/* $NetBSD: if_tun.c,v 1.173.4.3 2024/09/21 12:17:27 martin Exp $ */ /* * Copyright (c) 1988, Julian Onions * Nottingham University 1987. * * This source may be freely distributed, however I would be interested * in any changes that are made. * * This driver takes packets off the IP i/f and hands them up to a * user process to have its wicked way with. This driver has its * roots in a similar driver written by Phil Cockcroft (formerly) at * UCL. This driver is based much more on read/write/poll mode of * operation though. */ /* * tun - tunnel software network interface. */ #include __KERNEL_RCSID(0, "$NetBSD: if_tun.c,v 1.173.4.3 2024/09/21 12:17:27 martin Exp $"); #ifdef _KERNEL_OPT #include "opt_inet.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #include #include #include #endif #include #include "ioconf.h" #define TUNDEBUG if (tundebug) printf int tundebug = 0; extern int ifqmaxlen; static LIST_HEAD(, tun_softc) tun_softc_list; static LIST_HEAD(, tun_softc) tunz_softc_list; static kmutex_t tun_softc_lock; static int tun_ioctl(struct ifnet *, u_long, void *); static int tun_output(struct ifnet *, struct mbuf *, const struct sockaddr *, const struct rtentry *rt); static int tun_clone_create(struct if_clone *, int); static int tun_clone_destroy(struct ifnet *); static struct if_clone tun_cloner = IF_CLONE_INITIALIZER("tun", tun_clone_create, tun_clone_destroy); static void tunattach0(struct tun_softc *); static void tun_enable(struct tun_softc *, const struct ifaddr *); static void tun_i_softintr(void *); static void tun_o_softintr(void *); #ifdef ALTQ static void tunstart(struct ifnet *); #endif static struct tun_softc *tun_find_unit(dev_t); static struct tun_softc *tun_find_zunit(int); static dev_type_open(tunopen); static dev_type_close(tunclose); static dev_type_read(tunread); static dev_type_write(tunwrite); static dev_type_ioctl(tunioctl); static dev_type_poll(tunpoll); static dev_type_kqfilter(tunkqfilter); const struct cdevsw tun_cdevsw = { .d_open = tunopen, .d_close = tunclose, .d_read = tunread, .d_write = tunwrite, .d_ioctl = tunioctl, .d_stop = nostop, .d_tty = notty, .d_poll = tunpoll, .d_mmap = nommap, .d_kqfilter = tunkqfilter, .d_discard = nodiscard, .d_flag = D_OTHER | D_MPSAFE }; #ifdef _MODULE devmajor_t tun_bmajor = -1, tun_cmajor = -1; #endif void tunattach(int unused) { /* * Nothing to do here, initialization is handled by the * module initialization code in tuninit() below). */ } static void tuninit(void) { mutex_init(&tun_softc_lock, MUTEX_DEFAULT, IPL_NONE); LIST_INIT(&tun_softc_list); LIST_INIT(&tunz_softc_list); if_clone_attach(&tun_cloner); #ifdef _MODULE devsw_attach("tun", NULL, &tun_bmajor, &tun_cdevsw, &tun_cmajor); #endif } static int tundetach(void) { if_clone_detach(&tun_cloner); #ifdef _MODULE devsw_detach(NULL, &tun_cdevsw); #endif if (!LIST_EMPTY(&tun_softc_list) || !LIST_EMPTY(&tunz_softc_list)) { #ifdef _MODULE devsw_attach("tun", NULL, &tun_bmajor, &tun_cdevsw, &tun_cmajor); #endif if_clone_attach(&tun_cloner); return EBUSY; } mutex_destroy(&tun_softc_lock); return 0; } /* * Find driver instance from dev_t. * Returns with tp locked (if found). */ static struct tun_softc * tun_find_unit(dev_t dev) { struct tun_softc *tp; int unit = minor(dev); mutex_enter(&tun_softc_lock); LIST_FOREACH(tp, &tun_softc_list, tun_list) if (unit == tp->tun_unit) break; if (tp) mutex_enter(&tp->tun_lock); mutex_exit(&tun_softc_lock); return tp; } /* * Find zombie driver instance by unit number. * Remove tp from list and return it unlocked (if found). */ static struct tun_softc * tun_find_zunit(int unit) { struct tun_softc *tp; mutex_enter(&tun_softc_lock); LIST_FOREACH(tp, &tunz_softc_list, tun_list) if (unit == tp->tun_unit) break; if (tp) LIST_REMOVE(tp, tun_list); mutex_exit(&tun_softc_lock); KASSERTMSG(!tp || (tp->tun_flags & (TUN_INITED|TUN_OPEN)) == TUN_OPEN, "tun%d: inconsistent flags: %x", unit, tp->tun_flags); return tp; } static void tun_init(struct tun_softc *tp, int unit) { tp->tun_unit = unit; mutex_init(&tp->tun_lock, MUTEX_DEFAULT, IPL_SOFTNET); cv_init(&tp->tun_cv, "tunread"); selinit(&tp->tun_rsel); selinit(&tp->tun_wsel); tp->tun_osih = softint_establish(SOFTINT_CLOCK, tun_o_softintr, tp); tp->tun_isih = softint_establish(SOFTINT_CLOCK, tun_i_softintr, tp); } static void tun_fini(struct tun_softc *tp) { softint_disestablish(tp->tun_isih); softint_disestablish(tp->tun_osih); seldestroy(&tp->tun_wsel); seldestroy(&tp->tun_rsel); mutex_destroy(&tp->tun_lock); cv_destroy(&tp->tun_cv); } static struct tun_softc * tun_alloc(int unit) { struct tun_softc *tp; tp = kmem_zalloc(sizeof(*tp), KM_SLEEP); tun_init(tp, unit); return tp; } static void tun_recycle(struct tun_softc *tp) { memset(&tp->tun_if, 0, sizeof(struct ifnet)); /* XXX ??? */ } static void tun_free(struct tun_softc *tp) { tun_fini(tp); kmem_free(tp, sizeof(*tp)); } static int tun_clone_create(struct if_clone *ifc, int unit) { struct tun_softc *tp; if ((tp = tun_find_zunit(unit)) == NULL) { tp = tun_alloc(unit); } else { tun_recycle(tp); } if_initname(&tp->tun_if, ifc->ifc_name, unit); tunattach0(tp); tp->tun_flags |= TUN_INITED; mutex_enter(&tun_softc_lock); LIST_INSERT_HEAD(&tun_softc_list, tp, tun_list); mutex_exit(&tun_softc_lock); return 0; } static void tunattach0(struct tun_softc *tp) { struct ifnet *ifp; ifp = &tp->tun_if; ifp->if_softc = tp; ifp->if_mtu = TUNMTU; ifp->if_ioctl = tun_ioctl; ifp->if_output = tun_output; #ifdef ALTQ ifp->if_start = tunstart; #endif ifp->if_flags = IFF_POINTOPOINT; ifp->if_type = IFT_TUNNEL; ifp->if_snd.ifq_maxlen = ifqmaxlen; ifp->if_dlt = DLT_NULL; IFQ_SET_READY(&ifp->if_snd); if_attach(ifp); ifp->if_link_state = LINK_STATE_DOWN; if_alloc_sadl(ifp); bpf_attach(ifp, DLT_NULL, sizeof(uint32_t)); } static int tun_clone_destroy(struct ifnet *ifp) { struct tun_softc *tp = (void *)ifp; bool zombie = false; IF_PURGE(&ifp->if_snd); ifp->if_flags &= ~IFF_RUNNING; mutex_enter(&tun_softc_lock); mutex_enter(&tp->tun_lock); LIST_REMOVE(tp, tun_list); if (tp->tun_flags & TUN_OPEN) { /* Hang on to storage until last close. */ tp->tun_flags &= ~TUN_INITED; LIST_INSERT_HEAD(&tunz_softc_list, tp, tun_list); zombie = true; } mutex_exit(&tun_softc_lock); cv_broadcast(&tp->tun_cv); if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) fownsignal(tp->tun_pgid, SIGIO, POLL_HUP, 0, NULL); selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); mutex_exit(&tp->tun_lock); bpf_detach(ifp); if_detach(ifp); if (!zombie) { tun_free(tp); } return 0; } /* * tunnel open - must be superuser & the device must be * configured in */ static int tunopen(dev_t dev, int flag, int mode, struct lwp *l) { struct ifnet *ifp; struct tun_softc *tp; int error; error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE_TUN, KAUTH_REQ_NETWORK_INTERFACE_TUN_ADD, NULL, NULL, NULL); if (error) return error; tp = tun_find_unit(dev); if (tp == NULL) { (void)tun_clone_create(&tun_cloner, minor(dev)); tp = tun_find_unit(dev); if (tp == NULL) { return ENXIO; } } if (tp->tun_flags & TUN_OPEN) { mutex_exit(&tp->tun_lock); return EBUSY; } ifp = &tp->tun_if; tp->tun_flags |= TUN_OPEN; TUNDEBUG("%s: open\n", ifp->if_xname); if_link_state_change(ifp, LINK_STATE_UP); mutex_exit(&tp->tun_lock); return error; } /* * tunclose - close the device - mark i/f down & delete * routing info */ int tunclose(dev_t dev, int flag, int mode, struct lwp *l) { struct tun_softc *tp; struct ifnet *ifp; if ((tp = tun_find_zunit(minor(dev))) != NULL) { /* interface was "destroyed" before the close */ tun_free(tp); return 0; } if ((tp = tun_find_unit(dev)) == NULL) goto out_nolock; ifp = &tp->tun_if; tp->tun_flags &= ~TUN_OPEN; tp->tun_pgid = 0; selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); TUNDEBUG ("%s: closed\n", ifp->if_xname); mutex_exit(&tp->tun_lock); /* * junk all pending output */ IFQ_PURGE(&ifp->if_snd); if (ifp->if_flags & IFF_UP) { if_down(ifp); if (ifp->if_flags & IFF_RUNNING) { /* find internet addresses and delete routes */ struct ifaddr *ifa; IFADDR_READER_FOREACH(ifa, ifp) { #if defined(INET) || defined(INET6) if (ifa->ifa_addr->sa_family == AF_INET || ifa->ifa_addr->sa_family == AF_INET6) { rtinit(ifa, (int)RTM_DELETE, tp->tun_flags & TUN_DSTADDR ? RTF_HOST : 0); } #endif } } } if_link_state_change(ifp, LINK_STATE_DOWN); out_nolock: return 0; } static void tun_enable(struct tun_softc *tp, const struct ifaddr *ifa) { struct ifnet *ifp = &tp->tun_if; TUNDEBUG("%s: %s\n", __func__, ifp->if_xname); mutex_enter(&tp->tun_lock); tp->tun_flags &= ~(TUN_IASET|TUN_DSTADDR); switch (ifa->ifa_addr->sa_family) { #ifdef INET case AF_INET: { struct sockaddr_in *sin; sin = satosin(ifa->ifa_addr); if (sin && sin->sin_addr.s_addr) tp->tun_flags |= TUN_IASET; if (ifp->if_flags & IFF_POINTOPOINT) { sin = satosin(ifa->ifa_dstaddr); if (sin && sin->sin_addr.s_addr) tp->tun_flags |= TUN_DSTADDR; } break; } #endif #ifdef INET6 case AF_INET6: { struct sockaddr_in6 *sin; sin = satosin6(ifa->ifa_addr); if (!IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) tp->tun_flags |= TUN_IASET; if (ifp->if_flags & IFF_POINTOPOINT) { sin = satosin6(ifa->ifa_dstaddr); if (sin && !IN6_IS_ADDR_UNSPECIFIED(&sin->sin6_addr)) tp->tun_flags |= TUN_DSTADDR; } else tp->tun_flags &= ~TUN_DSTADDR; break; } #endif /* INET6 */ default: break; } ifp->if_flags |= IFF_UP | IFF_RUNNING; mutex_exit(&tp->tun_lock); } /* * Process an ioctl request. */ static int tun_ioctl(struct ifnet *ifp, u_long cmd, void *data) { struct tun_softc *tp = (struct tun_softc *)(ifp->if_softc); struct ifreq *ifr = (struct ifreq *)data; struct ifaddr *ifa = (struct ifaddr *)data; int error = 0; switch (cmd) { case SIOCINITIFADDR: tun_enable(tp, ifa); ifa->ifa_rtrequest = p2p_rtrequest; TUNDEBUG("%s: address set\n", ifp->if_xname); break; case SIOCSIFBRDADDR: TUNDEBUG("%s: broadcast address set\n", ifp->if_xname); break; case SIOCSIFMTU: if (ifr->ifr_mtu > TUNMTU || ifr->ifr_mtu < 576) { error = EINVAL; break; } TUNDEBUG("%s: interface mtu set\n", ifp->if_xname); if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) error = 0; break; case SIOCADDMULTI: case SIOCDELMULTI: if (ifr == NULL) { error = EAFNOSUPPORT; /* XXX */ break; } switch (ifreq_getaddr(cmd, ifr)->sa_family) { #ifdef INET case AF_INET: break; #endif #ifdef INET6 case AF_INET6: break; #endif default: error = EAFNOSUPPORT; break; } break; default: error = ifioctl_common(ifp, cmd, data); } return error; } /* * tun_output - queue packets from higher level ready to put out. */ static int tun_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst, const struct rtentry *rt) { struct tun_softc *tp = ifp->if_softc; int error; #if defined(INET) || defined(INET6) int mlen; uint32_t *af; #endif mutex_enter(&tp->tun_lock); TUNDEBUG ("%s: tun_output\n", ifp->if_xname); if ((tp->tun_flags & TUN_READY) != TUN_READY) { TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); error = EHOSTDOWN; mutex_exit(&tp->tun_lock); goto out; } // XXXrmind mutex_exit(&tp->tun_lock); /* * if the queueing discipline needs packet classification, * do it before prepending link headers. */ IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family); bpf_mtap_af(ifp, dst->sa_family, m0, BPF_D_OUT); if ((error = pfil_run_hooks(ifp->if_pfil, &m0, ifp, PFIL_OUT)) != 0) goto out; if (m0 == NULL) goto out; switch(dst->sa_family) { #ifdef INET6 case AF_INET6: #endif #ifdef INET case AF_INET: #endif #if defined(INET) || defined(INET6) if (tp->tun_flags & TUN_PREPADDR) { /* Simple link-layer header */ M_PREPEND(m0, dst->sa_len, M_DONTWAIT); if (m0 == NULL) { IF_DROP(&ifp->if_snd); error = ENOBUFS; goto out; } memcpy(mtod(m0, char *), dst, dst->sa_len); } else if (tp->tun_flags & TUN_IFHEAD) { /* Prepend the address family */ M_PREPEND(m0, sizeof(*af), M_DONTWAIT); if (m0 == NULL) { IF_DROP(&ifp->if_snd); error = ENOBUFS; goto out; } af = mtod(m0,uint32_t *); *af = htonl(dst->sa_family); } else { #ifdef INET if (dst->sa_family != AF_INET) #endif { error = EAFNOSUPPORT; goto out; } } /* FALLTHROUGH */ case AF_UNSPEC: mlen = m0->m_pkthdr.len; IFQ_ENQUEUE(&ifp->if_snd, m0, error); if (error) { if_statinc(ifp, if_collisions); error = EAFNOSUPPORT; m0 = NULL; goto out; } if_statadd2(ifp, if_opackets, 1, if_obytes, mlen); break; #endif default: error = EAFNOSUPPORT; goto out; } mutex_enter(&tp->tun_lock); cv_broadcast(&tp->tun_cv); if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) softint_schedule(tp->tun_isih); selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); mutex_exit(&tp->tun_lock); out: if (error && m0) m_freem(m0); return error; } static void tun_i_softintr(void *cookie) { struct tun_softc *tp = cookie; if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) fownsignal(tp->tun_pgid, SIGIO, POLL_IN, POLLIN|POLLRDNORM, NULL); } static void tun_o_softintr(void *cookie) { struct tun_softc *tp = cookie; if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) fownsignal(tp->tun_pgid, SIGIO, POLL_OUT, POLLOUT|POLLWRNORM, NULL); } /* * the cdevsw interface is now pretty minimal. */ int tunioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) { struct tun_softc *tp; int error = 0; tp = tun_find_unit(dev); /* interface was "destroyed" already */ if (tp == NULL) { return ENXIO; } switch (cmd) { case TUNSDEBUG: tundebug = *(int *)data; break; case TUNGDEBUG: *(int *)data = tundebug; break; case TUNSIFMODE: switch (*(int *)data & (IFF_POINTOPOINT|IFF_BROADCAST)) { case IFF_POINTOPOINT: case IFF_BROADCAST: if (tp->tun_if.if_flags & IFF_UP) { error = EBUSY; goto out; } tp->tun_if.if_flags &= ~(IFF_BROADCAST|IFF_POINTOPOINT|IFF_MULTICAST); tp->tun_if.if_flags |= *(int *)data; break; default: error = EINVAL; goto out; } break; case TUNSLMODE: if (*(int *)data) { tp->tun_flags |= TUN_PREPADDR; tp->tun_flags &= ~TUN_IFHEAD; } else tp->tun_flags &= ~TUN_PREPADDR; break; case TUNSIFHEAD: if (*(int *)data) { tp->tun_flags |= TUN_IFHEAD; tp->tun_flags &= ~TUN_PREPADDR; } else tp->tun_flags &= ~TUN_IFHEAD; break; case TUNGIFHEAD: *(int *)data = (tp->tun_flags & TUN_IFHEAD); break; case FIONBIO: if (*(int *)data) tp->tun_flags |= TUN_NBIO; else tp->tun_flags &= ~TUN_NBIO; break; case FIOASYNC: if (*(int *)data) tp->tun_flags |= TUN_ASYNC; else tp->tun_flags &= ~TUN_ASYNC; break; case FIONREAD: if (tp->tun_if.if_snd.ifq_head) *(int *)data = tp->tun_if.if_snd.ifq_head->m_pkthdr.len; else *(int *)data = 0; break; case TIOCSPGRP: case FIOSETOWN: error = fsetown(&tp->tun_pgid, cmd, data); break; case TIOCGPGRP: case FIOGETOWN: error = fgetown(tp->tun_pgid, cmd, data); break; default: error = ENOTTY; } out: mutex_exit(&tp->tun_lock); return error; } /* * The cdevsw read interface - reads a packet at a time, or at * least as much of a packet as can be read. */ int tunread(dev_t dev, struct uio *uio, int ioflag) { struct tun_softc *tp; struct ifnet *ifp; struct mbuf *m, *m0; int error = 0, len; tp = tun_find_unit(dev); /* interface was "destroyed" already */ if (tp == NULL) { return ENXIO; } ifp = &tp->tun_if; TUNDEBUG ("%s: read\n", ifp->if_xname); if ((tp->tun_flags & TUN_READY) != TUN_READY) { TUNDEBUG ("%s: not ready 0%o\n", ifp->if_xname, tp->tun_flags); error = EHOSTDOWN; goto out; } do { IFQ_DEQUEUE(&ifp->if_snd, m0); if (m0 == 0) { if (tp->tun_flags & TUN_NBIO) { error = EWOULDBLOCK; goto out; } if (cv_wait_sig(&tp->tun_cv, &tp->tun_lock)) { error = EINTR; goto out; } } } while (m0 == 0); mutex_exit(&tp->tun_lock); /* Copy the mbuf chain */ while (m0 && uio->uio_resid > 0 && error == 0) { len = uimin(uio->uio_resid, m0->m_len); if (len != 0) error = uiomove(mtod(m0, void *), len, uio); m0 = m = m_free(m0); } if (m0) { TUNDEBUG("Dropping mbuf\n"); m_freem(m0); } if (error) if_statinc(ifp, if_ierrors); return error; out: mutex_exit(&tp->tun_lock); return error; } /* * the cdevsw write interface - an atomic write is a packet - or else! */ int tunwrite(dev_t dev, struct uio *uio, int ioflag) { struct tun_softc *tp; struct ifnet *ifp; struct mbuf *top, **mp, *m; pktqueue_t *pktq; struct sockaddr dst; int error = 0, tlen, mlen; uint32_t family; tp = tun_find_unit(dev); if (tp == NULL) { /* Interface was "destroyed" already. */ return ENXIO; } /* Unlock until we've got the data */ mutex_exit(&tp->tun_lock); ifp = &tp->tun_if; TUNDEBUG("%s: tunwrite\n", ifp->if_xname); if (tp->tun_flags & TUN_PREPADDR) { if (uio->uio_resid < sizeof(dst)) { error = EIO; goto out0; } error = uiomove((void *)&dst, sizeof(dst), uio); if (error) goto out0; if (dst.sa_len > sizeof(dst)) { /* Duh.. */ int n = dst.sa_len - sizeof(dst); while (n--) { char discard; error = uiomove(&discard, 1, uio); if (error) { goto out0; } } } } else if (tp->tun_flags & TUN_IFHEAD) { if (uio->uio_resid < sizeof(family)){ error = EIO; goto out0; } error = uiomove((void *)&family, sizeof(family), uio); if (error) goto out0; dst.sa_family = ntohl(family); } else { #ifdef INET dst.sa_family = AF_INET; #endif } if (uio->uio_resid == 0 || uio->uio_resid > TUNMTU) { TUNDEBUG("%s: len=%lu!\n", ifp->if_xname, (unsigned long)uio->uio_resid); error = EIO; goto out0; } switch (dst.sa_family) { #ifdef INET case AF_INET: pktq = ip_pktq; break; #endif #ifdef INET6 case AF_INET6: pktq = ip6_pktq; break; #endif default: error = EAFNOSUPPORT; goto out0; } tlen = uio->uio_resid; /* get a header mbuf */ MGETHDR(m, M_DONTWAIT, MT_DATA); if (m == NULL) { error = ENOBUFS; goto out0; } mlen = MHLEN; top = NULL; mp = ⊤ while (error == 0 && uio->uio_resid > 0) { m->m_len = uimin(mlen, uio->uio_resid); error = uiomove(mtod(m, void *), m->m_len, uio); *mp = m; mp = &m->m_next; if (error == 0 && uio->uio_resid > 0) { MGET(m, M_DONTWAIT, MT_DATA); if (m == NULL) { error = ENOBUFS; break; } mlen = MLEN; } } if (error) { if (top != NULL) m_freem(top); if_statinc(ifp, if_ierrors); goto out0; } top->m_pkthdr.len = tlen; m_set_rcvif(top, ifp); bpf_mtap_af(ifp, dst.sa_family, top, BPF_D_IN); if ((error = pfil_run_hooks(ifp->if_pfil, &top, ifp, PFIL_IN)) != 0) goto out0; if (top == NULL) goto out0; mutex_enter(&tp->tun_lock); if ((tp->tun_flags & TUN_INITED) == 0) { /* Interface was destroyed */ error = ENXIO; goto out; } kpreempt_disable(); if (__predict_false(!pktq_enqueue(pktq, top, 0))) { kpreempt_enable(); if_statinc(ifp, if_collisions); mutex_exit(&tp->tun_lock); error = ENOBUFS; m_freem(top); goto out0; } kpreempt_enable(); if_statadd2(ifp, if_ipackets, 1, if_ibytes, tlen); out: mutex_exit(&tp->tun_lock); out0: return error; } #ifdef ALTQ /* * Start packet transmission on the interface. * when the interface queue is rate-limited by ALTQ or TBR, * if_start is needed to drain packets from the queue in order * to notify readers when outgoing packets become ready. */ static void tunstart(struct ifnet *ifp) { struct tun_softc *tp = ifp->if_softc; if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd)) return; mutex_enter(&tp->tun_lock); if (!IF_IS_EMPTY(&ifp->if_snd)) { cv_broadcast(&tp->tun_cv); if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid) softint_schedule(tp->tun_osih); selnotify(&tp->tun_rsel, 0, NOTE_SUBMIT); } mutex_exit(&tp->tun_lock); } #endif /* ALTQ */ /* * tunpoll - 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. */ int tunpoll(dev_t dev, int events, struct lwp *l) { struct tun_softc *tp; struct ifnet *ifp; int revents = 0; tp = tun_find_unit(dev); if (tp == NULL) { /* Interface was "destroyed" already. */ return 0; } ifp = &tp->tun_if; TUNDEBUG("%s: tunpoll\n", ifp->if_xname); if (events & (POLLIN | POLLRDNORM)) { if (!IFQ_IS_EMPTY(&ifp->if_snd)) { TUNDEBUG("%s: tunpoll q=%d\n", ifp->if_xname, ifp->if_snd.ifq_len); revents |= events & (POLLIN | POLLRDNORM); } else { TUNDEBUG("%s: tunpoll waiting\n", ifp->if_xname); selrecord(l, &tp->tun_rsel); } } if (events & (POLLOUT | POLLWRNORM)) revents |= events & (POLLOUT | POLLWRNORM); mutex_exit(&tp->tun_lock); return revents; } static void filt_tunrdetach(struct knote *kn) { struct tun_softc *tp = kn->kn_hook; mutex_enter(&tp->tun_lock); selremove_knote(&tp->tun_rsel, kn); mutex_exit(&tp->tun_lock); } static int filt_tunread(struct knote *kn, long hint) { struct tun_softc *tp = kn->kn_hook; struct ifnet *ifp = &tp->tun_if; struct mbuf *m; int ready; if (hint & NOTE_SUBMIT) KASSERT(mutex_owned(&tp->tun_lock)); else mutex_enter(&tp->tun_lock); IF_POLL(&ifp->if_snd, m); ready = (m != NULL); for (kn->kn_data = 0; m != NULL; m = m->m_next) kn->kn_data += m->m_len; if (hint & NOTE_SUBMIT) KASSERT(mutex_owned(&tp->tun_lock)); else mutex_exit(&tp->tun_lock); return ready; } static const struct filterops tunread_filtops = { .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE, .f_attach = NULL, .f_detach = filt_tunrdetach, .f_event = filt_tunread, }; int tunkqfilter(dev_t dev, struct knote *kn) { struct tun_softc *tp; int rv = 0; tp = tun_find_unit(dev); if (tp == NULL) goto out_nolock; switch (kn->kn_filter) { case EVFILT_READ: kn->kn_fop = &tunread_filtops; kn->kn_hook = tp; selrecord_knote(&tp->tun_rsel, kn); break; case EVFILT_WRITE: kn->kn_fop = &seltrue_filtops; break; default: rv = EINVAL; goto out; } out: mutex_exit(&tp->tun_lock); out_nolock: return rv; } /* * Module infrastructure */ #include "if_module.h" IF_MODULE(MODULE_CLASS_DRIVER, tun, NULL)