[PATCH] New option "lmtp_luser_relay" to specify a fallback mailbox

[Ralf Haferkamp]

Hi,

please consider the attached patch (against current master) for 
inclusion. It introduces the "lmtp_luser_relay" option in imapd.conf (I 
am open suggestions for a different name if needed) that allows to 
specify a mailbox to which all mail to non-existing folders will be 
dropped. I know that most of it's functionality can probably as well be 
configured inside the MTA but IMO having it in lmtpd can make the setup a 
lot easier.

Note: Just like the -fPIE patch I recently sent we are using this patch 
since quite some time in our packages. The original enhancement request 
was filed as:
http://bugzilla.cyrusimap.org/bugzilla3/show_bug.cgi?id=2360

-- 
regards,
        Ralf

SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nuernberg)

From f12e8a17b610025cfb2cc4a9d3c781045d3bd535 Mon Sep 17 00:00:00 2001
From: Ralf Haferkamp <rha...@suse.de>
Date: Mon, 8 Nov 2010 17:33:52 +0100
Subject: [PATCH] New option "lmtp_luser_relay" to specify a fallback mailbox

This patch introduces the new option "lmtp_luser_relay". Lmtpd will drop
mail to non-existing mailboxes into this mailbox. NOTE: This must be an
existing local mailbox name. NOT an email address!
(Bug#2360)
---
 imap/lmtpengine.c |   24 +++++++++++++++++++-----
 lib/imapoptions   |    4 ++++
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/imap/lmtpengine.c b/imap/lmtpengine.c
index 7159c34..5d8d526 100644
--- a/imap/lmtpengine.c
+++ b/imap/lmtpengine.c
@@ -812,6 +812,8 @@ static int process_recipient(char *addr, struct namespace *namespace,
     address_data_t *ret = (address_data_t *) xmalloc(sizeof(address_data_t));
     int forcedowncase = config_getswitch(IMAPOPT_LMTP_DOWNCASE_RCPT);
     int quoted, detail;
+    char *luser_relay = NULL;
+    int has_luser_relay = 0;
 
     assert(addr != NULL && msg != NULL);
 
@@ -868,6 +870,13 @@ static int process_recipient(char *addr, struct namespace *namespace,
     }
     *dest = '\0';
 	
+    luser_relay = config_getstring(IMAPOPT_LMTP_LUSER_RELAY);
+    if( luser_relay ) {
+      if( !verify_user(luser_relay, NULL, NULL, ignorequota ? -1 : msg->size, msg->authstate) ) {
+          has_luser_relay = 1;
+      }
+    }
+
     /* make a working copy of rcpt */
     ret->user = ret->rcpt = xstrdup(rcpt);
 
@@ -893,12 +902,17 @@ static int process_recipient(char *addr, struct namespace *namespace,
     r = verify_user(ret->user, ret->domain, ret->mailbox,
 		    (quota_t) (ignorequota ? -1 : msg->size), msg->authstate);
     if (r) {
-	/* we lost */
-	free(ret->all);
-	free(ret->rcpt);
-	free(ret);
-	return r;
+	if( r == IMAP_MAILBOX_NONEXISTENT && has_luser_relay ) {
+	    ret->user = xstrdup(luser_relay);
+	} else {
+	    /* we lost */
+   	    free(ret->all);
+   	    free(ret->rcpt);
+   	    free(ret);
+   	    return r;
+	}
     }
+
     ret->ignorequota = ignorequota;
 
     msg->rcpt[msg->rcpt_num] = ret;
diff --git a/lib/imapoptions b/lib/imapoptions
index 0289b34..8f994d8 100644
--- a/lib/imapoptions
+++ b/lib/imapoptions
@@ -1303,6 +1303,10 @@ product version in the capabilities */
    interface, otherwise the user is assumed to be in the default
    domain (if set). */
 
+{ "lmtp_luser_relay", NULL, STRING }
+/* Send mail to mailboxes, which do not exists, to this user. NOTE: This must
+   be an existing local mailbox name. NOT an email address! */
+
 /*
 .SH SEE ALSO
 .PP
-- 
1.7.1