1 /*
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>
30 #include <linux/kernel.h>
31 #include <linux/uaccess.h>
32 #include <linux/slab.h>
33 #include <linux/sched.h>
34 #include <linux/stddef.h>
35 #include <linux/types.h>
36 #include <net/9p/9p.h>
37 #include <net/9p/client.h>
38 #include "protocol.h"
39
40 #include <trace/events/9p.h>
41
42 static int
43 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...);
44
p9stat_free(struct p9_wstat * stbuf)45 void p9stat_free(struct p9_wstat *stbuf)
46 {
47 kfree(stbuf->name);
48 kfree(stbuf->uid);
49 kfree(stbuf->gid);
50 kfree(stbuf->muid);
51 kfree(stbuf->extension);
52 }
53 EXPORT_SYMBOL(p9stat_free);
54
pdu_read(struct p9_fcall * pdu,void * data,size_t size)55 size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size)
56 {
57 size_t len = min(pdu->size - pdu->offset, size);
58 memcpy(data, &pdu->sdata[pdu->offset], len);
59 pdu->offset += len;
60 return size - len;
61 }
62
pdu_write(struct p9_fcall * pdu,const void * data,size_t size)63 static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size)
64 {
65 size_t len = min(pdu->capacity - pdu->size, size);
66 memcpy(&pdu->sdata[pdu->size], data, len);
67 pdu->size += len;
68 return size - len;
69 }
70
71 static size_t
pdu_write_u(struct p9_fcall * pdu,const char __user * udata,size_t size)72 pdu_write_u(struct p9_fcall *pdu, const char __user *udata, size_t size)
73 {
74 size_t len = min(pdu->capacity - pdu->size, size);
75 if (copy_from_user(&pdu->sdata[pdu->size], udata, len))
76 len = 0;
77
78 pdu->size += len;
79 return size - len;
80 }
81
82 /*
83 b - int8_t
84 w - int16_t
85 d - int32_t
86 q - int64_t
87 s - string
88 S - stat
89 Q - qid
90 D - data blob (int32_t size followed by void *, results are not freed)
91 T - array of strings (int16_t count, followed by strings)
92 R - array of qids (int16_t count, followed by qids)
93 A - stat for 9p2000.L (p9_stat_dotl)
94 ? - if optional = 1, continue parsing
95 */
96
97 static int
p9pdu_vreadf(struct p9_fcall * pdu,int proto_version,const char * fmt,va_list ap)98 p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
99 va_list ap)
100 {
101 const char *ptr;
102 int errcode = 0;
103
104 for (ptr = fmt; *ptr; ptr++) {
105 switch (*ptr) {
106 case 'b':{
107 int8_t *val = va_arg(ap, int8_t *);
108 if (pdu_read(pdu, val, sizeof(*val))) {
109 errcode = -EFAULT;
110 break;
111 }
112 }
113 break;
114 case 'w':{
115 int16_t *val = va_arg(ap, int16_t *);
116 __le16 le_val;
117 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
118 errcode = -EFAULT;
119 break;
120 }
121 *val = le16_to_cpu(le_val);
122 }
123 break;
124 case 'd':{
125 int32_t *val = va_arg(ap, int32_t *);
126 __le32 le_val;
127 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
128 errcode = -EFAULT;
129 break;
130 }
131 *val = le32_to_cpu(le_val);
132 }
133 break;
134 case 'q':{
135 int64_t *val = va_arg(ap, int64_t *);
136 __le64 le_val;
137 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
138 errcode = -EFAULT;
139 break;
140 }
141 *val = le64_to_cpu(le_val);
142 }
143 break;
144 case 's':{
145 char **sptr = va_arg(ap, char **);
146 uint16_t len;
147
148 errcode = p9pdu_readf(pdu, proto_version,
149 "w", &len);
150 if (errcode)
151 break;
152
153 *sptr = kmalloc(len + 1, GFP_NOFS);
154 if (*sptr == NULL) {
155 errcode = -EFAULT;
156 break;
157 }
158 if (pdu_read(pdu, *sptr, len)) {
159 errcode = -EFAULT;
160 kfree(*sptr);
161 *sptr = NULL;
162 } else
163 (*sptr)[len] = 0;
164 }
165 break;
166 case 'Q':{
167 struct p9_qid *qid =
168 va_arg(ap, struct p9_qid *);
169
170 errcode = p9pdu_readf(pdu, proto_version, "bdq",
171 &qid->type, &qid->version,
172 &qid->path);
173 }
174 break;
175 case 'S':{
176 struct p9_wstat *stbuf =
177 va_arg(ap, struct p9_wstat *);
178
179 memset(stbuf, 0, sizeof(struct p9_wstat));
180 stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
181 -1;
182 errcode =
183 p9pdu_readf(pdu, proto_version,
184 "wwdQdddqssss?sddd",
185 &stbuf->size, &stbuf->type,
186 &stbuf->dev, &stbuf->qid,
187 &stbuf->mode, &stbuf->atime,
188 &stbuf->mtime, &stbuf->length,
189 &stbuf->name, &stbuf->uid,
190 &stbuf->gid, &stbuf->muid,
191 &stbuf->extension,
192 &stbuf->n_uid, &stbuf->n_gid,
193 &stbuf->n_muid);
194 if (errcode)
195 p9stat_free(stbuf);
196 }
197 break;
198 case 'D':{
199 uint32_t *count = va_arg(ap, uint32_t *);
200 void **data = va_arg(ap, void **);
201
202 errcode =
203 p9pdu_readf(pdu, proto_version, "d", count);
204 if (!errcode) {
205 *count =
206 min_t(uint32_t, *count,
207 pdu->size - pdu->offset);
208 *data = &pdu->sdata[pdu->offset];
209 }
210 }
211 break;
212 case 'T':{
213 uint16_t *nwname = va_arg(ap, uint16_t *);
214 char ***wnames = va_arg(ap, char ***);
215
216 errcode = p9pdu_readf(pdu, proto_version,
217 "w", nwname);
218 if (!errcode) {
219 *wnames =
220 kmalloc(sizeof(char *) * *nwname,
221 GFP_NOFS);
222 if (!*wnames)
223 errcode = -ENOMEM;
224 }
225
226 if (!errcode) {
227 int i;
228
229 for (i = 0; i < *nwname; i++) {
230 errcode =
231 p9pdu_readf(pdu,
232 proto_version,
233 "s",
234 &(*wnames)[i]);
235 if (errcode)
236 break;
237 }
238 }
239
240 if (errcode) {
241 if (*wnames) {
242 int i;
243
244 for (i = 0; i < *nwname; i++)
245 kfree((*wnames)[i]);
246 }
247 kfree(*wnames);
248 *wnames = NULL;
249 }
250 }
251 break;
252 case 'R':{
253 int16_t *nwqid = va_arg(ap, int16_t *);
254 struct p9_qid **wqids =
255 va_arg(ap, struct p9_qid **);
256
257 *wqids = NULL;
258
259 errcode =
260 p9pdu_readf(pdu, proto_version, "w", nwqid);
261 if (!errcode) {
262 *wqids =
263 kmalloc(*nwqid *
264 sizeof(struct p9_qid),
265 GFP_NOFS);
266 if (*wqids == NULL)
267 errcode = -ENOMEM;
268 }
269
270 if (!errcode) {
271 int i;
272
273 for (i = 0; i < *nwqid; i++) {
274 errcode =
275 p9pdu_readf(pdu,
276 proto_version,
277 "Q",
278 &(*wqids)[i]);
279 if (errcode)
280 break;
281 }
282 }
283
284 if (errcode) {
285 kfree(*wqids);
286 *wqids = NULL;
287 }
288 }
289 break;
290 case 'A': {
291 struct p9_stat_dotl *stbuf =
292 va_arg(ap, struct p9_stat_dotl *);
293
294 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
295 errcode =
296 p9pdu_readf(pdu, proto_version,
297 "qQdddqqqqqqqqqqqqqqq",
298 &stbuf->st_result_mask,
299 &stbuf->qid,
300 &stbuf->st_mode,
301 &stbuf->st_uid, &stbuf->st_gid,
302 &stbuf->st_nlink,
303 &stbuf->st_rdev, &stbuf->st_size,
304 &stbuf->st_blksize, &stbuf->st_blocks,
305 &stbuf->st_atime_sec,
306 &stbuf->st_atime_nsec,
307 &stbuf->st_mtime_sec,
308 &stbuf->st_mtime_nsec,
309 &stbuf->st_ctime_sec,
310 &stbuf->st_ctime_nsec,
311 &stbuf->st_btime_sec,
312 &stbuf->st_btime_nsec,
313 &stbuf->st_gen,
314 &stbuf->st_data_version);
315 }
316 break;
317 case '?':
318 if ((proto_version != p9_proto_2000u) &&
319 (proto_version != p9_proto_2000L))
320 return 0;
321 break;
322 default:
323 BUG();
324 break;
325 }
326
327 if (errcode)
328 break;
329 }
330
331 return errcode;
332 }
333
334 int
p9pdu_vwritef(struct p9_fcall * pdu,int proto_version,const char * fmt,va_list ap)335 p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
336 va_list ap)
337 {
338 const char *ptr;
339 int errcode = 0;
340
341 for (ptr = fmt; *ptr; ptr++) {
342 switch (*ptr) {
343 case 'b':{
344 int8_t val = va_arg(ap, int);
345 if (pdu_write(pdu, &val, sizeof(val)))
346 errcode = -EFAULT;
347 }
348 break;
349 case 'w':{
350 __le16 val = cpu_to_le16(va_arg(ap, int));
351 if (pdu_write(pdu, &val, sizeof(val)))
352 errcode = -EFAULT;
353 }
354 break;
355 case 'd':{
356 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
357 if (pdu_write(pdu, &val, sizeof(val)))
358 errcode = -EFAULT;
359 }
360 break;
361 case 'q':{
362 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
363 if (pdu_write(pdu, &val, sizeof(val)))
364 errcode = -EFAULT;
365 }
366 break;
367 case 's':{
368 const char *sptr = va_arg(ap, const char *);
369 uint16_t len = 0;
370 if (sptr)
371 len = min_t(uint16_t, strlen(sptr),
372 USHRT_MAX);
373
374 errcode = p9pdu_writef(pdu, proto_version,
375 "w", len);
376 if (!errcode && pdu_write(pdu, sptr, len))
377 errcode = -EFAULT;
378 }
379 break;
380 case 'Q':{
381 const struct p9_qid *qid =
382 va_arg(ap, const struct p9_qid *);
383 errcode =
384 p9pdu_writef(pdu, proto_version, "bdq",
385 qid->type, qid->version,
386 qid->path);
387 } break;
388 case 'S':{
389 const struct p9_wstat *stbuf =
390 va_arg(ap, const struct p9_wstat *);
391 errcode =
392 p9pdu_writef(pdu, proto_version,
393 "wwdQdddqssss?sddd",
394 stbuf->size, stbuf->type,
395 stbuf->dev, &stbuf->qid,
396 stbuf->mode, stbuf->atime,
397 stbuf->mtime, stbuf->length,
398 stbuf->name, stbuf->uid,
399 stbuf->gid, stbuf->muid,
400 stbuf->extension, stbuf->n_uid,
401 stbuf->n_gid, stbuf->n_muid);
402 } break;
403 case 'D':{
404 uint32_t count = va_arg(ap, uint32_t);
405 const void *data = va_arg(ap, const void *);
406
407 errcode = p9pdu_writef(pdu, proto_version, "d",
408 count);
409 if (!errcode && pdu_write(pdu, data, count))
410 errcode = -EFAULT;
411 }
412 break;
413 case 'U':{
414 int32_t count = va_arg(ap, int32_t);
415 const char __user *udata =
416 va_arg(ap, const void __user *);
417 errcode = p9pdu_writef(pdu, proto_version, "d",
418 count);
419 if (!errcode && pdu_write_u(pdu, udata, count))
420 errcode = -EFAULT;
421 }
422 break;
423 case 'T':{
424 uint16_t nwname = va_arg(ap, int);
425 const char **wnames = va_arg(ap, const char **);
426
427 errcode = p9pdu_writef(pdu, proto_version, "w",
428 nwname);
429 if (!errcode) {
430 int i;
431
432 for (i = 0; i < nwname; i++) {
433 errcode =
434 p9pdu_writef(pdu,
435 proto_version,
436 "s",
437 wnames[i]);
438 if (errcode)
439 break;
440 }
441 }
442 }
443 break;
444 case 'R':{
445 int16_t nwqid = va_arg(ap, int);
446 struct p9_qid *wqids =
447 va_arg(ap, struct p9_qid *);
448
449 errcode = p9pdu_writef(pdu, proto_version, "w",
450 nwqid);
451 if (!errcode) {
452 int i;
453
454 for (i = 0; i < nwqid; i++) {
455 errcode =
456 p9pdu_writef(pdu,
457 proto_version,
458 "Q",
459 &wqids[i]);
460 if (errcode)
461 break;
462 }
463 }
464 }
465 break;
466 case 'I':{
467 struct p9_iattr_dotl *p9attr = va_arg(ap,
468 struct p9_iattr_dotl *);
469
470 errcode = p9pdu_writef(pdu, proto_version,
471 "ddddqqqqq",
472 p9attr->valid,
473 p9attr->mode,
474 p9attr->uid,
475 p9attr->gid,
476 p9attr->size,
477 p9attr->atime_sec,
478 p9attr->atime_nsec,
479 p9attr->mtime_sec,
480 p9attr->mtime_nsec);
481 }
482 break;
483 case '?':
484 if ((proto_version != p9_proto_2000u) &&
485 (proto_version != p9_proto_2000L))
486 return 0;
487 break;
488 default:
489 BUG();
490 break;
491 }
492
493 if (errcode)
494 break;
495 }
496
497 return errcode;
498 }
499
p9pdu_readf(struct p9_fcall * pdu,int proto_version,const char * fmt,...)500 int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
501 {
502 va_list ap;
503 int ret;
504
505 va_start(ap, fmt);
506 ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
507 va_end(ap);
508
509 return ret;
510 }
511
512 static int
p9pdu_writef(struct p9_fcall * pdu,int proto_version,const char * fmt,...)513 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
514 {
515 va_list ap;
516 int ret;
517
518 va_start(ap, fmt);
519 ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
520 va_end(ap);
521
522 return ret;
523 }
524
p9stat_read(struct p9_client * clnt,char * buf,int len,struct p9_wstat * st)525 int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st)
526 {
527 struct p9_fcall fake_pdu;
528 int ret;
529
530 fake_pdu.size = len;
531 fake_pdu.capacity = len;
532 fake_pdu.sdata = buf;
533 fake_pdu.offset = 0;
534
535 ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st);
536 if (ret) {
537 p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
538 trace_9p_protocol_dump(clnt, &fake_pdu);
539 }
540
541 return ret;
542 }
543 EXPORT_SYMBOL(p9stat_read);
544
p9pdu_prepare(struct p9_fcall * pdu,int16_t tag,int8_t type)545 int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
546 {
547 pdu->id = type;
548 return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
549 }
550
p9pdu_finalize(struct p9_client * clnt,struct p9_fcall * pdu)551 int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu)
552 {
553 int size = pdu->size;
554 int err;
555
556 pdu->size = 0;
557 err = p9pdu_writef(pdu, 0, "d", size);
558 pdu->size = size;
559
560 trace_9p_protocol_dump(clnt, pdu);
561 p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n",
562 pdu->size, pdu->id, pdu->tag);
563
564 return err;
565 }
566
p9pdu_reset(struct p9_fcall * pdu)567 void p9pdu_reset(struct p9_fcall *pdu)
568 {
569 pdu->offset = 0;
570 pdu->size = 0;
571 }
572
p9dirent_read(struct p9_client * clnt,char * buf,int len,struct p9_dirent * dirent)573 int p9dirent_read(struct p9_client *clnt, char *buf, int len,
574 struct p9_dirent *dirent)
575 {
576 struct p9_fcall fake_pdu;
577 int ret;
578 char *nameptr;
579
580 fake_pdu.size = len;
581 fake_pdu.capacity = len;
582 fake_pdu.sdata = buf;
583 fake_pdu.offset = 0;
584
585 ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid,
586 &dirent->d_off, &dirent->d_type, &nameptr);
587 if (ret) {
588 p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
589 trace_9p_protocol_dump(clnt, &fake_pdu);
590 goto out;
591 }
592
593 strcpy(dirent->d_name, nameptr);
594 kfree(nameptr);
595
596 out:
597 return fake_pdu.offset;
598 }
599 EXPORT_SYMBOL(p9dirent_read);
600