Data verification using signature

Abstract

A system processes packets in a network device and includes a memory for buffering the packets. The memory may store the packets in memory in data cells. To expedite packet processing, portions of the packet are extracted and placed in a notification, which is then used for packet processing operations, such as route lookup, policing, and accounting. The notification may also include address elements, such as address offsets, that define the locations of the data cells in memory. The address elements can be used to read the data cells from the memory when packet processing is done. If the notification cannot hold all the address elements, additional cells, indirect cells, are created for holding the remaining address elements. The indirect cells are formed in a linked list. The notification contains an address element. To prevent reading incorrect indirect cells, each indirect cell is written with a signature that is created based on the notification. When an indirect cell is read out, the signature is checked to determine whether it belongs to that notification. If the signature is not correct, this may mean that the indirect cell has not yet been written to memory, or that the indirect cell was in some way corrupted during writing, storing, or reading.