// SPDX-License-Identifier: GPL-2.0-or-later
|
/*
|
* (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
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*
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* This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <linux/netlink.h>
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#include <linux/rculist.h>
|
#include <linux/slab.h>
|
#include <linux/types.h>
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#include <linux/list.h>
|
#include <linux/errno.h>
|
#include <linux/capability.h>
|
#include <net/netlink.h>
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#include <net/sock.h>
|
|
#include <net/netfilter/nf_conntrack_helper.h>
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#include <net/netfilter/nf_conntrack_expect.h>
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#include <net/netfilter/nf_conntrack_ecache.h>
|
|
#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nfnetlink_conntrack.h>
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#include <linux/netfilter/nfnetlink_cthelper.h>
|
|
MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
|
MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
|
|
struct nfnl_cthelper {
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struct list_head list;
|
struct nf_conntrack_helper helper;
|
};
|
|
static LIST_HEAD(nfnl_cthelper_list);
|
|
static int
|
nfnl_userspace_cthelper(struct sk_buff *skb, unsigned int protoff,
|
struct nf_conn *ct, enum ip_conntrack_info ctinfo)
|
{
|
const struct nf_conn_help *help;
|
struct nf_conntrack_helper *helper;
|
|
help = nfct_help(ct);
|
if (help == NULL)
|
return NF_DROP;
|
|
/* rcu_read_lock()ed by nf_hook_thresh */
|
helper = rcu_dereference(help->helper);
|
if (helper == NULL)
|
return NF_DROP;
|
|
/* This is a user-space helper not yet configured, skip. */
|
if ((helper->flags &
|
(NF_CT_HELPER_F_USERSPACE | NF_CT_HELPER_F_CONFIGURED)) ==
|
NF_CT_HELPER_F_USERSPACE)
|
return NF_ACCEPT;
|
|
/* If the user-space helper is not available, don't block traffic. */
|
return NF_QUEUE_NR(helper->queue_num) | NF_VERDICT_FLAG_QUEUE_BYPASS;
|
}
|
|
static const struct nla_policy nfnl_cthelper_tuple_pol[NFCTH_TUPLE_MAX+1] = {
|
[NFCTH_TUPLE_L3PROTONUM] = { .type = NLA_U16, },
|
[NFCTH_TUPLE_L4PROTONUM] = { .type = NLA_U8, },
|
};
|
|
static int
|
nfnl_cthelper_parse_tuple(struct nf_conntrack_tuple *tuple,
|
const struct nlattr *attr)
|
{
|
int err;
|
struct nlattr *tb[NFCTH_TUPLE_MAX+1];
|
|
err = nla_parse_nested_deprecated(tb, NFCTH_TUPLE_MAX, attr,
|
nfnl_cthelper_tuple_pol, NULL);
|
if (err < 0)
|
return err;
|
|
if (!tb[NFCTH_TUPLE_L3PROTONUM] || !tb[NFCTH_TUPLE_L4PROTONUM])
|
return -EINVAL;
|
|
/* Not all fields are initialized so first zero the tuple */
|
memset(tuple, 0, sizeof(struct nf_conntrack_tuple));
|
|
tuple->src.l3num = ntohs(nla_get_be16(tb[NFCTH_TUPLE_L3PROTONUM]));
|
tuple->dst.protonum = nla_get_u8(tb[NFCTH_TUPLE_L4PROTONUM]);
|
|
return 0;
|
}
|
|
static int
|
nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct)
|
{
|
struct nf_conn_help *help = nfct_help(ct);
|
|
if (attr == NULL)
|
return -EINVAL;
|
|
if (help->helper->data_len == 0)
|
return -EINVAL;
|
|
nla_memcpy(help->data, attr, sizeof(help->data));
|
return 0;
|
}
|
|
static int
|
nfnl_cthelper_to_nlattr(struct sk_buff *skb, const struct nf_conn *ct)
|
{
|
const struct nf_conn_help *help = nfct_help(ct);
|
|
if (help->helper->data_len &&
|
nla_put(skb, CTA_HELP_INFO, help->helper->data_len, &help->data))
|
goto nla_put_failure;
|
|
return 0;
|
|
nla_put_failure:
|
return -ENOSPC;
|
}
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|
static const struct nla_policy nfnl_cthelper_expect_pol[NFCTH_POLICY_MAX+1] = {
|
[NFCTH_POLICY_NAME] = { .type = NLA_NUL_STRING,
|
.len = NF_CT_HELPER_NAME_LEN-1 },
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[NFCTH_POLICY_EXPECT_MAX] = { .type = NLA_U32, },
|
[NFCTH_POLICY_EXPECT_TIMEOUT] = { .type = NLA_U32, },
|
};
|
|
static int
|
nfnl_cthelper_expect_policy(struct nf_conntrack_expect_policy *expect_policy,
|
const struct nlattr *attr)
|
{
|
int err;
|
struct nlattr *tb[NFCTH_POLICY_MAX+1];
|
|
err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_MAX, attr,
|
nfnl_cthelper_expect_pol, NULL);
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if (err < 0)
|
return err;
|
|
if (!tb[NFCTH_POLICY_NAME] ||
|
!tb[NFCTH_POLICY_EXPECT_MAX] ||
|
!tb[NFCTH_POLICY_EXPECT_TIMEOUT])
|
return -EINVAL;
|
|
nla_strlcpy(expect_policy->name,
|
tb[NFCTH_POLICY_NAME], NF_CT_HELPER_NAME_LEN);
|
expect_policy->max_expected =
|
ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
|
if (expect_policy->max_expected > NF_CT_EXPECT_MAX_CNT)
|
return -EINVAL;
|
|
expect_policy->timeout =
|
ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
|
|
return 0;
|
}
|
|
static const struct nla_policy
|
nfnl_cthelper_expect_policy_set[NFCTH_POLICY_SET_MAX+1] = {
|
[NFCTH_POLICY_SET_NUM] = { .type = NLA_U32, },
|
};
|
|
static int
|
nfnl_cthelper_parse_expect_policy(struct nf_conntrack_helper *helper,
|
const struct nlattr *attr)
|
{
|
int i, ret;
|
struct nf_conntrack_expect_policy *expect_policy;
|
struct nlattr *tb[NFCTH_POLICY_SET_MAX+1];
|
unsigned int class_max;
|
|
ret = nla_parse_nested_deprecated(tb, NFCTH_POLICY_SET_MAX, attr,
|
nfnl_cthelper_expect_policy_set,
|
NULL);
|
if (ret < 0)
|
return ret;
|
|
if (!tb[NFCTH_POLICY_SET_NUM])
|
return -EINVAL;
|
|
class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
|
if (class_max == 0)
|
return -EINVAL;
|
if (class_max > NF_CT_MAX_EXPECT_CLASSES)
|
return -EOVERFLOW;
|
|
expect_policy = kcalloc(class_max,
|
sizeof(struct nf_conntrack_expect_policy),
|
GFP_KERNEL);
|
if (expect_policy == NULL)
|
return -ENOMEM;
|
|
for (i = 0; i < class_max; i++) {
|
if (!tb[NFCTH_POLICY_SET+i])
|
goto err;
|
|
ret = nfnl_cthelper_expect_policy(&expect_policy[i],
|
tb[NFCTH_POLICY_SET+i]);
|
if (ret < 0)
|
goto err;
|
}
|
|
helper->expect_class_max = class_max - 1;
|
helper->expect_policy = expect_policy;
|
return 0;
|
err:
|
kfree(expect_policy);
|
return -EINVAL;
|
}
|
|
static int
|
nfnl_cthelper_create(const struct nlattr * const tb[],
|
struct nf_conntrack_tuple *tuple)
|
{
|
struct nf_conntrack_helper *helper;
|
struct nfnl_cthelper *nfcth;
|
unsigned int size;
|
int ret;
|
|
if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
|
return -EINVAL;
|
|
nfcth = kzalloc(sizeof(*nfcth), GFP_KERNEL);
|
if (nfcth == NULL)
|
return -ENOMEM;
|
helper = &nfcth->helper;
|
|
ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
|
if (ret < 0)
|
goto err1;
|
|
nla_strlcpy(helper->name,
|
tb[NFCTH_NAME], NF_CT_HELPER_NAME_LEN);
|
size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
|
if (size > sizeof_field(struct nf_conn_help, data)) {
|
ret = -ENOMEM;
|
goto err2;
|
}
|
helper->data_len = size;
|
|
helper->flags |= NF_CT_HELPER_F_USERSPACE;
|
memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
|
|
helper->me = THIS_MODULE;
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helper->help = nfnl_userspace_cthelper;
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helper->from_nlattr = nfnl_cthelper_from_nlattr;
|
helper->to_nlattr = nfnl_cthelper_to_nlattr;
|
|
/* Default to queue number zero, this can be updated at any time. */
|
if (tb[NFCTH_QUEUE_NUM])
|
helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
|
|
if (tb[NFCTH_STATUS]) {
|
int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
|
|
switch(status) {
|
case NFCT_HELPER_STATUS_ENABLED:
|
helper->flags |= NF_CT_HELPER_F_CONFIGURED;
|
break;
|
case NFCT_HELPER_STATUS_DISABLED:
|
helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
|
break;
|
}
|
}
|
|
ret = nf_conntrack_helper_register(helper);
|
if (ret < 0)
|
goto err2;
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|
list_add_tail(&nfcth->list, &nfnl_cthelper_list);
|
return 0;
|
err2:
|
kfree(helper->expect_policy);
|
err1:
|
kfree(nfcth);
|
return ret;
|
}
|
|
static int
|
nfnl_cthelper_update_policy_one(const struct nf_conntrack_expect_policy *policy,
|
struct nf_conntrack_expect_policy *new_policy,
|
const struct nlattr *attr)
|
{
|
struct nlattr *tb[NFCTH_POLICY_MAX + 1];
|
int err;
|
|
err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_MAX, attr,
|
nfnl_cthelper_expect_pol, NULL);
|
if (err < 0)
|
return err;
|
|
if (!tb[NFCTH_POLICY_NAME] ||
|
!tb[NFCTH_POLICY_EXPECT_MAX] ||
|
!tb[NFCTH_POLICY_EXPECT_TIMEOUT])
|
return -EINVAL;
|
|
if (nla_strcmp(tb[NFCTH_POLICY_NAME], policy->name))
|
return -EBUSY;
|
|
new_policy->max_expected =
|
ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_MAX]));
|
if (new_policy->max_expected > NF_CT_EXPECT_MAX_CNT)
|
return -EINVAL;
|
|
new_policy->timeout =
|
ntohl(nla_get_be32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]));
|
|
return 0;
|
}
|
|
static int nfnl_cthelper_update_policy_all(struct nlattr *tb[],
|
struct nf_conntrack_helper *helper)
|
{
|
struct nf_conntrack_expect_policy *new_policy;
|
struct nf_conntrack_expect_policy *policy;
|
int i, ret = 0;
|
|
new_policy = kmalloc_array(helper->expect_class_max + 1,
|
sizeof(*new_policy), GFP_KERNEL);
|
if (!new_policy)
|
return -ENOMEM;
|
|
/* Check first that all policy attributes are well-formed, so we don't
|
* leave things in inconsistent state on errors.
|
*/
|
for (i = 0; i < helper->expect_class_max + 1; i++) {
|
|
if (!tb[NFCTH_POLICY_SET + i]) {
|
ret = -EINVAL;
|
goto err;
|
}
|
|
ret = nfnl_cthelper_update_policy_one(&helper->expect_policy[i],
|
&new_policy[i],
|
tb[NFCTH_POLICY_SET + i]);
|
if (ret < 0)
|
goto err;
|
}
|
/* Now we can safely update them. */
|
for (i = 0; i < helper->expect_class_max + 1; i++) {
|
policy = (struct nf_conntrack_expect_policy *)
|
&helper->expect_policy[i];
|
policy->max_expected = new_policy->max_expected;
|
policy->timeout = new_policy->timeout;
|
}
|
|
err:
|
kfree(new_policy);
|
return ret;
|
}
|
|
static int nfnl_cthelper_update_policy(struct nf_conntrack_helper *helper,
|
const struct nlattr *attr)
|
{
|
struct nlattr *tb[NFCTH_POLICY_SET_MAX + 1];
|
unsigned int class_max;
|
int err;
|
|
err = nla_parse_nested_deprecated(tb, NFCTH_POLICY_SET_MAX, attr,
|
nfnl_cthelper_expect_policy_set,
|
NULL);
|
if (err < 0)
|
return err;
|
|
if (!tb[NFCTH_POLICY_SET_NUM])
|
return -EINVAL;
|
|
class_max = ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
|
if (helper->expect_class_max + 1 != class_max)
|
return -EBUSY;
|
|
return nfnl_cthelper_update_policy_all(tb, helper);
|
}
|
|
static int
|
nfnl_cthelper_update(const struct nlattr * const tb[],
|
struct nf_conntrack_helper *helper)
|
{
|
u32 size;
|
int ret;
|
|
if (tb[NFCTH_PRIV_DATA_LEN]) {
|
size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
|
if (size != helper->data_len)
|
return -EBUSY;
|
}
|
|
if (tb[NFCTH_POLICY]) {
|
ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]);
|
if (ret < 0)
|
return ret;
|
}
|
if (tb[NFCTH_QUEUE_NUM])
|
helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
|
|
if (tb[NFCTH_STATUS]) {
|
int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
|
|
switch(status) {
|
case NFCT_HELPER_STATUS_ENABLED:
|
helper->flags |= NF_CT_HELPER_F_CONFIGURED;
|
break;
|
case NFCT_HELPER_STATUS_DISABLED:
|
helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
|
break;
|
}
|
}
|
return 0;
|
}
|
|
static int nfnl_cthelper_new(struct net *net, struct sock *nfnl,
|
struct sk_buff *skb, const struct nlmsghdr *nlh,
|
const struct nlattr * const tb[],
|
struct netlink_ext_ack *extack)
|
{
|
const char *helper_name;
|
struct nf_conntrack_helper *cur, *helper = NULL;
|
struct nf_conntrack_tuple tuple;
|
struct nfnl_cthelper *nlcth;
|
int ret = 0;
|
|
if (!capable(CAP_NET_ADMIN))
|
return -EPERM;
|
|
if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
|
return -EINVAL;
|
|
helper_name = nla_data(tb[NFCTH_NAME]);
|
|
ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
|
if (ret < 0)
|
return ret;
|
|
list_for_each_entry(nlcth, &nfnl_cthelper_list, list) {
|
cur = &nlcth->helper;
|
|
if (strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
|
continue;
|
|
if ((tuple.src.l3num != cur->tuple.src.l3num ||
|
tuple.dst.protonum != cur->tuple.dst.protonum))
|
continue;
|
|
if (nlh->nlmsg_flags & NLM_F_EXCL)
|
return -EEXIST;
|
|
helper = cur;
|
break;
|
}
|
|
if (helper == NULL)
|
ret = nfnl_cthelper_create(tb, &tuple);
|
else
|
ret = nfnl_cthelper_update(tb, helper);
|
|
return ret;
|
}
|
|
static int
|
nfnl_cthelper_dump_tuple(struct sk_buff *skb,
|
struct nf_conntrack_helper *helper)
|
{
|
struct nlattr *nest_parms;
|
|
nest_parms = nla_nest_start(skb, NFCTH_TUPLE);
|
if (nest_parms == NULL)
|
goto nla_put_failure;
|
|
if (nla_put_be16(skb, NFCTH_TUPLE_L3PROTONUM,
|
htons(helper->tuple.src.l3num)))
|
goto nla_put_failure;
|
|
if (nla_put_u8(skb, NFCTH_TUPLE_L4PROTONUM, helper->tuple.dst.protonum))
|
goto nla_put_failure;
|
|
nla_nest_end(skb, nest_parms);
|
return 0;
|
|
nla_put_failure:
|
return -1;
|
}
|
|
static int
|
nfnl_cthelper_dump_policy(struct sk_buff *skb,
|
struct nf_conntrack_helper *helper)
|
{
|
int i;
|
struct nlattr *nest_parms1, *nest_parms2;
|
|
nest_parms1 = nla_nest_start(skb, NFCTH_POLICY);
|
if (nest_parms1 == NULL)
|
goto nla_put_failure;
|
|
if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
|
htonl(helper->expect_class_max + 1)))
|
goto nla_put_failure;
|
|
for (i = 0; i < helper->expect_class_max + 1; i++) {
|
nest_parms2 = nla_nest_start(skb, (NFCTH_POLICY_SET + i));
|
if (nest_parms2 == NULL)
|
goto nla_put_failure;
|
|
if (nla_put_string(skb, NFCTH_POLICY_NAME,
|
helper->expect_policy[i].name))
|
goto nla_put_failure;
|
|
if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_MAX,
|
htonl(helper->expect_policy[i].max_expected)))
|
goto nla_put_failure;
|
|
if (nla_put_be32(skb, NFCTH_POLICY_EXPECT_TIMEOUT,
|
htonl(helper->expect_policy[i].timeout)))
|
goto nla_put_failure;
|
|
nla_nest_end(skb, nest_parms2);
|
}
|
nla_nest_end(skb, nest_parms1);
|
return 0;
|
|
nla_put_failure:
|
return -1;
|
}
|
|
static int
|
nfnl_cthelper_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
|
int event, struct nf_conntrack_helper *helper)
|
{
|
struct nlmsghdr *nlh;
|
unsigned int flags = portid ? NLM_F_MULTI : 0;
|
int status;
|
|
event = nfnl_msg_type(NFNL_SUBSYS_CTHELPER, 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, NFCTH_NAME, helper->name))
|
goto nla_put_failure;
|
|
if (nla_put_be32(skb, NFCTH_QUEUE_NUM, htonl(helper->queue_num)))
|
goto nla_put_failure;
|
|
if (nfnl_cthelper_dump_tuple(skb, helper) < 0)
|
goto nla_put_failure;
|
|
if (nfnl_cthelper_dump_policy(skb, helper) < 0)
|
goto nla_put_failure;
|
|
if (nla_put_be32(skb, NFCTH_PRIV_DATA_LEN, htonl(helper->data_len)))
|
goto nla_put_failure;
|
|
if (helper->flags & NF_CT_HELPER_F_CONFIGURED)
|
status = NFCT_HELPER_STATUS_ENABLED;
|
else
|
status = NFCT_HELPER_STATUS_DISABLED;
|
|
if (nla_put_be32(skb, NFCTH_STATUS, htonl(status)))
|
goto nla_put_failure;
|
|
nlmsg_end(skb, nlh);
|
return skb->len;
|
|
nlmsg_failure:
|
nla_put_failure:
|
nlmsg_cancel(skb, nlh);
|
return -1;
|
}
|
|
static int
|
nfnl_cthelper_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
|
{
|
struct nf_conntrack_helper *cur, *last;
|
|
rcu_read_lock();
|
last = (struct nf_conntrack_helper *)cb->args[1];
|
for (; cb->args[0] < nf_ct_helper_hsize; cb->args[0]++) {
|
restart:
|
hlist_for_each_entry_rcu(cur,
|
&nf_ct_helper_hash[cb->args[0]], hnode) {
|
|
/* skip non-userspace conntrack helpers. */
|
if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
|
continue;
|
|
if (cb->args[1]) {
|
if (cur != last)
|
continue;
|
cb->args[1] = 0;
|
}
|
if (nfnl_cthelper_fill_info(skb,
|
NETLINK_CB(cb->skb).portid,
|
cb->nlh->nlmsg_seq,
|
NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
|
NFNL_MSG_CTHELPER_NEW, cur) < 0) {
|
cb->args[1] = (unsigned long)cur;
|
goto out;
|
}
|
}
|
}
|
if (cb->args[1]) {
|
cb->args[1] = 0;
|
goto restart;
|
}
|
out:
|
rcu_read_unlock();
|
return skb->len;
|
}
|
|
static int nfnl_cthelper_get(struct net *net, struct sock *nfnl,
|
struct sk_buff *skb, const struct nlmsghdr *nlh,
|
const struct nlattr * const tb[],
|
struct netlink_ext_ack *extack)
|
{
|
int ret = -ENOENT;
|
struct nf_conntrack_helper *cur;
|
struct sk_buff *skb2;
|
char *helper_name = NULL;
|
struct nf_conntrack_tuple tuple;
|
struct nfnl_cthelper *nlcth;
|
bool tuple_set = false;
|
|
if (!capable(CAP_NET_ADMIN))
|
return -EPERM;
|
|
if (nlh->nlmsg_flags & NLM_F_DUMP) {
|
struct netlink_dump_control c = {
|
.dump = nfnl_cthelper_dump_table,
|
};
|
return netlink_dump_start(nfnl, skb, nlh, &c);
|
}
|
|
if (tb[NFCTH_NAME])
|
helper_name = nla_data(tb[NFCTH_NAME]);
|
|
if (tb[NFCTH_TUPLE]) {
|
ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
|
if (ret < 0)
|
return ret;
|
|
tuple_set = true;
|
}
|
|
list_for_each_entry(nlcth, &nfnl_cthelper_list, list) {
|
cur = &nlcth->helper;
|
if (helper_name &&
|
strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
|
continue;
|
|
if (tuple_set &&
|
(tuple.src.l3num != cur->tuple.src.l3num ||
|
tuple.dst.protonum != cur->tuple.dst.protonum))
|
continue;
|
|
skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
|
if (skb2 == NULL) {
|
ret = -ENOMEM;
|
break;
|
}
|
|
ret = nfnl_cthelper_fill_info(skb2, NETLINK_CB(skb).portid,
|
nlh->nlmsg_seq,
|
NFNL_MSG_TYPE(nlh->nlmsg_type),
|
NFNL_MSG_CTHELPER_NEW, cur);
|
if (ret <= 0) {
|
kfree_skb(skb2);
|
break;
|
}
|
|
ret = netlink_unicast(nfnl, 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;
|
}
|
|
static int nfnl_cthelper_del(struct net *net, struct sock *nfnl,
|
struct sk_buff *skb, const struct nlmsghdr *nlh,
|
const struct nlattr * const tb[],
|
struct netlink_ext_ack *extack)
|
{
|
char *helper_name = NULL;
|
struct nf_conntrack_helper *cur;
|
struct nf_conntrack_tuple tuple;
|
bool tuple_set = false, found = false;
|
struct nfnl_cthelper *nlcth, *n;
|
int j = 0, ret;
|
|
if (!capable(CAP_NET_ADMIN))
|
return -EPERM;
|
|
if (tb[NFCTH_NAME])
|
helper_name = nla_data(tb[NFCTH_NAME]);
|
|
if (tb[NFCTH_TUPLE]) {
|
ret = nfnl_cthelper_parse_tuple(&tuple, tb[NFCTH_TUPLE]);
|
if (ret < 0)
|
return ret;
|
|
tuple_set = true;
|
}
|
|
ret = -ENOENT;
|
list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) {
|
cur = &nlcth->helper;
|
j++;
|
|
if (helper_name &&
|
strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
|
continue;
|
|
if (tuple_set &&
|
(tuple.src.l3num != cur->tuple.src.l3num ||
|
tuple.dst.protonum != cur->tuple.dst.protonum))
|
continue;
|
|
if (refcount_dec_if_one(&cur->refcnt)) {
|
found = true;
|
nf_conntrack_helper_unregister(cur);
|
kfree(cur->expect_policy);
|
|
list_del(&nlcth->list);
|
kfree(nlcth);
|
} else {
|
ret = -EBUSY;
|
}
|
}
|
|
/* Make sure we return success if we flush and there is no helpers */
|
return (found || j == 0) ? 0 : ret;
|
}
|
|
static const struct nla_policy nfnl_cthelper_policy[NFCTH_MAX+1] = {
|
[NFCTH_NAME] = { .type = NLA_NUL_STRING,
|
.len = NF_CT_HELPER_NAME_LEN-1 },
|
[NFCTH_QUEUE_NUM] = { .type = NLA_U32, },
|
[NFCTH_PRIV_DATA_LEN] = { .type = NLA_U32, },
|
[NFCTH_STATUS] = { .type = NLA_U32, },
|
};
|
|
static const struct nfnl_callback nfnl_cthelper_cb[NFNL_MSG_CTHELPER_MAX] = {
|
[NFNL_MSG_CTHELPER_NEW] = { .call = nfnl_cthelper_new,
|
.attr_count = NFCTH_MAX,
|
.policy = nfnl_cthelper_policy },
|
[NFNL_MSG_CTHELPER_GET] = { .call = nfnl_cthelper_get,
|
.attr_count = NFCTH_MAX,
|
.policy = nfnl_cthelper_policy },
|
[NFNL_MSG_CTHELPER_DEL] = { .call = nfnl_cthelper_del,
|
.attr_count = NFCTH_MAX,
|
.policy = nfnl_cthelper_policy },
|
};
|
|
static const struct nfnetlink_subsystem nfnl_cthelper_subsys = {
|
.name = "cthelper",
|
.subsys_id = NFNL_SUBSYS_CTHELPER,
|
.cb_count = NFNL_MSG_CTHELPER_MAX,
|
.cb = nfnl_cthelper_cb,
|
};
|
|
MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTHELPER);
|
|
static int __init nfnl_cthelper_init(void)
|
{
|
int ret;
|
|
ret = nfnetlink_subsys_register(&nfnl_cthelper_subsys);
|
if (ret < 0) {
|
pr_err("nfnl_cthelper: cannot register with nfnetlink.\n");
|
goto err_out;
|
}
|
return 0;
|
err_out:
|
return ret;
|
}
|
|
static void __exit nfnl_cthelper_exit(void)
|
{
|
struct nf_conntrack_helper *cur;
|
struct nfnl_cthelper *nlcth, *n;
|
|
nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
|
|
list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) {
|
cur = &nlcth->helper;
|
|
nf_conntrack_helper_unregister(cur);
|
kfree(cur->expect_policy);
|
kfree(nlcth);
|
}
|
}
|
|
module_init(nfnl_cthelper_init);
|
module_exit(nfnl_cthelper_exit);
|
