mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-10-19 09:59:04 +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>
133 lines
3.3 KiB
C
133 lines
3.3 KiB
C
/* Redirect. Simple mapping which alters dst to a local IP address. */
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/ip.h>
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#include <linux/timer.h>
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#include <linux/module.h>
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#include <linux/netfilter.h>
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#include <linux/netdevice.h>
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#include <linux/if.h>
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#include <linux/inetdevice.h>
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#include <net/protocol.h>
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#include <net/checksum.h>
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#include <linux/netfilter_ipv4.h>
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#include <linux/netfilter_ipv4/ip_nat_rule.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
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MODULE_DESCRIPTION("iptables REDIRECT target module");
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#if 0
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#define DEBUGP printk
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#else
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#define DEBUGP(format, args...)
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#endif
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/* FIXME: Take multiple ranges --RR */
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static int
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redirect_check(const char *tablename,
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const struct ipt_entry *e,
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void *targinfo,
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unsigned int targinfosize,
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unsigned int hook_mask)
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{
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const struct ip_nat_multi_range_compat *mr = targinfo;
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if (strcmp(tablename, "nat") != 0) {
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DEBUGP("redirect_check: bad table `%s'.\n", table);
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return 0;
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}
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if (targinfosize != IPT_ALIGN(sizeof(*mr))) {
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DEBUGP("redirect_check: size %u.\n", targinfosize);
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return 0;
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}
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if (hook_mask & ~((1 << NF_IP_PRE_ROUTING) | (1 << NF_IP_LOCAL_OUT))) {
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DEBUGP("redirect_check: bad hooks %x.\n", hook_mask);
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return 0;
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}
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if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
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DEBUGP("redirect_check: bad MAP_IPS.\n");
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return 0;
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}
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if (mr->rangesize != 1) {
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DEBUGP("redirect_check: bad rangesize %u.\n", mr->rangesize);
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return 0;
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}
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return 1;
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}
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static unsigned int
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redirect_target(struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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unsigned int hooknum,
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const void *targinfo,
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void *userinfo)
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{
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struct ip_conntrack *ct;
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enum ip_conntrack_info ctinfo;
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u_int32_t newdst;
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const struct ip_nat_multi_range_compat *mr = targinfo;
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struct ip_nat_range newrange;
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IP_NF_ASSERT(hooknum == NF_IP_PRE_ROUTING
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|| hooknum == NF_IP_LOCAL_OUT);
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ct = ip_conntrack_get(*pskb, &ctinfo);
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IP_NF_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
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/* Local packets: make them go to loopback */
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if (hooknum == NF_IP_LOCAL_OUT)
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newdst = htonl(0x7F000001);
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else {
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struct in_device *indev;
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struct in_ifaddr *ifa;
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newdst = 0;
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rcu_read_lock();
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indev = __in_dev_get_rcu((*pskb)->dev);
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if (indev && (ifa = indev->ifa_list))
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newdst = ifa->ifa_local;
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rcu_read_unlock();
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if (!newdst)
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return NF_DROP;
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}
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/* Transfer from original range. */
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newrange = ((struct ip_nat_range)
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{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
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newdst, newdst,
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mr->range[0].min, mr->range[0].max });
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/* Hand modified range to generic setup. */
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return ip_nat_setup_info(ct, &newrange, hooknum);
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}
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static struct ipt_target redirect_reg = {
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.name = "REDIRECT",
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.target = redirect_target,
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.checkentry = redirect_check,
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.me = THIS_MODULE,
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};
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static int __init init(void)
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{
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return ipt_register_target(&redirect_reg);
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}
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static void __exit fini(void)
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{
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ipt_unregister_target(&redirect_reg);
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}
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module_init(init);
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module_exit(fini);
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