github.com/sagernet/gvisor@v0.0.0-20240428053021-e691de28565f/pkg/abi/linux/msgqueue.go (about)

     1  // Copyright 2021 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package linux
    16  
    17  import (
    18  	"github.com/sagernet/gvisor/pkg/marshal/primitive"
    19  )
    20  
    21  // Linux-specific control commands. Source: include/uapi/linux/msg.h
    22  const (
    23  	MSG_STAT     = 11
    24  	MSG_INFO     = 12
    25  	MSG_STAT_ANY = 13
    26  )
    27  
    28  // msgrcv(2) options. Source: include/uapi/linux/msg.h
    29  const (
    30  	MSG_NOERROR = 010000 // No error if message is too big.
    31  	MSG_EXCEPT  = 020000 // Receive any message except of specified type.
    32  	MSG_COPY    = 040000 // Copy (not remove) all queue messages.
    33  )
    34  
    35  // System-wide limits for message queues. Source: include/uapi/linux/msg.h
    36  const (
    37  	MSGMNI = 32000 // Maximum number of message queue identifiers.
    38  	MSGMAX = 8192  // Maximum size of message (bytes).
    39  	MSGMNB = 16384 // Default max size of a message queue.
    40  )
    41  
    42  // System-wide limits. Unused. Source: include/uapi/linux/msg.h
    43  const (
    44  	MSGPOOL = (MSGMNI * MSGMNB / 1024)
    45  	MSGTQL  = MSGMNB
    46  	MSGMAP  = MSGMNB
    47  	MSGSSZ  = 16
    48  
    49  	// MSGSEG is simplified due to the inexistance of a ternary operator.
    50  	MSGSEG = 0xffff
    51  )
    52  
    53  // MsqidDS is equivalent to struct msqid64_ds. Source:
    54  // include/uapi/asm-generic/shmbuf.h
    55  //
    56  // +marshal
    57  type MsqidDS struct {
    58  	MsgPerm   IPCPerm // IPC permissions.
    59  	MsgStime  TimeT   // Last msgsnd time.
    60  	MsgRtime  TimeT   // Last msgrcv time.
    61  	MsgCtime  TimeT   // Last change time.
    62  	MsgCbytes uint64  // Current number of bytes on the queue.
    63  	MsgQnum   uint64  // Number of messages in the queue.
    64  	MsgQbytes uint64  // Max number of bytes in the queue.
    65  	MsgLspid  int32   // PID of last msgsnd.
    66  	MsgLrpid  int32   // PID of last msgrcv.
    67  	unused4   uint64
    68  	unused5   uint64
    69  }
    70  
    71  // MsgBuf is equivalent to struct msgbuf. Source: include/uapi/linux/msg.h
    72  //
    73  // +marshal dynamic
    74  type MsgBuf struct {
    75  	Type primitive.Int64
    76  	Text primitive.ByteSlice
    77  }
    78  
    79  // SizeBytes implements marshal.Marshallable.SizeBytes.
    80  func (b *MsgBuf) SizeBytes() int {
    81  	return b.Type.SizeBytes() + b.Text.SizeBytes()
    82  }
    83  
    84  // MarshalBytes implements marshal.Marshallable.MarshalBytes.
    85  func (b *MsgBuf) MarshalBytes(dst []byte) []byte {
    86  	dst = b.Type.MarshalUnsafe(dst)
    87  	return b.Text.MarshalBytes(dst)
    88  }
    89  
    90  // UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
    91  func (b *MsgBuf) UnmarshalBytes(src []byte) []byte {
    92  	src = b.Type.UnmarshalUnsafe(src)
    93  	return b.Text.UnmarshalBytes(src)
    94  }
    95  
    96  // MsgInfo is equivalent to struct msginfo. Source: include/uapi/linux/msg.h
    97  //
    98  // +marshal
    99  type MsgInfo struct {
   100  	MsgPool int32
   101  	MsgMap  int32
   102  	MsgMax  int32
   103  	MsgMnb  int32
   104  	MsgMni  int32
   105  	MsgSsz  int32
   106  	MsgTql  int32
   107  	MsgSeg  uint16 `marshal:"unaligned"`
   108  }