rfc9267v2.txt		rfc9267.txt
	skipping to change at line 235 ¶		skipping to change at line 235 ¶
	+----+----+----+----+----+----+----+----+----+----+----+----+		+----+----+----+----+----+----+----+----+----+----+----+----+
	->+0x0c |0xc0|0x0c| TYPE | CLASS |0x04| t | e | s | t |0x03|		->+0x0c |0xc0|0x0c| TYPE | CLASS |0x04| t | e | s | t |0x03|
	| +----+--|-+----+----+----+----+----+----+----+----+----+----+		| +----+--|-+----+----+----+----+----+----+----+----+----+----+
	| +0x18 | c | o| | m |0x00| TYPE | CLASS | ................ |		| +0x18 | c | o| | m |0x00| TYPE | CLASS | ................ |
	| +----+--|-+----+----+----+----+----+----+----+----+----+----+		| +----+--|-+----+----+----+----+----+----+----+----+----+----+
	| |		| |
	-----------------		-----------------
	The packet begins with a DNS header at offset +0x00, and its DNS		The packet begins with a DNS header at offset +0x00, and its DNS
	payload contains several RRs. The first RR begins at an offset of 12		payload contains several RRs. The first RR begins at an offset of 12
	octets (+0xc0); its first label length octet is set to the value		octets (+0x0c); its first label length octet is set to the value
	"0xc0", which indicates that it is a compression pointer. The		"0xc0", which indicates that it is a compression pointer. The
	compression pointer offset is computed from the two octets "0xc00c"		compression pointer offset is computed from the two octets "0xc00c"
	and is equal to 12. Since the broken implementation in Figure 1		and is equal to 12. Since the broken implementation in Figure 1
	follows this offset value blindly, the pointer will jump back to the		follows this offset value blindly, the pointer will jump back to the
	first octet of the first RR (+0xc0) over and over again. The code in		first octet of the first RR (+0x0c) over and over again. The code in
	Figure 1 will enter an infinite-loop state, since it will never leave		Figure 1 will enter an infinite-loop state, since it will never leave
	the "TRUE" branch of the "while" loop.		the "TRUE" branch of the "while" loop.
	Apart from achieving infinite loops, the implementation flaws in		Apart from achieving infinite loops, the implementation flaws in
	Figure 1 make it possible to achieve various pointer loops that have		Figure 1 make it possible to achieve various pointer loops that have
	other undesirable effects. For instance, consider the DNS packet		other undesirable effects. For instance, consider the DNS packet
	excerpt shown below:		excerpt shown below:
	+----+----+----+----+----+----+----+----+----+----+----+----+		+----+----+----+----+----+----+----+----+----+----+----+----+
	+0x00 | ID | FLAGS | QDCOUNT | ANCOUNT | NSCOUNT | ARCOUNT |		+0x00 | ID | FLAGS | QDCOUNT | ANCOUNT | NSCOUNT | ARCOUNT |
End of changes. 2 change blocks.
	2 lines changed or deleted		2 lines changed or added
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