Commit dc808fe2 authored by Harald Welte's avatar Harald Welte Committed by David S. Miller
Browse files

[NETFILTER] nf_conntrack: clean up to reduce size of 'struct nf_conn'



This patch moves all helper related data fields of 'struct nf_conn'
into a separate structure 'struct nf_conn_help'.  This new structure
is only present in conntrack entries for which we actually have a
helper loaded.

Also, this patch cleans up the nf_conntrack 'features' mechanism to
resemble what the original idea was: Just glue the feature-specific
data structures at the end of 'struct nf_conn', and explicitly
re-calculate the pointer to it when needed rather than keeping
pointers around.

Saves 20 bytes per conntrack on my x86_64 box. A non-helped conntrack
is 276 bytes. We still need to save another 20 bytes in order to fit
into to target of 256bytes.
Signed-off-by: default avatarHarald Welte <laforge@netfilter.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0d36f37b
......@@ -67,6 +67,18 @@ do { \
struct nf_conntrack_helper;
/* nf_conn feature for connections that have a helper */
struct nf_conn_help {
/* Helper. if any */
struct nf_conntrack_helper *helper;
union nf_conntrack_help help;
/* Current number of expected connections */
unsigned int expecting;
};
#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
struct nf_conn
{
......@@ -81,6 +93,9 @@ struct nf_conn
/* Have we seen traffic both ways yet? (bitset) */
unsigned long status;
/* If we were expected by an expectation, this will be it */
struct nf_conn *master;
/* Timer function; drops refcnt when it goes off. */
struct timer_list timeout;
......@@ -88,38 +103,22 @@ struct nf_conn
/* Accounting Information (same cache line as other written members) */
struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
#endif
/* If we were expected by an expectation, this will be it */
struct nf_conn *master;
/* Current number of expected connections */
unsigned int expecting;
/* Unique ID that identifies this conntrack*/
unsigned int id;
/* Helper. if any */
struct nf_conntrack_helper *helper;
/* features - nat, helper, ... used by allocating system */
u_int32_t features;
/* Storage reserved for other modules: */
union nf_conntrack_proto proto;
#if defined(CONFIG_NF_CONNTRACK_MARK)
u_int32_t mark;
#endif
/* These members are dynamically allocated. */
union nf_conntrack_help *help;
/* Storage reserved for other modules: */
union nf_conntrack_proto proto;
/* Layer 3 dependent members. (ex: NAT) */
union {
struct nf_conntrack_ipv4 *ipv4;
} l3proto;
void *data[0];
/* features dynamically at the end: helper, nat (both optional) */
char data[0];
};
struct nf_conntrack_expect
......@@ -373,10 +372,23 @@ nf_conntrack_expect_event(enum ip_conntrack_expect_events event,
#define NF_CT_F_NUM 4
extern int
nf_conntrack_register_cache(u_int32_t features, const char *name, size_t size,
int (*init_conntrack)(struct nf_conn *, u_int32_t));
nf_conntrack_register_cache(u_int32_t features, const char *name, size_t size);
extern void
nf_conntrack_unregister_cache(u_int32_t features);
/* valid combinations:
* basic: nf_conn, nf_conn .. nf_conn_help
* nat: nf_conn .. nf_conn_nat, nf_conn .. nf_conn_nat, nf_conn help
*/
static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
{
unsigned int offset = sizeof(struct nf_conn);
if (!(ct->features & NF_CT_F_HELP))
return NULL;
return (struct nf_conn_help *) ((void *)ct + offset);
}
#endif /* __KERNEL__ */
#endif /* _NF_CONNTRACK_H */
......@@ -141,19 +141,21 @@ static unsigned int ipv4_conntrack_help(unsigned int hooknum,
{
struct nf_conn *ct;
enum ip_conntrack_info ctinfo;
struct nf_conn_help *help;
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(*pskb, &ctinfo);
if (ct && ct->helper) {
unsigned int ret;
ret = ct->helper->help(pskb,
(*pskb)->nh.raw - (*pskb)->data
+ (*pskb)->nh.iph->ihl*4,
ct, ctinfo);
if (ret != NF_ACCEPT)
return ret;
}
return NF_ACCEPT;
if (!ct)
return NF_ACCEPT;
help = nfct_help(ct);
if (!help || !help->helper)
return NF_ACCEPT;
return help->helper->help(pskb,
(*pskb)->nh.raw - (*pskb)->data
+ (*pskb)->nh.iph->ihl*4,
ct, ctinfo);
}
static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
......
......@@ -179,31 +179,36 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
int (*okfn)(struct sk_buff *))
{
struct nf_conn *ct;
struct nf_conn_help *help;
enum ip_conntrack_info ctinfo;
unsigned int ret, protoff;
unsigned int extoff = (u8*)((*pskb)->nh.ipv6h + 1)
- (*pskb)->data;
unsigned char pnum = (*pskb)->nh.ipv6h->nexthdr;
/* This is where we call the helper: as the packet goes out. */
ct = nf_ct_get(*pskb, &ctinfo);
if (ct && ct->helper) {
unsigned int ret, protoff;
unsigned int extoff = (u8*)((*pskb)->nh.ipv6h + 1)
- (*pskb)->data;
unsigned char pnum = (*pskb)->nh.ipv6h->nexthdr;
protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum,
(*pskb)->len - extoff);
if (protoff < 0 || protoff > (*pskb)->len ||
pnum == NEXTHDR_FRAGMENT) {
DEBUGP("proto header not found\n");
return NF_ACCEPT;
}
if (!ct)
goto out;
ret = ct->helper->help(pskb, protoff, ct, ctinfo);
if (ret != NF_ACCEPT)
return ret;
help = nfct_help(ct);
if (!help || !help->helper)
goto out;
protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum,
(*pskb)->len - extoff);
if (protoff < 0 || protoff > (*pskb)->len ||
pnum == NEXTHDR_FRAGMENT) {
DEBUGP("proto header not found\n");
return NF_ACCEPT;
}
ret = help->helper->help(pskb, protoff, ct, ctinfo);
if (ret != NF_ACCEPT)
return ret;
out:
/* We've seen it coming out the other side: confirm it */
return nf_conntrack_confirm(pskb);
}
......
......@@ -3,7 +3,7 @@
extension. */
/* (C) 1999-2001 Paul `Rusty' Russell
* (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org>
* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
* (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org>
*
* This program is free software; you can redistribute it and/or modify
......@@ -20,6 +20,9 @@
* - generalize L3 protocol denendent part.
* 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
* - add support various size of conntrack structures.
* 26 Jan 2006: Harald Welte <laforge@netfilter.org>
* - restructure nf_conn (introduce nf_conn_help)
* - redesign 'features' how they were originally intended
*
* Derived from net/ipv4/netfilter/ip_conntrack_core.c
*/
......@@ -55,7 +58,7 @@
#include <net/netfilter/nf_conntrack_core.h>
#include <linux/netfilter_ipv4/listhelp.h>
#define NF_CONNTRACK_VERSION "0.4.1"
#define NF_CONNTRACK_VERSION "0.5.0"
#if 0
#define DEBUGP printk
......@@ -259,21 +262,8 @@ static inline u_int32_t hash_conntrack(const struct nf_conntrack_tuple *tuple)
nf_conntrack_hash_rnd);
}
/* Initialize "struct nf_conn" which has spaces for helper */
static int
init_conntrack_for_helper(struct nf_conn *conntrack, u_int32_t features)
{
conntrack->help = (union nf_conntrack_help *)
(((unsigned long)conntrack->data
+ (__alignof__(union nf_conntrack_help) - 1))
& (~((unsigned long)(__alignof__(union nf_conntrack_help) -1))));
return 0;
}
int nf_conntrack_register_cache(u_int32_t features, const char *name,
size_t size,
int (*init)(struct nf_conn *, u_int32_t))
size_t size)
{
int ret = 0;
char *cache_name;
......@@ -296,8 +286,7 @@ int nf_conntrack_register_cache(u_int32_t features, const char *name,
DEBUGP("nf_conntrack_register_cache: already resisterd.\n");
if ((!strncmp(nf_ct_cache[features].name, name,
NF_CT_FEATURES_NAMELEN))
&& nf_ct_cache[features].size == size
&& nf_ct_cache[features].init_conntrack == init) {
&& nf_ct_cache[features].size == size) {
DEBUGP("nf_conntrack_register_cache: reusing.\n");
nf_ct_cache[features].use++;
ret = 0;
......@@ -340,7 +329,6 @@ int nf_conntrack_register_cache(u_int32_t features, const char *name,
write_lock_bh(&nf_ct_cache_lock);
nf_ct_cache[features].use = 1;
nf_ct_cache[features].size = size;
nf_ct_cache[features].init_conntrack = init;
nf_ct_cache[features].cachep = cachep;
nf_ct_cache[features].name = cache_name;
write_unlock_bh(&nf_ct_cache_lock);
......@@ -377,7 +365,6 @@ void nf_conntrack_unregister_cache(u_int32_t features)
name = nf_ct_cache[features].name;
nf_ct_cache[features].cachep = NULL;
nf_ct_cache[features].name = NULL;
nf_ct_cache[features].init_conntrack = NULL;
nf_ct_cache[features].size = 0;
write_unlock_bh(&nf_ct_cache_lock);
......@@ -432,11 +419,15 @@ nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
/* nf_conntrack_expect helper functions */
void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
{
struct nf_conn_help *master_help = nfct_help(exp->master);
NF_CT_ASSERT(master_help);
ASSERT_WRITE_LOCK(&nf_conntrack_lock);
NF_CT_ASSERT(!timer_pending(&exp->timeout));
list_del(&exp->list);
NF_CT_STAT_INC(expect_delete);
exp->master->expecting--;
master_help->expecting--;
nf_conntrack_expect_put(exp);
}
......@@ -508,9 +499,10 @@ find_expectation(const struct nf_conntrack_tuple *tuple)
void nf_ct_remove_expectations(struct nf_conn *ct)
{
struct nf_conntrack_expect *i, *tmp;
struct nf_conn_help *help = nfct_help(ct);
/* Optimization: most connection never expect any others. */
if (ct->expecting == 0)
if (!help || help->expecting == 0)
return;
list_for_each_entry_safe(i, tmp, &nf_conntrack_expect_list, list) {
......@@ -713,6 +705,7 @@ __nf_conntrack_confirm(struct sk_buff **pskb)
conntrack_tuple_cmp,
struct nf_conntrack_tuple_hash *,
&ct->tuplehash[IP_CT_DIR_REPLY].tuple, NULL)) {
struct nf_conn_help *help;
/* Remove from unconfirmed list */
list_del(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list);
......@@ -726,7 +719,8 @@ __nf_conntrack_confirm(struct sk_buff **pskb)
set_bit(IPS_CONFIRMED_BIT, &ct->status);
NF_CT_STAT_INC(insert);
write_unlock_bh(&nf_conntrack_lock);
if (ct->helper)
help = nfct_help(ct);
if (help && help->helper)
nf_conntrack_event_cache(IPCT_HELPER, *pskb);
#ifdef CONFIG_NF_NAT_NEEDED
if (test_bit(IPS_SRC_NAT_DONE_BIT, &ct->status) ||
......@@ -842,8 +836,9 @@ __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
{
struct nf_conn *conntrack = NULL;
u_int32_t features = 0;
struct nf_conntrack_helper *helper;
if (!nf_conntrack_hash_rnd_initted) {
if (unlikely(!nf_conntrack_hash_rnd_initted)) {
get_random_bytes(&nf_conntrack_hash_rnd, 4);
nf_conntrack_hash_rnd_initted = 1;
}
......@@ -863,8 +858,11 @@ __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
/* find features needed by this conntrack. */
features = l3proto->get_features(orig);
/* FIXME: protect helper list per RCU */
read_lock_bh(&nf_conntrack_lock);
if (__nf_ct_helper_find(repl) != NULL)
helper = __nf_ct_helper_find(repl);
if (helper)
features |= NF_CT_F_HELP;
read_unlock_bh(&nf_conntrack_lock);
......@@ -872,7 +870,7 @@ __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
read_lock_bh(&nf_ct_cache_lock);
if (!nf_ct_cache[features].use) {
if (unlikely(!nf_ct_cache[features].use)) {
DEBUGP("nf_conntrack_alloc: not supported features = 0x%x\n",
features);
goto out;
......@@ -886,12 +884,10 @@ __nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
memset(conntrack, 0, nf_ct_cache[features].size);
conntrack->features = features;
if (nf_ct_cache[features].init_conntrack &&
nf_ct_cache[features].init_conntrack(conntrack, features) < 0) {
DEBUGP("nf_conntrack_alloc: failed to init\n");
kmem_cache_free(nf_ct_cache[features].cachep, conntrack);
conntrack = NULL;
goto out;
if (helper) {
struct nf_conn_help *help = nfct_help(conntrack);
NF_CT_ASSERT(help);
help->helper = helper;
}
atomic_set(&conntrack->ct_general.use, 1);
......@@ -972,11 +968,8 @@ init_conntrack(const struct nf_conntrack_tuple *tuple,
#endif
nf_conntrack_get(&conntrack->master->ct_general);
NF_CT_STAT_INC(expect_new);
} else {
conntrack->helper = __nf_ct_helper_find(&repl_tuple);
} else
NF_CT_STAT_INC(new);
}
/* Overload tuple linked list to put us in unconfirmed list. */
list_add(&conntrack->tuplehash[IP_CT_DIR_ORIGINAL].list, &unconfirmed);
......@@ -1206,14 +1199,16 @@ void nf_conntrack_expect_put(struct nf_conntrack_expect *exp)
static void nf_conntrack_expect_insert(struct nf_conntrack_expect *exp)
{
struct nf_conn_help *master_help = nfct_help(exp->master);
atomic_inc(&exp->use);
exp->master->expecting++;
master_help->expecting++;
list_add(&exp->list, &nf_conntrack_expect_list);
init_timer(&exp->timeout);
exp->timeout.data = (unsigned long)exp;
exp->timeout.function = expectation_timed_out;
exp->timeout.expires = jiffies + exp->master->helper->timeout * HZ;
exp->timeout.expires = jiffies + master_help->helper->timeout * HZ;
add_timer(&exp->timeout);
exp->id = ++nf_conntrack_expect_next_id;
......@@ -1239,10 +1234,12 @@ static void evict_oldest_expect(struct nf_conn *master)
static inline int refresh_timer(struct nf_conntrack_expect *i)
{
struct nf_conn_help *master_help = nfct_help(i->master);
if (!del_timer(&i->timeout))
return 0;
i->timeout.expires = jiffies + i->master->helper->timeout*HZ;
i->timeout.expires = jiffies + master_help->helper->timeout*HZ;
add_timer(&i->timeout);
return 1;
}
......@@ -1251,8 +1248,11 @@ int nf_conntrack_expect_related(struct nf_conntrack_expect *expect)
{
struct nf_conntrack_expect *i;
struct nf_conn *master = expect->master;
struct nf_conn_help *master_help = nfct_help(master);
int ret;
NF_CT_ASSERT(master_help);
DEBUGP("nf_conntrack_expect_related %p\n", related_to);
DEBUGP("tuple: "); NF_CT_DUMP_TUPLE(&expect->tuple);
DEBUGP("mask: "); NF_CT_DUMP_TUPLE(&expect->mask);
......@@ -1271,8 +1271,8 @@ int nf_conntrack_expect_related(struct nf_conntrack_expect *expect)
}
}
/* Will be over limit? */
if (master->helper->max_expected &&
master->expecting >= master->helper->max_expected)
if (master_help->helper->max_expected &&
master_help->expecting >= master_help->helper->max_expected)
evict_oldest_expect(master);
nf_conntrack_expect_insert(expect);
......@@ -1283,24 +1283,6 @@ out:
return ret;
}
/* Alter reply tuple (maybe alter helper). This is for NAT, and is
implicitly racy: see __nf_conntrack_confirm */
void nf_conntrack_alter_reply(struct nf_conn *conntrack,
const struct nf_conntrack_tuple *newreply)
{
write_lock_bh(&nf_conntrack_lock);
/* Should be unconfirmed, so not in hash table yet */
NF_CT_ASSERT(!nf_ct_is_confirmed(conntrack));
DEBUGP("Altering reply tuple of %p to ", conntrack);
NF_CT_DUMP_TUPLE(newreply);
conntrack->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
if (!conntrack->master && conntrack->expecting == 0)
conntrack->helper = __nf_ct_helper_find(newreply);
write_unlock_bh(&nf_conntrack_lock);
}
int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
{
int ret;
......@@ -1308,9 +1290,8 @@ int nf_conntrack_helper_register(struct nf_conntrack_helper *me)
ret = nf_conntrack_register_cache(NF_CT_F_HELP, "nf_conntrack:help",
sizeof(struct nf_conn)
+ sizeof(union nf_conntrack_help)
+ __alignof__(union nf_conntrack_help),
init_conntrack_for_helper);
+ sizeof(struct nf_conn_help)
+ __alignof__(struct nf_conn_help));
if (ret < 0) {
printk(KERN_ERR "nf_conntrack_helper_reigster: Unable to create slab cache for conntracks\n");
return ret;
......@@ -1338,9 +1319,12 @@ __nf_conntrack_helper_find_byname(const char *name)
static inline int unhelp(struct nf_conntrack_tuple_hash *i,
const struct nf_conntrack_helper *me)
{
if (nf_ct_tuplehash_to_ctrack(i)->helper == me) {
nf_conntrack_event(IPCT_HELPER, nf_ct_tuplehash_to_ctrack(i));
nf_ct_tuplehash_to_ctrack(i)->helper = NULL;
struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
struct nf_conn_help *help = nfct_help(ct);
if (help && help->helper == me) {
nf_conntrack_event(IPCT_HELPER, ct);
help->helper = NULL;
}
return 0;
}
......@@ -1356,7 +1340,8 @@ void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
/* Get rid of expectations */
list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list, list) {
if (exp->master->helper == me && del_timer(&exp->timeout)) {
struct nf_conn_help *help = nfct_help(exp->master);
if (help->helper == me && del_timer(&exp->timeout)) {
nf_ct_unlink_expect(exp);
nf_conntrack_expect_put(exp);
}
......@@ -1697,7 +1682,7 @@ int __init nf_conntrack_init(void)
}
ret = nf_conntrack_register_cache(NF_CT_F_BASIC, "nf_conntrack:basic",
sizeof(struct nf_conn), NULL);
sizeof(struct nf_conn));
if (ret < 0) {
printk(KERN_ERR "Unable to create nf_conn slab cache\n");
goto err_free_hash;
......
......@@ -440,7 +440,7 @@ static int help(struct sk_buff **pskb,
u32 seq;
int dir = CTINFO2DIR(ctinfo);
unsigned int matchlen, matchoff;
struct ip_ct_ftp_master *ct_ftp_info = &ct->help->ct_ftp_info;
struct ip_ct_ftp_master *ct_ftp_info = &nfct_help(ct)->help.ct_ftp_info;
struct nf_conntrack_expect *exp;
struct nf_conntrack_man cmd = {};
......
......@@ -2,7 +2,7 @@
* protocol helpers and general trouble making from userspace.
*
* (C) 2001 by Jay Schulist <jschlst@samba.org>
* (C) 2002-2005 by Harald Welte <laforge@gnumonks.org>
* (C) 2002-2006 by Harald Welte <laforge@gnumonks.org>
* (C) 2003 by Patrick Mchardy <kaber@trash.net>
* (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
*
......@@ -44,7 +44,7 @@
MODULE_LICENSE("GPL");
static char __initdata version[] = "0.92";
static char __initdata version[] = "0.93";
#if 0
#define DEBUGP printk
......@@ -165,15 +165,16 @@ static inline int
ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct nf_conn *ct)
{
struct nfattr *nest_helper;
const struct nf_conn_help *help = nfct_help(ct);
if (!ct->helper)
if (!help || !help->helper)
return 0;
nest_helper = NFA_NEST(skb, CTA_HELP);
NFA_PUT(skb, CTA_HELP_NAME, strlen(ct->helper->name), ct->helper->name);
NFA_PUT(skb, CTA_HELP_NAME, strlen(help->helper->name), help->helper->name);
if (ct->helper->to_nfattr)
ct->helper->to_nfattr(skb, ct);
if (help->helper->to_nfattr)
help->helper->to_nfattr(skb, ct);
NFA_NEST_END(skb, nest_helper);
......@@ -903,11 +904,17 @@ static inline int
ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[])
{
struct nf_conntrack_helper *helper;
struct nf_conn_help *help = nfct_help(ct);
char *helpname;
int err;
DEBUGP("entered %s\n", __FUNCTION__);
if (!help) {
/* FIXME: we need to reallocate and rehash */
return -EBUSY;
}
/* don't change helper of sibling connections */
if (ct->master)
return -EINVAL;
......@@ -924,18 +931,18 @@ ctnetlink_change_helper(struct nf_conn *ct, struct nfattr *cda[])
return -EINVAL;
}
if (ct->helper) {
if (help->helper) {
if (!helper) {
/* we had a helper before ... */
nf_ct_remove_expectations(ct);
ct->helper = NULL;
help->helper = NULL;
} else {
/* need to zero data of old helper */
memset(&ct->help, 0, sizeof(ct->help));
memset(&help->help, 0, sizeof(help->help));
}
}
ct->helper = helper;
help->helper = helper;
return 0;
}
......@@ -1050,14 +1057,9 @@ ctnetlink_create_conntrack(struct nfattr *cda[],
ct->mark = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_MARK-1]));
#endif
ct->helper = nf_ct_helper_find_get(rtuple);
add_timer(&ct->timeout);
nf_conntrack_hash_insert(ct);
if (ct->helper)
nf_ct_helper_put(ct->helper);
DEBUGP("conntrack with id %u inserted\n", ct->id);
return 0;
......@@ -1417,7 +1419,8 @@ ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
}
list_for_each_entry_safe(exp, tmp, &nf_conntrack_expect_list,
list) {
if (exp->master->helper == h
struct nf_conn_help *m_help = nfct_help(exp->master);
if (m_help->helper == h
&& del_timer(&exp->timeout)) {
nf_ct_unlink_expect(exp);
nf_conntrack_expect_put(exp);
......@@ -1452,6 +1455,7 @@ ctnetlink_create_expect(struct nfattr *cda[], u_int8_t u3)
struct nf_conntrack_tuple_hash *h = NULL;
struct nf_conntrack_expect *exp;
struct nf_conn *ct;
struct nf_conn_help *help;
int err = 0;
DEBUGP("entered %s\n", __FUNCTION__);
......@@ -1472,8 +1476,9 @@ ctnetlink_create_expect(struct nfattr *cda[], u_int8_t u3)
if (!h)
return -ENOENT;
ct = nf_ct_tuplehash_to_ctrack(h);
help = nfct_help(ct);
if (!ct->helper) {
if (!help<