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nfs.c revision 1.18 
      1 /*	$NetBSD: nfs.c,v 1.18 1996/10/10 22:46:27 christos Exp $	*/
      2 
      3 /*-
      4  *  Copyright (c) 1993 John Brezak
      5  *  All rights reserved.
      6  *
      7  *  Redistribution and use in source and binary forms, with or without
      8  *  modification, are permitted provided that the following conditions
      9  *  are met:
     10  *  1. Redistributions of source code must retain the above copyright
     11  *     notice, this list of conditions and the following disclaimer.
     12  *  2. Redistributions in binary form must reproduce the above copyright
     13  *     notice, this list of conditions and the following disclaimer in the
     14  *     documentation and/or other materials provided with the distribution.
     15  *  3. The name of the author may not be used to endorse or promote products
     16  *     derived from this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
     19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     21  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
     22  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
     27  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     28  * POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include <sys/param.h>
     32 #include <sys/time.h>
     33 #include <sys/socket.h>
     34 #include <sys/stat.h>
     35 #include <string.h>
     36 
     37 #include <netinet/in.h>
     38 #include <netinet/in_systm.h>
     39 
     40 #include "rpcv2.h"
     41 #include "nfsv2.h"
     42 
     43 #include "stand.h"
     44 #include "net.h"
     45 #include "netif.h"
     46 #include "nfs.h"
     47 #include "rpc.h"
     48 
     49 /* Define our own NFS attributes without NQNFS stuff. */
     50 struct nfsv2_fattrs {
     51 	n_long	fa_type;
     52 	n_long	fa_mode;
     53 	n_long	fa_nlink;
     54 	n_long	fa_uid;
     55 	n_long	fa_gid;
     56 	n_long	fa_size;
     57 	n_long	fa_blocksize;
     58 	n_long	fa_rdev;
     59 	n_long	fa_blocks;
     60 	n_long	fa_fsid;
     61 	n_long	fa_fileid;
     62 	struct nfsv2_time fa_atime;
     63 	struct nfsv2_time fa_mtime;
     64 	struct nfsv2_time fa_ctime;
     65 };
     66 
     67 
     68 struct nfs_read_args {
     69 	u_char	fh[NFS_FHSIZE];
     70 	n_long	off;
     71 	n_long	len;
     72 	n_long	xxx;			/* XXX what's this for? */
     73 };
     74 
     75 /* Data part of nfs rpc reply (also the largest thing we receive) */
     76 #define NFSREAD_SIZE 1024
     77 struct nfs_read_repl {
     78 	n_long	errno;
     79 	struct	nfsv2_fattrs fa;
     80 	n_long	count;
     81 	u_char	data[NFSREAD_SIZE];
     82 };
     83 
     84 struct nfs_readlnk_repl {
     85 	n_long	errno;
     86 	n_long	len;
     87 	char	path[NFS_MAXPATHLEN];
     88 };
     89 
     90 struct nfs_iodesc {
     91 	struct	iodesc	*iodesc;
     92 	off_t	off;
     93 	u_char	fh[NFS_FHSIZE];
     94 	struct nfsv2_fattrs fa;	/* all in network order */
     95 };
     96 
     97 struct nfs_iodesc nfs_root_node;
     98 
     99 
    100 /*
    101  * Fetch the root file handle (call mount daemon)
    102  * On error, return non-zero and set errno.
    103  */
    104 int
    105 nfs_getrootfh(d, path, fhp)
    106 	register struct iodesc *d;
    107 	char *path;
    108 	u_char *fhp;
    109 {
    110 	register int len;
    111 	struct args {
    112 		n_long	len;
    113 		char	path[FNAME_SIZE];
    114 	} *args;
    115 	struct repl {
    116 		n_long	errno;
    117 		u_char	fh[NFS_FHSIZE];
    118 	} *repl;
    119 	struct {
    120 		n_long	h[RPC_HEADER_WORDS];
    121 		struct args d;
    122 	} sdata;
    123 	struct {
    124 		n_long	h[RPC_HEADER_WORDS];
    125 		struct repl d;
    126 	} rdata;
    127 	size_t cc;
    128 
    129 #ifdef NFS_DEBUG
    130 	if (debug)
    131 		kprintf("nfs_getrootfh: %s\n", path);
    132 #endif
    133 
    134 	args = &sdata.d;
    135 	repl = &rdata.d;
    136 
    137 	bzero(args, sizeof(*args));
    138 	len = strlen(path);
    139 	if (len > sizeof(args->path))
    140 		len = sizeof(args->path);
    141 	args->len = htonl(len);
    142 	bcopy(path, args->path, len);
    143 	len = 4 + roundup(len, 4);
    144 
    145 	cc = rpc_call(d, RPCPROG_MNT, RPCMNT_VER1, RPCMNT_MOUNT,
    146 	    args, len, repl, sizeof(*repl));
    147 	if (cc == -1) {
    148 		/* errno was set by rpc_call */
    149 		return (-1);
    150 	}
    151 	if (cc < 4) {
    152 		errno = EBADRPC;
    153 		return (-1);
    154 	}
    155 	if (repl->errno) {
    156 		errno = ntohl(repl->errno);
    157 		return (-1);
    158 	}
    159 	bcopy(repl->fh, fhp, sizeof(repl->fh));
    160 	return (0);
    161 }
    162 
    163 /*
    164  * Lookup a file.  Store handle and attributes.
    165  * Return zero or error number.
    166  */
    167 int
    168 nfs_lookupfh(d, name, newfd)
    169 	struct nfs_iodesc *d;
    170 	char *name;
    171 	struct nfs_iodesc *newfd;
    172 {
    173 	register int len, rlen;
    174 	struct args {
    175 		u_char	fh[NFS_FHSIZE];
    176 		n_long	len;
    177 		char	name[FNAME_SIZE];
    178 	} *args;
    179 	struct repl {
    180 		n_long	errno;
    181 		u_char	fh[NFS_FHSIZE];
    182 		struct	nfsv2_fattrs fa;
    183 	} *repl;
    184 	struct {
    185 		n_long	h[RPC_HEADER_WORDS];
    186 		struct args d;
    187 	} sdata;
    188 	struct {
    189 		n_long	h[RPC_HEADER_WORDS];
    190 		struct repl d;
    191 	} rdata;
    192 	ssize_t cc;
    193 
    194 #ifdef NFS_DEBUG
    195 	if (debug)
    196 		kprintf("lookupfh: called\n");
    197 #endif
    198 
    199 	args = &sdata.d;
    200 	repl = &rdata.d;
    201 
    202 	bzero(args, sizeof(*args));
    203 	bcopy(d->fh, args->fh, sizeof(args->fh));
    204 	len = strlen(name);
    205 	if (len > sizeof(args->name))
    206 		len = sizeof(args->name);
    207 	bcopy(name, args->name, len);
    208 	args->len = htonl(len);
    209 	len = 4 + roundup(len, 4);
    210 	len += NFS_FHSIZE;
    211 
    212 	rlen = sizeof(*repl);
    213 
    214 	cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_LOOKUP,
    215 	    args, len, repl, rlen);
    216 	if (cc == -1)
    217 		return (errno);		/* XXX - from rpc_call */
    218 	if (cc < 4)
    219 		return (EIO);
    220 	if (repl->errno) {
    221 		/* saerrno.h now matches NFS error numbers. */
    222 		return (ntohl(repl->errno));
    223 	}
    224 	bcopy( repl->fh, &newfd->fh, sizeof(newfd->fh));
    225 	bcopy(&repl->fa, &newfd->fa, sizeof(newfd->fa));
    226 	return (0);
    227 }
    228 
    229 /*
    230  * Get the destination of a symbolic link.
    231  */
    232 int
    233 nfs_readlink(d, buf)
    234 	struct nfs_iodesc *d;
    235 	char *buf;
    236 {
    237 	struct {
    238 		n_long	h[RPC_HEADER_WORDS];
    239 		u_char fh[NFS_FHSIZE];
    240 	} sdata;
    241 	struct {
    242 		n_long	h[RPC_HEADER_WORDS];
    243 		struct nfs_readlnk_repl d;
    244 	} rdata;
    245 	ssize_t cc;
    246 
    247 #ifdef NFS_DEBUG
    248 	if (debug)
    249 		kprintf("readlink: called\n");
    250 #endif
    251 
    252 	bcopy(d->fh, sdata.fh, NFS_FHSIZE);
    253 	cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_READLINK,
    254 		      sdata.fh, NFS_FHSIZE,
    255 		      &rdata.d, sizeof(rdata.d));
    256 	if (cc == -1)
    257 		return (errno);
    258 
    259 	if (cc < 4)
    260 		return (EIO);
    261 
    262 	if (rdata.d.errno)
    263 		return (ntohl(rdata.d.errno));
    264 
    265 	rdata.d.len = ntohl(rdata.d.len);
    266 	if (rdata.d.len > NFS_MAXPATHLEN)
    267 		return (ENAMETOOLONG);
    268 
    269 	bcopy(rdata.d.path, buf, rdata.d.len);
    270 	buf[rdata.d.len] = 0;
    271 	return (0);
    272 }
    273 
    274 /*
    275  * Read data from a file.
    276  * Return transfer count or -1 (and set errno)
    277  */
    278 ssize_t
    279 nfs_readdata(d, off, addr, len)
    280 	struct nfs_iodesc *d;
    281 	off_t off;
    282 	void *addr;
    283 	size_t len;
    284 {
    285 	struct nfs_read_args *args;
    286 	struct nfs_read_repl *repl;
    287 	struct {
    288 		n_long	h[RPC_HEADER_WORDS];
    289 		struct nfs_read_args d;
    290 	} sdata;
    291 	struct {
    292 		n_long	h[RPC_HEADER_WORDS];
    293 		struct nfs_read_repl d;
    294 	} rdata;
    295 	size_t cc;
    296 	long x;
    297 	int hlen, rlen;
    298 
    299 	args = &sdata.d;
    300 	repl = &rdata.d;
    301 
    302 	bcopy(d->fh, args->fh, NFS_FHSIZE);
    303 	args->off = htonl((n_long)off);
    304 	if (len > NFSREAD_SIZE)
    305 		len = NFSREAD_SIZE;
    306 	args->len = htonl((n_long)len);
    307 	args->xxx = htonl((n_long)0);
    308 	hlen = sizeof(*repl) - NFSREAD_SIZE;
    309 
    310 	cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_READ,
    311 	    args, sizeof(*args),
    312 	    repl, sizeof(*repl));
    313 	if (cc == -1) {
    314 		/* errno was already set by rpc_call */
    315 		return (-1);
    316 	}
    317 	if (cc < hlen) {
    318 		errno = EBADRPC;
    319 		return (-1);
    320 	}
    321 	if (repl->errno) {
    322 		errno = ntohl(repl->errno);
    323 		return (-1);
    324 	}
    325 	rlen = cc - hlen;
    326 	x = ntohl(repl->count);
    327 	if (rlen < x) {
    328 		kprintf("nfsread: short packet, %d < %ld\n", rlen, x);
    329 		errno = EBADRPC;
    330 		return(-1);
    331 	}
    332 	bcopy(repl->data, addr, x);
    333 	return (x);
    334 }
    335 
    336 /*
    337  * nfs_mount - mount this nfs filesystem to a host
    338  * On error, return non-zero and set errno.
    339  */
    340 int
    341 nfs_mount(sock, ip, path)
    342 	int sock;
    343 	struct in_addr ip;
    344 	char *path;
    345 {
    346 	struct iodesc *desc;
    347 	struct nfsv2_fattrs *fa;
    348 
    349 	if (!(desc = socktodesc(sock))) {
    350 		errno = EINVAL;
    351 		return(-1);
    352 	}
    353 
    354 	/* Bind to a reserved port. */
    355 	desc->myport = htons(--rpc_port);
    356 	desc->destip = ip;
    357 	if (nfs_getrootfh(desc, path, nfs_root_node.fh))
    358 		return (-1);
    359 	nfs_root_node.iodesc = desc;
    360 	/* Fake up attributes for the root dir. */
    361 	fa = &nfs_root_node.fa;
    362 	fa->fa_type  = htonl(NFDIR);
    363 	fa->fa_mode  = htonl(0755);
    364 	fa->fa_nlink = htonl(2);
    365 
    366 #ifdef NFS_DEBUG
    367 	if (debug)
    368 		kprintf("nfs_mount: got fh for %s\n", path);
    369 #endif
    370 
    371 	return(0);
    372 }
    373 
    374 /*
    375  * Open a file.
    376  * return zero or error number
    377  */
    378 int
    379 nfs_open(path, f)
    380 	char *path;
    381 	struct open_file *f;
    382 {
    383 	struct nfs_iodesc *newfd, *currfd;
    384 	register char *cp, *ncp;
    385 	register int c;
    386 	char namebuf[NFS_MAXPATHLEN + 1];
    387 	char linkbuf[NFS_MAXPATHLEN + 1];
    388 	int nlinks = 0;
    389 	int error = 0;
    390 
    391 #ifdef NFS_DEBUG
    392  	if (debug)
    393  	    kprintf("nfs_open: %s\n", path);
    394 #endif
    395 	if (nfs_root_node.iodesc == NULL) {
    396 		kprintf("nfs_open: must mount first.\n");
    397 		return (ENXIO);
    398 	}
    399 
    400 	currfd = &nfs_root_node;
    401 	newfd = 0;
    402 
    403 	cp = path;
    404 	while (*cp) {
    405 		/*
    406 		 * Remove extra separators
    407 		 */
    408 		while (*cp == '/')
    409 			cp++;
    410 
    411 		if (*cp == '\0')
    412 			break;
    413 		/*
    414 		 * Check that current node is a directory.
    415 		 */
    416 		if (currfd->fa.fa_type != htonl(NFDIR)) {
    417 			error = ENOTDIR;
    418 			goto out;
    419 		}
    420 
    421 		/* allocate file system specific data structure */
    422 		newfd = alloc(sizeof(*newfd));
    423 		newfd->iodesc = currfd->iodesc;
    424 		newfd->off = 0;
    425 
    426 		/*
    427 		 * Get next component of path name.
    428 		 */
    429 		{
    430 			register int len = 0;
    431 
    432 			ncp = cp;
    433 			while ((c = *cp) != '\0' && c != '/') {
    434 				if (++len > NFS_MAXNAMLEN) {
    435 					error = ENOENT;
    436 					goto out;
    437 				}
    438 				cp++;
    439 			}
    440 			*cp = '\0';
    441 		}
    442 
    443 		/* lookup a file handle */
    444 		error = nfs_lookupfh(currfd, ncp, newfd);
    445 		*cp = c;
    446 		if (error)
    447 			goto out;
    448 
    449 		/*
    450 		 * Check for symbolic link
    451 		 */
    452 		if (newfd->fa.fa_type == htonl(NFLNK)) {
    453 			int link_len, len;
    454 
    455 			error = nfs_readlink(newfd, linkbuf);
    456 			if (error)
    457 				goto out;
    458 
    459 			link_len = strlen(linkbuf);
    460 			len = strlen(cp);
    461 
    462 			if (link_len + len > MAXPATHLEN
    463 			    || ++nlinks > MAXSYMLINKS) {
    464 				error = ENOENT;
    465 				goto out;
    466 			}
    467 
    468 			bcopy(cp, &namebuf[link_len], len + 1);
    469 			bcopy(linkbuf, namebuf, link_len);
    470 
    471 			/*
    472 			 * If absolute pathname, restart at root.
    473 			 * If relative pathname, restart at parent directory.
    474 			 */
    475 			cp = namebuf;
    476 			if (*cp == '/') {
    477 				if (currfd != &nfs_root_node)
    478 					free(currfd, sizeof(*currfd));
    479 				currfd = &nfs_root_node;
    480 			}
    481 
    482 			free(newfd, sizeof(*newfd));
    483 			newfd = 0;
    484 
    485 			continue;
    486 		}
    487 
    488 		if (currfd != &nfs_root_node)
    489 			free(currfd, sizeof(*currfd));
    490 		currfd = newfd;
    491 		newfd = 0;
    492 	}
    493 
    494 	error = 0;
    495 
    496 out:
    497 	if (!error) {
    498 		f->f_fsdata = (void *)currfd;
    499 		return (0);
    500 	}
    501 
    502 #ifdef NFS_DEBUG
    503 	if (debug)
    504 		kprintf("nfs_open: %s lookupfh failed: %s\n",
    505 		    path, strerror(error));
    506 #endif
    507 	if (currfd != &nfs_root_node)
    508 		free(currfd, sizeof(*currfd));
    509 	if (newfd)
    510 		free(newfd, sizeof(*newfd));
    511 
    512 	return (error);
    513 }
    514 
    515 int
    516 nfs_close(f)
    517 	struct open_file *f;
    518 {
    519 	register struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
    520 
    521 #ifdef NFS_DEBUG
    522 	if (debug)
    523 		kprintf("nfs_close: fp=0x%x\n", fp);
    524 #endif
    525 
    526 	if (fp)
    527 		free(fp, sizeof(struct nfs_iodesc));
    528 	f->f_fsdata = (void *)0;
    529 
    530 	return (0);
    531 }
    532 
    533 /*
    534  * read a portion of a file
    535  */
    536 int
    537 nfs_read(f, buf, size, resid)
    538 	struct open_file *f;
    539 	void *buf;
    540 	size_t size;
    541 	size_t *resid;	/* out */
    542 {
    543 	register struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
    544 	register ssize_t cc;
    545 	register char *addr = buf;
    546 
    547 #ifdef NFS_DEBUG
    548 	if (debug)
    549 		kprintf("nfs_read: size=%d off=%d\n", size, (int)fp->off);
    550 #endif
    551 	while ((int)size > 0) {
    552 		twiddle();
    553 		cc = nfs_readdata(fp, fp->off, (void *)addr, size);
    554 		/* XXX maybe should retry on certain errors */
    555 		if (cc == -1) {
    556 #ifdef NFS_DEBUG
    557 			if (debug)
    558 				kprintf("nfs_read: read: %s", strerror(errno));
    559 #endif
    560 			return (errno);	/* XXX - from nfs_readdata */
    561 		}
    562 		if (cc == 0) {
    563 			if (debug)
    564 				kprintf("nfs_read: hit EOF unexpectantly");
    565 			goto ret;
    566 		}
    567 		fp->off += cc;
    568 		addr += cc;
    569 		size -= cc;
    570 	}
    571 ret:
    572 	if (resid)
    573 		*resid = size;
    574 
    575 	return (0);
    576 }
    577 
    578 /*
    579  * Not implemented.
    580  */
    581 int
    582 nfs_write(f, buf, size, resid)
    583 	struct open_file *f;
    584 	void *buf;
    585 	size_t size;
    586 	size_t *resid;	/* out */
    587 {
    588 	return (EROFS);
    589 }
    590 
    591 off_t
    592 nfs_seek(f, offset, where)
    593 	struct open_file *f;
    594 	off_t offset;
    595 	int where;
    596 {
    597 	register struct nfs_iodesc *d = (struct nfs_iodesc *)f->f_fsdata;
    598 	n_long size = ntohl(d->fa.fa_size);
    599 
    600 	switch (where) {
    601 	case SEEK_SET:
    602 		d->off = offset;
    603 		break;
    604 	case SEEK_CUR:
    605 		d->off += offset;
    606 		break;
    607 	case SEEK_END:
    608 		d->off = size - offset;
    609 		break;
    610 	default:
    611 		return (-1);
    612 	}
    613 
    614 	return (d->off);
    615 }
    616 
    617 /* NFNON=0, NFREG=1, NFDIR=2, NFBLK=3, NFCHR=4, NFLNK=5 */
    618 int nfs_stat_types[8] = {
    619 	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 0 };
    620 
    621 int
    622 nfs_stat(f, sb)
    623 	struct open_file *f;
    624 	struct stat *sb;
    625 {
    626 	struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
    627 	register n_long ftype, mode;
    628 
    629 	ftype = ntohl(fp->fa.fa_type);
    630 	mode  = ntohl(fp->fa.fa_mode);
    631 	mode |= nfs_stat_types[ftype & 7];
    632 
    633 	sb->st_mode  = mode;
    634 	sb->st_nlink = ntohl(fp->fa.fa_nlink);
    635 	sb->st_uid   = ntohl(fp->fa.fa_uid);
    636 	sb->st_gid   = ntohl(fp->fa.fa_gid);
    637 	sb->st_size  = ntohl(fp->fa.fa_size);
    638 
    639 	return (0);
    640 }
    641