xref: /openbmc/linux/fs/nfsd/nfsxdr.c (revision eb3fcf00) 
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 	int v;
284 
285 	p = decode_fh(p, &args->fh);
286 	if (!p)
287 		return 0;
288 
289 	p++;				/* beginoffset */
290 	args->offset = ntohl(*p++);	/* offset */
291 	p++;				/* totalcount */
292 	len = args->len = ntohl(*p++);
293 	/*
294 	 * The protocol specifies a maximum of 8192 bytes.
295 	 */
296 	if (len > NFSSVC_MAXBLKSIZE_V2)
297 		return 0;
298 
299 	/*
300 	 * Check to make sure that we got the right number of
301 	 * bytes.
302 	 */
303 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
304 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
305 		- hdr;
306 
307 	/*
308 	 * Round the length of the data which was specified up to
309 	 * the next multiple of XDR units and then compare that
310 	 * against the length which was actually received.
311 	 * Note that when RPCSEC/GSS (for example) is used, the
312 	 * data buffer can be padded so dlen might be larger
313 	 * than required.  It must never be smaller.
314 	 */
315 	if (dlen < XDR_QUADLEN(len)*4)
316 		return 0;
317 
318 	rqstp->rq_vec[0].iov_base = (void*)p;
319 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
320 	v = 0;
321 	while (len > rqstp->rq_vec[v].iov_len) {
322 		len -= rqstp->rq_vec[v].iov_len;
323 		v++;
324 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
325 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
326 	}
327 	rqstp->rq_vec[v].iov_len = len;
328 	args->vlen = v + 1;
329 	return 1;
330 }
331 
332 int
333 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
334 					struct nfsd_createargs *args)
335 {
336 	if (   !(p = decode_fh(p, &args->fh))
337 	    || !(p = decode_filename(p, &args->name, &args->len)))
338 		return 0;
339 	p = decode_sattr(p, &args->attrs);
340 
341 	return xdr_argsize_check(rqstp, p);
342 }
343 
344 int
345 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
346 					struct nfsd_renameargs *args)
347 {
348 	if (!(p = decode_fh(p, &args->ffh))
349 	 || !(p = decode_filename(p, &args->fname, &args->flen))
350 	 || !(p = decode_fh(p, &args->tfh))
351 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
352 		return 0;
353 
354 	return xdr_argsize_check(rqstp, p);
355 }
356 
357 int
358 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
359 {
360 	p = decode_fh(p, &args->fh);
361 	if (!p)
362 		return 0;
363 	args->buffer = page_address(*(rqstp->rq_next_page++));
364 
365 	return xdr_argsize_check(rqstp, p);
366 }
367 
368 int
369 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
370 					struct nfsd_linkargs *args)
371 {
372 	if (!(p = decode_fh(p, &args->ffh))
373 	 || !(p = decode_fh(p, &args->tfh))
374 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
375 		return 0;
376 
377 	return xdr_argsize_check(rqstp, p);
378 }
379 
380 int
381 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
382 					struct nfsd_symlinkargs *args)
383 {
384 	if (   !(p = decode_fh(p, &args->ffh))
385 	    || !(p = decode_filename(p, &args->fname, &args->flen))
386 	    || !(p = decode_pathname(p, &args->tname, &args->tlen)))
387 		return 0;
388 	p = decode_sattr(p, &args->attrs);
389 
390 	return xdr_argsize_check(rqstp, p);
391 }
392 
393 int
394 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
395 					struct nfsd_readdirargs *args)
396 {
397 	p = decode_fh(p, &args->fh);
398 	if (!p)
399 		return 0;
400 	args->cookie = ntohl(*p++);
401 	args->count  = ntohl(*p++);
402 	args->count  = min_t(u32, args->count, PAGE_SIZE);
403 	args->buffer = page_address(*(rqstp->rq_next_page++));
404 
405 	return xdr_argsize_check(rqstp, p);
406 }
407 
408 /*
409  * XDR encode functions
410  */
411 int
412 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
413 {
414 	return xdr_ressize_check(rqstp, p);
415 }
416 
417 int
418 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
419 					struct nfsd_attrstat *resp)
420 {
421 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
422 	return xdr_ressize_check(rqstp, p);
423 }
424 
425 int
426 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
427 					struct nfsd_diropres *resp)
428 {
429 	p = encode_fh(p, &resp->fh);
430 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
431 	return xdr_ressize_check(rqstp, p);
432 }
433 
434 int
435 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
436 					struct nfsd_readlinkres *resp)
437 {
438 	*p++ = htonl(resp->len);
439 	xdr_ressize_check(rqstp, p);
440 	rqstp->rq_res.page_len = resp->len;
441 	if (resp->len & 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->len&3);
446 	}
447 	return 1;
448 }
449 
450 int
451 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
452 					struct nfsd_readres *resp)
453 {
454 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
455 	*p++ = htonl(resp->count);
456 	xdr_ressize_check(rqstp, p);
457 
458 	/* now update rqstp->rq_res to reflect data as well */
459 	rqstp->rq_res.page_len = resp->count;
460 	if (resp->count & 3) {
461 		/* need to pad the tail */
462 		rqstp->rq_res.tail[0].iov_base = p;
463 		*p = 0;
464 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
465 	}
466 	return 1;
467 }
468 
469 int
470 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
471 					struct nfsd_readdirres *resp)
472 {
473 	xdr_ressize_check(rqstp, p);
474 	p = resp->buffer;
475 	*p++ = 0;			/* no more entries */
476 	*p++ = htonl((resp->common.err == nfserr_eof));
477 	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
478 
479 	return 1;
480 }
481 
482 int
483 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
484 					struct nfsd_statfsres *resp)
485 {
486 	struct kstatfs	*stat = &resp->stats;
487 
488 	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
489 	*p++ = htonl(stat->f_bsize);
490 	*p++ = htonl(stat->f_blocks);
491 	*p++ = htonl(stat->f_bfree);
492 	*p++ = htonl(stat->f_bavail);
493 	return xdr_ressize_check(rqstp, p);
494 }
495 
496 int
497 nfssvc_encode_entry(void *ccdv, const char *name,
498 		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
499 {
500 	struct readdir_cd *ccd = ccdv;
501 	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
502 	__be32	*p = cd->buffer;
503 	int	buflen, slen;
504 
505 	/*
506 	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
507 			namlen, name, offset, ino);
508 	 */
509 
510 	if (offset > ~((u32) 0)) {
511 		cd->common.err = nfserr_fbig;
512 		return -EINVAL;
513 	}
514 	if (cd->offset)
515 		*cd->offset = htonl(offset);
516 
517 	/* truncate filename */
518 	namlen = min(namlen, NFS2_MAXNAMLEN);
519 	slen = XDR_QUADLEN(namlen);
520 
521 	if ((buflen = cd->buflen - slen - 4) < 0) {
522 		cd->common.err = nfserr_toosmall;
523 		return -EINVAL;
524 	}
525 	if (ino > ~((u32) 0)) {
526 		cd->common.err = nfserr_fbig;
527 		return -EINVAL;
528 	}
529 	*p++ = xdr_one;				/* mark entry present */
530 	*p++ = htonl((u32) ino);		/* file id */
531 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
532 	cd->offset = p;			/* remember pointer */
533 	*p++ = htonl(~0U);		/* offset of next entry */
534 
535 	cd->buflen = buflen;
536 	cd->buffer = p;
537 	cd->common.err = nfs_ok;
538 	return 0;
539 }
540 
541 /*
542  * XDR release functions
543  */
544 int
545 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
546 					struct nfsd_fhandle *resp)
547 {
548 	fh_put(&resp->fh);
549 	return 1;
550 }
551