Custom packet processing functionality in routers is one of the key characteristics of next-generation Internet architectures. Network services have been proposed as an abstraction to describe, compose, and deploy end-to-end connections with custom communication features. We present a novel hardware architecture for high-performance processing of such network services in the data path. The design provides simple processing units to implement services and a custom hardware infrastructure to manage packets and processing context. The design allows for simple software development, flexible network service allocation, and high scalability to handle traffic at Gigabit line rates.