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TOMOYO Linux Cross Reference
Linux/net/9p/protocol.c

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  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 
 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 
 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 
 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
 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         u - numeric uid
 89         g - numeric gid
 90         S - stat
 91         Q - qid
 92         D - data blob (int32_t size followed by void *, results are not freed)
 93         T - array of strings (int16_t count, followed by strings)
 94         R - array of qids (int16_t count, followed by qids)
 95         A - stat for 9p2000.L (p9_stat_dotl)
 96         ? - if optional = 1, continue parsing
 97 */
 98 
 99 static int
100 p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
101         va_list ap)
102 {
103         const char *ptr;
104         int errcode = 0;
105 
106         for (ptr = fmt; *ptr; ptr++) {
107                 switch (*ptr) {
108                 case 'b':{
109                                 int8_t *val = va_arg(ap, int8_t *);
110                                 if (pdu_read(pdu, val, sizeof(*val))) {
111                                         errcode = -EFAULT;
112                                         break;
113                                 }
114                         }
115                         break;
116                 case 'w':{
117                                 int16_t *val = va_arg(ap, int16_t *);
118                                 __le16 le_val;
119                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
120                                         errcode = -EFAULT;
121                                         break;
122                                 }
123                                 *val = le16_to_cpu(le_val);
124                         }
125                         break;
126                 case 'd':{
127                                 int32_t *val = va_arg(ap, int32_t *);
128                                 __le32 le_val;
129                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
130                                         errcode = -EFAULT;
131                                         break;
132                                 }
133                                 *val = le32_to_cpu(le_val);
134                         }
135                         break;
136                 case 'q':{
137                                 int64_t *val = va_arg(ap, int64_t *);
138                                 __le64 le_val;
139                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
140                                         errcode = -EFAULT;
141                                         break;
142                                 }
143                                 *val = le64_to_cpu(le_val);
144                         }
145                         break;
146                 case 's':{
147                                 char **sptr = va_arg(ap, char **);
148                                 uint16_t len;
149 
150                                 errcode = p9pdu_readf(pdu, proto_version,
151                                                                 "w", &len);
152                                 if (errcode)
153                                         break;
154 
155                                 *sptr = kmalloc(len + 1, GFP_NOFS);
156                                 if (*sptr == NULL) {
157                                         errcode = -EFAULT;
158                                         break;
159                                 }
160                                 if (pdu_read(pdu, *sptr, len)) {
161                                         errcode = -EFAULT;
162                                         kfree(*sptr);
163                                         *sptr = NULL;
164                                 } else
165                                         (*sptr)[len] = 0;
166                         }
167                         break;
168                 case 'u': {
169                                 kuid_t *uid = va_arg(ap, kuid_t *);
170                                 __le32 le_val;
171                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
172                                         errcode = -EFAULT;
173                                         break;
174                                 }
175                                 *uid = make_kuid(&init_user_ns,
176                                                  le32_to_cpu(le_val));
177                         } break;
178                 case 'g': {
179                                 kgid_t *gid = va_arg(ap, kgid_t *);
180                                 __le32 le_val;
181                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
182                                         errcode = -EFAULT;
183                                         break;
184                                 }
185                                 *gid = make_kgid(&init_user_ns,
186                                                  le32_to_cpu(le_val));
187                         } break;
188                 case 'Q':{
189                                 struct p9_qid *qid =
190                                     va_arg(ap, struct p9_qid *);
191 
192                                 errcode = p9pdu_readf(pdu, proto_version, "bdq",
193                                                       &qid->type, &qid->version,
194                                                       &qid->path);
195                         }
196                         break;
197                 case 'S':{
198                                 struct p9_wstat *stbuf =
199                                     va_arg(ap, struct p9_wstat *);
200 
201                                 memset(stbuf, 0, sizeof(struct p9_wstat));
202                                 stbuf->n_uid = stbuf->n_muid = INVALID_UID;
203                                 stbuf->n_gid = INVALID_GID;
204 
205                                 errcode =
206                                     p9pdu_readf(pdu, proto_version,
207                                                 "wwdQdddqssss?sugu",
208                                                 &stbuf->size, &stbuf->type,
209                                                 &stbuf->dev, &stbuf->qid,
210                                                 &stbuf->mode, &stbuf->atime,
211                                                 &stbuf->mtime, &stbuf->length,
212                                                 &stbuf->name, &stbuf->uid,
213                                                 &stbuf->gid, &stbuf->muid,
214                                                 &stbuf->extension,
215                                                 &stbuf->n_uid, &stbuf->n_gid,
216                                                 &stbuf->n_muid);
217                                 if (errcode)
218                                         p9stat_free(stbuf);
219                         }
220                         break;
221                 case 'D':{
222                                 uint32_t *count = va_arg(ap, uint32_t *);
223                                 void **data = va_arg(ap, void **);
224 
225                                 errcode =
226                                     p9pdu_readf(pdu, proto_version, "d", count);
227                                 if (!errcode) {
228                                         *count =
229                                             min_t(uint32_t, *count,
230                                                   pdu->size - pdu->offset);
231                                         *data = &pdu->sdata[pdu->offset];
232                                 }
233                         }
234                         break;
235                 case 'T':{
236                                 uint16_t *nwname = va_arg(ap, uint16_t *);
237                                 char ***wnames = va_arg(ap, char ***);
238 
239                                 errcode = p9pdu_readf(pdu, proto_version,
240                                                                 "w", nwname);
241                                 if (!errcode) {
242                                         *wnames =
243                                             kmalloc(sizeof(char *) * *nwname,
244                                                     GFP_NOFS);
245                                         if (!*wnames)
246                                                 errcode = -ENOMEM;
247                                 }
248 
249                                 if (!errcode) {
250                                         int i;
251 
252                                         for (i = 0; i < *nwname; i++) {
253                                                 errcode =
254                                                     p9pdu_readf(pdu,
255                                                                 proto_version,
256                                                                 "s",
257                                                                 &(*wnames)[i]);
258                                                 if (errcode)
259                                                         break;
260                                         }
261                                 }
262 
263                                 if (errcode) {
264                                         if (*wnames) {
265                                                 int i;
266 
267                                                 for (i = 0; i < *nwname; i++)
268                                                         kfree((*wnames)[i]);
269                                         }
270                                         kfree(*wnames);
271                                         *wnames = NULL;
272                                 }
273                         }
274                         break;
275                 case 'R':{
276                                 int16_t *nwqid = va_arg(ap, int16_t *);
277                                 struct p9_qid **wqids =
278                                     va_arg(ap, struct p9_qid **);
279 
280                                 *wqids = NULL;
281 
282                                 errcode =
283                                     p9pdu_readf(pdu, proto_version, "w", nwqid);
284                                 if (!errcode) {
285                                         *wqids =
286                                             kmalloc(*nwqid *
287                                                     sizeof(struct p9_qid),
288                                                     GFP_NOFS);
289                                         if (*wqids == NULL)
290                                                 errcode = -ENOMEM;
291                                 }
292 
293                                 if (!errcode) {
294                                         int i;
295 
296                                         for (i = 0; i < *nwqid; i++) {
297                                                 errcode =
298                                                     p9pdu_readf(pdu,
299                                                                 proto_version,
300                                                                 "Q",
301                                                                 &(*wqids)[i]);
302                                                 if (errcode)
303                                                         break;
304                                         }
305                                 }
306 
307                                 if (errcode) {
308                                         kfree(*wqids);
309                                         *wqids = NULL;
310                                 }
311                         }
312                         break;
313                 case 'A': {
314                                 struct p9_stat_dotl *stbuf =
315                                     va_arg(ap, struct p9_stat_dotl *);
316 
317                                 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
318                                 errcode =
319                                     p9pdu_readf(pdu, proto_version,
320                                         "qQdugqqqqqqqqqqqqqqq",
321                                         &stbuf->st_result_mask,
322                                         &stbuf->qid,
323                                         &stbuf->st_mode,
324                                         &stbuf->st_uid, &stbuf->st_gid,
325                                         &stbuf->st_nlink,
326                                         &stbuf->st_rdev, &stbuf->st_size,
327                                         &stbuf->st_blksize, &stbuf->st_blocks,
328                                         &stbuf->st_atime_sec,
329                                         &stbuf->st_atime_nsec,
330                                         &stbuf->st_mtime_sec,
331                                         &stbuf->st_mtime_nsec,
332                                         &stbuf->st_ctime_sec,
333                                         &stbuf->st_ctime_nsec,
334                                         &stbuf->st_btime_sec,
335                                         &stbuf->st_btime_nsec,
336                                         &stbuf->st_gen,
337                                         &stbuf->st_data_version);
338                         }
339                         break;
340                 case '?':
341                         if ((proto_version != p9_proto_2000u) &&
342                                 (proto_version != p9_proto_2000L))
343                                 return 0;
344                         break;
345                 default:
346                         BUG();
347                         break;
348                 }
349 
350                 if (errcode)
351                         break;
352         }
353 
354         return errcode;
355 }
356 
357 int
358 p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
359         va_list ap)
360 {
361         const char *ptr;
362         int errcode = 0;
363 
364         for (ptr = fmt; *ptr; ptr++) {
365                 switch (*ptr) {
366                 case 'b':{
367                                 int8_t val = va_arg(ap, int);
368                                 if (pdu_write(pdu, &val, sizeof(val)))
369                                         errcode = -EFAULT;
370                         }
371                         break;
372                 case 'w':{
373                                 __le16 val = cpu_to_le16(va_arg(ap, int));
374                                 if (pdu_write(pdu, &val, sizeof(val)))
375                                         errcode = -EFAULT;
376                         }
377                         break;
378                 case 'd':{
379                                 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
380                                 if (pdu_write(pdu, &val, sizeof(val)))
381                                         errcode = -EFAULT;
382                         }
383                         break;
384                 case 'q':{
385                                 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
386                                 if (pdu_write(pdu, &val, sizeof(val)))
387                                         errcode = -EFAULT;
388                         }
389                         break;
390                 case 's':{
391                                 const char *sptr = va_arg(ap, const char *);
392                                 uint16_t len = 0;
393                                 if (sptr)
394                                         len = min_t(size_t, strlen(sptr),
395                                                                 USHRT_MAX);
396 
397                                 errcode = p9pdu_writef(pdu, proto_version,
398                                                                 "w", len);
399                                 if (!errcode && pdu_write(pdu, sptr, len))
400                                         errcode = -EFAULT;
401                         }
402                         break;
403                 case 'u': {
404                                 kuid_t uid = va_arg(ap, kuid_t);
405                                 __le32 val = cpu_to_le32(
406                                                 from_kuid(&init_user_ns, uid));
407                                 if (pdu_write(pdu, &val, sizeof(val)))
408                                         errcode = -EFAULT;
409                         } break;
410                 case 'g': {
411                                 kgid_t gid = va_arg(ap, kgid_t);
412                                 __le32 val = cpu_to_le32(
413                                                 from_kgid(&init_user_ns, gid));
414                                 if (pdu_write(pdu, &val, sizeof(val)))
415                                         errcode = -EFAULT;
416                         } break;
417                 case 'Q':{
418                                 const struct p9_qid *qid =
419                                     va_arg(ap, const struct p9_qid *);
420                                 errcode =
421                                     p9pdu_writef(pdu, proto_version, "bdq",
422                                                  qid->type, qid->version,
423                                                  qid->path);
424                         } break;
425                 case 'S':{
426                                 const struct p9_wstat *stbuf =
427                                     va_arg(ap, const struct p9_wstat *);
428                                 errcode =
429                                     p9pdu_writef(pdu, proto_version,
430                                                  "wwdQdddqssss?sugu",
431                                                  stbuf->size, stbuf->type,
432                                                  stbuf->dev, &stbuf->qid,
433                                                  stbuf->mode, stbuf->atime,
434                                                  stbuf->mtime, stbuf->length,
435                                                  stbuf->name, stbuf->uid,
436                                                  stbuf->gid, stbuf->muid,
437                                                  stbuf->extension, stbuf->n_uid,
438                                                  stbuf->n_gid, stbuf->n_muid);
439                         } break;
440                 case 'D':{
441                                 uint32_t count = va_arg(ap, uint32_t);
442                                 const void *data = va_arg(ap, const void *);
443 
444                                 errcode = p9pdu_writef(pdu, proto_version, "d",
445                                                                         count);
446                                 if (!errcode && pdu_write(pdu, data, count))
447                                         errcode = -EFAULT;
448                         }
449                         break;
450                 case 'U':{
451                                 int32_t count = va_arg(ap, int32_t);
452                                 const char __user *udata =
453                                                 va_arg(ap, const void __user *);
454                                 errcode = p9pdu_writef(pdu, proto_version, "d",
455                                                                         count);
456                                 if (!errcode && pdu_write_u(pdu, udata, count))
457                                         errcode = -EFAULT;
458                         }
459                         break;
460                 case 'T':{
461                                 uint16_t nwname = va_arg(ap, int);
462                                 const char **wnames = va_arg(ap, const char **);
463 
464                                 errcode = p9pdu_writef(pdu, proto_version, "w",
465                                                                         nwname);
466                                 if (!errcode) {
467                                         int i;
468 
469                                         for (i = 0; i < nwname; i++) {
470                                                 errcode =
471                                                     p9pdu_writef(pdu,
472                                                                 proto_version,
473                                                                  "s",
474                                                                  wnames[i]);
475                                                 if (errcode)
476                                                         break;
477                                         }
478                                 }
479                         }
480                         break;
481                 case 'R':{
482                                 int16_t nwqid = va_arg(ap, int);
483                                 struct p9_qid *wqids =
484                                     va_arg(ap, struct p9_qid *);
485 
486                                 errcode = p9pdu_writef(pdu, proto_version, "w",
487                                                                         nwqid);
488                                 if (!errcode) {
489                                         int i;
490 
491                                         for (i = 0; i < nwqid; i++) {
492                                                 errcode =
493                                                     p9pdu_writef(pdu,
494                                                                 proto_version,
495                                                                  "Q",
496                                                                  &wqids[i]);
497                                                 if (errcode)
498                                                         break;
499                                         }
500                                 }
501                         }
502                         break;
503                 case 'I':{
504                                 struct p9_iattr_dotl *p9attr = va_arg(ap,
505                                                         struct p9_iattr_dotl *);
506 
507                                 errcode = p9pdu_writef(pdu, proto_version,
508                                                         "ddugqqqqq",
509                                                         p9attr->valid,
510                                                         p9attr->mode,
511                                                         p9attr->uid,
512                                                         p9attr->gid,
513                                                         p9attr->size,
514                                                         p9attr->atime_sec,
515                                                         p9attr->atime_nsec,
516                                                         p9attr->mtime_sec,
517                                                         p9attr->mtime_nsec);
518                         }
519                         break;
520                 case '?':
521                         if ((proto_version != p9_proto_2000u) &&
522                                 (proto_version != p9_proto_2000L))
523                                 return 0;
524                         break;
525                 default:
526                         BUG();
527                         break;
528                 }
529 
530                 if (errcode)
531                         break;
532         }
533 
534         return errcode;
535 }
536 
537 int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
538 {
539         va_list ap;
540         int ret;
541 
542         va_start(ap, fmt);
543         ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
544         va_end(ap);
545 
546         return ret;
547 }
548 
549 static int
550 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
551 {
552         va_list ap;
553         int ret;
554 
555         va_start(ap, fmt);
556         ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
557         va_end(ap);
558 
559         return ret;
560 }
561 
562 int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st)
563 {
564         struct p9_fcall fake_pdu;
565         int ret;
566 
567         fake_pdu.size = len;
568         fake_pdu.capacity = len;
569         fake_pdu.sdata = buf;
570         fake_pdu.offset = 0;
571 
572         ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "S", st);
573         if (ret) {
574                 p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
575                 trace_9p_protocol_dump(clnt, &fake_pdu);
576         }
577 
578         return ret;
579 }
580 EXPORT_SYMBOL(p9stat_read);
581 
582 int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
583 {
584         pdu->id = type;
585         return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
586 }
587 
588 int p9pdu_finalize(struct p9_client *clnt, struct p9_fcall *pdu)
589 {
590         int size = pdu->size;
591         int err;
592 
593         pdu->size = 0;
594         err = p9pdu_writef(pdu, 0, "d", size);
595         pdu->size = size;
596 
597         trace_9p_protocol_dump(clnt, pdu);
598         p9_debug(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n",
599                  pdu->size, pdu->id, pdu->tag);
600 
601         return err;
602 }
603 
604 void p9pdu_reset(struct p9_fcall *pdu)
605 {
606         pdu->offset = 0;
607         pdu->size = 0;
608 }
609 
610 int p9dirent_read(struct p9_client *clnt, char *buf, int len,
611                   struct p9_dirent *dirent)
612 {
613         struct p9_fcall fake_pdu;
614         int ret;
615         char *nameptr;
616 
617         fake_pdu.size = len;
618         fake_pdu.capacity = len;
619         fake_pdu.sdata = buf;
620         fake_pdu.offset = 0;
621 
622         ret = p9pdu_readf(&fake_pdu, clnt->proto_version, "Qqbs", &dirent->qid,
623                           &dirent->d_off, &dirent->d_type, &nameptr);
624         if (ret) {
625                 p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
626                 trace_9p_protocol_dump(clnt, &fake_pdu);
627                 goto out;
628         }
629 
630         strcpy(dirent->d_name, nameptr);
631         kfree(nameptr);
632 
633 out:
634         return fake_pdu.offset;
635 }
636 EXPORT_SYMBOL(p9dirent_read);
637 

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