Re: tcpsvd - Allow only x connections from somebody/hour

* 2004-08-26 Gerrit Pape:

> On Wed, Aug 25, 2004 at 03:27:26PM +0200, Maurice Lucas wrote:
>> I want to adjust my tcpsvd service to allow only a fixed amount of maximum
>> connections from an IP address a hour.
>
>> Is there some way to do this using tcpsvd?
>
> It's not a built-in feature of tcpsvd, no.  But it should be possible to do
> such things with a separate program put into the process chain between
> tcpsvd and the service program.  It gathers the necessary information, and
> execs into the service program, or doesn't, based on this information.

i just thought about this.  what would be the best database-implementation to
keep the IP/connection# tuples?  maurice, do you have less than a few dozen or
more than thousands of IPs connecting?  anyway, it might be easy to make a
little program keeping those tuples in a hash and do the exec(2)'ing, as the
relevant information is readily available:

  $ env - /command/tcpsvd 0 8181 /usr/bin/env
  
  $ mconnect 0 8181
  PROTO=TCP
  TCPLOCALIP=127.0.0.1
  TCPLOCALPORT=8181
  TCPLOCALHOST=localhost
  TCPREMOTEIP=127.0.0.1
  TCPREMOTEPORT=2340

(btw gerrit:  neither the man pages nor the ipsvd web pages mention
UCSPI-TCP!)

should the hash table ever get filled up, well the remote IP looses.  the
table size should be a runtime option.  as the information isn't huge, it can
be kept in memory, unless persistence or privacy are required.

  clemens