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package hotline
import (
"encoding/binary"
"golang.org/x/crypto/bcrypt"
"math/big"
"net"
)
type byClientID []*ClientConn
func (s byClientID) Len() int {
return len(s)
}
func (s byClientID) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s byClientID) Less(i, j int) bool {
return s[i].uint16ID() < s[j].uint16ID()
}
// ClientConn represents a client connected to a Server
type ClientConn struct {
Connection net.Conn
ID *[]byte
Icon *[]byte
Flags *[]byte
UserName []byte
Account *Account
IdleTime int
Server *Server
Version *[]byte
Idle bool
AutoReply []byte
Transfers map[int][]*FileTransfer
Agreed bool
}
func (cc *ClientConn) sendAll(t int, fields ...Field) {
for _, c := range sortedClients(cc.Server.Clients) {
cc.Server.outbox <- *NewTransaction(t, c.ID, fields...)
}
}
func (cc *ClientConn) handleTransaction(transaction *Transaction) error {
requestNum := binary.BigEndian.Uint16(transaction.Type)
if handler, ok := TransactionHandlers[requestNum]; ok {
for _, reqField := range handler.RequiredFields {
field := transaction.GetField(reqField.ID)
// Validate that required field is present
if field.ID == nil {
cc.Server.Logger.Errorw(
"Missing required field",
"Account", cc.Account.Login, "UserName", string(cc.UserName), "RequestType", handler.Name, "FieldID", reqField.ID,
)
return nil
}
if len(field.Data) < reqField.minLen {
cc.Server.Logger.Infow(
"Field does not meet minLen",
"Account", cc.Account.Login, "UserName", string(cc.UserName), "RequestType", handler.Name, "FieldID", reqField.ID,
)
return nil
}
}
if !authorize(cc.Account.Access, handler.Access) {
cc.Server.Logger.Infow(
"Unauthorized Action",
"Account", cc.Account.Login, "UserName", string(cc.UserName), "RequestType", handler.Name,
)
cc.Server.outbox <- cc.NewErrReply(transaction, handler.DenyMsg)
return nil
}
cc.Server.Logger.Infow(
"Received Transaction",
"login", cc.Account.Login,
"name", string(cc.UserName),
"RequestType", handler.Name,
)
transactions, err := handler.Handler(cc, transaction)
if err != nil {
return err
}
for _, t := range transactions {
cc.Server.outbox <- t
}
} else {
cc.Server.Logger.Errorw(
"Unimplemented transaction type received",
"UserName", string(cc.UserName), "RequestID", requestNum,
)
}
cc.Server.mux.Lock()
defer cc.Server.mux.Unlock()
if requestNum != tranKeepAlive {
// reset the user idle timer
cc.IdleTime = 0
// if user was previously idle, mark as not idle and notify other connected clients that
// the user is no longer away
if cc.Idle {
flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(*cc.Flags)))
flagBitmap.SetBit(flagBitmap, userFlagAway, 0)
binary.BigEndian.PutUint16(*cc.Flags, uint16(flagBitmap.Int64()))
cc.Idle = false
cc.sendAll(
tranNotifyChangeUser,
NewField(fieldUserID, *cc.ID),
NewField(fieldUserFlags, *cc.Flags),
NewField(fieldUserName, cc.UserName),
NewField(fieldUserIconID, *cc.Icon),
)
}
}
return nil
}
func (cc *ClientConn) Authenticate(login string, password []byte) bool {
if account, ok := cc.Server.Accounts[login]; ok {
return bcrypt.CompareHashAndPassword([]byte(account.Password), password) == nil
}
return false
}
func (cc *ClientConn) uint16ID() uint16 {
id, _ := byteToInt(*cc.ID)
return uint16(id)
}
// Authorize checks if the user account has the specified permission
func (cc *ClientConn) Authorize(access int) bool {
if access == 0 {
return true
}
accessBitmap := big.NewInt(int64(binary.BigEndian.Uint64(*cc.Account.Access)))
return accessBitmap.Bit(63-access) == 1
}
// Disconnect notifies other clients that a client has disconnected
func (cc ClientConn) Disconnect() {
cc.Server.mux.Lock()
defer cc.Server.mux.Unlock()
delete(cc.Server.Clients, binary.BigEndian.Uint16(*cc.ID))
cc.NotifyOthers(*NewTransaction(tranNotifyDeleteUser, nil, NewField(fieldUserID, *cc.ID)))
if err := cc.Connection.Close(); err != nil {
cc.Server.Logger.Errorw("error closing client connection", "RemoteAddr", cc.Connection.RemoteAddr())
}
}
// NotifyOthers sends transaction t to other clients connected to the server
func (cc ClientConn) NotifyOthers(t Transaction) {
for _, c := range sortedClients(cc.Server.Clients) {
if c.ID != cc.ID && c.Agreed {
t.clientID = c.ID
cc.Server.outbox <- t
}
}
}
// NewReply returns a reply Transaction with fields for the ClientConn
func (cc *ClientConn) NewReply(t *Transaction, fields ...Field) Transaction {
reply := Transaction{
Flags: 0x00,
IsReply: 0x01,
Type: t.Type,
ID: t.ID,
clientID: cc.ID,
ErrorCode: []byte{0, 0, 0, 0},
Fields: fields,
}
return reply
}
// NewErrReply returns an error reply Transaction with errMsg
func (cc *ClientConn) NewErrReply(t *Transaction, errMsg string) Transaction {
return Transaction{
clientID: cc.ID,
Flags: 0x00,
IsReply: 0x01,
Type: []byte{0, 0},
ID: t.ID,
ErrorCode: []byte{0, 0, 0, 1},
Fields: []Field{
NewField(fieldError, []byte(errMsg)),
},
}
}
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