wavefrontreceiver: Return error if partially quoted (open-telemetry#3…

…0315)

Signed-off-by: Bogdan Drutu <[email protected]>

.chloggen/fixpartialquote.yaml

@@ -0,0 +1,22 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'bug_fix'
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: wavefrontreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Return error if partially quoted"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [30315]
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

receiver/wavefrontreceiver/wavefront_parser.go

@@ -4,6 +4,7 @@
 package wavefrontreceiver // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/wavefrontreceiver"
 
 import (
+	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -23,8 +24,8 @@ type WavefrontParser struct {
 	ExtractCollectdTags bool `mapstructure:"extract_collectd_tags"`
 }
 
-var _ (protocol.Parser) = (*WavefrontParser)(nil)
-var _ (protocol.ParserConfig) = (*WavefrontParser)(nil)
+var _ protocol.Parser = (*WavefrontParser)(nil)
+var _ protocol.ParserConfig = (*WavefrontParser)(nil)
 
 // Only two chars can be espcaped per Wavafront SDK, see
 // https://github.com/wavefrontHQ/wavefront-sdk-go/blob/2c5891318fcd83c35c93bba2b411640495473333/senders/formatter.go#L20
@@ -82,9 +83,8 @@ func (wp *WavefrontParser) Parse(line string) (pmetric.Metric, error) {
 
 	attributes := pcommon.NewMap()
 	if tags != "" {
-		// to need for special treatment for source, treat it as a normal tag since
+		// no need for special treatment for source, treat it as a normal tag since
 		// tags are separated by space and are optionally double-quoted.
-
 		if err := buildLabels(attributes, tags); err != nil {
 			return pmetric.Metric{}, fmt.Errorf("invalid wavefront metric [%s]: %w", line, err)
 		}
@@ -136,61 +136,64 @@ func (wp *WavefrontParser) injectCollectDLabels(
 	return metricName
 }
 
-func buildLabels(attributes pcommon.Map, tags string) (err error) {
-	if tags == "" {
-		return
-	}
+func buildLabels(attributes pcommon.Map, tags string) error {
 	for {
-		parts := strings.SplitN(tags, "=", 2)
-		if len(parts) != 2 {
+		tags = strings.TrimLeft(tags, " ")
+		if len(tags) == 0 {
+			return nil
+		}
+
+		// First we need to find the key, find first '='
+		keyEnd := strings.IndexByte(tags, '=')
+		if keyEnd == -1 {
 			return fmt.Errorf("failed to break key for [%s]", tags)
 		}
+		key := tags[:keyEnd]
 
-		key := parts[0]
-		rest := parts[1]
-		tagLen := len(key) + 1 // Length of key plus separator and yet to be determined length of the value.
-		var value string
-		if len(rest) > 1 && rest[0] == '"' {
-			// Skip until non-escaped double quote.
+		tags = tags[keyEnd+1:]
+		if len(tags) > 1 && tags[0] == '"' {
+			// Quoted value, skip until non-escaped double quote.
+			foundEnd := false
 			foundEscape := false
-			i := 1
-			for ; i < len(rest); i++ {
-				if rest[i] != '"' && rest[i] != 'n' {
+			valueEnd := 1
+			for ; valueEnd < len(tags); valueEnd++ {
+				if tags[valueEnd] != '"' && tags[valueEnd] != 'n' {
 					continue
 				}
-				isPrevCharEscape := rest[i-1] == '\\'
-				if rest[i] == '"' && !isPrevCharEscape {
+				isPrevCharEscape := tags[valueEnd-1] == '\\'
+				if tags[valueEnd] == '"' && !isPrevCharEscape {
 					// Non-escaped double-quote, it is the end of the value.
+					foundEnd = true
 					break
 				}
 				foundEscape = foundEscape || isPrevCharEscape
 			}
 
-			value = rest[1:i]
-			tagLen += len(value) + 2 // plus 2 to account for the double-quotes.
+			// If we didn't find non-escaped double-quote then this is an error.
+			if !foundEnd {
+				return errors.New("partially quoted tag value")
+			}
+
+			value := tags[1:valueEnd]
+			tags = tags[valueEnd+1:]
 			if foundEscape {
 				// Per implementation of Wavefront SDK only double-quotes and
 				// newline characters are escaped. See the link below:
 				// https://github.com/wavefrontHQ/wavefront-sdk-go/blob/2c5891318fcd83c35c93bba2b411640495473333/senders/formatter.go#L20
 				value = escapedCharReplacer.Replace(value)
 			}
+			attributes.PutStr(key, value)
 		} else {
-			// Skip until space.
-			i := 0
-			for ; i < len(rest) && rest[i] != ' '; i++ { // nolint
+			valueEnd := strings.IndexByte(tags, ' ')
+			if valueEnd == -1 {
+				// The value is up to the end.
+				attributes.PutStr(key, tags)
+				return nil
 			}
-			value = rest[:i]
-			tagLen += i
-		}
-		attributes.PutStr(key, value)
-
-		tags = strings.TrimLeft(tags[tagLen:], " ")
-		if tags == "" {
-			break
+			attributes.PutStr(key, tags[:valueEnd])
+			tags = tags[valueEnd+1:]
 		}
 	}
-
-	return
 }
 
 func unDoubleQuote(s string) string {

receiver/wavefrontreceiver/wavefront_parser_test.go

@@ -46,10 +46,10 @@ func Test_buildLabels(t *testing.T) {
 		},
 		{
 			name: "end_with_quotes",
-			tags: "source=\"tst escape\\\" tst\" x=\"tst spc\"",
+			tags: "source=\"test escaped\\\" text\" x=\"tst spc\"",
 			wantAttributes: func() pcommon.Map {
 				m := pcommon.NewMap()
-				m.PutStr("source", "tst escape\" tst")
+				m.PutStr("source", "test escaped\" text")
 				m.PutStr("x", "tst spc")
 				return m
 			}(),
@@ -79,6 +79,17 @@ func Test_buildLabels(t *testing.T) {
 		},
 		{
 			name: "empty_tagValue",
+			tags: "k0=0 k1=" +
+				"",
+			wantAttributes: func() pcommon.Map {
+				m := pcommon.NewMap()
+				m.PutStr("k0", "0")
+				m.PutStr("k1", "")
+				return m
+			}(),
+		},
+		{
+			name: "empty_quoted_tagValue",
 			tags: "k0=0 k1=\"\"",
 			wantAttributes: func() pcommon.Map {
 				m := pcommon.NewMap()
@@ -92,6 +103,16 @@ func Test_buildLabels(t *testing.T) {
 			tags:    "k0=0 k1",
 			wantErr: true,
 		},
+		{
+			name:    "partially_quoted",
+			tags:    "k0=0 k1=\"test",
+			wantErr: true,
+		},
+		{
+			name:    "end_with_escaped_",
+			tags:    "k0=0 k1=\"test\\\"",
+			wantErr: true,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {