xref: /openbmc/linux/fs/nfsd/nfsxdr.c (revision af958a38)
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  	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