/*      $NetBSD: filecore_vnops.c,v 1.50 2022/03/27 17:10:55 christos Exp $     */

/*-
 * Copyright (c) 1994 The Regents of the University of California.
 * 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.
 * 3. 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.
 *
 *      filecore_vnops.c        1.2     1998/8/18
 */

/*-
 * Copyright (c) 1998 Andrew McMurry
 *
 * 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.
 *
 *      filecore_vnops.c        1.2     1998/8/18
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: filecore_vnops.c,v 1.50 2022/03/27 17:10:55 christos Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/conf.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/dirent.h>
#include <sys/kauth.h>

#include <miscfs/genfs/genfs.h>
#include <miscfs/specfs/specdev.h>

#include <fs/filecorefs/filecore.h>
#include <fs/filecorefs/filecore_extern.h>
#include <fs/filecorefs/filecore_node.h>

static int
filecore_check_possible(struct vnode *vp, struct filecore_node *ip,
    mode_t mode)
{

        /*
         * Disallow write attempts unless the file is a socket,
         * fifo, or a block or character device resident on the
         * file system.
         */
        if (mode & VWRITE) {
                switch (vp->v_type) {
                case VDIR:
                case VLNK:
                case VREG:
                        return (EROFS);
                default:
                        break;
                }
        }

        return 0;
}

/*
 * Check mode permission on inode pointer. Mode is READ, WRITE or EXEC.
 * The mode is shifted to select the owner/group/other fields. The
 * super user is granted all permissions.
 */
static int
filecore_check_permitted(struct vnode *vp, struct filecore_node *ip,
    accmode_t accmode, kauth_cred_t cred)
{
        struct filecore_mnt *fcmp = ip->i_mnt;

        return kauth_authorize_vnode(cred, KAUTH_ACCESS_ACTION(accmode,
            vp->v_type, filecore_mode(ip)), vp, NULL,
            genfs_can_access(vp, cred, fcmp->fc_uid, fcmp->fc_gid,
            filecore_mode(ip), NULL, accmode));
}

int
filecore_access(void *v)
{
        struct vop_access_args /* {
                struct vnode *a_vp;
                accmode_t  a_accmode;
                kauth_cred_t a_cred;
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        struct filecore_node *ip = VTOI(vp);
        int error;

        error = filecore_check_possible(vp, ip, ap->a_accmode);
        if (error)
                return error;

        error = filecore_check_permitted(vp, ip, ap->a_accmode, ap->a_cred);

        return error;
}

int
filecore_getattr(void *v)
{
        struct vop_getattr_args /* {
                struct vnode *a_vp;
                struct vattr *a_vap;
                kauth_cred_t a_cred;
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        struct filecore_node *ip = VTOI(vp);
        struct vattr *vap = ap->a_vap;
        struct filecore_mnt *fcmp = ip->i_mnt;

        vap->va_fsid    = ip->i_dev;
        vap->va_fileid  = ip->i_number;

        vap->va_mode    = filecore_mode(ip);
        vap->va_nlink   = 1;
        vap->va_uid     = fcmp->fc_uid;
        vap->va_gid     = fcmp->fc_gid;
        vap->va_atime   = filecore_time(ip);
        vap->va_mtime   = filecore_time(ip);
        vap->va_ctime   = filecore_time(ip);
        vap->va_rdev    = 0;  /* We don't support specials */

        vap->va_size    = (u_quad_t) ip->i_size;
        vap->va_flags   = 0;
        vap->va_gen     = 1;
        vap->va_blocksize = fcmp->blksize;
        vap->va_bytes   = vap->va_size;
        vap->va_type    = vp->v_type;
        return (0);
}

/*
 * Vnode op for reading.
 */
int
filecore_read(void *v)
{
        struct vop_read_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int a_ioflag;
                kauth_cred_t a_cred;
        } */ *ap = v;
        struct vnode *vp = ap->a_vp;
        struct uio *uio = ap->a_uio;
        struct filecore_node *ip = VTOI(vp);
        struct filecore_mnt *fcmp;
        struct buf *bp;
        daddr_t lbn;
        off_t diff;
        int error = 0;
        long size, n, on;

        if (uio->uio_resid == 0)
                return (0);
        if (uio->uio_offset < 0)
                return (EINVAL);
        if (uio->uio_offset >= ip->i_size)
                return (0);
        ip->i_flag |= IN_ACCESS;
        fcmp = ip->i_mnt;

        if (vp->v_type == VREG) {
                const int advice = IO_ADV_DECODE(ap->a_ioflag);
                error = 0;

                while (uio->uio_resid > 0) {
                        vsize_t bytelen = MIN(ip->i_size - uio->uio_offset,
                                              uio->uio_resid);

                        if (bytelen == 0) {
                                break;
                        }
                        error = ubc_uiomove(&vp->v_uobj, uio, bytelen, advice,
                            UBC_READ | UBC_PARTIALOK | UBC_VNODE_FLAGS(vp));
                        if (error) {
                                break;
                        }
                }
                goto out;
        }

        do {
                lbn = filecore_lblkno(fcmp, uio->uio_offset);
                on = filecore_blkoff(fcmp, uio->uio_offset);
                n = MIN(filecore_blksize(fcmp, ip, lbn) - on, uio->uio_resid);
                diff = (off_t)ip->i_size - uio->uio_offset;
                if (diff <= 0)
                        return (0);
                if (diff < n)
                        n = diff;
                size = filecore_blksize(fcmp, ip, lbn);
                if (ip->i_dirent.attr & FILECORE_ATTR_DIR) {
                        error = filecore_dbread(ip, &bp);
                        on = uio->uio_offset;
                        n = MIN(FILECORE_DIR_SIZE - on, uio->uio_resid);
                        size = FILECORE_DIR_SIZE;
                } else {
                        error = bread(vp, lbn, size, 0, &bp);
#ifdef FILECORE_DEBUG_BR
                        printf("bread(%p, %llx, %ld, CRED, %p)=%d\n",
                            vp, (long long)lbn, size, bp, error);
#endif
                }
                if (error) {
                        return (error);
                }
                n = MIN(n, size - bp->b_resid);

                error = uiomove((char *)(bp->b_data) + on, (int)n, uio);
#ifdef FILECORE_DEBUG_BR
                printf("brelse(%p) vn2\n", bp);
#endif
                brelse(bp, 0);
        } while (error == 0 && uio->uio_resid > 0 && n != 0);

out:
        return (error);
}

/*
 * Vnode op for readdir
 */
int
filecore_readdir(void *v)
{
        struct vop_readdir_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                kauth_cred_t a_cred;
                int *a_eofflag;
                off_t **a_cookies;
                int *a_ncookies;
        } */ *ap = v;
        struct uio *uio = ap->a_uio;
        struct vnode *vdp = ap->a_vp;
        struct filecore_node *dp;
        struct buf *bp = NULL;
        struct dirent *de;
        struct filecore_direntry *dep = NULL;
        int error = 0;
        off_t *cookies = NULL;
        int ncookies = 0;
        int i;
        off_t uiooff;

        dp = VTOI(vdp);

        if ((dp->i_dirent.attr & FILECORE_ATTR_DIR) == 0)
                return (ENOTDIR);

        if (uio->uio_offset % FILECORE_DIRENT_SIZE != 0)
                return (EINVAL);
        i = uio->uio_offset / FILECORE_DIRENT_SIZE;
        uiooff = uio->uio_offset;

        *ap->a_eofflag = 0;

        error = filecore_dbread(dp, &bp);
        if (error) {
                return error;
        }

        if (ap->a_ncookies == NULL)
                cookies = NULL;
        else {
                *ap->a_ncookies = 0;
                ncookies = uio->uio_resid / _DIRENT_MINSIZE((struct dirent *)0);
                cookies = malloc(ncookies * sizeof(off_t), M_TEMP, M_WAITOK);
        }

        de = kmem_zalloc(sizeof(struct dirent), KM_SLEEP);

        for (; ; i++) {
                switch (i) {
                case 0:
                        /* Fake the '.' entry */
                        de->d_fileno = dp->i_number;
                        de->d_type = DT_DIR;
                        de->d_namlen = 1;
                        strlcpy(de->d_name, ".", sizeof(de->d_name));
                        break;
                case 1:
                        /* Fake the '..' entry */
                        de->d_fileno = filecore_getparent(dp);
                        de->d_type = DT_DIR;
                        de->d_namlen = 2;
                        strlcpy(de->d_name, "..", sizeof(de->d_name));
                        break;
                default:
                        de->d_fileno = dp->i_dirent.addr +
                                        ((i - 2) << FILECORE_INO_INDEX);
                        dep = fcdirentry(bp->b_data, i - 2);
                        if (dep->attr & FILECORE_ATTR_DIR)
                                de->d_type = DT_DIR;
                        else
                                de->d_type = DT_REG;
                        if (filecore_fn2unix(dep->name, de->d_name,
/*###346 [cc] warning: passing arg 3 of `filecore_fn2unix' from incompatible pointer type%%%*/
                            &de->d_namlen)) {
                                *ap->a_eofflag = 1;
                                goto out;
                        }
                        break;
                }
                de->d_reclen = _DIRENT_SIZE(de);
                if (uio->uio_resid < de->d_reclen)
                        goto out;
                error = uiomove(de, de->d_reclen, uio);
                if (error)
                        goto out;
                uiooff += FILECORE_DIRENT_SIZE;

                if (cookies) {
                        *cookies++ = i*FILECORE_DIRENT_SIZE;
                        (*ap->a_ncookies)++;
                        if (--ncookies == 0) goto out;
                }
        }
out:
        if (cookies) {
                *ap->a_cookies = cookies;
                if (error) {
                        free(cookies, M_TEMP);
                        *ap->a_ncookies = 0;
                        *ap->a_cookies = NULL;
                }
        }
        uio->uio_offset = uiooff;

#ifdef FILECORE_DEBUG_BR
        printf("brelse(%p) vn3\n", bp);
#endif
        brelse (bp, 0);

        kmem_free(de, sizeof(*de));

        return (error);
}

/*
 * Return target name of a symbolic link
 * Shouldn't we get the parent vnode and read the data from there?
 * This could eventually result in deadlocks in filecore_lookup.
 * But otherwise the block read here is in the block buffer two times.
 */
int
filecore_readlink(void *v)
{
#if 0
        struct vop_readlink_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                kauth_cred_t a_cred;
        } */ *ap = v;
#endif

        return (EINVAL);
}

/*
 * Calculate the logical to physical mapping if not done already,
 * then call the device strategy routine.
 */
int
filecore_strategy(void *v)
{
        struct vop_strategy_args /* {
                struct vnode *a_vp;
                struct buf *a_bp;
        } */ *ap = v;
        struct buf *bp = ap->a_bp;
        struct vnode *vp = ap->a_vp;
        struct filecore_node *ip;
        int error;

        ip = VTOI(vp);
        if (bp->b_blkno == bp->b_lblkno) {
                error = VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL);
                if (error) {
                        bp->b_error = error;
                        biodone(bp);
                        return (error);
                }
                if ((long)bp->b_blkno == -1)
                        clrbuf(bp);
        }
        if ((long)bp->b_blkno == -1) {
                biodone(bp);
                return (0);
        }
        vp = ip->i_devvp;
        return (VOP_STRATEGY(vp, bp));
}

/*
 * Print out the contents of an inode.
 */
/*ARGSUSED*/
int
filecore_print(void *v)
{

        printf("tag VT_FILECORE, filecore vnode\n");
        return (0);
}

/*
 * Return POSIX pathconf information applicable to filecore filesystems.
 */
int
filecore_pathconf(void *v)
{
        struct vop_pathconf_args /* {
                struct vnode *a_vp;
                int a_name;
                register_t *a_retval;
        } */ *ap = v;
        switch (ap->a_name) {
        case _PC_LINK_MAX:
                *ap->a_retval = 1;
                return (0);
        case _PC_NAME_MAX:
                *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_namemax;
                return (0);
        case _PC_PATH_MAX:
                *ap->a_retval = 256;
                return (0);
        case _PC_CHOWN_RESTRICTED:
                *ap->a_retval = 1;
                return (0);
        case _PC_NO_TRUNC:
                *ap->a_retval = 1;
                return (0);
        case _PC_SYNC_IO:
                *ap->a_retval = 1;
                return (0);
        case _PC_FILESIZEBITS:
                *ap->a_retval = 32;
                return (0);
        default:
                return genfs_pathconf(ap);
        }
        /* NOTREACHED */
}

/*
 * Global vfs data structures for filecore
 */
int (**filecore_vnodeop_p)(void *);
const struct vnodeopv_entry_desc filecore_vnodeop_entries[] = {
        { &vop_default_desc, vn_default_error },
        { &vop_parsepath_desc, genfs_parsepath },       /* parsepath */
        { &vop_lookup_desc, filecore_lookup },          /* lookup */
        { &vop_create_desc, genfs_eopnotsupp },         /* create */
        { &vop_mknod_desc, genfs_eopnotsupp },          /* mknod */
        { &vop_open_desc, genfs_nullop },               /* open */
        { &vop_close_desc, genfs_nullop },              /* close */
        { &vop_access_desc, filecore_access },          /* access */
        { &vop_accessx_desc, genfs_accessx },           /* accessx */
        { &vop_getattr_desc, filecore_getattr },        /* getattr */
        { &vop_setattr_desc, genfs_eopnotsupp },        /* setattr */
        { &vop_read_desc, filecore_read },              /* read */
        { &vop_write_desc, genfs_eopnotsupp },          /* write */
        { &vop_fallocate_desc, genfs_eopnotsupp },      /* fallocate */
        { &vop_fdiscard_desc, genfs_eopnotsupp },       /* fdiscard */
        { &vop_fcntl_desc, genfs_fcntl },               /* fcntl */
        { &vop_ioctl_desc, genfs_enoioctl },            /* ioctl */
        { &vop_poll_desc, genfs_poll },                 /* poll */
        { &vop_kqfilter_desc, genfs_kqfilter },         /* kqfilter */
        { &vop_revoke_desc, genfs_revoke },             /* revoke */
        { &vop_mmap_desc, genfs_mmap },                 /* mmap */
        { &vop_fsync_desc, genfs_nullop },              /* fsync */
        { &vop_seek_desc, genfs_seek },                 /* seek */
        { &vop_remove_desc, genfs_eopnotsupp },         /* remove */
        { &vop_link_desc, genfs_erofs_link },           /* link */
        { &vop_rename_desc, genfs_eopnotsupp },         /* rename */
        { &vop_mkdir_desc, genfs_eopnotsupp },          /* mkdir */
        { &vop_rmdir_desc, genfs_eopnotsupp },          /* rmdir */
        { &vop_symlink_desc, genfs_erofs_symlink },     /* symlink */
        { &vop_readdir_desc, filecore_readdir },        /* readdir */
        { &vop_readlink_desc, filecore_readlink },      /* readlink */
        { &vop_abortop_desc, genfs_abortop },           /* abortop */
        { &vop_inactive_desc, filecore_inactive },      /* inactive */
        { &vop_reclaim_desc, filecore_reclaim },        /* reclaim */
        { &vop_lock_desc, genfs_lock },                 /* lock */
        { &vop_unlock_desc, genfs_unlock },             /* unlock */
        { &vop_bmap_desc, filecore_bmap },              /* bmap */
        { &vop_strategy_desc, filecore_strategy },      /* strategy */
        { &vop_print_desc, filecore_print },            /* print */
        { &vop_islocked_desc, genfs_islocked },         /* islocked */
        { &vop_pathconf_desc, filecore_pathconf },      /* pathconf */
        { &vop_advlock_desc, genfs_eopnotsupp },        /* advlock */
        { &vop_bwrite_desc, vn_bwrite },                /* bwrite */
        { &vop_getpages_desc, genfs_getpages },         /* getpages */
        { &vop_putpages_desc, genfs_putpages },         /* putpages */
        { NULL, NULL }
};
const struct vnodeopv_desc filecore_vnodeop_opv_desc =
        { &filecore_vnodeop_p, filecore_vnodeop_entries };