mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-10-19 18:09:05 +00:00
132 lines
3.5 KiB
C
132 lines
3.5 KiB
C
|
/*
|
||
|
* NetBIOS name service broadcast connection tracking helper
|
||
|
*
|
||
|
* (c) 2005 Patrick McHardy <kaber@trash.net>
|
||
|
*
|
||
|
* 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.
|
||
|
*/
|
||
|
/*
|
||
|
* This helper tracks locally originating NetBIOS name service
|
||
|
* requests by issuing permanent expectations (valid until
|
||
|
* timing out) matching all reply connections from the
|
||
|
* destination network. The only NetBIOS specific thing is
|
||
|
* actually the port number.
|
||
|
*/
|
||
|
#include <linux/kernel.h>
|
||
|
#include <linux/module.h>
|
||
|
#include <linux/init.h>
|
||
|
#include <linux/skbuff.h>
|
||
|
#include <linux/netdevice.h>
|
||
|
#include <linux/inetdevice.h>
|
||
|
#include <linux/in.h>
|
||
|
#include <linux/ip.h>
|
||
|
#include <linux/udp.h>
|
||
|
#include <net/route.h>
|
||
|
|
||
|
#include <linux/netfilter.h>
|
||
|
#include <linux/netfilter_ipv4.h>
|
||
|
#include <linux/netfilter_ipv4/ip_conntrack.h>
|
||
|
#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
|
||
|
|
||
|
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
|
||
|
MODULE_DESCRIPTION("NetBIOS name service broadcast connection tracking helper");
|
||
|
MODULE_LICENSE("GPL");
|
||
|
|
||
|
static unsigned int timeout = 3;
|
||
|
module_param(timeout, int, 0600);
|
||
|
MODULE_PARM_DESC(timeout, "timeout for master connection/replies in seconds");
|
||
|
|
||
|
static int help(struct sk_buff **pskb,
|
||
|
struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
|
||
|
{
|
||
|
struct ip_conntrack_expect *exp;
|
||
|
struct iphdr *iph = (*pskb)->nh.iph;
|
||
|
struct udphdr _uh, *uh;
|
||
|
struct rtable *rt = (struct rtable *)(*pskb)->dst;
|
||
|
struct in_device *in_dev;
|
||
|
u_int32_t mask = 0;
|
||
|
|
||
|
/* we're only interested in locally generated packets */
|
||
|
if ((*pskb)->sk == NULL)
|
||
|
goto out;
|
||
|
if (rt == NULL || !(rt->rt_flags & RTCF_BROADCAST))
|
||
|
goto out;
|
||
|
if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
|
||
|
goto out;
|
||
|
|
||
|
rcu_read_lock();
|
||
|
in_dev = __in_dev_get(rt->u.dst.dev);
|
||
|
if (in_dev != NULL) {
|
||
|
for_primary_ifa(in_dev) {
|
||
|
if (ifa->ifa_broadcast == iph->daddr) {
|
||
|
mask = ifa->ifa_mask;
|
||
|
break;
|
||
|
}
|
||
|
} endfor_ifa(in_dev);
|
||
|
}
|
||
|
rcu_read_unlock();
|
||
|
|
||
|
if (mask == 0)
|
||
|
goto out;
|
||
|
|
||
|
uh = skb_header_pointer(*pskb, iph->ihl * 4, sizeof(_uh), &_uh);
|
||
|
BUG_ON(uh == NULL);
|
||
|
|
||
|
exp = ip_conntrack_expect_alloc(ct);
|
||
|
if (exp == NULL)
|
||
|
goto out;
|
||
|
memset(&exp->tuple, 0, sizeof(exp->tuple));
|
||
|
exp->tuple.src.ip = iph->daddr & mask;
|
||
|
exp->tuple.dst.ip = iph->saddr;
|
||
|
exp->tuple.dst.u.udp.port = uh->source;
|
||
|
exp->tuple.dst.protonum = IPPROTO_UDP;
|
||
|
|
||
|
memset(&exp->mask, 0, sizeof(exp->mask));
|
||
|
exp->mask.src.ip = mask;
|
||
|
exp->mask.dst.ip = 0xFFFFFFFF;
|
||
|
exp->mask.dst.u.udp.port = 0xFFFF;
|
||
|
exp->mask.dst.protonum = 0xFF;
|
||
|
|
||
|
exp->expectfn = NULL;
|
||
|
exp->flags = IP_CT_EXPECT_PERMANENT;
|
||
|
|
||
|
ip_conntrack_expect_related(exp);
|
||
|
ip_conntrack_expect_put(exp);
|
||
|
|
||
|
ip_ct_refresh_acct(ct, ctinfo, NULL, timeout * HZ);
|
||
|
out:
|
||
|
return NF_ACCEPT;
|
||
|
}
|
||
|
|
||
|
static struct ip_conntrack_helper helper = {
|
||
|
.name = "netbios-ns",
|
||
|
.tuple = {
|
||
|
.src.u.udp.port = __constant_htons(137),
|
||
|
.dst.protonum = IPPROTO_UDP,
|
||
|
},
|
||
|
.mask = {
|
||
|
.src.u.udp.port = 0xFFFF,
|
||
|
.dst.protonum = 0xFF,
|
||
|
},
|
||
|
.max_expected = 1,
|
||
|
.me = THIS_MODULE,
|
||
|
.help = help,
|
||
|
};
|
||
|
|
||
|
static int __init init(void)
|
||
|
{
|
||
|
helper.timeout = timeout;
|
||
|
return ip_conntrack_helper_register(&helper);
|
||
|
}
|
||
|
|
||
|
static void __exit fini(void)
|
||
|
{
|
||
|
ip_conntrack_helper_unregister(&helper);
|
||
|
}
|
||
|
|
||
|
module_init(init);
|
||
|
module_exit(fini);
|