xref: /openbmc/linux/fs/nfsd/nfsxdr.c (revision f7d84fa7) 
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, void *dummy)
210 {
211 	return xdr_argsize_check(rqstp, p);
212 }
213 
214 int
215 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
216 {
217 	p = decode_fh(p, &args->fh);
218 	if (!p)
219 		return 0;
220 	return xdr_argsize_check(rqstp, p);
221 }
222 
223 int
224 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
225 					struct nfsd_sattrargs *args)
226 {
227 	p = decode_fh(p, &args->fh);
228 	if (!p)
229 		return 0;
230 	p = decode_sattr(p, &args->attrs);
231 
232 	return xdr_argsize_check(rqstp, p);
233 }
234 
235 int
236 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
237 					struct nfsd_diropargs *args)
238 {
239 	if (!(p = decode_fh(p, &args->fh))
240 	 || !(p = decode_filename(p, &args->name, &args->len)))
241 		return 0;
242 
243 	return xdr_argsize_check(rqstp, p);
244 }
245 
246 int
247 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
248 					struct nfsd_readargs *args)
249 {
250 	unsigned int len;
251 	int v;
252 	p = decode_fh(p, &args->fh);
253 	if (!p)
254 		return 0;
255 
256 	args->offset    = ntohl(*p++);
257 	len = args->count     = ntohl(*p++);
258 	p++; /* totalcount - unused */
259 
260 	len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
261 
262 	/* set up somewhere to store response.
263 	 * We take pages, put them on reslist and include in iovec
264 	 */
265 	v=0;
266 	while (len > 0) {
267 		struct page *p = *(rqstp->rq_next_page++);
268 
269 		rqstp->rq_vec[v].iov_base = page_address(p);
270 		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
271 		len -= rqstp->rq_vec[v].iov_len;
272 		v++;
273 	}
274 	args->vlen = v;
275 	return xdr_argsize_check(rqstp, p);
276 }
277 
278 int
279 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
280 					struct nfsd_writeargs *args)
281 {
282 	unsigned int len, hdr, dlen;
283 	struct kvec *head = rqstp->rq_arg.head;
284 	int v;
285 
286 	p = decode_fh(p, &args->fh);
287 	if (!p)
288 		return 0;
289 
290 	p++;				/* beginoffset */
291 	args->offset = ntohl(*p++);	/* offset */
292 	p++;				/* totalcount */
293 	len = args->len = ntohl(*p++);
294 	/*
295 	 * The protocol specifies a maximum of 8192 bytes.
296 	 */
297 	if (len > NFSSVC_MAXBLKSIZE_V2)
298 		return 0;
299 
300 	/*
301 	 * Check to make sure that we got the right number of
302 	 * bytes.
303 	 */
304 	hdr = (void*)p - head->iov_base;
305 	if (hdr > head->iov_len)
306 		return 0;
307 	dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
308 
309 	/*
310 	 * Round the length of the data which was specified up to
311 	 * the next multiple of XDR units and then compare that
312 	 * against the length which was actually received.
313 	 * Note that when RPCSEC/GSS (for example) is used, the
314 	 * data buffer can be padded so dlen might be larger
315 	 * than required.  It must never be smaller.
316 	 */
317 	if (dlen < XDR_QUADLEN(len)*4)
318 		return 0;
319 
320 	rqstp->rq_vec[0].iov_base = (void*)p;
321 	rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
322 	v = 0;
323 	while (len > rqstp->rq_vec[v].iov_len) {
324 		len -= rqstp->rq_vec[v].iov_len;
325 		v++;
326 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
327 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
328 	}
329 	rqstp->rq_vec[v].iov_len = len;
330 	args->vlen = v + 1;
331 	return 1;
332 }
333 
334 int
335 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
336 					struct nfsd_createargs *args)
337 {
338 	if (   !(p = decode_fh(p, &args->fh))
339 	    || !(p = decode_filename(p, &args->name, &args->len)))
340 		return 0;
341 	p = decode_sattr(p, &args->attrs);
342 
343 	return xdr_argsize_check(rqstp, p);
344 }
345 
346 int
347 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
348 					struct nfsd_renameargs *args)
349 {
350 	if (!(p = decode_fh(p, &args->ffh))
351 	 || !(p = decode_filename(p, &args->fname, &args->flen))
352 	 || !(p = decode_fh(p, &args->tfh))
353 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
354 		return 0;
355 
356 	return xdr_argsize_check(rqstp, p);
357 }
358 
359 int
360 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
361 {
362 	p = decode_fh(p, &args->fh);
363 	if (!p)
364 		return 0;
365 	args->buffer = page_address(*(rqstp->rq_next_page++));
366 
367 	return xdr_argsize_check(rqstp, p);
368 }
369 
370 int
371 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
372 					struct nfsd_linkargs *args)
373 {
374 	if (!(p = decode_fh(p, &args->ffh))
375 	 || !(p = decode_fh(p, &args->tfh))
376 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
377 		return 0;
378 
379 	return xdr_argsize_check(rqstp, p);
380 }
381 
382 int
383 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
384 					struct nfsd_symlinkargs *args)
385 {
386 	if (   !(p = decode_fh(p, &args->ffh))
387 	    || !(p = decode_filename(p, &args->fname, &args->flen))
388 	    || !(p = decode_pathname(p, &args->tname, &args->tlen)))
389 		return 0;
390 	p = decode_sattr(p, &args->attrs);
391 
392 	return xdr_argsize_check(rqstp, p);
393 }
394 
395 int
396 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
397 					struct nfsd_readdirargs *args)
398 {
399 	p = decode_fh(p, &args->fh);
400 	if (!p)
401 		return 0;
402 	args->cookie = ntohl(*p++);
403 	args->count  = ntohl(*p++);
404 	args->count  = min_t(u32, args->count, PAGE_SIZE);
405 	args->buffer = page_address(*(rqstp->rq_next_page++));
406 
407 	return xdr_argsize_check(rqstp, p);
408 }
409 
410 /*
411  * XDR encode functions
412  */
413 int
414 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
415 {
416 	return xdr_ressize_check(rqstp, p);
417 }
418 
419 int
420 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
421 					struct nfsd_attrstat *resp)
422 {
423 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
424 	return xdr_ressize_check(rqstp, p);
425 }
426 
427 int
428 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
429 					struct nfsd_diropres *resp)
430 {
431 	p = encode_fh(p, &resp->fh);
432 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
433 	return xdr_ressize_check(rqstp, p);
434 }
435 
436 int
437 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
438 					struct nfsd_readlinkres *resp)
439 {
440 	*p++ = htonl(resp->len);
441 	xdr_ressize_check(rqstp, p);
442 	rqstp->rq_res.page_len = resp->len;
443 	if (resp->len & 3) {
444 		/* need to pad the tail */
445 		rqstp->rq_res.tail[0].iov_base = p;
446 		*p = 0;
447 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
448 	}
449 	return 1;
450 }
451 
452 int
453 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
454 					struct nfsd_readres *resp)
455 {
456 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
457 	*p++ = htonl(resp->count);
458 	xdr_ressize_check(rqstp, p);
459 
460 	/* now update rqstp->rq_res to reflect data as well */
461 	rqstp->rq_res.page_len = resp->count;
462 	if (resp->count & 3) {
463 		/* need to pad the tail */
464 		rqstp->rq_res.tail[0].iov_base = p;
465 		*p = 0;
466 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
467 	}
468 	return 1;
469 }
470 
471 int
472 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
473 					struct nfsd_readdirres *resp)
474 {
475 	xdr_ressize_check(rqstp, p);
476 	p = resp->buffer;
477 	*p++ = 0;			/* no more entries */
478 	*p++ = htonl((resp->common.err == nfserr_eof));
479 	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
480 
481 	return 1;
482 }
483 
484 int
485 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
486 					struct nfsd_statfsres *resp)
487 {
488 	struct kstatfs	*stat = &resp->stats;
489 
490 	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
491 	*p++ = htonl(stat->f_bsize);
492 	*p++ = htonl(stat->f_blocks);
493 	*p++ = htonl(stat->f_bfree);
494 	*p++ = htonl(stat->f_bavail);
495 	return xdr_ressize_check(rqstp, p);
496 }
497 
498 int
499 nfssvc_encode_entry(void *ccdv, const char *name,
500 		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
501 {
502 	struct readdir_cd *ccd = ccdv;
503 	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
504 	__be32	*p = cd->buffer;
505 	int	buflen, slen;
506 
507 	/*
508 	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
509 			namlen, name, offset, ino);
510 	 */
511 
512 	if (offset > ~((u32) 0)) {
513 		cd->common.err = nfserr_fbig;
514 		return -EINVAL;
515 	}
516 	if (cd->offset)
517 		*cd->offset = htonl(offset);
518 
519 	/* truncate filename */
520 	namlen = min(namlen, NFS2_MAXNAMLEN);
521 	slen = XDR_QUADLEN(namlen);
522 
523 	if ((buflen = cd->buflen - slen - 4) < 0) {
524 		cd->common.err = nfserr_toosmall;
525 		return -EINVAL;
526 	}
527 	if (ino > ~((u32) 0)) {
528 		cd->common.err = nfserr_fbig;
529 		return -EINVAL;
530 	}
531 	*p++ = xdr_one;				/* mark entry present */
532 	*p++ = htonl((u32) ino);		/* file id */
533 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
534 	cd->offset = p;			/* remember pointer */
535 	*p++ = htonl(~0U);		/* offset of next entry */
536 
537 	cd->buflen = buflen;
538 	cd->buffer = p;
539 	cd->common.err = nfs_ok;
540 	return 0;
541 }
542 
543 /*
544  * XDR release functions
545  */
546 int
547 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
548 					struct nfsd_fhandle *resp)
549 {
550 	fh_put(&resp->fh);
551 	return 1;
552 }
553