The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/net/if_tap.c

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    1 /*-
    2  * Copyright (C) 1999-2000 by Maksim Yevmenkin <m_evmenkin@yahoo.com>
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  *
   26  * BASED ON:
   27  * -------------------------------------------------------------------------
   28  *
   29  * Copyright (c) 1988, Julian Onions <jpo@cs.nott.ac.uk>
   30  * Nottingham University 1987.
   31  */
   32 
   33 /*
   34  * $FreeBSD: releng/6.3/sys/net/if_tap.c 173886 2007-11-24 19:45:58Z cvs2svn $
   35  * $Id: if_tap.c,v 0.21 2000/07/23 21:46:02 max Exp $
   36  */
   37 
   38 #include "opt_compat.h"
   39 #include "opt_inet.h"
   40 
   41 #include <sys/param.h>
   42 #include <sys/conf.h>
   43 #include <sys/fcntl.h>
   44 #include <sys/filio.h>
   45 #include <sys/kernel.h>
   46 #include <sys/malloc.h>
   47 #include <sys/mbuf.h>
   48 #include <sys/module.h>
   49 #include <sys/poll.h>
   50 #include <sys/proc.h>
   51 #include <sys/selinfo.h>
   52 #include <sys/signalvar.h>
   53 #include <sys/socket.h>
   54 #include <sys/sockio.h>
   55 #include <sys/sysctl.h>
   56 #include <sys/systm.h>
   57 #include <sys/ttycom.h>
   58 #include <sys/uio.h>
   59 #include <sys/queue.h>
   60 
   61 #include <net/bpf.h>
   62 #include <net/ethernet.h>
   63 #include <net/if.h>
   64 #include <net/if_arp.h>
   65 #include <net/if_clone.h>
   66 #include <net/if_dl.h>
   67 #include <net/route.h>
   68 #include <net/if_types.h>
   69 
   70 #include <netinet/in.h>
   71 
   72 #include <net/if_tapvar.h>
   73 #include <net/if_tap.h>
   74 
   75 
   76 #define CDEV_NAME       "tap"
   77 #define TAPDEBUG        if (tapdebug) printf
   78 
   79 #define TAP             "tap"
   80 #define VMNET           "vmnet"
   81 #define TAPMAXUNIT      0x7fff
   82 #define VMNET_DEV_MASK  CLONE_FLAG0
   83 
   84 /* module */
   85 static int              tapmodevent(module_t, int, void *);
   86 
   87 /* device */
   88 static void             tapclone(void *, struct ucred *, char *, int,
   89                             struct cdev **);
   90 static void             tapcreate(struct cdev *);
   91 
   92 /* network interface */
   93 static void             tapifstart(struct ifnet *);
   94 static int              tapifioctl(struct ifnet *, u_long, caddr_t);
   95 static void             tapifinit(void *);
   96 
   97 static int              tap_clone_create(struct if_clone *, int);
   98 static void             tap_clone_destroy(struct ifnet *);
   99 static int              vmnet_clone_create(struct if_clone *, int);
  100 static void             vmnet_clone_destroy(struct ifnet *);
  101 
  102 IFC_SIMPLE_DECLARE(tap, 0);
  103 IFC_SIMPLE_DECLARE(vmnet, 0);
  104 
  105 /* character device */
  106 static d_open_t         tapopen;
  107 static d_close_t        tapclose;
  108 static d_read_t         tapread;
  109 static d_write_t        tapwrite;
  110 static d_ioctl_t        tapioctl;
  111 static d_poll_t         tappoll;
  112 static d_kqfilter_t     tapkqfilter;
  113 
  114 /* kqueue(2) */
  115 static int              tapkqread(struct knote *, long);
  116 static int              tapkqwrite(struct knote *, long);
  117 static void             tapkqdetach(struct knote *);
  118 
  119 static struct filterops tap_read_filterops = {
  120         .f_isfd =       1,
  121         .f_attach =     NULL,
  122         .f_detach =     tapkqdetach,
  123         .f_event =      tapkqread,
  124 };
  125 
  126 static struct filterops tap_write_filterops = {
  127         .f_isfd =       1,
  128         .f_attach =     NULL,
  129         .f_detach =     tapkqdetach,
  130         .f_event =      tapkqwrite,
  131 };
  132 
  133 static struct cdevsw    tap_cdevsw = {
  134         .d_version =    D_VERSION,
  135         .d_flags =      D_PSEUDO | D_NEEDGIANT,
  136         .d_open =       tapopen,
  137         .d_close =      tapclose,
  138         .d_read =       tapread,
  139         .d_write =      tapwrite,
  140         .d_ioctl =      tapioctl,
  141         .d_poll =       tappoll,
  142         .d_name =       CDEV_NAME,
  143         .d_kqfilter =   tapkqfilter,
  144 };
  145 
  146 /*
  147  * All global variables in if_tap.c are locked with tapmtx, with the
  148  * exception of tapdebug, which is accessed unlocked; tapclones is
  149  * static at runtime.
  150  */
  151 static struct mtx               tapmtx;
  152 static int                      tapdebug = 0;        /* debug flag   */
  153 static int                      tapuopen = 0;        /* allow user open() */
  154 static int                      tapuponopen = 0;    /* IFF_UP on open() */
  155 static int                      tapdclone = 1;  /* enable devfs cloning */
  156 static SLIST_HEAD(, tap_softc)  taphead;             /* first device */
  157 static struct clonedevs         *tapclones;
  158 
  159 MALLOC_DECLARE(M_TAP);
  160 MALLOC_DEFINE(M_TAP, CDEV_NAME, "Ethernet tunnel interface");
  161 SYSCTL_INT(_debug, OID_AUTO, if_tap_debug, CTLFLAG_RW, &tapdebug, 0, "");
  162 
  163 SYSCTL_DECL(_net_link);
  164 SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW, 0,
  165     "Ethernet tunnel software network interface");
  166 SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tapuopen, 0,
  167         "Allow user to open /dev/tap (based on node permissions)");
  168 SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0,
  169         "Bring interface up when /dev/tap is opened");
  170 SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RW, &tapdclone, 0,
  171         "Enably legacy devfs interface creation");
  172 SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tapdebug, 0, "");
  173 
  174 TUNABLE_INT("net.link.tap.devfs_cloning", &tapdclone);
  175 
  176 DEV_MODULE(if_tap, tapmodevent, NULL);
  177 
  178 static int
  179 tap_clone_create(struct if_clone *ifc, int unit)
  180 {
  181         struct cdev *dev;
  182         int i;
  183         int extra;
  184 
  185         if (strcmp(ifc->ifc_name, VMNET) == 0)
  186                 extra = VMNET_DEV_MASK;
  187         else
  188                 extra = 0;
  189 
  190         /* find any existing device, or allocate new unit number */
  191         i = clone_create(&tapclones, &tap_cdevsw, &unit, &dev, extra);
  192         if (i) {
  193                 dev = make_dev(&tap_cdevsw, unit2minor(unit | extra),
  194                      UID_ROOT, GID_WHEEL, 0600, "%s%d", ifc->ifc_name, unit);
  195                 if (dev != NULL) {
  196                         dev_ref(dev);
  197                         dev->si_flags |= SI_CHEAPCLONE;
  198                 }
  199         }
  200 
  201         tapcreate(dev);
  202         return (0);
  203 }
  204 
  205 /* vmnet devices are tap devices in disguise */
  206 static int
  207 vmnet_clone_create(struct if_clone *ifc, int unit)
  208 {
  209         return tap_clone_create(ifc, unit);
  210 }
  211 
  212 static void
  213 tap_destroy(struct tap_softc *tp)
  214 {
  215         struct ifnet *ifp = tp->tap_ifp;
  216         int s;
  217 
  218         /* Unlocked read. */
  219         KASSERT(!(tp->tap_flags & TAP_OPEN),
  220                 ("%s flags is out of sync", ifp->if_xname));
  221 
  222         knlist_destroy(&tp->tap_rsel.si_note);
  223         destroy_dev(tp->tap_dev);
  224         s = splimp();
  225         ether_ifdetach(ifp);
  226         if_free_type(ifp, IFT_ETHER);
  227         splx(s);
  228 
  229         mtx_destroy(&tp->tap_mtx);
  230         free(tp, M_TAP);
  231 }
  232 
  233 static void
  234 tap_clone_destroy(struct ifnet *ifp)
  235 {
  236         struct tap_softc *tp = ifp->if_softc;
  237 
  238         mtx_lock(&tapmtx);
  239         SLIST_REMOVE(&taphead, tp, tap_softc, tap_next);
  240         mtx_unlock(&tapmtx);
  241         tap_destroy(tp);
  242 }
  243 
  244 /* vmnet devices are tap devices in disguise */
  245 static void
  246 vmnet_clone_destroy(struct ifnet *ifp)
  247 {
  248         tap_clone_destroy(ifp);
  249 }
  250 
  251 /*
  252  * tapmodevent
  253  *
  254  * module event handler
  255  */
  256 static int
  257 tapmodevent(module_t mod, int type, void *data)
  258 {
  259         static eventhandler_tag  eh_tag = NULL;
  260         struct tap_softc        *tp = NULL;
  261         struct ifnet            *ifp = NULL;
  262 
  263         switch (type) {
  264         case MOD_LOAD:
  265 
  266                 /* intitialize device */
  267 
  268                 mtx_init(&tapmtx, "tapmtx", NULL, MTX_DEF);
  269                 SLIST_INIT(&taphead);
  270 
  271                 clone_setup(&tapclones);
  272                 eh_tag = EVENTHANDLER_REGISTER(dev_clone, tapclone, 0, 1000);
  273                 if (eh_tag == NULL) {
  274                         clone_cleanup(&tapclones);
  275                         mtx_destroy(&tapmtx);
  276                         return (ENOMEM);
  277                 }
  278                 if_clone_attach(&tap_cloner);
  279                 if_clone_attach(&vmnet_cloner);
  280                 return (0);
  281 
  282         case MOD_UNLOAD:
  283                 /*
  284                  * The EBUSY algorithm here can't quite atomically
  285                  * guarantee that this is race-free since we have to
  286                  * release the tap mtx to deregister the clone handler.
  287                  */
  288                 mtx_lock(&tapmtx);
  289                 SLIST_FOREACH(tp, &taphead, tap_next) {
  290                         mtx_lock(&tp->tap_mtx);
  291                         if (tp->tap_flags & TAP_OPEN) {
  292                                 mtx_unlock(&tp->tap_mtx);
  293                                 mtx_unlock(&tapmtx);
  294                                 return (EBUSY);
  295                         }
  296                         mtx_unlock(&tp->tap_mtx);
  297                 }
  298                 mtx_unlock(&tapmtx);
  299 
  300                 EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
  301                 if_clone_detach(&tap_cloner);
  302                 if_clone_detach(&vmnet_cloner);
  303 
  304                 mtx_lock(&tapmtx);
  305                 while ((tp = SLIST_FIRST(&taphead)) != NULL) {
  306                         SLIST_REMOVE_HEAD(&taphead, tap_next);
  307                         mtx_unlock(&tapmtx);
  308 
  309                         ifp = tp->tap_ifp;
  310 
  311                         TAPDEBUG("detaching %s\n", ifp->if_xname);
  312 
  313                         tap_destroy(tp);
  314                         mtx_lock(&tapmtx);
  315                 }
  316                 mtx_unlock(&tapmtx);
  317                 clone_cleanup(&tapclones);
  318 
  319                 mtx_destroy(&tapmtx);
  320 
  321                 break;
  322 
  323         default:
  324                 return (EOPNOTSUPP);
  325         }
  326 
  327         return (0);
  328 } /* tapmodevent */
  329 
  330 
  331 /*
  332  * DEVFS handler
  333  *
  334  * We need to support two kind of devices - tap and vmnet
  335  */
  336 static void
  337 tapclone(void *arg, struct ucred *cred, char *name, int namelen, struct cdev **dev)
  338 {
  339         char            devname[SPECNAMELEN + 1];
  340         int             i, unit, append_unit;
  341         int             extra;
  342 
  343         if (*dev != NULL)
  344                 return;
  345 
  346         if (!tapdclone ||
  347             (!tapuopen && suser_cred(cred, SUSER_ALLOWJAIL) != 0))
  348                 return;
  349 
  350         unit = 0;
  351         append_unit = 0;
  352         extra = 0;
  353 
  354         /* We're interested in only tap/vmnet devices. */
  355         if (strcmp(name, TAP) == 0) {
  356                 unit = -1;
  357         } else if (strcmp(name, VMNET) == 0) {
  358                 unit = -1;
  359                 extra = VMNET_DEV_MASK;
  360         } else if (dev_stdclone(name, NULL, TAP, &unit) != 1) {
  361                 if (dev_stdclone(name, NULL, VMNET, &unit) != 1) {
  362                         return;
  363                 } else {
  364                         extra = VMNET_DEV_MASK;
  365                 }
  366         }
  367 
  368         if (unit == -1)
  369                 append_unit = 1;
  370 
  371         /* find any existing device, or allocate new unit number */
  372         i = clone_create(&tapclones, &tap_cdevsw, &unit, dev, extra);
  373         if (i) {
  374                 if (append_unit) {
  375                         /*
  376                          * We were passed 'tun' or 'tap', with no unit specified
  377                          * so we'll need to append it now.
  378                          */
  379                         namelen = snprintf(devname, sizeof(devname), "%s%d", name,
  380                             unit);
  381                         name = devname;
  382                 }
  383 
  384                 *dev = make_dev(&tap_cdevsw, unit2minor(unit | extra),
  385                      UID_ROOT, GID_WHEEL, 0600, "%s", name);
  386                 if (*dev != NULL) {
  387                         dev_ref(*dev);
  388                         (*dev)->si_flags |= SI_CHEAPCLONE;
  389                 }
  390         }
  391 
  392         if_clone_create(name, namelen);
  393 } /* tapclone */
  394 
  395 
  396 /*
  397  * tapcreate
  398  *
  399  * to create interface
  400  */
  401 static void
  402 tapcreate(struct cdev *dev)
  403 {
  404         struct ifnet            *ifp = NULL;
  405         struct tap_softc        *tp = NULL;
  406         unsigned short           macaddr_hi;
  407         int                      unit, s;
  408         char                    *name = NULL;
  409         u_char                  eaddr[6];
  410 
  411         dev->si_flags &= ~SI_CHEAPCLONE;
  412 
  413         /* allocate driver storage and create device */
  414         MALLOC(tp, struct tap_softc *, sizeof(*tp), M_TAP, M_WAITOK | M_ZERO);
  415         mtx_init(&tp->tap_mtx, "tap_mtx", NULL, MTX_DEF);
  416         mtx_lock(&tapmtx);
  417         SLIST_INSERT_HEAD(&taphead, tp, tap_next);
  418         mtx_unlock(&tapmtx);
  419 
  420         unit = dev2unit(dev);
  421 
  422         /* select device: tap or vmnet */
  423         if (unit & VMNET_DEV_MASK) {
  424                 name = VMNET;
  425                 tp->tap_flags |= TAP_VMNET;
  426         } else
  427                 name = TAP;
  428 
  429         unit &= TAPMAXUNIT;
  430 
  431         TAPDEBUG("tapcreate(%s%d). minor = %#x\n", name, unit, minor(dev));
  432 
  433         /* generate fake MAC address: 00 bd xx xx xx unit_no */
  434         macaddr_hi = htons(0x00bd);
  435         bcopy(&macaddr_hi, eaddr, sizeof(short));
  436         bcopy(&ticks, &eaddr[2], sizeof(long));
  437         eaddr[5] = (u_char)unit;
  438 
  439         /* fill the rest and attach interface */
  440         ifp = tp->tap_ifp = if_alloc(IFT_ETHER);
  441         if (ifp == NULL)
  442                 panic("%s%d: can not if_alloc()", name, unit);
  443         ifp->if_softc = tp;
  444         if_initname(ifp, name, unit);
  445         ifp->if_init = tapifinit;
  446         ifp->if_start = tapifstart;
  447         ifp->if_ioctl = tapifioctl;
  448         ifp->if_mtu = ETHERMTU;
  449         ifp->if_flags = (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST);
  450         ifp->if_snd.ifq_maxlen = ifqmaxlen;
  451 
  452         dev->si_drv1 = tp;
  453         tp->tap_dev = dev;
  454 
  455         s = splimp();
  456         ether_ifattach(ifp, eaddr);
  457         splx(s);
  458 
  459         mtx_lock(&tp->tap_mtx);
  460         tp->tap_flags |= TAP_INITED;
  461         mtx_unlock(&tp->tap_mtx);
  462 
  463         knlist_init(&tp->tap_rsel.si_note, NULL, NULL, NULL, NULL);
  464 
  465         TAPDEBUG("interface %s is created. minor = %#x\n", 
  466                 ifp->if_xname, minor(dev));
  467 } /* tapcreate */
  468 
  469 
  470 /*
  471  * tapopen
  472  *
  473  * to open tunnel. must be superuser
  474  */
  475 static int
  476 tapopen(struct cdev *dev, int flag, int mode, struct thread *td)
  477 {
  478         struct tap_softc        *tp = NULL;
  479         struct ifnet            *ifp = NULL;
  480         int                      error, s;
  481 
  482         if (tapuopen == 0) {
  483                 error = suser(td);
  484                 if (error != 0)
  485                         return (error);
  486         }
  487 
  488         if ((dev2unit(dev) & CLONE_UNITMASK) > TAPMAXUNIT)
  489                 return (ENXIO);
  490 
  491         tp = dev->si_drv1;
  492 
  493         mtx_lock(&tp->tap_mtx);
  494         if (tp->tap_flags & TAP_OPEN) {
  495                 mtx_unlock(&tp->tap_mtx);
  496                 return (EBUSY);
  497         }
  498 
  499         bcopy(IFP2ENADDR(tp->tap_ifp), tp->ether_addr, sizeof(tp->ether_addr));
  500         tp->tap_pid = td->td_proc->p_pid;
  501         tp->tap_flags |= TAP_OPEN;
  502         ifp = tp->tap_ifp;
  503         mtx_unlock(&tp->tap_mtx);
  504 
  505         s = splimp();
  506         ifp->if_drv_flags |= IFF_DRV_RUNNING;
  507         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
  508         if (tapuponopen)
  509                 ifp->if_flags |= IFF_UP;
  510         splx(s);
  511 
  512         TAPDEBUG("%s is open. minor = %#x\n", ifp->if_xname, minor(dev));
  513 
  514         return (0);
  515 } /* tapopen */
  516 
  517 
  518 /*
  519  * tapclose
  520  *
  521  * close the device - mark i/f down & delete routing info
  522  */
  523 static int
  524 tapclose(struct cdev *dev, int foo, int bar, struct thread *td)
  525 {
  526         struct ifaddr           *ifa;
  527         struct tap_softc        *tp = dev->si_drv1;
  528         struct ifnet            *ifp = tp->tap_ifp;
  529         int                     s;
  530 
  531         /* junk all pending output */
  532         IF_DRAIN(&ifp->if_snd);
  533 
  534         /*
  535          * do not bring the interface down, and do not anything with
  536          * interface, if we are in VMnet mode. just close the device.
  537          */
  538 
  539         mtx_lock(&tp->tap_mtx);
  540         if (((tp->tap_flags & TAP_VMNET) == 0) && (ifp->if_flags & IFF_UP)) {
  541                 mtx_unlock(&tp->tap_mtx);
  542                 s = splimp();
  543                 if_down(ifp);
  544                 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
  545                         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
  546                                 rtinit(ifa, (int)RTM_DELETE, 0);
  547                         }
  548                         if_purgeaddrs(ifp);
  549                         ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
  550                 }
  551                 splx(s);
  552         } else
  553                 mtx_unlock(&tp->tap_mtx);
  554 
  555         funsetown(&tp->tap_sigio);
  556         selwakeuppri(&tp->tap_rsel, PZERO+1);
  557         KNOTE_UNLOCKED(&tp->tap_rsel.si_note, 0);
  558 
  559         mtx_lock(&tp->tap_mtx);
  560         tp->tap_flags &= ~TAP_OPEN;
  561         tp->tap_pid = 0;
  562         mtx_unlock(&tp->tap_mtx);
  563 
  564         TAPDEBUG("%s is closed. minor = %#x\n", 
  565                 ifp->if_xname, minor(dev));
  566 
  567         return (0);
  568 } /* tapclose */
  569 
  570 
  571 /*
  572  * tapifinit
  573  *
  574  * network interface initialization function
  575  */
  576 static void
  577 tapifinit(void *xtp)
  578 {
  579         struct tap_softc        *tp = (struct tap_softc *)xtp;
  580         struct ifnet            *ifp = tp->tap_ifp;
  581 
  582         TAPDEBUG("initializing %s\n", ifp->if_xname);
  583 
  584         ifp->if_drv_flags |= IFF_DRV_RUNNING;
  585         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
  586 
  587         /* attempt to start output */
  588         tapifstart(ifp);
  589 } /* tapifinit */
  590 
  591 
  592 /*
  593  * tapifioctl
  594  *
  595  * Process an ioctl request on network interface
  596  */
  597 static int
  598 tapifioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
  599 {
  600         struct tap_softc        *tp = ifp->if_softc;
  601         struct ifstat           *ifs = NULL;
  602         int                      s, dummy;
  603 
  604         switch (cmd) {
  605                 case SIOCSIFFLAGS: /* XXX -- just like vmnet does */
  606                 case SIOCADDMULTI:
  607                 case SIOCDELMULTI:
  608                         break;
  609 
  610                 case SIOCGIFSTATUS:
  611                         s = splimp();
  612                         ifs = (struct ifstat *)data;
  613                         dummy = strlen(ifs->ascii);
  614                         mtx_lock(&tp->tap_mtx);
  615                         if (tp->tap_pid != 0 && dummy < sizeof(ifs->ascii))
  616                                 snprintf(ifs->ascii + dummy,
  617                                         sizeof(ifs->ascii) - dummy,
  618                                         "\tOpened by PID %d\n", tp->tap_pid);
  619                         mtx_unlock(&tp->tap_mtx);
  620                         splx(s);
  621                         break;
  622 
  623                 default:
  624                         s = splimp();
  625                         dummy = ether_ioctl(ifp, cmd, data);
  626                         splx(s);
  627                         return (dummy);
  628                         /* NOT REACHED */
  629         }
  630 
  631         return (0);
  632 } /* tapifioctl */
  633 
  634 
  635 /*
  636  * tapifstart
  637  *
  638  * queue packets from higher level ready to put out
  639  */
  640 static void
  641 tapifstart(struct ifnet *ifp)
  642 {
  643         struct tap_softc        *tp = ifp->if_softc;
  644         int                      s;
  645 
  646         TAPDEBUG("%s starting\n", ifp->if_xname);
  647 
  648         /*
  649          * do not junk pending output if we are in VMnet mode.
  650          * XXX: can this do any harm because of queue overflow?
  651          */
  652 
  653         mtx_lock(&tp->tap_mtx);
  654         if (((tp->tap_flags & TAP_VMNET) == 0) &&
  655             ((tp->tap_flags & TAP_READY) != TAP_READY)) {
  656                 struct mbuf     *m = NULL;
  657 
  658                 mtx_unlock(&tp->tap_mtx);
  659 
  660                 /* Unlocked read. */
  661                 TAPDEBUG("%s not ready, tap_flags = 0x%x\n", ifp->if_xname, 
  662                     tp->tap_flags);
  663 
  664                 s = splimp();
  665                 do {
  666                         IF_DEQUEUE(&ifp->if_snd, m);
  667                         if (m != NULL)
  668                                 m_freem(m);
  669                         ifp->if_oerrors ++;
  670                 } while (m != NULL);
  671                 splx(s);
  672 
  673                 return;
  674         }
  675         mtx_unlock(&tp->tap_mtx);
  676 
  677         s = splimp();
  678         ifp->if_drv_flags |= IFF_DRV_OACTIVE;
  679 
  680         if (ifp->if_snd.ifq_len != 0) {
  681                 mtx_lock(&tp->tap_mtx);
  682                 if (tp->tap_flags & TAP_RWAIT) {
  683                         tp->tap_flags &= ~TAP_RWAIT;
  684                         wakeup(tp);
  685                 }
  686 
  687                 if ((tp->tap_flags & TAP_ASYNC) && (tp->tap_sigio != NULL)) {
  688                         mtx_unlock(&tp->tap_mtx);
  689                         pgsigio(&tp->tap_sigio, SIGIO, 0);
  690                 } else
  691                         mtx_unlock(&tp->tap_mtx);
  692 
  693                 selwakeuppri(&tp->tap_rsel, PZERO+1);
  694                 KNOTE_UNLOCKED(&tp->tap_rsel.si_note, 0);
  695                 ifp->if_opackets ++; /* obytes are counted in ether_output */
  696         }
  697 
  698         ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
  699         splx(s);
  700 } /* tapifstart */
  701 
  702 
  703 /*
  704  * tapioctl
  705  *
  706  * the cdevsw interface is now pretty minimal
  707  */
  708 static int
  709 tapioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
  710 {
  711         struct tap_softc        *tp = dev->si_drv1;
  712         struct ifnet            *ifp = tp->tap_ifp;
  713         struct tapinfo          *tapp = NULL;
  714         int                      s;
  715         int                      f;
  716 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
  717     defined(COMPAT_FREEBSD4)
  718         int                      ival;
  719 #endif
  720 
  721         switch (cmd) {
  722                 case TAPSIFINFO:
  723                         s = splimp();
  724                         tapp = (struct tapinfo *)data;
  725                         ifp->if_mtu = tapp->mtu;
  726                         ifp->if_type = tapp->type;
  727                         ifp->if_baudrate = tapp->baudrate;
  728                         splx(s);
  729                         break;
  730 
  731                 case TAPGIFINFO:
  732                         tapp = (struct tapinfo *)data;
  733                         tapp->mtu = ifp->if_mtu;
  734                         tapp->type = ifp->if_type;
  735                         tapp->baudrate = ifp->if_baudrate;
  736                         break;
  737 
  738                 case TAPSDEBUG:
  739                         tapdebug = *(int *)data;
  740                         break;
  741 
  742                 case TAPGDEBUG:
  743                         *(int *)data = tapdebug;
  744                         break;
  745 
  746                 case FIONBIO:
  747                         break;
  748 
  749                 case FIOASYNC:
  750                         s = splimp();
  751                         mtx_lock(&tp->tap_mtx);
  752                         if (*(int *)data)
  753                                 tp->tap_flags |= TAP_ASYNC;
  754                         else
  755                                 tp->tap_flags &= ~TAP_ASYNC;
  756                         mtx_unlock(&tp->tap_mtx);
  757                         splx(s);
  758                         break;
  759 
  760                 case FIONREAD:
  761                         s = splimp();
  762                         if (ifp->if_snd.ifq_head) {
  763                                 struct mbuf     *mb = ifp->if_snd.ifq_head;
  764 
  765                                 for(*(int *)data = 0;mb != NULL;mb = mb->m_next)
  766                                         *(int *)data += mb->m_len;
  767                         } else
  768                                 *(int *)data = 0;
  769                         splx(s);
  770                         break;
  771 
  772                 case FIOSETOWN:
  773                         return (fsetown(*(int *)data, &tp->tap_sigio));
  774 
  775                 case FIOGETOWN:
  776                         *(int *)data = fgetown(&tp->tap_sigio);
  777                         return (0);
  778 
  779                 /* this is deprecated, FIOSETOWN should be used instead */
  780                 case TIOCSPGRP:
  781                         return (fsetown(-(*(int *)data), &tp->tap_sigio));
  782 
  783                 /* this is deprecated, FIOGETOWN should be used instead */
  784                 case TIOCGPGRP:
  785                         *(int *)data = -fgetown(&tp->tap_sigio);
  786                         return (0);
  787 
  788                 /* VMware/VMnet port ioctl's */
  789 
  790                 case SIOCGIFFLAGS:      /* get ifnet flags */
  791                         bcopy(&ifp->if_flags, data, sizeof(ifp->if_flags));
  792                         break;
  793 
  794 #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
  795     defined(COMPAT_FREEBSD4)
  796                 case _IO('V', 0):
  797                         ival = IOCPARM_IVAL(data);
  798                         data = (caddr_t)&ival;
  799                         /* FALLTHROUGH */
  800 #endif
  801                 case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */
  802                         f = *(int *)data;
  803                         f &= 0x0fff;
  804                         f &= ~IFF_CANTCHANGE;
  805                         f |= IFF_UP;
  806 
  807                         s = splimp();
  808                         ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE);
  809                         splx(s);
  810                         break;
  811 
  812                 case OSIOCGIFADDR:      /* get MAC address of the remote side */
  813                 case SIOCGIFADDR:
  814                         mtx_lock(&tp->tap_mtx);
  815                         bcopy(tp->ether_addr, data, sizeof(tp->ether_addr));
  816                         mtx_unlock(&tp->tap_mtx);
  817                         break;
  818 
  819                 case SIOCSIFADDR:       /* set MAC address of the remote side */
  820                         mtx_lock(&tp->tap_mtx);
  821                         bcopy(data, tp->ether_addr, sizeof(tp->ether_addr));
  822                         mtx_unlock(&tp->tap_mtx);
  823                         break;
  824 
  825                 default:
  826                         return (ENOTTY);
  827         }
  828         return (0);
  829 } /* tapioctl */
  830 
  831 
  832 /*
  833  * tapread
  834  *
  835  * the cdevsw read interface - reads a packet at a time, or at
  836  * least as much of a packet as can be read
  837  */
  838 static int
  839 tapread(struct cdev *dev, struct uio *uio, int flag)
  840 {
  841         struct tap_softc        *tp = dev->si_drv1;
  842         struct ifnet            *ifp = tp->tap_ifp;
  843         struct mbuf             *m = NULL;
  844         int                      error = 0, len, s;
  845 
  846         TAPDEBUG("%s reading, minor = %#x\n", ifp->if_xname, minor(dev));
  847 
  848         mtx_lock(&tp->tap_mtx);
  849         if ((tp->tap_flags & TAP_READY) != TAP_READY) {
  850                 mtx_unlock(&tp->tap_mtx);
  851 
  852                 /* Unlocked read. */
  853                 TAPDEBUG("%s not ready. minor = %#x, tap_flags = 0x%x\n",
  854                         ifp->if_xname, minor(dev), tp->tap_flags);
  855 
  856                 return (EHOSTDOWN);
  857         }
  858 
  859         tp->tap_flags &= ~TAP_RWAIT;
  860         mtx_unlock(&tp->tap_mtx);
  861 
  862         /* sleep until we get a packet */
  863         do {
  864                 s = splimp();
  865                 IF_DEQUEUE(&ifp->if_snd, m);
  866                 splx(s);
  867 
  868                 if (m == NULL) {
  869                         if (flag & O_NONBLOCK)
  870                                 return (EWOULDBLOCK);
  871 
  872                         mtx_lock(&tp->tap_mtx);
  873                         tp->tap_flags |= TAP_RWAIT;
  874                         mtx_unlock(&tp->tap_mtx);
  875                         error = tsleep(tp,PCATCH|(PZERO+1),"taprd",0);
  876                         if (error)
  877                                 return (error);
  878                 }
  879         } while (m == NULL);
  880 
  881         /* feed packet to bpf */
  882         BPF_MTAP(ifp, m);
  883 
  884         /* xfer packet to user space */
  885         while ((m != NULL) && (uio->uio_resid > 0) && (error == 0)) {
  886                 len = min(uio->uio_resid, m->m_len);
  887                 if (len == 0)
  888                         break;
  889 
  890                 error = uiomove(mtod(m, void *), len, uio);
  891                 m = m_free(m);
  892         }
  893 
  894         if (m != NULL) {
  895                 TAPDEBUG("%s dropping mbuf, minor = %#x\n", ifp->if_xname, 
  896                         minor(dev));
  897                 m_freem(m);
  898         }
  899 
  900         return (error);
  901 } /* tapread */
  902 
  903 
  904 /*
  905  * tapwrite
  906  *
  907  * the cdevsw write interface - an atomic write is a packet - or else!
  908  */
  909 static int
  910 tapwrite(struct cdev *dev, struct uio *uio, int flag)
  911 {
  912         struct ether_header     *eh;
  913         struct tap_softc        *tp = dev->si_drv1;
  914         struct ifnet            *ifp = tp->tap_ifp;
  915         struct mbuf             *m;
  916 
  917         TAPDEBUG("%s writting, minor = %#x\n", 
  918                 ifp->if_xname, minor(dev));
  919 
  920         if (uio->uio_resid == 0)
  921                 return (0);
  922 
  923         if ((uio->uio_resid < 0) || (uio->uio_resid > TAPMRU)) {
  924                 TAPDEBUG("%s invalid packet len = %d, minor = %#x\n",
  925                         ifp->if_xname, uio->uio_resid, minor(dev));
  926 
  927                 return (EIO);
  928         }
  929 
  930         if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, ETHER_ALIGN)) == NULL) {
  931                 ifp->if_ierrors ++;
  932                 return (ENOBUFS);
  933         }
  934 
  935         m->m_pkthdr.rcvif = ifp;
  936 
  937         /*
  938          * Only pass a unicast frame to ether_input(), if it would actually
  939          * have been received by non-virtual hardware.
  940          */
  941         if (m->m_len < sizeof(struct ether_header)) {
  942                 m_freem(m);
  943                 return (0);
  944         }
  945         eh = mtod(m, struct ether_header *);
  946 
  947         if (eh && (ifp->if_flags & IFF_PROMISC) == 0 &&
  948             !ETHER_IS_MULTICAST(eh->ether_dhost) &&
  949             bcmp(eh->ether_dhost, IFP2ENADDR(ifp), ETHER_ADDR_LEN) != 0) {
  950                 m_freem(m);
  951                 return (0);
  952         }
  953 
  954         /* Pass packet up to parent. */
  955         (*ifp->if_input)(ifp, m);
  956         ifp->if_ipackets ++; /* ibytes are counted in parent */
  957 
  958         return (0);
  959 } /* tapwrite */
  960 
  961 
  962 /*
  963  * tappoll
  964  *
  965  * the poll interface, this is only useful on reads
  966  * really. the write detect always returns true, write never blocks
  967  * anyway, it either accepts the packet or drops it
  968  */
  969 static int
  970 tappoll(struct cdev *dev, int events, struct thread *td)
  971 {
  972         struct tap_softc        *tp = dev->si_drv1;
  973         struct ifnet            *ifp = tp->tap_ifp;
  974         int                      s, revents = 0;
  975 
  976         TAPDEBUG("%s polling, minor = %#x\n", 
  977                 ifp->if_xname, minor(dev));
  978 
  979         s = splimp();
  980         if (events & (POLLIN | POLLRDNORM)) {
  981                 if (ifp->if_snd.ifq_len > 0) {
  982                         TAPDEBUG("%s have data in queue. len = %d, " \
  983                                 "minor = %#x\n", ifp->if_xname,
  984                                 ifp->if_snd.ifq_len, minor(dev));
  985 
  986                         revents |= (events & (POLLIN | POLLRDNORM));
  987                 } else {
  988                         TAPDEBUG("%s waiting for data, minor = %#x\n",
  989                                 ifp->if_xname, minor(dev));
  990 
  991                         selrecord(td, &tp->tap_rsel);
  992                 }
  993         }
  994 
  995         if (events & (POLLOUT | POLLWRNORM))
  996                 revents |= (events & (POLLOUT | POLLWRNORM));
  997 
  998         splx(s);
  999         return (revents);
 1000 } /* tappoll */
 1001 
 1002 
 1003 /*
 1004  * tap_kqfilter
 1005  *
 1006  * support for kevent() system call
 1007  */
 1008 static int
 1009 tapkqfilter(struct cdev *dev, struct knote *kn)
 1010 {
 1011         int                      s;
 1012         struct tap_softc        *tp = dev->si_drv1;
 1013         struct ifnet            *ifp = tp->tap_ifp;
 1014 
 1015         s = splimp();
 1016         switch (kn->kn_filter) {
 1017         case EVFILT_READ:
 1018                 TAPDEBUG("%s kqfilter: EVFILT_READ, minor = %#x\n",
 1019                         ifp->if_xname, minor(dev));
 1020                 kn->kn_fop = &tap_read_filterops;
 1021                 break;
 1022 
 1023         case EVFILT_WRITE:
 1024                 TAPDEBUG("%s kqfilter: EVFILT_WRITE, minor = %#x\n",
 1025                         ifp->if_xname, minor(dev));
 1026                 kn->kn_fop = &tap_write_filterops;
 1027                 break;
 1028 
 1029         default:
 1030                 TAPDEBUG("%s kqfilter: invalid filter, minor = %#x\n",
 1031                         ifp->if_xname, minor(dev));
 1032                 splx(s);
 1033                 return (EINVAL);
 1034                 /* NOT REACHED */
 1035         }
 1036         splx(s);
 1037 
 1038         kn->kn_hook = (caddr_t) dev;
 1039         knlist_add(&tp->tap_rsel.si_note, kn, 0);
 1040 
 1041         return (0);
 1042 } /* tapkqfilter */
 1043 
 1044 
 1045 /*
 1046  * tap_kqread
 1047  * 
 1048  * Return true if there is data in the interface queue
 1049  */
 1050 static int
 1051 tapkqread(struct knote *kn, long hint)
 1052 {
 1053         int                      ret, s;
 1054         struct cdev             *dev = (struct cdev *)(kn->kn_hook);
 1055         struct tap_softc        *tp = dev->si_drv1;
 1056         struct ifnet            *ifp = tp->tap_ifp;
 1057 
 1058         s = splimp();
 1059         if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) {
 1060                 TAPDEBUG("%s have data in queue. len = %d, minor = %#x\n",
 1061                         ifp->if_xname, ifp->if_snd.ifq_len, minor(dev));
 1062                 ret = 1;
 1063         } else {
 1064                 TAPDEBUG("%s waiting for data, minor = %#x\n",
 1065                         ifp->if_xname, minor(dev));
 1066                 ret = 0;
 1067         }
 1068         splx(s);
 1069 
 1070         return (ret);
 1071 } /* tapkqread */
 1072 
 1073 
 1074 /*
 1075  * tap_kqwrite
 1076  *
 1077  * Always can write. Return the MTU in kn->data
 1078  */
 1079 static int
 1080 tapkqwrite(struct knote *kn, long hint)
 1081 {
 1082         int                      s;
 1083         struct tap_softc        *tp = ((struct cdev *) kn->kn_hook)->si_drv1;
 1084         struct ifnet            *ifp = tp->tap_ifp;
 1085 
 1086         s = splimp();
 1087         kn->kn_data = ifp->if_mtu;
 1088         splx(s);
 1089 
 1090         return (1);
 1091 } /* tapkqwrite */
 1092 
 1093 
 1094 static void
 1095 tapkqdetach(struct knote *kn)
 1096 {
 1097         struct tap_softc        *tp = ((struct cdev *) kn->kn_hook)->si_drv1;
 1098 
 1099         knlist_remove(&tp->tap_rsel.si_note, kn, 0);
 1100 } /* tapkqdetach */
 1101 

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