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338b915008
nuttx/net
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Jakub Łągwa 338b915008 While working with version 7.10 I discovered a problem in TCP stack that could be observed on high network load. Generally speaking, the problem is that RST flag is set in unnecessary case, in which between loss of some TCP packet and its proper retransmission, another packets had been successfully sent. The scenario is as follows: NuttX did not receive ACK for some sent packet, so it has been probably lost somewhere. But before its retransmission starts, NuttX is correctly issuing next TCP packets, with sequence numbers increasing properly. When the retransmission of previously lost packet finally succeeds, tcp_input receives the accumulated ACK value, which acknowledges also the packets sent in the meantime (i.e. between unsuccessful sending of lost packet and its proper retransmission). However, variable unackseq is still set to conn->isn + conn->sent, which is truth only if no further packets transmission occurred in the meantime. Because of incorrect (in such specific case) unackseq value, few lines further condition if (ackseq <= unackseq)is not met, and, as a result, we are going to reset label.
2016-06-20 06:55:29 -06:00
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6lowpan net/: Finish IEEE802154->6LOWPAN renaming; remove PF_IEEE804154; Move 6LoWPAN menu to inside Internet Protocol Menu 2016-02-27 07:26:20 -06:00
arp net/: Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition. 2016-06-11 17:37:21 -06:00
devif net/: Change some nerr() ERRORS to nwarn() WARNINGS. Anomolous network events are not errors. 2016-06-12 07:09:37 -06:00
icmp net/: Change some nerr() ERRORS to nwarn() WARNINGS. Anomolous network events are not errors. 2016-06-12 07:09:37 -06:00
icmpv6 net/: Change some nerr() ERRORS to nwarn() WARNINGS. Anomolous network events are not errors. 2016-06-12 07:09:37 -06:00
igmp net/: Change some nerr() ERRORS to nwarn() WARNINGS. Anomolous network events are not errors. 2016-06-12 07:09:37 -06:00
iob net/: Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition. 2016-06-11 17:37:21 -06:00
local net/: Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition. 2016-06-11 17:37:21 -06:00
loopback Networking: With these changes, I can ping the local loopback device from the simulator 2015-08-24 13:49:12 -06:00
neighbor Replace all occurrences of vdbg with vinfo 2016-06-11 11:59:51 -06:00
netdev net/: Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition. 2016-06-11 17:37:21 -06:00
pkt net/: Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition. 2016-06-11 17:37:21 -06:00
procfs Add CONFIG_DEBUG_ERROR. Change names of *dbg() * *err() 2016-06-11 15:50:49 -06:00
route Add CONFIG_DEBUG_ERROR. Change names of *dbg() * *err() 2016-06-11 15:50:49 -06:00
socket net/: Change some *err() message to *info() messages if what was a *dbg() message does not indicate and error condition. 2016-06-11 17:37:21 -06:00
tcp While working with version 7.10 I discovered a problem in TCP stack that could be observed on high network load. Generally speaking, the problem is that RST flag is set in unnecessary case, in which between loss of some TCP packet and its proper retransmission, another packets had been successfully sent. The scenario is as follows: NuttX did not receive ACK for some sent packet, so it has been probably lost somewhere. But before its retransmission starts, NuttX is correctly issuing next TCP packets, with sequence numbers increasing properly. When the retransmission of previously lost packet finally succeeds, tcp_input receives the accumulated ACK value, which acknowledges also the packets sent in the meantime (i.e. between unsuccessful sending of lost packet and its proper retransmission). However, variable unackseq is still set to conn->isn + conn->sent, which is truth only if no further packets transmission occurred in the meantime. Because of incorrect (in such specific case) unackseq value, few lines further condition if (ackseq <= unackseq)is not met, and, as a result, we are going to reset label. 2016-06-20 06:55:29 -06:00
udp net/: Change some nerr() ERRORS to nwarn() WARNINGS. Anomolous network events are not errors. 2016-06-12 07:09:37 -06:00
utils Remove some empty code section comments 2016-02-25 18:34:36 -06:00
.gitignore
Kconfig Replace confusing references to uIP with just 'the network' 2016-05-30 09:31:44 -06:00
Makefile Several Makefiles: Add .PHONY definitions to prevent 'clean up to date' message weirdness. 2016-05-10 15:44:06 -06:00
net_initialize.c Standardize some naming in code section comments 2016-02-21 18:09:04 -06:00
README.txt Networking: Add NetDB support for the local loopback device 2015-08-24 10:08:26 -06:00

README.txt 

README
======

Directory Structure
===================

  nuttx/
   |
   `- net/
       |
       +- arp      - Address resolution protocol (IPv4)
       +- devif    - Stack/device interface layer
       +- icmp     - Internet Control Message Protocol (IPv4)
       +- icmpv6   - Internet Control Message Protocol (IPv6)
       +- iob      - I/O buffering logic
       +- local    - Unix domain (local) sockets
       +- loopback - Local loopback
       +- neighbor - Neighbor Discovery Protocol (IPv6)
       +- netdev   - Socket network device interface
       +- pkt      - "Raw" packet socket support
       +- socket   - BSD socket interface
       +- route    - Routing table support
       +- tcp      - Transmission Control Protocol
       +- udp      - User Datagram Protocol
       `- utils    - Miscellaneous utility functions


    +----------------------------------------------------------------+
    |                     Application layer                          |
    +----------------------------------------------------------------+
    +----------------------------------------------------------------+
    |                   Socket layer (socket/)                       |
    +----------------------------------------------------------------+
    +------------++--------------------------------------------------+
    |  Network   || Protocol stacks (arp, ipv6, icmp, pkt, tcp, udp) |
    |   Device   |+--------------------------------------------------+
    | Interface  |+------------------------------------++------------+
    | (netdev/)  ||  Network Device Interface (devif/) || Utilities  |
    +------------++------------------------------------++------------+
    +----------------------------------------------------------------+
    |                    Network Device Drivers                      |
    +----------------------------------------------------------------+