bpf/flow_dissector: don't adjust nhoff by ETH_HLEN in BPF_PROG_TEST_RUN

Now that we use skb-less flow dissector let's return true nhoff and
thoff. We used to adjust them by ETH_HLEN because that's how it was
done in the skb case. For VLAN tests that looks confusing: nhoff is
pointing to vlan parts :-\

Warning, this is an API change for BPF_PROG_TEST_RUN! Feel free to drop
if you think that it's too late at this point to fix it.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index db2ec88..8606e5a 100644 (file)
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -418,9 +418,6 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
                retval = bpf_flow_dissect(prog, &ctx, eth->h_proto, ETH_HLEN,
                                          size);
 
-               flow_keys.nhoff -= ETH_HLEN;
-               flow_keys.thoff -= ETH_HLEN;
-
                if (signal_pending(current)) {
                        preempt_enable();
                        rcu_read_unlock();

diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
index 51758a0..8b54adf 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
+++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c
@@ -82,8 +82,8 @@ struct test tests[] = {
                        .tcp.doff = 5,
                },
                .keys = {
-                       .nhoff = 0,
-                       .thoff = sizeof(struct iphdr),
+                       .nhoff = ETH_HLEN,
+                       .thoff = ETH_HLEN + sizeof(struct iphdr),
                        .addr_proto = ETH_P_IP,
                        .ip_proto = IPPROTO_TCP,
                        .n_proto = __bpf_constant_htons(ETH_P_IP),
@@ -98,8 +98,8 @@ struct test tests[] = {
                        .tcp.doff = 5,
                },
                .keys = {
-                       .nhoff = 0,
-                       .thoff = sizeof(struct ipv6hdr),
+                       .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),
@@ -116,8 +116,8 @@ struct test tests[] = {
                        .tcp.doff = 5,
                },
                .keys = {
-                       .nhoff = VLAN_HLEN,
-                       .thoff = VLAN_HLEN + sizeof(struct iphdr),
+                       .nhoff = ETH_HLEN + VLAN_HLEN,
+                       .thoff = ETH_HLEN + VLAN_HLEN + sizeof(struct iphdr),
                        .addr_proto = ETH_P_IP,
                        .ip_proto = IPPROTO_TCP,
                        .n_proto = __bpf_constant_htons(ETH_P_IP),
@@ -134,8 +134,9 @@ struct test tests[] = {
                        .tcp.doff = 5,
                },
                .keys = {
-                       .nhoff = VLAN_HLEN * 2,
-                       .thoff = VLAN_HLEN * 2 + sizeof(struct ipv6hdr),
+                       .nhoff = ETH_HLEN + VLAN_HLEN * 2,
+                       .thoff = ETH_HLEN + VLAN_HLEN * 2 +
+                               sizeof(struct ipv6hdr),
                        .addr_proto = ETH_P_IPV6,
                        .ip_proto = IPPROTO_TCP,
                        .n_proto = __bpf_constant_htons(ETH_P_IPV6),
@@ -238,9 +239,6 @@ void test_flow_dissector(void)
         * We use a known path in the net/tun driver that calls
         * eth_get_headlen and we manually export bpf_flow_keys
         * via BPF map in this case.
-        *
-        * Note, that since eth_get_headlen operates on a L2 level,
-        * we adjust exported nhoff/thoff by ETH_HLEN.
         */
 
        err = bpf_prog_attach(prog_fd, 0, BPF_FLOW_DISSECTOR, 0);
@@ -262,9 +260,6 @@ void test_flow_dissector(void)
                err = bpf_map_lookup_elem(keys_fd, &key, &flow_keys);
                CHECK_ATTR(err, tests[i].name, "bpf_map_lookup_elem %d\n", err);
 
-               flow_keys.nhoff -= ETH_HLEN;
-               flow_keys.thoff -= ETH_HLEN;
-
                CHECK_ATTR(err, tests[i].name, "skb-less err %d\n", err);
                CHECK_FLOW_KEYS(tests[i].name, flow_keys, tests[i].keys);
        }