New stack

intro

As you may or may not know, I (hidnplayr) am since long time working on a new network stack for KolibriOS

I will use this page for myself as a total image of what I have done so far, but also to inform others.

I'm currently working on:

* Complete rewrite of TCP code based on that of 4.4BSD

* Fragmenting IPv4 packets
* updating netstat and netcfg applications
* Learning more about MII and transceiver chips
* Completing the dec21x4x driver
* Completing/testing SLIP compatible RS232 driver
* Finishing TFTP client

Kernel

The old kernel functions 52 and 53 have been removed and the New_network_api has been created.

Internally, the stack has been completely rewritten (mostly from scratch)

• What works

  • Attaching network drivers to the kernel
  • Sending and receiving Ethernet/IPv4/UDP/ICMP packets
  • IPv4/UDP/TCP checksum generation and confirmation
  • Queuing of packets (altough queing ethernet packets is disabled ATM)
  • UDP sockets
  • ~Working with multiple network card's (unfortunately, some kernel functions are hardcoded to a specific device ATM)

• TODO (items with a * are currently being worked on)

  • Sending fragmented IPv4 packets
  • finish TCP code*
  • finish ARP code
  • IPC sockets (unix-like sockets)
  • RAW sockets
  • Port trunking (IEEE 802.1AX-2008)
  • ..

Drivers

These new type network drivers are MS COFF files, just like the sound drivers in KolibriOS.

Notice that one driver can handle multiple devices.

Once the driver is loaded, an application (NetCFG) can use system function 68/17 ("Driver Control") to communicate with the driver.
For this, it uses the IOCTL structure wich looks like this: <asm> struc IOCTL {

  .handle      dd ?
  .io_code     dd ?
  .input       dd ?
  .inp_size    dd ?
  .output      dd ?
  .out_size    dd ?  

} </asm> for more info about this, please read Writing_drivers_for_KolibriOS

Here is a list of opcodes:

0 - Getversion

standard for all drivers, not only network drivers

1 - Hook

Attach driver to a device

IN: (ISA) <asm> type db 0 ; isa io_addr dw ? irq_line db ? </asm>

IN: (PCI) <asm> type db 1 ; pci pci_bus db ? pci_dev db ? </asm>

OUT:
eax = device number or -1 on error

---

Once the HOOK function of the driver has been called, the driver creates the NET_DEVICE structure, allocates some buffers needed for the driver, and calls the kernel function 'NetRegDev'.
This function registers a networkdevice (device, not driver!) to the kernel.
It only needs one parameter: pointer to device structure (NET_DEVICE) in ebx.
The function returns the device number in edi (..wich the driver then sends to the application in eax, see above..)

This NET_DEVICE structure is created and filled in by the driver, for every device it is hooked to.
The driver may use this to store pointers to buffers, descriptors,.. etc
But the top of the structure must always look like this: (Since it is shared by the driver and the kernel)

<asm> NET_DEVICE:

       .type           dd ?    ; Type field (ethernet/slip/...)
       .mtu            dd ?    ; Maximal Transmission Unit (in bytes)
       .name           dd ?    ; Ptr to 0 terminated string 

       .unload         dd ?    ; Ptrs to driver functions
       .reset          dd ?    ;
       .transmit       dd ?    ;

       .bytes_tx       dq ?    ; Statistics, updated by the driver
       .bytes_rx       dq ?    ;
       .packets_tx     dd ?    ;
       .packets_rx     dd ?    ;

       .end:

</asm>

This is appended by a Type-specific structure, for ethernet this will be:

<asm>

       .set_mode       dd ?
       .get_mode       dd ?

       .set_MAC        dd ?
       .get_MAC        dd ?

       .mode           dd ?
       .mac            dp ?    

</asm>

Wich is then followed by the private data for the driver.

When a packet is received by the driver, it copies it into a buffer allocated using 'KernelAlloc'.
Then the driver pushes the size of the buffer and the pointer to the buffer onto the stack (in this particular order)
And it calls 'EthReceiver' (or another procedure for another network device type).
This kernel function will but the packet into the incoming queue, so the appropriate protocol handler can handle it later.

When the kernel needs to send a packet, it simple looks up the appropriate driver in it's driver table.
In the table it will find the pointer to the device structure, so the driver can directly call the transmit function listed in the structure. NOTE: the kernel will put the address of buffer to send in [esp+4], and length of that buffer in [esp+8]

---

Current status of the drivers

• RTL8139: Working (FIXME: error occurs on wrapping of the RX buffer).
• SIS900: Working? (Written by clevermouse)
• 3c90x/3c59x: Working (only boomerang for now) (FIXME: may hang on UpUnstall procedure)
• RTL8029: Working
• PCnet32: Working
• DEC21x4x: Working in Virtual PC, but not on real hardware.

• i8255x (Intel eepro 100): Work in progress (hidnplayr)
• i8254x (Intel eepro 1000): Planned for future (hidnplayr)
• mtd80x: Planned for future (hidnplayr)

Programs

• NetCFG

  This is a program I wrote to load the drivers, it detects all network cards in your computer (PCI), and lets you load the appropriate driver for it.

You can run it with paramters 'F' to silently load first detected card, or parameter 'A' to load all cards

• Netstat

  This program allows you to read some variables from the stack.

• ARPcfg

  This program allows you to view the ARP entries, in future, you should be able to add and remove static entry's using this progam.

• Zeroconf

  This program is the newer version of what used to be 'autodhcp', it works with the new network API.

• nslookup

  Commandline DNS client from CleverMouse

 uses network.obj

• TFTPc

  A TFTP client with a GUI.

can receive and send files, using libio.obj, network.obj and box_lib.obj

• Telnet

  a new telnet client, based on the code of nslookup (usefull to test TCP code)

 uses network.obj

Upcoming

• ICMP

  program for sending ICMP echo reply's (ping) and trace-route.

Libraries

• network_lib

  The network library for KolibriOS, written by Clevermouse, was ported to the net branch, by the same person

I need your help!

I would really appreciate it if somebody could write some network applications,
so I can further test the kernel code without having to code them myself now :),
If you are interessed please contact me at hidnplayr@kolibrios.org (or find me in #general on irc.kolibrios.org)