86 lines
2.6 KiB
Go
86 lines
2.6 KiB
Go
// 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_FILTER_FLAG_TSYNC = 1
|
|
SECCOMP_GET_ACTION_AVAIL = 2
|
|
)
|
|
|
|
type BPFAction uint32
|
|
|
|
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_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:
|
|
return fmt.Sprintf("trap (%d)", a.Data())
|
|
case SECCOMP_RET_ERRNO:
|
|
return fmt.Sprintf("errno (%d)", a.Data())
|
|
case SECCOMP_RET_TRACE:
|
|
return fmt.Sprintf("trace (%d)", a.Data())
|
|
case SECCOMP_RET_ALLOW:
|
|
return "allow"
|
|
}
|
|
return fmt.Sprintf("invalid action: %#x", 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
|
|
}
|