Storage access validation to data messages using partial storage address data indexed entries containing permissible address range validation for message source

In a data processing system having a plurality of data communicating elements interconnected by a communication medium for communicating message data therebetween, the plurality of data communicating elements including a processor element having a memory unit storing data, the message data including either a request to write data to the memory unit or to read data from the memory unit, a source address identifying a sender data communicating element of the message data, length data indicative of the amount of data to be written or read, and a memory address indicative of a location in the memory unit whereat the data is to be written or from which the data is read, a method of validating access to the memory unit comprising the steps of:

• maintaining in the processor element a table containing, for each of the plurality of data communicating elements sending to the processor element message data with the request, at least one corresponding entry having a source identification indicative of such data communicating element, and access information indicative of access to the memory unit granted such data communicating element, the access information including a memory storage identification indicative of a predetermined memory area of the memory unit available for storage of the message data;
• receiving the message data and using at least a first portion of the memory address to identify and access the corresponding entry from the table;
• denying access to the memory unit if the source address does not match the source identification or if comparing the memory storage identification to the length data indicates the message data to be read or written is not wholly within the predetermined memory area;
• and
• using at least a second portion of the memory address to identify the location if the source address and source information match, and the access information permits the request.

A processing system, including a plurality of processing elements interconnected by a communication medium for communicating message data therebetween, at least one of the plurality of processing elements including a storage memory, the message data including address information and a request to (1) read data from, or (2) write data to, the storage memory at memory locations identified by the address information, a method for verifying access to the storage memory that includes the steps of:

• maintaining a table associated with the processor element, the table including a plurality of addressable entries, there being at least one entry for each of the other of the plurality of processing elements, each of the plurality of addressable entries containing memory data defining a plurality of memory locations of the storage memory whereat data resides to be read or whereat data is to be written;
• receiving at the processor element message data from a one of the plurality of processing elements;
• using at least a portion of the address information to form an address to select a one of the addressable entries corresponding to the one of the plurality of processing elements;
• comparing the memory data and the address information to deny access to the storage memory if any portion of the data requested to be read from or written to the storage memory is not within the plurality of memory locations of the storage memory.

A processing system having at least first and second processing elements interconnected for communicating messages therebetween, the first processing element including a storage for data, a method of validating access to the storage that includes the steps of:

• the second processing element sending a request message to the first processing element requesting to write data to, or read data from, the storage, and address data indicative of a predetermined number of storage locations of the storage whereat the data will be written or from which the data will be read;
• maintaining at the first processing element a table having a plurality of entries, each of the entries containing information describing a second number of storage locations of the storage whereat data to be read resides or whereat data can be written;
• selecting a one of the plurality of entries using as an entry address at least a portion of the address data;
• and
• denying access to the storage if comparison of the address data and information indicates the data to be read or to be written is not within the second number of storage locations.