From randy Sat May 29 14:15:39 1993
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From: hirai@cc.swarthmore.edu (Eiji Hirai)
Subject: Re; UNOFFICIAL PATCH to popper-1.831b
Message-ID: <M0ZSB51M@cc.swarthmore.edu>
Sender: randy
Nntp-Posting-Host: gingko
Organization: Information Services, Swarthmore College, Swarthmore, PA, USA
References: <Q0YSBG55@cc.swarthmore.edu>
Date: Tue, 10 Nov 1992 20:55:32 GMT
Status: O

I wrote:
: This adds an idle timeout routine to popper 1.831b

sdorner@qualcomm.com (Steve Dorner) pointed out a potential problem with the
patch.  Thanks Steve.  Here's a fixed patch.  You'll need to apply this
patch to the original popper source, not the patched source.  If you need the
original, it's at lilac.berkeley.edu:/pub/popper/.

--
hirai@cc.swarthmore.edu (Eiji Hirai)    :     :    :   :  : :: ::: :::: :::::
Unix Geek for Swarthmore College        :     :    :   :  : :: ::: :::: :::::
Information Services, Swarthmore, PA, US.       Copyright 1992 by Eiji Hirai.
I don't speak for Swarthmore College.                    All Rights Reserved.

Subject: idle timeout routines

Description:

	If a pop client has opened a connection to the popper server and the
	client host crashes, the connection to the popper server is never
	closed and the popper server will never quit.  After a large number
	of client host crashes, the server host will run out of file
	descriptors and memory.

Repeat-By:

	Run Eudora (say 1.3) on a Macintosh with MacTCP (say 1.1.1), then
	download a large mail file.  During the download, restart the
	Macintosh.  The popper server which was talking to that client will
	be running on your server host until you manually kill it.  Shout,
	"eek!"

Fix:
	Apply this patch.  Add -DTIMEOUT to CFLAGS in Makefile.

Index: version.h
Prereq: "1.831beta"
*** version.h.old	Wed Apr  3 18:25:44 1991
--- version.h	Mon Nov  9 20:34:28 1992
***************
*** 12,15 ****
--- 12,19 ----
   *  Current version of this POP implementation
   */
  
+ #ifdef TIMEOUT
+ #define VERSION         "1.831beta+timeout"
+ #else
  #define VERSION         "1.831beta"
+ #endif /* TIMEOUT */
*** popper.h.old	Wed Apr  3 18:25:43 1991
--- popper.h	Tue Nov 10 14:40:48 1992
***************
*** 170,172 ****
--- 170,176 ----
  extern int  pop_xtnd();
  extern int  pop_xmit();
  
+ #ifdef TIMEOUT
+ # define CHECKIDLE	60
+ # define MAXIDLE	600
+ #endif /* TIMEOUT */
*** popper.c.old	Wed Apr  3 18:25:42 1991
--- popper.c	Tue Nov 10 15:48:11 1992
***************
*** 15,20 ****
--- 15,28 ----
  
  extern  state_table *   pop_get_command();
  
+ #ifdef TIMEOUT
+ # include <signal.h>
+ # include <time.h>
+ # define p	main_p
+ POP	p;
+ time_t	lasttime;
+ #endif /* TIMEOUT */
+ 
  /* 
   *  popper: Handle a Post Office Protocol version 3 session
   */
***************
*** 22,28 ****
--- 30,40 ----
  int         argc;
  char    **  argv;
  {
+ #ifdef TIMEOUT
+ 	void timeout();
+ #else
      POP                 p;
+ #endif /* TIMEOUT */
      state_table     *   s;
      char                message[MAXLINELEN];
  
***************
*** 33,38 ****
--- 45,56 ----
      pop_msg(&p,POP_SUCCESS,
          "UCB Pop server (version %s) at %s starting.",VERSION,p.myhost);
  
+ #ifdef TIMEOUT
+ 	lasttime = time((time_t *)0);
+ 	signal(SIGALRM, timeout);
+ 	alarm(CHECKIDLE);  /* turn on idle timer */
+ #endif /* TIMEOUT */
+ 
      /*  State loop.  The POP server is always in a particular state in 
          which a specific suite of commands can be executed.  The following 
          loop reads a line from the client, gets the command, and processes 
***************
*** 47,52 ****
--- 65,73 ----
              pop_msg(&p,POP_FAILURE,"POP server at %s signing off.",p.myhost);
          }
          else {
+ #ifdef TIMEOUT
+ 		alarm(0); /* turn off idle timer */
+ #endif /* TIMEOUT */
              /*  Search for the command in the command/state table */
              if ((s = pop_get_command(&p,message)) == NULL) continue;
  
***************
*** 59,64 ****
--- 80,89 ----
                  p.CurrentState = s->success_state;
                  pop_msg(&p,POP_SUCCESS,NULL);
              }
+ #ifdef TIMEOUT
+ 	    lasttime = time((time_t *)0);
+ 	    alarm(CHECKIDLE);  /* turn on idle timer */
+ #endif /* TIMEOUT */
          }       
      }
  
***************
*** 100,102 ****
--- 125,142 ----
      return(0);
  }
  #endif STRNCASECMP
+ 
+ #ifdef TIMEOUT
+ void	timeout() {
+ 	if (time((time_t *)0) - lasttime >= MAXIDLE) {
+ 		pop_msg(&p,POP_SUCCESS,
+ 			"Pop server at %s signing off.",p.myhost);
+ 		pop_log(&p,POP_PRIORITY,
+ 	"(v%s) Idle timeout from \"%s\" at %s",VERSION,p.client,p.ipaddr);
+ 		closelog();
+ 		exit(0);
+ 	}
+ 	else
+ 		alarm(CHECKIDLE);
+ }
+ #endif /* TIMEOUT */