[NETNS][FRAGS]: Make the inet_frag_queue lookup work in namespaces.

Since fragment management code is consolidated, we cannot have the
pointer from inet_frag_queue to struct net, since we must know what
king of fragment this is.

So, I introduce the netns_frags structure. This one is currently
empty, but will be eventually filled with per-namespace
attributes. Each inet_frag_queue is tagged with this one.

The conntrack_reasm is not "netns-izated", so it has one static
netns_frags instance to keep working in init namespace.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 20 insertions, 15 deletions

diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
index 7379107..158c5f6 100644
--- a/net/ipv4/inet_fragment.c
+++ b/net/ipv4/inet_fragment.c
@@ -174,8 +174,9 @@ int inet_frag_evictor(struct inet_frags *f)
 }
 EXPORT_SYMBOL(inet_frag_evictor);
 
-static struct inet_frag_queue *inet_frag_intern(struct inet_frag_queue *qp_in,
-		struct inet_frags *f, unsigned int hash, void *arg)
+static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
+		struct inet_frag_queue *qp_in, struct inet_frags *f,
+		unsigned int hash, void *arg)
 {
 	struct inet_frag_queue *qp;
 #ifdef CONFIG_SMP
@@ -189,7 +190,7 @@ static struct inet_frag_queue *inet_frag_intern(struct inet_frag_queue *qp_in,
 	 * promoted read lock to write lock.
 	 */
 	hlist_for_each_entry(qp, n, &f->hash[hash], list) {
-		if (f->match(qp, arg)) {
+		if (qp->net == nf && f->match(qp, arg)) {
 			atomic_inc(&qp->refcnt);
 			write_unlock(&f->lock);
 			qp_in->last_in |= COMPLETE;
@@ -210,7 +211,8 @@ static struct inet_frag_queue *inet_frag_intern(struct inet_frag_queue *qp_in,
 	return qp;
 }
 
-static struct inet_frag_queue *inet_frag_alloc(struct inet_frags *f, void *arg)
+static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
+		struct inet_frags *f, void *arg)
 {
 	struct inet_frag_queue *q;
 
@@ -223,31 +225,32 @@ static struct inet_frag_queue *inet_frag_alloc(struct inet_frags *f, void *arg)
 	setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
 	spin_lock_init(&q->lock);
 	atomic_set(&q->refcnt, 1);
+	q->net = nf;
 
 	return q;
 }
 
-static struct inet_frag_queue *inet_frag_create(struct inet_frags *f,
-		void *arg, unsigned int hash)
+static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
+		struct inet_frags *f, void *arg, unsigned int hash)
 {
 	struct inet_frag_queue *q;
 
-	q = inet_frag_alloc(f, arg);
+	q = inet_frag_alloc(nf, f, arg);
 	if (q == NULL)
 		return NULL;
 
-	return inet_frag_intern(q, f, hash, arg);
+	return inet_frag_intern(nf, q, f, hash, arg);
 }
 
-struct inet_frag_queue *inet_frag_find(struct inet_frags *f, void *key,
-		unsigned int hash)
+struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
+		struct inet_frags *f, void *key, unsigned int hash)
 {
 	struct inet_frag_queue *q;
 	struct hlist_node *n;
 
 	read_lock(&f->lock);
 	hlist_for_each_entry(q, n, &f->hash[hash], list) {
-		if (f->match(q, key)) {
+		if (q->net == nf && f->match(q, key)) {
 			atomic_inc(&q->refcnt);
 			read_unlock(&f->lock);
 			return q;
@@ -255,6 +258,6 @@ struct inet_frag_queue *inet_frag_find(struct inet_frags *f, void *key,
 	}
 	read_unlock(&f->lock);
 
-	return inet_frag_create(f, key, hash);
+	return inet_frag_create(nf, f, key, hash);
 }
 EXPORT_SYMBOL(inet_frag_find);
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index a53463e..56211ef 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -236,7 +236,7 @@ out:
 /* Find the correct entry in the "incomplete datagrams" queue for
  * this IP datagram, and create new one, if nothing is found.
  */
-static inline struct ipq *ip_find(struct iphdr *iph, u32 user)
+static inline struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user)
 {
 	struct inet_frag_queue *q;
 	struct ip4_create_arg arg;
@@ -246,7 +246,7 @@ static inline struct ipq *ip_find(struct iphdr *iph, u32 user)
 	arg.user = user;
 	hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
 
-	q = inet_frag_find(&ip4_frags, &arg, hash);
+	q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash);
 	if (q == NULL)
 		goto out_nomem;
 
@@ -582,15 +582,17 @@ out_fail:
 int ip_defrag(struct sk_buff *skb, u32 user)
 {
 	struct ipq *qp;
+	struct net *net;
 
 	IP_INC_STATS_BH(IPSTATS_MIB_REASMREQDS);
 
+	net = skb->dev->nd_net;
 	/* Start by cleaning up the memory. */
 	if (atomic_read(&ip4_frags.mem) > ip4_frags_ctl.high_thresh)
 		ip_evictor();
 
 	/* Lookup (or create) queue header */
-	if ((qp = ip_find(ip_hdr(skb), user)) != NULL) {
+	if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
 		int ret;
 
 		spin_lock(&qp->q.lock);