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From: souza@telesoft.UUCP (Steve Souza @eldest)
Newsgroups: comp.lang.c,comp.unix.wizards
Subject: Network Software Bug
Message-ID: <126@telesoft.UUCP>
Date: Tue, 24-Nov-87 13:18:08 EST
Article-I.D.: telesoft.126
Posted: Tue Nov 24 13:18:08 1987
Date-Received: Sat, 28-Nov-87 11:15:21 EST
Organization: TeleSoft Inc., San Diego, CA
Lines: 57
Keywords: SunOS, 3.4, /etc/group
Xref: mnetor comp.lang.c:5575 comp.unix.wizards:5607

We've seen a strange symptom in a network software package that, until 
SunOS version 3.4 (on a Sun 160), functioned normally.  

The basic scenario is a server process that accepts network socket
connection requests from a client process, executes a specified command,
and sends the output back to the client process, not unlike the r-shell 
software.

Under 3.4, huge pieces of /etc/group randomly appear in the output
of the client process, often in a repeating pattern of usernames.

Here are excerpts from the code [pardon the crudity of the i/o -- I'm
still working on it!]:
----------------------------------------------------------------Server:
write_output(s, cmd)
int s;		/* `s' is a socket of type AF_INET */
char *cmd;	/* `cmd' is the command line */
{
	FILE *pp;
	char buf[BUFSIZ];

	pp = popen(cmd, "r");

	...

	while (fgets(buf, BUFSIZ, pp) != NULL)
		if (write(s, buf, BUFSIZ) < 0) {
			pclose(pp);
			return(1<<8);
		}
	return(pclose(pp));
}
----------------------------------------------------------------Client:
read_output()
{
	/* `sock' is the other end of the AF_INET socket */
	extern int sock;	
	char obuf[BUFSIZ];

	while (1) {
		if (read(sock, obuf, BUFSIZ) > 0)
			write(1, obuf, strlen(obuf));
		else
			break;
	}
}
-----------------------------------------------------------------------
Anybody know of changes in 3.4 that might cause this?  We don't run
YP, BTW.  Also, the server process calls initgroups().  Could that 
be related?

Any suggestions would be m u c h appreciated...

Thanks!

Steve Souza				...sdcsvax!telesoft!souza
TELESOFT Inc., San Diego, CA		(619)457-2700 x277