caif: Protected in-flight packets using dev or sock refcont.

CAIF Socket Layer and ip-interface registers reference counters
in CAIF service layer. The functions sock_hold, sock_put and
dev_hold, dev_put are used by CAIF Stack to protect from freeing
memory while packets are in-flight.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 2 deletions

diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index 20212424e2e8..01f612df7df1 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -209,6 +209,18 @@ static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
         return 0;
 }
 
+static void cfsk_hold(struct cflayer *layr)
+{
+        struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
+        sock_hold(&cf_sk->sk);
+}
+
+static void cfsk_put(struct cflayer *layr)
+{
+        struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
+        sock_put(&cf_sk->sk);
+}
+
 /* Packet Control Callback function called from CAIF */
 static void caif_ctrl_cb(struct cflayer *layr,
                                 enum caif_ctrlcmd flow,
@@ -232,6 +244,8 @@ static void caif_ctrl_cb(struct cflayer *layr,
 
         case CAIF_CTRLCMD_INIT_RSP:
                 /* We're now connected */
+                caif_client_register_refcnt(&cf_sk->layer,
+                                                cfsk_hold, cfsk_put);
                 dbfs_atomic_inc(&cnt.num_connect_resp);
                 cf_sk->sk.sk_state = CAIF_CONNECTED;
                 set_tx_flow_on(cf_sk);
@@ -242,7 +256,6 @@ static void caif_ctrl_cb(struct cflayer *layr,
                 /* We're now disconnected */
                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
                 cf_sk->sk.sk_state_change(&cf_sk->sk);
-                cfcnfg_release_adap_layer(&cf_sk->layer);
                 break;
 
         case CAIF_CTRLCMD_INIT_FAIL_RSP:
@@ -837,8 +850,10 @@ static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
 
         dbfs_atomic_inc(&cnt.num_connect_req);
         cf_sk->layer.receive = caif_sktrecv_cb;
+
         err = caif_connect_client(&cf_sk->conn_req,
                                 &cf_sk->layer, &ifindex, &headroom, &tailroom);
+
         if (err < 0) {
                 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
@@ -940,7 +955,6 @@ static int caif_release(struct socket *sock)
         wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
 
         sock_orphan(sk);
-        cf_sk->layer.dn = NULL;
         sk_stream_kill_queues(&cf_sk->sk);
         release_sock(sk);
         sock_put(sk);
@@ -1036,6 +1050,7 @@ static void caif_sock_destructor(struct sock *sk)
         }
         sk_stream_kill_queues(&cf_sk->sk);
         dbfs_atomic_dec(&cnt.caif_nr_socks);
+        caif_free_client(&cf_sk->layer);
 }
 
 static int caif_create(struct net *net, struct socket *sock, int protocol,