iSCSI - re-phrase of 4.1

["Julian Satran" <Julian_Satran@il.ibm.com>]

Here is an attemp to re-phrase 4.1.
Please note that the only substantive change introduced is the limit of 2**64 for the decimal encoding.
The fact that key names must start with a letter and that binaries are all unsigned is made explicit.

Please comment:

The initiator and target send a set of key=value pairs encoded in UTF-8 Unicode. All the text keys and text values specified in this docu-ment are to be presented and interpreted in the case they appear in this document. They are case sensitive. 

The following character symbols are used in this document for text items:

(a-z, A-Z) - letters
(0-9) - digits
" " (0x20) - space
"." (0x2e) - point
"-" (0x2d) - minus
"+" (0x2b) - plus
"@" (0x40) - commercial at
"_" (0x5f) - underscore
"=" (0x3d) - equal
":" (0x3a) - colon
"/" (0x2f) - solidus or slash
"[" (0x5b) - left bracket
"]" (0x5d) - right bracket
null(0x00) - null separator
"," (0x2c) - comma
"~" (0x7e) - tilde

A key is key-name followed by "=". The term key is used frequently in this document with the meaning of key-name.

A value is whatever follows the = that follows the key-name up to a null separator - that separates one key value from the next

A value is either a simple-value or a list-of-values.

The following definitions will be used in the rest of this document:

key-name: a string defined by the regular expression 
"[A-Z][a-zA-Z0-9.-+@_]*"

text-value: a string defined by the regular expression 
"[][a-zA-Z0-9.-+@_/\[\]=]*"

boolean-value: a string defined by the regular expression
"Yes|No"

hex-constant: unsigned hexadecimal constant described by regu-lar expression "0[xX][0-9a-zA-Z]+"

base-64-constant: unsigned base-64 constant described by regu-lar expression "0b[A-Za-z0-9+/=]+"

regular-binary-value :  an unsigned integer less than 2**64 encoded as a decimal constant, hex constant, or base-64 con-stant

large-binary-value :  an unsigned integer larger than 2**64-1 encoded as a hex constant, or base-64 constant

binary-value: a regular-binary-value or a large binary-value

numeric-range: two binary-values separated by a tilde

simple-value: text-value, boolean-value, binary-value or a numeric range.

list-of-values: a sequence of simple-values separated by comma


Key names MUST NOT exceed 63 bytes.  If not otherwise specified, the maximum length of a simple-value (not its encoded representation) is 255 bytes not including the delimiter (comma or null).

Any iSCSI target or initiator MUST support receiving at least 16384 bytes of key=value data in a negotiation sequence except when indicat-ing support for very long authentication items such as public key cer-tificates in which case they MUST support receiving at least 64 kilobytes of key=value data.