Sync buffer API with the one from ospfd. The dynamic buffers will make other

code much easier to write. OK henning@ some time ago.

3 files changed, 67 insertions, 19 deletions

diff --git a/usr.sbin/bgpd/bgpd.h b/usr.sbin/bgpd/bgpd.h
index fe7b77287b4..5764610296c 100644
--- a/usr.sbin/bgpd/bgpd.h
+++ b/usr.sbin/bgpd/bgpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bgpd.h,v 1.223 2008/12/12 23:15:12 claudio Exp $ */
+/*	$OpenBSD: bgpd.h,v 1.224 2009/03/13 04:40:55 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -109,6 +109,7 @@ struct buf {
 	TAILQ_ENTRY(buf)	 entry;
 	u_char			*buf;
 	size_t			 size;
+	size_t			 max;
 	size_t			 wpos;
 	size_t			 rpos;
 	int			 fd;
@@ -734,9 +735,12 @@ int		 bgpd_filternexthop(struct kroute *, struct kroute6 *);
 
 /* buffer.c */
 struct buf	*buf_open(size_t);
-struct buf	*buf_grow(struct buf *, size_t);
+struct buf	*buf_dynamic(size_t, 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 *);
 int		 buf_write(int, struct buf *);
 void		 buf_free(struct buf *);
diff --git a/usr.sbin/bgpd/buffer.c b/usr.sbin/bgpd/buffer.c
index 36574934d8e..bb4ac46d53f 100644
--- a/usr.sbin/bgpd/buffer.c
+++ b/usr.sbin/bgpd/buffer.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: buffer.c,v 1.40 2008/10/03 15:20:29 eric Exp $ */
+/*	$OpenBSD: buffer.c,v 1.41 2009/03/13 04:40:55 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -28,6 +28,7 @@
 
 #include "bgpd.h"
 
+int	buf_realloc(struct buf *, size_t);
 void	buf_enqueue(struct msgbuf *, struct buf *);
 void	buf_dequeue(struct msgbuf *, struct buf *);
 
@@ -42,35 +43,55 @@ buf_open(size_t len)
 		free(buf);
 		return (NULL);
 	}
-	buf->size = len;
+	buf->size = buf->max = len;
 	buf->fd = -1;
 
 	return (buf);
 }
 
 struct buf *
-buf_grow(struct buf *buf, size_t len)
+buf_dynamic(size_t len, size_t max)
 {
-	void	*p;
+	struct buf	*buf;
 
-	if ((p = realloc(buf->buf, buf->size + len)) == NULL) {
-		free(buf->buf);
-		buf->buf = NULL;
-		buf->size = 0;
+	if (max < len)
+		return (NULL);
+
+	if ((buf = buf_open(len)) == NULL)
 		return (NULL);
-	}
 
-	buf->buf = p;
-	buf->size += len;
+	if (max > 0)
+		buf->max = max;
 
 	return (buf);
 }
 
 int
+buf_realloc(struct buf *buf, size_t len)
+{
+	u_char	*b;
+
+	/* on static buffers max is eq size and so the following fails */
+	if (buf->wpos + len > buf->max) {
+		errno = ENOMEM;
+		return (-1);
+	}
+
+	b = realloc(buf->buf, buf->wpos + len);
+	if (b == NULL)
+		return (-1);
+	buf->buf = b;
+	buf->size = buf->wpos + len;
+
+	return (0);
+}
+
+int
 buf_add(struct buf *buf, const void *data, size_t len)
 {
 	if (buf->wpos + len > buf->size)
-		return (-1);
+		if (buf_realloc(buf, len) == -1)
+			return (-1);
 
 	memcpy(buf->buf + buf->wpos, data, len);
 	buf->wpos += len;
@@ -83,16 +104,41 @@ buf_reserve(struct buf *buf, size_t len)
 	void	*b;
 
 	if (buf->wpos + len > buf->size)
-		return (NULL);
+		if (buf_realloc(buf, len) == -1)
+			return (NULL);
 
 	b = buf->buf + buf->wpos;
 	buf->wpos += len;
 	return (b);
 }
 
+void *
+buf_seek(struct buf *buf, size_t pos, size_t len)
+{
+	/* only allowed to seek in already written parts */
+	if (pos + len > buf->wpos)
+		return (NULL);
+
+	return (buf->buf + pos);
+}
+
+size_t
+buf_size(struct buf *buf)
+{
+	return (buf->wpos);
+}
+
+size_t
+buf_left(struct buf *buf)
+{
+	return (buf->max - buf->wpos);
+}
+
 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/bgpd/session.c b/usr.sbin/bgpd/session.c
index b763e35814e..f3a4d9b8e55 100644
--- a/usr.sbin/bgpd/session.c
+++ b/usr.sbin/bgpd/session.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: session.c,v 1.284 2008/09/11 14:49:58 henning Exp $ */
+/*	$OpenBSD: session.c,v 1.285 2009/03/13 04:40:55 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004, 2005 Henning Brauer <henning@openbsd.org>
@@ -1253,8 +1253,6 @@ session_capa_add(struct peer *p, struct buf *opb, u_int8_t capa_code,
 	op_type = OPT_PARAM_CAPABILITIES;
 	op_len = sizeof(capa_code) + sizeof(capa_len) + capa_len;
 	tot_len = sizeof(op_type) + sizeof(op_len) + op_len;
-	if (buf_grow(opb, tot_len) == NULL)
-		return (1);
 	errs += buf_add(opb, &op_type, sizeof(op_type));
 	errs += buf_add(opb, &op_len, sizeof(op_len));
 	errs += buf_add(opb, &capa_code, sizeof(capa_code));
@@ -1346,7 +1344,7 @@ session_open(struct peer *p)
 	u_int			 errs = 0;
 
 
-	if ((opb = buf_open(0)) == NULL) {
+	if ((opb = buf_dynamic(0, MAX_PKTSIZE - MSGSIZE_OPEN_MIN)) == NULL) {
 		bgp_fsm(p, EVNT_CON_FATAL);
 		return;
 	}