2 files changed, 56 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
index 8e8c18aced9b..ef83f145a6f1 100644
--- a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
+++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
@@ -20,6 +20,7 @@
 	      "is_encap=%u/%u "						\
 	      "ip_proto=0x%x/0x%x "					\
 	      "n_proto=0x%x/0x%x "					\
+	      "flow_label=0x%x/0x%x "					\
 	      "sport=%u/%u "						\
 	      "dport=%u/%u\n",						\
 	      got.nhoff, expected.nhoff,				\
@@ -30,6 +31,7 @@
 	      got.is_encap, expected.is_encap,				\
 	      got.ip_proto, expected.ip_proto,				\
 	      got.n_proto, expected.n_proto,				\
+	      got.flow_label, expected.flow_label,			\
 	      got.sport, expected.sport,				\
 	      got.dport, expected.dport)
 
@@ -257,6 +259,50 @@ struct test tests[] = {
 			.is_first_frag = true,
 		},
 	},
+	{
+		.name = "ipv6-flow-label",
+		.pkt.ipv6 = {
+			.eth.h_proto = __bpf_constant_htons(ETH_P_IPV6),
+			.iph.nexthdr = IPPROTO_TCP,
+			.iph.payload_len = __bpf_constant_htons(MAGIC_BYTES),
+			.iph.flow_lbl = { 0xb, 0xee, 0xef },
+			.tcp.doff = 5,
+			.tcp.source = 80,
+			.tcp.dest = 8080,
+		},
+		.keys = {
+			.nhoff = ETH_HLEN,
+			.thoff = ETH_HLEN + sizeof(struct ipv6hdr),
+			.addr_proto = ETH_P_IPV6,
+			.ip_proto = IPPROTO_TCP,
+			.n_proto = __bpf_constant_htons(ETH_P_IPV6),
+			.sport = 80,
+			.dport = 8080,
+			.flow_label = __bpf_constant_htonl(0xbeeef),
+		},
+	},
+	{
+		.name = "ipv6-no-flow-label",
+		.pkt.ipv6 = {
+			.eth.h_proto = __bpf_constant_htons(ETH_P_IPV6),
+			.iph.nexthdr = IPPROTO_TCP,
+			.iph.payload_len = __bpf_constant_htons(MAGIC_BYTES),
+			.iph.flow_lbl = { 0xb, 0xee, 0xef },
+			.tcp.doff = 5,
+			.tcp.source = 80,
+			.tcp.dest = 8080,
+		},
+		.keys = {
+			.flags = BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL,
+			.nhoff = ETH_HLEN,
+			.thoff = ETH_HLEN + sizeof(struct ipv6hdr),
+			.addr_proto = ETH_P_IPV6,
+			.ip_proto = IPPROTO_TCP,
+			.n_proto = __bpf_constant_htons(ETH_P_IPV6),
+			.flow_label = __bpf_constant_htonl(0xbeeef),
+		},
+		.flags = BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL,
+	},
 };
 
 static int create_tap(const char *ifname)
diff --git a/tools/testing/selftests/bpf/progs/bpf_flow.c b/tools/testing/selftests/bpf/progs/bpf_flow.c
index f931cd3db9d4..7fbfa22f33df 100644
--- a/tools/testing/selftests/bpf/progs/bpf_flow.c
+++ b/tools/testing/selftests/bpf/progs/bpf_flow.c
@@ -83,6 +83,12 @@ static __always_inline int export_flow_keys(struct bpf_flow_keys *keys,
 	return ret;
 }
 
+#define IPV6_FLOWLABEL_MASK		__bpf_constant_htonl(0x000FFFFF)
+static inline __be32 ip6_flowlabel(const struct ipv6hdr *hdr)
+{
+	return *(__be32 *)hdr & IPV6_FLOWLABEL_MASK;
+}
+
 static __always_inline void *bpf_flow_dissect_get_header(struct __sk_buff *skb,
 							 __u16 hdr_size,
 							 void *buffer)
@@ -308,6 +314,10 @@ PROG(IPV6)(struct __sk_buff *skb)
 
 	keys->thoff += sizeof(struct ipv6hdr);
 	keys->ip_proto = ip6h->nexthdr;
+	keys->flow_label = ip6_flowlabel(ip6h);
+
+	if (keys->flags & BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
+		return export_flow_keys(keys, BPF_OK);
 
 	return parse_ipv6_proto(skb, ip6h->nexthdr);
 }