// 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 ) // 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_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 } // 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 }