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+/**
+ * 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