trafgen: parser: Parse IPv6 address by strict match pattern

Used IPv6 pattern from nftables project [1] to match valid only IPv6
address to do not mess with MAC or other syntax patterns with ':' symbol.

[1] http://git.netfilter.org/nftables/tree/src/scanner.l

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
[tk: add refrence to nftables source]
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 48 insertions, 4 deletions

diff --git a/trafgen_lexer.l b/trafgen_lexer.l
index 025fbfe..65ec245 100644
--- a/trafgen_lexer.l
+++ b/trafgen_lexer.l
@@ -77,13 +77,57 @@ number_bin	([0]?[b][0-1]+)
 number_dec	(([0])|([1-9][0-9]*))
 number_ascii	([a-zA-Z])
 
+/* rules taken from nftables scanner.l */
+hex4		([[:xdigit:]]{1,4})
+v680		(({hex4}:){7}{hex4})
+v670		((:)((:{hex4}){7}))
+v671		((({hex4}:){1})((:{hex4}){6}))
+v672		((({hex4}:){2})((:{hex4}){5}))
+v673		((({hex4}:){3})((:{hex4}){4}))
+v674		((({hex4}:){4})((:{hex4}){3}))
+v675		((({hex4}:){5})((:{hex4}){2}))
+v676		((({hex4}:){6})(:{hex4}{1}))
+v677		((({hex4}:){7})(:))
+v67		({v670}|{v671}|{v672}|{v673}|{v674}|{v675}|{v676}|{v677})
+v660		((:)((:{hex4}){6}))
+v661		((({hex4}:){1})((:{hex4}){5}))
+v662		((({hex4}:){2})((:{hex4}){4}))
+v663		((({hex4}:){3})((:{hex4}){3}))
+v664		((({hex4}:){4})((:{hex4}){2}))
+v665		((({hex4}:){5})((:{hex4}){1}))
+v666		((({hex4}:){6})(:))
+v66		({v660}|{v661}|{v662}|{v663}|{v664}|{v665}|{v666})
+v650		((:)((:{hex4}){5}))
+v651		((({hex4}:){1})((:{hex4}){4}))
+v652		((({hex4}:){2})((:{hex4}){3}))
+v653		((({hex4}:){3})((:{hex4}){2}))
+v654		((({hex4}:){4})(:{hex4}{1}))
+v655		((({hex4}:){5})(:))
+v65		({v650}|{v651}|{v652}|{v653}|{v654}|{v655})
+v640		((:)((:{hex4}){4}))
+v641		((({hex4}:){1})((:{hex4}){3}))
+v642		((({hex4}:){2})((:{hex4}){2}))
+v643		((({hex4}:){3})((:{hex4}){1}))
+v644		((({hex4}:){4})(:))
+v64		({v640}|{v641}|{v642}|{v643}|{v644})
+v630		((:)((:{hex4}){3}))
+v631		((({hex4}:){1})((:{hex4}){2}))
+v632		((({hex4}:){2})((:{hex4}){1}))
+v633		((({hex4}:){3})(:))
+v63		({v630}|{v631}|{v632}|{v633})
+v620		((:)((:{hex4}){2}))
+v621		((({hex4}:){1})((:{hex4}){1}))
+v622		((({hex4}:){2})(:))
+v62		({v620}|{v621}|{v622})
+v610		((:)(:{hex4}{1}))
+v611		((({hex4}:){1})(:))
+v61		({v610}|{v611})
+v60		(::)
+
 a_hex		([a-fA-F0-9]+)
 mac		({a_hex}:{a_hex}:{a_hex}:{a_hex}:{a_hex}:{a_hex})
 ip4_addr	([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)
-	/* We're very permissive about IPv6 addresses the grammar accepts, as
-	 * they can come in various different formats. In any case,
-	 * inet_pton(AF_INET6, ...) will reject the invalid ones later on. */
-ip6_addr	(({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex})?)
+ip6_addr	({v680}|{v67}|{v66}|{v65}|{v64}|{v63}|{v62}|{v61}|{v60})
 
 %%