1 files changed, 86 insertions, 28 deletions

diff --git a/net/mctp/route.c b/net/mctp/route.c
index 35f72e99e188..17e3482aa770 100644
--- a/net/mctp/route.c
+++ b/net/mctp/route.c
@@ -203,29 +203,38 @@ static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk)
 	return rc;
 }
 
-/* We're done with the key; unset valid and remove from lists. There may still
- * be outstanding refs on the key though...
+/* Helper for mctp_route_input().
+ * We're done with the key; unlock and unref the key.
+ * For the usual case of automatic expiry we remove the key from lists.
+ * In the case that manual allocation is set on a key we release the lock
+ * and local ref, reset reassembly, but don't remove from lists.
  */
-static void __mctp_key_unlock_drop(struct mctp_sk_key *key, struct net *net,
-				   unsigned long flags)
-	__releases(&key->lock)
+static void __mctp_key_done_in(struct mctp_sk_key *key, struct net *net,
+			       unsigned long flags, unsigned long reason)
+__releases(&key->lock)
 {
 	struct sk_buff *skb;
 
+	trace_mctp_key_release(key, reason);
 	skb = key->reasm_head;
 	key->reasm_head = NULL;
-	key->reasm_dead = true;
-	key->valid = false;
-	mctp_dev_release_key(key->dev, key);
+
+	if (!key->manual_alloc) {
+		key->reasm_dead = true;
+		key->valid = false;
+		mctp_dev_release_key(key->dev, key);
+	}
 	spin_unlock_irqrestore(&key->lock, flags);
 
-	spin_lock_irqsave(&net->mctp.keys_lock, flags);
-	hlist_del(&key->hlist);
-	hlist_del(&key->sklist);
-	spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
+	if (!key->manual_alloc) {
+		spin_lock_irqsave(&net->mctp.keys_lock, flags);
+		hlist_del(&key->hlist);
+		hlist_del(&key->sklist);
+		spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
 
-	/* one unref for the lists */
-	mctp_key_unref(key);
+		/* unref for the lists */
+		mctp_key_unref(key);
+	}
 
 	/* and one for the local reference */
 	mctp_key_unref(key);
@@ -379,9 +388,8 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 				/* we've hit a pending reassembly; not much we
 				 * can do but drop it
 				 */
-				trace_mctp_key_release(key,
-						       MCTP_TRACE_KEY_REPLIED);
-				__mctp_key_unlock_drop(key, net, f);
+				__mctp_key_done_in(key, net, f,
+						   MCTP_TRACE_KEY_REPLIED);
 				key = NULL;
 			}
 			rc = 0;
@@ -423,9 +431,8 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 		} else {
 			if (key->reasm_head || key->reasm_dead) {
 				/* duplicate start? drop everything */
-				trace_mctp_key_release(key,
-						       MCTP_TRACE_KEY_INVALIDATED);
-				__mctp_key_unlock_drop(key, net, f);
+				__mctp_key_done_in(key, net, f,
+						   MCTP_TRACE_KEY_INVALIDATED);
 				rc = -EEXIST;
 				key = NULL;
 			} else {
@@ -448,10 +455,10 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
 		 * the reassembly/response key
 		 */
 		if (!rc && flags & MCTP_HDR_FLAG_EOM) {
+			msk = container_of(key->sk, struct mctp_sock, sk);
 			sock_queue_rcv_skb(key->sk, key->reasm_head);
 			key->reasm_head = NULL;
-			trace_mctp_key_release(key, MCTP_TRACE_KEY_REPLIED);
-			__mctp_key_unlock_drop(key, net, f);
+			__mctp_key_done_in(key, net, f, MCTP_TRACE_KEY_REPLIED);
 			key = NULL;
 		}
 
@@ -579,9 +586,9 @@ static void mctp_reserve_tag(struct net *net, struct mctp_sk_key *key,
 /* Allocate a locally-owned tag value for (saddr, daddr), and reserve
  * it for the socket msk
  */
-static struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
-						mctp_eid_t saddr,
-						mctp_eid_t daddr, u8 *tagp)
+struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
+					 mctp_eid_t daddr, mctp_eid_t saddr,
+					 bool manual, u8 *tagp)
 {
 	struct net *net = sock_net(&msk->sk);
 	struct netns_mctp *mns = &net->mctp;
@@ -636,6 +643,7 @@ static struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
 		mctp_reserve_tag(net, key, msk);
 		trace_mctp_key_acquire(key);
 
+		key->manual_alloc = manual;
 		*tagp = key->tag;
 	}
 
@@ -649,6 +657,50 @@ static struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
 	return key;
 }
 
+static struct mctp_sk_key *mctp_lookup_prealloc_tag(struct mctp_sock *msk,
+						    mctp_eid_t daddr,
+						    u8 req_tag, u8 *tagp)
+{
+	struct net *net = sock_net(&msk->sk);
+	struct netns_mctp *mns = &net->mctp;
+	struct mctp_sk_key *key, *tmp;
+	unsigned long flags;
+
+	req_tag &= ~(MCTP_TAG_PREALLOC | MCTP_TAG_OWNER);
+	key = NULL;
+
+	spin_lock_irqsave(&mns->keys_lock, flags);
+
+	hlist_for_each_entry(tmp, &mns->keys, hlist) {
+		if (tmp->tag != req_tag)
+			continue;
+
+		if (!mctp_address_matches(tmp->peer_addr, daddr))
+			continue;
+
+		if (!tmp->manual_alloc)
+			continue;
+
+		spin_lock(&tmp->lock);
+		if (tmp->valid) {
+			key = tmp;
+			refcount_inc(&key->refs);
+			spin_unlock(&tmp->lock);
+			break;
+		}
+		spin_unlock(&tmp->lock);
+	}
+	spin_unlock_irqrestore(&mns->keys_lock, flags);
+
+	if (!key)
+		return ERR_PTR(-ENOENT);
+
+	if (tagp)
+		*tagp = key->tag;
+
+	return key;
+}
+
 /* routing lookups */
 static bool mctp_rt_match_eid(struct mctp_route *rt,
 			      unsigned int net, mctp_eid_t eid)
@@ -843,8 +895,14 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
 	if (rc)
 		goto out_release;
 
-	if (req_tag & MCTP_HDR_FLAG_TO) {
-		key = mctp_alloc_local_tag(msk, saddr, daddr, &tag);
+	if (req_tag & MCTP_TAG_OWNER) {
+		if (req_tag & MCTP_TAG_PREALLOC)
+			key = mctp_lookup_prealloc_tag(msk, daddr,
+						       req_tag, &tag);
+		else
+			key = mctp_alloc_local_tag(msk, daddr, saddr,
+						   false, &tag);
+
 		if (IS_ERR(key)) {
 			rc = PTR_ERR(key);
 			goto out_release;
@@ -855,7 +913,7 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt,
 		tag |= MCTP_HDR_FLAG_TO;
 	} else {
 		key = NULL;
-		tag = req_tag;
+		tag = req_tag & MCTP_TAG_MASK;
 	}
 
 	skb->protocol = htons(ETH_P_MCTP);