/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2017, Joyent, Inc.
 * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
 * Copyright 2018 Nexenta Systems, Inc.  All rights reserved.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * Portions of code from both of:
 *      syscall/open.c
 *      fs/vnode.c
 * heavily modified for this use.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/t_lock.h>
#include <sys/errno.h>
#include <sys/cred.h>
#include <sys/user.h>
#include <sys/uio.h>
#include <sys/file.h>
#include <sys/pathname.h>
#include <sys/vfs.h>
#include <sys/vfs_opreg.h>
#include <sys/vnode.h>
#include <sys/rwstlock.h>
#include <sys/fem.h>
#include <sys/stat.h>
#include <sys/mode.h>
#include <sys/conf.h>
#include <sys/sysmacros.h>
#include <sys/cmn_err.h>
#include <sys/systm.h>
#include <sys/kmem.h>
#include <sys/debug.h>
#include <sys/acl.h>
#include <sys/nbmlock.h>
#include <sys/fcntl.h>
#include <fs/fs_subr.h>
#include <sys/taskq.h>
#include <fs/fs_reparse.h>
#include <sys/time.h>

#include <libfksmbfs.h>

/* close and release */
int
vn_close_rele(vnode_t *vp, int flag)
{
        int error;

        error = VOP_CLOSE(vp, flag, 0, 0, CRED(), NULL);
        vn_rele(vp);

        return (error);
}

/*
 * Open/create a vnode.
 * This may be callable by the kernel, the only known use
 * of user context being that the current user credentials
 * are used for permissions.  crwhy is defined iff filemode & FCREAT.
 */
int
vn_open(
        char *pnamep,
        enum uio_seg seg,
        int filemode,
        int createmode,
        struct vnode **vpp,
        enum create crwhy,
        mode_t umask)
{
        struct vnode *vp;
        int mode;
        int accessflags;
        int error;
        int open_done = 0;
        struct vattr vattr;
        int estale_retry = 0;

        mode = 0;
        accessflags = 0;
        if (filemode & FREAD)
                mode |= VREAD;
        if (filemode & (FWRITE|FTRUNC))
                mode |= VWRITE;
        if (filemode & (FSEARCH|FEXEC|FXATTRDIROPEN))
                mode |= VEXEC;

        if (filemode & FAPPEND)
                accessflags |= V_APPEND;

top:
        if (filemode & FCREAT) {
                enum vcexcl excl;

                /*
                 * Wish to create a file.
                 */
                vattr.va_type = VREG;
                vattr.va_mode = createmode;
                vattr.va_mask = AT_TYPE|AT_MODE;
                if (filemode & FTRUNC) {
                        vattr.va_size = 0;
                        vattr.va_mask |= AT_SIZE;
                }
                if (filemode & FEXCL)
                        excl = EXCL;
                else
                        excl = NONEXCL;

                if ((error =
                    vn_create(pnamep, seg, &vattr, excl, mode, &vp, crwhy,
                    (filemode & ~(FTRUNC|FEXCL)), umask)) != 0)
                        return (error);
        } else {
                /*
                 * Wish to open a file.  Just look it up.
                 * Was lookupnameat()
                 */
                if ((error = fake_lookup(NULL, pnamep, &vp)) != 0) {
                        if ((error == ESTALE) &&
                            fs_need_estale_retry(estale_retry++))
                                goto top;
                        return (error);
                }

                /*
                 * Want the XATTRDIR under it?
                 */
                if (filemode & FXATTRDIROPEN) {
                        vnode_t *xvp = NULL;
                        error = VOP_LOOKUP(vp, NULL, &xvp, NULL,
                            LOOKUP_XATTR, rootdir, CRED(), NULL,
                            NULL, NULL);
                        VN_RELE(vp);
                        vp = xvp;
                        /* continue with vp */
                }

                /*
                 * Can't write directories, active texts, or
                 * read-only filesystems.  Can't truncate files
                 * on which mandatory locking is in effect.
                 */
                if (filemode & (FWRITE|FTRUNC)) {
                        if (vp->v_type == VDIR) {
                                error = EISDIR;
                                goto out;
                        }
                }
                /*
                 * Check permissions.
                 */
                if (error = VOP_ACCESS(vp, mode, accessflags, CRED(), NULL))
                        goto out;
                /*
                 * Require FSEARCH to return a directory.
                 * Require FEXEC to return a regular file.
                 */
                if ((filemode & FSEARCH) && vp->v_type != VDIR) {
                        error = ENOTDIR;
                        goto out;
                }
                if ((filemode & FEXEC) && vp->v_type != VREG) {
                        error = ENOEXEC;
                        goto out;
                }
        }

        /*
         * Do remaining checks for FNOFOLLOW and FNOLINKS.
         */
        if ((filemode & FNOFOLLOW) && vp->v_type == VLNK) {
                error = ELOOP;
                goto out;
        }
        if (filemode & FNOLINKS) {
                vattr.va_mask = AT_NLINK;
                if ((error = VOP_GETATTR(vp, &vattr, 0, CRED(), NULL))) {
                        goto out;
                }
                if (vattr.va_nlink != 1) {
                        error = EMLINK;
                        goto out;
                }
        }

        /*
         * Opening a socket corresponding to the AF_UNIX pathname
         * in the filesystem name space is not supported...
         */
        if (vp->v_type == VSOCK) {
                error = EOPNOTSUPP;
                goto out;
        }

        /*
         * Do opening protocol.
         */
        error = VOP_OPEN(&vp, filemode, CRED(), NULL);
        if (error)
                goto out;
        open_done = 1;

        /*
         * Truncate if required.
         */
        if ((filemode & FTRUNC) && !(filemode & FCREAT)) {
                vattr.va_size = 0;
                vattr.va_mask = AT_SIZE;
                if ((error = VOP_SETATTR(vp, &vattr, 0, CRED(), NULL)) != 0)
                        goto out;
        }
out:
        ASSERT(vp->v_count > 0);

        if (error) {
                if (open_done) {
                        (void) VOP_CLOSE(vp, filemode, 1, (offset_t)0, CRED(),
                            NULL);
                        open_done = 0;
                }
                VN_RELE(vp);
        } else
                *vpp = vp;
        return (error);
}


/*
 * Create a vnode (makenode).
 */
int
vn_create(
        char *pnamep,
        enum uio_seg seg,
        struct vattr *vap,
        enum vcexcl excl,
        int mode,
        struct vnode **vpp,
        enum create why,
        int flag,
        mode_t umask)
{
        struct vnode *dvp = NULL;       /* ptr to parent dir vnode */
        char *lastcomp = NULL;
        int error;

        ASSERT((vap->va_mask & (AT_TYPE|AT_MODE)) == (AT_TYPE|AT_MODE));

        flag &= ~(FNOFOLLOW|FNOLINKS);

        *vpp = NULL;

        /*
         * Lookup directory and last component
         */
        error = fake_lookup_dir(pnamep, &dvp, &lastcomp);
        if (error != 0) {
                /* dir not found */
                return (error);
        }

        /*
         * If default ACLs are defined for the directory don't apply the
         * umask if umask is passed.
         */

        if (umask) {
                /*
                 * Apply the umask if no default ACLs...
                 */
                vap->va_mode &= ~umask;
        }

        if (dvp->v_vfsp->vfs_flag & VFS_RDONLY) {
                error = EROFS;
                goto out;
        }

        /*
         * Call mkdir() if specified, otherwise create().
         */
        if (why == CRMKDIR) {
                /*
                 * N.B., if vn_createat() ever requests
                 * case-insensitive behavior then it will need
                 * to be passed to VOP_MKDIR().  VOP_CREATE()
                 * will already get it via "flag"
                 */
                error = VOP_MKDIR(dvp, lastcomp, vap, vpp, CRED(),
                    NULL, 0, NULL);
        } else {
                error = VOP_CREATE(dvp, lastcomp, vap,
                    excl, mode, vpp, CRED(), flag, NULL, NULL);
        }

out:
        if (dvp != NULL)
                VN_RELE(dvp);

        return (error);
}