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/*++
/* NAME
/* smtpd_dsn_fix 3
/* SUMMARY
/* fix DSN status
/* SYNOPSIS
/* #include <smtpd_dsn_fix.h>
/*
/* const char *smtpd_dsn_fix(status, reply_class)
/* const char *status;
/* const char *reply_class;
/* DESCRIPTION
/* smtpd_dsn_fix() transforms DSN status codes according to the
/* status information that is actually being reported. The
/* following transformations are implemented:
/* .IP \(bu
/* Transform a recipient address DSN into a sender address DSN
/* when reporting sender address status information, and vice
/* versa. This transformation may be needed because some Postfix
/* access control features don't know whether the address being
/* rejected is a sender or recipient. Examples are smtpd access
/* tables, rbl reply templates, and the error mailer.
/* .IP \(bu
/* Transform a sender or recipient address DSN into a non-address
/* DSN when reporting non-address status information. For
/* example, if something rejects HELO with DSN status 4.1.1
/* (unknown recipient address), then we send the more neutral
/* 4.0.0 DSN instead. This transformation is needed when the
/* same smtpd access map entry or rbl reply template is used
/* for both address and non-address information.
/* .PP
/* A non-address DSN is not transformed
/* when reporting sender or recipient address status information,
/* as there are many legitimate instances of such usage.
/*
/* It is left up to the caller to update the initial DSN digit
/* appropriately; in Postfix this is done as late as possible,
/* because hard rejects may be changed into soft rejects for
/* all kinds of reasons.
/*
/* Arguments:
/* .IP status
/* A DSN status as per RFC 3463.
/* .IP reply_class
/* SMTPD_NAME_SENDER, SMTPD_NAME_RECIPIENT or some other
/* null-terminated string.
/* 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 <ctype.h>
#include <string.h>
/* Utility library. */
#include <msg.h>
/* Global library. */
/* Application-specific. */
#include <smtpd_dsn_fix.h>
struct dsn_map {
const char *micro_code; /* Final digits in mailbox D.S.N. */
const char *sender_dsn; /* Replacement sender D.S.N. */
const char *rcpt_dsn; /* Replacement recipient D.S.N. */
};
static struct dsn_map dsn_map[] = {
/* - Sender - Recipient */
"1", SND_DSN, "4.1.1", /* 4.1.1: Bad dest mbox addr */
"2", "4.1.8", "4.1.2", /* 4.1.2: Bad dest system addr */
"3", "4.1.7", "4.1.3", /* 4.1.3: Bad dest mbox addr syntax */
"4", SND_DSN, "4.1.4", /* 4.1.4: Dest mbox addr ambiguous */
"5", "4.1.0", "4.1.5", /* 4.1.5: Dest mbox addr valid */
"6", SND_DSN, "4.1.6", /* 4.1.6: Mailbox has moved */
"7", "4.1.7", "4.1.3", /* 4.1.7: Bad sender mbox addr syntax */
"8", "4.1.8", "4.1.2", /* 4.1.8: Bad sender system addr */
0, "4.1.0", "4.1.0", /* Default mapping */
};
/* smtpd_dsn_fix - fix DSN status */
const char *smtpd_dsn_fix(const char *status, const char *reply_class)
{
struct dsn_map *dp;
const char *result = status;
/*
* Update an address-specific DSN according to what is being rejected.
*/
if (ISDIGIT(status[0]) && strncmp(status + 1, ".1.", 3) == 0) {
/*
* Fix recipient address DSN while rejecting a sender address. Don't
* let future recipient-specific DSN codes slip past us.
*/
if (strcmp(reply_class, SMTPD_NAME_SENDER) == 0) {
for (dp = dsn_map; dp->micro_code != 0; dp++)
if (strcmp(status + 4, dp->micro_code) == 0)
break;
result = dp->sender_dsn;
}
/*
* Fix sender address DSN while rejecting a recipient address. Don't
* let future sender-specific DSN codes slip past us.
*/
else if (strcmp(reply_class, SMTPD_NAME_RECIPIENT) == 0) {
for (dp = dsn_map; dp->micro_code != 0; dp++)
if (strcmp(status + 4, dp->micro_code) == 0)
break;
result = dp->rcpt_dsn;
}
/*
* Fix address-specific DSN while rejecting a non-address.
*/
else {
result = "4.0.0";
}
/*
* Give them a clue of what is going on.
*/
if (strcmp(status + 2, result + 2) != 0)
msg_info("mapping DSN status %s into %s status %c%s",
status, reply_class, status[0], result + 1);
return (result);
}
/*
* Don't update a non-address DSN. There are many legitimate uses for
* these while rejecting address or non-address information.
*/
else {
return (status);
}
}
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