From a0e0018c9a7ef5ce7f6d2c3ae16aecbbd16a8f67 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 4 May 2024 16:18:53 +0200 Subject: Adding upstream version 6.1.0. Signed-off-by: Daniel Baumann --- examples/bpf/bpf_shared.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 examples/bpf/bpf_shared.c (limited to 'examples/bpf/bpf_shared.c') diff --git a/examples/bpf/bpf_shared.c b/examples/bpf/bpf_shared.c new file mode 100644 index 0000000..99a332f --- /dev/null +++ b/examples/bpf/bpf_shared.c @@ -0,0 +1,53 @@ +#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 { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(key_size, sizeof(uint32_t)); + __uint(value_size, sizeof(uint32_t)); + __uint(max_entries, 1); + __uint(pinning, LIBBPF_PIN_BY_NAME); /* or LIBBPF_PIN_NONE */ +} map_sh __section(".maps"); + +__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"); -- cgit v1.2.3