blob: 05b2b9ef10c6aa38b516d03684900117049dab1f [file] [log] [blame]
#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");