seccomp.h (5990B)
- /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
- #ifndef _LINUX_SECCOMP_H
- #define _LINUX_SECCOMP_H
- #include <linux/types.h>
- /* Valid values for seccomp.mode and prctl(PR_SET_SECCOMP, <mode>) */
- #define SECCOMP_MODE_DISABLED 0 /* seccomp is not in use. */
- #define SECCOMP_MODE_STRICT 1 /* uses hard-coded filter. */
- #define SECCOMP_MODE_FILTER 2 /* uses user-supplied filter. */
- /* Valid operations for seccomp syscall. */
- #define SECCOMP_SET_MODE_STRICT 0
- #define SECCOMP_SET_MODE_FILTER 1
- #define SECCOMP_GET_ACTION_AVAIL 2
- #define SECCOMP_GET_NOTIF_SIZES 3
- /* Valid flags for SECCOMP_SET_MODE_FILTER */
- #define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)
- #define SECCOMP_FILTER_FLAG_LOG (1UL << 1)
- #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)
- #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)
- #define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)
- /* Received notifications wait in killable state (only respond to fatal signals) */
- #define SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV (1UL << 5)
- /*
- * All BPF programs must return a 32-bit value.
- * The bottom 16-bits are for optional return data.
- * The upper 16-bits are ordered from least permissive values to most,
- * as a signed value (so 0x8000000 is negative).
- *
- * The ordering ensures that a min_t() over composed return values always
- * selects the least permissive choice.
- */
- #define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */
- #define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
- #define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
- #define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */
- #define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */
- #define SECCOMP_RET_USER_NOTIF 0x7fc00000U /* notifies userspace */
- #define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */
- #define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */
- #define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
- /* Masks for the return value sections. */
- #define SECCOMP_RET_ACTION_FULL 0xffff0000U
- #define SECCOMP_RET_ACTION 0x7fff0000U
- #define SECCOMP_RET_DATA 0x0000ffffU
- /**
- * struct seccomp_data - the format the BPF program executes over.
- * @nr: the system call number
- * @arch: indicates system call convention as an AUDIT_ARCH_* value
- * as defined in <linux/audit.h>.
- * @instruction_pointer: at the time of the system call.
- * @args: up to 6 system call arguments always stored as 64-bit values
- * regardless of the architecture.
- */
- struct seccomp_data {
- int nr;
- __u32 arch;
- __u64 instruction_pointer;
- __u64 args[6];
- };
- struct seccomp_notif_sizes {
- __u16 seccomp_notif;
- __u16 seccomp_notif_resp;
- __u16 seccomp_data;
- };
- struct seccomp_notif {
- __u64 id;
- __u32 pid;
- __u32 flags;
- struct seccomp_data data;
- };
- /*
- * Valid flags for struct seccomp_notif_resp
- *
- * Note, the SECCOMP_USER_NOTIF_FLAG_CONTINUE flag must be used with caution!
- * If set by the process supervising the syscalls of another process the
- * syscall will continue. This is problematic because of an inherent TOCTOU.
- * An attacker can exploit the time while the supervised process is waiting on
- * a response from the supervising process to rewrite syscall arguments which
- * are passed as pointers of the intercepted syscall.
- * It should be absolutely clear that this means that the seccomp notifier
- * _cannot_ be used to implement a security policy! It should only ever be used
- * in scenarios where a more privileged process supervises the syscalls of a
- * lesser privileged process to get around kernel-enforced security
- * restrictions when the privileged process deems this safe. In other words,
- * in order to continue a syscall the supervising process should be sure that
- * another security mechanism or the kernel itself will sufficiently block
- * syscalls if arguments are rewritten to something unsafe.
- *
- * Similar precautions should be applied when stacking SECCOMP_RET_USER_NOTIF
- * or SECCOMP_RET_TRACE. For SECCOMP_RET_USER_NOTIF filters acting on the
- * same syscall, the most recently added filter takes precedence. This means
- * that the new SECCOMP_RET_USER_NOTIF filter can override any
- * SECCOMP_IOCTL_NOTIF_SEND from earlier filters, essentially allowing all
- * such filtered syscalls to be executed by sending the response
- * SECCOMP_USER_NOTIF_FLAG_CONTINUE. Note that SECCOMP_RET_TRACE can equally
- * be overriden by SECCOMP_USER_NOTIF_FLAG_CONTINUE.
- */
- #define SECCOMP_USER_NOTIF_FLAG_CONTINUE (1UL << 0)
- struct seccomp_notif_resp {
- __u64 id;
- __s64 val;
- __s32 error;
- __u32 flags;
- };
- #define SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP (1UL << 0)
- /* valid flags for seccomp_notif_addfd */
- #define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */
- #define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */
- /**
- * struct seccomp_notif_addfd
- * @id: The ID of the seccomp notification
- * @flags: SECCOMP_ADDFD_FLAG_*
- * @srcfd: The local fd number
- * @newfd: Optional remote FD number if SETFD option is set, otherwise 0.
- * @newfd_flags: The O_* flags the remote FD should have applied
- */
- struct seccomp_notif_addfd {
- __u64 id;
- __u32 flags;
- __u32 srcfd;
- __u32 newfd;
- __u32 newfd_flags;
- };
- #define SECCOMP_IOC_MAGIC '!'
- #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)
- #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)
- #define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)
- #define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)
- /* Flags for seccomp notification fd ioctl. */
- #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)
- #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \
- struct seccomp_notif_resp)
- #define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64)
- /* On success, the return value is the remote process's added fd number */
- #define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \
- struct seccomp_notif_addfd)
- #define SECCOMP_IOCTL_NOTIF_SET_FLAGS SECCOMP_IOW(4, __u64)
- #endif /* _LINUX_SECCOMP_H */