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caif: Protected in-flight packets using dev or sock refcont.
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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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@davem330
[email protected] authored and davem330 committed May 15, 2011
1 parent 43e3692 commit b3ccfbe
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Showing 3 changed files with 72 additions and 4 deletions.
29 changes: 29 additions & 0 deletions include/net/caif/caif_dev.h
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Original file line number Diff line number Diff line change
Expand Up @@ -73,6 +73,23 @@ int caif_connect_client(struct caif_connect_request *conn_req,
*/
int caif_disconnect_client(struct cflayer *client_layer);

/**
* caif_client_register_refcnt - register ref-count functions provided by client.
*
* @adapt_layer: Client layer using CAIF Stack.
* @hold: Function provided by client layer increasing ref-count
* @put: Function provided by client layer decreasing ref-count
*
* Client of the CAIF Stack must register functions for reference counting.
* These functions are called by the CAIF Stack for every upstream packet,
* and must therefore be implemented efficiently.
*
* Client should call caif_free_client when reference count degrease to zero.
*/

void caif_client_register_refcnt(struct cflayer *adapt_layer,
void (*hold)(struct cflayer *lyr),
void (*put)(struct cflayer *lyr));
/**
* caif_connect_req_to_link_param - Translate configuration parameters
* from socket format to internal format.
Expand All @@ -83,8 +100,20 @@ int caif_disconnect_client(struct cflayer *client_layer);
* setting up channels.
*
*/

int caif_connect_req_to_link_param(struct cfcnfg *cnfg,
struct caif_connect_request *con_req,
struct cfctrl_link_param *setup_param);

/**
* caif_free_client - Free memory used to manage the client in the CAIF Stack.
*
* @client_layer: Client layer to be removed.
*
* This function must be called from client layer in order to free memory.
* Caller must guarantee that no packets are in flight upstream when calling
* this function.
*/
void caif_free_client(struct cflayer *adap_layer);

#endif /* CAIF_DEV_H_ */
19 changes: 17 additions & 2 deletions net/caif/caif_socket.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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);
Expand All @@ -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:
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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,
Expand Down
28 changes: 26 additions & 2 deletions net/caif/chnl_net.c
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Original file line number Diff line number Diff line change
Expand Up @@ -153,6 +153,18 @@ static void close_work(struct work_struct *work)
}
static DECLARE_WORK(close_worker, close_work);

static void chnl_hold(struct cflayer *lyr)
{
struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
dev_hold(priv->netdev);
}

static void chnl_put(struct cflayer *lyr)
{
struct chnl_net *priv = container_of(lyr, struct chnl_net, chnl);
dev_put(priv->netdev);
}

static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
int phyid)
{
Expand Down Expand Up @@ -190,6 +202,7 @@ static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,
netif_wake_queue(priv->netdev);
break;
case CAIF_CTRLCMD_INIT_RSP:
caif_client_register_refcnt(&priv->chnl, chnl_hold, chnl_put);
priv->state = CAIF_CONNECTED;
priv->flowenabled = true;
netif_wake_queue(priv->netdev);
Expand Down Expand Up @@ -373,11 +386,18 @@ static const struct net_device_ops netdev_ops = {
.ndo_start_xmit = chnl_net_start_xmit,
};

static void chnl_net_destructor(struct net_device *dev)
{
struct chnl_net *priv = netdev_priv(dev);
caif_free_client(&priv->chnl);
free_netdev(dev);
}

static void ipcaif_net_setup(struct net_device *dev)
{
struct chnl_net *priv;
dev->netdev_ops = &netdev_ops;
dev->destructor = free_netdev;
dev->destructor = chnl_net_destructor;
dev->flags |= IFF_NOARP;
dev->flags |= IFF_POINTOPOINT;
dev->mtu = GPRS_PDP_MTU;
Expand All @@ -391,7 +411,7 @@ static void ipcaif_net_setup(struct net_device *dev)
priv->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
priv->conn_req.priority = CAIF_PRIO_LOW;
/* Insert illegal value */
priv->conn_req.sockaddr.u.dgm.connection_id = -1;
priv->conn_req.sockaddr.u.dgm.connection_id = 0;
priv->flowenabled = false;

init_waitqueue_head(&priv->netmgmt_wq);
Expand Down Expand Up @@ -453,6 +473,10 @@ static int ipcaif_newlink(struct net *src_net, struct net_device *dev,
pr_warn("device rtml registration failed\n");
else
list_add(&caifdev->list_field, &chnl_net_list);

/* Take ifindex as connection-id if null */
if (caifdev->conn_req.sockaddr.u.dgm.connection_id == 0)
caifdev->conn_req.sockaddr.u.dgm.connection_id = dev->ifindex;
return ret;
}

Expand Down

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