WSL2-Linux-Kernel/net/sched/act_nat.c

343 строки
7.4 KiB
C
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[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
/*
* 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 int nat_net_id;
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,
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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];
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
struct tc_nat *parm;
int ret = 0, err;
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
struct tcf_nat *p;
if (nla == NULL)
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
return -EINVAL;
err = nla_parse_nested(tb, TCA_NAT_MAX, nla, nat_policy);
if (err < 0)
return err;
if (tb[TCA_NAT_PARMS] == NULL)
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
return -EINVAL;
parm = nla_data(tb[TCA_NAT_PARMS]);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
if (!tcf_hash_check(tn, parm->index, a, bind)) {
ret = tcf_hash_create(tn, parm->index, est, a,
sizeof(*p), bind, false);
if (ret)
return ret;
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
ret = ACT_P_CREATED;
} else {
if (bind)
return 0;
tcf_hash_release(a, bind);
if (!ovr)
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
return -EEXIST;
}
p = to_tcf_nat(a);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
return ret;
}
static int tcf_nat(struct sk_buff *skb, const struct tc_action *a,
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
struct tcf_result *res)
{
struct tcf_nat *p = a->priv;
struct iphdr *iph;
__be32 old_addr;
__be32 new_addr;
__be32 mask;
__be32 addr;
int egress;
int action;
int ihl;
int noff;
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
spin_lock(&p->tcf_lock);
p->tcf_tm.lastuse = jiffies;
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);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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))
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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))
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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;
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
}
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))
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
goto drop;
tcph = (void *)(skb_network_header(skb) + ihl);
inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr,
true);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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))
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
if (!udph->check)
udph->check = CSUM_MANGLED_0;
}
break;
}
case IPPROTO_ICMP:
{
struct icmphdr *icmph;
if (!pskb_may_pull(skb, ihl + sizeof(*icmph) + noff))
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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))
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
break;
}
default:
break;
}
out:
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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);
struct tcf_nat *p = a->priv;
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,
};
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
struct tcf_t t;
if (nla_put(skb, TCA_NAT_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
if (nla_put(skb, TCA_NAT_TM, sizeof(t), &t))
goto nla_put_failure;
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
return skb->len;
nla_put_failure:
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
nlmsg_trim(skb, b);
return -1;
}
static int tcf_nat_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
struct tc_action *a)
{
struct tc_action_net *tn = net_generic(net, nat_net_id);
return tcf_generic_walker(tn, skb, cb, type, a);
}
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);
}
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
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,
};
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),
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
};
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);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
}
static void __exit nat_cleanup_module(void)
{
tcf_unregister_action(&act_nat_ops, &nat_net_ops);
[PKT_SCHED]: Add stateless NAT Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-27 23:48:05 +04:00
}
module_init(nat_init_module);
module_exit(nat_cleanup_module);