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>

2 files changed, 25 insertions, 11 deletions

diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index b30a1f2aac00..46e8966912b1 100644
--- 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 b4077be5f663..62bad229106b 100644
--- 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);
                                 }
                         }