/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2000-2001 Boris Popov
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/fnv_hash.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/vnode.h>

#include <netsmb/smb.h>
#include <netsmb/smb_conn.h>
#include <netsmb/smb_subr.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>
/*#include <vm/vm_page.h>
#include <vm/vm_object.h>*/

#include <fs/smbfs/smbfs.h>
#include <fs/smbfs/smbfs_node.h>
#include <fs/smbfs/smbfs_subr.h>

extern struct vop_vector smbfs_vnodeops;        /* XXX -> .h file */

static MALLOC_DEFINE(M_SMBNODE, "smbufs_node", "SMBFS vnode private part");
static MALLOC_DEFINE(M_SMBNODENAME, "smbufs_nname", "SMBFS node name");

u_int32_t __inline
smbfs_hash(const u_char *name, int nmlen)
{
        return (fnv_32_buf(name, nmlen, FNV1_32_INIT)); 
}

static char *
smbfs_name_alloc(const u_char *name, int nmlen)
{
        u_char *cp;

        nmlen++;
        cp = malloc(nmlen, M_SMBNODENAME, M_WAITOK);
        bcopy(name, cp, nmlen - 1);
        cp[nmlen - 1] = 0;
        return cp;
}

static void
smbfs_name_free(u_char *name)
{

        free(name, M_SMBNODENAME);
}

static int __inline
smbfs_vnode_cmp(struct vnode *vp, void *_sc) 
{
        struct smbnode *np;
        struct smbcmp *sc;

        np = (struct smbnode *) vp->v_data;
        sc = (struct smbcmp *) _sc;
        if (np->n_parent != sc->n_parent || np->n_nmlen != sc->n_nmlen ||
            bcmp(sc->n_name, np->n_name, sc->n_nmlen) != 0)
                return 1;
        return 0;
}

static int
smbfs_node_alloc(struct mount *mp, struct vnode *dvp, const char *dirnm, 
        int dirlen, const char *name, int nmlen, char sep, 
        struct smbfattr *fap, struct vnode **vpp)
{
        struct vattr vattr;
        struct thread *td = curthread;  /* XXX */
        struct smbmount *smp = VFSTOSMBFS(mp);
        struct smbnode *np, *dnp;
        struct vnode *vp, *vp2;
        struct smbcmp sc;
        char *p, *rpath;
        int error, rplen;

        sc.n_parent = dvp;
        sc.n_nmlen = nmlen;
        sc.n_name = name;       
        if (smp->sm_root != NULL && dvp == NULL) {
                SMBERROR("do not allocate root vnode twice!\n");
                return EINVAL;
        }
        if (nmlen == 2 && bcmp(name, "..", 2) == 0) {
                if (dvp == NULL)
                        return EINVAL;
                vp = VTOSMB(VTOSMB(dvp)->n_parent)->n_vnode;
                error = vget(vp, LK_EXCLUSIVE);
                if (error == 0)
                        *vpp = vp;
                return error;
        } else if (nmlen == 1 && name[0] == '.') {
                SMBERROR("do not call me with dot!\n");
                return EINVAL;
        }
        dnp = dvp ? VTOSMB(dvp) : NULL;
        if (dnp == NULL && dvp != NULL) {
                vn_printf(dvp, "smbfs_node_alloc: dead parent vnode ");
                return EINVAL;
        }
        error = vfs_hash_get(mp, smbfs_hash(name, nmlen), LK_EXCLUSIVE, td,
            vpp, smbfs_vnode_cmp, &sc);
        if (error)
                return (error);
        if (*vpp) {
                np = VTOSMB(*vpp);
                /* Force cached attributes to be refreshed if stale. */
                (void)VOP_GETATTR(*vpp, &vattr, td->td_ucred);
                /*
                 * If the file type on the server is inconsistent with
                 * what it was when we created the vnode, kill the
                 * bogus vnode now and fall through to the code below
                 * to create a new one with the right type.
                 */
                if (((*vpp)->v_type == VDIR && 
                    (np->n_dosattr & SMB_FA_DIR) == 0) ||
                    ((*vpp)->v_type == VREG && 
                    (np->n_dosattr & SMB_FA_DIR) != 0)) {
                        vgone(*vpp);
                        vput(*vpp);
                }
                else {
                        SMBVDEBUG("vnode taken from the hashtable\n");
                        return (0);
                }
        }
        /*
         * If we don't have node attributes, then it is an explicit lookup
         * for an existing vnode.
         */
        if (fap == NULL)
                return ENOENT;

        error = getnewvnode("smbfs", mp, &smbfs_vnodeops, vpp);
        if (error)
                return (error);
        vp = *vpp;
        np = malloc(sizeof *np, M_SMBNODE, M_WAITOK | M_ZERO);
        rplen = dirlen;
        if (sep != '\0')
                rplen++;
        rplen += nmlen;
        rpath = malloc(rplen + 1, M_SMBNODENAME, M_WAITOK);
        p = rpath;
        bcopy(dirnm, p, dirlen);
        p += dirlen;
        if (sep != '\0')
                *p++ = sep;
        if (name != NULL) {
                bcopy(name, p, nmlen);
                p += nmlen;
        }
        *p = '\0';
        MPASS(p == rpath + rplen);
        lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
        /* Vnode initialization */
        vp->v_type = fap->fa_attr & SMB_FA_DIR ? VDIR : VREG;
        vp->v_data = np;
        np->n_vnode = vp;
        np->n_mount = VFSTOSMBFS(mp);
        np->n_rpath = rpath;
        np->n_rplen = rplen;
        np->n_nmlen = nmlen;
        np->n_name = smbfs_name_alloc(name, nmlen);
        np->n_ino = fap->fa_ino;
        if (dvp) {
                ASSERT_VOP_LOCKED(dvp, "smbfs_node_alloc");
                np->n_parent = dvp;
                np->n_parentino = VTOSMB(dvp)->n_ino;
                if (/*vp->v_type == VDIR &&*/ (dvp->v_vflag & VV_ROOT) == 0) {
                        vref(dvp);
                        np->n_flag |= NREFPARENT;
                }
        } else if (vp->v_type == VREG)
                SMBERROR("new vnode '%s' born without parent ?\n", np->n_name);
        error = insmntque(vp, mp);
        if (error) {
                free(np, M_SMBNODE);
                return (error);
        }
        vn_set_state(vp, VSTATE_CONSTRUCTED);
        error = vfs_hash_insert(vp, smbfs_hash(name, nmlen), LK_EXCLUSIVE,
            td, &vp2, smbfs_vnode_cmp, &sc);
        if (error) 
                return (error);
        if (vp2 != NULL)
                *vpp = vp2;
        return (0);
}

int
smbfs_nget(struct mount *mp, struct vnode *dvp, const char *name, int nmlen,
        struct smbfattr *fap, struct vnode **vpp)
{
        struct smbnode *dnp;
        struct vnode *vp;
        int error, sep;

        dnp = (dvp) ? VTOSMB(dvp) : NULL;
        sep = 0;
        if (dnp != NULL) {
                sep = SMBFS_DNP_SEP(dnp); 
                error = smbfs_node_alloc(mp, dvp, dnp->n_rpath, dnp->n_rplen, 
                    name, nmlen, sep, fap, &vp); 
        } else
                error = smbfs_node_alloc(mp, NULL, "\\", 1, name, nmlen, 
                    sep, fap, &vp); 
        if (error)
                return error;
        MPASS(vp != NULL);
        if (fap)
                smbfs_attr_cacheenter(vp, fap);
        *vpp = vp;
        return 0;
}

/*
 * Free smbnode, and give vnode back to system
 */
int
smbfs_reclaim(struct vop_reclaim_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp;
        struct smbnode *np = VTOSMB(vp);
        struct smbmount *smp = VTOSMBFS(vp);

        SMBVDEBUG("%s,%d\n", np->n_name, vrefcnt(vp));

        KASSERT((np->n_flag & NOPEN) == 0, ("file not closed before reclaim"));

        dvp = (np->n_parent && (np->n_flag & NREFPARENT)) ?
            np->n_parent : NULL;

        /*
         * Remove the vnode from its hash chain.
         */
        vfs_hash_remove(vp);
        if (np->n_name)
                smbfs_name_free(np->n_name);
        if (np->n_rpath)
                free(np->n_rpath, M_SMBNODENAME);
        free(np, M_SMBNODE);
        vp->v_data = NULL;
        if (dvp != NULL) {
                vrele(dvp);
                /*
                 * Indicate that we released something; see comment
                 * in smbfs_unmount().
                 */
                smp->sm_didrele = 1;
        }
        return 0;
}

int
smbfs_inactive(struct vop_inactive_args *ap)
{
        struct thread *td = curthread;
        struct ucred *cred = td->td_ucred;
        struct vnode *vp = ap->a_vp;
        struct smbnode *np = VTOSMB(vp);
        struct smb_cred *scred;
        struct vattr va;

        SMBVDEBUG("%s: %d\n", VTOSMB(vp)->n_name, vrefcnt(vp));
        if ((np->n_flag & NOPEN) != 0) {
                scred = smbfs_malloc_scred();
                smb_makescred(scred, td, cred);
                smbfs_vinvalbuf(vp, td);
                if (vp->v_type == VREG) {
                        VOP_GETATTR(vp, &va, cred);
                        smbfs_smb_close(np->n_mount->sm_share, np->n_fid,
                            &np->n_mtime, scred);
                } else if (vp->v_type == VDIR) {
                        if (np->n_dirseq != NULL) {
                                smbfs_findclose(np->n_dirseq, scred);
                                np->n_dirseq = NULL;
                        }
                }
                np->n_flag &= ~NOPEN;
                smbfs_attr_cacheremove(vp);
                smbfs_free_scred(scred);
        }
        if (np->n_flag & NGONE)
                vrecycle(vp);
        return (0);
}
/*
 * routines to maintain vnode attributes cache
 * smbfs_attr_cacheenter: unpack np.i to vattr structure
 */
void
smbfs_attr_cacheenter(struct vnode *vp, struct smbfattr *fap)
{
        struct smbnode *np = VTOSMB(vp);

        if (vp->v_type == VREG) {
                if (np->n_size != fap->fa_size) {
                        np->n_size = fap->fa_size;
                        vnode_pager_setsize(vp, np->n_size);
                }
        } else if (vp->v_type == VDIR) {
                np->n_size = 16384;             /* should be a better way ... */
        } else
                return;
        np->n_mtime = fap->fa_mtime;
        np->n_dosattr = fap->fa_attr;
        np->n_attrage = time_second;
        return;
}

int
smbfs_attr_cachelookup(struct vnode *vp, struct vattr *va)
{
        struct smbnode *np = VTOSMB(vp);
        struct smbmount *smp = VTOSMBFS(vp);
        int diff;

        diff = time_second - np->n_attrage;
        if (diff > 2)   /* XXX should be configurable */
                return ENOENT;
        va->va_type = vp->v_type;               /* vnode type (for create) */
        va->va_flags = 0;                       /* flags defined for file */
        if (vp->v_type == VREG) {
                va->va_mode = smp->sm_file_mode; /* files access mode and type */
                if (np->n_dosattr & SMB_FA_RDONLY) {
                        va->va_mode &= ~(S_IWUSR|S_IWGRP|S_IWOTH);
                        va->va_flags |= UF_READONLY;
                }
        } else if (vp->v_type == VDIR) {
                va->va_mode = smp->sm_dir_mode; /* files access mode and type */
        } else
                return EINVAL;
        va->va_size = np->n_size;
        va->va_nlink = 1;               /* number of references to file */
        va->va_uid = smp->sm_uid;       /* owner user id */
        va->va_gid = smp->sm_gid;       /* owner group id */
        va->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
        va->va_fileid = np->n_ino;      /* file id */
        if (va->va_fileid == 0)
                va->va_fileid = 2;
        va->va_blocksize = SSTOVC(smp->sm_share)->vc_txmax;
        va->va_mtime = np->n_mtime;
        va->va_atime = va->va_ctime = va->va_mtime;     /* time file changed */
        va->va_gen = VNOVAL;            /* generation number of file */
        if (np->n_dosattr & SMB_FA_HIDDEN)
                va->va_flags |= UF_HIDDEN;
        if (np->n_dosattr & SMB_FA_SYSTEM)
                va->va_flags |= UF_SYSTEM;
        /*
         * We don't set the archive bit for directories.
         */
        if ((vp->v_type != VDIR) && (np->n_dosattr & SMB_FA_ARCHIVE))
                va->va_flags |= UF_ARCHIVE;
        va->va_rdev = NODEV;            /* device the special file represents */
        va->va_bytes = va->va_size;     /* bytes of disk space held by file */
        va->va_filerev = 0;             /* file modification number */
        va->va_vaflags = 0;             /* operations flags */
        return 0;
}