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>

6 files changed, 59 insertions, 3 deletions

diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig
index a2172f3f69e3..e7b478b49985 100644
--- a/fs/cifs/Kconfig
+++ b/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
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 22b289a3b1c4..71bf86e6de9a 100644
--- a/fs/cifs/cifsglob.h
+++ b/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 */
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 8383d5ea4202..9300b98d8584 100644
--- a/fs/cifs/connect.c
+++ b/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);
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 54daee5ad4c1..a7d520cc2cfd 100644
--- a/fs/cifs/smb2ops.c
+++ b/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 */
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 54cbe19d9c08..150dbe3e2822 100644
--- a/fs/cifs/smb2pdu.c
+++ b/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));
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 70867d54fb8b..994b34843c3a 100644
--- a/fs/cifs/smb2pdu.h
+++ b/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;