bounce_trace_service.c

[詳解]

/*++
/* NAME
/*  bounce_trace_service 3
/* SUMMARY
/*  send status report to sender, server side
/* SYNOPSIS
/*  #include "bounce_service.h"
/*
/*  int     bounce_trace_service(flags, service, queue_name, queue_id,
/*                  encoding, smtputf8, sender, envid,
/*                  ret, templates)
/*  int flags;
/*  char    *service;
/*  char    *queue_name;
/*  char    *queue_id;
/*  char    *encoding;
/*  int smtputf8;
/*  char    *sender;
/*  char    *envid;
/*  int ret;
/*  BOUNCE_TEMPLATES *templates;
/* DESCRIPTION
/*  This module implements the server side of the trace_flush()
/*  (send delivery notice) request. The logfile
/*  is removed after the notice is posted.
/*
/*  A status report includes a prelude with human-readable text,
/*  a DSN-style report, and the email message that was subject of
/*  the status report.
/*
/*  When a status report is sent, the sender address is the empty
/*  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 <stringops.h>

/* Global library. */

#include <mail_params.h>
#include <mail_queue.h>
#include <post_mail.h>
#include <mail_addr.h>
#include <mail_error.h>
#include <dsn_mask.h>
#include <rec_type.h>
#include <deliver_request.h>        /* USR_VRFY and RECORD flags */

/* Application-specific. */

#include "bounce_service.h"

#define STR vstring_str

/* bounce_trace_service - send a delivery status notice */

int     bounce_trace_service(int flags, char *service, char *queue_name,
                         char *queue_id, char *encoding,
                         int smtputf8,
                         char *recipient, char *dsn_envid,
                         int unused_dsn_ret,
                         BOUNCE_TEMPLATES *ts)
{
    BOUNCE_INFO *bounce_info;
    int     bounce_status = 1;
    VSTREAM *bounce;
    int     notify_mask = name_mask(VAR_NOTIFY_CLASSES, mail_error_masks,
                    var_notify_classes);
    VSTRING *new_id;
    int     count;
    const char *sender;

    /*
     * For consistency with fail/delay notifications, send notification for a
     * non-bounce message as a single-bounce message, send notification for a
     * single-bounce message as a double-bounce message, and drop requests to
     * send notification for a double-bounce message.
     */
#define NULL_SENDER     MAIL_ADDR_EMPTY /* special address */

    if (strcasecmp_utf8(recipient, mail_addr_double_bounce()) == 0) {
    msg_info("%s: not sending trace/success notification for "
         "double-bounce message", queue_id);
    return (0);
    } else if (*recipient == 0) {
    if ((notify_mask & MAIL_ERROR_2BOUNCE) != 0) {
        recipient = var_2bounce_rcpt;
        sender = mail_addr_double_bounce();
    } else {
        msg_info("%s: not sending trace/success notification "
             "for single-bounce message", queue_id);
        if (mail_queue_remove(service, queue_id) && errno != ENOENT)
        msg_fatal("remove %s %s: %m", service, queue_id);
        return (0);
    }
    } else {
    /* Always send notification for non-bounce message. */
    sender = NULL_SENDER;
    }

    /*
     * Initialize. Open queue file, bounce log, etc.
     * 
     * XXX DSN The trace service produces information from the trace logfile
     * which is used for three types of reports:
     * 
     * a) "what-if" reports that show what would happen without actually
     * delivering mail (sendmail -bv).
     * 
     * b) A report of actual deliveries (sendmail -v).
     * 
     * c) DSN NOTIFY=SUCCESS reports of successful delivery ("delivered",
     * "expanded" or "relayed").
     */
#define NON_DSN_FLAGS (DEL_REQ_FLAG_USR_VRFY | DEL_REQ_FLAG_RECORD)

    bounce_info = bounce_mail_init(service, queue_name, queue_id,
                   encoding, smtputf8, dsn_envid,
                   flags & NON_DSN_FLAGS ?
                   ts->verify : ts->success);

    /*
     * XXX With multi-recipient mail some queue file recipients may have
     * NOTIFY=SUCCESS and others not. Depending on what subset of recipients
     * are delivered, a trace file may or may not be created. Even when the
     * last partial delivery attempt had no NOTIFY=SUCCESS recipients, a
     * trace file may still exist from a previous partial delivery attempt.
     * So as long as any recipient in the original queue file had
     * NOTIFY=SUCCESS we have to always look for the trace file and be
     * prepared for the file not to exist.
     * 
     * See also comments in qmgr/qmgr_active.c.
     */
    if (bounce_info->log_handle == 0) {
    if (msg_verbose)
        msg_info("%s: no trace file -- not sending a notification",
             queue_id);
    bounce_mail_free(bounce_info);
    return (0);
    }
#define NULL_TRACE_FLAGS    0

    /*
     * Send a single bounce with a template message header, some boilerplate
     * text that pretends that we are a polite mail system, the text with
     * per-recipient status, and a copy of the original message.
     * 
     * XXX DSN We use the same trace file for "what-if", "verbose delivery" and
     * "success" delivery reports. This saves file system overhead because
     * there are fewer potential left-over files to remove up when we create
     * a new queue file.
     */
    new_id = vstring_alloc(10);
    if ((bounce = post_mail_fopen_nowait(sender, recipient,
                     MAIL_SRC_MASK_BOUNCE,
                     NULL_TRACE_FLAGS,
                     smtputf8,
                     new_id)) != 0) {
    count = -1;
    if (bounce_header(bounce, bounce_info, recipient,
              NO_POSTMASTER_COPY) == 0
        && bounce_boilerplate(bounce, bounce_info) == 0
        && (count = bounce_diagnostic_log(bounce, bounce_info,
                          DSN_NOTIFY_OVERRIDE)) > 0
        && bounce_header_dsn(bounce, bounce_info) == 0
        && bounce_diagnostic_dsn(bounce, bounce_info,
                     DSN_NOTIFY_OVERRIDE) > 0) {
        bounce_original(bounce, bounce_info, DSN_RET_HDRS);
        bounce_status = post_mail_fclose(bounce);
        if (bounce_status == 0)
        msg_info("%s: sender delivery status notification: %s",
             queue_id, STR(new_id));
    } else {
        (void) vstream_fclose(bounce);
        if (count == 0)
        bounce_status = 0;
    }
    }

    /*
     * Examine the completion status. Delete the trace log file only when the
     * status notice was posted successfully.
     */
    if (bounce_status == 0 && mail_queue_remove(service, queue_id)
    && errno != ENOENT)
    msg_fatal("remove %s %s: %m", service, queue_id);

    /*
     * Cleanup.
     */
    bounce_mail_free(bounce_info);
    vstring_free(new_id);

    return (bounce_status);
}