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 "cifspdu.h"
  25 #include "cifsglob.h"
  26 #include "cifsproto.h"
  27 #include "cifs_debug.h"
  28 #include "smberr.h"
  29 #include "nterr.h"
  30
  31 extern kmem_cache_t *cifs_req_cachep;
  32 extern struct task_struct * oplockThread;
  33
  34 __u16 GlobalMid;                /* multiplex id - rotating counter */
  35
  36 /* The xid serves as a useful identifier for each incoming vfs request,
  37    in a similar way to the mid which is useful to track each sent smb,
  38    and CurrentXid can also provide a running counter (although it
  39    will eventually wrap past zero) of the total vfs operations handled
  40    since the cifs fs was mounted */
  41
  42 unsigned int
  43 _GetXid(void)
  44 {
  45         unsigned int xid;
  46
  47         spin_lock(&GlobalMid_Lock);
  48         GlobalTotalActiveXid++;
  49         if (GlobalTotalActiveXid > GlobalMaxActiveXid)
  50                 GlobalMaxActiveXid = GlobalTotalActiveXid;      /* keep high water mark for number of simultaneous vfs ops in our filesystem */
  51         xid = GlobalCurrentXid++;
  52         spin_unlock(&GlobalMid_Lock);
  53         return xid;
  54 }
  55
  56 void
  57 _FreeXid(unsigned int xid)
  58 {
  59         spin_lock(&GlobalMid_Lock);
  60         /* if(GlobalTotalActiveXid == 0)
  61                 BUG(); */
  62         GlobalTotalActiveXid--;
  63         spin_unlock(&GlobalMid_Lock);
  64 }
  65
  66 struct cifsSesInfo *
  67 sesInfoAlloc(void)
  68 {
  69         struct cifsSesInfo *ret_buf;
  70
  71         ret_buf =
  72             (struct cifsSesInfo *) kmalloc(sizeof (struct cifsSesInfo),
  73                                            GFP_KERNEL);
  74         if (ret_buf) {
  75                 memset(ret_buf, 0, sizeof (struct cifsSesInfo));
  76                 write_lock(&GlobalSMBSeslock);
  77                 atomic_inc(&sesInfoAllocCount);
  78                 ret_buf->status = CifsNew;
  79                 list_add(&ret_buf->cifsSessionList, &GlobalSMBSessionList);
  80                 init_MUTEX(&ret_buf->sesSem);
  81                 write_unlock(&GlobalSMBSeslock);
  82         }
  83         return ret_buf;
  84 }
  85
  86 void
  87 sesInfoFree(struct cifsSesInfo *buf_to_free)
  88 {
  89         if (buf_to_free == NULL) {
  90                 cFYI(1, ("Null buffer passed to sesInfoFree"));
  91                 return;
  92         }
  93
  94         write_lock(&GlobalSMBSeslock);
  95         atomic_dec(&sesInfoAllocCount);
  96         list_del(&buf_to_free->cifsSessionList);
  97         write_unlock(&GlobalSMBSeslock);
  98         if (buf_to_free->serverOS)
  99                 kfree(buf_to_free->serverOS);
 100         if (buf_to_free->serverDomain)
 101                 kfree(buf_to_free->serverDomain);
 102         if (buf_to_free->serverNOS)
 103                 kfree(buf_to_free->serverNOS);
 104         if (buf_to_free->password)
 105                 kfree(buf_to_free->password);
 106         kfree(buf_to_free);
 107 }
 108
 109 struct cifsTconInfo *
 110 tconInfoAlloc(void)
 111 {
 112         struct cifsTconInfo *ret_buf;
 113         ret_buf =
 114             (struct cifsTconInfo *) kmalloc(sizeof (struct cifsTconInfo),
 115                                             GFP_KERNEL);
 116         if (ret_buf) {
 117                 memset(ret_buf, 0, sizeof (struct cifsTconInfo));
 118                 write_lock(&GlobalSMBSeslock);
 119                 atomic_inc(&tconInfoAllocCount);
 120                 list_add(&ret_buf->cifsConnectionList,
 121                          &GlobalTreeConnectionList);
 122                 ret_buf->tidStatus = CifsNew;
 123                 INIT_LIST_HEAD(&ret_buf->openFileList);
 124                 init_MUTEX(&ret_buf->tconSem);
 125                 write_unlock(&GlobalSMBSeslock);
 126         }
 127         return ret_buf;
 128 }
 129
 130 void
 131 tconInfoFree(struct cifsTconInfo *buf_to_free)
 132 {
 133         if (buf_to_free == NULL) {
 134                 cFYI(1, ("Null buffer passed to tconInfoFree"));
 135                 return;
 136         }
 137         write_lock(&GlobalSMBSeslock);
 138         atomic_dec(&tconInfoAllocCount);
 139         list_del(&buf_to_free->cifsConnectionList);
 140         write_unlock(&GlobalSMBSeslock);
 141         if (buf_to_free->nativeFileSystem)
 142                 kfree(buf_to_free->nativeFileSystem);
 143         kfree(buf_to_free);
 144 }
 145
 146 struct smb_hdr *
 147 cifs_buf_get(void)
 148 {
 149         struct smb_hdr *ret_buf = 0;
 150
 151 /* We could use negotiated size instead of max_msgsize -
 152    but it may be more efficient to always alloc same size
 153    albeit slightly larger than necessary and maxbuffersize
 154    defaults to this and can not be bigger */
 155         ret_buf =
 156             (struct smb_hdr *) kmem_cache_alloc(cifs_req_cachep, SLAB_KERNEL | SLAB_NOFS);
 157
 158         /* clear the first few header bytes */
 159         if (ret_buf) {
 160                 memset(ret_buf, 0, sizeof (struct smb_hdr));
 161                 atomic_inc(&bufAllocCount);
 162         }
 163
 164         return ret_buf;
 165 }
 166
 167 void
 168 cifs_buf_release(void *buf_to_free)
 169 {
 170
 171         if (buf_to_free == NULL) {
 172                 cFYI(1, ("Null buffer passed to cifs_buf_release"));
 173                 return;
 174         }
 175         kmem_cache_free(cifs_req_cachep, buf_to_free);
 176
 177         atomic_dec(&bufAllocCount);
 178         return;
 179 }
 180
 181 void
 182 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
 183                 const struct cifsTconInfo *treeCon, int word_count
 184                 /* length of fixed section (word count) in two byte units  */
 185     )
 186 {
 187         int i;
 188         __u32 tmp;
 189         struct list_head* temp_item;
 190         struct cifsSesInfo * ses;
 191         char *temp = (char *) buffer;
 192
 193         for (i = 0; i < MAX_CIFS_HDR_SIZE; i++) {
 194                 temp[i] = 0;    /* BB is this needed ?? */
 195         }
 196
 197         buffer->smb_buf_length =
 198             (2 * word_count) + sizeof (struct smb_hdr) -
 199             4 /*  RFC 1001 length field does not count */  +
 200             2 /* for bcc field itself */ ;
 201         /* 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 */
 202
 203         buffer->Protocol[0] = 0xFF;
 204         buffer->Protocol[1] = 'S';
 205         buffer->Protocol[2] = 'M';
 206         buffer->Protocol[3] = 'B';
 207         buffer->Command = smb_command;
 208         buffer->Flags = 0x00;   /* case sensitive */
 209         buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
 210         tmp = cpu_to_le32(current->tgid);
 211         buffer->Pid = tmp & 0xFFFF;
 212         tmp >>= 16;
 213         buffer->PidHigh = tmp & 0xFFFF;
 214         spin_lock(&GlobalMid_Lock);
 215         GlobalMid++;
 216         buffer->Mid = GlobalMid;
 217         spin_unlock(&GlobalMid_Lock);
 218         if (treeCon) {
 219                 buffer->Tid = treeCon->tid;
 220                 if (treeCon->ses) {
 221                         if (treeCon->ses->capabilities & CAP_UNICODE)
 222                                 buffer->Flags2 |= SMBFLG2_UNICODE;
 223                         if (treeCon->ses->capabilities & CAP_STATUS32) {
 224                                 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
 225                         }
 226
 227                         buffer->Uid = treeCon->ses->Suid;       /* always in LE format */
 228                         if(multiuser_mount != 0) {
 229                 /* For the multiuser case, there are few obvious technically  */
 230                 /* possible mechanisms to match the local linux user (uid)    */
 231                 /* to a valid remote smb user (smb_uid):                      */
 232                 /*      1) Query Winbind (or other local pam/nss daemon       */
 233                 /*        for userid/password/logon_domain or credential      */
 234                 /*      2) Query Winbind for uid to sid to username mapping   */
 235                 /*         and see if we have a matching password for existing*/
 236                 /*         session for that user perhas getting password by   */
 237                 /*         adding a new pam_cifs module that stores passwords */
 238                 /*         so that the cifs vfs can get at that for all logged*/
 239                 /*         on users                                           */
 240                 /*      3) (Which is the mechanism we have chosen)            */
 241                 /*         Search through sessions to the same server for a   */
 242                 /*         a match on the uid that was passed in on mount     */
 243                 /*         with the current processes uid (or euid?) and use  */
 244                 /*         that smb uid.   If no existing smb session for     */
 245                 /*         that uid found, use the default smb session ie     */
 246                 /*         the smb session for the volume mounted which is    */
 247                 /*         the same as would be used if the multiuser mount   */
 248                 /*         flag were disabled.  */
 249
 250                 /*  BB Add support for establishing new tCon and SMB Session  */
 251                 /*      with userid/password pairs found on the smb session   */
 252                 /*      for other target tcp/ip addresses               BB    */
 253                                 if(current->uid != treeCon->ses->linux_uid) {
 254                                         cFYI(1,("Multiuser mode and UID did not match tcon uid "));
 255                                         read_lock(&GlobalSMBSeslock);
 256                                         list_for_each(temp_item, &GlobalSMBSessionList) {
 257                                                 ses = list_entry(temp_item, struct cifsSesInfo, cifsSessionList);
 258                                                 if(ses->linux_uid == current->uid) {
 259                                                         if(ses->server == treeCon->ses->server) {
 260                                                                 cFYI(1,("found matching uid substitute right smb_uid"));
 261                                                                 buffer->Uid = ses->Suid;
 262                                                                 break;
 263                                                         } else {
 264                                                                 /* BB eventually call cifs_setup_session here */
 265                                                                 cFYI(1,("local UID found but smb sess with this server does not exist"));
 266                                                         }
 267                                                 }
 268                                         }
 269                                         read_unlock(&GlobalSMBSeslock);
 270                                 }
 271                         }
 272                 }
 273                 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
 274                         buffer->Flags2 |= SMBFLG2_DFS;
 275                 if(treeCon->ses->server)
 276                         if(treeCon->ses->server->secMode &
 277                           (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 278                                 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 279         }
 280
 281 /*  endian conversion of flags is now done just before sending */
 282         buffer->WordCount = (char) word_count;
 283         return;
 284 }
 285
 286 int
 287 checkSMBhdr(struct smb_hdr *smb, __u16 mid)
 288 {
 289         /* Make sure that this really is an SMB, that it is a response,
 290            and that the message ids match */
 291         if ((*(unsigned int *) smb->Protocol == cpu_to_le32(0x424d53ff)) &&
 292                 (mid == smb->Mid)) {
 293                 if(smb->Flags & SMBFLG_RESPONSE)
 294                         return 0;
 295                 else {
 296                 /* only one valid case where server sends us request */
 297                         if(smb->Command == SMB_COM_LOCKING_ANDX)
 298                                 return 0;
 299                         else
 300                                 cERROR(1, ("Rcvd Request not response "));
 301                 }
 302         } else { /* bad signature or mid */
 303                 if (*(unsigned int *) smb->Protocol != cpu_to_le32(0x424d53ff))
 304                         cERROR(1,
 305                                ("Bad protocol string signature header %x ",
 306                                 *(unsigned int *) smb->Protocol));
 307                 if (mid != smb->Mid)
 308                         cERROR(1, ("Mids do not match"));
 309         }
 310         cERROR(1, ("bad smb detected. The Mid=%d", smb->Mid));
 311         return 1;
 312 }
 313
 314 int
 315 checkSMB(struct smb_hdr *smb, __u16 mid, int length)
 316 {
 317         cFYI(0,
 318              ("Entering checkSMB with Length: %x, smb_buf_length: %x ",
 319               length, ntohl(smb->smb_buf_length)));
 320         if (((unsigned int)length < 2 + sizeof (struct smb_hdr))
 321             || (ntohl(smb->smb_buf_length) >
 322                 CIFS_MAX_MSGSIZE + MAX_CIFS_HDR_SIZE - 4)) {
 323                 if ((unsigned int)length < 2 + sizeof (struct smb_hdr)) {
 324                         cERROR(1, ("Length less than 2 + sizeof smb_hdr "));
 325                         if (((unsigned int)length >= sizeof (struct smb_hdr) - 1)
 326                             && (smb->Status.CifsError != 0))
 327                                 return 0;       /* some error cases do not return wct and bcc */
 328
 329                 }
 330                 if (ntohl(smb->smb_buf_length) >
 331                     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 + ntohl(smb->smb_buf_length) != smbCalcSize(smb))
 344             || (4 + ntohl(smb->smb_buf_length) != (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                         list_for_each(tmp1,&tcon->openFileList){
 395                                 netfile = list_entry(tmp1,struct cifsFileInfo,tlist);
 396                                 if(pSMB->Fid == netfile->netfid) {
 397                                         struct cifsInodeInfo *pCifsInode;
 398                                         read_unlock(&GlobalSMBSeslock);
 399                                         cFYI(1,("Matching file id, processing oplock break"));
 400                                         pCifsInode =
 401                                                 CIFS_I(netfile->pInode);
 402                                         pCifsInode->clientCanCacheAll = FALSE;
 403                                         if(pSMB->OplockLevel == 0)
 404                                                 pCifsInode->clientCanCacheRead = FALSE;
 405                                         pCifsInode->oplockPending = TRUE;
 406                                         AllocOplockQEntry(netfile->pInode, netfile->netfid, tcon);
 407                                         cFYI(1,("about to wake up oplock thd"));
 408                                         wake_up_process(oplockThread);
 409                                         return TRUE;
 410                                 }
 411                         }
 412                         read_unlock(&GlobalSMBSeslock);
 413                         cFYI(1,("No matching file for oplock break on connection"));
 414                         return TRUE;
 415                 }
 416         }
 417         read_unlock(&GlobalSMBSeslock);
 418         cFYI(1,("Can not process oplock break for non-existent connection"));
 419         return TRUE;
 420 }
 421
 422 void
 423 dump_smb(struct smb_hdr *smb_buf, int smb_buf_length)
 424 {
 425         int i, j;
 426         char debug_line[17];
 427         unsigned char *buffer;
 428
 429         if (traceSMB == 0)
 430                 return;
 431
 432         buffer = (unsigned char *) smb_buf;
 433         for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
 434                 if (i % 8 == 0) {       /* we have reached the beginning of line  */
 435                         printk(KERN_DEBUG "| ");
 436                         j = 0;
 437                 }
 438                 printk("%0#4x ", buffer[i]);
 439                 debug_line[2 * j] = ' ';
 440                 if (isprint(buffer[i]))
 441                         debug_line[1 + (2 * j)] = buffer[i];
 442                 else
 443                         debug_line[1 + (2 * j)] = '_';
 444
 445                 if (i % 8 == 7) {       /* we have reached end of line, time to print ascii */
 446                         debug_line[16] = 0;
 447                         printk(" | %s\n", debug_line);
 448                 }
 449         }
 450         for (; j < 8; j++) {
 451                 printk("     ");
 452                 debug_line[2 * j] = ' ';
 453                 debug_line[1 + (2 * j)] = ' ';
 454         }
 455         printk( " | %s\n", debug_line);
 456         return;
 457 }