/*- * Copyright (C) 1999-2000 by Maksim Yevmenkin * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * BASED ON: * ------------------------------------------------------------------------- * * Copyright (c) 1988, Julian Onions * Nottingham University 1987. */ /* * $FreeBSD$ * $Id: if_tap.c,v 0.21 2000/07/23 21:46:02 max Exp $ */ #include "opt_compat.h" #include "opt_inet.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define CDEV_NAME "tap" #define TAPDEBUG if (tapdebug) printf static const char tapname[] = "tap"; static const char vmnetname[] = "vmnet"; #define TAPMAXUNIT 0x7fff #define VMNET_DEV_MASK CLONE_FLAG0 /* module */ static int tapmodevent(module_t, int, void *); /* device */ static void tapclone(void *, struct ucred *, char *, int, struct cdev **); static void tapcreate(struct cdev *); /* network interface */ static void tapifstart(struct ifnet *); static int tapifioctl(struct ifnet *, u_long, caddr_t); static void tapifinit(void *); static int tap_clone_create(struct if_clone *, int, caddr_t); static void tap_clone_destroy(struct ifnet *); static struct if_clone *tap_cloner; static int vmnet_clone_create(struct if_clone *, int, caddr_t); static void vmnet_clone_destroy(struct ifnet *); static struct if_clone *vmnet_cloner; /* character device */ static d_open_t tapopen; static d_close_t tapclose; static d_read_t tapread; static d_write_t tapwrite; static d_ioctl_t tapioctl; static d_poll_t tappoll; static d_kqfilter_t tapkqfilter; /* kqueue(2) */ static int tapkqread(struct knote *, long); static int tapkqwrite(struct knote *, long); static void tapkqdetach(struct knote *); static struct filterops tap_read_filterops = { .f_isfd = 1, .f_attach = NULL, .f_detach = tapkqdetach, .f_event = tapkqread, }; static struct filterops tap_write_filterops = { .f_isfd = 1, .f_attach = NULL, .f_detach = tapkqdetach, .f_event = tapkqwrite, }; static struct cdevsw tap_cdevsw = { .d_version = D_VERSION, .d_flags = D_NEEDMINOR, .d_open = tapopen, .d_close = tapclose, .d_read = tapread, .d_write = tapwrite, .d_ioctl = tapioctl, .d_poll = tappoll, .d_name = CDEV_NAME, .d_kqfilter = tapkqfilter, }; /* * All global variables in if_tap.c are locked with tapmtx, with the * exception of tapdebug, which is accessed unlocked; tapclones is * static at runtime. */ static struct mtx tapmtx; static int tapdebug = 0; /* debug flag */ static int tapuopen = 0; /* allow user open() */ static int tapuponopen = 0; /* IFF_UP on open() */ static int tapdclone = 1; /* enable devfs cloning */ static SLIST_HEAD(, tap_softc) taphead; /* first device */ static struct clonedevs *tapclones; MALLOC_DECLARE(M_TAP); MALLOC_DEFINE(M_TAP, CDEV_NAME, "Ethernet tunnel interface"); SYSCTL_INT(_debug, OID_AUTO, if_tap_debug, CTLFLAG_RW, &tapdebug, 0, ""); SYSCTL_DECL(_net_link); static SYSCTL_NODE(_net_link, OID_AUTO, tap, CTLFLAG_RW, 0, "Ethernet tunnel software network interface"); SYSCTL_INT(_net_link_tap, OID_AUTO, user_open, CTLFLAG_RW, &tapuopen, 0, "Allow user to open /dev/tap (based on node permissions)"); SYSCTL_INT(_net_link_tap, OID_AUTO, up_on_open, CTLFLAG_RW, &tapuponopen, 0, "Bring interface up when /dev/tap is opened"); SYSCTL_INT(_net_link_tap, OID_AUTO, devfs_cloning, CTLFLAG_RWTUN, &tapdclone, 0, "Enable legacy devfs interface creation"); SYSCTL_INT(_net_link_tap, OID_AUTO, debug, CTLFLAG_RW, &tapdebug, 0, ""); DEV_MODULE(if_tap, tapmodevent, NULL); static int tap_clone_create(struct if_clone *ifc, int unit, caddr_t params) { struct cdev *dev; int i; /* Find any existing device, or allocate new unit number. */ i = clone_create(&tapclones, &tap_cdevsw, &unit, &dev, 0); if (i) { dev = make_dev(&tap_cdevsw, unit, UID_ROOT, GID_WHEEL, 0600, "%s%d", tapname, unit); } tapcreate(dev); return (0); } /* vmnet devices are tap devices in disguise */ static int vmnet_clone_create(struct if_clone *ifc, int unit, caddr_t params) { struct cdev *dev; int i; /* Find any existing device, or allocate new unit number. */ i = clone_create(&tapclones, &tap_cdevsw, &unit, &dev, VMNET_DEV_MASK); if (i) { dev = make_dev(&tap_cdevsw, unit | VMNET_DEV_MASK, UID_ROOT, GID_WHEEL, 0600, "%s%d", vmnetname, unit); } tapcreate(dev); return (0); } static void tap_destroy(struct tap_softc *tp) { struct ifnet *ifp = tp->tap_ifp; CURVNET_SET(ifp->if_vnet); destroy_dev(tp->tap_dev); seldrain(&tp->tap_rsel); knlist_clear(&tp->tap_rsel.si_note, 0); knlist_destroy(&tp->tap_rsel.si_note); ether_ifdetach(ifp); if_free(ifp); mtx_destroy(&tp->tap_mtx); free(tp, M_TAP); CURVNET_RESTORE(); } static void tap_clone_destroy(struct ifnet *ifp) { struct tap_softc *tp = ifp->if_softc; mtx_lock(&tapmtx); SLIST_REMOVE(&taphead, tp, tap_softc, tap_next); mtx_unlock(&tapmtx); tap_destroy(tp); } /* vmnet devices are tap devices in disguise */ static void vmnet_clone_destroy(struct ifnet *ifp) { tap_clone_destroy(ifp); } /* * tapmodevent * * module event handler */ static int tapmodevent(module_t mod, int type, void *data) { static eventhandler_tag eh_tag = NULL; struct tap_softc *tp = NULL; struct ifnet *ifp = NULL; switch (type) { case MOD_LOAD: /* intitialize device */ mtx_init(&tapmtx, "tapmtx", NULL, MTX_DEF); SLIST_INIT(&taphead); clone_setup(&tapclones); eh_tag = EVENTHANDLER_REGISTER(dev_clone, tapclone, 0, 1000); if (eh_tag == NULL) { clone_cleanup(&tapclones); mtx_destroy(&tapmtx); return (ENOMEM); } tap_cloner = if_clone_simple(tapname, tap_clone_create, tap_clone_destroy, 0); vmnet_cloner = if_clone_simple(vmnetname, vmnet_clone_create, vmnet_clone_destroy, 0); return (0); case MOD_UNLOAD: /* * The EBUSY algorithm here can't quite atomically * guarantee that this is race-free since we have to * release the tap mtx to deregister the clone handler. */ mtx_lock(&tapmtx); SLIST_FOREACH(tp, &taphead, tap_next) { mtx_lock(&tp->tap_mtx); if (tp->tap_flags & TAP_OPEN) { mtx_unlock(&tp->tap_mtx); mtx_unlock(&tapmtx); return (EBUSY); } mtx_unlock(&tp->tap_mtx); } mtx_unlock(&tapmtx); EVENTHANDLER_DEREGISTER(dev_clone, eh_tag); if_clone_detach(tap_cloner); if_clone_detach(vmnet_cloner); drain_dev_clone_events(); mtx_lock(&tapmtx); while ((tp = SLIST_FIRST(&taphead)) != NULL) { SLIST_REMOVE_HEAD(&taphead, tap_next); mtx_unlock(&tapmtx); ifp = tp->tap_ifp; TAPDEBUG("detaching %s\n", ifp->if_xname); tap_destroy(tp); mtx_lock(&tapmtx); } mtx_unlock(&tapmtx); clone_cleanup(&tapclones); mtx_destroy(&tapmtx); break; default: return (EOPNOTSUPP); } return (0); } /* tapmodevent */ /* * DEVFS handler * * We need to support two kind of devices - tap and vmnet */ static void tapclone(void *arg, struct ucred *cred, char *name, int namelen, struct cdev **dev) { char devname[SPECNAMELEN + 1]; int i, unit, append_unit; int extra; if (*dev != NULL) return; if (!tapdclone || (!tapuopen && priv_check_cred(cred, PRIV_NET_IFCREATE, 0) != 0)) return; unit = 0; append_unit = 0; extra = 0; /* We're interested in only tap/vmnet devices. */ if (strcmp(name, tapname) == 0) { unit = -1; } else if (strcmp(name, vmnetname) == 0) { unit = -1; extra = VMNET_DEV_MASK; } else if (dev_stdclone(name, NULL, tapname, &unit) != 1) { if (dev_stdclone(name, NULL, vmnetname, &unit) != 1) { return; } else { extra = VMNET_DEV_MASK; } } if (unit == -1) append_unit = 1; CURVNET_SET(CRED_TO_VNET(cred)); /* find any existing device, or allocate new unit number */ i = clone_create(&tapclones, &tap_cdevsw, &unit, dev, extra); if (i) { if (append_unit) { /* * We were passed 'tun' or 'tap', with no unit specified * so we'll need to append it now. */ namelen = snprintf(devname, sizeof(devname), "%s%d", name, unit); name = devname; } *dev = make_dev_credf(MAKEDEV_REF, &tap_cdevsw, unit | extra, cred, UID_ROOT, GID_WHEEL, 0600, "%s", name); } if_clone_create(name, namelen, NULL); CURVNET_RESTORE(); } /* tapclone */ /* * tapcreate * * to create interface */ static void tapcreate(struct cdev *dev) { struct ifnet *ifp = NULL; struct tap_softc *tp = NULL; unsigned short macaddr_hi; uint32_t macaddr_mid; int unit; const char *name = NULL; u_char eaddr[6]; /* allocate driver storage and create device */ tp = malloc(sizeof(*tp), M_TAP, M_WAITOK | M_ZERO); mtx_init(&tp->tap_mtx, "tap_mtx", NULL, MTX_DEF); mtx_lock(&tapmtx); SLIST_INSERT_HEAD(&taphead, tp, tap_next); mtx_unlock(&tapmtx); unit = dev2unit(dev); /* select device: tap or vmnet */ if (unit & VMNET_DEV_MASK) { name = vmnetname; tp->tap_flags |= TAP_VMNET; } else name = tapname; unit &= TAPMAXUNIT; TAPDEBUG("tapcreate(%s%d). minor = %#x\n", name, unit, dev2unit(dev)); /* generate fake MAC address: 00 bd xx xx xx unit_no */ macaddr_hi = htons(0x00bd); macaddr_mid = (uint32_t) ticks; bcopy(&macaddr_hi, eaddr, sizeof(short)); bcopy(&macaddr_mid, &eaddr[2], sizeof(uint32_t)); eaddr[5] = (u_char)unit; /* fill the rest and attach interface */ ifp = tp->tap_ifp = if_alloc(IFT_ETHER); if (ifp == NULL) panic("%s%d: can not if_alloc()", name, unit); ifp->if_softc = tp; if_initname(ifp, name, unit); ifp->if_init = tapifinit; ifp->if_start = tapifstart; ifp->if_ioctl = tapifioctl; ifp->if_mtu = ETHERMTU; ifp->if_flags = (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST); IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen); ifp->if_capabilities |= IFCAP_LINKSTATE; ifp->if_capenable |= IFCAP_LINKSTATE; dev->si_drv1 = tp; tp->tap_dev = dev; ether_ifattach(ifp, eaddr); mtx_lock(&tp->tap_mtx); tp->tap_flags |= TAP_INITED; mtx_unlock(&tp->tap_mtx); knlist_init_mtx(&tp->tap_rsel.si_note, &tp->tap_mtx); TAPDEBUG("interface %s is created. minor = %#x\n", ifp->if_xname, dev2unit(dev)); } /* tapcreate */ /* * tapopen * * to open tunnel. must be superuser */ static int tapopen(struct cdev *dev, int flag, int mode, struct thread *td) { struct tap_softc *tp = NULL; struct ifnet *ifp = NULL; int error; if (tapuopen == 0) { error = priv_check(td, PRIV_NET_TAP); if (error) return (error); } if ((dev2unit(dev) & CLONE_UNITMASK) > TAPMAXUNIT) return (ENXIO); tp = dev->si_drv1; mtx_lock(&tp->tap_mtx); if (tp->tap_flags & TAP_OPEN) { mtx_unlock(&tp->tap_mtx); return (EBUSY); } bcopy(IF_LLADDR(tp->tap_ifp), tp->ether_addr, sizeof(tp->ether_addr)); tp->tap_pid = td->td_proc->p_pid; tp->tap_flags |= TAP_OPEN; ifp = tp->tap_ifp; ifp->if_drv_flags |= IFF_DRV_RUNNING; ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; if (tapuponopen) ifp->if_flags |= IFF_UP; if_link_state_change(ifp, LINK_STATE_UP); mtx_unlock(&tp->tap_mtx); TAPDEBUG("%s is open. minor = %#x\n", ifp->if_xname, dev2unit(dev)); return (0); } /* tapopen */ /* * tapclose * * close the device - mark i/f down & delete routing info */ static int tapclose(struct cdev *dev, int foo, int bar, struct thread *td) { struct ifaddr *ifa; struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; /* junk all pending output */ mtx_lock(&tp->tap_mtx); CURVNET_SET(ifp->if_vnet); IF_DRAIN(&ifp->if_snd); /* * Do not bring the interface down, and do not anything with * interface, if we are in VMnet mode. Just close the device. */ if (((tp->tap_flags & TAP_VMNET) == 0) && (ifp->if_flags & (IFF_UP | IFF_LINK0)) == IFF_UP) { mtx_unlock(&tp->tap_mtx); if_down(ifp); mtx_lock(&tp->tap_mtx); if (ifp->if_drv_flags & IFF_DRV_RUNNING) { ifp->if_drv_flags &= ~IFF_DRV_RUNNING; mtx_unlock(&tp->tap_mtx); TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { rtinit(ifa, (int)RTM_DELETE, 0); } if_purgeaddrs(ifp); mtx_lock(&tp->tap_mtx); } } if_link_state_change(ifp, LINK_STATE_DOWN); CURVNET_RESTORE(); funsetown(&tp->tap_sigio); selwakeuppri(&tp->tap_rsel, PZERO+1); KNOTE_LOCKED(&tp->tap_rsel.si_note, 0); tp->tap_flags &= ~TAP_OPEN; tp->tap_pid = 0; mtx_unlock(&tp->tap_mtx); TAPDEBUG("%s is closed. minor = %#x\n", ifp->if_xname, dev2unit(dev)); return (0); } /* tapclose */ /* * tapifinit * * network interface initialization function */ static void tapifinit(void *xtp) { struct tap_softc *tp = (struct tap_softc *)xtp; struct ifnet *ifp = tp->tap_ifp; TAPDEBUG("initializing %s\n", ifp->if_xname); mtx_lock(&tp->tap_mtx); ifp->if_drv_flags |= IFF_DRV_RUNNING; ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; mtx_unlock(&tp->tap_mtx); /* attempt to start output */ tapifstart(ifp); } /* tapifinit */ /* * tapifioctl * * Process an ioctl request on network interface */ static int tapifioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { struct tap_softc *tp = ifp->if_softc; struct ifreq *ifr = (struct ifreq *)data; struct ifstat *ifs = NULL; struct ifmediareq *ifmr = NULL; int dummy, error = 0; switch (cmd) { case SIOCSIFFLAGS: /* XXX -- just like vmnet does */ case SIOCADDMULTI: case SIOCDELMULTI: break; case SIOCGIFMEDIA: ifmr = (struct ifmediareq *)data; dummy = ifmr->ifm_count; ifmr->ifm_count = 1; ifmr->ifm_status = IFM_AVALID; ifmr->ifm_active = IFM_ETHER; if (tp->tap_flags & TAP_OPEN) ifmr->ifm_status |= IFM_ACTIVE; ifmr->ifm_current = ifmr->ifm_active; if (dummy >= 1) { int media = IFM_ETHER; error = copyout(&media, ifmr->ifm_ulist, sizeof(int)); } break; case SIOCSIFMTU: ifp->if_mtu = ifr->ifr_mtu; break; case SIOCGIFSTATUS: ifs = (struct ifstat *)data; mtx_lock(&tp->tap_mtx); if (tp->tap_pid != 0) snprintf(ifs->ascii, sizeof(ifs->ascii), "\tOpened by PID %d\n", tp->tap_pid); else ifs->ascii[0] = '\0'; mtx_unlock(&tp->tap_mtx); break; default: error = ether_ioctl(ifp, cmd, data); break; } return (error); } /* tapifioctl */ /* * tapifstart * * queue packets from higher level ready to put out */ static void tapifstart(struct ifnet *ifp) { struct tap_softc *tp = ifp->if_softc; TAPDEBUG("%s starting\n", ifp->if_xname); /* * do not junk pending output if we are in VMnet mode. * XXX: can this do any harm because of queue overflow? */ mtx_lock(&tp->tap_mtx); if (((tp->tap_flags & TAP_VMNET) == 0) && ((tp->tap_flags & TAP_READY) != TAP_READY)) { struct mbuf *m; /* Unlocked read. */ TAPDEBUG("%s not ready, tap_flags = 0x%x\n", ifp->if_xname, tp->tap_flags); for (;;) { IF_DEQUEUE(&ifp->if_snd, m); if (m != NULL) { m_freem(m); if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); } else break; } mtx_unlock(&tp->tap_mtx); return; } ifp->if_drv_flags |= IFF_DRV_OACTIVE; if (!IFQ_IS_EMPTY(&ifp->if_snd)) { if (tp->tap_flags & TAP_RWAIT) { tp->tap_flags &= ~TAP_RWAIT; wakeup(tp); } if ((tp->tap_flags & TAP_ASYNC) && (tp->tap_sigio != NULL)) { mtx_unlock(&tp->tap_mtx); pgsigio(&tp->tap_sigio, SIGIO, 0); mtx_lock(&tp->tap_mtx); } selwakeuppri(&tp->tap_rsel, PZERO+1); KNOTE_LOCKED(&tp->tap_rsel.si_note, 0); if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); /* obytes are counted in ether_output */ } ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; mtx_unlock(&tp->tap_mtx); } /* tapifstart */ /* * tapioctl * * the cdevsw interface is now pretty minimal */ static int tapioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) { struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; struct tapinfo *tapp = NULL; int f; #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD4) int ival; #endif switch (cmd) { case TAPSIFINFO: tapp = (struct tapinfo *)data; if (ifp->if_type != tapp->type) return (EPROTOTYPE); mtx_lock(&tp->tap_mtx); ifp->if_mtu = tapp->mtu; ifp->if_baudrate = tapp->baudrate; mtx_unlock(&tp->tap_mtx); break; case TAPGIFINFO: tapp = (struct tapinfo *)data; mtx_lock(&tp->tap_mtx); tapp->mtu = ifp->if_mtu; tapp->type = ifp->if_type; tapp->baudrate = ifp->if_baudrate; mtx_unlock(&tp->tap_mtx); break; case TAPSDEBUG: tapdebug = *(int *)data; break; case TAPGDEBUG: *(int *)data = tapdebug; break; case TAPGIFNAME: { struct ifreq *ifr = (struct ifreq *) data; strlcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ); } break; case FIONBIO: break; case FIOASYNC: mtx_lock(&tp->tap_mtx); if (*(int *)data) tp->tap_flags |= TAP_ASYNC; else tp->tap_flags &= ~TAP_ASYNC; mtx_unlock(&tp->tap_mtx); break; case FIONREAD: if (!IFQ_IS_EMPTY(&ifp->if_snd)) { struct mbuf *mb; IFQ_LOCK(&ifp->if_snd); IFQ_POLL_NOLOCK(&ifp->if_snd, mb); for (*(int *)data = 0; mb != NULL; mb = mb->m_next) *(int *)data += mb->m_len; IFQ_UNLOCK(&ifp->if_snd); } else *(int *)data = 0; break; case FIOSETOWN: return (fsetown(*(int *)data, &tp->tap_sigio)); case FIOGETOWN: *(int *)data = fgetown(&tp->tap_sigio); return (0); /* this is deprecated, FIOSETOWN should be used instead */ case TIOCSPGRP: return (fsetown(-(*(int *)data), &tp->tap_sigio)); /* this is deprecated, FIOGETOWN should be used instead */ case TIOCGPGRP: *(int *)data = -fgetown(&tp->tap_sigio); return (0); /* VMware/VMnet port ioctl's */ #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD4) case _IO('V', 0): ival = IOCPARM_IVAL(data); data = (caddr_t)&ival; /* FALLTHROUGH */ #endif case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */ f = *(int *)data; f &= 0x0fff; f &= ~IFF_CANTCHANGE; f |= IFF_UP; mtx_lock(&tp->tap_mtx); ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE); mtx_unlock(&tp->tap_mtx); break; case SIOCGIFADDR: /* get MAC address of the remote side */ mtx_lock(&tp->tap_mtx); bcopy(tp->ether_addr, data, sizeof(tp->ether_addr)); mtx_unlock(&tp->tap_mtx); break; case SIOCSIFADDR: /* set MAC address of the remote side */ mtx_lock(&tp->tap_mtx); bcopy(data, tp->ether_addr, sizeof(tp->ether_addr)); mtx_unlock(&tp->tap_mtx); break; default: return (ENOTTY); } return (0); } /* tapioctl */ /* * tapread * * the cdevsw read interface - reads a packet at a time, or at * least as much of a packet as can be read */ static int tapread(struct cdev *dev, struct uio *uio, int flag) { struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; struct mbuf *m = NULL; int error = 0, len; TAPDEBUG("%s reading, minor = %#x\n", ifp->if_xname, dev2unit(dev)); mtx_lock(&tp->tap_mtx); if ((tp->tap_flags & TAP_READY) != TAP_READY) { mtx_unlock(&tp->tap_mtx); /* Unlocked read. */ TAPDEBUG("%s not ready. minor = %#x, tap_flags = 0x%x\n", ifp->if_xname, dev2unit(dev), tp->tap_flags); return (EHOSTDOWN); } tp->tap_flags &= ~TAP_RWAIT; /* sleep until we get a packet */ do { IF_DEQUEUE(&ifp->if_snd, m); if (m == NULL) { if (flag & O_NONBLOCK) { mtx_unlock(&tp->tap_mtx); return (EWOULDBLOCK); } tp->tap_flags |= TAP_RWAIT; error = mtx_sleep(tp, &tp->tap_mtx, PCATCH | (PZERO + 1), "taprd", 0); if (error) { mtx_unlock(&tp->tap_mtx); return (error); } } } while (m == NULL); mtx_unlock(&tp->tap_mtx); /* feed packet to bpf */ BPF_MTAP(ifp, m); /* xfer packet to user space */ while ((m != NULL) && (uio->uio_resid > 0) && (error == 0)) { len = min(uio->uio_resid, m->m_len); if (len == 0) break; error = uiomove(mtod(m, void *), len, uio); m = m_free(m); } if (m != NULL) { TAPDEBUG("%s dropping mbuf, minor = %#x\n", ifp->if_xname, dev2unit(dev)); m_freem(m); } return (error); } /* tapread */ /* * tapwrite * * the cdevsw write interface - an atomic write is a packet - or else! */ static int tapwrite(struct cdev *dev, struct uio *uio, int flag) { struct ether_header *eh; struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; struct mbuf *m; TAPDEBUG("%s writing, minor = %#x\n", ifp->if_xname, dev2unit(dev)); if (uio->uio_resid == 0) return (0); if ((uio->uio_resid < 0) || (uio->uio_resid > TAPMRU)) { TAPDEBUG("%s invalid packet len = %zd, minor = %#x\n", ifp->if_xname, uio->uio_resid, dev2unit(dev)); return (EIO); } if ((m = m_uiotombuf(uio, M_NOWAIT, 0, ETHER_ALIGN, M_PKTHDR)) == NULL) { if_inc_counter(ifp, IFCOUNTER_IERRORS, 1); return (ENOBUFS); } m->m_pkthdr.rcvif = ifp; /* * Only pass a unicast frame to ether_input(), if it would actually * have been received by non-virtual hardware. */ if (m->m_len < sizeof(struct ether_header)) { m_freem(m); return (0); } eh = mtod(m, struct ether_header *); if (eh && (ifp->if_flags & IFF_PROMISC) == 0 && !ETHER_IS_MULTICAST(eh->ether_dhost) && bcmp(eh->ether_dhost, IF_LLADDR(ifp), ETHER_ADDR_LEN) != 0) { m_freem(m); return (0); } /* Pass packet up to parent. */ CURVNET_SET(ifp->if_vnet); (*ifp->if_input)(ifp, m); CURVNET_RESTORE(); if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); /* ibytes are counted in parent */ return (0); } /* tapwrite */ /* * tappoll * * the poll interface, this is only useful on reads * really. the write detect always returns true, write never blocks * anyway, it either accepts the packet or drops it */ static int tappoll(struct cdev *dev, int events, struct thread *td) { struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; int revents = 0; TAPDEBUG("%s polling, minor = %#x\n", ifp->if_xname, dev2unit(dev)); if (events & (POLLIN | POLLRDNORM)) { IFQ_LOCK(&ifp->if_snd); if (!IFQ_IS_EMPTY(&ifp->if_snd)) { TAPDEBUG("%s have data in queue. len = %d, " \ "minor = %#x\n", ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev)); revents |= (events & (POLLIN | POLLRDNORM)); } else { TAPDEBUG("%s waiting for data, minor = %#x\n", ifp->if_xname, dev2unit(dev)); selrecord(td, &tp->tap_rsel); } IFQ_UNLOCK(&ifp->if_snd); } if (events & (POLLOUT | POLLWRNORM)) revents |= (events & (POLLOUT | POLLWRNORM)); return (revents); } /* tappoll */ /* * tap_kqfilter * * support for kevent() system call */ static int tapkqfilter(struct cdev *dev, struct knote *kn) { struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; switch (kn->kn_filter) { case EVFILT_READ: TAPDEBUG("%s kqfilter: EVFILT_READ, minor = %#x\n", ifp->if_xname, dev2unit(dev)); kn->kn_fop = &tap_read_filterops; break; case EVFILT_WRITE: TAPDEBUG("%s kqfilter: EVFILT_WRITE, minor = %#x\n", ifp->if_xname, dev2unit(dev)); kn->kn_fop = &tap_write_filterops; break; default: TAPDEBUG("%s kqfilter: invalid filter, minor = %#x\n", ifp->if_xname, dev2unit(dev)); return (EINVAL); /* NOT REACHED */ } kn->kn_hook = tp; knlist_add(&tp->tap_rsel.si_note, kn, 0); return (0); } /* tapkqfilter */ /* * tap_kqread * * Return true if there is data in the interface queue */ static int tapkqread(struct knote *kn, long hint) { int ret; struct tap_softc *tp = kn->kn_hook; struct cdev *dev = tp->tap_dev; struct ifnet *ifp = tp->tap_ifp; if ((kn->kn_data = ifp->if_snd.ifq_len) > 0) { TAPDEBUG("%s have data in queue. len = %d, minor = %#x\n", ifp->if_xname, ifp->if_snd.ifq_len, dev2unit(dev)); ret = 1; } else { TAPDEBUG("%s waiting for data, minor = %#x\n", ifp->if_xname, dev2unit(dev)); ret = 0; } return (ret); } /* tapkqread */ /* * tap_kqwrite * * Always can write. Return the MTU in kn->data */ static int tapkqwrite(struct knote *kn, long hint) { struct tap_softc *tp = kn->kn_hook; struct ifnet *ifp = tp->tap_ifp; kn->kn_data = ifp->if_mtu; return (1); } /* tapkqwrite */ static void tapkqdetach(struct knote *kn) { struct tap_softc *tp = kn->kn_hook; knlist_remove(&tp->tap_rsel.si_note, kn, 0); } /* tapkqdetach */