![Arushi Singhal](/assets/img/avatar_default.png)
Using pr_<loglevel>() is more concise than printk(KERN_<LOGLEVEL>). This patch: * Replace printks having a log level with the appropriate pr_*() macros. * Define pr_fmt() to include relevant name. * Remove redundant prefixes from pr_*() calls. * Indent the code where possible. * Remove the useless output messages. * Remove periods from messages. Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
863 lines
24 KiB
C
863 lines
24 KiB
C
/*
|
|
* (C) 1999-2001 Paul `Rusty' Russell
|
|
* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
|
|
* (C) 2011 Patrick McHardy <kaber@trash.net>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/gfp.h>
|
|
#include <net/xfrm.h>
|
|
#include <linux/jhash.h>
|
|
#include <linux/rtnetlink.h>
|
|
|
|
#include <net/netfilter/nf_conntrack.h>
|
|
#include <net/netfilter/nf_conntrack_core.h>
|
|
#include <net/netfilter/nf_nat.h>
|
|
#include <net/netfilter/nf_nat_l3proto.h>
|
|
#include <net/netfilter/nf_nat_l4proto.h>
|
|
#include <net/netfilter/nf_nat_core.h>
|
|
#include <net/netfilter/nf_nat_helper.h>
|
|
#include <net/netfilter/nf_conntrack_helper.h>
|
|
#include <net/netfilter/nf_conntrack_seqadj.h>
|
|
#include <net/netfilter/nf_conntrack_l3proto.h>
|
|
#include <net/netfilter/nf_conntrack_zones.h>
|
|
#include <linux/netfilter/nf_nat.h>
|
|
|
|
static spinlock_t nf_nat_locks[CONNTRACK_LOCKS];
|
|
|
|
static DEFINE_MUTEX(nf_nat_proto_mutex);
|
|
static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
|
|
__read_mostly;
|
|
static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
|
|
__read_mostly;
|
|
|
|
static struct hlist_head *nf_nat_bysource __read_mostly;
|
|
static unsigned int nf_nat_htable_size __read_mostly;
|
|
static unsigned int nf_nat_hash_rnd __read_mostly;
|
|
|
|
inline const struct nf_nat_l3proto *
|
|
__nf_nat_l3proto_find(u8 family)
|
|
{
|
|
return rcu_dereference(nf_nat_l3protos[family]);
|
|
}
|
|
|
|
inline const struct nf_nat_l4proto *
|
|
__nf_nat_l4proto_find(u8 family, u8 protonum)
|
|
{
|
|
return rcu_dereference(nf_nat_l4protos[family][protonum]);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find);
|
|
|
|
#ifdef CONFIG_XFRM
|
|
static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
|
|
{
|
|
const struct nf_nat_l3proto *l3proto;
|
|
const struct nf_conn *ct;
|
|
enum ip_conntrack_info ctinfo;
|
|
enum ip_conntrack_dir dir;
|
|
unsigned long statusbit;
|
|
u8 family;
|
|
|
|
ct = nf_ct_get(skb, &ctinfo);
|
|
if (ct == NULL)
|
|
return;
|
|
|
|
family = nf_ct_l3num(ct);
|
|
l3proto = __nf_nat_l3proto_find(family);
|
|
if (l3proto == NULL)
|
|
return;
|
|
|
|
dir = CTINFO2DIR(ctinfo);
|
|
if (dir == IP_CT_DIR_ORIGINAL)
|
|
statusbit = IPS_DST_NAT;
|
|
else
|
|
statusbit = IPS_SRC_NAT;
|
|
|
|
l3proto->decode_session(skb, ct, dir, statusbit, fl);
|
|
}
|
|
|
|
int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
|
|
{
|
|
struct flowi fl;
|
|
unsigned int hh_len;
|
|
struct dst_entry *dst;
|
|
int err;
|
|
|
|
err = xfrm_decode_session(skb, &fl, family);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
dst = skb_dst(skb);
|
|
if (dst->xfrm)
|
|
dst = ((struct xfrm_dst *)dst)->route;
|
|
dst_hold(dst);
|
|
|
|
dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
|
|
if (IS_ERR(dst))
|
|
return PTR_ERR(dst);
|
|
|
|
skb_dst_drop(skb);
|
|
skb_dst_set(skb, dst);
|
|
|
|
/* Change in oif may mean change in hh_len. */
|
|
hh_len = skb_dst(skb)->dev->hard_header_len;
|
|
if (skb_headroom(skb) < hh_len &&
|
|
pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(nf_xfrm_me_harder);
|
|
#endif /* CONFIG_XFRM */
|
|
|
|
/* We keep an extra hash for each conntrack, for fast searching. */
|
|
static unsigned int
|
|
hash_by_src(const struct net *n, const struct nf_conntrack_tuple *tuple)
|
|
{
|
|
unsigned int hash;
|
|
|
|
get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
|
|
|
|
/* Original src, to ensure we map it consistently if poss. */
|
|
hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
|
|
tuple->dst.protonum ^ nf_nat_hash_rnd ^ net_hash_mix(n));
|
|
|
|
return reciprocal_scale(hash, nf_nat_htable_size);
|
|
}
|
|
|
|
/* Is this tuple already taken? (not by us) */
|
|
int
|
|
nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
|
|
const struct nf_conn *ignored_conntrack)
|
|
{
|
|
/* Conntrack tracking doesn't keep track of outgoing tuples; only
|
|
* incoming ones. NAT means they don't have a fixed mapping,
|
|
* so we invert the tuple and look for the incoming reply.
|
|
*
|
|
* We could keep a separate hash if this proves too slow.
|
|
*/
|
|
struct nf_conntrack_tuple reply;
|
|
|
|
nf_ct_invert_tuplepr(&reply, tuple);
|
|
return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
|
|
}
|
|
EXPORT_SYMBOL(nf_nat_used_tuple);
|
|
|
|
/* If we source map this tuple so reply looks like reply_tuple, will
|
|
* that meet the constraints of range.
|
|
*/
|
|
static int in_range(const struct nf_nat_l3proto *l3proto,
|
|
const struct nf_nat_l4proto *l4proto,
|
|
const struct nf_conntrack_tuple *tuple,
|
|
const struct nf_nat_range *range)
|
|
{
|
|
/* If we are supposed to map IPs, then we must be in the
|
|
* range specified, otherwise let this drag us onto a new src IP.
|
|
*/
|
|
if (range->flags & NF_NAT_RANGE_MAP_IPS &&
|
|
!l3proto->in_range(tuple, range))
|
|
return 0;
|
|
|
|
if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) ||
|
|
l4proto->in_range(tuple, NF_NAT_MANIP_SRC,
|
|
&range->min_proto, &range->max_proto))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int
|
|
same_src(const struct nf_conn *ct,
|
|
const struct nf_conntrack_tuple *tuple)
|
|
{
|
|
const struct nf_conntrack_tuple *t;
|
|
|
|
t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
|
|
return (t->dst.protonum == tuple->dst.protonum &&
|
|
nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
|
|
t->src.u.all == tuple->src.u.all);
|
|
}
|
|
|
|
/* Only called for SRC manip */
|
|
static int
|
|
find_appropriate_src(struct net *net,
|
|
const struct nf_conntrack_zone *zone,
|
|
const struct nf_nat_l3proto *l3proto,
|
|
const struct nf_nat_l4proto *l4proto,
|
|
const struct nf_conntrack_tuple *tuple,
|
|
struct nf_conntrack_tuple *result,
|
|
const struct nf_nat_range *range)
|
|
{
|
|
unsigned int h = hash_by_src(net, tuple);
|
|
const struct nf_conn *ct;
|
|
|
|
hlist_for_each_entry_rcu(ct, &nf_nat_bysource[h], nat_bysource) {
|
|
if (same_src(ct, tuple) &&
|
|
net_eq(net, nf_ct_net(ct)) &&
|
|
nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
|
|
/* Copy source part from reply tuple. */
|
|
nf_ct_invert_tuplepr(result,
|
|
&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
|
|
result->dst = tuple->dst;
|
|
|
|
if (in_range(l3proto, l4proto, result, range))
|
|
return 1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* For [FUTURE] fragmentation handling, we want the least-used
|
|
* src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus
|
|
* if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
|
|
* 1-65535, we don't do pro-rata allocation based on ports; we choose
|
|
* the ip with the lowest src-ip/dst-ip/proto usage.
|
|
*/
|
|
static void
|
|
find_best_ips_proto(const struct nf_conntrack_zone *zone,
|
|
struct nf_conntrack_tuple *tuple,
|
|
const struct nf_nat_range *range,
|
|
const struct nf_conn *ct,
|
|
enum nf_nat_manip_type maniptype)
|
|
{
|
|
union nf_inet_addr *var_ipp;
|
|
unsigned int i, max;
|
|
/* Host order */
|
|
u32 minip, maxip, j, dist;
|
|
bool full_range;
|
|
|
|
/* No IP mapping? Do nothing. */
|
|
if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
|
|
return;
|
|
|
|
if (maniptype == NF_NAT_MANIP_SRC)
|
|
var_ipp = &tuple->src.u3;
|
|
else
|
|
var_ipp = &tuple->dst.u3;
|
|
|
|
/* Fast path: only one choice. */
|
|
if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
|
|
*var_ipp = range->min_addr;
|
|
return;
|
|
}
|
|
|
|
if (nf_ct_l3num(ct) == NFPROTO_IPV4)
|
|
max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
|
|
else
|
|
max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
|
|
|
|
/* Hashing source and destination IPs gives a fairly even
|
|
* spread in practice (if there are a small number of IPs
|
|
* involved, there usually aren't that many connections
|
|
* anyway). The consistency means that servers see the same
|
|
* client coming from the same IP (some Internet Banking sites
|
|
* like this), even across reboots.
|
|
*/
|
|
j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
|
|
range->flags & NF_NAT_RANGE_PERSISTENT ?
|
|
0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);
|
|
|
|
full_range = false;
|
|
for (i = 0; i <= max; i++) {
|
|
/* If first bytes of the address are at the maximum, use the
|
|
* distance. Otherwise use the full range.
|
|
*/
|
|
if (!full_range) {
|
|
minip = ntohl((__force __be32)range->min_addr.all[i]);
|
|
maxip = ntohl((__force __be32)range->max_addr.all[i]);
|
|
dist = maxip - minip + 1;
|
|
} else {
|
|
minip = 0;
|
|
dist = ~0;
|
|
}
|
|
|
|
var_ipp->all[i] = (__force __u32)
|
|
htonl(minip + reciprocal_scale(j, dist));
|
|
if (var_ipp->all[i] != range->max_addr.all[i])
|
|
full_range = true;
|
|
|
|
if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
|
|
j ^= (__force u32)tuple->dst.u3.all[i];
|
|
}
|
|
}
|
|
|
|
/* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
|
|
* we change the source to map into the range. For NF_INET_PRE_ROUTING
|
|
* and NF_INET_LOCAL_OUT, we change the destination to map into the
|
|
* range. It might not be possible to get a unique tuple, but we try.
|
|
* At worst (or if we race), we will end up with a final duplicate in
|
|
* __ip_conntrack_confirm and drop the packet. */
|
|
static void
|
|
get_unique_tuple(struct nf_conntrack_tuple *tuple,
|
|
const struct nf_conntrack_tuple *orig_tuple,
|
|
const struct nf_nat_range *range,
|
|
struct nf_conn *ct,
|
|
enum nf_nat_manip_type maniptype)
|
|
{
|
|
const struct nf_conntrack_zone *zone;
|
|
const struct nf_nat_l3proto *l3proto;
|
|
const struct nf_nat_l4proto *l4proto;
|
|
struct net *net = nf_ct_net(ct);
|
|
|
|
zone = nf_ct_zone(ct);
|
|
|
|
rcu_read_lock();
|
|
l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
|
|
l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
|
|
orig_tuple->dst.protonum);
|
|
|
|
/* 1) If this srcip/proto/src-proto-part is currently mapped,
|
|
* and that same mapping gives a unique tuple within the given
|
|
* range, use that.
|
|
*
|
|
* This is only required for source (ie. NAT/masq) mappings.
|
|
* So far, we don't do local source mappings, so multiple
|
|
* manips not an issue.
|
|
*/
|
|
if (maniptype == NF_NAT_MANIP_SRC &&
|
|
!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
|
|
/* try the original tuple first */
|
|
if (in_range(l3proto, l4proto, orig_tuple, range)) {
|
|
if (!nf_nat_used_tuple(orig_tuple, ct)) {
|
|
*tuple = *orig_tuple;
|
|
goto out;
|
|
}
|
|
} else if (find_appropriate_src(net, zone, l3proto, l4proto,
|
|
orig_tuple, tuple, range)) {
|
|
pr_debug("get_unique_tuple: Found current src map\n");
|
|
if (!nf_nat_used_tuple(tuple, ct))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* 2) Select the least-used IP/proto combination in the given range */
|
|
*tuple = *orig_tuple;
|
|
find_best_ips_proto(zone, tuple, range, ct, maniptype);
|
|
|
|
/* 3) The per-protocol part of the manip is made to map into
|
|
* the range to make a unique tuple.
|
|
*/
|
|
|
|
/* Only bother mapping if it's not already in range and unique */
|
|
if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) {
|
|
if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
|
|
if (l4proto->in_range(tuple, maniptype,
|
|
&range->min_proto,
|
|
&range->max_proto) &&
|
|
(range->min_proto.all == range->max_proto.all ||
|
|
!nf_nat_used_tuple(tuple, ct)))
|
|
goto out;
|
|
} else if (!nf_nat_used_tuple(tuple, ct)) {
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* Last change: get protocol to try to obtain unique tuple. */
|
|
l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
|
|
out:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
struct nf_conn_nat *nf_ct_nat_ext_add(struct nf_conn *ct)
|
|
{
|
|
struct nf_conn_nat *nat = nfct_nat(ct);
|
|
if (nat)
|
|
return nat;
|
|
|
|
if (!nf_ct_is_confirmed(ct))
|
|
nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
|
|
|
|
return nat;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_ct_nat_ext_add);
|
|
|
|
unsigned int
|
|
nf_nat_setup_info(struct nf_conn *ct,
|
|
const struct nf_nat_range *range,
|
|
enum nf_nat_manip_type maniptype)
|
|
{
|
|
struct net *net = nf_ct_net(ct);
|
|
struct nf_conntrack_tuple curr_tuple, new_tuple;
|
|
|
|
/* Can't setup nat info for confirmed ct. */
|
|
if (nf_ct_is_confirmed(ct))
|
|
return NF_ACCEPT;
|
|
|
|
WARN_ON(maniptype != NF_NAT_MANIP_SRC &&
|
|
maniptype != NF_NAT_MANIP_DST);
|
|
|
|
if (WARN_ON(nf_nat_initialized(ct, maniptype)))
|
|
return NF_DROP;
|
|
|
|
/* What we've got will look like inverse of reply. Normally
|
|
* this is what is in the conntrack, except for prior
|
|
* manipulations (future optimization: if num_manips == 0,
|
|
* orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
|
|
*/
|
|
nf_ct_invert_tuplepr(&curr_tuple,
|
|
&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
|
|
|
|
get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
|
|
|
|
if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
|
|
struct nf_conntrack_tuple reply;
|
|
|
|
/* Alter conntrack table so will recognize replies. */
|
|
nf_ct_invert_tuplepr(&reply, &new_tuple);
|
|
nf_conntrack_alter_reply(ct, &reply);
|
|
|
|
/* Non-atomic: we own this at the moment. */
|
|
if (maniptype == NF_NAT_MANIP_SRC)
|
|
ct->status |= IPS_SRC_NAT;
|
|
else
|
|
ct->status |= IPS_DST_NAT;
|
|
|
|
if (nfct_help(ct) && !nfct_seqadj(ct))
|
|
if (!nfct_seqadj_ext_add(ct))
|
|
return NF_DROP;
|
|
}
|
|
|
|
if (maniptype == NF_NAT_MANIP_SRC) {
|
|
unsigned int srchash;
|
|
spinlock_t *lock;
|
|
|
|
srchash = hash_by_src(net,
|
|
&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
|
|
lock = &nf_nat_locks[srchash % CONNTRACK_LOCKS];
|
|
spin_lock_bh(lock);
|
|
hlist_add_head_rcu(&ct->nat_bysource,
|
|
&nf_nat_bysource[srchash]);
|
|
spin_unlock_bh(lock);
|
|
}
|
|
|
|
/* It's done. */
|
|
if (maniptype == NF_NAT_MANIP_DST)
|
|
ct->status |= IPS_DST_NAT_DONE;
|
|
else
|
|
ct->status |= IPS_SRC_NAT_DONE;
|
|
|
|
return NF_ACCEPT;
|
|
}
|
|
EXPORT_SYMBOL(nf_nat_setup_info);
|
|
|
|
static unsigned int
|
|
__nf_nat_alloc_null_binding(struct nf_conn *ct, enum nf_nat_manip_type manip)
|
|
{
|
|
/* Force range to this IP; let proto decide mapping for
|
|
* per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
|
|
* Use reply in case it's already been mangled (eg local packet).
|
|
*/
|
|
union nf_inet_addr ip =
|
|
(manip == NF_NAT_MANIP_SRC ?
|
|
ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3 :
|
|
ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3);
|
|
struct nf_nat_range range = {
|
|
.flags = NF_NAT_RANGE_MAP_IPS,
|
|
.min_addr = ip,
|
|
.max_addr = ip,
|
|
};
|
|
return nf_nat_setup_info(ct, &range, manip);
|
|
}
|
|
|
|
unsigned int
|
|
nf_nat_alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
|
|
{
|
|
return __nf_nat_alloc_null_binding(ct, HOOK2MANIP(hooknum));
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_nat_alloc_null_binding);
|
|
|
|
/* Do packet manipulations according to nf_nat_setup_info. */
|
|
unsigned int nf_nat_packet(struct nf_conn *ct,
|
|
enum ip_conntrack_info ctinfo,
|
|
unsigned int hooknum,
|
|
struct sk_buff *skb)
|
|
{
|
|
const struct nf_nat_l3proto *l3proto;
|
|
const struct nf_nat_l4proto *l4proto;
|
|
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
|
|
unsigned long statusbit;
|
|
enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
|
|
|
|
if (mtype == NF_NAT_MANIP_SRC)
|
|
statusbit = IPS_SRC_NAT;
|
|
else
|
|
statusbit = IPS_DST_NAT;
|
|
|
|
/* Invert if this is reply dir. */
|
|
if (dir == IP_CT_DIR_REPLY)
|
|
statusbit ^= IPS_NAT_MASK;
|
|
|
|
/* Non-atomic: these bits don't change. */
|
|
if (ct->status & statusbit) {
|
|
struct nf_conntrack_tuple target;
|
|
|
|
/* We are aiming to look like inverse of other direction. */
|
|
nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
|
|
|
|
l3proto = __nf_nat_l3proto_find(target.src.l3num);
|
|
l4proto = __nf_nat_l4proto_find(target.src.l3num,
|
|
target.dst.protonum);
|
|
if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype))
|
|
return NF_DROP;
|
|
}
|
|
return NF_ACCEPT;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_nat_packet);
|
|
|
|
struct nf_nat_proto_clean {
|
|
u8 l3proto;
|
|
u8 l4proto;
|
|
};
|
|
|
|
/* kill conntracks with affected NAT section */
|
|
static int nf_nat_proto_remove(struct nf_conn *i, void *data)
|
|
{
|
|
const struct nf_nat_proto_clean *clean = data;
|
|
|
|
if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) ||
|
|
(clean->l4proto && nf_ct_protonum(i) != clean->l4proto))
|
|
return 0;
|
|
|
|
return i->status & IPS_NAT_MASK ? 1 : 0;
|
|
}
|
|
|
|
static void __nf_nat_cleanup_conntrack(struct nf_conn *ct)
|
|
{
|
|
unsigned int h;
|
|
|
|
h = hash_by_src(nf_ct_net(ct), &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
|
|
spin_lock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]);
|
|
hlist_del_rcu(&ct->nat_bysource);
|
|
spin_unlock_bh(&nf_nat_locks[h % CONNTRACK_LOCKS]);
|
|
}
|
|
|
|
static int nf_nat_proto_clean(struct nf_conn *ct, void *data)
|
|
{
|
|
if (nf_nat_proto_remove(ct, data))
|
|
return 1;
|
|
|
|
/* This module is being removed and conntrack has nat null binding.
|
|
* Remove it from bysource hash, as the table will be freed soon.
|
|
*
|
|
* Else, when the conntrack is destoyed, nf_nat_cleanup_conntrack()
|
|
* will delete entry from already-freed table.
|
|
*/
|
|
if (test_and_clear_bit(IPS_SRC_NAT_DONE_BIT, &ct->status))
|
|
__nf_nat_cleanup_conntrack(ct);
|
|
|
|
/* don't delete conntrack. Although that would make things a lot
|
|
* simpler, we'd end up flushing all conntracks on nat rmmod.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
|
|
{
|
|
struct nf_nat_proto_clean clean = {
|
|
.l3proto = l3proto,
|
|
.l4proto = l4proto,
|
|
};
|
|
|
|
nf_ct_iterate_destroy(nf_nat_proto_remove, &clean);
|
|
}
|
|
|
|
static void nf_nat_l3proto_clean(u8 l3proto)
|
|
{
|
|
struct nf_nat_proto_clean clean = {
|
|
.l3proto = l3proto,
|
|
};
|
|
|
|
nf_ct_iterate_destroy(nf_nat_proto_remove, &clean);
|
|
}
|
|
|
|
/* Protocol registration. */
|
|
int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto)
|
|
{
|
|
const struct nf_nat_l4proto **l4protos;
|
|
unsigned int i;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&nf_nat_proto_mutex);
|
|
if (nf_nat_l4protos[l3proto] == NULL) {
|
|
l4protos = kmalloc(IPPROTO_MAX * sizeof(struct nf_nat_l4proto *),
|
|
GFP_KERNEL);
|
|
if (l4protos == NULL) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < IPPROTO_MAX; i++)
|
|
RCU_INIT_POINTER(l4protos[i], &nf_nat_l4proto_unknown);
|
|
|
|
/* Before making proto_array visible to lockless readers,
|
|
* we must make sure its content is committed to memory.
|
|
*/
|
|
smp_wmb();
|
|
|
|
nf_nat_l4protos[l3proto] = l4protos;
|
|
}
|
|
|
|
if (rcu_dereference_protected(
|
|
nf_nat_l4protos[l3proto][l4proto->l4proto],
|
|
lockdep_is_held(&nf_nat_proto_mutex)
|
|
) != &nf_nat_l4proto_unknown) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], l4proto);
|
|
out:
|
|
mutex_unlock(&nf_nat_proto_mutex);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_nat_l4proto_register);
|
|
|
|
/* No one stores the protocol anywhere; simply delete it. */
|
|
void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto)
|
|
{
|
|
mutex_lock(&nf_nat_proto_mutex);
|
|
RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto],
|
|
&nf_nat_l4proto_unknown);
|
|
mutex_unlock(&nf_nat_proto_mutex);
|
|
synchronize_rcu();
|
|
|
|
nf_nat_l4proto_clean(l3proto, l4proto->l4proto);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister);
|
|
|
|
int nf_nat_l3proto_register(const struct nf_nat_l3proto *l3proto)
|
|
{
|
|
int err;
|
|
|
|
err = nf_ct_l3proto_try_module_get(l3proto->l3proto);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
mutex_lock(&nf_nat_proto_mutex);
|
|
RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_TCP],
|
|
&nf_nat_l4proto_tcp);
|
|
RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDP],
|
|
&nf_nat_l4proto_udp);
|
|
#ifdef CONFIG_NF_NAT_PROTO_DCCP
|
|
RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_DCCP],
|
|
&nf_nat_l4proto_dccp);
|
|
#endif
|
|
#ifdef CONFIG_NF_NAT_PROTO_SCTP
|
|
RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_SCTP],
|
|
&nf_nat_l4proto_sctp);
|
|
#endif
|
|
#ifdef CONFIG_NF_NAT_PROTO_UDPLITE
|
|
RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDPLITE],
|
|
&nf_nat_l4proto_udplite);
|
|
#endif
|
|
mutex_unlock(&nf_nat_proto_mutex);
|
|
|
|
RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], l3proto);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_nat_l3proto_register);
|
|
|
|
void nf_nat_l3proto_unregister(const struct nf_nat_l3proto *l3proto)
|
|
{
|
|
mutex_lock(&nf_nat_proto_mutex);
|
|
RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], NULL);
|
|
mutex_unlock(&nf_nat_proto_mutex);
|
|
synchronize_rcu();
|
|
|
|
nf_nat_l3proto_clean(l3proto->l3proto);
|
|
nf_ct_l3proto_module_put(l3proto->l3proto);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
|
|
|
|
/* No one using conntrack by the time this called. */
|
|
static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
|
|
{
|
|
if (ct->status & IPS_SRC_NAT_DONE)
|
|
__nf_nat_cleanup_conntrack(ct);
|
|
}
|
|
|
|
static struct nf_ct_ext_type nat_extend __read_mostly = {
|
|
.len = sizeof(struct nf_conn_nat),
|
|
.align = __alignof__(struct nf_conn_nat),
|
|
.destroy = nf_nat_cleanup_conntrack,
|
|
.id = NF_CT_EXT_NAT,
|
|
};
|
|
|
|
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
|
|
|
|
#include <linux/netfilter/nfnetlink.h>
|
|
#include <linux/netfilter/nfnetlink_conntrack.h>
|
|
|
|
static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = {
|
|
[CTA_PROTONAT_PORT_MIN] = { .type = NLA_U16 },
|
|
[CTA_PROTONAT_PORT_MAX] = { .type = NLA_U16 },
|
|
};
|
|
|
|
static int nfnetlink_parse_nat_proto(struct nlattr *attr,
|
|
const struct nf_conn *ct,
|
|
struct nf_nat_range *range)
|
|
{
|
|
struct nlattr *tb[CTA_PROTONAT_MAX+1];
|
|
const struct nf_nat_l4proto *l4proto;
|
|
int err;
|
|
|
|
err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr,
|
|
protonat_nla_policy, NULL);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
l4proto = __nf_nat_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
|
|
if (l4proto->nlattr_to_range)
|
|
err = l4proto->nlattr_to_range(tb, range);
|
|
|
|
return err;
|
|
}
|
|
|
|
static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = {
|
|
[CTA_NAT_V4_MINIP] = { .type = NLA_U32 },
|
|
[CTA_NAT_V4_MAXIP] = { .type = NLA_U32 },
|
|
[CTA_NAT_V6_MINIP] = { .len = sizeof(struct in6_addr) },
|
|
[CTA_NAT_V6_MAXIP] = { .len = sizeof(struct in6_addr) },
|
|
[CTA_NAT_PROTO] = { .type = NLA_NESTED },
|
|
};
|
|
|
|
static int
|
|
nfnetlink_parse_nat(const struct nlattr *nat,
|
|
const struct nf_conn *ct, struct nf_nat_range *range,
|
|
const struct nf_nat_l3proto *l3proto)
|
|
{
|
|
struct nlattr *tb[CTA_NAT_MAX+1];
|
|
int err;
|
|
|
|
memset(range, 0, sizeof(*range));
|
|
|
|
err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy, NULL);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
err = l3proto->nlattr_to_range(tb, range);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
if (!tb[CTA_NAT_PROTO])
|
|
return 0;
|
|
|
|
return nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range);
|
|
}
|
|
|
|
/* This function is called under rcu_read_lock() */
|
|
static int
|
|
nfnetlink_parse_nat_setup(struct nf_conn *ct,
|
|
enum nf_nat_manip_type manip,
|
|
const struct nlattr *attr)
|
|
{
|
|
struct nf_nat_range range;
|
|
const struct nf_nat_l3proto *l3proto;
|
|
int err;
|
|
|
|
/* Should not happen, restricted to creating new conntracks
|
|
* via ctnetlink.
|
|
*/
|
|
if (WARN_ON_ONCE(nf_nat_initialized(ct, manip)))
|
|
return -EEXIST;
|
|
|
|
/* Make sure that L3 NAT is there by when we call nf_nat_setup_info to
|
|
* attach the null binding, otherwise this may oops.
|
|
*/
|
|
l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct));
|
|
if (l3proto == NULL)
|
|
return -EAGAIN;
|
|
|
|
/* No NAT information has been passed, allocate the null-binding */
|
|
if (attr == NULL)
|
|
return __nf_nat_alloc_null_binding(ct, manip) == NF_DROP ? -ENOMEM : 0;
|
|
|
|
err = nfnetlink_parse_nat(attr, ct, &range, l3proto);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
return nf_nat_setup_info(ct, &range, manip) == NF_DROP ? -ENOMEM : 0;
|
|
}
|
|
#else
|
|
static int
|
|
nfnetlink_parse_nat_setup(struct nf_conn *ct,
|
|
enum nf_nat_manip_type manip,
|
|
const struct nlattr *attr)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
#endif
|
|
|
|
static struct nf_ct_helper_expectfn follow_master_nat = {
|
|
.name = "nat-follow-master",
|
|
.expectfn = nf_nat_follow_master,
|
|
};
|
|
|
|
static int __init nf_nat_init(void)
|
|
{
|
|
int ret, i;
|
|
|
|
/* Leave them the same for the moment. */
|
|
nf_nat_htable_size = nf_conntrack_htable_size;
|
|
if (nf_nat_htable_size < CONNTRACK_LOCKS)
|
|
nf_nat_htable_size = CONNTRACK_LOCKS;
|
|
|
|
nf_nat_bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size, 0);
|
|
if (!nf_nat_bysource)
|
|
return -ENOMEM;
|
|
|
|
ret = nf_ct_extend_register(&nat_extend);
|
|
if (ret < 0) {
|
|
nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
|
|
pr_err("Unable to register extension\n");
|
|
return ret;
|
|
}
|
|
|
|
for (i = 0; i < CONNTRACK_LOCKS; i++)
|
|
spin_lock_init(&nf_nat_locks[i]);
|
|
|
|
nf_ct_helper_expectfn_register(&follow_master_nat);
|
|
|
|
BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
|
|
RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook,
|
|
nfnetlink_parse_nat_setup);
|
|
#ifdef CONFIG_XFRM
|
|
BUG_ON(nf_nat_decode_session_hook != NULL);
|
|
RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static void __exit nf_nat_cleanup(void)
|
|
{
|
|
struct nf_nat_proto_clean clean = {};
|
|
unsigned int i;
|
|
|
|
nf_ct_iterate_destroy(nf_nat_proto_clean, &clean);
|
|
|
|
nf_ct_extend_unregister(&nat_extend);
|
|
nf_ct_helper_expectfn_unregister(&follow_master_nat);
|
|
RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL);
|
|
#ifdef CONFIG_XFRM
|
|
RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL);
|
|
#endif
|
|
synchronize_rcu();
|
|
|
|
for (i = 0; i < NFPROTO_NUMPROTO; i++)
|
|
kfree(nf_nat_l4protos[i]);
|
|
synchronize_net();
|
|
nf_ct_free_hashtable(nf_nat_bysource, nf_nat_htable_size);
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(nf_nat_init);
|
|
module_exit(nf_nat_cleanup);
|