xref: /linux/fs/nfsd/nfsxdr.c (revision 0dd9ac63ce26ec87b080ca9c3e6efed33c23ace6) 
1 /*
2  * XDR support for nfsd
3  *
4  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
5  */
6 
7 #include "xdr.h"
8 #include "auth.h"
9 
10 #define NFSDDBG_FACILITY		NFSDDBG_XDR
11 
12 /*
13  * Mapping of S_IF* types to NFS file types
14  */
15 static u32	nfs_ftypes[] = {
16 	NFNON,  NFCHR,  NFCHR, NFBAD,
17 	NFDIR,  NFBAD,  NFBLK, NFBAD,
18 	NFREG,  NFBAD,  NFLNK, NFBAD,
19 	NFSOCK, NFBAD,  NFLNK, NFBAD,
20 };
21 
22 
23 /*
24  * XDR functions for basic NFS types
25  */
26 static __be32 *
27 decode_fh(__be32 *p, struct svc_fh *fhp)
28 {
29 	fh_init(fhp, NFS_FHSIZE);
30 	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
31 	fhp->fh_handle.fh_size = NFS_FHSIZE;
32 
33 	/* FIXME: Look up export pointer here and verify
34 	 * Sun Secure RPC if requested */
35 	return p + (NFS_FHSIZE >> 2);
36 }
37 
38 /* Helper function for NFSv2 ACL code */
39 __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
40 {
41 	return decode_fh(p, fhp);
42 }
43 
44 static __be32 *
45 encode_fh(__be32 *p, struct svc_fh *fhp)
46 {
47 	memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
48 	return p + (NFS_FHSIZE>> 2);
49 }
50 
51 /*
52  * Decode a file name and make sure that the path contains
53  * no slashes or null bytes.
54  */
55 static __be32 *
56 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
57 {
58 	char		*name;
59 	unsigned int	i;
60 
61 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
62 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
63 			if (*name == '\0' || *name == '/')
64 				return NULL;
65 		}
66 	}
67 
68 	return p;
69 }
70 
71 static __be32 *
72 decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
73 {
74 	char		*name;
75 	unsigned int	i;
76 
77 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
78 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
79 			if (*name == '\0')
80 				return NULL;
81 		}
82 	}
83 
84 	return p;
85 }
86 
87 static __be32 *
88 decode_sattr(__be32 *p, struct iattr *iap)
89 {
90 	u32	tmp, tmp1;
91 
92 	iap->ia_valid = 0;
93 
94 	/* Sun client bug compatibility check: some sun clients seem to
95 	 * put 0xffff in the mode field when they mean 0xffffffff.
96 	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
97 	 */
98 	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
99 		iap->ia_valid |= ATTR_MODE;
100 		iap->ia_mode = tmp;
101 	}
102 	if ((tmp = ntohl(*p++)) != (u32)-1) {
103 		iap->ia_valid |= ATTR_UID;
104 		iap->ia_uid = tmp;
105 	}
106 	if ((tmp = ntohl(*p++)) != (u32)-1) {
107 		iap->ia_valid |= ATTR_GID;
108 		iap->ia_gid = tmp;
109 	}
110 	if ((tmp = ntohl(*p++)) != (u32)-1) {
111 		iap->ia_valid |= ATTR_SIZE;
112 		iap->ia_size = tmp;
113 	}
114 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
115 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
116 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
117 		iap->ia_atime.tv_sec = tmp;
118 		iap->ia_atime.tv_nsec = tmp1 * 1000;
119 	}
120 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
121 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
122 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
123 		iap->ia_mtime.tv_sec = tmp;
124 		iap->ia_mtime.tv_nsec = tmp1 * 1000;
125 		/*
126 		 * Passing the invalid value useconds=1000000 for mtime
127 		 * is a Sun convention for "set both mtime and atime to
128 		 * current server time".  It's needed to make permissions
129 		 * checks for the "touch" program across v2 mounts to
130 		 * Solaris and Irix boxes work correctly. See description of
131 		 * sattr in section 6.1 of "NFS Illustrated" by
132 		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
133 		 */
134 		if (tmp1 == 1000000)
135 			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
136 	}
137 	return p;
138 }
139 
140 static __be32 *
141 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
142 	     struct kstat *stat)
143 {
144 	struct dentry	*dentry = fhp->fh_dentry;
145 	int type;
146 	struct timespec time;
147 	u32 f;
148 
149 	type = (stat->mode & S_IFMT);
150 
151 	*p++ = htonl(nfs_ftypes[type >> 12]);
152 	*p++ = htonl((u32) stat->mode);
153 	*p++ = htonl((u32) stat->nlink);
154 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
155 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
156 
157 	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
158 		*p++ = htonl(NFS_MAXPATHLEN);
159 	} else {
160 		*p++ = htonl((u32) stat->size);
161 	}
162 	*p++ = htonl((u32) stat->blksize);
163 	if (S_ISCHR(type) || S_ISBLK(type))
164 		*p++ = htonl(new_encode_dev(stat->rdev));
165 	else
166 		*p++ = htonl(0xffffffff);
167 	*p++ = htonl((u32) stat->blocks);
168 	switch (fsid_source(fhp)) {
169 	default:
170 	case FSIDSOURCE_DEV:
171 		*p++ = htonl(new_encode_dev(stat->dev));
172 		break;
173 	case FSIDSOURCE_FSID:
174 		*p++ = htonl((u32) fhp->fh_export->ex_fsid);
175 		break;
176 	case FSIDSOURCE_UUID:
177 		f = ((u32*)fhp->fh_export->ex_uuid)[0];
178 		f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
179 		f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
180 		f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
181 		*p++ = htonl(f);
182 		break;
183 	}
184 	*p++ = htonl((u32) stat->ino);
185 	*p++ = htonl((u32) stat->atime.tv_sec);
186 	*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
187 	lease_get_mtime(dentry->d_inode, &time);
188 	*p++ = htonl((u32) time.tv_sec);
189 	*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
190 	*p++ = htonl((u32) stat->ctime.tv_sec);
191 	*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
192 
193 	return p;
194 }
195 
196 /* Helper function for NFSv2 ACL code */
197 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
198 {
199 	struct kstat stat;
200 	vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &stat);
201 	return encode_fattr(rqstp, p, fhp, &stat);
202 }
203 
204 /*
205  * XDR decode functions
206  */
207 int
208 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
209 {
210 	return xdr_argsize_check(rqstp, p);
211 }
212 
213 int
214 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
215 {
216 	if (!(p = decode_fh(p, &args->fh)))
217 		return 0;
218 	return xdr_argsize_check(rqstp, p);
219 }
220 
221 int
222 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
223 					struct nfsd_sattrargs *args)
224 {
225 	p = decode_fh(p, &args->fh);
226 	if (!p)
227 		return 0;
228 	p = decode_sattr(p, &args->attrs);
229 
230 	return xdr_argsize_check(rqstp, p);
231 }
232 
233 int
234 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
235 					struct nfsd_diropargs *args)
236 {
237 	if (!(p = decode_fh(p, &args->fh))
238 	 || !(p = decode_filename(p, &args->name, &args->len)))
239 		return 0;
240 
241 	 return xdr_argsize_check(rqstp, p);
242 }
243 
244 int
245 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
246 					struct nfsd_readargs *args)
247 {
248 	unsigned int len;
249 	int v,pn;
250 	if (!(p = decode_fh(p, &args->fh)))
251 		return 0;
252 
253 	args->offset    = ntohl(*p++);
254 	len = args->count     = ntohl(*p++);
255 	p++; /* totalcount - unused */
256 
257 	if (len > NFSSVC_MAXBLKSIZE_V2)
258 		len = NFSSVC_MAXBLKSIZE_V2;
259 
260 	/* set up somewhere to store response.
261 	 * We take pages, put them on reslist and include in iovec
262 	 */
263 	v=0;
264 	while (len > 0) {
265 		pn = rqstp->rq_resused++;
266 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
267 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
268 		len -= rqstp->rq_vec[v].iov_len;
269 		v++;
270 	}
271 	args->vlen = v;
272 	return xdr_argsize_check(rqstp, p);
273 }
274 
275 int
276 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
277 					struct nfsd_writeargs *args)
278 {
279 	unsigned int len, hdr, dlen;
280 	int v;
281 
282 	if (!(p = decode_fh(p, &args->fh)))
283 		return 0;
284 
285 	p++;				/* beginoffset */
286 	args->offset = ntohl(*p++);	/* offset */
287 	p++;				/* totalcount */
288 	len = args->len = ntohl(*p++);
289 	/*
290 	 * The protocol specifies a maximum of 8192 bytes.
291 	 */
292 	if (len > NFSSVC_MAXBLKSIZE_V2)
293 		return 0;
294 
295 	/*
296 	 * Check to make sure that we got the right number of
297 	 * bytes.
298 	 */
299 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
300 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
301 		- hdr;
302 
303 	/*
304 	 * Round the length of the data which was specified up to
305 	 * the next multiple of XDR units and then compare that
306 	 * against the length which was actually received.
307 	 * Note that when RPCSEC/GSS (for example) is used, the
308 	 * data buffer can be padded so dlen might be larger
309 	 * than required.  It must never be smaller.
310 	 */
311 	if (dlen < XDR_QUADLEN(len)*4)
312 		return 0;
313 
314 	rqstp->rq_vec[0].iov_base = (void*)p;
315 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
316 	v = 0;
317 	while (len > rqstp->rq_vec[v].iov_len) {
318 		len -= rqstp->rq_vec[v].iov_len;
319 		v++;
320 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
321 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
322 	}
323 	rqstp->rq_vec[v].iov_len = len;
324 	args->vlen = v + 1;
325 	return 1;
326 }
327 
328 int
329 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
330 					struct nfsd_createargs *args)
331 {
332 	if (   !(p = decode_fh(p, &args->fh))
333 	    || !(p = decode_filename(p, &args->name, &args->len)))
334 		return 0;
335 	p = decode_sattr(p, &args->attrs);
336 
337 	return xdr_argsize_check(rqstp, p);
338 }
339 
340 int
341 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
342 					struct nfsd_renameargs *args)
343 {
344 	if (!(p = decode_fh(p, &args->ffh))
345 	 || !(p = decode_filename(p, &args->fname, &args->flen))
346 	 || !(p = decode_fh(p, &args->tfh))
347 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
348 		return 0;
349 
350 	return xdr_argsize_check(rqstp, p);
351 }
352 
353 int
354 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
355 {
356 	if (!(p = decode_fh(p, &args->fh)))
357 		return 0;
358 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
359 
360 	return xdr_argsize_check(rqstp, p);
361 }
362 
363 int
364 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
365 					struct nfsd_linkargs *args)
366 {
367 	if (!(p = decode_fh(p, &args->ffh))
368 	 || !(p = decode_fh(p, &args->tfh))
369 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
370 		return 0;
371 
372 	return xdr_argsize_check(rqstp, p);
373 }
374 
375 int
376 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
377 					struct nfsd_symlinkargs *args)
378 {
379 	if (   !(p = decode_fh(p, &args->ffh))
380 	    || !(p = decode_filename(p, &args->fname, &args->flen))
381 	    || !(p = decode_pathname(p, &args->tname, &args->tlen)))
382 		return 0;
383 	p = decode_sattr(p, &args->attrs);
384 
385 	return xdr_argsize_check(rqstp, p);
386 }
387 
388 int
389 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
390 					struct nfsd_readdirargs *args)
391 {
392 	if (!(p = decode_fh(p, &args->fh)))
393 		return 0;
394 	args->cookie = ntohl(*p++);
395 	args->count  = ntohl(*p++);
396 	if (args->count > PAGE_SIZE)
397 		args->count = PAGE_SIZE;
398 
399 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
400 
401 	return xdr_argsize_check(rqstp, p);
402 }
403 
404 /*
405  * XDR encode functions
406  */
407 int
408 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
409 {
410 	return xdr_ressize_check(rqstp, p);
411 }
412 
413 int
414 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
415 					struct nfsd_attrstat *resp)
416 {
417 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
418 	return xdr_ressize_check(rqstp, p);
419 }
420 
421 int
422 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
423 					struct nfsd_diropres *resp)
424 {
425 	p = encode_fh(p, &resp->fh);
426 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
427 	return xdr_ressize_check(rqstp, p);
428 }
429 
430 int
431 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
432 					struct nfsd_readlinkres *resp)
433 {
434 	*p++ = htonl(resp->len);
435 	xdr_ressize_check(rqstp, p);
436 	rqstp->rq_res.page_len = resp->len;
437 	if (resp->len & 3) {
438 		/* need to pad the tail */
439 		rqstp->rq_res.tail[0].iov_base = p;
440 		*p = 0;
441 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
442 	}
443 	return 1;
444 }
445 
446 int
447 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
448 					struct nfsd_readres *resp)
449 {
450 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
451 	*p++ = htonl(resp->count);
452 	xdr_ressize_check(rqstp, p);
453 
454 	/* now update rqstp->rq_res to reflect data aswell */
455 	rqstp->rq_res.page_len = resp->count;
456 	if (resp->count & 3) {
457 		/* need to pad the tail */
458 		rqstp->rq_res.tail[0].iov_base = p;
459 		*p = 0;
460 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
461 	}
462 	return 1;
463 }
464 
465 int
466 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
467 					struct nfsd_readdirres *resp)
468 {
469 	xdr_ressize_check(rqstp, p);
470 	p = resp->buffer;
471 	*p++ = 0;			/* no more entries */
472 	*p++ = htonl((resp->common.err == nfserr_eof));
473 	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
474 
475 	return 1;
476 }
477 
478 int
479 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
480 					struct nfsd_statfsres *resp)
481 {
482 	struct kstatfs	*stat = &resp->stats;
483 
484 	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
485 	*p++ = htonl(stat->f_bsize);
486 	*p++ = htonl(stat->f_blocks);
487 	*p++ = htonl(stat->f_bfree);
488 	*p++ = htonl(stat->f_bavail);
489 	return xdr_ressize_check(rqstp, p);
490 }
491 
492 int
493 nfssvc_encode_entry(void *ccdv, const char *name,
494 		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
495 {
496 	struct readdir_cd *ccd = ccdv;
497 	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
498 	__be32	*p = cd->buffer;
499 	int	buflen, slen;
500 
501 	/*
502 	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
503 			namlen, name, offset, ino);
504 	 */
505 
506 	if (offset > ~((u32) 0)) {
507 		cd->common.err = nfserr_fbig;
508 		return -EINVAL;
509 	}
510 	if (cd->offset)
511 		*cd->offset = htonl(offset);
512 	if (namlen > NFS2_MAXNAMLEN)
513 		namlen = NFS2_MAXNAMLEN;/* truncate filename */
514 
515 	slen = XDR_QUADLEN(namlen);
516 	if ((buflen = cd->buflen - slen - 4) < 0) {
517 		cd->common.err = nfserr_toosmall;
518 		return -EINVAL;
519 	}
520 	if (ino > ~((u32) 0)) {
521 		cd->common.err = nfserr_fbig;
522 		return -EINVAL;
523 	}
524 	*p++ = xdr_one;				/* mark entry present */
525 	*p++ = htonl((u32) ino);		/* file id */
526 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
527 	cd->offset = p;			/* remember pointer */
528 	*p++ = htonl(~0U);		/* offset of next entry */
529 
530 	cd->buflen = buflen;
531 	cd->buffer = p;
532 	cd->common.err = nfs_ok;
533 	return 0;
534 }
535 
536 /*
537  * XDR release functions
538  */
539 int
540 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
541 					struct nfsd_fhandle *resp)
542 {
543 	fh_put(&resp->fh);
544 	return 1;
545 }
546