/*- * 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. * 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 */ #include __FBSDID("$FreeBSD$"); #include "opt_capsicum.h" #include "opt_compat.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #endif #include /* * The following macro defines how many bytes will be allocated from * the stack instead of memory allocated when passing the IOCTL data * structures from userspace and to the kernel. Some IOCTLs having * small data structures are used very frequently and this small * buffer on the stack gives a significant speedup improvement for * those requests. The value of this define should be greater or equal * to 64 bytes and should also be power of two. The data structure is * currently hard-aligned to a 8-byte boundary on the stack. This * should currently be sufficient for all supported platforms. */ #define SYS_IOCTL_SMALL_SIZE 128 /* bytes */ #define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */ int iosize_max_clamp = 1; SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX"); int devfs_iosize_max_clamp = 1; SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW, &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices"); /* * Assert that the return value of read(2) and write(2) syscalls fits * into a register. If not, an architecture will need to provide the * usermode wrappers to reconstruct the result. */ CTASSERT(sizeof(register_t) >= sizeof(size_t)); 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 pollout(struct thread *, struct pollfd *, struct pollfd *, u_int); static int pollscan(struct thread *, struct pollfd *, u_int); static int pollrescan(struct thread *); static int selscan(struct thread *, fd_mask **, fd_mask **, int); static int selrescan(struct thread *, fd_mask **, fd_mask **); static void selfdalloc(struct thread *, void *); static void selfdfree(struct seltd *, struct selfd *); static int dofileread(struct thread *, int, struct file *, struct uio *, off_t, int); static int dofilewrite(struct thread *, int, struct file *, struct uio *, off_t, int); static void doselwakeup(struct selinfo *, int); static void seltdinit(struct thread *); static int seltdwait(struct thread *, sbintime_t, sbintime_t); static void seltdclear(struct thread *); /* * One seltd per-thread allocated on demand as needed. * * t - protected by st_mtx * k - Only accessed by curthread or read-only */ struct seltd { STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */ struct selfd *st_free1; /* (k) free fd for read set. */ struct selfd *st_free2; /* (k) free fd for write set. */ struct mtx st_mtx; /* Protects struct seltd */ struct cv st_wait; /* (t) Wait channel. */ int st_flags; /* (t) SELTD_ flags. */ }; #define SELTD_PENDING 0x0001 /* We have pending events. */ #define SELTD_RESCAN 0x0002 /* Doing a rescan. */ /* * One selfd allocated per-thread per-file-descriptor. * f - protected by sf_mtx */ struct selfd { STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */ TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */ struct selinfo *sf_si; /* (f) selinfo when linked. */ struct mtx *sf_mtx; /* Pointer to selinfo mtx. */ struct seltd *sf_td; /* (k) owning seltd. */ void *sf_cookie; /* (k) fd or pollfd. */ }; static uma_zone_t selfd_zone; static struct mtx_pool *mtxpool_select; #ifndef _SYS_SYSPROTO_H_ struct read_args { int fd; void *buf; size_t nbyte; }; #endif int sys_read(td, uap) struct thread *td; struct read_args *uap; { struct uio auio; struct iovec aiov; int error; if (uap->nbyte > IOSIZE_MAX) return (EINVAL); aiov.iov_base = uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = uap->nbyte; auio.uio_segflg = UIO_USERSPACE; error = kern_readv(td, uap->fd, &auio); return(error); } /* * Positioned read system call */ #ifndef _SYS_SYSPROTO_H_ struct pread_args { int fd; void *buf; size_t nbyte; int pad; off_t offset; }; #endif int sys_pread(td, uap) struct thread *td; struct pread_args *uap; { struct uio auio; struct iovec aiov; int error; if (uap->nbyte > IOSIZE_MAX) return (EINVAL); aiov.iov_base = uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = uap->nbyte; auio.uio_segflg = UIO_USERSPACE; error = kern_preadv(td, uap->fd, &auio, uap->offset); return(error); } int freebsd6_pread(td, uap) struct thread *td; struct freebsd6_pread_args *uap; { struct pread_args oargs; oargs.fd = uap->fd; oargs.buf = uap->buf; oargs.nbyte = uap->nbyte; oargs.offset = uap->offset; return (sys_pread(td, &oargs)); } /* * Scatter read system call. */ #ifndef _SYS_SYSPROTO_H_ struct readv_args { int fd; struct iovec *iovp; u_int iovcnt; }; #endif int sys_readv(struct thread *td, struct readv_args *uap) { struct uio *auio; int error; error = copyinuio(uap->iovp, uap->iovcnt, &auio); if (error) return (error); error = kern_readv(td, uap->fd, auio); free(auio, M_IOV); return (error); } int kern_readv(struct thread *td, int fd, struct uio *auio) { struct file *fp; cap_rights_t rights; int error; error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp); if (error) return (error); error = dofileread(td, fd, fp, auio, (off_t)-1, 0); fdrop(fp, td); return (error); } /* * Scatter positioned read system call. */ #ifndef _SYS_SYSPROTO_H_ struct preadv_args { int fd; struct iovec *iovp; u_int iovcnt; off_t offset; }; #endif int sys_preadv(struct thread *td, struct preadv_args *uap) { struct uio *auio; int error; error = copyinuio(uap->iovp, uap->iovcnt, &auio); if (error) return (error); error = kern_preadv(td, uap->fd, auio, uap->offset); free(auio, M_IOV); return (error); } int kern_preadv(td, fd, auio, offset) struct thread *td; int fd; struct uio *auio; off_t offset; { struct file *fp; cap_rights_t rights; int error; error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp); if (error) return (error); if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) error = ESPIPE; else if (offset < 0 && fp->f_vnode->v_type != VCHR) error = EINVAL; else error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET); fdrop(fp, td); return (error); } /* * Common code for readv and preadv that reads data in * from a file using the passed in uio, offset, and flags. */ static int dofileread(td, fd, fp, auio, offset, flags) struct thread *td; int fd; struct file *fp; struct uio *auio; off_t offset; int flags; { ssize_t cnt; int error; #ifdef KTRACE struct uio *ktruio = NULL; #endif /* Finish zero length reads right here */ if (auio->uio_resid == 0) { td->td_retval[0] = 0; return(0); } auio->uio_rw = UIO_READ; auio->uio_offset = offset; auio->uio_td = td; #ifdef KTRACE if (KTRPOINT(td, KTR_GENIO)) ktruio = cloneuio(auio); #endif cnt = auio->uio_resid; if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { if (auio->uio_resid != cnt && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; } cnt -= auio->uio_resid; #ifdef KTRACE if (ktruio != NULL) { ktruio->uio_resid = cnt; ktrgenio(fd, UIO_READ, ktruio, error); } #endif td->td_retval[0] = cnt; return (error); } #ifndef _SYS_SYSPROTO_H_ struct write_args { int fd; const void *buf; size_t nbyte; }; #endif int sys_write(td, uap) struct thread *td; struct write_args *uap; { struct uio auio; struct iovec aiov; int error; if (uap->nbyte > IOSIZE_MAX) return (EINVAL); aiov.iov_base = (void *)(uintptr_t)uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = uap->nbyte; auio.uio_segflg = UIO_USERSPACE; error = kern_writev(td, uap->fd, &auio); return(error); } /* * Positioned write system call. */ #ifndef _SYS_SYSPROTO_H_ struct pwrite_args { int fd; const void *buf; size_t nbyte; int pad; off_t offset; }; #endif int sys_pwrite(td, uap) struct thread *td; struct pwrite_args *uap; { struct uio auio; struct iovec aiov; int error; if (uap->nbyte > IOSIZE_MAX) return (EINVAL); aiov.iov_base = (void *)(uintptr_t)uap->buf; aiov.iov_len = uap->nbyte; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = uap->nbyte; auio.uio_segflg = UIO_USERSPACE; error = kern_pwritev(td, uap->fd, &auio, uap->offset); return(error); } int freebsd6_pwrite(td, uap) struct thread *td; struct freebsd6_pwrite_args *uap; { struct pwrite_args oargs; oargs.fd = uap->fd; oargs.buf = uap->buf; oargs.nbyte = uap->nbyte; oargs.offset = uap->offset; return (sys_pwrite(td, &oargs)); } /* * Gather write system call. */ #ifndef _SYS_SYSPROTO_H_ struct writev_args { int fd; struct iovec *iovp; u_int iovcnt; }; #endif int sys_writev(struct thread *td, struct writev_args *uap) { struct uio *auio; int error; error = copyinuio(uap->iovp, uap->iovcnt, &auio); if (error) return (error); error = kern_writev(td, uap->fd, auio); free(auio, M_IOV); return (error); } int kern_writev(struct thread *td, int fd, struct uio *auio) { struct file *fp; cap_rights_t rights; int error; error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp); if (error) return (error); error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); fdrop(fp, td); return (error); } /* * Gather positioned write system call. */ #ifndef _SYS_SYSPROTO_H_ struct pwritev_args { int fd; struct iovec *iovp; u_int iovcnt; off_t offset; }; #endif int sys_pwritev(struct thread *td, struct pwritev_args *uap) { struct uio *auio; int error; error = copyinuio(uap->iovp, uap->iovcnt, &auio); if (error) return (error); error = kern_pwritev(td, uap->fd, auio, uap->offset); free(auio, M_IOV); return (error); } int kern_pwritev(td, fd, auio, offset) struct thread *td; struct uio *auio; int fd; off_t offset; { struct file *fp; cap_rights_t rights; int error; error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp); if (error) return (error); if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) error = ESPIPE; else if (offset < 0 && fp->f_vnode->v_type != VCHR) error = EINVAL; else error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET); fdrop(fp, td); return (error); } /* * Common code for writev and pwritev that writes data to * a file using the passed in uio, offset, and flags. */ static int dofilewrite(td, fd, fp, auio, offset, flags) struct thread *td; int fd; struct file *fp; struct uio *auio; off_t offset; int flags; { ssize_t cnt; int error; #ifdef KTRACE struct uio *ktruio = NULL; #endif auio->uio_rw = UIO_WRITE; auio->uio_td = td; auio->uio_offset = offset; #ifdef KTRACE if (KTRPOINT(td, KTR_GENIO)) ktruio = cloneuio(auio); #endif cnt = auio->uio_resid; if (fp->f_type == DTYPE_VNODE && (fp->f_vnread_flags & FDEVFS_VNODE) == 0) bwillwrite(); if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) { if (auio->uio_resid != cnt && (error == ERESTART || error == EINTR || error == EWOULDBLOCK)) error = 0; /* Socket layer is responsible for issuing SIGPIPE. */ if (fp->f_type != DTYPE_SOCKET && error == EPIPE) { PROC_LOCK(td->td_proc); tdsignal(td, SIGPIPE); PROC_UNLOCK(td->td_proc); } } cnt -= auio->uio_resid; #ifdef KTRACE if (ktruio != NULL) { ktruio->uio_resid = cnt; ktrgenio(fd, UIO_WRITE, ktruio, error); } #endif td->td_retval[0] = cnt; return (error); } /* * Truncate a file given a file descriptor. * * Can't use fget_write() here, since must return EINVAL and not EBADF if the * descriptor isn't writable. */ int kern_ftruncate(td, fd, length) struct thread *td; int fd; off_t length; { struct file *fp; cap_rights_t rights; int error; AUDIT_ARG_FD(fd); if (length < 0) return (EINVAL); error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp); if (error) return (error); AUDIT_ARG_FILE(td->td_proc, fp); if (!(fp->f_flag & FWRITE)) { fdrop(fp, td); return (EINVAL); } error = fo_truncate(fp, length, td->td_ucred, td); fdrop(fp, td); return (error); } #ifndef _SYS_SYSPROTO_H_ struct ftruncate_args { int fd; int pad; off_t length; }; #endif int sys_ftruncate(td, uap) struct thread *td; struct ftruncate_args *uap; { return (kern_ftruncate(td, uap->fd, uap->length)); } #if defined(COMPAT_43) #ifndef _SYS_SYSPROTO_H_ struct oftruncate_args { int fd; long length; }; #endif int oftruncate(td, uap) struct thread *td; struct oftruncate_args *uap; { return (kern_ftruncate(td, uap->fd, uap->length)); } #endif /* COMPAT_43 */ #ifndef _SYS_SYSPROTO_H_ struct ioctl_args { int fd; u_long com; caddr_t data; }; #endif /* ARGSUSED */ int sys_ioctl(struct thread *td, struct ioctl_args *uap) { u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); u_long com; int arg, error; u_int size; caddr_t data; if (uap->com > 0xffffffff) { printf( "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n", td->td_proc->p_pid, td->td_name, uap->com); uap->com &= 0xffffffff; } com = uap->com; /* * 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) || ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) || #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43) ((com & IOC_OUT) && size == 0) || #else ((com & (IOC_IN | IOC_OUT)) && size == 0) || #endif ((com & IOC_VOID) && size > 0 && size != sizeof(int))) return (ENOTTY); if (size > 0) { if (com & IOC_VOID) { /* Integer argument. */ arg = (intptr_t)uap->data; data = (void *)&arg; size = 0; } else { if (size > SYS_IOCTL_SMALL_SIZE) data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); else data = smalldata; } } else data = (void *)&uap->data; if (com & IOC_IN) { error = copyin(uap->data, data, (u_int)size); if (error != 0) goto out; } else if (com & IOC_OUT) { /* * Zero the buffer so the user always * gets back something deterministic. */ bzero(data, size); } error = kern_ioctl(td, uap->fd, com, data); if (error == 0 && (com & IOC_OUT)) error = copyout(data, uap->data, (u_int)size); out: if (size > SYS_IOCTL_SMALL_SIZE) free(data, M_IOCTLOPS); return (error); } int kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) { struct file *fp; struct filedesc *fdp; #ifndef CAPABILITIES cap_rights_t rights; #endif int error, tmp, locked; AUDIT_ARG_FD(fd); AUDIT_ARG_CMD(com); fdp = td->td_proc->p_fd; switch (com) { case FIONCLEX: case FIOCLEX: FILEDESC_XLOCK(fdp); locked = LA_XLOCKED; break; default: #ifdef CAPABILITIES FILEDESC_SLOCK(fdp); locked = LA_SLOCKED; #else locked = LA_UNLOCKED; #endif break; } #ifdef CAPABILITIES if ((fp = fget_locked(fdp, fd)) == NULL) { error = EBADF; goto out; } if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { fp = NULL; /* fhold() was not called yet */ goto out; } fhold(fp); if (locked == LA_SLOCKED) { FILEDESC_SUNLOCK(fdp); locked = LA_UNLOCKED; } #else error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp); if (error != 0) { fp = NULL; goto out; } #endif if ((fp->f_flag & (FREAD | FWRITE)) == 0) { error = EBADF; goto out; } switch (com) { case FIONCLEX: fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; goto out; case FIOCLEX: fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; goto out; case FIONBIO: if ((tmp = *(int *)data)) atomic_set_int(&fp->f_flag, FNONBLOCK); else atomic_clear_int(&fp->f_flag, FNONBLOCK); data = (void *)&tmp; break; case FIOASYNC: if ((tmp = *(int *)data)) atomic_set_int(&fp->f_flag, FASYNC); else atomic_clear_int(&fp->f_flag, FASYNC); data = (void *)&tmp; break; } error = fo_ioctl(fp, com, data, td->td_ucred, td); out: switch (locked) { case LA_XLOCKED: FILEDESC_XUNLOCK(fdp); break; #ifdef CAPABILITIES case LA_SLOCKED: FILEDESC_SUNLOCK(fdp); break; #endif default: FILEDESC_UNLOCK_ASSERT(fdp); break; } if (fp != NULL) fdrop(fp, td); return (error); } int poll_no_poll(int events) { /* * Return true for read/write. If the user asked for something * special, return POLLNVAL, so that clients have a way of * determining reliably whether or not the extended * functionality is present without hard-coding knowledge * of specific filesystem implementations. */ if (events & ~POLLSTANDARD) return (POLLNVAL); return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); } int sys_pselect(struct thread *td, struct pselect_args *uap) { struct timespec ts; struct timeval tv, *tvp; sigset_t set, *uset; int error; if (uap->ts != NULL) { error = copyin(uap->ts, &ts, sizeof(ts)); if (error != 0) return (error); TIMESPEC_TO_TIMEVAL(&tv, &ts); tvp = &tv; } else tvp = NULL; if (uap->sm != NULL) { error = copyin(uap->sm, &set, sizeof(set)); if (error != 0) return (error); uset = &set; } else uset = NULL; return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, uset, NFDBITS)); } int kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timeval *tvp, sigset_t *uset, int abi_nfdbits) { int error; if (uset != NULL) { error = kern_sigprocmask(td, SIG_SETMASK, uset, &td->td_oldsigmask, 0); if (error != 0) return (error); td->td_pflags |= TDP_OLDMASK; /* * Make sure that ast() is called on return to * usermode and TDP_OLDMASK is cleared, restoring old * sigmask. */ thread_lock(td); td->td_flags |= TDF_ASTPENDING; thread_unlock(td); } error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits); return (error); } #ifndef _SYS_SYSPROTO_H_ struct select_args { int nd; fd_set *in, *ou, *ex; struct timeval *tv; }; #endif int sys_select(struct thread *td, struct select_args *uap) { struct timeval tv, *tvp; int error; if (uap->tv != NULL) { error = copyin(uap->tv, &tv, sizeof(tv)); if (error) return (error); tvp = &tv; } else tvp = NULL; return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp, NFDBITS)); } /* * In the unlikely case when user specified n greater then the last * open file descriptor, check that no bits are set after the last * valid fd. We must return EBADF if any is set. * * There are applications that rely on the behaviour. * * nd is fd_lastfile + 1. */ static int select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits) { char *addr, *oaddr; int b, i, res; uint8_t bits; if (nd >= ndu || fd_in == NULL) return (0); oaddr = NULL; bits = 0; /* silence gcc */ for (i = nd; i < ndu; i++) { b = i / NBBY; #if BYTE_ORDER == LITTLE_ENDIAN addr = (char *)fd_in + b; #else addr = (char *)fd_in; if (abi_nfdbits == NFDBITS) { addr += rounddown(b, sizeof(fd_mask)) + sizeof(fd_mask) - 1 - b % sizeof(fd_mask); } else { addr += rounddown(b, sizeof(uint32_t)) + sizeof(uint32_t) - 1 - b % sizeof(uint32_t); } #endif if (addr != oaddr) { res = fubyte(addr); if (res == -1) return (EFAULT); oaddr = addr; bits = res; } if ((bits & (1 << (i % NBBY))) != 0) return (EBADF); } return (0); } int kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou, fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits) { struct filedesc *fdp; /* * 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 rtv; sbintime_t asbt, precision, rsbt; u_int nbufbytes, ncpbytes, ncpubytes, nfdbits; int error, lf, ndu; if (nd < 0) return (EINVAL); fdp = td->td_proc->p_fd; ndu = nd; lf = fdp->fd_lastfile; if (nd > lf + 1) nd = lf + 1; error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits); if (error != 0) return (error); error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits); if (error != 0) return (error); error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits); if (error != 0) return (error); /* * Allocate just enough bits for the non-null fd_sets. Use the * preallocated auto buffer if possible. */ nfdbits = roundup(nd, NFDBITS); ncpbytes = nfdbits / NBBY; ncpubytes = roundup(nd, abi_nfdbits) / NBBY; nbufbytes = 0; if (fd_in != NULL) nbufbytes += 2 * ncpbytes; if (fd_ou != NULL) nbufbytes += 2 * ncpbytes; if (fd_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 (name == NULL) { \ ibits[x] = NULL; \ obits[x] = NULL; \ } else { \ ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \ obits[x] = sbp; \ sbp += ncpbytes / sizeof *sbp; \ error = copyin(name, ibits[x], ncpubytes); \ if (error != 0) \ goto done; \ bzero((char *)ibits[x] + ncpubytes, \ ncpbytes - ncpubytes); \ } \ } while (0) getbits(fd_in, 0); getbits(fd_ou, 1); getbits(fd_ex, 2); #undef getbits #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__) /* * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS, * we are running under 32-bit emulation. This should be more * generic. */ #define swizzle_fdset(bits) \ if (abi_nfdbits != NFDBITS && bits != NULL) { \ int i; \ for (i = 0; i < ncpbytes / sizeof *sbp; i++) \ bits[i] = (bits[i] >> 32) | (bits[i] << 32); \ } #else #define swizzle_fdset(bits) #endif /* Make sure the bit order makes it through an ABI transition */ swizzle_fdset(ibits[0]); swizzle_fdset(ibits[1]); swizzle_fdset(ibits[2]); if (nbufbytes != 0) bzero(selbits, nbufbytes / 2); precision = 0; if (tvp != NULL) { rtv = *tvp; if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || rtv.tv_usec >= 1000000) { error = EINVAL; goto done; } if (!timevalisset(&rtv)) asbt = 0; else if (rtv.tv_sec <= INT32_MAX) { rsbt = tvtosbt(rtv); precision = rsbt; precision >>= tc_precexp; if (TIMESEL(&asbt, rsbt)) asbt += tc_tick_sbt; if (asbt <= INT64_MAX - rsbt) asbt += rsbt; else asbt = -1; } else asbt = -1; } else asbt = -1; seltdinit(td); /* Iterate until the timeout expires or descriptors become ready. */ for (;;) { error = selscan(td, ibits, obits, nd); if (error || td->td_retval[0] != 0) break; error = seltdwait(td, asbt, precision); if (error) break; error = selrescan(td, ibits, obits); if (error || td->td_retval[0] != 0) break; } seltdclear(td); done: /* select is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; /* swizzle bit order back, if necessary */ swizzle_fdset(obits[0]); swizzle_fdset(obits[1]); swizzle_fdset(obits[2]); #undef swizzle_fdset #define putbits(name, x) \ if (name && (error2 = copyout(obits[x], name, ncpubytes))) \ error = error2; if (error == 0) { int error2; putbits(fd_in, 0); putbits(fd_ou, 1); putbits(fd_ex, 2); #undef putbits } if (selbits != &s_selbits[0]) free(selbits, M_SELECT); return (error); } /* * Convert a select bit set to poll flags. * * The backend always returns POLLHUP/POLLERR if appropriate and we * return this as a set bit in any set. */ static int select_flags[3] = { POLLRDNORM | POLLHUP | POLLERR, POLLWRNORM | POLLHUP | POLLERR, POLLRDBAND | POLLERR }; /* * Compute the fo_poll flags required for a fd given by the index and * bit position in the fd_mask array. */ static __inline int selflags(fd_mask **ibits, int idx, fd_mask bit) { int flags; int msk; flags = 0; for (msk = 0; msk < 3; msk++) { if (ibits[msk] == NULL) continue; if ((ibits[msk][idx] & bit) == 0) continue; flags |= select_flags[msk]; } return (flags); } /* * Set the appropriate output bits given a mask of fired events and the * input bits originally requested. */ static __inline int selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) { int msk; int n; n = 0; for (msk = 0; msk < 3; msk++) { if ((events & select_flags[msk]) == 0) continue; if (ibits[msk] == NULL) continue; if ((ibits[msk][idx] & bit) == 0) continue; /* * XXX Check for a duplicate set. This can occur because a * socket calls selrecord() twice for each poll() call * resulting in two selfds per real fd. selrescan() will * call selsetbits twice as a result. */ if ((obits[msk][idx] & bit) != 0) continue; obits[msk][idx] |= bit; n++; } return (n); } static __inline int getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) { cap_rights_t rights; cap_rights_init(&rights, CAP_EVENT); return (fget_unlocked(fdp, fd, &rights, 0, fpp, NULL)); } /* * Traverse the list of fds attached to this thread's seltd and check for * completion. */ static int selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits) { struct filedesc *fdp; struct selinfo *si; struct seltd *stp; struct selfd *sfp; struct selfd *sfn; struct file *fp; fd_mask bit; int fd, ev, n, idx; int error; fdp = td->td_proc->p_fd; stp = td->td_sel; n = 0; STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { fd = (int)(uintptr_t)sfp->sf_cookie; si = sfp->sf_si; selfdfree(stp, sfp); /* If the selinfo wasn't cleared the event didn't fire. */ if (si != NULL) continue; error = getselfd_cap(fdp, fd, &fp); if (error) return (error); idx = fd / NFDBITS; bit = (fd_mask)1 << (fd % NFDBITS); ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td); fdrop(fp, td); if (ev != 0) n += selsetbits(ibits, obits, idx, bit, ev); } stp->st_flags = 0; td->td_retval[0] = n; return (0); } /* * Perform the initial filedescriptor scan and register ourselves with * each selinfo. */ static int selscan(td, ibits, obits, nfd) struct thread *td; fd_mask **ibits, **obits; int nfd; { struct filedesc *fdp; struct file *fp; fd_mask bit; int ev, flags, end, fd; int n, idx; int error; fdp = td->td_proc->p_fd; n = 0; for (idx = 0, fd = 0; fd < nfd; idx++) { end = imin(fd + NFDBITS, nfd); for (bit = 1; fd < end; bit <<= 1, fd++) { /* Compute the list of events we're interested in. */ flags = selflags(ibits, idx, bit); if (flags == 0) continue; error = getselfd_cap(fdp, fd, &fp); if (error) return (error); selfdalloc(td, (void *)(uintptr_t)fd); ev = fo_poll(fp, flags, td->td_ucred, td); fdrop(fp, td); if (ev != 0) n += selsetbits(ibits, obits, idx, bit, ev); } } td->td_retval[0] = n; return (0); } int sys_poll(struct thread *td, struct poll_args *uap) { struct timespec ts, *tsp; if (uap->timeout != INFTIM) { if (uap->timeout < 0) return (EINVAL); ts.tv_sec = uap->timeout / 1000; ts.tv_nsec = (uap->timeout % 1000) * 1000000; tsp = &ts; } else tsp = NULL; return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL)); } int kern_poll(struct thread *td, struct pollfd *fds, u_int nfds, struct timespec *tsp, sigset_t *uset) { struct pollfd *bits; struct pollfd smallbits[32]; sbintime_t sbt, precision, tmp; time_t over; struct timespec ts; int error; size_t ni; precision = 0; if (tsp != NULL) { if (tsp->tv_sec < 0) return (EINVAL); if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000) return (EINVAL); if (tsp->tv_sec == 0 && tsp->tv_nsec == 0) sbt = 0; else { ts = *tsp; if (ts.tv_sec > INT32_MAX / 2) { over = ts.tv_sec - INT32_MAX / 2; ts.tv_sec -= over; } else over = 0; tmp = tstosbt(ts); precision = tmp; precision >>= tc_precexp; if (TIMESEL(&sbt, tmp)) sbt += tc_tick_sbt; sbt += tmp; } } else sbt = -1; if (nfds > maxfilesperproc && 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(fds, bits, ni); if (error) goto done; if (uset != NULL) { error = kern_sigprocmask(td, SIG_SETMASK, uset, &td->td_oldsigmask, 0); if (error) goto done; td->td_pflags |= TDP_OLDMASK; /* * Make sure that ast() is called on return to * usermode and TDP_OLDMASK is cleared, restoring old * sigmask. */ thread_lock(td); td->td_flags |= TDF_ASTPENDING; thread_unlock(td); } seltdinit(td); /* Iterate until the timeout expires or descriptors become ready. */ for (;;) { error = pollscan(td, bits, nfds); if (error || td->td_retval[0] != 0) break; error = seltdwait(td, sbt, precision); if (error) break; error = pollrescan(td); if (error || td->td_retval[0] != 0) break; } seltdclear(td); done: /* poll is not restarted after signals... */ if (error == ERESTART) error = EINTR; if (error == EWOULDBLOCK) error = 0; if (error == 0) { error = pollout(td, bits, fds, nfds); if (error) goto out; } out: if (ni > sizeof(smallbits)) free(bits, M_TEMP); return (error); } int sys_ppoll(struct thread *td, struct ppoll_args *uap) { struct timespec ts, *tsp; sigset_t set, *ssp; int error; if (uap->ts != NULL) { error = copyin(uap->ts, &ts, sizeof(ts)); if (error) return (error); tsp = &ts; } else tsp = NULL; if (uap->set != NULL) { error = copyin(uap->set, &set, sizeof(set)); if (error) return (error); ssp = &set; } else ssp = NULL; /* * fds is still a pointer to user space. kern_poll() will * take care of copyin that array to the kernel space. */ return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp)); } static int pollrescan(struct thread *td) { struct seltd *stp; struct selfd *sfp; struct selfd *sfn; struct selinfo *si; struct filedesc *fdp; struct file *fp; struct pollfd *fd; #ifdef CAPABILITIES cap_rights_t rights; #endif int n; n = 0; fdp = td->td_proc->p_fd; stp = td->td_sel; FILEDESC_SLOCK(fdp); STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) { fd = (struct pollfd *)sfp->sf_cookie; si = sfp->sf_si; selfdfree(stp, sfp); /* If the selinfo wasn't cleared the event didn't fire. */ if (si != NULL) continue; fp = fdp->fd_ofiles[fd->fd].fde_file; #ifdef CAPABILITIES if (fp == NULL || cap_check(cap_rights(fdp, fd->fd), cap_rights_init(&rights, CAP_EVENT)) != 0) #else if (fp == NULL) #endif { fd->revents = POLLNVAL; n++; continue; } /* * Note: backend also returns POLLHUP and * POLLERR if appropriate. */ fd->revents = fo_poll(fp, fd->events, td->td_ucred, td); if (fd->revents != 0) n++; } FILEDESC_SUNLOCK(fdp); stp->st_flags = 0; td->td_retval[0] = n; return (0); } static int pollout(td, fds, ufds, nfd) struct thread *td; struct pollfd *fds; struct pollfd *ufds; u_int nfd; { int error = 0; u_int i = 0; u_int n = 0; for (i = 0; i < nfd; i++) { error = copyout(&fds->revents, &ufds->revents, sizeof(ufds->revents)); if (error) return (error); if (fds->revents != 0) n++; fds++; ufds++; } td->td_retval[0] = n; return (0); } static int pollscan(td, fds, nfd) struct thread *td; struct pollfd *fds; u_int nfd; { struct filedesc *fdp = td->td_proc->p_fd; struct file *fp; #ifdef CAPABILITIES cap_rights_t rights; #endif int i, n = 0; FILEDESC_SLOCK(fdp); for (i = 0; i < nfd; i++, fds++) { if (fds->fd > fdp->fd_lastfile) { fds->revents = POLLNVAL; n++; } else if (fds->fd < 0) { fds->revents = 0; } else { fp = fdp->fd_ofiles[fds->fd].fde_file; #ifdef CAPABILITIES if (fp == NULL || cap_check(cap_rights(fdp, fds->fd), cap_rights_init(&rights, CAP_EVENT)) != 0) #else if (fp == NULL) #endif { fds->revents = POLLNVAL; n++; } else { /* * Note: backend also returns POLLHUP and * POLLERR if appropriate. */ selfdalloc(td, fds); fds->revents = fo_poll(fp, fds->events, td->td_ucred, td); /* * POSIX requires POLLOUT to be never * set simultaneously with POLLHUP. */ if ((fds->revents & POLLHUP) != 0) fds->revents &= ~POLLOUT; if (fds->revents != 0) n++; } } } FILEDESC_SUNLOCK(fdp); td->td_retval[0] = n; return (0); } /* * OpenBSD poll system call. * * XXX this isn't quite a true representation.. OpenBSD uses select ops. */ #ifndef _SYS_SYSPROTO_H_ struct openbsd_poll_args { struct pollfd *fds; u_int nfds; int timeout; }; #endif int sys_openbsd_poll(td, uap) register struct thread *td; register struct openbsd_poll_args *uap; { return (sys_poll(td, (struct poll_args *)uap)); } /* * XXX This was created specifically to support netncp and netsmb. This * allows the caller to specify a socket to wait for events on. It returns * 0 if any events matched and an error otherwise. There is no way to * determine which events fired. */ int selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td) { struct timeval rtv; sbintime_t asbt, precision, rsbt; int error; precision = 0; /* stupid gcc! */ if (tvp != NULL) { rtv = *tvp; if (rtv.tv_sec < 0 || rtv.tv_usec < 0 || rtv.tv_usec >= 1000000) return (EINVAL); if (!timevalisset(&rtv)) asbt = 0; else if (rtv.tv_sec <= INT32_MAX) { rsbt = tvtosbt(rtv); precision = rsbt; precision >>= tc_precexp; if (TIMESEL(&asbt, rsbt)) asbt += tc_tick_sbt; if (asbt <= INT64_MAX - rsbt) asbt += rsbt; else asbt = -1; } else asbt = -1; } else asbt = -1; seltdinit(td); /* * Iterate until the timeout expires or the socket becomes ready. */ for (;;) { selfdalloc(td, NULL); error = sopoll(so, events, NULL, td); /* error here is actually the ready events. */ if (error) return (0); error = seltdwait(td, asbt, precision); if (error) break; } seltdclear(td); /* XXX Duplicates ncp/smb behavior. */ if (error == ERESTART) error = 0; return (error); } /* * Preallocate two selfds associated with 'cookie'. Some fo_poll routines * have two select sets, one for read and another for write. */ static void selfdalloc(struct thread *td, void *cookie) { struct seltd *stp; stp = td->td_sel; if (stp->st_free1 == NULL) stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); stp->st_free1->sf_td = stp; stp->st_free1->sf_cookie = cookie; if (stp->st_free2 == NULL) stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO); stp->st_free2->sf_td = stp; stp->st_free2->sf_cookie = cookie; } static void selfdfree(struct seltd *stp, struct selfd *sfp) { STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link); mtx_lock(sfp->sf_mtx); if (sfp->sf_si) TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads); mtx_unlock(sfp->sf_mtx); uma_zfree(selfd_zone, sfp); } /* Drain the waiters tied to all the selfd belonging the specified selinfo. */ void seldrain(sip) struct selinfo *sip; { /* * This feature is already provided by doselwakeup(), thus it is * enough to go for it. * Eventually, the context, should take care to avoid races * between thread calling select()/poll() and file descriptor * detaching, but, again, the races are just the same as * selwakeup(). */ doselwakeup(sip, -1); } /* * Record a select request. */ void selrecord(selector, sip) struct thread *selector; struct selinfo *sip; { struct selfd *sfp; struct seltd *stp; struct mtx *mtxp; stp = selector->td_sel; /* * Don't record when doing a rescan. */ if (stp->st_flags & SELTD_RESCAN) return; /* * Grab one of the preallocated descriptors. */ sfp = NULL; if ((sfp = stp->st_free1) != NULL) stp->st_free1 = NULL; else if ((sfp = stp->st_free2) != NULL) stp->st_free2 = NULL; else panic("selrecord: No free selfd on selq"); mtxp = sip->si_mtx; if (mtxp == NULL) mtxp = mtx_pool_find(mtxpool_select, sip); /* * Initialize the sfp and queue it in the thread. */ sfp->sf_si = sip; sfp->sf_mtx = mtxp; STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link); /* * Now that we've locked the sip, check for initialization. */ mtx_lock(mtxp); if (sip->si_mtx == NULL) { sip->si_mtx = mtxp; TAILQ_INIT(&sip->si_tdlist); } /* * Add this thread to the list of selfds listening on this selinfo. */ TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads); mtx_unlock(sip->si_mtx); } /* Wake up a selecting thread. */ void selwakeup(sip) struct selinfo *sip; { doselwakeup(sip, -1); } /* Wake up a selecting thread, and set its priority. */ void selwakeuppri(sip, pri) struct selinfo *sip; int pri; { doselwakeup(sip, pri); } /* * Do a wakeup when a selectable event occurs. */ static void doselwakeup(sip, pri) struct selinfo *sip; int pri; { struct selfd *sfp; struct selfd *sfn; struct seltd *stp; /* If it's not initialized there can't be any waiters. */ if (sip->si_mtx == NULL) return; /* * Locking the selinfo locks all selfds associated with it. */ mtx_lock(sip->si_mtx); TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) { /* * Once we remove this sfp from the list and clear the * sf_si seltdclear will know to ignore this si. */ TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads); sfp->sf_si = NULL; stp = sfp->sf_td; mtx_lock(&stp->st_mtx); stp->st_flags |= SELTD_PENDING; cv_broadcastpri(&stp->st_wait, pri); mtx_unlock(&stp->st_mtx); } mtx_unlock(sip->si_mtx); } static void seltdinit(struct thread *td) { struct seltd *stp; if ((stp = td->td_sel) != NULL) goto out; td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO); mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF); cv_init(&stp->st_wait, "select"); out: stp->st_flags = 0; STAILQ_INIT(&stp->st_selq); } static int seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision) { struct seltd *stp; int error; stp = td->td_sel; /* * An event of interest may occur while we do not hold the seltd * locked so check the pending flag before we sleep. */ mtx_lock(&stp->st_mtx); /* * Any further calls to selrecord will be a rescan. */ stp->st_flags |= SELTD_RESCAN; if (stp->st_flags & SELTD_PENDING) { mtx_unlock(&stp->st_mtx); return (0); } if (sbt == 0) error = EWOULDBLOCK; else if (sbt != -1) error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx, sbt, precision, C_ABSOLUTE); else error = cv_wait_sig(&stp->st_wait, &stp->st_mtx); mtx_unlock(&stp->st_mtx); return (error); } void seltdfini(struct thread *td) { struct seltd *stp; stp = td->td_sel; if (stp == NULL) return; if (stp->st_free1) uma_zfree(selfd_zone, stp->st_free1); if (stp->st_free2) uma_zfree(selfd_zone, stp->st_free2); td->td_sel = NULL; free(stp, M_SELECT); } /* * Remove the references to the thread from all of the objects we were * polling. */ static void seltdclear(struct thread *td) { struct seltd *stp; struct selfd *sfp; struct selfd *sfn; stp = td->td_sel; STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) selfdfree(stp, sfp); stp->st_flags = 0; } static void selectinit(void *); SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL); static void selectinit(void *dummy __unused) { selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF); }