/**
* BPF Language Definitions
*
* Copyright (c) 2012 Red Hat <pmoore@redhat.com>
* Author: Paul Moore <paul@paul-moore.com>
*/
/*
* This library is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License as
* published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, see <http://www.gnu.org/licenses>.
*/
#ifndef _BPF_H
#define _BPF_H
#include <inttypes.h>
#include <stddef.h>
/* most of these structures and values are designed to match the Linux Kernel's
* BPF interface (see /usr/include/linux/{filter,seccomp}.h), but we define our
* own here so that we can function independent of the host OS */
/* XXX - need to verify these values */
#define BPF_SCRATCH_SIZE 6
/**
* Syscall record data format used by seccomp
*/
#define BPF_SYS_ARG_MAX 6
struct seccomp_data {
int32_t nr;
uint32_t arch;
uint64_t instruction_pointer;
uint64_t args[BPF_SYS_ARG_MAX];
};
#define BPF_SYSCALL_MAX (sizeof(struct seccomp_data))
/**
* BPF instruction format
*/
struct sock_filter {
uint16_t code;
uint8_t jt;
uint8_t jf;
uint32_t k;
} __attribute__ ((packed));
typedef struct sock_filter bpf_instr_raw;
/* seccomp return masks */
#define SECCOMP_RET_ACTION_FULL 0xffff0000U
#define SECCOMP_RET_ACTION 0x7fff0000U
#define SECCOMP_RET_DATA 0x0000ffffU
/* seccomp action values */
#define SECCOMP_RET_KILL_PROCESS 0x80000000U
#define SECCOMP_RET_KILL_THREAD 0x00000000U
#define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
#define SECCOMP_RET_TRAP 0x00030000U
#define SECCOMP_RET_ERRNO 0x00050000U
#define SECCOMP_RET_TRACE 0x7ff00000U
#define SECCOMP_RET_LOG 0x7ffc0000U
#define SECCOMP_RET_ALLOW 0x7fff0000U
/* bpf command classes */
#define BPF_CLASS(code) ((code) & 0x07)
#define BPF_LD 0x00
#define BPF_LDX 0x01
#define BPF_ST 0x02
#define BPF_STX 0x03
#define BPF_ALU 0x04
#define BPF_JMP 0x05
#define BPF_RET 0x06
#define BPF_MISC 0x07
/* BPF_LD and BPF_LDX */
#define BPF_SIZE(code) ((code) & 0x18)
#define BPF_W 0x00
#define BPF_H 0x08
#define BPF_B 0x10
#define BPF_MODE(code) ((code) & 0xe0)
#define BPF_IMM 0x00
#define BPF_ABS 0x20
#define BPF_IND 0x40
#define BPF_MEM 0x60
#define BPF_LEN 0x80
#define BPF_MSH 0xa0
#define BPF_OP(code) ((code) & 0xf0)
/* BPF_ALU */
#define BPF_ADD 0x00
#define BPF_SUB 0x10
#define BPF_MUL 0x20
#define BPF_DIV 0x30
#define BPF_OR 0x40
#define BPF_AND 0x50
#define BPF_LSH 0x60
#define BPF_RSH 0x70
#define BPF_NEG 0x80
#define BPF_MOD 0x90
#define BPF_XOR 0xa0
/* BPF_JMP */
#define BPF_JA 0x00
#define BPF_JEQ 0x10
#define BPF_JGT 0x20
#define BPF_JGE 0x30
#define BPF_JSET 0x40
#define BPF_SRC(code) ((code) & 0x08)
#define BPF_K 0x00
#define BPF_X 0x08
/* BPF_RET (BPF_K and BPF_X also apply) */
#define BPF_RVAL(code) ((code) & 0x18)
#define BPF_A 0x10
/* BPF_MISC */
#define BPF_MISCOP(code) ((code) & 0xf8)
#define BPF_TAX 0x00
#define BPF_TXA 0x80
#endif