AmiNetXDuo

An IPv4+IPv6 TCP/IP stack for classic AmigaOS, with the network commands that go with it. It provides bsdsocket.library, the socket API that Amiga network software already speaks, on top of Eclipse ThreadX NetX Duo. It drives existing SANA-II network cards, and ships a SANA-II driver of its own.

It gets a DHCP lease, configures itself by SLAAC, answers ARP and neighbour discovery, and pings its gateway. It resolves DNS, moves TCP in both directions, does HTTPS, and accepts incoming connections from other machines. It scores 142 of 142 on the independent bsdsocktest conformance suite. ssh and scp run on it, and so do NFS mounts and ixemul programs.

Why

AmigaOS has never included a TCP/IP stack. Networking has always come from a third-party shared library, and each existing option has a limitation. AmiTCP 3.0b2 is free and dates from 1994. AmiTCP 4.x and Miami are proprietary and effectively unobtainable. Roadshow, the one modern stack, is commercial and closed.

AmiNetXDuo is MIT-licensed, with the exceptions named under Licence. It speaks the same socket API and reads the same configuration files as Roadshow, so existing software and existing habits carry over. It also speaks IPv6: on a network with an IPv6 router, a machine picks up an address without being configured for one.

Requirements

Any 68000 or better, AmigaOS 2.04 (Kickstart 37) or newer, 1 MB of RAM, and a SANA-II network card. One binary serves every 68k: the library picks the code for the processor when it opens, and nothing has to match the machine.

The archive carries three stacks. The installer asks which one to put on.

Stack	Leaves out	RAM while up
Full	nothing	426 KB
Minimal	IPv6, .local lookups, the packet filter, HTTPS, IPv4 multicast, the ARexx host, TCP:	256 KB
Micro	all of that, and carries one interface and no route or address-allocation calls. DHCP works	212 KB

The installer offers these cards by name: A2065, Ariadne, Ariadne II, AmigaNet, LAN Rover, X-Surf, X-Surf 100, PCMCIA (cnet.device, etherlink3.device for the 3Com 3C589, or prism2.device) and uaenet.device for emulators. Any other driver name can be typed in.

anxnet.device, the SANA-II driver AmiNetXDuo builds itself, drives the A2065, the Ariadne, the Ariadne II, the X-Surf, the X-Surf 100, NE2000-compatible PCMCIA cards and the 3C589. The installer offers to put it in DEVS:Networks; an interface file selects it with DEVICE=anxnet.device.

Installing

Download the .lha from Releases, unpack it, and run Install-AmiNetXDuo. It asks:

Question	Default
Which stack: Everything, Minimal, Micro	Everything
Install anxnet.device	yes
Where the AmiNetXDuo drawer of documentation and examples goes	any drawer; nothing in it is needed for the network
Into the system (LIBS:, C:, DEVS:), or into its own drawer selected at boot by ActivateAmiNetXDuo beside another stack's files (Intermediate and Expert)	into the system
Which card, and the interface name	the driver found in DEVS:
Answer to <hostname>.local on the network	no
DHCP, or a fixed address, netmask and gateway	DHCP
The machine's name	amiga- and the card's last three address octets
Start the network at boot	yes
Start httpd at boot, exposing mounted volumes with a browser file manager and Shell, on which port	no

The configuration follows the layout of Roadshow: DEVS:NetInterfaces/<name> defines an interface, DEVS:Internet/routes, DEVS:Internet/name_resolution and the /etc-style netdb files hold the rest. A definition does not start its interface. S:Network-Startup does, one AddNetInterface line per interface, and S:User-Startup runs that file. An installation from 0.26.x or earlier needs that one line added.

The archive also holds Docs/AmiNetXDuo.guide, the manual; Examples/, a commented copy of every configuration file; and Developer/, the headers that the NDK does not declare and the CPU profiler.

Commands

NetSetup	ask the questions for one interface, and write the configuration files
AddNetInterface, RemoveNetInterface	start an interface from its file, and take one out of the running network
Online, Offline	put a started interface on the wire and take it off
ConfigureNetInterface	change the address or MTU of a running interface, renew or release its DHCP lease, turn .local answering on
ShowNetStatus, netstat	interface state, addresses, routes, connections, multicast groups, counters
ShowNetServices	what else on this network is offering something
ping, host, nslookup	reachability, name lookups, and one kind of record from a named server
arp	the machines on this network that have answered, IPv4 and IPv6
sntp	set the clock from a time server
fetch	retrieve an http:// or https:// URL
httpd	expose mounted volumes over HTTP and WebDAV, so other machines mount them as one drive. -F adds a browser file manager, -T a Shell, and -C the machine's display
nc	connect or listen, TCP and UDP, port ranges, timeouts
iperf	measure throughput against an iperf server, or act as one
telnet	negotiates the options that a real server requires
ssh, scp	Dropbear's clients, public-key authentication, scp in both directions and recursive
NetCapture	capture what is on the wire to a .pcap file, filtered by host, port or protocol
NetTrace	the same file for a transfer it runs itself, with the throughput number beside it
traceroute, tftp, whois	trace the path to a host, and small TFTP and WHOIS clients
CheckNetConfig	read the configuration and report what is wrong with it
CheckNetDevice	what anxnet.device found, card by card, and why any card was refused
AddNetRoute, DeleteNetRoute	where packets go that are not for this network
GetNetStatus, NetShutdown	status for scripts, and a clean shutdown
hostname	the name of this machine, and where the name came from
ActivateAmiNetXDuo	select the stack's own drawer at boot, in the drawer layout

The installer copies all of them into C:. Every command that resolves a name takes -4 and -6.

Files, a Shell and the display in a web browser

httpd -F serves a file manager at http://<address>/files. It browses the mounted volumes and opens, uploads, creates, renames and deletes files and drawers through the same WebDAV interface that desktop file managers mount. Its CodeMirror editor provides line numbers, undo and redo, search, and Ctrl/Cmd+S saving without leaving the browser. Saves carry the file's ETag, so a copy changed after it was opened is refused instead of overwritten. It detects extensionless Amiga text such as startup-sequence, while keeping binary files as downloads. Nothing is fetched from the Internet; the whole page is about 107 KB compressed. Starting httpd with an explicit drawer, such as httpd Work:Public 8080 -F, keeps the older restricted-share form and exposes only that drawer.

httpd -T serves an AmigaDOS Shell at /shell, beside the volumes that it already shares. httpd -C serves the machine's display at /console, chipset and RTG screens alike. The installer offers to start the volume server, file manager and Shell when the machine boots.

The Shell is a real console, not a pipe. Ed and More work, and so do the cursor keys and the history. A program that asks how big the window is gets an answer. On an A1200 the prompt appears in 44 ms, and a press of Return shows the output about 23 ms later.

There is no password. Anyone who can reach the port gets the Shell, the display and every mounted volume.

Finding the machine by name

The Amiga answers to <hostname>.local on the local network, so another machine reaches it by name with no DNS server and no configuration. .local names resolve from the Amiga in the other direction too. This matters most when there is no DHCP server at all: the machine gives itself an address and is still reachable.

The responder is per interface and off until asked for, because it costs time on a slow machine. The installer asks. The setting is MDNS=YES in DEVS:NetInterfaces/<name>, or ConfigureNetInterface <name> MDNS=YES on an interface that is already up. The minimal and micro stacks do not carry it.

ShowNetServices lists the kinds of service that answer on the network; a named kind lists the machines behind it with their addresses and ports; ALL lists every instance of every kind. Printers, NAS boxes, media players and anything that runs Bonjour or Avahi appear without being configured anywhere.

HTTPS and SSH

fetch handles https:// URLs. Certificates are checked against Mozilla's root set. The cryptography is in tls.library, a separate library with its own SDK that also runs on Roadshow, AmiTCP and Miami, and that handles the server side of a handshake and ALPN as well.

A first handshake is the cryptography, not the network: about 4 to 9 seconds on a 68020, a minute or two on a 68000. A second connection to the same site takes under a second, because the session is kept in DEVS:Internet/tlssessions and survives a reboot. The minimal and micro stacks do not install tls.library.

ssh needs no special configuration at the far end and reaches the prompt in about five seconds on an A1200. Keys must be in Dropbear's own format; an OpenSSH key copied straight across is not read. Name the key with -i, and generate it on a PC, which has the entropy and the speed for it. The manual has the exact commands.

Existing software

Software that resolves a name with getaddrinfo() and connects to whatever it returns works over IPv6 without being changed. Software written for IPv4 keeps working over IPv4. A program is IPv4-only when it resolves with gethostbyname(), keeps an address in 32 bits, or reads a dotted quad out of a configuration file; for such a program the change is to resolve with getaddrinfo() and hand the result to connect().

usergroup.library reads an existing AmiTCP 4 passwd and group as they stand. AmiTCP: is assigned, so ixemul programs find what they open by path. NFS mounts with ch_nfsc authenticate. Up to four interfaces are online at once, and the first one named to AddNetInterface owns the default route.

Building from source

docs/DEVELOPMENT.md covers the build, its options, the test suites, continuous integration, the measurement method and the CPU profiler.

Licence

AmiNetXDuo is an independent implementation of a published ABI. No implementation code from AmiTCP, AROSTCP, Miami or Roadshow has been used, copied or disassembled. The ABI comes from interface definitions and documentation that exist to be read: Olaf Barthel's freely distributable Roadshow SDK headers and autodocs, the NDK's pragmas/bsdsocket_pragmas.h, and the .fd and .sfd function-descriptor files that AmiTCP and Roadshow publish.

MIT, with these exceptions, each confined to the files it names:

What	Licence	Where
ThreadX and NetX Duo	MIT (Microsoft and the Eclipse ThreadX contributors). Both are maintained forks: github.com/tinic/threadx is four commits past upstream 44d7c95c (hosted-port stack creation and overlap checks, and a pre-relinquish port hook); github.com/tinic/netxduo is an integrated line of patches past upstream 473d1928, pinned by the submodule, with each defect's patch also on its own branch	third_party/threadx, third_party/netxduo
The NE2000 core of anxnet.device	BSD-2-Clause, adapted from NetBSD's dp8390 driver	src/netdev/dp8390.c, ne2000.c, ed.c, netdev_mcaf.c
ssh and scp	Dropbear's MIT-style licence	third_party/dropbear, clients/dropbear
The /files text editor	CodeMirror 6 and its support packages, MIT	bundled into src/tools/web/files.html; notice in src/tools/web/vendor/codemirror
The CA root set	MPL 2.0, Mozilla's, file-scoped	DEVS:Internet/certificates, from third_party/cacert