From b851ba4731d9f7c5e38889875a83173fcc4d3f16 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 18 Oct 2015 20:02:16 +0200 Subject: src: add interface wildcard matching Contrary to iptables, we use the asterisk character '*' as wildcard. # nft --debug=netlink add rule test test iifname eth\* ip test test [ meta load iifname => reg 1 ] [ cmp eq reg 1 0x00687465 ] Note that this generates an optimized comparison without bitwise. In case you want to match a device that contains an asterisk, you have to escape the asterisk, ie. # nft add rule test test iifname eth\\* The wildcard string handling occurs from the evaluation step, where we convert from: relational / \ / \ meta value oifname eth* to: relational / \ / \ meta prefix ofiname As Patrick suggested, this not actually a wildcard but a prefix since it only applies to the string when placed at the end. More comments: * This relaxes the left->size > right->size from netlink_parse_cmp() for strings since the optimization that this patch applies may now result in bogus errors. * This patch can be later on extended to apply a similar optimization to payload expressions when: expr->len % BITS_PER_BYTE == 0 For meta and ct, the kernel checks for the exact length of the attributes (it expects integer 32 bits) so we can't do it unless we relax that. * Wildcard strings are not supported from sets and maps yet. Error reporting is not very good at this stage since expr_evaluate_prefix() doesn't have enough context (ctx->set is NULL, the set object is currently created later after evaluating the lhs and rhs of the relational). I'll be following up on this later. Signed-off-by: Pablo Neira Ayuso --- src/scanner.l | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'src/scanner.l') diff --git a/src/scanner.l b/src/scanner.l index 1a9f43f8..a98e7b6a 100644 --- a/src/scanner.l +++ b/src/scanner.l @@ -114,6 +114,7 @@ range ({decstring}?:{decstring}?) letter [a-zA-Z] string ({letter})({letter}|{digit}|[/\-_\.])* quotedstring \"[^"]*\" +asteriskstring ({string}\*|{string}\\\*) comment #.*$ slash \/ @@ -499,6 +500,11 @@ addrstring ({macaddr}|{ip4addr}|{ip6addr}) return QUOTED_STRING; } +{asteriskstring} { + yylval->string = xstrdup(yytext); + return ASTERISK_STRING; + } + {string} { yylval->string = xstrdup(yytext); return STRING; -- cgit v1.2.3