The foundation for all networking protocols for the Green Hills family
of operating systems is the GHNet TCP/IP stack. It's a full featured
and high performance dual mode IPv4/IPv6 stack for embedded systems with
options for advanced routing, and an extensive suite of security protocols.
GHNet is an ultra compact IPv4/IPv6 stack, designed for minimum footprint
and maximum performance, and is integrated and validated with INTEGRITY®, INTEGRITY-178B, and µ-velOSity™.
GHNet is suited for use in products ranging from small foot print consumer
devices to advanced core network equipment. It has broad RFC support
and has been through extensive protocol conformance and interoperability
testing. It is also integrated with a broad range of networking applications,
management, and security protocols. See the complete list of supported
GHNet is a true dual mode IPv4/IPv6 stack and can be configured for IPv4
only, IPv6 only, or to support both protocols simultaneously. This is
an important feature since the transition from IPv4 to IPv6 is expected
to take several years. Furthermore, the IPv6 functionality has been approved
by the industry standard IPv6 READY Program, which guarantees IPv6 interoperability.
Modular Design and Scalability
The GHNet protocol suite has a modular design and is highly configurable
providing maximum size and feature scalability. When a module is not
utilized, it is not just deactivated, it is removed entirely to save
valuable storage memory space in the often limited capacity of an embedded
device. This results in footprint sizes as small as 25 kilobytes for
a UDP only configured stack and 41 kilobytes for a TCP enabled stack.
GHNet can be configured to support host-only stack features with minimal
footprint, or enabled with advanced routing features. The built-in virtual
routing and forwarding support enables a single stack to assume the responsibility
of multiple TCP/IP stacks. This enables far more efficient use of existing
hardware and software capabilities than previously possible. Furthermore
GHNet can also work with advanced third party routing solutions like
OSPF, BGP, RIP, IS-IS, PIM-SIM, and DVMRP.
GHNet can be configured to run in either the kernel’s address space,
or in a separate partition for maximum security. It is also possible
to run multiple instances of the stack in separate partitions enabling
stacks to execute at multiple independent levels of security.
GHNet offers a zero copy API that provides the option for true zero copy
for raw sockets, UDP, and TCP from the application all the way through
the driver, including the TCP layer when the stack is running in kernel
mode. This optimizes processing speed and packet throughput.
Written by US citizens
GHNet is a clean room design, written by US citizens from the ground
up. It was not derived from publicly available Unix stacks or open
source software. The design achieves Berkeley 4.4 and Netlink socket
compatibility, small size, and high performance for both IP and UDP