nfs.c revision 1.46 
1/*	$NetBSD: nfs.c,v 1.46 2011/06/16 13:27:58 joerg 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/*
32 * XXX Does not currently implement:
33 * XXX
34 * XXX LIBSA_NO_FS_CLOSE
35 * XXX LIBSA_NO_FS_SEEK
36 * XXX LIBSA_NO_FS_WRITE
37 * XXX LIBSA_NO_FS_SYMLINK (does this even make sense?)
38 * XXX LIBSA_FS_SINGLECOMPONENT (does this even make sense?)
39 */
40
41#include <sys/param.h>
42#include <sys/time.h>
43#include <sys/socket.h>
44#include <sys/stat.h>
45#ifdef _STANDALONE
46#include <lib/libkern/libkern.h>
47#else
48#include <string.h>
49#endif
50
51#include <netinet/in.h>
52#include <netinet/in_systm.h>
53
54#include "rpcv2.h"
55#include "nfsv2.h"
56
57#include "stand.h"
58#include "net.h"
59#include "nfs.h"
60#include "rpc.h"
61
62/* Define our own NFS attributes */
63struct nfsv2_fattrs {
64	n_long	fa_type;
65	n_long	fa_mode;
66	n_long	fa_nlink;
67	n_long	fa_uid;
68	n_long	fa_gid;
69	n_long	fa_size;
70	n_long	fa_blocksize;
71	n_long	fa_rdev;
72	n_long	fa_blocks;
73	n_long	fa_fsid;
74	n_long	fa_fileid;
75	struct nfsv2_time fa_atime;
76	struct nfsv2_time fa_mtime;
77	struct nfsv2_time fa_ctime;
78};
79
80
81struct nfs_read_args {
82	u_char	fh[NFS_FHSIZE];
83	n_long	off;
84	n_long	len;
85	n_long	xxx;			/* XXX what's this for? */
86};
87
88/* Data part of nfs rpc reply (also the largest thing we receive) */
89#define NFSREAD_SIZE 1024
90struct nfs_read_repl {
91	n_long	errno;
92	struct	nfsv2_fattrs fa;
93	n_long	count;
94	u_char	data[NFSREAD_SIZE];
95};
96
97#ifndef NFS_NOSYMLINK
98struct nfs_readlnk_repl {
99	n_long	errno;
100	n_long	len;
101	char	path[NFS_MAXPATHLEN];
102};
103#endif
104
105struct nfs_iodesc {
106	struct	iodesc	*iodesc;
107	off_t	off;
108	u_char	fh[NFS_FHSIZE];
109	struct nfsv2_fattrs fa;	/* all in network order */
110};
111
112struct nfs_iodesc nfs_root_node;
113
114int	nfs_getrootfh(struct iodesc *, char *, u_char *);
115int	nfs_lookupfh(struct nfs_iodesc *, const char *, int,
116	    struct nfs_iodesc *);
117int	nfs_readlink(struct nfs_iodesc *, char *);
118ssize_t	nfs_readdata(struct nfs_iodesc *, off_t, void *, size_t);
119
120/*
121 * Fetch the root file handle (call mount daemon)
122 * On error, return non-zero and set errno.
123 */
124int
125nfs_getrootfh(struct iodesc *d, char *path, u_char *fhp)
126{
127	int len;
128	struct args {
129		n_long	len;
130		char	path[FNAME_SIZE];
131	} *args;
132	struct repl {
133		n_long	errno;
134		u_char	fh[NFS_FHSIZE];
135	} *repl;
136	struct {
137		n_long	h[RPC_HEADER_WORDS];
138		struct args d;
139	} sdata;
140	struct {
141		n_long	h[RPC_HEADER_WORDS];
142		struct repl d;
143	} rdata;
144	ssize_t cc;
145
146#ifdef NFS_DEBUG
147	if (debug)
148		printf("nfs_getrootfh: %s\n", path);
149#endif
150
151	args = &sdata.d;
152	repl = &rdata.d;
153
154	(void)memset(args, 0, sizeof(*args));
155	len = strlen(path);
156	if ((size_t)len > sizeof(args->path))
157		len = sizeof(args->path);
158	args->len = htonl(len);
159	(void)memcpy(args->path, path, len);
160	len = 4 + roundup(len, 4);
161
162	cc = rpc_call(d, RPCPROG_MNT, RPCMNT_VER1, RPCMNT_MOUNT,
163	    args, len, repl, sizeof(*repl));
164	if (cc == -1) {
165		/* errno was set by rpc_call */
166		return -1;
167	}
168	if (cc < 4) {
169		errno = EBADRPC;
170		return -1;
171	}
172	if (repl->errno) {
173		errno = ntohl(repl->errno);
174		return -1;
175	}
176	(void)memcpy(fhp, repl->fh, sizeof(repl->fh));
177	return 0;
178}
179
180/*
181 * Lookup a file.  Store handle and attributes.
182 * Return zero or error number.
183 */
184int
185nfs_lookupfh(struct nfs_iodesc *d, const char *name, int len,
186	struct nfs_iodesc *newfd)
187{
188	int rlen;
189	struct args {
190		u_char	fh[NFS_FHSIZE];
191		n_long	len;
192		char	name[FNAME_SIZE];
193	} *args;
194	struct repl {
195		n_long	errno;
196		u_char	fh[NFS_FHSIZE];
197		struct	nfsv2_fattrs fa;
198	} *repl;
199	struct {
200		n_long	h[RPC_HEADER_WORDS];
201		struct args d;
202	} sdata;
203	struct {
204		n_long	h[RPC_HEADER_WORDS];
205		struct repl d;
206	} rdata;
207	ssize_t cc;
208
209#ifdef NFS_DEBUG
210	if (debug)
211		printf("lookupfh: called\n");
212#endif
213
214	args = &sdata.d;
215	repl = &rdata.d;
216
217	(void)memset(args, 0, sizeof(*args));
218	(void)memcpy(args->fh, d->fh, sizeof(args->fh));
219	if ((size_t)len > sizeof(args->name))
220		len = sizeof(args->name);
221	(void)memcpy(args->name, name, len);
222	args->len = htonl(len);
223	len = 4 + roundup(len, 4);
224	len += NFS_FHSIZE;
225
226	rlen = sizeof(*repl);
227
228	cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_LOOKUP,
229	    args, len, repl, rlen);
230	if (cc == -1)
231		return errno;		/* XXX - from rpc_call */
232	if (cc < 4)
233		return EIO;
234	if (repl->errno) {
235		/* saerrno.h now matches NFS error numbers. */
236		return ntohl(repl->errno);
237	}
238	(void)memcpy(&newfd->fh, repl->fh, sizeof(newfd->fh));
239	(void)memcpy(&newfd->fa, &repl->fa, sizeof(newfd->fa));
240	return 0;
241}
242
243#ifndef NFS_NOSYMLINK
244/*
245 * Get the destination of a symbolic link.
246 */
247int
248nfs_readlink(struct nfs_iodesc *d, char *buf)
249{
250	struct {
251		n_long	h[RPC_HEADER_WORDS];
252		u_char fh[NFS_FHSIZE];
253	} sdata;
254	struct {
255		n_long	h[RPC_HEADER_WORDS];
256		struct nfs_readlnk_repl d;
257	} rdata;
258	ssize_t cc;
259
260#ifdef NFS_DEBUG
261	if (debug)
262		printf("readlink: called\n");
263#endif
264
265	(void)memcpy(sdata.fh, d->fh, NFS_FHSIZE);
266	cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_READLINK,
267	              sdata.fh, NFS_FHSIZE,
268	              &rdata.d, sizeof(rdata.d));
269	if (cc == -1)
270		return errno;
271
272	if (cc < 4)
273		return EIO;
274
275	if (rdata.d.errno)
276		return ntohl(rdata.d.errno);
277
278	rdata.d.len = ntohl(rdata.d.len);
279	if (rdata.d.len > NFS_MAXPATHLEN)
280		return ENAMETOOLONG;
281
282	(void)memcpy(buf, rdata.d.path, rdata.d.len);
283	buf[rdata.d.len] = 0;
284	return 0;
285}
286#endif
287
288/*
289 * Read data from a file.
290 * Return transfer count or -1 (and set errno)
291 */
292ssize_t
293nfs_readdata(struct nfs_iodesc *d, off_t off, void *addr, size_t len)
294{
295	struct nfs_read_args *args;
296	struct nfs_read_repl *repl;
297	struct {
298		n_long	h[RPC_HEADER_WORDS];
299		struct nfs_read_args d;
300	} sdata;
301	struct {
302		n_long	h[RPC_HEADER_WORDS];
303		struct nfs_read_repl d;
304	} rdata;
305	ssize_t cc;
306	long x;
307	size_t hlen, rlen;
308
309	args = &sdata.d;
310	repl = &rdata.d;
311
312	(void)memcpy(args->fh, d->fh, NFS_FHSIZE);
313	args->off = htonl((n_long)off);
314	if (len > NFSREAD_SIZE)
315		len = NFSREAD_SIZE;
316	args->len = htonl((n_long)len);
317	args->xxx = htonl((n_long)0);
318	hlen = sizeof(*repl) - NFSREAD_SIZE;
319
320	cc = rpc_call(d->iodesc, NFS_PROG, NFS_VER2, NFSPROC_READ,
321	    args, sizeof(*args),
322	    repl, sizeof(*repl));
323	if (cc == -1) {
324		/* errno was already set by rpc_call */
325		return -1;
326	}
327	if (cc < (ssize_t)hlen) {
328		errno = EBADRPC;
329		return -1;
330	}
331	if (repl->errno) {
332		errno = ntohl(repl->errno);
333		return -1;
334	}
335	rlen = cc - hlen;
336	x = ntohl(repl->count);
337	if (rlen < (size_t)x) {
338		printf("nfsread: short packet, %lu < %ld\n", (u_long) rlen, x);
339		errno = EBADRPC;
340		return -1;
341	}
342	(void)memcpy(addr, repl->data, x);
343	return x;
344}
345
346/*
347 * nfs_mount - mount this nfs filesystem to a host
348 * On error, return non-zero and set errno.
349 */
350int
351nfs_mount(int sock, struct in_addr ip, char *path)
352{
353	struct iodesc *desc;
354	struct nfsv2_fattrs *fa;
355
356	if (!(desc = socktodesc(sock))) {
357		errno = EINVAL;
358		return -1;
359	}
360
361	/* Bind to a reserved port. */
362	desc->myport = htons(--rpc_port);
363	desc->destip = ip;
364	if (nfs_getrootfh(desc, path, nfs_root_node.fh))
365		return -1;
366	nfs_root_node.iodesc = desc;
367	/* Fake up attributes for the root dir. */
368	fa = &nfs_root_node.fa;
369	fa->fa_type  = htonl(NFDIR);
370	fa->fa_mode  = htonl(0755);
371	fa->fa_nlink = htonl(2);
372
373#ifdef NFS_DEBUG
374	if (debug)
375		printf("nfs_mount: got fh for %s\n", path);
376#endif
377
378	return 0;
379}
380
381/*
382 * Open a file.
383 * return zero or error number
384 */
385__compactcall int
386nfs_open(const char *path, struct open_file *f)
387{
388	struct nfs_iodesc *newfd, *currfd;
389	const char *cp;
390#ifndef NFS_NOSYMLINK
391	const char *ncp;
392	int c;
393	char namebuf[NFS_MAXPATHLEN + 1];
394	char linkbuf[NFS_MAXPATHLEN + 1];
395	int nlinks = 0;
396#endif
397	int error = 0;
398
399#ifdef NFS_DEBUG
400 	if (debug)
401		printf("nfs_open: %s\n", path);
402#endif
403	if (nfs_root_node.iodesc == NULL) {
404		printf("nfs_open: must mount first.\n");
405		return ENXIO;
406	}
407
408	currfd = &nfs_root_node;
409	newfd = 0;
410
411#ifndef NFS_NOSYMLINK
412	cp = path;
413	while (*cp) {
414		/*
415		 * Remove extra separators
416		 */
417		while (*cp == '/')
418			cp++;
419
420		if (*cp == '\0')
421			break;
422		/*
423		 * Check that current node is a directory.
424		 */
425		if (currfd->fa.fa_type != htonl(NFDIR)) {
426			error = ENOTDIR;
427			goto out;
428		}
429
430		/* allocate file system specific data structure */
431		newfd = alloc(sizeof(*newfd));
432		newfd->iodesc = currfd->iodesc;
433		newfd->off = 0;
434
435		/*
436		 * Get next component of path name.
437		 */
438		{
439			int len = 0;
440
441			ncp = cp;
442			while ((c = *cp) != '\0' && c != '/') {
443				if (++len > NFS_MAXNAMLEN) {
444					error = ENOENT;
445					goto out;
446				}
447				cp++;
448			}
449		}
450
451		/* lookup a file handle */
452		error = nfs_lookupfh(currfd, ncp, cp - ncp, newfd);
453		if (error)
454			goto out;
455
456		/*
457		 * Check for symbolic link
458		 */
459		if (newfd->fa.fa_type == htonl(NFLNK)) {
460			int link_len, len;
461
462			error = nfs_readlink(newfd, linkbuf);
463			if (error)
464				goto out;
465
466			link_len = strlen(linkbuf);
467			len = strlen(cp);
468
469			if (link_len + len > MAXPATHLEN
470			    || ++nlinks > MAXSYMLINKS) {
471				error = ENOENT;
472				goto out;
473			}
474
475			(void)memcpy(&namebuf[link_len], cp, len + 1);
476			(void)memcpy(namebuf, linkbuf, link_len);
477
478			/*
479			 * If absolute pathname, restart at root.
480			 * If relative pathname, restart at parent directory.
481			 */
482			cp = namebuf;
483			if (*cp == '/') {
484				if (currfd != &nfs_root_node)
485					dealloc(currfd, sizeof(*currfd));
486				currfd = &nfs_root_node;
487			}
488
489			dealloc(newfd, sizeof(*newfd));
490			newfd = 0;
491
492			continue;
493		}
494
495		if (currfd != &nfs_root_node)
496			dealloc(currfd, sizeof(*currfd));
497		currfd = newfd;
498		newfd = 0;
499	}
500
501	error = 0;
502
503out:
504#else
505	/* allocate file system specific data structure */
506	currfd = alloc(sizeof(*currfd));
507	currfd->iodesc = nfs_root_node.iodesc;
508	currfd->off = 0;
509
510	cp = path;
511	/*
512	 * Remove extra separators
513	 */
514	while (*cp == '/')
515		cp++;
516
517	/* XXX: Check for empty path here? */
518
519	error = nfs_lookupfh(&nfs_root_node, cp, strlen(cp), currfd);
520#endif
521	if (!error) {
522		f->f_fsdata = (void *)currfd;
523		fsmod = "nfs";
524		return 0;
525	}
526
527#ifdef NFS_DEBUG
528	if (debug)
529		printf("nfs_open: %s lookupfh failed: %s\n",
530		    path, strerror(error));
531#endif
532	if (currfd != &nfs_root_node)
533		dealloc(currfd, sizeof(*currfd));
534	if (newfd)
535		dealloc(newfd, sizeof(*newfd));
536
537	return error;
538}
539
540__compactcall int
541nfs_close(struct open_file *f)
542{
543	struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
544
545#ifdef NFS_DEBUG
546	if (debug)
547		printf("nfs_close: fp=0x%lx\n", (u_long)fp);
548#endif
549
550	if (fp)
551		dealloc(fp, sizeof(struct nfs_iodesc));
552	f->f_fsdata = (void *)0;
553
554	return 0;
555}
556
557/*
558 * read a portion of a file
559 */
560__compactcall int
561nfs_read(struct open_file *f, void *buf, size_t size, size_t *resid)
562{
563	struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
564	ssize_t cc;
565	char *addr = buf;
566
567#ifdef NFS_DEBUG
568	if (debug)
569		printf("nfs_read: size=%lu off=%d\n", (u_long)size,
570		    (int)fp->off);
571#endif
572	while ((int)size > 0) {
573#if !defined(LIBSA_NO_TWIDDLE)
574		twiddle();
575#endif
576		cc = nfs_readdata(fp, fp->off, (void *)addr, size);
577		/* XXX maybe should retry on certain errors */
578		if (cc == -1) {
579#ifdef NFS_DEBUG
580			if (debug)
581				printf("nfs_read: read: %s\n",
582				       strerror(errno));
583#endif
584			return errno;	/* XXX - from nfs_readdata */
585		}
586		if (cc == 0) {
587#ifdef NFS_DEBUG
588			if (debug)
589				printf("nfs_read: hit EOF unexpectantly\n");
590#endif
591			goto ret;
592		}
593		fp->off += cc;
594		addr += cc;
595		size -= cc;
596	}
597ret:
598	if (resid)
599		*resid = size;
600
601	return 0;
602}
603
604/*
605 * Not implemented.
606 */
607__compactcall int
608nfs_write(struct open_file *f, void *buf, size_t size, size_t *resid)
609{
610	return EROFS;
611}
612
613__compactcall off_t
614nfs_seek(struct open_file *f, off_t offset, int where)
615{
616	struct nfs_iodesc *d = (struct nfs_iodesc *)f->f_fsdata;
617	n_long size = ntohl(d->fa.fa_size);
618
619	switch (where) {
620	case SEEK_SET:
621		d->off = offset;
622		break;
623	case SEEK_CUR:
624		d->off += offset;
625		break;
626	case SEEK_END:
627		d->off = size - offset;
628		break;
629	default:
630		return -1;
631	}
632
633	return d->off;
634}
635
636/* NFNON=0, NFREG=1, NFDIR=2, NFBLK=3, NFCHR=4, NFLNK=5 */
637const int nfs_stat_types[8] = {
638	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, 0 };
639
640__compactcall int
641nfs_stat(struct open_file *f, struct stat *sb)
642{
643	struct nfs_iodesc *fp = (struct nfs_iodesc *)f->f_fsdata;
644	n_long ftype, mode;
645
646	ftype = ntohl(fp->fa.fa_type);
647	mode  = ntohl(fp->fa.fa_mode);
648	mode |= nfs_stat_types[ftype & 7];
649
650	sb->st_mode  = mode;
651	sb->st_nlink = ntohl(fp->fa.fa_nlink);
652	sb->st_uid   = ntohl(fp->fa.fa_uid);
653	sb->st_gid   = ntohl(fp->fa.fa_gid);
654	sb->st_size  = ntohl(fp->fa.fa_size);
655
656	return 0;
657}
658