fs/cifs/misc.c

   1 /*
   2  *   fs/cifs/misc.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2004
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  *   This library is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU Lesser General Public License as published
   9  *   by the Free Software Foundation; either version 2.1 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This library is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15  *   the GNU Lesser General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU Lesser General Public License
  18  *   along with this library; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <linux/slab.h>
  23 #include <linux/ctype.h>
  24 #include <linux/mempool.h>
  25 #include "cifspdu.h"
  26 #include "cifsglob.h"
  27 #include "cifsproto.h"
  28 #include "cifs_debug.h"
  29 #include "smberr.h"
  30 #include "nterr.h"
  31
  32 extern mempool_t *cifs_sm_req_poolp;
  33 extern mempool_t *cifs_req_poolp;
  34 extern struct task_struct * oplockThread;
  35
  36 __u16 GlobalMid;                /* multiplex id - rotating counter */
  37
  38 /* The xid serves as a useful identifier for each incoming vfs request,
  39    in a similar way to the mid which is useful to track each sent smb,
  40    and CurrentXid can also provide a running counter (although it
  41    will eventually wrap past zero) of the total vfs operations handled
  42    since the cifs fs was mounted */
  43
  44 unsigned int
  45 _GetXid(void)
  46 {
  47         unsigned int xid;
  48
  49         spin_lock(&GlobalMid_Lock);
  50         GlobalTotalActiveXid++;
  51         if (GlobalTotalActiveXid > GlobalMaxActiveXid)
  52                 GlobalMaxActiveXid = GlobalTotalActiveXid;      /* keep high water mark for number of simultaneous vfs ops in our filesystem */
  53         xid = GlobalCurrentXid++;
  54         spin_unlock(&GlobalMid_Lock);
  55         return xid;
  56 }
  57
  58 void
  59 _FreeXid(unsigned int xid)
  60 {
  61         spin_lock(&GlobalMid_Lock);
  62         /* if(GlobalTotalActiveXid == 0)
  63                 BUG(); */
  64         GlobalTotalActiveXid--;
  65         spin_unlock(&GlobalMid_Lock);
  66 }
  67
  68 struct cifsSesInfo *
  69 sesInfoAlloc(void)
  70 {
  71         struct cifsSesInfo *ret_buf;
  72
  73         ret_buf =
  74             (struct cifsSesInfo *) kmalloc(sizeof (struct cifsSesInfo),
  75                                            GFP_KERNEL);
  76         if (ret_buf) {
  77                 memset(ret_buf, 0, sizeof (struct cifsSesInfo));
  78                 write_lock(&GlobalSMBSeslock);
  79                 atomic_inc(&sesInfoAllocCount);
  80                 ret_buf->status = CifsNew;
  81                 list_add(&ret_buf->cifsSessionList, &GlobalSMBSessionList);
  82                 init_MUTEX(&ret_buf->sesSem);
  83                 write_unlock(&GlobalSMBSeslock);
  84         }
  85         return ret_buf;
  86 }
  87
  88 void
  89 sesInfoFree(struct cifsSesInfo *buf_to_free)
  90 {
  91         if (buf_to_free == NULL) {
  92                 cFYI(1, ("Null buffer passed to sesInfoFree"));
  93                 return;
  94         }
  95
  96         write_lock(&GlobalSMBSeslock);
  97         atomic_dec(&sesInfoAllocCount);
  98         list_del(&buf_to_free->cifsSessionList);
  99         write_unlock(&GlobalSMBSeslock);
 100         if (buf_to_free->serverOS)
 101                 kfree(buf_to_free->serverOS);
 102         if (buf_to_free->serverDomain)
 103                 kfree(buf_to_free->serverDomain);
 104         if (buf_to_free->serverNOS)
 105                 kfree(buf_to_free->serverNOS);
 106         if (buf_to_free->password)
 107                 kfree(buf_to_free->password);
 108         kfree(buf_to_free);
 109 }
 110
 111 struct cifsTconInfo *
 112 tconInfoAlloc(void)
 113 {
 114         struct cifsTconInfo *ret_buf;
 115         ret_buf =
 116             (struct cifsTconInfo *) kmalloc(sizeof (struct cifsTconInfo),
 117                                             GFP_KERNEL);
 118         if (ret_buf) {
 119                 memset(ret_buf, 0, sizeof (struct cifsTconInfo));
 120                 write_lock(&GlobalSMBSeslock);
 121                 atomic_inc(&tconInfoAllocCount);
 122                 list_add(&ret_buf->cifsConnectionList,
 123                          &GlobalTreeConnectionList);
 124                 ret_buf->tidStatus = CifsNew;
 125                 INIT_LIST_HEAD(&ret_buf->openFileList);
 126                 init_MUTEX(&ret_buf->tconSem);
 127 #ifdef CONFIG_CIFS_STATS
 128                 spin_lock_init(&ret_buf->stat_lock);
 129 #endif
 130                 write_unlock(&GlobalSMBSeslock);
 131         }
 132         return ret_buf;
 133 }
 134
 135 void
 136 tconInfoFree(struct cifsTconInfo *buf_to_free)
 137 {
 138         if (buf_to_free == NULL) {
 139                 cFYI(1, ("Null buffer passed to tconInfoFree"));
 140                 return;
 141         }
 142         write_lock(&GlobalSMBSeslock);
 143         atomic_dec(&tconInfoAllocCount);
 144         list_del(&buf_to_free->cifsConnectionList);
 145         write_unlock(&GlobalSMBSeslock);
 146         if (buf_to_free->nativeFileSystem)
 147                 kfree(buf_to_free->nativeFileSystem);
 148         kfree(buf_to_free);
 149 }
 150
 151 struct smb_hdr *
 152 cifs_buf_get(void)
 153 {
 154         struct smb_hdr *ret_buf = NULL;
 155
 156 /* We could use negotiated size instead of max_msgsize -
 157    but it may be more efficient to always alloc same size
 158    albeit slightly larger than necessary and maxbuffersize
 159    defaults to this and can not be bigger */
 160         ret_buf =
 161             (struct smb_hdr *) mempool_alloc(cifs_req_poolp, SLAB_KERNEL | SLAB_NOFS);
 162
 163         /* clear the first few header bytes */
 164         /* for most paths, more is cleared in header_assemble */
 165         if (ret_buf) {
 166                 memset(ret_buf, 0, sizeof(struct smb_hdr) + 3);
 167                 atomic_inc(&bufAllocCount);
 168         }
 169
 170         return ret_buf;
 171 }
 172
 173 void
 174 cifs_buf_release(void *buf_to_free)
 175 {
 176
 177         if (buf_to_free == NULL) {
 178                 /* cFYI(1, ("Null buffer passed to cifs_buf_release"));*/
 179                 return;
 180         }
 181         mempool_free(buf_to_free,cifs_req_poolp);
 182
 183         atomic_dec(&bufAllocCount);
 184         return;
 185 }
 186
 187 struct smb_hdr *
 188 cifs_small_buf_get(void)
 189 {
 190         struct smb_hdr *ret_buf = NULL;
 191
 192 /* We could use negotiated size instead of max_msgsize -
 193    but it may be more efficient to always alloc same size
 194    albeit slightly larger than necessary and maxbuffersize
 195    defaults to this and can not be bigger */
 196         ret_buf =
 197             (struct smb_hdr *) mempool_alloc(cifs_sm_req_poolp, SLAB_KERNEL | SLAB_NOFS);
 198         if (ret_buf) {
 199         /* No need to clear memory here, cleared in header assemble */
 200         /*      memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
 201                 atomic_inc(&smBufAllocCount);
 202         }
 203         return ret_buf;
 204 }
 205
 206 void
 207 cifs_small_buf_release(void *buf_to_free)
 208 {
 209
 210         if (buf_to_free == NULL) {
 211                 cFYI(1, ("Null buffer passed to cifs_small_buf_release"));
 212                 return;
 213         }
 214         mempool_free(buf_to_free,cifs_sm_req_poolp);
 215
 216         atomic_dec(&smBufAllocCount);
 217         return;
 218 }
 219
 220 void
 221 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
 222                 const struct cifsTconInfo *treeCon, int word_count
 223                 /* length of fixed section (word count) in two byte units  */)
 224 {
 225         struct list_head* temp_item;
 226         struct cifsSesInfo * ses;
 227         char *temp = (char *) buffer;
 228
 229         memset(temp,0,MAX_CIFS_HDR_SIZE);
 230
 231         buffer->smb_buf_length =
 232             (2 * word_count) + sizeof (struct smb_hdr) -
 233             4 /*  RFC 1001 length field does not count */  +
 234             2 /* for bcc field itself */ ;
 235         /* Note that this is the only network field that has to be converted to big endian and it is done just before we send it */
 236
 237         buffer->Protocol[0] = 0xFF;
 238         buffer->Protocol[1] = 'S';
 239         buffer->Protocol[2] = 'M';
 240         buffer->Protocol[3] = 'B';
 241         buffer->Command = smb_command;
 242         buffer->Flags = 0x00;   /* case sensitive */
 243         buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
 244         buffer->Pid = cpu_to_le16((__u16)current->tgid);
 245         buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
 246         spin_lock(&GlobalMid_Lock);
 247         GlobalMid++;
 248         buffer->Mid = GlobalMid;
 249         spin_unlock(&GlobalMid_Lock);
 250         if (treeCon) {
 251                 buffer->Tid = treeCon->tid;
 252                 if (treeCon->ses) {
 253                         if (treeCon->ses->capabilities & CAP_UNICODE)
 254                                 buffer->Flags2 |= SMBFLG2_UNICODE;
 255                         if (treeCon->ses->capabilities & CAP_STATUS32) {
 256                                 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
 257                         }
 258
 259                         buffer->Uid = treeCon->ses->Suid;       /* always in LE format */
 260                         if(multiuser_mount != 0) {
 261                 /* For the multiuser case, there are few obvious technically  */
 262                 /* possible mechanisms to match the local linux user (uid)    */
 263                 /* to a valid remote smb user (smb_uid):                      */
 264                 /*      1) Query Winbind (or other local pam/nss daemon       */
 265                 /*        for userid/password/logon_domain or credential      */
 266                 /*      2) Query Winbind for uid to sid to username mapping   */
 267                 /*         and see if we have a matching password for existing*/
 268                 /*         session for that user perhas getting password by   */
 269                 /*         adding a new pam_cifs module that stores passwords */
 270                 /*         so that the cifs vfs can get at that for all logged*/
 271                 /*         on users                                           */
 272                 /*      3) (Which is the mechanism we have chosen)            */
 273                 /*         Search through sessions to the same server for a   */
 274                 /*         a match on the uid that was passed in on mount     */
 275                 /*         with the current processes uid (or euid?) and use  */
 276                 /*         that smb uid.   If no existing smb session for     */
 277                 /*         that uid found, use the default smb session ie     */
 278                 /*         the smb session for the volume mounted which is    */
 279                 /*         the same as would be used if the multiuser mount   */
 280                 /*         flag were disabled.  */
 281
 282                 /*  BB Add support for establishing new tCon and SMB Session  */
 283                 /*      with userid/password pairs found on the smb session   */
 284                 /*      for other target tcp/ip addresses               BB    */
 285                                 if(current->uid != treeCon->ses->linux_uid) {
 286                                         cFYI(1,("Multiuser mode and UID did not match tcon uid "));
 287                                         read_lock(&GlobalSMBSeslock);
 288                                         list_for_each(temp_item, &GlobalSMBSessionList) {
 289                                                 ses = list_entry(temp_item, struct cifsSesInfo, cifsSessionList);
 290                                                 if(ses->linux_uid == current->uid) {
 291                                                         if(ses->server == treeCon->ses->server) {
 292                                                                 cFYI(1,("found matching uid substitute right smb_uid"));
 293                                                                 buffer->Uid = ses->Suid;
 294                                                                 break;
 295                                                         } else {
 296                                                                 /* BB eventually call cifs_setup_session here */
 297                                                                 cFYI(1,("local UID found but smb sess with this server does not exist"));
 298                                                         }
 299                                                 }
 300                                         }
 301                                         read_unlock(&GlobalSMBSeslock);
 302                                 }
 303                         }
 304                 }
 305                 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
 306                         buffer->Flags2 |= SMBFLG2_DFS;
 307                 if((treeCon->ses) && (treeCon->ses->server))
 308                         if(treeCon->ses->server->secMode &
 309                           (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 310                                 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 311         }
 312
 313 /*  endian conversion of flags is now done just before sending */
 314         buffer->WordCount = (char) word_count;
 315         return;
 316 }
 317
 318 int
 319 checkSMBhdr(struct smb_hdr *smb, __u16 mid)
 320 {
 321         /* Make sure that this really is an SMB, that it is a response,
 322            and that the message ids match */
 323         if ((*(__le32 *) smb->Protocol == cpu_to_le32(0x424d53ff)) &&
 324                 (mid == smb->Mid)) {
 325                 if(smb->Flags & SMBFLG_RESPONSE)
 326                         return 0;
 327                 else {
 328                 /* only one valid case where server sends us request */
 329                         if(smb->Command == SMB_COM_LOCKING_ANDX)
 330                                 return 0;
 331                         else
 332                                 cERROR(1, ("Rcvd Request not response "));
 333                 }
 334         } else { /* bad signature or mid */
 335                 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff))
 336                         cERROR(1,
 337                                ("Bad protocol string signature header %x ",
 338                                 *(unsigned int *) smb->Protocol));
 339                 if (mid != smb->Mid)
 340                         cERROR(1, ("Mids do not match"));
 341         }
 342         cERROR(1, ("bad smb detected. The Mid=%d", smb->Mid));
 343         return 1;
 344 }
 345
 346 int
 347 checkSMB(struct smb_hdr *smb, __u16 mid, int length)
 348 {
 349         __u32 len = be32_to_cpu(smb->smb_buf_length);
 350         cFYI(0,
 351              ("Entering checkSMB with Length: %x, smb_buf_length: %x ",
 352               length, len));
 353         if (((unsigned int)length < 2 + sizeof (struct smb_hdr)) ||
 354             (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)) {
 355                 if ((unsigned int)length < 2 + sizeof (struct smb_hdr)) {
 356                         cERROR(1, ("Length less than 2 + sizeof smb_hdr "));
 357                         if (((unsigned int)length >= sizeof (struct smb_hdr) - 1)
 358                             && (smb->Status.CifsError != 0))
 359                                 return 0;       /* some error cases do not return wct and bcc */
 360
 361                 }
 362                 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)
 363                         cERROR(1,
 364                                ("smb_buf_length greater than MaxBufSize"));
 365                 cERROR(1,
 366                        ("bad smb detected. Illegal length. The mid=%d",
 367                         smb->Mid));
 368                 return 1;
 369         }
 370
 371         if (checkSMBhdr(smb, mid))
 372                 return 1;
 373
 374         if ((4 + len != smbCalcSize(smb))
 375             || (4 + len != (unsigned int)length)) {
 376                 return 0;
 377         } else {
 378                 cERROR(1, ("smbCalcSize %x ", smbCalcSize(smb)));
 379                 cERROR(1,
 380                        ("bad smb size detected. The Mid=%d", smb->Mid));
 381                 return 1;
 382         }
 383 }
 384 int
 385 is_valid_oplock_break(struct smb_hdr *buf)
 386 {
 387         struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)buf;
 388         struct list_head *tmp;
 389         struct list_head *tmp1;
 390         struct cifsTconInfo *tcon;
 391         struct cifsFileInfo *netfile;
 392
 393         cFYI(1,("Checking for oplock break or dnotify response"));
 394         if((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
 395            (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
 396                 struct smb_com_transaction_change_notify_rsp * pSMBr =
 397                         (struct smb_com_transaction_change_notify_rsp *)buf;
 398                 struct file_notify_information * pnotify;
 399                 __u32 data_offset = 0;
 400                 if(pSMBr->ByteCount > sizeof(struct file_notify_information)) {
 401                         data_offset = le32_to_cpu(pSMBr->DataOffset);
 402
 403                         pnotify = (struct file_notify_information *)((char *)&pSMBr->hdr.Protocol
 404                                 + data_offset);
 405                         cFYI(1,("dnotify on %s with action: 0x%x",pnotify->FileName,
 406                                 pnotify->Action));  /* BB removeme BB */
 407                      /*   cifs_dump_mem("Received notify Data is: ",buf,sizeof(struct smb_hdr)+60); */
 408                         return TRUE;
 409                 }
 410                 if(pSMBr->hdr.Status.CifsError) {
 411                         cFYI(1,("notify err 0x%d",pSMBr->hdr.Status.CifsError));
 412                         return TRUE;
 413                 }
 414                 return FALSE;
 415         }
 416         if(pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
 417                 return FALSE;
 418         if(pSMB->hdr.Flags & SMBFLG_RESPONSE) {
 419                 /* no sense logging error on invalid handle on oplock
 420                    break - harmless race between close request and oplock
 421                    break response is expected from time to time writing out
 422                    large dirty files cached on the client */
 423                 if ((NT_STATUS_INVALID_HANDLE) ==
 424                    le32_to_cpu(pSMB->hdr.Status.CifsError)) {
 425                         cFYI(1,("invalid handle on oplock break"));
 426                         return TRUE;
 427                 } else if (ERRbadfid ==
 428                    le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
 429                         return TRUE;
 430                 } else {
 431                         return FALSE; /* on valid oplock brk we get "request" */
 432                 }
 433         }
 434         if(pSMB->hdr.WordCount != 8)
 435                 return FALSE;
 436
 437         cFYI(1,(" oplock type 0x%d level 0x%d",pSMB->LockType,pSMB->OplockLevel));
 438         if(!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
 439                 return FALSE;
 440
 441         /* look up tcon based on tid & uid */
 442         read_lock(&GlobalSMBSeslock);
 443         list_for_each(tmp, &GlobalTreeConnectionList) {
 444                 tcon = list_entry(tmp, struct cifsTconInfo, cifsConnectionList);
 445                 if (tcon->tid == buf->Tid) {
 446 #ifdef CONFIG_CIFS_STATS
 447                         atomic_inc(&tcon->num_oplock_brks);
 448 #endif
 449                         list_for_each(tmp1,&tcon->openFileList){
 450                                 netfile = list_entry(tmp1,struct cifsFileInfo,tlist);
 451                                 if(pSMB->Fid == netfile->netfid) {
 452                                         struct cifsInodeInfo *pCifsInode;
 453                                         read_unlock(&GlobalSMBSeslock);
 454                                         cFYI(1,("Matching file id, processing oplock break"));
 455                                         pCifsInode =
 456                                                 CIFS_I(netfile->pInode);
 457                                         pCifsInode->clientCanCacheAll = FALSE;
 458                                         if(pSMB->OplockLevel == 0)
 459                                                 pCifsInode->clientCanCacheRead = FALSE;
 460                                         pCifsInode->oplockPending = TRUE;
 461                                         AllocOplockQEntry(netfile->pInode, netfile->netfid, tcon);
 462                                         cFYI(1,("about to wake up oplock thd"));
 463                                         wake_up_process(oplockThread);
 464                                         return TRUE;
 465                                 }
 466                         }
 467                         read_unlock(&GlobalSMBSeslock);
 468                         cFYI(1,("No matching file for oplock break on connection"));
 469                         return TRUE;
 470                 }
 471         }
 472         read_unlock(&GlobalSMBSeslock);
 473         cFYI(1,("Can not process oplock break for non-existent connection"));
 474         return TRUE;
 475 }
 476
 477 void
 478 dump_smb(struct smb_hdr *smb_buf, int smb_buf_length)
 479 {
 480         int i, j;
 481         char debug_line[17];
 482         unsigned char *buffer;
 483
 484         if (traceSMB == 0)
 485                 return;
 486
 487         buffer = (unsigned char *) smb_buf;
 488         for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
 489                 if (i % 8 == 0) {       /* we have reached the beginning of line  */
 490                         printk(KERN_DEBUG "| ");
 491                         j = 0;
 492                 }
 493                 printk("%0#4x ", buffer[i]);
 494                 debug_line[2 * j] = ' ';
 495                 if (isprint(buffer[i]))
 496                         debug_line[1 + (2 * j)] = buffer[i];
 497                 else
 498                         debug_line[1 + (2 * j)] = '_';
 499
 500                 if (i % 8 == 7) {       /* we have reached end of line, time to print ascii */
 501                         debug_line[16] = 0;
 502                         printk(" | %s\n", debug_line);
 503                 }
 504         }
 505         for (; j < 8; j++) {
 506                 printk("     ");
 507                 debug_line[2 * j] = ' ';
 508                 debug_line[1 + (2 * j)] = ' ';
 509         }
 510         printk( " | %s\n", debug_line);
 511         return;
 512 }