/* $NetBSD: kern_event.c,v 1.30 2006/07/23 22:06:11 ad Exp $ */ /*- * Copyright (c) 1999,2000,2001 Jonathan Lemon * 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. * * $FreeBSD: src/sys/kern/kern_event.c,v 1.27 2001/07/05 17:10:44 rwatson Exp $ */ #include __KERNEL_RCSID(0, "$NetBSD: kern_event.c,v 1.30 2006/07/23 22:06:11 ad Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static void kqueue_wakeup(struct kqueue *kq); static int kqueue_scan(struct file *, size_t, struct kevent *, const struct timespec *, struct lwp *, register_t *, const struct kevent_ops *); static int kqueue_read(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags); static int kqueue_write(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags); static int kqueue_ioctl(struct file *fp, u_long com, void *data, struct lwp *l); static int kqueue_fcntl(struct file *fp, u_int com, void *data, struct lwp *l); static int kqueue_poll(struct file *fp, int events, struct lwp *l); static int kqueue_kqfilter(struct file *fp, struct knote *kn); static int kqueue_stat(struct file *fp, struct stat *sp, struct lwp *l); static int kqueue_close(struct file *fp, struct lwp *l); static const struct fileops kqueueops = { kqueue_read, kqueue_write, kqueue_ioctl, kqueue_fcntl, kqueue_poll, kqueue_stat, kqueue_close, kqueue_kqfilter }; static void knote_attach(struct knote *kn, struct filedesc *fdp); static void knote_drop(struct knote *kn, struct lwp *l, struct filedesc *fdp); static void knote_enqueue(struct knote *kn); static void knote_dequeue(struct knote *kn); static void filt_kqdetach(struct knote *kn); static int filt_kqueue(struct knote *kn, long hint); static int filt_procattach(struct knote *kn); static void filt_procdetach(struct knote *kn); static int filt_proc(struct knote *kn, long hint); static int filt_fileattach(struct knote *kn); static void filt_timerexpire(void *knx); static int filt_timerattach(struct knote *kn); static void filt_timerdetach(struct knote *kn); static int filt_timer(struct knote *kn, long hint); static const struct filterops kqread_filtops = { 1, NULL, filt_kqdetach, filt_kqueue }; static const struct filterops proc_filtops = { 0, filt_procattach, filt_procdetach, filt_proc }; static const struct filterops file_filtops = { 1, filt_fileattach, NULL, NULL }; static const struct filterops timer_filtops = { 0, filt_timerattach, filt_timerdetach, filt_timer }; static POOL_INIT(kqueue_pool, sizeof(struct kqueue), 0, 0, 0, "kqueuepl", NULL); static POOL_INIT(knote_pool, sizeof(struct knote), 0, 0, 0, "knotepl", NULL); static int kq_ncallouts = 0; static int kq_calloutmax = (4 * 1024); MALLOC_DEFINE(M_KEVENT, "kevent", "kevents/knotes"); #define KNOTE_ACTIVATE(kn) \ do { \ kn->kn_status |= KN_ACTIVE; \ if ((kn->kn_status & (KN_QUEUED | KN_DISABLED)) == 0) \ knote_enqueue(kn); \ } while(0) #define KN_HASHSIZE 64 /* XXX should be tunable */ #define KN_HASH(val, mask) (((val) ^ (val >> 8)) & (mask)) extern const struct filterops sig_filtops; /* * Table for for all system-defined filters. * These should be listed in the numeric order of the EVFILT_* defines. * If filtops is NULL, the filter isn't implemented in NetBSD. * End of list is when name is NULL. */ struct kfilter { const char *name; /* name of filter */ uint32_t filter; /* id of filter */ const struct filterops *filtops;/* operations for filter */ }; /* System defined filters */ static const struct kfilter sys_kfilters[] = { { "EVFILT_READ", EVFILT_READ, &file_filtops }, { "EVFILT_WRITE", EVFILT_WRITE, &file_filtops }, { "EVFILT_AIO", EVFILT_AIO, NULL }, { "EVFILT_VNODE", EVFILT_VNODE, &file_filtops }, { "EVFILT_PROC", EVFILT_PROC, &proc_filtops }, { "EVFILT_SIGNAL", EVFILT_SIGNAL, &sig_filtops }, { "EVFILT_TIMER", EVFILT_TIMER, &timer_filtops }, { NULL, 0, NULL }, /* end of list */ }; /* User defined kfilters */ static struct kfilter *user_kfilters; /* array */ static int user_kfilterc; /* current offset */ static int user_kfiltermaxc; /* max size so far */ /* * Find kfilter entry by name, or NULL if not found. */ static const struct kfilter * kfilter_byname_sys(const char *name) { int i; for (i = 0; sys_kfilters[i].name != NULL; i++) { if (strcmp(name, sys_kfilters[i].name) == 0) return (&sys_kfilters[i]); } return (NULL); } static struct kfilter * kfilter_byname_user(const char *name) { int i; /* user_kfilters[] could be NULL if no filters were registered */ if (!user_kfilters) return (NULL); for (i = 0; user_kfilters[i].name != NULL; i++) { if (user_kfilters[i].name != '\0' && strcmp(name, user_kfilters[i].name) == 0) return (&user_kfilters[i]); } return (NULL); } static const struct kfilter * kfilter_byname(const char *name) { const struct kfilter *kfilter; if ((kfilter = kfilter_byname_sys(name)) != NULL) return (kfilter); return (kfilter_byname_user(name)); } /* * Find kfilter entry by filter id, or NULL if not found. * Assumes entries are indexed in filter id order, for speed. */ static const struct kfilter * kfilter_byfilter(uint32_t filter) { const struct kfilter *kfilter; if (filter < EVFILT_SYSCOUNT) /* it's a system filter */ kfilter = &sys_kfilters[filter]; else if (user_kfilters != NULL && filter < EVFILT_SYSCOUNT + user_kfilterc) /* it's a user filter */ kfilter = &user_kfilters[filter - EVFILT_SYSCOUNT]; else return (NULL); /* out of range */ KASSERT(kfilter->filter == filter); /* sanity check! */ return (kfilter); } /* * Register a new kfilter. Stores the entry in user_kfilters. * Returns 0 if operation succeeded, or an appropriate errno(2) otherwise. * If retfilter != NULL, the new filterid is returned in it. */ int kfilter_register(const char *name, const struct filterops *filtops, int *retfilter) { struct kfilter *kfilter; void *space; int len; if (name == NULL || name[0] == '\0' || filtops == NULL) return (EINVAL); /* invalid args */ if (kfilter_byname(name) != NULL) return (EEXIST); /* already exists */ if (user_kfilterc > 0xffffffff - EVFILT_SYSCOUNT) return (EINVAL); /* too many */ /* check if need to grow user_kfilters */ if (user_kfilterc + 1 > user_kfiltermaxc) { /* * Grow in KFILTER_EXTENT chunks. Use malloc(9), because we * want to traverse user_kfilters as an array. */ user_kfiltermaxc += KFILTER_EXTENT; kfilter = malloc(user_kfiltermaxc * sizeof(struct filter *), M_KEVENT, M_WAITOK); /* copy existing user_kfilters */ if (user_kfilters != NULL) memcpy((caddr_t)kfilter, (caddr_t)user_kfilters, user_kfilterc * sizeof(struct kfilter *)); /* zero new sections */ memset((caddr_t)kfilter + user_kfilterc * sizeof(struct kfilter *), 0, (user_kfiltermaxc - user_kfilterc) * sizeof(struct kfilter *)); /* switch to new kfilter */ if (user_kfilters != NULL) free(user_kfilters, M_KEVENT); user_kfilters = kfilter; } len = strlen(name) + 1; /* copy name */ space = malloc(len, M_KEVENT, M_WAITOK); memcpy(space, name, len); user_kfilters[user_kfilterc].name = space; user_kfilters[user_kfilterc].filter = user_kfilterc + EVFILT_SYSCOUNT; len = sizeof(struct filterops); /* copy filtops */ space = malloc(len, M_KEVENT, M_WAITOK); memcpy(space, filtops, len); user_kfilters[user_kfilterc].filtops = space; if (retfilter != NULL) *retfilter = user_kfilters[user_kfilterc].filter; user_kfilterc++; /* finally, increment count */ return (0); } /* * Unregister a kfilter previously registered with kfilter_register. * This retains the filter id, but clears the name and frees filtops (filter * operations), so that the number isn't reused during a boot. * Returns 0 if operation succeeded, or an appropriate errno(2) otherwise. */ int kfilter_unregister(const char *name) { struct kfilter *kfilter; if (name == NULL || name[0] == '\0') return (EINVAL); /* invalid name */ if (kfilter_byname_sys(name) != NULL) return (EINVAL); /* can't detach system filters */ kfilter = kfilter_byname_user(name); if (kfilter == NULL) /* not found */ return (ENOENT); if (kfilter->name[0] != '\0') { /* XXXUNCONST Cast away const (but we know it's safe. */ free(__UNCONST(kfilter->name), M_KEVENT); kfilter->name = ""; /* mark as `not implemented' */ } if (kfilter->filtops != NULL) { /* XXXUNCONST Cast away const (but we know it's safe. */ free(__UNCONST(kfilter->filtops), M_KEVENT); kfilter->filtops = NULL; /* mark as `not implemented' */ } return (0); } /* * Filter attach method for EVFILT_READ and EVFILT_WRITE on normal file * descriptors. Calls struct fileops kqfilter method for given file descriptor. */ static int filt_fileattach(struct knote *kn) { struct file *fp; fp = kn->kn_fp; return ((*fp->f_ops->fo_kqfilter)(fp, kn)); } /* * Filter detach method for EVFILT_READ on kqueue descriptor. */ static void filt_kqdetach(struct knote *kn) { struct kqueue *kq; kq = (struct kqueue *)kn->kn_fp->f_data; SLIST_REMOVE(&kq->kq_sel.sel_klist, kn, knote, kn_selnext); } /* * Filter event method for EVFILT_READ on kqueue descriptor. */ /*ARGSUSED*/ static int filt_kqueue(struct knote *kn, long hint) { struct kqueue *kq; kq = (struct kqueue *)kn->kn_fp->f_data; kn->kn_data = kq->kq_count; return (kn->kn_data > 0); } /* * Filter attach method for EVFILT_PROC. */ static int filt_procattach(struct knote *kn) { struct proc *p, *curp; struct lwp *curl; curl = curlwp; curp = curl->l_proc; p = pfind(kn->kn_id); if (p == NULL) return (ESRCH); /* * Fail if it's not owned by you, or the last exec gave us * setuid/setgid privs (unless you're root). */ if ((kauth_cred_getuid(p->p_cred) != kauth_cred_getuid(curl->l_cred) || (p->p_flag & P_SUGID)) && kauth_authorize_generic(curl->l_cred, KAUTH_GENERIC_ISSUSER, &curl->l_acflag) != 0) return (EACCES); kn->kn_ptr.p_proc = p; kn->kn_flags |= EV_CLEAR; /* automatically set */ /* * internal flag indicating registration done by kernel */ if (kn->kn_flags & EV_FLAG1) { kn->kn_data = kn->kn_sdata; /* ppid */ kn->kn_fflags = NOTE_CHILD; kn->kn_flags &= ~EV_FLAG1; } /* XXXSMP lock the process? */ SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); return (0); } /* * Filter detach method for EVFILT_PROC. * * The knote may be attached to a different process, which may exit, * leaving nothing for the knote to be attached to. So when the process * exits, the knote is marked as DETACHED and also flagged as ONESHOT so * it will be deleted when read out. However, as part of the knote deletion, * this routine is called, so a check is needed to avoid actually performing * a detach, because the original process might not exist any more. */ static void filt_procdetach(struct knote *kn) { struct proc *p; if (kn->kn_status & KN_DETACHED) return; p = kn->kn_ptr.p_proc; KASSERT(p->p_stat == SZOMB || pfind(kn->kn_id) == p); /* XXXSMP lock the process? */ SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); } /* * Filter event method for EVFILT_PROC. */ static int filt_proc(struct knote *kn, long hint) { u_int event; /* * mask off extra data */ event = (u_int)hint & NOTE_PCTRLMASK; /* * if the user is interested in this event, record it. */ if (kn->kn_sfflags & event) kn->kn_fflags |= event; /* * process is gone, so flag the event as finished. */ if (event == NOTE_EXIT) { /* * Detach the knote from watched process and mark * it as such. We can't leave this to kqueue_scan(), * since the process might not exist by then. And we * have to do this now, since psignal KNOTE() is called * also for zombies and we might end up reading freed * memory if the kevent would already be picked up * and knote g/c'ed. */ kn->kn_fop->f_detach(kn); kn->kn_status |= KN_DETACHED; /* Mark as ONESHOT, so that the knote it g/c'ed when read */ kn->kn_flags |= (EV_EOF | EV_ONESHOT); return (1); } /* * process forked, and user wants to track the new process, * so attach a new knote to it, and immediately report an * event with the parent's pid. */ if ((event == NOTE_FORK) && (kn->kn_sfflags & NOTE_TRACK)) { struct kevent kev; int error; /* * register knote with new process. */ kev.ident = hint & NOTE_PDATAMASK; /* pid */ kev.filter = kn->kn_filter; kev.flags = kn->kn_flags | EV_ADD | EV_ENABLE | EV_FLAG1; kev.fflags = kn->kn_sfflags; kev.data = kn->kn_id; /* parent */ kev.udata = kn->kn_kevent.udata; /* preserve udata */ error = kqueue_register(kn->kn_kq, &kev, NULL); if (error) kn->kn_fflags |= NOTE_TRACKERR; } return (kn->kn_fflags != 0); } static void filt_timerexpire(void *knx) { struct knote *kn = knx; int tticks; kn->kn_data++; KNOTE_ACTIVATE(kn); if ((kn->kn_flags & EV_ONESHOT) == 0) { tticks = mstohz(kn->kn_sdata); callout_schedule((struct callout *)kn->kn_hook, tticks); } } /* * data contains amount of time to sleep, in milliseconds */ static int filt_timerattach(struct knote *kn) { struct callout *calloutp; int tticks; if (kq_ncallouts >= kq_calloutmax) return (ENOMEM); kq_ncallouts++; tticks = mstohz(kn->kn_sdata); /* if the supplied value is under our resolution, use 1 tick */ if (tticks == 0) { if (kn->kn_sdata == 0) return (EINVAL); tticks = 1; } kn->kn_flags |= EV_CLEAR; /* automatically set */ MALLOC(calloutp, struct callout *, sizeof(*calloutp), M_KEVENT, 0); callout_init(calloutp); callout_reset(calloutp, tticks, filt_timerexpire, kn); kn->kn_hook = calloutp; return (0); } static void filt_timerdetach(struct knote *kn) { struct callout *calloutp; calloutp = (struct callout *)kn->kn_hook; callout_stop(calloutp); FREE(calloutp, M_KEVENT); kq_ncallouts--; } static int filt_timer(struct knote *kn, long hint) { return (kn->kn_data != 0); } /* * filt_seltrue: * * This filter "event" routine simulates seltrue(). */ int filt_seltrue(struct knote *kn, long hint) { /* * We don't know how much data can be read/written, * but we know that it *can* be. This is about as * good as select/poll does as well. */ kn->kn_data = 0; return (1); } /* * This provides full kqfilter entry for device switch tables, which * has same effect as filter using filt_seltrue() as filter method. */ static void filt_seltruedetach(struct knote *kn) { /* Nothing to do */ } static const struct filterops seltrue_filtops = { 1, NULL, filt_seltruedetach, filt_seltrue }; int seltrue_kqfilter(dev_t dev, struct knote *kn) { switch (kn->kn_filter) { case EVFILT_READ: case EVFILT_WRITE: kn->kn_fop = &seltrue_filtops; break; default: return (1); } /* Nothing more to do */ return (0); } /* * kqueue(2) system call. */ int sys_kqueue(struct lwp *l, void *v, register_t *retval) { struct filedesc *fdp; struct kqueue *kq; struct file *fp; int fd, error; fdp = l->l_proc->p_fd; error = falloc(l, &fp, &fd); /* setup a new file descriptor */ if (error) return (error); fp->f_flag = FREAD | FWRITE; fp->f_type = DTYPE_KQUEUE; fp->f_ops = &kqueueops; kq = pool_get(&kqueue_pool, PR_WAITOK); memset((char *)kq, 0, sizeof(struct kqueue)); simple_lock_init(&kq->kq_lock); TAILQ_INIT(&kq->kq_head); fp->f_data = (caddr_t)kq; /* store the kqueue with the fp */ *retval = fd; if (fdp->fd_knlistsize < 0) fdp->fd_knlistsize = 0; /* this process has a kq */ kq->kq_fdp = fdp; FILE_SET_MATURE(fp); FILE_UNUSE(fp, l); /* falloc() does FILE_USE() */ return (error); } /* * kevent(2) system call. */ static int kevent_fetch_changes(void *private, const struct kevent *changelist, struct kevent *changes, size_t index, int n) { return copyin(changelist + index, changes, n * sizeof(*changes)); } static int kevent_put_events(void *private, struct kevent *events, struct kevent *eventlist, size_t index, int n) { return copyout(events, eventlist + index, n * sizeof(*events)); } static const struct kevent_ops kevent_native_ops = { keo_private: NULL, keo_fetch_timeout: copyin, keo_fetch_changes: kevent_fetch_changes, keo_put_events: kevent_put_events, }; int sys_kevent(struct lwp *l, void *v, register_t *retval) { struct sys_kevent_args /* { syscallarg(int) fd; syscallarg(const struct kevent *) changelist; syscallarg(size_t) nchanges; syscallarg(struct kevent *) eventlist; syscallarg(size_t) nevents; syscallarg(const struct timespec *) timeout; } */ *uap = v; return kevent1(l, retval, SCARG(uap, fd), SCARG(uap, changelist), SCARG(uap, nchanges), SCARG(uap, eventlist), SCARG(uap, nevents), SCARG(uap, timeout), &kevent_native_ops); } int kevent1(struct lwp *l, register_t *retval, int fd, const struct kevent *changelist, size_t nchanges, struct kevent *eventlist, size_t nevents, const struct timespec *timeout, const struct kevent_ops *keops) { struct kevent *kevp; struct kqueue *kq; struct file *fp; struct timespec ts; struct proc *p; size_t i, n, ichange; int nerrors, error; p = l->l_proc; /* check that we're dealing with a kq */ fp = fd_getfile(p->p_fd, fd); if (fp == NULL) return (EBADF); if (fp->f_type != DTYPE_KQUEUE) { simple_unlock(&fp->f_slock); return (EBADF); } FILE_USE(fp); if (timeout != NULL) { error = (*keops->keo_fetch_timeout)(timeout, &ts, sizeof(ts)); if (error) goto done; timeout = &ts; } kq = (struct kqueue *)fp->f_data; nerrors = 0; ichange = 0; /* traverse list of events to register */ while (nchanges > 0) { /* copyin a maximum of KQ_EVENTS at each pass */ n = MIN(nchanges, KQ_NEVENTS); error = (*keops->keo_fetch_changes)(keops->keo_private, changelist, kq->kq_kev, ichange, n); if (error) goto done; for (i = 0; i < n; i++) { kevp = &kq->kq_kev[i]; kevp->flags &= ~EV_SYSFLAGS; /* register each knote */ error = kqueue_register(kq, kevp, l); if (error) { if (nevents != 0) { kevp->flags = EV_ERROR; kevp->data = error; error = (*keops->keo_put_events) (keops->keo_private, kevp, eventlist, nerrors, 1); if (error) goto done; nevents--; nerrors++; } else { goto done; } } } nchanges -= n; /* update the results */ ichange += n; } if (nerrors) { *retval = nerrors; error = 0; goto done; } /* actually scan through the events */ error = kqueue_scan(fp, nevents, eventlist, timeout, l, retval, keops); done: FILE_UNUSE(fp, l); return (error); } /* * Register a given kevent kev onto the kqueue */ int kqueue_register(struct kqueue *kq, struct kevent *kev, struct lwp *l) { const struct kfilter *kfilter; struct filedesc *fdp; struct file *fp; struct knote *kn; int s, error; fdp = kq->kq_fdp; fp = NULL; kn = NULL; error = 0; kfilter = kfilter_byfilter(kev->filter); if (kfilter == NULL || kfilter->filtops == NULL) { /* filter not found nor implemented */ return (EINVAL); } /* search if knote already exists */ if (kfilter->filtops->f_isfd) { /* monitoring a file descriptor */ if ((fp = fd_getfile(fdp, kev->ident)) == NULL) return (EBADF); /* validate descriptor */ FILE_USE(fp); if (kev->ident < fdp->fd_knlistsize) { SLIST_FOREACH(kn, &fdp->fd_knlist[kev->ident], kn_link) if (kq == kn->kn_kq && kev->filter == kn->kn_filter) break; } } else { /* * not monitoring a file descriptor, so * lookup knotes in internal hash table */ if (fdp->fd_knhashmask != 0) { struct klist *list; list = &fdp->fd_knhash[ KN_HASH((u_long)kev->ident, fdp->fd_knhashmask)]; SLIST_FOREACH(kn, list, kn_link) if (kev->ident == kn->kn_id && kq == kn->kn_kq && kev->filter == kn->kn_filter) break; } } if (kn == NULL && ((kev->flags & EV_ADD) == 0)) { error = ENOENT; /* filter not found */ goto done; } /* * kn now contains the matching knote, or NULL if no match */ if (kev->flags & EV_ADD) { /* add knote */ if (kn == NULL) { /* create new knote */ kn = pool_get(&knote_pool, PR_WAITOK); if (kn == NULL) { error = ENOMEM; goto done; } kn->kn_fp = fp; kn->kn_kq = kq; kn->kn_fop = kfilter->filtops; /* * apply reference count to knote structure, and * do not release it at the end of this routine. */ fp = NULL; kn->kn_sfflags = kev->fflags; kn->kn_sdata = kev->data; kev->fflags = 0; kev->data = 0; kn->kn_kevent = *kev; knote_attach(kn, fdp); if ((error = kfilter->filtops->f_attach(kn)) != 0) { knote_drop(kn, l, fdp); goto done; } } else { /* modify existing knote */ /* * The user may change some filter values after the * initial EV_ADD, but doing so will not reset any * filter which have already been triggered. */ kn->kn_sfflags = kev->fflags; kn->kn_sdata = kev->data; kn->kn_kevent.udata = kev->udata; } s = splsched(); if (kn->kn_fop->f_event(kn, 0)) KNOTE_ACTIVATE(kn); splx(s); } else if (kev->flags & EV_DELETE) { /* delete knote */ kn->kn_fop->f_detach(kn); knote_drop(kn, l, fdp); goto done; } /* disable knote */ if ((kev->flags & EV_DISABLE) && ((kn->kn_status & KN_DISABLED) == 0)) { s = splsched(); kn->kn_status |= KN_DISABLED; splx(s); } /* enable knote */ if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { s = splsched(); kn->kn_status &= ~KN_DISABLED; if ((kn->kn_status & KN_ACTIVE) && ((kn->kn_status & KN_QUEUED) == 0)) knote_enqueue(kn); splx(s); } done: if (fp != NULL) FILE_UNUSE(fp, l); return (error); } /* * Scan through the list of events on fp (for a maximum of maxevents), * returning the results in to ulistp. Timeout is determined by tsp; if * NULL, wait indefinitely, if 0 valued, perform a poll, otherwise wait * as appropriate. */ static int kqueue_scan(struct file *fp, size_t maxevents, struct kevent *ulistp, const struct timespec *tsp, struct lwp *l, register_t *retval, const struct kevent_ops *keops) { struct proc *p = l->l_proc; struct kqueue *kq; struct kevent *kevp; struct timeval atv, sleeptv; struct knote *kn, *marker=NULL; size_t count, nkev, nevents; int s, timeout, error; kq = (struct kqueue *)fp->f_data; count = maxevents; nkev = nevents = error = 0; if (count == 0) goto done; if (tsp) { /* timeout supplied */ TIMESPEC_TO_TIMEVAL(&atv, tsp); if (inittimeleft(&atv, &sleeptv) == -1) { error = EINVAL; goto done; } timeout = tvtohz(&atv); if (timeout <= 0) timeout = -1; /* do poll */ } else { /* no timeout, wait forever */ timeout = 0; } MALLOC(marker, struct knote *, sizeof(*marker), M_KEVENT, M_WAITOK); memset(marker, 0, sizeof(*marker)); goto start; retry: if (tsp && (timeout = gettimeleft(&atv, &sleeptv)) <= 0) { goto done; } start: kevp = kq->kq_kev; s = splsched(); simple_lock(&kq->kq_lock); if (kq->kq_count == 0) { if (timeout < 0) { error = EWOULDBLOCK; simple_unlock(&kq->kq_lock); } else { kq->kq_state |= KQ_SLEEP; error = ltsleep(kq, PSOCK | PCATCH | PNORELOCK, "kqread", timeout, &kq->kq_lock); } splx(s); if (error == 0) goto retry; /* don't restart after signals... */ if (error == ERESTART) error = EINTR; else if (error == EWOULDBLOCK) error = 0; goto done; } /* mark end of knote list */ TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); simple_unlock(&kq->kq_lock); while (count) { /* while user wants data ... */ simple_lock(&kq->kq_lock); kn = TAILQ_FIRST(&kq->kq_head); /* get next knote */ TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); if (kn == marker) { /* if it's our marker, stop */ /* What if it's some else's marker? */ simple_unlock(&kq->kq_lock); splx(s); if (count == maxevents) goto retry; goto done; } kq->kq_count--; simple_unlock(&kq->kq_lock); if (kn->kn_status & KN_DISABLED) { /* don't want disabled events */ kn->kn_status &= ~KN_QUEUED; continue; } if ((kn->kn_flags & EV_ONESHOT) == 0 && kn->kn_fop->f_event(kn, 0) == 0) { /* * non-ONESHOT event that hasn't * triggered again, so de-queue. */ kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); continue; } *kevp = kn->kn_kevent; kevp++; nkev++; if (kn->kn_flags & EV_ONESHOT) { /* delete ONESHOT events after retrieval */ kn->kn_status &= ~KN_QUEUED; splx(s); kn->kn_fop->f_detach(kn); knote_drop(kn, l, p->p_fd); s = splsched(); } else if (kn->kn_flags & EV_CLEAR) { /* clear state after retrieval */ kn->kn_data = 0; kn->kn_fflags = 0; kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); } else { /* add event back on list */ simple_lock(&kq->kq_lock); TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); kq->kq_count++; simple_unlock(&kq->kq_lock); } count--; if (nkev == KQ_NEVENTS) { /* do copyouts in KQ_NEVENTS chunks */ splx(s); error = (*keops->keo_put_events)(keops->keo_private, &kq->kq_kev[0], ulistp, nevents, nkev); nevents += nkev; nkev = 0; kevp = kq->kq_kev; s = splsched(); if (error) break; } } /* remove marker */ simple_lock(&kq->kq_lock); TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); simple_unlock(&kq->kq_lock); splx(s); done: if (marker) FREE(marker, M_KEVENT); if (nkev != 0) /* copyout remaining events */ error = (*keops->keo_put_events)(keops->keo_private, &kq->kq_kev[0], ulistp, nevents, nkev); *retval = maxevents - count; return (error); } /* * struct fileops read method for a kqueue descriptor. * Not implemented. * XXX: This could be expanded to call kqueue_scan, if desired. */ /*ARGSUSED*/ static int kqueue_read(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags) { return (ENXIO); } /* * struct fileops write method for a kqueue descriptor. * Not implemented. */ /*ARGSUSED*/ static int kqueue_write(struct file *fp, off_t *offset, struct uio *uio, kauth_cred_t cred, int flags) { return (ENXIO); } /* * struct fileops ioctl method for a kqueue descriptor. * * Two ioctls are currently supported. They both use struct kfilter_mapping: * KFILTER_BYNAME find name for filter, and return result in * name, which is of size len. * KFILTER_BYFILTER find filter for name. len is ignored. */ /*ARGSUSED*/ static int kqueue_ioctl(struct file *fp, u_long com, void *data, struct lwp *l) { struct kfilter_mapping *km; const struct kfilter *kfilter; char *name; int error; km = (struct kfilter_mapping *)data; error = 0; switch (com) { case KFILTER_BYFILTER: /* convert filter -> name */ kfilter = kfilter_byfilter(km->filter); if (kfilter != NULL) error = copyoutstr(kfilter->name, km->name, km->len, NULL); else error = ENOENT; break; case KFILTER_BYNAME: /* convert name -> filter */ MALLOC(name, char *, KFILTER_MAXNAME, M_KEVENT, M_WAITOK); error = copyinstr(km->name, name, KFILTER_MAXNAME, NULL); if (error) { FREE(name, M_KEVENT); break; } kfilter = kfilter_byname(name); if (kfilter != NULL) km->filter = kfilter->filter; else error = ENOENT; FREE(name, M_KEVENT); break; default: error = ENOTTY; } return (error); } /* * struct fileops fcntl method for a kqueue descriptor. * Not implemented. */ /*ARGSUSED*/ static int kqueue_fcntl(struct file *fp, u_int com, void *data, struct lwp *l) { return (ENOTTY); } /* * struct fileops poll method for a kqueue descriptor. * Determine if kqueue has events pending. */ static int kqueue_poll(struct file *fp, int events, struct lwp *l) { struct kqueue *kq; int revents; kq = (struct kqueue *)fp->f_data; revents = 0; if (events & (POLLIN | POLLRDNORM)) { if (kq->kq_count) { revents |= events & (POLLIN | POLLRDNORM); } else { selrecord(l, &kq->kq_sel); } } return (revents); } /* * struct fileops stat method for a kqueue descriptor. * Returns dummy info, with st_size being number of events pending. */ static int kqueue_stat(struct file *fp, struct stat *st, struct lwp *l) { struct kqueue *kq; kq = (struct kqueue *)fp->f_data; memset((void *)st, 0, sizeof(*st)); st->st_size = kq->kq_count; st->st_blksize = sizeof(struct kevent); st->st_mode = S_IFIFO; return (0); } /* * struct fileops close method for a kqueue descriptor. * Cleans up kqueue. */ static int kqueue_close(struct file *fp, struct lwp *l) { struct proc *p = l->l_proc; struct kqueue *kq; struct filedesc *fdp; struct knote **knp, *kn, *kn0; int i; kq = (struct kqueue *)fp->f_data; fdp = p->p_fd; for (i = 0; i < fdp->fd_knlistsize; i++) { knp = &SLIST_FIRST(&fdp->fd_knlist[i]); kn = *knp; while (kn != NULL) { kn0 = SLIST_NEXT(kn, kn_link); if (kq == kn->kn_kq) { kn->kn_fop->f_detach(kn); FILE_UNUSE(kn->kn_fp, l); pool_put(&knote_pool, kn); *knp = kn0; } else { knp = &SLIST_NEXT(kn, kn_link); } kn = kn0; } } if (fdp->fd_knhashmask != 0) { for (i = 0; i < fdp->fd_knhashmask + 1; i++) { knp = &SLIST_FIRST(&fdp->fd_knhash[i]); kn = *knp; while (kn != NULL) { kn0 = SLIST_NEXT(kn, kn_link); if (kq == kn->kn_kq) { kn->kn_fop->f_detach(kn); /* XXX non-fd release of kn->kn_ptr */ pool_put(&knote_pool, kn); *knp = kn0; } else { knp = &SLIST_NEXT(kn, kn_link); } kn = kn0; } } } pool_put(&kqueue_pool, kq); fp->f_data = NULL; return (0); } /* * wakeup a kqueue */ static void kqueue_wakeup(struct kqueue *kq) { int s; s = splsched(); simple_lock(&kq->kq_lock); if (kq->kq_state & KQ_SLEEP) { /* if currently sleeping ... */ kq->kq_state &= ~KQ_SLEEP; wakeup(kq); /* ... wakeup */ } /* Notify select/poll and kevent. */ selnotify(&kq->kq_sel, 0); simple_unlock(&kq->kq_lock); splx(s); } /* * struct fileops kqfilter method for a kqueue descriptor. * Event triggered when monitored kqueue changes. */ /*ARGSUSED*/ static int kqueue_kqfilter(struct file *fp, struct knote *kn) { struct kqueue *kq; KASSERT(fp == kn->kn_fp); kq = (struct kqueue *)kn->kn_fp->f_data; if (kn->kn_filter != EVFILT_READ) return (1); kn->kn_fop = &kqread_filtops; SLIST_INSERT_HEAD(&kq->kq_sel.sel_klist, kn, kn_selnext); return (0); } /* * Walk down a list of knotes, activating them if their event has triggered. */ void knote(struct klist *list, long hint) { struct knote *kn; SLIST_FOREACH(kn, list, kn_selnext) if (kn->kn_fop->f_event(kn, hint)) KNOTE_ACTIVATE(kn); } /* * Remove all knotes from a specified klist */ void knote_remove(struct lwp *l, struct klist *list) { struct knote *kn; while ((kn = SLIST_FIRST(list)) != NULL) { kn->kn_fop->f_detach(kn); knote_drop(kn, l, l->l_proc->p_fd); } } /* * Remove all knotes referencing a specified fd */ void knote_fdclose(struct lwp *l, int fd) { struct filedesc *fdp; struct klist *list; fdp = l->l_proc->p_fd; list = &fdp->fd_knlist[fd]; knote_remove(l, list); } /* * Attach a new knote to a file descriptor */ static void knote_attach(struct knote *kn, struct filedesc *fdp) { struct klist *list; int size; if (! kn->kn_fop->f_isfd) { /* if knote is not on an fd, store on internal hash table */ if (fdp->fd_knhashmask == 0) fdp->fd_knhash = hashinit(KN_HASHSIZE, HASH_LIST, M_KEVENT, M_WAITOK, &fdp->fd_knhashmask); list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; goto done; } /* * otherwise, knote is on an fd. * knotes are stored in fd_knlist indexed by kn->kn_id. */ if (fdp->fd_knlistsize <= kn->kn_id) { /* expand list, it's too small */ size = fdp->fd_knlistsize; while (size <= kn->kn_id) { /* grow in KQ_EXTENT chunks */ size += KQ_EXTENT; } list = malloc(size * sizeof(struct klist *), M_KEVENT,M_WAITOK); if (fdp->fd_knlist) { /* copy existing knlist */ memcpy((caddr_t)list, (caddr_t)fdp->fd_knlist, fdp->fd_knlistsize * sizeof(struct klist *)); } /* * Zero new memory. Stylistically, SLIST_INIT() should be * used here, but that does same thing as the memset() anyway. */ memset(&list[fdp->fd_knlistsize], 0, (size - fdp->fd_knlistsize) * sizeof(struct klist *)); /* switch to new knlist */ if (fdp->fd_knlist != NULL) free(fdp->fd_knlist, M_KEVENT); fdp->fd_knlistsize = size; fdp->fd_knlist = list; } /* get list head for this fd */ list = &fdp->fd_knlist[kn->kn_id]; done: /* add new knote */ SLIST_INSERT_HEAD(list, kn, kn_link); kn->kn_status = 0; } /* * Drop knote. * Should be called at spl == 0, since we don't want to hold spl * while calling FILE_UNUSE and free. */ static void knote_drop(struct knote *kn, struct lwp *l, struct filedesc *fdp) { struct klist *list; if (kn->kn_fop->f_isfd) list = &fdp->fd_knlist[kn->kn_id]; else list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; SLIST_REMOVE(list, kn, knote, kn_link); if (kn->kn_status & KN_QUEUED) knote_dequeue(kn); if (kn->kn_fop->f_isfd) FILE_UNUSE(kn->kn_fp, l); pool_put(&knote_pool, kn); } /* * Queue new event for knote. */ static void knote_enqueue(struct knote *kn) { struct kqueue *kq; int s; kq = kn->kn_kq; KASSERT((kn->kn_status & KN_QUEUED) == 0); s = splsched(); simple_lock(&kq->kq_lock); TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); kn->kn_status |= KN_QUEUED; kq->kq_count++; simple_unlock(&kq->kq_lock); splx(s); kqueue_wakeup(kq); } /* * Dequeue event for knote. */ static void knote_dequeue(struct knote *kn) { struct kqueue *kq; int s; KASSERT(kn->kn_status & KN_QUEUED); kq = kn->kn_kq; s = splsched(); simple_lock(&kq->kq_lock); TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); kn->kn_status &= ~KN_QUEUED; kq->kq_count--; simple_unlock(&kq->kq_lock); splx(s); }