NTFS: Fix sparse warnings that have crept in over time.

[linux-2.6/cjktty.git] / fs / cifs / misc.c

/*
 *   fs/cifs/misc.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2004
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
 */

#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/mempool.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "smberr.h"
#include "nterr.h"
#include "cifs_unicode.h"

extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;
extern struct task_struct * oplockThread;

static __u16 GlobalMid;         /* multiplex id - rotating counter */

/* The xid serves as a useful identifier for each incoming vfs request, 
   in a similar way to the mid which is useful to track each sent smb, 
   and CurrentXid can also provide a running counter (although it 
   will eventually wrap past zero) of the total vfs operations handled 
   since the cifs fs was mounted */

unsigned int
_GetXid(void)
{
        unsigned int xid;

        spin_lock(&GlobalMid_Lock);
        GlobalTotalActiveXid++;
        if (GlobalTotalActiveXid > GlobalMaxActiveXid)
                GlobalMaxActiveXid = GlobalTotalActiveXid;      /* keep high water mark for number of simultaneous vfs ops in our filesystem */
        xid = GlobalCurrentXid++;
        spin_unlock(&GlobalMid_Lock);
        return xid;
}

void
_FreeXid(unsigned int xid)
{
        spin_lock(&GlobalMid_Lock);
        /* if(GlobalTotalActiveXid == 0)
                BUG(); */
        GlobalTotalActiveXid--;
        spin_unlock(&GlobalMid_Lock);
}

struct cifsSesInfo *
sesInfoAlloc(void)
{
        struct cifsSesInfo *ret_buf;

        ret_buf =
            (struct cifsSesInfo *) kmalloc(sizeof (struct cifsSesInfo),
                                           GFP_KERNEL);
        if (ret_buf) {
                memset(ret_buf, 0, sizeof (struct cifsSesInfo));
                write_lock(&GlobalSMBSeslock);
                atomic_inc(&sesInfoAllocCount);
                ret_buf->status = CifsNew;
                list_add(&ret_buf->cifsSessionList, &GlobalSMBSessionList);
                init_MUTEX(&ret_buf->sesSem);
                write_unlock(&GlobalSMBSeslock);
        }
        return ret_buf;
}

void
sesInfoFree(struct cifsSesInfo *buf_to_free)
{
        if (buf_to_free == NULL) {
                cFYI(1, ("Null buffer passed to sesInfoFree"));
                return;
        }

        write_lock(&GlobalSMBSeslock);
        atomic_dec(&sesInfoAllocCount);
        list_del(&buf_to_free->cifsSessionList);
        write_unlock(&GlobalSMBSeslock);
        if (buf_to_free->serverOS)
                kfree(buf_to_free->serverOS);
        if (buf_to_free->serverDomain)
                kfree(buf_to_free->serverDomain);
        if (buf_to_free->serverNOS)
                kfree(buf_to_free->serverNOS);
        if (buf_to_free->password)
                kfree(buf_to_free->password);
        kfree(buf_to_free);
}

struct cifsTconInfo *
tconInfoAlloc(void)
{
        struct cifsTconInfo *ret_buf;
        ret_buf =
            (struct cifsTconInfo *) kmalloc(sizeof (struct cifsTconInfo),
                                            GFP_KERNEL);
        if (ret_buf) {
                memset(ret_buf, 0, sizeof (struct cifsTconInfo));
                write_lock(&GlobalSMBSeslock);
                atomic_inc(&tconInfoAllocCount);
                list_add(&ret_buf->cifsConnectionList,
                         &GlobalTreeConnectionList);
                ret_buf->tidStatus = CifsNew;
                INIT_LIST_HEAD(&ret_buf->openFileList);
                init_MUTEX(&ret_buf->tconSem);
#ifdef CONFIG_CIFS_STATS
                spin_lock_init(&ret_buf->stat_lock);
#endif
                write_unlock(&GlobalSMBSeslock);
        }
        return ret_buf;
}

void
tconInfoFree(struct cifsTconInfo *buf_to_free)
{
        if (buf_to_free == NULL) {
                cFYI(1, ("Null buffer passed to tconInfoFree"));
                return;
        }
        write_lock(&GlobalSMBSeslock);
        atomic_dec(&tconInfoAllocCount);
        list_del(&buf_to_free->cifsConnectionList);
        write_unlock(&GlobalSMBSeslock);
        if (buf_to_free->nativeFileSystem)
                kfree(buf_to_free->nativeFileSystem);
        kfree(buf_to_free);
}

struct smb_hdr *
cifs_buf_get(void)
{
        struct smb_hdr *ret_buf = NULL;

/* We could use negotiated size instead of max_msgsize - 
   but it may be more efficient to always alloc same size 
   albeit slightly larger than necessary and maxbuffersize 
   defaults to this and can not be bigger */
        ret_buf =
            (struct smb_hdr *) mempool_alloc(cifs_req_poolp, SLAB_KERNEL | SLAB_NOFS);

        /* clear the first few header bytes */
        /* for most paths, more is cleared in header_assemble */
        if (ret_buf) {
                memset(ret_buf, 0, sizeof(struct smb_hdr) + 3);
                atomic_inc(&bufAllocCount);
        }

        return ret_buf;
}

void
cifs_buf_release(void *buf_to_free)
{

        if (buf_to_free == NULL) {
                /* cFYI(1, ("Null buffer passed to cifs_buf_release"));*/
                return;
        }
        mempool_free(buf_to_free,cifs_req_poolp);

        atomic_dec(&bufAllocCount);
        return;
}

struct smb_hdr *
cifs_small_buf_get(void)
{
        struct smb_hdr *ret_buf = NULL;

/* We could use negotiated size instead of max_msgsize - 
   but it may be more efficient to always alloc same size 
   albeit slightly larger than necessary and maxbuffersize 
   defaults to this and can not be bigger */
        ret_buf =
            (struct smb_hdr *) mempool_alloc(cifs_sm_req_poolp, SLAB_KERNEL | SLAB_NOFS);
        if (ret_buf) {
        /* No need to clear memory here, cleared in header assemble */
        /*      memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
                atomic_inc(&smBufAllocCount);
        }
        return ret_buf;
}

void
cifs_small_buf_release(void *buf_to_free)
{

        if (buf_to_free == NULL) {
                cFYI(1, ("Null buffer passed to cifs_small_buf_release"));
                return;
        }
        mempool_free(buf_to_free,cifs_sm_req_poolp);

        atomic_dec(&smBufAllocCount);
        return;
}

void
header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
                const struct cifsTconInfo *treeCon, int word_count
                /* length of fixed section (word count) in two byte units  */)
{
        struct list_head* temp_item;
        struct cifsSesInfo * ses;
        char *temp = (char *) buffer;

        memset(temp,0,MAX_CIFS_HDR_SIZE);

        buffer->smb_buf_length =
            (2 * word_count) + sizeof (struct smb_hdr) -
            4 /*  RFC 1001 length field does not count */  +
            2 /* for bcc field itself */ ;
        /* 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 */

        buffer->Protocol[0] = 0xFF;
        buffer->Protocol[1] = 'S';
        buffer->Protocol[2] = 'M';
        buffer->Protocol[3] = 'B';
        buffer->Command = smb_command;
        buffer->Flags = 0x00;   /* case sensitive */
        buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
        buffer->Pid = cpu_to_le16((__u16)current->tgid);
        buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
        spin_lock(&GlobalMid_Lock);
        GlobalMid++;
        buffer->Mid = GlobalMid;
        spin_unlock(&GlobalMid_Lock);
        if (treeCon) {
                buffer->Tid = treeCon->tid;
                if (treeCon->ses) {
                        if (treeCon->ses->capabilities & CAP_UNICODE)
                                buffer->Flags2 |= SMBFLG2_UNICODE;
                        if (treeCon->ses->capabilities & CAP_STATUS32) {
                                buffer->Flags2 |= SMBFLG2_ERR_STATUS;
                        }

                        buffer->Uid = treeCon->ses->Suid;       /* always in LE format */
                        if(multiuser_mount != 0) {
                /* For the multiuser case, there are few obvious technically  */
                /* possible mechanisms to match the local linux user (uid)    */
                /* to a valid remote smb user (smb_uid):                      */
                /*      1) Query Winbind (or other local pam/nss daemon       */
                /*        for userid/password/logon_domain or credential      */
                /*      2) Query Winbind for uid to sid to username mapping   */
                /*         and see if we have a matching password for existing*/
                /*         session for that user perhas getting password by   */
                /*         adding a new pam_cifs module that stores passwords */
                /*         so that the cifs vfs can get at that for all logged*/
                /*         on users                                           */
                /*      3) (Which is the mechanism we have chosen)            */
                /*         Search through sessions to the same server for a   */
                /*         a match on the uid that was passed in on mount     */
                /*         with the current processes uid (or euid?) and use  */
                /*         that smb uid.   If no existing smb session for     */
                /*         that uid found, use the default smb session ie     */
                /*         the smb session for the volume mounted which is    */
                /*         the same as would be used if the multiuser mount   */
                /*         flag were disabled.  */

                /*  BB Add support for establishing new tCon and SMB Session  */
                /*      with userid/password pairs found on the smb session   */ 
                /*      for other target tcp/ip addresses               BB    */
                                if(current->uid != treeCon->ses->linux_uid) {
                                        cFYI(1,("Multiuser mode and UID did not match tcon uid "));
                                        read_lock(&GlobalSMBSeslock);
                                        list_for_each(temp_item, &GlobalSMBSessionList) {
                                                ses = list_entry(temp_item, struct cifsSesInfo, cifsSessionList);
                                                if(ses->linux_uid == current->uid) {
                                                        if(ses->server == treeCon->ses->server) {
                                                                cFYI(1,("found matching uid substitute right smb_uid"));  
                                                                buffer->Uid = ses->Suid;
                                                                break;
                                                        } else {
                                                                /* BB eventually call cifs_setup_session here */
                                                                cFYI(1,("local UID found but smb sess with this server does not exist"));  
                                                        }
                                                }
                                        }
                                        read_unlock(&GlobalSMBSeslock);
                                }
                        }
                }
                if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
                        buffer->Flags2 |= SMBFLG2_DFS;
                if((treeCon->ses) && (treeCon->ses->server))
                        if(treeCon->ses->server->secMode & 
                          (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
                                buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
        }

/*  endian conversion of flags is now done just before sending */
        buffer->WordCount = (char) word_count;
        return;
}

int
checkSMBhdr(struct smb_hdr *smb, __u16 mid)
{
        /* Make sure that this really is an SMB, that it is a response, 
           and that the message ids match */
        if ((*(__le32 *) smb->Protocol == cpu_to_le32(0x424d53ff)) && 
                (mid == smb->Mid)) {    
                if(smb->Flags & SMBFLG_RESPONSE)
                        return 0;                    
                else {        
                /* only one valid case where server sends us request */
                        if(smb->Command == SMB_COM_LOCKING_ANDX)
                                return 0;
                        else
                                cERROR(1, ("Rcvd Request not response "));         
                }
        } else { /* bad signature or mid */
                if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff))
                        cERROR(1,
                               ("Bad protocol string signature header %x ",
                                *(unsigned int *) smb->Protocol));
                if (mid != smb->Mid)
                        cERROR(1, ("Mids do not match"));
        }
        cERROR(1, ("bad smb detected. The Mid=%d", smb->Mid));
        return 1;
}

int
checkSMB(struct smb_hdr *smb, __u16 mid, int length)
{
        __u32 len = be32_to_cpu(smb->smb_buf_length);
        cFYI(0,
             ("Entering checkSMB with Length: %x, smb_buf_length: %x ",
              length, len));
        if (((unsigned int)length < 2 + sizeof (struct smb_hdr)) ||
            (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)) {
                if ((unsigned int)length < 2 + sizeof (struct smb_hdr)) {
                        if (((unsigned int)length >= 
                                sizeof (struct smb_hdr) - 1)
                            && (smb->Status.CifsError != 0)) {
                                smb->WordCount = 0;
                                return 0;       /* some error cases do not return wct and bcc */
                        } else {
                                cERROR(1, ("Length less than smb header size"));
                        }

                }
                if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4)
                        cERROR(1,
                               ("smb_buf_length greater than MaxBufSize"));
                cERROR(1,
                       ("bad smb detected. Illegal length. The mid=%d",
                        smb->Mid));
                return 1;
        }

        if (checkSMBhdr(smb, mid))
                return 1;

        if ((4 + len != smbCalcSize(smb))
            || (4 + len != (unsigned int)length)) {
                return 0;
        } else {
                cERROR(1, ("smbCalcSize %x ", smbCalcSize(smb)));
                cERROR(1,
                       ("bad smb size detected. The Mid=%d", smb->Mid));
                return 1;
        }
}
int
is_valid_oplock_break(struct smb_hdr *buf)
{    
        struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)buf;
        struct list_head *tmp;
        struct list_head *tmp1;
        struct cifsTconInfo *tcon;
        struct cifsFileInfo *netfile;

        cFYI(1,("Checking for oplock break or dnotify response"));
        if((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
           (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
                struct smb_com_transaction_change_notify_rsp * pSMBr =
                        (struct smb_com_transaction_change_notify_rsp *)buf;
                struct file_notify_information * pnotify;
                __u32 data_offset = 0;
                if(pSMBr->ByteCount > sizeof(struct file_notify_information)) {
                        data_offset = le32_to_cpu(pSMBr->DataOffset);

                        pnotify = (struct file_notify_information *)((char *)&pSMBr->hdr.Protocol
                                + data_offset);
                        cFYI(1,("dnotify on %s with action: 0x%x",pnotify->FileName,
                                pnotify->Action));  /* BB removeme BB */
                     /*   cifs_dump_mem("Received notify Data is: ",buf,sizeof(struct smb_hdr)+60); */
                        return TRUE;
                }
                if(pSMBr->hdr.Status.CifsError) {
                        cFYI(1,("notify err 0x%d",pSMBr->hdr.Status.CifsError));
                        return TRUE;
                }
                return FALSE;
        }  
        if(pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
                return FALSE;
        if(pSMB->hdr.Flags & SMBFLG_RESPONSE) {
                /* no sense logging error on invalid handle on oplock
                   break - harmless race between close request and oplock
                   break response is expected from time to time writing out
                   large dirty files cached on the client */
                if ((NT_STATUS_INVALID_HANDLE) == 
                   le32_to_cpu(pSMB->hdr.Status.CifsError)) { 
                        cFYI(1,("invalid handle on oplock break"));
                        return TRUE;
                } else if (ERRbadfid == 
                   le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
                        return TRUE;      
                } else {
                        return FALSE; /* on valid oplock brk we get "request" */
                }
        }
        if(pSMB->hdr.WordCount != 8)
                return FALSE;

        cFYI(1,(" oplock type 0x%d level 0x%d",pSMB->LockType,pSMB->OplockLevel));
        if(!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
                return FALSE;    

        /* look up tcon based on tid & uid */
        read_lock(&GlobalSMBSeslock);
        list_for_each(tmp, &GlobalTreeConnectionList) {
                tcon = list_entry(tmp, struct cifsTconInfo, cifsConnectionList);
                if (tcon->tid == buf->Tid) {
#ifdef CONFIG_CIFS_STATS
                        atomic_inc(&tcon->num_oplock_brks);
#endif
                        list_for_each(tmp1,&tcon->openFileList){
                                netfile = list_entry(tmp1,struct cifsFileInfo,
                                                     tlist);
                                if(pSMB->Fid == netfile->netfid) {
                                        struct cifsInodeInfo *pCifsInode;
                                        read_unlock(&GlobalSMBSeslock);
                                        cFYI(1,("file id match, oplock break"));
                                        pCifsInode = 
                                                CIFS_I(netfile->pInode);
                                        pCifsInode->clientCanCacheAll = FALSE;
                                        if(pSMB->OplockLevel == 0)
                                                pCifsInode->clientCanCacheRead
                                                        = FALSE;
                                        pCifsInode->oplockPending = TRUE;
                                        AllocOplockQEntry(netfile->pInode,
                                                          netfile->netfid,
                                                          tcon);
                                        cFYI(1,("about to wake up oplock thd"));
                                        if(oplockThread)
                                            wake_up_process(oplockThread);
                                        return TRUE;
                                }
                        }
                        read_unlock(&GlobalSMBSeslock);
                        cFYI(1,("No matching file for oplock break"));
                        return TRUE;
                }
        }
        read_unlock(&GlobalSMBSeslock);
        cFYI(1,("Can not process oplock break for non-existent connection"));
        return TRUE;
}

void
dump_smb(struct smb_hdr *smb_buf, int smb_buf_length)
{
        int i, j;
        char debug_line[17];
        unsigned char *buffer;

        if (traceSMB == 0)
                return;

        buffer = (unsigned char *) smb_buf;
        for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
                if (i % 8 == 0) {       /* have reached the beginning of line */
                        printk(KERN_DEBUG "| ");
                        j = 0;
                }
                printk("%0#4x ", buffer[i]);
                debug_line[2 * j] = ' ';
                if (isprint(buffer[i]))
                        debug_line[1 + (2 * j)] = buffer[i];
                else
                        debug_line[1 + (2 * j)] = '_';

                if (i % 8 == 7) { /* reached end of line, time to print ascii */
                        debug_line[16] = 0;
                        printk(" | %s\n", debug_line);
                }
        }
        for (; j < 8; j++) {
                printk("     ");
                debug_line[2 * j] = ' ';
                debug_line[1 + (2 * j)] = ' ';
        }
        printk( " | %s\n", debug_line);
        return;
}

/* Windows maps these to the user defined 16 bit Unicode range since they are
   reserved symbols (along with \ and /), otherwise illegal to store
   in filenames in NTFS */
#define UNI_ASTERIK     (__u16) ('*' + 0xF000)
#define UNI_QUESTION    (__u16) ('?' + 0xF000)
#define UNI_COLON       (__u16) (':' + 0xF000)
#define UNI_GRTRTHAN    (__u16) ('>' + 0xF000)
#define UNI_LESSTHAN    (__u16) ('<' + 0xF000)
#define UNI_PIPE        (__u16) ('|' + 0xF000)
#define UNI_SLASH       (__u16) ('\\' + 0xF000)

/* Convert 16 bit Unicode pathname from wire format to string in current code
   page.  Conversion may involve remapping up the seven characters that are
   only legal in POSIX-like OS (if they are present in the string). Path
   names are little endian 16 bit Unicode on the wire */
int
cifs_convertUCSpath(char *target, const __le16 * source, int maxlen,
                    const struct nls_table * cp)
{
        int i,j,len;
        __u16 src_char;

        for(i = 0, j = 0; i < maxlen; i++) {
                src_char = le16_to_cpu(source[i]);
                switch (src_char) {
                        case 0:
                                goto cUCS_out; /* BB check this BB */
                        case UNI_COLON:
                                target[j] = ':';
                                break;
                        case UNI_ASTERIK:
                                target[j] = '*';
                                break;
                        case UNI_QUESTION:
                                target[j] = '?';
                                break;
                        /* BB We can not handle remapping slash until
                           all the calls to build_path_from_dentry
                           are modified, as they use slash as separator BB */
                        /* case UNI_SLASH:
                                target[j] = '\\';
                                break;*/
                        case UNI_PIPE:
                                target[j] = '|';
                                break;
                        case UNI_GRTRTHAN:
                                target[j] = '>';
                                break;
                        case UNI_LESSTHAN:
                                target[j] = '<';
                                break;
                        default: 
                                len = cp->uni2char(src_char, &target[j], 
                                                NLS_MAX_CHARSET_SIZE);
                                if(len > 0) {
                                        j += len;
                                        continue;
                                } else {
                                        target[j] = '?';
                                }
                }
                j++;
                /* make sure we do not overrun callers allocated temp buffer */
                if(j >= (2 * NAME_MAX))
                        break;
        }
cUCS_out:
        target[j] = 0;
        return j;
}

/* Convert 16 bit Unicode pathname to wire format from string in current code
   page.  Conversion may involve remapping up the seven characters that are
   only legal in POSIX-like OS (if they are present in the string). Path
   names are little endian 16 bit Unicode on the wire */
int
cifsConvertToUCS(__le16 * target, const char *source, int maxlen, 
                 const struct nls_table * cp, int mapChars)
{
        int i,j,charlen;
        int len_remaining = maxlen;
        char src_char;

        if(!mapChars) 
                return cifs_strtoUCS((wchar_t *) target, source, PATH_MAX, cp);

        for(i = 0, j = 0; i < maxlen; j++) {
                src_char = source[i];
                switch (src_char) {
                        case 0:
                                target[j] = 0;
                                goto ctoUCS_out;
                        case ':':
                                target[j] = cpu_to_le16(UNI_COLON);
                                break;
                        case '*':
                                target[j] = cpu_to_le16(UNI_ASTERIK);
                                break;
                        case '?':
                                target[j] = cpu_to_le16(UNI_QUESTION);
                                break;
                        case '<':
                                target[j] = cpu_to_le16(UNI_LESSTHAN);
                                break;
                        case '>':
                                target[j] = cpu_to_le16(UNI_GRTRTHAN);
                                break;
                        case '|':
                                target[j] = cpu_to_le16(UNI_PIPE);
                                break;                  
                        /* BB We can not handle remapping slash until
                           all the calls to build_path_from_dentry
                           are modified, as they use slash as separator BB */
                        /* case '\\':
                                target[j] = cpu_to_le16(UNI_SLASH);
                                break;*/
                        default:
                                charlen = cp->char2uni(source+i,
                                        len_remaining, target+j);
                                /* if no match, use question mark, which
                                at least in some cases servers as wild card */
                                if(charlen < 1) {
                                        target[j] = cpu_to_le16(0x003f);
                                        charlen = 1;
                                }
                                len_remaining -= charlen;
                                /* character may take more than one byte in the
                                   the source string, but will take exactly two
                                   bytes in the target string */
                                i+= charlen;
                                continue;
                }
                i++; /* move to next char in source string */
                len_remaining--;
        }

ctoUCS_out:
        return i;
}