diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2020-03-27 16:58:54 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-03-27 19:40:39 -0700 |
| commit | 0f09abd105da6c37713d2b253730a86cb45e127a (patch) | |
| tree | 53099c731ea40e72c37abb521564cd08fc6c68e6 /tools/include | |
| parent | 5a52ae4e32a61ad06ef67f0b3123adbdbac4fb83 (diff) | |
bpf: Enable bpf cgroup hooks to retrieve cgroup v2 and ancestor id
Enable the bpf_get_current_cgroup_id() helper for connect(), sendmsg(),
recvmsg() and bind-related hooks in order to retrieve the cgroup v2
context which can then be used as part of the key for BPF map lookups,
for example. Given these hooks operate in process context 'current' is
always valid and pointing to the app that is performing mentioned
syscalls if it's subject to a v2 cgroup. Also with same motivation of
commit 7723628101aa ("bpf: Introduce bpf_skb_ancestor_cgroup_id helper")
enable retrieval of ancestor from current so the cgroup id can be used
for policy lookups which can then forbid connect() / bind(), for example.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/d2a7ef42530ad299e3cbb245e6c12374b72145ef.1585323121.git.daniel@iogearbox.net
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index bd81c4555206..222ba11966e3 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2963,6 +2963,24 @@ union bpf_attr { * instead of sockets. * Return * A 8-byte long opaque number. + * + * u64 bpf_get_current_ancestor_cgroup_id(int ancestor_level) + * Description + * Return id of cgroup v2 that is ancestor of the cgroup associated + * with the current task at the *ancestor_level*. The root cgroup + * is at *ancestor_level* zero and each step down the hierarchy + * increments the level. If *ancestor_level* == level of cgroup + * associated with the current task, then return value will be the + * same as that of **bpf_get_current_cgroup_id**\ (). + * + * The helper is useful to implement policies based on cgroups + * that are upper in hierarchy than immediate cgroup associated + * with the current task. + * + * The format of returned id and helper limitations are same as in + * **bpf_get_current_cgroup_id**\ (). + * Return + * The id is returned or 0 in case the id could not be retrieved. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3087,7 +3105,8 @@ union bpf_attr { FN(read_branch_records), \ FN(get_ns_current_pid_tgid), \ FN(xdp_output), \ - FN(get_netns_cookie), + FN(get_netns_cookie), \ + FN(get_current_ancestor_cgroup_id), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call |