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 static size_t
 118 pdu_write_urw(struct p9_fcall *pdu, const char *kdata, const char __user *udata,
 119                 size_t size)
 120 {
 121         BUG_ON(pdu->size > P9_IOHDRSZ);
 122         pdu->pubuf = (char __user *)udata;
 123         pdu->pkbuf = (char *)kdata;
 124         pdu->pbuf_size = size;
 125         return 0;
 126 }
 127
 128 static size_t
 129 pdu_write_readdir(struct p9_fcall *pdu, const char *kdata, size_t size)
 130 {
 131         BUG_ON(pdu->size > P9_READDIRHDRSZ);
 132         pdu->pkbuf = (char *)kdata;
 133         pdu->pbuf_size = size;
 134         return 0;
 135 }
 136
 137 /*
 138         b - int8_t
 139         w - int16_t
 140         d - int32_t
 141         q - int64_t
 142         s - string
 143         S - stat
 144         Q - qid
 145         D - data blob (int32_t size followed by void *, results are not freed)
 146         T - array of strings (int16_t count, followed by strings)
 147         R - array of qids (int16_t count, followed by qids)
 148         A - stat for 9p2000.L (p9_stat_dotl)
 149         ? - if optional = 1, continue parsing
 150 */
 151
 152 static int
 153 p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
 154         va_list ap)
 155 {
 156         const char *ptr;
 157         int errcode = 0;
 158
 159         for (ptr = fmt; *ptr; ptr++) {
 160                 switch (*ptr) {
 161                 case 'b':{
 162                                 int8_t *val = va_arg(ap, int8_t *);
 163                                 if (pdu_read(pdu, val, sizeof(*val))) {
 164                                         errcode = -EFAULT;
 165                                         break;
 166                                 }
 167                         }
 168                         break;
 169                 case 'w':{
 170                                 int16_t *val = va_arg(ap, int16_t *);
 171                                 __le16 le_val;
 172                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 173                                         errcode = -EFAULT;
 174                                         break;
 175                                 }
 176                                 *val = le16_to_cpu(le_val);
 177                         }
 178                         break;
 179                 case 'd':{
 180                                 int32_t *val = va_arg(ap, int32_t *);
 181                                 __le32 le_val;
 182                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 183                                         errcode = -EFAULT;
 184                                         break;
 185                                 }
 186                                 *val = le32_to_cpu(le_val);
 187                         }
 188                         break;
 189                 case 'q':{
 190                                 int64_t *val = va_arg(ap, int64_t *);
 191                                 __le64 le_val;
 192                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 193                                         errcode = -EFAULT;
 194                                         break;
 195                                 }
 196                                 *val = le64_to_cpu(le_val);
 197                         }
 198                         break;
 199                 case 's':{
 200                                 char **sptr = va_arg(ap, char **);
 201                                 uint16_t len;
 202
 203                                 errcode = p9pdu_readf(pdu, proto_version,
 204                                                                 "w", &len);
 205                                 if (errcode)
 206                                         break;
 207
 208                                 *sptr = kmalloc(len + 1, GFP_NOFS);
 209                                 if (*sptr == NULL) {
 210                                         errcode = -EFAULT;
 211                                         break;
 212                                 }
 213                                 if (pdu_read(pdu, *sptr, len)) {
 214                                         errcode = -EFAULT;
 215                                         kfree(*sptr);
 216                                         *sptr = NULL;
 217                                 } else
 218                                         (*sptr)[len] = 0;
 219                         }
 220                         break;
 221                 case 'Q':{
 222                                 struct p9_qid *qid =
 223                                     va_arg(ap, struct p9_qid *);
 224
 225                                 errcode = p9pdu_readf(pdu, proto_version, "bdq",
 226                                                       &qid->type, &qid->version,
 227                                                       &qid->path);
 228                         }
 229                         break;
 230                 case 'S':{
 231                                 struct p9_wstat *stbuf =
 232                                     va_arg(ap, struct p9_wstat *);
 233
 234                                 memset(stbuf, 0, sizeof(struct p9_wstat));
 235                                 stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
 236                                                                         -1;
 237                                 errcode =
 238                                     p9pdu_readf(pdu, proto_version,
 239                                                 "wwdQdddqssss?sddd",
 240                                                 &stbuf->size, &stbuf->type,
 241                                                 &stbuf->dev, &stbuf->qid,
 242                                                 &stbuf->mode, &stbuf->atime,
 243                                                 &stbuf->mtime, &stbuf->length,
 244                                                 &stbuf->name, &stbuf->uid,
 245                                                 &stbuf->gid, &stbuf->muid,
 246                                                 &stbuf->extension,
 247                                                 &stbuf->n_uid, &stbuf->n_gid,
 248                                                 &stbuf->n_muid);
 249                                 if (errcode)
 250                                         p9stat_free(stbuf);
 251                         }
 252                         break;
 253                 case 'D':{
 254                                 uint32_t *count = va_arg(ap, uint32_t *);
 255                                 void **data = va_arg(ap, void **);
 256
 257                                 errcode =
 258                                     p9pdu_readf(pdu, proto_version, "d", count);
 259                                 if (!errcode) {
 260                                         *count =
 261                                             min_t(uint32_t, *count,
 262                                                   pdu->size - pdu->offset);
 263                                         *data = &pdu->sdata[pdu->offset];
 264                                 }
 265                         }
 266                         break;
 267                 case 'T':{
 268                                 int16_t *nwname = va_arg(ap, int16_t *);
 269                                 char ***wnames = va_arg(ap, char ***);
 270
 271                                 errcode = p9pdu_readf(pdu, proto_version,
 272                                                                 "w", nwname);
 273                                 if (!errcode) {
 274                                         *wnames =
 275                                             kmalloc(sizeof(char *) * *nwname,
 276                                                     GFP_NOFS);
 277                                         if (!*wnames)
 278                                                 errcode = -ENOMEM;
 279                                 }
 280
 281                                 if (!errcode) {
 282                                         int i;
 283
 284                                         for (i = 0; i < *nwname; i++) {
 285                                                 errcode =
 286                                                     p9pdu_readf(pdu,
 287                                                                 proto_version,
 288                                                                 "s",
 289                                                                 &(*wnames)[i]);
 290                                                 if (errcode)
 291                                                         break;
 292                                         }
 293                                 }
 294
 295                                 if (errcode) {
 296                                         if (*wnames) {
 297                                                 int i;
 298
 299                                                 for (i = 0; i < *nwname; i++)
 300                                                         kfree((*wnames)[i]);
 301                                         }
 302                                         kfree(*wnames);
 303                                         *wnames = NULL;
 304                                 }
 305                         }
 306                         break;
 307                 case 'R':{
 308                                 int16_t *nwqid = va_arg(ap, int16_t *);
 309                                 struct p9_qid **wqids =
 310                                     va_arg(ap, struct p9_qid **);
 311
 312                                 *wqids = NULL;
 313
 314                                 errcode =
 315                                     p9pdu_readf(pdu, proto_version, "w", nwqid);
 316                                 if (!errcode) {
 317                                         *wqids =
 318                                             kmalloc(*nwqid *
 319                                                     sizeof(struct p9_qid),
 320                                                     GFP_NOFS);
 321                                         if (*wqids == NULL)
 322                                                 errcode = -ENOMEM;
 323                                 }
 324
 325                                 if (!errcode) {
 326                                         int i;
 327
 328                                         for (i = 0; i < *nwqid; i++) {
 329                                                 errcode =
 330                                                     p9pdu_readf(pdu,
 331                                                                 proto_version,
 332                                                                 "Q",
 333                                                                 &(*wqids)[i]);
 334                                                 if (errcode)
 335                                                         break;
 336                                         }
 337                                 }
 338
 339                                 if (errcode) {
 340                                         kfree(*wqids);
 341                                         *wqids = NULL;
 342                                 }
 343                         }
 344                         break;
 345                 case 'A': {
 346                                 struct p9_stat_dotl *stbuf =
 347                                     va_arg(ap, struct p9_stat_dotl *);
 348
 349                                 memset(stbuf, 0, sizeof(struct p9_stat_dotl));
 350                                 errcode =
 351                                     p9pdu_readf(pdu, proto_version,
 352                                         "qQdddqqqqqqqqqqqqqqq",
 353                                         &stbuf->st_result_mask,
 354                                         &stbuf->qid,
 355                                         &stbuf->st_mode,
 356                                         &stbuf->st_uid, &stbuf->st_gid,
 357                                         &stbuf->st_nlink,
 358                                         &stbuf->st_rdev, &stbuf->st_size,
 359                                         &stbuf->st_blksize, &stbuf->st_blocks,
 360                                         &stbuf->st_atime_sec,
 361                                         &stbuf->st_atime_nsec,
 362                                         &stbuf->st_mtime_sec,
 363                                         &stbuf->st_mtime_nsec,
 364                                         &stbuf->st_ctime_sec,
 365                                         &stbuf->st_ctime_nsec,
 366                                         &stbuf->st_btime_sec,
 367                                         &stbuf->st_btime_nsec,
 368                                         &stbuf->st_gen,
 369                                         &stbuf->st_data_version);
 370                         }
 371                         break;
 372                 case '?':
 373                         if ((proto_version != p9_proto_2000u) &&
 374                                 (proto_version != p9_proto_2000L))
 375                                 return 0;
 376                         break;
 377                 default:
 378                         BUG();
 379                         break;
 380                 }
 381
 382                 if (errcode)
 383                         break;
 384         }
 385
 386         return errcode;
 387 }
 388
 389 int
 390 p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 391         va_list ap)
 392 {
 393         const char *ptr;
 394         int errcode = 0;
 395
 396         for (ptr = fmt; *ptr; ptr++) {
 397                 switch (*ptr) {
 398                 case 'b':{
 399                                 int8_t val = va_arg(ap, int);
 400                                 if (pdu_write(pdu, &val, sizeof(val)))
 401                                         errcode = -EFAULT;
 402                         }
 403                         break;
 404                 case 'w':{
 405                                 __le16 val = cpu_to_le16(va_arg(ap, int));
 406                                 if (pdu_write(pdu, &val, sizeof(val)))
 407                                         errcode = -EFAULT;
 408                         }
 409                         break;
 410                 case 'd':{
 411                                 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
 412                                 if (pdu_write(pdu, &val, sizeof(val)))
 413                                         errcode = -EFAULT;
 414                         }
 415                         break;
 416                 case 'q':{
 417                                 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
 418                                 if (pdu_write(pdu, &val, sizeof(val)))
 419                                         errcode = -EFAULT;
 420                         }
 421                         break;
 422                 case 's':{
 423                                 const char *sptr = va_arg(ap, const char *);
 424                                 uint16_t len = 0;
 425                                 if (sptr)
 426                                         len = min_t(uint16_t, strlen(sptr),
 427                                                                 USHRT_MAX);
 428
 429                                 errcode = p9pdu_writef(pdu, proto_version,
 430                                                                 "w", len);
 431                                 if (!errcode && pdu_write(pdu, sptr, len))
 432                                         errcode = -EFAULT;
 433                         }
 434                         break;
 435                 case 'Q':{
 436                                 const struct p9_qid *qid =
 437                                     va_arg(ap, const struct p9_qid *);
 438                                 errcode =
 439                                     p9pdu_writef(pdu, proto_version, "bdq",
 440                                                  qid->type, qid->version,
 441                                                  qid->path);
 442                         } break;
 443                 case 'S':{
 444                                 const struct p9_wstat *stbuf =
 445                                     va_arg(ap, const struct p9_wstat *);
 446                                 errcode =
 447                                     p9pdu_writef(pdu, proto_version,
 448                                                  "wwdQdddqssss?sddd",
 449                                                  stbuf->size, stbuf->type,
 450                                                  stbuf->dev, &stbuf->qid,
 451                                                  stbuf->mode, stbuf->atime,
 452                                                  stbuf->mtime, stbuf->length,
 453                                                  stbuf->name, stbuf->uid,
 454                                                  stbuf->gid, stbuf->muid,
 455                                                  stbuf->extension, stbuf->n_uid,
 456                                                  stbuf->n_gid, stbuf->n_muid);
 457                         } break;
 458                 case 'D':{
 459                                 uint32_t count = va_arg(ap, uint32_t);
 460                                 const void *data = va_arg(ap, const void *);
 461
 462                                 errcode = p9pdu_writef(pdu, proto_version, "d",
 463                                                                         count);
 464                                 if (!errcode && pdu_write(pdu, data, count))
 465                                         errcode = -EFAULT;
 466                         }
 467                         break;
 468                 case 'E':{
 469                                  int32_t cnt = va_arg(ap, int32_t);
 470                                  const char *k = va_arg(ap, const void *);
 471                                  const char __user *u = va_arg(ap,
 472                                                         const void __user *);
 473                                  errcode = p9pdu_writef(pdu, proto_version, "d",
 474                                                  cnt);
 475                                  if (!errcode && pdu_write_urw(pdu, k, u, cnt))
 476                                         errcode = -EFAULT;
 477                          }
 478                          break;
 479                 case 'F':{
 480                                  int32_t cnt = va_arg(ap, int32_t);
 481                                  const char *k = va_arg(ap, const void *);
 482                                  errcode = p9pdu_writef(pdu, proto_version, "d",
 483                                                  cnt);
 484                                  if (!errcode && pdu_write_readdir(pdu, k, cnt))
 485                                         errcode = -EFAULT;
 486                          }
 487                          break;
 488                 case 'U':{
 489                                 int32_t count = va_arg(ap, int32_t);
 490                                 const char __user *udata =
 491                                                 va_arg(ap, const void __user *);
 492                                 errcode = p9pdu_writef(pdu, proto_version, "d",
 493                                                                         count);
 494                                 if (!errcode && pdu_write_u(pdu, udata, count))
 495                                         errcode = -EFAULT;
 496                         }
 497                         break;
 498                 case 'T':{
 499                                 int16_t nwname = va_arg(ap, int);
 500                                 const char **wnames = va_arg(ap, const char **);
 501
 502                                 errcode = p9pdu_writef(pdu, proto_version, "w",
 503                                                                         nwname);
 504                                 if (!errcode) {
 505                                         int i;
 506
 507                                         for (i = 0; i < nwname; i++) {
 508                                                 errcode =
 509                                                     p9pdu_writef(pdu,
 510                                                                 proto_version,
 511                                                                  "s",
 512                                                                  wnames[i]);
 513                                                 if (errcode)
 514                                                         break;
 515                                         }
 516                                 }
 517                         }
 518                         break;
 519                 case 'R':{
 520                                 int16_t nwqid = va_arg(ap, int);
 521                                 struct p9_qid *wqids =
 522                                     va_arg(ap, struct p9_qid *);
 523
 524                                 errcode = p9pdu_writef(pdu, proto_version, "w",
 525                                                                         nwqid);
 526                                 if (!errcode) {
 527                                         int i;
 528
 529                                         for (i = 0; i < nwqid; i++) {
 530                                                 errcode =
 531                                                     p9pdu_writef(pdu,
 532                                                                 proto_version,
 533                                                                  "Q",
 534                                                                  &wqids[i]);
 535                                                 if (errcode)
 536                                                         break;
 537                                         }
 538                                 }
 539                         }
 540                         break;
 541                 case 'I':{
 542                                 struct p9_iattr_dotl *p9attr = va_arg(ap,
 543                                                         struct p9_iattr_dotl *);
 544
 545                                 errcode = p9pdu_writef(pdu, proto_version,
 546                                                         "ddddqqqqq",
 547                                                         p9attr->valid,
 548                                                         p9attr->mode,
 549                                                         p9attr->uid,
 550                                                         p9attr->gid,
 551                                                         p9attr->size,
 552                                                         p9attr->atime_sec,
 553                                                         p9attr->atime_nsec,
 554                                                         p9attr->mtime_sec,
 555                                                         p9attr->mtime_nsec);
 556                         }
 557                         break;
 558                 case '?':
 559                         if ((proto_version != p9_proto_2000u) &&
 560                                 (proto_version != p9_proto_2000L))
 561                                 return 0;
 562                         break;
 563                 default:
 564                         BUG();
 565                         break;
 566                 }
 567
 568                 if (errcode)
 569                         break;
 570         }
 571
 572         return errcode;
 573 }
 574
 575 int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
 576 {
 577         va_list ap;
 578         int ret;
 579
 580         va_start(ap, fmt);
 581         ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
 582         va_end(ap);
 583
 584         return ret;
 585 }
 586
 587 static int
 588 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
 589 {
 590         va_list ap;
 591         int ret;
 592
 593         va_start(ap, fmt);
 594         ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
 595         va_end(ap);
 596
 597         return ret;
 598 }
 599
 600 int p9stat_read(char *buf, int len, struct p9_wstat *st, int proto_version)
 601 {
 602         struct p9_fcall fake_pdu;
 603         int ret;
 604
 605         fake_pdu.size = len;
 606         fake_pdu.capacity = len;
 607         fake_pdu.sdata = buf;
 608         fake_pdu.offset = 0;
 609
 610         ret = p9pdu_readf(&fake_pdu, proto_version, "S", st);
 611         if (ret) {
 612                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
 613                 p9pdu_dump(1, &fake_pdu);
 614         }
 615
 616         return ret;
 617 }
 618 EXPORT_SYMBOL(p9stat_read);
 619
 620 int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
 621 {
 622         pdu->id = type;
 623         return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
 624 }
 625
 626 int p9pdu_finalize(struct p9_fcall *pdu)
 627 {
 628         int size = pdu->size;
 629         int err;
 630
 631         pdu->size = 0;
 632         err = p9pdu_writef(pdu, 0, "d", size);
 633         pdu->size = size;
 634
 635 #ifdef CONFIG_NET_9P_DEBUG
 636         if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
 637                 p9pdu_dump(0, pdu);
 638 #endif
 639
 640         P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
 641                                                         pdu->id, pdu->tag);
 642
 643         return err;
 644 }
 645
 646 void p9pdu_reset(struct p9_fcall *pdu)
 647 {
 648         pdu->offset = 0;
 649         pdu->size = 0;
 650         pdu->private = NULL;
 651         pdu->pubuf = NULL;
 652         pdu->pkbuf = NULL;
 653         pdu->pbuf_size = 0;
 654 }
 655
 656 int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,
 657                                                 int proto_version)
 658 {
 659         struct p9_fcall fake_pdu;
 660         int ret;
 661         char *nameptr;
 662
 663         fake_pdu.size = len;
 664         fake_pdu.capacity = len;
 665         fake_pdu.sdata = buf;
 666         fake_pdu.offset = 0;
 667
 668         ret = p9pdu_readf(&fake_pdu, proto_version, "Qqbs", &dirent->qid,
 669                         &dirent->d_off, &dirent->d_type, &nameptr);
 670         if (ret) {
 671                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret);
 672                 p9pdu_dump(1, &fake_pdu);
 673                 goto out;
 674         }
 675
 676         strcpy(dirent->d_name, nameptr);
 677
 678 out:
 679         return fake_pdu.offset;
 680 }
 681 EXPORT_SYMBOL(p9dirent_read);