/*- * 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: head/sys/net/if_tap.c 147256 2005-06-10 16:49:24Z brooks $ * $Id: if_tap.c,v 0.21 2000/07/23 21:46:02 max Exp $ */ #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 #define CDEV_NAME "tap" #define TAPDEBUG if (tapdebug) printf #define TAP "tap" #define VMNET "vmnet" #define TAPMAXUNIT 0x7fff #define VMNET_DEV_MASK CLONE_FLAG0 /* module */ static int tapmodevent(module_t, int, void *); /* device */ static void tapclone(void *, 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 *); /* 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 struct cdevsw tap_cdevsw = { .d_version = D_VERSION, .d_flags = D_PSEUDO | D_NEEDGIANT, .d_open = tapopen, .d_close = tapclose, .d_read = tapread, .d_write = tapwrite, .d_ioctl = tapioctl, .d_poll = tappoll, .d_name = CDEV_NAME, }; /* * 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 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); 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, debug, CTLFLAG_RW, &tapdebug, 0, ""); DEV_MODULE(if_tap, tapmodevent, NULL); /* * tapmodevent * * module event handler */ static int tapmodevent(mod, type, data) module_t mod; int type; void *data; { static eventhandler_tag eh_tag = NULL; struct tap_softc *tp = NULL; struct ifnet *ifp = NULL; int s; 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); } 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); 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); /* Unlocked read. */ KASSERT(!(tp->tap_flags & TAP_OPEN), ("%s flags is out of sync", ifp->if_xname)); destroy_dev(tp->tap_dev); s = splimp(); ether_ifdetach(ifp); if_free_type(ifp, IFT_ETHER); splx(s); mtx_destroy(&tp->tap_mtx); free(tp, M_TAP); 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(arg, name, namelen, dev) void *arg; char *name; int namelen; struct cdev **dev; { u_int extra; int i, unit; char *device_name = name; if (*dev != NULL) return; device_name = TAP; extra = 0; if (strcmp(name, TAP) == 0) { unit = -1; } else if (strcmp(name, VMNET) == 0) { device_name = VMNET; extra = VMNET_DEV_MASK; unit = -1; } else if (dev_stdclone(name, NULL, device_name, &unit) != 1) { device_name = VMNET; extra = VMNET_DEV_MASK; if (dev_stdclone(name, NULL, device_name, &unit) != 1) return; } /* find any existing device, or allocate new unit number */ i = clone_create(&tapclones, &tap_cdevsw, &unit, dev, extra); if (i) { *dev = make_dev(&tap_cdevsw, unit2minor(unit | extra), UID_ROOT, GID_WHEEL, 0600, "%s%d", device_name, unit); if (*dev != NULL) { dev_ref(*dev); (*dev)->si_flags |= SI_CHEAPCLONE; } } } /* tapclone */ /* * tapcreate * * to create interface */ static void tapcreate(dev) struct cdev *dev; { struct ifnet *ifp = NULL; struct tap_softc *tp = NULL; unsigned short macaddr_hi; int unit, s; char *name = NULL; u_char eaddr[6]; dev->si_flags &= ~SI_CHEAPCLONE; /* allocate driver storage and create device */ MALLOC(tp, struct tap_softc *, 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 = VMNET; tp->tap_flags |= TAP_VMNET; } else name = TAP; unit &= TAPMAXUNIT; TAPDEBUG("tapcreate(%s%d). minor = %#x\n", name, unit, minor(dev)); /* generate fake MAC address: 00 bd xx xx xx unit_no */ macaddr_hi = htons(0x00bd); bcopy(&macaddr_hi, eaddr, sizeof(short)); bcopy(&ticks, &eaddr[2], sizeof(long)); 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); ifp->if_snd.ifq_maxlen = ifqmaxlen; dev->si_drv1 = tp; tp->tap_dev = dev; s = splimp(); ether_ifattach(ifp, eaddr); splx(s); mtx_lock(&tp->tap_mtx); tp->tap_flags |= TAP_INITED; mtx_unlock(&tp->tap_mtx); TAPDEBUG("interface %s is created. minor = %#x\n", ifp->if_xname, minor(dev)); } /* tapcreate */ /* * tapopen * * to open tunnel. must be superuser */ static int tapopen(dev, flag, mode, td) struct cdev *dev; int flag; int mode; struct thread *td; { struct tap_softc *tp = NULL; struct ifnet *ifp = NULL; int s; if (tapuopen == 0 && suser(td) != 0) return (EPERM); if ((dev2unit(dev) & CLONE_UNITMASK) > TAPMAXUNIT) return (ENXIO); /* * XXXRW: Non-atomic test-and-set of si_drv1. Currently protected * by Giant, but the race actually exists under memory pressure as * well even when running with Giant, as malloc() may sleep. */ tp = dev->si_drv1; if (tp == NULL) { tapcreate(dev); tp = dev->si_drv1; } mtx_lock(&tp->tap_mtx); if (tp->tap_flags & TAP_OPEN) { mtx_unlock(&tp->tap_mtx); return (EBUSY); } bcopy(IFP2ENADDR(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; mtx_unlock(&tp->tap_mtx); s = splimp(); ifp->if_flags |= IFF_RUNNING; ifp->if_flags &= ~IFF_OACTIVE; splx(s); TAPDEBUG("%s is open. minor = %#x\n", ifp->if_xname, minor(dev)); return (0); } /* tapopen */ /* * tapclose * * close the device - mark i/f down & delete routing info */ static int tapclose(dev, foo, bar, td) 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; int s; /* junk all pending output */ 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. */ mtx_lock(&tp->tap_mtx); if (((tp->tap_flags & TAP_VMNET) == 0) && (ifp->if_flags & IFF_UP)) { mtx_unlock(&tp->tap_mtx); s = splimp(); if_down(ifp); if (ifp->if_flags & IFF_RUNNING) { TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { rtinit(ifa, (int)RTM_DELETE, 0); } if_purgeaddrs(ifp); ifp->if_flags &= ~IFF_RUNNING; } splx(s); } else mtx_unlock(&tp->tap_mtx); funsetown(&tp->tap_sigio); selwakeuppri(&tp->tap_rsel, PZERO+1); mtx_lock(&tp->tap_mtx); tp->tap_flags &= ~TAP_OPEN; tp->tap_pid = 0; mtx_unlock(&tp->tap_mtx); TAPDEBUG("%s is closed. minor = %#x\n", ifp->if_xname, minor(dev)); return (0); } /* tapclose */ /* * tapifinit * * network interface initialization function */ static void tapifinit(xtp) void *xtp; { struct tap_softc *tp = (struct tap_softc *)xtp; struct ifnet *ifp = tp->tap_ifp; TAPDEBUG("initializing %s\n", ifp->if_xname); ifp->if_flags |= IFF_RUNNING; ifp->if_flags &= ~IFF_OACTIVE; /* attempt to start output */ tapifstart(ifp); } /* tapifinit */ /* * tapifioctl * * Process an ioctl request on network interface */ static int tapifioctl(ifp, cmd, data) struct ifnet *ifp; u_long cmd; caddr_t data; { struct tap_softc *tp = (struct tap_softc *)(ifp->if_softc); struct ifstat *ifs = NULL; int s, dummy; switch (cmd) { case SIOCSIFFLAGS: /* XXX -- just like vmnet does */ case SIOCADDMULTI: case SIOCDELMULTI: break; case SIOCGIFSTATUS: s = splimp(); ifs = (struct ifstat *)data; dummy = strlen(ifs->ascii); mtx_lock(&tp->tap_mtx); if (tp->tap_pid != 0 && dummy < sizeof(ifs->ascii)) snprintf(ifs->ascii + dummy, sizeof(ifs->ascii) - dummy, "\tOpened by PID %d\n", tp->tap_pid); mtx_unlock(&tp->tap_mtx); splx(s); break; default: s = splimp(); dummy = ether_ioctl(ifp, cmd, data); splx(s); return (dummy); } return (0); } /* tapifioctl */ /* * tapifstart * * queue packets from higher level ready to put out */ static void tapifstart(ifp) struct ifnet *ifp; { struct tap_softc *tp = ifp->if_softc; int s; 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 = NULL; mtx_unlock(&tp->tap_mtx); /* Unlocked read. */ TAPDEBUG("%s not ready, tap_flags = 0x%x\n", ifp->if_xname, tp->tap_flags); s = splimp(); do { IF_DEQUEUE(&ifp->if_snd, m); if (m != NULL) m_freem(m); ifp->if_oerrors ++; } while (m != NULL); splx(s); return; } mtx_unlock(&tp->tap_mtx); s = splimp(); ifp->if_flags |= IFF_OACTIVE; if (ifp->if_snd.ifq_len != 0) { mtx_lock(&tp->tap_mtx); 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); } else mtx_unlock(&tp->tap_mtx); selwakeuppri(&tp->tap_rsel, PZERO+1); ifp->if_opackets ++; /* obytes are counted in ether_output */ } ifp->if_flags &= ~IFF_OACTIVE; splx(s); } /* tapifstart */ /* * tapioctl * * the cdevsw interface is now pretty minimal */ static int tapioctl(dev, cmd, data, flag, td) 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 s; int f; switch (cmd) { case TAPSIFINFO: s = splimp(); tapp = (struct tapinfo *)data; ifp->if_mtu = tapp->mtu; ifp->if_type = tapp->type; ifp->if_baudrate = tapp->baudrate; splx(s); break; case TAPGIFINFO: tapp = (struct tapinfo *)data; tapp->mtu = ifp->if_mtu; tapp->type = ifp->if_type; tapp->baudrate = ifp->if_baudrate; break; case TAPSDEBUG: tapdebug = *(int *)data; break; case TAPGDEBUG: *(int *)data = tapdebug; break; case FIONBIO: break; case FIOASYNC: s = splimp(); mtx_lock(&tp->tap_mtx); if (*(int *)data) tp->tap_flags |= TAP_ASYNC; else tp->tap_flags &= ~TAP_ASYNC; mtx_unlock(&tp->tap_mtx); splx(s); break; case FIONREAD: s = splimp(); if (ifp->if_snd.ifq_head) { struct mbuf *mb = ifp->if_snd.ifq_head; for(*(int *)data = 0;mb != NULL;mb = mb->m_next) *(int *)data += mb->m_len; } else *(int *)data = 0; splx(s); 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 */ case SIOCGIFFLAGS: /* get ifnet flags */ bcopy(&ifp->if_flags, data, sizeof(ifp->if_flags)); break; case VMIO_SIOCSIFFLAGS: /* VMware/VMnet SIOCSIFFLAGS */ f = *(int *)data; f &= 0x0fff; f &= ~IFF_CANTCHANGE; f |= IFF_UP; s = splimp(); ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE); splx(s); break; case OSIOCGIFADDR: /* get MAC address of the remote side */ case SIOCGIFADDR: 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(dev, uio, flag) 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, s; TAPDEBUG("%s reading, minor = %#x\n", ifp->if_xname, minor(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, minor(dev), tp->tap_flags); return (EHOSTDOWN); } tp->tap_flags &= ~TAP_RWAIT; mtx_unlock(&tp->tap_mtx); /* sleep until we get a packet */ do { s = splimp(); IF_DEQUEUE(&ifp->if_snd, m); splx(s); if (m == NULL) { if (flag & O_NONBLOCK) return (EWOULDBLOCK); mtx_lock(&tp->tap_mtx); tp->tap_flags |= TAP_RWAIT; mtx_unlock(&tp->tap_mtx); error = tsleep(tp,PCATCH|(PZERO+1),"taprd",0); if (error) return (error); } } while (m == NULL); /* 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, minor(dev)); m_freem(m); } return (error); } /* tapread */ /* * tapwrite * * the cdevsw write interface - an atomic write is a packet - or else! */ static int tapwrite(dev, uio, flag) struct cdev *dev; struct uio *uio; int flag; { struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; struct mbuf *m; int error = 0; TAPDEBUG("%s writting, minor = %#x\n", ifp->if_xname, minor(dev)); if (uio->uio_resid == 0) return (0); if ((uio->uio_resid < 0) || (uio->uio_resid > TAPMRU)) { TAPDEBUG("%s invalid packet len = %d, minor = %#x\n", ifp->if_xname, uio->uio_resid, minor(dev)); return (EIO); } if ((m = m_uiotombuf(uio, M_DONTWAIT, 0, ETHER_ALIGN)) == NULL) { ifp->if_ierrors ++; return (error); } m->m_pkthdr.rcvif = ifp; /* Pass packet up to parent. */ (*ifp->if_input)(ifp, m); ifp->if_ipackets ++; /* 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(dev, events, td) struct cdev *dev; int events; struct thread *td; { struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; int s, revents = 0; TAPDEBUG("%s polling, minor = %#x\n", ifp->if_xname, minor(dev)); s = splimp(); if (events & (POLLIN | POLLRDNORM)) { if (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, minor(dev)); revents |= (events & (POLLIN | POLLRDNORM)); } else { TAPDEBUG("%s waiting for data, minor = %#x\n", ifp->if_xname, minor(dev)); selrecord(td, &tp->tap_rsel); } } if (events & (POLLOUT | POLLWRNORM)) revents |= (events & (POLLOUT | POLLWRNORM)); splx(s); return (revents); } /* tappoll */