git.r.bdr.sh - rbdr/mobius/blob - hotline/client_conn.go

   1 package hotline
   2
   3 import (
   4         "encoding/binary"
   5         "golang.org/x/crypto/bcrypt"
   6         "math/big"
   7         "net"
   8 )
   9
  10 type byClientID []*ClientConn
  11
  12 func (s byClientID) Len() int {
  13         return len(s)
  14 }
  15
  16 func (s byClientID) Swap(i, j int) {
  17         s[i], s[j] = s[j], s[i]
  18 }
  19
  20 func (s byClientID) Less(i, j int) bool {
  21         return s[i].uint16ID() < s[j].uint16ID()
  22 }
  23
  24 // ClientConn represents a client connected to a Server
  25 type ClientConn struct {
  26         Connection net.Conn
  27         ID         *[]byte
  28         Icon       *[]byte
  29         Flags      *[]byte
  30         UserName   []byte
  31         Account    *Account
  32         IdleTime   int
  33         Server     *Server
  34         Version    *[]byte
  35         Idle       bool
  36         AutoReply  []byte
  37         Transfers  map[int][]*FileTransfer
  38         Agreed     bool
  39 }
  40
  41 func (cc *ClientConn) sendAll(t int, fields ...Field) {
  42         for _, c := range sortedClients(cc.Server.Clients) {
  43                 cc.Server.outbox <- *NewTransaction(t, c.ID, fields...)
  44         }
  45 }
  46
  47 func (cc *ClientConn) handleTransaction(transaction *Transaction) error {
  48         requestNum := binary.BigEndian.Uint16(transaction.Type)
  49         if handler, ok := TransactionHandlers[requestNum]; ok {
  50                 for _, reqField := range handler.RequiredFields {
  51                         field := transaction.GetField(reqField.ID)
  52
  53                         // Validate that required field is present
  54                         if field.ID == nil {
  55                                 cc.Server.Logger.Errorw(
  56                                         "Missing required field",
  57                                         "Account", cc.Account.Login, "UserName", string(cc.UserName), "RequestType", handler.Name, "FieldID", reqField.ID,
  58                                 )
  59                                 return nil
  60                         }
  61
  62                         if len(field.Data) < reqField.minLen {
  63                                 cc.Server.Logger.Infow(
  64                                         "Field does not meet minLen",
  65                                         "Account", cc.Account.Login, "UserName", string(cc.UserName), "RequestType", handler.Name, "FieldID", reqField.ID,
  66                                 )
  67                                 return nil
  68                         }
  69                 }
  70                 if !authorize(cc.Account.Access, handler.Access) {
  71                         cc.Server.Logger.Infow(
  72                                 "Unauthorized Action",
  73                                 "Account", cc.Account.Login, "UserName", string(cc.UserName), "RequestType", handler.Name,
  74                         )
  75                         cc.Server.outbox <- cc.NewErrReply(transaction, handler.DenyMsg)
  76
  77                         return nil
  78                 }
  79
  80                 cc.Server.Logger.Infow(
  81                         "Received Transaction",
  82                         "login", cc.Account.Login,
  83                         "name", string(cc.UserName),
  84                         "RequestType", handler.Name,
  85                 )
  86
  87                 transactions, err := handler.Handler(cc, transaction)
  88                 if err != nil {
  89                         return err
  90                 }
  91                 for _, t := range transactions {
  92                         cc.Server.outbox <- t
  93                 }
  94         } else {
  95                 cc.Server.Logger.Errorw(
  96                         "Unimplemented transaction type received",
  97                         "UserName", string(cc.UserName), "RequestID", requestNum,
  98                 )
  99         }
 100
 101         cc.Server.mux.Lock()
 102         defer cc.Server.mux.Unlock()
 103
 104         if requestNum != tranKeepAlive {
 105                 // reset the user idle timer
 106                 cc.IdleTime = 0
 107
 108                 // if user was previously idle, mark as not idle and notify other connected clients that
 109                 // the user is no longer away
 110                 if cc.Idle {
 111                         flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*cc.Flags)))
 112                         flagBitmap.SetBit(flagBitmap, userFlagAway, 0)
 113                         binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
 114                         cc.Idle = false
 115
 116                         cc.sendAll(
 117                                 tranNotifyChangeUser,
 118                                 NewField(fieldUserID, *cc.ID),
 119                                 NewField(fieldUserFlags, *cc.Flags),
 120                                 NewField(fieldUserName, cc.UserName),
 121                                 NewField(fieldUserIconID, *cc.Icon),
 122                         )
 123                 }
 124         }
 125
 126         return nil
 127 }
 128
 129 func (cc *ClientConn) Authenticate(login string, password []byte) bool {
 130         if account, ok := cc.Server.Accounts[login]; ok {
 131                 return bcrypt.CompareHashAndPassword([]byte(account.Password), password) == nil
 132         }
 133
 134         return false
 135 }
 136
 137 func (cc *ClientConn) uint16ID() uint16 {
 138         id, _ := byteToInt(*cc.ID)
 139         return uint16(id)
 140 }
 141
 142 // Authorize checks if the user account has the specified permission
 143 func (cc *ClientConn) Authorize(access int) bool {
 144         if access == 0 {
 145                 return true
 146         }
 147
 148         accessBitmap := big.NewInt(int64(binary.BigEndian.Uint64(*cc.Account.Access)))
 149
 150         return accessBitmap.Bit(63-access) == 1
 151 }
 152
 153 // Disconnect notifies other clients that a client has disconnected
 154 func (cc ClientConn) Disconnect() {
 155         cc.Server.mux.Lock()
 156         defer cc.Server.mux.Unlock()
 157
 158         delete(cc.Server.Clients, binary.BigEndian.Uint16(*cc.ID))
 159
 160         cc.notifyOthers(*NewTransaction(tranNotifyDeleteUser, nil, NewField(fieldUserID, *cc.ID)))
 161
 162         if err := cc.Connection.Close(); err != nil {
 163                 cc.Server.Logger.Errorw("error closing client connection", "RemoteAddr", cc.Connection.RemoteAddr())
 164         }
 165 }
 166
 167 // notifyOthers sends transaction t to other clients connected to the server
 168 func (cc ClientConn) notifyOthers(t Transaction) {
 169         for _, c := range sortedClients(cc.Server.Clients) {
 170                 if c.ID != cc.ID && c.Agreed {
 171                         t.clientID = c.ID
 172                         cc.Server.outbox <- t
 173                 }
 174         }
 175 }
 176
 177 // NewReply returns a reply Transaction with fields for the ClientConn
 178 func (cc *ClientConn) NewReply(t *Transaction, fields ...Field) Transaction {
 179         reply := Transaction{
 180                 Flags:     0x00,
 181                 IsReply:   0x01,
 182                 Type:      t.Type,
 183                 ID:        t.ID,
 184                 clientID:  cc.ID,
 185                 ErrorCode: []byte{0, 0, 0, 0},
 186                 Fields:    fields,
 187         }
 188
 189         return reply
 190 }
 191
 192 // NewErrReply returns an error reply Transaction with errMsg
 193 func (cc *ClientConn) NewErrReply(t *Transaction, errMsg string) Transaction {
 194         return Transaction{
 195                 clientID:  cc.ID,
 196                 Flags:     0x00,
 197                 IsReply:   0x01,
 198                 Type:      []byte{0, 0},
 199                 ID:        t.ID,
 200                 ErrorCode: []byte{0, 0, 0, 1},
 201                 Fields: []Field{
 202                         NewField(fieldError, []byte(errMsg)),
 203                 },
 204         }
 205 }