1 files changed, 43 insertions, 14 deletions

diff --git a/bpf/bpf_usage.c b/bpf/bpf_usage.c
index 5e505da..8b2343a 100644
--- a/bpf/bpf_usage.c
+++ b/bpf/bpf_usage.c
@@ -12,14 +12,14 @@ char __license[] SEC("license") = "GPL";
 struct {
 	__uint(type, BPF_MAP_TYPE_LRU_HASH);
 	__uint(max_entries, MAX_MAP_ENTRIES);
-	__type(key, __u32);   // source IPv4 address
+	__type(key, __u64);   // source mac address
 	__type(value, __u64); // no of bytes
 } ingress_ip4_usage_map SEC(".maps");
 
 struct {
 	__uint(type, BPF_MAP_TYPE_LRU_HASH);
 	__uint(max_entries, MAX_MAP_ENTRIES);
-	__type(key, __u32);   // destination IPv4 address
+	__type(key, __u64);   // destination mac address
 	__type(value, __u64); // no of bytes
 } egress_ip4_usage_map SEC(".maps");
 
@@ -28,31 +28,60 @@ typedef enum {
 	UPDATE_USAGE_EGRESS,
 } update_usage_t;
 
+static __always_inline __u64 nchar6_to_u64(unsigned char bytes[6])
+{
+	union {
+		char bytes[6];
+		__u64 i;
+	} ret;
+
+	ret.i = 0;
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+	ret.bytes[0] = bytes[5];
+	ret.bytes[1] = bytes[4];
+	ret.bytes[2] = bytes[3];
+	ret.bytes[3] = bytes[2];
+	ret.bytes[4] = bytes[1];
+	ret.bytes[5] = bytes[0];
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+	ret.bytes[0] = bytes[0];
+	ret.bytes[1] = bytes[1];
+	ret.bytes[2] = bytes[2];
+	ret.bytes[3] = bytes[3];
+	ret.bytes[4] = bytes[4];
+	ret.bytes[5] = bytes[5];
+#endif
+
+	return ret.i;
+}
+
 static __always_inline int update_usage(void *map, struct __sk_buff *skb,
 					update_usage_t traffic)
 {
-	__u32 ip4;
-	__u64 len, *usage;
+	__u64 mac, len, *usage;
 
 	void *data_end = (void *)(long)skb->data_end;
-	void *data = (void *)(long)skb->data;
-	struct iphdr *ip = data + sizeof(struct ethhdr);
+	struct ethhdr *eth = (void *)(long)skb->data;
 
-	if (skb->protocol != bpf_htons(ETH_P_IP))
+	if ((void *) (eth + 1) > data_end)
 		return TCX_PASS;
-	else if ((void *)(ip + 1) > data_end)
+
+	if (skb->protocol != bpf_htons(ETH_P_IP) &&
+	    skb->protocol != bpf_htons(ETH_P_IPV6)) {
 		return TCX_PASS;
+	}
 
-	if (traffic == UPDATE_USAGE_INGRESS)
-		ip4 = ip->saddr;
-	else
-		ip4 = ip->daddr;
 	len = skb->len - sizeof(struct ethhdr);
+	if (traffic == UPDATE_USAGE_INGRESS) {
+		mac = nchar6_to_u64(eth->h_source);
+	} else {
+		mac = nchar6_to_u64(eth->h_dest);
+	}
 
-	usage = bpf_map_lookup_elem(map, &ip4);
+	usage = bpf_map_lookup_elem(map, &mac);
 	if (!usage) {
 		/* no entry in the map for this IP address yet. */
-		bpf_map_update_elem(map, &ip4, &len, BPF_ANY);
+		bpf_map_update_elem(map, &mac, &len, BPF_ANY);
 	} else {
 		__sync_fetch_and_add(usage, len);
 	}