fs/cifs/misc.c

   1 /*
   2  *   fs/cifs/misc.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2003
   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_req_poolp;
  33 extern struct task_struct * oplockThread;
  34
  35 __u16 GlobalMid;                /* multiplex id - rotating counter */
  36
  37 /* The xid serves as a useful identifier for each incoming vfs request,
  38    in a similar way to the mid which is useful to track each sent smb,
  39    and CurrentXid can also provide a running counter (although it
  40    will eventually wrap past zero) of the total vfs operations handled
  41    since the cifs fs was mounted */
  42
  43 unsigned int
  44 _GetXid(void)
  45 {
  46         unsigned int xid;
  47
  48         spin_lock(&GlobalMid_Lock);
  49         GlobalTotalActiveXid++;
  50         if (GlobalTotalActiveXid > GlobalMaxActiveXid)
  51                 GlobalMaxActiveXid = GlobalTotalActiveXid;      /* keep high water mark for number of simultaneous vfs ops in our filesystem */
  52         xid = GlobalCurrentXid++;
  53         spin_unlock(&GlobalMid_Lock);
  54         return xid;
  55 }
  56
  57 void
  58 _FreeXid(unsigned int xid)
  59 {
  60         spin_lock(&GlobalMid_Lock);
  61         /* if(GlobalTotalActiveXid == 0)
  62                 BUG(); */
  63         GlobalTotalActiveXid--;
  64         spin_unlock(&GlobalMid_Lock);
  65 }
  66
  67 struct cifsSesInfo *
  68 sesInfoAlloc(void)
  69 {
  70         struct cifsSesInfo *ret_buf;
  71
  72         ret_buf =
  73             (struct cifsSesInfo *) kmalloc(sizeof (struct cifsSesInfo),
  74                                            GFP_KERNEL);
  75         if (ret_buf) {
  76                 memset(ret_buf, 0, sizeof (struct cifsSesInfo));
  77                 write_lock(&GlobalSMBSeslock);
  78                 atomic_inc(&sesInfoAllocCount);
  79                 ret_buf->status = CifsNew;
  80                 list_add(&ret_buf->cifsSessionList, &GlobalSMBSessionList);
  81                 init_MUTEX(&ret_buf->sesSem);
  82                 write_unlock(&GlobalSMBSeslock);
  83         }
  84         return ret_buf;
  85 }
  86
  87 void
  88 sesInfoFree(struct cifsSesInfo *buf_to_free)
  89 {
  90         if (buf_to_free == NULL) {
  91                 cFYI(1, ("Null buffer passed to sesInfoFree"));
  92                 return;
  93         }
  94
  95         write_lock(&GlobalSMBSeslock);
  96         atomic_dec(&sesInfoAllocCount);
  97         list_del(&buf_to_free->cifsSessionList);
  98         write_unlock(&GlobalSMBSeslock);
  99         if (buf_to_free->serverOS)
 100                 kfree(buf_to_free->serverOS);
 101         if (buf_to_free->serverDomain)
 102                 kfree(buf_to_free->serverDomain);
 103         if (buf_to_free->serverNOS)
 104                 kfree(buf_to_free->serverNOS);
 105         if (buf_to_free->password)
 106                 kfree(buf_to_free->password);
 107         kfree(buf_to_free);
 108 }
 109
 110 struct cifsTconInfo *
 111 tconInfoAlloc(void)
 112 {
 113         struct cifsTconInfo *ret_buf;
 114         ret_buf =
 115             (struct cifsTconInfo *) kmalloc(sizeof (struct cifsTconInfo),
 116                                             GFP_KERNEL);
 117         if (ret_buf) {
 118                 memset(ret_buf, 0, sizeof (struct cifsTconInfo));
 119                 write_lock(&GlobalSMBSeslock);
 120                 atomic_inc(&tconInfoAllocCount);
 121                 list_add(&ret_buf->cifsConnectionList,
 122                          &GlobalTreeConnectionList);
 123                 ret_buf->tidStatus = CifsNew;
 124                 INIT_LIST_HEAD(&ret_buf->openFileList);
 125                 init_MUTEX(&ret_buf->tconSem);
 126 #ifdef CONFIG_CIFS_STATS
 127                 ret_buf->stat_lock = SPIN_LOCK_UNLOCKED;
 128 #endif
 129                 write_unlock(&GlobalSMBSeslock);
 130         }
 131         return ret_buf;
 132 }
 133
 134 void
 135 tconInfoFree(struct cifsTconInfo *buf_to_free)
 136 {
 137         if (buf_to_free == NULL) {
 138                 cFYI(1, ("Null buffer passed to tconInfoFree"));
 139                 return;
 140         }
 141         write_lock(&GlobalSMBSeslock);
 142         atomic_dec(&tconInfoAllocCount);
 143         list_del(&buf_to_free->cifsConnectionList);
 144         write_unlock(&GlobalSMBSeslock);
 145         if (buf_to_free->nativeFileSystem)
 146                 kfree(buf_to_free->nativeFileSystem);
 147         kfree(buf_to_free);
 148 }
 149
 150 struct smb_hdr *
 151 cifs_buf_get(void)
 152 {
 153         struct smb_hdr *ret_buf = NULL;
 154
 155 /* We could use negotiated size instead of max_msgsize -
 156    but it may be more efficient to always alloc same size
 157    albeit slightly larger than necessary and maxbuffersize
 158    defaults to this and can not be bigger */
 159         ret_buf =
 160             (struct smb_hdr *) mempool_alloc(cifs_req_poolp, SLAB_KERNEL | SLAB_NOFS);
 161
 162         /* clear the first few header bytes */
 163         if (ret_buf) {
 164                 memset(ret_buf, 0, sizeof (struct smb_hdr));
 165                 atomic_inc(&bufAllocCount);
 166         }
 167
 168         return ret_buf;
 169 }
 170
 171 void
 172 cifs_buf_release(void *buf_to_free)
 173 {
 174
 175         if (buf_to_free == NULL) {
 176                 cFYI(1, ("Null buffer passed to cifs_buf_release"));
 177                 return;
 178         }
 179         mempool_free(buf_to_free,cifs_req_poolp);
 180
 181         atomic_dec(&bufAllocCount);
 182         return;
 183 }
 184
 185 void
 186 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
 187                 const struct cifsTconInfo *treeCon, int word_count
 188                 /* length of fixed section (word count) in two byte units  */
 189     )
 190 {
 191         int i;
 192         struct list_head* temp_item;
 193         struct cifsSesInfo * ses;
 194         char *temp = (char *) buffer;
 195
 196         for (i = 0; i < MAX_CIFS_HDR_SIZE; i++) {
 197                 temp[i] = 0;    /* BB is this needed ?? */
 198         }
 199
 200         buffer->smb_buf_length =
 201             (2 * word_count) + sizeof (struct smb_hdr) -
 202             4 /*  RFC 1001 length field does not count */  +
 203             2 /* for bcc field itself */ ;
 204         /* 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 */
 205
 206         buffer->Protocol[0] = 0xFF;
 207         buffer->Protocol[1] = 'S';
 208         buffer->Protocol[2] = 'M';
 209         buffer->Protocol[3] = 'B';
 210         buffer->Command = smb_command;
 211         buffer->Flags = 0x00;   /* case sensitive */
 212         buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
 213         buffer->Pid = cpu_to_le16((__u16)current->tgid);
 214         buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
 215         spin_lock(&GlobalMid_Lock);
 216         GlobalMid++;
 217         buffer->Mid = GlobalMid;
 218         spin_unlock(&GlobalMid_Lock);
 219         if (treeCon) {
 220                 buffer->Tid = treeCon->tid;
 221                 if (treeCon->ses) {
 222                         if (treeCon->ses->capabilities & CAP_UNICODE)
 223                                 buffer->Flags2 |= SMBFLG2_UNICODE;
 224                         if (treeCon->ses->capabilities & CAP_STATUS32) {
 225                                 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
 226                         }
 227
 228                         buffer->Uid = treeCon->ses->Suid;       /* always in LE format */
 229                         if(multiuser_mount != 0) {
 230                 /* For the multiuser case, there are few obvious technically  */
 231                 /* possible mechanisms to match the local linux user (uid)    */
 232                 /* to a valid remote smb user (smb_uid):                      */
 233                 /*      1) Query Winbind (or other local pam/nss daemon       */
 234                 /*        for userid/password/logon_domain or credential      */
 235                 /*      2) Query Winbind for uid to sid to username mapping   */
 236                 /*         and see if we have a matching password for existing*/
 237                 /*         session for that user perhas getting password by   */
 238                 /*         adding a new pam_cifs module that stores passwords */
 239                 /*         so that the cifs vfs can get at that for all logged*/
 240                 /*         on users                                           */
 241                 /*      3) (Which is the mechanism we have chosen)            */
 242                 /*         Search through sessions to the same server for a   */
 243                 /*         a match on the uid that was passed in on mount     */
 244                 /*         with the current processes uid (or euid?) and use  */
 245                 /*         that smb uid.   If no existing smb session for     */
 246                 /*         that uid found, use the default smb session ie     */
 247                 /*         the smb session for the volume mounted which is    */
 248                 /*         the same as would be used if the multiuser mount   */
 249                 /*         flag were disabled.  */
 250
 251                 /*  BB Add support for establishing new tCon and SMB Session  */
 252                 /*      with userid/password pairs found on the smb session   */
 253                 /*      for other target tcp/ip addresses               BB    */
 254                                 if(current->uid != treeCon->ses->linux_uid) {
 255                                         cFYI(1,("Multiuser mode and UID did not match tcon uid "));
 256                                         read_lock(&GlobalSMBSeslock);
 257                                         list_for_each(temp_item, &GlobalSMBSessionList) {
 258                                                 ses = list_entry(temp_item, struct cifsSesInfo, cifsSessionList);
 259                                                 if(ses->linux_uid == current->uid) {
 260                                                         if(ses->server == treeCon->ses->server) {
 261                                                                 cFYI(1,("found matching uid substitute right smb_uid"));
 262                                                                 buffer->Uid = ses->Suid;
 263                                                                 break;
 264                                                         } else {
 265                                                                 /* BB eventually call cifs_setup_session here */
 266                                                                 cFYI(1,("local UID found but smb sess with this server does not exist"));
 267                                                         }
 268                                                 }
 269                                         }
 270                                         read_unlock(&GlobalSMBSeslock);
 271                                 }
 272                         }
 273                 }
 274                 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
 275                         buffer->Flags2 |= SMBFLG2_DFS;
 276                 if((treeCon->ses) && (treeCon->ses->server))
 277                         if(treeCon->ses->server->secMode &
 278                           (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 279                                 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 280         }
 281
 282 /*  endian conversion of flags is now done just before sending */
 283         buffer->WordCount = (char) word_count;
 284         return;
 285 }
 286
 287 int
 288 checkSMBhdr(struct smb_hdr *smb, __u16 mid)
 289 {
 290         /* Make sure that this really is an SMB, that it is a response,
 291            and that the message ids match */
 292         if ((*(__le32 *) smb->Protocol == cpu_to_le32(0x424d53ff)) &&
 293                 (mid == smb->Mid)) {
 294                 if(smb->Flags & SMBFLG_RESPONSE)
 295                         return 0;
 296                 else {
 297                 /* only one valid case where server sends us request */
 298                         if(smb->Command == SMB_COM_LOCKING_ANDX)
 299                                 return 0;
 300                         else
 301                                 cERROR(1, ("Rcvd Request not response "));
 302                 }
 303         } else { /* bad signature or mid */
 304                 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff))
 305                         cERROR(1,
 306                                ("Bad protocol string signature header %x ",
 307                                 *(unsigned int *) smb->Protocol));
 308                 if (mid != smb->Mid)
 309                         cERROR(1, ("Mids do not match"));
 310         }
 311         cERROR(1, ("bad smb detected. The Mid=%d", smb->Mid));
 312         return 1;
 313 }
 314
 315 int
 316 checkSMB(struct smb_hdr *smb, __u16 mid, int length)
 317 {
 318         __u32 len = be32_to_cpu(smb->smb_buf_length);
 319         cFYI(0,
 320              ("Entering checkSMB with Length: %x, smb_buf_length: %x ",
 321               length, len));
 322         if (((unsigned int)length < 2 + sizeof (struct smb_hdr)) ||
 323             (len > CIFS_MAX_MSGSIZE + MAX_CIFS_HDR_SIZE - 4)) {
 324                 if ((unsigned int)length < 2 + sizeof (struct smb_hdr)) {
 325                         cERROR(1, ("Length less than 2 + sizeof smb_hdr "));
 326                         if (((unsigned int)length >= sizeof (struct smb_hdr) - 1)
 327                             && (smb->Status.CifsError != 0))
 328                                 return 0;       /* some error cases do not return wct and bcc */
 329
 330                 }
 331                 if (len > CIFS_MAX_MSGSIZE + MAX_CIFS_HDR_SIZE - 4)
 332                         cERROR(1,
 333                                ("smb_buf_length greater than CIFS_MAX_MSGSIZE ... "));
 334                 cERROR(1,
 335                        ("bad smb detected. Illegal length. The mid=%d",
 336                         smb->Mid));
 337                 return 1;
 338         }
 339
 340         if (checkSMBhdr(smb, mid))
 341                 return 1;
 342
 343         if ((4 + len != smbCalcSize(smb))
 344             || (4 + len != (unsigned int)length)) {
 345                 return 0;
 346         } else {
 347                 cERROR(1, ("smbCalcSize %x ", smbCalcSize(smb)));
 348                 cERROR(1,
 349                        ("bad smb size detected. The Mid=%d", smb->Mid));
 350                 return 1;
 351         }
 352 }
 353 int
 354 is_valid_oplock_break(struct smb_hdr *buf)
 355 {
 356         struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)buf;
 357         struct list_head *tmp;
 358         struct list_head *tmp1;
 359         struct cifsTconInfo *tcon;
 360         struct cifsFileInfo *netfile;
 361
 362         /* could add check for smb response flag 0x80 */
 363         cFYI(1,("Checking for oplock break"));
 364         if(pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
 365                 return FALSE;
 366         if(pSMB->hdr.Flags & SMBFLG_RESPONSE) {
 367                 /* no sense logging error on invalid handle on oplock
 368                    break - harmless race between close request and oplock
 369                    break response is expected from time to time writing out
 370                    large dirty files cached on the client */
 371                 if ((NT_STATUS_INVALID_HANDLE) ==
 372                    le32_to_cpu(pSMB->hdr.Status.CifsError)) {
 373                         cFYI(1,("invalid handle on oplock break"));
 374                         return TRUE;
 375                 } else if (ERRbadfid ==
 376                    le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
 377                         return TRUE;
 378                 } else {
 379                         return FALSE; /* on valid oplock brk we get "request" */
 380                 }
 381         }
 382         if(pSMB->hdr.WordCount != 8)
 383                 return FALSE;
 384
 385         cFYI(1,(" oplock type 0x%d level 0x%d",pSMB->LockType,pSMB->OplockLevel));
 386         if(!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
 387                 return FALSE;
 388
 389         /* look up tcon based on tid & uid */
 390         read_lock(&GlobalSMBSeslock);
 391         list_for_each(tmp, &GlobalTreeConnectionList) {
 392                 tcon = list_entry(tmp, struct cifsTconInfo, cifsConnectionList);
 393                 if (tcon->tid == buf->Tid) {
 394 #ifdef CONFIG_CIFS_STATS
 395                         atomic_inc(&tcon->num_oplock_brks);
 396 #endif
 397                         list_for_each(tmp1,&tcon->openFileList){
 398                                 netfile = list_entry(tmp1,struct cifsFileInfo,tlist);
 399                                 if(pSMB->Fid == netfile->netfid) {
 400                                         struct cifsInodeInfo *pCifsInode;
 401                                         read_unlock(&GlobalSMBSeslock);
 402                                         cFYI(1,("Matching file id, processing oplock break"));
 403                                         pCifsInode =
 404                                                 CIFS_I(netfile->pInode);
 405                                         pCifsInode->clientCanCacheAll = FALSE;
 406                                         if(pSMB->OplockLevel == 0)
 407                                                 pCifsInode->clientCanCacheRead = FALSE;
 408                                         pCifsInode->oplockPending = TRUE;
 409                                         AllocOplockQEntry(netfile->pInode, netfile->netfid, tcon);
 410                                         cFYI(1,("about to wake up oplock thd"));
 411                                         wake_up_process(oplockThread);
 412                                         return TRUE;
 413                                 }
 414                         }
 415                         read_unlock(&GlobalSMBSeslock);
 416                         cFYI(1,("No matching file for oplock break on connection"));
 417                         return TRUE;
 418                 }
 419         }
 420         read_unlock(&GlobalSMBSeslock);
 421         cFYI(1,("Can not process oplock break for non-existent connection"));
 422         return TRUE;
 423 }
 424
 425 void
 426 dump_smb(struct smb_hdr *smb_buf, int smb_buf_length)
 427 {
 428         int i, j;
 429         char debug_line[17];
 430         unsigned char *buffer;
 431
 432         if (traceSMB == 0)
 433                 return;
 434
 435         buffer = (unsigned char *) smb_buf;
 436         for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
 437                 if (i % 8 == 0) {       /* we have reached the beginning of line  */
 438                         printk(KERN_DEBUG "| ");
 439                         j = 0;
 440                 }
 441                 printk("%0#4x ", buffer[i]);
 442                 debug_line[2 * j] = ' ';
 443                 if (isprint(buffer[i]))
 444                         debug_line[1 + (2 * j)] = buffer[i];
 445                 else
 446                         debug_line[1 + (2 * j)] = '_';
 447
 448                 if (i % 8 == 7) {       /* we have reached end of line, time to print ascii */
 449                         debug_line[16] = 0;
 450                         printk(" | %s\n", debug_line);
 451                 }
 452         }
 453         for (; j < 8; j++) {
 454                 printk("     ");
 455                 debug_line[2 * j] = ' ';
 456                 debug_line[1 + (2 * j)] = ' ';
 457         }
 458         printk( " | %s\n", debug_line);
 459         return;
 460 }