From c59311aa99036ce371e34955f8254c300369a3ec Mon Sep 17 00:00:00 2001
From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Sat, 28 Mar 2009 11:02:45 +0800
Subject: [PATCH] ipflow: Flush ipflow if a new route is successfully added.

ipflow suffers same problem as described in FreeBSD-PR: kern/10778
Though the time of mis-routing will not be "arbitrarily long time"
for intermittent packet flow (thanks to the ipflow timeout), it
still could be quite long for a constant packet flow.
---
 sys/netinet/in_rmx.c  | 12 ++++++++++++
 sys/netinet/ip_flow.c | 11 +++++++++++
 sys/netinet/ip_flow.h |  1 +
 3 files changed, 24 insertions(+)

diff --git a/sys/netinet/in_rmx.c b/sys/netinet/in_rmx.c
index 6fc1559c2c..9fb755c6a8 100644
--- a/sys/netinet/in_rmx.c
+++ b/sys/netinet/in_rmx.c
@@ -58,6 +58,7 @@
 #include <netinet/in.h>
 #include <netinet/in_var.h>
 #include <netinet/ip_var.h>
+#include <netinet/ip_flow.h>
 
 #define RTPRF_EXPIRING	RTF_PROTO3	/* set on routes we manage */
 
@@ -136,6 +137,17 @@ in_addroute(char *key, char *mask, struct radix_node_head *head,
 			}
 		}
 	}
+
+	/*
+	 * If the new route has been created successfully, and it is
+	 * not a multicast/broadcast or cloned route, then we will
+	 * have to flush the ipflow.  Otherwise, we may end up using
+	 * the wrong route.
+	 */
+	if (ret != NULL &&
+	    (rt->rt_flags &
+	     (RTF_MULTICAST | RTF_BROADCAST | RTF_WASCLONED)) == 0)
+		ipflow_flush_oncpu();
 	return ret;
 }
 
diff --git a/sys/netinet/ip_flow.c b/sys/netinet/ip_flow.c
index 3872761883..5792aea5c3 100644
--- a/sys/netinet/ip_flow.c
+++ b/sys/netinet/ip_flow.c
@@ -499,6 +499,17 @@ ipflow_create(const struct route *ro, struct mbuf *m)
 	IPFLOW_INSERT(&ipflowtable[hash], ipf);
 }
 
+void
+ipflow_flush_oncpu(void)
+{
+	struct ipflow *ipf;
+
+	while ((ipf = LIST_FIRST(&ipflowlist)) != NULL) {
+		IPFLOW_REMOVE(ipf);
+		IPFLOW_FREE(ipf);
+	}
+}
+
 static void
 ipflow_init(void)
 {
diff --git a/sys/netinet/ip_flow.h b/sys/netinet/ip_flow.h
index a5a7698134..c67e73865e 100644
--- a/sys/netinet/ip_flow.h
+++ b/sys/netinet/ip_flow.h
@@ -48,6 +48,7 @@ struct route;
 int	ipflow_fastforward(struct mbuf *);
 void	ipflow_create(const struct route *, struct mbuf *);
 void	ipflow_slowtimo(void);
+void	ipflow_flush_oncpu(void);
 
 #endif	/* _KERNEL */
 
-- 
2.41.0