snapshot: sagernet/gvisor v0.0.0-20250811.0-sing-box-mod.1

Содержимое пина, зафиксированного в go.mod sing-box-lx, одним коммитом
без истории. Полная история SagerNet/gvisor — 1.45 ГБ и клонируется в
каждой CI-джобе; наша дельта — одна вставка в одну функцию, история для
неё не нужна.

Module path github.com/sagernet/gvisor сохранён намеренно: на него
опирается replace-директива суперпроекта.

Патч поверх — отдельным коммитом, чтобы дельта читалась одним git show
и переносилась на новый пин копированием.

SPECS/TASKS/048-GVISOR_HANDSHAKE_NIL_CRASH

pkg/abi/linux/seccomp.go

@@ -0,0 +1,173 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package linux
+
+import "fmt"
+
+// Seccomp constants taken from <linux/seccomp.h>.
+const (
+	SECCOMP_MODE_NONE   = 0
+	SECCOMP_MODE_FILTER = 2
+
+	SECCOMP_RET_ACTION_FULL = 0xffff0000
+	SECCOMP_RET_ACTION      = 0x7fff0000
+	SECCOMP_RET_DATA        = 0x0000ffff
+
+	SECCOMP_SET_MODE_FILTER  = 1
+	SECCOMP_GET_ACTION_AVAIL = 2
+	SECCOMP_GET_NOTIF_SIZES  = 3
+
+	SECCOMP_FILTER_FLAG_TSYNC        = 1
+	SECCOMP_FILTER_FLAG_NEW_LISTENER = 1 << 3
+
+	SECCOMP_USER_NOTIF_FLAG_CONTINUE = 1
+
+	SECCOMP_IOCTL_NOTIF_RECV      = 0xc0502100
+	SECCOMP_IOCTL_NOTIF_SEND      = 0xc0182101
+	SECCOMP_IOCTL_NOTIF_SET_FLAGS = 0x40082104
+
+	SECCOMP_USER_NOTIF_FD_SYNC_WAKE_UP = 1
+)
+
+// BPFAction is an action for a BPF filter.
+type BPFAction uint32
+
+// BPFAction definitions.
+const (
+	SECCOMP_RET_KILL_PROCESS BPFAction = 0x80000000
+	SECCOMP_RET_KILL_THREAD  BPFAction = 0x00000000
+	SECCOMP_RET_TRAP         BPFAction = 0x00030000
+	SECCOMP_RET_ERRNO        BPFAction = 0x00050000
+	SECCOMP_RET_TRACE        BPFAction = 0x7ff00000
+	SECCOMP_RET_USER_NOTIF   BPFAction = 0x7fc00000
+	SECCOMP_RET_ALLOW        BPFAction = 0x7fff0000
+)
+
+func (a BPFAction) String() string {
+	switch a & SECCOMP_RET_ACTION_FULL {
+	case SECCOMP_RET_KILL_PROCESS:
+		return "kill process"
+	case SECCOMP_RET_KILL_THREAD:
+		return "kill thread"
+	case SECCOMP_RET_TRAP:
+		data := a.Data()
+		if data == 0 {
+			return "trap"
+		}
+		return fmt.Sprintf("trap (data=%#x)", data)
+	case SECCOMP_RET_ERRNO:
+		return fmt.Sprintf("return errno=%#x", a.Data())
+	case SECCOMP_RET_TRACE:
+		data := a.Data()
+		if data == 0 {
+			return "trace"
+		}
+		return fmt.Sprintf("trace (data=%#x)", data)
+	case SECCOMP_RET_ALLOW:
+		return "allow"
+	case SECCOMP_RET_USER_NOTIF:
+		return "unotify"
+	}
+	return fmt.Sprintf("invalid action: %#x", uint32(a))
+}
+
+// Data returns the SECCOMP_RET_DATA portion of the action.
+func (a BPFAction) Data() uint16 {
+	return uint16(a & SECCOMP_RET_DATA)
+}
+
+// WithReturnCode sets the lower 16 bits of the SECCOMP_RET_ERRNO or
+// SECCOMP_RET_TRACE actions to the provided return code, overwriting the previous
+// action, and returns a new BPFAction. If not SECCOMP_RET_ERRNO or
+// SECCOMP_RET_TRACE then this panics.
+func (a BPFAction) WithReturnCode(code uint16) BPFAction {
+	// mask out the previous return value
+	baseAction := a & SECCOMP_RET_ACTION_FULL
+	if baseAction == SECCOMP_RET_ERRNO || baseAction == SECCOMP_RET_TRACE {
+		return BPFAction(uint32(baseAction) | uint32(code))
+	}
+	panic("WithReturnCode only valid for SECCOMP_RET_ERRNO and SECCOMP_RET_TRACE")
+}
+
+// SockFprog is sock_fprog taken from <linux/filter.h>.
+type SockFprog struct {
+	Len    uint16
+	pad    [6]byte
+	Filter *BPFInstruction
+}
+
+// SeccompData is equivalent to struct seccomp_data, which contains the data
+// passed to seccomp-bpf filters.
+//
+// +marshal
+type SeccompData struct {
+	// Nr is the system call number.
+	Nr int32
+
+	// Arch is an AUDIT_ARCH_* value indicating the system call convention.
+	Arch uint32
+
+	// InstructionPointer is the value of the instruction pointer at the time
+	// of the system call.
+	InstructionPointer uint64
+
+	// Args contains the first 6 system call arguments.
+	Args [6]uint64
+}
+
+// SeccompNotifResp is equivalent to struct seccomp_notif_resp.
+//
+// +marshal
+type SeccompNotifResp struct {
+	ID    uint64
+	Val   int64
+	Error int32
+	Flags uint32
+}
+
+// SeccompNotifSizes is equivalent to struct seccomp_notif_sizes.
+//
+// +marshal
+type SeccompNotifSizes struct {
+	Notif      uint16
+	Notif_resp uint16
+	Data       uint16
+}
+
+// SeccompNotif is equivalent to struct seccomp_notif.
+//
+// +marshal
+type SeccompNotif struct {
+	ID    uint64
+	Pid   int32
+	Flags uint32
+	Data  SeccompData
+}
+
+// String returns a human-friendly representation of this `SeccompData`.
+func (sd SeccompData) String() string {
+	return fmt.Sprintf(
+		"sysno=%d arch=%#x rip=%#x args=[%#x %#x %#x %#x %#x %#x]",
+		sd.Nr,
+		sd.Arch,
+		sd.InstructionPointer,
+		sd.Args[0],
+		sd.Args[1],
+		sd.Args[2],
+		sd.Args[3],
+		sd.Args[4],
+		sd.Args[5],
+	)
+}