BUG/MEDIUM: cli: some err/warn msg dumps add LR into CSV output on stat's CLI

The initial purpose of CSV stats through CLI was to make it easely
parsable by scripts. But in some specific cases some error or warning
messages strings containing LF were dumped into cells of this CSV.

This made some parsing failure on several tools. In addition, if a
warning or message contains to successive LF, they will be dumped
directly but double LFs tag the end of the response on CLI and the
client may consider a truncated response.

This patch extends the 'csv_enc_append' and 'csv_enc' functions used
to format quoted string content according to RFC  with an additionnal
parameter to convert multi-lines strings to one line: CRs are skipped,
and LFs are replaced with spaces. In addition and optionally, it is
also possible to remove resulting trailing spaces.

The call of this function to fill strings into stat's CSV output is
updated to force this conversion.

This patch should be backported on all supported branches (issue was
already present in v2.0)

include/haproxy/tools.h

@@ -441,11 +441,19 @@ char *escape_string(char *start, char *stop,
  * It is useful if the escaped string is used between double quotes in the
  * format.
  *
- *    printf("..., \"%s\", ...\r\n", csv_enc(str, 0, &trash));
+ *    printf("..., \"%s\", ...\r\n", csv_enc(str, 0, 0, &trash));
  *
  * If <quote> is 1, the converter puts the quotes only if any character is
  * escaped. If <quote> is 2, the converter always puts the quotes.
  *
+ * If <oneline> is not 0, CRs are skipped and LFs are replaced by spaces.
+ * This re-format multi-lines strings to only one line. The purpose is to
+ * allow a line by line parsing but also to keep the output compliant with
+ * the CLI witch uses LF to defines the end of the response.
+ *
+ * If <oneline> is 2, In addition to previous action, the trailing spaces are
+ * removed.
+ *
  * <output> is a struct chunk used for storing the output string.
  *
  * The function returns the converted string on its output. If an error
@@ -458,14 +466,15 @@ char *escape_string(char *start, char *stop,
  * This function appends the encoding to the existing output chunk. Please
  * use csv_enc() instead if you want to replace the output chunk.
  */
-const char *csv_enc_append(const char *str, int quote, struct buffer *output);
+const char *csv_enc_append(const char *str, int quote, int online,
+			   struct buffer *output);
 
 /* same as above but the output chunk is reset first */
-static inline const char *csv_enc(const char *str, int quote,
+static inline const char *csv_enc(const char *str, int quote, int oneline,
 				  struct buffer *output)
 {
 	chunk_reset(output);
-	return csv_enc_append(str, quote, output);
+	return csv_enc_append(str, quote, oneline, output);
 }
 
 /* Decode an URL-encoded string in-place. The resulting string might

src/stats.c

@@ -409,7 +409,7 @@ int stats_emit_raw_data_field(struct buffer *out, const struct field *f)
 		out->data = flt_trim(out->area, prev_data, chunk_appendf(out, "%f", f->u.flt));
 		return out->data;
 	}
-	case FF_STR:   return csv_enc_append(field_str(f, 0), 1, out) != NULL;
+	case FF_STR:   return csv_enc_append(field_str(f, 0), 1, 2, out) != NULL;
 	default:       return chunk_appendf(out, "[INCORRECT_FIELD_TYPE_%08x]", f->type);
 	}
 }

src/tools.c

@@ -2065,11 +2065,19 @@ char *escape_string(char *start, char *stop,
  * It is useful if the escaped string is used between double quotes in the
  * format.
  *
- *    printf("..., \"%s\", ...\r\n", csv_enc(str, 0, &trash));
+ *    printf("..., \"%s\", ...\r\n", csv_enc(str, 0, 0, &trash));
  *
  * If <quote> is 1, the converter puts the quotes only if any reserved character
  * is present. If <quote> is 2, the converter always puts the quotes.
  *
+ * If <oneline> is not 0, CRs are skipped and LFs are replaced by spaces.
+ * This re-format multi-lines strings to only one line. The purpose is to
+ * allow a line by line parsing but also to keep the output compliant with
+ * the CLI witch uses LF to defines the end of the response.
+ *
+ * If <oneline> is 2, In addition to previous action, the trailing spaces are
+ * removed.
+ *
  * <output> is a struct buffer used for storing the output string.
  *
  * The function returns the converted string on its output. If an error
@@ -2084,7 +2092,7 @@ char *escape_string(char *start, char *stop,
  * the chunk. Please use csv_enc() instead if you want to replace the output
  * chunk.
  */
-const char *csv_enc_append(const char *str, int quote, struct buffer *output)
+const char *csv_enc_append(const char *str, int quote, int oneline, struct buffer *output)
 {
 	char *end = output->area + output->size;
 	char *out = output->area + output->data;
@@ -2100,6 +2108,19 @@ const char *csv_enc_append(const char *str, int quote, struct buffer *output)
 		*ptr++ = '"';
 
 	while (*str && ptr < end - 2) { /* -2 for reserving space for <"> and \0. */
+		if (oneline) {
+			if (*str == '\n' ) {
+				/* replace LF by a space */
+				*ptr++ = ' ';
+				str++;
+				continue;
+			}
+			else if (*str == '\r' ) {
+				/* skip CR */
+				str++;
+				continue;
+			}
+		}
 		*ptr = *str;
 		if (*str == '"') {
 			ptr++;
@@ -2113,6 +2134,12 @@ const char *csv_enc_append(const char *str, int quote, struct buffer *output)
 		str++;
 	}
 
+	if (oneline == 2) {
+		/* remove trailing spaces */
+		while (ptr > out && *(ptr - 1) == ' ')
+			ptr--;
+	}
+
 	if (quote)
 		*ptr++ = '"';