netfilter: xtables: remove almost-unused xt_match_param.data member
This member is taking up a "long" per match, yet is only used by one
module out of the roughly 90 modules, ip6t_hbh. ip6t_hbh can be
restructured a little to accomodate for the lack of the .data member.
This variant uses checking the par->match address, which should avoid
having to add two extra functions, including calls, i.e.
(hbh_mt6: call hbhdst_mt6(skb, par, NEXTHDR_OPT),
dst_mt6: call hbhdst_mt6(skb, par, NEXTHDR_DEST))
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index c68ff82..cf91473 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -315,9 +315,6 @@
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
- /* Free to use by each match */
- unsigned long data;
-
const char *table;
unsigned int matchsize;
#ifdef CONFIG_COMPAT
diff --git a/net/ipv6/netfilter/ip6t_hbh.c b/net/ipv6/netfilter/ip6t_hbh.c
index cbe8dec..82593c8 100644
--- a/net/ipv6/netfilter/ip6t_hbh.c
+++ b/net/ipv6/netfilter/ip6t_hbh.c
@@ -41,6 +41,8 @@
* 5 -> RTALERT 2 x x
*/
+static struct xt_match hbh_mt6_reg[] __read_mostly;
+
static bool
hbh_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
{
@@ -58,7 +60,9 @@
unsigned int optlen;
int err;
- err = ipv6_find_hdr(skb, &ptr, par->match->data, NULL);
+ err = ipv6_find_hdr(skb, &ptr,
+ (par->match == &hbh_mt6_reg[0]) ?
+ NEXTHDR_HOP : NEXTHDR_DEST, NULL);
if (err < 0) {
if (err != -ENOENT)
*par->hotdrop = true;
@@ -179,13 +183,13 @@
static struct xt_match hbh_mt6_reg[] __read_mostly = {
{
+ /* Note, hbh_mt6 relies on the order of hbh_mt6_reg */
.name = "hbh",
.family = NFPROTO_IPV6,
.match = hbh_mt6,
.matchsize = sizeof(struct ip6t_opts),
.checkentry = hbh_mt6_check,
.me = THIS_MODULE,
- .data = NEXTHDR_HOP,
},
{
.name = "dst",
@@ -194,7 +198,6 @@
.matchsize = sizeof(struct ip6t_opts),
.checkentry = hbh_mt6_check,
.me = THIS_MODULE,
- .data = NEXTHDR_DEST,
},
};
