xref: /linux/fs/nfsd/nfsxdr.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6) 
1 /*
2  * linux/fs/nfsd/nfsxdr.c
3  *
4  * XDR support for nfsd
5  *
6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/time.h>
11 #include <linux/nfs.h>
12 #include <linux/vfs.h>
13 #include <linux/sunrpc/xdr.h>
14 #include <linux/sunrpc/svc.h>
15 #include <linux/nfsd/nfsd.h>
16 #include <linux/nfsd/xdr.h>
17 #include <linux/mm.h>
18 
19 #define NFSDDBG_FACILITY		NFSDDBG_XDR
20 
21 /*
22  * Mapping of S_IF* types to NFS file types
23  */
24 static u32	nfs_ftypes[] = {
25 	NFNON,  NFCHR,  NFCHR, NFBAD,
26 	NFDIR,  NFBAD,  NFBLK, NFBAD,
27 	NFREG,  NFBAD,  NFLNK, NFBAD,
28 	NFSOCK, NFBAD,  NFLNK, NFBAD,
29 };
30 
31 
32 /*
33  * XDR functions for basic NFS types
34  */
35 static __be32 *
36 decode_fh(__be32 *p, struct svc_fh *fhp)
37 {
38 	fh_init(fhp, NFS_FHSIZE);
39 	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
40 	fhp->fh_handle.fh_size = NFS_FHSIZE;
41 
42 	/* FIXME: Look up export pointer here and verify
43 	 * Sun Secure RPC if requested */
44 	return p + (NFS_FHSIZE >> 2);
45 }
46 
47 /* Helper function for NFSv2 ACL code */
48 __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
49 {
50 	return decode_fh(p, fhp);
51 }
52 
53 static __be32 *
54 encode_fh(__be32 *p, struct svc_fh *fhp)
55 {
56 	memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
57 	return p + (NFS_FHSIZE>> 2);
58 }
59 
60 /*
61  * Decode a file name and make sure that the path contains
62  * no slashes or null bytes.
63  */
64 static __be32 *
65 decode_filename(__be32 *p, char **namp, int *lenp)
66 {
67 	char		*name;
68 	int		i;
69 
70 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
71 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
72 			if (*name == '\0' || *name == '/')
73 				return NULL;
74 		}
75 	}
76 
77 	return p;
78 }
79 
80 static __be32 *
81 decode_pathname(__be32 *p, char **namp, int *lenp)
82 {
83 	char		*name;
84 	int		i;
85 
86 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
87 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
88 			if (*name == '\0')
89 				return NULL;
90 		}
91 	}
92 
93 	return p;
94 }
95 
96 static __be32 *
97 decode_sattr(__be32 *p, struct iattr *iap)
98 {
99 	u32	tmp, tmp1;
100 
101 	iap->ia_valid = 0;
102 
103 	/* Sun client bug compatibility check: some sun clients seem to
104 	 * put 0xffff in the mode field when they mean 0xffffffff.
105 	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
106 	 */
107 	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
108 		iap->ia_valid |= ATTR_MODE;
109 		iap->ia_mode = tmp;
110 	}
111 	if ((tmp = ntohl(*p++)) != (u32)-1) {
112 		iap->ia_valid |= ATTR_UID;
113 		iap->ia_uid = tmp;
114 	}
115 	if ((tmp = ntohl(*p++)) != (u32)-1) {
116 		iap->ia_valid |= ATTR_GID;
117 		iap->ia_gid = tmp;
118 	}
119 	if ((tmp = ntohl(*p++)) != (u32)-1) {
120 		iap->ia_valid |= ATTR_SIZE;
121 		iap->ia_size = tmp;
122 	}
123 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
124 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
125 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
126 		iap->ia_atime.tv_sec = tmp;
127 		iap->ia_atime.tv_nsec = tmp1 * 1000;
128 	}
129 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
130 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
131 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
132 		iap->ia_mtime.tv_sec = tmp;
133 		iap->ia_mtime.tv_nsec = tmp1 * 1000;
134 		/*
135 		 * Passing the invalid value useconds=1000000 for mtime
136 		 * is a Sun convention for "set both mtime and atime to
137 		 * current server time".  It's needed to make permissions
138 		 * checks for the "touch" program across v2 mounts to
139 		 * Solaris and Irix boxes work correctly. See description of
140 		 * sattr in section 6.1 of "NFS Illustrated" by
141 		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
142 		 */
143 		if (tmp1 == 1000000)
144 			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
145 	}
146 	return p;
147 }
148 
149 static __be32 *
150 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
151 	     struct kstat *stat)
152 {
153 	struct dentry	*dentry = fhp->fh_dentry;
154 	int type;
155 	struct timespec time;
156 	u32 f;
157 
158 	type = (stat->mode & S_IFMT);
159 
160 	*p++ = htonl(nfs_ftypes[type >> 12]);
161 	*p++ = htonl((u32) stat->mode);
162 	*p++ = htonl((u32) stat->nlink);
163 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
164 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
165 
166 	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
167 		*p++ = htonl(NFS_MAXPATHLEN);
168 	} else {
169 		*p++ = htonl((u32) stat->size);
170 	}
171 	*p++ = htonl((u32) stat->blksize);
172 	if (S_ISCHR(type) || S_ISBLK(type))
173 		*p++ = htonl(new_encode_dev(stat->rdev));
174 	else
175 		*p++ = htonl(0xffffffff);
176 	*p++ = htonl((u32) stat->blocks);
177 	switch (fsid_source(fhp)) {
178 	default:
179 	case FSIDSOURCE_DEV:
180 		*p++ = htonl(new_encode_dev(stat->dev));
181 		break;
182 	case FSIDSOURCE_FSID:
183 		*p++ = htonl((u32) fhp->fh_export->ex_fsid);
184 		break;
185 	case FSIDSOURCE_UUID:
186 		f = ((u32*)fhp->fh_export->ex_uuid)[0];
187 		f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
188 		f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
189 		f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
190 		*p++ = htonl(f);
191 		break;
192 	}
193 	*p++ = htonl((u32) stat->ino);
194 	*p++ = htonl((u32) stat->atime.tv_sec);
195 	*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
196 	lease_get_mtime(dentry->d_inode, &time);
197 	*p++ = htonl((u32) time.tv_sec);
198 	*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
199 	*p++ = htonl((u32) stat->ctime.tv_sec);
200 	*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
201 
202 	return p;
203 }
204 
205 /* Helper function for NFSv2 ACL code */
206 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
207 {
208 	struct kstat stat;
209 	vfs_getattr(fhp->fh_export->ex_mnt, fhp->fh_dentry, &stat);
210 	return encode_fattr(rqstp, p, fhp, &stat);
211 }
212 
213 /*
214  * XDR decode functions
215  */
216 int
217 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
218 {
219 	return xdr_argsize_check(rqstp, p);
220 }
221 
222 int
223 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
224 {
225 	if (!(p = decode_fh(p, &args->fh)))
226 		return 0;
227 	return xdr_argsize_check(rqstp, p);
228 }
229 
230 int
231 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
232 					struct nfsd_sattrargs *args)
233 {
234 	if (!(p = decode_fh(p, &args->fh))
235 	 || !(p = decode_sattr(p, &args->attrs)))
236 		return 0;
237 
238 	return xdr_argsize_check(rqstp, p);
239 }
240 
241 int
242 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
243 					struct nfsd_diropargs *args)
244 {
245 	if (!(p = decode_fh(p, &args->fh))
246 	 || !(p = decode_filename(p, &args->name, &args->len)))
247 		return 0;
248 
249 	 return xdr_argsize_check(rqstp, p);
250 }
251 
252 int
253 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
254 					struct nfsd_readargs *args)
255 {
256 	unsigned int len;
257 	int v,pn;
258 	if (!(p = decode_fh(p, &args->fh)))
259 		return 0;
260 
261 	args->offset    = ntohl(*p++);
262 	len = args->count     = ntohl(*p++);
263 	p++; /* totalcount - unused */
264 
265 	if (len > NFSSVC_MAXBLKSIZE_V2)
266 		len = NFSSVC_MAXBLKSIZE_V2;
267 
268 	/* set up somewhere to store response.
269 	 * We take pages, put them on reslist and include in iovec
270 	 */
271 	v=0;
272 	while (len > 0) {
273 		pn = rqstp->rq_resused++;
274 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
275 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
276 		len -= rqstp->rq_vec[v].iov_len;
277 		v++;
278 	}
279 	args->vlen = v;
280 	return xdr_argsize_check(rqstp, p);
281 }
282 
283 int
284 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
285 					struct nfsd_writeargs *args)
286 {
287 	unsigned int len;
288 	int v;
289 	if (!(p = decode_fh(p, &args->fh)))
290 		return 0;
291 
292 	p++;				/* beginoffset */
293 	args->offset = ntohl(*p++);	/* offset */
294 	p++;				/* totalcount */
295 	len = args->len = ntohl(*p++);
296 	rqstp->rq_vec[0].iov_base = (void*)p;
297 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len -
298 				(((void*)p) - rqstp->rq_arg.head[0].iov_base);
299 	if (len > NFSSVC_MAXBLKSIZE_V2)
300 		len = NFSSVC_MAXBLKSIZE_V2;
301 	v = 0;
302 	while (len > rqstp->rq_vec[v].iov_len) {
303 		len -= rqstp->rq_vec[v].iov_len;
304 		v++;
305 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
306 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
307 	}
308 	rqstp->rq_vec[v].iov_len = len;
309 	args->vlen = v+1;
310 	return rqstp->rq_vec[0].iov_len > 0;
311 }
312 
313 int
314 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
315 					struct nfsd_createargs *args)
316 {
317 	if (!(p = decode_fh(p, &args->fh))
318 	 || !(p = decode_filename(p, &args->name, &args->len))
319 	 || !(p = decode_sattr(p, &args->attrs)))
320 		return 0;
321 
322 	return xdr_argsize_check(rqstp, p);
323 }
324 
325 int
326 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
327 					struct nfsd_renameargs *args)
328 {
329 	if (!(p = decode_fh(p, &args->ffh))
330 	 || !(p = decode_filename(p, &args->fname, &args->flen))
331 	 || !(p = decode_fh(p, &args->tfh))
332 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
333 		return 0;
334 
335 	return xdr_argsize_check(rqstp, p);
336 }
337 
338 int
339 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
340 {
341 	if (!(p = decode_fh(p, &args->fh)))
342 		return 0;
343 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
344 
345 	return xdr_argsize_check(rqstp, p);
346 }
347 
348 int
349 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
350 					struct nfsd_linkargs *args)
351 {
352 	if (!(p = decode_fh(p, &args->ffh))
353 	 || !(p = decode_fh(p, &args->tfh))
354 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
355 		return 0;
356 
357 	return xdr_argsize_check(rqstp, p);
358 }
359 
360 int
361 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
362 					struct nfsd_symlinkargs *args)
363 {
364 	if (!(p = decode_fh(p, &args->ffh))
365 	 || !(p = decode_filename(p, &args->fname, &args->flen))
366 	 || !(p = decode_pathname(p, &args->tname, &args->tlen))
367 	 || !(p = decode_sattr(p, &args->attrs)))
368 		return 0;
369 
370 	return xdr_argsize_check(rqstp, p);
371 }
372 
373 int
374 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
375 					struct nfsd_readdirargs *args)
376 {
377 	if (!(p = decode_fh(p, &args->fh)))
378 		return 0;
379 	args->cookie = ntohl(*p++);
380 	args->count  = ntohl(*p++);
381 	if (args->count > PAGE_SIZE)
382 		args->count = PAGE_SIZE;
383 
384 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
385 
386 	return xdr_argsize_check(rqstp, p);
387 }
388 
389 /*
390  * XDR encode functions
391  */
392 int
393 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
394 {
395 	return xdr_ressize_check(rqstp, p);
396 }
397 
398 int
399 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
400 					struct nfsd_attrstat *resp)
401 {
402 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
403 	return xdr_ressize_check(rqstp, p);
404 }
405 
406 int
407 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
408 					struct nfsd_diropres *resp)
409 {
410 	p = encode_fh(p, &resp->fh);
411 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
412 	return xdr_ressize_check(rqstp, p);
413 }
414 
415 int
416 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
417 					struct nfsd_readlinkres *resp)
418 {
419 	*p++ = htonl(resp->len);
420 	xdr_ressize_check(rqstp, p);
421 	rqstp->rq_res.page_len = resp->len;
422 	if (resp->len & 3) {
423 		/* need to pad the tail */
424 		rqstp->rq_res.tail[0].iov_base = p;
425 		*p = 0;
426 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
427 	}
428 	return 1;
429 }
430 
431 int
432 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
433 					struct nfsd_readres *resp)
434 {
435 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
436 	*p++ = htonl(resp->count);
437 	xdr_ressize_check(rqstp, p);
438 
439 	/* now update rqstp->rq_res to reflect data aswell */
440 	rqstp->rq_res.page_len = resp->count;
441 	if (resp->count & 3) {
442 		/* need to pad the tail */
443 		rqstp->rq_res.tail[0].iov_base = p;
444 		*p = 0;
445 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
446 	}
447 	return 1;
448 }
449 
450 int
451 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
452 					struct nfsd_readdirres *resp)
453 {
454 	xdr_ressize_check(rqstp, p);
455 	p = resp->buffer;
456 	*p++ = 0;			/* no more entries */
457 	*p++ = htonl((resp->common.err == nfserr_eof));
458 	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
459 
460 	return 1;
461 }
462 
463 int
464 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
465 					struct nfsd_statfsres *resp)
466 {
467 	struct kstatfs	*stat = &resp->stats;
468 
469 	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
470 	*p++ = htonl(stat->f_bsize);
471 	*p++ = htonl(stat->f_blocks);
472 	*p++ = htonl(stat->f_bfree);
473 	*p++ = htonl(stat->f_bavail);
474 	return xdr_ressize_check(rqstp, p);
475 }
476 
477 int
478 nfssvc_encode_entry(void *ccdv, const char *name,
479 		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
480 {
481 	struct readdir_cd *ccd = ccdv;
482 	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
483 	__be32	*p = cd->buffer;
484 	int	buflen, slen;
485 
486 	/*
487 	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
488 			namlen, name, offset, ino);
489 	 */
490 
491 	if (offset > ~((u32) 0)) {
492 		cd->common.err = nfserr_fbig;
493 		return -EINVAL;
494 	}
495 	if (cd->offset)
496 		*cd->offset = htonl(offset);
497 	if (namlen > NFS2_MAXNAMLEN)
498 		namlen = NFS2_MAXNAMLEN;/* truncate filename */
499 
500 	slen = XDR_QUADLEN(namlen);
501 	if ((buflen = cd->buflen - slen - 4) < 0) {
502 		cd->common.err = nfserr_toosmall;
503 		return -EINVAL;
504 	}
505 	*p++ = xdr_one;				/* mark entry present */
506 	*p++ = htonl((u32) ino);		/* file id */
507 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
508 	cd->offset = p;			/* remember pointer */
509 	*p++ = htonl(~0U);		/* offset of next entry */
510 
511 	cd->buflen = buflen;
512 	cd->buffer = p;
513 	cd->common.err = nfs_ok;
514 	return 0;
515 }
516 
517 /*
518  * XDR release functions
519  */
520 int
521 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
522 					struct nfsd_fhandle *resp)
523 {
524 	fh_put(&resp->fh);
525 	return 1;
526 }
527