/*
 * linux/fs/nfs/nfs3xdr.c
 *
 * XDR functions to encode/decode NFSv3 RPC arguments and results.
 *
 * Copyright (C) 1996, 1997 Olaf Kirch
 */

#include <linux/param.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/pagemap.h>
#include <linux/proc_fs.h>
#include <linux/kdev_t.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs3.h>
#include <linux/nfs_fs.h>
#include <linux/nfsacl.h>
#include "internal.h"

#define NFSDBG_FACILITY         NFSDBG_XDR

/* Mapping from NFS error code to "errno" error code. */
#define errno_NFSERR_IO         EIO

/*
 * Declare the space requirements for NFS arguments and replies as
 * number of 32bit-words
 */
#define NFS3_fhandle_sz         (1+16)
#define NFS3_fh_sz              (NFS3_fhandle_sz)       /* shorthand */
#define NFS3_sattr_sz           (15)
#define NFS3_filename_sz        (1+(NFS3_MAXNAMLEN>>2))
#define NFS3_path_sz            (1+(NFS3_MAXPATHLEN>>2))
#define NFS3_fattr_sz           (21)
#define NFS3_wcc_attr_sz                (6)
#define NFS3_pre_op_attr_sz     (1+NFS3_wcc_attr_sz)
#define NFS3_post_op_attr_sz    (1+NFS3_fattr_sz)
#define NFS3_wcc_data_sz                (NFS3_pre_op_attr_sz+NFS3_post_op_attr_sz)
#define NFS3_fsstat_sz          
#define NFS3_fsinfo_sz          
#define NFS3_pathconf_sz                
#define NFS3_entry_sz           (NFS3_filename_sz+3)

#define NFS3_sattrargs_sz       (NFS3_fh_sz+NFS3_sattr_sz+3)
#define NFS3_diropargs_sz       (NFS3_fh_sz+NFS3_filename_sz)
#define NFS3_removeargs_sz      (NFS3_fh_sz+NFS3_filename_sz)
#define NFS3_accessargs_sz      (NFS3_fh_sz+1)
#define NFS3_readlinkargs_sz    (NFS3_fh_sz)
#define NFS3_readargs_sz        (NFS3_fh_sz+3)
#define NFS3_writeargs_sz       (NFS3_fh_sz+5)
#define NFS3_createargs_sz      (NFS3_diropargs_sz+NFS3_sattr_sz)
#define NFS3_mkdirargs_sz       (NFS3_diropargs_sz+NFS3_sattr_sz)
#define NFS3_symlinkargs_sz     (NFS3_diropargs_sz+1+NFS3_sattr_sz)
#define NFS3_mknodargs_sz       (NFS3_diropargs_sz+2+NFS3_sattr_sz)
#define NFS3_renameargs_sz      (NFS3_diropargs_sz+NFS3_diropargs_sz)
#define NFS3_linkargs_sz                (NFS3_fh_sz+NFS3_diropargs_sz)
#define NFS3_readdirargs_sz     (NFS3_fh_sz+2)
#define NFS3_commitargs_sz      (NFS3_fh_sz+3)

#define NFS3_attrstat_sz        (1+NFS3_fattr_sz)
#define NFS3_wccstat_sz         (1+NFS3_wcc_data_sz)
#define NFS3_removeres_sz       (NFS3_wccstat_sz)
#define NFS3_lookupres_sz       (1+NFS3_fh_sz+(2 * NFS3_post_op_attr_sz))
#define NFS3_accessres_sz       (1+NFS3_post_op_attr_sz+1)
#define NFS3_readlinkres_sz     (1+NFS3_post_op_attr_sz+1)
#define NFS3_readres_sz         (1+NFS3_post_op_attr_sz+3)
#define NFS3_writeres_sz        (1+NFS3_wcc_data_sz+4)
#define NFS3_createres_sz       (1+NFS3_fh_sz+NFS3_post_op_attr_sz+NFS3_wcc_data_sz)
#define NFS3_renameres_sz       (1+(2 * NFS3_wcc_data_sz))
#define NFS3_linkres_sz         (1+NFS3_post_op_attr_sz+NFS3_wcc_data_sz)
#define NFS3_readdirres_sz      (1+NFS3_post_op_attr_sz+2)
#define NFS3_fsstatres_sz       (1+NFS3_post_op_attr_sz+13)
#define NFS3_fsinfores_sz       (1+NFS3_post_op_attr_sz+12)
#define NFS3_pathconfres_sz     (1+NFS3_post_op_attr_sz+6)
#define NFS3_commitres_sz       (1+NFS3_wcc_data_sz+2)

#define ACL3_getaclargs_sz      (NFS3_fh_sz+1)
#define ACL3_setaclargs_sz      (NFS3_fh_sz+1+ \
                                XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE))
#define ACL3_getaclres_sz       (1+NFS3_post_op_attr_sz+1+ \
                                XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE))
#define ACL3_setaclres_sz       (1+NFS3_post_op_attr_sz)

/*
 * Map file type to S_IFMT bits
 */
static const umode_t nfs_type2fmt[] = {
        [NF3BAD] = 0,
        [NF3REG] = S_IFREG,
        [NF3DIR] = S_IFDIR,
        [NF3BLK] = S_IFBLK,
        [NF3CHR] = S_IFCHR,
        [NF3LNK] = S_IFLNK,
        [NF3SOCK] = S_IFSOCK,
        [NF3FIFO] = S_IFIFO,
};

/*
 * Common NFS XDR functions as inlines
 */
static inline __be32 *
xdr_encode_fhandle(__be32 *p, const struct nfs_fh *fh)
{
        return xdr_encode_array(p, fh->data, fh->size);
}

static inline __be32 *
xdr_decode_fhandle(__be32 *p, struct nfs_fh *fh)
{
        if ((fh->size = ntohl(*p++)) <= NFS3_FHSIZE) {
                memcpy(fh->data, p, fh->size);
                return p + XDR_QUADLEN(fh->size);
        }
        return NULL;
}

/*
 * Encode/decode time.
 */
static inline __be32 *
xdr_encode_time3(__be32 *p, struct timespec *timep)
{
        *p++ = htonl(timep->tv_sec);
        *p++ = htonl(timep->tv_nsec);
        return p;
}

static inline __be32 *
xdr_decode_time3(__be32 *p, struct timespec *timep)
{
        timep->tv_sec = ntohl(*p++);
        timep->tv_nsec = ntohl(*p++);
        return p;
}

static __be32 *
xdr_decode_fattr(__be32 *p, struct nfs_fattr *fattr)
{
        unsigned int    type, major, minor;
        umode_t         fmode;

        type = ntohl(*p++);
        if (type > NF3FIFO)
                type = NF3NON;
        fmode = nfs_type2fmt[type];
        fattr->mode = (ntohl(*p++) & ~S_IFMT) | fmode;
        fattr->nlink = ntohl(*p++);
        fattr->uid = ntohl(*p++);
        fattr->gid = ntohl(*p++);
        p = xdr_decode_hyper(p, &fattr->size);
        p = xdr_decode_hyper(p, &fattr->du.nfs3.used);

        /* Turn remote device info into Linux-specific dev_t */
        major = ntohl(*p++);
        minor = ntohl(*p++);
        fattr->rdev = MKDEV(major, minor);
        if (MAJOR(fattr->rdev) != major || MINOR(fattr->rdev) != minor)
                fattr->rdev = 0;

        p = xdr_decode_hyper(p, &fattr->fsid.major);
        fattr->fsid.minor = 0;
        p = xdr_decode_hyper(p, &fattr->fileid);
        p = xdr_decode_time3(p, &fattr->atime);
        p = xdr_decode_time3(p, &fattr->mtime);
        p = xdr_decode_time3(p, &fattr->ctime);

        /* Update the mode bits */
        fattr->valid |= NFS_ATTR_FATTR_V3;
        return p;
}

static inline __be32 *
xdr_encode_sattr(__be32 *p, struct iattr *attr)
{
        if (attr->ia_valid & ATTR_MODE) {
                *p++ = xdr_one;
                *p++ = htonl(attr->ia_mode & S_IALLUGO);
        } else {
                *p++ = xdr_zero;
        }
        if (attr->ia_valid & ATTR_UID) {
                *p++ = xdr_one;
                *p++ = htonl(attr->ia_uid);
        } else {
                *p++ = xdr_zero;
        }
        if (attr->ia_valid & ATTR_GID) {
                *p++ = xdr_one;
                *p++ = htonl(attr->ia_gid);
        } else {
                *p++ = xdr_zero;
        }
        if (attr->ia_valid & ATTR_SIZE) {
                *p++ = xdr_one;
                p = xdr_encode_hyper(p, (__u64) attr->ia_size);
        } else {
                *p++ = xdr_zero;
        }
        if (attr->ia_valid & ATTR_ATIME_SET) {
                *p++ = xdr_two;
                p = xdr_encode_time3(p, &attr->ia_atime);
        } else if (attr->ia_valid & ATTR_ATIME) {
                *p++ = xdr_one;
        } else {
                *p++ = xdr_zero;
        }
        if (attr->ia_valid & ATTR_MTIME_SET) {
                *p++ = xdr_two;
                p = xdr_encode_time3(p, &attr->ia_mtime);
        } else if (attr->ia_valid & ATTR_MTIME) {
                *p++ = xdr_one;
        } else {
                *p++ = xdr_zero;
        }
        return p;
}

static inline __be32 *
xdr_decode_wcc_attr(__be32 *p, struct nfs_fattr *fattr)
{
        p = xdr_decode_hyper(p, &fattr->pre_size);
        p = xdr_decode_time3(p, &fattr->pre_mtime);
        p = xdr_decode_time3(p, &fattr->pre_ctime);
        fattr->valid |= NFS_ATTR_FATTR_PRESIZE
                | NFS_ATTR_FATTR_PREMTIME
                | NFS_ATTR_FATTR_PRECTIME;
        return p;
}

static inline __be32 *
xdr_decode_post_op_attr(__be32 *p, struct nfs_fattr *fattr)
{
        if (*p++)
                p = xdr_decode_fattr(p, fattr);
        return p;
}

static inline __be32 *
xdr_decode_pre_op_attr(__be32 *p, struct nfs_fattr *fattr)
{
        if (*p++)
                return xdr_decode_wcc_attr(p, fattr);
        return p;
}


static inline __be32 *
xdr_decode_wcc_data(__be32 *p, struct nfs_fattr *fattr)
{
        p = xdr_decode_pre_op_attr(p, fattr);
        return xdr_decode_post_op_attr(p, fattr);
}

/*
 * NFS encode functions
 */

/*
 * Encode file handle argument
 */
static int
nfs3_xdr_fhandle(struct rpc_rqst *req, __be32 *p, struct nfs_fh *fh)
{
        p = xdr_encode_fhandle(p, fh);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode SETATTR arguments
 */
static int
nfs3_xdr_sattrargs(struct rpc_rqst *req, __be32 *p, struct nfs3_sattrargs *args)
{
        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_sattr(p, args->sattr);
        *p++ = htonl(args->guard);
        if (args->guard)
                p = xdr_encode_time3(p, &args->guardtime);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode directory ops argument
 */
static int
nfs3_xdr_diropargs(struct rpc_rqst *req, __be32 *p, struct nfs3_diropargs *args)
{
        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_array(p, args->name, args->len);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode REMOVE argument
 */
static int
nfs3_xdr_removeargs(struct rpc_rqst *req, __be32 *p, const struct nfs_removeargs *args)
{
        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_array(p, args->name.name, args->name.len);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode access() argument
 */
static int
nfs3_xdr_accessargs(struct rpc_rqst *req, __be32 *p, struct nfs3_accessargs *args)
{
        p = xdr_encode_fhandle(p, args->fh);
        *p++ = htonl(args->access);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Arguments to a READ call. Since we read data directly into the page
 * cache, we also set up the reply iovec here so that iov[1] points
 * exactly to the page we want to fetch.
 */
static int
nfs3_xdr_readargs(struct rpc_rqst *req, __be32 *p, struct nfs_readargs *args)
{
        struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
        unsigned int replen;
        u32 count = args->count;

        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_hyper(p, args->offset);
        *p++ = htonl(count);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

        /* Inline the page array */
        replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readres_sz) << 2;
        xdr_inline_pages(&req->rq_rcv_buf, replen,
                         args->pages, args->pgbase, count);
        req->rq_rcv_buf.flags |= XDRBUF_READ;
        return 0;
}

/*
 * Write arguments. Splice the buffer to be written into the iovec.
 */
static int
nfs3_xdr_writeargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
{
        struct xdr_buf *sndbuf = &req->rq_snd_buf;
        u32 count = args->count;

        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_hyper(p, args->offset);
        *p++ = htonl(count);
        *p++ = htonl(args->stable);
        *p++ = htonl(count);
        sndbuf->len = xdr_adjust_iovec(sndbuf->head, p);

        /* Copy the page array */
        xdr_encode_pages(sndbuf, args->pages, args->pgbase, count);
        sndbuf->flags |= XDRBUF_WRITE;
        return 0;
}

/*
 * Encode CREATE arguments
 */
static int
nfs3_xdr_createargs(struct rpc_rqst *req, __be32 *p, struct nfs3_createargs *args)
{
        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_array(p, args->name, args->len);

        *p++ = htonl(args->createmode);
        if (args->createmode == NFS3_CREATE_EXCLUSIVE) {
                *p++ = args->verifier[0];
                *p++ = args->verifier[1];
        } else
                p = xdr_encode_sattr(p, args->sattr);

        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode MKDIR arguments
 */
static int
nfs3_xdr_mkdirargs(struct rpc_rqst *req, __be32 *p, struct nfs3_mkdirargs *args)
{
        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_array(p, args->name, args->len);
        p = xdr_encode_sattr(p, args->sattr);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode SYMLINK arguments
 */
static int
nfs3_xdr_symlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs3_symlinkargs *args)
{
        p = xdr_encode_fhandle(p, args->fromfh);
        p = xdr_encode_array(p, args->fromname, args->fromlen);
        p = xdr_encode_sattr(p, args->sattr);
        *p++ = htonl(args->pathlen);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

        /* Copy the page */
        xdr_encode_pages(&req->rq_snd_buf, args->pages, 0, args->pathlen);
        return 0;
}

/*
 * Encode MKNOD arguments
 */
static int
nfs3_xdr_mknodargs(struct rpc_rqst *req, __be32 *p, struct nfs3_mknodargs *args)
{
        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_array(p, args->name, args->len);
        *p++ = htonl(args->type);
        p = xdr_encode_sattr(p, args->sattr);
        if (args->type == NF3CHR || args->type == NF3BLK) {
                *p++ = htonl(MAJOR(args->rdev));
                *p++ = htonl(MINOR(args->rdev));
        }

        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode RENAME arguments
 */
static int
nfs3_xdr_renameargs(struct rpc_rqst *req, __be32 *p, struct nfs3_renameargs *args)
{
        p = xdr_encode_fhandle(p, args->fromfh);
        p = xdr_encode_array(p, args->fromname, args->fromlen);
        p = xdr_encode_fhandle(p, args->tofh);
        p = xdr_encode_array(p, args->toname, args->tolen);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode LINK arguments
 */
static int
nfs3_xdr_linkargs(struct rpc_rqst *req, __be32 *p, struct nfs3_linkargs *args)
{
        p = xdr_encode_fhandle(p, args->fromfh);
        p = xdr_encode_fhandle(p, args->tofh);
        p = xdr_encode_array(p, args->toname, args->tolen);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

/*
 * Encode arguments to readdir call
 */
static int
nfs3_xdr_readdirargs(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirargs *args)
{
        struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
        unsigned int replen;
        u32 count = args->count;

        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_hyper(p, args->cookie);
        *p++ = args->verf[0];
        *p++ = args->verf[1];
        if (args->plus) {
                /* readdirplus: need dircount + buffer size.
                 * We just make sure we make dircount big enough */
                *p++ = htonl(count >> 3);
        }
        *p++ = htonl(count);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

        /* Inline the page array */
        replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readdirres_sz) << 2;
        xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, 0, count);
        return 0;
}

/*
 * Decode the result of a readdir call.
 * We just check for syntactical correctness.
 */
static int
nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res)
{
        struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
        struct kvec *iov = rcvbuf->head;
        struct page **page;
        size_t hdrlen;
        u32 len, recvd, pglen;
        int status, nr = 0;
        __be32 *entry, *end, *kaddr;

        status = ntohl(*p++);
        /* Decode post_op_attrs */
        p = xdr_decode_post_op_attr(p, res->dir_attr);
        if (status)
                return nfs_stat_to_errno(status);
        /* Decode verifier cookie */
        if (res->verf) {
                res->verf[0] = *p++;
                res->verf[1] = *p++;
        } else {
                p += 2;
        }

        hdrlen = (u8 *) p - (u8 *) iov->iov_base;
        if (iov->iov_len < hdrlen) {
                dprintk("NFS: READDIR reply header overflowed:"
                                "length %Zu > %Zu\n", hdrlen, iov->iov_len);
                return -errno_NFSERR_IO;
        } else if (iov->iov_len != hdrlen) {
                dprintk("NFS: READDIR header is short. iovec will be shifted.\n");
                xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
        }

        pglen = rcvbuf->page_len;
        recvd = rcvbuf->len - hdrlen;
        if (pglen > recvd)
                pglen = recvd;
        page = rcvbuf->pages;
        kaddr = p = kmap_atomic(*page, KM_USER0);
        end = (__be32 *)((char *)p + pglen);
        entry = p;

        /* Make sure the packet actually has a value_follows and EOF entry */
        if ((entry + 1) > end)
                goto short_pkt;

        for (; *p++; nr++) {
                if (p + 3 > end)
                        goto short_pkt;
                p += 2;                         /* inode # */
                len = ntohl(*p++);              /* string length */
                p += XDR_QUADLEN(len) + 2;      /* name + cookie */
                if (len > NFS3_MAXNAMLEN) {
                        dprintk("NFS: giant filename in readdir (len 0x%x)!\n",
                                                len);
                        goto err_unmap;
                }

                if (res->plus) {
                        /* post_op_attr */
                        if (p + 2 > end)
                                goto short_pkt;
                        if (*p++) {
                                p += 21;
                                if (p + 1 > end)
                                        goto short_pkt;
                        }
                        /* post_op_fh3 */
                        if (*p++) {
                                if (p + 1 > end)
                                        goto short_pkt;
                                len = ntohl(*p++);
                                if (len > NFS3_FHSIZE) {
                                        dprintk("NFS: giant filehandle in "
                                                "readdir (len 0x%x)!\n", len);
                                        goto err_unmap;
                                }
                                p += XDR_QUADLEN(len);
                        }
                }

                if (p + 2 > end)
                        goto short_pkt;
                entry = p;
        }

        /*
         * Apparently some server sends responses that are a valid size, but
         * contain no entries, and have value_follows==0 and EOF==0. For
         * those, just set the EOF marker.
         */
        if (!nr && entry[1] == 0) {
                dprintk("NFS: readdir reply truncated!\n");
                entry[1] = 1;
        }
 out:
        kunmap_atomic(kaddr, KM_USER0);
        return nr;
 short_pkt:
        /*
         * When we get a short packet there are 2 possibilities. We can
         * return an error, or fix up the response to look like a valid
         * response and return what we have so far. If there are no
         * entries and the packet was short, then return -EIO. If there
         * are valid entries in the response, return them and pretend that
         * the call was successful, but incomplete. The caller can retry the
         * readdir starting at the last cookie.
         */
        entry[0] = entry[1] = 0;
        if (!nr)
                nr = -errno_NFSERR_IO;
        goto out;
err_unmap:
        nr = -errno_NFSERR_IO;
        goto out;
}

__be32 *
nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
{
        struct nfs_entry old = *entry;

        if (!*p++) {
                if (!*p)
                        return ERR_PTR(-EAGAIN);
                entry->eof = 1;
                return ERR_PTR(-EBADCOOKIE);
        }

        p = xdr_decode_hyper(p, &entry->ino);
        entry->len  = ntohl(*p++);
        entry->name = (const char *) p;
        p += XDR_QUADLEN(entry->len);
        entry->prev_cookie = entry->cookie;
        p = xdr_decode_hyper(p, &entry->cookie);

        if (plus) {
                entry->fattr->valid = 0;
                p = xdr_decode_post_op_attr(p, entry->fattr);
                /* In fact, a post_op_fh3: */
                if (*p++) {
                        p = xdr_decode_fhandle(p, entry->fh);
                        /* Ugh -- server reply was truncated */
                        if (p == NULL) {
                                dprintk("NFS: FH truncated\n");
                                *entry = old;
                                return ERR_PTR(-EAGAIN);
                        }
                } else
                        memset((u8*)(entry->fh), 0, sizeof(*entry->fh));
        }

        entry->eof = !p[0] && p[1];
        return p;
}

/*
 * Encode COMMIT arguments
 */
static int
nfs3_xdr_commitargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
{
        p = xdr_encode_fhandle(p, args->fh);
        p = xdr_encode_hyper(p, args->offset);
        *p++ = htonl(args->count);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        return 0;
}

#ifdef CONFIG_NFS_V3_ACL
/*
 * Encode GETACL arguments
 */
static int
nfs3_xdr_getaclargs(struct rpc_rqst *req, __be32 *p,
                    struct nfs3_getaclargs *args)
{
        struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
        unsigned int replen;

        p = xdr_encode_fhandle(p, args->fh);
        *p++ = htonl(args->mask);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

        if (args->mask & (NFS_ACL | NFS_DFACL)) {
                /* Inline the page array */
                replen = (RPC_REPHDRSIZE + auth->au_rslack +
                          ACL3_getaclres_sz) << 2;
                xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, 0,
                                 NFSACL_MAXPAGES << PAGE_SHIFT);
        }
        return 0;
}

/*
 * Encode SETACL arguments
 */
static int
nfs3_xdr_setaclargs(struct rpc_rqst *req, __be32 *p,
                   struct nfs3_setaclargs *args)
{
        struct xdr_buf *buf = &req->rq_snd_buf;
        unsigned int base;
        int err;

        p = xdr_encode_fhandle(p, NFS_FH(args->inode));
        *p++ = htonl(args->mask);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
        base = req->rq_slen;

        if (args->npages != 0)
                xdr_encode_pages(buf, args->pages, 0, args->len);
        else
                req->rq_slen = xdr_adjust_iovec(req->rq_svec,
                                p + XDR_QUADLEN(args->len));

        err = nfsacl_encode(buf, base, args->inode,
                            (args->mask & NFS_ACL) ?
                            args->acl_access : NULL, 1, 0);
        if (err > 0)
                err = nfsacl_encode(buf, base + err, args->inode,
                                    (args->mask & NFS_DFACL) ?
                                    args->acl_default : NULL, 1,
                                    NFS_ACL_DEFAULT);
        return (err > 0) ? 0 : err;
}
#endif  /* CONFIG_NFS_V3_ACL */

/*
 * NFS XDR decode functions
 */

/*
 * Decode attrstat reply.
 */
static int
nfs3_xdr_attrstat(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
        int     status;

        if ((status = ntohl(*p++)))
                return nfs_stat_to_errno(status);
        xdr_decode_fattr(p, fattr);
        return 0;
}

/*
 * Decode status+wcc_data reply
 * SATTR, REMOVE, RMDIR
 */
static int
nfs3_xdr_wccstat(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
        int     status;

        if ((status = ntohl(*p++)))
                status = nfs_stat_to_errno(status);
        xdr_decode_wcc_data(p, fattr);
        return status;
}

static int
nfs3_xdr_removeres(struct rpc_rqst *req, __be32 *p, struct nfs_removeres *res)
{
        return nfs3_xdr_wccstat(req, p, &res->dir_attr);
}

/*
 * Decode LOOKUP reply
 */
static int
nfs3_xdr_lookupres(struct rpc_rqst *req, __be32 *p, struct nfs3_diropres *res)
{
        int     status;

        if ((status = ntohl(*p++))) {
                status = nfs_stat_to_errno(status);
        } else {
                if (!(p = xdr_decode_fhandle(p, res->fh)))
                        return -errno_NFSERR_IO;
                p = xdr_decode_post_op_attr(p, res->fattr);
        }
        xdr_decode_post_op_attr(p, res->dir_attr);
        return status;
}

/*
 * Decode ACCESS reply
 */
static int
nfs3_xdr_accessres(struct rpc_rqst *req, __be32 *p, struct nfs3_accessres *res)
{
        int     status = ntohl(*p++);

        p = xdr_decode_post_op_attr(p, res->fattr);
        if (status)
                return nfs_stat_to_errno(status);
        res->access = ntohl(*p++);
        return 0;
}

static int
nfs3_xdr_readlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs3_readlinkargs *args)
{
        struct rpc_auth *auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
        unsigned int replen;

        p = xdr_encode_fhandle(p, args->fh);
        req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);

        /* Inline the page array */
        replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readlinkres_sz) << 2;
        xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, args->pgbase, args->pglen);
        return 0;
}

/*
 * Decode READLINK reply
 */
static int
nfs3_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
        struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
        struct kvec *iov = rcvbuf->head;
        size_t hdrlen;
        u32 len, recvd;
        char    *kaddr;
        int     status;

        status = ntohl(*p++);
        p = xdr_decode_post_op_attr(p, fattr);

        if (status != 0)
                return nfs_stat_to_errno(status);

        /* Convert length of symlink */
        len = ntohl(*p++);
        if (len >= rcvbuf->page_len) {
                dprintk("nfs: server returned giant symlink!\n");
                return -ENAMETOOLONG;
        }

        hdrlen = (u8 *) p - (u8 *) iov->iov_base;
        if (iov->iov_len < hdrlen) {
                dprintk("NFS: READLINK reply header overflowed:"
                                "length %Zu > %Zu\n", hdrlen, iov->iov_len);
                return -errno_NFSERR_IO;
        } else if (iov->iov_len != hdrlen) {
                dprintk("NFS: READLINK header is short. "
                        "iovec will be shifted.\n");
                xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
        }
        recvd = req->rq_rcv_buf.len - hdrlen;
        if (recvd < len) {
                dprintk("NFS: server cheating in readlink reply: "
                                "count %u > recvd %u\n", len, recvd);
                return -EIO;
        }

        /* NULL terminate the string we got */
        kaddr = (char*)kmap_atomic(rcvbuf->pages[0], KM_USER0);
        kaddr[len+rcvbuf->page_base] = '\0';
        kunmap_atomic(kaddr, KM_USER0);
        return 0;
}

/*
 * Decode READ reply
 */
static int
nfs3_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
{
        struct kvec *iov = req->rq_rcv_buf.head;
        size_t hdrlen;
        u32 count, ocount, recvd;
        int status;

        status = ntohl(*p++);
        p = xdr_decode_post_op_attr(p, res->fattr);

        if (status != 0)
                return nfs_stat_to_errno(status);

        /* Decode reply count and EOF flag. NFSv3 is somewhat redundant
         * in that it puts the count both in the res struct and in the
         * opaque data count. */
        count    = ntohl(*p++);
        res->eof = ntohl(*p++);
        ocount   = ntohl(*p++);

        if (ocount != count) {
                dprintk("NFS: READ count doesn't match RPC opaque count.\n");
                return -errno_NFSERR_IO;
        }

        hdrlen = (u8 *) p - (u8 *) iov->iov_base;
        if (iov->iov_len < hdrlen) {
                dprintk("NFS: READ reply header overflowed:"
                                "length %Zu > %Zu\n", hdrlen, iov->iov_len);
                return -errno_NFSERR_IO;
        } else if (iov->iov_len != hdrlen) {
                dprintk("NFS: READ header is short. iovec will be shifted.\n");
                xdr_shift_buf(&req->rq_rcv_buf, iov->iov_len - hdrlen);
        }

        recvd = req->rq_rcv_buf.len - hdrlen;
        if (count > recvd) {
                dprintk("NFS: server cheating in read reply: "
                        "count %u > recvd %u\n", count, recvd);
                count = recvd;
                res->eof = 0;
        }

        if (count < res->count)
                res->count = count;

        return count;
}

/*
 * Decode WRITE response
 */
static int
nfs3_xdr_writeres(struct rpc_rqst *req, __be32 *p, struct nfs_writeres *res)
{
        int     status;

        status = ntohl(*p++);
        p = xdr_decode_wcc_data(p, res->fattr);

        if (status != 0)
                return nfs_stat_to_errno(status);

        res->count = ntohl(*p++);
        res->verf->committed = (enum nfs3_stable_how)ntohl(*p++);
        res->verf->verifier[0] = *p++;
        res->verf->verifier[1] = *p++;

        return res->count;
}

/*
 * Decode a CREATE response
 */
static int
nfs3_xdr_createres(struct rpc_rqst *req, __be32 *p, struct nfs3_diropres *res)
{
        int     status;

        status = ntohl(*p++);
        if (status == 0) {
                if (*p++) {
                        if (!(p = xdr_decode_fhandle(p, res->fh)))
                                return -errno_NFSERR_IO;
                        p = xdr_decode_post_op_attr(p, res->fattr);
                } else {
                        memset(res->fh, 0, sizeof(*res->fh));
                        /* Do decode post_op_attr but set it to NULL */
                        p = xdr_decode_post_op_attr(p, res->fattr);
                        res->fattr->valid = 0;
                }
        } else {
                status = nfs_stat_to_errno(status);
        }
        p = xdr_decode_wcc_data(p, res->dir_attr);
        return status;
}

/*
 * Decode RENAME reply
 */
static int
nfs3_xdr_renameres(struct rpc_rqst *req, __be32 *p, struct nfs3_renameres *res)
{
        int     status;

        if ((status = ntohl(*p++)) != 0)
                status = nfs_stat_to_errno(status);
        p = xdr_decode_wcc_data(p, res->fromattr);
        p = xdr_decode_wcc_data(p, res->toattr);
        return status;
}

/*
 * Decode LINK reply
 */
static int
nfs3_xdr_linkres(struct rpc_rqst *req, __be32 *p, struct nfs3_linkres *res)
{
        int     status;

        if ((status = ntohl(*p++)) != 0)
                status = nfs_stat_to_errno(status);
        p = xdr_decode_post_op_attr(p, res->fattr);
        p = xdr_decode_wcc_data(p, res->dir_attr);
        return status;
}

/*

 * Decode FSSTAT reply
 */
static int
nfs3_xdr_fsstatres(struct rpc_rqst *req, __be32 *p, struct nfs_fsstat *res)
{
        int             status;

        status = ntohl(*p++);

        p = xdr_decode_post_op_attr(p, res->fattr);
        if (status != 0)
                return nfs_stat_to_errno(status);

        p = xdr_decode_hyper(p, &res->tbytes);
        p = xdr_decode_hyper(p, &res->fbytes);
        p = xdr_decode_hyper(p, &res->abytes);
        p = xdr_decode_hyper(p, &res->tfiles);
        p = xdr_decode_hyper(p, &res->ffiles);
        p = xdr_decode_hyper(p, &res->afiles);

        /* ignore invarsec */
        return 0;
}

/*
 * Decode FSINFO reply
 */
static int
nfs3_xdr_fsinfores(struct rpc_rqst *req, __be32 *p, struct nfs_fsinfo *res)
{
        int             status;

        status = ntohl(*p++);

        p = xdr_decode_post_op_attr(p, res->fattr);
        if (status != 0)
                return nfs_stat_to_errno(status);

        res->rtmax  = ntohl(*p++);
        res->rtpref = ntohl(*p++);
        res->rtmult = ntohl(*p++);
        res->wtmax  = ntohl(*p++);
        res->wtpref = ntohl(*p++);
        res->wtmult = ntohl(*p++);
        res->dtpref = ntohl(*p++);
        p = xdr_decode_hyper(p, &res->maxfilesize);

        /* ignore time_delta and properties */
        res->lease_time = 0;
        return 0;
}

/*
 * Decode PATHCONF reply
 */
static int
nfs3_xdr_pathconfres(struct rpc_rqst *req, __be32 *p, struct nfs_pathconf *res)
{
        int             status;

        status = ntohl(*p++);

        p = xdr_decode_post_op_attr(p, res->fattr);
        if (status != 0)
                return nfs_stat_to_errno(status);
        res->max_link = ntohl(*p++);
        res->max_namelen = ntohl(*p++);

        /* ignore remaining fields */
        return 0;
}

/*
 * Decode COMMIT reply
 */
static int
nfs3_xdr_commitres(struct rpc_rqst *req, __be32 *p, struct nfs_writeres *res)
{
        int             status;

        status = ntohl(*p++);
        p = xdr_decode_wcc_data(p, res->fattr);
        if (status != 0)
                return nfs_stat_to_errno(status);

        res->verf->verifier[0] = *p++;
        res->verf->verifier[1] = *p++;
        return 0;
}

#ifdef CONFIG_NFS_V3_ACL
/*
 * Decode GETACL reply
 */
static int
nfs3_xdr_getaclres(struct rpc_rqst *req, __be32 *p,
                   struct nfs3_getaclres *res)
{
        struct xdr_buf *buf = &req->rq_rcv_buf;
        int status = ntohl(*p++);
        struct posix_acl **acl;
        unsigned int *aclcnt;
        int err, base;

        if (status != 0)
                return nfs_stat_to_errno(status);
        p = xdr_decode_post_op_attr(p, res->fattr);
        res->mask = ntohl(*p++);
        if (res->mask & ~(NFS_ACL|NFS_ACLCNT|NFS_DFACL|NFS_DFACLCNT))
                return -EINVAL;
        base = (char *)p - (char *)req->rq_rcv_buf.head->iov_base;

        acl = (res->mask & NFS_ACL) ? &res->acl_access : NULL;
        aclcnt = (res->mask & NFS_ACLCNT) ? &res->acl_access_count : NULL;
        err = nfsacl_decode(buf, base, aclcnt, acl);

        acl = (res->mask & NFS_DFACL) ? &res->acl_default : NULL;
        aclcnt = (res->mask & NFS_DFACLCNT) ? &res->acl_default_count : NULL;
        if (err > 0)
                err = nfsacl_decode(buf, base + err, aclcnt, acl);
        return (err > 0) ? 0 : err;
}

/*
 * Decode setacl reply.
 */
static int
nfs3_xdr_setaclres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
        int status = ntohl(*p++);

        if (status)
                return nfs_stat_to_errno(status);
        xdr_decode_post_op_attr(p, fattr);
        return 0;
}
#endif  /* CONFIG_NFS_V3_ACL */

#define PROC(proc, argtype, restype, timer)                             \
[NFS3PROC_##proc] = {                                                   \
        .p_proc      = NFS3PROC_##proc,                                 \
        .p_encode    = (kxdrproc_t) nfs3_xdr_##argtype,                 \
        .p_decode    = (kxdrproc_t) nfs3_xdr_##restype,                 \
        .p_arglen    = NFS3_##argtype##_sz,                             \
        .p_replen    = NFS3_##restype##_sz,                             \
        .p_timer     = timer,                                           \
        .p_statidx   = NFS3PROC_##proc,                                 \
        .p_name      = #proc,                                           \
        }

struct rpc_procinfo     nfs3_procedures[] = {
  PROC(GETATTR,         fhandle,        attrstat, 1),
  PROC(SETATTR,         sattrargs,      wccstat, 0),
  PROC(LOOKUP,          diropargs,      lookupres, 2),
  PROC(ACCESS,          accessargs,     accessres, 1),
  PROC(READLINK,        readlinkargs,   readlinkres, 3),
  PROC(READ,            readargs,       readres, 3),
  PROC(WRITE,           writeargs,      writeres, 4),
  PROC(CREATE,          createargs,     createres, 0),
  PROC(MKDIR,           mkdirargs,      createres, 0),
  PROC(SYMLINK,         symlinkargs,    createres, 0),
  PROC(MKNOD,           mknodargs,      createres, 0),
  PROC(REMOVE,          removeargs,     removeres, 0),
  PROC(RMDIR,           diropargs,      wccstat, 0),
  PROC(RENAME,          renameargs,     renameres, 0),
  PROC(LINK,            linkargs,       linkres, 0),
  PROC(READDIR,         readdirargs,    readdirres, 3),
  PROC(READDIRPLUS,     readdirargs,    readdirres, 3),
  PROC(FSSTAT,          fhandle,        fsstatres, 0),
  PROC(FSINFO,          fhandle,        fsinfores, 0),
  PROC(PATHCONF,        fhandle,        pathconfres, 0),
  PROC(COMMIT,          commitargs,     commitres, 5),
};

struct rpc_version              nfs_version3 = {
        .number                 = 3,
        .nrprocs                = ARRAY_SIZE(nfs3_procedures),
        .procs                  = nfs3_procedures
};

#ifdef CONFIG_NFS_V3_ACL
static struct rpc_procinfo      nfs3_acl_procedures[] = {
        [ACLPROC3_GETACL] = {
                .p_proc = ACLPROC3_GETACL,
                .p_encode = (kxdrproc_t) nfs3_xdr_getaclargs,
                .p_decode = (kxdrproc_t) nfs3_xdr_getaclres,
                .p_arglen = ACL3_getaclargs_sz,
                .p_replen = ACL3_getaclres_sz,
                .p_timer = 1,
                .p_name = "GETACL",
        },
        [ACLPROC3_SETACL] = {
                .p_proc = ACLPROC3_SETACL,
                .p_encode = (kxdrproc_t) nfs3_xdr_setaclargs,
                .p_decode = (kxdrproc_t) nfs3_xdr_setaclres,
                .p_arglen = ACL3_setaclargs_sz,
                .p_replen = ACL3_setaclres_sz,
                .p_timer = 0,
                .p_name = "SETACL",
        },
};

struct rpc_version              nfsacl_version3 = {
        .number                 = 3,
        .nrprocs                = sizeof(nfs3_acl_procedures)/
                                  sizeof(nfs3_acl_procedures[0]),
        .procs                  = nfs3_acl_procedures,
};
#endif  /* CONFIG_NFS_V3_ACL */