/*++ /* 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) { const 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) { const 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) { const 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; }