bpf, cgroup: implement eBPF-based device controller for cgroup v2
Cgroup v2 lacks the device controller, provided by cgroup v1.
This patch adds a new eBPF program type, which in combination
of previously added ability to attach multiple eBPF programs
to a cgroup, will provide a similar functionality, but with some
additional flexibility.
This patch introduces a BPF_PROG_TYPE_CGROUP_DEVICE program type.
A program takes major and minor device numbers, device type
(block/character) and access type (mknod/read/write) as parameters
and returns an integer which defines if the operation should be
allowed or terminated with -EPERM.
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index e92f62c..b280f37 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -131,6 +131,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_LWT_XMIT,
BPF_PROG_TYPE_SOCK_OPS,
BPF_PROG_TYPE_SK_SKB,
+ BPF_PROG_TYPE_CGROUP_DEVICE,
};
enum bpf_attach_type {
@@ -140,6 +141,7 @@ enum bpf_attach_type {
BPF_CGROUP_SOCK_OPS,
BPF_SK_SKB_STREAM_PARSER,
BPF_SK_SKB_STREAM_VERDICT,
+ BPF_CGROUP_DEVICE,
__MAX_BPF_ATTACH_TYPE
};
@@ -990,4 +992,17 @@ struct bpf_perf_event_value {
__u64 running;
};
+#define BPF_DEVCG_ACC_MKNOD (1ULL << 0)
+#define BPF_DEVCG_ACC_READ (1ULL << 1)
+#define BPF_DEVCG_ACC_WRITE (1ULL << 2)
+
+#define BPF_DEVCG_DEV_BLOCK (1ULL << 0)
+#define BPF_DEVCG_DEV_CHAR (1ULL << 1)
+
+struct bpf_cgroup_dev_ctx {
+ __u32 access_type; /* (access << 16) | type */
+ __u32 major;
+ __u32 minor;
+};
+
#endif /* _UAPI__LINUX_BPF_H__ */