blob: d271df9df2b28baa9798101f79bffb63c5f9af37 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfs/callback_xdr.c
3 *
4 * Copyright (C) 2004 Trond Myklebust
5 *
6 * NFSv4 callback encode/decode procedures
7 */
8#include <linux/config.h>
9#include <linux/kernel.h>
10#include <linux/sunrpc/svc.h>
11#include <linux/nfs4.h>
12#include <linux/nfs_fs.h>
13#include "callback.h"
14
15#define CB_OP_TAGLEN_MAXSZ (512)
16#define CB_OP_HDR_RES_MAXSZ (2 + CB_OP_TAGLEN_MAXSZ)
17#define CB_OP_GETATTR_BITMAP_MAXSZ (4)
18#define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
19 CB_OP_GETATTR_BITMAP_MAXSZ + \
20 2 + 2 + 3 + 3)
21#define CB_OP_RECALL_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ)
22
23#define NFSDBG_FACILITY NFSDBG_CALLBACK
24
25typedef unsigned (*callback_process_op_t)(void *, void *);
26typedef unsigned (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
27typedef unsigned (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
28
29
30struct callback_op {
31 callback_process_op_t process_op;
32 callback_decode_arg_t decode_args;
33 callback_encode_res_t encode_res;
34 long res_maxsize;
35};
36
37static struct callback_op callback_ops[];
38
39static int nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
40{
41 return htonl(NFS4_OK);
42}
43
44static int nfs4_decode_void(struct svc_rqst *rqstp, uint32_t *p, void *dummy)
45{
46 return xdr_argsize_check(rqstp, p);
47}
48
49static int nfs4_encode_void(struct svc_rqst *rqstp, uint32_t *p, void *dummy)
50{
51 return xdr_ressize_check(rqstp, p);
52}
53
54static uint32_t *read_buf(struct xdr_stream *xdr, int nbytes)
55{
56 uint32_t *p;
57
58 p = xdr_inline_decode(xdr, nbytes);
59 if (unlikely(p == NULL))
60 printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
61 return p;
62}
63
64static unsigned decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
65{
66 uint32_t *p;
67
68 p = read_buf(xdr, 4);
69 if (unlikely(p == NULL))
70 return htonl(NFS4ERR_RESOURCE);
71 *len = ntohl(*p);
72
73 if (*len != 0) {
74 p = read_buf(xdr, *len);
75 if (unlikely(p == NULL))
76 return htonl(NFS4ERR_RESOURCE);
77 *str = (const char *)p;
78 } else
79 *str = NULL;
80
81 return 0;
82}
83
84static unsigned decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
85{
86 uint32_t *p;
87
88 p = read_buf(xdr, 4);
89 if (unlikely(p == NULL))
90 return htonl(NFS4ERR_RESOURCE);
91 fh->size = ntohl(*p);
92 if (fh->size > NFS4_FHSIZE)
93 return htonl(NFS4ERR_BADHANDLE);
94 p = read_buf(xdr, fh->size);
95 if (unlikely(p == NULL))
96 return htonl(NFS4ERR_RESOURCE);
97 memcpy(&fh->data[0], p, fh->size);
98 memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
99 return 0;
100}
101
102static unsigned decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
103{
104 uint32_t *p;
105 unsigned int attrlen;
106
107 p = read_buf(xdr, 4);
108 if (unlikely(p == NULL))
109 return htonl(NFS4ERR_RESOURCE);
110 attrlen = ntohl(*p);
111 p = read_buf(xdr, attrlen << 2);
112 if (unlikely(p == NULL))
113 return htonl(NFS4ERR_RESOURCE);
114 if (likely(attrlen > 0))
115 bitmap[0] = ntohl(*p++);
116 if (attrlen > 1)
117 bitmap[1] = ntohl(*p);
118 return 0;
119}
120
121static unsigned decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
122{
123 uint32_t *p;
124
125 p = read_buf(xdr, 16);
126 if (unlikely(p == NULL))
127 return htonl(NFS4ERR_RESOURCE);
128 memcpy(stateid->data, p, 16);
129 return 0;
130}
131
132static unsigned decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
133{
134 uint32_t *p;
135 unsigned int minor_version;
136 unsigned status;
137
138 status = decode_string(xdr, &hdr->taglen, &hdr->tag);
139 if (unlikely(status != 0))
140 return status;
141 /* We do not like overly long tags! */
142 if (hdr->taglen > CB_OP_TAGLEN_MAXSZ-12 || hdr->taglen < 0) {
143 printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
144 __FUNCTION__, hdr->taglen);
145 return htonl(NFS4ERR_RESOURCE);
146 }
147 p = read_buf(xdr, 12);
148 if (unlikely(p == NULL))
149 return htonl(NFS4ERR_RESOURCE);
150 minor_version = ntohl(*p++);
151 /* Check minor version is zero. */
152 if (minor_version != 0) {
153 printk(KERN_WARNING "%s: NFSv4 server callback with illegal minor version %u!\n",
154 __FUNCTION__, minor_version);
155 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
156 }
157 hdr->callback_ident = ntohl(*p++);
158 hdr->nops = ntohl(*p);
159 return 0;
160}
161
162static unsigned decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
163{
164 uint32_t *p;
165 p = read_buf(xdr, 4);
166 if (unlikely(p == NULL))
167 return htonl(NFS4ERR_RESOURCE);
168 *op = ntohl(*p);
169 return 0;
170}
171
172static unsigned decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
173{
174 unsigned status;
175
176 status = decode_fh(xdr, &args->fh);
177 if (unlikely(status != 0))
178 goto out;
179 args->addr = &rqstp->rq_addr;
180 status = decode_bitmap(xdr, args->bitmap);
181out:
182 dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
183 return status;
184}
185
186static unsigned decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
187{
188 uint32_t *p;
189 unsigned status;
190
191 args->addr = &rqstp->rq_addr;
192 status = decode_stateid(xdr, &args->stateid);
193 if (unlikely(status != 0))
194 goto out;
195 p = read_buf(xdr, 4);
196 if (unlikely(p == NULL)) {
197 status = htonl(NFS4ERR_RESOURCE);
198 goto out;
199 }
200 args->truncate = ntohl(*p);
201 status = decode_fh(xdr, &args->fh);
202out:
203 dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
204 return 0;
205}
206
207static unsigned encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
208{
209 uint32_t *p;
210
211 p = xdr_reserve_space(xdr, 4 + len);
212 if (unlikely(p == NULL))
213 return htonl(NFS4ERR_RESOURCE);
214 xdr_encode_opaque(p, str, len);
215 return 0;
216}
217
218#define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
219#define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
220static unsigned encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, uint32_t **savep)
221{
222 uint32_t bm[2];
223 uint32_t *p;
224
225 bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
226 bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
227 if (bm[1] != 0) {
228 p = xdr_reserve_space(xdr, 16);
229 if (unlikely(p == NULL))
230 return htonl(NFS4ERR_RESOURCE);
231 *p++ = htonl(2);
232 *p++ = bm[0];
233 *p++ = bm[1];
234 } else if (bm[0] != 0) {
235 p = xdr_reserve_space(xdr, 12);
236 if (unlikely(p == NULL))
237 return htonl(NFS4ERR_RESOURCE);
238 *p++ = htonl(1);
239 *p++ = bm[0];
240 } else {
241 p = xdr_reserve_space(xdr, 8);
242 if (unlikely(p == NULL))
243 return htonl(NFS4ERR_RESOURCE);
244 *p++ = htonl(0);
245 }
246 *savep = p;
247 return 0;
248}
249
250static unsigned encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
251{
252 uint32_t *p;
253
254 if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
255 return 0;
256 p = xdr_reserve_space(xdr, 8);
257 if (unlikely(p == 0))
258 return htonl(NFS4ERR_RESOURCE);
259 p = xdr_encode_hyper(p, change);
260 return 0;
261}
262
263static unsigned encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
264{
265 uint32_t *p;
266
267 if (!(bitmap[0] & FATTR4_WORD0_SIZE))
268 return 0;
269 p = xdr_reserve_space(xdr, 8);
270 if (unlikely(p == 0))
271 return htonl(NFS4ERR_RESOURCE);
272 p = xdr_encode_hyper(p, size);
273 return 0;
274}
275
276static unsigned encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
277{
278 uint32_t *p;
279
280 p = xdr_reserve_space(xdr, 12);
281 if (unlikely(p == 0))
282 return htonl(NFS4ERR_RESOURCE);
283 p = xdr_encode_hyper(p, time->tv_sec);
284 *p = htonl(time->tv_nsec);
285 return 0;
286}
287
288static unsigned encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
289{
290 if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
291 return 0;
292 return encode_attr_time(xdr,time);
293}
294
295static unsigned encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
296{
297 if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
298 return 0;
299 return encode_attr_time(xdr,time);
300}
301
302static unsigned encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
303{
304 unsigned status;
305
306 hdr->status = xdr_reserve_space(xdr, 4);
307 if (unlikely(hdr->status == NULL))
308 return htonl(NFS4ERR_RESOURCE);
309 status = encode_string(xdr, hdr->taglen, hdr->tag);
310 if (unlikely(status != 0))
311 return status;
312 hdr->nops = xdr_reserve_space(xdr, 4);
313 if (unlikely(hdr->nops == NULL))
314 return htonl(NFS4ERR_RESOURCE);
315 return 0;
316}
317
318static unsigned encode_op_hdr(struct xdr_stream *xdr, uint32_t op, uint32_t res)
319{
320 uint32_t *p;
321
322 p = xdr_reserve_space(xdr, 8);
323 if (unlikely(p == NULL))
324 return htonl(NFS4ERR_RESOURCE);
325 *p++ = htonl(op);
326 *p = res;
327 return 0;
328}
329
330static unsigned encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
331{
332 uint32_t *savep;
333 unsigned status = res->status;
334
335 if (unlikely(status != 0))
336 goto out;
337 status = encode_attr_bitmap(xdr, res->bitmap, &savep);
338 if (unlikely(status != 0))
339 goto out;
340 status = encode_attr_change(xdr, res->bitmap, res->change_attr);
341 if (unlikely(status != 0))
342 goto out;
343 status = encode_attr_size(xdr, res->bitmap, res->size);
344 if (unlikely(status != 0))
345 goto out;
346 status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
347 if (unlikely(status != 0))
348 goto out;
349 status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
350 *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
351out:
352 dprintk("%s: exit with status = %d\n", __FUNCTION__, status);
353 return status;
354}
355
356static unsigned process_op(struct svc_rqst *rqstp,
357 struct xdr_stream *xdr_in, void *argp,
358 struct xdr_stream *xdr_out, void *resp)
359{
360 struct callback_op *op;
361 unsigned int op_nr;
362 unsigned int status = 0;
363 long maxlen;
364 unsigned res;
365
366 dprintk("%s: start\n", __FUNCTION__);
367 status = decode_op_hdr(xdr_in, &op_nr);
368 if (unlikely(status != 0)) {
369 op_nr = OP_CB_ILLEGAL;
370 op = &callback_ops[0];
371 } else if (unlikely(op_nr != OP_CB_GETATTR && op_nr != OP_CB_RECALL)) {
372 op_nr = OP_CB_ILLEGAL;
373 op = &callback_ops[0];
374 status = htonl(NFS4ERR_OP_ILLEGAL);
375 } else
376 op = &callback_ops[op_nr];
377
378 maxlen = xdr_out->end - xdr_out->p;
379 if (maxlen > 0 && maxlen < PAGE_SIZE) {
380 if (likely(status == 0 && op->decode_args != NULL))
381 status = op->decode_args(rqstp, xdr_in, argp);
382 if (likely(status == 0 && op->process_op != NULL))
383 status = op->process_op(argp, resp);
384 } else
385 status = htonl(NFS4ERR_RESOURCE);
386
387 res = encode_op_hdr(xdr_out, op_nr, status);
388 if (status == 0)
389 status = res;
390 if (op->encode_res != NULL && status == 0)
391 status = op->encode_res(rqstp, xdr_out, resp);
392 dprintk("%s: done, status = %d\n", __FUNCTION__, status);
393 return status;
394}
395
396/*
397 * Decode, process and encode a COMPOUND
398 */
399static int nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
400{
401 struct cb_compound_hdr_arg hdr_arg;
402 struct cb_compound_hdr_res hdr_res;
403 struct xdr_stream xdr_in, xdr_out;
404 uint32_t *p;
405 unsigned int status;
406 unsigned int nops = 1;
407
408 dprintk("%s: start\n", __FUNCTION__);
409
410 xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
411
412 p = (uint32_t*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
413 rqstp->rq_res.head[0].iov_len = PAGE_SIZE;
414 xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
415
416 decode_compound_hdr_arg(&xdr_in, &hdr_arg);
417 hdr_res.taglen = hdr_arg.taglen;
418 hdr_res.tag = hdr_arg.tag;
419 encode_compound_hdr_res(&xdr_out, &hdr_res);
420
421 for (;;) {
422 status = process_op(rqstp, &xdr_in, argp, &xdr_out, resp);
423 if (status != 0)
424 break;
425 if (nops == hdr_arg.nops)
426 break;
427 nops++;
428 }
429 *hdr_res.status = status;
430 *hdr_res.nops = htonl(nops);
431 dprintk("%s: done, status = %u\n", __FUNCTION__, status);
432 return rpc_success;
433}
434
435/*
436 * Define NFS4 callback COMPOUND ops.
437 */
438static struct callback_op callback_ops[] = {
439 [0] = {
440 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
441 },
442 [OP_CB_GETATTR] = {
443 .process_op = (callback_process_op_t)nfs4_callback_getattr,
444 .decode_args = (callback_decode_arg_t)decode_getattr_args,
445 .encode_res = (callback_encode_res_t)encode_getattr_res,
446 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
447 },
448 [OP_CB_RECALL] = {
449 .process_op = (callback_process_op_t)nfs4_callback_recall,
450 .decode_args = (callback_decode_arg_t)decode_recall_args,
451 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
452 }
453};
454
455/*
456 * Define NFS4 callback procedures
457 */
458static struct svc_procedure nfs4_callback_procedures1[] = {
459 [CB_NULL] = {
460 .pc_func = nfs4_callback_null,
461 .pc_decode = (kxdrproc_t)nfs4_decode_void,
462 .pc_encode = (kxdrproc_t)nfs4_encode_void,
463 .pc_xdrressize = 1,
464 },
465 [CB_COMPOUND] = {
466 .pc_func = nfs4_callback_compound,
467 .pc_encode = (kxdrproc_t)nfs4_encode_void,
468 .pc_argsize = 256,
469 .pc_ressize = 256,
470 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
471 }
472};
473
474struct svc_version nfs4_callback_version1 = {
475 .vs_vers = 1,
476 .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
477 .vs_proc = nfs4_callback_procedures1,
478 .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
479 .vs_dispatch = NULL,
480};
481