xref: /openbmc/linux/fs/nfsd/nfsxdr.c (revision 12eb4683) 
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(dentry->d_inode, &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 	if (!(p = decode_fh(p, &args->fh)))
218 		return 0;
219 	return xdr_argsize_check(rqstp, p);
220 }
221 
222 int
223 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
224 					struct nfsd_sattrargs *args)
225 {
226 	p = decode_fh(p, &args->fh);
227 	if (!p)
228 		return 0;
229 	p = decode_sattr(p, &args->attrs);
230 
231 	return xdr_argsize_check(rqstp, p);
232 }
233 
234 int
235 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
236 					struct nfsd_diropargs *args)
237 {
238 	if (!(p = decode_fh(p, &args->fh))
239 	 || !(p = decode_filename(p, &args->name, &args->len)))
240 		return 0;
241 
242 	 return xdr_argsize_check(rqstp, p);
243 }
244 
245 int
246 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
247 					struct nfsd_readargs *args)
248 {
249 	unsigned int len;
250 	int v;
251 	if (!(p = decode_fh(p, &args->fh)))
252 		return 0;
253 
254 	args->offset    = ntohl(*p++);
255 	len = args->count     = ntohl(*p++);
256 	p++; /* totalcount - unused */
257 
258 	if (len > NFSSVC_MAXBLKSIZE_V2)
259 		len = NFSSVC_MAXBLKSIZE_V2;
260 
261 	/* set up somewhere to store response.
262 	 * We take pages, put them on reslist and include in iovec
263 	 */
264 	v=0;
265 	while (len > 0) {
266 		struct page *p = *(rqstp->rq_next_page++);
267 
268 		rqstp->rq_vec[v].iov_base = page_address(p);
269 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
270 		len -= rqstp->rq_vec[v].iov_len;
271 		v++;
272 	}
273 	args->vlen = v;
274 	return xdr_argsize_check(rqstp, p);
275 }
276 
277 int
278 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
279 					struct nfsd_writeargs *args)
280 {
281 	unsigned int len, hdr, dlen;
282 	int v;
283 
284 	if (!(p = decode_fh(p, &args->fh)))
285 		return 0;
286 
287 	p++;				/* beginoffset */
288 	args->offset = ntohl(*p++);	/* offset */
289 	p++;				/* totalcount */
290 	len = args->len = ntohl(*p++);
291 	/*
292 	 * The protocol specifies a maximum of 8192 bytes.
293 	 */
294 	if (len > NFSSVC_MAXBLKSIZE_V2)
295 		return 0;
296 
297 	/*
298 	 * Check to make sure that we got the right number of
299 	 * bytes.
300 	 */
301 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
302 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
303 		- hdr;
304 
305 	/*
306 	 * Round the length of the data which was specified up to
307 	 * the next multiple of XDR units and then compare that
308 	 * against the length which was actually received.
309 	 * Note that when RPCSEC/GSS (for example) is used, the
310 	 * data buffer can be padded so dlen might be larger
311 	 * than required.  It must never be smaller.
312 	 */
313 	if (dlen < XDR_QUADLEN(len)*4)
314 		return 0;
315 
316 	rqstp->rq_vec[0].iov_base = (void*)p;
317 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
318 	v = 0;
319 	while (len > rqstp->rq_vec[v].iov_len) {
320 		len -= rqstp->rq_vec[v].iov_len;
321 		v++;
322 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
323 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
324 	}
325 	rqstp->rq_vec[v].iov_len = len;
326 	args->vlen = v + 1;
327 	return 1;
328 }
329 
330 int
331 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
332 					struct nfsd_createargs *args)
333 {
334 	if (   !(p = decode_fh(p, &args->fh))
335 	    || !(p = decode_filename(p, &args->name, &args->len)))
336 		return 0;
337 	p = decode_sattr(p, &args->attrs);
338 
339 	return xdr_argsize_check(rqstp, p);
340 }
341 
342 int
343 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
344 					struct nfsd_renameargs *args)
345 {
346 	if (!(p = decode_fh(p, &args->ffh))
347 	 || !(p = decode_filename(p, &args->fname, &args->flen))
348 	 || !(p = decode_fh(p, &args->tfh))
349 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
350 		return 0;
351 
352 	return xdr_argsize_check(rqstp, p);
353 }
354 
355 int
356 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
357 {
358 	if (!(p = decode_fh(p, &args->fh)))
359 		return 0;
360 	args->buffer = page_address(*(rqstp->rq_next_page++));
361 
362 	return xdr_argsize_check(rqstp, p);
363 }
364 
365 int
366 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
367 					struct nfsd_linkargs *args)
368 {
369 	if (!(p = decode_fh(p, &args->ffh))
370 	 || !(p = decode_fh(p, &args->tfh))
371 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
372 		return 0;
373 
374 	return xdr_argsize_check(rqstp, p);
375 }
376 
377 int
378 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
379 					struct nfsd_symlinkargs *args)
380 {
381 	if (   !(p = decode_fh(p, &args->ffh))
382 	    || !(p = decode_filename(p, &args->fname, &args->flen))
383 	    || !(p = decode_pathname(p, &args->tname, &args->tlen)))
384 		return 0;
385 	p = decode_sattr(p, &args->attrs);
386 
387 	return xdr_argsize_check(rqstp, p);
388 }
389 
390 int
391 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
392 					struct nfsd_readdirargs *args)
393 {
394 	if (!(p = decode_fh(p, &args->fh)))
395 		return 0;
396 	args->cookie = ntohl(*p++);
397 	args->count  = ntohl(*p++);
398 	if (args->count > PAGE_SIZE)
399 		args->count = PAGE_SIZE;
400 
401 	args->buffer = page_address(*(rqstp->rq_next_page++));
402 
403 	return xdr_argsize_check(rqstp, p);
404 }
405 
406 /*
407  * XDR encode functions
408  */
409 int
410 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
411 {
412 	return xdr_ressize_check(rqstp, p);
413 }
414 
415 int
416 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
417 					struct nfsd_attrstat *resp)
418 {
419 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
420 	return xdr_ressize_check(rqstp, p);
421 }
422 
423 int
424 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
425 					struct nfsd_diropres *resp)
426 {
427 	p = encode_fh(p, &resp->fh);
428 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
429 	return xdr_ressize_check(rqstp, p);
430 }
431 
432 int
433 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
434 					struct nfsd_readlinkres *resp)
435 {
436 	*p++ = htonl(resp->len);
437 	xdr_ressize_check(rqstp, p);
438 	rqstp->rq_res.page_len = resp->len;
439 	if (resp->len & 3) {
440 		/* need to pad the tail */
441 		rqstp->rq_res.tail[0].iov_base = p;
442 		*p = 0;
443 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
444 	}
445 	return 1;
446 }
447 
448 int
449 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
450 					struct nfsd_readres *resp)
451 {
452 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
453 	*p++ = htonl(resp->count);
454 	xdr_ressize_check(rqstp, p);
455 
456 	/* now update rqstp->rq_res to reflect data as well */
457 	rqstp->rq_res.page_len = resp->count;
458 	if (resp->count & 3) {
459 		/* need to pad the tail */
460 		rqstp->rq_res.tail[0].iov_base = p;
461 		*p = 0;
462 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
463 	}
464 	return 1;
465 }
466 
467 int
468 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
469 					struct nfsd_readdirres *resp)
470 {
471 	xdr_ressize_check(rqstp, p);
472 	p = resp->buffer;
473 	*p++ = 0;			/* no more entries */
474 	*p++ = htonl((resp->common.err == nfserr_eof));
475 	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
476 
477 	return 1;
478 }
479 
480 int
481 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
482 					struct nfsd_statfsres *resp)
483 {
484 	struct kstatfs	*stat = &resp->stats;
485 
486 	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
487 	*p++ = htonl(stat->f_bsize);
488 	*p++ = htonl(stat->f_blocks);
489 	*p++ = htonl(stat->f_bfree);
490 	*p++ = htonl(stat->f_bavail);
491 	return xdr_ressize_check(rqstp, p);
492 }
493 
494 int
495 nfssvc_encode_entry(void *ccdv, const char *name,
496 		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
497 {
498 	struct readdir_cd *ccd = ccdv;
499 	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
500 	__be32	*p = cd->buffer;
501 	int	buflen, slen;
502 
503 	/*
504 	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
505 			namlen, name, offset, ino);
506 	 */
507 
508 	if (offset > ~((u32) 0)) {
509 		cd->common.err = nfserr_fbig;
510 		return -EINVAL;
511 	}
512 	if (cd->offset)
513 		*cd->offset = htonl(offset);
514 	if (namlen > NFS2_MAXNAMLEN)
515 		namlen = NFS2_MAXNAMLEN;/* truncate filename */
516 
517 	slen = XDR_QUADLEN(namlen);
518 	if ((buflen = cd->buflen - slen - 4) < 0) {
519 		cd->common.err = nfserr_toosmall;
520 		return -EINVAL;
521 	}
522 	if (ino > ~((u32) 0)) {
523 		cd->common.err = nfserr_fbig;
524 		return -EINVAL;
525 	}
526 	*p++ = xdr_one;				/* mark entry present */
527 	*p++ = htonl((u32) ino);		/* file id */
528 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
529 	cd->offset = p;			/* remember pointer */
530 	*p++ = htonl(~0U);		/* offset of next entry */
531 
532 	cd->buflen = buflen;
533 	cd->buffer = p;
534 	cd->common.err = nfs_ok;
535 	return 0;
536 }
537 
538 /*
539  * XDR release functions
540  */
541 int
542 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
543 					struct nfsd_fhandle *resp)
544 {
545 	fh_put(&resp->fh);
546 	return 1;
547 }
548