From 58e2af8b3a6b587e4ac8414343581da4349d3c0f Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 21 Sep 2016 11:43:57 +0100 Subject: bpf: expose internal verfier structures Move verifier's internal structures to a header file and prefix their names with bpf_ to avoid potential namespace conflicts. Those structures will soon be used by external analyzers. Signed-off-by: Jakub Kicinski Acked-by: Alexei Starovoitov Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- include/linux/bpf_verifier.h | 79 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 include/linux/bpf_verifier.h (limited to 'include/linux/bpf_verifier.h') diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h new file mode 100644 index 000000000000..9457a22fc6e0 --- /dev/null +++ b/include/linux/bpf_verifier.h @@ -0,0 +1,79 @@ +/* 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_VERIFIER_H +#define _LINUX_BPF_VERIFIER_H 1 + +#include /* for enum bpf_reg_type */ +#include /* for MAX_BPF_STACK */ + +struct bpf_reg_state { + enum bpf_reg_type type; + union { + /* valid when type == CONST_IMM | PTR_TO_STACK | UNKNOWN_VALUE */ + s64 imm; + + /* valid when type == PTR_TO_PACKET* */ + struct { + u32 id; + u16 off; + u16 range; + }; + + /* valid when type == CONST_PTR_TO_MAP | PTR_TO_MAP_VALUE | + * PTR_TO_MAP_VALUE_OR_NULL + */ + struct bpf_map *map_ptr; + }; +}; + +enum bpf_stack_slot_type { + STACK_INVALID, /* nothing was stored in this stack slot */ + STACK_SPILL, /* register spilled into stack */ + STACK_MISC /* BPF program wrote some data into this slot */ +}; + +#define BPF_REG_SIZE 8 /* size of eBPF register in bytes */ + +/* state of the program: + * type of all registers and stack info + */ +struct bpf_verifier_state { + struct bpf_reg_state regs[MAX_BPF_REG]; + u8 stack_slot_type[MAX_BPF_STACK]; + struct bpf_reg_state spilled_regs[MAX_BPF_STACK / BPF_REG_SIZE]; +}; + +/* linked list of verifier states used to prune search */ +struct bpf_verifier_state_list { + struct bpf_verifier_state state; + struct bpf_verifier_state_list *next; +}; + +struct bpf_insn_aux_data { + enum bpf_reg_type ptr_type; /* pointer type for load/store insns */ +}; + +#define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */ + +/* single container for all structs + * one verifier_env per bpf_check() call + */ +struct bpf_verifier_env { + struct bpf_prog *prog; /* eBPF program being verified */ + struct bpf_verifier_stack_elem *head; /* stack of verifier states to be processed */ + int stack_size; /* number of states to be processed */ + struct bpf_verifier_state cur_state; /* current verifier state */ + struct bpf_verifier_state_list **explored_states; /* search pruning optimization */ + struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */ + u32 used_map_cnt; /* number of used maps */ + u32 id_gen; /* used to generate unique reg IDs */ + bool allow_ptr_leaks; + bool seen_direct_write; + struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */ +}; + +#endif /* _LINUX_BPF_VERIFIER_H */ -- cgit v1.2.3