Don't read/check msg length

Remove leading and trailing spaces and/or newlines from syslog message
field.

plugins/inputs/syslog/syslog.go

@@ -1,6 +1,7 @@
 package syslog
 
 import (
+	"bytes"
 	"crypto/tls"
 	"fmt"
 	"io"
@@ -279,20 +280,51 @@ func (s *Syslog) handle(conn net.Conn, acc telegraf.Accumulator) {
 		conn.Close()
 	}()
 
-	if s.ReadTimeout != nil && s.ReadTimeout.Duration > 0 {
-		conn.SetReadDeadline(time.Now().Add(s.ReadTimeout.Duration))
-	}
+	for {
+		data := &bytes.Buffer{}
 
-	var p *rfc5425.Parser
-	if s.BestEffort {
-		p = rfc5425.NewParser(conn, rfc5425.WithBestEffort())
-	} else {
-		p = rfc5425.NewParser(conn)
-	}
+		// read the data
+		if s.ReadTimeout != nil && s.ReadTimeout.Duration > 0 {
+			conn.SetReadDeadline(time.Now().Add(s.ReadTimeout.Duration))
+		}
 
-	p.ParseExecuting(func(r *rfc5425.Result) {
-		s.store(*r, acc)
-	})
+		n, err := io.Copy(data, conn)
+		if err != nil {
+			// read timeout reached, parse what we have
+			if er, ok := err.(net.Error); ok && er.Timeout() {
+				if n == 0 {
+					continue
+				}
+				goto parseMsg
+			}
+			// client has closed connection, return
+			if err == io.EOF {
+				if n > 0 {
+					goto parseMsg
+				}
+				return
+			}
+			// other error, log and return
+			s.store(rfc5425.Result{Error: fmt.Errorf("failed reading from syslog client - %s", err.Error())}, acc)
+			return
+		}
+		// handle client disconnect
+		if n == 0 {
+			return
+		}
+
+	parseMsg:
+		var p *rfc5425.Parser
+		if s.BestEffort {
+			p = rfc5425.NewParser(data, rfc5425.WithBestEffort())
+		} else {
+			p = rfc5425.NewParser(data)
+		}
+
+		p.ParseExecuting(func(r *rfc5425.Result) {
+			s.store(*r, acc)
+		})
+	}
 }
 
 func (s *Syslog) setKeepAlive(c *net.TCPConn) error {
@@ -361,7 +393,7 @@ func fields(msg rfc5424.SyslogMessage, s *Syslog) map[string]interface{} {
 	}
 
 	if msg.Message() != nil {
-		flds["message"] = *msg.Message()
+		flds["message"] = strings.TrimSpace(*msg.Message())
 	}
 
 	if msg.StructuredData() != nil {