Alexander Lunev 36fbedcbfc net/devif/devif_callback.c: corrected the connection event list to work as FIFO instead of LIFO.
In case of enabled packet forwarding mode, packets were forwarded in a reverse order
because of LIFO behavior of the connection event list.
The issue exposed only during high network traffic. Thus the event list started to grow
that resulted in changing the order of packets inside of groups of several packets
like the following: 3, 2, 1, 6, 5, 4, 8, 7 etc.

Remarks concerning the connection event list implementation:
* Now the queue (list) is FIFO as it should be.
* The list is singly linked.
* The list has a head pointer (inside of outer net_driver_s structure),
  and a tail pointer is added into outer net_driver_s structure.
* The list item is devif_callback_s structure.
  It still has two pointers to two different list chains (*nxtconn and *nxtdev).
* As before the first argument (*dev) of the list functions can be NULL,
  while the other argument (*list) is effective (not NULL).
* An extra (*tail) argument is added to devif_callback_alloc()
  and devif_conn_callback_free() functions.
* devif_callback_alloc() time complexity is O(1) (i.e. O(n) to fill the whole list).
* devif_callback_free() time complexity is O(n) (i.e. O(n^2) to empty the whole list).
* devif_conn_event() time complexity is O(n).
2021-09-18 21:01:39 -05:00
..
2021-09-15 12:11:32 +08:00
2021-08-02 08:23:35 -03:00
2021-07-20 20:24:58 -07:00

README
======

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

  nuttx/
   |
   `- net/
       |
       +- arp        - Address resolution protocol (IPv4)
       +- bluetooth  - PF_BLUETOOTH socket interface
       +- devif      - Stack/device interface layer
       +- icmp       - Internet Control Message Protocol (IPv4)
       +- icmpv6     - Internet Control Message Protocol (IPv6)
       +- ieee802154 - PF_IEEE802154 socket interface
       +- inet       - PF_INET/PF_INET6 socket interface
       +- ipforward  - IP forwarding logic
       +- local      - Unix domain (local) sockets
       +- mld        - Multicast Listener Discovery (MLD)
       +- neighbor   - Neighbor Discovery Protocol (IPv6)
       +- netdev     - Socket network device interface
       +- netlink    - Netlink IPC socket interface
       +- pkt        - "Raw" packet socket support
       +- sixlowpan  - 6LoWPAN implementation
       +- socket     - BSD socket interface
       +- route      - Routing table support
       +- tcp        - Transmission Control Protocol
       +- udp        - User Datagram Protocol
       +- usrsock    - User socket API for user-space networking stack
       `- utils      - Miscellaneous utility functions

    +-------------------------------------------------------------------++------------------------+
    |                     Application layer                             || usrsock daemon         |
    +-------------------------------------------------------------------++------------------------+
    +-------------------------------------------------------------------++----------------+ +-----+
    |                   Socket layer (socket/)                          || /dev/usrsock   | |     |
    +-------------------------------------------------------------------++----------------+ |     |
    +------------++--------------------------------------------------++-------------------+ |     |
    |  Network   || Protocol stacks (arp, ipv6, icmp, pkt, tcp, udp) || usrsock/          | |     |
    |   Device   |+--------------------------------------------------++-------------------+ |     |
    | Interface  |+------------------------------------++---------------------------------+ |     |
    | (netdev/)  ||  Network Device Interface (devif/) || Utilities                       | |     |
    +------------++------------------------------------++---------------------------------+ |     |
    +----------------------------------------------------------------+                      |     |
    |                    Network Device Drivers                      |                      | HAL |
    +----------------------------------------------------------------+                      +-----+
    +----------------------------------------------------------------+ +--------------------------+
    |                    Networking Hardware                         | |  Hardware TCP/IP Stack   |
    +----------------------------------------------------------------+ +--------------------------+