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-rw-r--r--net/netfilter/nfnetlink_cthelper.c804
1 files changed, 804 insertions, 0 deletions
diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c
new file mode 100644
index 000000000..97248963a
--- /dev/null
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -0,0 +1,804 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * (C) 2012 Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * This software has been sponsored by Vyatta Inc. <http://www.vyatta.com>
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/capability.h>
+#include <net/netlink.h>
+#include <net/sock.h>
+
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+#include <linux/netfilter/nfnetlink_cthelper.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
+MODULE_DESCRIPTION("nfnl_cthelper: User-space connection tracking helpers");
+
+struct nfnl_cthelper {
+ 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);
+ const struct nf_conntrack_helper *helper;
+
+ if (attr == NULL)
+ return -EINVAL;
+
+ helper = rcu_dereference(help->helper);
+ if (!helper || 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);
+ const struct nf_conntrack_helper *helper;
+
+ helper = rcu_dereference(help->helper);
+ if (helper && helper->data_len &&
+ nla_put(skb, CTA_HELP_INFO, helper->data_len, &help->data))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -ENOSPC;
+}
+
+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 },
+ [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);
+ if (err < 0)
+ return err;
+
+ if (!tb[NFCTH_POLICY_NAME] ||
+ !tb[NFCTH_POLICY_EXPECT_MAX] ||
+ !tb[NFCTH_POLICY_EXPECT_TIMEOUT])
+ return -EINVAL;
+
+ nla_strscpy(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_strscpy(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;
+ helper->help = nfnl_userspace_cthelper;
+ 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;
+
+ 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 sk_buff *skb, const struct nfnl_info *info,
+ const struct nlattr * const tb[])
+{
+ 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 (info->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 sk_buff *skb, const struct nfnl_info *info,
+ const struct nlattr * const tb[])
+{
+ 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 (info->nlh->nlmsg_flags & NLM_F_DUMP) {
+ struct netlink_dump_control c = {
+ .dump = nfnl_cthelper_dump_table,
+ };
+ return netlink_dump_start(info->sk, skb, info->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,
+ info->nlh->nlmsg_seq,
+ NFNL_MSG_TYPE(info->nlh->nlmsg_type),
+ NFNL_MSG_CTHELPER_NEW, cur);
+ if (ret <= 0) {
+ kfree_skb(skb2);
+ break;
+ }
+
+ ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid);
+ break;
+ }
+
+ return ret;
+}
+
+static int nfnl_cthelper_del(struct sk_buff *skb, const struct nfnl_info *info,
+ const struct nlattr * const tb[])
+{
+ 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,
+ .type = NFNL_CB_MUTEX,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy
+ },
+ [NFNL_MSG_CTHELPER_GET] = {
+ .call = nfnl_cthelper_get,
+ .type = NFNL_CB_MUTEX,
+ .attr_count = NFCTH_MAX,
+ .policy = nfnl_cthelper_policy
+ },
+ [NFNL_MSG_CTHELPER_DEL] = {
+ .call = nfnl_cthelper_del,
+ .type = NFNL_CB_MUTEX,
+ .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);