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, 10 insertions, 6 deletions

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 7ee72b71d3cb9f..f8e1822f38d42d 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -74,11 +74,11 @@ static inline int ebt_do_watcher (struct ebt_entry_watcher *w,
 }
 
 static inline int ebt_do_match (struct ebt_entry_match *m,
-   const struct sk_buff *skb, const struct net_device *in,
-   const struct net_device *out, bool *hotdrop)
+   const struct sk_buff *skb, struct xt_match_param *par)
 {
-	return m->u.match->match(skb, in, out, m->u.match,
-	       m->data, 0, 0, hotdrop);
+	par->match     = m->u.match;
+	par->matchinfo = m->data;
+	return m->u.match->match(skb, par);
 }
 
 static inline int ebt_dev_check(char *entry, const struct net_device *device)
@@ -155,6 +155,11 @@ unsigned int ebt_do_table (unsigned int hook, struct sk_buff *skb,
 	char *base;
 	struct ebt_table_info *private;
 	bool hotdrop = false;
+	struct xt_match_param mtpar;
+
+	mtpar.in      = in;
+	mtpar.out     = out;
+	mtpar.hotdrop = &hotdrop;
 
 	read_lock_bh(&table->lock);
 	private = table->private;
@@ -175,8 +180,7 @@ unsigned int ebt_do_table (unsigned int hook, struct sk_buff *skb,
 		if (ebt_basic_match(point, eth_hdr(skb), in, out))
 			goto letscontinue;
 
-		if (EBT_MATCH_ITERATE(point, ebt_do_match, skb,
-		    in, out, &hotdrop) != 0)
+		if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &mtpar) != 0)
 			goto letscontinue;
 		if (hotdrop) {
 			read_unlock_bh(&table->lock);