From 847c6d482703c5b5a4f654d6e43b92bf5bb60117 Mon Sep 17 00:00:00 2001
From: Kenneth R Westerback <krw@cvs.openbsd.org>
Date: Thu, 28 Feb 2013 21:00:54 +0000
Subject: Try 10 times to obtain the routing table via sysctl(), and if it
 can't be done just abandon attempt to clean up the routing and arp tables and
 carry on. Code adapted from itojun's route6d.c.

May address problem reported on misc@ by Marc Peters.

Best we can do for now.

ok claudio@
---
 sbin/dhclient/kroute.c | 41 +++++++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 14 deletions(-)

diff --git a/sbin/dhclient/kroute.c b/sbin/dhclient/kroute.c
index 8737e010e29..9f636df340a 100644
--- a/sbin/dhclient/kroute.c
+++ b/sbin/dhclient/kroute.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kroute.c,v 1.39 2013/02/24 01:23:19 krw Exp $	*/
+/*	$OpenBSD: kroute.c,v 1.40 2013/02/28 21:00:53 krw Exp $	*/
 
 /*
  * Copyright 2012 Kenneth R Westerback <krw@openbsd.org>
@@ -66,14 +66,14 @@ priv_flush_routes_and_arp_cache(struct imsg_flush_routes *imsg)
 	struct sockaddr *rti_info[RTAX_MAX];
 	int mib[7];
 	size_t needed;
-	char *lim, *buf, *next, *routelabel;
+	char *lim, *buf, *next, *routelabel, *errmsg;
 	struct rt_msghdr *rtm;
 	struct sockaddr *sa;
 	struct sockaddr_dl *sdl;
 	struct sockaddr_in *sa_in;
 	struct sockaddr_inarp *sin;
 	struct sockaddr_rtlabel *sa_rl;
-	int s, seqno = 0, rlen, i;
+	int s, seqno = 0, rlen, retry, i;
 
 	mib[0] = CTL_NET;
 	mib[1] = PF_ROUTE;
@@ -83,20 +83,33 @@ priv_flush_routes_and_arp_cache(struct imsg_flush_routes *imsg)
 	mib[5] = 0;
 	mib[6] = imsg->rdomain;
 
-	if (sysctl(mib, 7, NULL, &needed, NULL, 0) == -1) {
-		if (imsg->rdomain != 0 && errno == EINVAL)
+	buf = NULL;
+	retry = 0;
+	do {
+		retry++;
+		errmsg = NULL;
+		if (buf)
+			free(buf);
+		if (sysctl(mib, 7, NULL, &needed, NULL, 0) == -1) {
+			errmsg = "sysctl size of routes:";
+			continue;
+		}
+		if (needed == 0)
 			return;
-		error("sysctl size of routes: %s", strerror(errno));
-	}
+		if ((buf = malloc(needed)) == NULL) {
+			errmsg = "routes buf malloc:";
+			continue;
+		}
+		if (sysctl(mib, 7, buf, &needed, NULL, 0) == -1) {
+			errmsg = "sysctl retrieval of routes:";
+		}
+	} while (retry < 10 && errmsg != NULL);
 
-	if (needed == 0)
+	if (errmsg) {
+		warning("route cleanup failed - %s %s (%d retries, msize=%zu)",
+		    errmsg, strerror(errno), retry, needed);
 		return;
-
-	if ((buf = malloc(needed)) == NULL)
-		error("no memory for sysctl routes");
-
-	if (sysctl(mib, 7, buf, &needed, NULL, 0) == -1)
-		error("sysctl retrieval of routes: %s", strerror(errno));
+	}
 
 	if ((s = socket(AF_ROUTE, SOCK_RAW, 0)) == -1)
 		error("opening socket to flush routes: %s", strerror(errno));
-- 
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