common/syscall/open.c

	open.c revision 794f0adb050e571bbfde4d2a19b9f88b852079dd
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER START
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * The contents of this file are subject to the terms of the
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Common Development and Distribution License (the "License").
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * You may not use this file except in compliance with the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * or http://www.opensolaris.org/os/licensing.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * See the License for the specific language governing permissions
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * and limitations under the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER END
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*    All Rights Reserved   */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Portions of this source code were derived from Berkeley 4.3 BSD
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * under license from the Regents of the University of California.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/param.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/isa_defs.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/types.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/sysmacros.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/user.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/systm.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/errno.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/fcntl.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/stat.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/vnode.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/vfs.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/file.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/mode.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/uio.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <sys/debug.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <c2/audit.h>
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Common code for openat().  Check permissions, allocate an open
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * file structure, and call the device open routine (if any).
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic int
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtiscopen(int startfd, char *fname, int filemode, int createmode)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis{
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    struct pathname pn;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    vnode_t *vp, *sdvp;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    file_t *fp, *startfp;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    enum vtype type;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    int error;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    int fd, dupfd;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    vnode_t *startvp;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    proc_t *p = curproc;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    uio_seg_t seg = UIO_USERSPACE;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    char *open_filename = fname;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    uint32_t auditing = AU_AUDITING();
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    char startchar;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (filemode & (FSEARCH|FEXEC)) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        /*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         * Must be one or the other and neither FREAD nor FWRITE
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         * Must not be any of FAPPEND FCREAT FTRUNC FXATTR FXATTRDIROPEN
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         * XXX: Should these just be silently ignored?
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if ((filemode & (FREAD|FWRITE)) ||
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            (filemode & (FSEARCH|FEXEC)) == (FSEARCH|FEXEC) ||
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            (filemode & (FAPPEND|FCREAT|FTRUNC|FXATTR|FXATTRDIROPEN)))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (set_errno(EINVAL));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (startfd == AT_FDCWD) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        /*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         * Regular open()
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        startvp = NULL;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        /*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         * We're here via openat()
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (copyin(fname, &startchar, sizeof (char)))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (set_errno(EFAULT));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        /*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         * if startchar is / then startfd is ignored
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis         */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (startchar == '/')
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            startvp = NULL;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        else {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if ((startfp = getf(startfd)) == NULL)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                return (set_errno(EBADF));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            startvp = startfp->f_vnode;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            VN_HOLD(startvp);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            releasef(startfd);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis     * Handle __openattrdirat() requests
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis     */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (filemode & FXATTRDIROPEN) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (auditing && startvp != NULL)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            audit_setfsat_path(1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (error = lookupnameat(fname, seg, FOLLOW,
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            NULLVPP, &vp, startvp))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (set_errno(error));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (startvp != NULL)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            VN_RELE(startvp);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        startvp = vp;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis     * Do we need to go into extended attribute space?
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis     */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (filemode & FXATTR) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (startfd == AT_FDCWD) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (copyin(fname, &startchar, sizeof (char)))
                return (set_errno(EFAULT));

            /*
             * If startchar == '/' then no extended attributes
             * are looked up.
             */
            if (startchar == '/') {
                startvp = NULL;
            } else {
                mutex_enter(&p->p_lock);
                startvp = PTOU(p)->u_cdir;
                VN_HOLD(startvp);
                mutex_exit(&p->p_lock);
            }
        }

        /*
         * Make sure we have a valid extended attribute request.
         * We must either have a real fd or AT_FDCWD and a relative
         * pathname.
         */
        if (startvp == NULL) {
            goto noxattr;
        }
    }

    if (filemode & (FXATTR|FXATTRDIROPEN)) {
        vattr_t vattr;

        if (error = pn_get(fname, UIO_USERSPACE, &pn)) {
            goto out;
        }

        /*
         * In order to access hidden attribute directory the
         * user must be able to stat() the file
         */
        vattr.va_mask = AT_ALL;
        if (error = VOP_GETATTR(startvp, &vattr, 0, CRED(), NULL)) {
            pn_free(&pn);
            goto out;
        }

        if ((startvp->v_vfsp->vfs_flag & VFS_XATTR) != 0 ||
            vfs_has_feature(startvp->v_vfsp, VFSFT_SYSATTR_VIEWS)) {
            error = VOP_LOOKUP(startvp, "", &sdvp, &pn,
                (filemode & FXATTRDIROPEN) ? LOOKUP_XATTR :
                LOOKUP_XATTR|CREATE_XATTR_DIR, rootvp, CRED(),
                NULL, NULL, NULL);
        } else {
            error = EINVAL;
        }

        /*
         * For __openattrdirat() use "." as filename to open
         * as part of vn_openat()
         */
        if (error == 0 && (filemode & FXATTRDIROPEN)) {
            open_filename = ".";
            seg = UIO_SYSSPACE;
        }

        pn_free(&pn);
        if (error != 0)
            goto out;

        VN_RELE(startvp);
        startvp = sdvp;
    }

noxattr:
    if ((filemode & (FREAD|FWRITE|FSEARCH|FEXEC|FXATTRDIROPEN)) != 0) {
        if ((filemode & (FNONBLOCK|FNDELAY)) == (FNONBLOCK|FNDELAY))
            filemode &= ~FNDELAY;
        error = falloc((vnode_t *)NULL, filemode, &fp, &fd);
        if (error == 0) {
            if (auditing && startvp != NULL)
                audit_setfsat_path(1);
            /*
             * Last arg is a don't-care term if
             * !(filemode & FCREAT).
             */
            error = vn_openat(open_filename, seg, filemode,
                (int)(createmode & MODEMASK),
                &vp, CRCREAT, PTOU(curproc)->u_cmask,
                startvp, fd);

            if (startvp != NULL)
                VN_RELE(startvp);
            if (error == 0) {
                if ((vp->v_flag & VDUP) == 0) {
                    fp->f_vnode = vp;
                    mutex_exit(&fp->f_tlock);
                    /*
                     * We must now fill in the slot
                     * falloc reserved.
                     */
                    setf(fd, fp);
                    return (fd);
                } else {
                    /*
                     * Special handling for /dev/fd.
                     * Give up the file pointer
                     * and dup the indicated file descriptor
                     * (in v_rdev). This is ugly, but I've
                     * seen worse.
                     */
                    unfalloc(fp);
                    dupfd = getminor(vp->v_rdev);
                    type = vp->v_type;
                    mutex_enter(&vp->v_lock);
                    vp->v_flag &= ~VDUP;
                    mutex_exit(&vp->v_lock);
                    VN_RELE(vp);
                    if (type != VCHR)
                        return (set_errno(EINVAL));
                    if ((fp = getf(dupfd)) == NULL) {
                        setf(fd, NULL);
                        return (set_errno(EBADF));
                    }
                    mutex_enter(&fp->f_tlock);
                    fp->f_count++;
                    mutex_exit(&fp->f_tlock);
                    setf(fd, fp);
                    releasef(dupfd);
                }
                return (fd);
            } else {
                setf(fd, NULL);
                unfalloc(fp);
                return (set_errno(error));
            }
        }
    } else {
        error = EINVAL;
    }
out:
    if (startvp != NULL)
        VN_RELE(startvp);
    return (set_errno(error));
}

#define OPENMODE32(fmode)   (((fmode) & (FSEARCH | FEXEC))? \
                    (fmode) : (fmode) - FOPEN)
#define OPENMODE64(fmode)   (OPENMODE32(fmode) | FOFFMAX)
#ifdef _LP64
#define OPENMODE(fmode)     OPENMODE64(fmode)
#else
#define OPENMODE(fmode)     OPENMODE32(fmode)
#endif

/*
 * Open a file.
 */
int
openat(int fd, char *path, int fmode, int cmode)
{
    return (copen(fd, path, OPENMODE(fmode), cmode));
}

int
open(char *path, int fmode, int cmode)
{
    return (openat(AT_FDCWD, path, fmode, cmode));
}

#if defined(_ILP32) || defined(_SYSCALL32_IMPL)
/*
 * Open for large files in 32-bit environment. Sets the FOFFMAX flag.
 */
int
openat64(int fd, char *path, int fmode, int cmode)
{
    return (copen(fd, path, OPENMODE64(fmode), cmode));
}

int
open64(char *path, int fmode, int cmode)
{
    return (openat64(AT_FDCWD, path, fmode, cmode));
}

#endif  /* _ILP32 || _SYSCALL32_IMPL */

#ifdef _SYSCALL32_IMPL
/*
 * Open for 32-bit compatibility on 64-bit kernel
 */
int
openat32(int fd, char *path, int fmode, int cmode)
{
    return (copen(fd, path, OPENMODE32(fmode), cmode));
}

int
open32(char *path, int fmode, int cmode)
{
    return (openat32(AT_FDCWD, path, fmode, cmode));
}

#endif  /* _SYSCALL32_IMPL */