[CIFS] Fix SMB2 negotiation support to select only one dialect (based on vers=)

Based on whether the user (on mount command) chooses:

vers=3.0 (for smb3.0 support)
vers=2.1 (for smb2.1 support)
or (with subsequent patch, which will allow SMB2 support)
vers=2.0 (for original smb2.02 dialect support)

send only one dialect at a time during negotiate (we
had been sending a list).
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/cifsglob.h

@@ -179,6 +179,7 @@ struct smb_rqst {
 enum smb_version {
 	Smb_1 = 1,
 	Smb_21,
+	Smb_30,
 };
 
 struct mid_q_entry;
@@ -372,6 +373,8 @@ struct smb_version_operations {
 
 struct smb_version_values {
 	char		*version_string;
+	__u16		protocol_id;
+	__u32		req_capabilities;
 	__u32		large_lock_type;
 	__u32		exclusive_lock_type;
 	__u32		shared_lock_type;
@@ -1496,7 +1499,13 @@ extern mempool_t *cifs_mid_poolp;
 #define SMB1_VERSION_STRING	"1.0"
 extern struct smb_version_operations smb1_operations;
 extern struct smb_version_values smb1_values;
+#define SMB20_VERSION_STRING	"2.0"
+/*extern struct smb_version_operations smb20_operations; */ /* not needed yet */
+extern struct smb_version_values smb20_values;
 #define SMB21_VERSION_STRING	"2.1"
 extern struct smb_version_operations smb21_operations;
 extern struct smb_version_values smb21_values;
+#define SMB30_VERSION_STRING	"3.0"
+/*extern struct smb_version_operations smb30_operations; */ /* not needed yet */
+extern struct smb_version_values smb30_values;
 #endif	/* _CIFS_GLOB_H */

fs/cifs/connect.c

@@ -272,6 +272,7 @@ static const match_table_t cifs_cacheflavor_tokens = {
 static const match_table_t cifs_smb_version_tokens = {
 	{ Smb_1, SMB1_VERSION_STRING },
 	{ Smb_21, SMB21_VERSION_STRING },
+	{ Smb_30, SMB30_VERSION_STRING },
 };
 
 static int ip_connect(struct TCP_Server_Info *server);
@@ -1074,6 +1075,10 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol)
 		vol->ops = &smb21_operations;
 		vol->vals = &smb21_values;
 		break;
+	case Smb_30:
+		vol->ops = &smb21_operations; /* currently identical with 2.1 */
+		vol->vals = &smb30_values;
+		break;
 #endif
 	default:
 		cERROR(1, "Unknown vers= option specified: %s", value);

fs/cifs/smb2ops.c

@@ -645,6 +645,25 @@ struct smb_version_operations smb21_operations = {
 
 struct smb_version_values smb21_values = {
 	.version_string = SMB21_VERSION_STRING,
+	.protocol_id = SMB21_PROT_ID,
+	.req_capabilities = 0, /* MBZ on negotiate req until SMB3 dialect */
+	.large_lock_type = 0,
+	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
+	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
+	.unlock_lock_type = SMB2_LOCKFLAG_UNLOCK,
+	.header_size = sizeof(struct smb2_hdr),
+	.max_header_size = MAX_SMB2_HDR_SIZE,
+	.read_rsp_size = sizeof(struct smb2_read_rsp) - 1,
+	.lock_cmd = SMB2_LOCK,
+	.cap_unix = 0,
+	.cap_nt_find = SMB2_NT_FIND,
+	.cap_large_files = SMB2_LARGE_FILES,
+};
+
+struct smb_version_values smb30_values = {
+	.version_string = SMB30_VERSION_STRING,
+	.protocol_id = SMB30_PROT_ID,
+	.req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING | SMB2_GLOBAL_CAP_LARGE_MTU,
 	.large_lock_type = 0,
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,

fs/cifs/smb2pdu.c

 /*
  *   fs/cifs/smb2pdu.c
  *
- *   Copyright (C) International Business Machines  Corp., 2009, 2011
+ *   Copyright (C) International Business Machines  Corp., 2009, 2012
  *                 Etersoft, 2012
  *   Author(s): Steve French (sfrench@us.ibm.com)
  *              Pavel Shilovsky (pshilovsky@samba.org) 2012
@@ -304,24 +304,6 @@ free_rsp_buf(int resp_buftype, void *rsp)
 		cifs_buf_release(rsp);
 }
 
-#define SMB2_NUM_PROT 2
-
-#define SMB2_PROT   0
-#define SMB21_PROT  1
-#define BAD_PROT 0xFFFF
-
-#define SMB2_PROT_ID  0x0202
-#define SMB21_PROT_ID 0x0210
-#define BAD_PROT_ID   0xFFFF
-
-static struct {
-	int index;
-	__le16 name;
-} smb2protocols[] = {
-	{SMB2_PROT,  cpu_to_le16(SMB2_PROT_ID)},
-	{SMB21_PROT, cpu_to_le16(SMB21_PROT_ID)},
-	{BAD_PROT,   cpu_to_le16(BAD_PROT_ID)}
-};
 
 /*
  *
@@ -348,7 +330,6 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 	int resp_buftype;
 	struct TCP_Server_Info *server;
 	unsigned int sec_flags;
-	u16 i;
 	u16 temp = 0;
 	int blob_offset, blob_length;
 	char *security_blob;
@@ -377,11 +358,10 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 
 	req->hdr.SessionId = 0;
 
-	for (i = 0; i < SMB2_NUM_PROT; i++)
-		req->Dialects[i] = smb2protocols[i].name;
+	req->Dialects[0] = cpu_to_le16(ses->server->vals->protocol_id);
 
-	req->DialectCount = cpu_to_le16(i);
-	inc_rfc1001_len(req, i * 2);
+	req->DialectCount = cpu_to_le16(1); /* One vers= at a time for now */
+	inc_rfc1001_len(req, 2);
 
 	/* only one of SMB2 signing flags may be set in SMB2 request */
 	if ((sec_flags & CIFSSEC_MUST_SIGN) == CIFSSEC_MUST_SIGN)
@@ -391,7 +371,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 
 	req->SecurityMode = cpu_to_le16(temp);
 
-	req->Capabilities = cpu_to_le32(SMB2_GLOBAL_CAP_DFS);
+	req->Capabilities = cpu_to_le32(ses->server->vals->req_capabilities);
 
 	memcpy(req->ClientGUID, cifs_client_guid, SMB2_CLIENT_GUID_SIZE);
 
@@ -411,10 +391,14 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 
 	cFYI(1, "mode 0x%x", rsp->SecurityMode);
 
-	if (rsp->DialectRevision == smb2protocols[SMB21_PROT].name)
+	/* BB we may eventually want to match the negotiated vs. requested
+	   dialect, even though we are only requesting one at a time */
+	if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID))
+		cFYI(1, "negotiated smb2.0 dialect");
+	else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID))
 		cFYI(1, "negotiated smb2.1 dialect");
-	else if (rsp->DialectRevision == smb2protocols[SMB2_PROT].name)
-		cFYI(1, "negotiated smb2 dialect");
+	else if (rsp->DialectRevision == cpu_to_le16(SMB30_PROT_ID))
+		cFYI(1, "negotiated smb3.0 dialect");
 	else {
 		cERROR(1, "Illegal dialect returned by server %d",
 			   le16_to_cpu(rsp->DialectRevision));

fs/cifs/smb2pdu.h

@@ -163,9 +163,15 @@ struct smb2_negotiate_req {
 	__le32 Capabilities;
 	__u8   ClientGUID[SMB2_CLIENT_GUID_SIZE];
 	__le64 ClientStartTime;	/* MBZ */
-	__le16 Dialects[2]; /* variable length */
+	__le16 Dialects[1]; /* One dialect (vers=) at a time for now */
 } __packed;
 
+/* Dialects */
+#define SMB20_PROT_ID 0x0202
+#define SMB21_PROT_ID 0x0210
+#define SMB30_PROT_ID 0x0300
+#define BAD_PROT_ID   0xFFFF
+
 /* SecurityMode flags */
 #define	SMB2_NEGOTIATE_SIGNING_ENABLED	0x0001
 #define SMB2_NEGOTIATE_SIGNING_REQUIRED	0x0002
@@ -173,6 +179,10 @@ struct smb2_negotiate_req {
 #define SMB2_GLOBAL_CAP_DFS		0x00000001
 #define SMB2_GLOBAL_CAP_LEASING		0x00000002 /* Resp only New to SMB2.1 */
 #define SMB2_GLOBAL_CAP_LARGE_MTU	0X00000004 /* Resp only New to SMB2.1 */
+#define SMB2_GLOBAL_CAP_MULTI_CHANNEL	0x00000008 /* New to SMB3 */
+#define SMB2_GLOBAL_CAP_PERSISTENT_HANDLES 0x00000010 /* New to SMB3 */
+#define SMB2_GLOBAL_CAP_DIRECTORY_LEASING  0x00000020 /* New to SMB3 */
+#define SMB2_GLOBAL_CAP_ENCRYPTION	0x00000040 /* New to SMB3 */
 /* Internal types */
 #define SMB2_NT_FIND			0x00100000
 #define SMB2_LARGE_FILES		0x00200000