On 7/25/23 6:09 PM, Yan Zhai wrote:
diff --git a/tools/testing/selftests/bpf/progs/test_lwt_redirect.c b/tools/testing/selftests/bpf/progs/test_lwt_redirect.c
new file mode 100644
index 000000000000..3674e101f68f
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_lwt_redirect.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_tracing_net.h"
+
+/* We don't care about whether the packet can be received by network stack.
+ * Just care if the packet is sent to the correct device at correct direction
+ * and not panic the kernel.
+ */
+static __always_inline int prepend_dummy_mac(struct __sk_buff *skb)
+{
__always_inline is no longer a must for a long time.
+ char mac[] = {0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0xf,
+ 0xe, 0xd, 0xc, 0xb, 0xa, 0x08, 0x00};
+
+ if (bpf_skb_change_head(skb, ETH_HLEN, 0)) {
+ bpf_printk("%s: fail to change head", __func__);
Avoid using bpf_printk(). The bpf CI runs other tests also.
+ return -1;
+ }
+
+ if (bpf_skb_store_bytes(skb, 0, mac, sizeof(mac), 0)) {
+ bpf_printk("%s: fail to update mac", __func__);
+ return -1;
+ }
+
+ return 0;
+}
+
+SEC("redir_ingress")
Use SEC("lwt_xmit"). Then the libbpf will figure out the prog type.
+int test_lwt_redirect_in(struct __sk_buff *skb)
+{
+ if (prepend_dummy_mac(skb))
+ return BPF_DROP;
+
+ bpf_printk("Redirect skb to link %d ingress", skb->mark);
+ return bpf_redirect(skb->mark, BPF_F_INGRESS);
+}
+
+SEC("redir_egress")
+int test_lwt_redirect_out(struct __sk_buff *skb)
+{
+ if (prepend_dummy_mac(skb))
+ return BPF_DROP;
+
+ bpf_printk("Redirect skb to link %d egress", skb->mark);
+ return bpf_redirect(skb->mark, 0);
+}
+
+SEC("redir_egress_nomac")
+int test_lwt_redirect_out_nomac(struct __sk_buff *skb)
+{
+ int ret = bpf_redirect(skb->mark, 0);
+
+ bpf_printk("Redirect skb to link %d egress nomac: %d", skb->mark, ret);
+ return ret;
+}
+
+SEC("redir_ingress_nomac")
+int test_lwt_redirect_in_nomac(struct __sk_buff *skb)
+{
+ int ret = bpf_redirect(skb->mark, BPF_F_INGRESS);
+
+ bpf_printk("Redirect skb to link %d ingress nomac: %d", skb->mark, ret);
+ return ret;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_lwt_redirect.sh b/tools/testing/selftests/bpf/test_lwt_redirect.sh
new file mode 100755
index 000000000000..1b7b78b48174
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_lwt_redirect.sh
This has to be written in the test_progs infrastructure in C. Only test_progs is
run by the BPF CI. Take a look at other tests in prog_tests/. For example,
tc_redirect.c and xdp_metadata.c which are having setup in netns/link/...etc. It
currently has helpers to add tc qdisc and filter but not adding route yet which
could be a useful addition.
--
pw-bot: cr
