aboutsummaryrefslogtreecommitdiffstats
path: root/fs/nfs/callback_xdr.c
blob: 849a2029975da9ddc1fac7f1da14fb52561c1106 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
/*
 * linux/fs/nfs/callback_xdr.c
 *
 * Copyright (C) 2004 Trond Myklebust
 *
 * NFSv4 callback encode/decode procedures
 */
#include <linux/kernel.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include "nfs4_fs.h"
#include "callback.h"

#define CB_OP_TAGLEN_MAXSZ	(512)
#define CB_OP_HDR_RES_MAXSZ	(2 + CB_OP_TAGLEN_MAXSZ)
#define CB_OP_GETATTR_BITMAP_MAXSZ	(4)
#define CB_OP_GETATTR_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ + \
				CB_OP_GETATTR_BITMAP_MAXSZ + \
				2 + 2 + 3 + 3)
#define CB_OP_RECALL_RES_MAXSZ	(CB_OP_HDR_RES_MAXSZ)

#define NFSDBG_FACILITY NFSDBG_CALLBACK

typedef __be32 (*callback_process_op_t)(void *, void *);
typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);


struct callback_op {
	callback_process_op_t process_op;
	callback_decode_arg_t decode_args;
	callback_encode_res_t encode_res;
	long res_maxsize;
};

static struct callback_op callback_ops[];

static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
{
	return htonl(NFS4_OK);
}

static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
	return xdr_argsize_check(rqstp, p);
}

static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
	return xdr_ressize_check(rqstp, p);
}

static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, nbytes);
	if (unlikely(p == NULL))
		printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
	return p;
}

static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
{
	__be32 *p;

	p = read_buf(xdr, 4);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	*len = ntohl(*p);

	if (*len != 0) {
		p = read_buf(xdr, *len);
		if (unlikely(p == NULL))
			return htonl(NFS4ERR_RESOURCE);
		*str = (const char *)p;
	} else
		*str = NULL;

	return 0;
}

static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
{
	__be32 *p;

	p = read_buf(xdr, 4);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	fh->size = ntohl(*p);
	if (fh->size > NFS4_FHSIZE)
		return htonl(NFS4ERR_BADHANDLE);
	p = read_buf(xdr, fh->size);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	memcpy(&fh->data[0], p, fh->size);
	memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
	return 0;
}

static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
{
	__be32 *p;
	unsigned int attrlen;

	p = read_buf(xdr, 4);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	attrlen = ntohl(*p);
	p = read_buf(xdr, attrlen << 2);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	if (likely(attrlen > 0))
		bitmap[0] = ntohl(*p++);
	if (attrlen > 1)
		bitmap[1] = ntohl(*p);
	return 0;
}

static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
{
	__be32 *p;

	p = read_buf(xdr, 16);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	memcpy(stateid->data, p, 16);
	return 0;
}

static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
{
	__be32 *p;
	unsigned int minor_version;
	__be32 status;

	status = decode_string(xdr, &hdr->taglen, &hdr->tag);
	if (unlikely(status != 0))
		return status;
	/* We do not like overly long tags! */
	if (hdr->taglen > CB_OP_TAGLEN_MAXSZ-12 || hdr->taglen < 0) {
		printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
				__FUNCTION__, hdr->taglen);
		return htonl(NFS4ERR_RESOURCE);
	}
	p = read_buf(xdr, 12);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	minor_version = ntohl(*p++);
	/* Check minor version is zero. */
	if (minor_version != 0) {
		printk(KERN_WARNING "%s: NFSv4 server callback with illegal minor version %u!\n",
				__FUNCTION__, minor_version);
		return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
	}
	hdr->callback_ident = ntohl(*p++);
	hdr->nops = ntohl(*p);
	return 0;
}

static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
{
	__be32 *p;
	p = read_buf(xdr, 4);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	*op = ntohl(*p);
	return 0;
}

static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
{
	__be32 status;

	status = decode_fh(xdr, &args->fh);
	if (unlikely(status != 0))
		goto out;
	args->addr = svc_addr_in(rqstp);
	status = decode_bitmap(xdr, args->bitmap);
out:
	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
	return status;
}

static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
{
	__be32 *p;
	__be32 status;

	args->addr = svc_addr_in(rqstp);
	status = decode_stateid(xdr, &args->stateid);
	if (unlikely(status != 0))
		goto out;
	p = read_buf(xdr, 4);
	if (unlikely(p == NULL)) {
		status = htonl(NFS4ERR_RESOURCE);
		goto out;
	}
	args->truncate = ntohl(*p);
	status = decode_fh(xdr, &args->fh);
out:
	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
	return status;
}

static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 4 + len);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	xdr_encode_opaque(p, str, len);
	return 0;
}

#define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
#define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
{
	__be32 bm[2];
	__be32 *p;

	bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
	bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
	if (bm[1] != 0) {
		p = xdr_reserve_space(xdr, 16);
		if (unlikely(p == NULL))
			return htonl(NFS4ERR_RESOURCE);
		*p++ = htonl(2);
		*p++ = bm[0];
		*p++ = bm[1];
	} else if (bm[0] != 0) {
		p = xdr_reserve_space(xdr, 12);
		if (unlikely(p == NULL))
			return htonl(NFS4ERR_RESOURCE);
		*p++ = htonl(1);
		*p++ = bm[0];
	} else {
		p = xdr_reserve_space(xdr, 8);
		if (unlikely(p == NULL))
			return htonl(NFS4ERR_RESOURCE);
		*p++ = htonl(0);
	}
	*savep = p;
	return 0;
}

static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
{
	__be32 *p;

	if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
		return 0;
	p = xdr_reserve_space(xdr, 8);
	if (unlikely(p == 0))
		return htonl(NFS4ERR_RESOURCE);
	p = xdr_encode_hyper(p, change);
	return 0;
}

static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
{
	__be32 *p;

	if (!(bitmap[0] & FATTR4_WORD0_SIZE))
		return 0;
	p = xdr_reserve_space(xdr, 8);
	if (unlikely(p == 0))
		return htonl(NFS4ERR_RESOURCE);
	p = xdr_encode_hyper(p, size);
	return 0;
}

static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 12);
	if (unlikely(p == 0))
		return htonl(NFS4ERR_RESOURCE);
	p = xdr_encode_hyper(p, time->tv_sec);
	*p = htonl(time->tv_nsec);
	return 0;
}

static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
{
	if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
		return 0;
	return encode_attr_time(xdr,time);
}

static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
{
	if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
		return 0;
	return encode_attr_time(xdr,time);
}

static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
{
	__be32 status;

	hdr->status = xdr_reserve_space(xdr, 4);
	if (unlikely(hdr->status == NULL))
		return htonl(NFS4ERR_RESOURCE);
	status = encode_string(xdr, hdr->taglen, hdr->tag);
	if (unlikely(status != 0))
		return status;
	hdr->nops = xdr_reserve_space(xdr, 4);
	if (unlikely(hdr->nops == NULL))
		return htonl(NFS4ERR_RESOURCE);
	return 0;
}

static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
{
	__be32 *p;
	
	p = xdr_reserve_space(xdr, 8);
	if (unlikely(p == NULL))
		return htonl(NFS4ERR_RESOURCE);
	*p++ = htonl(op);
	*p = res;
	return 0;
}

static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
{
	__be32 *savep = NULL;
	__be32 status = res->status;
	
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_bitmap(xdr, res->bitmap, &savep);
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_change(xdr, res->bitmap, res->change_attr);
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_size(xdr, res->bitmap, res->size);
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
	if (unlikely(status != 0))
		goto out;
	status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
	*savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
out:
	dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
	return status;
}

static __be32 process_op(struct svc_rqst *rqstp,
		struct xdr_stream *xdr_in, void *argp,
		struct xdr_stream *xdr_out, void *resp)
{
	struct callback_op *op = &callback_ops[0];
	unsigned int op_nr = OP_CB_ILLEGAL;
	__be32 status = 0;
	long maxlen;
	__be32 res;

	dprintk("%s: start\n", __FUNCTION__);
	status = decode_op_hdr(xdr_in, &op_nr);
	if (likely(status == 0)) {
		switch (op_nr) {
			case OP_CB_GETATTR:
			case OP_CB_RECALL:
				op = &callback_ops[op_nr];
				break;
			default:
				op_nr = OP_CB_ILLEGAL;
				op = &callback_ops[0];
				status = htonl(NFS4ERR_OP_ILLEGAL);
		}
	}

	maxlen = xdr_out->end - xdr_out->p;
	if (maxlen > 0 && maxlen < PAGE_SIZE) {
		if (likely(status == 0 && op->decode_args != NULL))
			status = op->decode_args(rqstp, xdr_in, argp);
		if (likely(status == 0 && op->process_op != NULL))
			status = op->process_op(argp, resp);
	} else
		status = htonl(NFS4ERR_RESOURCE);

	res = encode_op_hdr(xdr_out, op_nr, status);
	if (status == 0)
		status = res;
	if (op->encode_res != NULL && status == 0)
		status = op->encode_res(rqstp, xdr_out, resp);
	dprintk("%s: done, status = %d\n", __FUNCTION__, status);
	return status;
}

/*
 * Decode, process and encode a COMPOUND
 */
static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
{
	struct cb_compound_hdr_arg hdr_arg;
	struct cb_compound_hdr_res hdr_res;
	struct xdr_stream xdr_in, xdr_out;
	__be32 *p;
	__be32 status;
	unsigned int nops = 1;

	dprintk("%s: start\n", __FUNCTION__);

	xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);

	p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
	xdr_init_encode(&xdr_out, &rqstp->rq_res, p);

	decode_compound_hdr_arg(&xdr_in, &hdr_arg);
	hdr_res.taglen = hdr_arg.taglen;
	hdr_res.tag = hdr_arg.tag;
	hdr_res.nops = NULL;
	encode_compound_hdr_res(&xdr_out, &hdr_res);

	for (;;) {
		status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp);
		if (status != 0)
			break;
		if (nops == hdr_arg.nops)
			break;
		nops++;
	}
	*hdr_res.status = status;
	*hdr_res.nops = htonl(nops);
	dprintk("%s: done, status = %u\n", __FUNCTION__, status);
	return rpc_success;
}

/*
 * Define NFS4 callback COMPOUND ops.
 */
static struct callback_op callback_ops[] = {
	[0] = {
		.res_maxsize = CB_OP_HDR_RES_MAXSZ,
	},
	[OP_CB_GETATTR] = {
		.process_op = (callback_process_op_t)nfs4_callback_getattr,
		.decode_args = (callback_decode_arg_t)decode_getattr_args,
		.encode_res = (callback_encode_res_t)encode_getattr_res,
		.res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
	},
	[OP_CB_RECALL] = {
		.process_op = (callback_process_op_t)nfs4_callback_recall,
		.decode_args = (callback_decode_arg_t)decode_recall_args,
		.res_maxsize = CB_OP_RECALL_RES_MAXSZ,
	}
};

/*
 * Define NFS4 callback procedures
 */
static struct svc_procedure nfs4_callback_procedures1[] = {
	[CB_NULL] = {
		.pc_func = nfs4_callback_null,
		.pc_decode = (kxdrproc_t)nfs4_decode_void,
		.pc_encode = (kxdrproc_t)nfs4_encode_void,
		.pc_xdrressize = 1,
	},
	[CB_COMPOUND] = {
		.pc_func = nfs4_callback_compound,
		.pc_encode = (kxdrproc_t)nfs4_encode_void,
		.pc_argsize = 256,
		.pc_ressize = 256,
		.pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
	}
};

struct svc_version nfs4_callback_version1 = {
	.vs_vers = 1,
	.vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
	.vs_proc = nfs4_callback_procedures1,
	.vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
	.vs_dispatch = NULL,
};