Allow parsing vers=3.11 on cifs mount

Parses and recognizes "vers=3.1.1" on cifs mount and allows sending
0x0311 as a new CIFS/SMB3 dialect. Subsequent patches will add
the new negotiate contexts and updated session setup

Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Steve French <steve.french@primarydata.com>

fs/cifs/Kconfig

@@ -192,6 +192,15 @@ config CIFS_SMB2
 	  options are also slightly simpler (compared to CIFS) due
 	  to protocol improvements.
 
+config CIFS_SMB311
+	bool "SMB3.1.1 network file system support (Experimental)"
+	depends on CIFS_SMB2 && INET
+
+	help
+	  This enables experimental support for the newest, SMB3.1.1, dialect.
+	  This dialect includes improved security negotiation features.
+	  If unsure, say N
+
 config CIFS_FSCACHE
 	  bool "Provide CIFS client caching support"
 	  depends on CIFS=m && FSCACHE || CIFS=y && FSCACHE=y

fs/cifs/cifsglob.h

@@ -171,6 +171,10 @@ enum smb_version {
 	Smb_21,
 	Smb_30,
 	Smb_302,
+#ifdef CONFIG_CIFS_SMB311
+	Smb_311,
+#endif /* SMB311 */
+	Smb_version_err
 };
 
 struct mid_q_entry;
@@ -1617,4 +1621,7 @@ extern struct smb_version_values smb30_values;
 #define SMB302_VERSION_STRING	"3.02"
 /*extern struct smb_version_operations smb302_operations;*/ /* not needed yet */
 extern struct smb_version_values smb302_values;
+#define SMB311_VERSION_STRING	"3.1.1"
+/*extern struct smb_version_operations smb311_operations;*/ /* not needed yet */
+extern struct smb_version_values smb311_values;
 #endif	/* _CIFS_GLOB_H */

fs/cifs/connect.c

@@ -280,6 +280,10 @@ static const match_table_t cifs_smb_version_tokens = {
 	{ Smb_21, SMB21_VERSION_STRING },
 	{ Smb_30, SMB30_VERSION_STRING },
 	{ Smb_302, SMB302_VERSION_STRING },
+#ifdef CONFIG_CIFS_SMB311
+	{ Smb_311, SMB311_VERSION_STRING },
+#endif /* SMB311 */
+	{ Smb_version_err, NULL }
 };
 
 static int ip_connect(struct TCP_Server_Info *server);
@@ -1133,6 +1137,12 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol)
 		vol->ops = &smb30_operations; /* currently identical with 3.0 */
 		vol->vals = &smb302_values;
 		break;
+#ifdef CONFIG_CIFS_SMB311
+	case Smb_311:
+		vol->ops = &smb30_operations; /* currently identical with 3.0 */
+		vol->vals = &smb311_values;
+		break;
+#endif /* SMB311 */
 #endif
 	default:
 		cifs_dbg(VFS, "Unknown vers= option specified: %s\n", value);

fs/cifs/smb2ops.c

@@ -1714,3 +1714,25 @@ struct smb_version_values smb302_values = {
 	.signing_required = SMB2_NEGOTIATE_SIGNING_REQUIRED,
 	.create_lease_size = sizeof(struct create_lease_v2),
 };
+
+#ifdef CONFIG_CIFS_SMB311
+struct smb_version_values smb311_values = {
+	.version_string = SMB311_VERSION_STRING,
+	.protocol_id = SMB311_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,
+	.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,
+	.signing_enabled = SMB2_NEGOTIATE_SIGNING_ENABLED | SMB2_NEGOTIATE_SIGNING_REQUIRED,
+	.signing_required = SMB2_NEGOTIATE_SIGNING_REQUIRED,
+	.create_lease_size = sizeof(struct create_lease_v2),
+};
+#endif /* SMB311 */

fs/cifs/smb2pdu.c

@@ -393,6 +393,10 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 		cifs_dbg(FYI, "negotiated smb3.0 dialect\n");
 	else if (rsp->DialectRevision == cpu_to_le16(SMB302_PROT_ID))
 		cifs_dbg(FYI, "negotiated smb3.02 dialect\n");
+#ifdef CONFIG_CIFS_SMB311
+	else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID))
+		cifs_dbg(FYI, "negotiated smb3.1.1 dialect\n");
+#endif /* SMB311 */
 	else {
 		cifs_dbg(VFS, "Illegal dialect returned by server %d\n",
 			 le16_to_cpu(rsp->DialectRevision));

fs/cifs/smb2pdu.h

@@ -191,7 +191,10 @@ struct smb2_negotiate_req {
 	__le16 Reserved;	/* MBZ */
 	__le32 Capabilities;
 	__u8   ClientGUID[SMB2_CLIENT_GUID_SIZE];
-	__le64 ClientStartTime;	/* MBZ */
+	/* In SMB3.02 and earlier next three were MBZ le64 ClientStartTime */
+	__le32 NegotiateContextOffset; /* SMB3.1.1 only. MBZ earlier */
+	__le16 NegotiateContextCount;  /* SMB3.1.1 only. MBZ earlier */
+	__le16 Reserved2;
 	__le16 Dialects[1]; /* One dialect (vers=) at a time for now */
 } __packed;
 
@@ -200,6 +203,7 @@ struct smb2_negotiate_req {
 #define SMB21_PROT_ID 0x0210
 #define SMB30_PROT_ID 0x0300
 #define SMB302_PROT_ID 0x0302
+#define SMB311_PROT_ID 0x0311
 #define BAD_PROT_ID   0xFFFF
 
 /* SecurityMode flags */
@@ -222,7 +226,7 @@ struct smb2_negotiate_rsp {
 	__le16 StructureSize;	/* Must be 65 */
 	__le16 SecurityMode;
 	__le16 DialectRevision;
-	__le16 Reserved;	/* MBZ */
+	__le16 NegotiateContextCount;	/* Prior to SMB3.1.1 was Reserved & MBZ */
 	__u8   ServerGUID[16];
 	__le32 Capabilities;
 	__le32 MaxTransactSize;
@@ -232,7 +236,7 @@ struct smb2_negotiate_rsp {
 	__le64 ServerStartTime;
 	__le16 SecurityBufferOffset;
 	__le16 SecurityBufferLength;
-	__le32 Reserved2;	/* may be any value, ignore */
+	__le32 NegotiateContextOffset;	/* Pre:SMB3.1.1 was reserved/ignored */
 	__u8   Buffer[1];	/* variable length GSS security buffer */
 } __packed;