// NewConnection creates a SSMP connection out of a streaming netwrok connection.
//
// This method blocks until either a first message is received or a 10s timeout
// elapses.
//
// Each accepted connection spawns a goroutine continuously reading from the
// underlying network connection and triggering the Dispatcher. The caller must
// keep track of the returned Connection and call the Close method to stop the
// read goroutine and close the udnerlying netwrok connection.
//
// errInvalidLogin is returned if the first message is not a well-formed LOGIN
// request.
// errUnauthorized is returned if the authenticator doesn't accept the provided
// credentials.
func NewConnection(c net.Conn, a Authenticator, d *Dispatcher) (*Connection, error) {
r := ssmp.NewDecoder(c)
c.SetReadDeadline(time.Now().Add(10 * time.Second))
verb, err := r.DecodeVerb()
if err != nil || !ssmp.Equal(verb, ssmp.LOGIN) {
return nil, ErrInvalidLogin
}
user, err := r.DecodeId()
if err != nil {
return nil, ErrInvalidLogin
}
scheme, err := r.DecodeId()
if err != nil {
return nil, ErrInvalidLogin
}
var cred []byte
if r.AtEnd() {
cred = []byte{}
} else if cred, err = r.DecodePayload(); err != nil {
return nil, ErrInvalidLogin
}
if !a.Auth(c, user, scheme, cred) {
return nil, ErrUnauthorized
}
r.Reset()
cc := &Connection{
c: c,
r: r,
User: string(user),
}
go cc.readLoop(d)
cc.Write(respOk)
return cc, nil
}
func (c *client) readLoop() {
defer c.wg.Done()
defer close(c.responses)
idle := false
r := ssmp.NewDecoder(c.c)
for {
c.c.SetReadDeadline(time.Now().Add(30 * time.Second))
code, err := r.DecodeCode()
if err != nil {
if nerr, ok := err.(net.Error); ok && nerr.Timeout() && !idle {
idle = true
c.c.Write(ping)
continue
}
// unwrap network error
if oerr, ok := err.(*net.OpError); ok {
err = oerr.Err
}
if err != io.EOF && err.Error() != "use of closed network connection" {
fmt.Printf("Client[%p] Failed to read: %v\n", c, err)
}
break
}
idle = false
if code == ssmp.CodeEvent {
ev, err := parseEvent(r)
if err != nil {
fmt.Printf("Client[%p] Invalid event: %v\n", c, err)
break
}
r.Reset()
if ssmp.Equal(ev.Name, ssmp.PING) {
c.c.Write(pong)
continue
}
if ssmp.Equal(ev.Name, ssmp.PONG) {
continue
}
h := c.EventHandler()
if h == nil {
continue
}
h.HandleEvent(ev)
continue
}
var payload string
if !r.AtEnd() {
d, err := r.DecodePayload()
if err != nil {
fmt.Printf("Client[%p] Invalid response: %v\n", c, err)
break
}
payload = string(d)
}
r.Reset()
c.responses <- Response{
Code: code,
Message: payload,
}
}
c.c.Close()
}