Patchwork [1/3] netfilter: ctnetlink: attach expectations to unconfirmed conntracks

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Submitter Pablo Neira
Date May 23, 2013, 8:42 a.m.
Message ID <1369298557-5351-1-git-send-email-pablo@netfilter.org>
Download mbox | patch
Permalink /patch/245842/
State Superseded
Delegated to: Pablo Neira
Headers show

Comments

Pablo Neira - May 23, 2013, 8:42 a.m.
This patch adds the capability to attach expectations to unconfirmed
conntrack entries. This patch is required by the DHCPv6 helper in
user-space.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/netfilter/nf_conntrack.h               |    4 ++++
 include/uapi/linux/netfilter/nfnetlink_conntrack.h |    1 +
 net/netfilter/nf_conntrack_core.c                  |   20 ++++++++++++++++++++
 net/netfilter/nf_conntrack_netlink.c               |   14 ++++++++++++--
 4 files changed, 37 insertions(+), 2 deletions(-)
Gao feng - May 23, 2013, 9:34 a.m.
On 05/23/2013 04:42 PM, Pablo Neira Ayuso wrote:
> This patch adds the capability to attach expectations to unconfirmed
> conntrack entries. This patch is required by the DHCPv6 helper in
> user-space.
> 
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> ---
>  include/net/netfilter/nf_conntrack.h               |    4 ++++
>  include/uapi/linux/netfilter/nfnetlink_conntrack.h |    1 +
>  net/netfilter/nf_conntrack_core.c                  |   20 ++++++++++++++++++++
>  net/netfilter/nf_conntrack_netlink.c               |   14 ++++++++++++--
>  4 files changed, 37 insertions(+), 2 deletions(-)
> 
> diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
> index 644d9c2..d172fc5 100644
> --- a/include/net/netfilter/nf_conntrack.h
> +++ b/include/net/netfilter/nf_conntrack.h
> @@ -180,6 +180,10 @@ extern struct nf_conntrack_tuple_hash *
>  __nf_conntrack_find(struct net *net, u16 zone,
>  		    const struct nf_conntrack_tuple *tuple);
>  
> +struct nf_conntrack_tuple_hash *
> +nf_ct_unconfirmed_find(struct net *net, u16 zone,
> +		       const struct nf_conntrack_tuple *tuple);
> +
>  extern int nf_conntrack_hash_check_insert(struct nf_conn *ct);
>  extern void nf_ct_delete_from_lists(struct nf_conn *ct);
>  extern void nf_ct_dying_timeout(struct nf_conn *ct);
> diff --git a/include/uapi/linux/netfilter/nfnetlink_conntrack.h b/include/uapi/linux/netfilter/nfnetlink_conntrack.h
> index 08fabc6..8f7c2fe 100644
> --- a/include/uapi/linux/netfilter/nfnetlink_conntrack.h
> +++ b/include/uapi/linux/netfilter/nfnetlink_conntrack.h
> @@ -187,6 +187,7 @@ enum ctattr_expect {
>  	CTA_EXPECT_CLASS,
>  	CTA_EXPECT_NAT,
>  	CTA_EXPECT_FN,
> +	CTA_EXPECT_MASTER_STATUS,
>  	__CTA_EXPECT_MAX
>  };
>  #define CTA_EXPECT_MAX (__CTA_EXPECT_MAX - 1)
> diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
> index ebb81d6..a6e5764 100644
> --- a/net/netfilter/nf_conntrack_core.c
> +++ b/net/netfilter/nf_conntrack_core.c
> @@ -401,6 +401,26 @@ nf_conntrack_find_get(struct net *net, u16 zone,
>  }
>  EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
>  
> +struct nf_conntrack_tuple_hash *
> +nf_ct_unconfirmed_find(struct net *net, u16 zone,
> +		       const struct nf_conntrack_tuple *tuple)
> +{
> +	struct nf_conntrack_tuple_hash *h, *ret = NULL;
> +	struct hlist_nulls_node *n;
> +
> +	rcu_read_lock();
> +	hlist_nulls_for_each_entry_rcu(h, n, &net->ct.unconfirmed, hnnode) {
> +		if (nf_ct_tuple_equal(tuple, &h->tuple) &&
> +		    nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) {
> +			ret = h;

Shouldn't we get reference of nf_ct_tuplehash_to_ctrack(h) here?
ctnetlink_create_expect will call nf_ct_put to release the reference finally.

or I miss something?

> +			break;
> +		}
> +	}
> +	rcu_read_unlock();
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(nf_ct_unconfirmed_find);
> +
>  static void __nf_conntrack_hash_insert(struct nf_conn *ct,
>  				       unsigned int hash,
>  				       unsigned int repl_hash)
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index 6d0f8a1..3596682 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -2742,7 +2742,7 @@ ctnetlink_create_expect(struct net *net, u16 zone,
>  	struct nf_conn *ct;
>  	struct nf_conn_help *help;
>  	struct nf_conntrack_helper *helper = NULL;
> -	u_int32_t class = 0;
> +	u_int32_t class = 0, master_status;
>  	int err = 0;
>  
>  	/* caller guarantees that those three CTA_EXPECT_* exist */
> @@ -2756,8 +2756,18 @@ ctnetlink_create_expect(struct net *net, u16 zone,
>  	if (err < 0)
>  		return err;
>  
> +	if (cda[CTA_EXPECT_MASTER_STATUS]) {
> +		master_status =
> +			ntohl(nla_get_be32(cda[CTA_EXPECT_MASTER_STATUS]));
> +	} else
> +		master_status = IPS_CONFIRMED;
> +
>  	/* Look for master conntrack of this expectation */
> -	h = nf_conntrack_find_get(net, zone, &master_tuple);
> +	if (master_status & IPS_CONFIRMED)
> +		h = nf_conntrack_find_get(net, zone, &master_tuple);
> +	else
> +		h = nf_ct_unconfirmed_find(net, zone, &master_tuple);
> +
>  	if (!h)
>  		return -ENOENT;
>  	ct = nf_ct_tuplehash_to_ctrack(h);
> 

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Patch

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 644d9c2..d172fc5 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -180,6 +180,10 @@  extern struct nf_conntrack_tuple_hash *
 __nf_conntrack_find(struct net *net, u16 zone,
 		    const struct nf_conntrack_tuple *tuple);
 
+struct nf_conntrack_tuple_hash *
+nf_ct_unconfirmed_find(struct net *net, u16 zone,
+		       const struct nf_conntrack_tuple *tuple);
+
 extern int nf_conntrack_hash_check_insert(struct nf_conn *ct);
 extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 extern void nf_ct_dying_timeout(struct nf_conn *ct);
diff --git a/include/uapi/linux/netfilter/nfnetlink_conntrack.h b/include/uapi/linux/netfilter/nfnetlink_conntrack.h
index 08fabc6..8f7c2fe 100644
--- a/include/uapi/linux/netfilter/nfnetlink_conntrack.h
+++ b/include/uapi/linux/netfilter/nfnetlink_conntrack.h
@@ -187,6 +187,7 @@  enum ctattr_expect {
 	CTA_EXPECT_CLASS,
 	CTA_EXPECT_NAT,
 	CTA_EXPECT_FN,
+	CTA_EXPECT_MASTER_STATUS,
 	__CTA_EXPECT_MAX
 };
 #define CTA_EXPECT_MAX (__CTA_EXPECT_MAX - 1)
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index ebb81d6..a6e5764 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -401,6 +401,26 @@  nf_conntrack_find_get(struct net *net, u16 zone,
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 
+struct nf_conntrack_tuple_hash *
+nf_ct_unconfirmed_find(struct net *net, u16 zone,
+		       const struct nf_conntrack_tuple *tuple)
+{
+	struct nf_conntrack_tuple_hash *h, *ret = NULL;
+	struct hlist_nulls_node *n;
+
+	rcu_read_lock();
+	hlist_nulls_for_each_entry_rcu(h, n, &net->ct.unconfirmed, hnnode) {
+		if (nf_ct_tuple_equal(tuple, &h->tuple) &&
+		    nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)) == zone) {
+			ret = h;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nf_ct_unconfirmed_find);
+
 static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 				       unsigned int hash,
 				       unsigned int repl_hash)
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 6d0f8a1..3596682 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -2742,7 +2742,7 @@  ctnetlink_create_expect(struct net *net, u16 zone,
 	struct nf_conn *ct;
 	struct nf_conn_help *help;
 	struct nf_conntrack_helper *helper = NULL;
-	u_int32_t class = 0;
+	u_int32_t class = 0, master_status;
 	int err = 0;
 
 	/* caller guarantees that those three CTA_EXPECT_* exist */
@@ -2756,8 +2756,18 @@  ctnetlink_create_expect(struct net *net, u16 zone,
 	if (err < 0)
 		return err;
 
+	if (cda[CTA_EXPECT_MASTER_STATUS]) {
+		master_status =
+			ntohl(nla_get_be32(cda[CTA_EXPECT_MASTER_STATUS]));
+	} else
+		master_status = IPS_CONFIRMED;
+
 	/* Look for master conntrack of this expectation */
-	h = nf_conntrack_find_get(net, zone, &master_tuple);
+	if (master_status & IPS_CONFIRMED)
+		h = nf_conntrack_find_get(net, zone, &master_tuple);
+	else
+		h = nf_ct_unconfirmed_find(net, zone, &master_tuple);
+
 	if (!h)
 		return -ENOENT;
 	ct = nf_ct_tuplehash_to_ctrack(h);