readme.irix

基于TCP-WRAP原理的系统监控的c语言实现代码

@(#) README.IRIX 1.2 94/12/28 18:45:58

In the past few months I received several messages with questions from
people that tried to use my tcp wrapper on IRIX 5.x. Some mysteries
could be solved via email, and then some remained.

Today I finally had a chance to do some tests on someones IRIX 5.2
system.  Here is my first-hand experience with wrapper release 6.3.

(1) Inetd is broken. Normally one edits inetd.conf, sends a HUP signal
    to inetd and that's it. With IRIX evil things happen:  inetd is too
    stupid to remember that it is already listening on a port.

    In order to modify an entry in inetd.conf, first comment it out
    with a # at the beginning of the line, kill -HUP the inetd, then
    uncomment the inetd.conf entry and kill -HUP again.

    Even with this amount of care I have seen inetd messing up, like
    calling rusersd when I make a talk connection.  Even killing and
    restarting inetd does not solve all problems.

    I find it hard to believe, it but the best thing to do with IRIX is
    to reboot after changing inetd.conf.

(2) When tcpd is built according to the irix4 Makefile rules, it
    appears to work as expected with TCP-based services such as
    fingerd, and with UDP-based services such as ntalk and tftp.

(3) It does NOT work with RPC over UDP services such as rusersd and
    rstatd:  the wrapper hangs in the recvfrom() system call, and I
    have spent several hours looking for ways to work around it. No
    way.  After finding that none of the applicable socket primitives
    can be made to work (recvfrom recvmsg) I give up. So, the IRIX RPC
    services cannot be wrapped until SGI fixes their system so that it
    works like everyone elses code (HP Sun Dec AIX and so on).

(4) I didn't even bother to try the RPC over TCP services.

(5) When an IRIX 5.2 system is a NIS client, it can have problems with
    hosts that have more than one address: the wrapper will see only
    one address, and may complain when PARANOID mode is on. The fix is
    to change the name service lookup order in /etc/resolv.conf so that
    your system tries DNS before NIS (hostresorder bind nis local).

(6) IRIX 5.2 is not System V.4, and it shows. Do not link with the
    -lsocket and -lnsl libraries. They are completely broken, and the
    wrapper will be unable to figure out the client internet address.
    So, TLI services cannot be wrapped until SGI fixes their system so
    that it works the way it is supposed to.

I am not impressed by the quality of the IRIX system software.  There
are many things that work on almost every other system except with IRIX.

	Wietse