2 * broadcast connection tracking helper
4 * (c) 2005 Patrick McHardy <kaber@trash.net>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
14 #include <net/route.h>
15 #include <linux/inetdevice.h>
16 #include <linux/skbuff.h>
18 #include <net/netfilter/nf_conntrack.h>
19 #include <net/netfilter/nf_conntrack_helper.h>
20 #include <net/netfilter/nf_conntrack_expect.h>
22 int nf_conntrack_broadcast_help(struct sk_buff *skb,
24 enum ip_conntrack_info ctinfo,
27 struct nf_conntrack_expect *exp;
28 struct iphdr *iph = ip_hdr(skb);
29 struct rtable *rt = skb_rtable(skb);
30 struct in_device *in_dev;
31 struct nf_conn_help *help = nfct_help(ct);
34 /* we're only interested in locally generated packets */
35 if (skb->sk == NULL || !net_eq(nf_ct_net(ct), sock_net(skb->sk)))
37 if (rt == NULL || !(rt->rt_flags & RTCF_BROADCAST))
39 if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
42 in_dev = __in_dev_get_rcu(rt->dst.dev);
44 for_primary_ifa(in_dev) {
45 if (ifa->ifa_broadcast == iph->daddr) {
55 exp = nf_ct_expect_alloc(ct);
59 exp->tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple;
60 exp->tuple.src.u.udp.port = help->helper->tuple.src.u.udp.port;
62 exp->mask.src.u3.ip = mask;
63 exp->mask.src.u.udp.port = htons(0xFFFF);
66 exp->flags = NF_CT_EXPECT_PERMANENT;
67 exp->class = NF_CT_EXPECT_CLASS_DEFAULT;
70 nf_ct_expect_related(exp);
71 nf_ct_expect_put(exp);
73 nf_ct_refresh(ct, skb, timeout * HZ);
77 EXPORT_SYMBOL_GPL(nf_conntrack_broadcast_help);
79 MODULE_LICENSE("GPL");