5 files changed, 724 insertions, 0 deletions

diff --git a/src/log/syslog/syslog.go b/src/log/syslog/syslog.go
new file mode 100644
index 000000000..5e0959916
--- /dev/null
+++ b/src/log/syslog/syslog.go
@@ -0,0 +1,319 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows,!nacl,!plan9
+
+// Package syslog provides a simple interface to the system log
+// service. It can send messages to the syslog daemon using UNIX
+// domain sockets, UDP or TCP.
+//
+// Only one call to Dial is necessary. On write failures,
+// the syslog client will attempt to reconnect to the server
+// and write again.
+package syslog
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"strings"
+	"sync"
+	"time"
+)
+
+// The Priority is a combination of the syslog facility and
+// severity. For example, LOG_ALERT | LOG_FTP sends an alert severity
+// message from the FTP facility. The default severity is LOG_EMERG;
+// the default facility is LOG_KERN.
+type Priority int
+
+const severityMask = 0x07
+const facilityMask = 0xf8
+
+const (
+	// Severity.
+
+	// From /usr/include/sys/syslog.h.
+	// These are the same on Linux, BSD, and OS X.
+	LOG_EMERG Priority = iota
+	LOG_ALERT
+	LOG_CRIT
+	LOG_ERR
+	LOG_WARNING
+	LOG_NOTICE
+	LOG_INFO
+	LOG_DEBUG
+)
+
+const (
+	// Facility.
+
+	// From /usr/include/sys/syslog.h.
+	// These are the same up to LOG_FTP on Linux, BSD, and OS X.
+	LOG_KERN Priority = iota << 3
+	LOG_USER
+	LOG_MAIL
+	LOG_DAEMON
+	LOG_AUTH
+	LOG_SYSLOG
+	LOG_LPR
+	LOG_NEWS
+	LOG_UUCP
+	LOG_CRON
+	LOG_AUTHPRIV
+	LOG_FTP
+	_ // unused
+	_ // unused
+	_ // unused
+	_ // unused
+	LOG_LOCAL0
+	LOG_LOCAL1
+	LOG_LOCAL2
+	LOG_LOCAL3
+	LOG_LOCAL4
+	LOG_LOCAL5
+	LOG_LOCAL6
+	LOG_LOCAL7
+)
+
+// A Writer is a connection to a syslog server.
+type Writer struct {
+	priority Priority
+	tag      string
+	hostname string
+	network  string
+	raddr    string
+
+	mu   sync.Mutex // guards conn
+	conn serverConn
+}
+
+// This interface and the separate syslog_unix.go file exist for
+// Solaris support as implemented by gccgo.  On Solaris you can not
+// simply open a TCP connection to the syslog daemon.  The gccgo
+// sources have a syslog_solaris.go file that implements unixSyslog to
+// return a type that satisfies this interface and simply calls the C
+// library syslog function.
+type serverConn interface {
+	writeString(p Priority, hostname, tag, s, nl string) error
+	close() error
+}
+
+type netConn struct {
+	local bool
+	conn  net.Conn
+}
+
+// New establishes a new connection to the system log daemon.  Each
+// write to the returned writer sends a log message with the given
+// priority and prefix.
+func New(priority Priority, tag string) (w *Writer, err error) {
+	return Dial("", "", priority, tag)
+}
+
+// Dial establishes a connection to a log daemon by connecting to
+// address raddr on the specified network.  Each write to the returned
+// writer sends a log message with the given facility, severity and
+// tag.
+// If network is empty, Dial will connect to the local syslog server.
+func Dial(network, raddr string, priority Priority, tag string) (*Writer, error) {
+	if priority < 0 || priority > LOG_LOCAL7|LOG_DEBUG {
+		return nil, errors.New("log/syslog: invalid priority")
+	}
+
+	if tag == "" {
+		tag = os.Args[0]
+	}
+	hostname, _ := os.Hostname()
+
+	w := &Writer{
+		priority: priority,
+		tag:      tag,
+		hostname: hostname,
+		network:  network,
+		raddr:    raddr,
+	}
+
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	err := w.connect()
+	if err != nil {
+		return nil, err
+	}
+	return w, err
+}
+
+// connect makes a connection to the syslog server.
+// It must be called with w.mu held.
+func (w *Writer) connect() (err error) {
+	if w.conn != nil {
+		// ignore err from close, it makes sense to continue anyway
+		w.conn.close()
+		w.conn = nil
+	}
+
+	if w.network == "" {
+		w.conn, err = unixSyslog()
+		if w.hostname == "" {
+			w.hostname = "localhost"
+		}
+	} else {
+		var c net.Conn
+		c, err = net.Dial(w.network, w.raddr)
+		if err == nil {
+			w.conn = &netConn{conn: c}
+			if w.hostname == "" {
+				w.hostname = c.LocalAddr().String()
+			}
+		}
+	}
+	return
+}
+
+// Write sends a log message to the syslog daemon.
+func (w *Writer) Write(b []byte) (int, error) {
+	return w.writeAndRetry(w.priority, string(b))
+}
+
+// Close closes a connection to the syslog daemon.
+func (w *Writer) Close() error {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if w.conn != nil {
+		err := w.conn.close()
+		w.conn = nil
+		return err
+	}
+	return nil
+}
+
+// Emerg logs a message with severity LOG_EMERG, ignoring the severity
+// passed to New.
+func (w *Writer) Emerg(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_EMERG, m)
+	return err
+}
+
+// Alert logs a message with severity LOG_ALERT, ignoring the severity
+// passed to New.
+func (w *Writer) Alert(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_ALERT, m)
+	return err
+}
+
+// Crit logs a message with severity LOG_CRIT, ignoring the severity
+// passed to New.
+func (w *Writer) Crit(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_CRIT, m)
+	return err
+}
+
+// Err logs a message with severity LOG_ERR, ignoring the severity
+// passed to New.
+func (w *Writer) Err(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_ERR, m)
+	return err
+}
+
+// Warning logs a message with severity LOG_WARNING, ignoring the
+// severity passed to New.
+func (w *Writer) Warning(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_WARNING, m)
+	return err
+}
+
+// Notice logs a message with severity LOG_NOTICE, ignoring the
+// severity passed to New.
+func (w *Writer) Notice(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_NOTICE, m)
+	return err
+}
+
+// Info logs a message with severity LOG_INFO, ignoring the severity
+// passed to New.
+func (w *Writer) Info(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_INFO, m)
+	return err
+}
+
+// Debug logs a message with severity LOG_DEBUG, ignoring the severity
+// passed to New.
+func (w *Writer) Debug(m string) (err error) {
+	_, err = w.writeAndRetry(LOG_DEBUG, m)
+	return err
+}
+
+func (w *Writer) writeAndRetry(p Priority, s string) (int, error) {
+	pr := (w.priority & facilityMask) | (p & severityMask)
+
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if w.conn != nil {
+		if n, err := w.write(pr, s); err == nil {
+			return n, err
+		}
+	}
+	if err := w.connect(); err != nil {
+		return 0, err
+	}
+	return w.write(pr, s)
+}
+
+// write generates and writes a syslog formatted string. The
+// format is as follows: <PRI>TIMESTAMP HOSTNAME TAG[PID]: MSG
+func (w *Writer) write(p Priority, msg string) (int, error) {
+	// ensure it ends in a \n
+	nl := ""
+	if !strings.HasSuffix(msg, "\n") {
+		nl = "\n"
+	}
+
+	err := w.conn.writeString(p, w.hostname, w.tag, msg, nl)
+	if err != nil {
+		return 0, err
+	}
+	// Note: return the length of the input, not the number of
+	// bytes printed by Fprintf, because this must behave like
+	// an io.Writer.
+	return len(msg), nil
+}
+
+func (n *netConn) writeString(p Priority, hostname, tag, msg, nl string) error {
+	if n.local {
+		// Compared to the network form below, the changes are:
+		//	1. Use time.Stamp instead of time.RFC3339.
+		//	2. Drop the hostname field from the Fprintf.
+		timestamp := time.Now().Format(time.Stamp)
+		_, err := fmt.Fprintf(n.conn, "<%d>%s %s[%d]: %s%s",
+			p, timestamp,
+			tag, os.Getpid(), msg, nl)
+		return err
+	}
+	timestamp := time.Now().Format(time.RFC3339)
+	_, err := fmt.Fprintf(n.conn, "<%d>%s %s %s[%d]: %s%s",
+		p, timestamp, hostname,
+		tag, os.Getpid(), msg, nl)
+	return err
+}
+
+func (n *netConn) close() error {
+	return n.conn.Close()
+}
+
+// NewLogger creates a log.Logger whose output is written to
+// the system log service with the specified priority. The logFlag
+// argument is the flag set passed through to log.New to create
+// the Logger.
+func NewLogger(p Priority, logFlag int) (*log.Logger, error) {
+	s, err := New(p, "")
+	if err != nil {
+		return nil, err
+	}
+	return log.New(s, "", logFlag), nil
+}
diff --git a/src/log/syslog/syslog_plan9.go b/src/log/syslog/syslog_plan9.go
new file mode 100644
index 000000000..0c05f6f83
--- /dev/null
+++ b/src/log/syslog/syslog_plan9.go
@@ -0,0 +1,8 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package syslog provides a simple interface to the system log service.
+package syslog
+
+// BUG(akumar): This package is not implemented on Plan 9 yet.
diff --git a/src/log/syslog/syslog_test.go b/src/log/syslog/syslog_test.go
new file mode 100644
index 000000000..6a863fed3
--- /dev/null
+++ b/src/log/syslog/syslog_test.go
@@ -0,0 +1,358 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows,!nacl,!plan9
+
+package syslog
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"sync"
+	"testing"
+	"time"
+)
+
+func runPktSyslog(c net.PacketConn, done chan<- string) {
+	var buf [4096]byte
+	var rcvd string
+	ct := 0
+	for {
+		var n int
+		var err error
+
+		c.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
+		n, _, err = c.ReadFrom(buf[:])
+		rcvd += string(buf[:n])
+		if err != nil {
+			if oe, ok := err.(*net.OpError); ok {
+				if ct < 3 && oe.Temporary() {
+					ct++
+					continue
+				}
+			}
+			break
+		}
+	}
+	c.Close()
+	done <- rcvd
+}
+
+var crashy = false
+
+func runStreamSyslog(l net.Listener, done chan<- string, wg *sync.WaitGroup) {
+	for {
+		var c net.Conn
+		var err error
+		if c, err = l.Accept(); err != nil {
+			return
+		}
+		wg.Add(1)
+		go func(c net.Conn) {
+			defer wg.Done()
+			c.SetReadDeadline(time.Now().Add(5 * time.Second))
+			b := bufio.NewReader(c)
+			for ct := 1; !crashy || ct&7 != 0; ct++ {
+				s, err := b.ReadString('\n')
+				if err != nil {
+					break
+				}
+				done <- s
+			}
+			c.Close()
+		}(c)
+	}
+}
+
+func startServer(n, la string, done chan<- string) (addr string, sock io.Closer, wg *sync.WaitGroup) {
+	if n == "udp" || n == "tcp" {
+		la = "127.0.0.1:0"
+	} else {
+		// unix and unixgram: choose an address if none given
+		if la == "" {
+			// use ioutil.TempFile to get a name that is unique
+			f, err := ioutil.TempFile("", "syslogtest")
+			if err != nil {
+				log.Fatal("TempFile: ", err)
+			}
+			f.Close()
+			la = f.Name()
+		}
+		os.Remove(la)
+	}
+
+	wg = new(sync.WaitGroup)
+	if n == "udp" || n == "unixgram" {
+		l, e := net.ListenPacket(n, la)
+		if e != nil {
+			log.Fatalf("startServer failed: %v", e)
+		}
+		addr = l.LocalAddr().String()
+		sock = l
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			runPktSyslog(l, done)
+		}()
+	} else {
+		l, e := net.Listen(n, la)
+		if e != nil {
+			log.Fatalf("startServer failed: %v", e)
+		}
+		addr = l.Addr().String()
+		sock = l
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			runStreamSyslog(l, done, wg)
+		}()
+	}
+	return
+}
+
+func TestWithSimulated(t *testing.T) {
+	msg := "Test 123"
+	transport := []string{"unix", "unixgram", "udp", "tcp"}
+
+	for _, tr := range transport {
+		done := make(chan string)
+		addr, sock, srvWG := startServer(tr, "", done)
+		defer srvWG.Wait()
+		defer sock.Close()
+		if tr == "unix" || tr == "unixgram" {
+			defer os.Remove(addr)
+		}
+		s, err := Dial(tr, addr, LOG_INFO|LOG_USER, "syslog_test")
+		if err != nil {
+			t.Fatalf("Dial() failed: %v", err)
+		}
+		err = s.Info(msg)
+		if err != nil {
+			t.Fatalf("log failed: %v", err)
+		}
+		check(t, msg, <-done)
+		s.Close()
+	}
+}
+
+func TestFlap(t *testing.T) {
+	net := "unix"
+	done := make(chan string)
+	addr, sock, srvWG := startServer(net, "", done)
+	defer srvWG.Wait()
+	defer os.Remove(addr)
+	defer sock.Close()
+
+	s, err := Dial(net, addr, LOG_INFO|LOG_USER, "syslog_test")
+	if err != nil {
+		t.Fatalf("Dial() failed: %v", err)
+	}
+	msg := "Moo 2"
+	err = s.Info(msg)
+	if err != nil {
+		t.Fatalf("log failed: %v", err)
+	}
+	check(t, msg, <-done)
+
+	// restart the server
+	_, sock2, srvWG2 := startServer(net, addr, done)
+	defer srvWG2.Wait()
+	defer sock2.Close()
+
+	// and try retransmitting
+	msg = "Moo 3"
+	err = s.Info(msg)
+	if err != nil {
+		t.Fatalf("log failed: %v", err)
+	}
+	check(t, msg, <-done)
+
+	s.Close()
+}
+
+func TestNew(t *testing.T) {
+	if LOG_LOCAL7 != 23<<3 {
+		t.Fatalf("LOG_LOCAL7 has wrong value")
+	}
+	if testing.Short() {
+		// Depends on syslog daemon running, and sometimes it's not.
+		t.Skip("skipping syslog test during -short")
+	}
+
+	s, err := New(LOG_INFO|LOG_USER, "the_tag")
+	if err != nil {
+		t.Fatalf("New() failed: %s", err)
+	}
+	// Don't send any messages.
+	s.Close()
+}
+
+func TestNewLogger(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping syslog test during -short")
+	}
+	f, err := NewLogger(LOG_USER|LOG_INFO, 0)
+	if f == nil {
+		t.Error(err)
+	}
+}
+
+func TestDial(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping syslog test during -short")
+	}
+	f, err := Dial("", "", (LOG_LOCAL7|LOG_DEBUG)+1, "syslog_test")
+	if f != nil {
+		t.Fatalf("Should have trapped bad priority")
+	}
+	f, err = Dial("", "", -1, "syslog_test")
+	if f != nil {
+		t.Fatalf("Should have trapped bad priority")
+	}
+	l, err := Dial("", "", LOG_USER|LOG_ERR, "syslog_test")
+	if err != nil {
+		t.Fatalf("Dial() failed: %s", err)
+	}
+	l.Close()
+}
+
+func check(t *testing.T, in, out string) {
+	tmpl := fmt.Sprintf("<%d>%%s %%s syslog_test[%%d]: %s\n", LOG_USER+LOG_INFO, in)
+	if hostname, err := os.Hostname(); err != nil {
+		t.Error("Error retrieving hostname")
+	} else {
+		var parsedHostname, timestamp string
+		var pid int
+		if n, err := fmt.Sscanf(out, tmpl, &timestamp, &parsedHostname, &pid); n != 3 || err != nil || hostname != parsedHostname {
+			t.Errorf("Got %q, does not match template %q (%d %s)", out, tmpl, n, err)
+		}
+	}
+}
+
+func TestWrite(t *testing.T) {
+	tests := []struct {
+		pri Priority
+		pre string
+		msg string
+		exp string
+	}{
+		{LOG_USER | LOG_ERR, "syslog_test", "", "%s %s syslog_test[%d]: \n"},
+		{LOG_USER | LOG_ERR, "syslog_test", "write test", "%s %s syslog_test[%d]: write test\n"},
+		// Write should not add \n if there already is one
+		{LOG_USER | LOG_ERR, "syslog_test", "write test 2\n", "%s %s syslog_test[%d]: write test 2\n"},
+	}
+
+	if hostname, err := os.Hostname(); err != nil {
+		t.Fatalf("Error retrieving hostname")
+	} else {
+		for _, test := range tests {
+			done := make(chan string)
+			addr, sock, srvWG := startServer("udp", "", done)
+			defer srvWG.Wait()
+			defer sock.Close()
+			l, err := Dial("udp", addr, test.pri, test.pre)
+			if err != nil {
+				t.Fatalf("syslog.Dial() failed: %v", err)
+			}
+			defer l.Close()
+			_, err = io.WriteString(l, test.msg)
+			if err != nil {
+				t.Fatalf("WriteString() failed: %v", err)
+			}
+			rcvd := <-done
+			test.exp = fmt.Sprintf("<%d>", test.pri) + test.exp
+			var parsedHostname, timestamp string
+			var pid int
+			if n, err := fmt.Sscanf(rcvd, test.exp, &timestamp, &parsedHostname, &pid); n != 3 || err != nil || hostname != parsedHostname {
+				t.Errorf("s.Info() = '%q', didn't match '%q' (%d %s)", rcvd, test.exp, n, err)
+			}
+		}
+	}
+}
+
+func TestConcurrentWrite(t *testing.T) {
+	addr, sock, srvWG := startServer("udp", "", make(chan string, 1))
+	defer srvWG.Wait()
+	defer sock.Close()
+	w, err := Dial("udp", addr, LOG_USER|LOG_ERR, "how's it going?")
+	if err != nil {
+		t.Fatalf("syslog.Dial() failed: %v", err)
+	}
+	var wg sync.WaitGroup
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			err := w.Info("test")
+			if err != nil {
+				t.Errorf("Info() failed: %v", err)
+				return
+			}
+		}()
+	}
+	wg.Wait()
+}
+
+func TestConcurrentReconnect(t *testing.T) {
+	crashy = true
+	defer func() { crashy = false }()
+
+	const N = 10
+	const M = 100
+	net := "unix"
+	done := make(chan string, N*M)
+	addr, sock, srvWG := startServer(net, "", done)
+	defer os.Remove(addr)
+
+	// count all the messages arriving
+	count := make(chan int)
+	go func() {
+		ct := 0
+		for range done {
+			ct++
+			// we are looking for 500 out of 1000 events
+			// here because lots of log messages are lost
+			// in buffers (kernel and/or bufio)
+			if ct > N*M/2 {
+				break
+			}
+		}
+		count <- ct
+	}()
+
+	var wg sync.WaitGroup
+	wg.Add(N)
+	for i := 0; i < N; i++ {
+		go func() {
+			defer wg.Done()
+			w, err := Dial(net, addr, LOG_USER|LOG_ERR, "tag")
+			if err != nil {
+				t.Fatalf("syslog.Dial() failed: %v", err)
+			}
+			defer w.Close()
+			for i := 0; i < M; i++ {
+				err := w.Info("test")
+				if err != nil {
+					t.Errorf("Info() failed: %v", err)
+					return
+				}
+			}
+		}()
+	}
+	wg.Wait()
+	sock.Close()
+	srvWG.Wait()
+	close(done)
+
+	select {
+	case <-count:
+	case <-time.After(100 * time.Millisecond):
+		t.Error("timeout in concurrent reconnect")
+	}
+}
diff --git a/src/log/syslog/syslog_unix.go b/src/log/syslog/syslog_unix.go
new file mode 100644
index 000000000..1cdabec69
--- /dev/null
+++ b/src/log/syslog/syslog_unix.go
@@ -0,0 +1,31 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !windows,!nacl,!plan9
+
+package syslog
+
+import (
+	"errors"
+	"net"
+)
+
+// unixSyslog opens a connection to the syslog daemon running on the
+// local machine using a Unix domain socket.
+
+func unixSyslog() (conn serverConn, err error) {
+	logTypes := []string{"unixgram", "unix"}
+	logPaths := []string{"/dev/log", "/var/run/syslog", "/var/run/log"}
+	for _, network := range logTypes {
+		for _, path := range logPaths {
+			conn, err := net.Dial(network, path)
+			if err != nil {
+				continue
+			} else {
+				return &netConn{conn: conn, local: true}, nil
+			}
+		}
+	}
+	return nil, errors.New("Unix syslog delivery error")
+}
diff --git a/src/log/syslog/syslog_windows.go b/src/log/syslog/syslog_windows.go
new file mode 100644
index 000000000..8d99e2e59
--- /dev/null
+++ b/src/log/syslog/syslog_windows.go
@@ -0,0 +1,8 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package syslog provides a simple interface to the system log service.
+package syslog
+
+// BUG(brainman): This package is not implemented on Windows yet.