mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-10-19 18:09:05 +00:00
e5ed639913
The following patch renames __in_dev_get() to __in_dev_get_rtnl() and introduces __in_dev_get_rcu() to cover the second case. 1) RCU with refcnt should use in_dev_get(). 2) RCU without refcnt should use __in_dev_get_rcu(). 3) All others must hold RTNL and use __in_dev_get_rtnl(). There is one exception in net/ipv4/route.c which is in fact a pre-existing race condition. I've marked it as such so that we remember to fix it. This patch is based on suggestions and prior work by Suzanne Wood and Paul McKenney. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
142 lines
3.3 KiB
C
142 lines
3.3 KiB
C
/*
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* NetBIOS name service broadcast connection tracking helper
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*
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* (c) 2005 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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/*
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* This helper tracks locally originating NetBIOS name service
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* requests by issuing permanent expectations (valid until
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* timing out) matching all reply connections from the
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* destination network. The only NetBIOS specific thing is
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* actually the port number.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/inetdevice.h>
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#include <linux/in.h>
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#include <linux/ip.h>
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#include <net/route.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv4.h>
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#include <linux/netfilter_ipv4/ip_conntrack.h>
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#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
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#define NMBD_PORT 137
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_DESCRIPTION("NetBIOS name service broadcast connection tracking helper");
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MODULE_LICENSE("GPL");
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static unsigned int timeout = 3;
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module_param(timeout, int, 0600);
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MODULE_PARM_DESC(timeout, "timeout for master connection/replies in seconds");
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static int help(struct sk_buff **pskb,
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struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
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{
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struct ip_conntrack_expect *exp;
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struct iphdr *iph = (*pskb)->nh.iph;
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struct rtable *rt = (struct rtable *)(*pskb)->dst;
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struct in_device *in_dev;
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u_int32_t mask = 0;
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/* we're only interested in locally generated packets */
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if ((*pskb)->sk == NULL)
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goto out;
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if (rt == NULL || !(rt->rt_flags & RTCF_BROADCAST))
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goto out;
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if (CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL)
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goto out;
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rcu_read_lock();
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in_dev = __in_dev_get_rcu(rt->u.dst.dev);
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if (in_dev != NULL) {
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for_primary_ifa(in_dev) {
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if (ifa->ifa_broadcast == iph->daddr) {
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mask = ifa->ifa_mask;
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break;
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}
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} endfor_ifa(in_dev);
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}
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rcu_read_unlock();
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if (mask == 0)
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goto out;
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exp = ip_conntrack_expect_alloc(ct);
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if (exp == NULL)
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goto out;
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exp->tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple;
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exp->tuple.src.u.udp.port = ntohs(NMBD_PORT);
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exp->mask.src.ip = mask;
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exp->mask.src.u.udp.port = 0xFFFF;
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exp->mask.dst.ip = 0xFFFFFFFF;
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exp->mask.dst.u.udp.port = 0xFFFF;
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exp->mask.dst.protonum = 0xFF;
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exp->expectfn = NULL;
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exp->flags = IP_CT_EXPECT_PERMANENT;
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ip_conntrack_expect_related(exp);
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ip_conntrack_expect_put(exp);
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ip_ct_refresh(ct, *pskb, timeout * HZ);
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out:
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return NF_ACCEPT;
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}
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static struct ip_conntrack_helper helper = {
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.name = "netbios-ns",
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.tuple = {
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.src = {
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.u = {
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.udp = {
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.port = __constant_htons(NMBD_PORT),
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}
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}
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},
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.dst = {
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.protonum = IPPROTO_UDP,
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},
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},
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.mask = {
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.src = {
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.u = {
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.udp = {
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.port = 0xFFFF,
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}
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}
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},
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.dst = {
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.protonum = 0xFF,
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},
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},
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.max_expected = 1,
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.me = THIS_MODULE,
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.help = help,
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};
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static int __init init(void)
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{
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helper.timeout = timeout;
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return ip_conntrack_helper_register(&helper);
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}
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static void __exit fini(void)
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{
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ip_conntrack_helper_unregister(&helper);
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}
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module_init(init);
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module_exit(fini);
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