Remote Programs

The implementation of the qrsh feature in Gridengine makes use of operating system facilities like rsh and rlogin.

Unfortunately these programs usually lack some features:

rsh / rlogin connect to a rshd / rlogind on a fixed port number but Gridengine has to start (multiple) rshd / rlogind on variable port numbers
rshd / rlogind do not pass correctly accounting information to their parent process - they do not call wait to collect usage information
most rshd's fail, if the user root cannot chdir to the target users (nfs mounted) home directory

Therefore part of a Gridengine distribution are the following programs:

rsh
rlogin
rshd

A special rlogin program is not yet part of Gridengine - the rlogin process is much more complicated than rsh - we would probably not only have to provide a special rlogind, but also the login program.

1 Rsh

The Gridengine extended version of rsh is based on NetBSD-release, rsh.c, CVS Revision 1.12,
ftp://sunsite.cnlab-switch.ch/mirror/NetBSD/NetBSD-release/src/usr.bin/rsh

It has been extended by a commandline option -p <port> to specify the tcp port rsh tries to access to build a connection to the corresponding rshd and some porting had to be done to support all current Gridengine platforms.

2 Rshd

The Gridengine extended version of rshd is based on NetBSD-release, rshd.c, Revision 1.16,
ftp://sunsite.cnlab-switch.ch/mirror/NetBSD/NetBSD-release/src/libexec/rshd

The following changes have been applied:

Port to all Gridengine platforms
Set osjobid / additional group id to allow process control by Gridengine
Cleaned up wait for child process to obtain usage information
chdir to users homedir is done only after setuid to user to allow rsh access even if homedir of user (nfs-mounted) is not readable by root (requires additionally rshd option -l)

3 rlogin

The Gridengine extended version of rlogin is based on NetBSD-release, rlogin.c, CVS Revision 1.23,
ftp://sunsite.cnlab-switch.ch/mirror/NetBSD/NetBSD-release/src/usr.bin/rlogin

It has been extended by a commandline option -p <port> to specify the tcp port rlogin tries to access to build a connection to the corresponding rlogind and some porting had to be done to support all current Gridengine platforms.