feat(inputs.snmp): Add displayhint conversion (influxdata#15935)

internal/snmp/field.go

@@ -12,6 +12,9 @@ import (
 	"unicode/utf8"
 
 	"github.com/gosnmp/gosnmp"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/config"
 )
 
 // Field holds the configuration for a Field to look up.
@@ -36,6 +39,7 @@ type Field struct {
 	//  "hwaddr" will convert a 6-byte string to a MAC address.
 	//  "ipaddr" will convert the value to an IPv4 or IPv6 address.
 	//  "enum"/"enum(1)" will convert the value according to its syntax. (Only supported with gosmi translator)
+	//  "displayhint" will format the value according to the textual convention. (Only supported with gosmi translator)
 	Conversion string
 	// Translate tells if the value of the field should be snmptranslated
 	Translate bool
@@ -78,7 +82,6 @@ func (f *Field) Init(tr Translator) error {
 		if f.Conversion == "" {
 			f.Conversion = conversion
 		}
-		// TODO use textual convention conversion from the MIB
 	}
 
 	if f.SecondaryIndexTable && f.SecondaryIndexUse {
@@ -89,38 +92,46 @@ func (f *Field) Init(tr Translator) error {
 		return errors.New("SecondaryOuterJoin set to true, but field is not being used in join")
 	}
 
+	switch f.Conversion {
+	case "hwaddr", "enum(1)":
+		config.PrintOptionValueDeprecationNotice("inputs.snmp", "field.conversion", f.Conversion, telegraf.DeprecationInfo{
+			Since:  "1.33.0",
+			Notice: "Use 'displayhint' instead",
+		})
+	}
+
 	f.initialized = true
 	return nil
 }
 
 // fieldConvert converts from any type according to the conv specification
 func (f *Field) Convert(ent gosnmp.SnmpPDU) (interface{}, error) {
+	v := ent.Value
+
 	// snmptranslate table field value here
 	if f.Translate {
-		if entOid, ok := ent.Value.(string); ok {
+		if entOid, ok := v.(string); ok {
 			_, _, oidText, _, err := f.translator.SnmpTranslate(entOid)
 			if err == nil {
-				// If no error translating, the original value for ent.Value should be replaced
-				ent.Value = oidText
+				// If no error translating, the original value should be replaced
+				v = oidText
 			}
 		}
 	}
 
 	if f.Conversion == "" {
 		// OctetStrings may contain hex data that needs its own conversion
-		if ent.Type == gosnmp.OctetString && !utf8.Valid(ent.Value.([]byte)[:]) {
-			return hex.EncodeToString(ent.Value.([]byte)), nil
+		if ent.Type == gosnmp.OctetString && !utf8.Valid(v.([]byte)[:]) {
+			return hex.EncodeToString(v.([]byte)), nil
 		}
-		if bs, ok := ent.Value.([]byte); ok {
+		if bs, ok := v.([]byte); ok {
 			return string(bs), nil
 		}
-		return ent.Value, nil
+		return v, nil
 	}
 
-	var v interface{}
 	var d int
 	if _, err := fmt.Sscanf(f.Conversion, "float(%d)", &d); err == nil || f.Conversion == "float" {
-		v = ent.Value
 		switch vt := v.(type) {
 		case float32:
 			v = float64(vt) / math.Pow10(d)
@@ -163,7 +174,6 @@ func (f *Field) Convert(ent gosnmp.SnmpPDU) (interface{}, error) {
 	}
 
 	if f.Conversion == "int" {
-		v = ent.Value
 		var err error
 		switch vt := v.(type) {
 		case float32:
@@ -198,8 +208,9 @@ func (f *Field) Convert(ent gosnmp.SnmpPDU) (interface{}, error) {
 		return v, err
 	}
 
+	// Deprecated: Use displayhint instead
 	if f.Conversion == "hwaddr" {
-		switch vt := ent.Value.(type) {
+		switch vt := v.(type) {
 		case string:
 			v = net.HardwareAddr(vt).String()
 		case []byte:
@@ -211,7 +222,7 @@ func (f *Field) Convert(ent gosnmp.SnmpPDU) (interface{}, error) {
 	}
 
 	if f.Conversion == "hex" {
-		switch vt := ent.Value.(type) {
+		switch vt := v.(type) {
 		case string:
 			switch ent.Type {
 			case gosnmp.IPAddress:
@@ -237,9 +248,9 @@ func (f *Field) Convert(ent gosnmp.SnmpPDU) (interface{}, error) {
 		endian := split[1]
 		bit := split[2]
 
-		bv, ok := ent.Value.([]byte)
+		bv, ok := v.([]byte)
 		if !ok {
-			return ent.Value, nil
+			return v, nil
 		}
 
 		switch endian {
@@ -275,7 +286,7 @@ func (f *Field) Convert(ent gosnmp.SnmpPDU) (interface{}, error) {
 	if f.Conversion == "ipaddr" {
 		var ipbs []byte
 
-		switch vt := ent.Value.(type) {
+		switch vt := v.(type) {
 		case string:
 			ipbs = []byte(vt)
 		case []byte:
@@ -298,9 +309,14 @@ func (f *Field) Convert(ent gosnmp.SnmpPDU) (interface{}, error) {
 		return f.translator.SnmpFormatEnum(ent.Name, ent.Value, false)
 	}
 
+	// Deprecated: Use displayhint instead
 	if f.Conversion == "enum(1)" {
 		return f.translator.SnmpFormatEnum(ent.Name, ent.Value, true)
 	}
 
+	if f.Conversion == "displayhint" {
+		return f.translator.SnmpFormatDisplayHint(ent.Name, ent.Value)
+	}
+
 	return nil, fmt.Errorf("invalid conversion type %q", f.Conversion)
 }

internal/snmp/testdata/gosmi/server

@@ -14,6 +14,39 @@ TestMIB MODULE-IDENTITY
         "
     ::= { iso 1 }
 
+DateAndTime ::= TEXTUAL-CONVENTION
+    DISPLAY-HINT "2d-1d-1d,1d:1d:1d.1d,1a1d:1d"
+    STATUS       current
+    DESCRIPTION
+            "A date-time specification.
+
+            field  octets  contents                  range
+            -----  ------  --------                  -----
+              1      1-2   year*                     0..65536
+              2       3    month                     1..12
+              3       4    day                       1..31
+              4       5    hour                      0..23
+              5       6    minutes                   0..59
+              6       7    seconds                   0..60
+                           (use 60 for leap-second)
+              7       8    deci-seconds              0..9
+              8       9    direction from UTC        '+' / '-'
+              9      10    hours from UTC*           0..13
+             10      11    minutes from UTC          0..59
+
+            * Notes:
+            - the value of year is in network-byte order
+            - daylight saving time in New Zealand is +13
+
+            For example, Tuesday May 26, 1992 at 1:30:15 PM EDT would be
+            displayed as:
+
+                             1992-5-26,13:30:15.0,-4:0
+
+            Note that if only local time is known, then timezone
+            information (fields 8-10) is not present."
+    SYNTAX       OCTET STRING (SIZE (8 | 11))
+
 testingObjects OBJECT IDENTIFIER ::= { iso 0 }
 testObjects OBJECT IDENTIFIER ::= { testingObjects 0 }
 hostnameone OBJECT IDENTIFIER ::= {testObjects 1 }
@@ -54,4 +87,12 @@ description OBJECT-TYPE
                 "server mib for testing"
             ::= { testMIBObjects 4 }   
 
-END
+dateAndTime OBJECT-TYPE 
+    SYNTAX DateAndTime
+    ACCESS read-only
+    STATUS current 
+    DESCRIPTION
+        "A date-time specification."
+    ::= { testMIBObjects 5 }   
+
+END

internal/snmp/testdata/gosmi/tableMib

@@ -25,12 +25,12 @@ DisplayString ::=
 --
 --      SIZE (0..255)
 
-PhysAddress ::=
-    OCTET STRING
--- This data type is used to model media addresses.  For many
--- types of media, this will be in a binary representation.
--- For example, an ethernet address would be represented as
--- a string of 6 octets.
+PhysAddress ::= TEXTUAL-CONVENTION
+    DISPLAY-HINT "1x:"
+    STATUS       current
+    DESCRIPTION
+            "Represents media- or physical-level addresses."
+    SYNTAX       OCTET STRING
 
 -- groups in MIB-II
 

internal/snmp/translator.go

@@ -21,4 +21,9 @@ type Translator interface {
 		formatted string,
 		err error,
 	)
+
+	SnmpFormatDisplayHint(oid string, value interface{}) (
+		formatted string,
+		err error,
+	)
 }

internal/snmp/translator_gosmi.go

@@ -74,6 +74,22 @@ func (g *gosmiTranslator) SnmpFormatEnum(oid string, value interface{}, full boo
 	return v.Formatted, nil
 }
 
+func (g *gosmiTranslator) SnmpFormatDisplayHint(oid string, value interface{}) (string, error) {
+	if value == nil {
+		return "", nil
+	}
+
+	//nolint:dogsled // only need to get the node
+	_, _, _, _, node, err := snmpTranslateCall(oid)
+	if err != nil {
+		return "", err
+	}
+
+	v := node.FormatValue(value)
+
+	return v.Formatted, nil
+}
+
 func getIndex(mibPrefix string, node gosmi.SmiNode) (col []string, tagOids map[string]struct{}) {
 	// first attempt to get the table's tags
 	tagOids = map[string]struct{}{}
@@ -154,18 +170,20 @@ func snmpTranslateCall(oid string) (mibName string, oidNum string, oidText strin
 	}
 
 	tc := out.GetSubtree()
-
 	for i := range tc {
 		// case where the mib doesn't have a conversion so Type struct will be nil
 		// prevents seg fault
 		if tc[i].Type == nil {
 			break
 		}
-		switch tc[i].Type.Name {
-		case "MacAddress", "PhysAddress":
-			conversion = "hwaddr"
-		case "InetAddressIPv4", "InetAddressIPv6", "InetAddress", "IPSIpAddress":
-			conversion = "ipaddr"
+
+		if tc[i].Type.Format != "" {
+			conversion = "displayhint"
+		} else {
+			switch tc[i].Type.Name {
+			case "InetAddress", "IPSIpAddress":
+				conversion = "ipaddr"
+			}
 		}
 	}
 

internal/snmp/translator_gosmi_test.go

@@ -42,9 +42,10 @@ func TestFieldInitGosmi(t *testing.T) {
 		{".1.2.3", "foo", "", ".1.2.3", "foo", ""},
 		{".iso.2.3", "foo", "", ".1.2.3", "foo", ""},
 		{".1.0.0.0.1.1", "", "", ".1.0.0.0.1.1", "server", ""},
-		{"IF-MIB::ifPhysAddress.1", "", "", ".1.3.6.1.2.1.2.2.1.6.1", "ifPhysAddress.1", "hwaddr"},
+		{".1.0.0.0.1.5", "", "", ".1.0.0.0.1.5", "dateAndTime", "displayhint"},
+		{"IF-MIB::ifPhysAddress.1", "", "", ".1.3.6.1.2.1.2.2.1.6.1", "ifPhysAddress.1", "displayhint"},
 		{"IF-MIB::ifPhysAddress.1", "", "none", ".1.3.6.1.2.1.2.2.1.6.1", "ifPhysAddress.1", "none"},
-		{"BRIDGE-MIB::dot1dTpFdbAddress.1", "", "", ".1.3.6.1.2.1.17.4.3.1.1.1", "dot1dTpFdbAddress.1", "hwaddr"},
+		{"BRIDGE-MIB::dot1dTpFdbAddress.1", "", "", ".1.3.6.1.2.1.17.4.3.1.1.1", "dot1dTpFdbAddress.1", "displayhint"},
 		{"TCP-MIB::tcpConnectionLocalAddress.1", "", "", ".1.3.6.1.2.1.6.19.1.2.1", "tcpConnectionLocalAddress.1", "ipaddr"},
 		{".999", "", "", ".999", ".999", ""},
 	}
@@ -89,7 +90,7 @@ func TestTableInitGosmi(t *testing.T) {
 	require.Equal(t, ".1.3.6.1.2.1.3.1.1.2", tbl.Fields[2].Oid)
 	require.Equal(t, "atPhysAddress", tbl.Fields[2].Name)
 	require.False(t, tbl.Fields[2].IsTag)
-	require.Equal(t, "hwaddr", tbl.Fields[2].Conversion)
+	require.Equal(t, "displayhint", tbl.Fields[2].Conversion)
 
 	require.Equal(t, ".1.3.6.1.2.1.3.1.1.3", tbl.Fields[4].Oid)
 	require.Equal(t, "atNetAddress", tbl.Fields[4].Name)
@@ -355,6 +356,48 @@ func TestFieldConvertGosmi(t *testing.T) {
 	}
 }
 
+func TestSnmpFormatDisplayHint(t *testing.T) {
+	tests := []struct {
+		name     string
+		oid      string
+		input    interface{}
+		expected string
+	}{
+		{
+			name:     "ifOperStatus",
+			oid:      ".1.3.6.1.2.1.2.2.1.8",
+			input:    3,
+			expected: "testing(3)",
+		}, {
+			name:     "ifPhysAddress",
+			oid:      ".1.3.6.1.2.1.2.2.1.6",
+			input:    []byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef},
+			expected: "01:23:45:67:89:ab:cd:ef",
+		}, {
+			name:     "DateAndTime short",
+			oid:      ".1.0.0.0.1.5",
+			input:    []byte{0x07, 0xe8, 0x09, 0x18, 0x10, 0x24, 0x27, 0x05},
+			expected: "2024-9-24,16:36:39.5",
+		}, {
+			name:     "DateAndTime long",
+			oid:      ".1.0.0.0.1.5",
+			input:    []byte{0x07, 0xe8, 0x09, 0x18, 0x10, 0x24, 0x27, 0x05, 0x2b, 0x02, 0x00},
+			expected: "2024-9-24,16:36:39.5,+2:0",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tr := getGosmiTr(t)
+
+			actual, err := tr.SnmpFormatDisplayHint(tt.oid, tt.input)
+			require.NoError(t, err)
+
+			require.Equal(t, tt.expected, actual)
+		})
+	}
+}
+
 func TestTableJoin_walkGosmi(t *testing.T) {
 	tbl := Table{
 		Name:       "mytable",

internal/snmp/translator_netsnmp.go

@@ -266,3 +266,7 @@ func (n *netsnmpTranslator) snmpTranslateCall(oid string) (mibName string, oidNu
 func (n *netsnmpTranslator) SnmpFormatEnum(_ string, _ interface{}, _ bool) (string, error) {
 	return "", errors.New("not implemented in netsnmp translator")
 }
+
+func (n *netsnmpTranslator) SnmpFormatDisplayHint(_ string, _ interface{}) (string, error) {
+	return "", errors.New("not implemented in netsnmp translator")
+}

plugins/inputs/snmp/README.md

@@ -169,18 +169,17 @@ option operate similar to the `snmpget` utility.
     ##   float:       Convert the value into a float with no adjustment. Same
     ##                as `float(0)`.
     ##   int:         Convert the value into an integer.
-    ##   hwaddr:      Convert the value to a MAC address.
     ##   ipaddr:      Convert the value to an IP address.
     ##   hex:         Convert bytes to a hex string.
     ##   hextoint:X:Y Convert bytes to integer, where X is the endian and Y the
     ##                bit size. For example: hextoint:LittleEndian:uint64 or
     ##                hextoint:BigEndian:uint32. Valid options for the endian
     ##                are: BigEndian and LittleEndian. For the bit size: 
     ##                uint16, uint32 and uint64.
-    ##   enum(1):     Convert the value according to its syntax in the MIB (full).
-    ##                (Only supported with gosmi translator)
     ##   enum:        Convert the value according to its syntax in the MIB.
     ##                (Only supported with gosmi translator)
+    ##   displayhint: Format the value according to the textual convention in the MIB.
+    ##                (Only supported with gosmi translator)
     ##
     # conversion = ""
 ```

plugins/inputs/snmp/snmp_test.go

@@ -647,7 +647,7 @@ func TestSnmpInitGosmi(t *testing.T) {
 	require.Equal(t, ".1.3.6.1.2.1.3.1.1.2", s.Tables[0].Fields[1].Oid)
 	require.Equal(t, "atPhysAddress", s.Tables[0].Fields[1].Name)
 	require.False(t, s.Tables[0].Fields[1].IsTag)
-	require.Equal(t, "hwaddr", s.Tables[0].Fields[1].Conversion)
+	require.Equal(t, "displayhint", s.Tables[0].Fields[1].Conversion)
 
 	require.Equal(t, ".1.3.6.1.2.1.3.1.1.3", s.Tables[0].Fields[2].Oid)
 	require.Equal(t, "atNetAddress", s.Tables[0].Fields[2].Name)
@@ -657,7 +657,7 @@ func TestSnmpInitGosmi(t *testing.T) {
 	require.Equal(t, ".1.3.6.1.2.1.3.1.1.2", s.Fields[0].Oid)
 	require.Equal(t, "atPhysAddress", s.Fields[0].Name)
 	require.False(t, s.Fields[0].IsTag)
-	require.Equal(t, "hwaddr", s.Fields[0].Conversion)
+	require.Equal(t, "displayhint", s.Fields[0].Conversion)
 }
 
 func TestSnmpInit_noTranslateGosmi(t *testing.T) {