NetBSD/gnu/dist/postfix/bounce/bounce_append_service.c

125 lines
3.6 KiB
C

/*++
/* NAME
/* bounce_append_service 3
/* SUMMARY
/* append record to bounce log, server side
/* SYNOPSIS
/* #include "bounce_service.h"
/*
/* int bounce_append_service(queue_id, recipient, why)
/* char *queue_id;
/* char *recipient;
/* char *why;
/* DESCRIPTION
/* This module implements the server side of the bounce_append()
/* (append bounce log) request. This routine either succeeds or
/* it raises a fatal error.
/* DIAGNOSTICS
/* Fatal errors: all file access errors; memory allocation errors.
/* BUGS
/* SEE ALSO
/* bounce(3) basic bounce service client interface
/* 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 <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <string.h>
/* Utility library. */
#include <msg.h>
#include <vstring.h>
#include <vstream.h>
#include <stringops.h>
/* Global library. */
#include <mail_queue.h>
#include <quote_822_local.h>
#include <deliver_flock.h>
/* Application-specific. */
#include "bounce_service.h"
/* bounce_append_service - append bounce log */
int bounce_append_service(char *service, char *queue_id,
char *recipient, char *why)
{
VSTRING *in_buf = vstring_alloc(100);
VSTRING *out_buf = vstring_alloc(100);
VSTREAM *log;
long orig_length;
/*
* This code is paranoid for a good reason. Once the bounce service takes
* responsibility, the mail system will make no further attempts to
* deliver this recipient. Whenever file access fails, assume that the
* system is under stress or that something has been mis-configured, and
* force a backoff by raising a fatal run-time error.
*/
log = mail_queue_open(service, queue_id,
O_WRONLY | O_APPEND | O_CREAT, 0600);
if (log == 0)
msg_fatal("open file %s %s: %m", service, queue_id);
/*
* Lock out other processes to avoid truncating someone else's data in
* case of trouble.
*/
if (deliver_flock(vstream_fileno(log), (VSTRING *) 0) < 0)
msg_fatal("lock file %s %s: %m", service, queue_id);
/*
* Now, go for it. Append a record. Truncate the log to the original
* length when the append operation fails. We use the plain stream-lf
* file format because we do not need anything more complicated. As a
* benefit, we can still recover some data when the file is a little
* garbled.
*/
if ((orig_length = vstream_fseek(log, 0L, SEEK_END)) < 0)
msg_fatal("seek file %s %s: %m", service, queue_id);
if (*recipient)
vstream_fprintf(log, "<%s>: ",
printable(vstring_str(quote_822_local(in_buf, recipient)), '?'));
vstream_fputs(printable(why, '?'), log);
vstream_fputs("\n\n", log);
if (vstream_fflush(log) != 0 || fsync(vstream_fileno(log)) < 0) {
#ifndef NO_TRUNCATE
if (ftruncate(vstream_fileno(log), (off_t) orig_length) < 0)
msg_fatal("truncate file %s %s: %m", service, queue_id);
#endif
msg_fatal("append file %s %s: %m", service, queue_id);
}
/*
* Darn. If closing the log detects a problem, the only way to undo the
* damage is to open the log once more, and to truncate the log to the
* original length. But, this could happen only when the log is kept on a
* remote file system, and that is not recommended practice anyway.
*/
if (vstream_fclose(log) != 0)
msg_warn("append file %s %s: %m", service, queue_id);
vstring_free(in_buf);
vstring_free(out_buf);
return (0);
}