net/9p/protocol.c

   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/uaccess.h>
  31 #include <linux/slab.h>
  32 #include <linux/sched.h>
  33 #include <linux/types.h>
  34 #include <net/9p/9p.h>
  35 #include <net/9p/client.h>
  36 #include "protocol.h"
  37
  38 #ifndef MIN
  39 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
  40 #endif
  41
  42 #ifndef MAX
  43 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
  44 #endif
  45
  46 #ifndef offset_of
  47 #define offset_of(type, memb) \
  48         ((unsigned long)(&((type *)0)->memb))
  49 #endif
  50 #ifndef container_of
  51 #define container_of(obj, type, memb) \
  52         ((type *)(((char *)obj) - offset_of(type, memb)))
  53 #endif
  54
  55 static int
  56 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...);
  57
  58 #ifdef CONFIG_NET_9P_DEBUG
  59 void
  60 p9pdu_dump(int way, struct p9_fcall *pdu)
  61 {
  62         int i, n;
  63         u8 *data = pdu->sdata;
  64         int datalen = pdu->size;
  65         char buf[255];
  66         int buflen = 255;
  67
  68         i = n = 0;
  69         if (datalen > (buflen-16))
  70                 datalen = buflen-16;
  71         while (i < datalen) {
  72                 n += scnprintf(buf + n, buflen - n, "%02x ", data[i]);
  73                 if (i%4 == 3)
  74                         n += scnprintf(buf + n, buflen - n, " ");
  75                 if (i%32 == 31)
  76                         n += scnprintf(buf + n, buflen - n, "\n");
  77
  78                 i++;
  79         }
  80         n += scnprintf(buf + n, buflen - n, "\n");
  81
  82         if (way)
  83                 P9_DPRINTK(P9_DEBUG_PKT, "[[[(%d) %s\n", datalen, buf);
  84         else
  85                 P9_DPRINTK(P9_DEBUG_PKT, "]]](%d) %s\n", datalen, buf);
  86 }
  87 #else
  88 void
  89 p9pdu_dump(int way, struct p9_fcall *pdu)
  90 {
  91 }
  92 #endif
  93 EXPORT_SYMBOL(p9pdu_dump);
  94
  95 void p9stat_free(struct p9_wstat *stbuf)
  96 {
  97         kfree(stbuf->name);
  98         kfree(stbuf->uid);
  99         kfree(stbuf->gid);
 100         kfree(stbuf->muid);
 101         kfree(stbuf->extension);
 102 }
 103 EXPORT_SYMBOL(p9stat_free);
 104
 105 static size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size)
 106 {
 107         size_t len = MIN(pdu->size - pdu->offset, size);
 108         memcpy(data, &pdu->sdata[pdu->offset], len);
 109         pdu->offset += len;
 110         return size - len;
 111 }
 112
 113 static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size)
 114 {
 115         size_t len = MIN(pdu->capacity - pdu->size, size);
 116         memcpy(&pdu->sdata[pdu->size], data, len);
 117         pdu->size += len;
 118         return size - len;
 119 }
 120
 121 static size_t
 122 pdu_write_u(struct p9_fcall *pdu, const char __user *udata, size_t size)
 123 {
 124         size_t len = MIN(pdu->capacity - pdu->size, size);
 125         int err = copy_from_user(&pdu->sdata[pdu->size], udata, len);
 126         if (err)
 127                 printk(KERN_WARNING "pdu_write_u returning: %d\n", err);
 128
 129         pdu->size += len;
 130         return size - len;
 131 }
 132
 133 /*
 134         b - int8_t
 135         w - int16_t
 136         d - int32_t
 137         q - int64_t
 138         s - string
 139         S - stat
 140         Q - qid
 141         D - data blob (int32_t size followed by void *, results are not freed)
 142         T - array of strings (int16_t count, followed by strings)
 143         R - array of qids (int16_t count, followed by qids)
 144         A - stat for 9p2000.L (p9_stat_dotl)
 145         ? - if optional = 1, continue parsing
 146 */
 147
 148 static int
 149 p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
 150         va_list ap)
 151 {
 152         const char *ptr;
 153         int errcode = 0;
 154
 155         for (ptr = fmt; *ptr; ptr++) {
 156                 switch (*ptr) {
 157                 case 'b':{
 158                                 int8_t *val = va_arg(ap, int8_t *);
 159                                 if (pdu_read(pdu, val, sizeof(*val))) {
 160                                         errcode = -EFAULT;
 161                                         break;
 162                                 }
 163                         }
 164                         break;
 165                 case 'w':{
 166                                 int16_t *val = va_arg(ap, int16_t *);
 167                                 __le16 le_val;
 168                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 169                                         errcode = -EFAULT;
 170                                         break;
 171                                 }
 172                                 *val = le16_to_cpu(le_val);
 173                         }
 174                         break;
 175                 case 'd':{
 176                                 int32_t *val = va_arg(ap, int32_t *);
 177                                 __le32 le_val;
 178                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 179                                         errcode = -EFAULT;
 180                                         break;
 181                                 }
 182                                 *val = le32_to_cpu(le_val);
 183                         }
 184                         break;
 185                 case 'q':{
 186                                 int64_t *val = va_arg(ap, int64_t *);
 187                                 __le64 le_val;
 188                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 189                                         errcode = -EFAULT;
 190                                         break;
 191                                 }
 192                                 *val = le64_to_cpu(le_val);
 193                         }
 194                         break;
 195                 case 's':{
 196                                 char **sptr = va_arg(ap, char **);
 197                                 int16_t len;
 198                                 int size;
 199
 200                                 errcode = p9pdu_readf(pdu, proto_version,
 201                                                                 "w", &len);
 202                                 if (errcode)
 203                                         break;
 204
 205                                 size = MAX(len, 0);
 206
 207                                 *sptr = kmalloc(size + 1, GFP_KERNEL);
 208                                 if (*sptr == NULL) {
 209                                         errcode = -EFAULT;
 210                                         break;
 211                                 }
 212                                 if (pdu_read(pdu, *sptr, size)) {
 213                                         errcode = -EFAULT;
 214                                         kfree(*sptr);
 215                                         *sptr = NULL;
 216                                 } else
 217                                         (*sptr)[size] = 0;
 218                         }
 219                         break;
 220                 case 'Q':{
 221                                 struct p9_qid *qid =
 222                                     va_arg(ap, struct p9_qid *);
 223
 224                                 errcode = p9pdu_readf(pdu, proto_version, "bdq",
 225                                                       &qid->type, &qid->version,
 226                                                       &qid->path);
 227                         }
 228                         break;
 229                 case 'S':{
 230                                 struct p9_wstat *stbuf =
 231                                     va_arg(ap, struct p9_wstat *);
 232
 233                                 memset(stbuf, 0, sizeof(struct p9_wstat));
 234                                 stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
 235                                                                         -1;
 236                                 errcode =
 237                                     p9pdu_readf(pdu, proto_version,
 238                                                 "wwdQdddqssss?sddd",
 239                                                 &stbuf->size, &stbuf->type,
 240                                                 &stbuf->dev, &stbuf->qid,
 241                                                 &stbuf->mode, &stbuf->atime,
 242                                                 &stbuf->mtime, &stbuf->length,
 243                                                 &stbuf->name, &stbuf->uid,
 244                                                 &stbuf->gid, &stbuf->muid,
 245                                                 &stbuf->extension,
 246                                                 &stbuf->n_uid, &stbuf->n_gid,
 247                                                 &stbuf->n_muid);
 248                                 if (errcode)
 249                                         p9stat_free(stbuf);
 250                         }
 251                         break;
 252                 case 'D':{
 253                                 int32_t *count = va_arg(ap, int32_t *);
 254                                 void **data = va_arg(ap, void **);
 255
 256                                 errcode =
 257                                     p9pdu_readf(pdu, proto_version, "d", count);
 258                                 if (!errcode) {
 259                                         *count =
 260                                             MIN(*count,
 261                                                 pdu->size - pdu->offset);
 262                                         *data = &pdu->sdata[pdu->offset];
 263                                 }
 264                         }
 265                         break;
 266                 case 'T':{
 267                                 int16_t *nwname = va_arg(ap, int16_t *);
 268                                 char ***wnames = va_arg(ap, char ***);
 269
 270                                 errcode = p9pdu_readf(pdu, proto_version,
 271                                                                 "w", nwname);
 272                                 if (!errcode) {
 273                                         *wnames =
 274                                             kmalloc(sizeof(char *) * *nwname,
 275                                                     GFP_KERNEL);
 276                                         if (!*wnames)
 277                                                 errcode = -ENOMEM;
 278                                 }
 279
 280                                 if (!errcode) {
 281                                         int i;
 282
 283                                         for (i = 0; i < *nwname; i++) {
 284                                                 errcode =
 285                                                     p9pdu_readf(pdu,
 286                                                                 proto_version,
 287                                                                 "s",
 288                                                                 &(*wnames)[i]);
 289                                                 if (errcode)
 290                                                         break;
 291                                         }
 292                                 }
 293
 294                                 if (errcode) {
 295                                         if (*wnames) {
 296                                                 int i;
 297
 298                                                 for (i = 0; i < *nwname; i++)
 299                                                         kfree((*wnames)[i]);
 300                                         }
 301                                         kfree(*wnames);
 302                                         *wnames = NULL;
 303                                 }
 304                         }
 305                         break;
 306                 case 'R':{
 307                                 int16_t *nwqid = va_arg(ap, int16_t *);
 308                                 struct p9_qid **wqids =
 309                                     va_arg(ap, struct p9_qid **);
 310
 311                                 *wqids = NULL;
 312
 313                                 errcode =
 314                                     p9pdu_readf(pdu, proto_version, "w", nwqid);
 315                                 if (!errcode) {
 316                                         *wqids =
 317                                             kmalloc(*nwqid *
 318                                                     sizeof(struct p9_qid),
 319                                                     GFP_KERNEL);
 320                                         if (*wqids == NULL)
 321                                                 errcode = -ENOMEM;
 322                                 }
 323
 324                                 if (!errcode) {
 325                                         int i;
 326
 327                                         for (i = 0; i < *nwqid; i++) {
 328                                                 errcode =
 329                                                     p9pdu_readf(pdu,
 330                                                                 proto_version,
 331                                                                 "Q",
 332                                                                 &(*wqids)[i]);
 333                                                 if (errcode)
 334                                                         break;
 335                                         }
 336                                 }
 337
 338                                 if (errcode) {
 339                                         kfree(*wqids);
 340                                         *wqids = NULL;
 341                                 }
 342                         }
 343                         break;
 344                 case 'A': {
 345                                 struct p9_stat_dotl *stbuf =
 346                                     va_arg(ap, struct p9_stat_dotl *);
 347
 348                                 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
 349                                 errcode =
 350                                     p9pdu_readf(pdu, proto_version,
 351                                         "qQdddqqqqqqqqqqqqqqq",
 352                                         &stbuf->st_result_mask,
 353                                         &stbuf->qid,
 354                                         &stbuf->st_mode,
 355                                         &stbuf->st_uid, &stbuf->st_gid,
 356                                         &stbuf->st_nlink,
 357                                         &stbuf->st_rdev, &stbuf->st_size,
 358                                         &stbuf->st_blksize, &stbuf->st_blocks,
 359                                         &stbuf->st_atime_sec,
 360                                         &stbuf->st_atime_nsec,
 361                                         &stbuf->st_mtime_sec,
 362                                         &stbuf->st_mtime_nsec,
 363                                         &stbuf->st_ctime_sec,
 364                                         &stbuf->st_ctime_nsec,
 365                                         &stbuf->st_btime_sec,
 366                                         &stbuf->st_btime_nsec,
 367                                         &stbuf->st_gen,
 368                                         &stbuf->st_data_version);
 369                         }
 370                         break;
 371                 case '?':
 372                         if ((proto_version != p9_proto_2000u) &&
 373                                 (proto_version != p9_proto_2000L))
 374                                 return 0;
 375                         break;
 376                 default:
 377                         BUG();
 378                         break;
 379                 }
 380
 381                 if (errcode)
 382                         break;
 383         }
 384
 385         return errcode;
 386 }
 387
 388 int
 389 p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 390         va_list ap)
 391 {
 392         const char *ptr;
 393         int errcode = 0;
 394
 395         for (ptr = fmt; *ptr; ptr++) {
 396                 switch (*ptr) {
 397                 case 'b':{
 398                                 int8_t val = va_arg(ap, int);
 399                                 if (pdu_write(pdu, &val, sizeof(val)))
 400                                         errcode = -EFAULT;
 401                         }
 402                         break;
 403                 case 'w':{
 404                                 __le16 val = cpu_to_le16(va_arg(ap, int));
 405                                 if (pdu_write(pdu, &val, sizeof(val)))
 406                                         errcode = -EFAULT;
 407                         }
 408                         break;
 409                 case 'd':{
 410                                 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
 411                                 if (pdu_write(pdu, &val, sizeof(val)))
 412                                         errcode = -EFAULT;
 413                         }
 414                         break;
 415                 case 'q':{
 416                                 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
 417                                 if (pdu_write(pdu, &val, sizeof(val)))
 418                                         errcode = -EFAULT;
 419                         }
 420                         break;
 421                 case 's':{
 422                                 const char *sptr = va_arg(ap, const char *);
 423                                 int16_t len = 0;
 424                                 if (sptr)
 425                                         len = MIN(strlen(sptr), USHRT_MAX);
 426
 427                                 errcode = p9pdu_writef(pdu, proto_version,
 428                                                                 "w", len);
 429                                 if (!errcode && pdu_write(pdu, sptr, len))
 430                                         errcode = -EFAULT;
 431                         }
 432                         break;
 433                 case 'Q':{
 434                                 const struct p9_qid *qid =
 435                                     va_arg(ap, const struct p9_qid *);
 436                                 errcode =
 437                                     p9pdu_writef(pdu, proto_version, "bdq",
 438                                                  qid->type, qid->version,
 439                                                  qid->path);
 440                         } break;
 441                 case 'S':{
 442                                 const struct p9_wstat *stbuf =
 443                                     va_arg(ap, const struct p9_wstat *);
 444                                 errcode =
 445                                     p9pdu_writef(pdu, proto_version,
 446                                                  "wwdQdddqssss?sddd",
 447                                                  stbuf->size, stbuf->type,
 448                                                  stbuf->dev, &stbuf->qid,
 449                                                  stbuf->mode, stbuf->atime,
 450                                                  stbuf->mtime, stbuf->length,
 451                                                  stbuf->name, stbuf->uid,
 452                                                  stbuf->gid, stbuf->muid,
 453                                                  stbuf->extension, stbuf->n_uid,
 454                                                  stbuf->n_gid, stbuf->n_muid);
 455                         } break;
 456                 case 'D':{
 457                                 int32_t count = va_arg(ap, int32_t);
 458                                 const void *data = va_arg(ap, const void *);
 459
 460                                 errcode = p9pdu_writef(pdu, proto_version, "d",
 461                                                                         count);
 462                                 if (!errcode && pdu_write(pdu, data, count))
 463                                         errcode = -EFAULT;
 464                         }
 465                         break;
 466                 case 'U':{
 467                                 int32_t count = va_arg(ap, int32_t);
 468                                 const char __user *udata =
 469                                                 va_arg(ap, const void __user *);
 470                                 errcode = p9pdu_writef(pdu, proto_version, "d",
 471                                                                         count);
 472                                 if (!errcode && pdu_write_u(pdu, udata, count))
 473                                         errcode = -EFAULT;
 474                         }
 475                         break;
 476                 case 'T':{
 477                                 int16_t nwname = va_arg(ap, int);
 478                                 const char **wnames = va_arg(ap, const char **);
 479
 480                                 errcode = p9pdu_writef(pdu, proto_version, "w",
 481                                                                         nwname);
 482                                 if (!errcode) {
 483                                         int i;
 484
 485                                         for (i = 0; i < nwname; i++) {
 486                                                 errcode =
 487                                                     p9pdu_writef(pdu,
 488                                                                 proto_version,
 489                                                                  "s",
 490                                                                  wnames[i]);
 491                                                 if (errcode)
 492                                                         break;
 493                                         }
 494                                 }
 495                         }
 496                         break;
 497                 case 'R':{
 498                                 int16_t nwqid = va_arg(ap, int);
 499                                 struct p9_qid *wqids =
 500                                     va_arg(ap, struct p9_qid *);
 501
 502                                 errcode = p9pdu_writef(pdu, proto_version, "w",
 503                                                                         nwqid);
 504                                 if (!errcode) {
 505                                         int i;
 506
 507                                         for (i = 0; i < nwqid; i++) {
 508                                                 errcode =
 509                                                     p9pdu_writef(pdu,
 510                                                                 proto_version,
 511                                                                  "Q",
 512                                                                  &wqids[i]);
 513                                                 if (errcode)
 514                                                         break;
 515                                         }
 516                                 }
 517                         }
 518                         break;
 519                 case 'I':{
 520                                 struct p9_iattr_dotl *p9attr = va_arg(ap,
 521                                                         struct p9_iattr_dotl *);
 522
 523                                 errcode = p9pdu_writef(pdu, proto_version,
 524                                                         "ddddqqqqq",
 525                                                         p9attr->valid,
 526                                                         p9attr->mode,
 527                                                         p9attr->uid,
 528                                                         p9attr->gid,
 529                                                         p9attr->size,
 530                                                         p9attr->atime_sec,
 531                                                         p9attr->atime_nsec,
 532                                                         p9attr->mtime_sec,
 533                                                         p9attr->mtime_nsec);
 534                         }
 535                         break;
 536                 case '?':
 537                         if ((proto_version != p9_proto_2000u) &&
 538                                 (proto_version != p9_proto_2000L))
 539                                 return 0;
 540                         break;
 541                 default:
 542                         BUG();
 543                         break;
 544                 }
 545
 546                 if (errcode)
 547                         break;
 548         }
 549
 550         return errcode;
 551 }
 552
 553 int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
 554 {
 555         va_list ap;
 556         int ret;
 557
 558         va_start(ap, fmt);
 559         ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
 560         va_end(ap);
 561
 562         return ret;
 563 }
 564
 565 static int
 566 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
 567 {
 568         va_list ap;
 569         int ret;
 570
 571         va_start(ap, fmt);
 572         ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
 573         va_end(ap);
 574
 575         return ret;
 576 }
 577
 578 int p9stat_read(char *buf, int len, struct p9_wstat *st, int proto_version)
 579 {
 580         struct p9_fcall fake_pdu;
 581         int ret;
 582
 583         fake_pdu.size = len;
 584         fake_pdu.capacity = len;
 585         fake_pdu.sdata = buf;
 586         fake_pdu.offset = 0;
 587
 588         ret = p9pdu_readf(&fake_pdu, proto_version, "S", st);
 589         if (ret) {
 590                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
 591                 p9pdu_dump(1, &fake_pdu);
 592         }
 593
 594         return ret;
 595 }
 596 EXPORT_SYMBOL(p9stat_read);
 597
 598 int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
 599 {
 600         return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
 601 }
 602
 603 int p9pdu_finalize(struct p9_fcall *pdu)
 604 {
 605         int size = pdu->size;
 606         int err;
 607
 608         pdu->size = 0;
 609         err = p9pdu_writef(pdu, 0, "d", size);
 610         pdu->size = size;
 611
 612 #ifdef CONFIG_NET_9P_DEBUG
 613         if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
 614                 p9pdu_dump(0, pdu);
 615 #endif
 616
 617         P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
 618                                                         pdu->id, pdu->tag);
 619
 620         return err;
 621 }
 622
 623 void p9pdu_reset(struct p9_fcall *pdu)
 624 {
 625         pdu->offset = 0;
 626         pdu->size = 0;
 627 }
 628
 629 int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,
 630                                                 int proto_version)
 631 {
 632         struct p9_fcall fake_pdu;
 633         int ret;
 634         char *nameptr;
 635
 636         fake_pdu.size = len;
 637         fake_pdu.capacity = len;
 638         fake_pdu.sdata = buf;
 639         fake_pdu.offset = 0;
 640
 641         ret = p9pdu_readf(&fake_pdu, proto_version, "Qqbs", &dirent->qid,
 642                         &dirent->d_off, &dirent->d_type, &nameptr);
 643         if (ret) {
 644                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
 645                 p9pdu_dump(1, &fake_pdu);
 646                 goto out;
 647         }
 648
 649         strcpy(dirent->d_name, nameptr);
 650
 651 out:
 652         return fake_pdu.offset;
 653 }
 654 EXPORT_SYMBOL(p9dirent_read);