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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// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * net/9p/protocol.c
4 *
5 * 9P Protocol Support Code
6 *
7 * Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
8 *
9 * Base on code from Anthony Liguori <aliguori@us.ibm.com>
10 * Copyright (C) 2008 by IBM, Corp.
11 */
12
13#include <linux/module.h>
14#include <linux/errno.h>
15#include <linux/kernel.h>
16#include <linux/uaccess.h>
17#include <linux/slab.h>
18#include <linux/sched.h>
19#include <linux/stddef.h>
20#include <linux/types.h>
21#include <linux/uio.h>
22#include <net/9p/9p.h>
23#include <net/9p/client.h>
24#include "protocol.h"
25
26#include <trace/events/9p.h>
27
28static int
29p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...);
30
31void p9stat_free(struct p9_wstat *stbuf)
32{
33 kfree(stbuf->name);
34 stbuf->name = NULL;
35 kfree(stbuf->uid);
36 stbuf->uid = NULL;
37 kfree(stbuf->gid);
38 stbuf->gid = NULL;
39 kfree(stbuf->muid);
40 stbuf->muid = NULL;
41 kfree(stbuf->extension);
42 stbuf->extension = NULL;
43}
44EXPORT_SYMBOL(p9stat_free);
45
46size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size)
47{
48 size_t len = min(pdu->size - pdu->offset, size);
49 memcpy(data, &pdu->sdata[pdu->offset], len);
50 pdu->offset += len;
51 return size - len;
52}
53
54static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size)
55{
56 size_t len = min(pdu->capacity - pdu->size, size);
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 struct iov_iter i = *from;
67 if (!copy_from_iter_full(&pdu->sdata[pdu->size], len, &i))
68 len = 0;
69
70 pdu->size += len;
71 return size - len;
72}
73
74/*
75 b - int8_t
76 w - int16_t
77 d - int32_t
78 q - int64_t
79 s - string
80 u - numeric uid
81 g - numeric gid
82 S - stat
83 Q - qid
84 D - data blob (int32_t size followed by void *, results are not freed)
85 T - array of strings (int16_t count, followed by strings)
86 R - array of qids (int16_t count, followed by qids)
87 A - stat for 9p2000.L (p9_stat_dotl)
88 ? - if optional = 1, continue parsing
89*/
90
91static int
92p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
93 va_list ap)
94{
95 const char *ptr;
96 int errcode = 0;
97
98 for (ptr = fmt; *ptr; ptr++) {
99 switch (*ptr) {
100 case 'b':{
101 int8_t *val = va_arg(ap, int8_t *);
102 if (pdu_read(pdu, val, sizeof(*val))) {
103 errcode = -EFAULT;
104 break;
105 }
106 }
107 break;
108 case 'w':{
109 int16_t *val = va_arg(ap, int16_t *);
110 __le16 le_val;
111 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
112 errcode = -EFAULT;
113 break;
114 }
115 *val = le16_to_cpu(le_val);
116 }
117 break;
118 case 'd':{
119 int32_t *val = va_arg(ap, int32_t *);
120 __le32 le_val;
121 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
122 errcode = -EFAULT;
123 break;
124 }
125 *val = le32_to_cpu(le_val);
126 }
127 break;
128 case 'q':{
129 int64_t *val = va_arg(ap, int64_t *);
130 __le64 le_val;
131 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
132 errcode = -EFAULT;
133 break;
134 }
135 *val = le64_to_cpu(le_val);
136 }
137 break;
138 case 's':{
139 char **sptr = va_arg(ap, char **);
140 uint16_t len;
141
142 errcode = p9pdu_readf(pdu, proto_version,
143 "w", &len);
144 if (errcode)
145 break;
146
147 *sptr = kmalloc(len + 1, GFP_NOFS);
148 if (*sptr == NULL) {
149 errcode = -ENOMEM;
150 break;
151 }
152 if (pdu_read(pdu, *sptr, len)) {
153 errcode = -EFAULT;
154 kfree(*sptr);
155 *sptr = NULL;
156 } else
157 (*sptr)[len] = 0;
158 }
159 break;
160 case 'u': {
161 kuid_t *uid = va_arg(ap, kuid_t *);
162 __le32 le_val;
163 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
164 errcode = -EFAULT;
165 break;
166 }
167 *uid = make_kuid(&init_user_ns,
168 le32_to_cpu(le_val));
169 } break;
170 case 'g': {
171 kgid_t *gid = va_arg(ap, kgid_t *);
172 __le32 le_val;
173 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
174 errcode = -EFAULT;
175 break;
176 }
177 *gid = make_kgid(&init_user_ns,
178 le32_to_cpu(le_val));
179 } break;
180 case 'Q':{
181 struct p9_qid *qid =
182 va_arg(ap, struct p9_qid *);
183
184 errcode = p9pdu_readf(pdu, proto_version, "bdq",
185 &qid->type, &qid->version,
186 &qid->path);
187 }
188 break;
189 case 'S':{
190 struct p9_wstat *stbuf =
191 va_arg(ap, struct p9_wstat *);
192
193 memset(stbuf, 0, sizeof(struct p9_wstat));
194 stbuf->n_uid = stbuf->n_muid = INVALID_UID;
195 stbuf->n_gid = INVALID_GID;
196
197 errcode =
198 p9pdu_readf(pdu, proto_version,
199 "wwdQdddqssss?sugu",
200 &stbuf->size, &stbuf->type,
201 &stbuf->dev, &stbuf->qid,
202 &stbuf->mode, &stbuf->atime,
203 &stbuf->mtime, &stbuf->length,
204 &stbuf->name, &stbuf->uid,
205 &stbuf->gid, &stbuf->muid,
206 &stbuf->extension,
207 &stbuf->n_uid, &stbuf->n_gid,
208 &stbuf->n_muid);
209 if (errcode)
210 p9stat_free(stbuf);
211 }
212 break;
213 case 'D':{
214 uint32_t *count = va_arg(ap, uint32_t *);
215 void **data = va_arg(ap, void **);
216
217 errcode =
218 p9pdu_readf(pdu, proto_version, "d", count);
219 if (!errcode) {
220 *count =
221 min_t(uint32_t, *count,
222 pdu->size - pdu->offset);
223 *data = &pdu->sdata[pdu->offset];
224 }
225 }
226 break;
227 case 'T':{
228 uint16_t *nwname = va_arg(ap, uint16_t *);
229 char ***wnames = va_arg(ap, char ***);
230
231 errcode = p9pdu_readf(pdu, proto_version,
232 "w", nwname);
233 if (!errcode) {
234 *wnames =
235 kmalloc_array(*nwname,
236 sizeof(char *),
237 GFP_NOFS);
238 if (!*wnames)
239 errcode = -ENOMEM;
240 }
241
242 if (!errcode) {
243 int i;
244
245 for (i = 0; i < *nwname; i++) {
246 errcode =
247 p9pdu_readf(pdu,
248 proto_version,
249 "s",
250 &(*wnames)[i]);
251 if (errcode)
252 break;
253 }
254 }
255
256 if (errcode) {
257 if (*wnames) {
258 int i;
259
260 for (i = 0; i < *nwname; i++)
261 kfree((*wnames)[i]);
262 }
263 kfree(*wnames);
264 *wnames = NULL;
265 }
266 }
267 break;
268 case 'R':{
269 uint16_t *nwqid = va_arg(ap, uint16_t *);
270 struct p9_qid **wqids =
271 va_arg(ap, struct p9_qid **);
272
273 *wqids = NULL;
274
275 errcode =
276 p9pdu_readf(pdu, proto_version, "w", nwqid);
277 if (!errcode) {
278 *wqids =
279 kmalloc_array(*nwqid,
280 sizeof(struct p9_qid),
281 GFP_NOFS);
282 if (*wqids == NULL)
283 errcode = -ENOMEM;
284 }
285
286 if (!errcode) {
287 int i;
288
289 for (i = 0; i < *nwqid; i++) {
290 errcode =
291 p9pdu_readf(pdu,
292 proto_version,
293 "Q",
294 &(*wqids)[i]);
295 if (errcode)
296 break;
297 }
298 }
299
300 if (errcode) {
301 kfree(*wqids);
302 *wqids = NULL;
303 }
304 }
305 break;
306 case 'A': {
307 struct p9_stat_dotl *stbuf =
308 va_arg(ap, struct p9_stat_dotl *);
309
310 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
311 errcode =
312 p9pdu_readf(pdu, proto_version,
313 "qQdugqqqqqqqqqqqqqqq",
314 &stbuf->st_result_mask,
315 &stbuf->qid,
316 &stbuf->st_mode,
317 &stbuf->st_uid, &stbuf->st_gid,
318 &stbuf->st_nlink,
319 &stbuf->st_rdev, &stbuf->st_size,
320 &stbuf->st_blksize, &stbuf->st_blocks,
321 &stbuf->st_atime_sec,
322 &stbuf->st_atime_nsec,
323 &stbuf->st_mtime_sec,
324 &stbuf->st_mtime_nsec,
325 &stbuf->st_ctime_sec,
326 &stbuf->st_ctime_nsec,
327 &stbuf->st_btime_sec,
328 &stbuf->st_btime_nsec,
329 &stbuf->st_gen,
330 &stbuf->st_data_version);
331 }
332 break;
333 case '?':
334 if ((proto_version != p9_proto_2000u) &&
335 (proto_version != p9_proto_2000L))
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 proto_version, const char *fmt,
352 va_list ap)
353{
354 const char *ptr;
355 int errcode = 0;
356
357 for (ptr = fmt; *ptr; ptr++) {
358 switch (*ptr) {
359 case 'b':{
360 int8_t val = va_arg(ap, int);
361 if (pdu_write(pdu, &val, sizeof(val)))
362 errcode = -EFAULT;
363 }
364 break;
365 case 'w':{
366 __le16 val = cpu_to_le16(va_arg(ap, int));
367 if (pdu_write(pdu, &val, sizeof(val)))
368 errcode = -EFAULT;
369 }
370 break;
371 case 'd':{
372 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
373 if (pdu_write(pdu, &val, sizeof(val)))
374 errcode = -EFAULT;
375 }
376 break;
377 case 'q':{
378 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
379 if (pdu_write(pdu, &val, sizeof(val)))
380 errcode = -EFAULT;
381 }
382 break;
383 case 's':{
384 const char *sptr = va_arg(ap, const char *);
385 uint16_t len = 0;
386 if (sptr)
387 len = min_t(size_t, strlen(sptr),
388 USHRT_MAX);
389
390 errcode = p9pdu_writef(pdu, proto_version,
391 "w", len);
392 if (!errcode && pdu_write(pdu, sptr, len))
393 errcode = -EFAULT;
394 }
395 break;
396 case 'u': {
397 kuid_t uid = va_arg(ap, kuid_t);
398 __le32 val = cpu_to_le32(
399 from_kuid(&init_user_ns, uid));
400 if (pdu_write(pdu, &val, sizeof(val)))
401 errcode = -EFAULT;
402 } break;
403 case 'g': {
404 kgid_t gid = va_arg(ap, kgid_t);
405 __le32 val = cpu_to_le32(
406 from_kgid(&init_user_ns, gid));
407 if (pdu_write(pdu, &val, sizeof(val)))
408 errcode = -EFAULT;
409 } break;
410 case 'Q':{
411 const struct p9_qid *qid =
412 va_arg(ap, const struct p9_qid *);
413 errcode =
414 p9pdu_writef(pdu, proto_version, "bdq",
415 qid->type, qid->version,
416 qid->path);
417 } break;
418 case 'S':{
419 const struct p9_wstat *stbuf =
420 va_arg(ap, const struct p9_wstat *);
421 errcode =
422 p9pdu_writef(pdu, proto_version,
423 "wwdQdddqssss?sugu",
424 stbuf->size, stbuf->type,
425 stbuf->dev, &stbuf->qid,
426 stbuf->mode, stbuf->atime,
427 stbuf->mtime, stbuf->length,
428 stbuf->name, stbuf->uid,
429 stbuf->gid, stbuf->muid,
430 stbuf->extension, stbuf->n_uid,
431 stbuf->n_gid, stbuf->n_muid);
432 } break;
433 case 'V':{
434 uint32_t count = va_arg(ap, uint32_t);
435 struct iov_iter *from =
436 va_arg(ap, struct iov_iter *);
437 errcode = p9pdu_writef(pdu, proto_version, "d",
438 count);
439 if (!errcode && pdu_write_u(pdu, from, count))
440 errcode = -EFAULT;
441 }
442 break;
443 case 'T':{
444 uint16_t nwname = va_arg(ap, int);
445 const char **wnames = va_arg(ap, const char **);
446
447 errcode = p9pdu_writef(pdu, proto_version, "w",
448 nwname);
449 if (!errcode) {
450 int i;
451
452 for (i = 0; i < nwname; i++) {
453 errcode =
454 p9pdu_writef(pdu,
455 proto_version,
456 "s",
457 wnames[i]);
458 if (errcode)
459 break;
460 }
461 }
462 }
463 break;
464 case 'R':{
465 uint16_t nwqid = va_arg(ap, int);
466 struct p9_qid *wqids =
467 va_arg(ap, struct p9_qid *);
468
469 errcode = p9pdu_writef(pdu, proto_version, "w",
470 nwqid);
471 if (!errcode) {
472 int i;
473
474 for (i = 0; i < nwqid; i++) {
475 errcode =
476 p9pdu_writef(pdu,
477 proto_version,
478 "Q",
479 &wqids[i]);
480 if (errcode)
481 break;
482 }
483 }
484 }
485 break;
486 case 'I':{
487 struct p9_iattr_dotl *p9attr = va_arg(ap,
488 struct p9_iattr_dotl *);
489
490 errcode = p9pdu_writef(pdu, proto_version,
491 "ddugqqqqq",
492 p9attr->valid,
493 p9attr->mode,
494 p9attr->uid,
495 p9attr->gid,
496 p9attr->size,
497 p9attr->atime_sec,
498 p9attr->atime_nsec,
499 p9attr->mtime_sec,
500 p9attr->mtime_nsec);
501 }
502 break;
503 case '?':
504 if ((proto_version != p9_proto_2000u) &&
505 (proto_version != p9_proto_2000L))
506 return 0;
507 break;
508 default:
509 BUG();
510 break;
511 }
512
513 if (errcode)
514 break;
515 }
516
517 return errcode;
518}
519
520int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
521{
522 va_list ap;
523 int ret;
524
525 va_start(ap, fmt);
526 ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
527 va_end(ap);
528
529 return ret;
530}
531
532static int
533p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
534{
535 va_list ap;
536 int ret;
537
538 va_start(ap, fmt);
539 ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
540 va_end(ap);
541
542 return ret;
543}
544
545int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st)
546{
547 struct p9_fcall fake_pdu;
548 int ret;
549
550 fake_pdu.size = len;
551 fake_pdu.capacity = len;
552 fake_pdu.sdata = buf;
553 fake_pdu.offset = 0;
554
555 ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st);
556 if (ret) {
557 p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
558 trace_9p_protocol_dump(clnt, &fake_pdu);
559 return ret;
560 }
561
562 return fake_pdu.offset;
563}
564EXPORT_SYMBOL(p9stat_read);
565
566int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
567{
568 pdu->id = type;
569 return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
570}
571
572int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu)
573{
574 int size = pdu->size;
575 int err;
576
577 pdu->size = 0;
578 err = p9pdu_writef(pdu, 0, "d", size);
579 pdu->size = size;
580
581 trace_9p_protocol_dump(clnt, pdu);
582 p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n",
583 pdu->size, pdu->id, pdu->tag);
584
585 return err;
586}
587
588void p9pdu_reset(struct p9_fcall *pdu)
589{
590 pdu->offset = 0;
591 pdu->size = 0;
592}
593
594int p9dirent_read(struct p9_client *clnt, char *buf, int len,
595 struct p9_dirent *dirent)
596{
597 struct p9_fcall fake_pdu;
598 int ret;
599 char *nameptr;
600
601 fake_pdu.size = len;
602 fake_pdu.capacity = len;
603 fake_pdu.sdata = buf;
604 fake_pdu.offset = 0;
605
606 ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid,
607 &dirent->d_off, &dirent->d_type, &nameptr);
608 if (ret) {
609 p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
610 trace_9p_protocol_dump(clnt, &fake_pdu);
611 return ret;
612 }
613
614 ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name));
615 if (ret < 0) {
616 p9_debug(P9_DEBUG_ERROR,
617 "On the wire dirent name too long: %s\n",
618 nameptr);
619 kfree(nameptr);
620 return ret;
621 }
622 kfree(nameptr);
623
624 return fake_pdu.offset;
625}
626EXPORT_SYMBOL(p9dirent_read);