samples/bpf: Add tunnel set/get tests.

The patch creates sample code exercising bpf_skb_{set,get}_tunnel_key,
and bpf_skb_{set,get}_tunnel_opt for GRE, VXLAN, and GENEVE.  A native
tunnel device is created in a namespace to interact with a lwtunnel
device out of the namespace, with metadata enabled.  The bpf_skb_set_*
program is attached to tc egress and bpf_skb_get_* is attached to egress
qdisc.  A ping between two tunnels is used to verify correctness and
the result of bpf_skb_get_* printed by bpf_trace_printk.

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 191 insertions, 0 deletions

diff --git a/samples/bpf/tcbpf2_kern.c b/samples/bpf/tcbpf2_kern.c
new file mode 100644
index 000000000000..7a15289da6cc
--- /dev/null
+++ b/samples/bpf/tcbpf2_kern.c
@@ -0,0 +1,191 @@
+/* Copyright (c) 2016 VMware
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/filter.h>
+#include <uapi/linux/pkt_cls.h>
+#include "bpf_helpers.h"
+
+#define ERROR(ret) do {\
+		char fmt[] = "ERROR line:%d ret:%d\n";\
+		bpf_trace_printk(fmt, sizeof(fmt), __LINE__, ret); \
+	} while(0)
+
+struct geneve_opt {
+	__be16	opt_class;
+	u8	type;
+	u8	length:5;
+	u8	r3:1;
+	u8	r2:1;
+	u8	r1:1;
+	u8	opt_data[8]; /* hard-coded to 8 byte */
+};
+
+struct vxlan_metadata {
+	u32     gbp;
+};
+
+SEC("gre_set_tunnel")
+int _gre_set_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+	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) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("gre_get_tunnel")
+int _gre_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	char fmt[] = "key %d remote ip 0x%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt), key.tunnel_id, key.remote_ipv4);
+	return TC_ACT_OK;
+}
+
+SEC("vxlan_set_tunnel")
+int _vxlan_set_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	struct vxlan_metadata md;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+	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) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	md.gbp = 0x800FF; /* Set VXLAN Group Policy extension */
+	ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("vxlan_get_tunnel")
+int _vxlan_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	struct vxlan_metadata md;
+	char fmt[] = "key %d remote ip 0x%x vxlan gbp 0x%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_get_tunnel_opt(skb, &md, sizeof(md));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			key.tunnel_id, key.remote_ipv4, md.gbp);
+
+	return TC_ACT_OK;
+}
+
+SEC("geneve_set_tunnel")
+int _geneve_set_tunnel(struct __sk_buff *skb)
+{
+	int ret, ret2;
+	struct bpf_tunnel_key key;
+	struct geneve_opt gopt;
+
+	__builtin_memset(&key, 0x0, sizeof(key));
+	key.remote_ipv4 = 0xac100164; /* 172.16.1.100 */
+	key.tunnel_id = 2;
+	key.tunnel_tos = 0;
+	key.tunnel_ttl = 64;
+
+	__builtin_memset(&gopt, 0x0, sizeof(gopt));
+	gopt.opt_class = 0x102; /* Open Virtual Networking (OVN) */
+	gopt.type = 0x08;
+	gopt.r1 = 1;
+	gopt.r2 = 0;
+	gopt.r3 = 1;
+	gopt.length = 2; /* 4-byte multiple */
+	*(int *) &gopt.opt_data = 0xdeadbeef;
+
+	ret = bpf_skb_set_tunnel_key(skb, &key, sizeof(key), BPF_F_ZERO_CSUM_TX);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_set_tunnel_opt(skb, &gopt, sizeof(gopt));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("geneve_get_tunnel")
+int _geneve_get_tunnel(struct __sk_buff *skb)
+{
+	int ret;
+	struct bpf_tunnel_key key;
+	struct geneve_opt gopt;
+	char fmt[] = "key %d remote ip 0x%x geneve class 0x%x\n";
+
+	ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	ret = bpf_skb_get_tunnel_opt(skb, &gopt, sizeof(gopt));
+	if (ret < 0) {
+		ERROR(ret);
+		return TC_ACT_SHOT;
+	}
+
+	bpf_trace_printk(fmt, sizeof(fmt),
+			key.tunnel_id, key.remote_ipv4, gopt.opt_class);
+	return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";