Add sshchat dependencies in vendor

vendor/github.com/shazow/ssh-chat/sshd/net.go

@@ -0,0 +1,67 @@
+package sshd
+
+import (
+	"net"
+
+	"github.com/shazow/rateio"
+	"golang.org/x/crypto/ssh"
+)
+
+// Container for the connection and ssh-related configuration
+type SSHListener struct {
+	net.Listener
+	config *ssh.ServerConfig
+
+	RateLimit   func() rateio.Limiter
+	HandlerFunc func(term *Terminal)
+}
+
+// Make an SSH listener socket
+func ListenSSH(laddr string, config *ssh.ServerConfig) (*SSHListener, error) {
+	socket, err := net.Listen("tcp", laddr)
+	if err != nil {
+		return nil, err
+	}
+	l := SSHListener{Listener: socket, config: config}
+	return &l, nil
+}
+
+func (l *SSHListener) handleConn(conn net.Conn) (*Terminal, error) {
+	if l.RateLimit != nil {
+		// TODO: Configurable Limiter?
+		conn = ReadLimitConn(conn, l.RateLimit())
+	}
+
+	// Upgrade TCP connection to SSH connection
+	sshConn, channels, requests, err := ssh.NewServerConn(conn, l.config)
+	if err != nil {
+		return nil, err
+	}
+
+	// FIXME: Disconnect if too many faulty requests? (Avoid DoS.)
+	go ssh.DiscardRequests(requests)
+	return NewSession(sshConn, channels)
+}
+
+// Accept incoming connections as terminal requests and yield them
+func (l *SSHListener) Serve() {
+	defer l.Close()
+	for {
+		conn, err := l.Accept()
+
+		if err != nil {
+			logger.Printf("Failed to accept connection: %s", err)
+			break
+		}
+
+		// Goroutineify to resume accepting sockets early
+		go func() {
+			term, err := l.handleConn(conn)
+			if err != nil {
+				logger.Printf("[%s] Failed to handshake: %s", conn.RemoteAddr(), err)
+				return
+			}
+			l.HandlerFunc(term)
+		}()
+	}
+}