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linux/net/sched/act_nat.c
Johannes Berg fceb6435e8 netlink: pass extended ACK struct to parsing functions
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:22 -04:00

344 lines
7.4 KiB
C

/*
* Stateless NAT actions
*
* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
*
* 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.
*/
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/tc_act/tc_nat.h>
#include <net/act_api.h>
#include <net/icmp.h>
#include <net/ip.h>
#include <net/netlink.h>
#include <net/tc_act/tc_nat.h>
#include <net/tcp.h>
#include <net/udp.h>
#define NAT_TAB_MASK 15
static unsigned int nat_net_id;
static struct tc_action_ops act_nat_ops;
static const struct nla_policy nat_policy[TCA_NAT_MAX + 1] = {
[TCA_NAT_PARMS] = { .len = sizeof(struct tc_nat) },
};
static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est,
struct tc_action **a, int ovr, int bind)
{
struct tc_action_net *tn = net_generic(net, nat_net_id);
struct nlattr *tb[TCA_NAT_MAX + 1];
struct tc_nat *parm;
int ret = 0, err;
struct tcf_nat *p;
if (nla == NULL)
return -EINVAL;
err = nla_parse_nested(tb, TCA_NAT_MAX, nla, nat_policy, NULL);
if (err < 0)
return err;
if (tb[TCA_NAT_PARMS] == NULL)
return -EINVAL;
parm = nla_data(tb[TCA_NAT_PARMS]);
if (!tcf_hash_check(tn, parm->index, a, bind)) {
ret = tcf_hash_create(tn, parm->index, est, a,
&act_nat_ops, bind, false);
if (ret)
return ret;
ret = ACT_P_CREATED;
} else {
if (bind)
return 0;
tcf_hash_release(*a, bind);
if (!ovr)
return -EEXIST;
}
p = to_tcf_nat(*a);
spin_lock_bh(&p->tcf_lock);
p->old_addr = parm->old_addr;
p->new_addr = parm->new_addr;
p->mask = parm->mask;
p->flags = parm->flags;
p->tcf_action = parm->action;
spin_unlock_bh(&p->tcf_lock);
if (ret == ACT_P_CREATED)
tcf_hash_insert(tn, *a);
return ret;
}
static int tcf_nat(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_nat *p = to_tcf_nat(a);
struct iphdr *iph;
__be32 old_addr;
__be32 new_addr;
__be32 mask;
__be32 addr;
int egress;
int action;
int ihl;
int noff;
spin_lock(&p->tcf_lock);
tcf_lastuse_update(&p->tcf_tm);
old_addr = p->old_addr;
new_addr = p->new_addr;
mask = p->mask;
egress = p->flags & TCA_NAT_FLAG_EGRESS;
action = p->tcf_action;
bstats_update(&p->tcf_bstats, skb);
spin_unlock(&p->tcf_lock);
if (unlikely(action == TC_ACT_SHOT))
goto drop;
noff = skb_network_offset(skb);
if (!pskb_may_pull(skb, sizeof(*iph) + noff))
goto drop;
iph = ip_hdr(skb);
if (egress)
addr = iph->saddr;
else
addr = iph->daddr;
if (!((old_addr ^ addr) & mask)) {
if (skb_try_make_writable(skb, sizeof(*iph) + noff))
goto drop;
new_addr &= mask;
new_addr |= addr & ~mask;
/* Rewrite IP header */
iph = ip_hdr(skb);
if (egress)
iph->saddr = new_addr;
else
iph->daddr = new_addr;
csum_replace4(&iph->check, addr, new_addr);
} else if ((iph->frag_off & htons(IP_OFFSET)) ||
iph->protocol != IPPROTO_ICMP) {
goto out;
}
ihl = iph->ihl * 4;
/* It would be nice to share code with stateful NAT. */
switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
case IPPROTO_TCP:
{
struct tcphdr *tcph;
if (!pskb_may_pull(skb, ihl + sizeof(*tcph) + noff) ||
skb_try_make_writable(skb, ihl + sizeof(*tcph) + noff))
goto drop;
tcph = (void *)(skb_network_header(skb) + ihl);
inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr,
true);
break;
}
case IPPROTO_UDP:
{
struct udphdr *udph;
if (!pskb_may_pull(skb, ihl + sizeof(*udph) + noff) ||
skb_try_make_writable(skb, ihl + sizeof(*udph) + noff))
goto drop;
udph = (void *)(skb_network_header(skb) + ihl);
if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
inet_proto_csum_replace4(&udph->check, skb, addr,
new_addr, true);
if (!udph->check)
udph->check = CSUM_MANGLED_0;
}
break;
}
case IPPROTO_ICMP:
{
struct icmphdr *icmph;
if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + noff))
goto drop;
icmph = (void *)(skb_network_header(skb) + ihl);
if ((icmph->type != ICMP_DEST_UNREACH) &&
(icmph->type != ICMP_TIME_EXCEEDED) &&
(icmph->type != ICMP_PARAMETERPROB))
break;
if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + sizeof(*iph) +
noff))
goto drop;
icmph = (void *)(skb_network_header(skb) + ihl);
iph = (void *)(icmph + 1);
if (egress)
addr = iph->daddr;
else
addr = iph->saddr;
if ((old_addr ^ addr) & mask)
break;
if (skb_try_make_writable(skb, ihl + sizeof(*icmph) +
sizeof(*iph) + noff))
goto drop;
icmph = (void *)(skb_network_header(skb) + ihl);
iph = (void *)(icmph + 1);
new_addr &= mask;
new_addr |= addr & ~mask;
/* XXX Fix up the inner checksums. */
if (egress)
iph->daddr = new_addr;
else
iph->saddr = new_addr;
inet_proto_csum_replace4(&icmph->checksum, skb, addr, new_addr,
false);
break;
}
default:
break;
}
out:
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);
struct tcf_nat *p = to_tcf_nat(a);
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,
.refcnt = p->tcf_refcnt - ref,
.bindcnt = p->tcf_bindcnt - bind,
};
struct tcf_t t;
if (nla_put(skb, TCA_NAT_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
tcf_tm_dump(&t, &p->tcf_tm);
if (nla_put_64bit(skb, TCA_NAT_TM, sizeof(t), &t, TCA_NAT_PAD))
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static int tcf_nat_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops)
{
struct tc_action_net *tn = net_generic(net, nat_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops);
}
static int tcf_nat_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, nat_net_id);
return tcf_hash_search(tn, a, index);
}
static struct tc_action_ops act_nat_ops = {
.kind = "nat",
.type = TCA_ACT_NAT,
.owner = THIS_MODULE,
.act = tcf_nat,
.dump = tcf_nat_dump,
.init = tcf_nat_init,
.walk = tcf_nat_walker,
.lookup = tcf_nat_search,
.size = sizeof(struct tcf_nat),
};
static __net_init int nat_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, nat_net_id);
return tc_action_net_init(tn, &act_nat_ops, NAT_TAB_MASK);
}
static void __net_exit nat_exit_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, nat_net_id);
tc_action_net_exit(tn);
}
static struct pernet_operations nat_net_ops = {
.init = nat_init_net,
.exit = nat_exit_net,
.id = &nat_net_id,
.size = sizeof(struct tc_action_net),
};
MODULE_DESCRIPTION("Stateless NAT actions");
MODULE_LICENSE("GPL");
static int __init nat_init_module(void)
{
return tcf_register_action(&act_nat_ops, &nat_net_ops);
}
static void __exit nat_cleanup_module(void)
{
tcf_unregister_action(&act_nat_ops, &nat_net_ops);
}
module_init(nat_init_module);
module_exit(nat_cleanup_module);