/*
 * linux/fs/nfsd/xdr.c
 *
 * XDR support for nfsd
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/time.h>
#include <linux/nfs.h>

#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/xdr.h>

#define NFSDDBG_FACILITY                NFSDDBG_XDR


#ifdef NFSD_OPTIMIZE_SPACE
# define inline
#endif

/*
 * Mapping of S_IF* types to NFS file types
 */
static u32      nfs_ftypes[] = {
        NFNON,  NFCHR,  NFCHR, NFBAD,
        NFDIR,  NFBAD,  NFBLK, NFBAD,
        NFREG,  NFBAD,  NFLNK, NFBAD,
        NFSOCK, NFBAD,  NFLNK, NFBAD,
};


/*
 * XDR functions for basic NFS types
 */
static inline u32 *
decode_fh(u32 *p, struct svc_fh *fhp)
{
        fh_init(fhp, NFS_FHSIZE);
        memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
        fhp->fh_handle.fh_size = NFS_FHSIZE;

        /* FIXME: Look up export pointer here and verify
         * Sun Secure RPC if requested */
        return p + (NFS_FHSIZE >> 2);
}

static inline u32 *
encode_fh(u32 *p, struct svc_fh *fhp)
{
        memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
        return p + (NFS_FHSIZE>> 2);
}

/*
 * Decode a file name and make sure that the path contains
 * no slashes or null bytes.
 */
static inline u32 *
decode_filename(u32 *p, char **namp, int *lenp)
{
        char            *name;
        int             i;

        if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
                for (i = 0, name = *namp; i < *lenp; i++, name++) {
                        if (*name == '\0' || *name == '/')
                                return NULL;
                }
        }

        return p;
}

static inline u32 *
decode_pathname(u32 *p, char **namp, int *lenp)
{
        char            *name;
        int             i;

        if ((p = xdr_decode_string(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
                for (i = 0, name = *namp; i < *lenp; i++, name++) {
                        if (*name == '\0')
                                return NULL;
                }
        }

        return p;
}

static inline u32 *
decode_sattr(u32 *p, struct iattr *iap)
{
        u32     tmp, tmp1;

        iap->ia_valid = 0;

        /* Sun client bug compatibility check: some sun clients seem to
         * put 0xffff in the mode field when they mean 0xffffffff.
         * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
         */
        if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
                iap->ia_valid |= ATTR_MODE;
                iap->ia_mode = tmp;
        }
        if ((tmp = ntohl(*p++)) != (u32)-1) {
                iap->ia_valid |= ATTR_UID;
                iap->ia_uid = tmp;
        }
        if ((tmp = ntohl(*p++)) != (u32)-1) {
                iap->ia_valid |= ATTR_GID;
                iap->ia_gid = tmp;
        }
        if ((tmp = ntohl(*p++)) != (u32)-1) {
                iap->ia_valid |= ATTR_SIZE;
                iap->ia_size = tmp;
        }
        tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
        if (tmp != (u32)-1 && tmp1 != (u32)-1) {
                iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
                iap->ia_atime = tmp;
        }
        tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
        if (tmp != (u32)-1 && tmp1 != (u32)-1) {
                iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
                iap->ia_mtime = tmp;
        }
        return p;
}

static inline u32 *
encode_fattr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
{
        struct vfsmount *mnt = fhp->fh_export->ex_mnt;
        struct dentry   *dentry = fhp->fh_dentry;
        struct kstat stat;
        int type;

        vfs_getattr(mnt, dentry, &stat);
        type = (stat.mode & S_IFMT);

        *p++ = htonl(nfs_ftypes[type >> 12]);
        *p++ = htonl((u32) stat.mode);
        *p++ = htonl((u32) stat.nlink);
        *p++ = htonl((u32) nfsd_ruid(rqstp, stat.uid));
        *p++ = htonl((u32) nfsd_rgid(rqstp, stat.gid));

        if (S_ISLNK(type) && stat.size > NFS_MAXPATHLEN) {
                *p++ = htonl(NFS_MAXPATHLEN);
        } else {
                *p++ = htonl((u32) stat.size);
        }
        *p++ = htonl((u32) stat.blksize);
        if (S_ISCHR(type) || S_ISBLK(type))
                *p++ = htonl((u32) stat.rdev);
        else
                *p++ = htonl(0xffffffff);
        *p++ = htonl((u32) stat.blocks);
        if (rqstp->rq_reffh->fh_version == 1 
            && rqstp->rq_reffh->fh_fsid_type == 1
            && (fhp->fh_export->ex_flags & NFSEXP_FSID))
                *p++ = htonl((u32) fhp->fh_export->ex_fsid);
        else
                *p++ = htonl((u32) stat.dev);
        *p++ = htonl((u32) stat.ino);
        *p++ = htonl((u32) stat.atime);
        *p++ = 0;
        *p++ = htonl((u32) lease_get_mtime(dentry->d_inode));
        *p++ = 0;
        *p++ = htonl((u32) stat.ctime);
        *p++ = 0;

        return p;
}

/*
 * Check buffer bounds after decoding arguments
 */
static inline int
xdr_argsize_check(struct svc_rqst *rqstp, u32 *p)
{
        struct svc_buf  *buf = &rqstp->rq_argbuf;

        return p - buf->base <= buf->buflen;
}

static inline int
xdr_ressize_check(struct svc_rqst *rqstp, u32 *p)
{
        struct svc_buf  *buf = &rqstp->rq_resbuf;

        buf->len = p - buf->base;
        dprintk("nfsd: ressize_check p %p base %p len %d\n",
                        p, buf->base, buf->buflen);
        return (buf->len <= buf->buflen);
}

/*
 * XDR decode functions
 */
int
nfssvc_decode_void(struct svc_rqst *rqstp, u32 *p, void *dummy)
{
        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_fhandle(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
{
        if (!(p = decode_fh(p, fhp)))
                return 0;
        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_sattrargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_sattrargs *args)
{
        if (!(p = decode_fh(p, &args->fh))
         || !(p = decode_sattr(p, &args->attrs)))
                return 0;

        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_diropargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_diropargs *args)
{
        if (!(p = decode_fh(p, &args->fh))
         || !(p = decode_filename(p, &args->name, &args->len)))
                return 0;

         return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_readargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_readargs *args)
{
        if (!(p = decode_fh(p, &args->fh)))
                return 0;

        args->offset    = ntohl(*p++);
        args->count     = ntohl(*p++);
        args->totalsize = ntohl(*p++);

        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_writeargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_writeargs *args)
{
        if (!(p = decode_fh(p, &args->fh)))
                return 0;

        p++;                            /* beginoffset */
        args->offset = ntohl(*p++);     /* offset */
        p++;                            /* totalcount */
        args->len = ntohl(*p++);
        args->data = (char *) p;
        p += XDR_QUADLEN(args->len);

        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_createargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_createargs *args)
{
        if (!(p = decode_fh(p, &args->fh))
         || !(p = decode_filename(p, &args->name, &args->len))
         || !(p = decode_sattr(p, &args->attrs)))
                return 0;

        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_renameargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_renameargs *args)
{
        if (!(p = decode_fh(p, &args->ffh))
         || !(p = decode_filename(p, &args->fname, &args->flen))
         || !(p = decode_fh(p, &args->tfh))
         || !(p = decode_filename(p, &args->tname, &args->tlen)))
                return 0;

        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_linkargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_linkargs *args)
{
        if (!(p = decode_fh(p, &args->ffh))
         || !(p = decode_fh(p, &args->tfh))
         || !(p = decode_filename(p, &args->tname, &args->tlen)))
                return 0;

        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_symlinkargs *args)
{
        if (!(p = decode_fh(p, &args->ffh))
         || !(p = decode_filename(p, &args->fname, &args->flen))
         || !(p = decode_pathname(p, &args->tname, &args->tlen))
         || !(p = decode_sattr(p, &args->attrs)))
                return 0;

        return xdr_argsize_check(rqstp, p);
}

int
nfssvc_decode_readdirargs(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_readdirargs *args)
{
        if (!(p = decode_fh(p, &args->fh)))
                return 0;
        args->cookie = ntohl(*p++);
        args->count  = ntohl(*p++);

        return xdr_argsize_check(rqstp, p);
}

/*
 * XDR encode functions
 */
int
nfssvc_encode_void(struct svc_rqst *rqstp, u32 *p, void *dummy)
{
        return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_attrstat(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_attrstat *resp)
{
        p = encode_fattr(rqstp, p, &resp->fh);
        return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_diropres(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_diropres *resp)
{
        p = encode_fh(p, &resp->fh);
        p = encode_fattr(rqstp, p, &resp->fh);
        return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_readlinkres(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_readlinkres *resp)
{
        *p++ = htonl(resp->len);
        p += XDR_QUADLEN(resp->len);
        return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_readres(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_readres *resp)
{
        p = encode_fattr(rqstp, p, &resp->fh);
        *p++ = htonl(resp->count);
        p += XDR_QUADLEN(resp->count);

        return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_readdirres(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_readdirres *resp)
{
        p += XDR_QUADLEN(resp->count);
        return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_statfsres(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_statfsres *resp)
{
        struct statfs   *stat = &resp->stats;

        *p++ = htonl(NFSSVC_MAXBLKSIZE);        /* max transfer size */
        *p++ = htonl(stat->f_bsize);
        *p++ = htonl(stat->f_blocks);
        *p++ = htonl(stat->f_bfree);
        *p++ = htonl(stat->f_bavail);
        return xdr_ressize_check(rqstp, p);
}

int
nfssvc_encode_entry(struct readdir_cd *cd, const char *name,
                    int namlen, loff_t offset, ino_t ino, unsigned int d_type)
{
        u32     *p = cd->buffer;
        int     buflen, slen;

        /*
        dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
                        namlen, name, offset, ino);
         */

        if (offset > ~((u32) 0))
                return -EINVAL;
        if (cd->offset)
                *cd->offset = htonl(offset);
        if (namlen > NFS2_MAXNAMLEN)
                namlen = NFS2_MAXNAMLEN;/* truncate filename */

        slen = XDR_QUADLEN(namlen);
        if ((buflen = cd->buflen - slen - 4) < 0) {
                cd->eob = 1;
                return -EINVAL;
        }
        *p++ = xdr_one;                         /* mark entry present */
        *p++ = htonl((u32) ino);                /* file id */
        p    = xdr_encode_array(p, name, namlen);/* name length & name */
        cd->offset = p;                 /* remember pointer */
        *p++ = ~(u32) 0;                /* offset of next entry */

        cd->buflen = buflen;
        cd->buffer = p;
        return 0;
}

/*
 * XDR release functions
 */
int
nfssvc_release_fhandle(struct svc_rqst *rqstp, u32 *p,
                                        struct nfsd_fhandle *resp)
{
        fh_put(&resp->fh);
        return 1;
}