github.com/dolthub/go-mysql-server@v0.18.0/internal/sockstate/netstat.go (about)

     1  // Copyright 2020-2021 Dolthub, Inc.
     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 sockstate
    16  
    17  import (
    18  	"fmt"
    19  	"net"
    20  
    21  	"gopkg.in/src-d/go-errors.v1"
    22  )
    23  
    24  // OS independent part of the netstat_[OS].go modules
    25  // Taken (simplified, privatized and with utility functions added) from:
    26  // https://github.com/cakturk/go-netstat
    27  
    28  // skState type represents socket connection state
    29  type skState uint8
    30  
    31  func (s skState) String() string {
    32  	return skStates[s]
    33  }
    34  
    35  // ErrSocketCheckNotImplemented will be returned for OS where the socket checks is not implemented yet
    36  var ErrSocketCheckNotImplemented = errors.NewKind("socket checking not implemented for this OS")
    37  
    38  // Socket states
    39  const (
    40  	Established skState = 0x01
    41  	SynSent     skState = 0x02
    42  	SynRecv     skState = 0x03
    43  	FinWait1    skState = 0x04
    44  	FinWait2    skState = 0x05
    45  	TimeWait    skState = 0x06
    46  	Close       skState = 0x07
    47  	CloseWait   skState = 0x08
    48  	LastAck     skState = 0x09
    49  	Listen      skState = 0x0a
    50  	Closing     skState = 0x0b
    51  )
    52  
    53  var skStates = [...]string{
    54  	"UNKNOWN",
    55  	"ESTABLISHED",
    56  	"SYN_SENT",
    57  	"SYN_RECV",
    58  	"FIN_WAIT1",
    59  	"FIN_WAIT2",
    60  	"TIME_WAIT",
    61  	"", // CLOSE
    62  	"CLOSE_WAIT",
    63  	"LAST_ACK",
    64  	"LISTEN",
    65  	"CLOSING",
    66  }
    67  
    68  // sockAddr represents an ip:port pair
    69  type sockAddr struct {
    70  	IP   net.IP
    71  	Port uint16
    72  }
    73  
    74  func (s *sockAddr) String() string {
    75  	return fmt.Sprintf("%v:%d", s.IP, s.Port)
    76  }
    77  
    78  // sockTabEntry type represents each line of the /proc/net/tcp
    79  type sockTabEntry struct {
    80  	Ino        string
    81  	LocalAddr  *sockAddr
    82  	RemoteAddr *sockAddr
    83  	State      skState
    84  	UID        uint32
    85  	Process    *process
    86  }
    87  
    88  // process holds the PID and process name to which each socket belongs
    89  type process struct {
    90  	pid  int
    91  	name string
    92  }
    93  
    94  func (p *process) String() string {
    95  	return fmt.Sprintf("%d/%s", p.pid, p.name)
    96  }
    97  
    98  // AcceptFn is used to filter socket entries. The value returned indicates
    99  // whether the element is to be appended to the socket list.
   100  type AcceptFn func(*sockTabEntry) bool