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- // Copyright (c) 2012-2014 Jeremy Latt
- // Copyright (c) 2016-2017 Daniel Oaks <daniel@danieloaks.net>
- // released under the MIT license
-
- package irc
-
- import (
- "bufio"
- "crypto/sha256"
- "crypto/tls"
- "encoding/hex"
- "errors"
- "io"
- "net"
- "strings"
- "sync"
- "time"
- )
-
- var (
- errNotTLS = errors.New("Not a TLS connection")
- errNoPeerCerts = errors.New("Client did not provide a certificate")
- handshakeTimeout, _ = time.ParseDuration("5s")
- )
-
- // Socket represents an IRC socket.
- type Socket struct {
- conn net.Conn
- reader *bufio.Reader
-
- MaxSendQBytes uint64
-
- closed bool
- closedMutex sync.Mutex
-
- finalData string // what to send when we die
- finalDataMutex sync.Mutex
-
- lineToSendExists chan bool
- linesToSend []string
- linesToSendMutex sync.Mutex
- }
-
- // NewSocket returns a new Socket.
- func NewSocket(conn net.Conn, maxSendQBytes uint64) Socket {
- return Socket{
- conn: conn,
- reader: bufio.NewReader(conn),
- MaxSendQBytes: maxSendQBytes,
- lineToSendExists: make(chan bool),
- }
- }
-
- // Close stops a Socket from being able to send/receive any more data.
- func (socket *Socket) Close() {
- socket.closedMutex.Lock()
- defer socket.closedMutex.Unlock()
- if socket.closed {
- return
- }
- socket.closed = true
-
- // force close loop to happen if it hasn't already
- go socket.timedFillLineToSendExists(200 * time.Millisecond)
- }
-
- // CertFP returns the fingerprint of the certificate provided by the client.
- func (socket *Socket) CertFP() (string, error) {
- var tlsConn, isTLS = socket.conn.(*tls.Conn)
- if !isTLS {
- return "", errNotTLS
- }
-
- // ensure handehake is performed, and timeout after a few seconds
- tlsConn.SetDeadline(time.Now().Add(handshakeTimeout))
- err := tlsConn.Handshake()
- tlsConn.SetDeadline(time.Time{})
-
- if err != nil {
- return "", err
- }
-
- peerCerts := tlsConn.ConnectionState().PeerCertificates
- if len(peerCerts) < 1 {
- return "", errNoPeerCerts
- }
-
- rawCert := sha256.Sum256(peerCerts[0].Raw)
- fingerprint := hex.EncodeToString(rawCert[:])
-
- return fingerprint, nil
- }
-
- // Read returns a single IRC line from a Socket.
- func (socket *Socket) Read() (string, error) {
- if socket.IsClosed() {
- return "", io.EOF
- }
-
- lineBytes, err := socket.reader.ReadBytes('\n')
-
- // convert bytes to string
- line := string(lineBytes[:])
-
- // read last message properly (such as ERROR/QUIT/etc), just fail next reads/writes
- if err == io.EOF {
- socket.Close()
- }
-
- if err == io.EOF && strings.TrimSpace(line) != "" {
- // don't do anything
- } else if err != nil {
- return "", err
- }
-
- return strings.TrimRight(line, "\r\n"), nil
- }
-
- // Write sends the given string out of Socket.
- func (socket *Socket) Write(data string) error {
- if socket.IsClosed() {
- return io.EOF
- }
-
- socket.linesToSendMutex.Lock()
- socket.linesToSend = append(socket.linesToSend, data)
- socket.linesToSendMutex.Unlock()
-
- go socket.timedFillLineToSendExists(15 * time.Second)
-
- return nil
- }
-
- // timedFillLineToSendExists either sends the note or times out.
- func (socket *Socket) timedFillLineToSendExists(duration time.Duration) {
- lineToSendTimeout := time.NewTimer(duration)
- defer lineToSendTimeout.Stop()
- select {
- case socket.lineToSendExists <- true:
- // passed data successfully
- case <-lineToSendTimeout.C:
- // timed out send
- }
- }
-
- // SetFinalData sets the final data to send when the SocketWriter closes.
- func (socket *Socket) SetFinalData(data string) {
- socket.finalDataMutex.Lock()
- socket.finalData = data
- socket.finalDataMutex.Unlock()
- }
-
- // IsClosed returns whether the socket is closed.
- func (socket *Socket) IsClosed() bool {
- socket.closedMutex.Lock()
- defer socket.closedMutex.Unlock()
- return socket.closed
- }
-
- // RunSocketWriter starts writing messages to the outgoing socket.
- func (socket *Socket) RunSocketWriter() {
- for {
- // wait for new lines
- select {
- case <-socket.lineToSendExists:
- socket.linesToSendMutex.Lock()
-
- // check if we're closed
- if socket.IsClosed() {
- socket.linesToSendMutex.Unlock()
- break
- }
-
- // check whether new lines actually exist or not
- if len(socket.linesToSend) < 1 {
- socket.linesToSendMutex.Unlock()
- continue
- }
-
- // check sendq
- var sendQBytes uint64
- for _, line := range socket.linesToSend {
- sendQBytes += uint64(len(line))
- if socket.MaxSendQBytes < sendQBytes {
- // don't unlock mutex because this break is just to escape this for loop
- break
- }
- }
- if socket.MaxSendQBytes < sendQBytes {
- socket.SetFinalData("\r\nERROR :SendQ Exceeded\r\n")
- socket.linesToSendMutex.Unlock()
- break
- }
-
- // get all existing data
- data := strings.Join(socket.linesToSend, "")
- socket.linesToSend = []string{}
-
- socket.linesToSendMutex.Unlock()
-
- // write data
- if 0 < len(data) {
- _, err := socket.conn.Write([]byte(data))
- if err != nil {
- break
- }
- }
- }
- if socket.IsClosed() {
- // error out or we've been closed
- break
- }
- }
- // force closure of socket
- socket.closedMutex.Lock()
- if !socket.closed {
- socket.closed = true
- }
- socket.closedMutex.Unlock()
-
- // write error lines
- socket.finalDataMutex.Lock()
- if 0 < len(socket.finalData) {
- socket.conn.Write([]byte(socket.finalData))
- }
- socket.finalDataMutex.Unlock()
-
- // close the connection
- socket.conn.Close()
-
- // empty the lineToSendExists channel
- for 0 < len(socket.lineToSendExists) {
- <-socket.lineToSendExists
- }
- }
-
- // WriteLine writes the given line out of Socket.
- func (socket *Socket) WriteLine(line string) error {
- return socket.Write(line + "\r\n")
- }
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