// SPDX-License-Identifier: GPL-2.0-or-later
|
/*
|
* (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
|
* (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
|
*/
|
#include <linux/init.h>
|
#include <linux/module.h>
|
#include <linux/kernel.h>
|
#include <linux/rculist.h>
|
#include <linux/rculist_nulls.h>
|
#include <linux/types.h>
|
#include <linux/timer.h>
|
#include <linux/security.h>
|
#include <linux/skbuff.h>
|
#include <linux/errno.h>
|
#include <linux/netlink.h>
|
#include <linux/spinlock.h>
|
#include <linux/interrupt.h>
|
#include <linux/slab.h>
|
|
#include <linux/netfilter.h>
|
#include <net/netlink.h>
|
#include <net/sock.h>
|
#include <net/netfilter/nf_conntrack.h>
|
#include <net/netfilter/nf_conntrack_core.h>
|
#include <net/netfilter/nf_conntrack_l4proto.h>
|
#include <net/netfilter/nf_conntrack_tuple.h>
|
#include <net/netfilter/nf_conntrack_timeout.h>
|
|
#include <linux/netfilter/nfnetlink.h>
|
#include <linux/netfilter/nfnetlink_cttimeout.h>
|
|
MODULE_LICENSE("GPL");
|
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
|
MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
|
|
static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
|
[CTA_TIMEOUT_NAME] = { .type = NLA_NUL_STRING,
|
.len = CTNL_TIMEOUT_NAME_MAX - 1},
|
[CTA_TIMEOUT_L3PROTO] = { .type = NLA_U16 },
|
[CTA_TIMEOUT_L4PROTO] = { .type = NLA_U8 },
|
[CTA_TIMEOUT_DATA] = { .type = NLA_NESTED },
|
};
|
|
static int
|
ctnl_timeout_parse_policy(void *timeout,
|
const struct nf_conntrack_l4proto *l4proto,
|
struct net *net, const struct nlattr *attr)
|
{
|
struct nlattr **tb;
|
int ret = 0;
|
|
tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
|
GFP_KERNEL);
|
|
if (!tb)
|
return -ENOMEM;
|
|
ret = nla_parse_nested_deprecated(tb,
|
l4proto->ctnl_timeout.nlattr_max,
|
attr,
|
l4proto->ctnl_timeout.nla_policy,
|
NULL);
|
if (ret < 0)
|
goto err;
|
|
ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
|
|
err:
|
kfree(tb);
|
return ret;
|
}
|
|
static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
|
struct sk_buff *skb,
|
const struct nlmsghdr *nlh,
|
const struct nlattr * const cda[],
|
struct netlink_ext_ack *extack)
|
{
|
__u16 l3num;
|
__u8 l4num;
|
const struct nf_conntrack_l4proto *l4proto;
|
struct ctnl_timeout *timeout, *matching = NULL;
|
char *name;
|
int ret;
|
|
if (!cda[CTA_TIMEOUT_NAME] ||
|
!cda[CTA_TIMEOUT_L3PROTO] ||
|
!cda[CTA_TIMEOUT_L4PROTO] ||
|
!cda[CTA_TIMEOUT_DATA])
|
return -EINVAL;
|
|
name = nla_data(cda[CTA_TIMEOUT_NAME]);
|
l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
|
l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
|
|
list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
|
if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
|
continue;
|
|
if (nlh->nlmsg_flags & NLM_F_EXCL)
|
return -EEXIST;
|
|
matching = timeout;
|
break;
|
}
|
|
if (matching) {
|
if (nlh->nlmsg_flags & NLM_F_REPLACE) {
|
/* You cannot replace one timeout policy by another of
|
* different kind, sorry.
|
*/
|
if (matching->timeout.l3num != l3num ||
|
matching->timeout.l4proto->l4proto != l4num)
|
return -EINVAL;
|
|
return ctnl_timeout_parse_policy(&matching->timeout.data,
|
matching->timeout.l4proto,
|
net, cda[CTA_TIMEOUT_DATA]);
|
}
|
|
return -EBUSY;
|
}
|
|
l4proto = nf_ct_l4proto_find(l4num);
|
|
/* This protocol is not supportted, skip. */
|
if (l4proto->l4proto != l4num) {
|
ret = -EOPNOTSUPP;
|
goto err_proto_put;
|
}
|
|
timeout = kzalloc(sizeof(struct ctnl_timeout) +
|
l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
|
if (timeout == NULL) {
|
ret = -ENOMEM;
|
goto err_proto_put;
|
}
|
|
ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto, net,
|
cda[CTA_TIMEOUT_DATA]);
|
if (ret < 0)
|
goto err;
|
|
strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
|
timeout->timeout.l3num = l3num;
|
timeout->timeout.l4proto = l4proto;
|
refcount_set(&timeout->refcnt, 1);
|
list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
|
|
return 0;
|
err:
|
kfree(timeout);
|
err_proto_put:
|
return ret;
|
}
|
|
static int
|
ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
|
int event, struct ctnl_timeout *timeout)
|
{
|
struct nlmsghdr *nlh;
|
unsigned int flags = portid ? NLM_F_MULTI : 0;
|
const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
|
struct nlattr *nest_parms;
|
int ret;
|
|
event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
|
nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
|
NFNETLINK_V0, 0);
|
if (!nlh)
|
goto nlmsg_failure;
|
|
if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
|
nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
|
htons(timeout->timeout.l3num)) ||
|
nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
|
nla_put_be32(skb, CTA_TIMEOUT_USE,
|
htonl(refcount_read(&timeout->refcnt))))
|
goto nla_put_failure;
|
|
nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
|
if (!nest_parms)
|
goto nla_put_failure;
|
|
ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->timeout.data);
|
if (ret < 0)
|
goto nla_put_failure;
|
|
nla_nest_end(skb, nest_parms);
|
|
nlmsg_end(skb, nlh);
|
return skb->len;
|
|
nlmsg_failure:
|
nla_put_failure:
|
nlmsg_cancel(skb, nlh);
|
return -1;
|
}
|
|
static int
|
ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
|
{
|
struct net *net = sock_net(skb->sk);
|
struct ctnl_timeout *cur, *last;
|
|
if (cb->args[2])
|
return 0;
|
|
last = (struct ctnl_timeout *)cb->args[1];
|
if (cb->args[1])
|
cb->args[1] = 0;
|
|
rcu_read_lock();
|
list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
|
if (last) {
|
if (cur != last)
|
continue;
|
|
last = NULL;
|
}
|
if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
|
cb->nlh->nlmsg_seq,
|
NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
|
IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
|
cb->args[1] = (unsigned long)cur;
|
break;
|
}
|
}
|
if (!cb->args[1])
|
cb->args[2] = 1;
|
rcu_read_unlock();
|
return skb->len;
|
}
|
|
static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
|
struct sk_buff *skb,
|
const struct nlmsghdr *nlh,
|
const struct nlattr * const cda[],
|
struct netlink_ext_ack *extack)
|
{
|
int ret = -ENOENT;
|
char *name;
|
struct ctnl_timeout *cur;
|
|
if (nlh->nlmsg_flags & NLM_F_DUMP) {
|
struct netlink_dump_control c = {
|
.dump = ctnl_timeout_dump,
|
};
|
return netlink_dump_start(ctnl, skb, nlh, &c);
|
}
|
|
if (!cda[CTA_TIMEOUT_NAME])
|
return -EINVAL;
|
name = nla_data(cda[CTA_TIMEOUT_NAME]);
|
|
list_for_each_entry(cur, &net->nfct_timeout_list, head) {
|
struct sk_buff *skb2;
|
|
if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
|
continue;
|
|
skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
|
if (skb2 == NULL) {
|
ret = -ENOMEM;
|
break;
|
}
|
|
ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
|
nlh->nlmsg_seq,
|
NFNL_MSG_TYPE(nlh->nlmsg_type),
|
IPCTNL_MSG_TIMEOUT_NEW, cur);
|
if (ret <= 0) {
|
kfree_skb(skb2);
|
break;
|
}
|
ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
|
MSG_DONTWAIT);
|
if (ret > 0)
|
ret = 0;
|
|
/* this avoids a loop in nfnetlink. */
|
return ret == -EAGAIN ? -ENOBUFS : ret;
|
}
|
return ret;
|
}
|
|
/* try to delete object, fail if it is still in use. */
|
static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
|
{
|
int ret = 0;
|
|
/* We want to avoid races with ctnl_timeout_put. So only when the
|
* current refcnt is 1, we decrease it to 0.
|
*/
|
if (refcount_dec_if_one(&timeout->refcnt)) {
|
/* We are protected by nfnl mutex. */
|
list_del_rcu(&timeout->head);
|
nf_ct_untimeout(net, &timeout->timeout);
|
kfree_rcu(timeout, rcu_head);
|
} else {
|
ret = -EBUSY;
|
}
|
return ret;
|
}
|
|
static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
|
struct sk_buff *skb,
|
const struct nlmsghdr *nlh,
|
const struct nlattr * const cda[],
|
struct netlink_ext_ack *extack)
|
{
|
struct ctnl_timeout *cur, *tmp;
|
int ret = -ENOENT;
|
char *name;
|
|
if (!cda[CTA_TIMEOUT_NAME]) {
|
list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
|
head)
|
ctnl_timeout_try_del(net, cur);
|
|
return 0;
|
}
|
name = nla_data(cda[CTA_TIMEOUT_NAME]);
|
|
list_for_each_entry(cur, &net->nfct_timeout_list, head) {
|
if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
|
continue;
|
|
ret = ctnl_timeout_try_del(net, cur);
|
if (ret < 0)
|
return ret;
|
|
break;
|
}
|
return ret;
|
}
|
|
static int cttimeout_default_set(struct net *net, struct sock *ctnl,
|
struct sk_buff *skb,
|
const struct nlmsghdr *nlh,
|
const struct nlattr * const cda[],
|
struct netlink_ext_ack *extack)
|
{
|
const struct nf_conntrack_l4proto *l4proto;
|
__u8 l4num;
|
int ret;
|
|
if (!cda[CTA_TIMEOUT_L3PROTO] ||
|
!cda[CTA_TIMEOUT_L4PROTO] ||
|
!cda[CTA_TIMEOUT_DATA])
|
return -EINVAL;
|
|
l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
|
l4proto = nf_ct_l4proto_find(l4num);
|
|
/* This protocol is not supported, skip. */
|
if (l4proto->l4proto != l4num) {
|
ret = -EOPNOTSUPP;
|
goto err;
|
}
|
|
ret = ctnl_timeout_parse_policy(NULL, l4proto, net,
|
cda[CTA_TIMEOUT_DATA]);
|
if (ret < 0)
|
goto err;
|
|
return 0;
|
err:
|
return ret;
|
}
|
|
static int
|
cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
|
u32 seq, u32 type, int event, u16 l3num,
|
const struct nf_conntrack_l4proto *l4proto,
|
const unsigned int *timeouts)
|
{
|
struct nlmsghdr *nlh;
|
unsigned int flags = portid ? NLM_F_MULTI : 0;
|
struct nlattr *nest_parms;
|
int ret;
|
|
event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
|
nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
|
NFNETLINK_V0, 0);
|
if (!nlh)
|
goto nlmsg_failure;
|
|
if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l3num)) ||
|
nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
|
goto nla_put_failure;
|
|
nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA);
|
if (!nest_parms)
|
goto nla_put_failure;
|
|
ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
|
if (ret < 0)
|
goto nla_put_failure;
|
|
nla_nest_end(skb, nest_parms);
|
|
nlmsg_end(skb, nlh);
|
return skb->len;
|
|
nlmsg_failure:
|
nla_put_failure:
|
nlmsg_cancel(skb, nlh);
|
return -1;
|
}
|
|
static int cttimeout_default_get(struct net *net, struct sock *ctnl,
|
struct sk_buff *skb,
|
const struct nlmsghdr *nlh,
|
const struct nlattr * const cda[],
|
struct netlink_ext_ack *extack)
|
{
|
const struct nf_conntrack_l4proto *l4proto;
|
unsigned int *timeouts = NULL;
|
struct sk_buff *skb2;
|
int ret, err;
|
__u16 l3num;
|
__u8 l4num;
|
|
if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
|
return -EINVAL;
|
|
l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
|
l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
|
l4proto = nf_ct_l4proto_find(l4num);
|
|
err = -EOPNOTSUPP;
|
if (l4proto->l4proto != l4num)
|
goto err;
|
|
switch (l4proto->l4proto) {
|
case IPPROTO_ICMP:
|
timeouts = &nf_icmp_pernet(net)->timeout;
|
break;
|
case IPPROTO_TCP:
|
timeouts = nf_tcp_pernet(net)->timeouts;
|
break;
|
case IPPROTO_UDP:
|
case IPPROTO_UDPLITE:
|
timeouts = nf_udp_pernet(net)->timeouts;
|
break;
|
case IPPROTO_DCCP:
|
#ifdef CONFIG_NF_CT_PROTO_DCCP
|
timeouts = nf_dccp_pernet(net)->dccp_timeout;
|
#endif
|
break;
|
case IPPROTO_ICMPV6:
|
timeouts = &nf_icmpv6_pernet(net)->timeout;
|
break;
|
case IPPROTO_SCTP:
|
#ifdef CONFIG_NF_CT_PROTO_SCTP
|
timeouts = nf_sctp_pernet(net)->timeouts;
|
#endif
|
break;
|
case IPPROTO_GRE:
|
#ifdef CONFIG_NF_CT_PROTO_GRE
|
timeouts = nf_gre_pernet(net)->timeouts;
|
#endif
|
break;
|
case 255:
|
timeouts = &nf_generic_pernet(net)->timeout;
|
break;
|
default:
|
WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
|
break;
|
}
|
|
if (!timeouts)
|
goto err;
|
|
skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
|
if (skb2 == NULL) {
|
err = -ENOMEM;
|
goto err;
|
}
|
|
ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
|
nlh->nlmsg_seq,
|
NFNL_MSG_TYPE(nlh->nlmsg_type),
|
IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
|
l3num, l4proto, timeouts);
|
if (ret <= 0) {
|
kfree_skb(skb2);
|
err = -ENOMEM;
|
goto err;
|
}
|
ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
|
if (ret > 0)
|
ret = 0;
|
|
/* this avoids a loop in nfnetlink. */
|
return ret == -EAGAIN ? -ENOBUFS : ret;
|
err:
|
return err;
|
}
|
|
static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,
|
const char *name)
|
{
|
struct ctnl_timeout *timeout, *matching = NULL;
|
|
list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
|
if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
|
continue;
|
|
if (!try_module_get(THIS_MODULE))
|
goto err;
|
|
if (!refcount_inc_not_zero(&timeout->refcnt)) {
|
module_put(THIS_MODULE);
|
goto err;
|
}
|
matching = timeout;
|
break;
|
}
|
err:
|
return matching ? &matching->timeout : NULL;
|
}
|
|
static void ctnl_timeout_put(struct nf_ct_timeout *t)
|
{
|
struct ctnl_timeout *timeout =
|
container_of(t, struct ctnl_timeout, timeout);
|
|
if (refcount_dec_and_test(&timeout->refcnt))
|
kfree_rcu(timeout, rcu_head);
|
|
module_put(THIS_MODULE);
|
}
|
|
static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
|
[IPCTNL_MSG_TIMEOUT_NEW] = { .call = cttimeout_new_timeout,
|
.attr_count = CTA_TIMEOUT_MAX,
|
.policy = cttimeout_nla_policy },
|
[IPCTNL_MSG_TIMEOUT_GET] = { .call = cttimeout_get_timeout,
|
.attr_count = CTA_TIMEOUT_MAX,
|
.policy = cttimeout_nla_policy },
|
[IPCTNL_MSG_TIMEOUT_DELETE] = { .call = cttimeout_del_timeout,
|
.attr_count = CTA_TIMEOUT_MAX,
|
.policy = cttimeout_nla_policy },
|
[IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
|
.attr_count = CTA_TIMEOUT_MAX,
|
.policy = cttimeout_nla_policy },
|
[IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
|
.attr_count = CTA_TIMEOUT_MAX,
|
.policy = cttimeout_nla_policy },
|
};
|
|
static const struct nfnetlink_subsystem cttimeout_subsys = {
|
.name = "conntrack_timeout",
|
.subsys_id = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
|
.cb_count = IPCTNL_MSG_TIMEOUT_MAX,
|
.cb = cttimeout_cb,
|
};
|
|
MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
|
|
static int __net_init cttimeout_net_init(struct net *net)
|
{
|
INIT_LIST_HEAD(&net->nfct_timeout_list);
|
|
return 0;
|
}
|
|
static void __net_exit cttimeout_net_exit(struct net *net)
|
{
|
struct ctnl_timeout *cur, *tmp;
|
|
nf_ct_unconfirmed_destroy(net);
|
nf_ct_untimeout(net, NULL);
|
|
list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
|
list_del_rcu(&cur->head);
|
|
if (refcount_dec_and_test(&cur->refcnt))
|
kfree_rcu(cur, rcu_head);
|
}
|
}
|
|
static struct pernet_operations cttimeout_ops = {
|
.init = cttimeout_net_init,
|
.exit = cttimeout_net_exit,
|
};
|
|
static int __init cttimeout_init(void)
|
{
|
int ret;
|
|
ret = register_pernet_subsys(&cttimeout_ops);
|
if (ret < 0)
|
return ret;
|
|
ret = nfnetlink_subsys_register(&cttimeout_subsys);
|
if (ret < 0) {
|
pr_err("cttimeout_init: cannot register cttimeout with "
|
"nfnetlink.\n");
|
goto err_out;
|
}
|
RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
|
RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
|
return 0;
|
|
err_out:
|
unregister_pernet_subsys(&cttimeout_ops);
|
return ret;
|
}
|
|
static void __exit cttimeout_exit(void)
|
{
|
nfnetlink_subsys_unregister(&cttimeout_subsys);
|
|
unregister_pernet_subsys(&cttimeout_ops);
|
RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
|
RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
|
synchronize_rcu();
|
}
|
|
module_init(cttimeout_init);
|
module_exit(cttimeout_exit);
|
