/*      $NetBSD: nfs.c,v 1.2 1998/01/24 12:43:09 drochner 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.
 */

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <string.h>
#include <stddef.h>

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

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

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

#define NFS_DEBUGxx

#define NFSREAD_MIN_SIZE 1024
#define NFSREAD_MAX_SIZE 16384

/* NFSv3 definitions */
#define NFS_V3MAXFHSIZE         64
#define NFS_VER3                3
#define RPCMNT_VER3             3
#define NFSPROCV3_LOOKUP        3
#define NFSPROCV3_READLINK      5
#define NFSPROCV3_READ          6
#define NFSPROCV3_READDIR       16

typedef struct {
        uint32_t val[2];
} n_quad;

struct nfsv3_time {
        uint32_t nfs_sec;
        uint32_t nfs_nsec;
};

struct nfsv3_fattrs {
        uint32_t fa_type;
        uint32_t fa_mode;
        uint32_t fa_nlink;
        uint32_t fa_uid;
        uint32_t fa_gid;
        n_quad fa_size;
        n_quad fa_used;
        n_quad fa_rdev;
        n_quad fa_fsid;
        n_quad fa_fileid;
        struct nfsv3_time fa_atime;
        struct nfsv3_time fa_mtime;
        struct nfsv3_time fa_ctime;
};

/*
 * For NFSv3, the file handle is variable in size, so most fixed sized
 * structures for arguments won't work. For most cases, a structure
 * that starts with any fixed size section is followed by an array
 * that covers the maximum size required.
 */
struct nfsv3_readdir_repl {
        uint32_t errno;
        uint32_t ok;
        struct nfsv3_fattrs fa;
        uint32_t cookiev0;
        uint32_t cookiev1;
};

struct nfsv3_readdir_entry {
        uint32_t follows;
        uint32_t fid0;
        uint32_t fid1;
        uint32_t len;
        uint32_t nameplus[0];
};

struct nfs_iodesc {
        struct iodesc *iodesc;
        off_t off;
        uint32_t fhsize;
        u_char fh[NFS_V3MAXFHSIZE];
        struct nfsv3_fattrs fa; /* all in network order */
        uint64_t cookie;
};

/*
 * XXX interactions with tftp? See nfswrapper.c for a confusing
 *     issue.
 */
int             nfs_open(const char *path, struct open_file *f);
static int      nfs_close(struct open_file *f);
static int      nfs_read(struct open_file *f, void *buf, size_t size, size_t *resid);
static off_t    nfs_seek(struct open_file *f, off_t offset, int where);
static int      nfs_stat(struct open_file *f, struct stat *sb);
static int      nfs_readdir(struct open_file *f, struct dirent *d);

struct  nfs_iodesc nfs_root_node;

struct fs_ops nfs_fsops = {
        .fs_name = "nfs",
        .fs_flags = 0,
        .fo_open = nfs_open,
        .fo_close = nfs_close,
        .fo_read = nfs_read,
        .fo_write = null_write,
        .fo_seek = nfs_seek,
        .fo_stat = nfs_stat,
        .fo_readdir = nfs_readdir,
};

static int nfs_read_size = NFSREAD_MIN_SIZE;

/*
 * Improve boot performance over NFS
 */
static void
set_nfs_read_size(void)
{
        char *env, *end;
        char buf[10];

        if ((env = getenv("nfs.read_size")) != NULL) {
                errno = 0;
                nfs_read_size = (int)strtol(env, &end, 0);
                if (errno != 0 || *env == '\0' || *end != '\0') {
                        printf("%s: bad value: \"%s\", defaulting to %d\n",
                            "nfs.read_size", env, NFSREAD_MIN_SIZE);
                        nfs_read_size = NFSREAD_MIN_SIZE;
                }
        }
        if (nfs_read_size < NFSREAD_MIN_SIZE) {
                printf("%s: bad value: \"%d\", defaulting to %d\n",
                    "nfs.read_size", nfs_read_size, NFSREAD_MIN_SIZE);
                nfs_read_size = NFSREAD_MIN_SIZE;
        }
        if (nfs_read_size > NFSREAD_MAX_SIZE) {
                printf("%s: bad value: \"%d\", defaulting to %d\n",
                    "nfs.read_size", nfs_read_size, NFSREAD_MIN_SIZE);
                nfs_read_size = NFSREAD_MAX_SIZE;
        }
        snprintf(buf, sizeof (buf), "%d", nfs_read_size);
        setenv("nfs.read_size", buf, 1);
}

/*
 * Fetch the root file handle (call mount daemon)
 * Return zero or error number.
 */
int
nfs_getrootfh(struct iodesc *d, char *path, uint32_t *fhlenp, u_char *fhp)
{
        void *pkt = NULL;
        int len;
        struct args {
                uint32_t len;
                char path[FNAME_SIZE];
        } *args;
        struct repl {
                uint32_t errno;
                uint32_t fhsize;
                u_char fh[NFS_V3MAXFHSIZE];
                uint32_t authcnt;
                uint32_t auth[7];
        } *repl;
        struct {
                uint32_t h[RPC_HEADER_WORDS];
                struct args d;
        } sdata;
        size_t cc;

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

        args = &sdata.d;

        bzero(args, sizeof(*args));
        len = strlen(path);
        if (len > sizeof(args->path))
                len = sizeof(args->path);
        args->len = htonl(len);
        bcopy(path, args->path, len);
        len = sizeof(uint32_t) + roundup(len, sizeof(uint32_t));

        cc = rpc_call(d, RPCPROG_MNT, RPCMNT_VER3, RPCMNT_MOUNT,
            args, len, (void **)&repl, &pkt);
        if (cc == -1) {
                free(pkt);
                /* errno was set by rpc_call */
                return (errno);
        }
        if (cc < 2 * sizeof (uint32_t)) {
                free(pkt);
                return (EBADRPC);
        }
        if (repl->errno != 0) {
                free(pkt);
                return (ntohl(repl->errno));
        }
        *fhlenp = ntohl(repl->fhsize);
        bcopy(repl->fh, fhp, *fhlenp);

        set_nfs_read_size();
        free(pkt);
        return (0);
}

/*
 * Lookup a file.  Store handle and attributes.
 * Return zero or error number.
 */
int
nfs_lookupfh(struct nfs_iodesc *d, const char *name, struct nfs_iodesc *newfd)
{
        void *pkt = NULL;
        int len, pos;
        struct args {
                uint32_t fhsize;
                uint32_t fhplusname[1 +
                    (NFS_V3MAXFHSIZE + FNAME_SIZE) / sizeof(uint32_t)];
        } *args;
        struct repl {
                uint32_t errno;
                uint32_t fhsize;
                uint32_t fhplusattr[(NFS_V3MAXFHSIZE +
                    2 * (sizeof(uint32_t) +
                    sizeof(struct nfsv3_fattrs))) / sizeof(uint32_t)];
        } *repl;
        struct {
                uint32_t h[RPC_HEADER_WORDS];
                struct args d;
        } sdata;
        ssize_t cc;

#ifdef NFS_DEBUG
        if (debug)
                printf("lookupfh: called\n");
#endif

        args = &sdata.d;

        bzero(args, sizeof(*args));
        args->fhsize = htonl(d->fhsize);
        bcopy(d->fh, args->fhplusname, d->fhsize);
        len = strlen(name);
        if (len > FNAME_SIZE)
                len = FNAME_SIZE;
        pos = roundup(d->fhsize, sizeof(uint32_t)) / sizeof(uint32_t);
        args->fhplusname[pos++] = htonl(len);
        bcopy(name, &args->fhplusname[pos], len);
        len = sizeof(uint32_t) + pos * sizeof(uint32_t) +
            roundup(len, sizeof(uint32_t));

        cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER3, NFSPROCV3_LOOKUP,
            args, len, (void **)&repl, &pkt);
        if (cc == -1) {
                free(pkt);
                return (errno);         /* XXX - from rpc_call */
        }
        if (cc < 2 * sizeof(uint32_t)) {
                free(pkt);
                return (EIO);
        }
        if (repl->errno != 0) {
                free(pkt);
                /* saerrno.h now matches NFS error numbers. */
                return (ntohl(repl->errno));
        }
        newfd->fhsize = ntohl(repl->fhsize);
        bcopy(repl->fhplusattr, &newfd->fh, newfd->fhsize);
        pos = roundup(newfd->fhsize, sizeof(uint32_t)) / sizeof(uint32_t);
        if (repl->fhplusattr[pos++] == 0) {
                free(pkt);
                return (EIO);
        }
        bcopy(&repl->fhplusattr[pos], &newfd->fa, sizeof(newfd->fa));
        free(pkt);
        return (0);
}

#ifndef NFS_NOSYMLINK
/*
 * Get the destination of a symbolic link.
 */
int
nfs_readlink(struct nfs_iodesc *d, char *buf)
{
        void *pkt = NULL;
        struct args {
                uint32_t fhsize;
                u_char fh[NFS_V3MAXFHSIZE];
        } *args;
        struct repl {
                uint32_t errno;
                uint32_t ok;
                struct nfsv3_fattrs fa;
                uint32_t len;
                u_char path[NFS_MAXPATHLEN];
        } *repl;
        struct {
                uint32_t h[RPC_HEADER_WORDS];
                struct args d;
        } sdata;
        ssize_t cc;
        int rc = 0;

#ifdef NFS_DEBUG
        if (debug)
                printf("readlink: called\n");
#endif

        args = &sdata.d;

        bzero(args, sizeof(*args));
        args->fhsize = htonl(d->fhsize);
        bcopy(d->fh, args->fh, d->fhsize);
        cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER3, NFSPROCV3_READLINK,
            args, sizeof(uint32_t) + roundup(d->fhsize, sizeof(uint32_t)),
            (void **)&repl, &pkt);
        if (cc == -1)
                return (errno);

        if (cc < 2 * sizeof(uint32_t)) {
                rc = EIO;
                goto done;
        }

        if (repl->errno != 0) {
                rc = ntohl(repl->errno);
                goto done;
        }

        if (repl->ok == 0) {
                rc = EIO;
                goto done;
        }

        repl->len = ntohl(repl->len);
        if (repl->len > NFS_MAXPATHLEN) {
                rc = ENAMETOOLONG;
                goto done;
        }

        bcopy(repl->path, buf, repl->len);
        buf[repl->len] = 0;
done:
        free(pkt);
        return (rc);
}
#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)
{
        void *pkt = NULL;
        struct args {
                uint32_t fhsize;
                uint32_t fhoffcnt[NFS_V3MAXFHSIZE / sizeof(uint32_t) + 3];
        } *args;
        struct repl {
                uint32_t errno;
                uint32_t ok;
                struct nfsv3_fattrs fa;
                uint32_t count;
                uint32_t eof;
                uint32_t len;
                u_char data[NFSREAD_MAX_SIZE];
        } *repl;
        struct {
                uint32_t h[RPC_HEADER_WORDS];
                struct args d;
        } sdata;
        size_t cc;
        long x;
        int hlen, rlen, pos;

        args = &sdata.d;

        bzero(args, sizeof(*args));
        args->fhsize = htonl(d->fhsize);
        bcopy(d->fh, args->fhoffcnt, d->fhsize);
        pos = roundup(d->fhsize, sizeof(uint32_t)) / sizeof(uint32_t);
        args->fhoffcnt[pos++] = 0;
        args->fhoffcnt[pos++] = htonl((uint32_t)off);
        if (len > nfs_read_size)
                len = nfs_read_size;
        args->fhoffcnt[pos] = htonl((uint32_t)len);
        hlen = offsetof(struct repl, data[0]);

        cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER3, NFSPROCV3_READ,
            args, 4 * sizeof(uint32_t) + roundup(d->fhsize, sizeof(uint32_t)),
            (void **)&repl, &pkt);
        if (cc == -1) {
                /* errno was already set by rpc_call */
                return (-1);
        }
        if (cc < hlen) {
                errno = EBADRPC;
                free(pkt);
                return (-1);
        }
        if (repl->errno != 0) {
                errno = ntohl(repl->errno);
                free(pkt);
                return (-1);
        }
        rlen = cc - hlen;
        x = ntohl(repl->count);
        if (rlen < x) {
                printf("nfsread: short packet, %d < %ld\n", rlen, x);
                errno = EBADRPC;
                free(pkt);
                return (-1);
        }
        bcopy(repl->data, addr, x);
        free(pkt);
        return (x);
}

/*
 * Open a file.
 * return zero or error number
 */
int
nfs_open(const char *upath, struct open_file *f)
{
        struct devdesc *dev;
        struct iodesc *desc;
        struct nfs_iodesc *currfd = NULL;
        char buf[2 * NFS_V3MAXFHSIZE + 3];
        u_char *fh;
        char *cp;
        int i;
#ifndef NFS_NOSYMLINK
        struct nfs_iodesc *newfd = NULL;
        char *ncp;
        int c;
        char namebuf[NFS_MAXPATHLEN + 1];
        char linkbuf[NFS_MAXPATHLEN + 1];
        int nlinks = 0;
#endif
        int error;
        char *path = NULL;

        if (netproto != NET_NFS)
                return (EINVAL);

        dev = f->f_devdata;
#ifdef NFS_DEBUG
        if (debug)
                printf("nfs_open: %s (rootip=%s rootpath=%s)\n", upath,
                    inet_ntoa(rootip), rootpath);
#endif
        if (!rootpath[0]) {
                printf("no rootpath, no nfs\n");
                return (ENXIO);
        }

        if (f->f_dev->dv_type != DEVT_NET)
                return (EINVAL);

        if (!(desc = socktodesc(*(int *)(dev->d_opendata))))
                return (EINVAL);

        /* Bind to a reserved port. */
        desc->myport = htons(--rpc_port);
        desc->destip = rootip;
        if ((error = nfs_getrootfh(desc, rootpath, &nfs_root_node.fhsize,
            nfs_root_node.fh)))
                return (error);
        nfs_root_node.fa.fa_type  = htonl(NFDIR);
        nfs_root_node.fa.fa_mode  = htonl(0755);
        nfs_root_node.fa.fa_nlink = htonl(2);
        nfs_root_node.iodesc = desc;

        fh = &nfs_root_node.fh[0];
        buf[0] = 'X';
        cp = &buf[1];
        for (i = 0; i < nfs_root_node.fhsize; i++, cp += 2)
                sprintf(cp, "%02x", fh[i]);
        sprintf(cp, "X");
        setenv("boot.nfsroot.server", inet_ntoa(rootip), 1);
        setenv("boot.nfsroot.path", rootpath, 1);
        setenv("boot.nfsroot.nfshandle", buf, 1);
        sprintf(buf, "%d", nfs_root_node.fhsize);
        setenv("boot.nfsroot.nfshandlelen", buf, 1);

        /* Allocate file system specific data structure */
        currfd = malloc(sizeof(*newfd));
        if (currfd == NULL) {
                error = ENOMEM;
                goto out;
        }
#ifndef NFS_NOSYMLINK
        bcopy(&nfs_root_node, currfd, sizeof(*currfd));
        newfd = NULL;

        cp = path = strdup(upath);
        if (path == NULL) {
                error = ENOMEM;
                goto out;
        }
        while (*cp) {
                /*
                 * Remove extra separators
                 */
                while (*cp == '/')
                        cp++;

                if (*cp == '\0')
                        break;
                /*
                 * Check that current node is a directory.
                 */
                if (currfd->fa.fa_type != htonl(NFDIR)) {
                        error = ENOTDIR;
                        goto out;
                }

                /* allocate file system specific data structure */
                newfd = malloc(sizeof(*newfd));
                if (newfd == NULL) {
                        error = ENOMEM;
                        goto out;
                }
                newfd->iodesc = currfd->iodesc;

                /*
                 * 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++;
                        }
                        *cp = '\0';
                }

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

                /*
                 * Check for symbolic link
                 */
                if (newfd->fa.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;
                        }

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

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

                        free(newfd);
                        newfd = NULL;

                        continue;
                }

                free(currfd);
                currfd = newfd;
                newfd = NULL;
        }

        error = 0;

out:
        free(newfd);
        free(path);
#else
        currfd->iodesc = desc;

        error = nfs_lookupfh(&nfs_root_node, upath, currfd);
#endif
        if (!error) {
                currfd->off = 0;
                currfd->cookie = 0;
                f->f_fsdata = (void *)currfd;
                return (0);
        }

#ifdef NFS_DEBUG
        if (debug)
                printf("nfs_open: %s lookupfh failed: %s\n",
                    path, strerror(error));
#endif
        free(currfd);

        return (error);
}

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

#ifdef NFS_DEBUG
        if (debug)
                printf("nfs_close: fp=0x%lx\n", (u_long)fp);
#endif

        free(fp);
        f->f_fsdata = NULL;

        return (0);
}

/*
 * read a portion of a file
 */
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("nfs_read: size=%lu off=%d\n", (u_long)size,
                       (int)fp->off);
#endif
        while ((int)size > 0) {
                twiddle(16);
                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("nfs_read: read: %s\n", strerror(errno));
#endif
                        return (errno); /* XXX - from nfs_readdata */
                }
                if (cc == 0) {
#ifdef NFS_DEBUG
                        if (debug)
                                printf("nfs_read: hit EOF unexpectedly\n");
#endif
                        goto ret;
                }
                fp->off += cc;
                addr += cc;
                size -= cc;
        }
ret:
        if (resid)
                *resid = size;

        return (0);
}

off_t
nfs_seek(struct open_file *f, off_t offset, int where)
{
        struct nfs_iodesc *d = (struct nfs_iodesc *)f->f_fsdata;
        uint32_t size = ntohl(d->fa.fa_size.val[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:
                errno = EINVAL;
                return (-1);
        }

        return (d->off);
}

/* NFNON=0, NFREG=1, NFDIR=2, NFBLK=3, NFCHR=4, NFLNK=5, NFSOCK=6, NFFIFO=7 */
int nfs_stat_types[9] = {
        0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, S_IFSOCK, S_IFIFO, 0 };

int
nfs_stat(struct open_file *f, struct stat *sb)
{
        struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
        uint32_t ftype, mode;

        ftype = ntohl(fp->fa.fa_type);
        mode  = ntohl(fp->fa.fa_mode);
        mode |= nfs_stat_types[ftype & 7];

        sb->st_mode  = mode;
        sb->st_nlink = ntohl(fp->fa.fa_nlink);
        sb->st_uid   = ntohl(fp->fa.fa_uid);
        sb->st_gid   = ntohl(fp->fa.fa_gid);
        sb->st_size  = ntohl(fp->fa.fa_size.val[1]);

        return (0);
}

static int
nfs_readdir(struct open_file *f, struct dirent *d)
{
        struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
        struct nfsv3_readdir_repl *repl;
        struct nfsv3_readdir_entry *rent;
        static void *pkt = NULL;
        static char *buf;
        static struct nfs_iodesc *pfp = NULL;
        static uint64_t cookie = 0;
        size_t cc;
        int pos, rc;

        struct args {
                uint32_t fhsize;
                uint32_t fhpluscookie[5 + NFS_V3MAXFHSIZE];
        } *args;
        struct {
                uint32_t h[RPC_HEADER_WORDS];
                struct args d;
        } sdata;

        if (fp != pfp || fp->off != cookie) {
                pfp = NULL;
        refill:
                free(pkt);
                pkt = NULL;
                args = &sdata.d;
                bzero(args, sizeof(*args));

                args->fhsize = htonl(fp->fhsize);
                bcopy(fp->fh, args->fhpluscookie, fp->fhsize);
                pos = roundup(fp->fhsize, sizeof(uint32_t)) / sizeof(uint32_t);
                args->fhpluscookie[pos++] = htonl(fp->off >> 32);
                args->fhpluscookie[pos++] = htonl(fp->off);
                args->fhpluscookie[pos++] = htonl(fp->cookie >> 32);
                args->fhpluscookie[pos++] = htonl(fp->cookie);
                args->fhpluscookie[pos] = htonl(NFS_READDIRSIZE);

                cc = rpc_call(fp->iodesc, NFS_PROG, NFS_VER3, NFSPROCV3_READDIR,
                    args, 6 * sizeof(uint32_t) +
                    roundup(fp->fhsize, sizeof(uint32_t)),
                    (void **)&buf, &pkt);
                if (cc == -1) {
                        rc = errno;
                        goto err;
                }
                repl = (struct nfsv3_readdir_repl *)buf;
                if (repl->errno != 0) {
                        rc = ntohl(repl->errno);
                        goto err;
                }
                pfp = fp;
                cookie = fp->off;
                fp->cookie = ((uint64_t)ntohl(repl->cookiev0) << 32) |
                    ntohl(repl->cookiev1);
                buf += sizeof (struct nfsv3_readdir_repl);
        }
        rent = (struct nfsv3_readdir_entry *)buf;

        if (rent->follows == 0) {
                /* fid0 is actually eof */
                if (rent->fid0 != 0) {
                        rc = ENOENT;
                        goto err;
                }
                goto refill;
        }

        d->d_namlen = ntohl(rent->len);
        bcopy(rent->nameplus, d->d_name, d->d_namlen);
        d->d_name[d->d_namlen] = '\0';

        pos = roundup(d->d_namlen, sizeof(uint32_t)) / sizeof(uint32_t);
        fp->off = cookie = ((uint64_t)ntohl(rent->nameplus[pos]) << 32) |
            ntohl(rent->nameplus[pos + 1]);
        pos += 2;
        buf = (char *)&rent->nameplus[pos];
        return (0);

err:
        free(pkt);
        pkt = NULL;
        pfp = NULL;
        cookie = 0;
        return (rc);
}