cifssmb.c

Linux Kernel 2.6.9 for OMAP1710

/*
 *   fs/cifs/cifssmb.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2003
 *   Author(s): Steve French ([e-mail])
 *
 *   Contains the routines for constructing the SMB PDUs themselves
 *
 *   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
 */

 /* SMB/CIFS PDU handling routines here - except for leftovers in connect.c   */
 /* These are mostly routines that operate on a pathname, or on a tree id     */
 /* (mounted volume), but there are eight handle based routines which must be */
 /* treated slightly different for reconnection purposes since we never want  */
 /* to reuse a stale file handle and the caller knows the file handle */

#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/vfs.h>
#include <asm/uaccess.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"

#ifdef CONFIG_CIFS_POSIX
static struct {
	int index;
	char *name;
} protocols[] = {
	{CIFS_PROT, "\2NT LM 0.12"}, 
	{CIFS_PROT, "\2POSIX 2"},
	{BAD_PROT, "\2"}
};
#else
static struct {
	int index;
	char *name;
} protocols[] = {
	{CIFS_PROT, "\2NT LM 0.12"}, 
	{BAD_PROT, "\2"}
};
#endif


/* Mark as invalid, all open files on tree connections since they
   were closed when session to server was lost */
static void mark_open_files_invalid(struct cifsTconInfo * pTcon)
{
	struct cifsFileInfo *open_file = NULL;
	struct list_head * tmp;
	struct list_head * tmp1;

/* list all files open on tree connection and mark them invalid */
	write_lock(&GlobalSMBSeslock);
	list_for_each_safe(tmp, tmp1, &pTcon->openFileList) {
		open_file = list_entry(tmp,struct cifsFileInfo, tlist);
		if(open_file) {
			open_file->invalidHandle = TRUE;
		}
	}
	write_unlock(&GlobalSMBSeslock);
	/* BB Add call to invalidate_inodes(sb) for all superblocks mounted to this tcon */
}

static int
smb_init(int smb_command, int wct, struct cifsTconInfo *tcon,
	 void **request_buf /* returned */ ,
	 void **response_buf /* returned */ )
{
	int rc = 0;

	/* SMBs NegProt, SessSetup, uLogoff do not have tcon yet so
	   check for tcp and smb session status done differently
	   for those three - in the calling routine */
	if(tcon) {
		if((tcon->ses) && (tcon->ses->server)){
			struct nls_table *nls_codepage;
				/* Give Demultiplex thread up to 10 seconds to 
					reconnect, should be greater than cifs socket
					timeout which is 7 seconds */
			while(tcon->ses->server->tcpStatus == CifsNeedReconnect) {
				wait_event_interruptible_timeout(tcon->ses->server->response_q,
					(tcon->ses->server->tcpStatus == CifsGood), 10 * HZ);
				if(tcon->ses->server->tcpStatus == CifsNeedReconnect) {
					/* on "soft" mounts we wait once */
					if((tcon->retry == FALSE) || 
					   (tcon->ses->status == CifsExiting)) {
						cFYI(1,("gave up waiting on reconnect in smb_init"));
						return -EHOSTDOWN;
					} /* else "hard" mount - keep retrying until 
					process is killed or server comes back up */
				} else /* TCP session is reestablished now */
					break;
				 
			}
			
			nls_codepage = load_nls_default();
		/* need to prevent multiple threads trying to
		simultaneously reconnect the same SMB session */
			down(&tcon->ses->sesSem);
			if(tcon->ses->status == CifsNeedReconnect)
				rc = cifs_setup_session(0, tcon->ses, nls_codepage);
			if(!rc && (tcon->tidStatus == CifsNeedReconnect)) {
				mark_open_files_invalid(tcon);
				rc = CIFSTCon(0, tcon->ses, tcon->treeName, tcon,
					nls_codepage);
				up(&tcon->ses->sesSem);
				if(rc == 0)
					atomic_inc(&tconInfoReconnectCount);

				cFYI(1, ("reconnect tcon rc = %d", rc));
				/* Removed call to reopen open files here - 
					it is safer (and faster) to reopen files
					one at a time as needed in read and write */

				/* Check if handle based operation so we 
					know whether we can continue or not without
					returning to caller to reset file handle */
				switch(smb_command) {
					case SMB_COM_READ_ANDX:
					case SMB_COM_WRITE_ANDX:
					case SMB_COM_CLOSE:
					case SMB_COM_FIND_CLOSE2:
					case SMB_COM_LOCKING_ANDX: {
						unload_nls(nls_codepage);
						return -EAGAIN;
					}
				}
			} else {
				up(&tcon->ses->sesSem);
			}
			unload_nls(nls_codepage);

		} else {
			return -EIO;
		}
	}
	if(rc)
		return rc;

	*request_buf = cifs_buf_get();
	if (*request_buf == 0) {
		/* BB should we add a retry in here if not a writepage? */
		return -ENOMEM;
	}
    /* Although the original thought was we needed the response buf for  */
    /* potential retries of smb operations it turns out we can determine */
    /* from the mid flags when the request buffer can be resent without  */
    /* having to use a second distinct buffer for the response */
	*response_buf = *request_buf; 

	header_assemble((struct smb_hdr *) *request_buf, smb_command, tcon,
			wct /*wct */ );

#ifdef CONFIG_CIFS_STATS
        if(tcon != NULL) {
                atomic_inc(&tcon->num_smbs_sent);
        }
#endif
	return rc;
}

int
CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
{
	NEGOTIATE_REQ *pSMB;
	NEGOTIATE_RSP *pSMBr;
	int rc = 0;
	int bytes_returned;
	struct TCP_Server_Info * server;
	u16 count;

	if(ses->server)
		server = ses->server;
	else {
		rc = -EIO;
		return rc;
	}
	rc = smb_init(SMB_COM_NEGOTIATE, 0, NULL /* no tcon yet */ ,
		      (void **) &pSMB, (void **) &pSMBr);
	if (rc)
		return rc;

	pSMB->hdr.Flags2 |= SMBFLG2_UNICODE;
	if (extended_security)
		pSMB->hdr.Flags2 |= SMBFLG2_EXT_SEC;

	count = strlen(protocols[0].name) + 1;
	strncpy(pSMB->DialectsArray, protocols[0].name, 30);	
    /* null guaranteed to be at end of source and target buffers anyway */

	pSMB->hdr.smb_buf_length += count;
	pSMB->ByteCount = cpu_to_le16(count);

	rc = SendReceive(xid, ses, (struct smb_hdr *) pSMB,
			 (struct smb_hdr *) pSMBr, &bytes_returned, 0);
	if (rc == 0) {
		server->secMode = pSMBr->SecurityMode;	
		server->secType = NTLM; /* BB override default for NTLMv2 or krb*/
		/* one byte - no need to convert this or EncryptionKeyLen from le,*/
		server->maxReq = le16_to_cpu(pSMBr->MaxMpxCount);
		/* probably no need to store and check maxvcs */
		server->maxBuf =
			min(le32_to_cpu(pSMBr->MaxBufferSize),
			(__u32) CIFS_MAX_MSGSIZE + MAX_CIFS_HDR_SIZE);
		server->maxRw = le32_to_cpu(pSMBr->MaxRawSize);
		cFYI(0, ("Max buf = %d ", ses->server->maxBuf));
		GETU32(ses->server->sessid) = le32_to_cpu(pSMBr->SessionKey);
		server->capabilities = le32_to_cpu(pSMBr->Capabilities);
		server->timeZone = le16_to_cpu(pSMBr->ServerTimeZone);	
        /* BB with UTC do we ever need to be using srvr timezone? */
		if (pSMBr->EncryptionKeyLength == CIFS_CRYPTO_KEY_SIZE) {
			memcpy(server->cryptKey, pSMBr->u.EncryptionKey,
			       CIFS_CRYPTO_KEY_SIZE);
		} else if ((pSMBr->hdr.Flags2 & SMBFLG2_EXT_SEC)
			   && (pSMBr->EncryptionKeyLength == 0)) {
			/* decode security blob */
		} else
			rc = -EIO;

		/* BB might be helpful to save off the domain of server here */

		if ((pSMBr->hdr.Flags2 & SMBFLG2_EXT_SEC) && 
			(server->capabilities & CAP_EXTENDED_SECURITY)) {
			count = pSMBr->ByteCount;
			if (count < 16)
				rc = -EIO;
			else if (count == 16) {
				server->secType = RawNTLMSSP;
				if (server->socketUseCount.counter > 1) {
					if (memcmp
						(server->server_GUID,
						pSMBr->u.extended_response.
						GUID, 16) != 0) {
						cFYI(1,
							("UID of server does not match previous connection to same ip address"));
						memcpy(server->
							server_GUID,
							pSMBr->u.
							extended_response.
							GUID, 16);
					}
				} else
					memcpy(server->server_GUID,
					       pSMBr->u.extended_response.
					       GUID, 16);
			} else {
				rc = decode_negTokenInit(pSMBr->u.
							 extended_response.
							 SecurityBlob,
							 count - 16,
							 &server->secType);
			}
		} else
			server->capabilities &= ~CAP_EXTENDED_SECURITY;
		if(sign_CIFS_PDUs == FALSE) {        
			if(server->secMode & SECMODE_SIGN_REQUIRED)
				cERROR(1,
				 ("Server requires /proc/fs/cifs/PacketSigningEnabled"));
			server->secMode &= ~(SECMODE_SIGN_ENABLED | SECMODE_SIGN_REQUIRED);
		} else if(sign_CIFS_PDUs == 1) {
			if((server->secMode & SECMODE_SIGN_REQUIRED) == 0)
				server->secMode &= ~(SECMODE_SIGN_ENABLED | SECMODE_SIGN_REQUIRED);
		}
				
	}
	if (pSMB)
		cifs_buf_release(pSMB);
	return rc;
}

int
CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon)
{
	struct smb_hdr *smb_buffer;
	struct smb_hdr *smb_buffer_response;
	int rc = 0;
	int length;

	cFYI(1, ("In tree disconnect"));
	/*
	 *  If last user of the connection and
	 *  connection alive - disconnect it
	 *  If this is the last connection on the server session disconnect it
	 *  (and inside session disconnect we should check if tcp socket needs 
	 *  to be freed and kernel thread woken up).
	 */
	if (tcon)
		down(&tcon->tconSem);
	else
		return -EIO;

	atomic_dec(&tcon->useCount);
	if (atomic_read(&tcon->useCount) > 0) {
		up(&tcon->tconSem);
		return -EBUSY;
	}

	/* No need to return error on this operation if tid invalidated and 
	closed on server already e.g. due to tcp session crashing */
	if(tcon->tidStatus == CifsNeedReconnect) {
		up(&tcon->tconSem);
		return 0;  
	}

	if((tcon->ses == 0) || (tcon->ses->server == 0)) {    
		up(&tcon->tconSem);
		return -EIO;
	}

	rc = smb_init(SMB_COM_TREE_DISCONNECT, 0, tcon,
		      (void **) &smb_buffer, (void **) &smb_buffer_response);
	if (rc) {
		up(&tcon->tconSem);
		return rc;
	}
	rc = SendReceive(xid, tcon->ses, smb_buffer, smb_buffer_response,
			 &length, 0);
	if (rc)
		cFYI(1, (" Tree disconnect failed %d", rc));

	if (smb_buffer)
		cifs_buf_release(smb_buffer);
	up(&tcon->tconSem);

	/* No need to return error on this operation if tid invalidated and 
	closed on server already e.g. due to tcp session crashing */
	if (rc == -EAGAIN)
		rc = 0;

	return rc;
}

int
CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses)
{
	struct smb_hdr *smb_buffer_response;
	LOGOFF_ANDX_REQ *pSMB;
	int rc = 0;
	int length;

	cFYI(1, ("In SMBLogoff for session disconnect"));
	if (ses)
		down(&ses->sesSem);
	else
		return -EIO;

	atomic_dec(&ses->inUse);
	if (atomic_read(&ses->inUse) > 0) {
		up(&ses->sesSem);
		return -EBUSY;
	}

	rc = smb_init(SMB_COM_LOGOFF_ANDX, 2, NULL /* no tcon anymore */,
		 (void **) &pSMB, (void **) &smb_buffer_response);
	
	if(ses->server) {
		if(ses->server->secMode & 
		   (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
			pSMB->hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
	}

	if (rc) {
		up(&ses->sesSem);
		return rc;
	}

	pSMB->hdr.Uid = ses->Suid;

	pSMB->AndXCommand = 0xFF;
	rc = SendReceive(xid, ses, (struct smb_hdr *) pSMB,
			 smb_buffer_response, &length, 0);
	if (ses->server) {
		atomic_dec(&ses->server->socketUseCount);
		if (atomic_read(&ses->server->socketUseCount) == 0) {
			spin_lock(&GlobalMid_Lock);
			ses->server->tcpStatus = CifsExiting;
			spin_unlock(&GlobalMid_Lock);
			rc = -ESHUTDOWN;
		}
	}
	if (pSMB)
		cifs_buf_release(pSMB);
	up(&ses->sesSem);

	/* if session dead then we do not need to do ulogoff,
		since server closed smb session, no sense reporting 
		error */
	if (rc == -EAGAIN)
		rc = 0;
	return rc;
}

int
CIFSSMBDelFile(const int xid, struct cifsTconInfo *tcon,
	       const char *fileName, const struct nls_table *nls_codepage)
{
	DELETE_FILE_REQ *pSMB = NULL;
	DELETE_FILE_RSP *pSMBr = NULL;
	int rc = 0;
	int bytes_returned;
	int name_len;

DelFileRetry:
	rc = smb_init(SMB_COM_DELETE, 1, tcon, (void **) &pSMB,
		      (void **) &pSMBr);
	if (rc)
		return rc;

	if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
		name_len =
		    cifs_strtoUCS((wchar_t *) pSMB->fileName, fileName, 530
				  /* find define for this maxpathcomponent */
				  , nls_codepage);
		name_len++;	/* trailing null */
		name_len *= 2;