fix to irritating rsh(1) quirk

[Neal Ziring]

Description:
        The rsh(1) command executes a shell command-sequence on a 
        remote host.  It attempts to do execute the command while
        pretending to `be' some user, usually the same user who
        ran the command on his local host.  However, the rsh-demon
        on the remote host will not even attempt to execute the
        specified command if the user has no home directory on 
        the remote host.  In our environment this is intolerable,
	because with several machines, some running VMS, a user may
	not log onto all of them ever.  This is especially true
	of people who use applications packages that reside on a
	single host.
	Nevertheless, it is sometimes important for these users to
	do an rsh on a remote Un*x host.  In particular, the VMS
	machines use rsh when sending graphics output to a Unix
	printer.

Repeat-By:

        Let's say you have two hosts, unixa and unixb.  The user
        bob has an account on each of them.
        Do this command sequence, start as root on unixa.

              a# rlogin unixb
                      ---- stuff ----
              b# cd ~bob/..
              b# mv bob bob_directory_backup    # bob now has no HOME on unixb
              b# logout
              a# su bob
              bob_a% rsh unixb ls -al
              rsh: No remote directory.

        If the user has no home directory on the remote
        host, he should still be allowed to execute commands there. 

Fix:
	The problem reported above is not really a bug, so this cannot
	really be a fix, but I submit this patch(1) input for those of
	you who may have a similar problem.
        This is a quick fix to the rsh-demon.  I am working on a more
        comprehensive fix that will also allow your path to be sent
        down to the remote host, but for now this does work.  Note
	that this change is transparent to users and programmers.  This
	fix also works for rshd's that have been converted to use the
	general netd.
	
        The source code for the rshd is in /src/etc/rshd.c

        Note: the line numbers here will almost certainly be different
        from the line numbers in your source code.  Subtract about 15
        to approach the correct line numbers.  
        The first chunk of diff is a local addition to the PATH
        in the environment.  The original default environment has a 
        rather scanty PATH.  Fixing the path is not neccesary to fixing
        the no-home-directory problem.


132c132,134
< 	    {homedir, shell, "PATH=:/usr/ucb:/bin:/usr/bin", username, 0};
---
> 	    {homedir, shell, 
> 	    "PATH=:/usr/ucb:/bin:/usr/new/bin:/usr/bin:/usr/local/bin:/etc",
> 	    username, 0};
134a137,138
> #define DEFAULTDIR  "/tmp"	/* last resort directory for rshell */
> 
232,235c236,240
< 	if (chdir(pwd->pw_dir) < 0) {
< 		error("No remote directory.\n");
< 		exit(1);
< 	}
---
> 	if (chdir(pwd->pw_dir) < 0) 
> 		if (chdir(DEFAULTDIR) < 0) {
> 			error("No remote directory.\n");
> 			exit(1);
> 		}
-- 
-- 
========
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	Washington University Engineering Computer Laboratory
	[ Remember: You can't spell `eCStacy' without `CS' ]

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