Update vendor (#1265)

vendor/github.com/wiggin77/srslog/dialer.go

@@ -0,0 +1,104 @@
+package srslog
+
+import (
+	"crypto/tls"
+	"net"
+)
+
+// dialerFunctionWrapper is a simple object that consists of a dialer function
+// and its name. This is primarily for testing, so we can make sure that the
+// getDialer method returns the correct dialer function. However, if you ever
+// find that you need to check which dialer function you have, this would also
+// be useful for you without having to use reflection.
+type dialerFunctionWrapper struct {
+	Name   string
+	Dialer func() (serverConn, string, error)
+}
+
+// Call the wrapped dialer function and return its return values.
+func (df dialerFunctionWrapper) Call() (serverConn, string, error) {
+	return df.Dialer()
+}
+
+// getDialer returns a "dialer" function that can be called to connect to a
+// syslog server.
+//
+// Each dialer function is responsible for dialing the remote host and returns
+// a serverConn, the hostname (or a default if the Writer has not specified a
+// hostname), and an error in case dialing fails.
+//
+// The reason for separate dialers is that different network types may need
+// to dial their connection differently, yet still provide a net.Conn interface
+// that you can use once they have dialed. Rather than an increasingly long
+// conditional, we have a map of network -> dialer function (with a sane default
+// value), and adding a new network type is as easy as writing the dialer
+// function and adding it to the map.
+func (w *Writer) getDialer() dialerFunctionWrapper {
+	dialers := map[string]dialerFunctionWrapper{
+		"":        dialerFunctionWrapper{"unixDialer", w.unixDialer},
+		"tcp+tls": dialerFunctionWrapper{"tlsDialer", w.tlsDialer},
+		"custom":  dialerFunctionWrapper{"customDialer", w.customDialer},
+	}
+	dialer, ok := dialers[w.network]
+	if !ok {
+		dialer = dialerFunctionWrapper{"basicDialer", w.basicDialer}
+	}
+	return dialer
+}
+
+// unixDialer uses the unixSyslog method to open a connection to the syslog
+// daemon running on the local machine.
+func (w *Writer) unixDialer() (serverConn, string, error) {
+	sc, err := unixSyslog()
+	hostname := w.hostname
+	if hostname == "" {
+		hostname = "localhost"
+	}
+	return sc, hostname, err
+}
+
+// tlsDialer connects to TLS over TCP, and is used for the "tcp+tls" network
+// type.
+func (w *Writer) tlsDialer() (serverConn, string, error) {
+	c, err := tls.Dial("tcp", w.raddr, w.tlsConfig)
+	var sc serverConn
+	hostname := w.hostname
+	if err == nil {
+		sc = newNetConn(c)
+		if hostname == "" {
+			hostname = c.LocalAddr().String()
+		}
+	}
+	return sc, hostname, err
+}
+
+// basicDialer is the most common dialer for syslog, and supports both TCP and
+// UDP connections.
+func (w *Writer) basicDialer() (serverConn, string, error) {
+	c, err := net.Dial(w.network, w.raddr)
+	var sc serverConn
+	hostname := w.hostname
+	if err == nil {
+		sc = newNetConn(c)
+		if hostname == "" {
+			hostname = c.LocalAddr().String()
+		}
+	}
+	return sc, hostname, err
+}
+
+// customDialer uses the custom dialer when the Writer was created
+// giving developers total control over how connections are made and returned.
+// Note it does not check if cdialer is nil, as it should only be referenced from getDialer.
+func (w *Writer) customDialer() (serverConn, string, error) {
+	c, err := w.customDial(w.network, w.raddr)
+	var sc serverConn
+	hostname := w.hostname
+	if err == nil {
+		sc = newNetConn(c)
+		if hostname == "" {
+			hostname = c.LocalAddr().String()
+		}
+	}
+	return sc, hostname, err
+}