xref: /linux/fs/nfsd/nfsxdr.c (revision d060296cc0300ae8ed08004ebd3994bf325fa257) 
1 /*
2  * XDR support for nfsd
3  *
4  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
5  */
6 
7 #include "vfs.h"
8 #include "xdr.h"
9 #include "auth.h"
10 
11 #define NFSDDBG_FACILITY		NFSDDBG_XDR
12 
13 /*
14  * Mapping of S_IF* types to NFS file types
15  */
16 static u32	nfs_ftypes[] = {
17 	NFNON,  NFCHR,  NFCHR, NFBAD,
18 	NFDIR,  NFBAD,  NFBLK, NFBAD,
19 	NFREG,  NFBAD,  NFLNK, NFBAD,
20 	NFSOCK, NFBAD,  NFLNK, NFBAD,
21 };
22 
23 
24 /*
25  * XDR functions for basic NFS types
26  */
27 static __be32 *
28 decode_fh(__be32 *p, struct svc_fh *fhp)
29 {
30 	fh_init(fhp, NFS_FHSIZE);
31 	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
32 	fhp->fh_handle.fh_size = NFS_FHSIZE;
33 
34 	/* FIXME: Look up export pointer here and verify
35 	 * Sun Secure RPC if requested */
36 	return p + (NFS_FHSIZE >> 2);
37 }
38 
39 /* Helper function for NFSv2 ACL code */
40 __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
41 {
42 	return decode_fh(p, fhp);
43 }
44 
45 static __be32 *
46 encode_fh(__be32 *p, struct svc_fh *fhp)
47 {
48 	memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
49 	return p + (NFS_FHSIZE>> 2);
50 }
51 
52 /*
53  * Decode a file name and make sure that the path contains
54  * no slashes or null bytes.
55  */
56 static __be32 *
57 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
58 {
59 	char		*name;
60 	unsigned int	i;
61 
62 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
63 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
64 			if (*name == '\0' || *name == '/')
65 				return NULL;
66 		}
67 	}
68 
69 	return p;
70 }
71 
72 static __be32 *
73 decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
74 {
75 	char		*name;
76 	unsigned int	i;
77 
78 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
79 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
80 			if (*name == '\0')
81 				return NULL;
82 		}
83 	}
84 
85 	return p;
86 }
87 
88 static __be32 *
89 decode_sattr(__be32 *p, struct iattr *iap)
90 {
91 	u32	tmp, tmp1;
92 
93 	iap->ia_valid = 0;
94 
95 	/* Sun client bug compatibility check: some sun clients seem to
96 	 * put 0xffff in the mode field when they mean 0xffffffff.
97 	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
98 	 */
99 	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
100 		iap->ia_valid |= ATTR_MODE;
101 		iap->ia_mode = tmp;
102 	}
103 	if ((tmp = ntohl(*p++)) != (u32)-1) {
104 		iap->ia_uid = make_kuid(&init_user_ns, tmp);
105 		if (uid_valid(iap->ia_uid))
106 			iap->ia_valid |= ATTR_UID;
107 	}
108 	if ((tmp = ntohl(*p++)) != (u32)-1) {
109 		iap->ia_gid = make_kgid(&init_user_ns, tmp);
110 		if (gid_valid(iap->ia_gid))
111 			iap->ia_valid |= ATTR_GID;
112 	}
113 	if ((tmp = ntohl(*p++)) != (u32)-1) {
114 		iap->ia_valid |= ATTR_SIZE;
115 		iap->ia_size = tmp;
116 	}
117 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
118 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
119 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
120 		iap->ia_atime.tv_sec = tmp;
121 		iap->ia_atime.tv_nsec = tmp1 * 1000;
122 	}
123 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
124 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
125 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
126 		iap->ia_mtime.tv_sec = tmp;
127 		iap->ia_mtime.tv_nsec = tmp1 * 1000;
128 		/*
129 		 * Passing the invalid value useconds=1000000 for mtime
130 		 * is a Sun convention for "set both mtime and atime to
131 		 * current server time".  It's needed to make permissions
132 		 * checks for the "touch" program across v2 mounts to
133 		 * Solaris and Irix boxes work correctly. See description of
134 		 * sattr in section 6.1 of "NFS Illustrated" by
135 		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
136 		 */
137 		if (tmp1 == 1000000)
138 			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
139 	}
140 	return p;
141 }
142 
143 static __be32 *
144 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
145 	     struct kstat *stat)
146 {
147 	struct dentry	*dentry = fhp->fh_dentry;
148 	int type;
149 	struct timespec time;
150 	u32 f;
151 
152 	type = (stat->mode & S_IFMT);
153 
154 	*p++ = htonl(nfs_ftypes[type >> 12]);
155 	*p++ = htonl((u32) stat->mode);
156 	*p++ = htonl((u32) stat->nlink);
157 	*p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
158 	*p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
159 
160 	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
161 		*p++ = htonl(NFS_MAXPATHLEN);
162 	} else {
163 		*p++ = htonl((u32) stat->size);
164 	}
165 	*p++ = htonl((u32) stat->blksize);
166 	if (S_ISCHR(type) || S_ISBLK(type))
167 		*p++ = htonl(new_encode_dev(stat->rdev));
168 	else
169 		*p++ = htonl(0xffffffff);
170 	*p++ = htonl((u32) stat->blocks);
171 	switch (fsid_source(fhp)) {
172 	default:
173 	case FSIDSOURCE_DEV:
174 		*p++ = htonl(new_encode_dev(stat->dev));
175 		break;
176 	case FSIDSOURCE_FSID:
177 		*p++ = htonl((u32) fhp->fh_export->ex_fsid);
178 		break;
179 	case FSIDSOURCE_UUID:
180 		f = ((u32*)fhp->fh_export->ex_uuid)[0];
181 		f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
182 		f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
183 		f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
184 		*p++ = htonl(f);
185 		break;
186 	}
187 	*p++ = htonl((u32) stat->ino);
188 	*p++ = htonl((u32) stat->atime.tv_sec);
189 	*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
190 	lease_get_mtime(d_inode(dentry), &time);
191 	*p++ = htonl((u32) time.tv_sec);
192 	*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
193 	*p++ = htonl((u32) stat->ctime.tv_sec);
194 	*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
195 
196 	return p;
197 }
198 
199 /* Helper function for NFSv2 ACL code */
200 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat)
201 {
202 	return encode_fattr(rqstp, p, fhp, stat);
203 }
204 
205 /*
206  * XDR decode functions
207  */
208 int
209 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p)
210 {
211 	return xdr_argsize_check(rqstp, p);
212 }
213 
214 int
215 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
216 {
217 	struct nfsd_fhandle *args = rqstp->rq_argp;
218 
219 	p = decode_fh(p, &args->fh);
220 	if (!p)
221 		return 0;
222 	return xdr_argsize_check(rqstp, p);
223 }
224 
225 int
226 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
227 {
228 	struct nfsd_sattrargs *args = rqstp->rq_argp;
229 
230 	p = decode_fh(p, &args->fh);
231 	if (!p)
232 		return 0;
233 	p = decode_sattr(p, &args->attrs);
234 
235 	return xdr_argsize_check(rqstp, p);
236 }
237 
238 int
239 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
240 {
241 	struct nfsd_diropargs *args = rqstp->rq_argp;
242 
243 	if (!(p = decode_fh(p, &args->fh))
244 	 || !(p = decode_filename(p, &args->name, &args->len)))
245 		return 0;
246 
247 	return xdr_argsize_check(rqstp, p);
248 }
249 
250 int
251 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
252 {
253 	struct nfsd_readargs *args = rqstp->rq_argp;
254 	unsigned int len;
255 	int v;
256 	p = decode_fh(p, &args->fh);
257 	if (!p)
258 		return 0;
259 
260 	args->offset    = ntohl(*p++);
261 	len = args->count     = ntohl(*p++);
262 	p++; /* totalcount - unused */
263 
264 	len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
265 
266 	/* set up somewhere to store response.
267 	 * We take pages, put them on reslist and include in iovec
268 	 */
269 	v=0;
270 	while (len > 0) {
271 		struct page *p = *(rqstp->rq_next_page++);
272 
273 		rqstp->rq_vec[v].iov_base = page_address(p);
274 		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
275 		len -= rqstp->rq_vec[v].iov_len;
276 		v++;
277 	}
278 	args->vlen = v;
279 	return xdr_argsize_check(rqstp, p);
280 }
281 
282 int
283 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
284 {
285 	struct nfsd_writeargs *args = rqstp->rq_argp;
286 	unsigned int len, hdr, dlen;
287 	struct kvec *head = rqstp->rq_arg.head;
288 	int v;
289 
290 	p = decode_fh(p, &args->fh);
291 	if (!p)
292 		return 0;
293 
294 	p++;				/* beginoffset */
295 	args->offset = ntohl(*p++);	/* offset */
296 	p++;				/* totalcount */
297 	len = args->len = ntohl(*p++);
298 	/*
299 	 * The protocol specifies a maximum of 8192 bytes.
300 	 */
301 	if (len > NFSSVC_MAXBLKSIZE_V2)
302 		return 0;
303 
304 	/*
305 	 * Check to make sure that we got the right number of
306 	 * bytes.
307 	 */
308 	hdr = (void*)p - head->iov_base;
309 	if (hdr > head->iov_len)
310 		return 0;
311 	dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
312 
313 	/*
314 	 * Round the length of the data which was specified up to
315 	 * the next multiple of XDR units and then compare that
316 	 * against the length which was actually received.
317 	 * Note that when RPCSEC/GSS (for example) is used, the
318 	 * data buffer can be padded so dlen might be larger
319 	 * than required.  It must never be smaller.
320 	 */
321 	if (dlen < XDR_QUADLEN(len)*4)
322 		return 0;
323 
324 	rqstp->rq_vec[0].iov_base = (void*)p;
325 	rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
326 	v = 0;
327 	while (len > rqstp->rq_vec[v].iov_len) {
328 		len -= rqstp->rq_vec[v].iov_len;
329 		v++;
330 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
331 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
332 	}
333 	rqstp->rq_vec[v].iov_len = len;
334 	args->vlen = v + 1;
335 	return 1;
336 }
337 
338 int
339 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
340 {
341 	struct nfsd_createargs *args = rqstp->rq_argp;
342 
343 	if (   !(p = decode_fh(p, &args->fh))
344 	    || !(p = decode_filename(p, &args->name, &args->len)))
345 		return 0;
346 	p = decode_sattr(p, &args->attrs);
347 
348 	return xdr_argsize_check(rqstp, p);
349 }
350 
351 int
352 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
353 {
354 	struct nfsd_renameargs *args = rqstp->rq_argp;
355 
356 	if (!(p = decode_fh(p, &args->ffh))
357 	 || !(p = decode_filename(p, &args->fname, &args->flen))
358 	 || !(p = decode_fh(p, &args->tfh))
359 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
360 		return 0;
361 
362 	return xdr_argsize_check(rqstp, p);
363 }
364 
365 int
366 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
367 {
368 	struct nfsd_readlinkargs *args = rqstp->rq_argp;
369 
370 	p = decode_fh(p, &args->fh);
371 	if (!p)
372 		return 0;
373 	args->buffer = page_address(*(rqstp->rq_next_page++));
374 
375 	return xdr_argsize_check(rqstp, p);
376 }
377 
378 int
379 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
380 {
381 	struct nfsd_linkargs *args = rqstp->rq_argp;
382 
383 	if (!(p = decode_fh(p, &args->ffh))
384 	 || !(p = decode_fh(p, &args->tfh))
385 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
386 		return 0;
387 
388 	return xdr_argsize_check(rqstp, p);
389 }
390 
391 int
392 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
393 {
394 	struct nfsd_symlinkargs *args = rqstp->rq_argp;
395 
396 	if (   !(p = decode_fh(p, &args->ffh))
397 	    || !(p = decode_filename(p, &args->fname, &args->flen))
398 	    || !(p = decode_pathname(p, &args->tname, &args->tlen)))
399 		return 0;
400 	p = decode_sattr(p, &args->attrs);
401 
402 	return xdr_argsize_check(rqstp, p);
403 }
404 
405 int
406 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
407 {
408 	struct nfsd_readdirargs *args = rqstp->rq_argp;
409 
410 	p = decode_fh(p, &args->fh);
411 	if (!p)
412 		return 0;
413 	args->cookie = ntohl(*p++);
414 	args->count  = ntohl(*p++);
415 	args->count  = min_t(u32, args->count, PAGE_SIZE);
416 	args->buffer = page_address(*(rqstp->rq_next_page++));
417 
418 	return xdr_argsize_check(rqstp, p);
419 }
420 
421 /*
422  * XDR encode functions
423  */
424 int
425 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p)
426 {
427 	return xdr_ressize_check(rqstp, p);
428 }
429 
430 int
431 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
432 {
433 	struct nfsd_attrstat *resp = rqstp->rq_resp;
434 
435 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
436 	return xdr_ressize_check(rqstp, p);
437 }
438 
439 int
440 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
441 {
442 	struct nfsd_diropres *resp = rqstp->rq_resp;
443 
444 	p = encode_fh(p, &resp->fh);
445 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
446 	return xdr_ressize_check(rqstp, p);
447 }
448 
449 int
450 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
451 {
452 	struct nfsd_readlinkres *resp = rqstp->rq_resp;
453 
454 	*p++ = htonl(resp->len);
455 	xdr_ressize_check(rqstp, p);
456 	rqstp->rq_res.page_len = resp->len;
457 	if (resp->len & 3) {
458 		/* need to pad the tail */
459 		rqstp->rq_res.tail[0].iov_base = p;
460 		*p = 0;
461 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
462 	}
463 	return 1;
464 }
465 
466 int
467 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
468 {
469 	struct nfsd_readres *resp = rqstp->rq_resp;
470 
471 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
472 	*p++ = htonl(resp->count);
473 	xdr_ressize_check(rqstp, p);
474 
475 	/* now update rqstp->rq_res to reflect data as well */
476 	rqstp->rq_res.page_len = resp->count;
477 	if (resp->count & 3) {
478 		/* need to pad the tail */
479 		rqstp->rq_res.tail[0].iov_base = p;
480 		*p = 0;
481 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
482 	}
483 	return 1;
484 }
485 
486 int
487 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
488 {
489 	struct nfsd_readdirres *resp = rqstp->rq_resp;
490 
491 	xdr_ressize_check(rqstp, p);
492 	p = resp->buffer;
493 	*p++ = 0;			/* no more entries */
494 	*p++ = htonl((resp->common.err == nfserr_eof));
495 	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
496 
497 	return 1;
498 }
499 
500 int
501 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p)
502 {
503 	struct nfsd_statfsres *resp = rqstp->rq_resp;
504 	struct kstatfs	*stat = &resp->stats;
505 
506 	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
507 	*p++ = htonl(stat->f_bsize);
508 	*p++ = htonl(stat->f_blocks);
509 	*p++ = htonl(stat->f_bfree);
510 	*p++ = htonl(stat->f_bavail);
511 	return xdr_ressize_check(rqstp, p);
512 }
513 
514 int
515 nfssvc_encode_entry(void *ccdv, const char *name,
516 		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
517 {
518 	struct readdir_cd *ccd = ccdv;
519 	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
520 	__be32	*p = cd->buffer;
521 	int	buflen, slen;
522 
523 	/*
524 	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
525 			namlen, name, offset, ino);
526 	 */
527 
528 	if (offset > ~((u32) 0)) {
529 		cd->common.err = nfserr_fbig;
530 		return -EINVAL;
531 	}
532 	if (cd->offset)
533 		*cd->offset = htonl(offset);
534 
535 	/* truncate filename */
536 	namlen = min(namlen, NFS2_MAXNAMLEN);
537 	slen = XDR_QUADLEN(namlen);
538 
539 	if ((buflen = cd->buflen - slen - 4) < 0) {
540 		cd->common.err = nfserr_toosmall;
541 		return -EINVAL;
542 	}
543 	if (ino > ~((u32) 0)) {
544 		cd->common.err = nfserr_fbig;
545 		return -EINVAL;
546 	}
547 	*p++ = xdr_one;				/* mark entry present */
548 	*p++ = htonl((u32) ino);		/* file id */
549 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
550 	cd->offset = p;			/* remember pointer */
551 	*p++ = htonl(~0U);		/* offset of next entry */
552 
553 	cd->buflen = buflen;
554 	cd->buffer = p;
555 	cd->common.err = nfs_ok;
556 	return 0;
557 }
558 
559 /*
560  * XDR release functions
561  */
562 void
563 nfssvc_release_fhandle(struct svc_rqst *rqstp)
564 {
565 	struct nfsd_fhandle *resp = rqstp->rq_resp;
566 
567 	fh_put(&resp->fh);
568 }
569