bounce.c

[詳解]

/*++
/* NAME
/*  bounce 3
/* SUMMARY
/*  bounce service client
/* SYNOPSIS
/*  #include <bounce.h>
/*
/*  int bounce_append(flags, id, stats, recipient, relay, dsn)
/*  int flags;
/*  const char *id;
/*  MSG_STATS *stats;
/*  RECIPIENT *rcpt;
/*  const char *relay;
/*  DSN *dsn;
/*
/*  int bounce_flush(flags, queue, id, encoding, smtputf8, sender,
/*              dsn_envid, dsn_ret)
/*  int flags;
/*  const char *queue;
/*  const char *id;
/*  const char *encoding;
/*  int smtputf8;
/*  const char *sender;
/*  const char *dsn_envid;
/*  int dsn_ret;
/*
/*  int bounce_flush_verp(flags, queue, id, encoding, smtputf8,
/*              sender, dsn_envid, dsn_ret, verp_delims)
/*  int flags;
/*  const char *queue;
/*  const char *id;
/*  const char *encoding;
/*  int smtputf8;
/*  const char *sender;
/*  const char *dsn_envid;
/*  int dsn_ret;
/*  const char *verp_delims;
/*
/*  int bounce_one(flags, queue, id, encoding, smtputf8, sender,
/*              dsn_envid, ret, stats, recipient, relay, dsn)
/*  int flags;
/*  const char *queue;
/*  const char *id;
/*  const char *encoding;
/*  int smtputf8;
/*  const char *sender;
/*  const char *dsn_envid;
/*  int dsn_ret;
/*  MSG_STATS *stats;
/*  RECIPIENT *rcpt;
/*  const char *relay;
/*  DSN *dsn;
/*
/*  void    bounce_client_init(title, maps)
/*  const char *title;
/*  const char *maps;
/* INTERNAL API
/*  DSN_FILTER *delivery_status_filter;
/*
/*  int bounce_append_intern(flags, id, stats, recipient, relay, dsn)
/*  int flags;
/*  const char *id;
/*  MSG_STATS *stats;
/*  RECIPIENT *rcpt;
/*  const char *relay;
/*
/*  int bounce_one_intern(flags, queue, id, encoding, smtputf8, sender,
/*              dsn_envid, ret, stats, recipient, relay, dsn)
/*  int flags;
/*  const char *queue;
/*  const char *id;
/*  const char *encoding;
/*  int smtputf8;
/*  const char *sender;
/*  const char *dsn_envid;
/*  int dsn_ret;
/*  MSG_STATS *stats;
/*  RECIPIENT *rcpt;
/*  const char *relay;
/*  DSN *dsn;
/* DESCRIPTION
/*  This module implements the client interface to the message
/*  bounce service, which maintains a per-message log of status
/*  records with recipients that were bounced, and the dsn_text why.
/*
/*  bounce_append() appends a dsn_text for non-delivery to the
/*  bounce log for the named recipient, updates the address
/*  verification service, or updates a message delivery record
/*  on request by the sender. The flags argument determines
/*  the action.
/*
/*  bounce_flush() actually bounces the specified message to
/*  the specified sender, including the bounce log that was
/*  built with bounce_append(). The bounce logfile is removed
/*  upon successful completion.
/*
/*  bounce_flush_verp() is like bounce_flush(), but sends one
/*  notification per recipient, with the failed recipient encoded
/*  into the sender address.
/*
/*  bounce_one() bounces one recipient and immediately sends a
/*  notification to the sender. This procedure does not append
/*  the recipient and dsn_text to the per-message bounce log, and
/*  should be used when a delivery agent changes the error
/*  return address in a manner that depends on the recipient
/*  address.
/*
/*  bounce_client_init() initializes an optional DSN filter.
/*
/*  bounce_append_intern() and bounce_one_intern() are for use
/*  after the DSN filter.
/*
/*  Arguments:
/* .IP flags
/*  The bitwise OR of zero or more of the following (specify
/*  BOUNCE_FLAG_NONE to request no special processing):
/* .RS
/* .IP BOUNCE_FLAG_CLEAN
/*  Delete the bounce log in case of an error (as in: pretend
/*  that we never even tried to bounce this message).
/* .IP BOUNCE_FLAG_DELRCPT
/*  When specified with a flush request, request that
/*  recipients be deleted from the queue file.
/*
/*  Note: the bounce daemon ignores this request when the
/*  recipient queue file offset is <= 0.
/* .IP DEL_REQ_FLAG_MTA_VRFY
/*  The message is an MTA-requested address verification probe.
/*  Update the address verification database instead of bouncing
/*  mail.
/* .IP DEL_REQ_FLAG_USR_VRFY
/*  The message is a user-requested address expansion probe.
/*  Update the message delivery record instead of bouncing mail.
/* .IP DEL_REQ_FLAG_RECORD
/*  This is a normal message with logged delivery. Update the
/*  message delivery record and bounce the mail.
/* .RE
/* .IP queue
/*  The message queue name of the original message file.
/* .IP id
/*  The message queue id if the original message file. The bounce log
/*  file has the same name as the original message file.
/* .IP stats
/*  Time stamps from different message delivery stages
/*  and session reuse count.
/* .IP rcpt
/*  Recipient information. See recipient_list(3).
/* .IP relay
/*  Name of the host that the message could not be delivered to.
/*  This information is used for syslogging only.
/* .IP encoding
/*  The body content encoding: MAIL_ATTR_ENC_{7BIT,8BIT,NONE}.
/* .IP smtputf8
/*  The level of SMTPUTF8 support (to be defined).
/* .IP sender
/*  The sender envelope address.
/* .IP dsn_envid
/*  Optional DSN envelope ID.
/* .IP dsn_ret
/*  Optional DSN return full/headers option.
/* .IP dsn
/*  Delivery status. See dsn(3). The specified action is ignored.
/* .IP verp_delims
/*  VERP delimiter characters, used when encoding the failed
/*  sender into the envelope sender address.
/* DIAGNOSTICS
/*  In case of success, these functions log the action, and return a
/*  zero value. Otherwise, the functions return a non-zero result,
/*  and when BOUNCE_FLAG_CLEAN is disabled, log that message
/*  delivery is deferred.
/* .IP title
/*  The origin of the optional DSN filter lookup table names.
/* .IP maps
/*  The optional "type:table" DSN filter lookup table names,
/*  separated by comma or whitespace.
/* BUGS
/*  Should be replaced by routines with an attribute-value based
/*  interface instead of an interface that uses a rigid argument list.
/* 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 <string.h>

/* Utility library. */

#include <msg.h>
#include <vstring.h>
#include <mymalloc.h>

/* Global library. */

#define DSN_INTERN
#include <mail_params.h>
#include <mail_proto.h>
#include <log_adhoc.h>
#include <dsn_util.h>
#include <rcpt_print.h>
#include <dsn_print.h>
#include <verify.h>
#include <defer.h>
#include <trace.h>
#include <bounce.h>

/* Shared internally, between bounce and defer clients. */

DSN_FILTER *delivery_status_filter;

/* bounce_append - append delivery status to per-message bounce log */

int     bounce_append(int flags, const char *id, MSG_STATS *stats,
                      RECIPIENT *rcpt, const char *relay,
                      DSN *dsn)
{
    DSN     my_dsn = *dsn;
    DSN    *dsn_res;

    /*
     * Sanity check. If we're really confident, change this into msg_panic
     * (remember, this information may be under control by a hostile server).
     */
    if (my_dsn.status[0] != '5' || !dsn_valid(my_dsn.status)) {
    msg_warn("bounce_append: ignoring dsn code \"%s\"", my_dsn.status);
    my_dsn.status = "5.0.0";
    }

    /*
     * DSN filter (Postfix 3.0).
     */
    if (delivery_status_filter != 0
    && (dsn_res = dsn_filter_lookup(delivery_status_filter, &my_dsn)) != 0) {
    if (dsn_res->status[0] == '4')
        return (defer_append_intern(flags, id, stats, rcpt, relay, dsn_res));
    my_dsn = *dsn_res;
    }
    return (bounce_append_intern(flags, id, stats, rcpt, relay, &my_dsn));
}

/* bounce_append_intern - append delivery status to per-message bounce log */

int     bounce_append_intern(int flags, const char *id, MSG_STATS *stats,
                         RECIPIENT *rcpt, const char *relay,
                         DSN *dsn)
{
    DSN     my_dsn = *dsn;
    int     status;

    /*
     * MTA-requested address verification information is stored in the verify
     * service database.
     */
    if (flags & DEL_REQ_FLAG_MTA_VRFY) {
    my_dsn.action = "undeliverable";
    status = verify_append(id, stats, rcpt, relay, &my_dsn,
                   DEL_RCPT_STAT_BOUNCE);
    return (status);
    }

    /*
     * User-requested address verification information is logged and mailed
     * to the requesting user.
     */
    if (flags & DEL_REQ_FLAG_USR_VRFY) {
    my_dsn.action = "undeliverable";
    status = trace_append(flags, id, stats, rcpt, relay, &my_dsn);
    return (status);
    }

    /*
     * Normal (well almost) delivery. When we're pretending that we can't
     * bounce, don't create a defer log file when we wouldn't keep the bounce
     * log file. That's a lot of negatives in one sentence.
     */
    else if (var_soft_bounce && (flags & BOUNCE_FLAG_CLEAN)) {
    return (-1);
    }

    /*
     * Normal mail delivery. May also send a delivery record to the user.
     * 
     * XXX DSN We write all recipients to the bounce logfile regardless of DSN
     * NOTIFY options, because those options don't apply to postmaster
     * notifications.
     */
    else {
    char   *my_status = mystrdup(my_dsn.status);
    const char *log_status = var_soft_bounce ? "SOFTBOUNCE" : "bounced";

    /*
     * Supply default action.
     */
    my_dsn.status = my_status;
    if (var_soft_bounce) {
        my_status[0] = '4';
        my_dsn.action = "delayed";
    } else {
        my_dsn.action = "failed";
    }

    if (mail_command_client(MAIL_CLASS_PRIVATE, var_soft_bounce ?
                var_defer_service : var_bounce_service,
               SEND_ATTR_INT(MAIL_ATTR_NREQ, BOUNCE_CMD_APPEND),
                SEND_ATTR_INT(MAIL_ATTR_FLAGS, flags),
                SEND_ATTR_STR(MAIL_ATTR_QUEUEID, id),
                SEND_ATTR_FUNC(rcpt_print, (void *) rcpt),
                SEND_ATTR_FUNC(dsn_print, (void *) &my_dsn),
                ATTR_TYPE_END) == 0
        && ((flags & DEL_REQ_FLAG_RECORD) == 0
        || trace_append(flags, id, stats, rcpt, relay,
                &my_dsn) == 0)) {
        log_adhoc(id, stats, rcpt, relay, &my_dsn, log_status);
        status = (var_soft_bounce ? -1 : 0);
    } else if ((flags & BOUNCE_FLAG_CLEAN) == 0) {
        VSTRING *junk = vstring_alloc(100);

        my_dsn.status = "4.3.0";
        vstring_sprintf(junk, "%s or %s service failure",
                var_bounce_service, var_trace_service);
        my_dsn.reason = vstring_str(junk);
        status = defer_append_intern(flags, id, stats, rcpt, relay, &my_dsn);
        vstring_free(junk);
    } else {
        status = -1;
    }
    myfree(my_status);
    return (status);
    }
}

/* bounce_flush - flush the bounce log and deliver to the sender */

int     bounce_flush(int flags, const char *queue, const char *id,
                     const char *encoding, int smtputf8,
                     const char *sender, const char *dsn_envid,
                     int dsn_ret)
{

    /*
     * When we're pretending that we can't bounce, don't send a bounce
     * message.
     */
    if (var_soft_bounce)
    return (-1);
    if (mail_command_client(MAIL_CLASS_PRIVATE, var_bounce_service,
                SEND_ATTR_INT(MAIL_ATTR_NREQ, BOUNCE_CMD_FLUSH),
                SEND_ATTR_INT(MAIL_ATTR_FLAGS, flags),
                SEND_ATTR_STR(MAIL_ATTR_QUEUE, queue),
                SEND_ATTR_STR(MAIL_ATTR_QUEUEID, id),
                SEND_ATTR_STR(MAIL_ATTR_ENCODING, encoding),
                SEND_ATTR_INT(MAIL_ATTR_SMTPUTF8, smtputf8),
                SEND_ATTR_STR(MAIL_ATTR_SENDER, sender),
                SEND_ATTR_STR(MAIL_ATTR_DSN_ENVID, dsn_envid),
                SEND_ATTR_INT(MAIL_ATTR_DSN_RET, dsn_ret),
                ATTR_TYPE_END) == 0) {
    return (0);
    } else if ((flags & BOUNCE_FLAG_CLEAN) == 0) {
    msg_info("%s: status=deferred (bounce failed)", id);
    return (-1);
    } else {
    return (-1);
    }
}

/* bounce_flush_verp - verpified notification */

int     bounce_flush_verp(int flags, const char *queue, const char *id,
                      const char *encoding, int smtputf8,
                      const char *sender, const char *dsn_envid,
                      int dsn_ret, const char *verp_delims)
{

    /*
     * When we're pretending that we can't bounce, don't send a bounce
     * message.
     */
    if (var_soft_bounce)
    return (-1);
    if (mail_command_client(MAIL_CLASS_PRIVATE, var_bounce_service,
                SEND_ATTR_INT(MAIL_ATTR_NREQ, BOUNCE_CMD_VERP),
                SEND_ATTR_INT(MAIL_ATTR_FLAGS, flags),
                SEND_ATTR_STR(MAIL_ATTR_QUEUE, queue),
                SEND_ATTR_STR(MAIL_ATTR_QUEUEID, id),
                SEND_ATTR_STR(MAIL_ATTR_ENCODING, encoding),
                SEND_ATTR_INT(MAIL_ATTR_SMTPUTF8, smtputf8),
                SEND_ATTR_STR(MAIL_ATTR_SENDER, sender),
                SEND_ATTR_STR(MAIL_ATTR_DSN_ENVID, dsn_envid),
                SEND_ATTR_INT(MAIL_ATTR_DSN_RET, dsn_ret),
                SEND_ATTR_STR(MAIL_ATTR_VERPDL, verp_delims),
                ATTR_TYPE_END) == 0) {
    return (0);
    } else if ((flags & BOUNCE_FLAG_CLEAN) == 0) {
    msg_info("%s: status=deferred (bounce failed)", id);
    return (-1);
    } else {
    return (-1);
    }
}

/* bounce_one - send notice for one recipient */

int     bounce_one(int flags, const char *queue, const char *id,
                   const char *encoding, int smtputf8,
                   const char *sender, const char *dsn_envid,
                   int dsn_ret, MSG_STATS *stats, RECIPIENT *rcpt,
                   const char *relay, DSN *dsn)
{
    DSN     my_dsn = *dsn;
    DSN    *dsn_res;

    /*
     * Sanity check.
     */
    if (my_dsn.status[0] != '5' || !dsn_valid(my_dsn.status)) {
    msg_warn("bounce_one: ignoring dsn code \"%s\"", my_dsn.status);
    my_dsn.status = "5.0.0";
    }

    /*
     * DSN filter (Postfix 3.0).
     */
    if (delivery_status_filter != 0
    && (dsn_res = dsn_filter_lookup(delivery_status_filter, &my_dsn)) != 0) {
    if (dsn_res->status[0] == '4')
        return (defer_append_intern(flags, id, stats, rcpt, relay, dsn_res));
    my_dsn = *dsn_res;
    }
    return (bounce_one_intern(flags, queue, id, encoding, smtputf8, sender,
              dsn_envid, dsn_ret, stats, rcpt, relay, &my_dsn));
}

/* bounce_one_intern - send notice for one recipient */

int     bounce_one_intern(int flags, const char *queue, const char *id,
                      const char *encoding, int smtputf8,
                      const char *sender, const char *dsn_envid,
                      int dsn_ret, MSG_STATS *stats,
                      RECIPIENT *rcpt, const char *relay,
                      DSN *dsn)
{
    DSN     my_dsn = *dsn;
    int     status;

    /*
     * MTA-requested address verification information is stored in the verify
     * service database.
     */
    if (flags & DEL_REQ_FLAG_MTA_VRFY) {
    my_dsn.action = "undeliverable";
    status = verify_append(id, stats, rcpt, relay, &my_dsn,
                   DEL_RCPT_STAT_BOUNCE);
    return (status);
    }

    /*
     * User-requested address verification information is logged and mailed
     * to the requesting user.
     */
    if (flags & DEL_REQ_FLAG_USR_VRFY) {
    my_dsn.action = "undeliverable";
    status = trace_append(flags, id, stats, rcpt, relay, &my_dsn);
    return (status);
    }

    /*
     * When we're not bouncing, then use the standard multi-recipient logfile
     * based procedure.
     */
    else if (var_soft_bounce) {
    return (bounce_append_intern(flags, id, stats, rcpt, relay, &my_dsn));
    }

    /*
     * Normal mail delivery. May also send a delivery record to the user.
     * 
     * XXX DSN We send all recipients regardless of DSN NOTIFY options, because
     * those options don't apply to postmaster notifications.
     */
    else {

    /*
     * Supply default action.
     */
    my_dsn.action = "failed";

    if (mail_command_client(MAIL_CLASS_PRIVATE, var_bounce_service,
                  SEND_ATTR_INT(MAIL_ATTR_NREQ, BOUNCE_CMD_ONE),
                SEND_ATTR_INT(MAIL_ATTR_FLAGS, flags),
                SEND_ATTR_STR(MAIL_ATTR_QUEUE, queue),
                SEND_ATTR_STR(MAIL_ATTR_QUEUEID, id),
                SEND_ATTR_STR(MAIL_ATTR_ENCODING, encoding),
                SEND_ATTR_INT(MAIL_ATTR_SMTPUTF8, smtputf8),
                SEND_ATTR_STR(MAIL_ATTR_SENDER, sender),
                  SEND_ATTR_STR(MAIL_ATTR_DSN_ENVID, dsn_envid),
                SEND_ATTR_INT(MAIL_ATTR_DSN_RET, dsn_ret),
                SEND_ATTR_FUNC(rcpt_print, (void *) rcpt),
                SEND_ATTR_FUNC(dsn_print, (void *) &my_dsn),
                ATTR_TYPE_END) == 0
        && ((flags & DEL_REQ_FLAG_RECORD) == 0
        || trace_append(flags, id, stats, rcpt, relay,
                &my_dsn) == 0)) {
        log_adhoc(id, stats, rcpt, relay, &my_dsn, "bounced");
        status = 0;
    } else if ((flags & BOUNCE_FLAG_CLEAN) == 0) {
        VSTRING *junk = vstring_alloc(100);

        my_dsn.status = "4.3.0";
        vstring_sprintf(junk, "%s or %s service failure",
                var_bounce_service, var_trace_service);
        my_dsn.reason = vstring_str(junk);
        status = defer_append_intern(flags, id, stats, rcpt, relay, &my_dsn);
        vstring_free(junk);
    } else {
        status = -1;
    }
    return (status);
    }
}

/* bounce_client_init - initialize bounce/defer DSN filter */

void    bounce_client_init(const char *title, const char *maps)
{
    static const char myname[] = "bounce_client_init";

    if (delivery_status_filter != 0)
    msg_panic("%s: duplicate initialization", myname);
    if (*maps)
    delivery_status_filter = dsn_filter_create(title, maps);
}