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 <[email protected]>
   7  *
   8  *  Base on code from Anthony Liguori <[email protected]>
   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 static int
  41 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...);
  42
  43 #ifdef CONFIG_NET_9P_DEBUG
  44 void
  45 p9pdu_dump(int way, struct p9_fcall *pdu)
  46 {
  47         int i, n;
  48         u8 *data = pdu->sdata;
  49         int datalen = pdu->size;
  50         char buf[255];
  51         int buflen = 255;
  52
  53         i = n = 0;
  54         if (datalen > (buflen-16))
  55                 datalen = buflen-16;
  56         while (i < datalen) {
  57                 n += scnprintf(buf + n, buflen - n, "%02x ", data[i]);
  58                 if (i%4 == 3)
  59                         n += scnprintf(buf + n, buflen - n, " ");
  60                 if (i%32 == 31)
  61                         n += scnprintf(buf + n, buflen - n, "\n");
  62
  63                 i++;
  64         }
  65         n += scnprintf(buf + n, buflen - n, "\n");
  66
  67         if (way)
  68                 P9_DPRINTK(P9_DEBUG_PKT, "[[[(%d) %s\n", datalen, buf);
  69         else
  70                 P9_DPRINTK(P9_DEBUG_PKT, "]]](%d) %s\n", datalen, buf);
  71 }
  72 #else
  73 void
  74 p9pdu_dump(int way, struct p9_fcall *pdu)
  75 {
  76 }
  77 #endif
  78 EXPORT_SYMBOL(p9pdu_dump);
  79
  80 void p9stat_free(struct p9_wstat *stbuf)
  81 {
  82         kfree(stbuf->name);
  83         kfree(stbuf->uid);
  84         kfree(stbuf->gid);
  85         kfree(stbuf->muid);
  86         kfree(stbuf->extension);
  87 }
  88 EXPORT_SYMBOL(p9stat_free);
  89
  90 static size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size)
  91 {
  92         size_t len = min(pdu->size - pdu->offset, size);
  93         memcpy(data, &pdu->sdata[pdu->offset], len);
  94         pdu->offset += len;
  95         return size - len;
  96 }
  97
  98 static size_t pdu_write(struct p9_fcall *pdu, const void *data, size_t size)
  99 {
 100         size_t len = min(pdu->capacity - pdu->size, size);
 101         memcpy(&pdu->sdata[pdu->size], data, len);
 102         pdu->size += len;
 103         return size - len;
 104 }
 105
 106 static size_t
 107 pdu_write_u(struct p9_fcall *pdu, const char __user *udata, size_t size)
 108 {
 109         size_t len = min(pdu->capacity - pdu->size, size);
 110         if (copy_from_user(&pdu->sdata[pdu->size], udata, len))
 111                 len = 0;
 112
 113         pdu->size += len;
 114         return size - len;
 115 }
 116
 117 /*
 118         b - int8_t
 119         w - int16_t
 120         d - int32_t
 121         q - int64_t
 122         s - string
 123         S - stat
 124         Q - qid
 125         D - data blob (int32_t size followed by void *, results are not freed)
 126         T - array of strings (int16_t count, followed by strings)
 127         R - array of qids (int16_t count, followed by qids)
 128         A - stat for 9p2000.L (p9_stat_dotl)
 129         ? - if optional = 1, continue parsing
 130 */
 131
 132 static int
 133 p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
 134         va_list ap)
 135 {
 136         const char *ptr;
 137         int errcode = 0;
 138
 139         for (ptr = fmt; *ptr; ptr++) {
 140                 switch (*ptr) {
 141                 case 'b':{
 142                                 int8_t *val = va_arg(ap, int8_t *);
 143                                 if (pdu_read(pdu, val, sizeof(*val))) {
 144                                         errcode = -EFAULT;
 145                                         break;
 146                                 }
 147                         }
 148                         break;
 149                 case 'w':{
 150                                 int16_t *val = va_arg(ap, int16_t *);
 151                                 __le16 le_val;
 152                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 153                                         errcode = -EFAULT;
 154                                         break;
 155                                 }
 156                                 *val = le16_to_cpu(le_val);
 157                         }
 158                         break;
 159                 case 'd':{
 160                                 int32_t *val = va_arg(ap, int32_t *);
 161                                 __le32 le_val;
 162                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 163                                         errcode = -EFAULT;
 164                                         break;
 165                                 }
 166                                 *val = le32_to_cpu(le_val);
 167                         }
 168                         break;
 169                 case 'q':{
 170                                 int64_t *val = va_arg(ap, int64_t *);
 171                                 __le64 le_val;
 172                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 173                                         errcode = -EFAULT;
 174                                         break;
 175                                 }
 176                                 *val = le64_to_cpu(le_val);
 177                         }
 178                         break;
 179                 case 's':{
 180                                 char **sptr = va_arg(ap, char **);
 181                                 int16_t len;
 182                                 int size;
 183
 184                                 errcode = p9pdu_readf(pdu, proto_version,
 185                                                                 "w", &len);
 186                                 if (errcode)
 187                                         break;
 188
 189                                 size = max_t(int16_t, len, 0);
 190
 191                                 *sptr = kmalloc(size + 1, GFP_KERNEL);
 192                                 if (*sptr == NULL) {
 193                                         errcode = -EFAULT;
 194                                         break;
 195                                 }
 196                                 if (pdu_read(pdu, *sptr, size)) {
 197                                         errcode = -EFAULT;
 198                                         kfree(*sptr);
 199                                         *sptr = NULL;
 200                                 } else
 201                                         (*sptr)[size] = 0;
 202                         }
 203                         break;
 204                 case 'Q':{
 205                                 struct p9_qid *qid =
 206                                     va_arg(ap, struct p9_qid *);
 207
 208                                 errcode = p9pdu_readf(pdu, proto_version, "bdq",
 209                                                       &qid->type, &qid->version,
 210                                                       &qid->path);
 211                         }
 212                         break;
 213                 case 'S':{
 214                                 struct p9_wstat *stbuf =
 215                                     va_arg(ap, struct p9_wstat *);
 216
 217                                 memset(stbuf, 0, sizeof(struct p9_wstat));
 218                                 stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
 219                                                                         -1;
 220                                 errcode =
 221                                     p9pdu_readf(pdu, proto_version,
 222                                                 "wwdQdddqssss?sddd",
 223                                                 &stbuf->size, &stbuf->type,
 224                                                 &stbuf->dev, &stbuf->qid,
 225                                                 &stbuf->mode, &stbuf->atime,
 226                                                 &stbuf->mtime, &stbuf->length,
 227                                                 &stbuf->name, &stbuf->uid,
 228                                                 &stbuf->gid, &stbuf->muid,
 229                                                 &stbuf->extension,
 230                                                 &stbuf->n_uid, &stbuf->n_gid,
 231                                                 &stbuf->n_muid);
 232                                 if (errcode)
 233                                         p9stat_free(stbuf);
 234                         }
 235                         break;
 236                 case 'D':{
 237                                 int32_t *count = va_arg(ap, int32_t *);
 238                                 void **data = va_arg(ap, void **);
 239
 240                                 errcode =
 241                                     p9pdu_readf(pdu, proto_version, "d", count);
 242                                 if (!errcode) {
 243                                         *count =
 244                                             min_t(int32_t, *count,
 245                                                   pdu->size - pdu->offset);
 246                                         *data = &pdu->sdata[pdu->offset];
 247                                 }
 248                         }
 249                         break;
 250                 case 'T':{
 251                                 int16_t *nwname = va_arg(ap, int16_t *);
 252                                 char ***wnames = va_arg(ap, char ***);
 253
 254                                 errcode = p9pdu_readf(pdu, proto_version,
 255                                                                 "w", nwname);
 256                                 if (!errcode) {
 257                                         *wnames =
 258                                             kmalloc(sizeof(char *) * *nwname,
 259                                                     GFP_KERNEL);
 260                                         if (!*wnames)
 261                                                 errcode = -ENOMEM;
 262                                 }
 263
 264                                 if (!errcode) {
 265                                         int i;
 266
 267                                         for (i = 0; i < *nwname; i++) {
 268                                                 errcode =
 269                                                     p9pdu_readf(pdu,
 270                                                                 proto_version,
 271                                                                 "s",
 272                                                                 &(*wnames)[i]);
 273                                                 if (errcode)
 274                                                         break;
 275                                         }
 276                                 }
 277
 278                                 if (errcode) {
 279                                         if (*wnames) {
 280                                                 int i;
 281
 282                                                 for (i = 0; i < *nwname; i++)
 283                                                         kfree((*wnames)[i]);
 284                                         }
 285                                         kfree(*wnames);
 286                                         *wnames = NULL;
 287                                 }
 288                         }
 289                         break;
 290                 case 'R':{
 291                                 int16_t *nwqid = va_arg(ap, int16_t *);
 292                                 struct p9_qid **wqids =
 293                                     va_arg(ap, struct p9_qid **);
 294
 295                                 *wqids = NULL;
 296
 297                                 errcode =
 298                                     p9pdu_readf(pdu, proto_version, "w", nwqid);
 299                                 if (!errcode) {
 300                                         *wqids =
 301                                             kmalloc(*nwqid *
 302                                                     sizeof(struct p9_qid),
 303                                                     GFP_KERNEL);
 304                                         if (*wqids == NULL)
 305                                                 errcode = -ENOMEM;
 306                                 }
 307
 308                                 if (!errcode) {
 309                                         int i;
 310
 311                                         for (i = 0; i < *nwqid; i++) {
 312                                                 errcode =
 313                                                     p9pdu_readf(pdu,
 314                                                                 proto_version,
 315                                                                 "Q",
 316                                                                 &(*wqids)[i]);
 317                                                 if (errcode)
 318                                                         break;
 319                                         }
 320                                 }
 321
 322                                 if (errcode) {
 323                                         kfree(*wqids);
 324                                         *wqids = NULL;
 325                                 }
 326                         }
 327                         break;
 328                 case 'A': {
 329                                 struct p9_stat_dotl *stbuf =
 330                                     va_arg(ap, struct p9_stat_dotl *);
 331
 332                                 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
 333                                 errcode =
 334                                     p9pdu_readf(pdu, proto_version,
 335                                         "qQdddqqqqqqqqqqqqqqq",
 336                                         &stbuf->st_result_mask,
 337                                         &stbuf->qid,
 338                                         &stbuf->st_mode,
 339                                         &stbuf->st_uid, &stbuf->st_gid,
 340                                         &stbuf->st_nlink,
 341                                         &stbuf->st_rdev, &stbuf->st_size,
 342                                         &stbuf->st_blksize, &stbuf->st_blocks,
 343                                         &stbuf->st_atime_sec,
 344                                         &stbuf->st_atime_nsec,
 345                                         &stbuf->st_mtime_sec,
 346                                         &stbuf->st_mtime_nsec,
 347                                         &stbuf->st_ctime_sec,
 348                                         &stbuf->st_ctime_nsec,
 349                                         &stbuf->st_btime_sec,
 350                                         &stbuf->st_btime_nsec,
 351                                         &stbuf->st_gen,
 352                                         &stbuf->st_data_version);
 353                         }
 354                         break;
 355                 case '?':
 356                         if ((proto_version != p9_proto_2000u) &&
 357                                 (proto_version != p9_proto_2000L))
 358                                 return 0;
 359                         break;
 360                 default:
 361                         BUG();
 362                         break;
 363                 }
 364
 365                 if (errcode)
 366                         break;
 367         }
 368
 369         return errcode;
 370 }
 371
 372 int
 373 p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 374         va_list ap)
 375 {
 376         const char *ptr;
 377         int errcode = 0;
 378
 379         for (ptr = fmt; *ptr; ptr++) {
 380                 switch (*ptr) {
 381                 case 'b':{
 382                                 int8_t val = va_arg(ap, int);
 383                                 if (pdu_write(pdu, &val, sizeof(val)))
 384                                         errcode = -EFAULT;
 385                         }
 386                         break;
 387                 case 'w':{
 388                                 __le16 val = cpu_to_le16(va_arg(ap, int));
 389                                 if (pdu_write(pdu, &val, sizeof(val)))
 390                                         errcode = -EFAULT;
 391                         }
 392                         break;
 393                 case 'd':{
 394                                 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
 395                                 if (pdu_write(pdu, &val, sizeof(val)))
 396                                         errcode = -EFAULT;
 397                         }
 398                         break;
 399                 case 'q':{
 400                                 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
 401                                 if (pdu_write(pdu, &val, sizeof(val)))
 402                                         errcode = -EFAULT;
 403                         }
 404                         break;
 405                 case 's':{
 406                                 const char *sptr = va_arg(ap, const char *);
 407                                 int16_t len = 0;
 408                                 if (sptr)
 409                                         len = min_t(int16_t, strlen(sptr), USHRT_MAX);
 410
 411                                 errcode = p9pdu_writef(pdu, proto_version,
 412                                                                 "w", len);
 413                                 if (!errcode && pdu_write(pdu, sptr, len))
 414                                         errcode = -EFAULT;
 415                         }
 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?sddd",
 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                                 int32_t count = va_arg(ap, int32_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                                 int16_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                                                         "ddddqqqqq",
 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(char *buf, int len, struct p9_wstat *st, int proto_version)
 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, proto_version, "S", st);
 573         if (ret) {
 574                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
 575                 p9pdu_dump(1, &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         return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
 585 }
 586
 587 int p9pdu_finalize(struct p9_fcall *pdu)
 588 {
 589         int size = pdu->size;
 590         int err;
 591
 592         pdu->size = 0;
 593         err = p9pdu_writef(pdu, 0, "d", size);
 594         pdu->size = size;
 595
 596 #ifdef CONFIG_NET_9P_DEBUG
 597         if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
 598                 p9pdu_dump(0, pdu);
 599 #endif
 600
 601         P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
 602                                                         pdu->id, pdu->tag);
 603
 604         return err;
 605 }
 606
 607 void p9pdu_reset(struct p9_fcall *pdu)
 608 {
 609         pdu->offset = 0;
 610         pdu->size = 0;
 611 }
 612
 613 int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,
 614                                                 int proto_version)
 615 {
 616         struct p9_fcall fake_pdu;
 617         int ret;
 618         char *nameptr;
 619
 620         fake_pdu.size = len;
 621         fake_pdu.capacity = len;
 622         fake_pdu.sdata = buf;
 623         fake_pdu.offset = 0;
 624
 625         ret = p9pdu_readf(&fake_pdu, proto_version, "Qqbs", &dirent->qid,
 626                         &dirent->d_off, &dirent->d_type, &nameptr);
 627         if (ret) {
 628                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
 629                 p9pdu_dump(1, &fake_pdu);
 630                 goto out;
 631         }
 632
 633         strcpy(dirent->d_name, nameptr);
 634
 635 out:
 636         return fake_pdu.offset;
 637 }
 638 EXPORT_SYMBOL(p9dirent_read);