Bundle libseccomp 2.3.1

[linux-seccomp.git] / libseccomp / tools / bpf.h

diff --git a/libseccomp/tools/bpf.h b/libseccomp/tools/bpf.h
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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     0x7fff0000U
+#define SECCOMP_RET_DATA       0x0000ffffU
+
+/* seccomp action values */
+#define SECCOMP_RET_KILL       0x00000000U
+#define SECCOMP_RET_TRAP       0x00030000U
+#define SECCOMP_RET_ERRNO      0x00050000U
+#define SECCOMP_RET_TRACE      0x7ff00000U
+#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
+/* 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