/* SPDX-License-Identifier: GPL-2.0 */ /* * Example wrapper around BPF macros. * * Copyright (c) 2012 The Chromium OS Authors <[email protected]> * Author: Will Drewry <[email protected]> * * The code may be used by anyone for any purpose, * and can serve as a starting point for developing * applications using prctl(PR_SET_SECCOMP, 2, ...). * * No guarantees are provided with respect to the correctness * or functionality of this code. */ #ifndef __BPF_HELPER_H__ #define __BPF_HELPER_H__ #include <asm/bitsperlong.h> /* for __BITS_PER_LONG */ #include <endian.h> #include <linux/filter.h> #include <linux/seccomp.h> /* for seccomp_data */ #include <linux/types.h> #include <linux/unistd.h> #include <stddef.h> #define BPF_LABELS_MAX … struct bpf_labels { … }; int bpf_resolve_jumps(struct bpf_labels *labels, struct sock_filter *filter, size_t count); __u32 seccomp_bpf_label(struct bpf_labels *labels, const char *label); void seccomp_bpf_print(struct sock_filter *filter, size_t count); #define JUMP_JT … #define JUMP_JF … #define LABEL_JT … #define LABEL_JF … #define ALLOW … #define DENY … #define JUMP(labels, label) … #define LABEL(labels, label) … #define SYSCALL(nr, jt) … /* Lame, but just an example */ #define FIND_LABEL(labels, label) … #define EXPAND(...) … /* Ensure that we load the logically correct offset. */ #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ #define LO_ARG(idx) … #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ #define LO_ARG … #else #error "Unknown endianness" #endif /* Map all width-sensitive operations */ #if __BITS_PER_LONG == 32 #define JEQ … #define JNE … #define JGT … #define JLT … #define JGE … #define JLE … #define JA … #define ARG … #elif __BITS_PER_LONG == 64 /* Ensure that we load the logically correct offset. */ #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ #define ENDIAN(_lo, _hi) … #define HI_ARG(idx) … #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ #define ENDIAN … #define HI_ARG … #endif arg64; #define JEQ(x, jt) … #define JGT(x, jt) … #define JGE(x, jt) … #define JNE(x, jt) … #define JLT(x, jt) … #define JLE(x, jt) … #define JA(x, jt) … #define ARG(i) … #else #error __BITS_PER_LONG value unusable. #endif /* Loads the arg into A */ #define ARG_32(idx) … /* Loads lo into M[0] and hi into M[1] and A */ #define ARG_64(idx) … #define JEQ32(value, jt) … #define JNE32(value, jt) … #define JA32(value, jt) … #define JGE32(value, jt) … #define JGT32(value, jt) … #define JLE32(value, jt) … #define JLT32(value, jt) … /* * All the JXX64 checks assume lo is saved in M[0] and hi is saved in both * A and M[1]. This invariant is kept by restoring A if necessary. */ #define JEQ64(lo, hi, jt) … #define JNE64(lo, hi, jt) … #define JA64(lo, hi, jt) … #define JGE64(lo, hi, jt) … #define JGT64(lo, hi, jt) … #define JLE64(lo, hi, jt) … #define JLT64(lo, hi, jt) … #define LOAD_SYSCALL_NR … #endif /* __BPF_HELPER_H__ */
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