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)
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(tb, NFCTH_POLICY_SET_MAX, attr,
nfnl_cthelper_expect_policy_set);
if (!tb[NFCTH_POLICY_SET_NUM])
return -EINVAL;
- helper->expect_class_max =
- ntohl(nla_get_be32(tb[NFCTH_POLICY_SET_NUM]));
-
- if (helper->expect_class_max != 0 &&
- helper->expect_class_max > NF_CT_MAX_EXPECT_CLASSES)
+ 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 = kzalloc(sizeof(struct nf_conntrack_expect_policy) *
- helper->expect_class_max, GFP_KERNEL);
+ class_max, GFP_KERNEL);
if (expect_policy == NULL)
return -ENOMEM;
- for (i=0; i<helper->expect_class_max; i++) {
+ for (i = 0; i < class_max; i++) {
if (!tb[NFCTH_POLICY_SET+i])
goto err;
if (ret < 0)
goto err;
}
+
+ helper->expect_class_max = class_max - 1;
helper->expect_policy = expect_policy;
return 0;
err:
struct nf_conntrack_tuple *tuple)
{
struct nf_conntrack_helper *helper;
+ struct nfnl_cthelper *nfcth;
int ret;
if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
return -EINVAL;
- helper = kzalloc(sizeof(struct nf_conntrack_helper), GFP_KERNEL);
- if (helper == NULL)
+ 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 err;
+ goto err1;
strncpy(helper->name, nla_data(tb[NFCTH_NAME]), NF_CT_HELPER_NAME_LEN);
helper->data_len = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
ret = nf_conntrack_helper_register(helper);
if (ret < 0)
- goto err;
+ goto err2;
+ list_add_tail(&nfcth->list, &nfnl_cthelper_list);
return 0;
-err:
- kfree(helper);
+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(tb, NFCTH_POLICY_MAX, attr,
+ nfnl_cthelper_expect_pol);
+ 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]));
+ 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[helper->expect_class_max + 1];
+ struct nf_conntrack_expect_policy *policy;
+ int i, err;
+
+ /* 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])
+ return -EINVAL;
+
+ err = nfnl_cthelper_update_policy_one(&helper->expect_policy[i],
+ &new_policy[i],
+ tb[NFCTH_POLICY_SET + i]);
+ if (err < 0)
+ return 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;
+ }
+
+ return 0;
+}
+
+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(tb, NFCTH_POLICY_SET_MAX, attr,
+ nfnl_cthelper_expect_policy_set);
+ 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)
{
return -EBUSY;
if (tb[NFCTH_POLICY]) {
- ret = nfnl_cthelper_parse_expect_policy(helper,
- tb[NFCTH_POLICY]);
+ ret = nfnl_cthelper_update_policy(helper, tb[NFCTH_POLICY]);
if (ret < 0)
return ret;
}
const char *helper_name;
struct nf_conntrack_helper *cur, *helper = NULL;
struct nf_conntrack_tuple tuple;
- int ret = 0, i;
+ struct nfnl_cthelper *nlcth;
+ int ret = 0;
if (!tb[NFCTH_NAME] || !tb[NFCTH_TUPLE])
return -EINVAL;
if (ret < 0)
return ret;
- rcu_read_lock();
- for (i = 0; i < nf_ct_helper_hsize && !helper; i++) {
- hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) {
+ list_for_each_entry(nlcth, &nfnl_cthelper_list, list) {
+ cur = &nlcth->helper;
- /* skip non-userspace conntrack helpers. */
- if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
- continue;
+ if (strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
+ continue;
- if (strncmp(cur->name, helper_name,
- NF_CT_HELPER_NAME_LEN) != 0)
- continue;
+ if ((tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ 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;
- if (nlh->nlmsg_flags & NLM_F_EXCL) {
- ret = -EEXIST;
- goto err;
- }
- helper = cur;
- break;
- }
+ helper = cur;
+ break;
}
- rcu_read_unlock();
if (helper == NULL)
ret = nfnl_cthelper_create(tb, &tuple);
ret = nfnl_cthelper_update(tb, helper);
return ret;
-err:
- rcu_read_unlock();
- return ret;
}
static int
goto nla_put_failure;
if (nla_put_be32(skb, NFCTH_POLICY_SET_NUM,
- htonl(helper->expect_class_max)))
+ htonl(helper->expect_class_max + 1)))
goto nla_put_failure;
- for (i=0; i<helper->expect_class_max; i++) {
+ for (i = 0; i < helper->expect_class_max + 1; i++) {
nest_parms2 = nla_nest_start(skb,
(NFCTH_POLICY_SET+i) | NLA_F_NESTED);
if (nest_parms2 == NULL)
struct sk_buff *skb, const struct nlmsghdr *nlh,
const struct nlattr * const tb[])
{
- int ret = -ENOENT, i;
+ 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 (nlh->nlmsg_flags & NLM_F_DUMP) {
tuple_set = true;
}
- for (i = 0; i < nf_ct_helper_hsize; i++) {
- hlist_for_each_entry_rcu(cur, &nf_ct_helper_hash[i], hnode) {
+ 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;
- /* skip non-userspace conntrack helpers. */
- if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
- continue;
+ if (tuple_set &&
+ (tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
- if (helper_name && strncmp(cur->name, helper_name,
- NF_CT_HELPER_NAME_LEN) != 0) {
- 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;
- }
+ 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 = 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;
+ 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;
- }
+ /* this avoids a loop in nfnetlink. */
+ return ret == -EAGAIN ? -ENOBUFS : ret;
}
return ret;
}
{
char *helper_name = NULL;
struct nf_conntrack_helper *cur;
- struct hlist_node *tmp;
struct nf_conntrack_tuple tuple;
bool tuple_set = false, found = false;
- int i, j = 0, ret;
+ struct nfnl_cthelper *nlcth, *n;
+ int j = 0, ret;
if (tb[NFCTH_NAME])
helper_name = nla_data(tb[NFCTH_NAME]);
tuple_set = true;
}
- for (i = 0; i < nf_ct_helper_hsize; i++) {
- hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i],
- hnode) {
- /* skip non-userspace conntrack helpers. */
- if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
- continue;
+ list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) {
+ cur = &nlcth->helper;
+ j++;
- j++;
+ if (helper_name &&
+ strncmp(cur->name, helper_name, NF_CT_HELPER_NAME_LEN))
+ continue;
- if (helper_name && strncmp(cur->name, helper_name,
- NF_CT_HELPER_NAME_LEN) != 0) {
- continue;
- }
- if (tuple_set &&
- (tuple.src.l3num != cur->tuple.src.l3num ||
- tuple.dst.protonum != cur->tuple.dst.protonum))
- continue;
+ if (tuple_set &&
+ (tuple.src.l3num != cur->tuple.src.l3num ||
+ tuple.dst.protonum != cur->tuple.dst.protonum))
+ continue;
- found = true;
- nf_conntrack_helper_unregister(cur);
- }
+ found = true;
+ nf_conntrack_helper_unregister(cur);
+ kfree(cur->expect_policy);
+
+ list_del(&nlcth->list);
+ kfree(nlcth);
}
+
/* Make sure we return success if we flush and there is no helpers */
return (found || j == 0) ? 0 : -ENOENT;
}
static void __exit nfnl_cthelper_exit(void)
{
struct nf_conntrack_helper *cur;
- struct hlist_node *tmp;
- int i;
+ struct nfnl_cthelper *nlcth, *n;
nfnetlink_subsys_unregister(&nfnl_cthelper_subsys);
- for (i=0; i<nf_ct_helper_hsize; i++) {
- hlist_for_each_entry_safe(cur, tmp, &nf_ct_helper_hash[i],
- hnode) {
- /* skip non-userspace conntrack helpers. */
- if (!(cur->flags & NF_CT_HELPER_F_USERSPACE))
- continue;
+ list_for_each_entry_safe(nlcth, n, &nfnl_cthelper_list, list) {
+ cur = &nlcth->helper;
- nf_conntrack_helper_unregister(cur);
- }
+ nf_conntrack_helper_unregister(cur);
+ kfree(cur->expect_policy);
+ kfree(nlcth);
}
}
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