// SPDX-License-Identifier: GPL-2.0
/*
 *  ncplib_kernel.c
 *
 *  Copyright (C) 1995, 1996 by Volker Lendecke
 *  Modified for big endian by J.F. Chadima and David S. Miller
 *  Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache
 *  Modified 1999 Wolfram Pienkoss for NLS
 *  Modified 2000 Ben Harris, University of Cambridge for NFS NS meta-info
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "ncp_fs.h"

static inline void assert_server_locked(struct ncp_server *server)
{
        if (server->lock == 0) {
                ncp_dbg(1, "server not locked!\n");
        }
}

static void ncp_add_byte(struct ncp_server *server, __u8 x)
{
        assert_server_locked(server);
        *(__u8 *) (&(server->packet[server->current_size])) = x;
        server->current_size += 1;
        return;
}

static void ncp_add_word(struct ncp_server *server, __le16 x)
{
        assert_server_locked(server);
        put_unaligned(x, (__le16 *) (&(server->packet[server->current_size])));
        server->current_size += 2;
        return;
}

static void ncp_add_be16(struct ncp_server *server, __u16 x)
{
        assert_server_locked(server);
        put_unaligned(cpu_to_be16(x), (__be16 *) (&(server->packet[server->current_size])));
        server->current_size += 2;
}

static void ncp_add_dword(struct ncp_server *server, __le32 x)
{
        assert_server_locked(server);
        put_unaligned(x, (__le32 *) (&(server->packet[server->current_size])));
        server->current_size += 4;
        return;
}

static void ncp_add_be32(struct ncp_server *server, __u32 x)
{
        assert_server_locked(server);
        put_unaligned(cpu_to_be32(x), (__be32 *)(&(server->packet[server->current_size])));
        server->current_size += 4;
}

static inline void ncp_add_dword_lh(struct ncp_server *server, __u32 x) {
        ncp_add_dword(server, cpu_to_le32(x));
}

static void ncp_add_mem(struct ncp_server *server, const void *source, int size)
{
        assert_server_locked(server);
        memcpy(&(server->packet[server->current_size]), source, size);
        server->current_size += size;
        return;
}

static void ncp_add_pstring(struct ncp_server *server, const char *s)
{
        int len = strlen(s);
        assert_server_locked(server);
        if (len > 255) {
                ncp_dbg(1, "string too long: %s\n", s);
                len = 255;
        }
        ncp_add_byte(server, len);
        ncp_add_mem(server, s, len);
        return;
}

static inline void ncp_init_request(struct ncp_server *server)
{
        ncp_lock_server(server);

        server->current_size = sizeof(struct ncp_request_header);
        server->has_subfunction = 0;
}

static inline void ncp_init_request_s(struct ncp_server *server, int subfunction)
{
        ncp_lock_server(server);
        
        server->current_size = sizeof(struct ncp_request_header) + 2;
        ncp_add_byte(server, subfunction);

        server->has_subfunction = 1;
}

static inline char *
ncp_reply_data(struct ncp_server *server, int offset)
{
        return &(server->packet[sizeof(struct ncp_reply_header) + offset]);
}

static inline u8 BVAL(const void *data)
{
        return *(const u8 *)data;
}

static u8 ncp_reply_byte(struct ncp_server *server, int offset)
{
        return *(const u8 *)ncp_reply_data(server, offset);
}

static inline u16 WVAL_LH(const void *data)
{
        return get_unaligned_le16(data);
}

static u16
ncp_reply_le16(struct ncp_server *server, int offset)
{
        return get_unaligned_le16(ncp_reply_data(server, offset));
}

static u16
ncp_reply_be16(struct ncp_server *server, int offset)
{
        return get_unaligned_be16(ncp_reply_data(server, offset));
}

static inline u32 DVAL_LH(const void *data)
{
        return get_unaligned_le32(data);
}

static __le32
ncp_reply_dword(struct ncp_server *server, int offset)
{
        return get_unaligned((__le32 *)ncp_reply_data(server, offset));
}

static inline __u32 ncp_reply_dword_lh(struct ncp_server* server, int offset) {
        return le32_to_cpu(ncp_reply_dword(server, offset));
}

int
ncp_negotiate_buffersize(struct ncp_server *server, int size, int *target)
{
        int result;

        ncp_init_request(server);
        ncp_add_be16(server, size);

        if ((result = ncp_request(server, 33)) != 0) {
                ncp_unlock_server(server);
                return result;
        }
        *target = min_t(unsigned int, ncp_reply_be16(server, 0), size);

        ncp_unlock_server(server);
        return 0;
}


/* options: 
 *      bit 0   ipx checksum
 *      bit 1   packet signing
 */
int
ncp_negotiate_size_and_options(struct ncp_server *server, 
        int size, int options, int *ret_size, int *ret_options) {
        int result;

        /* there is minimum */
        if (size < NCP_BLOCK_SIZE) size = NCP_BLOCK_SIZE;

        ncp_init_request(server);
        ncp_add_be16(server, size);
        ncp_add_byte(server, options);
        
        if ((result = ncp_request(server, 0x61)) != 0)
        {
                ncp_unlock_server(server);
                return result;
        }

        /* NCP over UDP returns 0 (!!!) */
        result = ncp_reply_be16(server, 0);
        if (result >= NCP_BLOCK_SIZE)
                size = min(result, size);
        *ret_size = size;
        *ret_options = ncp_reply_byte(server, 4);

        ncp_unlock_server(server);
        return 0;
}

int ncp_get_volume_info_with_number(struct ncp_server* server,
                             int n, struct ncp_volume_info* target) {
        int result;
        int len;

        ncp_init_request_s(server, 44);
        ncp_add_byte(server, n);

        if ((result = ncp_request(server, 22)) != 0) {
                goto out;
        }
        target->total_blocks = ncp_reply_dword_lh(server, 0);
        target->free_blocks = ncp_reply_dword_lh(server, 4);
        target->purgeable_blocks = ncp_reply_dword_lh(server, 8);
        target->not_yet_purgeable_blocks = ncp_reply_dword_lh(server, 12);
        target->total_dir_entries = ncp_reply_dword_lh(server, 16);
        target->available_dir_entries = ncp_reply_dword_lh(server, 20);
        target->sectors_per_block = ncp_reply_byte(server, 28);

        memset(&(target->volume_name), 0, sizeof(target->volume_name));

        result = -EIO;
        len = ncp_reply_byte(server, 29);
        if (len > NCP_VOLNAME_LEN) {
                ncp_dbg(1, "volume name too long: %d\n", len);
                goto out;
        }
        memcpy(&(target->volume_name), ncp_reply_data(server, 30), len);
        result = 0;
out:
        ncp_unlock_server(server);
        return result;
}

int ncp_get_directory_info(struct ncp_server* server, __u8 n, 
                           struct ncp_volume_info* target) {
        int result;
        int len;

        ncp_init_request_s(server, 45);
        ncp_add_byte(server, n);

        if ((result = ncp_request(server, 22)) != 0) {
                goto out;
        }
        target->total_blocks = ncp_reply_dword_lh(server, 0);
        target->free_blocks = ncp_reply_dword_lh(server, 4);
        target->purgeable_blocks = 0;
        target->not_yet_purgeable_blocks = 0;
        target->total_dir_entries = ncp_reply_dword_lh(server, 8);
        target->available_dir_entries = ncp_reply_dword_lh(server, 12);
        target->sectors_per_block = ncp_reply_byte(server, 20);

        memset(&(target->volume_name), 0, sizeof(target->volume_name));

        result = -EIO;
        len = ncp_reply_byte(server, 21);
        if (len > NCP_VOLNAME_LEN) {
                ncp_dbg(1, "volume name too long: %d\n", len);
                goto out;
        }
        memcpy(&(target->volume_name), ncp_reply_data(server, 22), len);
        result = 0;
out:
        ncp_unlock_server(server);
        return result;
}

int
ncp_close_file(struct ncp_server *server, const char *file_id)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 0);
        ncp_add_mem(server, file_id, 6);

        result = ncp_request(server, 66);
        ncp_unlock_server(server);
        return result;
}

int
ncp_make_closed(struct inode *inode)
{
        int err;

        err = 0;
        mutex_lock(&NCP_FINFO(inode)->open_mutex);
        if (atomic_read(&NCP_FINFO(inode)->opened) == 1) {
                atomic_set(&NCP_FINFO(inode)->opened, 0);
                err = ncp_close_file(NCP_SERVER(inode), NCP_FINFO(inode)->file_handle);

                if (!err)
                        ncp_vdbg("volnum=%d, dirent=%u, error=%d\n",
                                 NCP_FINFO(inode)->volNumber,
                                 NCP_FINFO(inode)->dirEntNum, err);
        }
        mutex_unlock(&NCP_FINFO(inode)->open_mutex);
        return err;
}

static void ncp_add_handle_path(struct ncp_server *server, __u8 vol_num,
                                __le32 dir_base, int have_dir_base, 
                                const char *path)
{
        ncp_add_byte(server, vol_num);
        ncp_add_dword(server, dir_base);
        if (have_dir_base != 0) {
                ncp_add_byte(server, 1);        /* dir_base */
        } else {
                ncp_add_byte(server, 0xff);     /* no handle */
        }
        if (path != NULL) {
                ncp_add_byte(server, 1);        /* 1 component */
                ncp_add_pstring(server, path);
        } else {
                ncp_add_byte(server, 0);
        }
}

int ncp_dirhandle_alloc(struct ncp_server* server, __u8 volnum, __le32 dirent,
                        __u8* dirhandle) {
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 12);               /* subfunction */
        ncp_add_byte(server, NW_NS_DOS);
        ncp_add_byte(server, 0);
        ncp_add_word(server, 0);
        ncp_add_handle_path(server, volnum, dirent, 1, NULL);
        if ((result = ncp_request(server, 87)) == 0) {
                *dirhandle = ncp_reply_byte(server, 0);
        }
        ncp_unlock_server(server);
        return result;
}

int ncp_dirhandle_free(struct ncp_server* server, __u8 dirhandle) {
        int result;
        
        ncp_init_request_s(server, 20);
        ncp_add_byte(server, dirhandle);
        result = ncp_request(server, 22);
        ncp_unlock_server(server);
        return result;
}

void ncp_extract_file_info(const void *structure, struct nw_info_struct *target)
{
        const __u8 *name_len;
        const int info_struct_size = offsetof(struct nw_info_struct, nameLen);

        memcpy(target, structure, info_struct_size);
        name_len = structure + info_struct_size;
        target->nameLen = *name_len;
        memcpy(target->entryName, name_len + 1, *name_len);
        target->entryName[*name_len] = '\0';
        target->volNumber = le32_to_cpu(target->volNumber);
        return;
}

#ifdef CONFIG_NCPFS_NFS_NS
static inline void ncp_extract_nfs_info(const unsigned char *structure,
                                 struct nw_nfs_info *target)
{
        target->mode = DVAL_LH(structure);
        target->rdev = DVAL_LH(structure + 8);
}
#endif

int ncp_obtain_nfs_info(struct ncp_server *server,
                        struct nw_info_struct *target)

{
        int result = 0;
#ifdef CONFIG_NCPFS_NFS_NS
        __u32 volnum = target->volNumber;

        if (ncp_is_nfs_extras(server, volnum)) {
                ncp_init_request(server);
                ncp_add_byte(server, 19);       /* subfunction */
                ncp_add_byte(server, server->name_space[volnum]);
                ncp_add_byte(server, NW_NS_NFS);
                ncp_add_byte(server, 0);
                ncp_add_byte(server, volnum);
                ncp_add_dword(server, target->dirEntNum);
                /* We must retrieve both nlinks and rdev, otherwise some server versions
                   report zeroes instead of valid data */
                ncp_add_dword_lh(server, NSIBM_NFS_MODE | NSIBM_NFS_NLINKS | NSIBM_NFS_RDEV);

                if ((result = ncp_request(server, 87)) == 0) {
                        ncp_extract_nfs_info(ncp_reply_data(server, 0), &target->nfs);
                        ncp_dbg(1, "(%s) mode=0%o, rdev=0x%x\n",
                                target->entryName, target->nfs.mode,
                                target->nfs.rdev);
                } else {
                        target->nfs.mode = 0;
                        target->nfs.rdev = 0;
                }
                ncp_unlock_server(server);

        } else
#endif
        {
                target->nfs.mode = 0;
                target->nfs.rdev = 0;
        }
        return result;
}

/*
 * Returns information for a (one-component) name relative to
 * the specified directory.
 */
int ncp_obtain_info(struct ncp_server *server, struct inode *dir, const char *path,
                        struct nw_info_struct *target)
{
        __u8  volnum = NCP_FINFO(dir)->volNumber;
        __le32 dirent = NCP_FINFO(dir)->dirEntNum;
        int result;

        if (target == NULL) {
                pr_err("%s: invalid call\n", __func__);
                return -EINVAL;
        }
        ncp_init_request(server);
        ncp_add_byte(server, 6);        /* subfunction */
        ncp_add_byte(server, server->name_space[volnum]);
        ncp_add_byte(server, server->name_space[volnum]); /* N.B. twice ?? */
        ncp_add_word(server, cpu_to_le16(0x8006));      /* get all */
        ncp_add_dword(server, RIM_ALL);
        ncp_add_handle_path(server, volnum, dirent, 1, path);

        if ((result = ncp_request(server, 87)) != 0)
                goto out;
        ncp_extract_file_info(ncp_reply_data(server, 0), target);
        ncp_unlock_server(server);
        
        result = ncp_obtain_nfs_info(server, target);
        return result;

out:
        ncp_unlock_server(server);
        return result;
}

#ifdef CONFIG_NCPFS_NFS_NS
static int
ncp_obtain_DOS_dir_base(struct ncp_server *server,
                __u8 ns, __u8 volnum, __le32 dirent,
                const char *path, /* At most 1 component */
                __le32 *DOS_dir_base)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 6); /* subfunction */
        ncp_add_byte(server, ns);
        ncp_add_byte(server, ns);
        ncp_add_word(server, cpu_to_le16(0x8006)); /* get all */
        ncp_add_dword(server, RIM_DIRECTORY);
        ncp_add_handle_path(server, volnum, dirent, 1, path);

        if ((result = ncp_request(server, 87)) == 0)
        {
                if (DOS_dir_base) *DOS_dir_base=ncp_reply_dword(server, 0x34);
        }
        ncp_unlock_server(server);
        return result;
}
#endif /* CONFIG_NCPFS_NFS_NS */

static inline int
ncp_get_known_namespace(struct ncp_server *server, __u8 volume)
{
#if defined(CONFIG_NCPFS_OS2_NS) || defined(CONFIG_NCPFS_NFS_NS)
        int result;
        __u8 *namespace;
        __u16 no_namespaces;

        ncp_init_request(server);
        ncp_add_byte(server, 24);       /* Subfunction: Get Name Spaces Loaded */
        ncp_add_word(server, 0);
        ncp_add_byte(server, volume);

        if ((result = ncp_request(server, 87)) != 0) {
                ncp_unlock_server(server);
                return NW_NS_DOS; /* not result ?? */
        }

        result = NW_NS_DOS;
        no_namespaces = ncp_reply_le16(server, 0);
        namespace = ncp_reply_data(server, 2);

        while (no_namespaces > 0) {
                ncp_dbg(1, "found %d on %d\n", *namespace, volume);

#ifdef CONFIG_NCPFS_NFS_NS
                if ((*namespace == NW_NS_NFS) && !(server->m.flags&NCP_MOUNT_NO_NFS)) 
                {
                        result = NW_NS_NFS;
                        break;
                }
#endif  /* CONFIG_NCPFS_NFS_NS */
#ifdef CONFIG_NCPFS_OS2_NS
                if ((*namespace == NW_NS_OS2) && !(server->m.flags&NCP_MOUNT_NO_OS2))
                {
                        result = NW_NS_OS2;
                }
#endif  /* CONFIG_NCPFS_OS2_NS */
                namespace += 1;
                no_namespaces -= 1;
        }
        ncp_unlock_server(server);
        return result;
#else   /* neither OS2 nor NFS - only DOS */
        return NW_NS_DOS;
#endif  /* defined(CONFIG_NCPFS_OS2_NS) || defined(CONFIG_NCPFS_NFS_NS) */
}

int
ncp_update_known_namespace(struct ncp_server *server, __u8 volume, int *ret_ns)
{
        int ns = ncp_get_known_namespace(server, volume);

        if (ret_ns)
                *ret_ns = ns;

        ncp_dbg(1, "namespace[%d] = %d\n", volume, server->name_space[volume]);

        if (server->name_space[volume] == ns)
                return 0;
        server->name_space[volume] = ns;
        return 1;
}

static int
ncp_ObtainSpecificDirBase(struct ncp_server *server,
                __u8 nsSrc, __u8 nsDst, __u8 vol_num, __le32 dir_base,
                const char *path, /* At most 1 component */
                __le32 *dirEntNum, __le32 *DosDirNum)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 6); /* subfunction */
        ncp_add_byte(server, nsSrc);
        ncp_add_byte(server, nsDst);
        ncp_add_word(server, cpu_to_le16(0x8006)); /* get all */
        ncp_add_dword(server, RIM_ALL);
        ncp_add_handle_path(server, vol_num, dir_base, 1, path);

        if ((result = ncp_request(server, 87)) != 0)
        {
                ncp_unlock_server(server);
                return result;
        }

        if (dirEntNum)
                *dirEntNum = ncp_reply_dword(server, 0x30);
        if (DosDirNum)
                *DosDirNum = ncp_reply_dword(server, 0x34);
        ncp_unlock_server(server);
        return 0;
}

int
ncp_mount_subdir(struct ncp_server *server,
                 __u8 volNumber, __u8 srcNS, __le32 dirEntNum,
                 __u32* volume, __le32* newDirEnt, __le32* newDosEnt)
{
        int dstNS;
        int result;

        ncp_update_known_namespace(server, volNumber, &dstNS);
        if ((result = ncp_ObtainSpecificDirBase(server, srcNS, dstNS, volNumber, 
                                      dirEntNum, NULL, newDirEnt, newDosEnt)) != 0)
        {
                return result;
        }
        *volume = volNumber;
        server->m.mounted_vol[1] = 0;
        server->m.mounted_vol[0] = 'X';
        return 0;
}

int 
ncp_get_volume_root(struct ncp_server *server,
                    const char *volname, __u32* volume, __le32* dirent, __le32* dosdirent)
{
        int result;

        ncp_dbg(1, "looking up vol %s\n", volname);

        ncp_init_request(server);
        ncp_add_byte(server, 22);       /* Subfunction: Generate dir handle */
        ncp_add_byte(server, 0);        /* DOS namespace */
        ncp_add_byte(server, 0);        /* reserved */
        ncp_add_byte(server, 0);        /* reserved */
        ncp_add_byte(server, 0);        /* reserved */

        ncp_add_byte(server, 0);        /* faked volume number */
        ncp_add_dword(server, 0);       /* faked dir_base */
        ncp_add_byte(server, 0xff);     /* Don't have a dir_base */
        ncp_add_byte(server, 1);        /* 1 path component */
        ncp_add_pstring(server, volname);

        if ((result = ncp_request(server, 87)) != 0) {
                ncp_unlock_server(server);
                return result;
        }
        *dirent = *dosdirent = ncp_reply_dword(server, 4);
        *volume = ncp_reply_byte(server, 8);
        ncp_unlock_server(server);
        return 0;
}

int
ncp_lookup_volume(struct ncp_server *server,
                  const char *volname, struct nw_info_struct *target)
{
        int result;

        memset(target, 0, sizeof(*target));
        result = ncp_get_volume_root(server, volname,
                        &target->volNumber, &target->dirEntNum, &target->DosDirNum);
        if (result) {
                return result;
        }
        ncp_update_known_namespace(server, target->volNumber, NULL);
        target->nameLen = strlen(volname);
        memcpy(target->entryName, volname, target->nameLen+1);
        target->attributes = aDIR;
        /* set dates to Jan 1, 1986  00:00 */
        target->creationTime = target->modifyTime = cpu_to_le16(0x0000);
        target->creationDate = target->modifyDate = target->lastAccessDate = cpu_to_le16(0x0C21);
        target->nfs.mode = 0;
        return 0;
}

int ncp_modify_file_or_subdir_dos_info_path(struct ncp_server *server,
                                            struct inode *dir,
                                            const char *path,
                                            __le32 info_mask,
                                            const struct nw_modify_dos_info *info)
{
        __u8  volnum = NCP_FINFO(dir)->volNumber;
        __le32 dirent = NCP_FINFO(dir)->dirEntNum;
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 7);        /* subfunction */
        ncp_add_byte(server, server->name_space[volnum]);
        ncp_add_byte(server, 0);        /* reserved */
        ncp_add_word(server, cpu_to_le16(0x8006));      /* search attribs: all */

        ncp_add_dword(server, info_mask);
        ncp_add_mem(server, info, sizeof(*info));
        ncp_add_handle_path(server, volnum, dirent, 1, path);

        result = ncp_request(server, 87);
        ncp_unlock_server(server);
        return result;
}

int ncp_modify_file_or_subdir_dos_info(struct ncp_server *server,
                                       struct inode *dir,
                                       __le32 info_mask,
                                       const struct nw_modify_dos_info *info)
{
        return ncp_modify_file_or_subdir_dos_info_path(server, dir, NULL,
                info_mask, info);
}

#ifdef CONFIG_NCPFS_NFS_NS
int ncp_modify_nfs_info(struct ncp_server *server, __u8 volnum, __le32 dirent,
                               __u32 mode, __u32 rdev)

{
        int result = 0;

        ncp_init_request(server);
        if (server->name_space[volnum] == NW_NS_NFS) {
                ncp_add_byte(server, 25);       /* subfunction */
                ncp_add_byte(server, server->name_space[volnum]);
                ncp_add_byte(server, NW_NS_NFS);
                ncp_add_byte(server, volnum);
                ncp_add_dword(server, dirent);
                /* we must always operate on both nlinks and rdev, otherwise
                   rdev is not set */
                ncp_add_dword_lh(server, NSIBM_NFS_MODE | NSIBM_NFS_NLINKS | NSIBM_NFS_RDEV);
                ncp_add_dword_lh(server, mode);
                ncp_add_dword_lh(server, 1);    /* nlinks */
                ncp_add_dword_lh(server, rdev);
                result = ncp_request(server, 87);
        }
        ncp_unlock_server(server);
        return result;
}
#endif


static int
ncp_DeleteNSEntry(struct ncp_server *server,
                  __u8 have_dir_base, __u8 volnum, __le32 dirent,
                  const char* name, __u8 ns, __le16 attr)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 8);        /* subfunction */
        ncp_add_byte(server, ns);
        ncp_add_byte(server, 0);        /* reserved */
        ncp_add_word(server, attr);     /* search attribs: all */
        ncp_add_handle_path(server, volnum, dirent, have_dir_base, name);

        result = ncp_request(server, 87);
        ncp_unlock_server(server);
        return result;
}

int
ncp_del_file_or_subdir2(struct ncp_server *server,
                        struct dentry *dentry)
{
        struct inode *inode = d_inode(dentry);
        __u8  volnum;
        __le32 dirent;

        if (!inode) {
                return 0xFF;    /* Any error */
        }
        volnum = NCP_FINFO(inode)->volNumber;
        dirent = NCP_FINFO(inode)->DosDirNum;
        return ncp_DeleteNSEntry(server, 1, volnum, dirent, NULL, NW_NS_DOS, cpu_to_le16(0x8006));
}

int
ncp_del_file_or_subdir(struct ncp_server *server,
                       struct inode *dir, const char *name)
{
        __u8  volnum = NCP_FINFO(dir)->volNumber;
        __le32 dirent = NCP_FINFO(dir)->dirEntNum;
        int name_space;

        name_space = server->name_space[volnum];
#ifdef CONFIG_NCPFS_NFS_NS
        if (name_space == NW_NS_NFS)
        {
                int result;
 
                result=ncp_obtain_DOS_dir_base(server, name_space, volnum, dirent, name, &dirent);
                if (result) return result;
                name = NULL;
                name_space = NW_NS_DOS;
        }
#endif  /* CONFIG_NCPFS_NFS_NS */
        return ncp_DeleteNSEntry(server, 1, volnum, dirent, name, name_space, cpu_to_le16(0x8006));
}

static inline void ConvertToNWfromDWORD(__u16 v0, __u16 v1, __u8 ret[6])
{
        __le16 *dest = (__le16 *) ret;
        dest[1] = cpu_to_le16(v0);
        dest[2] = cpu_to_le16(v1);
        dest[0] = cpu_to_le16(v0 + 1);
        return;
}

/* If both dir and name are NULL, then in target there's already a
   looked-up entry that wants to be opened. */
int ncp_open_create_file_or_subdir(struct ncp_server *server,
                                   struct inode *dir, const char *name,
                                   int open_create_mode,
                                   __le32 create_attributes,
                                   __le16 desired_acc_rights,
                                   struct ncp_entry_info *target)
{
        __le16 search_attribs = cpu_to_le16(0x0006);
        __u8  volnum;
        __le32 dirent;
        int result;

        volnum = NCP_FINFO(dir)->volNumber;
        dirent = NCP_FINFO(dir)->dirEntNum;

        if ((create_attributes & aDIR) != 0) {
                search_attribs |= cpu_to_le16(0x8000);
        }
        ncp_init_request(server);
        ncp_add_byte(server, 1);        /* subfunction */
        ncp_add_byte(server, server->name_space[volnum]);
        ncp_add_byte(server, open_create_mode);
        ncp_add_word(server, search_attribs);
        ncp_add_dword(server, RIM_ALL);
        ncp_add_dword(server, create_attributes);
        /* The desired acc rights seem to be the inherited rights mask
           for directories */
        ncp_add_word(server, desired_acc_rights);
        ncp_add_handle_path(server, volnum, dirent, 1, name);

        if ((result = ncp_request(server, 87)) != 0)
                goto out;
        if (!(create_attributes & aDIR))
                target->opened = 1;

        /* in target there's a new finfo to fill */
        ncp_extract_file_info(ncp_reply_data(server, 6), &(target->i));
        target->volume = target->i.volNumber;
        ConvertToNWfromDWORD(ncp_reply_le16(server, 0),
                             ncp_reply_le16(server, 2),
                             target->file_handle);
        
        ncp_unlock_server(server);

        (void)ncp_obtain_nfs_info(server, &(target->i));
        return 0;

out:
        ncp_unlock_server(server);
        return result;
}

int
ncp_initialize_search(struct ncp_server *server, struct inode *dir,
                        struct nw_search_sequence *target)
{
        __u8  volnum = NCP_FINFO(dir)->volNumber;
        __le32 dirent = NCP_FINFO(dir)->dirEntNum;
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 2);        /* subfunction */
        ncp_add_byte(server, server->name_space[volnum]);
        ncp_add_byte(server, 0);        /* reserved */
        ncp_add_handle_path(server, volnum, dirent, 1, NULL);

        result = ncp_request(server, 87);
        if (result)
                goto out;
        memcpy(target, ncp_reply_data(server, 0), sizeof(*target));

out:
        ncp_unlock_server(server);
        return result;
}

int ncp_search_for_fileset(struct ncp_server *server,
                           struct nw_search_sequence *seq,
                           int* more,
                           int* cnt,
                           char* buffer,
                           size_t bufsize,
                           char** rbuf,
                           size_t* rsize)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 20);
        ncp_add_byte(server, server->name_space[seq->volNumber]);
        ncp_add_byte(server, 0);                /* datastream */
        ncp_add_word(server, cpu_to_le16(0x8006));
        ncp_add_dword(server, RIM_ALL);
        ncp_add_word(server, cpu_to_le16(32767));       /* max returned items */
        ncp_add_mem(server, seq, 9);
#ifdef CONFIG_NCPFS_NFS_NS
        if (server->name_space[seq->volNumber] == NW_NS_NFS) {
                ncp_add_byte(server, 0);        /* 0 byte pattern */
        } else 
#endif
        {
                ncp_add_byte(server, 2);        /* 2 byte pattern */
                ncp_add_byte(server, 0xff);     /* following is a wildcard */
                ncp_add_byte(server, '*');
        }
        result = ncp_request2(server, 87, buffer, bufsize);
        if (result) {
                ncp_unlock_server(server);
                return result;
        }
        if (server->ncp_reply_size < 12) {
                ncp_unlock_server(server);
                return 0xFF;
        }
        *rsize = server->ncp_reply_size - 12;
        ncp_unlock_server(server);
        buffer = buffer + sizeof(struct ncp_reply_header);
        *rbuf = buffer + 12;
        *cnt = WVAL_LH(buffer + 10);
        *more = BVAL(buffer + 9);
        memcpy(seq, buffer, 9);
        return 0;
}

static int
ncp_RenameNSEntry(struct ncp_server *server,
                  struct inode *old_dir, const char *old_name, __le16 old_type,
                  struct inode *new_dir, const char *new_name)
{
        int result = -EINVAL;

        if ((old_dir == NULL) || (old_name == NULL) ||
            (new_dir == NULL) || (new_name == NULL))
                goto out;

        ncp_init_request(server);
        ncp_add_byte(server, 4);        /* subfunction */
        ncp_add_byte(server, server->name_space[NCP_FINFO(old_dir)->volNumber]);
        ncp_add_byte(server, 1);        /* rename flag */
        ncp_add_word(server, old_type); /* search attributes */

        /* source Handle Path */
        ncp_add_byte(server, NCP_FINFO(old_dir)->volNumber);
        ncp_add_dword(server, NCP_FINFO(old_dir)->dirEntNum);
        ncp_add_byte(server, 1);
        ncp_add_byte(server, 1);        /* 1 source component */

        /* dest Handle Path */
        ncp_add_byte(server, NCP_FINFO(new_dir)->volNumber);
        ncp_add_dword(server, NCP_FINFO(new_dir)->dirEntNum);
        ncp_add_byte(server, 1);
        ncp_add_byte(server, 1);        /* 1 destination component */

        /* source path string */
        ncp_add_pstring(server, old_name);
        /* dest path string */
        ncp_add_pstring(server, new_name);

        result = ncp_request(server, 87);
        ncp_unlock_server(server);
out:
        return result;
}

int ncp_ren_or_mov_file_or_subdir(struct ncp_server *server,
                                struct inode *old_dir, const char *old_name,
                                struct inode *new_dir, const char *new_name)
{
        int result;
        __le16 old_type = cpu_to_le16(0x06);

/* If somebody can do it atomic, call me... vandrove@vc.cvut.cz */
        result = ncp_RenameNSEntry(server, old_dir, old_name, old_type,
                                           new_dir, new_name);
        if (result == 0xFF)     /* File Not Found, try directory */
        {
                old_type = cpu_to_le16(0x16);
                result = ncp_RenameNSEntry(server, old_dir, old_name, old_type,
                                                   new_dir, new_name);
        }
        if (result != 0x92) return result;      /* All except NO_FILES_RENAMED */
        result = ncp_del_file_or_subdir(server, new_dir, new_name);
        if (result != 0) return -EACCES;
        result = ncp_RenameNSEntry(server, old_dir, old_name, old_type,
                                           new_dir, new_name);
        return result;
}
        

/* We have to transfer to/from user space */
int
ncp_read_kernel(struct ncp_server *server, const char *file_id,
             __u32 offset, __u16 to_read, char *target, int *bytes_read)
{
        const char *source;
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 0);
        ncp_add_mem(server, file_id, 6);
        ncp_add_be32(server, offset);
        ncp_add_be16(server, to_read);

        if ((result = ncp_request(server, 72)) != 0) {
                goto out;
        }
        *bytes_read = ncp_reply_be16(server, 0);
        if (*bytes_read > to_read) {
                result = -EINVAL;
                goto out;
        }
        source = ncp_reply_data(server, 2 + (offset & 1));

        memcpy(target, source, *bytes_read);
out:
        ncp_unlock_server(server);
        return result;
}

/* There is a problem... egrep and some other silly tools do:
        x = mmap(NULL, MAP_PRIVATE, PROT_READ|PROT_WRITE, <ncpfs fd>, 32768);
        read(<ncpfs fd>, x, 32768);
   Now copying read result by copy_to_user causes pagefault. This pagefault
   could not be handled because of server was locked due to read. So we have

   to use temporary buffer. So ncp_unlock_server must be done before
   copy_to_user (and for write, copy_from_user must be done before 
   ncp_init_request... same applies for send raw packet ioctl). Because of
   file is normally read in bigger chunks, caller provides kmalloced 
   (vmalloced) chunk of memory with size >= to_read...
 */
int
ncp_read_bounce(struct ncp_server *server, const char *file_id,
         __u32 offset, __u16 to_read, struct iov_iter *to,
         int *bytes_read, void *bounce, __u32 bufsize)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 0);
        ncp_add_mem(server, file_id, 6);
        ncp_add_be32(server, offset);
        ncp_add_be16(server, to_read);
        result = ncp_request2(server, 72, bounce, bufsize);
        ncp_unlock_server(server);
        if (!result) {
                int len = get_unaligned_be16((char *)bounce +
                          sizeof(struct ncp_reply_header));
                result = -EIO;
                if (len <= to_read) {
                        char* source;

                        source = (char*)bounce + 
                                 sizeof(struct ncp_reply_header) + 2 + 
                                 (offset & 1);
                        *bytes_read = len;
                        result = 0;
                        if (copy_to_iter(source, len, to) != len)
                                result = -EFAULT;
                }
        }
        return result;
}

int
ncp_write_kernel(struct ncp_server *server, const char *file_id,
                 __u32 offset, __u16 to_write,
                 const char *source, int *bytes_written)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 0);
        ncp_add_mem(server, file_id, 6);
        ncp_add_be32(server, offset);
        ncp_add_be16(server, to_write);
        ncp_add_mem(server, source, to_write);
        
        if ((result = ncp_request(server, 73)) == 0)
                *bytes_written = to_write;
        ncp_unlock_server(server);
        return result;
}

#ifdef CONFIG_NCPFS_IOCTL_LOCKING
int
ncp_LogPhysicalRecord(struct ncp_server *server, const char *file_id,
          __u8 locktype, __u32 offset, __u32 length, __u16 timeout)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, locktype);
        ncp_add_mem(server, file_id, 6);
        ncp_add_be32(server, offset);
        ncp_add_be32(server, length);
        ncp_add_be16(server, timeout);

        if ((result = ncp_request(server, 0x1A)) != 0)
        {
                ncp_unlock_server(server);
                return result;
        }
        ncp_unlock_server(server);
        return 0;
}

int
ncp_ClearPhysicalRecord(struct ncp_server *server, const char *file_id,
          __u32 offset, __u32 length)
{
        int result;

        ncp_init_request(server);
        ncp_add_byte(server, 0);        /* who knows... lanalyzer says that */
        ncp_add_mem(server, file_id, 6);
        ncp_add_be32(server, offset);
        ncp_add_be32(server, length);

        if ((result = ncp_request(server, 0x1E)) != 0)
        {
                ncp_unlock_server(server);
                return result;
        }
        ncp_unlock_server(server);
        return 0;
}
#endif  /* CONFIG_NCPFS_IOCTL_LOCKING */

#ifdef CONFIG_NCPFS_NLS
/* This are the NLS conversion routines with inspirations and code parts
 * from the vfat file system and hints from Petr Vandrovec.
 */

int
ncp__io2vol(struct ncp_server *server, unsigned char *vname, unsigned int *vlen,
                const unsigned char *iname, unsigned int ilen, int cc)
{
        struct nls_table *in = server->nls_io;
        struct nls_table *out = server->nls_vol;
        unsigned char *vname_start;
        unsigned char *vname_end;
        const unsigned char *iname_end;

        iname_end = iname + ilen;
        vname_start = vname;
        vname_end = vname + *vlen - 1;

        while (iname < iname_end) {
                int chl;
                wchar_t ec;

                if (NCP_IS_FLAG(server, NCP_FLAG_UTF8)) {
                        int k;
                        unicode_t u;

                        k = utf8_to_utf32(iname, iname_end - iname, &u);
                        if (k < 0 || u > MAX_WCHAR_T)
                                return -EINVAL;
                        iname += k;
                        ec = u;
                } else {
                        if (*iname == NCP_ESC) {
                                int k;

                                if (iname_end - iname < 5)
                                        goto nospec;

                                ec = 0;
                                for (k = 1; k < 5; k++) {
                                        unsigned char nc;

                                        nc = iname[k] - '0';
                                        if (nc >= 10) {
                                                nc -= 'A' - '0' - 10;
                                                if ((nc < 10) || (nc > 15)) {
                                                        goto nospec;
                                                }
                                        }
                                        ec = (ec << 4) | nc;
                                }
                                iname += 5;
                        } else {
nospec:;                        
                                if ( (chl = in->char2uni(iname, iname_end - iname, &ec)) < 0)
                                        return chl;
                                iname += chl;
                        }
                }

                /* unitoupper should be here! */

                chl = out->uni2char(ec, vname, vname_end - vname);
                if (chl < 0)
                        return chl;

                /* this is wrong... */
                if (cc) {
                        int chi;

                        for (chi = 0; chi < chl; chi++){
                                vname[chi] = ncp_toupper(out, vname[chi]);
                        }
                }
                vname += chl;
        }

        *vname = 0;
        *vlen = vname - vname_start;
        return 0;
}

int
ncp__vol2io(struct ncp_server *server, unsigned char *iname, unsigned int *ilen,
                const unsigned char *vname, unsigned int vlen, int cc)
{
        struct nls_table *in = server->nls_vol;
        struct nls_table *out = server->nls_io;
        const unsigned char *vname_end;
        unsigned char *iname_start;
        unsigned char *iname_end;
        unsigned char *vname_cc;
        int err;

        vname_cc = NULL;

        if (cc) {
                int i;

                /* this is wrong! */
                vname_cc = kmalloc(vlen, GFP_KERNEL);
                if (!vname_cc)
                        return -ENOMEM;
                for (i = 0; i < vlen; i++)
                        vname_cc[i] = ncp_tolower(in, vname[i]);
                vname = vname_cc;
        }

        iname_start = iname;
        iname_end = iname + *ilen - 1;
        vname_end = vname + vlen;

        while (vname < vname_end) {
                wchar_t ec;
                int chl;

                if ( (chl = in->char2uni(vname, vname_end - vname, &ec)) < 0) {
                        err = chl;
                        goto quit;
                }
                vname += chl;

                /* unitolower should be here! */

                if (NCP_IS_FLAG(server, NCP_FLAG_UTF8)) {
                        int k;

                        k = utf32_to_utf8(ec, iname, iname_end - iname);
                        if (k < 0) {
                                err = -ENAMETOOLONG;
                                goto quit;
                        }
                        iname += k;
                } else {
                        if ( (chl = out->uni2char(ec, iname, iname_end - iname)) >= 0) {
                                iname += chl;
                        } else {
                                int k;

                                if (iname_end - iname < 5) {
                                        err = -ENAMETOOLONG;
                                        goto quit;
                                }
                                *iname = NCP_ESC;
                                for (k = 4; k > 0; k--) {
                                        unsigned char v;
                                        
                                        v = (ec & 0xF) + '0';
                                        if (v > '9') {
                                                v += 'A' - '9' - 1;
                                        }
                                        iname[k] = v;
                                        ec >>= 4;
                                }
                                iname += 5;
                        }
                }
        }

        *iname = 0;
        *ilen = iname - iname_start;
        err = 0;
quit:;
        if (cc)
                kfree(vname_cc);
        return err;
}

#else

int
ncp__io2vol(unsigned char *vname, unsigned int *vlen,
                const unsigned char *iname, unsigned int ilen, int cc)
{
        int i;

        if (*vlen <= ilen)
                return -ENAMETOOLONG;

        if (cc)
                for (i = 0; i < ilen; i++) {
                        *vname = toupper(*iname);
                        vname++;
                        iname++;
                }
        else {
                memmove(vname, iname, ilen);
                vname += ilen;
        }

        *vlen = ilen;
        *vname = 0;
        return 0;
}

int
ncp__vol2io(unsigned char *iname, unsigned int *ilen,
                const unsigned char *vname, unsigned int vlen, int cc)
{
        int i;

        if (*ilen <= vlen)
                return -ENAMETOOLONG;

        if (cc)
                for (i = 0; i < vlen; i++) {
                        *iname = tolower(*vname);
                        iname++;
                        vname++;
                }
        else {
                memmove(iname, vname, vlen);
                iname += vlen;
        }

        *ilen = vlen;
        *iname = 0;
        return 0;
}

#endif