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[NETFILTER]: Fix invalid module autoloading by splitting iptable_nat 

When you've enabled conntrack and NAT as a module (standard case in all
distributions), and you've also enabled the new conntrack netlink
interface, loading ip_conntrack_netlink.ko will auto-load iptable_nat.ko.
This causes a huge performance penalty, since for every packet you iterate
the nat code, even if you don't want it.

This patch splits iptable_nat.ko into the NAT core (ip_nat.ko) and the
iptables frontend (iptable_nat.ko).  Threfore, ip_conntrack_netlink.ko will
only pull ip_nat.ko, but not the frontend.  ip_nat.ko will "only" allocate
some resources, but not affect runtime performance.

This separation is also a nice step in anticipation of new packet filters
(nf-hipac, ipset, pkttables) being able to use the NAT core.

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Harald Welte 2005-09-26 15:25:11 -07:00 committed by David S. Miller
parent b85daee0e4
commit 188bab3ae0
5 changed files with 40 additions and 41 deletions
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12
include/linux/netfilter_ipv4/ip_nat_core.h
View File

@ -5,16 +5,14 @@
/* This header used to share core functionality between the standalone
NAT module, and the compatibility layer's use of NAT for masquerading. */
extern int ip_nat_init(void);
extern void ip_nat_cleanup(void);
extern unsigned int nat_packet(struct ip_conntrack *ct,
extern unsigned int ip_nat_packet(struct ip_conntrack *ct,
enum ip_conntrack_info conntrackinfo,
unsigned int hooknum,
struct sk_buff **pskb);
extern int icmp_reply_translation(struct sk_buff **pskb,
struct ip_conntrack *ct,
enum ip_nat_manip_type manip,
enum ip_conntrack_dir dir);
extern int ip_nat_icmp_reply_translation(struct sk_buff **pskb,
struct ip_conntrack *ct,
enum ip_nat_manip_type manip,
enum ip_conntrack_dir dir);
#endif /* _IP_NAT_CORE_H */

5
net/ipv4/netfilter/Makefile
View File

@ -4,7 +4,8 @@
# objects for the standalone - connection tracking / NAT
ip_conntrack-objs := ip_conntrack_standalone.o ip_conntrack_core.o ip_conntrack_proto_generic.o ip_conntrack_proto_tcp.o ip_conntrack_proto_udp.o ip_conntrack_proto_icmp.o
iptable_nat-objs := ip_nat_standalone.o ip_nat_rule.o ip_nat_core.o ip_nat_helper.o ip_nat_proto_unknown.o ip_nat_proto_tcp.o ip_nat_proto_udp.o ip_nat_proto_icmp.o
ip_nat-objs := ip_nat_core.o ip_nat_helper.o ip_nat_proto_unknown.o ip_nat_proto_tcp.o ip_nat_proto_udp.o ip_nat_proto_icmp.o
iptable_nat-objs := ip_nat_rule.o ip_nat_standalone.o
ip_conntrack_pptp-objs := ip_conntrack_helper_pptp.o ip_conntrack_proto_gre.o
ip_nat_pptp-objs := ip_nat_helper_pptp.o ip_nat_proto_gre.o
@ -40,7 +41,7 @@ obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
# the three instances of ip_tables
obj-$(CONFIG_IP_NF_FILTER) += iptable_filter.o
obj-$(CONFIG_IP_NF_MANGLE) += iptable_mangle.o
obj-$(CONFIG_IP_NF_NAT) += iptable_nat.o
obj-$(CONFIG_IP_NF_NAT) += iptable_nat.o ip_nat.o
obj-$(CONFIG_IP_NF_RAW) += iptable_raw.o
# matches

35
net/ipv4/netfilter/ip_nat_core.c
View File

@ -74,12 +74,14 @@ ip_nat_proto_find_get(u_int8_t protonum)
return p;
}
EXPORT_SYMBOL_GPL(ip_nat_proto_find_get);
void
ip_nat_proto_put(struct ip_nat_protocol *p)
{
module_put(p->me);
}
EXPORT_SYMBOL_GPL(ip_nat_proto_put);
/* We keep an extra hash for each conntrack, for fast searching. */
static inline unsigned int
@ -111,6 +113,7 @@ ip_nat_cheat_check(u_int32_t oldvalinv, u_int32_t newval, u_int16_t oldcheck)
return csum_fold(csum_partial((char *)diffs, sizeof(diffs),
oldcheck^0xFFFF));
}
EXPORT_SYMBOL(ip_nat_cheat_check);
/* Is this tuple already taken? (not by us) */
int
@ -127,6 +130,7 @@ ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple,
invert_tuplepr(&reply, tuple);
return ip_conntrack_tuple_taken(&reply, ignored_conntrack);
}
EXPORT_SYMBOL(ip_nat_used_tuple);
/* If we source map this tuple so reply looks like reply_tuple, will
* that meet the constraints of range. */
@ -347,6 +351,7 @@ ip_nat_setup_info(struct ip_conntrack *conntrack,
return NF_ACCEPT;
}
EXPORT_SYMBOL(ip_nat_setup_info);
/* Returns true if succeeded. */
static int
@ -387,10 +392,10 @@ manip_pkt(u_int16_t proto,
}
/* Do packet manipulations according to ip_nat_setup_info. */
unsigned int nat_packet(struct ip_conntrack *ct,
enum ip_conntrack_info ctinfo,
unsigned int hooknum,
struct sk_buff **pskb)
unsigned int ip_nat_packet(struct ip_conntrack *ct,
enum ip_conntrack_info ctinfo,
unsigned int hooknum,
struct sk_buff **pskb)
{
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
unsigned long statusbit;
@ -417,12 +422,13 @@ unsigned int nat_packet(struct ip_conntrack *ct,
}
return NF_ACCEPT;
}
EXPORT_SYMBOL_GPL(ip_nat_packet);
/* Dir is direction ICMP is coming from (opposite to packet it contains) */
int icmp_reply_translation(struct sk_buff **pskb,
struct ip_conntrack *ct,
enum ip_nat_manip_type manip,
enum ip_conntrack_dir dir)
int ip_nat_icmp_reply_translation(struct sk_buff **pskb,
struct ip_conntrack *ct,
enum ip_nat_manip_type manip,
enum ip_conntrack_dir dir)
{
struct {
struct icmphdr icmp;
@ -509,6 +515,7 @@ int icmp_reply_translation(struct sk_buff **pskb,
return 1;
}
EXPORT_SYMBOL_GPL(ip_nat_icmp_reply_translation);
/* Protocol registration. */
int ip_nat_protocol_register(struct ip_nat_protocol *proto)
@ -525,6 +532,7 @@ int ip_nat_protocol_register(struct ip_nat_protocol *proto)
write_unlock_bh(&ip_nat_lock);
return ret;
}
EXPORT_SYMBOL(ip_nat_protocol_register);
/* Noone stores the protocol anywhere; simply delete it. */
void ip_nat_protocol_unregister(struct ip_nat_protocol *proto)
@ -536,6 +544,7 @@ void ip_nat_protocol_unregister(struct ip_nat_protocol *proto)
/* Someone could be still looking at the proto in a bh. */
synchronize_net();
}
EXPORT_SYMBOL(ip_nat_protocol_unregister);
#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
@ -582,7 +591,7 @@ EXPORT_SYMBOL_GPL(ip_nat_port_nfattr_to_range);
EXPORT_SYMBOL_GPL(ip_nat_port_range_to_nfattr);
#endif
int __init ip_nat_init(void)
static int __init ip_nat_init(void)
{
size_t i;
@ -624,10 +633,14 @@ static int clean_nat(struct ip_conntrack *i, void *data)
return 0;
}
/* Not __exit: called from ip_nat_standalone.c:init_or_cleanup() --RR */
void ip_nat_cleanup(void)
static void __exit ip_nat_cleanup(void)
{
ip_ct_iterate_cleanup(&clean_nat, NULL);
ip_conntrack_destroyed = NULL;
vfree(bysource);
}
MODULE_LICENSE("GPL");
module_init(ip_nat_init);
module_exit(ip_nat_cleanup);

4
net/ipv4/netfilter/ip_nat_helper.c
View File

@ -199,6 +199,7 @@ ip_nat_mangle_tcp_packet(struct sk_buff **pskb,
}
return 1;
}
EXPORT_SYMBOL(ip_nat_mangle_tcp_packet);
/* Generic function for mangling variable-length address changes inside
* NATed UDP connections (like the CONNECT DATA XXXXX MESG XXXXX INDEX XXXXX
@ -256,6 +257,7 @@ ip_nat_mangle_udp_packet(struct sk_buff **pskb,
return 1;
}
EXPORT_SYMBOL(ip_nat_mangle_udp_packet);
/* Adjust one found SACK option including checksum correction */
static void
@ -399,6 +401,7 @@ ip_nat_seq_adjust(struct sk_buff **pskb,
return 1;
}
EXPORT_SYMBOL(ip_nat_seq_adjust);
/* Setup NAT on this expected conntrack so it follows master. */
/* If we fail to get a free NAT slot, we'll get dropped on confirm */
@ -425,3 +428,4 @@ void ip_nat_follow_master(struct ip_conntrack *ct,
/* hook doesn't matter, but it has to do destination manip */
ip_nat_setup_info(ct, &range, NF_IP_PRE_ROUTING);
}
EXPORT_SYMBOL(ip_nat_follow_master);

25
net/ipv4/netfilter/ip_nat_standalone.c
View File

@ -108,8 +108,8 @@ ip_nat_fn(unsigned int hooknum,
case IP_CT_RELATED:
case IP_CT_RELATED+IP_CT_IS_REPLY:
if ((*pskb)->nh.iph->protocol == IPPROTO_ICMP) {
if (!icmp_reply_translation(pskb, ct, maniptype,
CTINFO2DIR(ctinfo)))
if (!ip_nat_icmp_reply_translation(pskb, ct, maniptype,
CTINFO2DIR(ctinfo)))
return NF_DROP;
else
return NF_ACCEPT;
@ -152,7 +152,7 @@ ip_nat_fn(unsigned int hooknum,
}
IP_NF_ASSERT(info);
return nat_packet(ct, ctinfo, hooknum, pskb);
return ip_nat_packet(ct, ctinfo, hooknum, pskb);
}
static unsigned int
@ -325,15 +325,10 @@ static int init_or_cleanup(int init)
printk("ip_nat_init: can't setup rules.\n");
goto cleanup_nothing;
}
ret = ip_nat_init();
if (ret < 0) {
printk("ip_nat_init: can't setup rules.\n");
goto cleanup_rule_init;
}
ret = nf_register_hook(&ip_nat_in_ops);
if (ret < 0) {
printk("ip_nat_init: can't register in hook.\n");
goto cleanup_nat;
goto cleanup_rule_init;
}
ret = nf_register_hook(&ip_nat_out_ops);
if (ret < 0) {
@ -374,8 +369,6 @@ static int init_or_cleanup(int init)
nf_unregister_hook(&ip_nat_out_ops);
cleanup_inops:
nf_unregister_hook(&ip_nat_in_ops);
cleanup_nat:
ip_nat_cleanup();
cleanup_rule_init:
ip_nat_rule_cleanup();
cleanup_nothing:
@ -395,14 +388,4 @@ static void __exit fini(void)
module_init(init);
module_exit(fini);
EXPORT_SYMBOL(ip_nat_setup_info);
EXPORT_SYMBOL(ip_nat_protocol_register);
EXPORT_SYMBOL(ip_nat_protocol_unregister);
EXPORT_SYMBOL_GPL(ip_nat_proto_find_get);
EXPORT_SYMBOL_GPL(ip_nat_proto_put);
EXPORT_SYMBOL(ip_nat_cheat_check);
EXPORT_SYMBOL(ip_nat_mangle_tcp_packet);
EXPORT_SYMBOL(ip_nat_mangle_udp_packet);
EXPORT_SYMBOL(ip_nat_used_tuple);
EXPORT_SYMBOL(ip_nat_follow_master);
MODULE_LICENSE("GPL");