diff options
Diffstat (limited to 'vendor/github.com/wiggin77/srslog/dialer.go')
-rw-r--r-- | vendor/github.com/wiggin77/srslog/dialer.go | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/vendor/github.com/wiggin77/srslog/dialer.go b/vendor/github.com/wiggin77/srslog/dialer.go new file mode 100644 index 00000000..1ecf29b2 --- /dev/null +++ b/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 +} |