Skip to contentSkip to conversation

send conntrack events on ctnetlink actions

PATCH In review Pablo Neira Ayuso 1 participant 1 message Jul 7, 2006

Subsystems (2)
lore
Share & tools
lore

Pablo Neira Ayuso

author maintainer
#0 lore raw

PATCH 7/10 send conntrack events on ctnetlink actions

Currently only conntrack events generated by the conntrack core are delivered to userspace via ctnetlink. This patch force the generation of event notifications on ctnetlink actions.

Example scenario: you have two process listening to ctnetlink and one of them creates/changes/destroy a conntrack upon certain events

Signature · 2 lines
The dawn of the fourth age of Linux firewalling is coming; a time of
great struggle and heroic deeds -- J.Kadlecsik got inspired by J.Morris

[CTNETLINK] send conntrack events on ctnetlink actions

Currently only conntrack events generated by the conntrack core are delivered to userspace via ctnetlink. This patch force the generation of event notifications on ctnetlink actions.

net/ipv4/netfilter/ip_conntrack_netlink.c +45 -19
Index: net-2.6/net/ipv4/netfilter/ip_conntrack_netlink.c
===================================================================
@@ -986,7 +986,9 @@ ctnetlink_change_protoinfo(struct ip_con
 }
 
 static int
-ctnetlink_change_conntrack(struct ip_conntrack *ct, struct nfattr *cda[])
+ctnetlink_change_conntrack(struct ip_conntrack *ct,
+			   struct nfattr *cda[],
+			   unsigned int *changeset)
 {
 	int err;
 
@@ -996,29 +998,35 @@ ctnetlink_change_conntrack(struct ip_con
 		err = ctnetlink_change_helper(ct, cda);
 		if (err < 0)
 			return err;
+		*changeset |= IPCT_HELPER;
 	}
 
 	if (cda[CTA_TIMEOUT-1]) {
 		err = ctnetlink_change_timeout(ct, cda);
 		if (err < 0)
 			return err;
+		*changeset |= IPCT_REFRESH;
 	}
 
 	if (cda[CTA_STATUS-1]) {
 		err = ctnetlink_change_status(ct, cda);
 		if (err < 0)
 			return err;
+		*changeset |= IPCT_STATUS;
 	}
 
 	if (cda[CTA_PROTOINFO-1]) {
 		err = ctnetlink_change_protoinfo(ct, cda);
 		if (err < 0)
 			return err;
+		*changeset |= IPCT_PROTOINFO;
 	}
 
 #if defined(CONFIG_IP_NF_CONNTRACK_MARK)
-	if (cda[CTA_MARK-1])
+	if (cda[CTA_MARK-1]) {
 		ct->mark = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_MARK-1]));
+		*changeset |= IPCT_MARK;
+	}
 #endif
 
 	DEBUGP("all done\n");
@@ -1032,6 +1040,7 @@ ctnetlink_create_conntrack(struct nfattr
 {
 	struct ip_conntrack *ct;
 	int err = -EINVAL;
+	unsigned int changeset = IPCT_NEW|IPCT_REFRESH|IPCT_STATUS;
 
 	DEBUGP("entered %s\n", __FUNCTION__);
 
@@ -1054,12 +1063,17 @@ ctnetlink_create_conntrack(struct nfattr
 		err = ctnetlink_change_protoinfo(ct, cda);
 		if (err < 0)
 			return err;
+		changeset |= IPCT_PROTOINFO;
 	}
 
 #if defined(CONFIG_IP_NF_CONNTRACK_MARK)
-	if (cda[CTA_MARK-1])
+	if (cda[CTA_MARK-1]) {
 		ct->mark = ntohl(*(u_int32_t *)NFA_DATA(cda[CTA_MARK-1]));
+		changeset |= IPCT_MARK;
+	}
 #endif
+	/* increase refcount to 2 for event notification */
+	atomic_inc(&ct->ct_general.use);
 
 	/* we do no want any races on hash insertion */
 	write_lock_bh(&ip_conntrack_lock);
@@ -1068,6 +1082,10 @@ ctnetlink_create_conntrack(struct nfattr
 	add_timer(&ct->timeout);
 	write_unlock_bh(&ip_conntrack_lock);
 
+	/* now, notify the creation of this conntrack */
+	ip_conntrack_event(changeset, ct);
+	ip_conntrack_put(ct);
+
 	DEBUGP("conntrack with id %u inserted\n", ct->id);
 	return 0;
 
@@ -1083,6 +1101,7 @@ ctnetlink_new_conntrack(struct sock *ctn
 	struct ip_conntrack_tuple otuple, rtuple;
 	struct ip_conntrack_tuple_hash *h = NULL;
 	int err = 0;
+	unsigned int changeset = 0;
 
 	DEBUGP("entered %s\n", __FUNCTION__);
 
@@ -1108,30 +1127,36 @@ ctnetlink_new_conntrack(struct sock *ctn
 		h = __ip_conntrack_find(&rtuple, NULL);
 
 	if (h == NULL) {
+		/* create new conntrack */
 		write_unlock_bh(&ip_conntrack_lock);
 		DEBUGP("no such conntrack, create new\n");
 		err = -ENOENT;
 		if (nlh->nlmsg_flags & NLM_F_CREATE)
 			err = ctnetlink_create_conntrack(cda, &otuple, &rtuple);
-		return err;
-	}
-	/* implicit 'else' */
+	} else {
+		/* update existing conntrack */
+		struct ip_conntrack *ct = tuplehash_to_ctrack(h);
 
-	/* we only allow nat config for new conntracks */
-	if (cda[CTA_NAT_SRC-1] || cda[CTA_NAT_DST-1]) {
-		err = -EINVAL;
-		goto out_unlock;
-	}
+		/* we only allow nat config for new conntracks */
+		if (cda[CTA_NAT_SRC-1] || cda[CTA_NAT_DST-1]) {
+			write_unlock_bh(&ip_conntrack_lock);
+			return -EINVAL;
+		}
 
-	/* We manipulate the conntrack inside the global conntrack table lock,
-	 * so there's no need to increase the refcount */
-	DEBUGP("conntrack found\n");
-	err = -EEXIST;
-	if (!(nlh->nlmsg_flags & NLM_F_EXCL))
-		err = ctnetlink_change_conntrack(tuplehash_to_ctrack(h), cda);
+		DEBUGP("conntrack found\n");
+		err = -EEXIST;
+		if (!(nlh->nlmsg_flags & NLM_F_EXCL))
+			err = ctnetlink_change_conntrack(ct, cda, &changeset);
 
-out_unlock:
-	write_unlock_bh(&ip_conntrack_lock);
+		atomic_inc(&ct->ct_general.use);
+		write_unlock_bh(&ip_conntrack_lock);
+
+		/* report update event if no error happened */
+		if (err >= 0)
+			ip_conntrack_event(changeset, ct);
+
+		ip_conntrack_put(ct);
+	}
 	return err;
 }
 
@@ -1523,6 +1548,7 @@ ctnetlink_create_expect(struct nfattr *c
 	memcpy(&exp->mask, &mask, sizeof(struct ip_conntrack_tuple));
 
 	err = ip_conntrack_expect_related(exp);
+	ip_conntrack_expect_event(IPEXP_NEW, exp);
 	ip_conntrack_expect_put(exp);
 
 out:	
net/ipv4/netfilter/ip_conntrack_core.c +1 -0
Index: net-2.6/net/ipv4/netfilter/ip_conntrack_core.c
===================================================================
@@ -1324,6 +1324,7 @@ static struct nf_sockopt_ops so_getorigd
 
 static int kill_all(struct ip_conntrack *i, void *data)
 {
+	ip_conntrack_event(IPCT_DESTROY, i);
 	return 1;
 }
 
net/netfilter/nf_conntrack_netlink.c +45 -20

149 lines not on this page · raw message

net/netfilter/nf_conntrack_core.c +1 -0
Index: net-2.6/net/netfilter/nf_conntrack_core.c
===================================================================
@@ -1525,6 +1525,7 @@ nf_ct_iterate_cleanup(int (*iter)(struct
 
 static int kill_all(struct nf_conn *i, void *data)
 {
+	nf_conntrack_event(IPCT_DESTROY, i);
 	return 1;
 }