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Eric Van Hensbergenace51c42008-10-13 20:40:27 -05001/*
2 * net/9p/protocol.c
3 *
4 * 9P Protocol Support Code
5 *
6 * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
7 *
8 * Base on code from Anthony Liguori <aliguori@us.ibm.com>
9 * Copyright (C) 2008 by IBM, Corp.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2
13 * as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to:
22 * Free Software Foundation
23 * 51 Franklin Street, Fifth Floor
24 * Boston, MA 02111-1301 USA
25 *
26 */
27
28#include <linux/module.h>
29#include <linux/errno.h>
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -050030#include <linux/uaccess.h>
Eric Van Hensbergene7f4b8f2008-10-17 16:20:07 -050031#include <linux/sched.h>
Eric Van Hensbergenace51c42008-10-13 20:40:27 -050032#include <net/9p/9p.h>
33#include <net/9p/client.h>
34#include "protocol.h"
35
36#ifndef MIN
37#define MIN(a, b) (((a) < (b)) ? (a) : (b))
38#endif
39
40#ifndef MAX
41#define MAX(a, b) (((a) > (b)) ? (a) : (b))
42#endif
43
44#ifndef offset_of
45#define offset_of(type, memb) \
46 ((unsigned long)(&((type *)0)->memb))
47#endif
48#ifndef container_of
49#define container_of(obj, type, memb) \
50 ((type *)(((char *)obj) - offset_of(type, memb)))
51#endif
52
53static int
54p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...);
55
Eric Van Hensbergen0b15a3a2008-10-22 18:47:40 -050056#ifdef CONFIG_NET_9P_DEBUG
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -050057void
58p9pdu_dump(int way, struct p9_fcall *pdu)
59{
60 int i, n;
61 u8 *data = pdu->sdata;
62 int datalen = pdu->size;
63 char buf[255];
64 int buflen = 255;
65
66 i = n = 0;
67 if (datalen > (buflen-16))
68 datalen = buflen-16;
69 while (i < datalen) {
70 n += scnprintf(buf + n, buflen - n, "%02x ", data[i]);
71 if (i%4 == 3)
72 n += scnprintf(buf + n, buflen - n, " ");
73 if (i%32 == 31)
74 n += scnprintf(buf + n, buflen - n, "\n");
75
76 i++;
77 }
78 n += scnprintf(buf + n, buflen - n, "\n");
79
80 if (way)
Eric Van Hensbergene7f4b8f2008-10-17 16:20:07 -050081 P9_DPRINTK(P9_DEBUG_PKT, "[[[(%d) %s\n", datalen, buf);
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -050082 else
Eric Van Hensbergene7f4b8f2008-10-17 16:20:07 -050083 P9_DPRINTK(P9_DEBUG_PKT, "]]](%d) %s\n", datalen, buf);
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -050084}
Eric Van Hensbergen0b15a3a2008-10-22 18:47:40 -050085#else
86void
87p9pdu_dump(int way, struct p9_fcall *pdu)
88{
89}
90#endif
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -050091EXPORT_SYMBOL(p9pdu_dump);
92
Eric Van Hensbergenace51c42008-10-13 20:40:27 -050093void p9stat_free(struct p9_wstat *stbuf)
94{
95 kfree(stbuf->name);
96 kfree(stbuf->uid);
97 kfree(stbuf->gid);
98 kfree(stbuf->muid);
99 kfree(stbuf->extension);
100}
101EXPORT_SYMBOL(p9stat_free);
102
103static size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size)
104{
105 size_t len = MIN(pdu->size - pdu->offset, size);
106 memcpy(data, &pdu->sdata[pdu->offset], len);
107 pdu->offset += len;
108 return size - len;
109}
110
111static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size)
112{
113 size_t len = MIN(pdu->capacity - pdu->size, size);
114 memcpy(&pdu->sdata[pdu->size], data, len);
115 pdu->size += len;
116 return size - len;
117}
118
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500119static size_t
120pdu_write_u(struct p9_fcall *pdu, const char __user *udata, size_t size)
121{
122 size_t len = MIN(pdu->capacity - pdu->size, size);
123 int err = copy_from_user(&pdu->sdata[pdu->size], udata, len);
124 if (err)
125 printk(KERN_WARNING "pdu_write_u returning: %d\n", err);
126
127 pdu->size += len;
128 return size - len;
129}
130
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500131/*
132 b - int8_t
133 w - int16_t
134 d - int32_t
135 q - int64_t
136 s - string
137 S - stat
138 Q - qid
139 D - data blob (int32_t size followed by void *, results are not freed)
140 T - array of strings (int16_t count, followed by strings)
141 R - array of qids (int16_t count, followed by qids)
142 ? - if optional = 1, continue parsing
143*/
144
145static int
146p9pdu_vreadf(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap)
147{
148 const char *ptr;
149 int errcode = 0;
150
151 for (ptr = fmt; *ptr; ptr++) {
152 switch (*ptr) {
153 case 'b':{
154 int8_t *val = va_arg(ap, int8_t *);
155 if (pdu_read(pdu, val, sizeof(*val))) {
156 errcode = -EFAULT;
157 break;
158 }
159 }
160 break;
161 case 'w':{
162 int16_t *val = va_arg(ap, int16_t *);
163 if (pdu_read(pdu, val, sizeof(*val))) {
164 errcode = -EFAULT;
165 break;
166 }
167 *val = cpu_to_le16(*val);
168 }
169 break;
170 case 'd':{
171 int32_t *val = va_arg(ap, int32_t *);
172 if (pdu_read(pdu, val, sizeof(*val))) {
173 errcode = -EFAULT;
174 break;
175 }
176 *val = cpu_to_le32(*val);
177 }
178 break;
179 case 'q':{
180 int64_t *val = va_arg(ap, int64_t *);
181 if (pdu_read(pdu, val, sizeof(*val))) {
182 errcode = -EFAULT;
183 break;
184 }
185 *val = cpu_to_le64(*val);
186 }
187 break;
188 case 's':{
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500189 char **sptr = va_arg(ap, char **);
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500190 int16_t len;
191 int size;
192
193 errcode = p9pdu_readf(pdu, optional, "w", &len);
194 if (errcode)
195 break;
196
197 size = MAX(len, 0);
198
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500199 *sptr = kmalloc(size + 1, GFP_KERNEL);
200 if (*sptr == NULL) {
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500201 errcode = -EFAULT;
202 break;
203 }
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500204 if (pdu_read(pdu, *sptr, size)) {
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500205 errcode = -EFAULT;
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500206 kfree(*sptr);
207 *sptr = NULL;
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500208 } else
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500209 (*sptr)[size] = 0;
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500210 }
211 break;
212 case 'Q':{
213 struct p9_qid *qid =
214 va_arg(ap, struct p9_qid *);
215
216 errcode = p9pdu_readf(pdu, optional, "bdq",
217 &qid->type, &qid->version,
218 &qid->path);
219 }
220 break;
221 case 'S':{
222 struct p9_wstat *stbuf =
223 va_arg(ap, struct p9_wstat *);
224
Eric Van Hensbergenf0a0ac22008-10-17 12:45:23 -0500225 memset(stbuf, 0, sizeof(struct p9_wstat));
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500226 stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
Eric Van Hensbergenf0a0ac22008-10-17 12:45:23 -0500227 -1;
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500228 errcode =
229 p9pdu_readf(pdu, optional,
230 "wwdQdddqssss?sddd",
231 &stbuf->size, &stbuf->type,
232 &stbuf->dev, &stbuf->qid,
233 &stbuf->mode, &stbuf->atime,
234 &stbuf->mtime, &stbuf->length,
235 &stbuf->name, &stbuf->uid,
236 &stbuf->gid, &stbuf->muid,
237 &stbuf->extension,
238 &stbuf->n_uid, &stbuf->n_gid,
239 &stbuf->n_muid);
240 if (errcode)
241 p9stat_free(stbuf);
242 }
243 break;
244 case 'D':{
245 int32_t *count = va_arg(ap, int32_t *);
246 void **data = va_arg(ap, void **);
247
248 errcode =
249 p9pdu_readf(pdu, optional, "d", count);
250 if (!errcode) {
251 *count =
252 MIN(*count,
253 pdu->size - pdu->offset);
254 *data = &pdu->sdata[pdu->offset];
255 }
256 }
257 break;
258 case 'T':{
259 int16_t *nwname = va_arg(ap, int16_t *);
260 char ***wnames = va_arg(ap, char ***);
261
262 errcode =
263 p9pdu_readf(pdu, optional, "w", nwname);
264 if (!errcode) {
265 *wnames =
266 kmalloc(sizeof(char *) * *nwname,
267 GFP_KERNEL);
268 if (!*wnames)
269 errcode = -ENOMEM;
270 }
271
272 if (!errcode) {
273 int i;
274
275 for (i = 0; i < *nwname; i++) {
276 errcode =
277 p9pdu_readf(pdu, optional,
278 "s",
279 &(*wnames)[i]);
280 if (errcode)
281 break;
282 }
283 }
284
285 if (errcode) {
286 if (*wnames) {
287 int i;
288
289 for (i = 0; i < *nwname; i++)
290 kfree((*wnames)[i]);
291 }
292 kfree(*wnames);
293 *wnames = NULL;
294 }
295 }
296 break;
297 case 'R':{
298 int16_t *nwqid = va_arg(ap, int16_t *);
299 struct p9_qid **wqids =
300 va_arg(ap, struct p9_qid **);
301
302 *wqids = NULL;
303
304 errcode =
305 p9pdu_readf(pdu, optional, "w", nwqid);
306 if (!errcode) {
307 *wqids =
308 kmalloc(*nwqid *
309 sizeof(struct p9_qid),
310 GFP_KERNEL);
311 if (*wqids == NULL)
312 errcode = -ENOMEM;
313 }
314
315 if (!errcode) {
316 int i;
317
318 for (i = 0; i < *nwqid; i++) {
319 errcode =
320 p9pdu_readf(pdu, optional,
321 "Q",
322 &(*wqids)[i]);
323 if (errcode)
324 break;
325 }
326 }
327
328 if (errcode) {
329 kfree(*wqids);
330 *wqids = NULL;
331 }
332 }
333 break;
334 case '?':
335 if (!optional)
336 return 0;
337 break;
338 default:
339 BUG();
340 break;
341 }
342
343 if (errcode)
344 break;
345 }
346
347 return errcode;
348}
349
350int
351p9pdu_vwritef(struct p9_fcall *pdu, int optional, const char *fmt, va_list ap)
352{
353 const char *ptr;
354 int errcode = 0;
355
356 for (ptr = fmt; *ptr; ptr++) {
357 switch (*ptr) {
358 case 'b':{
359 int8_t val = va_arg(ap, int);
360 if (pdu_write(pdu, &val, sizeof(val)))
361 errcode = -EFAULT;
362 }
363 break;
364 case 'w':{
365 int16_t val = va_arg(ap, int);
366 if (pdu_write(pdu, &val, sizeof(val)))
367 errcode = -EFAULT;
368 }
369 break;
370 case 'd':{
371 int32_t val = va_arg(ap, int32_t);
372 if (pdu_write(pdu, &val, sizeof(val)))
373 errcode = -EFAULT;
374 }
375 break;
376 case 'q':{
377 int64_t val = va_arg(ap, int64_t);
378 if (pdu_write(pdu, &val, sizeof(val)))
379 errcode = -EFAULT;
380 }
381 break;
382 case 's':{
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500383 const char *sptr = va_arg(ap, const char *);
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500384 int16_t len = 0;
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500385 if (sptr)
386 len = MIN(strlen(sptr), USHORT_MAX);
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500387
388 errcode = p9pdu_writef(pdu, optional, "w", len);
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500389 if (!errcode && pdu_write(pdu, sptr, len))
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500390 errcode = -EFAULT;
391 }
392 break;
393 case 'Q':{
394 const struct p9_qid *qid =
395 va_arg(ap, const struct p9_qid *);
396 errcode =
397 p9pdu_writef(pdu, optional, "bdq",
398 qid->type, qid->version,
399 qid->path);
400 } break;
401 case 'S':{
402 const struct p9_wstat *stbuf =
403 va_arg(ap, const struct p9_wstat *);
404 errcode =
405 p9pdu_writef(pdu, optional,
406 "wwdQdddqssss?sddd",
407 stbuf->size, stbuf->type,
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500408 stbuf->dev, &stbuf->qid,
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500409 stbuf->mode, stbuf->atime,
410 stbuf->mtime, stbuf->length,
411 stbuf->name, stbuf->uid,
412 stbuf->gid, stbuf->muid,
413 stbuf->extension, stbuf->n_uid,
414 stbuf->n_gid, stbuf->n_muid);
415 } break;
416 case 'D':{
417 int32_t count = va_arg(ap, int32_t);
418 const void *data = va_arg(ap, const void *);
419
420 errcode =
421 p9pdu_writef(pdu, optional, "d", count);
422 if (!errcode && pdu_write(pdu, data, count))
423 errcode = -EFAULT;
424 }
425 break;
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500426 case 'U':{
427 int32_t count = va_arg(ap, int32_t);
428 const char __user *udata =
Eric Van Hensbergene45c5402008-10-22 18:54:47 -0500429 va_arg(ap, const void __user *);
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500430 errcode =
431 p9pdu_writef(pdu, optional, "d", count);
432 if (!errcode && pdu_write_u(pdu, udata, count))
433 errcode = -EFAULT;
434 }
435 break;
Eric Van Hensbergenace51c42008-10-13 20:40:27 -0500436 case 'T':{
437 int16_t nwname = va_arg(ap, int);
438 const char **wnames = va_arg(ap, const char **);
439
440 errcode =
441 p9pdu_writef(pdu, optional, "w", nwname);
442 if (!errcode) {
443 int i;
444
445 for (i = 0; i < nwname; i++) {
446 errcode =
447 p9pdu_writef(pdu, optional,
448 "s",
449 wnames[i]);
450 if (errcode)
451 break;
452 }
453 }
454 }
455 break;
456 case 'R':{
457 int16_t nwqid = va_arg(ap, int);
458 struct p9_qid *wqids =
459 va_arg(ap, struct p9_qid *);
460
461 errcode =
462 p9pdu_writef(pdu, optional, "w", nwqid);
463 if (!errcode) {
464 int i;
465
466 for (i = 0; i < nwqid; i++) {
467 errcode =
468 p9pdu_writef(pdu, optional,
469 "Q",
470 &wqids[i]);
471 if (errcode)
472 break;
473 }
474 }
475 }
476 break;
477 case '?':
478 if (!optional)
479 return 0;
480 break;
481 default:
482 BUG();
483 break;
484 }
485
486 if (errcode)
487 break;
488 }
489
490 return errcode;
491}
492
493int p9pdu_readf(struct p9_fcall *pdu, int optional, const char *fmt, ...)
494{
495 va_list ap;
496 int ret;
497
498 va_start(ap, fmt);
499 ret = p9pdu_vreadf(pdu, optional, fmt, ap);
500 va_end(ap);
501
502 return ret;
503}
504
505static int
506p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...)
507{
508 va_list ap;
509 int ret;
510
511 va_start(ap, fmt);
512 ret = p9pdu_vwritef(pdu, optional, fmt, ap);
513 va_end(ap);
514
515 return ret;
516}
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500517
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500518int p9stat_read(char *buf, int len, struct p9_wstat *st, int dotu)
519{
520 struct p9_fcall fake_pdu;
Eric Van Hensbergene7f4b8f2008-10-17 16:20:07 -0500521 int ret;
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500522
523 fake_pdu.size = len;
524 fake_pdu.capacity = len;
525 fake_pdu.sdata = buf;
526 fake_pdu.offset = 0;
527
Eric Van Hensbergene7f4b8f2008-10-17 16:20:07 -0500528 ret = p9pdu_readf(&fake_pdu, dotu, "S", st);
529 if (ret) {
530 P9_DPRINTK(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
531 p9pdu_dump(1, &fake_pdu);
532 }
533
534 return ret;
Eric Van Hensbergen02da3982008-10-16 08:29:30 -0500535}
536EXPORT_SYMBOL(p9stat_read);
537
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500538int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
539{
540 return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
541}
542
543int p9pdu_finalize(struct p9_fcall *pdu)
544{
545 int size = pdu->size;
546 int err;
547
548 pdu->size = 0;
549 err = p9pdu_writef(pdu, 0, "d", size);
550 pdu->size = size;
551
Eric Van Hensbergen0b15a3a2008-10-22 18:47:40 -0500552#ifdef CONFIG_NET_9P_DEBUG
Eric Van Hensbergene7f4b8f2008-10-17 16:20:07 -0500553 if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500554 p9pdu_dump(0, pdu);
Eric Van Hensbergen0b15a3a2008-10-22 18:47:40 -0500555#endif
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500556
Eric Van Hensbergene7f4b8f2008-10-17 16:20:07 -0500557 P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
558 pdu->id, pdu->tag);
559
Eric Van Hensbergen51a87c52008-10-16 08:30:07 -0500560 return err;
561}
562
563void p9pdu_reset(struct p9_fcall *pdu)
564{
565 pdu->offset = 0;
566 pdu->size = 0;
567}