/* iptables module for the IPv4 and TCP ECN bits, Version 1.5
*
* (C) 2002 by Harald Welte <laforge@netfilter.org>
- *
+ *
* This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
+ * it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
- *
- * ipt_ECN.c,v 1.5 2002/08/18 19:36:51 laforge Exp
*/
+#include <linux/in.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
+#include <net/ip.h>
#include <linux/tcp.h>
#include <net/checksum.h>
+#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_ECN.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
-MODULE_DESCRIPTION("iptables ECN modification module");
+MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag modification");
/* set ECT codepoint from IP header.
- * return 0 if there was an error. */
-static inline int
-set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
+ * return false if there was an error. */
+static inline bool
+set_ect_ip(struct sk_buff *skb, const struct ipt_ECN_info *einfo)
{
- struct iphdr *iph = (*pskb)->nh.iph;
- u_int16_t oldtos;
+ struct iphdr *iph = ip_hdr(skb);
if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
- if (!skb_make_writable(pskb, sizeof(struct iphdr)))
- return 0;
- iph = (*pskb)->nh.iph;
+ __u8 oldtos;
+ if (!skb_make_writable(skb, sizeof(struct iphdr)))
+ return false;
+ iph = ip_hdr(skb);
oldtos = iph->tos;
iph->tos &= ~IPT_ECN_IP_MASK;
iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK);
- iph->check = nf_csum_update(htons(oldtos) ^ htons(0xFFFF),
- htons(iph->tos), iph->check);
- }
- return 1;
+ csum_replace2(&iph->check, htons(oldtos), htons(iph->tos));
+ }
+ return true;
}
-/* Return 0 if there was an error. */
-static inline int
-set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
+/* Return false if there was an error. */
+static inline bool
+set_ect_tcp(struct sk_buff *skb, const struct ipt_ECN_info *einfo)
{
struct tcphdr _tcph, *tcph;
__be16 oldval;
- /* Not enought header? */
- tcph = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
- sizeof(_tcph), &_tcph);
+ /* Not enough header? */
+ tcph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
if (!tcph)
- return 0;
+ return false;
if ((!(einfo->operation & IPT_ECN_OP_SET_ECE) ||
tcph->ece == einfo->proto.tcp.ece) &&
- ((!(einfo->operation & IPT_ECN_OP_SET_CWR) ||
- tcph->cwr == einfo->proto.tcp.cwr)))
- return 1;
+ (!(einfo->operation & IPT_ECN_OP_SET_CWR) ||
+ tcph->cwr == einfo->proto.tcp.cwr))
+ return true;
- if (!skb_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(*tcph)))
- return 0;
- tcph = (void *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl*4;
+ if (!skb_make_writable(skb, ip_hdrlen(skb) + sizeof(*tcph)))
+ return false;
+ tcph = (void *)ip_hdr(skb) + ip_hdrlen(skb);
oldval = ((__be16 *)tcph)[6];
if (einfo->operation & IPT_ECN_OP_SET_ECE)
if (einfo->operation & IPT_ECN_OP_SET_CWR)
tcph->cwr = einfo->proto.tcp.cwr;
- tcph->check = nf_proto_csum_update((*pskb),
- oldval ^ htons(0xFFFF),
- ((__be16 *)tcph)[6],
- tcph->check, 0);
- return 1;
+ inet_proto_csum_replace2(&tcph->check, skb,
+ oldval, ((__be16 *)tcph)[6], 0);
+ return true;
}
static unsigned int
-target(struct sk_buff **pskb,
- const struct net_device *in,
- const struct net_device *out,
- unsigned int hooknum,
- const struct xt_target *target,
- const void *targinfo)
+ecn_tg(struct sk_buff *skb, const struct xt_target_param *par)
{
- const struct ipt_ECN_info *einfo = targinfo;
+ const struct ipt_ECN_info *einfo = par->targinfo;
if (einfo->operation & IPT_ECN_OP_SET_IP)
- if (!set_ect_ip(pskb, einfo))
+ if (!set_ect_ip(skb, einfo))
return NF_DROP;
if (einfo->operation & (IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR)
- && (*pskb)->nh.iph->protocol == IPPROTO_TCP)
- if (!set_ect_tcp(pskb, einfo))
+ && ip_hdr(skb)->protocol == IPPROTO_TCP)
+ if (!set_ect_tcp(skb, einfo))
return NF_DROP;
- return IPT_CONTINUE;
+ return XT_CONTINUE;
}
-static int
-checkentry(const char *tablename,
- const void *e_void,
- const struct xt_target *target,
- void *targinfo,
- unsigned int hook_mask)
+static bool ecn_tg_check(const struct xt_tgchk_param *par)
{
- const struct ipt_ECN_info *einfo = (struct ipt_ECN_info *)targinfo;
- const struct ipt_entry *e = e_void;
+ const struct ipt_ECN_info *einfo = par->targinfo;
+ const struct ipt_entry *e = par->entryinfo;
if (einfo->operation & IPT_ECN_OP_MASK) {
printk(KERN_WARNING "ECN: unsupported ECN operation %x\n",
einfo->operation);
- return 0;
+ return false;
}
if (einfo->ip_ect & ~IPT_ECN_IP_MASK) {
printk(KERN_WARNING "ECN: new ECT codepoint %x out of mask\n",
einfo->ip_ect);
- return 0;
+ return false;
}
if ((einfo->operation & (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR))
- && (e->ip.proto != IPPROTO_TCP || (e->ip.invflags & IPT_INV_PROTO))) {
+ && (e->ip.proto != IPPROTO_TCP || (e->ip.invflags & XT_INV_PROTO))) {
printk(KERN_WARNING "ECN: cannot use TCP operations on a "
"non-tcp rule\n");
- return 0;
+ return false;
}
- return 1;
+ return true;
}
-static struct ipt_target ipt_ecn_reg = {
+static struct xt_target ecn_tg_reg __read_mostly = {
.name = "ECN",
- .target = target,
+ .family = NFPROTO_IPV4,
+ .target = ecn_tg,
.targetsize = sizeof(struct ipt_ECN_info),
.table = "mangle",
- .checkentry = checkentry,
+ .checkentry = ecn_tg_check,
.me = THIS_MODULE,
};
-static int __init ipt_ecn_init(void)
+static int __init ecn_tg_init(void)
{
- return ipt_register_target(&ipt_ecn_reg);
+ return xt_register_target(&ecn_tg_reg);
}
-static void __exit ipt_ecn_fini(void)
+static void __exit ecn_tg_exit(void)
{
- ipt_unregister_target(&ipt_ecn_reg);
+ xt_unregister_target(&ecn_tg_reg);
}
-module_init(ipt_ecn_init);
-module_exit(ipt_ecn_fini);
+module_init(ecn_tg_init);
+module_exit(ecn_tg_exit);