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/x_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 tos_tg(struct sk_buff *skb, const struct net_device *in,
25 const struct net_device *out, unsigned int hooknum,
26 const struct xt_target *target, const void *targinfo)
28 const struct ipt_tos_target_info *tosinfo = targinfo;
29 struct iphdr *iph = ip_hdr(skb);
31 if ((iph->tos & IPTOS_TOS_MASK) != tosinfo->tos) {
33 if (!skb_make_writable(skb, sizeof(struct iphdr)))
37 iph->tos = (iph->tos & IPTOS_PREC_MASK) | tosinfo->tos;
38 csum_replace2(&iph->check, htons(oldtos), htons(iph->tos));
44 tos_tg_check(const char *tablename, const void *e_void,
45 const struct xt_target *target, void *targinfo,
46 unsigned int hook_mask)
48 const u_int8_t tos = ((struct ipt_tos_target_info *)targinfo)->tos;
50 if (tos != IPTOS_LOWDELAY
51 && tos != IPTOS_THROUGHPUT
52 && tos != IPTOS_RELIABILITY
53 && tos != IPTOS_MINCOST
54 && tos != IPTOS_NORMALSVC) {
55 printk(KERN_WARNING "TOS: bad tos value %#x\n", tos);
61 static struct xt_target tos_tg_reg __read_mostly = {
65 .targetsize = sizeof(struct ipt_tos_target_info),
67 .checkentry = tos_tg_check,
71 static int __init tos_tg_init(void)
73 return xt_register_target(&tos_tg_reg);
76 static void __exit tos_tg_exit(void)
78 xt_unregister_target(&tos_tg_reg);
81 module_init(tos_tg_init);
82 module_exit(tos_tg_exit);