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Path: utzoo!watmath!clyde!floyd!harpo!decvax!ucbvax!ucbcad!tektronix!hplabs!sri-unix!cak@Purdue.ARPA
From: cak@Purdue.ARPA
Newsgroups: net.unix-wizards
Subject: ftpd doesn't work on multi-homed hosts
Message-ID: <273@sri-arpa.UUCP>
Date: Sun, 25-Mar-84 21:18:00 EST
Article-I.D.: sri-arpa.273
Posted: Sun Mar 25 21:18:00 1984
Date-Received: Fri, 30-Mar-84 00:33:39 EST
Lines: 57

From:  Christopher A Kent <cak@Purdue.ARPA>

Description:
	On multi-homed hosts, ftpd won't always work because the code to 
	anchor the reply socket is incorrect; the getsockname() call
	has a bad argument, thus the filled in address is always 0.

Repeat-By:
	ftp to a multi-homed host on the same net as yours, but specify
	the alternate address as the host to connect to.

Fix:
	getsockname() wants an int *, not an int, for the namelen. I
	did it this way (don't trust the line numbers):

*** ftpd.c.old
--- ftpd.c	
***************
*** 168,173
  			continue;
  		}
  		if (fork() == 0) {
  			signal (SIGCHLD, SIG_IGN);
  			openlog("ftpd", LOG_PID);
  			dolog(&his_addr);

--- 168,175 -----
  			continue;
  		}
  		if (fork() == 0) {
+ 			int addrsize;
+ 
  			signal (SIGCHLD, SIG_IGN);
  			openlog("ftpd", LOG_PID);
  			dolog(&his_addr);
***************
*** 183,189
  			form = FORM_N;
  			stru = STRU_F;
  			mode = MODE_S;
! 			(void) getsockname(0, &ctrl_addr, sizeof (ctrl_addr));
  			gethostname(hostname, sizeof (hostname));
  			reply(220, "%s FTP server (%s) ready.",
  				hostname, version);

--- 185,192 -----
  			form = FORM_N;
  			stru = STRU_F;
  			mode = MODE_S;
! 			addrsize = sizeof(ctrl_addr);
! 			(void) getsockname(0, &ctrl_addr, &addrsize);
  			gethostname(hostname, sizeof (hostname));
  			reply(220, "%s FTP server (%s) ready.",
  				hostname, version);


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