zscanner: split long TXT/SPF strings into more substrings with length <= 255 chars.

src/zscanner/scanner.h

@@ -138,6 +138,8 @@ struct scanner {
 	apl_t    apl;
 	/*! Auxiliary loc structure. */
 	loc_t    loc;
+	/*! Allow text strings longer than 255 characters. */
+	bool     long_string;
 
 	/*! Pointer to the actual dname storage (origin/owner/rdata). */
 	uint8_t  *dname;

src/zscanner/scanner_body.rl

@@ -213,7 +213,12 @@
 
 	# BEGIN - Common r_data item processing
 	action _item_length_init {
-		s->item_length_location = rdata_tail++;
+		if (rdata_tail <= rdata_stop) {
+			s->item_length_location = rdata_tail++;
+		} else {
+			WARN(ZS_RDATA_OVERFLOW);
+			fhold; fgoto err_line;
+		}
 	}
 	action _item_length_exit {
 		s->item_length = rdata_tail - s->item_length_location - 1;
@@ -502,6 +507,15 @@
 	# BEGIN - Text processing
 	action _text_char {
 		if (rdata_tail <= rdata_stop) {
+			// Split long string.
+			if (s->long_string &&
+			    rdata_tail - s->item_length_location == 1 + MAX_ITEM_LENGTH) {
+				// _item_length_exit equivalent.
+				*(s->item_length_location) = MAX_ITEM_LENGTH;
+				// _item_length_init equivalent.
+				s->item_length_location = rdata_tail++;
+			}
+
 			*(rdata_tail++) = fc;
 		} else {
 			WARN(ZS_TEXT_OVERFLOW);
@@ -519,6 +533,15 @@
 
 	action _text_dec_init {
 		if (rdata_tail <= rdata_stop) {
+			// Split long string.
+			if (s->long_string &&
+			    rdata_tail - s->item_length_location == 1 + MAX_ITEM_LENGTH) {
+				// _item_length_exit equivalent.
+				*(s->item_length_location) = MAX_ITEM_LENGTH;
+				// _item_length_init equivalent.
+				s->item_length_location = rdata_tail++;
+			}
+
 			*rdata_tail = 0;
 			s->item_length++;
 		} else {
@@ -569,8 +592,17 @@
 	# Text string with forward 1-byte length.
 	text_string = text >_item_length_init %_item_length_exit;
 
+	action _text_array_init {
+		s->long_string = true;
+	}
+	action _text_array_exit {
+		s->long_string = false;
+	}
+
 	# Text string array as one rdata item.
-	text_array = (text_string . (sep . text_string)* . sep?);
+	text_array =
+		( (text_string . (sep . text_string)* . sep?)
+		) >_text_array_init %_text_array_exit $!_text_array_exit;
 	# END
 
 	# BEGIN - TTL directive processing

src/zscanner/tests/data/12_TXT.in

@@ -24,6 +24,8 @@ second"
 third						; Second string
 )
 @	TXT	"abcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMN1234\053"	; Text string of maximal length (255 chars)
+@	TXT	"abcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMN1234\0536"	; Minimum overflowed text string which should be divided into two strings.
+@	TXT	"abcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMN1234\053\054"	; Minimum overflowed text string which should be divided into two strings (decimal version).
 @	txt	""				; Type in lower-case
 
 ; KO
@@ -33,4 +35,3 @@ third						; Second string
 @	TXT	\01		; Missing digit in decimal notation
 @	TXT	\256		; 8bit overflow in decimal notation
 @	TXT	"""		; '"' char without forward slash
-@	TXT	"abcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNabcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMN1234\0536"	; Maximal length overflow

src/zscanner/tests/data/12_TXT.out

@@ -110,6 +110,18 @@ OWNER=00
 CLASS=0001
 RRTTL=00000001
 RTYPE=0010
+RDATA=FF6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E31323334350136
+------
+OWNER=00
+CLASS=0001
+RRTTL=00000001
+RTYPE=0010
+RDATA=FF6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E6162636465666768696A6B6C6D6E6F707172737475767778797A313233343536373839304142434445464748494A4B4C4D4E31323334350136
+------
+OWNER=00
+CLASS=0001
+RRTTL=00000001
+RTYPE=0010
 RDATA=00
 ------
 WARNG=ZS_BAD_RDATA
@@ -124,5 +136,3 @@ WARNG=ZS_NUMBER8_OVERFLOW
 ------
 WARNG=ZS_BAD_TEXT
 ------
-WARNG=ZS_ITEM_OVERFLOW
-------