Merge "bpf_headers: rename KernelVersion.h to KernelUtils.h" into udc-dev
diff --git a/common/native/bpf_headers/include/bpf/bpf_helpers.h b/common/native/bpf_headers/include/bpf/bpf_helpers.h
index 4939483..20b5bf1 100644
--- a/common/native/bpf_headers/include/bpf/bpf_helpers.h
+++ b/common/native/bpf_headers/include/bpf/bpf_helpers.h
@@ -103,6 +103,30 @@
#define KVER(a, b, c) (((a) << 24) + ((b) << 16) + (c))
#define KVER_INF 0xFFFFFFFFu
+/*
+ * BPFFS (ie. /sys/fs/bpf) labelling is as follows:
+ * subdirectory selinux context mainline usecase / usable by
+ * / fs_bpf no [*] core operating system (ie. platform)
+ * /loader fs_bpf_loader no, U+ (as yet unused)
+ * /net_private fs_bpf_net_private yes, T+ network_stack
+ * /net_shared fs_bpf_net_shared yes, T+ network_stack & system_server
+ * /netd_readonly fs_bpf_netd_readonly yes, T+ network_stack & system_server & r/o to netd
+ * /netd_shared fs_bpf_netd_shared yes, T+ network_stack & system_server & netd [**]
+ * /tethering fs_bpf_tethering yes, S+ network_stack
+ * /vendor fs_bpf_vendor no, T+ vendor
+ *
+ * [*] initial support for bpf was added back in P,
+ * but things worked differently back then with no bpfloader,
+ * and instead netd doing stuff by hand,
+ * bpfloader with pinning into /sys/fs/bpf was (I believe) added in Q
+ * (and was definitely there in R).
+ *
+ * [**] additionally bpf programs are accessible to netutils_wrapper
+ * for use by iptables xt_bpf extensions.
+ *
+ * See cs/p:aosp-master%20-file:prebuilts/%20file:genfs_contexts%20"genfscon%20bpf"
+ */
+
/* generic functions */
/*