bpf: fixing dirty cb state from the kernel

Signed-off-by: André Martins <andre@cilium.io>
cilium · Feb 7, 2017 · 3195992 · 3195992
1 parent 011f048
commit 3195992
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Showing 5 changed files with 19 additions and 0 deletions.
diff --git a/bpf/bpf_lb.c b/bpf/bpf_lb.c
@@ -171,6 +171,8 @@ int from_netdev(struct __sk_buff *skb)
 {
 	int ret;
 
+	bpf_clear_cb(skb);
+
 	switch (skb->protocol) {
 #ifndef LB_DISABLE_IPV6
 	case __constant_htons(ETH_P_IPV6):

diff --git a/bpf/bpf_lxc.c b/bpf/bpf_lxc.c
@@ -564,6 +564,8 @@ int handle_ingress(struct __sk_buff *skb)
 {
 	int ret;
 
+	bpf_clear_cb(skb);
+
 	cilium_trace_capture(skb, DBG_CAPTURE_FROM_LXC, skb->ingress_ifindex);
 
 	switch (skb->protocol) {

diff --git a/bpf/bpf_netdev.c b/bpf/bpf_netdev.c
@@ -149,6 +149,8 @@ int from_netdev(struct __sk_buff *skb)
 {
 	int ret;
 
+	bpf_clear_cb(skb);
+
 	cilium_trace_capture(skb, DBG_CAPTURE_FROM_NETDEV, skb->ingress_ifindex);
 
 	switch (skb->protocol) {

diff --git a/bpf/bpf_overlay.c b/bpf/bpf_overlay.c
@@ -118,6 +118,8 @@ int from_overlay(struct __sk_buff *skb)
 {
 	int ret;
 
+	bpf_clear_cb(skb);
+
 	cilium_trace_capture(skb, DBG_CAPTURE_FROM_OVERLAY, skb->ingress_ifindex);
 
 	switch (skb->protocol) {

diff --git a/bpf/lib/utils.h b/bpf/lib/utils.h
@@ -36,4 +36,15 @@
 	_x > _y ? _x : _y;	\
 })
 
+/* Clear CB values */
+static inline void bpf_clear_cb(struct __sk_buff *skb)
+{
+	__u32 zero = 0;
+	skb->cb[0] = zero;
+	skb->cb[1] = zero;
+	skb->cb[2] = zero;
+	skb->cb[3] = zero;
+	skb->cb[4] = zero;
+}
+
 #endif