US Patent 9860168 Network packet header modification for hardware-based packet processing

A packet processor may implement network packet modification. A network packet may be received at a packet processor. A packet header modification may be identified for the network packet. The packet processor may access a memory to traverse a dependency graph for the packet header modification to obtain an operation to apply the packet header modification and dependent operations to update fields in the packet header to be changed as a result of the packet header modification. The dependency graph may have been stored in the memory prior to receiving the network packet. The obtained operations may be performed according to the traversal of the dependency graph. The modified packet may then be transmitted.