diff options
author | jhb <jhb@FreeBSD.org> | 2010-09-22 21:02:43 +0000 |
---|---|---|
committer | jhb <jhb@FreeBSD.org> | 2010-09-22 21:02:43 +0000 |
commit | b8914d3479db5650649ae5be1ae05dfdbdcc6b6c (patch) | |
tree | fc434fa0474d6dd93c7659408c21921cc4525ec1 /sys/net/if_tap.c | |
parent | 1efa60231a30195287137b26cd7f9fb666f48677 (diff) | |
download | FreeBSD-src-b8914d3479db5650649ae5be1ae05dfdbdcc6b6c.zip FreeBSD-src-b8914d3479db5650649ae5be1ae05dfdbdcc6b6c.tar.gz |
- Expand scope of tun/tap softc locks to cover more softc fields and
driver-maintained ifnet fields (such as if_drv_flags).
- Use soft locks as the mutex that protects each interface's knote list
rather than using the global knote list lock. Also, use the softc
for kn_hook instead of the cdev.
- Use mtx_sleep() instead of tsleep() when blocking in the read routines.
This fixes a lost wakeup race.
- Remove D_NEEDGIANT now that the cdevsw routines use the softc lock
where locking is needed.
- Lock IFQ when calculating the result for FIONREAD in tap(4). tun(4)
already did this.
- Remove remaining spl calls.
Submitted by: Marcin Cieslak saper of saper|info (3)
MFC after: 2 weeks
Diffstat (limited to 'sys/net/if_tap.c')
-rw-r--r-- | sys/net/if_tap.c | 154 |
1 files changed, 63 insertions, 91 deletions
diff --git a/sys/net/if_tap.c b/sys/net/if_tap.c index eb81e81..ad29da0 100644 --- a/sys/net/if_tap.c +++ b/sys/net/if_tap.c @@ -132,7 +132,7 @@ static struct filterops tap_write_filterops = { static struct cdevsw tap_cdevsw = { .d_version = D_VERSION, - .d_flags = D_PSEUDO | D_NEEDGIANT | D_NEEDMINOR, + .d_flags = D_PSEUDO | D_NEEDMINOR, .d_open = tapopen, .d_close = tapclose, .d_read = tapread, @@ -209,7 +209,6 @@ static void tap_destroy(struct tap_softc *tp) { struct ifnet *ifp = tp->tap_ifp; - int s; /* Unlocked read. */ KASSERT(!(tp->tap_flags & TAP_OPEN), @@ -217,10 +216,8 @@ tap_destroy(struct tap_softc *tp) knlist_destroy(&tp->tap_rsel.si_note); 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); @@ -398,7 +395,7 @@ tapcreate(struct cdev *dev) struct tap_softc *tp = NULL; unsigned short macaddr_hi; uint32_t macaddr_mid; - int unit, s; + int unit; char *name = NULL; u_char eaddr[6]; @@ -442,22 +439,20 @@ tapcreate(struct cdev *dev) ifp->if_ioctl = tapifioctl; ifp->if_mtu = ETHERMTU; ifp->if_flags = (IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST); - ifp->if_snd.ifq_maxlen = ifqmaxlen; + 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; - s = splimp(); ether_ifattach(ifp, eaddr); - splx(s); mtx_lock(&tp->tap_mtx); tp->tap_flags |= TAP_INITED; mtx_unlock(&tp->tap_mtx); - knlist_init_mtx(&tp->tap_rsel.si_note, NULL); + knlist_init_mtx(&tp->tap_rsel.si_note, &tp->tap_mtx); TAPDEBUG("interface %s is created. minor = %#x\n", ifp->if_xname, dev2unit(dev)); @@ -474,7 +469,7 @@ tapopen(struct cdev *dev, int flag, int mode, struct thread *td) { struct tap_softc *tp = NULL; struct ifnet *ifp = NULL; - int error, s; + int error; if (tapuopen == 0) { error = priv_check(td, PRIV_NET_TAP); @@ -497,15 +492,13 @@ tapopen(struct cdev *dev, int flag, int mode, struct thread *td) 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_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); - splx(s); + mtx_unlock(&tp->tap_mtx); TAPDEBUG("%s is open. minor = %#x\n", ifp->if_xname, dev2unit(dev)); @@ -524,9 +517,9 @@ 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; - int s; /* junk all pending output */ + mtx_lock(&tp->tap_mtx); IF_DRAIN(&ifp->if_snd); /* @@ -534,28 +527,26 @@ tapclose(struct cdev *dev, int foo, int bar, struct thread *td) * 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); + 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); - ifp->if_drv_flags &= ~IFF_DRV_RUNNING; + mtx_lock(&tp->tap_mtx); } - splx(s); - } else - mtx_unlock(&tp->tap_mtx); + } if_link_state_change(ifp, LINK_STATE_DOWN); funsetown(&tp->tap_sigio); selwakeuppri(&tp->tap_rsel, PZERO+1); - KNOTE_UNLOCKED(&tp->tap_rsel.si_note, 0); + KNOTE_LOCKED(&tp->tap_rsel.si_note, 0); - mtx_lock(&tp->tap_mtx); tp->tap_flags &= ~TAP_OPEN; tp->tap_pid = 0; mtx_unlock(&tp->tap_mtx); @@ -580,8 +571,10 @@ tapifinit(void *xtp) 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); @@ -599,7 +592,7 @@ 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; - int s, dummy; + int dummy; switch (cmd) { case SIOCSIFFLAGS: /* XXX -- just like vmnet does */ @@ -612,7 +605,6 @@ tapifioctl(struct ifnet *ifp, u_long cmd, caddr_t data) break; case SIOCGIFSTATUS: - s = splimp(); ifs = (struct ifstat *)data; dummy = strlen(ifs->ascii); mtx_lock(&tp->tap_mtx); @@ -621,14 +613,10 @@ tapifioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 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 (ether_ioctl(ifp, cmd, data)); /* NOT REACHED */ } @@ -645,7 +633,6 @@ static void tapifstart(struct ifnet *ifp) { struct tap_softc *tp = ifp->if_softc; - int s; TAPDEBUG("%s starting\n", ifp->if_xname); @@ -657,32 +644,28 @@ tapifstart(struct ifnet *ifp) 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); + struct mbuf *m; /* Unlocked read. */ TAPDEBUG("%s not ready, tap_flags = 0x%x\n", ifp->if_xname, tp->tap_flags); - s = splimp(); - do { + for (;;) { IF_DEQUEUE(&ifp->if_snd, m); - if (m != NULL) + if (m != NULL) { m_freem(m); - ifp->if_oerrors ++; - } while (m != NULL); - splx(s); + ifp->if_oerrors++; + } else + break; + } + mtx_unlock(&tp->tap_mtx); return; } - mtx_unlock(&tp->tap_mtx); - s = splimp(); ifp->if_drv_flags |= IFF_DRV_OACTIVE; - if (ifp->if_snd.ifq_len != 0) { - mtx_lock(&tp->tap_mtx); + if (!IFQ_IS_EMPTY(&ifp->if_snd)) { if (tp->tap_flags & TAP_RWAIT) { tp->tap_flags &= ~TAP_RWAIT; wakeup(tp); @@ -691,16 +674,16 @@ tapifstart(struct ifnet *ifp) 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); + mtx_lock(&tp->tap_mtx); + } selwakeuppri(&tp->tap_rsel, PZERO+1); - KNOTE_UNLOCKED(&tp->tap_rsel.si_note, 0); + KNOTE_LOCKED(&tp->tap_rsel.si_note, 0); ifp->if_opackets ++; /* obytes are counted in ether_output */ } ifp->if_drv_flags &= ~IFF_DRV_OACTIVE; - splx(s); + mtx_unlock(&tp->tap_mtx); } /* tapifstart */ @@ -715,7 +698,6 @@ 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 s; int f; #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD4) @@ -724,19 +706,21 @@ tapioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td switch (cmd) { case TAPSIFINFO: - s = splimp(); tapp = (struct tapinfo *)data; + mtx_lock(&tp->tap_mtx); ifp->if_mtu = tapp->mtu; ifp->if_type = tapp->type; ifp->if_baudrate = tapp->baudrate; - splx(s); + 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: @@ -757,26 +741,26 @@ tapioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td 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; + if (!IFQ_IS_EMPTY(&ifp->if_snd)) { + struct mbuf *mb; - for(*(int *)data = 0;mb != NULL;mb = mb->m_next) + 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; - splx(s); break; case FIOSETOWN: @@ -797,10 +781,6 @@ tapioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td /* VMware/VMnet port ioctl's */ - case SIOCGIFFLAGS: /* get ifnet flags */ - bcopy(&ifp->if_flags, data, sizeof(ifp->if_flags)); - break; - #if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD4) case _IO('V', 0): @@ -814,9 +794,9 @@ tapioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td f &= ~IFF_CANTCHANGE; f |= IFF_UP; - s = splimp(); + mtx_lock(&tp->tap_mtx); ifp->if_flags = f | (ifp->if_flags & IFF_CANTCHANGE); - splx(s); + mtx_unlock(&tp->tap_mtx); break; case OSIOCGIFADDR: /* get MAC address of the remote side */ @@ -851,7 +831,7 @@ 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, s; + int error = 0, len; TAPDEBUG("%s reading, minor = %#x\n", ifp->if_xname, dev2unit(dev)); @@ -867,26 +847,27 @@ tapread(struct cdev *dev, struct uio *uio, int flag) } 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) + if (flag & O_NONBLOCK) { + mtx_unlock(&tp->tap_mtx); 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) + 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); @@ -982,14 +963,14 @@ tappoll(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; + int revents = 0; TAPDEBUG("%s polling, minor = %#x\n", ifp->if_xname, dev2unit(dev)); - s = splimp(); if (events & (POLLIN | POLLRDNORM)) { - if (ifp->if_snd.ifq_len > 0) { + 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)); @@ -1001,12 +982,12 @@ tappoll(struct cdev *dev, int events, struct thread *td) selrecord(td, &tp->tap_rsel); } + IFQ_UNLOCK(&ifp->if_snd); } if (events & (POLLOUT | POLLWRNORM)) revents |= (events & (POLLOUT | POLLWRNORM)); - splx(s); return (revents); } /* tappoll */ @@ -1019,11 +1000,9 @@ tappoll(struct cdev *dev, int events, struct thread *td) static int tapkqfilter(struct cdev *dev, struct knote *kn) { - int s; struct tap_softc *tp = dev->si_drv1; struct ifnet *ifp = tp->tap_ifp; - s = splimp(); switch (kn->kn_filter) { case EVFILT_READ: TAPDEBUG("%s kqfilter: EVFILT_READ, minor = %#x\n", @@ -1040,13 +1019,11 @@ tapkqfilter(struct cdev *dev, struct knote *kn) default: TAPDEBUG("%s kqfilter: invalid filter, minor = %#x\n", ifp->if_xname, dev2unit(dev)); - splx(s); return (EINVAL); /* NOT REACHED */ } - splx(s); - kn->kn_hook = (caddr_t) dev; + kn->kn_hook = tp; knlist_add(&tp->tap_rsel.si_note, kn, 0); return (0); @@ -1061,12 +1038,11 @@ tapkqfilter(struct cdev *dev, struct knote *kn) static int tapkqread(struct knote *kn, long hint) { - int ret, s; - struct cdev *dev = (struct cdev *)(kn->kn_hook); - struct tap_softc *tp = dev->si_drv1; + int ret; + struct tap_softc *tp = kn->kn_hook; + struct cdev *dev = tp->tap_dev; struct ifnet *ifp = tp->tap_ifp; - s = splimp(); 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)); @@ -1076,7 +1052,6 @@ tapkqread(struct knote *kn, long hint) ifp->if_xname, dev2unit(dev)); ret = 0; } - splx(s); return (ret); } /* tapkqread */ @@ -1090,13 +1065,10 @@ tapkqread(struct knote *kn, long hint) static int tapkqwrite(struct knote *kn, long hint) { - int s; - struct tap_softc *tp = ((struct cdev *) kn->kn_hook)->si_drv1; + struct tap_softc *tp = kn->kn_hook; struct ifnet *ifp = tp->tap_ifp; - s = splimp(); kn->kn_data = ifp->if_mtu; - splx(s); return (1); } /* tapkqwrite */ @@ -1105,7 +1077,7 @@ tapkqwrite(struct knote *kn, long hint) static void tapkqdetach(struct knote *kn) { - struct tap_softc *tp = ((struct cdev *) kn->kn_hook)->si_drv1; + struct tap_softc *tp = kn->kn_hook; knlist_remove(&tp->tap_rsel.si_note, kn, 0); } /* tapkqdetach */ |