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Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_skb_cgroup_id_kern.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_skb_cgroup_id_kern.c b/tools/testing/selftests/bpf/progs/test_skb_cgroup_id_kern.c new file mode 100644 index 000000000..552f20906 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_skb_cgroup_id_kern.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include <linux/bpf.h> +#include <linux/pkt_cls.h> + +#include <string.h> + +#include <bpf/bpf_helpers.h> + +#define NUM_CGROUP_LEVELS 4 + +struct bpf_map_def SEC("maps") cgroup_ids = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(__u32), + .value_size = sizeof(__u64), + .max_entries = NUM_CGROUP_LEVELS, +}; + +static __always_inline void log_nth_level(struct __sk_buff *skb, __u32 level) +{ + __u64 id; + + /* [1] &level passed to external function that may change it, it's + * incompatible with loop unroll. + */ + id = bpf_skb_ancestor_cgroup_id(skb, level); + bpf_map_update_elem(&cgroup_ids, &level, &id, 0); +} + +SEC("cgroup_id_logger") +int log_cgroup_id(struct __sk_buff *skb) +{ + /* Loop unroll can't be used here due to [1]. Unrolling manually. + * Number of calls should be in sync with NUM_CGROUP_LEVELS. + */ + log_nth_level(skb, 0); + log_nth_level(skb, 1); + log_nth_level(skb, 2); + log_nth_level(skb, 3); + + return TC_ACT_OK; +} + +int _version SEC("version") = 1; + +char _license[] SEC("license") = "GPL"; |