On 9/11/22 5:23 AM, Shmulik Ladkani wrote:
Add geneve test to test_tunnel. The test setup and scheme resembles the
existing vxlan test.
The test also exercises tunnel option assignment using
bpf_skb_set_tunnel_opt_dynptr.
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@xxxxxxxxx>
---
v6:
- Fix missing retcodes in progs/test_tunnel_kern.c
spotted by John Fastabend <john.fastabend@xxxxxxxxx>
- Simplify bpf_skb_set_tunnel_opt_dynptr's interface, removing the
superfluous 'len' parameter
suggested by Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx>
---
.../selftests/bpf/prog_tests/test_tunnel.c | 108 ++++++++++++++
.../selftests/bpf/progs/test_tunnel_kern.c | 138 ++++++++++++++++++
2 files changed, 246 insertions(+)
[...]
diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
index b11f6952b0c8..cb901b76a547 100644
--- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c
@@ -24,6 +24,20 @@
#define log_err(__ret) bpf_printk("ERROR line:%d ret:%d\n", __LINE__, __ret)
+#define GENEVE_OPTS_LEN0 12
+#define GENEVE_OPTS_LEN1 20
+
+struct tun_opts_raw {
+ __u8 data[64];
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, __u32);
+ __type(value, struct tun_opts_raw);
+} geneve_opts SEC(".maps");
+
struct geneve_opt {
__be16 opt_class;
__u8 type;
@@ -286,6 +300,130 @@ int ip4ip6erspan_get_tunnel(struct __sk_buff *skb)
return TC_ACT_OK;
}
+SEC("tc")
+int geneve_set_tunnel_dst(struct __sk_buff *skb)
+{
+ int ret;
+ struct bpf_tunnel_key key;
+ struct tun_opts_raw *opts;
+ struct bpf_dynptr dptr;
+ __u32 index = 0;
+ __u32 *local_ip = NULL;
+
+ local_ip = bpf_map_lookup_elem(&local_ip_map, &index);
+ if (!local_ip) {
+ log_err(-1);
+ return TC_ACT_SHOT;
+ }
+
+ index = 0;
+ opts = bpf_map_lookup_elem(&geneve_opts, &index);
+ if (!opts) {
+ log_err(-1);
+ return TC_ACT_SHOT;
+ }
+
+ __builtin_memset(&key, 0x0, sizeof(key));
+ key.local_ipv4 = 0xac100164; /* 172.16.1.100 */
+ key.remote_ipv4 = *local_ip;
+ key.tunnel_id = 2;
+ key.tunnel_tos = 0;
+ key.tunnel_ttl = 64;
+
+ ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key),
+ BPF_F_ZERO_CSUM_TX);
+ if (ret < 0) {
+ log_err(ret);
+ return TC_ACT_SHOT;
+ }
+
+ /* set empty geneve options (of runtime length) using a dynptr */
+ __builtin_memset(opts, 0x0, sizeof(*opts));
+ if (*local_ip % 2)
+ bpf_dynptr_from_mem(opts, GENEVE_OPTS_LEN1, 0, &dptr);
+ else
+ bpf_dynptr_from_mem(opts, GENEVE_OPTS_LEN0, 0, &dptr);
+ ret = bpf_skb_set_tunnel_opt_dynptr(skb, &dptr);
I think the above example is not good. since it can write as
if (*local_ip % 2)
ret = bpf_skb_set_tunnel_opt(skb, opts, GENEVE_OPTS_LEN1);
else
ret = bpf_skb_set_tunnel_opt(skb, opts, GENEVE_OPTS_LEN0);
In the commit message of Patch 2, we have
===
For example, we have an ebpf program that gets geneve options on
incoming packets, stores them into a map (using a key representing
the incoming flow), and later needs to assign *same* options to
reply packets (belonging to same flow).
===
It would be great if you can create a test case for the above
use case.
+ if (ret < 0) {
+ log_err(ret);
+ return TC_ACT_SHOT;
+ }
+
+ return TC_ACT_OK;
+}
+
[...]
