blob: 0e3e1a01820677768d7a58eeb9f97f8112e2f670 [file] [log] [blame]
/*
* (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
* (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
*
* 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 (or any later at your option).
*/
#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(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_get(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:
nf_ct_l4proto_put(l4proto);
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;
struct nfgenmsg *nfmsg;
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 = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
if (nlh == NULL)
goto nlmsg_failure;
nfmsg = nlmsg_data(nlh);
nfmsg->nfgen_family = AF_UNSPEC;
nfmsg->version = NFNETLINK_V0;
nfmsg->res_id = 0;
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 | NLA_F_NESTED);
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_l4proto_put(timeout->timeout.l4proto);
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_get(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;
nf_ct_l4proto_put(l4proto);
return 0;
err:
nf_ct_l4proto_put(l4proto);
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;
struct nfgenmsg *nfmsg;
unsigned int flags = portid ? NLM_F_MULTI : 0;
struct nlattr *nest_parms;
int ret;
event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
if (nlh == NULL)
goto nlmsg_failure;
nfmsg = nlmsg_data(nlh);
nfmsg->nfgen_family = AF_UNSPEC;
nfmsg->version = NFNETLINK_V0;
nfmsg->res_id = 0;
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 | NLA_F_NESTED);
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_get(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: /* fallthrough */
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:
nf_ct_l4proto_put(l4proto);
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);
nf_ct_l4proto_put(cur->timeout.l4proto);
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);