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/*++
/* NAME
/* bounce_cleanup 3
/* SUMMARY
/* cleanup logfile upon error
/* SYNOPSIS
/* #include "bounce_service.h"
/*
/* int bounce_cleanup_registered()
/*
/* void bounce_cleanup_register(queue_id)
/* char *queue_id;
/*
/* void bounce_cleanup_log(void)
/*
/* void bounce_cleanup_unregister(void)
/* DESCRIPTION
/* This module implements support for deleting the current
/* bounce logfile in case of errors, and upon the arrival
/* of a SIGTERM signal (shutdown).
/*
/* bounce_cleanup_register() registers a callback routine with the
/* run-time error handler, for automatic logfile removal in case
/* of a fatal run-time error.
/*
/* bounce_cleanup_unregister() cleans up storage used by
/* bounce_cleanup_register().
/*
/* In-between bounce_cleanup_register() and bounce_cleanup_unregister()
/* calls, a call of bounce_cleanup_log() will delete the registered
/* bounce logfile.
/*
/* bounce_cleanup_registered() returns non-zero when a cleanup
/* trap has been set.
/* DIAGNOSTICS
/* Fatal error: all file access errors. Panic: nested calls of
/* bounce_cleanup_register(); any calls of bounce_cleanup_unregister()
/* or bounce_cleanup_log() without preceding bounce_cleanup_register()
/* call.
/* BUGS
/* SEE ALSO
/* master(8) process manager
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
/* Utility library. */
#include <msg.h>
#include <mymalloc.h>
#include <vstring.h>
/* Global library. */
#include <mail_queue.h>
/* Application-specific. */
#include "bounce_service.h"
/*
* Support for removing a logfile when an update fails. In order to do this,
* we save a copy of the currently-open logfile name, and register a
* callback function pointer with the run-time error handler. The saved
* pathname is made global so that the application can see whether or not a
* trap was set up.
*/
static MSG_CLEANUP_FN bounce_cleanup_func; /* saved callback */
VSTRING *bounce_cleanup_path; /* saved path name */
/* bounce_cleanup_callback - run-time callback to cleanup logfile */
static void bounce_cleanup_callback(void)
{
/*
* Remove the logfile.
*/
if (bounce_cleanup_path)
bounce_cleanup_log();
/*
* Execute the saved cleanup action.
*/
if (bounce_cleanup_func)
bounce_cleanup_func();
}
/* bounce_cleanup_log - clean up the logfile */
void bounce_cleanup_log(void)
{
char *myname = "bounce_cleanup_log";
/*
* Sanity checks.
*/
if (bounce_cleanup_path == 0)
msg_panic("%s: no cleanup context", myname);
/*
* This function may be called before a logfile is created or after it
* has been deleted, so do not complain.
*/
(void) unlink(vstring_str(bounce_cleanup_path));
}
/* bounce_cleanup_sig - signal handler */
static void bounce_cleanup_sig(int sig)
{
/*
* Running as a signal handler - don't do complicated stuff.
*/
if (bounce_cleanup_path)
(void) unlink(vstring_str(bounce_cleanup_path));
exit(sig);
}
/* bounce_cleanup_register - register logfile to clean up */
void bounce_cleanup_register(char *service, char *queue_id)
{
char *myname = "bounce_cleanup_register";
/*
* Sanity checks.
*/
if (bounce_cleanup_path)
msg_panic("%s: nested call", myname);
/*
* Save a copy of the logfile path, and of the last callback function
* pointer registered with the run-time error handler.
*/
bounce_cleanup_path = vstring_alloc(10);
(void) mail_queue_path(bounce_cleanup_path, service, queue_id);
bounce_cleanup_func = msg_cleanup(bounce_cleanup_callback);
signal(SIGTERM, bounce_cleanup_sig);
}
/* bounce_cleanup_unregister - unregister logfile to clean up */
void bounce_cleanup_unregister(void)
{
char *myname = "bounce_cleanup_unregister";
/*
* Sanity checks.
*/
if (bounce_cleanup_path == 0)
msg_panic("%s: no cleanup context", myname);
/*
* Restore the saved callback function pointer, and release storage for
* the saved logfile pathname.
*/
signal(SIGTERM, SIG_DFL);
(void) msg_cleanup(bounce_cleanup_func);
vstring_free(bounce_cleanup_path);
bounce_cleanup_path = 0;
}
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