2007-09-27 19:48:05 +00:00
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/*
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* Stateless NAT actions
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*
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* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*/
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/netfilter.h>
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#include <linux/rtnetlink.h>
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#include <linux/skbuff.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/string.h>
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#include <linux/tc_act/tc_nat.h>
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#include <net/act_api.h>
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#include <net/icmp.h>
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#include <net/ip.h>
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#include <net/netlink.h>
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#include <net/tc_act/tc_nat.h>
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#include <net/tcp.h>
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#include <net/udp.h>
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netns: make struct pernet_operations::id unsigned int
Make struct pernet_operations::id unsigned.
There are 2 reasons to do so:
1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.
2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.
"int" being used as an array index needs to be sign-extended
to 64-bit before being used.
void f(long *p, int i)
{
g(p[i]);
}
roughly translates to
movsx rsi, esi
mov rdi, [rsi+...]
call g
MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.
Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:
static inline void *net_generic(const struct net *net, int id)
{
...
ptr = ng->ptr[id - 1];
...
}
And this function is used a lot, so those sign extensions add up.
Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):
add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]
However, overall balance is in negative direction:
add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
function old new delta
nfsd4_lock 3886 3959 +73
tipc_link_build_proto_msg 1096 1140 +44
mac80211_hwsim_new_radio 2776 2808 +32
tipc_mon_rcv 1032 1058 +26
svcauth_gss_legacy_init 1413 1429 +16
tipc_bcbase_select_primary 379 392 +13
nfsd4_exchange_id 1247 1260 +13
nfsd4_setclientid_confirm 782 793 +11
...
put_client_renew_locked 494 480 -14
ip_set_sockfn_get 730 716 -14
geneve_sock_add 829 813 -16
nfsd4_sequence_done 721 703 -18
nlmclnt_lookup_host 708 686 -22
nfsd4_lockt 1085 1063 -22
nfs_get_client 1077 1050 -27
tcf_bpf_init 1106 1076 -30
nfsd4_encode_fattr 5997 5930 -67
Total: Before=154856051, After=154854321, chg -0.00%
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-17 01:58:21 +00:00
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static unsigned int nat_net_id;
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2016-07-25 23:09:41 +00:00
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static struct tc_action_ops act_nat_ops;
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2016-02-22 23:57:53 +00:00
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2008-01-24 04:36:30 +00:00
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static const struct nla_policy nat_policy[TCA_NAT_MAX + 1] = {
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[TCA_NAT_PARMS] = { .len = sizeof(struct tc_nat) },
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};
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2013-01-14 05:15:39 +00:00
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static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est,
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2018-02-15 15:54:56 +00:00
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struct tc_action **a, int ovr, int bind,
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2018-07-05 14:24:25 +00:00
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bool rtnl_held, struct netlink_ext_ack *extack)
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2007-09-27 19:48:05 +00:00
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{
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2016-02-22 23:57:53 +00:00
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struct tc_action_net *tn = net_generic(net, nat_net_id);
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2008-01-23 06:11:50 +00:00
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struct nlattr *tb[TCA_NAT_MAX + 1];
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2007-09-27 19:48:05 +00:00
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struct tc_nat *parm;
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2008-01-24 04:33:32 +00:00
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int ret = 0, err;
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2007-09-27 19:48:05 +00:00
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struct tcf_nat *p;
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2008-01-24 04:33:32 +00:00
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if (nla == NULL)
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2007-09-27 19:48:05 +00:00
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return -EINVAL;
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2017-04-12 12:34:07 +00:00
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err = nla_parse_nested(tb, TCA_NAT_MAX, nla, nat_policy, NULL);
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2008-01-24 04:33:32 +00:00
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if (err < 0)
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return err;
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2008-01-24 04:36:30 +00:00
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if (tb[TCA_NAT_PARMS] == NULL)
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2007-09-27 19:48:05 +00:00
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return -EINVAL;
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2008-01-23 06:11:50 +00:00
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parm = nla_data(tb[TCA_NAT_PARMS]);
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2007-09-27 19:48:05 +00:00
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2018-07-05 14:24:32 +00:00
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err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
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if (!err) {
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2017-08-30 06:31:59 +00:00
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ret = tcf_idr_create(tn, parm->index, est, a,
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&act_nat_ops, bind, false);
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2018-07-05 14:24:32 +00:00
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if (ret) {
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tcf_idr_cleanup(tn, parm->index);
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2014-02-12 01:07:31 +00:00
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return ret;
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2018-07-05 14:24:32 +00:00
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}
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2007-09-27 19:48:05 +00:00
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ret = ACT_P_CREATED;
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2018-07-05 14:24:32 +00:00
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} else if (err > 0) {
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2013-12-23 13:02:11 +00:00
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if (bind)
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return 0;
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2018-07-05 14:24:30 +00:00
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if (!ovr) {
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tcf_idr_release(*a, bind);
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2007-09-27 19:48:05 +00:00
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return -EEXIST;
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2018-07-05 14:24:30 +00:00
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}
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2018-07-05 14:24:32 +00:00
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} else {
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return err;
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2007-09-27 19:48:05 +00:00
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}
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2016-07-25 23:09:41 +00:00
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p = to_tcf_nat(*a);
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2007-09-27 19:48:05 +00:00
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spin_lock_bh(&p->tcf_lock);
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p->old_addr = parm->old_addr;
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p->new_addr = parm->new_addr;
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p->mask = parm->mask;
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p->flags = parm->flags;
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p->tcf_action = parm->action;
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spin_unlock_bh(&p->tcf_lock);
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if (ret == ACT_P_CREATED)
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2017-08-30 06:31:59 +00:00
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tcf_idr_insert(tn, *a);
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2007-09-27 19:48:05 +00:00
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return ret;
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}
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2018-08-12 13:34:54 +00:00
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static int tcf_nat_act(struct sk_buff *skb, const struct tc_action *a,
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struct tcf_result *res)
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2007-09-27 19:48:05 +00:00
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{
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2016-07-25 23:09:41 +00:00
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struct tcf_nat *p = to_tcf_nat(a);
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2007-09-27 19:48:05 +00:00
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struct iphdr *iph;
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__be32 old_addr;
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__be32 new_addr;
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__be32 mask;
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__be32 addr;
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int egress;
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int action;
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int ihl;
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2010-08-03 17:39:18 +00:00
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int noff;
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2007-09-27 19:48:05 +00:00
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spin_lock(&p->tcf_lock);
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2016-06-06 10:32:53 +00:00
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tcf_lastuse_update(&p->tcf_tm);
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2007-09-27 19:48:05 +00:00
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old_addr = p->old_addr;
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new_addr = p->new_addr;
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mask = p->mask;
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egress = p->flags & TCA_NAT_FLAG_EGRESS;
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action = p->tcf_action;
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2011-01-09 08:30:54 +00:00
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bstats_update(&p->tcf_bstats, skb);
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2007-09-27 19:48:05 +00:00
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spin_unlock(&p->tcf_lock);
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if (unlikely(action == TC_ACT_SHOT))
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goto drop;
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2010-08-03 17:39:18 +00:00
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noff = skb_network_offset(skb);
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if (!pskb_may_pull(skb, sizeof(*iph) + noff))
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2007-09-27 19:48:05 +00:00
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goto drop;
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iph = ip_hdr(skb);
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if (egress)
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addr = iph->saddr;
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else
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addr = iph->daddr;
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if (!((old_addr ^ addr) & mask)) {
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2016-02-19 22:05:25 +00:00
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if (skb_try_make_writable(skb, sizeof(*iph) + noff))
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2007-09-27 19:48:05 +00:00
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goto drop;
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new_addr &= mask;
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new_addr |= addr & ~mask;
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/* Rewrite IP header */
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iph = ip_hdr(skb);
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if (egress)
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iph->saddr = new_addr;
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else
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iph->daddr = new_addr;
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2007-11-29 14:17:11 +00:00
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csum_replace4(&iph->check, addr, new_addr);
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2010-05-29 14:26:59 +00:00
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} else if ((iph->frag_off & htons(IP_OFFSET)) ||
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iph->protocol != IPPROTO_ICMP) {
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goto out;
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2007-09-27 19:48:05 +00:00
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}
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ihl = iph->ihl * 4;
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/* It would be nice to share code with stateful NAT. */
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switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
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case IPPROTO_TCP:
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{
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struct tcphdr *tcph;
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|
2010-08-03 17:39:18 +00:00
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if (!pskb_may_pull(skb, ihl + sizeof(*tcph) + noff) ||
|
2016-02-19 22:05:25 +00:00
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skb_try_make_writable(skb, ihl + sizeof(*tcph) + noff))
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2007-09-27 19:48:05 +00:00
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goto drop;
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tcph = (void *)(skb_network_header(skb) + ihl);
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2015-08-17 20:42:25 +00:00
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inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr,
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true);
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2007-09-27 19:48:05 +00:00
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break;
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}
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case IPPROTO_UDP:
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{
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struct udphdr *udph;
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|
2010-08-03 17:39:18 +00:00
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if (!pskb_may_pull(skb, ihl + sizeof(*udph) + noff) ||
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2016-02-19 22:05:25 +00:00
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skb_try_make_writable(skb, ihl + sizeof(*udph) + noff))
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2007-09-27 19:48:05 +00:00
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goto drop;
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udph = (void *)(skb_network_header(skb) + ihl);
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if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
|
2007-11-29 14:17:11 +00:00
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inet_proto_csum_replace4(&udph->check, skb, addr,
|
2015-08-17 20:42:25 +00:00
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new_addr, true);
|
2007-09-27 19:48:05 +00:00
|
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if (!udph->check)
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udph->check = CSUM_MANGLED_0;
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}
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break;
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}
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case IPPROTO_ICMP:
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{
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struct icmphdr *icmph;
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|
2010-08-03 17:39:18 +00:00
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if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + noff))
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2007-09-27 19:48:05 +00:00
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goto drop;
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icmph = (void *)(skb_network_header(skb) + ihl);
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if ((icmph->type != ICMP_DEST_UNREACH) &&
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|
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(icmph->type != ICMP_TIME_EXCEEDED) &&
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|
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(icmph->type != ICMP_PARAMETERPROB))
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break;
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|
|
2010-08-03 17:39:18 +00:00
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if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + sizeof(*iph) +
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|
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noff))
|
2010-07-09 15:33:25 +00:00
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goto drop;
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|
2010-07-29 13:41:46 +00:00
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icmph = (void *)(skb_network_header(skb) + ihl);
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2007-09-27 19:48:05 +00:00
|
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iph = (void *)(icmph + 1);
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|
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if (egress)
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|
|
addr = iph->daddr;
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|
|
|
else
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|
|
|
addr = iph->saddr;
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|
|
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|
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if ((old_addr ^ addr) & mask)
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|
|
break;
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|
|
|
2016-02-19 22:05:25 +00:00
|
|
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if (skb_try_make_writable(skb, ihl + sizeof(*icmph) +
|
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|
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sizeof(*iph) + noff))
|
2007-09-27 19:48:05 +00:00
|
|
|
goto drop;
|
|
|
|
|
|
|
|
icmph = (void *)(skb_network_header(skb) + ihl);
|
|
|
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iph = (void *)(icmph + 1);
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|
|
|
|
|
|
|
new_addr &= mask;
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|
|
|
new_addr |= addr & ~mask;
|
|
|
|
|
|
|
|
/* XXX Fix up the inner checksums. */
|
|
|
|
if (egress)
|
|
|
|
iph->daddr = new_addr;
|
|
|
|
else
|
|
|
|
iph->saddr = new_addr;
|
|
|
|
|
2007-11-29 14:17:11 +00:00
|
|
|
inet_proto_csum_replace4(&icmph->checksum, skb, addr, new_addr,
|
2015-08-17 20:42:25 +00:00
|
|
|
false);
|
2007-09-27 19:48:05 +00:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
default:
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
2010-05-29 14:26:59 +00:00
|
|
|
out:
|
2007-09-27 19:48:05 +00:00
|
|
|
return action;
|
|
|
|
|
|
|
|
drop:
|
|
|
|
spin_lock(&p->tcf_lock);
|
|
|
|
p->tcf_qstats.drops++;
|
|
|
|
spin_unlock(&p->tcf_lock);
|
|
|
|
return TC_ACT_SHOT;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int tcf_nat_dump(struct sk_buff *skb, struct tc_action *a,
|
|
|
|
int bind, int ref)
|
|
|
|
{
|
|
|
|
unsigned char *b = skb_tail_pointer(skb);
|
2016-07-25 23:09:41 +00:00
|
|
|
struct tcf_nat *p = to_tcf_nat(a);
|
2010-08-16 20:04:22 +00:00
|
|
|
struct tc_nat opt = {
|
|
|
|
.old_addr = p->old_addr,
|
|
|
|
.new_addr = p->new_addr,
|
|
|
|
.mask = p->mask,
|
|
|
|
.flags = p->flags,
|
|
|
|
|
|
|
|
.index = p->tcf_index,
|
|
|
|
.action = p->tcf_action,
|
2018-07-05 14:24:24 +00:00
|
|
|
.refcnt = refcount_read(&p->tcf_refcnt) - ref,
|
|
|
|
.bindcnt = atomic_read(&p->tcf_bindcnt) - bind,
|
2010-08-16 20:04:22 +00:00
|
|
|
};
|
2007-09-27 19:48:05 +00:00
|
|
|
struct tcf_t t;
|
|
|
|
|
2012-03-29 09:11:39 +00:00
|
|
|
if (nla_put(skb, TCA_NAT_PARMS, sizeof(opt), &opt))
|
|
|
|
goto nla_put_failure;
|
2016-06-06 10:32:55 +00:00
|
|
|
|
|
|
|
tcf_tm_dump(&t, &p->tcf_tm);
|
2016-04-26 08:06:18 +00:00
|
|
|
if (nla_put_64bit(skb, TCA_NAT_TM, sizeof(t), &t, TCA_NAT_PAD))
|
2012-03-29 09:11:39 +00:00
|
|
|
goto nla_put_failure;
|
2007-09-27 19:48:05 +00:00
|
|
|
|
|
|
|
return skb->len;
|
|
|
|
|
2008-01-23 06:11:50 +00:00
|
|
|
nla_put_failure:
|
2007-09-27 19:48:05 +00:00
|
|
|
nlmsg_trim(skb, b);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
2016-02-22 23:57:53 +00:00
|
|
|
static int tcf_nat_walker(struct net *net, struct sk_buff *skb,
|
|
|
|
struct netlink_callback *cb, int type,
|
2018-02-15 15:54:58 +00:00
|
|
|
const struct tc_action_ops *ops,
|
|
|
|
struct netlink_ext_ack *extack)
|
2016-02-22 23:57:53 +00:00
|
|
|
{
|
|
|
|
struct tc_action_net *tn = net_generic(net, nat_net_id);
|
|
|
|
|
2018-02-15 15:54:59 +00:00
|
|
|
return tcf_generic_walker(tn, skb, cb, type, ops, extack);
|
2016-02-22 23:57:53 +00:00
|
|
|
}
|
|
|
|
|
2018-08-29 17:15:35 +00:00
|
|
|
static int tcf_nat_search(struct net *net, struct tc_action **a, u32 index)
|
2016-02-22 23:57:53 +00:00
|
|
|
{
|
|
|
|
struct tc_action_net *tn = net_generic(net, nat_net_id);
|
|
|
|
|
2017-08-30 06:31:59 +00:00
|
|
|
return tcf_idr_search(tn, a, index);
|
2016-02-22 23:57:53 +00:00
|
|
|
}
|
|
|
|
|
2007-09-27 19:48:05 +00:00
|
|
|
static struct tc_action_ops act_nat_ops = {
|
|
|
|
.kind = "nat",
|
|
|
|
.type = TCA_ACT_NAT,
|
|
|
|
.owner = THIS_MODULE,
|
2018-08-12 13:34:54 +00:00
|
|
|
.act = tcf_nat_act,
|
2007-09-27 19:48:05 +00:00
|
|
|
.dump = tcf_nat_dump,
|
|
|
|
.init = tcf_nat_init,
|
2016-02-22 23:57:53 +00:00
|
|
|
.walk = tcf_nat_walker,
|
|
|
|
.lookup = tcf_nat_search,
|
2016-07-25 23:09:41 +00:00
|
|
|
.size = sizeof(struct tcf_nat),
|
2016-02-22 23:57:53 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
static __net_init int nat_init_net(struct net *net)
|
|
|
|
{
|
|
|
|
struct tc_action_net *tn = net_generic(net, nat_net_id);
|
|
|
|
|
2017-11-06 21:47:18 +00:00
|
|
|
return tc_action_net_init(tn, &act_nat_ops);
|
2016-02-22 23:57:53 +00:00
|
|
|
}
|
|
|
|
|
2017-12-11 23:35:03 +00:00
|
|
|
static void __net_exit nat_exit_net(struct list_head *net_list)
|
2016-02-22 23:57:53 +00:00
|
|
|
{
|
2017-12-11 23:35:03 +00:00
|
|
|
tc_action_net_exit(net_list, nat_net_id);
|
2016-02-22 23:57:53 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
static struct pernet_operations nat_net_ops = {
|
|
|
|
.init = nat_init_net,
|
2017-12-11 23:35:03 +00:00
|
|
|
.exit_batch = nat_exit_net,
|
2016-02-22 23:57:53 +00:00
|
|
|
.id = &nat_net_id,
|
|
|
|
.size = sizeof(struct tc_action_net),
|
2007-09-27 19:48:05 +00:00
|
|
|
};
|
|
|
|
|
|
|
|
MODULE_DESCRIPTION("Stateless NAT actions");
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
|
|
|
|
static int __init nat_init_module(void)
|
|
|
|
{
|
2016-02-22 23:57:53 +00:00
|
|
|
return tcf_register_action(&act_nat_ops, &nat_net_ops);
|
2007-09-27 19:48:05 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
static void __exit nat_cleanup_module(void)
|
|
|
|
{
|
2016-02-22 23:57:53 +00:00
|
|
|
tcf_unregister_action(&act_nat_ops, &nat_net_ops);
|
2007-09-27 19:48:05 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
module_init(nat_init_module);
|
|
|
|
module_exit(nat_cleanup_module);
|