/*- * Copyright (c) 1999,2000 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. * * $FreeBSD$ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, const struct timespec *timeout, struct proc *p); static int kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct proc *p); static int kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct proc *p); static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p); static int kqueue_poll(struct file *fp, int events, struct ucred *cred, struct proc *p); static int kqueue_kqfilter(struct file *fp, struct knote *kn); static int kqueue_stat(struct file *fp, struct stat *st, struct proc *p); static int kqueue_close(struct file *fp, struct proc *p); static void kqueue_wakeup(struct kqueue *kq); static struct fileops kqueueops = { kqueue_read, kqueue_write, kqueue_ioctl, kqueue_poll, kqueue_kqfilter, kqueue_stat, kqueue_close }; static void knote_attach(struct knote *kn, struct filedesc *fdp); static void knote_drop(struct knote *kn, struct proc *p); static void knote_enqueue(struct knote *kn); static void knote_dequeue(struct knote *kn); static void knote_init(void); static struct knote *knote_alloc(void); static void knote_free(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 struct filterops kqread_filtops = { 1, NULL, filt_kqdetach, filt_kqueue }; static struct filterops proc_filtops = { 0, filt_procattach, filt_procdetach, filt_proc }; static struct filterops file_filtops = { 1, filt_fileattach, NULL, NULL }; static vm_zone_t knote_zone; #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 struct filterops aio_filtops; extern struct filterops sig_filtops; /* * Table for for all system-defined filters. */ static struct filterops *sysfilt_ops[] = { &file_filtops, /* EVFILT_READ */ &file_filtops, /* EVFILT_WRITE */ &aio_filtops, /* EVFILT_AIO */ &file_filtops, /* EVFILT_VNODE */ &proc_filtops, /* EVFILT_PROC */ &sig_filtops, /* EVFILT_SIGNAL */ }; static int filt_fileattach(struct knote *kn) { return (fo_kqfilter(kn->kn_fp, kn)); } /*ARGSUSED*/ static int kqueue_kqfilter(struct file *fp, struct knote *kn) { struct kqueue *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.si_note, kn, kn_selnext); return (0); } static void filt_kqdetach(struct knote *kn) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; SLIST_REMOVE(&kq->kq_sel.si_note, kn, knote, kn_selnext); } /*ARGSUSED*/ static int filt_kqueue(struct knote *kn, long hint) { struct kqueue *kq = (struct kqueue *)kn->kn_fp->f_data; kn->kn_data = kq->kq_count; return (kn->kn_data > 0); } static int filt_procattach(struct knote *kn) { struct proc *p; p = pfind(kn->kn_id); if (p == NULL) return (ESRCH); if (p_can(curproc, p, P_CAN_SEE, NULL)) 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; } PROC_LOCK(p); SLIST_INSERT_HEAD(&p->p_klist, kn, kn_selnext); PROC_UNLOCK(p); return (0); } /* * 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 does not exist any more. */ static void filt_procdetach(struct knote *kn) { struct proc *p = kn->kn_ptr.p_proc; if (kn->kn_status & KN_DETACHED) return; PROC_LOCK(p); SLIST_REMOVE(&p->p_klist, kn, knote, kn_selnext); PROC_UNLOCK(p); } 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) { kn->kn_status |= KN_DETACHED; 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); } int kqueue(struct proc *p, struct kqueue_args *uap) { struct filedesc *fdp = p->p_fd; struct kqueue *kq; struct file *fp; int fd, error; error = falloc(p, &fp, &fd); if (error) return (error); fp->f_flag = FREAD | FWRITE; fp->f_type = DTYPE_KQUEUE; fp->f_ops = &kqueueops; kq = malloc(sizeof(struct kqueue), M_TEMP, M_WAITOK | M_ZERO); TAILQ_INIT(&kq->kq_head); fp->f_data = (caddr_t)kq; p->p_retval[0] = fd; if (fdp->fd_knlistsize < 0) fdp->fd_knlistsize = 0; /* this process has a kq */ kq->kq_fdp = fdp; return (error); } #ifndef _SYS_SYSPROTO_H_ struct kevent_args { int fd; const struct kevent *changelist; int nchanges; struct kevent *eventlist; int nevents; const struct timespec *timeout; }; #endif int kevent(struct proc *p, struct kevent_args *uap) { struct filedesc* fdp = p->p_fd; struct kevent *kevp; struct kqueue *kq; struct file *fp = NULL; struct timespec ts; int i, n, nerrors, error; if (((u_int)uap->fd) >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[uap->fd]) == NULL || (fp->f_type != DTYPE_KQUEUE)) return (EBADF); fhold(fp); if (uap->timeout != NULL) { error = copyin(uap->timeout, &ts, sizeof(ts)); if (error) goto done; uap->timeout = &ts; } kq = (struct kqueue *)fp->f_data; nerrors = 0; while (uap->nchanges > 0) { n = uap->nchanges > KQ_NEVENTS ? KQ_NEVENTS : uap->nchanges; error = copyin(uap->changelist, kq->kq_kev, n * sizeof(struct kevent)); if (error) goto done; for (i = 0; i < n; i++) { kevp = &kq->kq_kev[i]; kevp->flags &= ~EV_SYSFLAGS; error = kqueue_register(kq, kevp, p); if (error) { if (uap->nevents != 0) { kevp->flags = EV_ERROR; kevp->data = error; (void) copyout((caddr_t)kevp, (caddr_t)uap->eventlist, sizeof(*kevp)); uap->eventlist++; uap->nevents--; nerrors++; } else { goto done; } } } uap->nchanges -= n; uap->changelist += n; } if (nerrors) { p->p_retval[0] = nerrors; error = 0; goto done; } error = kqueue_scan(fp, uap->nevents, uap->eventlist, uap->timeout, p); done: if (fp != NULL) fdrop(fp, p); return (error); } int kqueue_register(struct kqueue *kq, struct kevent *kev, struct proc *p) { struct filedesc *fdp = kq->kq_fdp; struct filterops *fops; struct file *fp = NULL; struct knote *kn = NULL; int s, error = 0; if (kev->filter < 0) { if (kev->filter + EVFILT_SYSCOUNT < 0) return (EINVAL); fops = sysfilt_ops[~kev->filter]; /* to 0-base index */ } else { /* * XXX * filter attach routine is responsible for insuring that * the identifier can be attached to it. */ printf("unknown filter: %d\n", kev->filter); return (EINVAL); } if (fops->f_isfd) { /* validate descriptor */ if ((u_int)kev->ident >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[kev->ident]) == NULL) return (EBADF); fhold(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 { 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; goto done; } /* * kn now contains the matching knote, or NULL if no match */ if (kev->flags & EV_ADD) { if (kn == NULL) { kn = knote_alloc(); if (kn == NULL) { error = ENOMEM; goto done; } kn->kn_fp = fp; kn->kn_kq = kq; kn->kn_fop = fops; /* * apply reference count to knode structure, so * 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 = fops->f_attach(kn)) != 0) { knote_drop(kn, p); goto done; } } else { /* * 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 = splhigh(); if (kn->kn_fop->f_event(kn, 0)) KNOTE_ACTIVATE(kn); splx(s); } else if (kev->flags & EV_DELETE) { kn->kn_fop->f_detach(kn); knote_drop(kn, p); goto done; } if ((kev->flags & EV_DISABLE) && ((kn->kn_status & KN_DISABLED) == 0)) { s = splhigh(); kn->kn_status |= KN_DISABLED; splx(s); } if ((kev->flags & EV_ENABLE) && (kn->kn_status & KN_DISABLED)) { s = splhigh(); 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) fdrop(fp, p); return (error); } static int kqueue_scan(struct file *fp, int maxevents, struct kevent *ulistp, const struct timespec *tsp, struct proc *p) { struct kqueue *kq = (struct kqueue *)fp->f_data; struct kevent *kevp; struct timeval atv, rtv, ttv; struct knote *kn, marker; int s, count, timeout, nkev = 0, error = 0; count = maxevents; if (count == 0) goto done; if (tsp != NULL) { TIMESPEC_TO_TIMEVAL(&atv, tsp); if (itimerfix(&atv)) { error = EINVAL; goto done; } if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) timeout = -1; else timeout = atv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz(&atv); getmicrouptime(&rtv); timevaladd(&atv, &rtv); } else { atv.tv_sec = 0; atv.tv_usec = 0; timeout = 0; } goto start; retry: if (atv.tv_sec || atv.tv_usec) { getmicrouptime(&rtv); if (timevalcmp(&rtv, &atv, >=)) goto done; ttv = atv; timevalsub(&ttv, &rtv); timeout = ttv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz(&ttv); } start: kevp = kq->kq_kev; s = splhigh(); if (kq->kq_count == 0) { if (timeout < 0) { error = EWOULDBLOCK; } else { kq->kq_state |= KQ_SLEEP; error = tsleep(kq, PSOCK | PCATCH, "kqread", timeout); } 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; } TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); while (count) { kn = TAILQ_FIRST(&kq->kq_head); TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); if (kn == &marker) { splx(s); if (count == maxevents) goto retry; goto done; } if (kn->kn_status & KN_DISABLED) { kn->kn_status &= ~KN_QUEUED; kq->kq_count--; continue; } if ((kn->kn_flags & EV_ONESHOT) == 0 && kn->kn_fop->f_event(kn, 0) == 0) { kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); kq->kq_count--; continue; } *kevp = kn->kn_kevent; kevp++; nkev++; if (kn->kn_flags & EV_ONESHOT) { kn->kn_status &= ~KN_QUEUED; kq->kq_count--; splx(s); kn->kn_fop->f_detach(kn); knote_drop(kn, p); s = splhigh(); } else if (kn->kn_flags & EV_CLEAR) { kn->kn_data = 0; kn->kn_fflags = 0; kn->kn_status &= ~(KN_QUEUED | KN_ACTIVE); kq->kq_count--; } else { TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); } count--; if (nkev == KQ_NEVENTS) { splx(s); error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, sizeof(struct kevent) * nkev); ulistp += nkev; nkev = 0; kevp = kq->kq_kev; s = splhigh(); if (error) break; } } TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); splx(s); done: if (nkev != 0) error = copyout((caddr_t)&kq->kq_kev, (caddr_t)ulistp, sizeof(struct kevent) * nkev); p->p_retval[0] = maxevents - count; return (error); } /* * XXX * This could be expanded to call kqueue_scan, if desired. */ /*ARGSUSED*/ static int kqueue_read(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct proc *p) { return (ENXIO); } /*ARGSUSED*/ static int kqueue_write(struct file *fp, struct uio *uio, struct ucred *cred, int flags, struct proc *p) { return (ENXIO); } /*ARGSUSED*/ static int kqueue_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p) { return (ENOTTY); } /*ARGSUSED*/ static int kqueue_poll(struct file *fp, int events, struct ucred *cred, struct proc *p) { struct kqueue *kq = (struct kqueue *)fp->f_data; int revents = 0; int s = splnet(); if (events & (POLLIN | POLLRDNORM)) { if (kq->kq_count) { revents |= events & (POLLIN | POLLRDNORM); } else { selrecord(p, &kq->kq_sel); kq->kq_state |= KQ_SEL; } } splx(s); return (revents); } /*ARGSUSED*/ static int kqueue_stat(struct file *fp, struct stat *st, struct proc *p) { struct kqueue *kq = (struct kqueue *)fp->f_data; bzero((void *)st, sizeof(*st)); st->st_size = kq->kq_count; st->st_blksize = sizeof(struct kevent); st->st_mode = S_IFIFO; return (0); } /*ARGSUSED*/ static int kqueue_close(struct file *fp, struct proc *p) { struct kqueue *kq = (struct kqueue *)fp->f_data; struct filedesc *fdp = p->p_fd; struct knote **knp, *kn, *kn0; int i; 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); fdrop(kn->kn_fp, p); knote_free(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 */ knote_free(kn); *knp = kn0; } else { knp = &SLIST_NEXT(kn, kn_link); } kn = kn0; } } } free(kq, M_TEMP); fp->f_data = NULL; return (0); } static void kqueue_wakeup(struct kqueue *kq) { if (kq->kq_state & KQ_SLEEP) { kq->kq_state &= ~KQ_SLEEP; wakeup(kq); } if (kq->kq_state & KQ_SEL) { kq->kq_state &= ~KQ_SEL; selwakeup(&kq->kq_sel); } KNOTE(&kq->kq_sel.si_note, 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 proc *p, struct klist *list) { struct knote *kn; while ((kn = SLIST_FIRST(list)) != NULL) { kn->kn_fop->f_detach(kn); knote_drop(kn, p); } } /* * remove all knotes referencing a specified fd */ void knote_fdclose(struct proc *p, int fd) { struct filedesc *fdp = p->p_fd; struct klist *list = &fdp->fd_knlist[fd]; knote_remove(p, list); } static void knote_attach(struct knote *kn, struct filedesc *fdp) { struct klist *list; int size; if (! kn->kn_fop->f_isfd) { if (fdp->fd_knhashmask == 0) fdp->fd_knhash = hashinit(KN_HASHSIZE, M_TEMP, &fdp->fd_knhashmask); list = &fdp->fd_knhash[KN_HASH(kn->kn_id, fdp->fd_knhashmask)]; goto done; } if (fdp->fd_knlistsize <= kn->kn_id) { size = fdp->fd_knlistsize; while (size <= kn->kn_id) size += KQEXTENT; MALLOC(list, struct klist *, size * sizeof(struct klist *), M_TEMP, M_WAITOK); bcopy((caddr_t)fdp->fd_knlist, (caddr_t)list, fdp->fd_knlistsize * sizeof(struct klist *)); bzero((caddr_t)list + fdp->fd_knlistsize * sizeof(struct klist *), (size - fdp->fd_knlistsize) * sizeof(struct klist *)); if (fdp->fd_knlist != NULL) FREE(fdp->fd_knlist, M_TEMP); fdp->fd_knlistsize = size; fdp->fd_knlist = list; } list = &fdp->fd_knlist[kn->kn_id]; done: SLIST_INSERT_HEAD(list, kn, kn_link); kn->kn_status = 0; } /* * should be called at spl == 0, since we don't want to hold spl * while calling fdrop and free. */ static void knote_drop(struct knote *kn, struct proc *p) { struct filedesc *fdp = p->p_fd; 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) fdrop(kn->kn_fp, p); knote_free(kn); } static void knote_enqueue(struct knote *kn) { struct kqueue *kq = kn->kn_kq; int s = splhigh(); KASSERT((kn->kn_status & KN_QUEUED) == 0, ("knote already queued")); TAILQ_INSERT_TAIL(&kq->kq_head, kn, kn_tqe); kn->kn_status |= KN_QUEUED; kq->kq_count++; splx(s); kqueue_wakeup(kq); } static void knote_dequeue(struct knote *kn) { struct kqueue *kq = kn->kn_kq; int s = splhigh(); KASSERT(kn->kn_status & KN_QUEUED, ("knote not queued")); TAILQ_REMOVE(&kq->kq_head, kn, kn_tqe); kn->kn_status &= ~KN_QUEUED; kq->kq_count--; splx(s); } static void knote_init(void) { knote_zone = zinit("KNOTE", sizeof(struct knote), 0, 0, 1); } SYSINIT(knote, SI_SUB_PSEUDO, SI_ORDER_ANY, knote_init, NULL) static struct knote * knote_alloc(void) { return ((struct knote *)zalloc(knote_zone)); } static void knote_free(struct knote *kn) { zfree(knote_zone, kn); }