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 */
16static 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 */
27static __be32 *
28decode_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
45static __be32 *
46encode_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 */
56static __be32 *
57decode_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
72static __be32 *
73decode_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
88static __be32 *
89decode_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
143static __be32 *
144encode_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 */
208int
209nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
210{
211	return xdr_argsize_check(rqstp, p);
212}
213
214int
215nfssvc_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
223int
224nfssvc_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
235int
236nfssvc_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
246int
247nfssvc_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
278int
279nfssvc_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
332int
333nfssvc_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
344int
345nfssvc_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
357int
358nfssvc_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
368int
369nfssvc_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
380int
381nfssvc_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
393int
394nfssvc_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 */
411int
412nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
413{
414	return xdr_ressize_check(rqstp, p);
415}
416
417int
418nfssvc_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
425int
426nfssvc_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
434int
435nfssvc_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
450int
451nfssvc_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
469int
470nfssvc_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
482int
483nfssvc_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
496int
497nfssvc_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 */
544int
545nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
546					struct nfsd_fhandle *resp)
547{
548	fh_put(&resp->fh);
549	return 1;
550}
551