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// SPDX-License-Identifier: GPL-2.0-or-later
/* Structure dynamic extension infrastructure
* Copyright (C) 2004 Rusty Russell IBM Corporation
* Copyright (C) 2007 Netfilter Core Team <coreteam@netfilter.org>
* Copyright (C) 2007 USAGI/WIDE Project <http://www.linux-ipv6.org>
*/
#include <linux/kernel.h>
#include <linux/kmemleak.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_conntrack_timestamp.h>
#include <net/netfilter/nf_conntrack_timeout.h>
#include <net/netfilter/nf_conntrack_labels.h>
#include <net/netfilter/nf_conntrack_synproxy.h>
#include <net/netfilter/nf_conntrack_act_ct.h>
#include <net/netfilter/nf_nat.h>
static struct nf_ct_ext_type __rcu *nf_ct_ext_types[NF_CT_EXT_NUM];
static DEFINE_MUTEX(nf_ct_ext_type_mutex);
#define NF_CT_EXT_PREALLOC 128u /* conntrack events are on by default */
static const u8 nf_ct_ext_type_len[NF_CT_EXT_NUM] = {
[NF_CT_EXT_HELPER] = sizeof(struct nf_conn_help),
#if IS_ENABLED(CONFIG_NF_NAT)
[NF_CT_EXT_NAT] = sizeof(struct nf_conn_nat),
#endif
[NF_CT_EXT_SEQADJ] = sizeof(struct nf_conn_seqadj),
[NF_CT_EXT_ACCT] = sizeof(struct nf_conn_acct),
#ifdef CONFIG_NF_CONNTRACK_EVENTS
[NF_CT_EXT_ECACHE] = sizeof(struct nf_conntrack_ecache),
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
[NF_CT_EXT_TSTAMP] = sizeof(struct nf_conn_acct),
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
[NF_CT_EXT_TIMEOUT] = sizeof(struct nf_conn_tstamp),
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
[NF_CT_EXT_LABELS] = sizeof(struct nf_conn_labels),
#endif
#if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
[NF_CT_EXT_SYNPROXY] = sizeof(struct nf_conn_synproxy),
#endif
#if IS_ENABLED(CONFIG_NET_ACT_CT)
[NF_CT_EXT_ACT_CT] = sizeof(struct nf_conn_act_ct_ext),
#endif
};
static __always_inline unsigned int total_extension_size(void)
{
/* remember to add new extensions below */
BUILD_BUG_ON(NF_CT_EXT_NUM > 10);
return sizeof(struct nf_ct_ext) +
sizeof(struct nf_conn_help)
#if IS_ENABLED(CONFIG_NF_NAT)
+ sizeof(struct nf_conn_nat)
#endif
+ sizeof(struct nf_conn_seqadj)
+ sizeof(struct nf_conn_acct)
#ifdef CONFIG_NF_CONNTRACK_EVENTS
+ sizeof(struct nf_conntrack_ecache)
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
+ sizeof(struct nf_conn_tstamp)
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
+ sizeof(struct nf_conn_timeout)
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
+ sizeof(struct nf_conn_labels)
#endif
#if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
+ sizeof(struct nf_conn_synproxy)
#endif
#if IS_ENABLED(CONFIG_NET_ACT_CT)
+ sizeof(struct nf_conn_act_ct_ext)
#endif
;
}
void nf_ct_ext_destroy(struct nf_conn *ct)
{
unsigned int i;
struct nf_ct_ext_type *t;
for (i = 0; i < NF_CT_EXT_NUM; i++) {
rcu_read_lock();
t = rcu_dereference(nf_ct_ext_types[i]);
/* Here the nf_ct_ext_type might have been unregisterd.
* I.e., it has responsible to cleanup private
* area in all conntracks when it is unregisterd.
*/
if (t && t->destroy)
t->destroy(ct);
rcu_read_unlock();
}
kfree(ct->ext);
}
void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
{
unsigned int newlen, newoff, oldlen, alloc;
struct nf_ct_ext *new;
/* Conntrack must not be confirmed to avoid races on reallocation. */
WARN_ON(nf_ct_is_confirmed(ct));
if (ct->ext) {
const struct nf_ct_ext *old = ct->ext;
if (__nf_ct_ext_exist(old, id))
return NULL;
oldlen = old->len;
} else {
oldlen = sizeof(*new);
}
newoff = ALIGN(oldlen, __alignof__(struct nf_ct_ext));
newlen = newoff + nf_ct_ext_type_len[id];
alloc = max(newlen, NF_CT_EXT_PREALLOC);
new = krealloc(ct->ext, alloc, gfp);
if (!new)
return NULL;
if (!ct->ext)
memset(new->offset, 0, sizeof(new->offset));
new->offset[id] = newoff;
new->len = newlen;
memset((void *)new + newoff, 0, newlen - newoff);
ct->ext = new;
return (void *)new + newoff;
}
EXPORT_SYMBOL(nf_ct_ext_add);
/* This MUST be called in process context. */
int nf_ct_extend_register(const struct nf_ct_ext_type *type)
{
int ret = 0;
/* struct nf_ct_ext uses u8 to store offsets/size */
BUILD_BUG_ON(total_extension_size() > 255u);
mutex_lock(&nf_ct_ext_type_mutex);
if (nf_ct_ext_types[type->id]) {
ret = -EBUSY;
goto out;
}
rcu_assign_pointer(nf_ct_ext_types[type->id], type);
out:
mutex_unlock(&nf_ct_ext_type_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(nf_ct_extend_register);
/* This MUST be called in process context. */
void nf_ct_extend_unregister(const struct nf_ct_ext_type *type)
{
mutex_lock(&nf_ct_ext_type_mutex);
RCU_INIT_POINTER(nf_ct_ext_types[type->id], NULL);
mutex_unlock(&nf_ct_ext_type_mutex);
synchronize_rcu();
}
EXPORT_SYMBOL_GPL(nf_ct_extend_unregister);
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