/*
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by Boris Popov.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * 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.
 *
 * $FreeBSD: src/sys/fs/smbfs/smbfs_node.c,v 1.2.2.3 2003/01/17 08:20:26 tjr Exp $
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
/*#include <vm/vm_page.h>
#include <vm/vm_object.h>*/
#include <sys/queue.h>

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

#include "smbfs.h"
#include "smbfs_node.h"
#include "smbfs_subr.h"

#define SMBFS_NOHASH(smp, hval) (&(smp)->sm_hash[(hval) & (smp)->sm_hashlen])
#define smbfs_hash_lock(smp, td)        lockmgr(&smp->sm_hashlock, LK_EXCLUSIVE)
#define smbfs_hash_unlock(smp, td)      lockmgr(&smp->sm_hashlock, LK_RELEASE)


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

int smbfs_hashprint(struct mount *mp);

#if 0
#ifdef SYSCTL_DECL
SYSCTL_DECL(_vfs_smbfs);
#endif
SYSCTL_PROC(_vfs_smbfs, OID_AUTO, vnprint, CTLFLAG_WR|CTLTYPE_OPAQUE,
            NULL, 0, smbfs_hashprint, "S,vnlist", "vnode hash");
#endif

#define FNV_32_PRIME ((u_int32_t) 0x01000193UL)
#define FNV1_32_INIT ((u_int32_t) 33554467UL)

u_int32_t
smbfs_hash(const u_char *name, int nmlen)
{
        u_int32_t v;

        for (v = FNV1_32_INIT; nmlen; name++, nmlen--) {
                v *= FNV_32_PRIME;
                v ^= (u_int32_t)*name;
        }
        return v;
}

int
smbfs_hashprint(struct mount *mp)
{
        struct smbmount *smp = VFSTOSMBFS(mp);
        struct smbnode_hashhead *nhpp;
        struct smbnode *np;
        int i;

        for(i = 0; i <= smp->sm_hashlen; i++) {
                nhpp = &smp->sm_hash[i];
                LIST_FOREACH(np, nhpp, n_hash)
                        vprint(NULL, SMBTOV(np));
        }
        return 0;
}

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

        nmlen++;
#ifdef SMBFS_NAME_DEBUG
        cp = kmalloc(nmlen + 2 + sizeof(int), M_SMBNODENAME, M_WAITOK);
        *(int*)cp = nmlen;
        cp += sizeof(int);
        cp[0] = 0xfc;
        cp++;
        bcopy(name, cp, nmlen - 1);
        cp[nmlen] = 0xfe;
#else
        cp = kmalloc(nmlen, M_SMBNODENAME, M_WAITOK);
        bcopy(name, cp, nmlen - 1);
#endif
        cp[nmlen - 1] = 0;
        return cp;
}

static void
smbfs_name_free(u_char *name)
{
#ifdef SMBFS_NAME_DEBUG
        int nmlen, slen;
        u_char *cp;

        cp = name;
        cp--;
        if (*cp != 0xfc) {
                kprintf("First byte of name entry '%s' corrupted\n", name);
                Debugger("ditto");
        }
        cp -= sizeof(int);
        nmlen = *(int*)cp;
        slen = strlen(name) + 1;
        if (nmlen != slen) {
                kprintf("Name length mismatch: was %d, now %d name '%s'\n",
                    nmlen, slen, name);
                Debugger("ditto");
        }
        if (name[nmlen] != 0xfe) {
                kprintf("Last byte of name entry '%s' corrupted\n", name);
                Debugger("ditto");
        }
        kfree(cp, M_SMBNODENAME);
#else
        kfree(name, M_SMBNODENAME);
#endif
}

static int
smbfs_node_alloc(struct mount *mp, struct vnode *dvp,
                 const char *name, int nmlen, struct smbfattr *fap,
                 struct vnode **vpp)
{
        struct smbmount *smp = VFSTOSMBFS(mp);
        struct smbnode_hashhead *nhpp;
        struct smbnode *np, *np2, *dnp;
        struct vnode *vp;
        u_long hashval;
        int error;

        *vpp = NULL;
        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) {
                vprint("smbfs_node_alloc: dead parent vnode", dvp);
                return EINVAL;
        }
        hashval = smbfs_hash(name, nmlen);
retry:
        smbfs_hash_lock(smp, td);
loop:
        nhpp = SMBFS_NOHASH(smp, hashval);
        LIST_FOREACH(np, nhpp, n_hash) {
                if (np->n_parent != dvp ||
                    np->n_nmlen != nmlen || bcmp(name, np->n_name, nmlen) != 0)
                        continue;
                vp = SMBTOV(np);
                smbfs_hash_unlock(smp, td);
                if (vget(vp, LK_EXCLUSIVE) != 0)
                        goto retry;
                /*
                 * relookup after we blocked.
                 */
                LIST_FOREACH(np2, nhpp, n_hash) {
                        if (np2->n_parent == dvp && np2->n_nmlen == nmlen &&
                            bcmp(name, np2->n_name, nmlen) == 0)
                                break;
                }
                if (np2 != np || SMBTOV(np2) != vp) {
                        vput(vp);
                        goto retry;
                }
                *vpp = vp;
                return 0;
        }
        smbfs_hash_unlock(smp, td);
        /*
         * If we don't have node attributes, then it is an explicit lookup
         * for an existing vnode.
         */
        if (fap == NULL)
                return ENOENT;

        np = kmalloc(sizeof *np, M_SMBNODE, M_WAITOK | M_ZERO);
        error = getnewvnode(VT_SMBFS, mp, &vp, VLKTIMEOUT, LK_CANRECURSE);
        if (error) {
                kfree(np, M_SMBNODE);
                return error;
        }
        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_nmlen = nmlen;
        np->n_name = smbfs_name_alloc(name, nmlen);
        np->n_ino = fap->fa_ino;

        if (dvp) {
                np->n_parent = dvp;
                if (/*vp->v_type == VDIR &&*/ (dvp->v_flag & VROOT) == 0) {
                        vref(dvp);
                        np->n_flag |= NREFPARENT;
                }
        } else if (vp->v_type == VREG)
                SMBERROR("new vnode '%s' born without parent ?\n", np->n_name);

        smbfs_hash_lock(smp, td);
        LIST_FOREACH(np2, nhpp, n_hash) {
                if (np2->n_parent != dvp ||
                    np2->n_nmlen != nmlen || bcmp(name, np2->n_name, nmlen) != 0)
                        continue;
                vx_put(vp);
/*              smb_name_free(np->n_name);
                FREE(np, M_SMBNODE);*/
                goto loop;
        }
        LIST_INSERT_HEAD(nhpp, np, n_hash);
        smbfs_hash_unlock(smp, td);
        /*
         * Return a locked and refd vnode
         */
        vx_downgrade(vp);
        *vpp = vp;
        return 0;
}

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

        *vpp = NULL;
        error = smbfs_node_alloc(mp, dvp, name, nmlen, fap, &vp);
        if (error)
                return error;
        if (fap)
                smbfs_attr_cacheenter(vp, fap);
        *vpp = vp;
        return 0;
}

/*
 * Free smbnode, and give vnode back to system
 *
 * smbfs_reclaim(struct vnode *a_vp)
 */
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,%08x\n", np->n_name, vp->v_refcnt);

        smbfs_hash_lock(smp, td);

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

        if (np->n_hash.le_prev)
                LIST_REMOVE(np, n_hash);
        if (smp->sm_root == np) {
                SMBVDEBUG("root vnode\n");
                smp->sm_root = NULL;
        }
        vp->v_data = NULL;
        smbfs_hash_unlock(smp, td);
        if (np->n_name)
                smbfs_name_free(np->n_name);
        kfree(np, M_SMBNODE);
        if (dvp) {
                /*
                 * Indicate that we released something; see comment
                 * in smbfs_unmount().
                 */
                smp->sm_didrele = 1;
                vrele(dvp);
        }
        return 0;
}

/*
 * smbfs_inactive(struct vnode *a_vp)
 */
int
smbfs_inactive(struct vop_inactive_args *ap)
{
        struct ucred *cred;
        struct vnode *vp = ap->a_vp;
        struct smbnode *np = VTOSMB(vp);
        struct smb_cred scred;
        int error;

        SMBVDEBUG("%s: %08x\n", VTOSMB(vp)->n_name, vp->v_refcnt);
        if (np->n_opencount) {
                error = smbfs_vinvalbuf(vp, V_SAVE, 1);
                cred = np->n_cached_cred;
                np->n_cached_cred = NULL;
                smb_makescred(&scred, curthread, cred);
                error = smbfs_smb_close(np->n_mount->sm_share, np->n_fid, 
                   &np->n_mtime, &scred);
                np->n_opencount = 0;
                crfree(cred);
        }
        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_uptime;
        return;
}

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

        diff = (int)(time_uptime - np->n_attrage);
        if (diff > 2)   /* XXX should be configurable */
                return ENOENT;
        va->va_type = vp->v_type;               /* vnode type (for create) */
        if (vp->v_type == VREG) {
                va->va_mode = smp->sm_args.file_mode;   /* files access mode and type */
        } else if (vp->v_type == VDIR) {
                va->va_mode = smp->sm_args.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_args.uid;  /* owner user id */
        va->va_gid = smp->sm_args.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 */
        va->va_flags = 0;               /* flags defined for file */
        va->va_rmajor = VNOVAL;         /* device the special file represents */
        va->va_rminor = VNOVAL;
        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;
}

void
smbfs_attr_cacherename(struct vnode *vp, const char *name, int nmlen)
{
        struct smbnode_hashhead *nhpp;
        struct smbmount *smp = VTOSMBFS(vp);
        struct smbnode *np;
        u_long hashval;

        hashval = smbfs_hash(name, nmlen);

        smbfs_hash_lock(smp, td);

        np = VTOSMB(vp);
        if (np->n_hash.le_prev)
                LIST_REMOVE(np, n_hash);

        smbfs_name_free(np->n_name);
        np->n_nmlen = nmlen;
        np->n_name = smbfs_name_alloc(name, nmlen);

        nhpp = SMBFS_NOHASH(smp, hashval);
        LIST_INSERT_HEAD(nhpp, np, n_hash);

        smbfs_hash_unlock(smp, td);
}