- change callback prototypes in filter.c to allow stricter checks

- introduce STATUS_WAITING, filters will reroute async DNS queries through
  LKA in a near future
- filter_api.c will contain our filter API (empty for now)
- Makefile to build libsmtpdfilter (not linked to the build,dev stuff only)

4 files changed, 82 insertions, 28 deletions

diff --git a/usr.sbin/smtpd/filter.c b/usr.sbin/smtpd/filter.c
index 59ca75b47e7..1f11b6c3f8d 100644
--- a/usr.sbin/smtpd/filter.c
+++ b/usr.sbin/smtpd/filter.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: filter.c,v 1.2 2011/08/31 18:56:30 gilles Exp $	*/
+/*	$OpenBSD: filter.c,v 1.3 2011/11/15 23:22:47 gilles Exp $	*/
 
 /*
  * Copyright (c) 2011 Gilles Chehade <gilles@openbsd.org>
@@ -35,19 +35,19 @@ static struct filter_internals {
 	struct event	ev;
 	struct imsgbuf	ibuf;
 
-	int (*helo_cb)(u_int64_t, struct filter_helo *, void *);
+	enum filter_status (*helo_cb)(u_int64_t, struct filter_helo *, void *);
 	void *helo_cb_arg;
 
-	int (*ehlo_cb)(u_int64_t, struct filter_helo *, void *);
+	enum filter_status (*ehlo_cb)(u_int64_t, struct filter_helo *, void *);
 	void *ehlo_cb_arg;
 
-	int (*mail_cb)(u_int64_t, struct filter_mail *, void *);
+	enum filter_status (*mail_cb)(u_int64_t, struct filter_mail *, void *);
 	void *mail_cb_arg;
 
-	int (*rcpt_cb)(u_int64_t, struct filter_rcpt *, void *);
+	enum filter_status (*rcpt_cb)(u_int64_t, struct filter_rcpt *, void *);
 	void *rcpt_cb_arg;
 
-	int (*dataline_cb)(u_int64_t, struct filter_dataline *, void *);
+	enum filter_status (*dataline_cb)(u_int64_t, struct filter_dataline *, void *);
 	void *dataline_cb_arg;
 } fi;
 
@@ -74,31 +74,31 @@ filter_loop(void)
 }
 
 void
-filter_register_helo_callback(int (*cb)(u_int64_t, struct filter_helo *, void *), void *cb_arg)
+filter_register_helo_callback(enum filter_status (*cb)(u_int64_t, struct filter_helo *, void *), void *cb_arg)
 {
 	filter_register_callback(FILTER_HELO, cb, cb_arg);
 }
 
 void
-filter_register_ehlo_callback(int (*cb)(u_int64_t, struct filter_helo *, void *), void *cb_arg)
+filter_register_ehlo_callback(enum filter_status (*cb)(u_int64_t, struct filter_helo *, void *), void *cb_arg)
 {
 	filter_register_callback(FILTER_EHLO, cb, cb_arg);
 }
 
 void
-filter_register_mail_callback(int (*cb)(u_int64_t, struct filter_mail *, void *), void *cb_arg)
+filter_register_mail_callback(enum filter_status (*cb)(u_int64_t, struct filter_mail *, void *), void *cb_arg)
 {
 	filter_register_callback(FILTER_MAIL, cb, cb_arg);
 }
 
 void
-filter_register_rcpt_callback(int (*cb)(u_int64_t, struct filter_rcpt *, void *), void *cb_arg)
+filter_register_rcpt_callback(enum filter_status (*cb)(u_int64_t, struct filter_rcpt *, void *), void *cb_arg)
 {
 	filter_register_callback(FILTER_RCPT, cb, cb_arg);
 }
 
 void
-filter_register_dataline_callback(int (*cb)(u_int64_t, struct filter_dataline *, void *), void *cb_arg)
+filter_register_dataline_callback(enum filter_status (*cb)(u_int64_t, struct filter_dataline *, void *), void *cb_arg)
 {
 	filter_register_callback(FILTER_DATALINE, cb, cb_arg);
 }
@@ -140,6 +140,7 @@ filter_handler(int fd, short event, void *p)
 	struct imsg		imsg;
 	ssize_t			n;
 	short			evflags = EV_READ;
+	enum filter_status	ret;
 	struct filter_msg	fm;
 
 	if (event & EV_READ) {
@@ -179,42 +180,52 @@ filter_handler(int fd, short event, void *p)
 		case FILTER_HELO:
 			if (fi.helo_cb == NULL)
 				goto ignore;
-			fm.code = fi.helo_cb(fm.cl_id, &fm.u.helo,
+			ret = fi.helo_cb(fm.cl_id, &fm.u.helo,
 			    fi.helo_cb_arg);
 			break;
 		case FILTER_EHLO:
 			if (fi.ehlo_cb == NULL)
 				goto ignore;
-			fm.code = fi.ehlo_cb(fm.cl_id, &fm.u.helo,
+			ret = fi.ehlo_cb(fm.cl_id, &fm.u.helo,
 			    fi.ehlo_cb_arg);
 			break;
 		case FILTER_MAIL:
 			if (fi.mail_cb == NULL)
 				goto ignore;
-			fm.code = fi.mail_cb(fm.cl_id, &fm.u.mail,
+			ret = fi.mail_cb(fm.cl_id, &fm.u.mail,
 			    fi.mail_cb_arg);
 			break;
 		case FILTER_RCPT:
 			if (fi.rcpt_cb == NULL)
 				goto ignore;
-			fm.code = fi.rcpt_cb(fm.cl_id, &fm.u.rcpt,
+			ret = fi.rcpt_cb(fm.cl_id, &fm.u.rcpt,
 			    fi.rcpt_cb_arg);
 			break;
 		case FILTER_DATALINE:
 			if (fi.dataline_cb == NULL)
 				goto ignore;
-			fm.code = fi.dataline_cb(fm.cl_id, &fm.u.dataline,
+			ret = fi.dataline_cb(fm.cl_id, &fm.u.dataline,
 			    fi.dataline_cb_arg);
 			break;
 		default:
 			errx(1, "unsupported imsg");
 		}
 
-		if (! fm.code)
-			fm.code = -1;
-			
-		imsg_compose(&fi.ibuf, imsg.hdr.type, 0, 0, -1, &fm, sizeof fm);
-		evflags |= EV_WRITE;
+		switch (fm.code) {
+		case STATUS_ACCEPT:
+		case STATUS_REJECT:
+			fm.code = ret;
+			if (ret == STATUS_REJECT)
+				fm.code = -1;
+			imsg_compose(&fi.ibuf, imsg.hdr.type, 0, 0, -1, &fm,
+			    sizeof fm);
+			evflags |= EV_WRITE;
+			break;
+		case STATUS_WAITING:
+			/* waiting for asynchronous call ... */
+			break;
+		}
+
 		imsg_free(&imsg);
 	}
 
diff --git a/usr.sbin/smtpd/filter.h b/usr.sbin/smtpd/filter.h
index 8ce989c319f..e445f4742b1 100644
--- a/usr.sbin/smtpd/filter.h
+++ b/usr.sbin/smtpd/filter.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: filter.h,v 1.3 2011/09/12 20:47:15 gilles Exp $	*/
+/*	$OpenBSD: filter.h,v 1.4 2011/11/15 23:22:47 gilles Exp $	*/
 
 /*
  * Copyright (c) 2011 Gilles Chehade <gilles@openbsd.org>
@@ -31,6 +31,12 @@
 #define MAX_DOMAINPART_SIZE	 (MAX_LINE_SIZE-MAX_LOCALPART_SIZE)
 #endif
 
+enum filter_status {
+	STATUS_REJECT,
+	STATUS_ACCEPT,
+	STATUS_WAITING
+};
+
 enum filter_type {
 	FILTER_HELO		= 0x01,
 	FILTER_EHLO		= 0x02,
@@ -67,7 +73,7 @@ union filter_union {
 struct filter_msg {
 	u_int64_t		id;	 /* set by smtpd(8) */
 	u_int64_t		cl_id;	 /* set by smtpd(8) */
-	int8_t			code;
+	u_int8_t       		code;
 	u_int8_t		version;
 	enum filter_type	type;
 	union filter_union	u;
@@ -77,8 +83,8 @@ struct filter_msg {
 void filter_init(void);
 void filter_loop(void);
 
-void filter_register_helo_callback(int (*)(u_int64_t, struct filter_helo *, void *), void *);
-void filter_register_ehlo_callback(int (*)(u_int64_t, struct filter_helo *, void *), void *);
-void filter_register_mail_callback(int (*)(u_int64_t, struct filter_mail *, void *), void *);
-void filter_register_rcpt_callback(int (*)(u_int64_t, struct filter_rcpt *, void *), void *);
-void filter_register_dataline_callback(int (*)(u_int64_t, struct filter_dataline *, void *), void *);
+void filter_register_helo_callback(enum filter_status (*)(u_int64_t, struct filter_helo *, void *), void *);
+void filter_register_ehlo_callback(enum filter_status (*)(u_int64_t, struct filter_helo *, void *), void *);
+void filter_register_mail_callback(enum filter_status (*)(u_int64_t, struct filter_mail *, void *), void *);
+void filter_register_rcpt_callback(enum filter_status (*)(u_int64_t, struct filter_rcpt *, void *), void *);
+void filter_register_dataline_callback(enum filter_status (*)(u_int64_t, struct filter_dataline *, void *), void *);
diff --git a/usr.sbin/smtpd/filter_api.c b/usr.sbin/smtpd/filter_api.c
new file mode 100644
index 00000000000..eb41d13ea1e
--- /dev/null
+++ b/usr.sbin/smtpd/filter_api.c
@@ -0,0 +1,21 @@
+/*	$OpenBSD: filter_api.c,v 1.1 2011/11/15 23:22:47 gilles Exp $	*/
+
+/*
+ * Copyright (c) 2011 Gilles Chehade <gilles@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+
+#include "filter.h"
diff --git a/usr.sbin/smtpd/libsmtpdfilter/Makefile b/usr.sbin/smtpd/libsmtpdfilter/Makefile
new file mode 100644
index 00000000000..d90a68570ab
--- /dev/null
+++ b/usr.sbin/smtpd/libsmtpdfilter/Makefile
@@ -0,0 +1,16 @@
+#	$OpenBSD: Makefile,v 1.1 2011/11/15 23:22:47 gilles Exp $
+
+.PATH:		${.CURDIR}/..
+
+LIB=	smtpdfilter
+WANTLINT=no
+SRCS=	filter.c filter_api.c
+DEBUGLIBS= no
+NOPROFILE= yes
+NOPIC=	yes
+
+install:
+	@echo -n
+
+.include <bsd.own.mk>
+.include <bsd.lib.mk>