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, 7 insertions, 10 deletions

diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
index 4a916e2624d3..baeb90a56231 100644
--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -204,19 +204,16 @@ static void recent_table_flush(struct recent_table *t)
 }
 
 static bool
-recent_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)
+recent_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct xt_recent_mtinfo *info = matchinfo;
+	const struct xt_recent_mtinfo *info = par->matchinfo;
 	struct recent_table *t;
 	struct recent_entry *e;
 	union nf_inet_addr addr = {};
 	u_int8_t ttl;
 	bool ret = info->invert;
 
-	if (match->family == NFPROTO_IPV4) {
+	if (par->match->family == NFPROTO_IPV4) {
 		const struct iphdr *iph = ip_hdr(skb);
 
 		if (info->side == XT_RECENT_DEST)
@@ -237,19 +234,19 @@ recent_mt(const struct sk_buff *skb, const struct net_device *in,
 	}
 
 	/* use TTL as seen before forwarding */
-	if (out && !skb->sk)
+	if (par->out != NULL && skb->sk == NULL)
 		ttl++;
 
 	spin_lock_bh(&recent_lock);
 	t = recent_table_lookup(info->name);
-	e = recent_entry_lookup(t, &addr, match->family,
+	e = recent_entry_lookup(t, &addr, par->match->family,
 				(info->check_set & XT_RECENT_TTL) ? ttl : 0);
 	if (e == NULL) {
 		if (!(info->check_set & XT_RECENT_SET))
 			goto out;
-		e = recent_entry_init(t, &addr, match->family, ttl);
+		e = recent_entry_init(t, &addr, par->match->family, ttl);
 		if (e == NULL)
-			*hotdrop = true;
+			*par->hotdrop = true;
 		ret = !ret;
 		goto out;
 	}