fix(inputs.snmp_trap): Handle octet strings (#14619)

plugins/inputs/snmp_trap/snmp_trap.go

@@ -3,11 +3,13 @@ package snmp_trap
 
 import (
 	_ "embed"
+	"encoding/hex"
 	"fmt"
 	"net"
 	"strconv"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"github.com/gosnmp/gosnmp"
 
@@ -343,6 +345,13 @@ func makeTrapHandler(s *SnmpTrap) gosnmp.TrapHandlerFunc {
 					setTrapOid(tags, val, e)
 					continue
 				}
+			case gosnmp.OctetString:
+				// OctetStrings may contain hex data that needs its own conversion
+				if !utf8.ValidString(string(v.Value.([]byte)[:])) {
+					value = hex.EncodeToString(v.Value.([]byte))
+				} else {
+					value = v.Value
+				}
 			default:
 				value = v.Value
 			}

plugins/inputs/snmp_trap/snmp_trap_test.go

@@ -319,6 +319,11 @@ func TestReceiveTrap(t *testing.T) {
 						Type:  gosnmp.OctetString,
 						Value: "payload",
 					},
+					{
+						Name:  ".1.2.3.4.6",
+						Type:  gosnmp.OctetString,
+						Value: []byte{0x7, 0xe8, 0x1, 0x4, 0xe, 0x2, 0x19, 0x0, 0x0, 0xe, 0x2},
+					},
 				},
 				Enterprise:   ".1.2.3",
 				AgentAddress: "10.20.30.40",
@@ -334,6 +339,13 @@ func TestReceiveTrap(t *testing.T) {
 						OidText: "valueOID",
 					},
 				},
+				{
+					".1.2.3.4.6",
+					snmp.MibEntry{
+						MibName: "valueMIB",
+						OidText: "valueHexOID",
+					},
+				},
 				{
 					".1.3.6.1.6.3.1.1.5.1",
 					snmp.MibEntry{
@@ -357,6 +369,7 @@ func TestReceiveTrap(t *testing.T) {
 					map[string]interface{}{ // fields
 						"sysUpTimeInstance": uint(now),
 						"valueOID":          "payload",
+						"valueHexOID":       "07e801040e021900000e02",
 					},
 					fakeTime,
 				),