]>
git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - net/ipv4/netfilter/ipt_ecn.c
1 /* IP tables module for matching the value of the IPv4 and TCP ECN bits
3 * ipt_ecn.c,v 1.3 2002/05/29 15:09:00 laforge Exp
5 * (C) 2002 by Harald Welte <laforge@gnumonks.org>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
15 #include <linux/module.h>
16 #include <linux/skbuff.h>
17 #include <linux/tcp.h>
19 #include <linux/netfilter/x_tables.h>
20 #include <linux/netfilter_ipv4/ip_tables.h>
21 #include <linux/netfilter_ipv4/ipt_ecn.h>
23 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
24 MODULE_DESCRIPTION("iptables ECN matching module");
25 MODULE_LICENSE("GPL");
27 static inline int match_ip(const struct sk_buff
*skb
,
28 const struct ipt_ecn_info
*einfo
)
30 return ((skb
->nh
.iph
->tos
&IPT_ECN_IP_MASK
) == einfo
->ip_ect
);
33 static inline int match_tcp(const struct sk_buff
*skb
,
34 const struct ipt_ecn_info
*einfo
,
37 struct tcphdr _tcph
, *th
;
39 /* In practice, TCP match does this, so can't fail. But let's
42 th
= skb_header_pointer(skb
, ip_hdrlen(skb
), sizeof(_tcph
), &_tcph
);
48 if (einfo
->operation
& IPT_ECN_OP_MATCH_ECE
) {
49 if (einfo
->invert
& IPT_ECN_OP_MATCH_ECE
) {
58 if (einfo
->operation
& IPT_ECN_OP_MATCH_CWR
) {
59 if (einfo
->invert
& IPT_ECN_OP_MATCH_CWR
) {
71 static int match(const struct sk_buff
*skb
,
72 const struct net_device
*in
, const struct net_device
*out
,
73 const struct xt_match
*match
, const void *matchinfo
,
74 int offset
, unsigned int protoff
, int *hotdrop
)
76 const struct ipt_ecn_info
*info
= matchinfo
;
78 if (info
->operation
& IPT_ECN_OP_MATCH_IP
)
79 if (!match_ip(skb
, info
))
82 if (info
->operation
& (IPT_ECN_OP_MATCH_ECE
|IPT_ECN_OP_MATCH_CWR
)) {
83 if (skb
->nh
.iph
->protocol
!= IPPROTO_TCP
)
85 if (!match_tcp(skb
, info
, hotdrop
))
92 static int checkentry(const char *tablename
, const void *ip_void
,
93 const struct xt_match
*match
,
94 void *matchinfo
, unsigned int hook_mask
)
96 const struct ipt_ecn_info
*info
= matchinfo
;
97 const struct ipt_ip
*ip
= ip_void
;
99 if (info
->operation
& IPT_ECN_OP_MATCH_MASK
)
102 if (info
->invert
& IPT_ECN_OP_MATCH_MASK
)
105 if (info
->operation
& (IPT_ECN_OP_MATCH_ECE
|IPT_ECN_OP_MATCH_CWR
)
106 && ip
->proto
!= IPPROTO_TCP
) {
107 printk(KERN_WARNING
"ipt_ecn: can't match TCP bits in rule for"
108 " non-tcp packets\n");
115 static struct xt_match ecn_match
= {
119 .matchsize
= sizeof(struct ipt_ecn_info
),
120 .checkentry
= checkentry
,
124 static int __init
ipt_ecn_init(void)
126 return xt_register_match(&ecn_match
);
129 static void __exit
ipt_ecn_fini(void)
131 xt_unregister_match(&ecn_match
);
134 module_init(ipt_ecn_init
);
135 module_exit(ipt_ecn_fini
);