[PATCH] PR#502: cleanup use of longjmp/setjmp for IdentityCheck

["Roy T. Fielding" <fi...@kiwi.ICS.UCI.EDU>]

>PR#502: timeout still a problem with IdentityCheck On.
>Roy thinks it may be a problem with how longjmp and signal are
>used in rfc1413.c (try replacing 
>     static jmp_buf timebuf;
>with
>     JMP_BUF timebuf;
>and replacing the longjmp/setjmp calls with the definitions
>used within http_main.c

Below is a patch that will do this (against current 1.2b11-dev).
I have no idea if it will fix the problem, since I don't have Irix
and haven't been able to reproduce it.  However, it is a bad idea
to use unreliable jumps with reliable signals, so it is worth testing.

....Roy


Index: conf.h
===================================================================
RCS file: /export/home/cvs/apache/src/conf.h,v
retrieving revision 1.97
diff -c -r1.97 conf.h
*** conf.h	1997/05/01 17:36:24	1.97
--- conf.h	1997/05/28 01:20:17
***************
*** 61,67 ****
  
  /* Define one of these according to your system. */
  #if defined(MPE)
- #include <setjmp.h>
  #include <sys/times.h>
  #define JMP_BUF sigjmp_buf
  #define NO_SETSID
--- 61,66 ----
***************
*** 650,655 ****
--- 649,664 ----
  #endif
  #define signal(s,f)	ap_signal(s,f)
  Sigfunc *signal(int signo, Sigfunc *func);
+ #endif
+ 
+ #include <setjmp.h>
+ 
+ #if defined(USE_LONGJMP)
+ #define ap_longjmp(x, y)        longjmp((x), (y))
+ #define ap_setjmp(x)            setjmp(x)
+ #else
+ #define ap_longjmp(x, y)        siglongjmp((x), (y))
+ #define ap_setjmp(x)            sigsetjmp((x), 1)
  #endif
  
  /* Finding offsets of elements within structures.
Index: http_main.c
===================================================================
RCS file: /export/home/cvs/apache/src/http_main.c,v
retrieving revision 1.146
diff -c -r1.146 http_main.c
*** http_main.c	1997/05/27 04:41:50	1.146
--- http_main.c	1997/05/28 01:20:17
***************
*** 84,90 ****
  #include "http_conf_globals.h"
  #include "http_core.h"          /* for get_remote_host */
  #include "scoreboard.h"
- #include <setjmp.h>
  #include <assert.h>
  #include <sys/stat.h>
  #ifdef HAVE_SHMGET
--- 84,89 ----
***************
*** 180,193 ****
  #define ap_killpg(x, y)		(kill (-(x), (y)))
  #else
  #define ap_killpg(x, y)		(killpg ((x), (y)))
- #endif
- 
- #if defined(USE_LONGJMP)
- #define ap_longjmp(x, y)	(longjmp ((x), (y)))
- #define ap_setjmp(x)		(setjmp (x))
- #else
- #define ap_longjmp(x, y)	(siglongjmp ((x), (y)))
- #define ap_setjmp(x)		(sigsetjmp ((x), 1))
  #endif
  
  #if defined(USE_FCNTL_SERIALIZED_ACCEPT)
--- 179,184 ----
Index: rfc1413.c
===================================================================
RCS file: /export/home/cvs/apache/src/rfc1413.c,v
retrieving revision 1.9
diff -c -r1.9 rfc1413.c
*** rfc1413.c	1997/03/07 17:43:36	1.9
--- rfc1413.c	1997/05/28 01:20:17
***************
*** 72,85 ****
  
  /* Rewritten by David Robinson */
  
! #include "httpd.h"    /* for server_rec, conn_rec */
  #include "http_log.h" /* for log_unixerr */
  #include "rfc1413.h"
  
- /* System libraries. */
- 
- #include <setjmp.h>
- 
  #ifndef SCO
  extern char *strchr();
  extern char *inet_ntoa();
--- 72,81 ----
  
  /* Rewritten by David Robinson */
  
! #include "httpd.h"    /* for server_rec, conn_rec, ap_longjmp, etc. */
  #include "http_log.h" /* for log_unixerr */
  #include "rfc1413.h"
  
  #ifndef SCO
  extern char *strchr();
  extern char *inet_ntoa();
***************
*** 93,105 ****
  /* rough limit on the amount of data we accept. */
  #define RFC1413_MAXDATA 1000
  
  #define RFC1413_TIMEOUT	30
  #define	ANY_PORT	0		/* Any old port will do */
  #define FROM_UNKNOWN  "unknown"
  
! int rfc1413_timeout = RFC1413_TIMEOUT;/* Global so it can be changed */
! 
! static jmp_buf timebuf;
  
  /* bind_connect - bind both ends of a socket */
  
--- 89,101 ----
  /* rough limit on the amount of data we accept. */
  #define RFC1413_MAXDATA 1000
  
+ #ifndef RFC1413_TIMEOUT
  #define RFC1413_TIMEOUT	30
+ #endif
  #define	ANY_PORT	0		/* Any old port will do */
  #define FROM_UNKNOWN  "unknown"
  
! JMP_BUF timebuf;
  
  /* bind_connect - bind both ends of a socket */
  
***************
*** 182,192 ****
      return 0;
  }
  
! /* timeout - handle timeouts */
  static void
! timeout(int sig)
  {
!     longjmp(timebuf, sig);
  }
  
  /* rfc1413 - return remote user name, given socket structures */
--- 178,188 ----
      return 0;
  }
  
! /* ident_timeout - handle timeouts */
  static void
! ident_timeout(int sig)
  {
!     ap_longjmp(timebuf, sig);
  }
  
  /* rfc1413 - return remote user name, given socket structures */
***************
*** 209,218 ****
      /*
       * Set up a timer so we won't get stuck while waiting for the server.
       */
!     if (setjmp(timebuf) == 0)
      {
! 	signal(SIGALRM, timeout);
! 	alarm(rfc1413_timeout);
  	
  	if (get_rfc1413(sock, &conn->local_addr, &conn->remote_addr, user,
  		      srv)
--- 205,214 ----
      /*
       * Set up a timer so we won't get stuck while waiting for the server.
       */
!     if (ap_setjmp(timebuf) == 0)
      {
! 	signal(SIGALRM, ident_timeout);
! 	alarm(RFC1413_TIMEOUT);
  	
  	if (get_rfc1413(sock, &conn->local_addr, &conn->remote_addr, user,
  		      srv)