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