Hi, I noticed in my maillog that smtpd is dropping bounce messages
destined for me on the floor, like so:
Nov 27 16:04:44 quickman smtpd[66508]: 0000000000000000 mda delivery
evpid=75062f6aefbfab27 from=<> to=<[email protected]>
rcpt=<[email protected]> user=lotheac delay=0s result=PermFail stat=Error
("smtpd: mda command line could not be expanded: No such file or directory")
my smtpd.conf is as follows:
# $OpenBSD: smtpd.conf,v 1.11 2018/06/04 21:10:58 jmc Exp $
# This is the smtpd server system-wide configuration file.
# See smtpd.conf(5) for more information.
table aliases file:/etc/mail/aliases
pki quickman.lotheac.fi cert "/etc/ssl/quickman.lotheac.fi.fullchain.pem"
pki quickman.lotheac.fi key "/etc/ssl/private/quickman.lotheac.fi.key"
# To accept external mail, replace with: listen on all
#
listen on all tls
listen on lo0 port 10028 tag DKIM
#action "local" maildir alias <aliases>
action "local" mda "/etc/mail/mda.sh '%{sender}'"
action "relay" relay
action "relay_dkim" relay host smtp://127.0.0.1:10027
table maildest { "lotheac.fi" "quickman.lotheac.fi" }
# Uncomment the following to accept external mail for domain "example.org"
#
match from any for domain <maildest> action "local"
match for local action "local"
match tag DKIM for any action "relay"
match for any action "relay_dkim"
so, it seems that the %{sender} expansion is failing somehow. From
smtpd.conf(5):
%{sender} sender email address, may be empty string
clearly, in this case it *should* expand to the empty string - there is
no envelope sender. However mda_expand_token returns 0 if the string
ends up empty:
204 /* expanded string is empty */
205 i = strlen(string);
206 if (i == 0)
207 return 0;
and it does, because above 'string' has been set to the empty string
(lines 119-121):
115 if (!strcasecmp("sender", rtoken)) {
116 if (snprintf(tmp, sizeof tmp, "%s@%s",
117 dlv->sender.user, dlv->sender.domain) >=
(int)sizeof tmp)
118 return -1;
119 if (strcmp(tmp, "@") == 0)
120 (void)strlcpy(tmp, "", sizeof tmp);
121 string = tmp;
122 }
As an aside the error exit happens with err(), but mda_expand_format
doesn't actually set errno, so ENOENT is not actually what is happening.
Maybe that's another bug.
So, mda_expand_format() assumes that a 0 retval from mda_expand_token()
is an error, even though it's a valid value (ie. the length of the empty
string). Maybe it should return (size_t)-1 instead for errors? Diff for
that below, it makes the expansion work for me.
I found this on 6.4, but also applies to -CURRENT.
diff --git a/usr.sbin/smtpd/mda_variables.c b/usr.sbin/smtpd/mda_variables.c
index a23112c71e8..0a1605772f2 100644
--- a/usr.sbin/smtpd/mda_variables.c
+++ b/usr.sbin/smtpd/mda_variables.c
@@ -75,14 +75,14 @@ mda_expand_token(char *dest, size_t len, const char *token,
mods = NULL;
if (strlcpy(rtoken, token, sizeof rtoken) >= sizeof rtoken)
- return 0;
+ return -1;
/* token[x[:y]] -> extracts optional x and y, converts into offsets */
if ((lbracket = strchr(rtoken, '[')) &&
(rbracket = strchr(rtoken, ']'))) {
/* ] before [ ... or empty */
if (rbracket < lbracket || rbracket - lbracket <= 1)
- return 0;
+ return -1;
*lbracket = *rbracket = '\0';
content = lbracket + 1;
@@ -102,7 +102,7 @@ mda_expand_token(char *dest, size_t len, const char *token,
}
}
if (errstr)
- return 0;
+ return -1;
/* token:mod_1,mod_2,mod_n -> extract modifiers */
mods = strchr(rbracket + 1, ':');
@@ -115,7 +115,7 @@ mda_expand_token(char *dest, size_t len, const char *token,
if (!strcasecmp("sender", rtoken)) {
if (snprintf(tmp, sizeof tmp, "%s@%s",
dlv->sender.user, dlv->sender.domain) >= (int)sizeof
tmp)
- return 0;
+ return -1;
if (strcmp(tmp, "@") == 0)
(void)strlcpy(tmp, "", sizeof tmp);
string = tmp;
@@ -123,7 +123,7 @@ mda_expand_token(char *dest, size_t len, const char *token,
else if (!strcasecmp("rcpt", rtoken)) {
if (snprintf(tmp, sizeof tmp, "%s@%s",
dlv->rcpt.user, dlv->rcpt.domain) >= (int)sizeof tmp)
- return 0;
+ return -1;
if (strcmp(tmp, "@") == 0)
(void)strlcpy(tmp, "", sizeof tmp);
string = tmp;
@@ -131,7 +131,7 @@ mda_expand_token(char *dest, size_t len, const char *token,
else if (!strcasecmp("dest", rtoken)) {
if (snprintf(tmp, sizeof tmp, "%s@%s",
dlv->dest.user, dlv->dest.domain) >= (int)sizeof tmp)
- return 0;
+ return -1;
if (strcmp(tmp, "@") == 0)
(void)strlcpy(tmp, "", sizeof tmp);
string = tmp;
@@ -161,17 +161,17 @@ mda_expand_token(char *dest, size_t len, const char
*token,
else if (!strcasecmp("mbox.from", rtoken)) {
if (snprintf(tmp, sizeof tmp, "%s@%s",
dlv->sender.user, dlv->sender.domain) >= (int)sizeof
tmp)
- return 0;
+ return -1;
if (strcmp(tmp, "@") == 0)
(void)strlcpy(tmp, "MAILER-DAEMON", sizeof tmp);
string = tmp;
}
else
- return 0;
+ return -1;
if (string != tmp) {
if (strlcpy(tmp, string, sizeof tmp) >= sizeof tmp)
- return 0;
+ return -1;
string = tmp;
}
@@ -187,12 +187,12 @@ mda_expand_token(char *dest, size_t len, const char
*token,
break;
}
if (!token_modifiers[i].f(tmp, sizeof
tmp))
- return 0; /* modifier error */
+ return -1; /* modifier error */
break;
}
}
if ((size_t)i == nitems(token_modifiers))
- return 0; /* modifier not found */
+ return -1; /* modifier not found */
} while ((mods = sep) != NULL);
}
@@ -208,7 +208,7 @@ mda_expand_token(char *dest, size_t len, const char *token,
/* begin offset beyond end of string */
if (begoff >= i)
- return 0;
+ return -1;
/* end offset beyond end of string, make it end of string */
if (endoff >= i)
@@ -225,13 +225,13 @@ mda_expand_token(char *dest, size_t len, const char
*token,
/* check that final offsets are valid */
if (begoff < 0 || endoff < 0 || endoff < begoff)
- return 0;
+ return -1;
endoff += 1; /* end offset is inclusive */
/* check that substring does not exceed destination buffer length */
i = endoff - begoff;
if ((size_t)i + 1 >= len)
- return 0;
+ return -1;
string += begoff;
for (; i; i--) {
@@ -308,7 +308,7 @@ mda_expand_format(char *buf, size_t len, const struct
deliver *dlv,
exptoklen = mda_expand_token(exptok, sizeof exptok, token, dlv,
ui, mda_command);
- if (exptoklen == 0)
+ if (exptoklen == (size_t)-1)
return 0;
/* writing expanded token at ptmp will overflow tmpbuf */
--
Lauri Tirkkonen | lotheac @ IRCnet
