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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */2#ifndef _UAPI_LINUX_SECCOMP_H3#define _UAPI_LINUX_SECCOMP_H4 5#include <linux/compiler.h>6#include <linux/types.h>7 8 9/* Valid values for seccomp.mode and prctl(PR_SET_SECCOMP, <mode>) */10#define SECCOMP_MODE_DISABLED 0 /* seccomp is not in use. */11#define SECCOMP_MODE_STRICT 1 /* uses hard-coded filter. */12#define SECCOMP_MODE_FILTER 2 /* uses user-supplied filter. */13 14/* Valid operations for seccomp syscall. */15#define SECCOMP_SET_MODE_STRICT 016#define SECCOMP_SET_MODE_FILTER 117#define SECCOMP_GET_ACTION_AVAIL 218#define SECCOMP_GET_NOTIF_SIZES 319 20/* Valid flags for SECCOMP_SET_MODE_FILTER */21#define SECCOMP_FILTER_FLAG_TSYNC (1UL << 0)22#define SECCOMP_FILTER_FLAG_LOG (1UL << 1)23#define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2)24#define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3)25#define SECCOMP_FILTER_FLAG_TSYNC_ESRCH (1UL << 4)26/* Received notifications wait in killable state (only respond to fatal signals) */27#define SECCOMP_FILTER_FLAG_WAIT_KILLABLE_RECV (1UL << 5)28 29/*30 * All BPF programs must return a 32-bit value.31 * The bottom 16-bits are for optional return data.32 * The upper 16-bits are ordered from least permissive values to most,33 * as a signed value (so 0x8000000 is negative).34 *35 * The ordering ensures that a min_t() over composed return values always36 * selects the least permissive choice.37 */38#define SECCOMP_RET_KILL_PROCESS 0x80000000U /* kill the process */39#define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */40#define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD41#define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */42#define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */43#define SECCOMP_RET_USER_NOTIF 0x7fc00000U /* notifies userspace */44#define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */45#define SECCOMP_RET_LOG 0x7ffc0000U /* allow after logging */46#define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */47 48/* Masks for the return value sections. */49#define SECCOMP_RET_ACTION_FULL 0xffff0000U50#define SECCOMP_RET_ACTION 0x7fff0000U51#define SECCOMP_RET_DATA 0x0000ffffU52 53/**54 * struct seccomp_data - the format the BPF program executes over.55 * @nr: the system call number56 * @arch: indicates system call convention as an AUDIT_ARCH_* value57 * as defined in <linux/audit.h>.58 * @instruction_pointer: at the time of the system call.59 * @args: up to 6 system call arguments always stored as 64-bit values60 * regardless of the architecture.61 */62struct seccomp_data {63 int nr;64 __u32 arch;65 __u64 instruction_pointer;66 __u64 args[6];67};68 69struct seccomp_notif_sizes {70 __u16 seccomp_notif;71 __u16 seccomp_notif_resp;72 __u16 seccomp_data;73};74 75struct seccomp_notif {76 __u64 id;77 __u32 pid;78 __u32 flags;79 struct seccomp_data data;80};81 82/*83 * Valid flags for struct seccomp_notif_resp84 *85 * Note, the SECCOMP_USER_NOTIF_FLAG_CONTINUE flag must be used with caution!86 * If set by the process supervising the syscalls of another process the87 * syscall will continue. This is problematic because of an inherent TOCTOU.88 * An attacker can exploit the time while the supervised process is waiting on89 * a response from the supervising process to rewrite syscall arguments which90 * are passed as pointers of the intercepted syscall.91 * It should be absolutely clear that this means that the seccomp notifier92 * _cannot_ be used to implement a security policy! It should only ever be used93 * in scenarios where a more privileged process supervises the syscalls of a94 * lesser privileged process to get around kernel-enforced security95 * restrictions when the privileged process deems this safe. In other words,96 * in order to continue a syscall the supervising process should be sure that97 * another security mechanism or the kernel itself will sufficiently block98 * syscalls if arguments are rewritten to something unsafe.99 *100 * Similar precautions should be applied when stacking SECCOMP_RET_USER_NOTIF101 * or SECCOMP_RET_TRACE. For SECCOMP_RET_USER_NOTIF filters acting on the102 * same syscall, the most recently added filter takes precedence. This means103 * that the new SECCOMP_RET_USER_NOTIF filter can override any104 * SECCOMP_IOCTL_NOTIF_SEND from earlier filters, essentially allowing all105 * such filtered syscalls to be executed by sending the response106 * SECCOMP_USER_NOTIF_FLAG_CONTINUE. Note that SECCOMP_RET_TRACE can equally107 * be overriden by SECCOMP_USER_NOTIF_FLAG_CONTINUE.108 */109#define SECCOMP_USER_NOTIF_FLAG_CONTINUE (1UL << 0)110 111struct seccomp_notif_resp {112 __u64 id;113 __s64 val;114 __s32 error;115 __u32 flags;116};117 118#define SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP (1UL << 0)119 120/* valid flags for seccomp_notif_addfd */121#define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */122#define SECCOMP_ADDFD_FLAG_SEND (1UL << 1) /* Addfd and return it, atomically */123 124/**125 * struct seccomp_notif_addfd126 * @id: The ID of the seccomp notification127 * @flags: SECCOMP_ADDFD_FLAG_*128 * @srcfd: The local fd number129 * @newfd: Optional remote FD number if SETFD option is set, otherwise 0.130 * @newfd_flags: The O_* flags the remote FD should have applied131 */132struct seccomp_notif_addfd {133 __u64 id;134 __u32 flags;135 __u32 srcfd;136 __u32 newfd;137 __u32 newfd_flags;138};139 140#define SECCOMP_IOC_MAGIC '!'141#define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr)142#define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type)143#define SECCOMP_IOW(nr, type) _IOW(SECCOMP_IOC_MAGIC, nr, type)144#define SECCOMP_IOWR(nr, type) _IOWR(SECCOMP_IOC_MAGIC, nr, type)145 146/* Flags for seccomp notification fd ioctl. */147#define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif)148#define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \149 struct seccomp_notif_resp)150#define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64)151/* On success, the return value is the remote process's added fd number */152#define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \153 struct seccomp_notif_addfd)154 155#define SECCOMP_IOCTL_NOTIF_SET_FLAGS SECCOMP_IOW(4, __u64)156 157#endif /* _UAPI_LINUX_SECCOMP_H */158