From: Ben Pfaff <blp@nicira.com>
Date: Mon, 10 May 2010 20:53:26 +0000 (-0700)
Subject: datapath: Avoid possibility of negative 'n_flows' in struct odp_flowvec.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6d7568dc38fb832b7e152c184b0bdfdca6bb9527;p=openvswitch

datapath: Avoid possibility of negative 'n_flows' in struct odp_flowvec.

do_flowvec_ioctl() was checking for too-big 'n_flows' but not negative
'n_flows'.  We could add that check too, but 'n_flows' should never be
negative so it's better to just use an unsigned type.
---

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 79a1f632..eec998ca 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -1143,7 +1143,8 @@ error:
 static int query_flows(struct datapath *dp, const struct odp_flowvec *flowvec)
 {
 	struct tbl *table = rcu_dereference(dp->table);
-	int i;
+	u32 i;
+
 	for (i = 0; i < flowvec->n_flows; i++) {
 		struct __user odp_flow *ufp = &flowvec->flows[i];
 		struct odp_flow uf;
@@ -1167,8 +1168,8 @@ static int query_flows(struct datapath *dp, const struct odp_flowvec *flowvec)
 
 struct list_flows_cbdata {
 	struct odp_flow __user *uflows;
-	int n_flows;
-	int listed_flows;
+	u32 n_flows;
+	u32 listed_flows;
 };
 
 static int list_flow(struct tbl_node *node, void *cbdata_)
diff --git a/include/openvswitch/datapath-protocol.h b/include/openvswitch/datapath-protocol.h
index 94723ef0..1c2dba9b 100644
--- a/include/openvswitch/datapath-protocol.h
+++ b/include/openvswitch/datapath-protocol.h
@@ -242,7 +242,7 @@ struct odp_flow_put {
 
 struct odp_flowvec {
     struct odp_flow *flows;
-    int n_flows;
+    __u32 n_flows;
 };
 
 /* The VLAN id is 12 bits, so we can use the entire 16 bits to indicate