[PATCH bpf-next v1 03/13] bpf: lsm: Introduce types for eBPF based LSM

[KP Singh]

From: KP Singh <kpsingh at google.com>

A new eBPF program type BPF_PROG_TYPE_LSM with an
expected attach type of BPF_LSM_MAC. An -EINVAL error is returned if an
attachment is currently requested.

Signed-off-by: KP Singh <kpsingh at google.com>
---
 include/linux/bpf_types.h      |  4 ++++
 include/uapi/linux/bpf.h       |  2 ++
 kernel/bpf/syscall.c           |  6 ++++++
 security/bpf/Makefile          |  2 +-
 security/bpf/ops.c             | 14 ++++++++++++++
 tools/include/uapi/linux/bpf.h |  2 ++
 6 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 security/bpf/ops.c

diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index 93740b3614d7..5f48161529b4 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -65,6 +65,10 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_LIRC_MODE2, lirc_mode2,
 BPF_PROG_TYPE(BPF_PROG_TYPE_SK_REUSEPORT, sk_reuseport,
 	      struct sk_reuseport_md, struct sk_reuseport_kern)
 #endif
+#ifdef CONFIG_SECURITY_BPF
+BPF_PROG_TYPE(BPF_PROG_TYPE_LSM, lsm,
+	       void *, void *)
+#endif
 
 BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY, array_map_ops)
 BPF_MAP_TYPE(BPF_MAP_TYPE_PERCPU_ARRAY, percpu_array_map_ops)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index dbbcf0b02970..fc64ae865526 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -174,6 +174,7 @@ enum bpf_prog_type {
 	BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
 	BPF_PROG_TYPE_CGROUP_SOCKOPT,
 	BPF_PROG_TYPE_TRACING,
+	BPF_PROG_TYPE_LSM,
 };
 
 enum bpf_attach_type {
@@ -203,6 +204,7 @@ enum bpf_attach_type {
 	BPF_TRACE_RAW_TP,
 	BPF_TRACE_FENTRY,
 	BPF_TRACE_FEXIT,
+	BPF_LSM_MAC,
 	__MAX_BPF_ATTACH_TYPE
 };
 
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e3461ec59570..5a773fc6f9f5 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2096,6 +2096,9 @@ static int bpf_prog_attach(const union bpf_attr *attr)
 	case BPF_LIRC_MODE2:
 		ptype = BPF_PROG_TYPE_LIRC_MODE2;
 		break;
+	case BPF_LSM_MAC:
+		ptype = BPF_PROG_TYPE_LSM;
+		break;
 	case BPF_FLOW_DISSECTOR:
 		ptype = BPF_PROG_TYPE_FLOW_DISSECTOR;
 		break;
@@ -2127,6 +2130,9 @@ static int bpf_prog_attach(const union bpf_attr *attr)
 	case BPF_PROG_TYPE_LIRC_MODE2:
 		ret = lirc_prog_attach(attr, prog);
 		break;
+	case BPF_PROG_TYPE_LSM:
+		ret = -EINVAL;
+		break;
 	case BPF_PROG_TYPE_FLOW_DISSECTOR:
 		ret = skb_flow_dissector_bpf_prog_attach(attr, prog);
 		break;
diff --git a/security/bpf/Makefile b/security/bpf/Makefile
index 26a0ab6f99b7..c78a8a056e7e 100644
--- a/security/bpf/Makefile
+++ b/security/bpf/Makefile
@@ -2,4 +2,4 @@
 #
 # Copyright 2019 Google LLC.
 
-obj-$(CONFIG_SECURITY_BPF) := lsm.o
+obj-$(CONFIG_SECURITY_BPF) := lsm.o ops.o
diff --git a/security/bpf/ops.c b/security/bpf/ops.c
new file mode 100644
index 000000000000..2fa3ebdf598d
--- /dev/null
+++ b/security/bpf/ops.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright 2019 Google LLC.
+ */
+
+#include <linux/filter.h>
+#include <linux/bpf.h>
+
+const struct bpf_prog_ops lsm_prog_ops = {
+};
+
+const struct bpf_verifier_ops lsm_verifier_ops = {
+};
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index dbbcf0b02970..fc64ae865526 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -174,6 +174,7 @@ enum bpf_prog_type {
 	BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
 	BPF_PROG_TYPE_CGROUP_SOCKOPT,
 	BPF_PROG_TYPE_TRACING,
+	BPF_PROG_TYPE_LSM,
 };
 
 enum bpf_attach_type {
@@ -203,6 +204,7 @@ enum bpf_attach_type {
 	BPF_TRACE_RAW_TP,
 	BPF_TRACE_FENTRY,
 	BPF_TRACE_FEXIT,
+	BPF_LSM_MAC,
 	__MAX_BPF_ATTACH_TYPE
 };
 
-- 
2.20.1