handle write() returning 0 correctly, adjust the msgbuf API appropriately,

and make all callers cope.

6 files changed, 54 insertions, 38 deletions

diff --git a/usr.sbin/bgpd/bgpd.c b/usr.sbin/bgpd/bgpd.c
index 346f94cc78a..c725ce9b971 100644
--- a/usr.sbin/bgpd/bgpd.c
+++ b/usr.sbin/bgpd/bgpd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bgpd.c,v 1.21 2003/12/23 19:14:49 deraadt Exp $ */
+/*	$OpenBSD: bgpd.c,v 1.22 2003/12/24 13:28:01 henning Exp $ */
 
 /*
  * Copyright (c) 2003 Henning Brauer <henning@openbsd.org>
@@ -221,11 +221,11 @@ main(int argc, char *argv[])
 				fatal("poll error", errno);
 
 		if (nfds > 0 && (pfd[PFD_PIPE_SESSION].revents & POLLOUT))
-			if ((n = msgbuf_write(&ibuf_se.w)) == -1)
+			if ((n = msgbuf_write(&ibuf_se.w)) < 0)
 				fatal("pipe write error", errno);
 
 		if (nfds > 0 && (pfd[PFD_PIPE_ROUTE].revents & POLLOUT))
-			if ((n = msgbuf_write(&ibuf_rde.w)) == -1)
+			if ((n = msgbuf_write(&ibuf_rde.w)) < 0)
 				fatal("pipe write error", errno);
 
 		if (nfds > 0 && pfd[PFD_PIPE_SESSION].revents & POLLIN) {
@@ -240,7 +240,7 @@ main(int argc, char *argv[])
 
 		for (j = PFD_MRT_START; j < i && nfds > 0 ; j++) {
 			if (pfd[j].revents & POLLOUT) {
-				if ((n = msgbuf_write(&mrt[i]->msgbuf)) == -1)
+				if ((n = msgbuf_write(&mrt[i]->msgbuf)) < 0)
 					fatal("pipe write error", errno);
 			}
 		}
@@ -341,7 +341,7 @@ dispatch_imsg(struct imsgbuf *ibuf, int idx, struct mrt_config *conf)
 					fatal("buf_open error", 0);
 				if (buf_add(wbuf, imsg.data, len) == -1)
 					fatal("buf_add error", 0);
-				if ((n = buf_close(&m->msgbuf, wbuf)) == -1)
+				if ((n = buf_close(&m->msgbuf, wbuf)) < 0)
 					fatal("buf_close error", 0);
 				break;
 			}
diff --git a/usr.sbin/bgpd/buffer.c b/usr.sbin/bgpd/buffer.c
index 71db8737494..3cb2df56b38 100644
--- a/usr.sbin/bgpd/buffer.c
+++ b/usr.sbin/bgpd/buffer.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: buffer.c,v 1.8 2003/12/23 19:14:49 deraadt Exp $ */
+/*	$OpenBSD: buffer.c,v 1.9 2003/12/24 13:28:01 henning Exp $ */
 
 /*
  * Copyright (c) 2003 Henning Brauer <henning@openbsd.org>
@@ -78,8 +78,8 @@ buf_close(struct msgbuf *msgbuf, struct buf *buf)
 
 	/* first try to write out directly */
 	if (msgbuf->queued == 0) {
-		if ((n = buf_write(msgbuf->sock, buf)) == -1)
-			return (-1);
+		if ((n = buf_write(msgbuf->sock, buf)) < 0)
+			return (n);
 
 		if (n == 1) {		/* all data written out */
 			buf_free(buf);
@@ -101,14 +101,13 @@ buf_write(int sock, struct buf *buf)
 	    buf->size-buf->rpos)) == -1) {
 		if (errno == EAGAIN)	/* cannot write immediately */
 			return (0);
-		else {
-			/* XXX better let caller log with info which sock etc */
-			logit(LOG_CRIT, "buf_write: write error: %s",
-			    strerror(errno));
+		else
 			return (-1);
-		}
 	}
 
+	if (n == 0)			/* connection closed */
+		return (-2);
+
 	if (n < buf->size - buf->rpos) {	/* not all data written yet */
 		buf->rpos += n;
 		return (0);
@@ -158,8 +157,9 @@ msgbuf_write(struct msgbuf *msgbuf)
 
 	for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL; buf = next) {
 		next = TAILQ_NEXT(buf, entries);
-		if ((n = buf_write(msgbuf->sock, buf)) == -1)
-			return (-1);
+		if ((n = buf_write(msgbuf->sock, buf)) < 0)
+			return (n);
+
 		if (n == 1)	/* everything written out */
 			buf_dequeue(msgbuf, buf);
 		else
diff --git a/usr.sbin/bgpd/imsg.c b/usr.sbin/bgpd/imsg.c
index 0424062d18c..fbaa7c1a55e 100644
--- a/usr.sbin/bgpd/imsg.c
+++ b/usr.sbin/bgpd/imsg.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: imsg.c,v 1.8 2003/12/21 23:28:39 henning Exp $ */
+/*	$OpenBSD: imsg.c,v 1.9 2003/12/24 13:28:02 henning Exp $ */
 
 /*
  * Copyright (c) 2003 Henning Brauer <henning@openbsd.org>
@@ -111,8 +111,8 @@ imsg_compose(struct imsgbuf *ibuf, int type, u_int32_t peerid, void *data,
 	if (datalen)
 		if (buf_add(wbuf, data, datalen) == -1)
 			fatal("imsg_compose: buf_add error", 0);
-	if ((n = buf_close(&ibuf->w, wbuf)) == -1)
-		fatal("imsg_compose: buf_close error", 0);
+	if ((n = buf_close(&ibuf->w, wbuf)) < 0)
+		fatal("imsg_compose: buf_close error", errno);
 
 	return (n);
 }
diff --git a/usr.sbin/bgpd/mrt.c b/usr.sbin/bgpd/mrt.c
index 414dc9016a1..4c24c0f62a0 100644
--- a/usr.sbin/bgpd/mrt.c
+++ b/usr.sbin/bgpd/mrt.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mrt.c,v 1.9 2003/12/23 19:14:49 deraadt Exp $ */
+/*	$OpenBSD: mrt.c,v 1.10 2003/12/24 13:28:02 henning Exp $ */
 
 /*
  * Copyright (c) 2003 Claudio Jeker <claudio@openbsd.org>
@@ -113,7 +113,7 @@ mrt_dump_bgp_msg(struct mrt *mrt, void *pkg, u_int16_t pkglen, int type,
 	if (buf_add(buf, pkg, pkglen) == -1)
 		fatal("buf_add error", 0);
 
-	if ((n = buf_close(mrt->msgbuf, buf)) == -1)
+	if ((n = buf_close(mrt->msgbuf, buf)) < 0)
 		fatal("buf_close error", 0);
 
 	return (n);
@@ -159,7 +159,7 @@ mrt_dump_entry(struct mrt *mrt, struct prefix *p, u_int16_t snum,
 	if (attr_dump(bptr, attr_len, &p->aspath->flags) == -1)
 		fatal("attr_dump error", 0);
 
-	if ((n = buf_close(mrt->msgbuf, buf)) == -1)
+	if ((n = buf_close(mrt->msgbuf, buf)) < 0)
 		fatal("buf_close error", 0);
 
 	return (n);
diff --git a/usr.sbin/bgpd/rde.c b/usr.sbin/bgpd/rde.c
index e7f8352b879..16af16b34e0 100644
--- a/usr.sbin/bgpd/rde.c
+++ b/usr.sbin/bgpd/rde.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde.c,v 1.23 2003/12/23 19:14:49 deraadt Exp $ */
+/*	$OpenBSD: rde.c,v 1.24 2003/12/24 13:28:02 henning Exp $ */
 
 /*
  * Copyright (c) 2003 Henning Brauer <henning@openbsd.org>
@@ -148,15 +148,14 @@ rde_main(struct bgpd_config *config, int pipe_m2r[2], int pipe_s2r[2])
 		if (nfds > 0 && (pfd[PFD_PIPE_MAIN].revents & POLLOUT) &&
 		    ibuf_main.w.queued) {
 			nfds--;
-			if ((n = msgbuf_write(&ibuf_main.w)) == -1)
+			if ((n = msgbuf_write(&ibuf_main.w)) < 0)
 				fatal("pipe write error", errno);
 		}
 
 		if (nfds > 0 && (pfd[PFD_PIPE_SESSION].revents & POLLOUT) &&
 		    ibuf_se.w.queued) {
 			nfds--;
-			if ((n = msgbuf_write(&ibuf_se.w)) ==
-			    -1)
+			if ((n = msgbuf_write(&ibuf_se.w)) < 0)
 				fatal("pipe write error", errno);
 		}
 	}
diff --git a/usr.sbin/bgpd/session.c b/usr.sbin/bgpd/session.c
index dc3dc5df3fb..111f7bbe2ae 100644
--- a/usr.sbin/bgpd/session.c
+++ b/usr.sbin/bgpd/session.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: session.c,v 1.33 2003/12/24 11:39:43 henning Exp $ */
+/*	$OpenBSD: session.c,v 1.34 2003/12/24 13:28:02 henning Exp $ */
 
 /*
  * Copyright (c) 2003 Henning Brauer <henning@openbsd.org>
@@ -269,8 +269,8 @@ session_main(struct bgpd_config *config, int pipe_m2s[2], int pipe_s2r[2])
 		}
 
 		if (nfds > 0 && pfd[PFD_PIPE_ROUTE].revents & POLLOUT)
-			if (msgbuf_write(&ibuf_rde.w) == -1)
-				fatal("pipe write error", 0);
+			if (msgbuf_write(&ibuf_rde.w) < 0)
+				fatal("pipe write error", errno);
 
 		if (nfds > 0 && pfd[PFD_PIPE_ROUTE].revents & POLLIN) {
 			nfds--;
@@ -750,7 +750,7 @@ session_open(struct peer *peer)
 	struct msg_open	 msg;
 	struct buf	*buf;
 	u_int16_t	 len;
-	int		 errs = 0;
+	int		 errs = 0, n;
 
 	len = MSGSIZE_OPEN_MIN;
 
@@ -775,7 +775,11 @@ session_open(struct peer *peer)
 	errs += buf_add(buf, &msg.optparamlen, sizeof(msg.optparamlen));
 
 	if (errs == 0) {
-		if (buf_close(&peer->wbuf, buf) == -1) {
+		if ((n = buf_close(&peer->wbuf, buf)) < 0) {
+			if (n == -2)
+				log_errx(peer, "Connection closed");
+			else
+				log_err(peer, "Write error");
 			buf_free(buf);
 			bgp_fsm(peer, EVNT_CON_FATAL);
 		}
@@ -791,7 +795,7 @@ session_keepalive(struct peer *peer)
 	struct msg_header	 msg;
 	struct buf		*buf;
 	ssize_t			 len;
-	int			 errs = 0;
+	int			 errs = 0, n;
 
 	len = MSGSIZE_KEEPALIVE;
 
@@ -811,11 +815,15 @@ session_keepalive(struct peer *peer)
 		return;
 	}
 
-	if (buf_close(&peer->wbuf, buf) == -1) {
+	if ((n = buf_close(&peer->wbuf, buf)) < 0) {
+		if (n == -2)
+			log_errx(peer, "Connection closed");
+		else
+			log_err(peer, "Write error");
 		buf_free(buf);
 		bgp_fsm(peer, EVNT_CON_FATAL);
-		return;
 	}
+
 	start_timer_keepalive(peer);
 }
 
@@ -832,7 +840,7 @@ session_notification(struct peer *peer, u_int8_t errcode, u_int8_t subcode,
 	struct msg_header	 msg;
 	struct buf		*buf;
 	ssize_t			 len;
-	int			 errs = 0;
+	int			 errs = 0, n;
 
 	len = MSGSIZE_NOTIFICATION_MIN + datalen;
 
@@ -857,7 +865,11 @@ session_notification(struct peer *peer, u_int8_t errcode, u_int8_t subcode,
 		return;
 	}
 
-	if (buf_close(&peer->wbuf, buf) == -1) {
+	if ((n = buf_close(&peer->wbuf, buf)) < 0) {
+		if (n == -2)
+			log_errx(peer, "Connection closed");
+		else
+			log_err(peer, "Write error");
 		buf_free(buf);
 		bgp_fsm(peer, EVNT_CON_FATAL);
 	}
@@ -908,8 +920,13 @@ session_dispatch_msg(struct pollfd *pfd, struct peer *peer)
 	}
 
 	if (pfd->revents & POLLOUT && peer->wbuf.queued) {
-		if (msgbuf_write(&peer->wbuf))
+		if ((error = msgbuf_write(&peer->wbuf)) < 0) {
+			if (error == -2)
+				log_errx(peer, "Connection closed");
+			else
+				log_err(peer, "Write error");
 			bgp_fsm(peer, EVNT_CON_FATAL);
+		}
 		if (!(pfd->revents & POLLIN))
 			return (1);
 	}
@@ -966,8 +983,8 @@ session_dispatch_msg(struct pollfd *pfd, struct peer *peer)
 					}
 					n = 0;	/* give others a chance... */
 					if (peer->rbuf != NULL) {
-						bzero(peer->rbuf,
-						    sizeof(struct peer_buf_read));
+						bzero(peer->rbuf, sizeof(struct
+						    peer_buf_read));
 						peer->rbuf->wptr =
 						    peer->rbuf->buf;
 						peer->rbuf->pkt_len =