/* * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94 * $FreeBSD: src/sys/kern/sys_generic.c,v 1.55.2.10 2001/03/17 10:39:32 peter Exp $ * $DragonFly: src/sys/kern/sys_generic.c,v 1.16 2004/01/07 11:04:18 dillon Exp $ */ #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include #include #include #include static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer"); static MALLOC_DEFINE(M_SELECT, "select", "select() buffer"); MALLOC_DEFINE(M_IOV, "iov", "large iov's"); static int pollscan (struct proc *, struct pollfd *, u_int, int *); static int selscan (struct proc *, fd_mask **, fd_mask **, int, int *); struct file* holdfp(fdp, fd, flag) struct filedesc* fdp; int fd, flag; { struct file* fp; if (((u_int)fd) >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL || (fp->f_flag & flag) == 0) { return (NULL); } fhold(fp); return (fp); } /* * Read system call. */ int read(struct read_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov; int error; aiov.iov_base = uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = -1; auio.uio_resid = uap->nbyte; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_readv(uap->fd, &auio, 0, &uap->sysmsg_result); return(error); } /* * Pread system call */ int pread(struct pread_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov; int error; aiov.iov_base = uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = uap->offset; auio.uio_resid = uap->nbyte; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_readv(uap->fd, &auio, FOF_OFFSET, &uap->sysmsg_result); return(error); } int readv(struct readv_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov[UIO_SMALLIOV], *iov = NULL; int error; error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt, &auio.uio_resid); if (error) return (error); auio.uio_iov = iov; auio.uio_iovcnt = uap->iovcnt; auio.uio_offset = -1; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_readv(uap->fd, &auio, 0, &uap->sysmsg_result); iovec_free(&iov, aiov); return (error); } int kern_readv(int fd, struct uio *auio, int flags, int *res) { struct thread *td = curthread; struct proc *p = td->td_proc; struct file *fp; struct filedesc *fdp = p->p_fd; int len, error; #ifdef KTRACE struct iovec *ktriov = NULL; struct uio ktruio; #endif KKASSERT(p); fp = holdfp(fdp, fd, FREAD); if (fp == NULL) return (EBADF); if (flags & FOF_OFFSET && fp->f_type != DTYPE_VNODE) { error = ESPIPE; goto done; } if (auio->uio_resid < 0) { error = EINVAL; goto done; } #ifdef KTRACE /* * if tracing, save a copy of iovec */ if (KTRPOINT(td, KTR_GENIO)) { int iovlen = auio->uio_iovcnt * sizeof(struct iovec); MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen); ktruio = *auio; } #endif len = auio->uio_resid; error = fo_read(fp, auio, fp->f_cred, flags, td); if (error) { if (auio->uio_resid != len && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; } #ifdef KTRACE if (ktriov != NULL) { if (error == 0) { ktruio.uio_iov = ktriov; ktruio.uio_resid = len - auio->uio_resid; ktrgenio(p->p_tracep, fd, UIO_READ, &ktruio, error); } FREE(ktriov, M_TEMP); } #endif if (error == 0) *res = len - auio->uio_resid; done: fdrop(fp, td); return (error); } /* * Write system call */ int write(struct write_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov; int error; aiov.iov_base = (void *)(uintptr_t)uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = -1; auio.uio_resid = uap->nbyte; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_writev(uap->fd, &auio, 0, &uap->sysmsg_result); return(error); } /* * Pwrite system call */ int pwrite(struct pwrite_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov; int error; aiov.iov_base = (void *)(uintptr_t)uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_offset = uap->offset; auio.uio_resid = uap->nbyte; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_writev(uap->fd, &auio, FOF_OFFSET, &uap->sysmsg_result); return(error); } int writev(struct writev_args *uap) { struct thread *td = curthread; struct uio auio; struct iovec aiov[UIO_SMALLIOV], *iov = NULL; int error; error = iovec_copyin(uap->iovp, &iov, aiov, uap->iovcnt, &auio.uio_resid); if (error) return (error); auio.uio_iov = iov; auio.uio_iovcnt = uap->iovcnt; auio.uio_offset = -1; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_USERSPACE; auio.uio_td = td; error = kern_writev(uap->fd, &auio, 0, &uap->sysmsg_result); iovec_free(&iov, aiov); return (error); } /* * Gather write system call */ int kern_writev(int fd, struct uio *auio, int flags, int *res) { struct thread *td = curthread; struct proc *p = td->td_proc; struct file *fp; struct filedesc *fdp = p->p_fd; long len, error; #ifdef KTRACE struct iovec *ktriov = NULL; struct uio ktruio; #endif KKASSERT(p); fp = holdfp(fdp, fd, FWRITE); if (fp == NULL) return (EBADF); if ((flags & FOF_OFFSET) && fp->f_type != DTYPE_VNODE) { error = ESPIPE; goto done; } if (auio->uio_resid < 0) { error = EINVAL; goto done; } #ifdef KTRACE /* * if tracing, save a copy of iovec and uio */ if (KTRPOINT(td, KTR_GENIO)) { int iovlen = auio->uio_iovcnt * sizeof(struct iovec); MALLOC(ktriov, struct iovec *, iovlen, M_TEMP, M_WAITOK); bcopy((caddr_t)auio->uio_iov, (caddr_t)ktriov, iovlen); ktruio = *auio; } #endif len = auio->uio_resid; if (fp->f_type == DTYPE_VNODE) bwillwrite(); error = fo_write(fp, auio, fp->f_cred, flags, td); if (error) { if (auio->uio_resid != len && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; if (error == EPIPE) psignal(p, SIGPIPE); } #ifdef KTRACE if (ktriov != NULL) { if (error == 0) { ktruio.uio_iov = ktriov; ktruio.uio_resid = len - auio->uio_resid; ktrgenio(p->p_tracep, fd, UIO_WRITE, &ktruio, error); } FREE(ktriov, M_TEMP); } #endif if (error == 0) *res = len - auio->uio_resid; done: fdrop(fp, td); return (error); } /* * Ioctl system call */ /* ARGSUSED */ int ioctl(struct ioctl_args *uap) { struct thread *td = curthread; struct proc *p = td->td_proc; struct file *fp; struct filedesc *fdp; u_long com; int error; u_int size; caddr_t data, memp; int tmp; #define STK_PARAMS 128 union { char stkbuf[STK_PARAMS]; long align; } ubuf; KKASSERT(p); fdp = p->p_fd; if ((u_int)uap->fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[uap->fd]) == NULL) return (EBADF); if ((fp->f_flag & (FREAD | FWRITE)) == 0) return (EBADF); switch (com = uap->com) { case FIONCLEX: fdp->fd_ofileflags[uap->fd] &= ~UF_EXCLOSE; return (0); case FIOCLEX: fdp->fd_ofileflags[uap->fd] |= UF_EXCLOSE; return (0); } /* * Interpret high order word to find amount of data to be * copied to/from the user's address space. */ size = IOCPARM_LEN(com); if (size > IOCPARM_MAX) return (ENOTTY); fhold(fp); memp = NULL; if (size > sizeof (ubuf.stkbuf)) { memp = (caddr_t)malloc((u_long)size, M_IOCTLOPS, M_WAITOK); data = memp; } else { data = ubuf.stkbuf; } if (com&IOC_IN) { if (size) { error = copyin(uap->data, data, (u_int)size); if (error) { if (memp) free(memp, M_IOCTLOPS); fdrop(fp, td); return (error); } } else { *(caddr_t *)data = uap->data; } } else if ((com&IOC_OUT) && size) { /* * Zero the buffer so the user always * gets back something deterministic. */ bzero(data, size); } else if (com&IOC_VOID) { *(caddr_t *)data = uap->data; } switch (com) { case FIONBIO: if ((tmp = *(int *)data)) fp->f_flag |= FNONBLOCK; else fp->f_flag &= ~FNONBLOCK; error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td); break; case FIOASYNC: if ((tmp = *(int *)data)) fp->f_flag |= FASYNC; else fp->f_flag &= ~FASYNC; error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, td); break; default: error = fo_ioctl(fp, com, data, td); /* * Copy any data to user, size was * already set and checked above. */ if (error == 0 && (com&IOC_OUT) && size) error = copyout(data, uap->data, (u_int)size); break; } if (memp) free(memp, M_IOCTLOPS); fdrop(fp, td); return (error); } static int nselcoll; /* Select collisions since boot */ int selwait; SYSCTL_INT(_kern, OID_AUTO, nselcoll, CTLFLAG_RD, &nselcoll, 0, ""); /* * Select system call. */ int select(struct select_args *uap) { struct proc *p = curproc; /* * The magic 2048 here is chosen to be just enough for FD_SETSIZE * infds with the new FD_SETSIZE of 1024, and more than enough for * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE * of 256. */ fd_mask s_selbits[howmany(2048, NFDBITS)]; fd_mask *ibits[3], *obits[3], *selbits, *sbp; struct timeval atv, rtv, ttv; int s, ncoll, error, timo; u_int nbufbytes, ncpbytes, nfdbits; if (uap->nd < 0) return (EINVAL); if (uap->nd > p->p_fd->fd_nfiles) uap->nd = p->p_fd->fd_nfiles; /* forgiving; slightly wrong */ /* * Allocate just enough bits for the non-null fd_sets. Use the * preallocated auto buffer if possible. */ nfdbits = roundup(uap->nd, NFDBITS); ncpbytes = nfdbits / NBBY; nbufbytes = 0; if (uap->in != NULL) nbufbytes += 2 * ncpbytes; if (uap->ou != NULL) nbufbytes += 2 * ncpbytes; if (uap->ex != NULL) nbufbytes += 2 * ncpbytes; if (nbufbytes <= sizeof s_selbits) selbits = &s_selbits[0]; else selbits = malloc(nbufbytes, M_SELECT, M_WAITOK); /* * Assign pointers into the bit buffers and fetch the input bits. * Put the output buffers together so that they can be bzeroed * together. */ sbp = selbits; #define getbits(name, x) \ do { \ if (uap->name == NULL) \ ibits[x] = NULL; \ else { \ ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ obits[x] = sbp; \ sbp += ncpbytes / sizeof *sbp; \ error = copyin(uap->name, ibits[x], ncpbytes); \ if (error != 0) \ goto done; \ } \ } while (0) getbits(in, 0); getbits(ou, 1); getbits(ex, 2); #undef getbits if (nbufbytes != 0) bzero(selbits, nbufbytes / 2); if (uap->tv) { error = copyin((caddr_t)uap->tv, (caddr_t)&atv, sizeof (atv)); if (error) goto done; if (itimerfix(&atv)) { error = EINVAL; goto done; } getmicrouptime(&rtv); timevaladd(&atv, &rtv); } else { atv.tv_sec = 0; atv.tv_usec = 0; } timo = 0; retry: ncoll = nselcoll; p->p_flag |= P_SELECT; error = selscan(p, ibits, obits, uap->nd, &uap->sysmsg_result); if (error || uap->sysmsg_result) goto done; if (atv.tv_sec || atv.tv_usec) { getmicrouptime(&rtv); if (timevalcmp(&rtv, &atv, >=)) goto done; ttv = atv; timevalsub(&ttv, &rtv); timo = ttv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz_high(&ttv); } s = splhigh(); if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { splx(s); goto retry; } p->p_flag &= ~P_SELECT; error = tsleep((caddr_t)&selwait, PCATCH, "select", timo); splx(s); if (error == 0) goto retry; done: p->p_flag &= ~P_SELECT; /* select is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; #define putbits(name, x) \ if (uap->name && (error2 = copyout(obits[x], uap->name, ncpbytes))) \ error = error2; if (error == 0) { int error2; putbits(in, 0); putbits(ou, 1); putbits(ex, 2); #undef putbits } if (selbits != &s_selbits[0]) free(selbits, M_SELECT); return (error); } static int selscan(struct proc *p, fd_mask **ibits, fd_mask **obits, int nfd, int *res) { struct thread *td = p->p_thread; struct filedesc *fdp = p->p_fd; int msk, i, fd; fd_mask bits; struct file *fp; int n = 0; /* Note: backend also returns POLLHUP/POLLERR if appropriate. */ static int flag[3] = { POLLRDNORM, POLLWRNORM, POLLRDBAND }; for (msk = 0; msk < 3; msk++) { if (ibits[msk] == NULL) continue; for (i = 0; i < nfd; i += NFDBITS) { bits = ibits[msk][i/NFDBITS]; /* ffs(int mask) not portable, fd_mask is long */ for (fd = i; bits && fd < nfd; fd++, bits >>= 1) { if (!(bits & 1)) continue; fp = fdp->fd_ofiles[fd]; if (fp == NULL) return (EBADF); if (fo_poll(fp, flag[msk], fp->f_cred, td)) { obits[msk][(fd)/NFDBITS] |= ((fd_mask)1 << ((fd) % NFDBITS)); n++; } } } } *res = n; return (0); } /* * Poll system call. */ int poll(struct poll_args *uap) { caddr_t bits; char smallbits[32 * sizeof(struct pollfd)]; struct timeval atv, rtv, ttv; int s, ncoll, error = 0, timo; u_int nfds; size_t ni; struct proc *p = curproc; nfds = SCARG(uap, nfds); /* * This is kinda bogus. We have fd limits, but that is not * really related to the size of the pollfd array. Make sure * we let the process use at least FD_SETSIZE entries and at * least enough for the current limits. We want to be reasonably * safe, but not overly restrictive. */ if (nfds > p->p_rlimit[RLIMIT_NOFILE].rlim_cur && nfds > FD_SETSIZE) return (EINVAL); ni = nfds * sizeof(struct pollfd); if (ni > sizeof(smallbits)) bits = malloc(ni, M_TEMP, M_WAITOK); else bits = smallbits; error = copyin(SCARG(uap, fds), bits, ni); if (error) goto done; if (SCARG(uap, timeout) != INFTIM) { atv.tv_sec = SCARG(uap, timeout) / 1000; atv.tv_usec = (SCARG(uap, timeout) % 1000) * 1000; if (itimerfix(&atv)) { error = EINVAL; goto done; } getmicrouptime(&rtv); timevaladd(&atv, &rtv); } else { atv.tv_sec = 0; atv.tv_usec = 0; } timo = 0; retry: ncoll = nselcoll; p->p_flag |= P_SELECT; error = pollscan(p, (struct pollfd *)bits, nfds, &uap->sysmsg_result); if (error || uap->sysmsg_result) goto done; if (atv.tv_sec || atv.tv_usec) { getmicrouptime(&rtv); if (timevalcmp(&rtv, &atv, >=)) goto done; ttv = atv; timevalsub(&ttv, &rtv); timo = ttv.tv_sec > 24 * 60 * 60 ? 24 * 60 * 60 * hz : tvtohz_high(&ttv); } s = splhigh(); if ((p->p_flag & P_SELECT) == 0 || nselcoll != ncoll) { splx(s); goto retry; } p->p_flag &= ~P_SELECT; error = tsleep((caddr_t)&selwait, PCATCH, "poll", timo); splx(s); if (error == 0) goto retry; done: p->p_flag &= ~P_SELECT; /* poll is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; if (error == 0) { error = copyout(bits, SCARG(uap, fds), ni); if (error) goto out; } out: if (ni > sizeof(smallbits)) free(bits, M_TEMP); return (error); } static int pollscan(struct proc *p, struct pollfd *fds, u_int nfd, int *res) { struct thread *td = p->p_thread; struct filedesc *fdp = p->p_fd; int i; struct file *fp; int n = 0; for (i = 0; i < nfd; i++, fds++) { if (fds->fd >= fdp->fd_nfiles) { fds->revents = POLLNVAL; n++; } else if (fds->fd < 0) { fds->revents = 0; } else { fp = fdp->fd_ofiles[fds->fd]; if (fp == NULL) { fds->revents = POLLNVAL; n++; } else { /* * Note: backend also returns POLLHUP and * POLLERR if appropriate. */ fds->revents = fo_poll(fp, fds->events, fp->f_cred, td); if (fds->revents != 0) n++; } } } *res = n; return (0); } /* * OpenBSD poll system call. * XXX this isn't quite a true representation.. OpenBSD uses select ops. */ int openbsd_poll(struct openbsd_poll_args *uap) { return (poll((struct poll_args *)uap)); } /*ARGSUSED*/ int seltrue(dev_t dev, int events, struct thread *td) { return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); } /* * Record a select request. A global wait must be used since a process/thread * might go away after recording its request. */ void selrecord(struct thread *selector, struct selinfo *sip) { struct proc *p; pid_t mypid; if ((p = selector->td_proc) == NULL) panic("selrecord: thread needs a process"); mypid = p->p_pid; if (sip->si_pid == mypid) return; if (sip->si_pid && (p = pfind(sip->si_pid)) && p->p_wchan == (caddr_t)&selwait) { sip->si_flags |= SI_COLL; } else { sip->si_pid = mypid; } } /* * Do a wakeup when a selectable event occurs. */ void selwakeup(struct selinfo *sip) { struct proc *p; int s; if (sip->si_pid == 0) return; if (sip->si_flags & SI_COLL) { nselcoll++; sip->si_flags &= ~SI_COLL; wakeup((caddr_t)&selwait); /* YYY fixable */ } p = pfind(sip->si_pid); sip->si_pid = 0; if (p != NULL) { s = splhigh(); if (p->p_wchan == (caddr_t)&selwait) { if (p->p_stat == SSLEEP) setrunnable(p); else unsleep(p->p_thread); } else if (p->p_flag & P_SELECT) p->p_flag &= ~P_SELECT; splx(s); } }