Update IsIPv6ULA (project-chip#32879)

achaulk-goog · web-flow · commit 5b3828f1b78f · 2024-04-08T18:22:27.000Z
Per spec https://datatracker.ietf.org/doc/html/rfc4193#section-3.1 fc/7 prefixes are local addresses, fe/8 uses a specific method and address format, but fc/8 is still a unique local address block, just with an undefined format
diff --git a/src/inet/IPAddress.cpp b/src/inet/IPAddress.cpp
@@ -319,7 +319,7 @@ bool IPAddress::IsIPv6GlobalUnicast() const
 // Is address an IPv6 Unique Local Address?
 bool IPAddress::IsIPv6ULA() const
 {
-    return (ntohl(Addr[0]) & 0xFF000000U) == 0xFD000000U;
+    return (ntohl(Addr[0]) & 0xFE000000U) == 0xFC000000U;
 }
 
 // Is address an IPv6 Link-local Address?

Original file line number	Diff line number	Diff line change
`@@ -319,7 +319,7 @@ bool IPAddress::IsIPv6GlobalUnicast() const`
`319`	`319`	`// Is address an IPv6 Unique Local Address?`
`320`	`320`	`bool IPAddress::IsIPv6ULA() const`
`321`	`321`	`{`
`322`		`- return (ntohl(Addr[0]) & 0xFF000000U) == 0xFD000000U;`
	`322`	`+ return (ntohl(Addr[0]) & 0xFE000000U) == 0xFC000000U;`
`323`	`323`	`}`
`324`	`324`
`325`	`325`	`// Is address an IPv6 Link-local Address?`