SMB2 dialect negotiation

SMB2 dialect negotiation

[Steve French]

Respinning the SMB2/SMB3 mount patch.  As Jeff suggested, if we are
going to negotiate only one dialect at a time, we will need a change
something like the following.  In addition, we should pull the
capabilities out of the structure which contains the default "values"
for each dialect.  It also adds some missing SMB3 negotiated
capabilities (which for the moment we don't turn on, but which we will
need soon).

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index a39e5b7..e94825c 100644
--- a/fs/cifs/cifsglob.h
+++ b/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;
@@ -371,6 +372,8 @@ 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;
@@ -1495,7 +1498,13 @@ 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 */
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a792282..2fdbe08 100644
--- a/fs/cifs/connect.c
+++ b/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);
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 2183bb3..503c1e8 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -643,8 +643,45 @@ struct smb_version_operations smb21_operations = {
 	.new_lease_key = smb2_new_lease_key,
 };

+
+struct smb_version_values smb20_values = {
+	.version_string = SMB20_VERSION_STRING,
+	.protocol_id = SMB20_PROT_ID,
+	.req_capabilities = SMB2_GLOBAL_CAP_DFS,
+	.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 smb21_values = {
 	.version_string = SMB21_VERSION_STRING,
+	.protocol_id = SMB21_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,
+};
+
+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,
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index a7db95f..39d26cb 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1,7 +1,7 @@
 /*
  *   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-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org)
  *              Pavel Shilovsky (pshilovsky-eUNUBHrolfbYtjvyW6yDsg@public.gmane.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);

@@ -416,10 +396,14 @@ 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));
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index da09922..4cb4ced 100644
--- a/fs/cifs/smb2pdu.h
+++ b/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

-- 
Thanks,

Steve

Re: SMB2 dialect negotiation

[Pavel Shilovsky]

2012/9/20 Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
> Respinning the SMB2/SMB3 mount patch.  As Jeff suggested, if we are
> going to negotiate only one dialect at a time, we will need a change
> something like the following.  In addition, we should pull the
> capabilities out of the structure which contains the default "values"
> for each dialect.  It also adds some missing SMB3 negotiated
> capabilities (which for the moment we don't turn on, but which we will
> need soon).
>
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index a39e5b7..e94825c 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/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;
> @@ -371,6 +372,8 @@ 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;
> @@ -1495,7 +1498,13 @@ 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 */
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index a792282..2fdbe08 100644
> --- a/fs/cifs/connect.c
> +++ b/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);
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 2183bb3..503c1e8 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -643,8 +643,45 @@ struct smb_version_operations smb21_operations = {
>         .new_lease_key = smb2_new_lease_key,
>  };
>
> +
> +struct smb_version_values smb20_values = {
> +       .version_string = SMB20_VERSION_STRING,
> +       .protocol_id = SMB20_PROT_ID,
> +       .req_capabilities = SMB2_GLOBAL_CAP_DFS,
> +       .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,
> +};

I think we need vers=2.0 mount option to let user choose this structure.

> +
>  struct smb_version_values smb21_values = {
>         .version_string = SMB21_VERSION_STRING,
> +       .protocol_id = SMB21_PROT_ID,
> +       .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING |
> SMB2_GLOBAL_CAP_LARGE_MTU,

A client can specify only SMB2_GLOBAL_CAP_DFS in request - other two
are set by the server in a response.

> +       .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,
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index a7db95f..39d26cb 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -1,7 +1,7 @@
>  /*
>   *   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-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org)
>   *              Pavel Shilovsky (pshilovsky-eUNUBHrolfbYtjvyW6yDsg@public.gmane.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);

I think we need to separate Negotiate capabilities field and Session
Setup one. So, setting it to SMB2_GLOBAL_CAP_DFS here looks like my
bug: it should be 0 for SMB2.0/SMB2.1 and not 0 for SMB3.0.

The only place where we should set capabilities for SMB2.0/SMB2.1 is
Session Setup capabilities filed that can be 0 or SMB2_GLOBAL_CAP_DFS
for SMB2.0/SMB2.1/SMB3.0.

>
>         memcpy(req->ClientGUID, cifs_client_guid, SMB2_CLIENT_GUID_SIZE);
>
> @@ -416,10 +396,14 @@ 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));
> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> index da09922..4cb4ced 100644
> --- a/fs/cifs/smb2pdu.h
> +++ b/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
>
> --
> Thanks,
>
> Steve



-- 
Best regards,
Pavel Shilovsky.

Re: SMB2 dialect negotiation

[Jeff Layton]

On Thu, 20 Sep 2012 14:46:42 +0400
Pavel Shilovsky <piastryyy-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> 2012/9/20 Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
> > Respinning the SMB2/SMB3 mount patch.  As Jeff suggested, if we are
> > going to negotiate only one dialect at a time, we will need a change
> > something like the following.  In addition, we should pull the
> > capabilities out of the structure which contains the default "values"
> > for each dialect.  It also adds some missing SMB3 negotiated
> > capabilities (which for the moment we don't turn on, but which we will
> > need soon).
> >
> > diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> > index a39e5b7..e94825c 100644
> > --- a/fs/cifs/cifsglob.h
> > +++ b/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;
> > @@ -371,6 +372,8 @@ 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;
> > @@ -1495,7 +1498,13 @@ 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 */
> > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> > index a792282..2fdbe08 100644
> > --- a/fs/cifs/connect.c
> > +++ b/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);
> > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> > index 2183bb3..503c1e8 100644
> > --- a/fs/cifs/smb2ops.c
> > +++ b/fs/cifs/smb2ops.c
> > @@ -643,8 +643,45 @@ struct smb_version_operations smb21_operations = {
> >         .new_lease_key = smb2_new_lease_key,
> >  };
> >
> > +
> > +struct smb_version_values smb20_values = {
> > +       .version_string = SMB20_VERSION_STRING,
> > +       .protocol_id = SMB20_PROT_ID,
> > +       .req_capabilities = SMB2_GLOBAL_CAP_DFS,
> > +       .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,
> > +};
> 
> I think we need vers=2.0 mount option to let user choose this structure.
> 

Let's not add data structures that have no code to back them up. That's
just a maintenance headache and waste of memory for no benefit. I
suggest just dropping the smb20_values struct from the patch. Once
there's a coherent plan to add 2.0 support then it can be added back at
the same time as you add the code needed to support it.

> > +
> >  struct smb_version_values smb21_values = {
> >         .version_string = SMB21_VERSION_STRING,
> > +       .protocol_id = SMB21_PROT_ID,
> > +       .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING |
> > SMB2_GLOBAL_CAP_LARGE_MTU,
> 
> A client can specify only SMB2_GLOBAL_CAP_DFS in request - other two
> are set by the server in a response.
> 
> > +       .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,
> > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> > index a7db95f..39d26cb 100644
> > --- a/fs/cifs/smb2pdu.c
> > +++ b/fs/cifs/smb2pdu.c
> > @@ -1,7 +1,7 @@
> >  /*
> >   *   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-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org)
> >   *              Pavel Shilovsky (pshilovsky-eUNUBHrolfbYtjvyW6yDsg@public.gmane.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);
> 
> I think we need to separate Negotiate capabilities field and Session
> Setup one. So, setting it to SMB2_GLOBAL_CAP_DFS here looks like my
> bug: it should be 0 for SMB2.0/SMB2.1 and not 0 for SMB3.0.
> 
> The only place where we should set capabilities for SMB2.0/SMB2.1 is
> Session Setup capabilities filed that can be 0 or SMB2_GLOBAL_CAP_DFS
> for SMB2.0/SMB2.1/SMB3.0.
> 
> >
> >         memcpy(req->ClientGUID, cifs_client_guid, SMB2_CLIENT_GUID_SIZE);
> >
> > @@ -416,10 +396,14 @@ 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));

For now, this is probably ok but there's a problem we'll have to deal
with eventually...

If we ever want to make autonegotiation work then you'll need a way to
set the server->ops and server->vals after the negprot response has
come back.

What may be best is to rethink what the vers= option actually does.
Instead of having it set vol->ops and vol->vals, have it just affect
how the negprot is performed and only set vol->ops and ->vals after
that has completed.


> > diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> > index da09922..4cb4ced 100644
> > --- a/fs/cifs/smb2pdu.h
> > +++ b/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 */

These comments are unhelpful. How about comments that describe what
these flags mean instead?

> >  /* Internal types */
> >  #define SMB2_NT_FIND                   0x00100000
> >  #define SMB2_LARGE_FILES               0x00200000
> >
> > --
> > Thanks,
> >
> > Steve
> 
> 
> 


-- 
Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>