xref: /openbmc/linux/fs/nfsd/nfsxdr.c (revision 5a244f48) 
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(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   */
208  int
209  nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p)
210  {
211  	return xdr_argsize_check(rqstp, p);
212  }
213  
214  int
215  nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
216  {
217  	struct nfsd_fhandle *args = rqstp->rq_argp;
218  
219  	p = decode_fh(p, &args->fh);
220  	if (!p)
221  		return 0;
222  	return xdr_argsize_check(rqstp, p);
223  }
224  
225  int
226  nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
227  {
228  	struct nfsd_sattrargs *args = rqstp->rq_argp;
229  
230  	p = decode_fh(p, &args->fh);
231  	if (!p)
232  		return 0;
233  	p = decode_sattr(p, &args->attrs);
234  
235  	return xdr_argsize_check(rqstp, p);
236  }
237  
238  int
239  nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
240  {
241  	struct nfsd_diropargs *args = rqstp->rq_argp;
242  
243  	if (!(p = decode_fh(p, &args->fh))
244  	 || !(p = decode_filename(p, &args->name, &args->len)))
245  		return 0;
246  
247  	return xdr_argsize_check(rqstp, p);
248  }
249  
250  int
251  nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
252  {
253  	struct nfsd_readargs *args = rqstp->rq_argp;
254  	unsigned int len;
255  	int v;
256  	p = decode_fh(p, &args->fh);
257  	if (!p)
258  		return 0;
259  
260  	args->offset    = ntohl(*p++);
261  	len = args->count     = ntohl(*p++);
262  	p++; /* totalcount - unused */
263  
264  	len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
265  
266  	/* set up somewhere to store response.
267  	 * We take pages, put them on reslist and include in iovec
268  	 */
269  	v=0;
270  	while (len > 0) {
271  		struct page *p = *(rqstp->rq_next_page++);
272  
273  		rqstp->rq_vec[v].iov_base = page_address(p);
274  		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
275  		len -= rqstp->rq_vec[v].iov_len;
276  		v++;
277  	}
278  	args->vlen = v;
279  	return xdr_argsize_check(rqstp, p);
280  }
281  
282  int
283  nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
284  {
285  	struct nfsd_writeargs *args = rqstp->rq_argp;
286  	unsigned int len, hdr, dlen;
287  	struct kvec *head = rqstp->rq_arg.head;
288  	int v;
289  
290  	p = decode_fh(p, &args->fh);
291  	if (!p)
292  		return 0;
293  
294  	p++;				/* beginoffset */
295  	args->offset = ntohl(*p++);	/* offset */
296  	p++;				/* totalcount */
297  	len = args->len = ntohl(*p++);
298  	/*
299  	 * The protocol specifies a maximum of 8192 bytes.
300  	 */
301  	if (len > NFSSVC_MAXBLKSIZE_V2)
302  		return 0;
303  
304  	/*
305  	 * Check to make sure that we got the right number of
306  	 * bytes.
307  	 */
308  	hdr = (void*)p - head->iov_base;
309  	if (hdr > head->iov_len)
310  		return 0;
311  	dlen = head->iov_len + rqstp->rq_arg.page_len - 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 = head->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  {
341  	struct nfsd_createargs *args = rqstp->rq_argp;
342  
343  	if (   !(p = decode_fh(p, &args->fh))
344  	    || !(p = decode_filename(p, &args->name, &args->len)))
345  		return 0;
346  	p = decode_sattr(p, &args->attrs);
347  
348  	return xdr_argsize_check(rqstp, p);
349  }
350  
351  int
352  nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
353  {
354  	struct nfsd_renameargs *args = rqstp->rq_argp;
355  
356  	if (!(p = decode_fh(p, &args->ffh))
357  	 || !(p = decode_filename(p, &args->fname, &args->flen))
358  	 || !(p = decode_fh(p, &args->tfh))
359  	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
360  		return 0;
361  
362  	return xdr_argsize_check(rqstp, p);
363  }
364  
365  int
366  nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
367  {
368  	struct nfsd_readlinkargs *args = rqstp->rq_argp;
369  
370  	p = decode_fh(p, &args->fh);
371  	if (!p)
372  		return 0;
373  	args->buffer = page_address(*(rqstp->rq_next_page++));
374  
375  	return xdr_argsize_check(rqstp, p);
376  }
377  
378  int
379  nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
380  {
381  	struct nfsd_linkargs *args = rqstp->rq_argp;
382  
383  	if (!(p = decode_fh(p, &args->ffh))
384  	 || !(p = decode_fh(p, &args->tfh))
385  	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
386  		return 0;
387  
388  	return xdr_argsize_check(rqstp, p);
389  }
390  
391  int
392  nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
393  {
394  	struct nfsd_symlinkargs *args = rqstp->rq_argp;
395  
396  	if (   !(p = decode_fh(p, &args->ffh))
397  	    || !(p = decode_filename(p, &args->fname, &args->flen))
398  	    || !(p = decode_pathname(p, &args->tname, &args->tlen)))
399  		return 0;
400  	p = decode_sattr(p, &args->attrs);
401  
402  	return xdr_argsize_check(rqstp, p);
403  }
404  
405  int
406  nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
407  {
408  	struct nfsd_readdirargs *args = rqstp->rq_argp;
409  
410  	p = decode_fh(p, &args->fh);
411  	if (!p)
412  		return 0;
413  	args->cookie = ntohl(*p++);
414  	args->count  = ntohl(*p++);
415  	args->count  = min_t(u32, args->count, PAGE_SIZE);
416  	args->buffer = page_address(*(rqstp->rq_next_page++));
417  
418  	return xdr_argsize_check(rqstp, p);
419  }
420  
421  /*
422   * XDR encode functions
423   */
424  int
425  nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p)
426  {
427  	return xdr_ressize_check(rqstp, p);
428  }
429  
430  int
431  nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
432  {
433  	struct nfsd_attrstat *resp = rqstp->rq_resp;
434  
435  	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
436  	return xdr_ressize_check(rqstp, p);
437  }
438  
439  int
440  nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
441  {
442  	struct nfsd_diropres *resp = rqstp->rq_resp;
443  
444  	p = encode_fh(p, &resp->fh);
445  	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
446  	return xdr_ressize_check(rqstp, p);
447  }
448  
449  int
450  nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
451  {
452  	struct nfsd_readlinkres *resp = rqstp->rq_resp;
453  
454  	*p++ = htonl(resp->len);
455  	xdr_ressize_check(rqstp, p);
456  	rqstp->rq_res.page_len = resp->len;
457  	if (resp->len & 3) {
458  		/* need to pad the tail */
459  		rqstp->rq_res.tail[0].iov_base = p;
460  		*p = 0;
461  		rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
462  	}
463  	return 1;
464  }
465  
466  int
467  nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
468  {
469  	struct nfsd_readres *resp = rqstp->rq_resp;
470  
471  	p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
472  	*p++ = htonl(resp->count);
473  	xdr_ressize_check(rqstp, p);
474  
475  	/* now update rqstp->rq_res to reflect data as well */
476  	rqstp->rq_res.page_len = resp->count;
477  	if (resp->count & 3) {
478  		/* need to pad the tail */
479  		rqstp->rq_res.tail[0].iov_base = p;
480  		*p = 0;
481  		rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
482  	}
483  	return 1;
484  }
485  
486  int
487  nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
488  {
489  	struct nfsd_readdirres *resp = rqstp->rq_resp;
490  
491  	xdr_ressize_check(rqstp, p);
492  	p = resp->buffer;
493  	*p++ = 0;			/* no more entries */
494  	*p++ = htonl((resp->common.err == nfserr_eof));
495  	rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
496  
497  	return 1;
498  }
499  
500  int
501  nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p)
502  {
503  	struct nfsd_statfsres *resp = rqstp->rq_resp;
504  	struct kstatfs	*stat = &resp->stats;
505  
506  	*p++ = htonl(NFSSVC_MAXBLKSIZE_V2);	/* max transfer size */
507  	*p++ = htonl(stat->f_bsize);
508  	*p++ = htonl(stat->f_blocks);
509  	*p++ = htonl(stat->f_bfree);
510  	*p++ = htonl(stat->f_bavail);
511  	return xdr_ressize_check(rqstp, p);
512  }
513  
514  int
515  nfssvc_encode_entry(void *ccdv, const char *name,
516  		    int namlen, loff_t offset, u64 ino, unsigned int d_type)
517  {
518  	struct readdir_cd *ccd = ccdv;
519  	struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
520  	__be32	*p = cd->buffer;
521  	int	buflen, slen;
522  
523  	/*
524  	dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
525  			namlen, name, offset, ino);
526  	 */
527  
528  	if (offset > ~((u32) 0)) {
529  		cd->common.err = nfserr_fbig;
530  		return -EINVAL;
531  	}
532  	if (cd->offset)
533  		*cd->offset = htonl(offset);
534  
535  	/* truncate filename */
536  	namlen = min(namlen, NFS2_MAXNAMLEN);
537  	slen = XDR_QUADLEN(namlen);
538  
539  	if ((buflen = cd->buflen - slen - 4) < 0) {
540  		cd->common.err = nfserr_toosmall;
541  		return -EINVAL;
542  	}
543  	if (ino > ~((u32) 0)) {
544  		cd->common.err = nfserr_fbig;
545  		return -EINVAL;
546  	}
547  	*p++ = xdr_one;				/* mark entry present */
548  	*p++ = htonl((u32) ino);		/* file id */
549  	p    = xdr_encode_array(p, name, namlen);/* name length & name */
550  	cd->offset = p;			/* remember pointer */
551  	*p++ = htonl(~0U);		/* offset of next entry */
552  
553  	cd->buflen = buflen;
554  	cd->buffer = p;
555  	cd->common.err = nfs_ok;
556  	return 0;
557  }
558  
559  /*
560   * XDR release functions
561   */
562  void
563  nfssvc_release_fhandle(struct svc_rqst *rqstp)
564  {
565  	struct nfsd_fhandle *resp = rqstp->rq_resp;
566  
567  	fh_put(&resp->fh);
568  }
569