1INTRODUCTION 2 3lwIP is a small independent implementation of the TCP/IP protocol suite. 4 5The focus of the lwIP TCP/IP implementation is to reduce the RAM usage 6while still having a full scale TCP. This making lwIP suitable for use 7in embedded systems with tens of kilobytes of free RAM and room for 8around 40 kilobytes of code ROM. 9 10lwIP was originally developed by Adam Dunkels at the Computer and Networks 11Architectures (CNA) lab at the Swedish Institute of Computer Science (SICS) 12and is now developed and maintained by a worldwide network of developers. 13 14FEATURES 15 16 * IP (Internet Protocol, IPv4 and IPv6) including packet forwarding over 17 multiple network interfaces 18 * ICMP (Internet Control Message Protocol) for network maintenance and debugging 19 * IGMP (Internet Group Management Protocol) for multicast traffic management 20 * MLD (Multicast listener discovery for IPv6). Aims to be compliant with 21 RFC 2710. No support for MLDv2 22 * ND (Neighbor discovery and stateless address autoconfiguration for IPv6). 23 Aims to be compliant with RFC 4861 (Neighbor discovery) and RFC 4862 24 (Address autoconfiguration) 25 * DHCP, AutoIP/APIPA (Zeroconf), ACD (Address Conflict Detection) 26 and (stateless) DHCPv6 27 * UDP (User Datagram Protocol) including experimental UDP-lite extensions 28 * TCP (Transmission Control Protocol) with congestion control, RTT estimation 29 fast recovery/fast retransmit and sending SACKs 30 * raw/native API for enhanced performance 31 * Optional Berkeley-like socket API 32 * TLS: optional layered TCP ("altcp") for nearly transparent TLS for any 33 TCP-based protocol (ported to mbedTLS) (see changelog for more info) 34 * PPPoS and PPPoE (Point-to-point protocol over Serial/Ethernet) 35 * DNS (Domain name resolver incl. mDNS) 36 * 6LoWPAN (via IEEE 802.15.4, BLE or ZEP) 37 38 39APPLICATIONS 40 41 * HTTP server with SSI and CGI (HTTPS via altcp) 42 * SNMPv2c agent with MIB compiler (Simple Network Management Protocol), v3 via altcp 43 * SNTP (Simple network time protocol) 44 * NetBIOS name service responder 45 * MDNS (Multicast DNS) responder 46 * iPerf server implementation 47 * MQTT client (TLS support via altcp) 48 49 50LICENSE 51 52lwIP is freely available under a BSD license. 53 54 55DEVELOPMENT 56 57lwIP has grown into an excellent TCP/IP stack for embedded devices, 58and developers using the stack often submit bug fixes, improvements, 59and additions to the stack to further increase its usefulness. 60 61Development of lwIP is hosted on Savannah, a central point for 62software development, maintenance and distribution. Everyone can 63help improve lwIP by use of Savannah's interface, Git and the 64mailing list. A core team of developers will commit changes to the 65Git source tree. 66 67The lwIP TCP/IP stack is maintained in the 'src' directory and 68contributions (such as platform ports and applications) are in 69the 'contrib' directory. 70 71See doc/savannah.txt for details on Git server access for users and 72developers. 73 74The current Git tree is web-browsable: 75 https://git.savannah.gnu.org/cgit/lwip.git 76 77Submit patches and bugs via the lwIP project page: 78 https://savannah.nongnu.org/projects/lwip/ 79 80Continuous integration builds (GCC, clang): 81 https://github.com/lwip-tcpip/lwip/actions 82 83 84DOCUMENTATION 85 86Self documentation of the source code is regularly extracted from the current 87Git sources and is available from this web page: 88 https://www.nongnu.org/lwip/ 89 90Also, there are mailing lists you can subscribe at 91 https://savannah.nongnu.org/mail/?group=lwip 92plus searchable archives: 93 https://lists.nongnu.org/archive/html/lwip-users/ 94 https://lists.nongnu.org/archive/html/lwip-devel/ 95 96There is a wiki about lwIP at 97 https://lwip.wikia.com/wiki/LwIP_Wiki 98You might get questions answered there, but unfortunately, it is not as 99well maintained as it should be. 100 101lwIP was originally written by Adam Dunkels: 102 http://dunkels.com/adam/ 103 104Reading Adam's papers, the files in docs/, browsing the source code 105documentation and browsing the mailing list archives is a good way to 106become familiar with the design of lwIP. 107 108Adam Dunkels <adam@sics.se> 109Leon Woestenberg <leon.woestenberg@gmx.net> 110