diff options
author | Lennart Poettering <lennart@poettering.net> | 2012-07-17 04:17:53 +0200 |
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committer | Lennart Poettering <lennart@poettering.net> | 2012-07-17 04:17:53 +0200 |
commit | 8351ceaea9480d9c2979aa2ff0f4982cfdfef58d (patch) | |
tree | fc1f94e5a17679960774da386a54d145255e4ef1 /src/shared/linux/seccomp-bpf.h | |
parent | cd96b3b86abb4a88cac2722bdfb6e5d4413f6831 (diff) |
execute: support syscall filtering using seccomp filters
Diffstat (limited to 'src/shared/linux/seccomp-bpf.h')
-rw-r--r-- | src/shared/linux/seccomp-bpf.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/src/shared/linux/seccomp-bpf.h b/src/shared/linux/seccomp-bpf.h new file mode 100644 index 0000000000..1e3d136739 --- /dev/null +++ b/src/shared/linux/seccomp-bpf.h @@ -0,0 +1,76 @@ +/* + * seccomp example for x86 (32-bit and 64-bit) with BPF macros + * + * Copyright (c) 2012 The Chromium OS Authors <chromium-os-dev@chromium.org> + * Authors: + * Will Drewry <wad@chromium.org> + * Kees Cook <keescook@chromium.org> + * + * The code may be used by anyone for any purpose, and can serve as a + * starting point for developing applications using mode 2 seccomp. + */ +#ifndef _SECCOMP_BPF_H_ +#define _SECCOMP_BPF_H_ + +#include <stdio.h> +#include <stddef.h> +#include <stdlib.h> +#include <errno.h> +#include <signal.h> +#include <string.h> +#include <unistd.h> + +#include <sys/prctl.h> + +#include <linux/unistd.h> +#include <linux/audit.h> +#include <linux/filter.h> +#include <linux/seccomp.h> + +#ifndef SECCOMP_MODE_FILTER +# define SECCOMP_MODE_FILTER 2 /* uses user-supplied filter. */ +# define SECCOMP_RET_KILL 0x00000000U /* kill the task immediately */ +# define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */ +# define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */ +struct seccomp_data { + int nr; + __u32 arch; + __u64 instruction_pointer; + __u64 args[6]; +}; +#endif +#ifndef SYS_SECCOMP +# define SYS_SECCOMP 1 +#endif + +#define syscall_nr (offsetof(struct seccomp_data, nr)) +#define arch_nr (offsetof(struct seccomp_data, arch)) + +#if defined(__i386__) +# define REG_SYSCALL REG_EAX +# define ARCH_NR AUDIT_ARCH_I386 +#elif defined(__x86_64__) +# define REG_SYSCALL REG_RAX +# define ARCH_NR AUDIT_ARCH_X86_64 +#else +# warning "Platform does not support seccomp filter yet" +# define REG_SYSCALL 0 +# define ARCH_NR 0 +#endif + +#define VALIDATE_ARCHITECTURE \ + BPF_STMT(BPF_LD+BPF_W+BPF_ABS, arch_nr), \ + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, ARCH_NR, 1, 0), \ + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_KILL) + +#define EXAMINE_SYSCALL \ + BPF_STMT(BPF_LD+BPF_W+BPF_ABS, syscall_nr) + +#define ALLOW_SYSCALL(name) \ + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, __NR_##name, 0, 1), \ + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW) + +#define _KILL_PROCESS \ + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_KILL) + +#endif /* _SECCOMP_BPF_H_ */ |