fs/cifs/cifsglob.h

   1 /*
   2  *   fs/cifs/cifsglob.h
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2006
   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  */
  18 #include <linux/in.h>
  19 #include <linux/in6.h>
  20 #include "cifs_fs_sb.h"
  21 /*
  22  * The sizes of various internal tables and strings
  23  */
  24 #define MAX_UID_INFO 16
  25 #define MAX_SES_INFO 2
  26 #define MAX_TCON_INFO 4
  27
  28 #define MAX_TREE_SIZE 2 + MAX_SERVER_SIZE + 1 + MAX_SHARE_SIZE + 1
  29 #define MAX_SERVER_SIZE 15
  30 #define MAX_SHARE_SIZE  64      /* used to be 20 - this should still be enough */
  31 #define MAX_USERNAME_SIZE 32    /* 32 is to allow for 15 char names + null
  32                                    termination then *2 for unicode versions */
  33 #define MAX_PASSWORD_SIZE 16
  34
  35 #define CIFS_MIN_RCV_POOL 4
  36
  37 /*
  38  * MAX_REQ is the maximum number of requests that WE will send
  39  * on one socket concurently. It also matches the most common
  40  * value of max multiplex returned by servers.  We may
  41  * eventually want to use the negotiated value (in case
  42  * future servers can handle more) when we are more confident that
  43  * we will not have problems oveloading the socket with pending
  44  * write data.
  45  */
  46 #define CIFS_MAX_REQ 50
  47
  48 #define SERVER_NAME_LENGTH 15
  49 #define SERVER_NAME_LEN_WITH_NULL     (SERVER_NAME_LENGTH + 1)
  50
  51 /* used to define string lengths for reversing unicode strings */
  52 /*         (256+1)*2 = 514                                     */
  53 /*           (max path length + 1 for null) * 2 for unicode    */
  54 #define MAX_NAME 514
  55
  56 #include "cifspdu.h"
  57
  58 #ifndef FALSE
  59 #define FALSE 0
  60 #endif
  61
  62 #ifndef TRUE
  63 #define TRUE 1
  64 #endif
  65
  66 #ifndef XATTR_DOS_ATTRIB
  67 #define XATTR_DOS_ATTRIB "user.DOSATTRIB"
  68 #endif
  69
  70 /*
  71  * This information is kept on every Server we know about.
  72  *
  73  * Some things to note:
  74  *
  75  */
  76 #define SERVER_NAME_LEN_WITH_NULL       (SERVER_NAME_LENGTH + 1)
  77
  78 /*
  79  * CIFS vfs client Status information (based on what we know.)
  80  */
  81
  82  /* associated with each tcp and smb session */
  83 enum statusEnum {
  84         CifsNew = 0,
  85         CifsGood,
  86         CifsExiting,
  87         CifsNeedReconnect
  88 };
  89
  90 enum securityEnum {
  91         LANMAN = 0,             /* Legacy LANMAN auth */
  92         NTLM,                   /* Legacy NTLM012 auth with NTLM hash */
  93         NTLMv2,                 /* Legacy NTLM auth with NTLMv2 hash */
  94         RawNTLMSSP,             /* NTLMSSP without SPNEGO */
  95         NTLMSSP,                /* NTLMSSP via SPNEGO */
  96         Kerberos                /* Kerberos via SPNEGO */
  97 };
  98
  99 enum protocolEnum {
 100         IPV4 = 0,
 101         IPV6,
 102         SCTP
 103         /* Netbios frames protocol not supported at this time */
 104 };
 105
 106 /*
 107  *****************************************************************
 108  * Except the CIFS PDUs themselves all the
 109  * globally interesting structs should go here
 110  *****************************************************************
 111  */
 112
 113 struct TCP_Server_Info {
 114         /* 15 character server name + 0x20 16th byte indicating type = srv */
 115         char server_RFC1001_name[SERVER_NAME_LEN_WITH_NULL];
 116         char unicode_server_Name[SERVER_NAME_LEN_WITH_NULL * 2];
 117         struct socket *ssocket;
 118         union {
 119                 struct sockaddr_in sockAddr;
 120                 struct sockaddr_in6 sockAddr6;
 121         } addr;
 122         wait_queue_head_t response_q;
 123         wait_queue_head_t request_q; /* if more than maxmpx to srvr must block*/
 124         struct list_head pending_mid_q;
 125         void *Server_NlsInfo;   /* BB - placeholder for future NLS info  */
 126         unsigned short server_codepage; /* codepage for the server    */
 127         unsigned long ip_address;       /* IP addr for the server if known */
 128         enum protocolEnum protocolType;
 129         char versionMajor;
 130         char versionMinor;
 131         unsigned svlocal:1;     /* local server or remote */
 132         atomic_t socketUseCount; /* number of open cifs sessions on socket */
 133         atomic_t inFlight;  /* number of requests on the wire to server */
 134 #ifdef CONFIG_CIFS_STATS2
 135         atomic_t inSend; /* requests trying to send */
 136         atomic_t num_waiters;   /* blocked waiting to get in sendrecv */
 137 #endif
 138         enum statusEnum tcpStatus; /* what we think the status is */
 139         struct semaphore tcpSem;
 140         struct task_struct *tsk;
 141         char server_GUID[16];
 142         char secMode;
 143         enum securityEnum secType;
 144         unsigned int maxReq;    /* Clients should submit no more */
 145         /* than maxReq distinct unanswered SMBs to the server when using  */
 146         /* multiplexed reads or writes */
 147         unsigned int maxBuf;    /* maxBuf specifies the maximum */
 148         /* message size the server can send or receive for non-raw SMBs */
 149         unsigned int maxRw;     /* maxRw specifies the maximum */
 150         /* message size the server can send or receive for */
 151         /* SMB_COM_WRITE_RAW or SMB_COM_READ_RAW. */
 152         char sessid[4];         /* unique token id for this session */
 153         /* (returned on Negotiate */
 154         int capabilities; /* allow selective disabling of caps by smb sess */
 155         __u16 timeZone;
 156         __u16 CurrentMid;         /* multiplex id - rotating counter */
 157         char cryptKey[CIFS_CRYPTO_KEY_SIZE];
 158         /* 16th byte of RFC1001 workstation name is always null */
 159         char workstation_RFC1001_name[SERVER_NAME_LEN_WITH_NULL];
 160         __u32 sequence_number; /* needed for CIFS PDU signature */
 161         char mac_signing_key[CIFS_SESS_KEY_SIZE + 16];
 162 };
 163
 164 /*
 165  * The following is our shortcut to user information.  We surface the uid,
 166  * and name. We always get the password on the fly in case it
 167  * has changed. We also hang a list of sessions owned by this user off here.
 168  */
 169 struct cifsUidInfo {
 170         struct list_head userList;
 171         struct list_head sessionList; /* SMB sessions for this user */
 172         uid_t linux_uid;
 173         char user[MAX_USERNAME_SIZE + 1];       /* ascii name of user */
 174         /* BB may need ptr or callback for PAM or WinBind info */
 175 };
 176
 177 /*
 178  * Session structure.  One of these for each uid session with a particular host
 179  */
 180 struct cifsSesInfo {
 181         struct list_head cifsSessionList;
 182         struct semaphore sesSem;
 183 #if 0
 184         struct cifsUidInfo *uidInfo;    /* pointer to user info */
 185 #endif
 186         struct TCP_Server_Info *server; /* pointer to server info */
 187         atomic_t inUse; /* # of mounts (tree connections) on this ses */
 188         enum statusEnum status;
 189         unsigned overrideSecFlg;  /* if non-zero override global sec flags */
 190         __u16 ipc_tid;          /* special tid for connection to IPC share */
 191         __u16 flags;
 192         char *serverOS;         /* name of operating system underlying server */
 193         char *serverNOS;        /* name of network operating system of server */
 194         char *serverDomain;     /* security realm of server */
 195         int Suid;               /* remote smb uid  */
 196         uid_t linux_uid;        /* local Linux uid */
 197         int capabilities;
 198         char serverName[SERVER_NAME_LEN_WITH_NULL * 2]; /* BB make bigger for
 199                                 TCP names - will ipv6 and sctp addresses fit? */
 200         char userName[MAX_USERNAME_SIZE + 1];
 201         char * domainName;
 202         char * password;
 203 };
 204 /* session flags */
 205 #define CIFS_SES_NT4 1
 206
 207 /*
 208  * there is one of these for each connection to a resource on a particular
 209  * session
 210  */
 211 struct cifsTconInfo {
 212         struct list_head cifsConnectionList;
 213         struct list_head openFileList;
 214         struct semaphore tconSem;
 215         struct cifsSesInfo *ses;        /* pointer to session associated with */
 216         char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource in ASCII */
 217         char *nativeFileSystem;
 218         __u16 tid;              /* The 2 byte tree id */
 219         __u16 Flags;            /* optional support bits */
 220         enum statusEnum tidStatus;
 221         atomic_t useCount;      /* how many explicit/implicit mounts to share */
 222 #ifdef CONFIG_CIFS_STATS
 223         atomic_t num_smbs_sent;
 224         atomic_t num_writes;
 225         atomic_t num_reads;
 226         atomic_t num_oplock_brks;
 227         atomic_t num_opens;
 228         atomic_t num_closes;
 229         atomic_t num_deletes;
 230         atomic_t num_mkdirs;
 231         atomic_t num_rmdirs;
 232         atomic_t num_renames;
 233         atomic_t num_t2renames;
 234         atomic_t num_ffirst;
 235         atomic_t num_fnext;
 236         atomic_t num_fclose;
 237         atomic_t num_hardlinks;
 238         atomic_t num_symlinks;
 239         atomic_t num_locks;
 240         atomic_t num_acl_get;
 241         atomic_t num_acl_set;
 242 #ifdef CONFIG_CIFS_STATS2
 243         unsigned long long time_writes;
 244         unsigned long long time_reads;
 245         unsigned long long time_opens;
 246         unsigned long long time_deletes;
 247         unsigned long long time_closes;
 248         unsigned long long time_mkdirs;
 249         unsigned long long time_rmdirs;
 250         unsigned long long time_renames;
 251         unsigned long long time_t2renames;
 252         unsigned long long time_ffirst;
 253         unsigned long long time_fnext;
 254         unsigned long long time_fclose;
 255 #endif /* CONFIG_CIFS_STATS2 */
 256         __u64    bytes_read;
 257         __u64    bytes_written;
 258         spinlock_t stat_lock;
 259 #endif /* CONFIG_CIFS_STATS */
 260         FILE_SYSTEM_DEVICE_INFO fsDevInfo;
 261         FILE_SYSTEM_ATTRIBUTE_INFO fsAttrInfo; /* ok if fs name truncated */
 262         FILE_SYSTEM_UNIX_INFO fsUnixInfo;
 263         unsigned retry:1;
 264         unsigned nocase:1;
 265         /* BB add field for back pointer to sb struct? */
 266 };
 267
 268 /*
 269  * This info hangs off the cifsFileInfo structure.  This is used to track
 270  * byte stream locks on the file
 271  */
 272 struct cifsLockInfo {
 273         struct cifsLockInfo *next;
 274         int start;
 275         int length;
 276         int type;
 277 };
 278
 279 /*
 280  * One of these for each open instance of a file
 281  */
 282 struct cifs_search_info {
 283         loff_t index_of_last_entry;
 284         __u16 entries_in_buffer;
 285         __u16 info_level;
 286         __u32 resume_key;
 287         char * ntwrk_buf_start;
 288         char * srch_entries_start;
 289         char * presume_name;
 290         unsigned int resume_name_len;
 291         unsigned endOfSearch:1;
 292         unsigned emptyDir:1;
 293         unsigned unicode:1;
 294         unsigned smallBuf:1; /* so we know which buf_release function to call */
 295 };
 296
 297 struct cifsFileInfo {
 298         struct list_head tlist; /* pointer to next fid owned by tcon */
 299         struct list_head flist; /* next fid (file instance) for this inode */
 300         unsigned int uid;       /* allows finding which FileInfo structure */
 301         __u32 pid;              /* process id who opened file */
 302         __u16 netfid;           /* file id from remote */
 303         /* BB add lock scope info here if needed */ ;
 304         /* lock scope id (0 if none) */
 305         struct file * pfile; /* needed for writepage */
 306         struct inode * pInode; /* needed for oplock break */
 307         unsigned closePend:1;   /* file is marked to close */
 308         unsigned invalidHandle:1;  /* file closed via session abend */
 309         atomic_t wrtPending;   /* handle in use - defer close */
 310         struct semaphore fh_sem; /* prevents reopen race after dead ses*/
 311         char * search_resume_name; /* BB removeme BB */
 312         struct cifs_search_info srch_inf;
 313 };
 314
 315 /*
 316  * One of these for each file inode
 317  */
 318
 319 struct cifsInodeInfo {
 320         struct list_head lockList;
 321         /* BB add in lists for dirty pages - i.e. write caching info for oplock */
 322         struct list_head openFileList;
 323         int write_behind_rc;
 324         __u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */
 325         atomic_t inUse;  /* num concurrent users (local openers cifs) of file*/
 326         unsigned long time;     /* jiffies of last update/check of inode */
 327         unsigned clientCanCacheRead:1; /* read oplock */
 328         unsigned clientCanCacheAll:1;  /* read and writebehind oplock */
 329         unsigned oplockPending:1;
 330         struct inode vfs_inode;
 331 };
 332
 333 static inline struct cifsInodeInfo *
 334 CIFS_I(struct inode *inode)
 335 {
 336         return container_of(inode, struct cifsInodeInfo, vfs_inode);
 337 }
 338
 339 static inline struct cifs_sb_info *
 340 CIFS_SB(struct super_block *sb)
 341 {
 342         return sb->s_fs_info;
 343 }
 344
 345 static inline char CIFS_DIR_SEP(const struct cifs_sb_info *cifs_sb)
 346 {
 347         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS)
 348                 return '/';
 349         else
 350                 return '\\';
 351 }
 352
 353 #ifdef CONFIG_CIFS_STATS
 354 #define cifs_stats_inc atomic_inc
 355
 356 static inline void cifs_stats_bytes_written(struct cifsTconInfo *tcon,
 357                                             unsigned int bytes)
 358 {
 359         if (bytes) {
 360                 spin_lock(&tcon->stat_lock);
 361                 tcon->bytes_written += bytes;
 362                 spin_unlock(&tcon->stat_lock);
 363         }
 364 }
 365
 366 static inline void cifs_stats_bytes_read(struct cifsTconInfo *tcon,
 367                                          unsigned int bytes)
 368 {
 369         spin_lock(&tcon->stat_lock);
 370         tcon->bytes_read += bytes;
 371         spin_unlock(&tcon->stat_lock);
 372 }
 373 #else
 374
 375 #define  cifs_stats_inc(field) do {} while(0)
 376 #define  cifs_stats_bytes_written(tcon, bytes) do {} while(0)
 377 #define  cifs_stats_bytes_read(tcon, bytes) do {} while(0)
 378
 379 #endif
 380
 381 /* one of these for every pending CIFS request to the server */
 382 struct mid_q_entry {
 383         struct list_head qhead; /* mids waiting on reply from this server */
 384         __u16 mid;              /* multiplex id */
 385         __u16 pid;              /* process id */
 386         __u32 sequence_number;  /* for CIFS signing */
 387         unsigned long when_alloc;  /* when mid was created */
 388 #ifdef CONFIG_CIFS_STATS2
 389         unsigned long when_sent; /* time when smb send finished */
 390         unsigned long when_received; /* when demux complete (taken off wire) */
 391 #endif
 392         struct cifsSesInfo *ses;        /* smb was sent to this server */
 393         struct task_struct *tsk;        /* task waiting for response */
 394         struct smb_hdr *resp_buf;       /* response buffer */
 395         int midState;   /* wish this were enum but can not pass to wait_event */
 396         __u8 command;   /* smb command code */
 397         unsigned largeBuf:1;    /* if valid response, is pointer to large buf */
 398         unsigned multiRsp:1;   /* multiple trans2 responses for one request  */
 399         unsigned multiEnd:1; /* both received */
 400 };
 401
 402 struct oplock_q_entry {
 403         struct list_head qhead;
 404         struct inode * pinode;
 405         struct cifsTconInfo * tcon;
 406         __u16 netfid;
 407 };
 408
 409 /* for pending dnotify requests */
 410 struct dir_notify_req {
 411        struct list_head lhead;
 412        __le16 Pid;
 413        __le16 PidHigh;
 414        __u16 Mid;
 415        __u16 Tid;
 416        __u16 Uid;
 417        __u16 netfid;
 418        __u32 filter; /* CompletionFilter (for multishot) */
 419        int multishot;
 420        struct file * pfile;
 421 };
 422
 423 #define   MID_FREE 0
 424 #define   MID_REQUEST_ALLOCATED 1
 425 #define   MID_REQUEST_SUBMITTED 2
 426 #define   MID_RESPONSE_RECEIVED 4
 427 #define   MID_RETRY_NEEDED      8 /* session closed while this request out */
 428 #define   MID_NO_RESP_NEEDED 0x10
 429
 430 /* Types of response buffer returned from SendReceive2 */
 431 #define   CIFS_NO_BUFFER        0    /* Response buffer not returned */
 432 #define   CIFS_SMALL_BUFFER     1
 433 #define   CIFS_LARGE_BUFFER     2
 434 #define   CIFS_IOVEC            4    /* array of response buffers */
 435
 436 /* Security Flags: indicate type of session setup needed */
 437 #define   CIFSSEC_MAY_SIGN      0x00001
 438 #define   CIFSSEC_MAY_NTLM      0x00002
 439 #define   CIFSSEC_MAY_NTLMV2    0x00004
 440 #define   CIFSSEC_MAY_KRB5      0x00008
 441 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 442 #define   CIFSSEC_MAY_LANMAN    0x00010
 443 #define   CIFSSEC_MAY_PLNTXT    0x00020
 444 #endif /* weak passwords */
 445 #define   CIFSSEC_MAY_SEAL      0x00040 /* not supported yet */
 446
 447 #define   CIFSSEC_MUST_SIGN     0x01001
 448 /* note that only one of the following can be set so the
 449 result of setting MUST flags more than once will be to
 450 require use of the stronger protocol */
 451 #define   CIFSSEC_MUST_NTLM     0x02002
 452 #define   CIFSSEC_MUST_NTLMV2   0x04004
 453 #define   CIFSSEC_MUST_KRB5     0x08008
 454 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 455 #define   CIFSSEC_MUST_LANMAN   0x10010
 456 #define   CIFSSEC_MUST_PLNTXT   0x20020
 457 #define   CIFSSEC_MASK          0x37037 /* current flags supported if weak */
 458 #else
 459 #define   CIFSSEC_MASK          0x07007 /* flags supported if no weak config */
 460 #endif /* WEAK_PW_HASH */
 461 #define   CIFSSEC_MUST_SEAL     0x40040 /* not supported yet */
 462
 463 #define   CIFSSEC_DEF  CIFSSEC_MAY_SIGN | CIFSSEC_MAY_NTLM | CIFSSEC_MAY_NTLMV2
 464 #define   CIFSSEC_MAX  CIFSSEC_MUST_SIGN | CIFSSEC_MUST_NTLMV2
 465 /*
 466  *****************************************************************
 467  * All constants go here
 468  *****************************************************************
 469  */
 470
 471 #define UID_HASH (16)
 472
 473 /*
 474  * Note that ONE module should define _DECLARE_GLOBALS_HERE to cause the
 475  * following to be declared.
 476  */
 477
 478 /****************************************************************************
 479  *  Locking notes.  All updates to global variables and lists should be
 480  *                  protected by spinlocks or semaphores.
 481  *
 482  *  Spinlocks
 483  *  ---------
 484  *  GlobalMid_Lock protects:
 485  *      list operations on pending_mid_q and oplockQ
 486  *      updates to XID counters, multiplex id  and SMB sequence numbers
 487  *  GlobalSMBSesLock protects:
 488  *      list operations on tcp and SMB session lists and tCon lists
 489  *  f_owner.lock protects certain per file struct operations
 490  *  mapping->page_lock protects certain per page operations
 491  *
 492  *  Semaphores
 493  *  ----------
 494  *  sesSem     operations on smb session
 495  *  tconSem    operations on tree connection
 496  *  fh_sem      file handle reconnection operations
 497  *
 498  ****************************************************************************/
 499
 500 #ifdef DECLARE_GLOBALS_HERE
 501 #define GLOBAL_EXTERN
 502 #else
 503 #define GLOBAL_EXTERN extern
 504 #endif
 505
 506 /*
 507  * The list of servers that did not respond with NT LM 0.12.
 508  * This list helps improve performance and eliminate the messages indicating
 509  * that we had a communications error talking to the server in this list.
 510  */
 511 GLOBAL_EXTERN struct servers_not_supported *NotSuppList;        /*@z4a */
 512
 513 /*
 514  * The following is a hash table of all the users we know about.
 515  */
 516 GLOBAL_EXTERN struct smbUidInfo *GlobalUidList[UID_HASH];
 517
 518 GLOBAL_EXTERN struct list_head GlobalServerList; /* BB not implemented yet */
 519 GLOBAL_EXTERN struct list_head GlobalSMBSessionList;
 520 GLOBAL_EXTERN struct list_head GlobalTreeConnectionList;
 521 GLOBAL_EXTERN rwlock_t GlobalSMBSeslock;  /* protects list inserts on 3 above */
 522
 523 GLOBAL_EXTERN struct list_head GlobalOplock_Q;
 524
 525 GLOBAL_EXTERN struct list_head GlobalDnotifyReqList; /* Outstanding dir notify requests */
 526 GLOBAL_EXTERN struct list_head GlobalDnotifyRsp_Q;/* DirNotify response queue */
 527
 528 /*
 529  * Global transaction id (XID) information
 530  */
 531 GLOBAL_EXTERN unsigned int GlobalCurrentXid;    /* protected by GlobalMid_Sem */
 532 GLOBAL_EXTERN unsigned int GlobalTotalActiveXid; /* prot by GlobalMid_Sem */
 533 GLOBAL_EXTERN unsigned int GlobalMaxActiveXid;  /* prot by GlobalMid_Sem */
 534 GLOBAL_EXTERN spinlock_t GlobalMid_Lock;  /* protects above & list operations */
 535                                           /* on midQ entries */
 536 GLOBAL_EXTERN char Local_System_Name[15];
 537
 538 /*
 539  *  Global counters, updated atomically
 540  */
 541 GLOBAL_EXTERN atomic_t sesInfoAllocCount;
 542 GLOBAL_EXTERN atomic_t tconInfoAllocCount;
 543 GLOBAL_EXTERN atomic_t tcpSesAllocCount;
 544 GLOBAL_EXTERN atomic_t tcpSesReconnectCount;
 545 GLOBAL_EXTERN atomic_t tconInfoReconnectCount;
 546
 547 /* Various Debug counters to remove someday (BB) */
 548 GLOBAL_EXTERN atomic_t bufAllocCount;    /* current number allocated  */
 549 #ifdef CONFIG_CIFS_STATS2
 550 GLOBAL_EXTERN atomic_t totBufAllocCount; /* total allocated over all time */
 551 GLOBAL_EXTERN atomic_t totSmBufAllocCount;
 552 #endif
 553 GLOBAL_EXTERN atomic_t smBufAllocCount;
 554 GLOBAL_EXTERN atomic_t midCount;
 555
 556 /* Misc globals */
 557 GLOBAL_EXTERN unsigned int multiuser_mount; /* if enabled allows new sessions
 558                                 to be established on existing mount if we
 559                                 have the uid/password or Kerberos credential
 560                                 or equivalent for current user */
 561 GLOBAL_EXTERN unsigned int oplockEnabled;
 562 GLOBAL_EXTERN unsigned int experimEnabled;
 563 GLOBAL_EXTERN unsigned int lookupCacheEnabled;
 564 GLOBAL_EXTERN unsigned int extended_security;   /* if on, session setup sent
 565                                 with more secure ntlmssp2 challenge/resp */
 566 GLOBAL_EXTERN unsigned int sign_CIFS_PDUs;  /* enable smb packet signing */
 567 GLOBAL_EXTERN unsigned int secFlags;
 568 GLOBAL_EXTERN unsigned int linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
 569 GLOBAL_EXTERN unsigned int CIFSMaxBufSize;  /* max size not including hdr */
 570 GLOBAL_EXTERN unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */
 571 GLOBAL_EXTERN unsigned int cifs_min_small;  /* min size of small buf pool */
 572 GLOBAL_EXTERN unsigned int cifs_max_pending; /* MAX requests at once to server*/
 573