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/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                                 uint16_t len;
 182
 183                                 errcode = p9pdu_readf(pdu, proto_version,
 184                                                                 "w", &len);
 185                                 if (errcode)
 186                                         break;
 187
 188                                 *sptr = kmalloc(len + 1, GFP_KERNEL);
 189                                 if (*sptr == NULL) {
 190                                         errcode = -EFAULT;
 191                                         break;
 192                                 }
 193                                 if (pdu_read(pdu, *sptr, len)) {
 194                                         errcode = -EFAULT;
 195                                         kfree(*sptr);
 196                                         *sptr = NULL;
 197                                 } else
 198                                         (*sptr)[len] = 0;
 199                         }
 200                         break;
 201                 case 'Q':{
 202                                 struct p9_qid *qid =
 203                                     va_arg(ap, struct p9_qid *);
 204
 205                                 errcode = p9pdu_readf(pdu, proto_version, "bdq",
 206                                                       &qid->type, &qid->version,
 207                                                       &qid->path);
 208                         }
 209                         break;
 210                 case 'S':{
 211                                 struct p9_wstat *stbuf =
 212                                     va_arg(ap, struct p9_wstat *);
 213
 214                                 memset(stbuf, 0, sizeof(struct p9_wstat));
 215                                 stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
 216                                                                         -1;
 217                                 errcode =
 218                                     p9pdu_readf(pdu, proto_version,
 219                                                 "wwdQdddqssss?sddd",
 220                                                 &stbuf->size, &stbuf->type,
 221                                                 &stbuf->dev, &stbuf->qid,
 222                                                 &stbuf->mode, &stbuf->atime,
 223                                                 &stbuf->mtime, &stbuf->length,
 224                                                 &stbuf->name, &stbuf->uid,
 225                                                 &stbuf->gid, &stbuf->muid,
 226                                                 &stbuf->extension,
 227                                                 &stbuf->n_uid, &stbuf->n_gid,
 228                                                 &stbuf->n_muid);
 229                                 if (errcode)
 230                                         p9stat_free(stbuf);
 231                         }
 232                         break;
 233                 case 'D':{
 234                                 uint32_t *count = va_arg(ap, uint32_t *);
 235                                 void **data = va_arg(ap, void **);
 236
 237                                 errcode =
 238                                     p9pdu_readf(pdu, proto_version, "d", count);
 239                                 if (!errcode) {
 240                                         *count =
 241                                             min_t(uint32_t, *count,
 242                                                   pdu->size - pdu->offset);
 243                                         *data = &pdu->sdata[pdu->offset];
 244                                 }
 245                         }
 246                         break;
 247                 case 'T':{
 248                                 int16_t *nwname = va_arg(ap, int16_t *);
 249                                 char ***wnames = va_arg(ap, char ***);
 250
 251                                 errcode = p9pdu_readf(pdu, proto_version,
 252                                                                 "w", nwname);
 253                                 if (!errcode) {
 254                                         *wnames =
 255                                             kmalloc(sizeof(char *) * *nwname,
 256                                                     GFP_KERNEL);
 257                                         if (!*wnames)
 258                                                 errcode = -ENOMEM;
 259                                 }
 260
 261                                 if (!errcode) {
 262                                         int i;
 263
 264                                         for (i = 0; i < *nwname; i++) {
 265                                                 errcode =
 266                                                     p9pdu_readf(pdu,
 267                                                                 proto_version,
 268                                                                 "s",
 269                                                                 &(*wnames)[i]);
 270                                                 if (errcode)
 271                                                         break;
 272                                         }
 273                                 }
 274
 275                                 if (errcode) {
 276                                         if (*wnames) {
 277                                                 int i;
 278
 279                                                 for (i = 0; i < *nwname; i++)
 280                                                         kfree((*wnames)[i]);
 281                                         }
 282                                         kfree(*wnames);
 283                                         *wnames = NULL;
 284                                 }
 285                         }
 286                         break;
 287                 case 'R':{
 288                                 int16_t *nwqid = va_arg(ap, int16_t *);
 289                                 struct p9_qid **wqids =
 290                                     va_arg(ap, struct p9_qid **);
 291
 292                                 *wqids = NULL;
 293
 294                                 errcode =
 295                                     p9pdu_readf(pdu, proto_version, "w", nwqid);
 296                                 if (!errcode) {
 297                                         *wqids =
 298                                             kmalloc(*nwqid *
 299                                                     sizeof(struct p9_qid),
 300                                                     GFP_KERNEL);
 301                                         if (*wqids == NULL)
 302                                                 errcode = -ENOMEM;
 303                                 }
 304
 305                                 if (!errcode) {
 306                                         int i;
 307
 308                                         for (i = 0; i < *nwqid; i++) {
 309                                                 errcode =
 310                                                     p9pdu_readf(pdu,
 311                                                                 proto_version,
 312                                                                 "Q",
 313                                                                 &(*wqids)[i]);
 314                                                 if (errcode)
 315                                                         break;
 316                                         }
 317                                 }
 318
 319                                 if (errcode) {
 320                                         kfree(*wqids);
 321                                         *wqids = NULL;
 322                                 }
 323                         }
 324                         break;
 325                 case 'A': {
 326                                 struct p9_stat_dotl *stbuf =
 327                                     va_arg(ap, struct p9_stat_dotl *);
 328
 329                                 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
 330                                 errcode =
 331                                     p9pdu_readf(pdu, proto_version,
 332                                         "qQdddqqqqqqqqqqqqqqq",
 333                                         &stbuf->st_result_mask,
 334                                         &stbuf->qid,
 335                                         &stbuf->st_mode,
 336                                         &stbuf->st_uid, &stbuf->st_gid,
 337                                         &stbuf->st_nlink,
 338                                         &stbuf->st_rdev, &stbuf->st_size,
 339                                         &stbuf->st_blksize, &stbuf->st_blocks,
 340                                         &stbuf->st_atime_sec,
 341                                         &stbuf->st_atime_nsec,
 342                                         &stbuf->st_mtime_sec,
 343                                         &stbuf->st_mtime_nsec,
 344                                         &stbuf->st_ctime_sec,
 345                                         &stbuf->st_ctime_nsec,
 346                                         &stbuf->st_btime_sec,
 347                                         &stbuf->st_btime_nsec,
 348                                         &stbuf->st_gen,
 349                                         &stbuf->st_data_version);
 350                         }
 351                         break;
 352                 case '?':
 353                         if ((proto_version != p9_proto_2000u) &&
 354                                 (proto_version != p9_proto_2000L))
 355                                 return 0;
 356                         break;
 357                 default:
 358                         BUG();
 359                         break;
 360                 }
 361
 362                 if (errcode)
 363                         break;
 364         }
 365
 366         return errcode;
 367 }
 368
 369 int
 370 p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 371         va_list ap)
 372 {
 373         const char *ptr;
 374         int errcode = 0;
 375
 376         for (ptr = fmt; *ptr; ptr++) {
 377                 switch (*ptr) {
 378                 case 'b':{
 379                                 int8_t val = va_arg(ap, int);
 380                                 if (pdu_write(pdu, &val, sizeof(val)))
 381                                         errcode = -EFAULT;
 382                         }
 383                         break;
 384                 case 'w':{
 385                                 __le16 val = cpu_to_le16(va_arg(ap, int));
 386                                 if (pdu_write(pdu, &val, sizeof(val)))
 387                                         errcode = -EFAULT;
 388                         }
 389                         break;
 390                 case 'd':{
 391                                 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
 392                                 if (pdu_write(pdu, &val, sizeof(val)))
 393                                         errcode = -EFAULT;
 394                         }
 395                         break;
 396                 case 'q':{
 397                                 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
 398                                 if (pdu_write(pdu, &val, sizeof(val)))
 399                                         errcode = -EFAULT;
 400                         }
 401                         break;
 402                 case 's':{
 403                                 const char *sptr = va_arg(ap, const char *);
 404                                 uint16_t len = 0;
 405                                 if (sptr)
 406                                         len = min_t(uint16_t, strlen(sptr),
 407                                                                 USHRT_MAX);
 408
 409                                 errcode = p9pdu_writef(pdu, proto_version,
 410                                                                 "w", len);
 411                                 if (!errcode && pdu_write(pdu, sptr, len))
 412                                         errcode = -EFAULT;
 413                         }
 414                         break;
 415                 case 'Q':{
 416                                 const struct p9_qid *qid =
 417                                     va_arg(ap, const struct p9_qid *);
 418                                 errcode =
 419                                     p9pdu_writef(pdu, proto_version, "bdq",
 420                                                  qid->type, qid->version,
 421                                                  qid->path);
 422                         } break;
 423                 case 'S':{
 424                                 const struct p9_wstat *stbuf =
 425                                     va_arg(ap, const struct p9_wstat *);
 426                                 errcode =
 427                                     p9pdu_writef(pdu, proto_version,
 428                                                  "wwdQdddqssss?sddd",
 429                                                  stbuf->size, stbuf->type,
 430                                                  stbuf->dev, &stbuf->qid,
 431                                                  stbuf->mode, stbuf->atime,
 432                                                  stbuf->mtime, stbuf->length,
 433                                                  stbuf->name, stbuf->uid,
 434                                                  stbuf->gid, stbuf->muid,
 435                                                  stbuf->extension, stbuf->n_uid,
 436                                                  stbuf->n_gid, stbuf->n_muid);
 437                         } break;
 438                 case 'D':{
 439                                 uint32_t count = va_arg(ap, uint32_t);
 440                                 const void *data = va_arg(ap, const void *);
 441
 442                                 errcode = p9pdu_writef(pdu, proto_version, "d",
 443                                                                         count);
 444                                 if (!errcode && pdu_write(pdu, data, count))
 445                                         errcode = -EFAULT;
 446                         }
 447                         break;
 448                 case 'U':{
 449                                 int32_t count = va_arg(ap, int32_t);
 450                                 const char __user *udata =
 451                                                 va_arg(ap, const void __user *);
 452                                 errcode = p9pdu_writef(pdu, proto_version, "d",
 453                                                                         count);
 454                                 if (!errcode && pdu_write_u(pdu, udata, count))
 455                                         errcode = -EFAULT;
 456                         }
 457                         break;
 458                 case 'T':{
 459                                 int16_t nwname = va_arg(ap, int);
 460                                 const char **wnames = va_arg(ap, const char **);
 461
 462                                 errcode = p9pdu_writef(pdu, proto_version, "w",
 463                                                                         nwname);
 464                                 if (!errcode) {
 465                                         int i;
 466
 467                                         for (i = 0; i < nwname; i++) {
 468                                                 errcode =
 469                                                     p9pdu_writef(pdu,
 470                                                                 proto_version,
 471                                                                  "s",
 472                                                                  wnames[i]);
 473                                                 if (errcode)
 474                                                         break;
 475                                         }
 476                                 }
 477                         }
 478                         break;
 479                 case 'R':{
 480                                 int16_t nwqid = va_arg(ap, int);
 481                                 struct p9_qid *wqids =
 482                                     va_arg(ap, struct p9_qid *);
 483
 484                                 errcode = p9pdu_writef(pdu, proto_version, "w",
 485                                                                         nwqid);
 486                                 if (!errcode) {
 487                                         int i;
 488
 489                                         for (i = 0; i < nwqid; i++) {
 490                                                 errcode =
 491                                                     p9pdu_writef(pdu,
 492                                                                 proto_version,
 493                                                                  "Q",
 494                                                                  &wqids[i]);
 495                                                 if (errcode)
 496                                                         break;
 497                                         }
 498                                 }
 499                         }
 500                         break;
 501                 case 'I':{
 502                                 struct p9_iattr_dotl *p9attr = va_arg(ap,
 503                                                         struct p9_iattr_dotl *);
 504
 505                                 errcode = p9pdu_writef(pdu, proto_version,
 506                                                         "ddddqqqqq",
 507                                                         p9attr->valid,
 508                                                         p9attr->mode,
 509                                                         p9attr->uid,
 510                                                         p9attr->gid,
 511                                                         p9attr->size,
 512                                                         p9attr->atime_sec,
 513                                                         p9attr->atime_nsec,
 514                                                         p9attr->mtime_sec,
 515                                                         p9attr->mtime_nsec);
 516                         }
 517                         break;
 518                 case '?':
 519                         if ((proto_version != p9_proto_2000u) &&
 520                                 (proto_version != p9_proto_2000L))
 521                                 return 0;
 522                         break;
 523                 default:
 524                         BUG();
 525                         break;
 526                 }
 527
 528                 if (errcode)
 529                         break;
 530         }
 531
 532         return errcode;
 533 }
 534
 535 int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
 536 {
 537         va_list ap;
 538         int ret;
 539
 540         va_start(ap, fmt);
 541         ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
 542         va_end(ap);
 543
 544         return ret;
 545 }
 546
 547 static int
 548 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
 549 {
 550         va_list ap;
 551         int ret;
 552
 553         va_start(ap, fmt);
 554         ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
 555         va_end(ap);
 556
 557         return ret;
 558 }
 559
 560 int p9stat_read(char *buf, int len, struct p9_wstat *st, int proto_version)
 561 {
 562         struct p9_fcall fake_pdu;
 563         int ret;
 564
 565         fake_pdu.size = len;
 566         fake_pdu.capacity = len;
 567         fake_pdu.sdata = buf;
 568         fake_pdu.offset = 0;
 569
 570         ret = p9pdu_readf(&fake_pdu, proto_version, "S", st);
 571         if (ret) {
 572                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
 573                 p9pdu_dump(1, &fake_pdu);
 574         }
 575
 576         return ret;
 577 }
 578 EXPORT_SYMBOL(p9stat_read);
 579
 580 int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
 581 {
 582         return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
 583 }
 584
 585 int p9pdu_finalize(struct p9_fcall *pdu)
 586 {
 587         int size = pdu->size;
 588         int err;
 589
 590         pdu->size = 0;
 591         err = p9pdu_writef(pdu, 0, "d", size);
 592         pdu->size = size;
 593
 594 #ifdef CONFIG_NET_9P_DEBUG
 595         if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
 596                 p9pdu_dump(0, pdu);
 597 #endif
 598
 599         P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
 600                                                         pdu->id, pdu->tag);
 601
 602         return err;
 603 }
 604
 605 void p9pdu_reset(struct p9_fcall *pdu)
 606 {
 607         pdu->offset = 0;
 608         pdu->size = 0;
 609 }
 610
 611 int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,
 612                                                 int proto_version)
 613 {
 614         struct p9_fcall fake_pdu;
 615         int ret;
 616         char *nameptr;
 617
 618         fake_pdu.size = len;
 619         fake_pdu.capacity = len;
 620         fake_pdu.sdata = buf;
 621         fake_pdu.offset = 0;
 622
 623         ret = p9pdu_readf(&fake_pdu, proto_version, "Qqbs", &dirent->qid,
 624                         &dirent->d_off, &dirent->d_type, &nameptr);
 625         if (ret) {
 626                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
 627                 p9pdu_dump(1, &fake_pdu);
 628                 goto out;
 629         }
 630
 631         strcpy(dirent->d_name, nameptr);
 632
 633 out:
 634         return fake_pdu.offset;
 635 }
 636 EXPORT_SYMBOL(p9dirent_read);