| lwIP | |
|---|---|
| Original author | Adam Dunkels |
| Developer | lwIP developers group |
| Initial release | 1.0.0[1] 10 August 2004; 21 years ago (2004-08-10) |
| Stable release | |
| Written in | C |
| Operating system | multiple |
| Platform | embedded systems |
| Type | IP stack |
| License | Modified BSD license |
| Website | www |
| Repository | |
lwIP (lightweight IP) is a widely usedopen-sourceTCP/IP stack designed forembedded systems. lwIP was originally developed byAdam Dunkels in 2001[3] at theSwedish Institute of Computer Science and is now developed and maintained by a worldwide network of developers.
lwIP is used by many manufacturers of embedded systems, includingIntel/Altera,Analog Devices,[4]Xilinx,[5]TI,ST andFreescale.
The focus of the lwIP network stack implementation is to reduce resource usage while still having a full-scale TCP stack.[6] This makes lwIP suitable for use in embedded systems with tens of kilobytes of free RAM and room for around 40 kilobytes of code ROM.
Aside from theTCP/IP stack, lwIP has several other important parts, such as anetwork interface, an operating system emulation layer, buffers and a memory management section. The operating system emulation layer and the network interface allow the network stack to be transplanted into an operating system, as it provides a common interface between lwIP code and theoperating system kernel.[6]
The network stack of lwIP includes anIP (Internet Protocol) implementation at theInternet layer that can handle packet forwarding over multiple network interfaces.[6] BothIPv4 andIPv6 are supported dual stack since lwIP v2.0.0 .[7] For network maintenance and debugging, lwIP implementsICMP (Internet Control Message Protocol).[6]IGMP (Internet Group Management Protocol) is supported for multicast traffic management. WhileICMPv6 (includingMLD) is implemented to support the use of IPv6.[citation needed]
lwIP includes an implementation of IPv4ARP (Address Resolution Protocol) and IPv6Neighbor Discovery Protocol to supportEthernet at thedata link layer. lwIP may also be operated on top of aPPP (Point-to-Point Protocol) implementation at the data link layer.[citation needed]
At thetransport layer lwIP implementsTCP (Transmission Control Protocol) with congestion control, RTT estimation and fast recovery/fast retransmit.[6]UDP (User Datagram Protocol) is implemented with experimentalUDP-Lite extensions.[citation needed]
lwIP provides a specialized no-copyapplication programming interface (API) for enhanced network stack performance. TheBerkeley socket API is optional.[6]Raw sockets, or raw pcbs (protocol control blocks), are provided depending on the API used.[8]
At the application layer the lwIP network stack may be supported through the implementation of the following protocols. TheDNS (Domain Name System), anSNMP (Simple Network Management Protocol) agent, in v1, v2 or v3, with private MIB (management information base) support and MIB compiler.
Operating systems that implement the lwIP TCP/IP stack may provide a range of supporting clients and servers at the application layer. Such as an IPv4DHCP (Dynamic Host Configuration Protocol) client or IPv4link-local addresses (AutoIP). Specialized raw API applications include: anHTTP server, aSNTP client, aSMTP client, aNetBIOS nameserver, amDNS responder, aMQTT client and aTFTP server.[citation needed]
lwIP is used as network stack inReactOS andGenode[9] and can be used inMinix andGNU Hurd to implement network servers.
