Initial import

1 files changed, 164 insertions, 0 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
new file mode 100644
index 000000000..d5cda0671
--- /dev/null
+++ b/include/linux/bpf.h
@@ -0,0 +1,164 @@
+/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#ifndef _LINUX_BPF_H
+#define _LINUX_BPF_H 1
+
+#include <uapi/linux/bpf.h>
+#include <linux/workqueue.h>
+#include <linux/file.h>
+
+struct bpf_map;
+
+/* map is generic key/value storage optionally accesible by eBPF programs */
+struct bpf_map_ops {
+	/* funcs callable from userspace (via syscall) */
+	struct bpf_map *(*map_alloc)(union bpf_attr *attr);
+	void (*map_free)(struct bpf_map *);
+	int (*map_get_next_key)(struct bpf_map *map, void *key, void *next_key);
+
+	/* funcs callable from userspace and from eBPF programs */
+	void *(*map_lookup_elem)(struct bpf_map *map, void *key);
+	int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags);
+	int (*map_delete_elem)(struct bpf_map *map, void *key);
+};
+
+struct bpf_map {
+	atomic_t refcnt;
+	enum bpf_map_type map_type;
+	u32 key_size;
+	u32 value_size;
+	u32 max_entries;
+	const struct bpf_map_ops *ops;
+	struct work_struct work;
+};
+
+struct bpf_map_type_list {
+	struct list_head list_node;
+	const struct bpf_map_ops *ops;
+	enum bpf_map_type type;
+};
+
+/* function argument constraints */
+enum bpf_arg_type {
+	ARG_DONTCARE = 0,	/* unused argument in helper function */
+
+	/* the following constraints used to prototype
+	 * bpf_map_lookup/update/delete_elem() functions
+	 */
+	ARG_CONST_MAP_PTR,	/* const argument used as pointer to bpf_map */
+	ARG_PTR_TO_MAP_KEY,	/* pointer to stack used as map key */
+	ARG_PTR_TO_MAP_VALUE,	/* pointer to stack used as map value */
+
+	/* the following constraints used to prototype bpf_memcmp() and other
+	 * functions that access data on eBPF program stack
+	 */
+	ARG_PTR_TO_STACK,	/* any pointer to eBPF program stack */
+	ARG_CONST_STACK_SIZE,	/* number of bytes accessed from stack */
+
+	ARG_PTR_TO_CTX,		/* pointer to context */
+	ARG_ANYTHING,		/* any (initialized) argument is ok */
+};
+
+/* type of values returned from helper functions */
+enum bpf_return_type {
+	RET_INTEGER,			/* function returns integer */
+	RET_VOID,			/* function doesn't return anything */
+	RET_PTR_TO_MAP_VALUE_OR_NULL,	/* returns a pointer to map elem value or NULL */
+};
+
+/* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
+ * to in-kernel helper functions and for adjusting imm32 field in BPF_CALL
+ * instructions after verifying
+ */
+struct bpf_func_proto {
+	u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
+	bool gpl_only;
+	enum bpf_return_type ret_type;
+	enum bpf_arg_type arg1_type;
+	enum bpf_arg_type arg2_type;
+	enum bpf_arg_type arg3_type;
+	enum bpf_arg_type arg4_type;
+	enum bpf_arg_type arg5_type;
+};
+
+/* bpf_context is intentionally undefined structure. Pointer to bpf_context is
+ * the first argument to eBPF programs.
+ * For socket filters: 'struct bpf_context *' == 'struct sk_buff *'
+ */
+struct bpf_context;
+
+enum bpf_access_type {
+	BPF_READ = 1,
+	BPF_WRITE = 2
+};
+
+struct bpf_verifier_ops {
+	/* return eBPF function prototype for verification */
+	const struct bpf_func_proto *(*get_func_proto)(enum bpf_func_id func_id);
+
+	/* return true if 'size' wide access at offset 'off' within bpf_context
+	 * with 'type' (read or write) is allowed
+	 */
+	bool (*is_valid_access)(int off, int size, enum bpf_access_type type);
+
+	u32 (*convert_ctx_access)(int dst_reg, int src_reg, int ctx_off,
+				  struct bpf_insn *insn);
+};
+
+struct bpf_prog_type_list {
+	struct list_head list_node;
+	const struct bpf_verifier_ops *ops;
+	enum bpf_prog_type type;
+};
+
+struct bpf_prog;
+
+struct bpf_prog_aux {
+	atomic_t refcnt;
+	u32 used_map_cnt;
+	const struct bpf_verifier_ops *ops;
+	struct bpf_map **used_maps;
+	struct bpf_prog *prog;
+	struct work_struct work;
+};
+
+#ifdef CONFIG_BPF_SYSCALL
+void bpf_register_prog_type(struct bpf_prog_type_list *tl);
+void bpf_register_map_type(struct bpf_map_type_list *tl);
+
+struct bpf_prog *bpf_prog_get(u32 ufd);
+void bpf_prog_put(struct bpf_prog *prog);
+
+struct bpf_map *bpf_map_get(struct fd f);
+void bpf_map_put(struct bpf_map *map);
+
+/* verify correctness of eBPF program */
+int bpf_check(struct bpf_prog **fp, union bpf_attr *attr);
+#else
+static inline void bpf_register_prog_type(struct bpf_prog_type_list *tl)
+{
+}
+
+static inline struct bpf_prog *bpf_prog_get(u32 ufd)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline void bpf_prog_put(struct bpf_prog *prog)
+{
+}
+#endif /* CONFIG_BPF_SYSCALL */
+
+/* verifier prototypes for helper functions called from eBPF programs */
+extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
+extern const struct bpf_func_proto bpf_map_update_elem_proto;
+extern const struct bpf_func_proto bpf_map_delete_elem_proto;
+
+extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
+extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
+
+#endif /* _LINUX_BPF_H */