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         ? - if optional = 1, continue parsing
 145 */
 146
 147 static int
 148 p9pdu_vreadf(struct p9_fcall *pdu, int proto_version, const char *fmt,
 149         va_list ap)
 150 {
 151         const char *ptr;
 152         int errcode = 0;
 153
 154         for (ptr = fmt; *ptr; ptr++) {
 155                 switch (*ptr) {
 156                 case 'b':{
 157                                 int8_t *val = va_arg(ap, int8_t *);
 158                                 if (pdu_read(pdu, val, sizeof(*val))) {
 159                                         errcode = -EFAULT;
 160                                         break;
 161                                 }
 162                         }
 163                         break;
 164                 case 'w':{
 165                                 int16_t *val = va_arg(ap, int16_t *);
 166                                 __le16 le_val;
 167                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 168                                         errcode = -EFAULT;
 169                                         break;
 170                                 }
 171                                 *val = le16_to_cpu(le_val);
 172                         }
 173                         break;
 174                 case 'd':{
 175                                 int32_t *val = va_arg(ap, int32_t *);
 176                                 __le32 le_val;
 177                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 178                                         errcode = -EFAULT;
 179                                         break;
 180                                 }
 181                                 *val = le32_to_cpu(le_val);
 182                         }
 183                         break;
 184                 case 'q':{
 185                                 int64_t *val = va_arg(ap, int64_t *);
 186                                 __le64 le_val;
 187                                 if (pdu_read(pdu, &le_val, sizeof(le_val))) {
 188                                         errcode = -EFAULT;
 189                                         break;
 190                                 }
 191                                 *val = le64_to_cpu(le_val);
 192                         }
 193                         break;
 194                 case 's':{
 195                                 char **sptr = va_arg(ap, char **);
 196                                 int16_t len;
 197                                 int size;
 198
 199                                 errcode = p9pdu_readf(pdu, proto_version,
 200                                                                 "w", &len);
 201                                 if (errcode)
 202                                         break;
 203
 204                                 size = MAX(len, 0);
 205
 206                                 *sptr = kmalloc(size + 1, GFP_KERNEL);
 207                                 if (*sptr == NULL) {
 208                                         errcode = -EFAULT;
 209                                         break;
 210                                 }
 211                                 if (pdu_read(pdu, *sptr, size)) {
 212                                         errcode = -EFAULT;
 213                                         kfree(*sptr);
 214                                         *sptr = NULL;
 215                                 } else
 216                                         (*sptr)[size] = 0;
 217                         }
 218                         break;
 219                 case 'Q':{
 220                                 struct p9_qid *qid =
 221                                     va_arg(ap, struct p9_qid *);
 222
 223                                 errcode = p9pdu_readf(pdu, proto_version, "bdq",
 224                                                       &qid->type, &qid->version,
 225                                                       &qid->path);
 226                         }
 227                         break;
 228                 case 'S':{
 229                                 struct p9_wstat *stbuf =
 230                                     va_arg(ap, struct p9_wstat *);
 231
 232                                 memset(stbuf, 0, sizeof(struct p9_wstat));
 233                                 stbuf->n_uid = stbuf->n_gid = stbuf->n_muid =
 234                                                                         -1;
 235                                 errcode =
 236                                     p9pdu_readf(pdu, proto_version,
 237                                                 "wwdQdddqssss?sddd",
 238                                                 &stbuf->size, &stbuf->type,
 239                                                 &stbuf->dev, &stbuf->qid,
 240                                                 &stbuf->mode, &stbuf->atime,
 241                                                 &stbuf->mtime, &stbuf->length,
 242                                                 &stbuf->name, &stbuf->uid,
 243                                                 &stbuf->gid, &stbuf->muid,
 244                                                 &stbuf->extension,
 245                                                 &stbuf->n_uid, &stbuf->n_gid,
 246                                                 &stbuf->n_muid);
 247                                 if (errcode)
 248                                         p9stat_free(stbuf);
 249                         }
 250                         break;
 251                 case 'D':{
 252                                 int32_t *count = va_arg(ap, int32_t *);
 253                                 void **data = va_arg(ap, void **);
 254
 255                                 errcode =
 256                                     p9pdu_readf(pdu, proto_version, "d", count);
 257                                 if (!errcode) {
 258                                         *count =
 259                                             MIN(*count,
 260                                                 pdu->size - pdu->offset);
 261                                         *data = &pdu->sdata[pdu->offset];
 262                                 }
 263                         }
 264                         break;
 265                 case 'T':{
 266                                 int16_t *nwname = va_arg(ap, int16_t *);
 267                                 char ***wnames = va_arg(ap, char ***);
 268
 269                                 errcode = p9pdu_readf(pdu, proto_version,
 270                                                                 "w", nwname);
 271                                 if (!errcode) {
 272                                         *wnames =
 273                                             kmalloc(sizeof(char *) * *nwname,
 274                                                     GFP_KERNEL);
 275                                         if (!*wnames)
 276                                                 errcode = -ENOMEM;
 277                                 }
 278
 279                                 if (!errcode) {
 280                                         int i;
 281
 282                                         for (i = 0; i < *nwname; i++) {
 283                                                 errcode =
 284                                                     p9pdu_readf(pdu,
 285                                                                 proto_version,
 286                                                                 "s",
 287                                                                 &(*wnames)[i]);
 288                                                 if (errcode)
 289                                                         break;
 290                                         }
 291                                 }
 292
 293                                 if (errcode) {
 294                                         if (*wnames) {
 295                                                 int i;
 296
 297                                                 for (i = 0; i < *nwname; i++)
 298                                                         kfree((*wnames)[i]);
 299                                         }
 300                                         kfree(*wnames);
 301                                         *wnames = NULL;
 302                                 }
 303                         }
 304                         break;
 305                 case 'R':{
 306                                 int16_t *nwqid = va_arg(ap, int16_t *);
 307                                 struct p9_qid **wqids =
 308                                     va_arg(ap, struct p9_qid **);
 309
 310                                 *wqids = NULL;
 311
 312                                 errcode =
 313                                     p9pdu_readf(pdu, proto_version, "w", nwqid);
 314                                 if (!errcode) {
 315                                         *wqids =
 316                                             kmalloc(*nwqid *
 317                                                     sizeof(struct p9_qid),
 318                                                     GFP_KERNEL);
 319                                         if (*wqids == NULL)
 320                                                 errcode = -ENOMEM;
 321                                 }
 322
 323                                 if (!errcode) {
 324                                         int i;
 325
 326                                         for (i = 0; i < *nwqid; i++) {
 327                                                 errcode =
 328                                                     p9pdu_readf(pdu,
 329                                                                 proto_version,
 330                                                                 "Q",
 331                                                                 &(*wqids)[i]);
 332                                                 if (errcode)
 333                                                         break;
 334                                         }
 335                                 }
 336
 337                                 if (errcode) {
 338                                         kfree(*wqids);
 339                                         *wqids = NULL;
 340                                 }
 341                         }
 342                         break;
 343                 case '?':
 344                         if ((proto_version != p9_proto_2000u) &&
 345                                 (proto_version != p9_proto_2000L))
 346                                 return 0;
 347                         break;
 348                 default:
 349                         BUG();
 350                         break;
 351                 }
 352
 353                 if (errcode)
 354                         break;
 355         }
 356
 357         return errcode;
 358 }
 359
 360 int
 361 p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 362         va_list ap)
 363 {
 364         const char *ptr;
 365         int errcode = 0;
 366
 367         for (ptr = fmt; *ptr; ptr++) {
 368                 switch (*ptr) {
 369                 case 'b':{
 370                                 int8_t val = va_arg(ap, int);
 371                                 if (pdu_write(pdu, &val, sizeof(val)))
 372                                         errcode = -EFAULT;
 373                         }
 374                         break;
 375                 case 'w':{
 376                                 __le16 val = cpu_to_le16(va_arg(ap, int));
 377                                 if (pdu_write(pdu, &val, sizeof(val)))
 378                                         errcode = -EFAULT;
 379                         }
 380                         break;
 381                 case 'd':{
 382                                 __le32 val = cpu_to_le32(va_arg(ap, int32_t));
 383                                 if (pdu_write(pdu, &val, sizeof(val)))
 384                                         errcode = -EFAULT;
 385                         }
 386                         break;
 387                 case 'q':{
 388                                 __le64 val = cpu_to_le64(va_arg(ap, int64_t));
 389                                 if (pdu_write(pdu, &val, sizeof(val)))
 390                                         errcode = -EFAULT;
 391                         }
 392                         break;
 393                 case 's':{
 394                                 const char *sptr = va_arg(ap, const char *);
 395                                 int16_t len = 0;
 396                                 if (sptr)
 397                                         len = MIN(strlen(sptr), USHRT_MAX);
 398
 399                                 errcode = p9pdu_writef(pdu, proto_version,
 400                                                                 "w", len);
 401                                 if (!errcode && pdu_write(pdu, sptr, len))
 402                                         errcode = -EFAULT;
 403                         }
 404                         break;
 405                 case 'Q':{
 406                                 const struct p9_qid *qid =
 407                                     va_arg(ap, const struct p9_qid *);
 408                                 errcode =
 409                                     p9pdu_writef(pdu, proto_version, "bdq",
 410                                                  qid->type, qid->version,
 411                                                  qid->path);
 412                         } break;
 413                 case 'S':{
 414                                 const struct p9_wstat *stbuf =
 415                                     va_arg(ap, const struct p9_wstat *);
 416                                 errcode =
 417                                     p9pdu_writef(pdu, proto_version,
 418                                                  "wwdQdddqssss?sddd",
 419                                                  stbuf->size, stbuf->type,
 420                                                  stbuf->dev, &stbuf->qid,
 421                                                  stbuf->mode, stbuf->atime,
 422                                                  stbuf->mtime, stbuf->length,
 423                                                  stbuf->name, stbuf->uid,
 424                                                  stbuf->gid, stbuf->muid,
 425                                                  stbuf->extension, stbuf->n_uid,
 426                                                  stbuf->n_gid, stbuf->n_muid);
 427                         } break;
 428                 case 'D':{
 429                                 int32_t count = va_arg(ap, int32_t);
 430                                 const void *data = va_arg(ap, const void *);
 431
 432                                 errcode = p9pdu_writef(pdu, proto_version, "d",
 433                                                                         count);
 434                                 if (!errcode && pdu_write(pdu, data, count))
 435                                         errcode = -EFAULT;
 436                         }
 437                         break;
 438                 case 'U':{
 439                                 int32_t count = va_arg(ap, int32_t);
 440                                 const char __user *udata =
 441                                                 va_arg(ap, const void __user *);
 442                                 errcode = p9pdu_writef(pdu, proto_version, "d",
 443                                                                         count);
 444                                 if (!errcode && pdu_write_u(pdu, udata, count))
 445                                         errcode = -EFAULT;
 446                         }
 447                         break;
 448                 case 'T':{
 449                                 int16_t nwname = va_arg(ap, int);
 450                                 const char **wnames = va_arg(ap, const char **);
 451
 452                                 errcode = p9pdu_writef(pdu, proto_version, "w",
 453                                                                         nwname);
 454                                 if (!errcode) {
 455                                         int i;
 456
 457                                         for (i = 0; i < nwname; i++) {
 458                                                 errcode =
 459                                                     p9pdu_writef(pdu,
 460                                                                 proto_version,
 461                                                                  "s",
 462                                                                  wnames[i]);
 463                                                 if (errcode)
 464                                                         break;
 465                                         }
 466                                 }
 467                         }
 468                         break;
 469                 case 'R':{
 470                                 int16_t nwqid = va_arg(ap, int);
 471                                 struct p9_qid *wqids =
 472                                     va_arg(ap, struct p9_qid *);
 473
 474                                 errcode = p9pdu_writef(pdu, proto_version, "w",
 475                                                                         nwqid);
 476                                 if (!errcode) {
 477                                         int i;
 478
 479                                         for (i = 0; i < nwqid; i++) {
 480                                                 errcode =
 481                                                     p9pdu_writef(pdu,
 482                                                                 proto_version,
 483                                                                  "Q",
 484                                                                  &wqids[i]);
 485                                                 if (errcode)
 486                                                         break;
 487                                         }
 488                                 }
 489                         }
 490                         break;
 491                 case '?':
 492                         if ((proto_version != p9_proto_2000u) &&
 493                                 (proto_version != p9_proto_2000L))
 494                                 return 0;
 495                         break;
 496                 default:
 497                         BUG();
 498                         break;
 499                 }
 500
 501                 if (errcode)
 502                         break;
 503         }
 504
 505         return errcode;
 506 }
 507
 508 int p9pdu_readf(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
 509 {
 510         va_list ap;
 511         int ret;
 512
 513         va_start(ap, fmt);
 514         ret = p9pdu_vreadf(pdu, proto_version, fmt, ap);
 515         va_end(ap);
 516
 517         return ret;
 518 }
 519
 520 static int
 521 p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...)
 522 {
 523         va_list ap;
 524         int ret;
 525
 526         va_start(ap, fmt);
 527         ret = p9pdu_vwritef(pdu, proto_version, fmt, ap);
 528         va_end(ap);
 529
 530         return ret;
 531 }
 532
 533 int p9stat_read(char *buf, int len, struct p9_wstat *st, int proto_version)
 534 {
 535         struct p9_fcall fake_pdu;
 536         int ret;
 537
 538         fake_pdu.size = len;
 539         fake_pdu.capacity = len;
 540         fake_pdu.sdata = buf;
 541         fake_pdu.offset = 0;
 542
 543         ret = p9pdu_readf(&fake_pdu, proto_version, "S", st);
 544         if (ret) {
 545                 P9_DPRINTK(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret);
 546                 p9pdu_dump(1, &fake_pdu);
 547         }
 548
 549         return ret;
 550 }
 551 EXPORT_SYMBOL(p9stat_read);
 552
 553 int p9pdu_prepare(struct p9_fcall *pdu, int16_t tag, int8_t type)
 554 {
 555         return p9pdu_writef(pdu, 0, "dbw", 0, type, tag);
 556 }
 557
 558 int p9pdu_finalize(struct p9_fcall *pdu)
 559 {
 560         int size = pdu->size;
 561         int err;
 562
 563         pdu->size = 0;
 564         err = p9pdu_writef(pdu, 0, "d", size);
 565         pdu->size = size;
 566
 567 #ifdef CONFIG_NET_9P_DEBUG
 568         if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
 569                 p9pdu_dump(0, pdu);
 570 #endif
 571
 572         P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
 573                                                         pdu->id, pdu->tag);
 574
 575         return err;
 576 }
 577
 578 void p9pdu_reset(struct p9_fcall *pdu)
 579 {
 580         pdu->offset = 0;
 581         pdu->size = 0;
 582 }