CIFS] Support for older servers which require plaintext passwords - part 2

Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/README

@@ -485,14 +485,34 @@ PacketSigningEnabled	If set to one, cifs packet signing is enabled
 			it.  If set to two, cifs packet signing is
 			required even if the server considers packet
 			signing optional. (default 1)
+SecurityFlags		Flags which control security negotiation and
+			also packet signing. Authentication (may/must)
+			flags (e.g. for NTLM and/or NTLMv2) may be combined with
+			the signing flags.  Specifying two different password
+			hashing mechanisms (as "must use") on the other hand 
+			does not make much sense. Default flags are 
+				0x07007 
+			(NTLM, NTLMv2 and packet signing allowed).  Maximum 
+			allowable flags if you want to allow mounts to servers
+			using weaker password hashes is 0x37037 (lanman,
+			plaintext, ntlm, ntlmv2, signing allowed):
+ 
+			may use packet signing 				0x00001
+			must use packet signing				0x01001
+			may use NTLM (most common password hash)	0x00002
+			must use NTLM					0x02002
+			may use NTLMv2					0x00004
+			must use NTLMv2					0x04004
+			may use Kerberos security (not implemented yet) 0x00008
+			must use Kerberos (not implemented yet)         0x08008
+			may use lanman (weak) password hash  		0x00010
+			must use lanman password hash			0x10010
+			may use plaintext passwords    			0x00020
+			must use plaintext passwords			0x20020
+			(reserved for future packet encryption)		0x00040
+
 cifsFYI			If set to one, additional debug information is
 			logged to the system error log. (default 0)
-ExtendedSecurity	If set to one, SPNEGO session establishment
-			is allowed which enables more advanced 
-			secure CIFS session establishment (default 0)
-NTLMV2Enabled		If set to one, more secure password hashes
-			are used when the server supports them and
-			when kerberos is not negotiated (default 0)
 traceSMB		If set to one, debug information is logged to the
 			system error log with the start of smb requests
 			and responses (default 0)

fs/cifs/cifsglob.h

@@ -212,12 +212,12 @@ struct cifsTconInfo {
 	struct list_head openFileList;
 	struct semaphore tconSem;
 	struct cifsSesInfo *ses;	/* pointer to session associated with */
-	char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource (in ASCII not UTF) */
+	char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource in ASCII */
 	char *nativeFileSystem;
 	__u16 tid;		/* The 2 byte tree id */
 	__u16 Flags;		/* optional support bits */
 	enum statusEnum tidStatus;
-	atomic_t useCount;	/* how many mounts (explicit or implicit) to this share */
+	atomic_t useCount;	/* how many explicit/implicit mounts to share */
 #ifdef CONFIG_CIFS_STATS
 	atomic_t num_smbs_sent;
 	atomic_t num_writes;
@@ -257,7 +257,7 @@ struct cifsTconInfo {
 	spinlock_t stat_lock;
 #endif /* CONFIG_CIFS_STATS */
 	FILE_SYSTEM_DEVICE_INFO fsDevInfo;
-	FILE_SYSTEM_ATTRIBUTE_INFO fsAttrInfo;	/* ok if file system name truncated */
+	FILE_SYSTEM_ATTRIBUTE_INFO fsAttrInfo; /* ok if fs name truncated */
 	FILE_SYSTEM_UNIX_INFO fsUnixInfo;
 	unsigned retry:1;
 	unsigned nocase:1;
@@ -308,7 +308,6 @@ struct cifsFileInfo {
 	atomic_t wrtPending;   /* handle in use - defer close */
 	struct semaphore fh_sem; /* prevents reopen race after dead ses*/
 	char * search_resume_name; /* BB removeme BB */
-	unsigned int resume_name_length; /* BB removeme - field renamed and moved BB */
 	struct cifs_search_info srch_inf;
 };
 
@@ -523,7 +522,7 @@ GLOBAL_EXTERN rwlock_t GlobalSMBSeslock;  /* protects list inserts on 3 above */
 GLOBAL_EXTERN struct list_head GlobalOplock_Q;
 
 GLOBAL_EXTERN struct list_head GlobalDnotifyReqList; /* Outstanding dir notify requests */
-GLOBAL_EXTERN struct list_head GlobalDnotifyRsp_Q; /* Dir notify response queue */
+GLOBAL_EXTERN struct list_head GlobalDnotifyRsp_Q;/* DirNotify response queue */
 
 /*
  * Global transaction id (XID) information
@@ -531,7 +530,7 @@ GLOBAL_EXTERN struct list_head GlobalDnotifyRsp_Q; /* Dir notify response queue
 GLOBAL_EXTERN unsigned int GlobalCurrentXid;	/* protected by GlobalMid_Sem */
 GLOBAL_EXTERN unsigned int GlobalTotalActiveXid; /* prot by GlobalMid_Sem */
 GLOBAL_EXTERN unsigned int GlobalMaxActiveXid;	/* prot by GlobalMid_Sem */
-GLOBAL_EXTERN spinlock_t GlobalMid_Lock;  /* protects above and list operations */
+GLOBAL_EXTERN spinlock_t GlobalMid_Lock;  /* protects above & list operations */
 					  /* on midQ entries */
 GLOBAL_EXTERN char Local_System_Name[15];
 

fs/cifs/cifspdu.h

@@ -426,6 +426,10 @@ typedef struct lanman_neg_rsp {
 	unsigned char EncryptionKey[1];
 } __attribute__((packed)) LANMAN_NEG_RSP;
 
+#define READ_RAW_ENABLE 1
+#define WRITE_RAW_ENABLE 2
+#define RAW_ENABLE (READ_RAW_ENABLE | WRITE_RAW_ENABLE)
+
 typedef struct negotiate_rsp {
 	struct smb_hdr hdr;	/* wct = 17 */
 	__le16 DialectIndex;

fs/cifs/cifssmb.c

@@ -411,8 +411,8 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 		return rc;
 	pSMB->hdr.Mid = GetNextMid(server);
 	pSMB->hdr.Flags2 |= SMBFLG2_UNICODE;
-/*	if (extended_security)
-		pSMB->hdr.Flags2 |= SMBFLG2_EXT_SEC;*/
+	if((extended_security & CIFSSEC_MUST_KRB5) == CIFSSEC_MUST_KRB5)
+		pSMB->hdr.Flags2 |= SMBFLG2_EXT_SEC;
 	
 	count = 0;
 	for(i=0;i<CIFS_NUM_PROT;i++) {
@@ -425,22 +425,21 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 
 	rc = SendReceive(xid, ses, (struct smb_hdr *) pSMB,
 			 (struct smb_hdr *) pSMBr, &bytes_returned, 0);
-	if (rc == 0) {
+	if (rc != 0) 
+		goto neg_err_exit;
+
 	cFYI(1,("Dialect: %d", pSMBr->DialectIndex));
 	/* Check wct = 1 error case */
-		if((pSMBr->hdr.WordCount < 13)  
-			|| (pSMBr->DialectIndex == BAD_PROT)) {
-			/* core returns wct = 1, but we do not ask for
-			core - otherwise it just comes when dialect
-			index is -1 indicating we could not negotiate
-			a common dialect */
+	if((pSMBr->hdr.WordCount < 13) || (pSMBr->DialectIndex == BAD_PROT)) {
+		/* core returns wct = 1, but we do not ask for core - otherwise
+		small wct just comes when dialect index is -1 indicating we 
+		could not negotiate a common dialect */
 		rc = -EOPNOTSUPP;
 		goto neg_err_exit;
 #ifdef CONFIG_CIFS_WEAK_PW_HASH 
 	} else if((pSMBr->hdr.WordCount == 13)
 			&& (pSMBr->DialectIndex == LANMAN_PROT)) {
-			struct lanman_neg_rsp * rsp = 
-				(struct lanman_neg_rsp *)pSMBr;
+		struct lanman_neg_rsp * rsp = (struct lanman_neg_rsp *)pSMBr;
 
 		if((extended_security & CIFSSEC_MAY_LANMAN) || 
 			(extended_security & CIFSSEC_MAY_PLNTXT))
@@ -455,27 +454,33 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 		server->maxReq = le16_to_cpu(rsp->MaxMpxCount);
 		server->maxBuf = min((__u32)le16_to_cpu(rsp->MaxBufSize),
 				(__u32)CIFSMaxBufSize + MAX_CIFS_HDR_SIZE);
-
-			/* BB what do we do with raw mode? BB */
+		GETU32(server->sessid) = le32_to_cpu(rsp->SessionKey);
+		/* even though we do not use raw we might as well set this
+		accurately, in case we ever find a need for it */
+		if((le16_to_cpu(rsp->RawMode) & RAW_ENABLE) == RAW_ENABLE) {
+			server->maxRw = 0xFF00;
+			server->capabilities = CAP_MPX_MODE | CAP_RAW_MODE;
+		} else {
+			server->maxRw = 0;/* we do not need to use raw anyway */
+			server->capabilities = CAP_MPX_MODE;
+		}
 		server->timeZone = le16_to_cpu(rsp->ServerTimeZone);
-			/* Do we have to set signing flags? no signing
-			was available LANMAN - default should be ok */
-
-			/* BB FIXME set default dummy capabilities since
-			they are not returned by the server in this dialect */
 
-			/* get server time for time conversions and add
+		/* BB get server time for time conversions and add
 		code to use it and timezone since this is not UTC */	
 
 		if (rsp->EncryptionKeyLength == CIFS_CRYPTO_KEY_SIZE) {
 			memcpy(server->cryptKey, rsp->EncryptionKey,
 				CIFS_CRYPTO_KEY_SIZE);
-			} else {
-				rc = -EIO;
+		} else if (server->secMode & SECMODE_PW_ENCRYPT) {
+			rc = -EIO; /* need cryptkey unless plain text */
 			goto neg_err_exit;
 		}
 
-			cFYI(1,("LANMAN negotiated")); /* BB removeme BB */
+		cFYI(1,("LANMAN negotiated"));
+		/* we will not end up setting signing flags - as no signing
+		was in LANMAN and server did not return the flags on */
+		goto signing_check;
 #else /* weak security disabled */
 	} else if(pSMBr->hdr.WordCount == 13) {
 		cERROR(1,("mount failed, cifs module not built "
@@ -488,7 +493,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 		rc = -EOPNOTSUPP;
 		goto neg_err_exit;
 	}
-
+	/* else wct == 17 NTLM */
 	server->secMode = pSMBr->SecurityMode;
 	if((server->secMode & SECMODE_USER) == 0)
 		cFYI(1,("share mode security"));
@@ -506,27 +511,27 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 		server->secType = NTLM;
 	/* else krb5 ... */
 
-		/* one byte - no need to convert this or EncryptionKeyLen
-		   from little endian */
+	/* one byte, so no need to convert this or EncryptionKeyLen from
+	   little endian */
 	server->maxReq = le16_to_cpu(pSMBr->MaxMpxCount);
 	/* probably no need to store and check maxvcs */
-		server->maxBuf =
-			min(le32_to_cpu(pSMBr->MaxBufferSize),
+	server->maxBuf = min(le32_to_cpu(pSMBr->MaxBufferSize),
 			(__u32) CIFSMaxBufSize + 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;
+	} else if (server->secMode & SECMODE_PW_ENCRYPT) {
+		rc = -EIO; /* no crypt key only if plain text pwd */
+		goto neg_err_exit;
+	}
 
 	/* BB might be helpful to save off the domain of server here */
 
@@ -538,24 +543,19 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 		else if (count == 16) {
 			server->secType = RawNTLMSSP;
 			if (server->socketUseCount.counter > 1) {
-					if (memcmp
-						(server->server_GUID,
+				if (memcmp(server->server_GUID,
 					   pSMBr->u.extended_response.
 					   GUID, 16) != 0) {
 					cFYI(1, ("server UID changed"));
-						memcpy(server->
-							server_GUID,
-							pSMBr->u.
-							extended_response.
-							GUID, 16);
+					memcpy(server->server_GUID,
+						pSMBr->u.extended_response.GUID,
+						16);
 				}
 			} else
 				memcpy(server->server_GUID,
-					       pSMBr->u.extended_response.
-					       GUID, 16);
+				       pSMBr->u.extended_response.GUID, 16);
 		} else {
-				rc = decode_negTokenInit(pSMBr->u.
-							 extended_response.
+			rc = decode_negTokenInit(pSMBr->u.extended_response.
 						 SecurityBlob,
 						 count - 16,
 						 &server->secType);
@@ -568,19 +568,28 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 		}
 	} else
 		server->capabilities &= ~CAP_EXTENDED_SECURITY;
+
+signing_check:
 	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);
+			cERROR(1,("Server requires "
+				 "/proc/fs/cifs/PacketSigningEnabled to be on"));
+		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);
+			server->secMode &= 
+				~(SECMODE_SIGN_ENABLED | SECMODE_SIGN_REQUIRED);
+	} else if(sign_CIFS_PDUs == 2) {
+		if((server->secMode & 
+			(SECMODE_SIGN_ENABLED | SECMODE_SIGN_REQUIRED)) == 0) {
+			cERROR(1,("signing required but server lacks support"));
 		}
-				
 	}
 neg_err_exit:	
 	cifs_buf_release(pSMB);
+
+	cFYI(1,("negprot rc %d",rc));
 	return rc;
 }
 

fs/cifs/sess.c

@@ -324,6 +324,7 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
 	__u16 action;
 	int bytes_remaining;
 
+	cFYI(1,("new sess setup"));
 	if(ses == NULL)
 		return -EINVAL;