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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
26/* len[2] text[len] */
27#define P9_STRLEN(s) \
28 (2 + min_t(size_t, s ? strlen(s) : 0, USHRT_MAX))
29
30/**
31 * p9_msg_buf_size - Returns a buffer size sufficiently large to hold the
32 * intended 9p message.
33 * @c: client
34 * @type: message type
35 * @fmt: format template for assembling request message
36 * (see p9pdu_vwritef)
37 * @ap: variable arguments to be fed to passed format template
38 * (see p9pdu_vwritef)
39 *
40 * Note: Even for response types (P9_R*) the format template and variable
41 * arguments must always be for the originating request type (P9_T*).
42 */
43size_t p9_msg_buf_size(struct p9_client *c, enum p9_msg_t type,
44 const char *fmt, va_list ap)
45{
46 /* size[4] type[1] tag[2] */
47 const int hdr = 4 + 1 + 2;
48 /* ename[s] errno[4] */
49 const int rerror_size = hdr + P9_ERRMAX + 4;
50 /* ecode[4] */
51 const int rlerror_size = hdr + 4;
52 const int err_size =
53 c->proto_version == p9_proto_2000L ? rlerror_size : rerror_size;
54
55 static_assert(NAME_MAX <= 4*1024, "p9_msg_buf_size() currently assumes "
56 "a max. allowed directory entry name length of 4k");
57
58 switch (type) {
59
60 /* message types not used at all */
61 case P9_TERROR:
62 case P9_TLERROR:
63 case P9_TAUTH:
64 case P9_RAUTH:
65 BUG();
66
67 /* variable length & potentially large message types */
68 case P9_TATTACH:
69 BUG_ON(strcmp("ddss?u", fmt));
70 va_arg(ap, int32_t);
71 va_arg(ap, int32_t);
72 {
73 const char *uname = va_arg(ap, const char *);
74 const char *aname = va_arg(ap, const char *);
75 /* fid[4] afid[4] uname[s] aname[s] n_uname[4] */
76 return hdr + 4 + 4 + P9_STRLEN(uname) + P9_STRLEN(aname) + 4;
77 }
78 case P9_TWALK:
79 BUG_ON(strcmp("ddT", fmt));
80 va_arg(ap, int32_t);
81 va_arg(ap, int32_t);
82 {
83 uint i, nwname = va_arg(ap, int);
84 size_t wname_all;
85 const char **wnames = va_arg(ap, const char **);
86 for (i = 0, wname_all = 0; i < nwname; ++i) {
87 wname_all += P9_STRLEN(wnames[i]);
88 }
89 /* fid[4] newfid[4] nwname[2] nwname*(wname[s]) */
90 return hdr + 4 + 4 + 2 + wname_all;
91 }
92 case P9_RWALK:
93 BUG_ON(strcmp("ddT", fmt));
94 va_arg(ap, int32_t);
95 va_arg(ap, int32_t);
96 {
97 uint nwname = va_arg(ap, int);
98 /* nwqid[2] nwqid*(wqid[13]) */
99 return max_t(size_t, hdr + 2 + nwname * 13, err_size);
100 }
101 case P9_TCREATE:
102 BUG_ON(strcmp("dsdb?s", fmt));
103 va_arg(ap, int32_t);
104 {
105 const char *name = va_arg(ap, const char *);
106 if (c->proto_version == p9_proto_legacy) {
107 /* fid[4] name[s] perm[4] mode[1] */
108 return hdr + 4 + P9_STRLEN(name) + 4 + 1;
109 } else {
110 va_arg(ap, int32_t);
111 va_arg(ap, int);
112 {
113 const char *ext = va_arg(ap, const char *);
114 /* fid[4] name[s] perm[4] mode[1] extension[s] */
115 return hdr + 4 + P9_STRLEN(name) + 4 + 1 + P9_STRLEN(ext);
116 }
117 }
118 }
119 case P9_TLCREATE:
120 BUG_ON(strcmp("dsddg", fmt));
121 va_arg(ap, int32_t);
122 {
123 const char *name = va_arg(ap, const char *);
124 /* fid[4] name[s] flags[4] mode[4] gid[4] */
125 return hdr + 4 + P9_STRLEN(name) + 4 + 4 + 4;
126 }
127 case P9_RREAD:
128 case P9_RREADDIR:
129 BUG_ON(strcmp("dqd", fmt));
130 va_arg(ap, int32_t);
131 va_arg(ap, int64_t);
132 {
133 const int32_t count = va_arg(ap, int32_t);
134 /* count[4] data[count] */
135 return max_t(size_t, hdr + 4 + count, err_size);
136 }
137 case P9_TWRITE:
138 BUG_ON(strcmp("dqV", fmt));
139 va_arg(ap, int32_t);
140 va_arg(ap, int64_t);
141 {
142 const int32_t count = va_arg(ap, int32_t);
143 /* fid[4] offset[8] count[4] data[count] */
144 return hdr + 4 + 8 + 4 + count;
145 }
146 case P9_TRENAMEAT:
147 BUG_ON(strcmp("dsds", fmt));
148 va_arg(ap, int32_t);
149 {
150 const char *oldname, *newname;
151 oldname = va_arg(ap, const char *);
152 va_arg(ap, int32_t);
153 newname = va_arg(ap, const char *);
154 /* olddirfid[4] oldname[s] newdirfid[4] newname[s] */
155 return hdr + 4 + P9_STRLEN(oldname) + 4 + P9_STRLEN(newname);
156 }
157 case P9_TSYMLINK:
158 BUG_ON(strcmp("dssg", fmt));
159 va_arg(ap, int32_t);
160 {
161 const char *name = va_arg(ap, const char *);
162 const char *symtgt = va_arg(ap, const char *);
163 /* fid[4] name[s] symtgt[s] gid[4] */
164 return hdr + 4 + P9_STRLEN(name) + P9_STRLEN(symtgt) + 4;
165 }
166
167 case P9_RERROR:
168 return rerror_size;
169 case P9_RLERROR:
170 return rlerror_size;
171
172 /* small message types */
173 case P9_TWSTAT:
174 case P9_RSTAT:
175 case P9_RREADLINK:
176 case P9_TXATTRWALK:
177 case P9_TXATTRCREATE:
178 case P9_TLINK:
179 case P9_TMKDIR:
180 case P9_TMKNOD:
181 case P9_TRENAME:
182 case P9_TUNLINKAT:
183 case P9_TLOCK:
184 return 8 * 1024;
185
186 /* tiny message types */
187 default:
188 return 4 * 1024;
189
190 }
191}
192
193static int
194p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...);
195
196void p9stat_free(struct p9_wstat *stbuf)
197{
198 kfree(stbuf->name);
199 stbuf->name = NULL;
200 kfree(stbuf->uid);
201 stbuf->uid = NULL;
202 kfree(stbuf->gid);
203 stbuf->gid = NULL;
204 kfree(stbuf->muid);
205 stbuf->muid = NULL;
206 kfree(stbuf->extension);
207 stbuf->extension = NULL;
208}
209EXPORT_SYMBOL(p9stat_free);
210
211size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size)
212{
213 size_t len = min(pdu->size - pdu->offset, size);
214
215 memcpy(data, &pdu->sdata[pdu->offset], len);
216 pdu->offset += len;
217 return size - len;
218}
219
220static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size)
221{
222 size_t len = min(pdu->capacity - pdu->size, size);
223
224 memcpy(&pdu->sdata[pdu->size], data, len);
225 pdu->size += len;
226 return size - len;
227}
228
229static size_t
230pdu_write_u(struct p9_fcall *pdu, struct iov_iter *from, size_t size)
231{
232 size_t len = min(pdu->capacity - pdu->size, size);
233
234 if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, from))
235 len = 0;
236
237 pdu->size += len;
238 return size - len;
239}
240
241/* b - int8_t
242 * w - int16_t
243 * d - int32_t
244 * q - int64_t
245 * s - string
246 * u - numeric uid
247 * g - numeric gid
248 * S - stat
249 * Q - qid
250 * D - data blob (int32_t size followed by void *, results are not freed)
251 * T - array of strings (int16_t count, followed by strings)
252 * R - array of qids (int16_t count, followed by qids)
253 * A - stat for 9p2000.L (p9_stat_dotl)
254 * ? - if optional = 1, continue parsing
255 */
256
257static int
258p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
259 va_list ap)
260{
261 const char *ptr;
262 int errcode = 0;
263
264 for (ptr = fmt; *ptr; ptr++) {
265 switch (*ptr) {
266 case 'b':{
267 int8_t *val = va_arg(ap, int8_t *);
268 if (pdu_read(pdu, val, sizeof(*val))) {
269 errcode = -EFAULT;
270 break;
271 }
272 }
273 break;
274 case 'w':{
275 int16_t *val = va_arg(ap, int16_t *);
276 __le16 le_val;
277 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
278 errcode = -EFAULT;
279 break;
280 }
281 *val = le16_to_cpu(le_val);
282 }
283 break;
284 case 'd':{
285 int32_t *val = va_arg(ap, int32_t *);
286 __le32 le_val;
287 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
288 errcode = -EFAULT;
289 break;
290 }
291 *val = le32_to_cpu(le_val);
292 }
293 break;
294 case 'q':{
295 int64_t *val = va_arg(ap, int64_t *);
296 __le64 le_val;
297 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
298 errcode = -EFAULT;
299 break;
300 }
301 *val = le64_to_cpu(le_val);
302 }
303 break;
304 case 's':{
305 char **sptr = va_arg(ap, char **);
306 uint16_t len;
307
308 errcode = p9pdu_readf(pdu, proto_version,
309 "w", &len);
310 if (errcode)
311 break;
312
313 *sptr = kmalloc(len + 1, GFP_NOFS);
314 if (*sptr == NULL) {
315 errcode = -ENOMEM;
316 break;
317 }
318 if (pdu_read(pdu, *sptr, len)) {
319 errcode = -EFAULT;
320 kfree(*sptr);
321 *sptr = NULL;
322 } else
323 (*sptr)[len] = 0;
324 }
325 break;
326 case 'u': {
327 kuid_t *uid = va_arg(ap, kuid_t *);
328 __le32 le_val;
329 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
330 errcode = -EFAULT;
331 break;
332 }
333 *uid = make_kuid(&init_user_ns,
334 le32_to_cpu(le_val));
335 } break;
336 case 'g': {
337 kgid_t *gid = va_arg(ap, kgid_t *);
338 __le32 le_val;
339 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
340 errcode = -EFAULT;
341 break;
342 }
343 *gid = make_kgid(&init_user_ns,
344 le32_to_cpu(le_val));
345 } break;
346 case 'Q':{
347 struct p9_qid *qid =
348 va_arg(ap, struct p9_qid *);
349
350 errcode = p9pdu_readf(pdu, proto_version, "bdq",
351 &qid->type, &qid->version,
352 &qid->path);
353 }
354 break;
355 case 'S':{
356 struct p9_wstat *stbuf =
357 va_arg(ap, struct p9_wstat *);
358
359 memset(stbuf, 0, sizeof(struct p9_wstat));
360 stbuf->n_uid = stbuf->n_muid = INVALID_UID;
361 stbuf->n_gid = INVALID_GID;
362
363 errcode =
364 p9pdu_readf(pdu, proto_version,
365 "wwdQdddqssss?sugu",
366 &stbuf->size, &stbuf->type,
367 &stbuf->dev, &stbuf->qid,
368 &stbuf->mode, &stbuf->atime,
369 &stbuf->mtime, &stbuf->length,
370 &stbuf->name, &stbuf->uid,
371 &stbuf->gid, &stbuf->muid,
372 &stbuf->extension,
373 &stbuf->n_uid, &stbuf->n_gid,
374 &stbuf->n_muid);
375 if (errcode)
376 p9stat_free(stbuf);
377 }
378 break;
379 case 'D':{
380 uint32_t *count = va_arg(ap, uint32_t *);
381 void **data = va_arg(ap, void **);
382
383 errcode =
384 p9pdu_readf(pdu, proto_version, "d", count);
385 if (!errcode) {
386 *count =
387 min_t(uint32_t, *count,
388 pdu->size - pdu->offset);
389 *data = &pdu->sdata[pdu->offset];
390 }
391 }
392 break;
393 case 'T':{
394 uint16_t *nwname = va_arg(ap, uint16_t *);
395 char ***wnames = va_arg(ap, char ***);
396
397 errcode = p9pdu_readf(pdu, proto_version,
398 "w", nwname);
399 if (!errcode) {
400 *wnames =
401 kmalloc_array(*nwname,
402 sizeof(char *),
403 GFP_NOFS);
404 if (!*wnames)
405 errcode = -ENOMEM;
406 }
407
408 if (!errcode) {
409 int i;
410
411 for (i = 0; i < *nwname; i++) {
412 errcode =
413 p9pdu_readf(pdu,
414 proto_version,
415 "s",
416 &(*wnames)[i]);
417 if (errcode)
418 break;
419 }
420 }
421
422 if (errcode) {
423 if (*wnames) {
424 int i;
425
426 for (i = 0; i < *nwname; i++)
427 kfree((*wnames)[i]);
428 }
429 kfree(*wnames);
430 *wnames = NULL;
431 }
432 }
433 break;
434 case 'R':{
435 uint16_t *nwqid = va_arg(ap, uint16_t *);
436 struct p9_qid **wqids =
437 va_arg(ap, struct p9_qid **);
438
439 *wqids = NULL;
440
441 errcode =
442 p9pdu_readf(pdu, proto_version, "w", nwqid);
443 if (!errcode) {
444 *wqids =
445 kmalloc_array(*nwqid,
446 sizeof(struct p9_qid),
447 GFP_NOFS);
448 if (*wqids == NULL)
449 errcode = -ENOMEM;
450 }
451
452 if (!errcode) {
453 int i;
454
455 for (i = 0; i < *nwqid; i++) {
456 errcode =
457 p9pdu_readf(pdu,
458 proto_version,
459 "Q",
460 &(*wqids)[i]);
461 if (errcode)
462 break;
463 }
464 }
465
466 if (errcode) {
467 kfree(*wqids);
468 *wqids = NULL;
469 }
470 }
471 break;
472 case 'A': {
473 struct p9_stat_dotl *stbuf =
474 va_arg(ap, struct p9_stat_dotl *);
475
476 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
477 errcode =
478 p9pdu_readf(pdu, proto_version,
479 "qQdugqqqqqqqqqqqqqqq",
480 &stbuf->st_result_mask,
481 &stbuf->qid,
482 &stbuf->st_mode,
483 &stbuf->st_uid, &stbuf->st_gid,
484 &stbuf->st_nlink,
485 &stbuf->st_rdev, &stbuf->st_size,
486 &stbuf->st_blksize, &stbuf->st_blocks,
487 &stbuf->st_atime_sec,
488 &stbuf->st_atime_nsec,
489 &stbuf->st_mtime_sec,
490 &stbuf->st_mtime_nsec,
491 &stbuf->st_ctime_sec,
492 &stbuf->st_ctime_nsec,
493 &stbuf->st_btime_sec,
494 &stbuf->st_btime_nsec,
495 &stbuf->st_gen,
496 &stbuf->st_data_version);
497 }
498 break;
499 case '?':
500 if ((proto_version != p9_proto_2000u) &&
501 (proto_version != p9_proto_2000L))
502 return 0;
503 break;
504 default:
505 BUG();
506 break;
507 }
508
509 if (errcode)
510 break;
511 }
512
513 return errcode;
514}
515
516int
517p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
518 va_list ap)
519{
520 const char *ptr;
521 int errcode = 0;
522
523 for (ptr = fmt; *ptr; ptr++) {
524 switch (*ptr) {
525 case 'b':{
526 int8_t val = va_arg(ap, int);
527 if (pdu_write(pdu, &val, sizeof(val)))
528 errcode = -EFAULT;
529 }
530 break;
531 case 'w':{
532 __le16 val = cpu_to_le16(va_arg(ap, int));
533 if (pdu_write(pdu, &val, sizeof(val)))
534 errcode = -EFAULT;
535 }
536 break;
537 case 'd':{
538 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
539 if (pdu_write(pdu, &val, sizeof(val)))
540 errcode = -EFAULT;
541 }
542 break;
543 case 'q':{
544 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
545 if (pdu_write(pdu, &val, sizeof(val)))
546 errcode = -EFAULT;
547 }
548 break;
549 case 's':{
550 const char *sptr = va_arg(ap, const char *);
551 uint16_t len = 0;
552 if (sptr)
553 len = min_t(size_t, strlen(sptr),
554 USHRT_MAX);
555
556 errcode = p9pdu_writef(pdu, proto_version,
557 "w", len);
558 if (!errcode && pdu_write(pdu, sptr, len))
559 errcode = -EFAULT;
560 }
561 break;
562 case 'u': {
563 kuid_t uid = va_arg(ap, kuid_t);
564 __le32 val = cpu_to_le32(
565 from_kuid(&init_user_ns, uid));
566 if (pdu_write(pdu, &val, sizeof(val)))
567 errcode = -EFAULT;
568 } break;
569 case 'g': {
570 kgid_t gid = va_arg(ap, kgid_t);
571 __le32 val = cpu_to_le32(
572 from_kgid(&init_user_ns, gid));
573 if (pdu_write(pdu, &val, sizeof(val)))
574 errcode = -EFAULT;
575 } break;
576 case 'Q':{
577 const struct p9_qid *qid =
578 va_arg(ap, const struct p9_qid *);
579 errcode =
580 p9pdu_writef(pdu, proto_version, "bdq",
581 qid->type, qid->version,
582 qid->path);
583 } break;
584 case 'S':{
585 const struct p9_wstat *stbuf =
586 va_arg(ap, const struct p9_wstat *);
587 errcode =
588 p9pdu_writef(pdu, proto_version,
589 "wwdQdddqssss?sugu",
590 stbuf->size, stbuf->type,
591 stbuf->dev, &stbuf->qid,
592 stbuf->mode, stbuf->atime,
593 stbuf->mtime, stbuf->length,
594 stbuf->name, stbuf->uid,
595 stbuf->gid, stbuf->muid,
596 stbuf->extension, stbuf->n_uid,
597 stbuf->n_gid, stbuf->n_muid);
598 } break;
599 case 'V':{
600 uint32_t count = va_arg(ap, uint32_t);
601 struct iov_iter *from =
602 va_arg(ap, struct iov_iter *);
603 errcode = p9pdu_writef(pdu, proto_version, "d",
604 count);
605 if (!errcode && pdu_write_u(pdu, from, count))
606 errcode = -EFAULT;
607 }
608 break;
609 case 'T':{
610 uint16_t nwname = va_arg(ap, int);
611 const char **wnames = va_arg(ap, const char **);
612
613 errcode = p9pdu_writef(pdu, proto_version, "w",
614 nwname);
615 if (!errcode) {
616 int i;
617
618 for (i = 0; i < nwname; i++) {
619 errcode =
620 p9pdu_writef(pdu,
621 proto_version,
622 "s",
623 wnames[i]);
624 if (errcode)
625 break;
626 }
627 }
628 }
629 break;
630 case 'R':{
631 uint16_t nwqid = va_arg(ap, int);
632 struct p9_qid *wqids =
633 va_arg(ap, struct p9_qid *);
634
635 errcode = p9pdu_writef(pdu, proto_version, "w",
636 nwqid);
637 if (!errcode) {
638 int i;
639
640 for (i = 0; i < nwqid; i++) {
641 errcode =
642 p9pdu_writef(pdu,
643 proto_version,
644 "Q",
645 &wqids[i]);
646 if (errcode)
647 break;
648 }
649 }
650 }
651 break;
652 case 'I':{
653 struct p9_iattr_dotl *p9attr = va_arg(ap,
654 struct p9_iattr_dotl *);
655
656 errcode = p9pdu_writef(pdu, proto_version,
657 "ddugqqqqq",
658 p9attr->valid,
659 p9attr->mode,
660 p9attr->uid,
661 p9attr->gid,
662 p9attr->size,
663 p9attr->atime_sec,
664 p9attr->atime_nsec,
665 p9attr->mtime_sec,
666 p9attr->mtime_nsec);
667 }
668 break;
669 case '?':
670 if ((proto_version != p9_proto_2000u) &&
671 (proto_version != p9_proto_2000L))
672 return 0;
673 break;
674 default:
675 BUG();
676 break;
677 }
678
679 if (errcode)
680 break;
681 }
682
683 return errcode;
684}
685
686int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
687{
688 va_list ap;
689 int ret;
690
691 va_start(ap, fmt);
692 ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
693 va_end(ap);
694
695 return ret;
696}
697
698static int
699p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
700{
701 va_list ap;
702 int ret;
703
704 va_start(ap, fmt);
705 ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
706 va_end(ap);
707
708 return ret;
709}
710
711int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st)
712{
713 struct p9_fcall fake_pdu;
714 int ret;
715
716 fake_pdu.size = len;
717 fake_pdu.capacity = len;
718 fake_pdu.sdata = buf;
719 fake_pdu.offset = 0;
720
721 ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st);
722 if (ret) {
723 p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
724 trace_9p_protocol_dump(clnt, &fake_pdu);
725 return ret;
726 }
727
728 return fake_pdu.offset;
729}
730EXPORT_SYMBOL(p9stat_read);
731
732int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
733{
734 pdu->id = type;
735 return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
736}
737
738int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu)
739{
740 int size = pdu->size;
741 int err;
742
743 pdu->size = 0;
744 err = p9pdu_writef(pdu, 0, "d", size);
745 pdu->size = size;
746
747 trace_9p_protocol_dump(clnt, pdu);
748 p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n",
749 pdu->size, pdu->id, pdu->tag);
750
751 return err;
752}
753
754void p9pdu_reset(struct p9_fcall *pdu)
755{
756 pdu->offset = 0;
757 pdu->size = 0;
758}
759
760int p9dirent_read(struct p9_client *clnt, char *buf, int len,
761 struct p9_dirent *dirent)
762{
763 struct p9_fcall fake_pdu;
764 int ret;
765 char *nameptr;
766
767 fake_pdu.size = len;
768 fake_pdu.capacity = len;
769 fake_pdu.sdata = buf;
770 fake_pdu.offset = 0;
771
772 ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid,
773 &dirent->d_off, &dirent->d_type, &nameptr);
774 if (ret) {
775 p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
776 trace_9p_protocol_dump(clnt, &fake_pdu);
777 return ret;
778 }
779
780 ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name));
781 if (ret < 0) {
782 p9_debug(P9_DEBUG_ERROR,
783 "On the wire dirent name too long: %s\n",
784 nameptr);
785 kfree(nameptr);
786 return ret;
787 }
788 kfree(nameptr);
789
790 return fake_pdu.offset;
791}
792EXPORT_SYMBOL(p9dirent_read);
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
42static int
43p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...);
44
45void 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}
53EXPORT_SYMBOL(p9stat_free);
54
55size_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
63static 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
71static size_t
72pdu_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
97static int
98p9pdu_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
334int
335p9pdu_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(size_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
500int 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
512static int
513p9pdu_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
525int 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}
543EXPORT_SYMBOL(p9stat_read);
544
545int 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
551int 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
567void p9pdu_reset(struct p9_fcall *pdu)
568{
569 pdu->offset = 0;
570 pdu->size = 0;
571}
572
573int 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
596out:
597 return fake_pdu.offset;
598}
599EXPORT_SYMBOL(p9dirent_read);