Fix several influx parser issues (#5484)

- Add line/column position
- Allow handlers to return errors
- Fix tag value escaping
- Allow newline in string fields

plugins/parsers/influx/handler.go

@@ -2,16 +2,17 @@ package influx
 
 import (
 	"bytes"
+	"errors"
+	"strconv"
 	"time"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/metric"
-	"github.com/prometheus/common/log"
 )
 
 type MetricHandler struct {
 	builder   *metric.Builder
-	metrics   []telegraf.Metric
+	err       error
 	precision time.Duration
 }
 
@@ -32,75 +33,88 @@ func (h *MetricHandler) SetTimePrecision(precision time.Duration) {
 }
 
 func (h *MetricHandler) Metric() (telegraf.Metric, error) {
-	return h.builder.Metric()
+	m, err := h.builder.Metric()
+	h.builder.Reset()
+	return m, err
 }
 
-func (h *MetricHandler) SetMeasurement(name []byte) {
+func (h *MetricHandler) SetMeasurement(name []byte) error {
 	h.builder.SetName(nameUnescape(name))
+	return nil
 }
 
-func (h *MetricHandler) AddTag(key []byte, value []byte) {
+func (h *MetricHandler) AddTag(key []byte, value []byte) error {
 	tk := unescape(key)
 	tv := unescape(value)
 	h.builder.AddTag(tk, tv)
+	return nil
 }
 
-func (h *MetricHandler) AddInt(key []byte, value []byte) {
+func (h *MetricHandler) AddInt(key []byte, value []byte) error {
 	fk := unescape(key)
 	fv, err := parseIntBytes(bytes.TrimSuffix(value, []byte("i")), 10, 64)
 	if err != nil {
-		log.Errorf("E! Received unparseable int value: %q: %v", value, err)
-		return
+		if numerr, ok := err.(*strconv.NumError); ok {
+			return numerr.Err
+		}
+		return err
 	}
 	h.builder.AddField(fk, fv)
+	return nil
 }
 
-func (h *MetricHandler) AddUint(key []byte, value []byte) {
+func (h *MetricHandler) AddUint(key []byte, value []byte) error {
 	fk := unescape(key)
 	fv, err := parseUintBytes(bytes.TrimSuffix(value, []byte("u")), 10, 64)
 	if err != nil {
-		log.Errorf("E! Received unparseable uint value: %q: %v", value, err)
-		return
+		if numerr, ok := err.(*strconv.NumError); ok {
+			return numerr.Err
+		}
+		return err
 	}
 	h.builder.AddField(fk, fv)
+	return nil
 }
 
-func (h *MetricHandler) AddFloat(key []byte, value []byte) {
+func (h *MetricHandler) AddFloat(key []byte, value []byte) error {
 	fk := unescape(key)
 	fv, err := parseFloatBytes(value, 64)
 	if err != nil {
-		log.Errorf("E! Received unparseable float value: %q: %v", value, err)
-		return
+		if numerr, ok := err.(*strconv.NumError); ok {
+			return numerr.Err
+		}
+		return err
 	}
 	h.builder.AddField(fk, fv)
+	return nil
 }
 
-func (h *MetricHandler) AddString(key []byte, value []byte) {
+func (h *MetricHandler) AddString(key []byte, value []byte) error {
 	fk := unescape(key)
 	fv := stringFieldUnescape(value)
 	h.builder.AddField(fk, fv)
+	return nil
 }
 
-func (h *MetricHandler) AddBool(key []byte, value []byte) {
+func (h *MetricHandler) AddBool(key []byte, value []byte) error {
 	fk := unescape(key)
 	fv, err := parseBoolBytes(value)
 	if err != nil {
-		log.Errorf("E! Received unparseable boolean value: %q: %v", value, err)
-		return
+		return errors.New("unparseable bool")
 	}
 	h.builder.AddField(fk, fv)
+	return nil
 }
 
-func (h *MetricHandler) SetTimestamp(tm []byte) {
+func (h *MetricHandler) SetTimestamp(tm []byte) error {
 	v, err := parseIntBytes(tm, 10, 64)
 	if err != nil {
-		log.Errorf("E! Received unparseable timestamp: %q: %v", tm, err)
-		return
+		if numerr, ok := err.(*strconv.NumError); ok {
+			return numerr.Err
+		}
+		return err
 	}
 	ns := v * int64(h.precision)
 	h.builder.SetTime(time.Unix(0, ns))
-}
-
-func (h *MetricHandler) Reset() {
-	h.builder.Reset()
+	return nil
 }

plugins/parsers/influx/machine.go.rl

@@ -10,6 +10,7 @@ var (
 	ErrTagParse = errors.New("expected tag")
 	ErrTimestampParse = errors.New("expected timestamp")
 	ErrParse = errors.New("parse error")
+	EOF = errors.New("EOF")
 )
 
 %%{
@@ -19,58 +20,67 @@ action begin {
 	m.pb = m.p
 }
 
-action yield {
-	yield = true
-	fnext align;
-	fbreak;
-}
-
 action name_error {
-	m.err = ErrNameParse
+	err = ErrNameParse
 	fhold;
 	fnext discard_line;
 	fbreak;
 }
 
 action field_error {
-	m.err = ErrFieldParse
+	err = ErrFieldParse
 	fhold;
 	fnext discard_line;
 	fbreak;
 }
 
 action tagset_error {
-	m.err = ErrTagParse
+	err = ErrTagParse
 	fhold;
 	fnext discard_line;
 	fbreak;
 }
 
 action timestamp_error {
-	m.err = ErrTimestampParse
+	err = ErrTimestampParse
 	fhold;
 	fnext discard_line;
 	fbreak;
 }
 
 action parse_error {
-	m.err = ErrParse
+	err = ErrParse
 	fhold;
 	fnext discard_line;
 	fbreak;
 }
 
+action align_error {
+	err = ErrParse
+	fnext discard_line;
+	fbreak;
+}
+
 action hold_recover {
 	fhold;
 	fgoto main;
 }
 
-action discard {
+action goto_align {
 	fgoto align;
 }
 
+action found_metric {
+	foundMetric = true
+}
+
 action name {
-	m.handler.SetMeasurement(m.text())
+	err = m.handler.SetMeasurement(m.text())
+	if err != nil {
+		fhold;
+		fnext discard_line;
+		fbreak;
+	}
 }
 
 action tagkey {
@@ -78,7 +88,12 @@ action tagkey {
 }
 
 action tagvalue {
-	m.handler.AddTag(key, m.text())
+	err = m.handler.AddTag(key, m.text())
+	if err != nil {
+		fhold;
+		fnext discard_line;
+		fbreak;
+	}
 }
 
 action fieldkey {
@@ -86,32 +101,76 @@ action fieldkey {
 }
 
 action integer {
-	m.handler.AddInt(key, m.text())
+	err = m.handler.AddInt(key, m.text())
+	if err != nil {
+		fhold;
+		fnext discard_line;
+		fbreak;
+	}
 }
 
 action unsigned {
-	m.handler.AddUint(key, m.text())
+	err = m.handler.AddUint(key, m.text())
+	if err != nil {
+		fhold;
+		fnext discard_line;
+		fbreak;
+	}
 }
 
 action float {
-	m.handler.AddFloat(key, m.text())
+	err = m.handler.AddFloat(key, m.text())
+	if err != nil {
+		fhold;
+		fnext discard_line;
+		fbreak;
+	}
 }
 
 action bool {
-	m.handler.AddBool(key, m.text())
+	err = m.handler.AddBool(key, m.text())
+	if err != nil {
+		fhold;
+		fnext discard_line;
+		fbreak;
+	}
 }
 
 action string {
-	m.handler.AddString(key, m.text())
+	err = m.handler.AddString(key, m.text())
+	if err != nil {
+		fhold;
+		fnext discard_line;
+		fbreak;
+	}
 }
 
 action timestamp {
-	m.handler.SetTimestamp(m.text())
+	err = m.handler.SetTimestamp(m.text())
+	if err != nil {
+		fhold;
+		fnext discard_line;
+		fbreak;
+	}
+}
+
+action incr_newline {
+	m.lineno++
+	m.sol = m.p
+	m.sol++ // next char will be the first column in the line
+}
+
+action eol {
+	fnext align;
+	fbreak;
 }
 
 ws =
 	[\t\v\f ];
 
+newline =
+	'\r'? '\n' %to(incr_newline);
+
 non_zero_digit =
 	[1-9];
 
@@ -155,7 +214,7 @@ fieldbool =
 	(true | false) >begin %bool;
 
 fieldstringchar =
-	[^\n\f\r\\"] | '\\' [\\"];
+	[^\f\r\n\\"] | '\\' [\\"] | newline;
 
 fieldstring =
 	fieldstringchar* >begin %string;
@@ -172,16 +231,16 @@ fieldset =
 	field ( ',' field )*;
 
 tagchar =
-	[^\t\n\f\r ,=\\] | ( '\\' [^\t\n\f\r] );
+	[^\t\n\f\r ,=\\] | ( '\\' [^\t\n\f\r\\] ) | '\\\\' %to{ fhold; };
 
 tagkey =
 	tagchar+ >begin %tagkey;
 
 tagvalue =
-	tagchar+ >begin %tagvalue;
+	tagchar+ >begin %eof(tagvalue) %tagvalue;
 
 tagset =
-	(',' (tagkey '=' tagvalue) $err(tagset_error))*;
+	((',' tagkey '=' tagvalue) $err(tagset_error))*;
 
 measurement_chars =
 	[^\t\n\f\r ,\\] | ( '\\' [^\t\n\f\r] );
@@ -190,52 +249,71 @@ measurement_start =
 	measurement_chars - '#';
 
 measurement =
-	(measurement_start measurement_chars*) >begin %name;
+	(measurement_start measurement_chars*) >begin %eof(name) %name;
 
-newline =
-	[\r\n];
+eol_break =
+	newline %to(eol)
+	;
 
-comment =
-	'#' (any -- newline)* newline;
-
-eol =
-	ws* newline? >yield %eof(yield);
-
-line =
-	measurement
+metric =
+	measurement >err(name_error)
 	tagset
-	(ws+ fieldset) $err(field_error)
+	ws+ fieldset $err(field_error)
 	(ws+ timestamp)? $err(timestamp_error)
-	eol;
+	;
 
-# The main machine parses a single line of line protocol.
-main := line $err(parse_error);
+line_with_term =
+	ws* metric ws* eol_break
+	;
+
+line_without_term =
+	ws* metric ws*
+	;
+
+main :=
+	(line_with_term*
+	(line_with_term | line_without_term?)
+    ) >found_metric
+	;
 
 # The discard_line machine discards the current line.  Useful for recovering
 # on the next line when an error occurs.
 discard_line :=
-	(any - newline)* newline @discard;
+	(any -- newline)* newline @goto_align;
+
+commentline =
+	ws* '#' (any -- newline)* newline;
+
+emptyline =
+	ws* newline;
 
 # The align machine scans forward to the start of the next line.  This machine
 # is used to skip over whitespace and comments, keeping this logic out of the
 # main machine.
+#
+# Skip valid lines that don't contain line protocol, any other data will move
+# control to the main parser via the err action.
 align :=
-	(space* comment)* space* measurement_start @hold_recover %eof(yield);
+	(emptyline | commentline | ws+)* %err(hold_recover);
 
-series := measurement tagset $err(parse_error) eol;
+# Series is a machine for matching measurement+tagset
+series :=
+	(measurement >err(name_error) tagset eol_break?)
+	>found_metric
+	;
 }%%
 
 %% write data;
 
 type Handler interface {
-	SetMeasurement(name []byte)
-	AddTag(key []byte, value []byte)
-	AddInt(key []byte, value []byte)
-	AddUint(key []byte, value []byte)
-	AddFloat(key []byte, value []byte)
-	AddString(key []byte, value []byte)
-	AddBool(key []byte, value []byte)
-	SetTimestamp(tm []byte)
+	SetMeasurement(name []byte) error
+	AddTag(key []byte, value []byte) error
+	AddInt(key []byte, value []byte) error
+	AddUint(key []byte, value []byte) error
+	AddFloat(key []byte, value []byte) error
+	AddString(key []byte, value []byte) error
+	AddBool(key []byte, value []byte) error
+	SetTimestamp(tm []byte) error
 }
 
 type machine struct {
@@ -243,9 +321,10 @@ type machine struct {
 	cs         int
 	p, pe, eof int
 	pb         int
+	lineno     int
+	sol        int
 	handler    Handler
 	initState  int
-	err        error
 }
 
 func NewMachine(handler Handler) *machine {
@@ -256,6 +335,7 @@ func NewMachine(handler Handler) *machine {
 
 	%% access m.;
 	%% variable p m.p;
+	%% variable cs m.cs;
 	%% variable pe m.pe;
 	%% variable eof m.eof;
 	%% variable data m.data;
@@ -284,55 +364,76 @@ func (m *machine) SetData(data []byte) {
 	m.data = data
 	m.p = 0
 	m.pb = 0
+	m.lineno = 1
+	m.sol = 0
 	m.pe = len(data)
 	m.eof = len(data)
-	m.err = nil
 
 	%% write init;
 	m.cs = m.initState
 }
 
-// ParseLine parses a line of input and returns true if more data can be
-// parsed.
-func (m *machine) ParseLine() bool {
-	if m.data == nil || m.p >= m.pe {
-		m.err = nil
-		return false
+// Next parses the next metric line and returns nil if it was successfully
+// processed.  If the line contains a syntax error an error is returned,
+// otherwise if the end of file is reached before finding a metric line then
+// EOF is returned.
+func (m *machine) Next() error {
+	if m.p == m.pe && m.pe == m.eof {
+		return EOF
 	}
 
-	m.err = nil
+	var err error
 	var key []byte
-	var yield bool
+	foundMetric := false
 
 	%% write exec;
 
-	// Even if there was an error, return true. On the next call to this
-	// function we will attempt to scan to the next line of input and recover.
-	if m.err != nil {
-		return true
+	if err != nil {
+		return err
 	}
 
-	// Don't check the error state in the case that we just yielded, because
-	// the yield indicates we just completed parsing a line.
-	if !yield && m.cs == LineProtocol_error {
-		m.err = ErrParse
-		return true
+	// This would indicate an error in the machine that was reported with a
+	// more specific error.  We return a generic error but this should
+	// possibly be a panic.
+	if m.cs == %%{ write error; }%% {
+		m.cs = LineProtocol_en_discard_line
+		return ErrParse
 	}
 
-	return true
+	// If we haven't found a metric line yet and we reached the EOF, report it
+	// now.  This happens when the data ends with a comment or whitespace.
+	//
+	// Otherwise we have successfully parsed a metric line, so if we are at
+	// the EOF we will report it the next call.
+	if !foundMetric && m.p == m.pe && m.pe == m.eof {
+		return EOF
+	}
+
+	return nil
 }
 
-// Err returns the error that occurred on the last call to ParseLine.  If the
-// result is nil, then the line was parsed successfully.
-func (m *machine) Err() error {
-	return m.err
-}
-
-// Position returns the current position into the input.
+// Position returns the current byte offset into the data.
 func (m *machine) Position() int {
 	return m.p
 }
 
+// LineOffset returns the byte offset of the current line.
+func (m *machine) LineOffset() int {
+	return m.sol
+}
+
+// LineNumber returns the current line number.  Lines are counted based on the
+// regular expression `\r?\n`.
+func (m *machine) LineNumber() int {
+	return m.lineno
+}
+
+// Column returns the current column.
+func (m *machine) Column() int {
+	lineOffset := m.p - m.sol
+	return lineOffset + 1
+}
+
 func (m *machine) text() []byte {
 	return m.data[m.pb:m.p]
 }

plugins/parsers/influx/parser.go

@@ -3,6 +3,7 @@ package influx
 import (
 	"errors"
 	"fmt"
+	"strings"
 	"sync"
 
 	"github.com/influxdata/telegraf"
@@ -18,16 +19,23 @@ var (
 
 type ParseError struct {
 	Offset     int
+	LineOffset int
+	LineNumber int
+	Column     int
 	msg        string
 	buf        string
 }
 
 func (e *ParseError) Error() string {
-	buffer := e.buf
+	buffer := e.buf[e.LineOffset:]
+	eol := strings.IndexAny(buffer, "\r\n")
+	if eol >= 0 {
+		buffer = buffer[:eol]
+	}
 	if len(buffer) > maxErrorBufferSize {
 		buffer = buffer[:maxErrorBufferSize] + "..."
 	}
-	return fmt.Sprintf("metric parse error: %s at offset %d: %q", e.msg, e.Offset, buffer)
+	return fmt.Sprintf("metric parse error: %s at %d:%d: %q", e.msg, e.LineNumber, e.Column, buffer)
 }
 
 type Parser struct {
@@ -60,12 +68,18 @@ func (p *Parser) Parse(input []byte) ([]telegraf.Metric, error) {
 	metrics := make([]telegraf.Metric, 0)
 	p.machine.SetData(input)
 
-	for p.machine.ParseLine() {
-		err := p.machine.Err()
+	for {
+		err := p.machine.Next()
+		if err == EOF {
+			break
+		}
+
 		if err != nil {
-			p.handler.Reset()
 			return nil, &ParseError{
 				Offset:     p.machine.Position(),
+				LineOffset: p.machine.LineOffset(),
+				LineNumber: p.machine.LineNumber(),
+				Column:     p.machine.Column(),
 				msg:        err.Error(),
 				buf:        string(input),
 			}
@@ -75,7 +89,11 @@ func (p *Parser) Parse(input []byte) ([]telegraf.Metric, error) {
 		if err != nil {
 			return nil, err
 		}
-		p.handler.Reset()
+
+		if metric == nil {
+			continue
+		}
+
 		metrics = append(metrics, metric)
 	}
 
@@ -84,7 +102,7 @@ func (p *Parser) Parse(input []byte) ([]telegraf.Metric, error) {
 }
 
 func (p *Parser) ParseLine(line string) (telegraf.Metric, error) {
-	metrics, err := p.Parse([]byte(line + "\n"))
+	metrics, err := p.Parse([]byte(line))
 	if err != nil {
 		return nil, err
 	}

plugins/parsers/influx/parser_test.go

@@ -1,6 +1,8 @@
 package influx
 
 import (
+	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -173,6 +175,63 @@ var ptests = []struct {
 		},
 		err: nil,
 	},
+	{
+		name:  "tag value escape space",
+		input: []byte(`cpu,host=two\ words value=42`),
+		metrics: []telegraf.Metric{
+			Metric(
+				metric.New(
+					"cpu",
+					map[string]string{
+						"host": "two words",
+					},
+					map[string]interface{}{
+						"value": 42.0,
+					},
+					time.Unix(42, 0),
+				),
+			),
+		},
+		err: nil,
+	},
+	{
+		name:  "tag value double escape space",
+		input: []byte(`cpu,host=two\\ words value=42`),
+		metrics: []telegraf.Metric{
+			Metric(
+				metric.New(
+					"cpu",
+					map[string]string{
+						"host": `two\ words`,
+					},
+					map[string]interface{}{
+						"value": 42.0,
+					},
+					time.Unix(42, 0),
+				),
+			),
+		},
+		err: nil,
+	},
+	{
+		name:  "tag value triple escape space",
+		input: []byte(`cpu,host=two\\\ words value=42`),
+		metrics: []telegraf.Metric{
+			Metric(
+				metric.New(
+					"cpu",
+					map[string]string{
+						"host": `two\\ words`,
+					},
+					map[string]interface{}{
+						"value": 42.0,
+					},
+					time.Unix(42, 0),
+				),
+			),
+		},
+		err: nil,
+	},
 	{
 		name:  "field key escape not escapable",
 		input: []byte(`cpu va\lue=42`),
@@ -259,19 +318,16 @@ var ptests = []struct {
 		err: nil,
 	},
 	{
-		name:  "field int overflow dropped",
+		name:    "field int overflow",
 		input:   []byte("cpu value=9223372036854775808i"),
-		metrics: []telegraf.Metric{
-			Metric(
-				metric.New(
-					"cpu",
-					map[string]string{},
-					map[string]interface{}{},
-					time.Unix(42, 0),
-				),
-			),
+		metrics: nil,
+		err: &ParseError{
+			Offset:     30,
+			LineNumber: 1,
+			Column:     31,
+			msg:        strconv.ErrRange.Error(),
+			buf:        "cpu value=9223372036854775808i",
 		},
-		err: nil,
 	},
 	{
 		name:  "field int max value",
@@ -308,19 +364,16 @@ var ptests = []struct {
 		err: nil,
 	},
 	{
-		name:  "field uint overflow dropped",
+		name:    "field uint overflow",
 		input:   []byte("cpu value=18446744073709551616u"),
-		metrics: []telegraf.Metric{
-			Metric(
-				metric.New(
-					"cpu",
-					map[string]string{},
-					map[string]interface{}{},
-					time.Unix(42, 0),
-				),
-			),
+		metrics: nil,
+		err: &ParseError{
+			Offset:     31,
+			LineNumber: 1,
+			Column:     32,
+			msg:        strconv.ErrRange.Error(),
+			buf:        "cpu value=18446744073709551616u",
 		},
-		err: nil,
 	},
 	{
 		name:  "field uint max value",
@@ -407,6 +460,23 @@ var ptests = []struct {
 		},
 		err: nil,
 	},
+	{
+		name:  "field string newline",
+		input: []byte("cpu value=\"4\n2\""),
+		metrics: []telegraf.Metric{
+			Metric(
+				metric.New(
+					"cpu",
+					map[string]string{},
+					map[string]interface{}{
+						"value": "4\n2",
+					},
+					time.Unix(42, 0),
+				),
+			),
+		},
+		err: nil,
+	},
 	{
 		name:  "no timestamp",
 		input: []byte("cpu value=42"),
@@ -498,7 +568,9 @@ var ptests = []struct {
 		metrics: nil,
 		err: &ParseError{
 			Offset:     3,
-			msg:    ErrFieldParse.Error(),
+			LineNumber: 1,
+			Column:     4,
+			msg:        ErrTagParse.Error(),
 			buf:        "cpu",
 		},
 	},
@@ -668,6 +740,8 @@ func TestSeriesParser(t *testing.T) {
 			metrics: []telegraf.Metric{},
 			err: &ParseError{
 				Offset:     6,
+				LineNumber: 1,
+				Column:     7,
 				msg:        ErrTagParse.Error(),
 				buf:        "cpu,a=",
 			},
@@ -696,3 +770,37 @@ func TestSeriesParser(t *testing.T) {
 		})
 	}
 }
+
+func TestParserErrorString(t *testing.T) {
+	var ptests = []struct {
+		name      string
+		input     []byte
+		errString string
+	}{
+		{
+			name:      "multiple line error",
+			input:     []byte("cpu value=42\ncpu value=invalid\ncpu value=42"),
+			errString: `metric parse error: expected field at 2:11: "cpu value=invalid"`,
+		},
+		{
+			name:      "handler error",
+			input:     []byte("cpu value=9223372036854775808i\ncpu value=42"),
+			errString: `metric parse error: value out of range at 1:31: "cpu value=9223372036854775808i"`,
+		},
+		{
+			name:      "buffer too long",
+			input:     []byte("cpu " + strings.Repeat("ab", maxErrorBufferSize) + "=invalid\ncpu value=42"),
+			errString: "metric parse error: expected field at 1:2054: \"cpu " + strings.Repeat("ab", maxErrorBufferSize)[:maxErrorBufferSize-4] + "...\"",
+		},
+	}
+
+	for _, tt := range ptests {
+		t.Run(tt.name, func(t *testing.T) {
+			handler := NewMetricHandler()
+			parser := NewParser(handler)
+
+			_, err := parser.Parse(tt.input)
+			require.Equal(t, tt.errString, err.Error())
+		})
+	}
+}

plugins/serializers/influx/escape.go

@@ -29,10 +29,6 @@ var (
 	)
 
 	stringFieldEscaper = strings.NewReplacer(
-		"\t", `\t`,
-		"\n", `\n`,
-		"\f", `\f`,
-		"\r", `\r`,
 		`"`, `\"`,
 		`\`, `\\`,
 	)

plugins/serializers/influx/influx_test.go

@@ -335,7 +335,7 @@ var tests = []struct {
 				time.Unix(0, 0),
 			),
 		),
-		output: []byte("cpu value=\"x\\ny\" 0\n"),
+		output: []byte("cpu value=\"x\ny\" 0\n"),
 	},
 	{
 		name:     "need more space",