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/*++
/* NAME
/* bounce_one_service 3
/* SUMMARY
/* send non-delivery report to sender, server side
/* SYNOPSIS
/* #include "bounce_service.h"
/*
/* int bounce_one_service(flags, queue_name, queue_id, encoding,
/* smtputf8, orig_sender, envid, ret,
/* rcpt_buf, dsn_buf, templates)
/* int flags;
/* char *queue_name;
/* char *queue_id;
/* char *encoding;
/* int smtputf8;
/* char *orig_sender;
/* char *envid;
/* int ret;
/* RCPT_BUF *rcpt_buf;
/* DSN_BUF *dsn_buf;
/* BOUNCE_TEMPLATES *templates;
/* DESCRIPTION
/* This module implements the server side of the bounce_one()
/* (send bounce message for one recipient) request.
/*
/* When a message bounces, a full copy is sent to the originator,
/* and an optional copy of the diagnostics with message headers is
/* sent to the postmaster. The result is non-zero when the operation
/* should be tried again.
/*
/* When a bounce is sent, the sender address is the empty
/* address. When a bounce bounces, an optional double bounce
/* with the entire undeliverable mail is sent to the postmaster,
/* with as sender address the double bounce address.
/* DIAGNOSTICS
/* Fatal error: error opening existing file.
/* 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 <fcntl.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
/* Utility library. */
#include <msg.h>
#include <vstream.h>
#include <name_mask.h>
#include <stringops.h>
/* Global library. */
#include <mail_params.h>
#include <post_mail.h>
#include <mail_addr.h>
#include <mail_error.h>
#include <bounce.h>
#include <dsn_mask.h>
#include <rec_type.h>
/* Application-specific. */
#include "bounce_service.h"
#define STR vstring_str
/* bounce_one_service - send a bounce for one recipient */
int bounce_one_service(int flags, char *queue_name, char *queue_id,
char *encoding, int smtputf8,
char *orig_sender, char *dsn_envid,
int dsn_ret, RCPT_BUF *rcpt_buf,
DSN_BUF *dsn_buf, BOUNCE_TEMPLATES *ts)
{
BOUNCE_INFO *bounce_info;
int bounce_status = 1;
int postmaster_status = 1;
VSTREAM *bounce;
int notify_mask = name_mask(VAR_NOTIFY_CLASSES, mail_error_masks,
var_notify_classes);
VSTRING *new_id = vstring_alloc(10);
/*
* Initialize. Open queue file, bounce log, etc.
*/
bounce_info = bounce_mail_one_init(queue_name, queue_id, encoding,
smtputf8, dsn_envid, rcpt_buf,
dsn_buf, ts->failure);
#define NULL_SENDER MAIL_ADDR_EMPTY /* special address */
#define NULL_TRACE_FLAGS 0
/*
* The choice of bounce sender address depends on the original sender
* address. For a single bounce (a non-delivery notification to the
* message originator), the sender address is the empty string. For a
* double bounce (typically a failed single bounce, or a postmaster
* notification that was produced by any of the mail processes) the
* sender address is defined by the var_double_bounce_sender
* configuration variable. When a double bounce cannot be delivered, the
* queue manager blackholes the resulting triple bounce message.
*/
/*
* Double bounce failed. Never send a triple bounce.
*
* However, this does not prevent double bounces from bouncing on other
* systems. In order to cope with this, either the queue manager must
* recognize the double-bounce original sender address and discard mail,
* or every delivery agent must recognize the double-bounce sender
* address and substitute something else so mail does not come back at
* us.
*/
if (strcasecmp_utf8(orig_sender, mail_addr_double_bounce()) == 0) {
msg_warn("%s: undeliverable postmaster notification discarded",
queue_id);
bounce_status = 0;
}
/*
* Single bounce failed. Optionally send a double bounce to postmaster,
* subject to notify_classes restrictions.
*/
#define ANY_BOUNCE (MAIL_ERROR_2BOUNCE | MAIL_ERROR_BOUNCE)
#define SEND_POSTMASTER_ANY_BOUNCE_NOTICE (notify_mask & ANY_BOUNCE)
else if (*orig_sender == 0) {
if (!SEND_POSTMASTER_ANY_BOUNCE_NOTICE) {
bounce_status = 0;
} else {
if ((bounce = post_mail_fopen_nowait(mail_addr_double_bounce(),
var_2bounce_rcpt,
MAIL_SRC_MASK_BOUNCE,
NULL_TRACE_FLAGS,
smtputf8,
new_id)) != 0) {
/*
* Double bounce to Postmaster. This is the last opportunity
* for this message to be delivered. Send the text with
* reason for the bounce, and the headers of the original
* message. Don't bother sending the boiler-plate text.
*/
if (!bounce_header(bounce, bounce_info, var_2bounce_rcpt,
POSTMASTER_COPY)
&& bounce_recipient_log(bounce, bounce_info) == 0
&& bounce_header_dsn(bounce, bounce_info) == 0
&& bounce_recipient_dsn(bounce, bounce_info) == 0)
bounce_original(bounce, bounce_info, DSN_RET_FULL);
bounce_status = post_mail_fclose(bounce);
if (bounce_status == 0)
msg_info("%s: postmaster non-delivery notification: %s",
queue_id, STR(new_id));
}
}
}
/*
* Non-bounce failed. Send a single bounce, subject to DSN NOTIFY
* restrictions.
*/
else {
RECIPIENT *rcpt = &bounce_info->rcpt_buf->rcpt;
if (rcpt->dsn_notify != 0 /* compat */
&& (rcpt->dsn_notify & DSN_NOTIFY_FAILURE) == 0) {
bounce_status = 0;
} else {
if ((bounce = post_mail_fopen_nowait(NULL_SENDER, orig_sender,
MAIL_SRC_MASK_BOUNCE,
NULL_TRACE_FLAGS,
smtputf8,
new_id)) != 0) {
/*
* Send the bounce message header, some boilerplate text that
* pretends that we are a polite mail system, the text with
* reason for the bounce, and a copy of the original message.
*/
if (bounce_header(bounce, bounce_info, orig_sender,
NO_POSTMASTER_COPY) == 0
&& bounce_boilerplate(bounce, bounce_info) == 0
&& bounce_recipient_log(bounce, bounce_info) == 0
&& bounce_header_dsn(bounce, bounce_info) == 0
&& bounce_recipient_dsn(bounce, bounce_info) == 0)
bounce_original(bounce, bounce_info, dsn_ret ?
dsn_ret : DSN_RET_FULL);
bounce_status = post_mail_fclose(bounce);
if (bounce_status == 0)
msg_info("%s: sender non-delivery notification: %s",
queue_id, STR(new_id));
}
}
/*
* Optionally send a postmaster notice, subject to notify_classes
* restrictions.
*
* This postmaster notice is not critical, so if it fails don't
* retransmit the bounce that we just generated, just log a warning.
*/
#define SEND_POSTMASTER_SINGLE_BOUNCE_NOTICE (notify_mask & MAIL_ERROR_BOUNCE)
if (bounce_status == 0 && SEND_POSTMASTER_SINGLE_BOUNCE_NOTICE
&& strcasecmp_utf8(orig_sender, mail_addr_double_bounce()) != 0) {
/*
* Send the text with reason for the bounce, and the headers of
* the original message. Don't bother sending the boiler-plate
* text. This postmaster notice is not critical, so if it fails
* don't retransmit the bounce that we just generated, just log a
* warning.
*/
if ((bounce = post_mail_fopen_nowait(mail_addr_double_bounce(),
var_bounce_rcpt,
MAIL_SRC_MASK_BOUNCE,
NULL_TRACE_FLAGS,
smtputf8,
new_id)) != 0) {
if (bounce_header(bounce, bounce_info, var_bounce_rcpt,
POSTMASTER_COPY) == 0
&& bounce_recipient_log(bounce, bounce_info) == 0
&& bounce_header_dsn(bounce, bounce_info) == 0
&& bounce_recipient_dsn(bounce, bounce_info) == 0)
bounce_original(bounce, bounce_info, DSN_RET_HDRS);
postmaster_status = post_mail_fclose(bounce);
if (postmaster_status == 0)
msg_info("%s: postmaster non-delivery notification: %s",
queue_id, STR(new_id));
}
if (postmaster_status)
msg_warn("%s: postmaster notice failed while bouncing to %s",
queue_id, orig_sender);
}
}
/*
* Optionally, delete the recipient from the queue file.
*/
if (bounce_status == 0 && (flags & BOUNCE_FLAG_DELRCPT))
bounce_delrcpt_one(bounce_info);
/*
* Cleanup.
*/
bounce_mail_free(bounce_info);
vstring_free(new_id);
return (bounce_status);
}
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