/*      $NetBSD: nfs.c,v 1.54 2026/06/04 10:05:02 mlelstv Exp $ */

/*-
 *  Copyright (c) 1993 John Brezak
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * XXX Does not currently implement:
 * XXX
 * XXX LIBSA_NO_FS_CLOSE
 * XXX LIBSA_NO_FS_SEEK
 * XXX LIBSA_NO_FS_WRITE
 * XXX LIBSA_NO_FS_SYMLINK (does this even make sense?)
 * XXX LIBSA_FS_SINGLECOMPONENT (does this even make sense?)
 */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/stat.h>
#ifdef _STANDALONE
#include <lib/libkern/libkern.h>
#else
#include <string.h>
#endif

#include <netinet/in.h>
#include <netinet/in_systm.h>

#include "rpcv2.h"
#include "nfsv2.h"
#include "nfsv3.h"

#include "stand.h"
#include "net.h"
#include "nfs.h"
#include "rpc.h"

/* Storage for any filehandle (including length for V3) */
#define NFS_FHSTORE (NFS_FHSIZE < NFS_V3FHSIZE ? NFS_V3FHSIZE + 4: NFS_FHSIZE)

/* Data part of nfs rpc reply (also the largest thing we receive) */
#define NFSREAD_SIZE 1024

#ifndef NFS_NOSYMLINK
struct nfs_readlnk_repl {
        n_long  errno;
        n_long  len;
        char    path[NFS_MAXPATHLEN];
};
#endif

static inline uint64_t
getnquad(n_long x[2]) {
        return (uint64_t)ntohl(x[0]) << 32 | ntohl(x[1]);
}

static inline void
setnquad(n_long x[2], uint64_t v)
{
        x[0] = htonl((n_long)(v >> 32));
        x[1] = htonl((n_long)(v & 0xffffffff));
}

struct nfs_iodesc {
        struct  iodesc  *iodesc;
        off_t   off;
        int     version;
        u_char  fh[NFS_FHSTORE];
        union {
                /* all in network order */
                struct nfsv2_fattr v2;
                struct nfsv3_fattr v3;
        } u_fa;
};

static inline size_t
fhstore(int version, u_char *fh)
{
        size_t len;

        switch (version) {
        case NFS_VER2:
                len = NFS_FHSIZE;
                break;
        case NFS_VER3:
                len = fh[0] << 24 | fh[1] << 16 | fh[2] << 8 | fh[3];
                if (len > NFS_V3FHSIZE)
                        len = NFS_V3FHSIZE;
                len = 4 + roundup(len, 4);
                break;
        default:
                len = 0;
                break;
        }

        return len;
}

static inline size_t
fhcopy(int version, u_char *src, u_char *dst)
{
        size_t len = fhstore(version, src);
        memcpy(dst, src, len);
        return len;
}

#define setfh(d, s) fhcopy((d)->version, (s), (d)->fh)
#define getfh(d, s) fhcopy((d)->version, (d)->fh, (s))


struct nfs_iodesc nfs_root_node;

int     nfs_getrootfh(struct iodesc *, char *, u_char *, int *);
int     nfs_lookupfh(struct nfs_iodesc *, const char *, int,
            struct nfs_iodesc *);
int     nfs_readlink(struct nfs_iodesc *, char *);
ssize_t nfs_readdata(struct nfs_iodesc *, off_t, void *, size_t);

/*
 * Fetch the root file handle (call mount daemon)
 * On error, return non-zero and set errno.
 */
int
nfs_getrootfh(struct iodesc *d, char *path, u_char *fhp, int *versionp)
{
        int len;
        struct args {
                n_long  len;
                char    path[FNAME_SIZE];
        } *args;
        struct repl {
                n_long  errno;
                u_char  fh[NFS_FHSTORE];
        } *repl;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                struct args d;
        } sdata;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                struct repl d;
        } rdata;
        ssize_t cc;

#ifdef NFS_DEBUG
        if (debug)
                printf("%s: %s\n", __func__, path);
#endif

        args = &sdata.d;
        repl = &rdata.d;

        (void)memset(args, 0, sizeof(*args));
        len = strlen(path);
        if ((size_t)len > sizeof(args->path))
                len = sizeof(args->path);
        args->len = htonl(len);
        (void)memcpy(args->path, path, len);
        len = 4 + roundup(len, 4);

        *versionp = NFS_VER3;
        cc = rpc_call(d, RPCPROG_MNT, RPCMNT_VER3, RPCMNT_MOUNT,
            args, len, repl, sizeof(*repl));
        if (cc == -1 || cc < 4 || repl->errno) {
                *versionp = NFS_VER2;
                cc = rpc_call(d, RPCPROG_MNT, RPCMNT_VER1, RPCMNT_MOUNT,
                    args, len, repl, sizeof(*repl));
        }
        if (cc == -1) {
                /* errno was set by rpc_call */
                return -1;
        }
        if (cc < 4) {
                errno = EBADRPC;
                return -1;
        }
        if (repl->errno) {
                errno = ntohl(repl->errno);
                return -1;
        }
        fhcopy(*versionp, repl->fh, fhp);
        return 0;
}

/*
 * Lookup a file.  Store handle and attributes.
 * Return zero or error number.
 */
int
nfs_lookupfh(struct nfs_iodesc *d, const char *name, int len,
        struct nfs_iodesc *newfd)
{
        struct argsv2 {
                u_char  fh[NFS_FHSIZE];
                n_long  len;
                char    name[FNAME_SIZE];
        } *argsv2;
        struct argsv3 {
                u_char  fh[NFS_FHSTORE];
                n_long  len;
                char    name[FNAME_SIZE];
        } *argsv3;
        struct replv2 {
                n_long  errno;
                u_char  fh[NFS_FHSIZE];
                struct  nfsv2_fattr fa;
        } *replv2;
        struct replv3 {
                n_long  errno;
                u_char  fh[NFS_FHSTORE];
                n_long  fattrflag;
                struct  nfsv3_fattr fa;
                n_long  dattrflag;
                struct  nfsv3_fattr da;
        } *replv3;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                union {
                        struct argsv2 v2;
                        struct argsv3 v3;
                } u_d;
        } sdata;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                union {
                        struct replv2 v2;
                        struct replv3 v3;
                } u_d;
        } rdata;
        ssize_t cc;
        size_t alen;

#ifdef NFS_DEBUG
        if (debug)
                printf("%s: called\n", __func__);
#endif

        argsv2 = &sdata.u_d.v2;
        argsv3 = &sdata.u_d.v3;
        replv2 = &rdata.u_d.v2;
        replv3 = &rdata.u_d.v3;

        switch (d->version) {
        case NFS_VER2:
                (void)memset(argsv2, 0, sizeof(*argsv2));
                getfh(d, argsv2->fh);
                if ((size_t)len > sizeof(argsv2->name))
                        len = sizeof(argsv2->name);
                (void)memcpy(argsv2->name, name, len);
                argsv2->len = htonl(len);

                /* padded name, name length */
                len = roundup(len, 4) + 4;
                /* filehandle size */
                alen = fhstore(d->version, argsv2->fh);

                cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_LOOKUP,
                    argsv2, alen+len, replv2, sizeof(*replv2));
                break;
        case NFS_VER3:
                (void)memset(argsv3, 0, sizeof(*argsv3));
                getfh(d, argsv3->fh);
                if ((size_t)len > sizeof(argsv3->name))
                        len = sizeof(argsv3->name);
                (void)memcpy(argsv3->name, name, len);
                argsv3->len = htonl(len);

                /* padded name, name length */
                len = roundup(len, 4) + 4;
                /* filehandle size */
                alen = fhstore(d->version, argsv3->fh);

                /* adjust for variable sized file handle */
                memmove(argsv3->fh + alen, &argsv3->len, len);

                cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER3, NFSV3PROC_LOOKUP,
                    argsv3, alen+len, replv3, sizeof(*replv3));
                break;
        default:
                return ENOSYS;
        }

        if (cc == -1)
                return errno;           /* XXX - from rpc_call */
        if (cc < 4)
                return EIO;

        switch (d->version) {
        case NFS_VER2:
                if (replv2->errno) {
                        /* saerrno.h now matches NFS error numbers. */
                        return ntohl(replv2->errno);
                }

                if (cc < sizeof(*replv2))
                        return EIO;

                setfh(newfd, replv2->fh);
                (void)memcpy(&newfd->u_fa.v2, &replv2->fa,
                    sizeof(newfd->u_fa.v2));
                break;
        case NFS_VER3:
                if (replv3->errno) {
                        /* saerrno.h now matches NFS error numbers. */
                        return ntohl(replv3->errno);
                }

                if (cc < sizeof(*replv3) - (NFS_FHSTORE - 4))
                        return EIO;

                setfh(newfd, replv3->fh);

                /* adjust for variable sized file handle */
                alen = fhstore(d->version, replv3->fh);
                cc -= offsetof(struct replv3, fattrflag);
                if (cc > 0)
                        memmove(&replv3->fattrflag, &replv3->fh + alen, cc);

                if (replv3->fattrflag) {
                        (void)memcpy(&newfd->u_fa.v3, &replv3->fa,
                            sizeof(newfd->u_fa.v3));
                }
                break;
        }
        return 0;
}

#ifndef NFS_NOSYMLINK
/*
 * Get the destination of a symbolic link.
 */
int
nfs_readlink(struct nfs_iodesc *d, char *buf)
{
        struct {
                n_long  h[RPC_HEADER_WORDS];
                u_char  fh[NFS_FHSTORE];
        } sdata;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                struct nfs_readlnk_repl d;
        } rdata;
        ssize_t cc;

#ifdef NFS_DEBUG
        if (debug)
                printf("%s: called\n", __func__);
#endif

        getfh(d, sdata.fh);
        cc = rpc_call(d->iodesc, NFS_PROG, d->version, NFSPROC_READLINK,
                      sdata.fh, fhstore(d->version, sdata.fh),
                      &rdata.d, sizeof(rdata.d));
        if (cc == -1)
                return errno;

        if (cc < 4)
                return EIO;

        if (rdata.d.errno)
                return ntohl(rdata.d.errno);

        rdata.d.len = ntohl(rdata.d.len);
        if (rdata.d.len > NFS_MAXPATHLEN)
                return ENAMETOOLONG;

        (void)memcpy(buf, rdata.d.path, rdata.d.len);
        buf[rdata.d.len] = 0;
        return 0;
}
#endif

/*
 * Read data from a file.
 * Return transfer count or -1 (and set errno)
 */
ssize_t
nfs_readdata(struct nfs_iodesc *d, off_t off, void *addr, size_t len)
{
        struct argsv2 {
                u_char  fh[NFS_FHSIZE];
                n_long  off;
                n_long  len;
                n_long  xxx;                    /* XXX what's this for? */
        } *argsv2;
        struct argsv3 {
                u_char  fh[NFS_FHSTORE];
                n_long  off[2];
                n_long  len;
        } *argsv3;
        struct replv2 {
                n_long  errno;
                struct  nfsv2_fattr fa;
                n_long  count;
                u_char  data[NFSREAD_SIZE];
        } *replv2;
        struct replv3 {
                n_long  errno;
                n_long  attrflag;
                struct  nfsv3_fattr fa;
                n_long  count;
                n_long  eof;
                n_long  length;
                u_char  data[NFSREAD_SIZE];
        } *replv3;
        struct replv3_noattr {
                n_long  errno;
                n_long  attrflag;
                n_long  count;
                n_long  eof;
                n_long  length;
                u_char  data[NFSREAD_SIZE];
        } *replv3no;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                union {
                        struct argsv2 v2;
                        struct argsv3 v3;
                } u_d;
        } sdata;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                union {
                        struct replv2 v2;
                        struct replv3 v3;
                } u_d;
        } rdata;
        ssize_t cc;
        long x;
        size_t hlen, rlen, alen;
        u_char *data;

        argsv2 = &sdata.u_d.v2;
        argsv3 = &sdata.u_d.v3;
        replv2 = &rdata.u_d.v2;
        replv3 = &rdata.u_d.v3;

        if (len > NFSREAD_SIZE)
                len = NFSREAD_SIZE;

        switch (d->version) {
        case NFS_VER2:
                getfh(d, argsv2->fh);
                argsv2->off = htonl((n_long)off);
                argsv2->len = htonl((n_long)len);
                argsv2->xxx = htonl((n_long)0);
                hlen = sizeof(*replv2) - NFSREAD_SIZE;
                cc = rpc_call(d->iodesc, NFS_PROG, d->version, NFSPROC_READ,
                    argsv2, sizeof(*argsv2),
                    replv2, sizeof(*replv2));
                break;
        case NFS_VER3:
                getfh(d, argsv3->fh);
                setnquad(argsv3->off, (uint64_t)off);
                argsv3->len = htonl((n_long)len);
                hlen = sizeof(*replv3) - NFSREAD_SIZE;

                /* adjust for variable sized file handle */
                alen = sizeof(*argsv3) - offsetof(struct argsv3, off);
                memmove(argsv3->fh + fhstore(d->version, argsv3->fh),
                    &argsv3->off, alen);
                alen += fhstore(d->version, argsv3->fh);

                cc = rpc_call(d->iodesc, NFS_PROG, d->version, NFSPROC_READ,
                    argsv3, alen,
                    replv3, sizeof(*replv3));
                break;
        default:
                errno = ENOSYS;
                return -1;
        }

        if (cc == -1) {
                /* errno was already set by rpc_call */
                return -1;
        }
        if (cc < (ssize_t)hlen) {
                errno = EBADRPC;
                return -1;
        }

        switch (d->version) {
        case NFS_VER2:
                if (replv2->errno) {
                        errno = ntohl(replv2->errno);
                        return -1;
                }
                x = ntohl(replv2->count);
                data = replv2->data;
                break;
        case NFS_VER3:
                if (replv3->errno) {
                        errno = ntohl(replv3->errno);
                        return -1;
                }

                /* adjust for optional attributes */
                if (replv3->attrflag) {
                        x = ntohl(replv3->length);
                        data = replv3->data;
                } else {
                        replv3no = (struct replv3_noattr *)replv3;
                        x = ntohl(replv3no->length);
                        data = replv3no->data;
                }
                break;
        default:
                errno = ENOSYS;
                return -1;
        }

        rlen = cc - hlen;
        if (rlen < (size_t)x) {
                printf("%s: short packet, %zu < %ld\n", __func__, rlen, x);
                errno = EBADRPC;
                return -1;
        }
        (void)memcpy(addr, data, x);
        return x;
}

/*
 * nfs_mount - mount this nfs filesystem to a host
 * On error, return non-zero and set errno.
 */
int
nfs_mount(int sock, struct in_addr ip, char *path)
{
        struct iodesc *desc;
        struct nfsv2_fattr *fa2;
        struct nfsv3_fattr *fa3;

        if (!(desc = socktodesc(sock))) {
                errno = EINVAL;
                return -1;
        }

        /* Bind to a reserved port. */
        desc->myport = htons(--rpc_port);
        desc->destip = ip;
        if (nfs_getrootfh(desc, path, nfs_root_node.fh, &nfs_root_node.version))
                return -1;
        nfs_root_node.iodesc = desc;
        /* Fake up attributes for the root dir. */
        switch (nfs_root_node.version) {
        case NFS_VER2:
                fa2 = &nfs_root_node.u_fa.v2;
                fa2->fa_type  = htonl(NFDIR);
                fa2->fa_mode  = htonl(0755);
                fa2->fa_nlink = htonl(2);
                break;
        case NFS_VER3:
                fa3 = &nfs_root_node.u_fa.v3;
                fa3->fa_type  = htonl(NFDIR);
                fa3->fa_mode  = htonl(0755);
                fa3->fa_nlink = htonl(2);
                break;
        default:
                errno = ENOSYS;
                return -1;
        }

#ifdef NFS_DEBUG
        if (debug)
                printf("%s: got fh for %s\n", __func__, path);
#endif

        return 0;
}

/*
 * Open a file.
 * return zero or error number
 */
__compactcall int
nfs_open(const char *path, struct open_file *f)
{
        struct nfs_iodesc *newfd, *currfd;
        const char *cp;
#ifndef NFS_NOSYMLINK
        const char *ncp;
        int c;
        char namebuf[NFS_MAXPATHLEN + 1];
        char linkbuf[NFS_MAXPATHLEN + 1];
        int nlinks = 0;
        n_long fa_type;
#endif
        int error = 0;

#ifdef NFS_DEBUG
        if (debug)
                printf("%s: %s\n", __func__, path);
#endif

#ifdef LIBSA_NFS_IMPLICIT_MOUNT
        if (nfs_mount(*((int *)(f->f_devdata)), rootip, rootpath))
                return errno;
#endif

        if (nfs_root_node.iodesc == NULL) {
                printf("%s: must mount first.\n", __func__);
                return ENXIO;
        }

        currfd = &nfs_root_node;
        newfd = 0;

#ifndef NFS_NOSYMLINK
        cp = path;
        while (*cp) {
                /*
                 * Remove extra separators
                 */
                while (*cp == '/')
                        cp++;

                if (*cp == '\0')
                        break;
                /*
                 * Check that current node is a directory.
                 */
                switch (currfd->version) {
                case NFS_VER2:
                        fa_type = currfd->u_fa.v2.fa_type;
                        break;
                case NFS_VER3:
                        fa_type = currfd->u_fa.v3.fa_type;
                        break;
                default:
                        fa_type = htonl(NFNON);
                        break;
                }
                if (fa_type != htonl(NFDIR)) {
                        error = ENOTDIR;
                        goto out;
                }

                /* allocate file system specific data structure */
                newfd = alloc(sizeof(*newfd));
                newfd->iodesc = currfd->iodesc;
                newfd->off = 0;
                newfd->version = currfd->version;

                /*
                 * Get next component of path name.
                 */
                {
                        int len = 0;

                        ncp = cp;
                        while ((c = *cp) != '\0' && c != '/') {
                                if (++len > NFS_MAXNAMLEN) {
                                        error = ENOENT;
                                        goto out;
                                }
                                cp++;
                        }
                }

                /* lookup a file handle */
                error = nfs_lookupfh(currfd, ncp, cp - ncp, newfd);
                if (error)
                        goto out;

                /*
                 * Check for symbolic link
                 */
                switch (newfd->version) {
                case NFS_VER2:
                        fa_type = newfd->u_fa.v2.fa_type;
                        break;
                case NFS_VER3:
                        fa_type = newfd->u_fa.v3.fa_type;
                        break;
                default:
                        fa_type = htonl(NFNON);
                        break;
                }
                if (fa_type == htonl(NFLNK)) {
                        int link_len, len;

                        error = nfs_readlink(newfd, linkbuf);
                        if (error)
                                goto out;

                        link_len = strlen(linkbuf);
                        len = strlen(cp);

                        if (link_len + len > MAXPATHLEN
                            || ++nlinks > MAXSYMLINKS) {
                                error = ENOENT;
                                goto out;
                        }

                        (void)memcpy(&namebuf[link_len], cp, len + 1);
                        (void)memcpy(namebuf, linkbuf, link_len);

                        /*
                         * If absolute pathname, restart at root.
                         * If relative pathname, restart at parent directory.
                         */
                        cp = namebuf;
                        if (*cp == '/') {
                                if (currfd != &nfs_root_node)
                                        dealloc(currfd, sizeof(*currfd));
                                currfd = &nfs_root_node;
                        }

                        dealloc(newfd, sizeof(*newfd));
                        newfd = 0;

                        continue;
                }

                if (currfd != &nfs_root_node)
                        dealloc(currfd, sizeof(*currfd));
                currfd = newfd;
                newfd = 0;
        }

        error = 0;

out:
#else
        /* allocate file system specific data structure */
        currfd = alloc(sizeof(*currfd));
        currfd->iodesc = nfs_root_node.iodesc;
        currfd->off = 0;
        currfd->version = nfs_root_node.version;

        cp = path;
        /*
         * Remove extra separators
         */
        while (*cp == '/')
                cp++;

        /* XXX: Check for empty path here? */

        error = nfs_lookupfh(&nfs_root_node, cp, strlen(cp), currfd);
#endif
        if (!error) {
                f->f_fsdata = (void *)currfd;
                fsmod = "nfs";
                return 0;
        }

#ifdef NFS_DEBUG
        if (debug)
                printf("%s: %s lookupfh failed: %s\n", __func__,
                    path, strerror(error));
#endif
        if (currfd != &nfs_root_node)
                dealloc(currfd, sizeof(*currfd));
        if (newfd)
                dealloc(newfd, sizeof(*newfd));

        return error;
}

__compactcall int
nfs_close(struct open_file *f)
{
        struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;

#ifdef NFS_DEBUG
        if (debug)
                printf("%s: fp=%p\n", __func__, fp);
#endif

        if (fp)
                dealloc(fp, sizeof(struct nfs_iodesc));
        f->f_fsdata = (void *)0;

        return 0;
}

/*
 * read a portion of a file
 */
__compactcall int
nfs_read(struct open_file *f, void *buf, size_t size, size_t *resid)
{
        struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
        ssize_t cc;
        char *addr = buf;

#ifdef NFS_DEBUG
        if (debug)
                printf("%s: size=%zu off=%" PRIx64 "\n", __func__, size, fp->off);
#endif
        while ((int)size > 0) {
#if !defined(LIBSA_NO_TWIDDLE)
                twiddle();
#endif
                cc = nfs_readdata(fp, fp->off, (void *)addr, size);
                /* XXX maybe should retry on certain errors */
                if (cc == -1) {
#ifdef NFS_DEBUG
                        if (debug)
                                printf("%s: read: %s\n", __func__, 
                                    strerror(errno));
#endif
                        return errno;   /* XXX - from nfs_readdata */
                }
                if (cc == 0) {
#ifdef NFS_DEBUG
                        if (debug)
                                printf("%s: hit EOF unexpectedly\n", __func__);
#endif
                        goto ret;
                }
                fp->off += cc;
                addr += cc;
                size -= cc;
        }
ret:
        if (resid)
                *resid = size;

        return 0;
}

/*
 * Not implemented.
 */
__compactcall int
nfs_write(struct open_file *f, void *buf, size_t size, size_t *resid)
{
        return EROFS;
}

__compactcall off_t
nfs_seek(struct open_file *f, off_t offset, int where)
{
        struct nfs_iodesc *d = (struct nfs_iodesc *)f->f_fsdata;
        off_t size;

        switch (d->version) {
        case NFS_VER2:
                size = ntohl(d->u_fa.v2.fa_size);
                break;
        case NFS_VER3:
                size = getnquad(d->u_fa.v3.fa_size);
                break;
        default:
                return -1;
        }

        switch (where) {
        case SEEK_SET:
                d->off = offset;
                break;
        case SEEK_CUR:
                d->off += offset;
                break;
        case SEEK_END:
                d->off = size - offset;
                break;
        default:
                return -1;
        }

        return d->off;
}

/* NFNON=0, NFREG=1, NFDIR=2, NFBLK=3, NFCHR=4, NFLNK=5 */
const int nfs_stat_types[8] = {
        0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 0 };

__compactcall int
nfs_stat(struct open_file *f, struct stat *sb)
{
        struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
        n_long ftype, mode;

        switch (fp->version) {
        case NFS_VER2:
                ftype = ntohl(fp->u_fa.v2.fa_type);
                mode  = ntohl(fp->u_fa.v2.fa_mode);
                sb->st_nlink = ntohl(fp->u_fa.v2.fa_nlink);
                sb->st_uid   = ntohl(fp->u_fa.v2.fa_uid);
                sb->st_gid   = ntohl(fp->u_fa.v2.fa_gid);
                sb->st_size  = ntohl(fp->u_fa.v2.fa_size);
                break;
        case NFS_VER3:
                ftype = ntohl(fp->u_fa.v3.fa_type);
                mode  = ntohl(fp->u_fa.v3.fa_mode);
                sb->st_nlink = ntohl(fp->u_fa.v3.fa_nlink);
                sb->st_uid   = ntohl(fp->u_fa.v3.fa_uid);
                sb->st_gid   = ntohl(fp->u_fa.v3.fa_gid);
                sb->st_size  = getnquad(fp->u_fa.v3.fa_size);
                break;
        default:
                return -1;
        }

        mode |= nfs_stat_types[ftype & 7];
        sb->st_mode  = mode;

        return 0;
}

#if defined(LIBSA_ENABLE_LS_OP)
#include "ls.h"
__compactcall void
nfs_ls(struct open_file *f, const char *pattern)
{
        lsunsup("nfs");
}
#endif