 0) 370 aprint_error_dev(self, "sysctl_createv returned %d, ignoring\n", 371 error); 372 #endif 373 } 374 375 /* 376 * When detaching, we do the inverse of what is done in the attach 377 * routine, in reversed order. 378 */ 379 static int 380 tap_detach(device_t self, int flags) 381 { 382 struct tap_softc *sc = device_private(self); 383 struct ifnet *ifp = &sc->sc_ec.ec_if; 384 #if defined(COMPAT_40) || defined(MODULAR) 385 int error; 386 #endif 387 int s; 388 389 sc->sc_flags |= TAP_GOING; 390 s = splnet(); 391 tap_stop(ifp, 1); 392 if_down(ifp); 393 splx(s); 394 395 if (sc->sc_sih != NULL) { 396 softint_disestablish(sc->sc_sih); 397 sc->sc_sih = NULL; 398 } 399 400 #if defined(COMPAT_40) || defined(MODULAR) 401 /* 402 * Destroying a single leaf is a very straightforward operation using 403 * sysctl_destroyv. One should be sure to always end the path with 404 * CTL_EOL. 405 */ 406 if ((error = sysctl_destroyv(NULL, CTL_NET, AF_LINK, tap_node, 407 device_unit(sc->sc_dev), CTL_EOL)) != 0) 408 aprint_error_dev(self, 409 "sysctl_destroyv returned %d, ignoring\n", error); 410 #endif 411 ether_ifdetach(ifp); 412 if_detach(ifp); 413 ifmedia_delete_instance(&sc->sc_im, IFM_INST_ANY); 414 seldestroy(&sc->sc_rsel); 415 mutex_destroy(&sc->sc_rdlock); 416 mutex_destroy(&sc->sc_kqlock); 417 418 pmf_device_deregister(self); 419 420 return (0); 421 } 422 423 /* 424 * This function is called by the ifmedia layer to notify the driver 425 * that the user requested a media change. A real driver would 426 * reconfigure the hardware. 427 */ 428 static int 429 tap_mediachange(struct ifnet *ifp) 430 { 431 return (0); 432 } 433 434 /* 435 * Here the user asks for the currently used media. 436 */ 437 static void 438 tap_mediastatus(struct ifnet *ifp, struct ifmediareq *imr) 439 { 440 struct tap_softc *sc = (struct tap_softc *)ifp->if_softc; 441 imr->ifm_active = sc->sc_im.ifm_cur->ifm_media; 442 } 443 444 /* 445 * This is the function where we SEND packets. 446 * 447 * There is no 'receive' equivalent. A typical driver will get 448 * interrupts from the hardware, and from there will inject new packets 449 * into the network stack. 450 * 451 * Once handled, a packet must be freed. A real driver might not be able 452 * to fit all the pending packets into the hardware, and is allowed to 453 * return before having sent all the packets. It should then use the 454 * if_flags flag IFF_OACTIVE to notify the upper layer. 455 * 456 * There are also other flags one should check, such as IFF_PAUSE. 457 * 458 * It is our duty to make packets available to BPF listeners. 459 * 460 * You should be aware that this function is called by the Ethernet layer 461 * at splnet(). 462 * 463 * When the device is opened, we have to pass the packet(s) to the 464 * userland. For that we stay in OACTIVE mode while the userland gets 465 * the packets, and we send a signal to the processes waiting to read. 466 * 467 * wakeup(sc) is the counterpart to the tsleep call in 468 * tap_dev_read, while selnotify() is used for kevent(2) and 469 * poll(2) (which includes select(2)) listeners. 470 */ 471 static void 472 tap_start(struct ifnet *ifp) 473 { 474 struct tap_softc *sc = (struct tap_softc *)ifp->if_softc; 475 struct mbuf *m0; 476 477 if ((sc->sc_flags & TAP_INUSE) == 0) { 478 /* Simply drop packets */ 479 for(;;) { 480 IFQ_DEQUEUE(&ifp->if_snd, m0); 481 if (m0 == NULL) 482 return; 483 484 ifp->if_opackets++; 485 bpf_mtap(ifp, m0); 486 487 m_freem(m0); 488 } 489 } else if (!IFQ_IS_EMPTY(&ifp->if_snd)) { 490 ifp->if_flags |= IFF_OACTIVE; 491 wakeup(sc); 492 selnotify(&sc->sc_rsel, 0, 1); 493 if (sc->sc_flags & TAP_ASYNCIO) 494 softint_schedule(sc->sc_sih); 495 } 496 } 497 498 static void 499 tap_softintr(void *cookie) 500 { 501 struct tap_softc *sc; 502 struct ifnet *ifp; 503 int a, b; 504 505 sc = cookie; 506 507 if (sc->sc_flags & TAP_ASYNCIO) { 508 ifp = &sc->sc_ec.ec_if; 509 if (ifp->if_flags & IFF_RUNNING) { 510 a = POLL_IN; 511 b = POLLIN|POLLRDNORM; 512 } else { 513 a = POLL_HUP; 514 b = 0; 515 } 516 fownsignal(sc->sc_pgid, SIGIO, a, b, NULL); 517 } 518 } 519 520 /* 521 * A typical driver will only contain the following handlers for 522 * ioctl calls, except SIOCSIFPHYADDR. 523 * The latter is a hack I used to set the Ethernet address of the 524 * faked device. 525 * 526 * Note that both ifmedia_ioctl() and ether_ioctl() have to be 527 * called under splnet(). 528 */ 529 static int 530 tap_ioctl(struct ifnet *ifp, u_long cmd, void *data) 531 { 532 struct tap_softc *sc = (struct tap_softc *)ifp->if_softc; 533 struct ifreq *ifr = (struct ifreq *)data; 534 int s, error; 535 536 s = splnet(); 537 538 switch (cmd) { 539 #ifdef OSIOCSIFMEDIA 540 case OSIOCSIFMEDIA: 541 #endif 542 case SIOCSIFMEDIA: 543 case SIOCGIFMEDIA: 544 error = ifmedia_ioctl(ifp, ifr, &sc->sc_im, cmd); 545 break; 546 #if defined(COMPAT_40) || defined(MODULAR) 547 case SIOCSIFPHYADDR: 548 error = tap_lifaddr(ifp, cmd, (struct ifaliasreq *)data); 549 break; 550 #endif 551 default: 552 error = ether_ioctl(ifp, cmd, data); 553 if (error == ENETRESET) 554 error = 0; 555 break; 556 } 557 558 splx(s); 559 560 return (error); 561 } 562 563 #if defined(COMPAT_40) || defined(MODULAR) 564 /* 565 * Helper function to set Ethernet address. This has been replaced by 566 * the generic SIOCALIFADDR ioctl on a PF_LINK socket. 567 */ 568 static int 569 tap_lifaddr(struct ifnet *ifp, u_long cmd, struct ifaliasreq *ifra) 570 { 571 const struct sockaddr *sa = &ifra->ifra_addr; 572 573 if (sa->sa_family != AF_LINK) 574 return (EINVAL); 575 576 if_set_sadl(ifp, sa->sa_data, ETHER_ADDR_LEN, false); 577 578 return (0); 579 } 580 #endif 581 582 /* 583 * _init() would typically be called when an interface goes up, 584 * meaning it should configure itself into the state in which it 585 * can send packets. 586 */ 587 static int 588 tap_init(struct ifnet *ifp) 589 { 590 ifp->if_flags |= IFF_RUNNING; 591 592 tap_start(ifp); 593 594 return (0); 595 } 596 597 /* 598 * _stop() is called when an interface goes down. It is our 599 * responsability to validate that state by clearing the 600 * IFF_RUNNING flag. 601 * 602 * We have to wake up all the sleeping processes to have the pending 603 * read requests cancelled. 604 */ 605 static void 606 tap_stop(struct ifnet *ifp, int disable) 607 { 608 struct tap_softc *sc = (struct tap_softc *)ifp->if_softc; 609 610 ifp->if_flags &= ~IFF_RUNNING; 611 wakeup(sc); 612 selnotify(&sc->sc_rsel, 0, 1); 613 if (sc->sc_flags & TAP_ASYNCIO) 614 softint_schedule(sc->sc_sih); 615 } 616 617 /* 618 * The 'create' command of ifconfig can be used to create 619 * any numbered instance of a given device. Thus we have to 620 * make sure we have enough room in cd_devs to create the 621 * user-specified instance. config_attach_pseudo will do this 622 * for us. 623 */ 624 static int 625 tap_clone_create(struct if_clone *ifc, int unit) 626 { 627 if (tap_clone_creator(unit) == NULL) { 628 aprint_error("%s%d: unable to attach an instance\n", 629 tap_cd.cd_name, unit); 630 return (ENXIO); 631 } 632 633 return (0); 634 } 635 636 /* 637 * tap(4) can be cloned by two ways: 638 * using 'ifconfig tap0 create', which will use the network 639 * interface cloning API, and call tap_clone_create above. 640 * opening the cloning device node, whose minor number is TAP_CLONER. 641 * See below for an explanation on how this part work. 642 */ 643 static struct tap_softc * 644 tap_clone_creator(int unit) 645 { 646 struct cfdata *cf; 647 648 cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK); 649 cf->cf_name = tap_cd.cd_name; 650 cf->cf_atname = tap_ca.ca_name; 651 if (unit == -1) { 652 /* let autoconf find the first free one */ 653 cf->cf_unit = 0; 654 cf->cf_fstate = FSTATE_STAR; 655 } else { 656 cf->cf_unit = unit; 657 cf->cf_fstate = FSTATE_NOTFOUND; 658 } 659 660 return device_private(config_attach_pseudo(cf)); 661 } 662 663 /* 664 * The clean design of if_clone and autoconf(9) makes that part 665 * really straightforward. The second argument of config_detach 666 * means neither QUIET nor FORCED. 667 */ 668 static int 669 tap_clone_destroy(struct ifnet *ifp) 670 { 671 struct tap_softc *sc = ifp->if_softc; 672 673 return tap_clone_destroyer(sc->sc_dev); 674 } 675 676 int 677 tap_clone_destroyer(device_t dev) 678 { 679 cfdata_t cf = device_cfdata(dev); 680 int error; 681 682 if ((error = config_detach(dev, 0)) != 0) 683 aprint_error_dev(dev, "unable to detach instance\n"); 684 free(cf, M_DEVBUF); 685 686 return (error); 687 } 688 689 /* 690 * tap(4) is a bit of an hybrid device. It can be used in two different 691 * ways: 692 * 1. ifconfig tapN create, then use /dev/tapN to read/write off it. 693 * 2. open /dev/tap, get a new interface created and read/write off it. 694 * That interface is destroyed when the process that had it created exits. 695 * 696 * The first way is managed by the cdevsw structure, and you access interfaces 697 * through a (major, minor) mapping: tap4 is obtained by the minor number 698 * 4. The entry points for the cdevsw interface are prefixed by tap_cdev_. 699 * 700 * The second way is the so-called "cloning" device. It's a special minor 701 * number (chosen as the maximal number, to allow as much tap devices as 702 * possible). The user first opens the cloner (e.g., /dev/tap), and that 703 * call ends in tap_cdev_open. The actual place where it is handled is 704 * tap_dev_cloner. 705 * 706 * An tap device cannot be opened more than once at a time, so the cdevsw 707 * part of open() does nothing but noting that the interface is being used and 708 * hence ready to actually handle packets. 709 */ 710 711 static int 712 tap_cdev_open(dev_t dev, int flags, int fmt, struct lwp *l) 713 { 714 struct tap_softc *sc; 715 716 if (minor(dev) == TAP_CLONER) 717 return tap_dev_cloner(l); 718 719 sc = device_lookup_private(&tap_cd, minor(dev)); 720 if (sc == NULL) 721 return (ENXIO); 722 723 /* The device can only be opened once */ 724 if (sc->sc_flags & TAP_INUSE) 725 return (EBUSY); 726 sc->sc_flags |= TAP_INUSE; 727 return (0); 728 } 729 730 /* 731 * There are several kinds of cloning devices, and the most simple is the one 732 * tap(4) uses. What it does is change the file descriptor with a new one, 733 * with its own fileops structure (which maps to the various read, write, 734 * ioctl functions). It starts allocating a new file descriptor with falloc, 735 * then actually creates the new tap devices. 736 * 737 * Once those two steps are successful, we can re-wire the existing file 738 * descriptor to its new self. This is done with fdclone(): it fills the fp 739 * structure as needed (notably f_devunit gets filled with the fifth parameter 740 * passed, the unit of the tap device which will allows us identifying the 741 * device later), and returns EMOVEFD. 742 * 743 * That magic value is interpreted by sys_open() which then replaces the 744 * current file descriptor by the new one (through a magic member of struct 745 * lwp, l_dupfd). 746 * 747 * The tap device is flagged as being busy since it otherwise could be 748 * externally accessed through the corresponding device node with the cdevsw 749 * interface. 750 */ 751 752 static int 753 tap_dev_cloner(struct lwp *l) 754 { 755 struct tap_softc *sc; 756 file_t *fp; 757 int error, fd; 758 759 if ((error = fd_allocfile(&fp, &fd)) != 0) 760 return (error); 761 762 if ((sc = tap_clone_creator(-1)) == NULL) { 763 fd_abort(curproc, fp, fd); 764 return (ENXIO); 765 } 766 767 sc->sc_flags |= TAP_INUSE; 768 769 return fd_clone(fp, fd, FREAD|FWRITE, &tap_fileops, 770 (void *)(intptr_t)device_unit(sc->sc_dev)); 771 } 772 773 /* 774 * While all other operations (read, write, ioctl, poll and kqfilter) are 775 * really the same whether we are in cdevsw or fileops mode, the close() 776 * function is slightly different in the two cases. 777 * 778 * As for the other, the core of it is shared in tap_dev_close. What 779 * it does is sufficient for the cdevsw interface, but the cloning interface 780 * needs another thing: the interface is destroyed when the processes that 781 * created it closes it. 782 */ 783 static int 784 tap_cdev_close(dev_t dev, int flags, int fmt, 785 struct lwp *l) 786 { 787 struct tap_softc *sc = 788 device_lookup_private(&tap_cd, minor(dev)); 789 790 if (sc == NULL) 791 return (ENXIO); 792 793 return tap_dev_close(sc); 794 } 795 796 /* 797 * It might happen that the administrator used ifconfig to externally destroy 798 * the interface. In that case, tap_fops_close will be called while 799 * tap_detach is already happening. If we called it again from here, we 800 * would dead lock. TAP_GOING ensures that this situation doesn't happen. 801 */ 802 static int 803 tap_fops_close(file_t *fp) 804 { 805 int unit = fp->f_devunit; 806 struct tap_softc *sc; 807 int error; 808 809 sc = device_lookup_private(&tap_cd, unit); 810 if (sc == NULL) 811 return (ENXIO); 812 813 /* tap_dev_close currently always succeeds, but it might not 814 * always be the case. */ 815 KERNEL_LOCK(1, NULL); 816 if ((error = tap_dev_close(sc)) != 0) { 817 KERNEL_UNLOCK_ONE(NULL); 818 return (error); 819 } 820 821 /* Destroy the device now that it is no longer useful, 822 * unless it's already being destroyed. */ 823 if ((sc->sc_flags & TAP_GOING) != 0) { 824 KERNEL_UNLOCK_ONE(NULL); 825 return (0); 826 } 827 828 error = tap_clone_destroyer(sc->sc_dev); 829 KERNEL_UNLOCK_ONE(NULL); 830 return error; 831 } 832 833 static int 834 tap_dev_close(struct tap_softc *sc) 835 { 836 struct ifnet *ifp; 837 int s; 838 839 s = splnet(); 840 /* Let tap_start handle packets again */ 841 ifp = &sc->sc_ec.ec_if; 842 ifp->if_flags &= ~IFF_OACTIVE; 843 844 /* Purge output queue */ 845 if (!(IFQ_IS_EMPTY(&ifp->if_snd))) { 846 struct mbuf *m; 847 848 for (;;) { 849 IFQ_DEQUEUE(&ifp->if_snd, m); 850 if (m == NULL) 851 break; 852 853 ifp->if_opackets++; 854 bpf_mtap(ifp, m); 855 m_freem(m); 856 } 857 } 858 splx(s); 859 860 if (sc->sc_sih != NULL) { 861 softint_disestablish(sc->sc_sih); 862 sc->sc_sih = NULL; 863 } 864 sc->sc_flags &= ~(TAP_INUSE | TAP_ASYNCIO); 865 866 return (0); 867 } 868 869 static int 870 tap_cdev_read(dev_t dev, struct uio *uio, int flags) 871 { 872 return tap_dev_read(minor(dev), uio, flags); 873 } 874 875 static int 876 tap_fops_read(file_t *fp, off_t *offp, struct uio *uio, 877 kauth_cred_t cred, int flags) 878 { 879 int error; 880 881 KERNEL_LOCK(1, NULL); 882 error = tap_dev_read(fp->f_devunit, uio, flags); 883 KERNEL_UNLOCK_ONE(NULL); 884 return error; 885 } 886 887 static int 888 tap_dev_read(int unit, struct uio *uio, int flags) 889 { 890 struct tap_softc *sc = device_lookup_private(&tap_cd, unit); 891 struct ifnet *ifp; 892 struct mbuf *m, *n; 893 int error = 0, s; 894 895 if (sc == NULL) 896 return (ENXIO); 897 898 getnanotime(&sc->sc_atime); 899 900 ifp = &sc->sc_ec.ec_if; 901 if ((ifp->if_flags & IFF_UP) == 0) 902 return (EHOSTDOWN); 903 904 /* 905 * In the TAP_NBIO case, we have to make sure we won't be sleeping 906 */ 907 if ((sc->sc_flags & TAP_NBIO) != 0) { 908 if (!mutex_tryenter(&sc->sc_rdlock)) 909 return (EWOULDBLOCK); 910 } else { 911 mutex_enter(&sc->sc_rdlock); 912 } 913 914 s = splnet(); 915 if (IFQ_IS_EMPTY(&ifp->if_snd)) { 916 ifp->if_flags &= ~IFF_OACTIVE; 917 /* 918 * We must release the lock before sleeping, and re-acquire it 919 * after. 920 */ 921 mutex_exit(&sc->sc_rdlock); 922 if (sc->sc_flags & TAP_NBIO) 923 error = EWOULDBLOCK; 924 else 925 error = tsleep(sc, PSOCK|PCATCH, "tap", 0); 926 splx(s); 927 928 if (error != 0) 929 return (error); 930 /* The device might have been downed */ 931 if ((ifp->if_flags & IFF_UP) == 0) 932 return (EHOSTDOWN); 933 if ((sc->sc_flags & TAP_NBIO)) { 934 if (!mutex_tryenter(&sc->sc_rdlock)) 935 return (EWOULDBLOCK); 936 } else { 937 mutex_enter(&sc->sc_rdlock); 938 } 939 s = splnet(); 940 } 941 942 IFQ_DEQUEUE(&ifp->if_snd, m); 943 ifp->if_flags &= ~IFF_OACTIVE; 944 splx(s); 945 if (m == NULL) { 946 error = 0; 947 goto out; 948 } 949 950 ifp->if_opackets++; 951 bpf_mtap(ifp, m); 952 953 /* 954 * One read is one packet. 955 */ 956 do { 957 error = uiomove(mtod(m, void *), 958 min(m->m_len, uio->uio_resid), uio); 959 MFREE(m, n); 960 m = n; 961 } while (m != NULL && uio->uio_resid > 0 && error == 0); 962 963 if (m != NULL) 964 m_freem(m); 965 966 out: 967 mutex_exit(&sc->sc_rdlock); 968 return (error); 969 } 970 971 static int 972 tap_fops_stat(file_t *fp, struct stat *st) 973 { 974 int error = 0; 975 struct tap_softc *sc; 976 int unit = fp->f_devunit; 977 978 (void)memset(st, 0, sizeof(*st)); 979 980 KERNEL_LOCK(1, NULL); 981 sc = device_lookup_private(&tap_cd, unit); 982 if (sc == NULL) { 983 error = ENXIO; 984 goto out; 985 } 986 987 st->st_dev = makedev(cdevsw_lookup_major(&tap_cdevsw), unit); 988 st->st_atimespec = sc->sc_atime; 989 st->st_mtimespec = sc->sc_mtime; 990 st->st_ctimespec = st->st_birthtimespec = sc->sc_btime; 991 st->st_uid = kauth_cred_geteuid(fp->f_cred); 992 st->st_gid = kauth_cred_getegid(fp->f_cred); 993 out: 994 KERNEL_UNLOCK_ONE(NULL); 995 return error; 996 } 997 998 static int 999 tap_cdev_write(dev_t dev, struct uio *uio, int flags) 1000 { 1001 return tap_dev_write(minor(dev), uio, flags); 1002 } 1003 1004 static int 1005 tap_fops_write(file_t *fp, off_t *offp, struct uio *uio, 1006 kauth_cred_t cred, int flags) 1007 { 1008 int error; 1009 1010 KERNEL_LOCK(1, NULL); 1011 error = tap_dev_write(fp->f_devunit, uio, flags); 1012 KERNEL_UNLOCK_ONE(NULL); 1013 return error; 1014 } 1015 1016 static int 1017 tap_dev_write(int unit, struct uio *uio, int flags) 1018 { 1019 struct tap_softc *sc = 1020 device_lookup_private(&tap_cd, unit); 1021 struct ifnet *ifp; 1022 struct mbuf *m, **mp; 1023 int error = 0; 1024 int s; 1025 1026 if (sc == NULL) 1027 return (ENXIO); 1028 1029 getnanotime(&sc->sc_mtime); 1030 ifp = &sc->sc_ec.ec_if; 1031 1032 /* One write, one packet, that's the rule */ 1033 MGETHDR(m, M_DONTWAIT, MT_DATA); 1034 if (m == NULL) { 1035 ifp->if_ierrors++; 1036 return (ENOBUFS); 1037 } 1038 m->m_pkthdr.len = uio->uio_resid; 1039 1040 mp = &m; 1041 while (error == 0 && uio->uio_resid > 0) { 1042 if (*mp != m) { 1043 MGET(*mp, M_DONTWAIT, MT_DATA); 1044 if (*mp == NULL) { 1045 error = ENOBUFS; 1046 break; 1047 } 1048 } 1049 (*mp)->m_len = min(MHLEN, uio->uio_resid); 1050 error = uiomove(mtod(*mp, void *), (*mp)->m_len, uio); 1051 mp = &(*mp)->m_next; 1052 } 1053 if (error) { 1054 ifp->if_ierrors++; 1055 m_freem(m); 1056 return (error); 1057 } 1058 1059 ifp->if_ipackets++; 1060 m->m_pkthdr.rcvif = ifp; 1061 1062 bpf_mtap(ifp, m); 1063 s = splnet(); 1064 (*ifp->if_input)(ifp, m); 1065 splx(s); 1066 1067 return (0); 1068 } 1069 1070 static int 1071 tap_cdev_ioctl(dev_t dev, u_long cmd, void *data, int flags, 1072 struct lwp *l) 1073 { 1074 return tap_dev_ioctl(minor(dev), cmd, data, l); 1075 } 1076 1077 static int 1078 tap_fops_ioctl(file_t *fp, u_long cmd, void *data) 1079 { 1080 return tap_dev_ioctl(fp->f_devunit, cmd, data, curlwp); 1081 } 1082 1083 static int 1084 tap_dev_ioctl(int unit, u_long cmd, void *data, struct lwp *l) 1085 { 1086 struct tap_softc *sc = device_lookup_private(&tap_cd, unit); 1087 1088 if (sc == NULL) 1089 return ENXIO; 1090 1091 switch (cmd) { 1092 case FIONREAD: 1093 { 1094 struct ifnet *ifp = &sc->sc_ec.ec_if; 1095 struct mbuf *m; 1096 int s; 1097 1098 s = splnet(); 1099 IFQ_POLL(&ifp->if_snd, m); 1100 1101 if (m == NULL) 1102 *(int *)data = 0; 1103 else 1104 *(int *)data = m->m_pkthdr.len; 1105 splx(s); 1106 return 0; 1107 } 1108 case TIOCSPGRP: 1109 case FIOSETOWN: 1110 return fsetown(&sc->sc_pgid, cmd, data); 1111 case TIOCGPGRP: 1112 case FIOGETOWN: 1113 return fgetown(sc->sc_pgid, cmd, data); 1114 case FIOASYNC: 1115 if (*(int *)data) { 1116 if (sc->sc_sih == NULL) { 1117 sc->sc_sih = softint_establish(SOFTINT_CLOCK, 1118 tap_softintr, sc); 1119 if (sc->sc_sih == NULL) 1120 return EBUSY; /* XXX */ 1121 } 1122 sc->sc_flags |= TAP_ASYNCIO; 1123 } else { 1124 sc->sc_flags &= ~TAP_ASYNCIO; 1125 if (sc->sc_sih != NULL) { 1126 softint_disestablish(sc->sc_sih); 1127 sc->sc_sih = NULL; 1128 } 1129 } 1130 return 0; 1131 case FIONBIO: 1132 if (*(int *)data) 1133 sc->sc_flags |= TAP_NBIO; 1134 else 1135 sc->sc_flags &= ~TAP_NBIO; 1136 return 0; 1137 #ifdef OTAPGIFNAME 1138 case OTAPGIFNAME: 1139 #endif 1140 case TAPGIFNAME: 1141 { 1142 struct ifreq *ifr = (struct ifreq *)data; 1143 struct ifnet *ifp = &sc->sc_ec.ec_if; 1144 1145 strlcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ); 1146 return 0; 1147 } 1148 default: 1149 return ENOTTY; 1150 } 1151 } 1152 1153 static int 1154 tap_cdev_poll(dev_t dev, int events, struct lwp *l) 1155 { 1156 return tap_dev_poll(minor(dev), events, l); 1157 } 1158 1159 static int 1160 tap_fops_poll(file_t *fp, int events) 1161 { 1162 return tap_dev_poll(fp->f_devunit, events, curlwp); 1163 } 1164 1165 static int 1166 tap_dev_poll(int unit, int events, struct lwp *l) 1167 { 1168 struct tap_softc *sc = 1169 device_lookup_private(&tap_cd, unit); 1170 int revents = 0; 1171 1172 if (sc == NULL) 1173 return POLLERR; 1174 1175 if (events & (POLLIN|POLLRDNORM)) { 1176 struct ifnet *ifp = &sc->sc_ec.ec_if; 1177 struct mbuf *m; 1178 int s; 1179 1180 s = splnet(); 1181 IFQ_POLL(&ifp->if_snd, m); 1182 1183 if (m != NULL) 1184 revents |= events & (POLLIN|POLLRDNORM); 1185 else { 1186 mutex_spin_enter(&sc->sc_kqlock); 1187 selrecord(l, &sc->sc_rsel); 1188 mutex_spin_exit(&sc->sc_kqlock); 1189 } 1190 splx(s); 1191 } 1192 revents |= events & (POLLOUT|POLLWRNORM); 1193 1194 return (revents); 1195 } 1196 1197 static struct filterops tap_read_filterops = { 1, NULL, tap_kqdetach, 1198 tap_kqread }; 1199 static struct filterops tap_seltrue_filterops = { 1, NULL, tap_kqdetach, 1200 filt_seltrue }; 1201 1202 static int 1203 tap_cdev_kqfilter(dev_t dev, struct knote *kn) 1204 { 1205 return tap_dev_kqfilter(minor(dev), kn); 1206 } 1207 1208 static int 1209 tap_fops_kqfilter(file_t *fp, struct knote *kn) 1210 { 1211 return tap_dev_kqfilter(fp->f_devunit, kn); 1212 } 1213 1214 static int 1215 tap_dev_kqfilter(int unit, struct knote *kn) 1216 { 1217 struct tap_softc *sc = 1218 device_lookup_private(&tap_cd, unit); 1219 1220 if (sc == NULL) 1221 return (ENXIO); 1222 1223 KERNEL_LOCK(1, NULL); 1224 switch(kn->kn_filter) { 1225 case EVFILT_READ: 1226 kn->kn_fop = &tap_read_filterops; 1227 break; 1228 case EVFILT_WRITE: 1229 kn->kn_fop = &tap_seltrue_filterops; 1230 break; 1231 default: 1232 KERNEL_UNLOCK_ONE(NULL); 1233 return (EINVAL); 1234 } 1235 1236 kn->kn_hook = sc; 1237 mutex_spin_enter(&sc->sc_kqlock); 1238 SLIST_INSERT_HEAD(&sc->sc_rsel.sel_klist, kn, kn_selnext); 1239 mutex_spin_exit(&sc->sc_kqlock); 1240 KERNEL_UNLOCK_ONE(NULL); 1241 return (0); 1242 } 1243 1244 static void 1245 tap_kqdetach(struct knote *kn) 1246 { 1247 struct tap_softc *sc = (struct tap_softc *)kn->kn_hook; 1248 1249 KERNEL_LOCK(1, NULL); 1250 mutex_spin_enter(&sc->sc_kqlock); 1251 SLIST_REMOVE(&sc->sc_rsel.sel_klist, kn, knote, kn_selnext); 1252 mutex_spin_exit(&sc->sc_kqlock); 1253 KERNEL_UNLOCK_ONE(NULL); 1254 } 1255 1256 static int 1257 tap_kqread(struct knote *kn, long hint) 1258 { 1259 struct tap_softc *sc = (struct tap_softc *)kn->kn_hook; 1260 struct ifnet *ifp = &sc->sc_ec.ec_if; 1261 struct mbuf *m; 1262 int s, rv; 1263 1264 KERNEL_LOCK(1, NULL); 1265 s = splnet(); 1266 IFQ_POLL(&ifp->if_snd, m); 1267 1268 if (m == NULL) 1269 kn->kn_data = 0; 1270 else 1271 kn->kn_data = m->m_pkthdr.len; 1272 splx(s); 1273 rv = (kn->kn_data != 0 ? 1 : 0); 1274 KERNEL_UNLOCK_ONE(NULL); 1275 return rv; 1276 } 1277 1278 #if defined(COMPAT_40) || defined(MODULAR) 1279 /* 1280 * sysctl management routines 1281 * You can set the address of an interface through: 1282 * net.link.tap.tap<number> 1283 * 1284 * Note the consistent use of tap_log in order to use 1285 * sysctl_teardown at unload time. 1286 * 1287 * In the kernel you will find a lot of SYSCTL_SETUP blocks. Those 1288 * blocks register a function in a special section of the kernel 1289 * (called a link set) which is used at init_sysctl() time to cycle 1290 * through all those functions to create the kernel's sysctl tree. 1291 * 1292 * It is not possible to use link sets in a module, so the 1293 * easiest is to simply call our own setup routine at load time. 1294 * 1295 * In the SYSCTL_SETUP blocks you find in the kernel, nodes have the 1296 * CTLFLAG_PERMANENT flag, meaning they cannot be removed. Once the 1297 * whole kernel sysctl tree is built, it is not possible to add any 1298 * permanent node. 1299 * 1300 * It should be noted that we're not saving the sysctlnode pointer 1301 * we are returned when creating the "tap" node. That structure 1302 * cannot be trusted once out of the calling function, as it might 1303 * get reused. So we just save the MIB number, and always give the 1304 * full path starting from the root for later calls to sysctl_createv 1305 * and sysctl_destroyv. 1306 */ 1307 SYSCTL_SETUP(sysctl_tap_setup, "sysctl net.link.tap subtree setup") 1308 { 1309 const struct sysctlnode *node; 1310 int error = 0; 1311 1312 if ((error = sysctl_createv(clog, 0, NULL, NULL, 1313 CTLFLAG_PERMANENT, 1314 CTLTYPE_NODE, "link", NULL, 1315 NULL, 0, NULL, 0, 1316 CTL_NET, AF_LINK, CTL_EOL)) != 0) 1317 return; 1318 1319 /* 1320 * The first four parameters of sysctl_createv are for management. 1321 * 1322 * The four that follows, here starting with a '0' for the flags, 1323 * describe the node. 1324 * 1325 * The next series of four set its value, through various possible 1326 * means. 1327 * 1328 * Last but not least, the path to the node is described. That path 1329 * is relative to the given root (third argument). Here we're 1330 * starting from the root. 1331 */ 1332 if ((error = sysctl_createv(clog, 0, NULL, &node, 1333 CTLFLAG_PERMANENT, 1334 CTLTYPE_NODE, "tap", NULL, 1335 NULL, 0, NULL, 0, 1336 CTL_NET, AF_LINK, CTL_CREATE, CTL_EOL)) != 0) 1337 return; 1338 tap_node = node->sysctl_num; 1339 } 1340 1341 /* 1342 * The helper functions make Andrew Brown's interface really 1343 * shine. It makes possible to create value on the fly whether 1344 * the sysctl value is read or written. 1345 * 1346 * As shown as an example in the man page, the first step is to 1347 * create a copy of the node to have sysctl_lookup work on it. 1348 * 1349 * Here, we have more work to do than just a copy, since we have 1350 * to create the string. The first step is to collect the actual 1351 * value of the node, which is a convenient pointer to the softc 1352 * of the interface. From there we create the string and use it 1353 * as the value, but only for the *copy* of the node. 1354 * 1355 * Then we let sysctl_lookup do the magic, which consists in 1356 * setting oldp and newp as required by the operation. When the 1357 * value is read, that means that the string will be copied to 1358 * the user, and when it is written, the new value will be copied 1359 * over in the addr array. 1360 * 1361 * If newp is NULL, the user was reading the value, so we don't 1362 * have anything else to do. If a new value was written, we 1363 * have to check it. 1364 * 1365 * If it is incorrect, we can return an error and leave 'node' as 1366 * it is: since it is a copy of the actual node, the change will 1367 * be forgotten. 1368 * 1369 * Upon a correct input, we commit the change to the ifnet 1370 * structure of our interface. 1371 */ 1372 static int 1373 tap_sysctl_handler(SYSCTLFN_ARGS) 1374 { 1375 struct sysctlnode node; 1376 struct tap_softc *sc; 1377 struct ifnet *ifp; 1378 int error; 1379 size_t len; 1380 char addr[3 * ETHER_ADDR_LEN]; 1381 uint8_t enaddr[ETHER_ADDR_LEN]; 1382 1383 node = *rnode; 1384 sc = node.sysctl_data; 1385 ifp = &sc->sc_ec.ec_if; 1386 (void)ether_snprintf(addr, sizeof(addr), CLLADDR(ifp->if_sadl)); 1387 node.sysctl_data = addr; 1388 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 1389 if (error || newp == NULL) 1390 return (error); 1391 1392 len = strlen(addr); 1393 if (len < 11 || len > 17) 1394 return (EINVAL); 1395 1396 /* Commit change */ 1397 if (ether_aton_r(enaddr, sizeof(enaddr), addr) != 0) 1398 return (EINVAL); 1399 if_set_sadl(ifp, enaddr, ETHER_ADDR_LEN, false); 1400 return (error); 1401 } 1402 #endif 1403