[REBOL] Re: TCP/IP ports problem (bug ?)
From: ryanc:iesco-dms at: 24-Apr-2001 11:08
Good one PeO,
I cant find any work arounds. Interesting bit of behavior, scanning an openable port
over and over has no ill effect. Scanning a failed to open port has no ill effects
for exactly 1019 times. On the 1020 all hell breaks loose, you cant even open local
files.
--Ryan
P-O Yliniemi wrote:
> Wrote a small port scanner, which just tries to open a range of ports,
> and closes them directly afterwards..
>
> With the Amiga version of REBOL/Core and /View, I can't open any port
> at all after running the test against another of my systems (unix
> machine with a lot of services running)
>
> I get the same problem with the UNIX versions, but here I can open and
> close more ports before failing.. Quitting and restarting REBOL lets
> me open ports again.
>
> /PeO
>
> scan-ports: func [
> ip [string! tuple!] {IP address to scan}
> start-port [integer!] {First port to test}
> end-port [integer!] {Last port to test}
> /local port-num test-port fail success
> ][
> fail: 0
> success: 0
> port-num: start-port
> num-ports: end-port - start-port + 1
> loop num-ports [
> either error? try [test-port: open to-url rejoin ["tcp://" ip ":" port-num]] [
> ; print "nope"
> fail: fail + 1
> ][
> success: success + 1
> print [port-num "is open"]
> close test-port
> ]
> port-num: port-num + 1
> if port-num // 1000 = 0 [prin ["at" port-num " "]]
> ]
> print [newline "Failed to open " fail " ports, " success " ports opened"]
> ]
>
> ----------------------------------------------------------
>
> >> do %portscan.r
> Script: "Untitled" (none)
> >> scan-ports 172.16.0.5 1 53
> 7 is open
> 9 is open
> 13 is open
> 19 is open
> 21 is open
> 23 is open
> 25 is open
> 37 is open
> 53 is open
>
> Failed to open 44 ports, 9 ports opened
> >> scan-ports 172.16.0.5 1 53
> 7 is open
> 9 is open
> 13 is open
> 19 is open
> 21 is open
> 23 is open
> 25 is open
>
> Failed to open 46 ports, 7 ports opened
> >> scan-ports 172.16.0.5 1 53
>
> Failed to open 53 ports, 0 ports opened
> >> test-port: open tcp://172.16.0.5:7
> ** Access Error: Error opening socket 172.16.0.5
> ** Near: test-port: open tcp://172.16.0.5:7
> >>
>
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--
Ryan Cole
Programmer Analyst
www.iesco-dms.com
707-468-5400
I am enough of an artist to draw freely upon my imagination.
Imagination is more important than knowledge. Knowledge is
limited. Imagination encircles the world.
-Einstein
