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Linux kernel mirror (for testing)
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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * 9P Protocol Support Code
4 *
5 * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
6 *
7 * Base on code from Anthony Liguori <aliguori@us.ibm.com>
8 * Copyright (C) 2008 by IBM, Corp.
9 */
10
11#include <linux/module.h>
12#include <linux/errno.h>
13#include <linux/kernel.h>
14#include <linux/uaccess.h>
15#include <linux/slab.h>
16#include <linux/sched.h>
17#include <linux/stddef.h>
18#include <linux/types.h>
19#include <linux/uio.h>
20#include <net/9p/9p.h>
21#include <net/9p/client.h>
22#include "protocol.h"
23
24#include <trace/events/9p.h>
25
26static int
27p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...);
28
29void p9stat_free(struct p9_wstat *stbuf)
30{
31 kfree(stbuf->name);
32 stbuf->name = NULL;
33 kfree(stbuf->uid);
34 stbuf->uid = NULL;
35 kfree(stbuf->gid);
36 stbuf->gid = NULL;
37 kfree(stbuf->muid);
38 stbuf->muid = NULL;
39 kfree(stbuf->extension);
40 stbuf->extension = NULL;
41}
42EXPORT_SYMBOL(p9stat_free);
43
44size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size)
45{
46 size_t len = min(pdu->size - pdu->offset, size);
47
48 memcpy(data, &pdu->sdata[pdu->offset], len);
49 pdu->offset += len;
50 return size - len;
51}
52
53static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size)
54{
55 size_t len = min(pdu->capacity - pdu->size, size);
56
57 memcpy(&pdu->sdata[pdu->size], data, len);
58 pdu->size += len;
59 return size - len;
60}
61
62static size_t
63pdu_write_u(struct p9_fcall *pdu, struct iov_iter *from, size_t size)
64{
65 size_t len = min(pdu->capacity - pdu->size, size);
66
67 if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, from))
68 len = 0;
69
70 pdu->size += len;
71 return size - len;
72}
73
74/* b - int8_t
75 * w - int16_t
76 * d - int32_t
77 * q - int64_t
78 * s - string
79 * u - numeric uid
80 * g - numeric gid
81 * S - stat
82 * Q - qid
83 * D - data blob (int32_t size followed by void *, results are not freed)
84 * T - array of strings (int16_t count, followed by strings)
85 * R - array of qids (int16_t count, followed by qids)
86 * A - stat for 9p2000.L (p9_stat_dotl)
87 * ? - if optional = 1, continue parsing
88 */
89
90static int
91p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
92 va_list ap)
93{
94 const char *ptr;
95 int errcode = 0;
96
97 for (ptr = fmt; *ptr; ptr++) {
98 switch (*ptr) {
99 case 'b':{
100 int8_t *val = va_arg(ap, int8_t *);
101 if (pdu_read(pdu, val, sizeof(*val))) {
102 errcode = -EFAULT;
103 break;
104 }
105 }
106 break;
107 case 'w':{
108 int16_t *val = va_arg(ap, int16_t *);
109 __le16 le_val;
110 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
111 errcode = -EFAULT;
112 break;
113 }
114 *val = le16_to_cpu(le_val);
115 }
116 break;
117 case 'd':{
118 int32_t *val = va_arg(ap, int32_t *);
119 __le32 le_val;
120 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
121 errcode = -EFAULT;
122 break;
123 }
124 *val = le32_to_cpu(le_val);
125 }
126 break;
127 case 'q':{
128 int64_t *val = va_arg(ap, int64_t *);
129 __le64 le_val;
130 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
131 errcode = -EFAULT;
132 break;
133 }
134 *val = le64_to_cpu(le_val);
135 }
136 break;
137 case 's':{
138 char **sptr = va_arg(ap, char **);
139 uint16_t len;
140
141 errcode = p9pdu_readf(pdu, proto_version,
142 "w", &len);
143 if (errcode)
144 break;
145
146 *sptr = kmalloc(len + 1, GFP_NOFS);
147 if (*sptr == NULL) {
148 errcode = -ENOMEM;
149 break;
150 }
151 if (pdu_read(pdu, *sptr, len)) {
152 errcode = -EFAULT;
153 kfree(*sptr);
154 *sptr = NULL;
155 } else
156 (*sptr)[len] = 0;
157 }
158 break;
159 case 'u': {
160 kuid_t *uid = va_arg(ap, kuid_t *);
161 __le32 le_val;
162 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
163 errcode = -EFAULT;
164 break;
165 }
166 *uid = make_kuid(&init_user_ns,
167 le32_to_cpu(le_val));
168 } break;
169 case 'g': {
170 kgid_t *gid = va_arg(ap, kgid_t *);
171 __le32 le_val;
172 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
173 errcode = -EFAULT;
174 break;
175 }
176 *gid = make_kgid(&init_user_ns,
177 le32_to_cpu(le_val));
178 } break;
179 case 'Q':{
180 struct p9_qid *qid =
181 va_arg(ap, struct p9_qid *);
182
183 errcode = p9pdu_readf(pdu, proto_version, "bdq",
184 &qid->type, &qid->version,
185 &qid->path);
186 }
187 break;
188 case 'S':{
189 struct p9_wstat *stbuf =
190 va_arg(ap, struct p9_wstat *);
191
192 memset(stbuf, 0, sizeof(struct p9_wstat));
193 stbuf->n_uid = stbuf->n_muid = INVALID_UID;
194 stbuf->n_gid = INVALID_GID;
195
196 errcode =
197 p9pdu_readf(pdu, proto_version,
198 "wwdQdddqssss?sugu",
199 &stbuf->size, &stbuf->type,
200 &stbuf->dev, &stbuf->qid,
201 &stbuf->mode, &stbuf->atime,
202 &stbuf->mtime, &stbuf->length,
203 &stbuf->name, &stbuf->uid,
204 &stbuf->gid, &stbuf->muid,
205 &stbuf->extension,
206 &stbuf->n_uid, &stbuf->n_gid,
207 &stbuf->n_muid);
208 if (errcode)
209 p9stat_free(stbuf);
210 }
211 break;
212 case 'D':{
213 uint32_t *count = va_arg(ap, uint32_t *);
214 void **data = va_arg(ap, void **);
215
216 errcode =
217 p9pdu_readf(pdu, proto_version, "d", count);
218 if (!errcode) {
219 *count =
220 min_t(uint32_t, *count,
221 pdu->size - pdu->offset);
222 *data = &pdu->sdata[pdu->offset];
223 }
224 }
225 break;
226 case 'T':{
227 uint16_t *nwname = va_arg(ap, uint16_t *);
228 char ***wnames = va_arg(ap, char ***);
229
230 errcode = p9pdu_readf(pdu, proto_version,
231 "w", nwname);
232 if (!errcode) {
233 *wnames =
234 kmalloc_array(*nwname,
235 sizeof(char *),
236 GFP_NOFS);
237 if (!*wnames)
238 errcode = -ENOMEM;
239 }
240
241 if (!errcode) {
242 int i;
243
244 for (i = 0; i < *nwname; i++) {
245 errcode =
246 p9pdu_readf(pdu,
247 proto_version,
248 "s",
249 &(*wnames)[i]);
250 if (errcode)
251 break;
252 }
253 }
254
255 if (errcode) {
256 if (*wnames) {
257 int i;
258
259 for (i = 0; i < *nwname; i++)
260 kfree((*wnames)[i]);
261 }
262 kfree(*wnames);
263 *wnames = NULL;
264 }
265 }
266 break;
267 case 'R':{
268 uint16_t *nwqid = va_arg(ap, uint16_t *);
269 struct p9_qid **wqids =
270 va_arg(ap, struct p9_qid **);
271
272 *wqids = NULL;
273
274 errcode =
275 p9pdu_readf(pdu, proto_version, "w", nwqid);
276 if (!errcode) {
277 *wqids =
278 kmalloc_array(*nwqid,
279 sizeof(struct p9_qid),
280 GFP_NOFS);
281 if (*wqids == NULL)
282 errcode = -ENOMEM;
283 }
284
285 if (!errcode) {
286 int i;
287
288 for (i = 0; i < *nwqid; i++) {
289 errcode =
290 p9pdu_readf(pdu,
291 proto_version,
292 "Q",
293 &(*wqids)[i]);
294 if (errcode)
295 break;
296 }
297 }
298
299 if (errcode) {
300 kfree(*wqids);
301 *wqids = NULL;
302 }
303 }
304 break;
305 case 'A': {
306 struct p9_stat_dotl *stbuf =
307 va_arg(ap, struct p9_stat_dotl *);
308
309 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
310 errcode =
311 p9pdu_readf(pdu, proto_version,
312 "qQdugqqqqqqqqqqqqqqq",
313 &stbuf->st_result_mask,
314 &stbuf->qid,
315 &stbuf->st_mode,
316 &stbuf->st_uid, &stbuf->st_gid,
317 &stbuf->st_nlink,
318 &stbuf->st_rdev, &stbuf->st_size,
319 &stbuf->st_blksize, &stbuf->st_blocks,
320 &stbuf->st_atime_sec,
321 &stbuf->st_atime_nsec,
322 &stbuf->st_mtime_sec,
323 &stbuf->st_mtime_nsec,
324 &stbuf->st_ctime_sec,
325 &stbuf->st_ctime_nsec,
326 &stbuf->st_btime_sec,
327 &stbuf->st_btime_nsec,
328 &stbuf->st_gen,
329 &stbuf->st_data_version);
330 }
331 break;
332 case '?':
333 if ((proto_version != p9_proto_2000u) &&
334 (proto_version != p9_proto_2000L))
335 return 0;
336 break;
337 default:
338 BUG();
339 break;
340 }
341
342 if (errcode)
343 break;
344 }
345
346 return errcode;
347}
348
349int
350p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
351 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 __le16 val = cpu_to_le16(va_arg(ap, int));
366 if (pdu_write(pdu, &val, sizeof(val)))
367 errcode = -EFAULT;
368 }
369 break;
370 case 'd':{
371 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
372 if (pdu_write(pdu, &val, sizeof(val)))
373 errcode = -EFAULT;
374 }
375 break;
376 case 'q':{
377 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
378 if (pdu_write(pdu, &val, sizeof(val)))
379 errcode = -EFAULT;
380 }
381 break;
382 case 's':{
383 const char *sptr = va_arg(ap, const char *);
384 uint16_t len = 0;
385 if (sptr)
386 len = min_t(size_t, strlen(sptr),
387 USHRT_MAX);
388
389 errcode = p9pdu_writef(pdu, proto_version,
390 "w", len);
391 if (!errcode && pdu_write(pdu, sptr, len))
392 errcode = -EFAULT;
393 }
394 break;
395 case 'u': {
396 kuid_t uid = va_arg(ap, kuid_t);
397 __le32 val = cpu_to_le32(
398 from_kuid(&init_user_ns, uid));
399 if (pdu_write(pdu, &val, sizeof(val)))
400 errcode = -EFAULT;
401 } break;
402 case 'g': {
403 kgid_t gid = va_arg(ap, kgid_t);
404 __le32 val = cpu_to_le32(
405 from_kgid(&init_user_ns, gid));
406 if (pdu_write(pdu, &val, sizeof(val)))
407 errcode = -EFAULT;
408 } break;
409 case 'Q':{
410 const struct p9_qid *qid =
411 va_arg(ap, const struct p9_qid *);
412 errcode =
413 p9pdu_writef(pdu, proto_version, "bdq",
414 qid->type, qid->version,
415 qid->path);
416 } break;
417 case 'S':{
418 const struct p9_wstat *stbuf =
419 va_arg(ap, const struct p9_wstat *);
420 errcode =
421 p9pdu_writef(pdu, proto_version,
422 "wwdQdddqssss?sugu",
423 stbuf->size, stbuf->type,
424 stbuf->dev, &stbuf->qid,
425 stbuf->mode, stbuf->atime,
426 stbuf->mtime, stbuf->length,
427 stbuf->name, stbuf->uid,
428 stbuf->gid, stbuf->muid,
429 stbuf->extension, stbuf->n_uid,
430 stbuf->n_gid, stbuf->n_muid);
431 } break;
432 case 'V':{
433 uint32_t count = va_arg(ap, uint32_t);
434 struct iov_iter *from =
435 va_arg(ap, struct iov_iter *);
436 errcode = p9pdu_writef(pdu, proto_version, "d",
437 count);
438 if (!errcode && pdu_write_u(pdu, from, count))
439 errcode = -EFAULT;
440 }
441 break;
442 case 'T':{
443 uint16_t nwname = va_arg(ap, int);
444 const char **wnames = va_arg(ap, const char **);
445
446 errcode = p9pdu_writef(pdu, proto_version, "w",
447 nwname);
448 if (!errcode) {
449 int i;
450
451 for (i = 0; i < nwname; i++) {
452 errcode =
453 p9pdu_writef(pdu,
454 proto_version,
455 "s",
456 wnames[i]);
457 if (errcode)
458 break;
459 }
460 }
461 }
462 break;
463 case 'R':{
464 uint16_t nwqid = va_arg(ap, int);
465 struct p9_qid *wqids =
466 va_arg(ap, struct p9_qid *);
467
468 errcode = p9pdu_writef(pdu, proto_version, "w",
469 nwqid);
470 if (!errcode) {
471 int i;
472
473 for (i = 0; i < nwqid; i++) {
474 errcode =
475 p9pdu_writef(pdu,
476 proto_version,
477 "Q",
478 &wqids[i]);
479 if (errcode)
480 break;
481 }
482 }
483 }
484 break;
485 case 'I':{
486 struct p9_iattr_dotl *p9attr = va_arg(ap,
487 struct p9_iattr_dotl *);
488
489 errcode = p9pdu_writef(pdu, proto_version,
490 "ddugqqqqq",
491 p9attr->valid,
492 p9attr->mode,
493 p9attr->uid,
494 p9attr->gid,
495 p9attr->size,
496 p9attr->atime_sec,
497 p9attr->atime_nsec,
498 p9attr->mtime_sec,
499 p9attr->mtime_nsec);
500 }
501 break;
502 case '?':
503 if ((proto_version != p9_proto_2000u) &&
504 (proto_version != p9_proto_2000L))
505 return 0;
506 break;
507 default:
508 BUG();
509 break;
510 }
511
512 if (errcode)
513 break;
514 }
515
516 return errcode;
517}
518
519int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
520{
521 va_list ap;
522 int ret;
523
524 va_start(ap, fmt);
525 ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
526 va_end(ap);
527
528 return ret;
529}
530
531static int
532p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
533{
534 va_list ap;
535 int ret;
536
537 va_start(ap, fmt);
538 ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
539 va_end(ap);
540
541 return ret;
542}
543
544int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st)
545{
546 struct p9_fcall fake_pdu;
547 int ret;
548
549 fake_pdu.size = len;
550 fake_pdu.capacity = len;
551 fake_pdu.sdata = buf;
552 fake_pdu.offset = 0;
553
554 ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st);
555 if (ret) {
556 p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
557 trace_9p_protocol_dump(clnt, &fake_pdu);
558 return ret;
559 }
560
561 return fake_pdu.offset;
562}
563EXPORT_SYMBOL(p9stat_read);
564
565int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
566{
567 pdu->id = type;
568 return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
569}
570
571int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu)
572{
573 int size = pdu->size;
574 int err;
575
576 pdu->size = 0;
577 err = p9pdu_writef(pdu, 0, "d", size);
578 pdu->size = size;
579
580 trace_9p_protocol_dump(clnt, pdu);
581 p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n",
582 pdu->size, pdu->id, pdu->tag);
583
584 return err;
585}
586
587void p9pdu_reset(struct p9_fcall *pdu)
588{
589 pdu->offset = 0;
590 pdu->size = 0;
591}
592
593int p9dirent_read(struct p9_client *clnt, char *buf, int len,
594 struct p9_dirent *dirent)
595{
596 struct p9_fcall fake_pdu;
597 int ret;
598 char *nameptr;
599
600 fake_pdu.size = len;
601 fake_pdu.capacity = len;
602 fake_pdu.sdata = buf;
603 fake_pdu.offset = 0;
604
605 ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid,
606 &dirent->d_off, &dirent->d_type, &nameptr);
607 if (ret) {
608 p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
609 trace_9p_protocol_dump(clnt, &fake_pdu);
610 return ret;
611 }
612
613 ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name));
614 if (ret < 0) {
615 p9_debug(P9_DEBUG_ERROR,
616 "On the wire dirent name too long: %s\n",
617 nameptr);
618 kfree(nameptr);
619 return ret;
620 }
621 kfree(nameptr);
622
623 return fake_pdu.offset;
624}
625EXPORT_SYMBOL(p9dirent_read);