in mda variables expansions, do not consider empty strings as errors since

an empty %{sender} is really a mailer-daemon and not an error

reported and initial diff by Lauri Tirkkonen <lotheac@iki.fi>
commit is a revised version of the diff based on a discussion with eric@

3 files changed, 34 insertions, 34 deletions

diff --git a/usr.sbin/smtpd/mda_unpriv.c b/usr.sbin/smtpd/mda_unpriv.c
index e519d4c26e5..59c899416af 100644
--- a/usr.sbin/smtpd/mda_unpriv.c
+++ b/usr.sbin/smtpd/mda_unpriv.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mda_unpriv.c,v 1.3 2018/12/02 11:34:21 gilles Exp $	*/
+/*	$OpenBSD: mda_unpriv.c,v 1.4 2018/12/06 12:32:11 gilles Exp $	*/
 
 /*
  * Copyright (c) 2018 Gilles Chehade <gilles@poolp.org>
@@ -56,8 +56,8 @@ mda_unpriv(struct dispatcher *dsp, struct deliver *deliver,
 	    >= sizeof (mda_exec))
 		errx(1, "mda command line too long");
 
-	if (! mda_expand_format(mda_exec, sizeof mda_exec, deliver,
-		&deliver->userinfo, NULL))
+	if (mda_expand_format(mda_exec, sizeof mda_exec, deliver,
+		&deliver->userinfo, NULL) == -1)
 		errx(1, "mda command line could not be expanded");
 
 	mda_command = mda_exec;
@@ -90,8 +90,8 @@ mda_unpriv(struct dispatcher *dsp, struct deliver *deliver,
 		    >= sizeof (mda_wrapper))
 			errx(1, "mda command line too long");
 
-		if (! mda_expand_format(mda_wrapper, sizeof mda_wrapper, deliver,
-			&deliver->userinfo, mda_command))
+		if (mda_expand_format(mda_wrapper, sizeof mda_wrapper, deliver,
+			&deliver->userinfo, mda_command) == -1)
 			errx(1, "mda command line could not be expanded");
 		mda_command = mda_wrapper;
 	}
diff --git a/usr.sbin/smtpd/mda_variables.c b/usr.sbin/smtpd/mda_variables.c
index a23112c71e8..03052e21554 100644
--- a/usr.sbin/smtpd/mda_variables.c
+++ b/usr.sbin/smtpd/mda_variables.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mda_variables.c,v 1.4 2018/06/15 08:57:17 gilles Exp $	*/
+/*	$OpenBSD: mda_variables.c,v 1.5 2018/12/06 12:32:11 gilles Exp $	*/
 
 /*
  * Copyright (c) 2011-2017 Gilles Chehade <gilles@poolp.org>
@@ -36,9 +36,9 @@
 
 #define	EXPAND_DEPTH	10
 
-size_t mda_expand_format(char *, size_t, const struct deliver *,
+ssize_t mda_expand_format(char *, size_t, const struct deliver *,
     const struct userinfo *, const char *);
-static size_t mda_expand_token(char *, size_t, const char *,
+static ssize_t mda_expand_token(char *, size_t, const char *,
     const struct deliver *, const struct userinfo *, const char *);
 static int mod_lowercase(char *, size_t);
 static int mod_uppercase(char *, size_t);
@@ -56,7 +56,7 @@ static struct modifiers {
 
 #define	MAXTOKENLEN	128
 
-static size_t
+static ssize_t
 mda_expand_token(char *dest, size_t len, const char *token,
     const struct deliver *dlv, const struct userinfo *ui, const char *mda_command)
 {
@@ -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--) {
@@ -244,19 +244,19 @@ mda_expand_token(char *dest, size_t len, const char *token,
 }
 
 
-size_t
+ssize_t
 mda_expand_format(char *buf, size_t len, const struct deliver *dlv,
     const struct userinfo *ui, const char *mda_command)
 {
 	char		tmpbuf[EXPAND_BUFFER], *ptmp, *pbuf, *ebuf;
 	char		exptok[EXPAND_BUFFER];
-	size_t		exptoklen;
+	ssize_t		exptoklen;
 	char		token[MAXTOKENLEN];
 	size_t		ret, tmpret;
 
 	if (len < sizeof tmpbuf) {
 		log_warnx("mda_expand_format: tmp buffer < rule buffer");
-		return 0;
+		return -1;
 	}
 
 	memset(tmpbuf, 0, sizeof tmpbuf);
@@ -308,12 +308,12 @@ 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)
-			return 0;
+		if (exptoklen == -1)
+			return -1;
 
 		/* writing expanded token at ptmp will overflow tmpbuf */
-		if (sizeof (tmpbuf) - (ptmp - tmpbuf) <= exptoklen)
-			return 0;
+		if (sizeof (tmpbuf) - (ptmp - tmpbuf) <= (size_t)exptoklen)
+			return -1;
 
 		memcpy(ptmp, exptok, exptoklen);
 		pbuf   = ebuf + 1;
@@ -321,10 +321,10 @@ mda_expand_format(char *buf, size_t len, const struct deliver *dlv,
 		tmpret = exptoklen;
 	}
 	if (ret >= sizeof tmpbuf)
-		return 0;
+		return -1;
 
 	if ((ret = strlcpy(buf, tmpbuf, len)) >= len)
-		return 0;
+		return -1;
 
 	return ret;
 }
diff --git a/usr.sbin/smtpd/smtpd.h b/usr.sbin/smtpd/smtpd.h
index a653888f4e1..0ea27ea86a6 100644
--- a/usr.sbin/smtpd/smtpd.h
+++ b/usr.sbin/smtpd/smtpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: smtpd.h,v 1.576 2018/12/06 12:09:50 gilles Exp $	*/
+/*	$OpenBSD: smtpd.h,v 1.577 2018/12/06 12:32:11 gilles Exp $	*/
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@poolp.org>
@@ -1352,7 +1352,7 @@ void mda_unpriv(struct dispatcher *, struct deliver *, const char *, const char
 
 
 /* mda_variables.c */
-size_t mda_expand_format(char *, size_t, const struct deliver *,
+ssize_t mda_expand_format(char *, size_t, const struct deliver *,
     const struct userinfo *, const char *);