iscsi-target: remove support for obsolete markers

Support for markers is currently broken because of a bug in
iscsi_enforce_integrity_rules(): the "IFMarkInt_Reject" and
"OFMarkInt_Reject" variables are always equal to 1 in
iscsi_enforce_integrity_rules().

Moreover, fixed interval markers keys (IFMarker, OFMarker, IFMarkInt
and OFMarkInt) are obsolete according to iSCSI RFC 7143:

>From http://tools.ietf.org/html/rfc7143#section-13.25:

   13.25.  Obsoleted Keys

   This document obsoletes the following keys defined in [RFC3720]:
   IFMarker, OFMarker, OFMarkInt, and IFMarkInt.  However, iSCSI
   implementations compliant to this document may still receive these
   obsoleted keys -- i.e., in a responder role -- in a text negotiation.

   When an IFMarker or OFMarker key is received, a compliant iSCSI
   implementation SHOULD respond with the constant "Reject" value.  The
   implementation MAY alternatively respond with a "No" value.

   However, the implementation MUST NOT respond with a "NotUnderstood"
   value for either of these keys.

   When an IFMarkInt or OFMarkInt key is received, a compliant iSCSI
   implementation MUST respond with the constant "Reject" value.  The
   implementation MUST NOT respond with a "NotUnderstood" value for
   either of these keys.

This patch disables markers by turning the corresponding parameters to
read-only. The default value of IFMarker and OFMarker remains "No" but
the user cannot change it to "Yes" anymore. The new value of IFMarkInt
and OFMarkInt is "Reject".

(Drop left-over iscsi_get_value_from_number_range + make configfs
 parameters attrs R/W nops - nab)

Signed-off-by: Christophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/iscsi/iscsi_target_parameters.h b/drivers/target/iscsi/iscsi_target_parameters.h
index a47046a..a0751e3 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.h
+++ b/drivers/target/iscsi/iscsi_target_parameters.h
@@ -138,8 +138,8 @@
 #define INITIAL_SESSIONTYPE			NORMAL
 #define INITIAL_IFMARKER			NO
 #define INITIAL_OFMARKER			NO
-#define INITIAL_IFMARKINT			"2048~65535"
-#define INITIAL_OFMARKINT			"2048~65535"
+#define INITIAL_IFMARKINT			REJECT
+#define INITIAL_OFMARKINT			REJECT
 
 /*
  * Initial values for iSER parameters following RFC-5046 Section 6
@@ -239,10 +239,9 @@
 #define TYPERANGE_AUTH			0x0200
 #define TYPERANGE_DIGEST		0x0400
 #define TYPERANGE_ISCSINAME		0x0800
-#define TYPERANGE_MARKINT		0x1000
-#define TYPERANGE_SESSIONTYPE		0x2000
-#define TYPERANGE_TARGETADDRESS		0x4000
-#define TYPERANGE_UTF8			0x8000
+#define TYPERANGE_SESSIONTYPE		0x1000
+#define TYPERANGE_TARGETADDRESS		0x2000
+#define TYPERANGE_UTF8			0x4000
 
 #define IS_TYPERANGE_0_TO_2(p)		((p)->type_range & TYPERANGE_0_TO_2)
 #define IS_TYPERANGE_0_TO_3600(p)	((p)->type_range & TYPERANGE_0_TO_3600)