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103 lines
3.2 KiB
103 lines
3.2 KiB
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of version 2 of the GNU General Public |
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* License as published by the Free Software Foundation. |
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*/ |
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#ifndef _LINUX_BPF_VERIFIER_H |
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#define _LINUX_BPF_VERIFIER_H 1 |
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#include <linux/bpf.h> /* for enum bpf_reg_type */ |
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#include <linux/filter.h> /* for MAX_BPF_STACK */ |
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/* Just some arbitrary values so we can safely do math without overflowing and |
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* are obviously wrong for any sort of memory access. |
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*/ |
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#define BPF_REGISTER_MAX_RANGE (1024 * 1024 * 1024) |
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#define BPF_REGISTER_MIN_RANGE -1 |
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struct bpf_reg_state { |
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enum bpf_reg_type type; |
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union { |
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/* valid when type == CONST_IMM | PTR_TO_STACK | UNKNOWN_VALUE */ |
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s64 imm; |
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/* valid when type == PTR_TO_PACKET* */ |
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struct { |
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u16 off; |
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u16 range; |
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}; |
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/* valid when type == CONST_PTR_TO_MAP | PTR_TO_MAP_VALUE | |
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* PTR_TO_MAP_VALUE_OR_NULL |
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*/ |
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struct bpf_map *map_ptr; |
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}; |
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u32 id; |
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/* Used to determine if any memory access using this register will |
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* result in a bad access. These two fields must be last. |
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* See states_equal() |
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*/ |
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s64 min_value; |
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u64 max_value; |
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}; |
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enum bpf_stack_slot_type { |
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STACK_INVALID, /* nothing was stored in this stack slot */ |
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STACK_SPILL, /* register spilled into stack */ |
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STACK_MISC /* BPF program wrote some data into this slot */ |
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}; |
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#define BPF_REG_SIZE 8 /* size of eBPF register in bytes */ |
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/* state of the program: |
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* type of all registers and stack info |
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*/ |
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struct bpf_verifier_state { |
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struct bpf_reg_state regs[MAX_BPF_REG]; |
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u8 stack_slot_type[MAX_BPF_STACK]; |
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struct bpf_reg_state spilled_regs[MAX_BPF_STACK / BPF_REG_SIZE]; |
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}; |
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/* linked list of verifier states used to prune search */ |
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struct bpf_verifier_state_list { |
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struct bpf_verifier_state state; |
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struct bpf_verifier_state_list *next; |
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}; |
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struct bpf_insn_aux_data { |
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enum bpf_reg_type ptr_type; /* pointer type for load/store insns */ |
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}; |
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#define MAX_USED_MAPS 64 /* max number of maps accessed by one eBPF program */ |
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struct bpf_verifier_env; |
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struct bpf_ext_analyzer_ops { |
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int (*insn_hook)(struct bpf_verifier_env *env, |
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int insn_idx, int prev_insn_idx); |
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}; |
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/* single container for all structs |
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* one verifier_env per bpf_check() call |
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*/ |
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struct bpf_verifier_env { |
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struct bpf_prog *prog; /* eBPF program being verified */ |
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struct bpf_verifier_stack_elem *head; /* stack of verifier states to be processed */ |
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int stack_size; /* number of states to be processed */ |
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struct bpf_verifier_state cur_state; /* current verifier state */ |
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struct bpf_verifier_state_list **explored_states; /* search pruning optimization */ |
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const struct bpf_ext_analyzer_ops *analyzer_ops; /* external analyzer ops */ |
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void *analyzer_priv; /* pointer to external analyzer's private data */ |
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struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */ |
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u32 used_map_cnt; /* number of used maps */ |
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u32 id_gen; /* used to generate unique reg IDs */ |
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bool allow_ptr_leaks; |
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bool seen_direct_write; |
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bool varlen_map_value_access; |
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struct bpf_insn_aux_data *insn_aux_data; /* array of per-insn state */ |
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}; |
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int bpf_analyzer(struct bpf_prog *prog, const struct bpf_ext_analyzer_ops *ops, |
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void *priv); |
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#endif /* _LINUX_BPF_VERIFIER_H */
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