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>

11 files changed, 30 insertions, 47 deletions

diff --git a/net/bridge/netfilter/ebt_802_3.c b/net/bridge/netfilter/ebt_802_3.c
index 6fc2a59..c9e1bc1 100644
--- a/net/bridge/netfilter/ebt_802_3.c
+++ b/net/bridge/netfilter/ebt_802_3.c
@@ -13,11 +13,9 @@
 #include <linux/netfilter_bridge/ebt_802_3.h>
 
 static bool
-ebt_802_3_mt(const struct sk_buff *skb, const struct net_device *in,
-	     const struct net_device *out, const struct xt_match *match,
-	     const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_802_3_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_802_3_info *info = data;
+	const struct ebt_802_3_info *info = par->matchinfo;
 	const struct ebt_802_3_hdr *hdr = ebt_802_3_hdr(skb);
 	__be16 type = hdr->llc.ui.ctrl & IS_UI ? hdr->llc.ui.type : hdr->llc.ni.type;
 
diff --git a/net/bridge/netfilter/ebt_among.c b/net/bridge/netfilter/ebt_among.c
index 084559e..0ad0db3 100644
--- a/net/bridge/netfilter/ebt_among.c
+++ b/net/bridge/netfilter/ebt_among.c
@@ -128,11 +128,9 @@ static int get_ip_src(const struct sk_buff *skb, __be32 *addr)
 }
 
 static bool
-ebt_among_mt(const struct sk_buff *skb, const struct net_device *in,
-	     const struct net_device *out, const struct xt_match *match,
-	     const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_among_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_among_info *info = data;
+	const struct ebt_among_info *info = par->matchinfo;
 	const char *dmac, *smac;
 	const struct ebt_mac_wormhash *wh_dst, *wh_src;
 	__be32 dip = 0, sip = 0;
diff --git a/net/bridge/netfilter/ebt_arp.c b/net/bridge/netfilter/ebt_arp.c
index a073dff..1ff8fa3 100644
--- a/net/bridge/netfilter/ebt_arp.c
+++ b/net/bridge/netfilter/ebt_arp.c
@@ -16,11 +16,9 @@
 #include <linux/netfilter_bridge/ebt_arp.h>
 
 static bool
-ebt_arp_mt(const struct sk_buff *skb, const struct net_device *in,
-	   const struct net_device *out, const struct xt_match *match,
-	   const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_arp_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_arp_info *info = data;
+	const struct ebt_arp_info *info = par->matchinfo;
 	const struct arphdr *ah;
 	struct arphdr _arph;
 
diff --git a/net/bridge/netfilter/ebt_ip.c b/net/bridge/netfilter/ebt_ip.c
index b42c7ce..c70ea39 100644
--- a/net/bridge/netfilter/ebt_ip.c
+++ b/net/bridge/netfilter/ebt_ip.c
@@ -25,11 +25,9 @@ struct tcpudphdr {
 };
 
 static bool
-ebt_ip_mt(const struct sk_buff *skb, const struct net_device *in,
-	  const struct net_device *out, const struct xt_match *match,
-	  const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_ip_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_ip_info *info = data;
+	const struct ebt_ip_info *info = par->matchinfo;
 	const struct iphdr *ih;
 	struct iphdr _iph;
 	const struct tcpudphdr *pptr;
diff --git a/net/bridge/netfilter/ebt_ip6.c b/net/bridge/netfilter/ebt_ip6.c
index 7bd9831..5acee02 100644
--- a/net/bridge/netfilter/ebt_ip6.c
+++ b/net/bridge/netfilter/ebt_ip6.c
@@ -28,11 +28,9 @@ struct tcpudphdr {
 };
 
 static bool
-ebt_ip6_mt(const struct sk_buff *skb, const struct net_device *in,
-	   const struct net_device *out, const struct xt_match *match,
-	   const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_ip6_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_ip6_info *info = data;
+	const struct ebt_ip6_info *info = par->matchinfo;
 	const struct ipv6hdr *ih6;
 	struct ipv6hdr _ip6h;
 	const struct tcpudphdr *pptr;
diff --git a/net/bridge/netfilter/ebt_limit.c b/net/bridge/netfilter/ebt_limit.c
index 58aaaa1..9a3ec8c 100644
--- a/net/bridge/netfilter/ebt_limit.c
+++ b/net/bridge/netfilter/ebt_limit.c
@@ -31,11 +31,9 @@ static DEFINE_SPINLOCK(limit_lock);
 #define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ)
 
 static bool
-ebt_limit_mt(const struct sk_buff *skb, const struct net_device *in,
-	     const struct net_device *out, const struct xt_match *match,
-	     const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_limit_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	struct ebt_limit_info *info = (void *)data;
+	struct ebt_limit_info *info = (void *)par->matchinfo;
 	unsigned long now = jiffies;
 
 	spin_lock_bh(&limit_lock);
diff --git a/net/bridge/netfilter/ebt_mark_m.c b/net/bridge/netfilter/ebt_mark_m.c
index aa6781c..5b22ef9 100644
--- a/net/bridge/netfilter/ebt_mark_m.c
+++ b/net/bridge/netfilter/ebt_mark_m.c
@@ -13,11 +13,9 @@
 #include <linux/netfilter_bridge/ebt_mark_m.h>
 
 static bool
-ebt_mark_mt(const struct sk_buff *skb, const struct net_device *in,
-	    const struct net_device *out, const struct xt_match *match,
-	    const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_mark_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_mark_m_info *info = data;
+	const struct ebt_mark_m_info *info = par->matchinfo;
 
 	if (info->bitmask & EBT_MARK_OR)
 		return !!(skb->mark & info->mask) ^ info->invert;
diff --git a/net/bridge/netfilter/ebt_pkttype.c b/net/bridge/netfilter/ebt_pkttype.c
index 1c04ce5..b756f88 100644
--- a/net/bridge/netfilter/ebt_pkttype.c
+++ b/net/bridge/netfilter/ebt_pkttype.c
@@ -13,12 +13,9 @@
 #include <linux/netfilter_bridge/ebt_pkttype.h>
 
 static bool
-ebt_pkttype_mt(const struct sk_buff *skb, const struct net_device *in,
-	       const struct net_device *out, const struct xt_match *match,
-	       const void *data, int offset, unsigned int protoff,
-	       bool *hotdrop)
+ebt_pkttype_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_pkttype_info *info = data;
+	const struct ebt_pkttype_info *info = par->matchinfo;
 
 	return (skb->pkt_type == info->pkt_type) ^ info->invert;
 }
diff --git a/net/bridge/netfilter/ebt_stp.c b/net/bridge/netfilter/ebt_stp.c
index 28bb48b..06d777c 100644
--- a/net/bridge/netfilter/ebt_stp.c
+++ b/net/bridge/netfilter/ebt_stp.c
@@ -120,11 +120,9 @@ static bool ebt_filter_config(const struct ebt_stp_info *info,
 }
 
 static bool
-ebt_stp_mt(const struct sk_buff *skb, const struct net_device *in,
-	   const struct net_device *out, const struct xt_match *match,
-	   const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_stp_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_stp_info *info = data;
+	const struct ebt_stp_info *info = par->matchinfo;
 	const struct stp_header *sp;
 	struct stp_header _stph;
 	const uint8_t header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00};
diff --git a/net/bridge/netfilter/ebt_vlan.c b/net/bridge/netfilter/ebt_vlan.c
index 5addef6..b05b4a8 100644
--- a/net/bridge/netfilter/ebt_vlan.c
+++ b/net/bridge/netfilter/ebt_vlan.c
@@ -41,11 +41,9 @@ MODULE_LICENSE("GPL");
 #define EXIT_ON_MISMATCH(_MATCH_,_MASK_) {if (!((info->_MATCH_ == _MATCH_)^!!(info->invflags & _MASK_))) return false; }
 
 static bool
-ebt_vlan_mt(const struct sk_buff *skb, const struct net_device *in,
-	    const struct net_device *out, const struct xt_match *match,
-	    const void *data, int offset, unsigned int protoff, bool *hotdrop)
+ebt_vlan_mt(const struct sk_buff *skb, const struct xt_match_param *par)
 {
-	const struct ebt_vlan_info *info = data;
+	const struct ebt_vlan_info *info = par->matchinfo;
 	const struct vlan_hdr *fp;
 	struct vlan_hdr _frame;
 
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 7ee72b7..f8e1822 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);