Commit b4940402 authored by Alexis Lothoré (eBPF Foundation)'s avatar Alexis Lothoré (eBPF Foundation) Committed by Alexei Starovoitov
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selftests/bpf: add gre packets testing to flow_dissector 



The bpf_flow program is able to handle GRE headers in IP packets. Add a
few test data input simulating those GRE packets, with 2 different
cases:
- parse GRE and the encapsulated packet
- parse GRE only

Acked-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Signed-off-by: default avatarAlexis Lothoré (eBPF Foundation) <alexis.lothore@bootlin.com>
Link: https://lore.kernel.org/r/20241120-flow_dissector-v3-6-45b46494f937@bootlin.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent a2cc66bb

tools/testing/selftests/bpf/prog_tests/flow_dissector.c

+76 −0
Original line number Diff line number Diff line
@@ -63,6 +63,19 @@ struct dvlan_ipv6_pkt { 
	struct tcphdr tcp;

} __packed;



struct gre_base_hdr {

	__be16 flags;

	__be16 protocol;

} gre_base_hdr;



struct gre_minimal_pkt {

	struct ethhdr eth;

	struct iphdr iph;

	struct gre_base_hdr gre_hdr;

	struct iphdr iph_inner;

	struct tcphdr tcp;

} __packed;



struct test {

	const char *name;

	union {
@@ -72,6 +85,7 @@ struct test { 
		struct ipv6_pkt ipv6;

		struct ipv6_frag_pkt ipv6_frag;

		struct dvlan_ipv6_pkt dvlan_ipv6;

		struct gre_minimal_pkt gre_minimal;

	} pkt;

	struct bpf_flow_keys keys;

	__u32 flags;
@@ -417,6 +431,68 @@ struct test tests[] = { 
		},

		.retval = BPF_FLOW_DISSECTOR_CONTINUE,

	},

	{

		.name = "ip-gre",

		.pkt.gre_minimal = {

			.eth.h_proto = __bpf_constant_htons(ETH_P_IP),

			.iph.ihl = 5,

			.iph.protocol = IPPROTO_GRE,

			.iph.tot_len = __bpf_constant_htons(MAGIC_BYTES),

			.gre_hdr = {

				.flags = 0,

				.protocol = __bpf_constant_htons(ETH_P_IP),

			},

			.iph_inner.ihl = 5,

			.iph_inner.protocol = IPPROTO_TCP,

			.iph_inner.tot_len =

				__bpf_constant_htons(MAGIC_BYTES -

				sizeof(struct iphdr)),

			.tcp.doff = 5,

			.tcp.source = 80,

			.tcp.dest = 8080,

		},

		.keys = {

			.nhoff = ETH_HLEN,

			.thoff = ETH_HLEN + sizeof(struct iphdr) * 2 +

				 sizeof(struct gre_base_hdr),

			.addr_proto = ETH_P_IP,

			.ip_proto = IPPROTO_TCP,

			.n_proto = __bpf_constant_htons(ETH_P_IP),

			.is_encap = true,

			.sport = 80,

			.dport = 8080,

		},

		.retval = BPF_OK,

	},

	{

		.name = "ip-gre-no-encap",

		.pkt.ipip = {

			.eth.h_proto = __bpf_constant_htons(ETH_P_IP),

			.iph.ihl = 5,

			.iph.protocol = IPPROTO_GRE,

			.iph.tot_len = __bpf_constant_htons(MAGIC_BYTES),

			.iph_inner.ihl = 5,

			.iph_inner.protocol = IPPROTO_TCP,

			.iph_inner.tot_len =

				__bpf_constant_htons(MAGIC_BYTES -

				sizeof(struct iphdr)),

			.tcp.doff = 5,

			.tcp.source = 80,

			.tcp.dest = 8080,

		},

		.keys = {

			.flags = BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP,

			.nhoff = ETH_HLEN,

			.thoff = ETH_HLEN + sizeof(struct iphdr)

				 + sizeof(struct gre_base_hdr),

			.addr_proto = ETH_P_IP,

			.ip_proto = IPPROTO_GRE,

			.n_proto = __bpf_constant_htons(ETH_P_IP),

			.is_encap = true,

		},

		.flags = BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP,

		.retval = BPF_OK,

	},

};



static int create_tap(const char *ifname)