[HECnet] Announcing TCP/IP for RSX-11M-PLUS

[Johnny Billquist]

Time for a new release announcement of TCP/IP for RSX-11M-PLUS.

This release address some bugs and also address some security issues.
I strongly encourage people to upgrade to the latest version to get 
these fixes, since they can otherwise cause system crashes.

This is definitely the best release yet, and a great way to finish off 
2016. I hope people find it usable, and truth be told, the errors and 
crashes I mostly work on now are obscure corner cases, that I mostly 
only actually get to see on Magica.Update.UU.SE, which is a real 
PDP-11/70. Something about running on slower hardware seems to bring out 
some interesting corner cases. :-)
Mim.Update.UU.SE have been running very solid for very long times in the 
face of constant probing by random places all over the internet. On 
average, there is about 2 attempts per minute to probe Mim and Magica, 
24 hours a day, 7 days a week. As you can guess, this runs up to serious 
numbers given a few days. Also, over a general week, Mim will serve 
around 1G of data to various people and crawlers all over the Internet. 
(Yes, there is a reason some counters in TCP/IP is 64 bits wide...)

Things that have been done since the last release:

TCP:
- TCP receive packet sequence number checking could erroneously accept 
some packets that was not inside the current window. The chance of any 
packet getting by this is very small, but if some specific sequence 
numbers came in, which did manage to get past the checks, this could 
cause a system crash.
- Improved queuing of SYN packets for services that were already serving
the max number of concurrent requests. Previously such packets were 
immediately rejected. Now they can be queued.
- Improved task activation control to avoid DOS attack vulnerability. If 
many requests get queued up, and the system was getting continued high 
loads, the TCP connections got torn down, but requested processes could 
queue up in unlimited numbers, causing pool exhaustion.
- Added correct handling or errors during task activation. Previously, 
TCP would just cause a system crash under this circumstance. Now, the 
task is instead removed, and the connection being created is torn down.
- Added new statistics counters for failed task creations, failed daemon 
initiations, and improved statistics counters for TCP data outside of 
window.

FTP:
- Added SUPERSEDE command, to control if existing local files should be 
overwritten or not when retrieving files.
- Improved handling of file version numbers. If given, FTP will now make 
use of file version information, including using the same version number 
as on the remote system for MGET, when the file version field is given 
in the filename argument.
- Changed code so that already existing file error is not considered 
fatal, and will not abort an ongoing MGET command.

FTPD:
- Added SPOOF notification from FTPD, so that abusive sites 
automatically get blocked when abusing through FTPD.

BP2LIB:
- Added RECV function, which can read from TCP or UDP without any 
interpretation of data the way LINPUT will do.

HTTP:
- Changed code to use RECV instead of LINPUT for reading from remote side.
- Fix content length calculation for case where the web server adds a 
little bit of own information in addition to what is read from a file.

IRCBOT:
- Changed code to use RECV instead of LINPUT for reading from remote side.

SPOOF:
- Changed register usage layout for better information when looking at 
the task with TAL.
- Added SEND DATA interface to SPOOF.

TELNETD:
- Changed register usage layout for better information when looking at 
the task with TAL.
- Improved connection tracking code to avoid some race conditions in 
connection counting.

NTPDATE:
- Task default priority changed to 100. to improve the response times 
needed for this task.

IPRMD:
- Corrected erroneous build files (fix provided by Oleg Safiullin.)

Installation scripts:
- Corrected erroneous code in installation that checked for already 
installed commons. (Fix provided by Oleg Safiullin.)


As usual, the distribution is available from:
ftp://mim.update.uu.se/bqtcp.dsk
ftp://mim.update.uu.se/bqtcp.tap
ftp://ftp.update.uu.se/pub/pdp11/rsx/tcpip/tcpip.dsk

The documentation is also available through ftp on Mim, or also at 
http://mim.update.uu.se/tcpipdoc

The firewall for Mim have now been removed, so no need for the alternate 
ports, but Mim is still listening to the alternate ports as well.
ftp: 10021
telnet: 10023

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                      ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol