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Dirk Ziegelmeier 6aed6e659f Rework DHCP PCB handling: Old code registered one UDP PCB per netif where DHCP was active and there was a special case in udp_input() for this. New implementation uses one PCB for all netifs and removes special case in udp_input().
The old approach called udp_bind() on each of the PCBs, which puts them into udp_pcbs list. The PCBs were iterated on all non-DHCP udp_inputs() with no effect.
My cleanup removes the special handling in udp.c, and uses only one DHCP UDP PCB to catch all DHCP messages from all netifs. The dhcp_recv function then checks whether ip_current_input_netif() has DHCP enabled - if not, the message is ignored. The PCB is only created/registered when one or more PCBs have DHCP enabled.
2016-02-29 19:31:19 +01:00
doc PPP, Documentation, fixed mistake about pppos_input_sys 2016-01-18 12:45:40 +01:00
src Rework DHCP PCB handling: Old code registered one UDP PCB per netif where DHCP was active and there was a special case in udp_input() for this. New implementation uses one PCB for all netifs and removes special case in udp_input(). 2016-02-29 19:31:19 +01:00
test/unit all: trivial include changes related to the new "lwip/priv/" include directory 2015-10-10 22:46:47 +02:00
.gitattributes Added .gitattributes to normalize CRLF 2014-02-07 09:36:03 +01:00
.gitignore Add .userprefs file to .gitignore 2016-01-11 19:23:09 +01:00
CHANGELOG Add note to CHANGELOG about 6LoWPAN 2016-02-22 20:46:15 +01:00
COPYING Re-added without vendor tag. 2002-10-20 15:13:14 +00:00
FILES etharp_query() has error return type now. Matched dhcp.c with this change. 2003-04-01 14:02:50 +00:00
README README: replaced CVS references to Git 2015-09-22 20:39:32 +02:00
UPGRADING Fixed UPGRADING regarding 1.4.0 2015-08-27 21:38:30 +02:00

INTRODUCTION

lwIP is a small independent implementation of the TCP/IP protocol
suite that has been developed by Adam Dunkels at the Computer and
Networks Architectures (CNA) lab at the Swedish Institute of Computer
Science (SICS).

The focus of the lwIP TCP/IP implementation is to reduce the RAM usage
while still having a full scale TCP. This making lwIP suitable for use
in embedded systems with tens of kilobytes of free RAM and room for
around 40 kilobytes of code ROM.

FEATURES

  * IP (Internet Protocol) including packet forwarding over multiple network
    interfaces
  * ICMP (Internet Control Message Protocol) for network maintenance and debugging
  * IGMP (Internet Group Management Protocol) for multicast traffic management
  * UDP (User Datagram Protocol) including experimental UDP-lite extensions
  * TCP (Transmission Control Protocol) with congestion control, RTT estimation
    and fast recovery/fast retransmit
  * Specialized raw/native API for enhanced performance
  * Optional Berkeley-like socket API
  * DNS (Domain names resolver)
  * SNMP (Simple Network Management Protocol)
  * DHCP (Dynamic Host Configuration Protocol)
  * AUTOIP (for IPv4, conform with RFC 3927)
  * PPP (Point-to-Point Protocol)
  * ARP (Address Resolution Protocol) for Ethernet

LICENSE

lwIP is freely available under a BSD license.

DEVELOPMENT

lwIP has grown into an excellent TCP/IP stack for embedded devices,
and developers using the stack often submit bug fixes, improvements,
and additions to the stack to further increase its usefulness.

Development of lwIP is hosted on Savannah, a central point for
software development, maintenance and distribution. Everyone can
help improve lwIP by use of Savannah's interface, Git and the
mailing list. A core team of developers will commit changes to the
Git source tree.

The lwIP TCP/IP stack is maintained in the 'lwip' Git module and
contributions (such as platform ports) are in the 'contrib' Git module.

See doc/savannah.txt for details on Git server access for users and
developers.

The current Git trees are web-browsable:
  http://git.savannah.gnu.org/cgit/lwip.git
  http://git.savannah.gnu.org/cgit/lwip/lwip-contrib.git

Submit patches and bugs via the lwIP project page:
  http://savannah.nongnu.org/projects/lwip/


DOCUMENTATION

The original out-dated homepage of lwIP and Adam Dunkels' papers on
lwIP are at the official lwIP home page:
  http://www.sics.se/~adam/lwip/

Self documentation of the source code is regularly extracted from the
current Git sources and is available from this web page:
  http://www.nongnu.org/lwip/

There is now a constantly growin wiki about lwIP at
  http://lwip.wikia.com/wiki/LwIP_Wiki

Also, there are mailing lists you can subscribe at
  http://savannah.nongnu.org/mail/?group=lwip
plus searchable archives:
  http://lists.nongnu.org/archive/html/lwip-users/
  http://lists.nongnu.org/archive/html/lwip-devel/

Reading Adam's papers, the files in docs/, browsing the source code
documentation and browsing the mailing list archives is a good way to
become familiar with the design of lwIP.

Adam Dunkels <adam@sics.se>
Leon Woestenberg <leon.woestenberg@gmx.net>