xref: /openbmc/linux/fs/nfsd/nfsxdr.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
1 /*
2  * linux/fs/nfsd/xdr.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 
19 #define NFSDDBG_FACILITY		NFSDDBG_XDR
20 
21 
22 #ifdef NFSD_OPTIMIZE_SPACE
23 # define inline
24 #endif
25 
26 /*
27  * Mapping of S_IF* types to NFS file types
28  */
29 static u32	nfs_ftypes[] = {
30 	NFNON,  NFCHR,  NFCHR, NFBAD,
31 	NFDIR,  NFBAD,  NFBLK, NFBAD,
32 	NFREG,  NFBAD,  NFLNK, NFBAD,
33 	NFSOCK, NFBAD,  NFLNK, NFBAD,
34 };
35 
36 
37 /*
38  * XDR functions for basic NFS types
39  */
40 static inline u32 *
41 decode_fh(u32 *p, struct svc_fh *fhp)
42 {
43 	fh_init(fhp, NFS_FHSIZE);
44 	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
45 	fhp->fh_handle.fh_size = NFS_FHSIZE;
46 
47 	/* FIXME: Look up export pointer here and verify
48 	 * Sun Secure RPC if requested */
49 	return p + (NFS_FHSIZE >> 2);
50 }
51 
52 /* Helper function for NFSv2 ACL code */
53 u32 *nfs2svc_decode_fh(u32 *p, struct svc_fh *fhp)
54 {
55 	return decode_fh(p, fhp);
56 }
57 
58 static inline u32 *
59 encode_fh(u32 *p, struct svc_fh *fhp)
60 {
61 	memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
62 	return p + (NFS_FHSIZE>> 2);
63 }
64 
65 /*
66  * Decode a file name and make sure that the path contains
67  * no slashes or null bytes.
68  */
69 static inline u32 *
70 decode_filename(u32 *p, char **namp, int *lenp)
71 {
72 	char		*name;
73 	int		i;
74 
75 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
76 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
77 			if (*name == '\0' || *name == '/')
78 				return NULL;
79 		}
80 	}
81 
82 	return p;
83 }
84 
85 static inline u32 *
86 decode_pathname(u32 *p, char **namp, int *lenp)
87 {
88 	char		*name;
89 	int		i;
90 
91 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
92 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
93 			if (*name == '\0')
94 				return NULL;
95 		}
96 	}
97 
98 	return p;
99 }
100 
101 static inline u32 *
102 decode_sattr(u32 *p, struct iattr *iap)
103 {
104 	u32	tmp, tmp1;
105 
106 	iap->ia_valid = 0;
107 
108 	/* Sun client bug compatibility check: some sun clients seem to
109 	 * put 0xffff in the mode field when they mean 0xffffffff.
110 	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
111 	 */
112 	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
113 		iap->ia_valid |= ATTR_MODE;
114 		iap->ia_mode = tmp;
115 	}
116 	if ((tmp = ntohl(*p++)) != (u32)-1) {
117 		iap->ia_valid |= ATTR_UID;
118 		iap->ia_uid = tmp;
119 	}
120 	if ((tmp = ntohl(*p++)) != (u32)-1) {
121 		iap->ia_valid |= ATTR_GID;
122 		iap->ia_gid = tmp;
123 	}
124 	if ((tmp = ntohl(*p++)) != (u32)-1) {
125 		iap->ia_valid |= ATTR_SIZE;
126 		iap->ia_size = tmp;
127 	}
128 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
129 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
130 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
131 		iap->ia_atime.tv_sec = tmp;
132 		iap->ia_atime.tv_nsec = tmp1 * 1000;
133 	}
134 	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
135 	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
136 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
137 		iap->ia_mtime.tv_sec = tmp;
138 		iap->ia_mtime.tv_nsec = tmp1 * 1000;
139 		/*
140 		 * Passing the invalid value useconds=1000000 for mtime
141 		 * is a Sun convention for "set both mtime and atime to
142 		 * current server time".  It's needed to make permissions
143 		 * checks for the "touch" program across v2 mounts to
144 		 * Solaris and Irix boxes work correctly. See description of
145 		 * sattr in section 6.1 of "NFS Illustrated" by
146 		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
147 		 */
148 		if (tmp1 == 1000000)
149 			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
150 	}
151 	return p;
152 }
153 
154 static inline u32 *
155 encode_fattr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
156 {
157 	struct vfsmount *mnt = fhp->fh_export->ex_mnt;
158 	struct dentry	*dentry = fhp->fh_dentry;
159 	struct kstat stat;
160 	int type;
161 	struct timespec time;
162 
163 	vfs_getattr(mnt, dentry, &stat);
164 	type = (stat.mode & S_IFMT);
165 
166 	*p++ = htonl(nfs_ftypes[type >> 12]);
167 	*p++ = htonl((u32) stat.mode);
168 	*p++ = htonl((u32) stat.nlink);
169 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat.uid));
170 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat.gid));
171 
172 	if (S_ISLNK(type) && stat.size > NFS_MAXPATHLEN) {
173 		*p++ = htonl(NFS_MAXPATHLEN);
174 	} else {
175 		*p++ = htonl((u32) stat.size);
176 	}
177 	*p++ = htonl((u32) stat.blksize);
178 	if (S_ISCHR(type) || S_ISBLK(type))
179 		*p++ = htonl(new_encode_dev(stat.rdev));
180 	else
181 		*p++ = htonl(0xffffffff);
182 	*p++ = htonl((u32) stat.blocks);
183 	if (is_fsid(fhp, rqstp->rq_reffh))
184 		*p++ = htonl((u32) fhp->fh_export->ex_fsid);
185 	else
186 		*p++ = htonl(new_encode_dev(stat.dev));
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 u32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
201 {
202 	return encode_fattr(rqstp, p, fhp);
203 }
204 
205 /*
206  * XDR decode functions
207  */
208 int
209 nfssvc_decode_void(struct svc_rqst *rqstp, u32 *p, void *dummy)
210 {
211 	return xdr_argsize_check(rqstp, p);
212 }
213 
214 int
215 nfssvc_decode_fhandle(struct svc_rqst *rqstp, u32 *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, u32 *p,
224 					struct nfsd_sattrargs *args)
225 {
226 	if (!(p = decode_fh(p, &args->fh))
227 	 || !(p = decode_sattr(p, &args->attrs)))
228 		return 0;
229 
230 	return xdr_argsize_check(rqstp, p);
231 }
232 
233 int
234 nfssvc_decode_diropargs(struct svc_rqst *rqstp, u32 *p,
235 					struct nfsd_diropargs *args)
236 {
237 	if (!(p = decode_fh(p, &args->fh))
238 	 || !(p = decode_filename(p, &args->name, &args->len)))
239 		return 0;
240 
241 	 return xdr_argsize_check(rqstp, p);
242 }
243 
244 int
245 nfssvc_decode_readargs(struct svc_rqst *rqstp, u32 *p,
246 					struct nfsd_readargs *args)
247 {
248 	unsigned int len;
249 	int v,pn;
250 	if (!(p = decode_fh(p, &args->fh)))
251 		return 0;
252 
253 	args->offset    = ntohl(*p++);
254 	len = args->count     = ntohl(*p++);
255 	p++; /* totalcount - unused */
256 
257 	if (len > NFSSVC_MAXBLKSIZE)
258 		len = NFSSVC_MAXBLKSIZE;
259 
260 	/* set up somewhere to store response.
261 	 * We take pages, put them on reslist and include in iovec
262 	 */
263 	v=0;
264 	while (len > 0) {
265 		pn=rqstp->rq_resused;
266 		svc_take_page(rqstp);
267 		args->vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
268 		args->vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
269 		len -= args->vec[v].iov_len;
270 		v++;
271 	}
272 	args->vlen = v;
273 	return xdr_argsize_check(rqstp, p);
274 }
275 
276 int
277 nfssvc_decode_writeargs(struct svc_rqst *rqstp, u32 *p,
278 					struct nfsd_writeargs *args)
279 {
280 	unsigned int len;
281 	int v;
282 	if (!(p = decode_fh(p, &args->fh)))
283 		return 0;
284 
285 	p++;				/* beginoffset */
286 	args->offset = ntohl(*p++);	/* offset */
287 	p++;				/* totalcount */
288 	len = args->len = ntohl(*p++);
289 	args->vec[0].iov_base = (void*)p;
290 	args->vec[0].iov_len = rqstp->rq_arg.head[0].iov_len -
291 				(((void*)p) - rqstp->rq_arg.head[0].iov_base);
292 	if (len > NFSSVC_MAXBLKSIZE)
293 		len = NFSSVC_MAXBLKSIZE;
294 	v = 0;
295 	while (len > args->vec[v].iov_len) {
296 		len -= args->vec[v].iov_len;
297 		v++;
298 		args->vec[v].iov_base = page_address(rqstp->rq_argpages[v]);
299 		args->vec[v].iov_len = PAGE_SIZE;
300 	}
301 	args->vec[v].iov_len = len;
302 	args->vlen = v+1;
303 	return args->vec[0].iov_len > 0;
304 }
305 
306 int
307 nfssvc_decode_createargs(struct svc_rqst *rqstp, u32 *p,
308 					struct nfsd_createargs *args)
309 {
310 	if (!(p = decode_fh(p, &args->fh))
311 	 || !(p = decode_filename(p, &args->name, &args->len))
312 	 || !(p = decode_sattr(p, &args->attrs)))
313 		return 0;
314 
315 	return xdr_argsize_check(rqstp, p);
316 }
317 
318 int
319 nfssvc_decode_renameargs(struct svc_rqst *rqstp, u32 *p,
320 					struct nfsd_renameargs *args)
321 {
322 	if (!(p = decode_fh(p, &args->ffh))
323 	 || !(p = decode_filename(p, &args->fname, &args->flen))
324 	 || !(p = decode_fh(p, &args->tfh))
325 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
326 		return 0;
327 
328 	return xdr_argsize_check(rqstp, p);
329 }
330 
331 int
332 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, u32 *p, struct nfsd_readlinkargs *args)
333 {
334 	if (!(p = decode_fh(p, &args->fh)))
335 		return 0;
336 	svc_take_page(rqstp);
337 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
338 
339 	return xdr_argsize_check(rqstp, p);
340 }
341 
342 int
343 nfssvc_decode_linkargs(struct svc_rqst *rqstp, u32 *p,
344 					struct nfsd_linkargs *args)
345 {
346 	if (!(p = decode_fh(p, &args->ffh))
347 	 || !(p = decode_fh(p, &args->tfh))
348 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
349 		return 0;
350 
351 	return xdr_argsize_check(rqstp, p);
352 }
353 
354 int
355 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, u32 *p,
356 					struct nfsd_symlinkargs *args)
357 {
358 	if (!(p = decode_fh(p, &args->ffh))
359 	 || !(p = decode_filename(p, &args->fname, &args->flen))
360 	 || !(p = decode_pathname(p, &args->tname, &args->tlen))
361 	 || !(p = decode_sattr(p, &args->attrs)))
362 		return 0;
363 
364 	return xdr_argsize_check(rqstp, p);
365 }
366 
367 int
368 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, u32 *p,
369 					struct nfsd_readdirargs *args)
370 {
371 	if (!(p = decode_fh(p, &args->fh)))
372 		return 0;
373 	args->cookie = ntohl(*p++);
374 	args->count  = ntohl(*p++);
375 	if (args->count > PAGE_SIZE)
376 		args->count = PAGE_SIZE;
377 
378 	svc_take_page(rqstp);
379 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
380 
381 	return xdr_argsize_check(rqstp, p);
382 }
383 
384 /*
385  * XDR encode functions
386  */
387 int
388 nfssvc_encode_void(struct svc_rqst *rqstp, u32 *p, void *dummy)
389 {
390 	return xdr_ressize_check(rqstp, p);
391 }
392 
393 int
394 nfssvc_encode_attrstat(struct svc_rqst *rqstp, u32 *p,
395 					struct nfsd_attrstat *resp)
396 {
397 	p = encode_fattr(rqstp, p, &resp->fh);
398 	return xdr_ressize_check(rqstp, p);
399 }
400 
401 int
402 nfssvc_encode_diropres(struct svc_rqst *rqstp, u32 *p,
403 					struct nfsd_diropres *resp)
404 {
405 	p = encode_fh(p, &resp->fh);
406 	p = encode_fattr(rqstp, p, &resp->fh);
407 	return xdr_ressize_check(rqstp, p);
408 }
409 
410 int
411 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, u32 *p,
412 					struct nfsd_readlinkres *resp)
413 {
414 	*p++ = htonl(resp->len);
415 	xdr_ressize_check(rqstp, p);
416 	rqstp->rq_res.page_len = resp->len;
417 	if (resp->len & 3) {
418 		/* need to pad the tail */
419 		rqstp->rq_restailpage = 0;
420 		rqstp->rq_res.tail[0].iov_base = p;
421 		*p = 0;
422 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
423 	}
424 	return 1;
425 }
426 
427 int
428 nfssvc_encode_readres(struct svc_rqst *rqstp, u32 *p,
429 					struct nfsd_readres *resp)
430 {
431 	p = encode_fattr(rqstp, p, &resp->fh);
432 	*p++ = htonl(resp->count);
433 	xdr_ressize_check(rqstp, p);
434 
435 	/* now update rqstp->rq_res to reflect data aswell */
436 	rqstp->rq_res.page_len = resp->count;
437 	if (resp->count & 3) {
438 		/* need to pad the tail */
439 		rqstp->rq_restailpage = 0;
440 		rqstp->rq_res.tail[0].iov_base = p;
441 		*p = 0;
442 		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
443 	}
444 	return 1;
445 }
446 
447 int
448 nfssvc_encode_readdirres(struct svc_rqst *rqstp, u32 *p,
449 					struct nfsd_readdirres *resp)
450 {
451 	xdr_ressize_check(rqstp, p);
452 	p = resp->buffer;
453 	*p++ = 0;			/* no more entries */
454 	*p++ = htonl((resp->common.err == nfserr_eof));
455 	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
456 
457 	return 1;
458 }
459 
460 int
461 nfssvc_encode_statfsres(struct svc_rqst *rqstp, u32 *p,
462 					struct nfsd_statfsres *resp)
463 {
464 	struct kstatfs	*stat = &resp->stats;
465 
466 	*p++ = htonl(NFSSVC_MAXBLKSIZE);	/* max transfer size */
467 	*p++ = htonl(stat->f_bsize);
468 	*p++ = htonl(stat->f_blocks);
469 	*p++ = htonl(stat->f_bfree);
470 	*p++ = htonl(stat->f_bavail);
471 	return xdr_ressize_check(rqstp, p);
472 }
473 
474 int
475 nfssvc_encode_entry(struct readdir_cd *ccd, const char *name,
476 		    int namlen, loff_t offset, ino_t ino, unsigned int d_type)
477 {
478 	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
479 	u32	*p = cd->buffer;
480 	int	buflen, slen;
481 
482 	/*
483 	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
484 			namlen, name, offset, ino);
485 	 */
486 
487 	if (offset > ~((u32) 0)) {
488 		cd->common.err = nfserr_fbig;
489 		return -EINVAL;
490 	}
491 	if (cd->offset)
492 		*cd->offset = htonl(offset);
493 	if (namlen > NFS2_MAXNAMLEN)
494 		namlen = NFS2_MAXNAMLEN;/* truncate filename */
495 
496 	slen = XDR_QUADLEN(namlen);
497 	if ((buflen = cd->buflen - slen - 4) < 0) {
498 		cd->common.err = nfserr_toosmall;
499 		return -EINVAL;
500 	}
501 	*p++ = xdr_one;				/* mark entry present */
502 	*p++ = htonl((u32) ino);		/* file id */
503 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
504 	cd->offset = p;			/* remember pointer */
505 	*p++ = ~(u32) 0;		/* offset of next entry */
506 
507 	cd->buflen = buflen;
508 	cd->buffer = p;
509 	cd->common.err = nfs_ok;
510 	return 0;
511 }
512 
513 /*
514  * XDR release functions
515  */
516 int
517 nfssvc_release_fhandle(struct svc_rqst *rqstp, u32 *p,
518 					struct nfsd_fhandle *resp)
519 {
520 	fh_put(&resp->fh);
521 	return 1;
522 }
523