netfilter: xtables: move extension arguments into compound structure (1/6)

The function signatures for Xtables extensions have grown over time.
It involves a lot of typing/replication, and also a bit of stack space
even if they are not used. Realize an NFWS2008 idea and pack them into
structs. The skb remains outside of the struct so gcc can continue to
apply its optimizations.

This patch does this for match extensions' match functions.

A few ambiguities have also been addressed. The "offset" parameter for
example has been renamed to "fragoff" (there are so many different
offsets already) and "protoff" to "thoff" (there is more than just one
protocol here, so clarify).

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 4 insertions, 10 deletions

diff --git a/net/netfilter/xt_length.c b/net/netfilter/xt_length.c
index b8612d1914b7..c4871ca6c86d 100644
--- a/net/netfilter/xt_length.c
+++ b/net/netfilter/xt_length.c
@@ -21,24 +21,18 @@ MODULE_ALIAS("ipt_length");
 MODULE_ALIAS("ip6t_length");
 
 static bool
-length_mt(const struct sk_buff *skb, const struct net_device *in,
-          const struct net_device *out, const struct xt_match *match,
-          const void *matchinfo, int offset, unsigned int protoff,
-          bool *hotdrop)
+length_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct xt_length_info *info = matchinfo;
+	const struct xt_length_info *info = par->matchinfo;
 	u_int16_t pktlen = ntohs(ip_hdr(skb)->tot_len);
 
 	return (pktlen >= info->min && pktlen <= info->max) ^ info->invert;
 }
 
 static bool
-length_mt6(const struct sk_buff *skb, const struct net_device *in,
-           const struct net_device *out, const struct xt_match *match,
-           const void *matchinfo, int offset, unsigned int protoff,
-           bool *hotdrop)
+length_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct xt_length_info *info = matchinfo;
+	const struct xt_length_info *info = par->matchinfo;
 	const u_int16_t pktlen = ntohs(ipv6_hdr(skb)->payload_len) +
 				 sizeof(struct ipv6hdr);