TUN-9467: bump coredns to solve CVE

* TUN-9467: bump coredns to solve CVE

vendor/github.com/prometheus/common/expfmt/decode.go

@@ -45,7 +45,7 @@ func ResponseFormat(h http.Header) Format {
 
 	mediatype, params, err := mime.ParseMediaType(ct)
 	if err != nil {
-		return fmtUnknown
+		return FmtUnknown
 	}
 
 	const textType = "text/plain"
@@ -53,21 +53,21 @@ func ResponseFormat(h http.Header) Format {
 	switch mediatype {
 	case ProtoType:
 		if p, ok := params["proto"]; ok && p != ProtoProtocol {
-			return fmtUnknown
+			return FmtUnknown
 		}
 		if e, ok := params["encoding"]; ok && e != "delimited" {
-			return fmtUnknown
+			return FmtUnknown
 		}
-		return fmtProtoDelim
+		return FmtProtoDelim
 
 	case textType:
 		if v, ok := params["version"]; ok && v != TextVersion {
-			return fmtUnknown
+			return FmtUnknown
 		}
-		return fmtText
+		return FmtText
 	}
 
-	return fmtUnknown
+	return FmtUnknown
 }
 
 // NewDecoder returns a new decoder based on the given input format.

vendor/github.com/prometheus/common/expfmt/encode.go

@@ -21,9 +21,10 @@ import (
 	"google.golang.org/protobuf/encoding/protodelim"
 	"google.golang.org/protobuf/encoding/prototext"
 
-	"github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg"
 	"github.com/prometheus/common/model"
 
+	"github.com/munnerz/goautoneg"
+
 	dto "github.com/prometheus/client_model/go"
 )
 
@@ -67,7 +68,7 @@ func Negotiate(h http.Header) Format {
 		if escapeParam := ac.Params[model.EscapingKey]; escapeParam != "" {
 			switch Format(escapeParam) {
 			case model.AllowUTF8, model.EscapeUnderscores, model.EscapeDots, model.EscapeValues:
-				escapingScheme = Format(fmt.Sprintf("; escaping=%s", escapeParam))
+				escapingScheme = Format("; escaping=" + escapeParam)
 			default:
 				// If the escaping parameter is unknown, ignore it.
 			}
@@ -76,18 +77,18 @@ func Negotiate(h http.Header) Format {
 		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
 			switch ac.Params["encoding"] {
 			case "delimited":
-				return fmtProtoDelim + escapingScheme
+				return FmtProtoDelim + escapingScheme
 			case "text":
-				return fmtProtoText + escapingScheme
+				return FmtProtoText + escapingScheme
 			case "compact-text":
-				return fmtProtoCompact + escapingScheme
+				return FmtProtoCompact + escapingScheme
 			}
 		}
 		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
-			return fmtText + escapingScheme
+			return FmtText + escapingScheme
 		}
 	}
-	return fmtText + escapingScheme
+	return FmtText + escapingScheme
 }
 
 // NegotiateIncludingOpenMetrics works like Negotiate but includes
@@ -100,7 +101,7 @@ func NegotiateIncludingOpenMetrics(h http.Header) Format {
 		if escapeParam := ac.Params[model.EscapingKey]; escapeParam != "" {
 			switch Format(escapeParam) {
 			case model.AllowUTF8, model.EscapeUnderscores, model.EscapeDots, model.EscapeValues:
-				escapingScheme = Format(fmt.Sprintf("; escaping=%s", escapeParam))
+				escapingScheme = Format("; escaping=" + escapeParam)
 			default:
 				// If the escaping parameter is unknown, ignore it.
 			}
@@ -109,26 +110,26 @@ func NegotiateIncludingOpenMetrics(h http.Header) Format {
 		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
 			switch ac.Params["encoding"] {
 			case "delimited":
-				return fmtProtoDelim + escapingScheme
+				return FmtProtoDelim + escapingScheme
 			case "text":
-				return fmtProtoText + escapingScheme
+				return FmtProtoText + escapingScheme
 			case "compact-text":
-				return fmtProtoCompact + escapingScheme
+				return FmtProtoCompact + escapingScheme
 			}
 		}
 		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
-			return fmtText + escapingScheme
+			return FmtText + escapingScheme
 		}
 		if ac.Type+"/"+ac.SubType == OpenMetricsType && (ver == OpenMetricsVersion_0_0_1 || ver == OpenMetricsVersion_1_0_0 || ver == "") {
 			switch ver {
 			case OpenMetricsVersion_1_0_0:
-				return fmtOpenMetrics_1_0_0 + escapingScheme
+				return FmtOpenMetrics_1_0_0 + escapingScheme
 			default:
-				return fmtOpenMetrics_0_0_1 + escapingScheme
+				return FmtOpenMetrics_0_0_1 + escapingScheme
 			}
 		}
 	}
-	return fmtText + escapingScheme
+	return FmtText + escapingScheme
 }
 
 // NewEncoder returns a new encoder based on content type negotiation. All

vendor/github.com/prometheus/common/expfmt/expfmt.go

@@ -15,7 +15,7 @@
 package expfmt
 
 import (
-	"fmt"
+	"errors"
 	"strings"
 
 	"github.com/prometheus/common/model"
@@ -32,24 +32,31 @@ type Format string
 // it on the wire, new content-type strings will have to be agreed upon and
 // added here.
 const (
-	TextVersion              = "0.0.4"
-	ProtoType                = `application/vnd.google.protobuf`
-	ProtoProtocol            = `io.prometheus.client.MetricFamily`
-	protoFmt                 = ProtoType + "; proto=" + ProtoProtocol + ";"
+	TextVersion   = "0.0.4"
+	ProtoType     = `application/vnd.google.protobuf`
+	ProtoProtocol = `io.prometheus.client.MetricFamily`
+	// Deprecated: Use expfmt.NewFormat(expfmt.TypeProtoCompact) instead.
+	ProtoFmt                 = ProtoType + "; proto=" + ProtoProtocol + ";"
 	OpenMetricsType          = `application/openmetrics-text`
 	OpenMetricsVersion_0_0_1 = "0.0.1"
 	OpenMetricsVersion_1_0_0 = "1.0.0"
 
-	// The Content-Type values for the different wire protocols. Note that these
-	// values are now unexported. If code was relying on comparisons to these
-	// constants, instead use FormatType().
-	fmtUnknown           Format = `<unknown>`
-	fmtText              Format = `text/plain; version=` + TextVersion + `; charset=utf-8`
-	fmtProtoDelim        Format = protoFmt + ` encoding=delimited`
-	fmtProtoText         Format = protoFmt + ` encoding=text`
-	fmtProtoCompact      Format = protoFmt + ` encoding=compact-text`
-	fmtOpenMetrics_1_0_0 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_1_0_0 + `; charset=utf-8`
-	fmtOpenMetrics_0_0_1 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_0_0_1 + `; charset=utf-8`
+	// The Content-Type values for the different wire protocols. Do not do direct
+	// comparisons to these constants, instead use the comparison functions.
+	// Deprecated: Use expfmt.NewFormat(expfmt.TypeUnknown) instead.
+	FmtUnknown Format = `<unknown>`
+	// Deprecated: Use expfmt.NewFormat(expfmt.TypeTextPlain) instead.
+	FmtText Format = `text/plain; version=` + TextVersion + `; charset=utf-8`
+	// Deprecated: Use expfmt.NewFormat(expfmt.TypeProtoDelim) instead.
+	FmtProtoDelim Format = ProtoFmt + ` encoding=delimited`
+	// Deprecated: Use expfmt.NewFormat(expfmt.TypeProtoText) instead.
+	FmtProtoText Format = ProtoFmt + ` encoding=text`
+	// Deprecated: Use expfmt.NewFormat(expfmt.TypeProtoCompact) instead.
+	FmtProtoCompact Format = ProtoFmt + ` encoding=compact-text`
+	// Deprecated: Use expfmt.NewFormat(expfmt.TypeOpenMetrics) instead.
+	FmtOpenMetrics_1_0_0 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_1_0_0 + `; charset=utf-8`
+	// Deprecated: Use expfmt.NewFormat(expfmt.TypeOpenMetrics) instead.
+	FmtOpenMetrics_0_0_1 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_0_0_1 + `; charset=utf-8`
 )
 
 const (
@@ -79,17 +86,17 @@ const (
 func NewFormat(t FormatType) Format {
 	switch t {
 	case TypeProtoCompact:
-		return fmtProtoCompact
+		return FmtProtoCompact
 	case TypeProtoDelim:
-		return fmtProtoDelim
+		return FmtProtoDelim
 	case TypeProtoText:
-		return fmtProtoText
+		return FmtProtoText
 	case TypeTextPlain:
-		return fmtText
+		return FmtText
 	case TypeOpenMetrics:
-		return fmtOpenMetrics_1_0_0
+		return FmtOpenMetrics_1_0_0
 	default:
-		return fmtUnknown
+		return FmtUnknown
 	}
 }
 
@@ -97,12 +104,35 @@ func NewFormat(t FormatType) Format {
 // specified version number.
 func NewOpenMetricsFormat(version string) (Format, error) {
 	if version == OpenMetricsVersion_0_0_1 {
-		return fmtOpenMetrics_0_0_1, nil
+		return FmtOpenMetrics_0_0_1, nil
 	}
 	if version == OpenMetricsVersion_1_0_0 {
-		return fmtOpenMetrics_1_0_0, nil
+		return FmtOpenMetrics_1_0_0, nil
 	}
-	return fmtUnknown, fmt.Errorf("unknown open metrics version string")
+	return FmtUnknown, errors.New("unknown open metrics version string")
+}
+
+// WithEscapingScheme returns a copy of Format with the specified escaping
+// scheme appended to the end. If an escaping scheme already exists it is
+// removed.
+func (f Format) WithEscapingScheme(s model.EscapingScheme) Format {
+	var terms []string
+	for _, p := range strings.Split(string(f), ";") {
+		toks := strings.Split(p, "=")
+		if len(toks) != 2 {
+			trimmed := strings.TrimSpace(p)
+			if len(trimmed) > 0 {
+				terms = append(terms, trimmed)
+			}
+			continue
+		}
+		key := strings.TrimSpace(toks[0])
+		if key != model.EscapingKey {
+			terms = append(terms, strings.TrimSpace(p))
+		}
+	}
+	terms = append(terms, model.EscapingKey+"="+s.String())
+	return Format(strings.Join(terms, "; "))
 }
 
 // FormatType deduces an overall FormatType for the given format.

vendor/github.com/prometheus/common/expfmt/openmetrics_create.go

@@ -38,7 +38,7 @@ type EncoderOption func(*encoderOption)
 
 // WithCreatedLines is an EncoderOption that configures the OpenMetrics encoder
 // to include _created lines (See
-// https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#counter-1).
+// https://github.com/prometheus/OpenMetrics/blob/v1.0.0/specification/OpenMetrics.md#counter-1).
 // Created timestamps can improve the accuracy of series reset detection, but
 // come with a bandwidth cost.
 //
@@ -102,7 +102,7 @@ func WithUnit() EncoderOption {
 //
 //   - According to the OM specs, the `# UNIT` line is optional, but if populated,
 //     the unit has to be present in the metric name as its suffix:
-//     (see https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#unit).
+//     (see https://github.com/prometheus/OpenMetrics/blob/v1.0.0/specification/OpenMetrics.md#unit).
 //     However, in order to accommodate any potential scenario where such a change in the
 //     metric name is not desirable, the users are here given the choice of either explicitly
 //     opt in, in case they wish for the unit to be included in the output AND in the metric name
@@ -152,8 +152,8 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily, options ...E
 	if metricType == dto.MetricType_COUNTER && strings.HasSuffix(compliantName, "_total") {
 		compliantName = name[:len(name)-6]
 	}
-	if toOM.withUnit && in.Unit != nil && !strings.HasSuffix(compliantName, fmt.Sprintf("_%s", *in.Unit)) {
-		compliantName = compliantName + fmt.Sprintf("_%s", *in.Unit)
+	if toOM.withUnit && in.Unit != nil && !strings.HasSuffix(compliantName, "_"+*in.Unit) {
+		compliantName = compliantName + "_" + *in.Unit
 	}
 
 	// Comments, first HELP, then TYPE.
@@ -477,7 +477,7 @@ func writeOpenMetricsNameAndLabelPairs(
 	if name != "" {
 		// If the name does not pass the legacy validity check, we must put the
 		// metric name inside the braces, quoted.
-		if !model.IsValidLegacyMetricName(model.LabelValue(name)) {
+		if !model.IsValidLegacyMetricName(name) {
 			metricInsideBraces = true
 			err := w.WriteByte(separator)
 			written++

vendor/github.com/prometheus/common/expfmt/text_create.go

@@ -354,7 +354,7 @@ func writeNameAndLabelPairs(
 	if name != "" {
 		// If the name does not pass the legacy validity check, we must put the
 		// metric name inside the braces.
-		if !model.IsValidLegacyMetricName(model.LabelValue(name)) {
+		if !model.IsValidLegacyMetricName(name) {
 			metricInsideBraces = true
 			err := w.WriteByte(separator)
 			written++
@@ -498,7 +498,7 @@ func writeInt(w enhancedWriter, i int64) (int, error) {
 // writeName writes a string as-is if it complies with the legacy naming
 // scheme, or escapes it in double quotes if not.
 func writeName(w enhancedWriter, name string) (int, error) {
-	if model.IsValidLegacyMetricName(model.LabelValue(name)) {
+	if model.IsValidLegacyMetricName(name) {
 		return w.WriteString(name)
 	}
 	var written int

vendor/github.com/prometheus/common/expfmt/text_parse.go

@@ -22,9 +22,9 @@ import (
 	"math"
 	"strconv"
 	"strings"
+	"unicode/utf8"
 
 	dto "github.com/prometheus/client_model/go"
-
 	"google.golang.org/protobuf/proto"
 
 	"github.com/prometheus/common/model"
@@ -60,6 +60,7 @@ type TextParser struct {
 	currentMF            *dto.MetricFamily
 	currentMetric        *dto.Metric
 	currentLabelPair     *dto.LabelPair
+	currentLabelPairs    []*dto.LabelPair // Temporarily stores label pairs while parsing a metric line.
 
 	// The remaining member variables are only used for summaries/histograms.
 	currentLabels map[string]string // All labels including '__name__' but excluding 'quantile'/'le'
@@ -74,6 +75,9 @@ type TextParser struct {
 	// count and sum of that summary/histogram.
 	currentIsSummaryCount, currentIsSummarySum     bool
 	currentIsHistogramCount, currentIsHistogramSum bool
+	// These indicate if the metric name from the current line being parsed is inside
+	// braces and if that metric name was found respectively.
+	currentMetricIsInsideBraces, currentMetricInsideBracesIsPresent bool
 }
 
 // TextToMetricFamilies reads 'in' as the simple and flat text-based exchange
@@ -137,12 +141,15 @@ func (p *TextParser) reset(in io.Reader) {
 	}
 	p.currentQuantile = math.NaN()
 	p.currentBucket = math.NaN()
+	p.currentMF = nil
 }
 
 // startOfLine represents the state where the next byte read from p.buf is the
 // start of a line (or whitespace leading up to it).
 func (p *TextParser) startOfLine() stateFn {
 	p.lineCount++
+	p.currentMetricIsInsideBraces = false
+	p.currentMetricInsideBracesIsPresent = false
 	if p.skipBlankTab(); p.err != nil {
 		// This is the only place that we expect to see io.EOF,
 		// which is not an error but the signal that we are done.
@@ -158,6 +165,9 @@ func (p *TextParser) startOfLine() stateFn {
 		return p.startComment
 	case '\n':
 		return p.startOfLine // Empty line, start the next one.
+	case '{':
+		p.currentMetricIsInsideBraces = true
+		return p.readingLabels
 	}
 	return p.readingMetricName
 }
@@ -275,6 +285,8 @@ func (p *TextParser) startLabelName() stateFn {
 		return nil // Unexpected end of input.
 	}
 	if p.currentByte == '}' {
+		p.currentMetric.Label = append(p.currentMetric.Label, p.currentLabelPairs...)
+		p.currentLabelPairs = nil
 		if p.skipBlankTab(); p.err != nil {
 			return nil // Unexpected end of input.
 		}
@@ -287,6 +299,45 @@ func (p *TextParser) startLabelName() stateFn {
 		p.parseError(fmt.Sprintf("invalid label name for metric %q", p.currentMF.GetName()))
 		return nil
 	}
+	if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte != '=' {
+		if p.currentMetricIsInsideBraces {
+			if p.currentMetricInsideBracesIsPresent {
+				p.parseError(fmt.Sprintf("multiple metric names for metric %q", p.currentMF.GetName()))
+				return nil
+			}
+			switch p.currentByte {
+			case ',':
+				p.setOrCreateCurrentMF()
+				if p.currentMF.Type == nil {
+					p.currentMF.Type = dto.MetricType_UNTYPED.Enum()
+				}
+				p.currentMetric = &dto.Metric{}
+				p.currentMetricInsideBracesIsPresent = true
+				return p.startLabelName
+			case '}':
+				p.setOrCreateCurrentMF()
+				if p.currentMF.Type == nil {
+					p.currentMF.Type = dto.MetricType_UNTYPED.Enum()
+				}
+				p.currentMetric = &dto.Metric{}
+				p.currentMetric.Label = append(p.currentMetric.Label, p.currentLabelPairs...)
+				p.currentLabelPairs = nil
+				if p.skipBlankTab(); p.err != nil {
+					return nil // Unexpected end of input.
+				}
+				return p.readingValue
+			default:
+				p.parseError(fmt.Sprintf("unexpected end of metric name %q", p.currentByte))
+				return nil
+			}
+		}
+		p.parseError(fmt.Sprintf("expected '=' after label name, found %q", p.currentByte))
+		p.currentLabelPairs = nil
+		return nil
+	}
 	p.currentLabelPair = &dto.LabelPair{Name: proto.String(p.currentToken.String())}
 	if p.currentLabelPair.GetName() == string(model.MetricNameLabel) {
 		p.parseError(fmt.Sprintf("label name %q is reserved", model.MetricNameLabel))
@@ -294,25 +345,19 @@ func (p *TextParser) startLabelName() stateFn {
 	}
 	// Special summary/histogram treatment. Don't add 'quantile' and 'le'
 	// labels to 'real' labels.
-	if !(p.currentMF.GetType() == dto.MetricType_SUMMARY && p.currentLabelPair.GetName() == model.QuantileLabel) &&
-		!(p.currentMF.GetType() == dto.MetricType_HISTOGRAM && p.currentLabelPair.GetName() == model.BucketLabel) {
-		p.currentMetric.Label = append(p.currentMetric.Label, p.currentLabelPair)
-	}
-	if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
-		return nil // Unexpected end of input.
-	}
-	if p.currentByte != '=' {
-		p.parseError(fmt.Sprintf("expected '=' after label name, found %q", p.currentByte))
-		return nil
+	if (p.currentMF.GetType() != dto.MetricType_SUMMARY || p.currentLabelPair.GetName() != model.QuantileLabel) &&
+		(p.currentMF.GetType() != dto.MetricType_HISTOGRAM || p.currentLabelPair.GetName() != model.BucketLabel) {
+		p.currentLabelPairs = append(p.currentLabelPairs, p.currentLabelPair)
 	}
 	// Check for duplicate label names.
 	labels := make(map[string]struct{})
-	for _, l := range p.currentMetric.Label {
+	for _, l := range p.currentLabelPairs {
 		lName := l.GetName()
 		if _, exists := labels[lName]; !exists {
 			labels[lName] = struct{}{}
 		} else {
 			p.parseError(fmt.Sprintf("duplicate label names for metric %q", p.currentMF.GetName()))
+			p.currentLabelPairs = nil
 			return nil
 		}
 	}
@@ -345,6 +390,7 @@ func (p *TextParser) startLabelValue() stateFn {
 			if p.currentQuantile, p.err = parseFloat(p.currentLabelPair.GetValue()); p.err != nil {
 				// Create a more helpful error message.
 				p.parseError(fmt.Sprintf("expected float as value for 'quantile' label, got %q", p.currentLabelPair.GetValue()))
+				p.currentLabelPairs = nil
 				return nil
 			}
 		} else {
@@ -371,12 +417,19 @@ func (p *TextParser) startLabelValue() stateFn {
 		return p.startLabelName
 
 	case '}':
+		if p.currentMF == nil {
+			p.parseError("invalid metric name")
+			return nil
+		}
+		p.currentMetric.Label = append(p.currentMetric.Label, p.currentLabelPairs...)
+		p.currentLabelPairs = nil
 		if p.skipBlankTab(); p.err != nil {
 			return nil // Unexpected end of input.
 		}
 		return p.readingValue
 	default:
 		p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.GetValue()))
+		p.currentLabelPairs = nil
 		return nil
 	}
 }
@@ -585,6 +638,8 @@ func (p *TextParser) readTokenUntilNewline(recognizeEscapeSequence bool) {
 				p.currentToken.WriteByte(p.currentByte)
 			case 'n':
 				p.currentToken.WriteByte('\n')
+			case '"':
+				p.currentToken.WriteByte('"')
 			default:
 				p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
 				return
@@ -610,13 +665,45 @@ func (p *TextParser) readTokenUntilNewline(recognizeEscapeSequence bool) {
 // but not into p.currentToken.
 func (p *TextParser) readTokenAsMetricName() {
 	p.currentToken.Reset()
+	// A UTF-8 metric name must be quoted and may have escaped characters.
+	quoted := false
+	escaped := false
 	if !isValidMetricNameStart(p.currentByte) {
 		return
 	}
-	for {
-		p.currentToken.WriteByte(p.currentByte)
+	for p.err == nil {
+		if escaped {
+			switch p.currentByte {
+			case '\\':
+				p.currentToken.WriteByte(p.currentByte)
+			case 'n':
+				p.currentToken.WriteByte('\n')
+			case '"':
+				p.currentToken.WriteByte('"')
+			default:
+				p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
+				return
+			}
+			escaped = false
+		} else {
+			switch p.currentByte {
+			case '"':
+				quoted = !quoted
+				if !quoted {
+					p.currentByte, p.err = p.buf.ReadByte()
+					return
+				}
+			case '\n':
+				p.parseError(fmt.Sprintf("metric name %q contains unescaped new-line", p.currentToken.String()))
+				return
+			case '\\':
+				escaped = true
+			default:
+				p.currentToken.WriteByte(p.currentByte)
+			}
+		}
 		p.currentByte, p.err = p.buf.ReadByte()
-		if p.err != nil || !isValidMetricNameContinuation(p.currentByte) {
+		if !isValidMetricNameContinuation(p.currentByte, quoted) || (!quoted && p.currentByte == ' ') {
 			return
 		}
 	}
@@ -628,13 +715,45 @@ func (p *TextParser) readTokenAsMetricName() {
 // but not into p.currentToken.
 func (p *TextParser) readTokenAsLabelName() {
 	p.currentToken.Reset()
+	// A UTF-8 label name must be quoted and may have escaped characters.
+	quoted := false
+	escaped := false
 	if !isValidLabelNameStart(p.currentByte) {
 		return
 	}
-	for {
-		p.currentToken.WriteByte(p.currentByte)
+	for p.err == nil {
+		if escaped {
+			switch p.currentByte {
+			case '\\':
+				p.currentToken.WriteByte(p.currentByte)
+			case 'n':
+				p.currentToken.WriteByte('\n')
+			case '"':
+				p.currentToken.WriteByte('"')
+			default:
+				p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
+				return
+			}
+			escaped = false
+		} else {
+			switch p.currentByte {
+			case '"':
+				quoted = !quoted
+				if !quoted {
+					p.currentByte, p.err = p.buf.ReadByte()
+					return
+				}
+			case '\n':
+				p.parseError(fmt.Sprintf("label name %q contains unescaped new-line", p.currentToken.String()))
+				return
+			case '\\':
+				escaped = true
+			default:
+				p.currentToken.WriteByte(p.currentByte)
+			}
+		}
 		p.currentByte, p.err = p.buf.ReadByte()
-		if p.err != nil || !isValidLabelNameContinuation(p.currentByte) {
+		if !isValidLabelNameContinuation(p.currentByte, quoted) || (!quoted && p.currentByte == '=') {
 			return
 		}
 	}
@@ -660,6 +779,7 @@ func (p *TextParser) readTokenAsLabelValue() {
 				p.currentToken.WriteByte('\n')
 			default:
 				p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
+				p.currentLabelPairs = nil
 				return
 			}
 			escaped = false
@@ -718,19 +838,19 @@ func (p *TextParser) setOrCreateCurrentMF() {
 }
 
 func isValidLabelNameStart(b byte) bool {
-	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_'
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || b == '"'
 }
 
-func isValidLabelNameContinuation(b byte) bool {
-	return isValidLabelNameStart(b) || (b >= '0' && b <= '9')
+func isValidLabelNameContinuation(b byte, quoted bool) bool {
+	return isValidLabelNameStart(b) || (b >= '0' && b <= '9') || (quoted && utf8.ValidString(string(b)))
 }
 
 func isValidMetricNameStart(b byte) bool {
 	return isValidLabelNameStart(b) || b == ':'
 }
 
-func isValidMetricNameContinuation(b byte) bool {
-	return isValidLabelNameContinuation(b) || b == ':'
+func isValidMetricNameContinuation(b byte, quoted bool) bool {
+	return isValidLabelNameContinuation(b, quoted) || b == ':'
 }
 
 func isBlankOrTab(b byte) bool {
@@ -775,7 +895,7 @@ func histogramMetricName(name string) string {
 
 func parseFloat(s string) (float64, error) {
 	if strings.ContainsAny(s, "pP_") {
-		return 0, fmt.Errorf("unsupported character in float")
+		return 0, errors.New("unsupported character in float")
 	}
 	return strconv.ParseFloat(s, 64)
 }