/* $FreeBSD: src/lib/libstand/nfs.c,v 1.2.6.3 2000/09/10 01:33:25 ps Exp $ */
/*      $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 our own NFS attributes without NQNFS stuff. */
struct nfsv2_fattrs {
        n_long  fa_type;
        n_long  fa_mode;
        n_long  fa_nlink;
        n_long  fa_uid;
        n_long  fa_gid;
        n_long  fa_size;
        n_long  fa_blocksize;
        n_long  fa_rdev;
        n_long  fa_blocks;
        n_long  fa_fsid;
        n_long  fa_fileid;
        struct nfsv2_time fa_atime;
        struct nfsv2_time fa_mtime;
        struct nfsv2_time fa_ctime;
};


struct nfs_read_args {
        u_char  fh[NFS_FHSIZE];
        n_long  off;
        n_long  len;
        n_long  xxx;                    /* XXX what's this for? */
};

/*
 * Data part of nfs rpc reply (also the largest thing we receive).
 * Worry about the size of the structure declared on the stack.
 */

#define NFSREAD_MIN_SIZE 1024
#define NFSREAD_MAX_SIZE 4096

struct nfs_read_repl {
        n_long  errno;
        struct  nfsv2_fattrs fa;
        n_long  count;
        u_char  data[NFSREAD_MAX_SIZE];
};

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

struct nfs_readdir_args {
        u_char  fh[NFS_FHSIZE];
        n_long  cookie;
        n_long  count;
};

struct nfs_readdir_data {
        n_long  fileid;
        n_long  len;
        char    name[0];
};

struct nfs_readdir_off {
        n_long  cookie;
        n_long  follows;
};

struct nfs_iodesc {
        struct  iodesc  *iodesc;
        off_t   off;
        u_char  fh[NFS_FHSIZE];
        struct nfsv2_fattrs fa; /* all in network order */
};

/*
 * 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 int      nfs_write(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 = {
        "nfs",
        nfs_open,
        nfs_close,
        nfs_read,
        nfs_write,
        nfs_seek,
        nfs_stat,
        nfs_readdir
};

static int nfs_read_size = NFSREAD_MIN_SIZE;

/*
 * Fetch the root file handle (call mount daemon)
 * Return zero or error number.
 */
int
nfs_getrootfh(struct iodesc *d, char *path, u_char *fhp)
{
        int len;
        struct args {
                n_long  len;
                char    path[FNAME_SIZE];
        } *args;
        struct repl {
                n_long  errno;
                u_char  fh[NFS_FHSIZE];
        } *repl;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                struct args d;
        } sdata;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                struct repl d;
        } rdata;
        size_t cc;
        
#ifdef NFS_DEBUG
        if (debug)
                printf("nfs_getrootfh: %s\n", path);
#endif

        args = &sdata.d;
        repl = &rdata.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 = 4 + roundup(len, 4);

        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 (errno);
        }
        if (cc < 4)
                return (EBADRPC);
        if (repl->errno)
                return (ntohl(repl->errno));
        bcopy(repl->fh, fhp, sizeof(repl->fh));

        /*
         * Improve boot performance over NFS
         */
        if (getenv("nfs.read_size") != NULL)
                nfs_read_size = strtol(getenv("nfs.read_size"), NULL, 0);
        if (nfs_read_size < NFSREAD_MIN_SIZE)
                nfs_read_size = NFSREAD_MIN_SIZE;
        if (nfs_read_size > NFSREAD_MAX_SIZE)
                nfs_read_size = NFSREAD_MAX_SIZE;

        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)
{
        int len, rlen;
        struct args {
                u_char  fh[NFS_FHSIZE];
                n_long  len;
                char    name[FNAME_SIZE];
        } *args;
        struct repl {
                n_long  errno;
                u_char  fh[NFS_FHSIZE];
                struct  nfsv2_fattrs fa;
        } *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("lookupfh: called\n");
#endif

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

        bzero(args, sizeof(*args));
        bcopy(d->fh, args->fh, sizeof(args->fh));
        len = strlen(name);
        if (len > sizeof(args->name))
                len = sizeof(args->name);
        bcopy(name, args->name, len);
        args->len = htonl(len);
        len = 4 + roundup(len, 4);
        len += NFS_FHSIZE;

        rlen = sizeof(*repl);

        cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_LOOKUP,
            args, len, repl, rlen);
        if (cc == -1)
                return (errno);         /* XXX - from rpc_call */
        if (cc < 4)
                return (EIO);
        if (repl->errno) {
                /* saerrno.h now matches NFS error numbers. */
                return (ntohl(repl->errno));
        }
        bcopy( repl->fh, &newfd->fh, sizeof(newfd->fh));
        bcopy(&repl->fa, &newfd->fa, sizeof(newfd->fa));
        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_FHSIZE];
        } sdata;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                struct nfs_readlnk_repl d;
        } rdata;
        ssize_t cc;

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

        bcopy(d->fh, sdata.fh, NFS_FHSIZE);
        cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_READLINK,
                      sdata.fh, NFS_FHSIZE,
                      &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);

        bcopy(rdata.d.path, buf, 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 nfs_read_args *args;
        struct nfs_read_repl *repl;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                struct nfs_read_args d;
        } sdata;
        struct {
                n_long  h[RPC_HEADER_WORDS];
                struct nfs_read_repl d;
        } rdata;
        size_t cc;
        long x;
        int hlen, rlen;

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

        bcopy(d->fh, args->fh, NFS_FHSIZE);
        args->off = htonl((n_long)off);
        if (len > nfs_read_size)
                len = nfs_read_size;
        args->len = htonl((n_long)len);
        args->xxx = htonl((n_long)0);
        hlen = offsetof(struct nfs_read_repl, data[0]);

        cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_READ,
            args, sizeof(*args),
            repl, sizeof(*repl));
        if (cc == -1) {
                /* errno was already set by rpc_call */
                return (-1);
        }
        if (cc < hlen) {
                errno = EBADRPC;
                return (-1);
        }
        if (repl->errno) {
                errno = ntohl(repl->errno);
                return (-1);
        }
        rlen = cc - hlen;
        x = ntohl(repl->count);
        if (rlen < x) {
                printf("nfsread: short packet, %d < %ld\n", rlen, x);
                errno = EBADRPC;
                return(-1);
        }
        bcopy(repl->data, addr, x);
        return (x);
}

/*
 * Open a file.
 * return zero or error number
 */
int
nfs_open(const char *upath, struct open_file *f)
{
        struct iodesc *desc;
        struct nfs_iodesc *currfd;
#ifndef NFS_NOSYMLINK
        struct nfs_iodesc *newfd;
        struct nfsv2_fattrs *fa;
        char *cp, *ncp;
        int c;
        char namebuf[NFS_MAXPATHLEN + 1];
        char linkbuf[NFS_MAXPATHLEN + 1];
        int nlinks = 0;
#endif
        int error;
        char *path;

#ifdef NFS_DEBUG
        if (debug)
            printf("nfs_open: %s (rootpath=%s)\n", path, rootpath);
#endif
        if (!rootpath[0]) {
                printf("no rootpath, no nfs\n");
                return (ENXIO);
        }

        /* Avoid trying out nfs_open for disk devices in the EFI loader */
#ifndef __i386__
        if (strcmp(f->f_dev->dv_name, "net") != 0)
                return (EINVAL);
#endif

        if (!(desc = socktodesc(*(int *)(f->f_devdata))))
                return(EINVAL);

        /* Bind to a reserved port. */
        desc->myport = htons(rpc_newport());
        desc->destip = rootip;
        if ((error = nfs_getrootfh(desc, rootpath, nfs_root_node.fh)))
                return (error);
        nfs_root_node.iodesc = desc;

#ifndef NFS_NOSYMLINK
        /* Fake up attributes for the root dir. */
        fa = &nfs_root_node.fa;
        fa->fa_type  = htonl(NFDIR);
        fa->fa_mode  = htonl(0755);
        fa->fa_nlink = htonl(2);

        currfd = &nfs_root_node;
        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));
                newfd->iodesc = currfd->iodesc;
                newfd->off = 0;
        
                /*
                 * 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 == '/') {
                                if (currfd != &nfs_root_node)
                                        free(currfd);
                                currfd = &nfs_root_node;
                        }

                        free(newfd);
                        newfd = NULL;
                        
                        continue;
                }
                
                if (currfd != &nfs_root_node)
                        free(currfd);
                currfd = newfd;
                newfd = NULL;
        }

        error = 0;

out:
        if (newfd)
                free(newfd);
        if (path)
                free(path);
#else
        /* allocate file system specific data structure */
        currfd = malloc(sizeof(*currfd));
        currfd->iodesc = desc;
        currfd->off = 0;

        error = nfs_lookupfh(&nfs_root_node, upath, currfd);
#endif
        if (!error) {
                f->f_fsdata = (void *)currfd;
                return (0);
        }
                
#ifdef NFS_DEBUG
        if (debug)
                printf("nfs_open: %s lookupfh failed: %s\n",
                    path, strerror(error));
#endif
#ifndef NFS_NOSYMLINK
        if (currfd != &nfs_root_node)
#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

        f->f_fsdata = NULL;
        if (fp && fp != &nfs_root_node)
                free(fp);
        
        return (0);
}

/*
 * read a portion of a file
 *
 * Parameters:
 *      resid:  out
 */
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;
        static int tc;
        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) {
                if (!(tc++ % 256))
                        twiddle();
                cc = nfs_readdata(fp, fp->off, addr, size);
                /* XXX maybe should retry on certain errors */
                if (cc == -1) {
#ifdef NFS_DEBUG
                        if (debug)
                                printf("nfs_read: read: %s", strerror(errno));
#endif
                        return (errno); /* XXX - from nfs_readdata */
                }
                if (cc == 0) {
#ifdef NFS_DEBUG
                        if (debug)
                                printf("nfs_read: hit EOF unexpectantly");
#endif
                        goto ret;
                }
                fp->off += cc;
                addr += cc;
                size -= cc;
        }
ret:
        if (resid)
                *resid = size;

        return (0);
}

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

off_t
nfs_seek(struct open_file *f, off_t offset, int where)
{
        struct nfs_iodesc *d = (struct nfs_iodesc *)f->f_fsdata;
        n_long size = ntohl(d->fa.fa_size);

        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 */
int nfs_stat_types[8] = {
        0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 0 };

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

        return (0);
}

static int
nfs_readdir(struct open_file *f, struct dirent *d)
{
        struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
        struct nfs_readdir_args *args;
        struct nfs_readdir_data *rd;
        struct nfs_readdir_off  *roff = NULL;
        static char *buf;
        static n_long cookie = 0;
        size_t cc;
        n_long eof;
        
        struct {
                n_long h[RPC_HEADER_WORDS];
                struct nfs_readdir_args d;
        } sdata;
        static struct {
                n_long h[RPC_HEADER_WORDS];
                u_char d[NFS_READDIRSIZE];
        } rdata;

        if (cookie == 0) {
        refill:
                args = &sdata.d;
                bzero(args, sizeof(*args));

                bcopy(fp->fh, args->fh, NFS_FHSIZE);
                args->cookie = htonl(cookie);
                args->count  = htonl(NFS_READDIRSIZE);
                
                cc = rpc_call(fp->iodesc, NFS_PROG, NFS_VER2, NFSPROC_READDIR,
                              args, sizeof(*args),
                              rdata.d, sizeof(rdata.d));
                buf  = rdata.d;
                roff = (struct nfs_readdir_off *)buf;
                if (ntohl(roff->cookie) != 0)
                        return 1;
        }
        roff = (struct nfs_readdir_off *)buf;

        if (ntohl(roff->follows) == 0) {
                eof = ntohl((roff+1)->cookie);
                if (eof) {
                        cookie = 0;
                        return 1;
                }
                goto refill;
        }

        buf += sizeof(struct nfs_readdir_off);
        rd = (struct nfs_readdir_data *)buf;
        d->d_namlen = ntohl(rd->len);
        bcopy(rd->name, d->d_name, d->d_namlen);
        d->d_name[d->d_namlen] = '\0';

        buf += (sizeof(struct nfs_readdir_data) + roundup(htonl(rd->len),4));
        roff = (struct nfs_readdir_off *)buf;
        cookie = ntohl(roff->cookie);
        return 0;
}