#include <linux/netfilter/x_tables.h>
MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
-MODULE_DESCRIPTION("IP tables packet length matching module");
+MODULE_DESCRIPTION("Xtables: Packet length (Layer3,4,5) match");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_length");
MODULE_ALIAS("ip6t_length");
-static int
-match(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,
- int *hotdrop)
+static bool
+length_mt(const struct sk_buff *skb, const struct xt_match_param *par)
{
- const struct xt_length_info *info = matchinfo;
- u_int16_t pktlen = ntohs(skb->nh.iph->tot_len);
-
+ 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 int
-match6(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,
- int *hotdrop)
+static bool
+length_mt6(const struct sk_buff *skb, const struct xt_match_param *par)
{
- const struct xt_length_info *info = matchinfo;
- u_int16_t pktlen = ntohs(skb->nh.ipv6h->payload_len) + sizeof(struct ipv6hdr);
-
+ const struct xt_length_info *info = par->matchinfo;
+ const u_int16_t pktlen = ntohs(ipv6_hdr(skb)->payload_len) +
+ sizeof(struct ipv6hdr);
+
return (pktlen >= info->min && pktlen <= info->max) ^ info->invert;
}
-static struct xt_match length_match = {
- .name = "length",
- .match = match,
- .matchsize = sizeof(struct xt_length_info),
- .family = AF_INET,
- .me = THIS_MODULE,
+static struct xt_match length_mt_reg[] __read_mostly = {
+ {
+ .name = "length",
+ .family = NFPROTO_IPV4,
+ .match = length_mt,
+ .matchsize = sizeof(struct xt_length_info),
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "length",
+ .family = NFPROTO_IPV6,
+ .match = length_mt6,
+ .matchsize = sizeof(struct xt_length_info),
+ .me = THIS_MODULE,
+ },
};
-static struct xt_match length6_match = {
- .name = "length",
- .match = match6,
- .matchsize = sizeof(struct xt_length_info),
- .family = AF_INET6,
- .me = THIS_MODULE,
-};
-
-static int __init init(void)
+static int __init length_mt_init(void)
{
- int ret;
- ret = xt_register_match(&length_match);
- if (ret)
- return ret;
- ret = xt_register_match(&length6_match);
- if (ret)
- xt_unregister_match(&length_match);
-
- return ret;
+ return xt_register_matches(length_mt_reg, ARRAY_SIZE(length_mt_reg));
}
-static void __exit fini(void)
+static void __exit length_mt_exit(void)
{
- xt_unregister_match(&length_match);
- xt_unregister_match(&length6_match);
+ xt_unregister_matches(length_mt_reg, ARRAY_SIZE(length_mt_reg));
}
-module_init(init);
-module_exit(fini);
+module_init(length_mt_init);
+module_exit(length_mt_exit);