#include "../../../include/bpf_api.h"

/* Minimal, stand-alone toy map pinning example:

 *

 * clang -target bpf -O2 [...] -o bpf_shared.o -c bpf_shared.c

 * tc filter add dev foo parent 1: bpf obj bpf_shared.o sec egress

 * tc filter add dev foo parent ffff: bpf obj bpf_shared.o sec ingress

 *

 * Both classifier will share the very same map instance in this example,

 * so map content can be accessed from ingress *and* egress side!

 *

 * This example has a pinning of PIN_OBJECT_NS, so it's private and

 * thus shared among various program sections within the object.

 *

 * A setting of PIN_GLOBAL_NS would place it into a global namespace,

 * so that it can be shared among different object files. A setting

 * of PIN_NONE (= 0) means no sharing, so each tc invocation a new map

 * instance is being created.

 */

struct bpf_elf_map __section_maps map_sh = {

	.type		= BPF_MAP_TYPE_ARRAY,

	.size_key	= sizeof(uint32_t),

	.size_value	= sizeof(uint32_t),

	.pinning	= PIN_OBJECT_NS, /* or PIN_GLOBAL_NS, or PIN_NONE */

	.max_elem	= 1,

};

__section("egress")

int emain(struct __sk_buff *skb)

{

	int key = 0, *val;

	val = map_lookup_elem(&map_sh, &key);

	if (val)

		lock_xadd(val, 1);

	return BPF_H_DEFAULT;

}

__section("ingress")

int imain(struct __sk_buff *skb)

{

	int key = 0, *val;

	val = map_lookup_elem(&map_sh, &key);

	if (val)

		printt("map val: %d\n", *val);

	return BPF_H_DEFAULT;

}

BPF_LICENSE("GPL");