netfilter: ctnetlink: add expectation deletion events

This patch allows to listen to events that inform about
expectations destroyed.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/linux/netfilter/nf_conntrack_common.h b/include/linux/netfilter/nf_conntrack_common.h
index 23a1a08..50cdc25 100644 (file)
--- a/include/linux/netfilter/nf_conntrack_common.h
+++ b/include/linux/netfilter/nf_conntrack_common.h
@@ -98,6 +98,7 @@ enum ip_conntrack_events {
 
 enum ip_conntrack_expect_events {
        IPEXP_NEW,              /* new expectation */
+       IPEXP_DESTROY,          /* destroyed expectation */
 };
 
 /* expectation flags */

diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index 416b838..0f8a8c5 100644 (file)
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -82,7 +82,13 @@ struct nf_conntrack_expect *
 nf_ct_find_expectation(struct net *net, u16 zone,
                       const struct nf_conntrack_tuple *tuple);
 
-void nf_ct_unlink_expect(struct nf_conntrack_expect *exp);
+void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
+                               u32 pid, int report);
+static inline void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
+{
+       nf_ct_unlink_expect_report(exp, 0, 0);
+}
+
 void nf_ct_remove_expectations(struct nf_conn *ct);
 void nf_ct_unexpect_related(struct nf_conntrack_expect *exp);
 void nf_ct_remove_userspace_expectations(void);

diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index b30a1f2..46e8966 100644 (file)
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -41,7 +41,8 @@ static struct kmem_cache *nf_ct_expect_cachep __read_mostly;
 static HLIST_HEAD(nf_ct_userspace_expect_list);
 
 /* nf_conntrack_expect helper functions */
-void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
+void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
+                               u32 pid, int report)
 {
        struct nf_conn_help *master_help = nfct_help(exp->master);
        struct net *net = nf_ct_exp_net(exp);
@@ -55,11 +56,12 @@ void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
        if (!(exp->flags & NF_CT_EXPECT_USERSPACE))
                master_help->expecting[exp->class]--;
 
+       nf_ct_expect_event_report(IPEXP_DESTROY, exp, pid, report);
        nf_ct_expect_put(exp);
 
        NF_CT_STAT_INC(net, expect_delete);
 }
-EXPORT_SYMBOL_GPL(nf_ct_unlink_expect);
+EXPORT_SYMBOL_GPL(nf_ct_unlink_expect_report);
 
 static void nf_ct_expectation_timed_out(unsigned long ul_expect)
 {

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index b4077be..62bad22 100644 (file)
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1632,17 +1632,20 @@ ctnetlink_expect_event(unsigned int events, struct nf_exp_event *item)
        struct nlmsghdr *nlh;
        struct nfgenmsg *nfmsg;
        struct sk_buff *skb;
-       unsigned int type;
+       unsigned int type, group;
        int flags = 0;
 
-       if (events & (1 << IPEXP_NEW)) {
+       if (events & (1 << IPEXP_DESTROY)) {
+               type = IPCTNL_MSG_EXP_DELETE;
+               group = NFNLGRP_CONNTRACK_EXP_DESTROY;
+       } else if (events & (1 << IPEXP_NEW)) {
                type = IPCTNL_MSG_EXP_NEW;
                flags = NLM_F_CREATE|NLM_F_EXCL;
+               group = NFNLGRP_CONNTRACK_EXP_NEW;
        } else
                return 0;
 
-       if (!item->report &&
-           !nfnetlink_has_listeners(net, NFNLGRP_CONNTRACK_EXP_NEW))
+       if (!item->report && !nfnetlink_has_listeners(net, group))
                return 0;
 
        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
@@ -1665,8 +1668,7 @@ ctnetlink_expect_event(unsigned int events, struct nf_exp_event *item)
        rcu_read_unlock();
 
        nlmsg_end(skb, nlh);
-       nfnetlink_send(skb, net, item->pid, NFNLGRP_CONNTRACK_EXP_NEW,
-                      item->report, GFP_ATOMIC);
+       nfnetlink_send(skb, net, item->pid, group, item->report, GFP_ATOMIC);
        return 0;
 
 nla_put_failure:
@@ -1849,7 +1851,13 @@ ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
                }
 
                /* after list removal, usage count == 1 */
-               nf_ct_unexpect_related(exp);
+               spin_lock_bh(&nf_conntrack_lock);
+               if (del_timer(&exp->timeout)) {
+                       nf_ct_unlink_expect_report(exp, NETLINK_CB(skb).pid,
+                                                  nlmsg_report(nlh));
+                       nf_ct_expect_put(exp);
+               }
+               spin_unlock_bh(&nf_conntrack_lock);
                /* have to put what we 'get' above.
                 * after this line usage count == 0 */
                nf_ct_expect_put(exp);
@@ -1866,7 +1874,9 @@ ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
                                m_help = nfct_help(exp->master);
                                if (!strcmp(m_help->helper->name, name) &&
                                    del_timer(&exp->timeout)) {
-                                       nf_ct_unlink_expect(exp);
+                                       nf_ct_unlink_expect_report(exp,
+                                                       NETLINK_CB(skb).pid,
+                                                       nlmsg_report(nlh));
                                        nf_ct_expect_put(exp);
                                }
                        }
@@ -1880,7 +1890,9 @@ ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
                                                  &net->ct.expect_hash[i],
                                                  hnode) {
                                if (del_timer(&exp->timeout)) {
-                                       nf_ct_unlink_expect(exp);
+                                       nf_ct_unlink_expect_report(exp,
+                                                       NETLINK_CB(skb).pid,
+                                                       nlmsg_report(nlh));
                                        nf_ct_expect_put(exp);
                                }
                        }