--- /dev/null	2005-01-29 13:33:32.773091056 -0500
+++ 2611-rc3+bk3/include/net/tc_act/tc_csuma.h	2005-02-07 08:39:52.594700248 -0500
@@ -0,0 +1,28 @@
+#ifndef __NET_TCA_CSUMA_H
+#define __NET_TCA_CSUMA_H
+
+#include <net/act_api.h>
+#include <net/checksum.h>
+
+struct tcf_csum {
+	u16 ctype;
+	u16 atype;
+	u32 vldact;
+	u32 invact;
+};
+
+enum
+{
+	CSUMA_INVALID = -1,
+	CSUMA_IPVLD,
+	CSUMA_IPSET,
+	CSUMA_TCPVLD,
+	CSUMA_TCPSET,
+	CSUMA_UDPVLD,
+	CSUMA_UDPSET,
+	__CSUMA_MAX
+};
+#define CSUMA_MAX (__CSUMA_MAX - 1)
+
+
+#endif
--- /dev/null	2005-01-29 13:33:32.773091056 -0500
+++ 2611-rc3+bk3/net/sched/csumact.c	2005-02-07 08:37:33.000000000 -0500
@@ -0,0 +1,208 @@
+/*
+ * net/sched/csumact.c	Checksum validate+recompute action
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * Authors:	Jamal Hadi Salim (2005)
+ *
+ */
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/bitops.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <net/sock.h>
+#include <net/pkt_sched.h>
+
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/checksum.h>
+
+#define TCA_ACT_CSUMA 23
+
+#define MY_TAB_SIZE     8
+#define MY_TAB_MASK     (MY_TAB_SIZE - 1)
+#include <linux/tc_act/tc_defact.h>
+#include <net/tc_act/tc_defact.h>
+#include <net/tc_act/tc_csuma.h>
+
+static u32 idx_gen;
+static struct tcf_defact *tcf_csuma_ht[MY_TAB_SIZE]; 
+static DEFINE_RWLOCK(csuma_lock);
+
+/* override the defaults */
+#define tcf_st		tcf_defact
+#define tc_st		tc_defact
+#define tcf_t_lock	csuma_lock
+#define tcf_ht		tcf_csuma_ht
+
+#define CONFIG_NET_ACT_INIT 1
+#include <net/pkt_act.h>
+#include <net/act_generic.h>
+
+/* the diffferent csum computers and validators */
+/* 
+ * XXXX: There is a lot of optimizations that could be
+ * done here. each valid and set could share code and 
+ * all the tcp/udp really should be sharing the same code
+ * base
+*/
+static int ipvalid(struct tcf_csum *p, struct sk_buff *skb)
+{
+	struct iphdr *iph = skb->nh.iph;
+	if (ip_fast_csum((unsigned char *)iph, iph->ihl))
+			return p->invact;
+	return p->vldact;
+}
+
+/* XXXX: the usual rules for trampling on pkts must be followed */
+static int ipset(struct tcf_csum *p, struct sk_buff *skb)
+{
+	struct iphdr *iph = skb->nh.iph;
+	iph->check = 0;
+	iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
+	return p->vldact;
+}
+
+static int tcpvalid(struct tcf_csum *p, struct sk_buff *skb)
+{
+	struct iphdr *iph = skb->nh.iph;
+	unsigned int tcphoff = skb->nh.iph->ihl * 4;
+	unsigned int tcplen = skb->len - tcphoff;
+
+	skb->csum = skb_checksum(skb, tcphoff, tcplen, 0);
+
+	if (csum_tcpudp_magic(iph->saddr, iph->daddr, tcplen, IPPROTO_TCP, skb->csum))
+		return p->invact;
+
+	return p->vldact;
+}
+
+/* XXXX: the usual rules for trampling on pkts must be followed */
+static int tcpset(struct tcf_csum *p, struct sk_buff *skb)
+{
+	struct tcphdr *tcph = skb->h.th;
+	struct iphdr *iph = skb->nh.iph;
+	unsigned int tcphoff = skb->nh.iph->ihl * 4;
+	unsigned int tcplen = skb->len - tcphoff;
+
+	tcph->check = 0;
+	skb->csum = skb_checksum(skb, tcphoff, tcplen, 0);
+
+	tcph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
+			tcplen, IPPROTO_TCP, skb->csum);
+
+	return p->vldact;
+}
+
+static int udpvalid(struct tcf_csum *p, struct sk_buff *skb)
+{
+	struct iphdr *iph = skb->nh.iph;
+	unsigned int udphoff = skb->nh.iph->ihl * 4;
+	unsigned int udplen = skb->len - udphoff;
+
+	skb->csum = skb_checksum(skb, udphoff, udplen, 0);
+
+	if (csum_tcpudp_magic(iph->saddr, iph->daddr, udplen, IPPROTO_UDP, skb->csum))
+		return p->invact;
+
+	return p->vldact;
+}
+
+/* XXXX: the usual rules for trampling on pkts must be followed */
+static int udpset(struct tcf_csum *p, struct sk_buff *skb)
+{
+	struct udphdr *udph = skb->h.uh;
+	struct iphdr *iph = skb->nh.iph;
+	unsigned int udphoff = skb->nh.iph->ihl * 4;
+	unsigned int udplen = skb->len - udphoff;
+
+	udph->check = 0;
+	skb->csum = skb_checksum(skb, udphoff, udplen, 0);
+
+	udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
+			udplen, IPPROTO_UDP, skb->csum);
+
+	return p->vldact;
+}
+
+typedef int (*f_csum)(struct tcf_csum *p, struct sk_buff *skb);
+static f_csum csumfuncs[CSUMA_MAX + 1] = {ipvalid,ipset,tcpvalid,tcpset,udpvalid,udpset };
+
+static int tcf_csuma(struct sk_buff **pskb, struct tc_action *a)
+{
+	int ret;
+	struct sk_buff *skb = *pskb;
+	struct tcf_defact *p = PRIV(a, defact);
+	struct tcf_csum *c = p->defdata;
+
+	spin_lock(&p->lock);
+	p->tm.lastuse = jiffies;
+	p->bstats.bytes += skb->len;
+	p->bstats.packets++;
+	ret = csumfuncs[c->ctype](c, skb);
+	spin_unlock(&p->lock);
+	return ret;
+}
+
+static inline int
+tcf_csuma_init(struct rtattr *rta, struct rtattr *est,
+	       struct tc_action *a, int ovr, int bind)
+{
+	/* cutnpaste tcf_defact_init and check that
+	 * the ctype passed is valid */
+	       return 0;
+}
+
+static struct tc_action_ops act_csuma_ops = {
+	.kind = "csumact",
+	.type = TCA_ACT_CSUMA,
+	.capab = TCA_CAP_NONE,
+	.owner = THIS_MODULE,
+	.act = tcf_csuma,
+	tca_use_default_ops
+};
+
+MODULE_AUTHOR("Jamal Hadi Salim(2005)");
+MODULE_DESCRIPTION("checksum action");
+MODULE_LICENSE("GPL");
+
+static int __init csuma_init_module(void)
+{
+	int ret = tcf_register_action(&act_csuma_ops);
+	if (!ret) {
+		printk("Simple TC action Loaded\n");
+		/* overwrite the init */
+		act_csuma_ops.init = tcf_csuma_init;
+	}
+	return ret;
+}
+
+static void __exit csuma_cleanup_module(void)
+{
+	tcf_unregister_action(&act_csuma_ops);
+}
+
+module_init(csuma_init_module);
+module_exit(csuma_cleanup_module);