Introduce and use buf_size(buf) instead of buf->wpos -- at least in the non

buf/imsg specific code. buf_close() will no force a truncation of the buffer
to the wpos but actually add code in imsg.c to detect and report such silly
behaviour. Makes the buf API a bit more sane.

5 files changed, 35 insertions, 22 deletions

diff --git a/usr.sbin/ospfd/auth.c b/usr.sbin/ospfd/auth.c
index cbb439ea43b..4e92a50b029 100644
--- a/usr.sbin/ospfd/auth.c
+++ b/usr.sbin/ospfd/auth.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: auth.c,v 1.14 2008/07/24 18:46:59 claudio Exp $ */
+/*	$OpenBSD: auth.c,v 1.15 2009/03/04 12:51:01 claudio Exp $ */
 
 /*
  * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
@@ -148,18 +148,18 @@ auth_gen(struct buf *buf, struct iface *iface)
 		fatalx("auth_gen: buf_seek failed");
 
 	/* update length */
-	if (buf->wpos > USHRT_MAX)
+	if (buf_size(buf) > USHRT_MAX)
 		fatalx("auth_gen: resulting ospf packet too big");
-	ospf_hdr->len = htons((u_int16_t)buf->wpos);
+	ospf_hdr->len = htons(buf_size(buf));
 	/* clear auth_key field */
 	bzero(ospf_hdr->auth_key.simple, sizeof(ospf_hdr->auth_key.simple));
 
 	switch (iface->auth_type) {
 	case AUTH_NONE:
-		ospf_hdr->chksum = in_cksum(buf->buf, buf->wpos);
+		ospf_hdr->chksum = in_cksum(buf->buf, buf_size(buf));
 		break;
 	case AUTH_SIMPLE:
-		ospf_hdr->chksum = in_cksum(buf->buf, buf->wpos);
+		ospf_hdr->chksum = in_cksum(buf->buf, buf_size(buf));
 
 		strncpy(ospf_hdr->auth_key.simple, iface->auth_key,
 		    sizeof(ospf_hdr->auth_key.simple));
@@ -184,7 +184,7 @@ auth_gen(struct buf *buf, struct iface *iface)
 
 		/* calculate MD5 digest */
 		MD5Init(&hash);
-		MD5Update(&hash, buf->buf, buf->wpos);
+		MD5Update(&hash, buf->buf, buf_size(buf));
 		MD5Update(&hash, digest, MD5_DIGEST_LENGTH);
 		MD5Final(digest, &hash);
 
diff --git a/usr.sbin/ospfd/buffer.c b/usr.sbin/ospfd/buffer.c
index 87890529185..c6e6aff7459 100644
--- a/usr.sbin/ospfd/buffer.c
+++ b/usr.sbin/ospfd/buffer.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: buffer.c,v 1.10 2009/01/31 11:44:49 claudio Exp $ */
+/*	$OpenBSD: buffer.c,v 1.11 2009/03/04 12:51:01 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -86,7 +86,7 @@ buf_realloc(struct buf *buf, size_t len)
 }
 
 int
-buf_add(struct buf *buf, void *data, size_t len)
+buf_add(struct buf *buf, const void *data, size_t len)
 {
 	if (buf->wpos + len > buf->size)
 		if (buf_realloc(buf, len) == -1)
@@ -122,6 +122,12 @@ buf_seek(struct buf *buf, size_t pos, size_t len)
 }
 
 size_t
+buf_size(struct buf *buf)
+{
+	return (buf->wpos);
+}
+
+size_t
 buf_left(struct buf *buf)
 {
 	return (buf->max - buf->wpos);
@@ -130,6 +136,8 @@ buf_left(struct buf *buf)
 int
 buf_close(struct msgbuf *msgbuf, struct buf *buf)
 {
+	/* truncate buffer to the correct length before queuing */
+	buf->size = buf->wpos;
 	buf_enqueue(msgbuf, buf);
 	return (1);
 }
diff --git a/usr.sbin/ospfd/imsg.c b/usr.sbin/ospfd/imsg.c
index 9bd6cabd33f..ef14fb8d088 100644
--- a/usr.sbin/ospfd/imsg.c
+++ b/usr.sbin/ospfd/imsg.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg.c,v 1.9 2007/07/24 16:46:09 pyr Exp $ */
+/*	$OpenBSD: imsg.c,v 1.10 2009/03/04 12:51:01 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -159,19 +159,23 @@ imsg_add(struct buf *msg, void *data, u_int16_t datalen)
 int
 imsg_close(struct imsgbuf *ibuf, struct buf *msg)
 {
-	int		 n;
 	struct imsg_hdr	*hdr;
 
 	hdr = (struct imsg_hdr *)msg->buf;
-	hdr->len = (u_int16_t)msg->wpos;
-	if ((n = buf_close(&ibuf->w, msg)) < 0) {
+	if (msg->size != msg->wpos) {
+			log_warnx("imsg_close: buffer is not correctly filled");
+			buf_free(msg);
+			return (-1);
+	}
+	hdr->len = (u_int16_t)msg->size;
+	if (buf_close(&ibuf->w, msg) < 0) {
 			log_warnx("imsg_close: buf_close error");
 			buf_free(msg);
 			return (-1);
 	}
 	imsg_event_add(ibuf);
 
-	return (n);
+	return (0);
 }
 
 void
diff --git a/usr.sbin/ospfd/ospfd.h b/usr.sbin/ospfd/ospfd.h
index b164d1d674f..397c94a76b0 100644
--- a/usr.sbin/ospfd/ospfd.h
+++ b/usr.sbin/ospfd/ospfd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ospfd.h,v 1.75 2009/01/31 11:44:49 claudio Exp $ */
+/*	$OpenBSD: ospfd.h,v 1.76 2009/03/04 12:51:01 claudio Exp $ */
 
 /*
  * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
@@ -558,9 +558,10 @@ u_int8_t	 area_ospf_options(struct area *);
 /* buffer.c */
 struct buf	*buf_open(size_t);
 struct buf	*buf_dynamic(size_t, size_t);
-int		 buf_add(struct buf *, void *, size_t);
+int		 buf_add(struct buf *, const void *, size_t);
 void		*buf_reserve(struct buf *, size_t);
 void		*buf_seek(struct buf *, size_t, size_t);
+size_t		 buf_size(struct buf *);
 size_t		 buf_left(struct buf *);
 int		 buf_close(struct msgbuf *, struct buf *);
 void		 buf_free(struct buf *);
diff --git a/usr.sbin/ospfd/ospfe.c b/usr.sbin/ospfd/ospfe.c
index 05ce44f2679..80e37e6ba42 100644
--- a/usr.sbin/ospfd/ospfe.c
+++ b/usr.sbin/ospfd/ospfe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ospfe.c,v 1.62 2009/01/07 21:16:36 claudio Exp $ */
+/*	$OpenBSD: ospfe.c,v 1.63 2009/03/04 12:51:01 claudio Exp $ */
 
 /*
  * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
@@ -955,17 +955,17 @@ orig_rtr_lsa(struct area *area)
 	lsa_hdr.ls_id = oeconf->rtr_id.s_addr;
 	lsa_hdr.adv_rtr = oeconf->rtr_id.s_addr;
 	lsa_hdr.seq_num = htonl(INIT_SEQ_NUM);
-	lsa_hdr.len = htons(buf->wpos);
+	lsa_hdr.len = htons(buf_size(buf));
 	lsa_hdr.ls_chksum = 0;		/* updated later */
 	memcpy(buf_seek(buf, 0, sizeof(lsa_hdr)), &lsa_hdr, sizeof(lsa_hdr));
 
-	chksum = htons(iso_cksum(buf->buf, buf->wpos, LS_CKSUM_OFFSET));
+	chksum = htons(iso_cksum(buf->buf, buf_size(buf), LS_CKSUM_OFFSET));
 	memcpy(buf_seek(buf, LS_CKSUM_OFFSET, sizeof(chksum)),
 	    &chksum, sizeof(chksum));
 
 	if (self)
 		imsg_compose(ibuf_rde, IMSG_LS_UPD, self->peerid, 0,
-		    buf->buf, buf->wpos);
+		    buf->buf, buf_size(buf));
 	else
 		log_warnx("orig_rtr_lsa: empty area %s",
 		    inet_ntoa(area->id));
@@ -1019,16 +1019,16 @@ orig_net_lsa(struct iface *iface)
 	lsa_hdr.ls_id = iface->addr.s_addr;
 	lsa_hdr.adv_rtr = oeconf->rtr_id.s_addr;
 	lsa_hdr.seq_num = htonl(INIT_SEQ_NUM);
-	lsa_hdr.len = htons(buf->wpos);
+	lsa_hdr.len = htons(buf_size(buf));
 	lsa_hdr.ls_chksum = 0;		/* updated later */
 	memcpy(buf_seek(buf, 0, sizeof(lsa_hdr)), &lsa_hdr, sizeof(lsa_hdr));
 
-	chksum = htons(iso_cksum(buf->buf, buf->wpos, LS_CKSUM_OFFSET));
+	chksum = htons(iso_cksum(buf->buf, buf_size(buf), LS_CKSUM_OFFSET));
 	memcpy(buf_seek(buf, LS_CKSUM_OFFSET, sizeof(chksum)),
 	    &chksum, sizeof(chksum));
 
 	imsg_compose(ibuf_rde, IMSG_LS_UPD, iface->self->peerid, 0,
-	    buf->buf, buf->wpos);
+	    buf->buf, buf_size(buf));
 
 	buf_free(buf);
 }