1 /* This is a module which is used for setting the TOS field of a packet. */
3 /* (C) 1999-2001 Paul `Rusty' Russell
4 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
11 #include <linux/module.h>
12 #include <linux/skbuff.h>
14 #include <net/checksum.h>
16 #include <linux/netfilter_ipv4/ip_tables.h>
17 #include <linux/netfilter_ipv4/ipt_TOS.h>
19 MODULE_LICENSE("GPL");
20 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
21 MODULE_DESCRIPTION("iptables TOS mangling module");
24 target(struct sk_buff **pskb,
25 const struct net_device *in,
26 const struct net_device *out,
28 const struct xt_target *target,
32 const struct ipt_tos_target_info *tosinfo = targinfo;
33 struct iphdr *iph = (*pskb)->nh.iph;
36 if ((iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
37 if (!skb_make_writable(pskb, sizeof(struct iphdr)))
39 iph = (*pskb)->nh.iph;
41 iph->tos = (iph->tos & IPTOS_PREC_MASK) | tosinfo->tos;
42 iph->check = nf_csum_update(oldtos ^ 0xFFFF, iph->tos,
49 checkentry(const char *tablename,
51 const struct xt_target *target,
53 unsigned int targinfosize,
54 unsigned int hook_mask)
56 const u_int8_t tos = ((struct ipt_tos_target_info *)targinfo)->tos;
58 if (tos != IPTOS_LOWDELAY
59 && tos != IPTOS_THROUGHPUT
60 && tos != IPTOS_RELIABILITY
61 && tos != IPTOS_MINCOST
62 && tos != IPTOS_NORMALSVC) {
63 printk(KERN_WARNING "TOS: bad tos value %#x\n", tos);
69 static struct ipt_target ipt_tos_reg = {
72 .targetsize = sizeof(struct ipt_tos_target_info),
74 .checkentry = checkentry,
78 static int __init ipt_tos_init(void)
80 return ipt_register_target(&ipt_tos_reg);
83 static void __exit ipt_tos_fini(void)
85 ipt_unregister_target(&ipt_tos_reg);
88 module_init(ipt_tos_init);
89 module_exit(ipt_tos_fini);