xref: /openbmc/linux/fs/nfsd/nfsxdr.c (revision 22246614)
1 /*
2  * linux/fs/nfsd/nfsxdr.c
3  *
4  * XDR support for nfsd
5  *
6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/time.h>
11 #include <linux/nfs.h>
12 #include <linux/vfs.h>
13 #include <linux/sunrpc/xdr.h>
14 #include <linux/sunrpc/svc.h>
15 #include <linux/nfsd/nfsd.h>
16 #include <linux/nfsd/xdr.h>
17 #include <linux/mm.h>
18 #include "auth.h"
19 
20 #define NFSDDBG_FACILITY		NFSDDBG_XDR
21 
22 /*
23  * Mapping of S_IF* types to NFS file types
24  */
25 static u32	nfs_ftypes[] = {
26 	NFNON,  NFCHR,  NFCHR, NFBAD,
27 	NFDIR,  NFBAD,  NFBLK, NFBAD,
28 	NFREG,  NFBAD,  NFLNK, NFBAD,
29 	NFSOCK, NFBAD,  NFLNK, NFBAD,
30 };
31 
32 
33 /*
34  * XDR functions for basic NFS types
35  */
36 static __be32 *
37 decode_fh(__be32 *p, struct svc_fh *fhp)
38 {
39 	fh_init(fhp, NFS_FHSIZE);
40 	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
41 	fhp->fh_handle.fh_size = NFS_FHSIZE;
42 
43 	/* FIXME: Look up export pointer here and verify
44 	 * Sun Secure RPC if requested */
45 	return p + (NFS_FHSIZE >> 2);
46 }
47 
48 /* Helper function for NFSv2 ACL code */
49 __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
50 {
51 	return decode_fh(p, fhp);
52 }
53 
54 static __be32 *
55 encode_fh(__be32 *p, struct svc_fh *fhp)
56 {
57 	memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
58 	return p + (NFS_FHSIZE>> 2);
59 }
60 
61 /*
62  * Decode a file name and make sure that the path contains
63  * no slashes or null bytes.
64  */
65 static __be32 *
66 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
67 {
68 	char		*name;
69 	unsigned int	i;
70 
71 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
72 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
73 			if (*name == '\0' || *name == '/')
74 				return NULL;
75 		}
76 	}
77 
78 	return p;
79 }
80 
81 static __be32 *
82 decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
83 {
84 	char		*name;
85 	unsigned int	i;
86 
87 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
88 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
89 			if (*name == '\0')
90 				return NULL;
91 		}
92 	}
93 
94 	return p;
95 }
96 
97 static __be32 *
98 decode_sattr(__be32 *p, struct iattr *iap)
99 {
100 	u32	tmp, tmp1;
101 
102 	iap->ia_valid = 0;
103 
104 	/* Sun client bug compatibility check: some sun clients seem to
105 	 * put 0xffff in the mode field when they mean 0xffffffff.
106 	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
107 	 */
108 	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
109 		iap->ia_valid |= ATTR_MODE;
110 		iap->ia_mode = tmp;
111 	}
112 	if ((tmp = ntohl(*p++)) != (u32)-1) {
113 		iap->ia_valid |= ATTR_UID;
114 		iap->ia_uid = tmp;
115 	}
116 	if ((tmp = ntohl(*p++)) != (u32)-1) {
117 		iap->ia_valid |= ATTR_GID;
118 		iap->ia_gid = tmp;
119 	}
120 	if ((tmp = ntohl(*p++)) != (u32)-1) {
121 		iap->ia_valid |= ATTR_SIZE;
122 		iap->ia_size = tmp;
123 	}
124 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
125 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
126 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
127 		iap->ia_atime.tv_sec = tmp;
128 		iap->ia_atime.tv_nsec = tmp1 * 1000;
129 	}
130 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
131 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
132 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
133 		iap->ia_mtime.tv_sec = tmp;
134 		iap->ia_mtime.tv_nsec = tmp1 * 1000;
135 		/*
136 		 * Passing the invalid value useconds=1000000 for mtime
137 		 * is a Sun convention for "set both mtime and atime to
138 		 * current server time".  It's needed to make permissions
139 		 * checks for the "touch" program across v2 mounts to
140 		 * Solaris and Irix boxes work correctly. See description of
141 		 * sattr in section 6.1 of "NFS Illustrated" by
142 		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
143 		 */
144 		if (tmp1 == 1000000)
145 			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
146 	}
147 	return p;
148 }
149 
150 static __be32 *
151 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
152 	     struct kstat *stat)
153 {
154 	struct dentry	*dentry = fhp->fh_dentry;
155 	int type;
156 	struct timespec time;
157 	u32 f;
158 
159 	type = (stat->mode & S_IFMT);
160 
161 	*p++ = htonl(nfs_ftypes[type >> 12]);
162 	*p++ = htonl((u32) stat->mode);
163 	*p++ = htonl((u32) stat->nlink);
164 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
165 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
166 
167 	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
168 		*p++ = htonl(NFS_MAXPATHLEN);
169 	} else {
170 		*p++ = htonl((u32) stat->size);
171 	}
172 	*p++ = htonl((u32) stat->blksize);
173 	if (S_ISCHR(type) || S_ISBLK(type))
174 		*p++ = htonl(new_encode_dev(stat->rdev));
175 	else
176 		*p++ = htonl(0xffffffff);
177 	*p++ = htonl((u32) stat->blocks);
178 	switch (fsid_source(fhp)) {
179 	default:
180 	case FSIDSOURCE_DEV:
181 		*p++ = htonl(new_encode_dev(stat->dev));
182 		break;
183 	case FSIDSOURCE_FSID:
184 		*p++ = htonl((u32) fhp->fh_export->ex_fsid);
185 		break;
186 	case FSIDSOURCE_UUID:
187 		f = ((u32*)fhp->fh_export->ex_uuid)[0];
188 		f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
189 		f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
190 		f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
191 		*p++ = htonl(f);
192 		break;
193 	}
194 	*p++ = htonl((u32) stat->ino);
195 	*p++ = htonl((u32) stat->atime.tv_sec);
196 	*p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
197 	lease_get_mtime(dentry->d_inode, &time);
198 	*p++ = htonl((u32) time.tv_sec);
199 	*p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
200 	*p++ = htonl((u32) stat->ctime.tv_sec);
201 	*p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
202 
203 	return p;
204 }
205 
206 /* Helper function for NFSv2 ACL code */
207 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
208 {
209 	struct kstat stat;
210 	vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &stat);
211 	return encode_fattr(rqstp, p, fhp, &stat);
212 }
213 
214 /*
215  * XDR decode functions
216  */
217 int
218 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
219 {
220 	return xdr_argsize_check(rqstp, p);
221 }
222 
223 int
224 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
225 {
226 	if (!(p = decode_fh(p, &args->fh)))
227 		return 0;
228 	return xdr_argsize_check(rqstp, p);
229 }
230 
231 int
232 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
233 					struct nfsd_sattrargs *args)
234 {
235 	p = decode_fh(p, &args->fh);
236 	if (!p)
237 		return 0;
238 	p = decode_sattr(p, &args->attrs);
239 
240 	return xdr_argsize_check(rqstp, p);
241 }
242 
243 int
244 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
245 					struct nfsd_diropargs *args)
246 {
247 	if (!(p = decode_fh(p, &args->fh))
248 	 || !(p = decode_filename(p, &args->name, &args->len)))
249 		return 0;
250 
251 	 return xdr_argsize_check(rqstp, p);
252 }
253 
254 int
255 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
256 					struct nfsd_readargs *args)
257 {
258 	unsigned int len;
259 	int v,pn;
260 	if (!(p = decode_fh(p, &args->fh)))
261 		return 0;
262 
263 	args->offset    = ntohl(*p++);
264 	len = args->count     = ntohl(*p++);
265 	p++; /* totalcount - unused */
266 
267 	if (len > NFSSVC_MAXBLKSIZE_V2)
268 		len = NFSSVC_MAXBLKSIZE_V2;
269 
270 	/* set up somewhere to store response.
271 	 * We take pages, put them on reslist and include in iovec
272 	 */
273 	v=0;
274 	while (len > 0) {
275 		pn = rqstp->rq_resused++;
276 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
277 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
278 		len -= rqstp->rq_vec[v].iov_len;
279 		v++;
280 	}
281 	args->vlen = v;
282 	return xdr_argsize_check(rqstp, p);
283 }
284 
285 int
286 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
287 					struct nfsd_writeargs *args)
288 {
289 	unsigned int len, hdr, dlen;
290 	int v;
291 
292 	if (!(p = decode_fh(p, &args->fh)))
293 		return 0;
294 
295 	p++;				/* beginoffset */
296 	args->offset = ntohl(*p++);	/* offset */
297 	p++;				/* totalcount */
298 	len = args->len = ntohl(*p++);
299 	/*
300 	 * The protocol specifies a maximum of 8192 bytes.
301 	 */
302 	if (len > NFSSVC_MAXBLKSIZE_V2)
303 		return 0;
304 
305 	/*
306 	 * Check to make sure that we got the right number of
307 	 * bytes.
308 	 */
309 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
310 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
311 		- 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 = rqstp->rq_arg.head[0].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 					struct nfsd_createargs *args)
341 {
342 	if (   !(p = decode_fh(p, &args->fh))
343 	    || !(p = decode_filename(p, &args->name, &args->len)))
344 		return 0;
345 	p = decode_sattr(p, &args->attrs);
346 
347 	return xdr_argsize_check(rqstp, p);
348 }
349 
350 int
351 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
352 					struct nfsd_renameargs *args)
353 {
354 	if (!(p = decode_fh(p, &args->ffh))
355 	 || !(p = decode_filename(p, &args->fname, &args->flen))
356 	 || !(p = decode_fh(p, &args->tfh))
357 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
358 		return 0;
359 
360 	return xdr_argsize_check(rqstp, p);
361 }
362 
363 int
364 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
365 {
366 	if (!(p = decode_fh(p, &args->fh)))
367 		return 0;
368 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
369 
370 	return xdr_argsize_check(rqstp, p);
371 }
372 
373 int
374 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
375 					struct nfsd_linkargs *args)
376 {
377 	if (!(p = decode_fh(p, &args->ffh))
378 	 || !(p = decode_fh(p, &args->tfh))
379 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
380 		return 0;
381 
382 	return xdr_argsize_check(rqstp, p);
383 }
384 
385 int
386 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
387 					struct nfsd_symlinkargs *args)
388 {
389 	if (   !(p = decode_fh(p, &args->ffh))
390 	    || !(p = decode_filename(p, &args->fname, &args->flen))
391 	    || !(p = decode_pathname(p, &args->tname, &args->tlen)))
392 		return 0;
393 	p = decode_sattr(p, &args->attrs);
394 
395 	return xdr_argsize_check(rqstp, p);
396 }
397 
398 int
399 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
400 					struct nfsd_readdirargs *args)
401 {
402 	if (!(p = decode_fh(p, &args->fh)))
403 		return 0;
404 	args->cookie = ntohl(*p++);
405 	args->count  = ntohl(*p++);
406 	if (args->count > PAGE_SIZE)
407 		args->count = PAGE_SIZE;
408 
409 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
410 
411 	return xdr_argsize_check(rqstp, p);
412 }
413 
414 /*
415  * XDR encode functions
416  */
417 int
418 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
419 {
420 	return xdr_ressize_check(rqstp, p);
421 }
422 
423 int
424 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
425 					struct nfsd_attrstat *resp)
426 {
427 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
428 	return xdr_ressize_check(rqstp, p);
429 }
430 
431 int
432 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
433 					struct nfsd_diropres *resp)
434 {
435 	p = encode_fh(p, &resp->fh);
436 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
437 	return xdr_ressize_check(rqstp, p);
438 }
439 
440 int
441 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
442 					struct nfsd_readlinkres *resp)
443 {
444 	*p++ = htonl(resp->len);
445 	xdr_ressize_check(rqstp, p);
446 	rqstp->rq_res.page_len = resp->len;
447 	if (resp->len & 3) {
448 		/* need to pad the tail */
449 		rqstp->rq_res.tail[0].iov_base = p;
450 		*p = 0;
451 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
452 	}
453 	return 1;
454 }
455 
456 int
457 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
458 					struct nfsd_readres *resp)
459 {
460 	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
461 	*p++ = htonl(resp->count);
462 	xdr_ressize_check(rqstp, p);
463 
464 	/* now update rqstp->rq_res to reflect data aswell */
465 	rqstp->rq_res.page_len = resp->count;
466 	if (resp->count & 3) {
467 		/* need to pad the tail */
468 		rqstp->rq_res.tail[0].iov_base = p;
469 		*p = 0;
470 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
471 	}
472 	return 1;
473 }
474 
475 int
476 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
477 					struct nfsd_readdirres *resp)
478 {
479 	xdr_ressize_check(rqstp, p);
480 	p = resp->buffer;
481 	*p++ = 0;			/* no more entries */
482 	*p++ = htonl((resp->common.err == nfserr_eof));
483 	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
484 
485 	return 1;
486 }
487 
488 int
489 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
490 					struct nfsd_statfsres *resp)
491 {
492 	struct kstatfs	*stat = &resp->stats;
493 
494 	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
495 	*p++ = htonl(stat->f_bsize);
496 	*p++ = htonl(stat->f_blocks);
497 	*p++ = htonl(stat->f_bfree);
498 	*p++ = htonl(stat->f_bavail);
499 	return xdr_ressize_check(rqstp, p);
500 }
501 
502 int
503 nfssvc_encode_entry(void *ccdv, const char *name,
504 		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
505 {
506 	struct readdir_cd *ccd = ccdv;
507 	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
508 	__be32	*p = cd->buffer;
509 	int	buflen, slen;
510 
511 	/*
512 	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
513 			namlen, name, offset, ino);
514 	 */
515 
516 	if (offset > ~((u32) 0)) {
517 		cd->common.err = nfserr_fbig;
518 		return -EINVAL;
519 	}
520 	if (cd->offset)
521 		*cd->offset = htonl(offset);
522 	if (namlen > NFS2_MAXNAMLEN)
523 		namlen = NFS2_MAXNAMLEN;/* truncate filename */
524 
525 	slen = XDR_QUADLEN(namlen);
526 	if ((buflen = cd->buflen - slen - 4) < 0) {
527 		cd->common.err = nfserr_toosmall;
528 		return -EINVAL;
529 	}
530 	if (ino > ~((u32) 0)) {
531 		cd->common.err = nfserr_fbig;
532 		return -EINVAL;
533 	}
534 	*p++ = xdr_one;				/* mark entry present */
535 	*p++ = htonl((u32) ino);		/* file id */
536 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
537 	cd->offset = p;			/* remember pointer */
538 	*p++ = htonl(~0U);		/* offset of next entry */
539 
540 	cd->buflen = buflen;
541 	cd->buffer = p;
542 	cd->common.err = nfs_ok;
543 	return 0;
544 }
545 
546 /*
547  * XDR release functions
548  */
549 int
550 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
551 					struct nfsd_fhandle *resp)
552 {
553 	fh_put(&resp->fh);
554 	return 1;
555 }
556