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Commit cc36a070 authored by Sjur Braendeland's avatar Sjur Braendeland Committed by David S. Miller
Browse files

net-caif: add CAIF netdevice 



Adding GPRS Net Device for PDP Contexts.
The device can be managed by RTNL as defined in if_caif.h.

Signed-off-by: default avatarSjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e6f95ec8

net/caif/chnl_net.c

0 → 100644
+451 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) ST-Ericsson AB 2010

 * Authors:	Sjur Brendeland/sjur.brandeland@stericsson.com

 *		Daniel Martensson / Daniel.Martensson@stericsson.com

 * License terms: GNU General Public License (GPL) version 2

 */



#include <linux/version.h>

#include <linux/fs.h>

#include <linux/init.h>

#include <linux/module.h>

#include <linux/netdevice.h>

#include <linux/if_ether.h>

#include <linux/moduleparam.h>

#include <linux/ip.h>

#include <linux/sched.h>

#include <linux/sockios.h>

#include <linux/caif/if_caif.h>

#include <net/rtnetlink.h>

#include <net/caif/caif_layer.h>

#include <net/caif/cfcnfg.h>

#include <net/caif/cfpkt.h>

#include <net/caif/caif_dev.h>



#define CAIF_CONNECT_TIMEOUT 30

#define SIZE_MTU 1500

#define SIZE_MTU_MAX 4080

#define SIZE_MTU_MIN 68

#define CAIF_NET_DEFAULT_QUEUE_LEN 500



#undef pr_debug

#define pr_debug pr_warning



/*This list is protected by the rtnl lock. */

static LIST_HEAD(chnl_net_list);



MODULE_LICENSE("GPL");

MODULE_ALIAS_RTNL_LINK("caif");



struct chnl_net {

	struct cflayer chnl;

	struct net_device_stats stats;

	struct caif_connect_request conn_req;

	struct list_head list_field;

	struct net_device *netdev;

	char name[256];

	wait_queue_head_t netmgmt_wq;

	/* Flow status to remember and control the transmission. */

	bool flowenabled;

	bool pending_close;

};



static void robust_list_del(struct list_head *delete_node)

{

	struct list_head *list_node;

	struct list_head *n;

	ASSERT_RTNL();

	list_for_each_safe(list_node, n, &chnl_net_list) {

		if (list_node == delete_node) {

			list_del(list_node);

			break;

		}

	}

}



static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)

{

	struct sk_buff *skb;

	struct chnl_net *priv  = NULL;

	int pktlen;

	int err = 0;



	priv = container_of(layr, struct chnl_net, chnl);



	if (!priv)

		return -EINVAL;



	/* Get length of CAIF packet. */

	pktlen = cfpkt_getlen(pkt);



	skb = (struct sk_buff *) cfpkt_tonative(pkt);

	/* Pass some minimum information and

	 * send the packet to the net stack.

	 */

	skb->dev = priv->netdev;

	skb->protocol = htons(ETH_P_IP);



	/* If we change the header in loop mode, the checksum is corrupted. */

	if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)

		skb->ip_summed = CHECKSUM_UNNECESSARY;

	else

		skb->ip_summed = CHECKSUM_NONE;



	/* FIXME: Drivers should call this in tasklet context. */

	if (in_interrupt())

		netif_rx(skb);

	else

		netif_rx_ni(skb);



	/* Update statistics. */

	priv->netdev->stats.rx_packets++;

	priv->netdev->stats.rx_bytes += pktlen;



	return err;

}



static int delete_device(struct chnl_net *dev)

{

	ASSERT_RTNL();

	if (dev->netdev)

		unregister_netdevice(dev->netdev);

	return 0;

}



static void close_work(struct work_struct *work)

{

	struct chnl_net *dev = NULL;

	struct list_head *list_node;

	struct list_head *_tmp;

	rtnl_lock();

	list_for_each_safe(list_node, _tmp, &chnl_net_list) {

		dev = list_entry(list_node, struct chnl_net, list_field);

		if (!dev->pending_close)

			continue;

		list_del(list_node);

		delete_device(dev);

	}

	rtnl_unlock();

}

static DECLARE_WORK(close_worker, close_work);



static void chnl_flowctrl_cb(struct cflayer *layr, enum caif_ctrlcmd flow,

				int phyid)

{

	struct chnl_net *priv;

	pr_debug("CAIF: %s(): NET flowctrl func called flow: %s.\n",

		__func__,

		flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :

		flow == CAIF_CTRLCMD_INIT_RSP ? "INIT" :

		flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :

		flow == CAIF_CTRLCMD_DEINIT_RSP ? "CLOSE/DEINIT" :

		flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "OPEN_FAIL" :

		flow == CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ?

		 "REMOTE_SHUTDOWN" : "UKNOWN CTRL COMMAND");



	priv = container_of(layr, struct chnl_net, chnl);



	switch (flow) {

	case CAIF_CTRLCMD_FLOW_OFF_IND:

	case CAIF_CTRLCMD_DEINIT_RSP:

	case CAIF_CTRLCMD_INIT_FAIL_RSP:

	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:

		priv->flowenabled = false;

		netif_tx_disable(priv->netdev);

		pr_warning("CAIF: %s(): done\n", __func__);

		priv->pending_close = 1;

		schedule_work(&close_worker);

		break;

	case CAIF_CTRLCMD_FLOW_ON_IND:

	case CAIF_CTRLCMD_INIT_RSP:

		priv->flowenabled = true;

		netif_wake_queue(priv->netdev);

		wake_up_interruptible(&priv->netmgmt_wq);

		break;

	default:

		break;

	}

}



static int chnl_net_start_xmit(struct sk_buff *skb, struct net_device *dev)

{

	struct chnl_net *priv;

	struct cfpkt *pkt = NULL;

	int len;

	int result = -1;

	/* Get our private data. */

	priv = netdev_priv(dev);



	if (skb->len > priv->netdev->mtu) {

		pr_warning("CAIF: %s(): Size of skb exceeded MTU\n", __func__);

		return -ENOSPC;

	}



	if (!priv->flowenabled) {

		pr_debug("CAIF: %s(): dropping packets flow off\n", __func__);

		return NETDEV_TX_BUSY;

	}



	if (priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP)

		swap(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);



	/* Store original SKB length. */

	len = skb->len;



	pkt = cfpkt_fromnative(CAIF_DIR_OUT, (void *) skb);



	pr_debug("CAIF: %s(): transmit inst %s %d,%p\n",

		__func__, dev->name, priv->chnl.dn->id, &priv->chnl.dn);



	/* Send the packet down the stack. */

	result = priv->chnl.dn->transmit(priv->chnl.dn, pkt);

	if (result) {

		if (result == -EAGAIN)

			result = NETDEV_TX_BUSY;

		return result;

	}



	/* Update statistics. */

	dev->stats.tx_packets++;

	dev->stats.tx_bytes += len;



	return NETDEV_TX_OK;

}



static int chnl_net_open(struct net_device *dev)

{

	struct chnl_net *priv = NULL;

	int result = -1;

	ASSERT_RTNL();



	priv = netdev_priv(dev);

	pr_debug("CAIF: %s(): dev name: %s\n", __func__, priv->name);



	if (!priv) {

		pr_debug("CAIF: %s(): chnl_net_open: no priv\n", __func__);

		return -ENODEV;

	}

	result = caif_connect_client(&priv->conn_req, &priv->chnl);

	if (result != 0) {

		pr_debug("CAIF: %s(): err: "

			 "Unable to register and open device, Err:%d\n",

			__func__,

			result);

		return -ENODEV;

	}

	result = wait_event_interruptible(priv->netmgmt_wq, priv->flowenabled);



	if (result == -ERESTARTSYS) {

		pr_debug("CAIF: %s(): wait_event_interruptible"

			 " woken by a signal\n", __func__);

		return -ERESTARTSYS;

	} else

		pr_debug("CAIF: %s(): Flow on recieved\n", __func__);



	return 0;

}



static int chnl_net_stop(struct net_device *dev)

{

	struct chnl_net *priv;

	int result = -1;

	ASSERT_RTNL();

	priv = netdev_priv(dev);



	result = caif_disconnect_client(&priv->chnl);

	if (result != 0) {

		pr_debug("CAIF: %s(): chnl_net_stop: err: "

			 "Unable to STOP device, Err:%d\n",

			 __func__, result);

		return -EBUSY;

	}

	result = wait_event_interruptible(priv->netmgmt_wq,

					  !priv->flowenabled);



	if (result == -ERESTARTSYS) {

		pr_debug("CAIF: %s(): wait_event_interruptible woken by"

			 " signal, signal_pending(current) = %d\n",

			 __func__,

			 signal_pending(current));

	} else {

		pr_debug("CAIF: %s(): disconnect received\n", __func__);



	}



	return 0;

}



static int chnl_net_init(struct net_device *dev)

{

	struct chnl_net *priv;

	ASSERT_RTNL();

	priv = netdev_priv(dev);

	strncpy(priv->name, dev->name, sizeof(priv->name));

	return 0;

}



static void chnl_net_uninit(struct net_device *dev)

{

	struct chnl_net *priv;

	ASSERT_RTNL();

	priv = netdev_priv(dev);

	robust_list_del(&priv->list_field);

}



static const struct net_device_ops netdev_ops = {

	.ndo_open = chnl_net_open,

	.ndo_stop = chnl_net_stop,

	.ndo_init = chnl_net_init,

	.ndo_uninit = chnl_net_uninit,

	.ndo_start_xmit = chnl_net_start_xmit,

};



static void ipcaif_net_setup(struct net_device *dev)

{

	struct chnl_net *priv;

	dev->netdev_ops = &netdev_ops;

	dev->destructor = free_netdev;

	dev->flags |= IFF_NOARP;

	dev->flags |= IFF_POINTOPOINT;

	dev->needed_headroom = CAIF_NEEDED_HEADROOM;

	dev->needed_tailroom = CAIF_NEEDED_TAILROOM;

	dev->mtu = SIZE_MTU;

	dev->tx_queue_len = CAIF_NET_DEFAULT_QUEUE_LEN;



	priv = netdev_priv(dev);

	priv->chnl.receive = chnl_recv_cb;

	priv->chnl.ctrlcmd = chnl_flowctrl_cb;

	priv->netdev = dev;

	priv->conn_req.protocol = CAIFPROTO_DATAGRAM;

	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->flowenabled = false;



	ASSERT_RTNL();

	init_waitqueue_head(&priv->netmgmt_wq);

	list_add(&priv->list_field, &chnl_net_list);

}





static int ipcaif_fill_info(struct sk_buff *skb, const struct net_device *dev)

{

	struct chnl_net *priv;

	u8 loop;

	priv = netdev_priv(dev);

	NLA_PUT_U32(skb, IFLA_CAIF_IPV4_CONNID,

		    priv->conn_req.sockaddr.u.dgm.connection_id);

	NLA_PUT_U32(skb, IFLA_CAIF_IPV6_CONNID,

		    priv->conn_req.sockaddr.u.dgm.connection_id);

	loop = priv->conn_req.protocol == CAIFPROTO_DATAGRAM_LOOP;

	NLA_PUT_U8(skb, IFLA_CAIF_LOOPBACK, loop);





	return 0;

nla_put_failure:

	return -EMSGSIZE;



}



static void caif_netlink_parms(struct nlattr *data[],

				struct caif_connect_request *conn_req)

{

	if (!data) {

		pr_warning("CAIF: %s: no params data found\n", __func__);

		return;

	}

	if (data[IFLA_CAIF_IPV4_CONNID])

		conn_req->sockaddr.u.dgm.connection_id =

			nla_get_u32(data[IFLA_CAIF_IPV4_CONNID]);

	if (data[IFLA_CAIF_IPV6_CONNID])

		conn_req->sockaddr.u.dgm.connection_id =

			nla_get_u32(data[IFLA_CAIF_IPV6_CONNID]);

	if (data[IFLA_CAIF_LOOPBACK]) {

		if (nla_get_u8(data[IFLA_CAIF_LOOPBACK]))

			conn_req->protocol = CAIFPROTO_DATAGRAM_LOOP;

		else

			conn_req->protocol = CAIFPROTO_DATAGRAM;

	}

}



static int ipcaif_newlink(struct net *src_net, struct net_device *dev,

			  struct nlattr *tb[], struct nlattr *data[])

{

	int ret;

	struct chnl_net *caifdev;

	ASSERT_RTNL();

	caifdev = netdev_priv(dev);

	caif_netlink_parms(data, &caifdev->conn_req);

	ret = register_netdevice(dev);

	if (ret)

		pr_warning("CAIF: %s(): device rtml registration failed\n",

			   __func__);

	return ret;

}



static int ipcaif_changelink(struct net_device *dev, struct nlattr *tb[],

				struct nlattr *data[])

{

	struct chnl_net *caifdev;

	ASSERT_RTNL();

	caifdev = netdev_priv(dev);

	caif_netlink_parms(data, &caifdev->conn_req);

	netdev_state_change(dev);

	return 0;

}



static size_t ipcaif_get_size(const struct net_device *dev)

{

	return

		/* IFLA_CAIF_IPV4_CONNID */

		nla_total_size(4) +

		/* IFLA_CAIF_IPV6_CONNID */

		nla_total_size(4) +

		/* IFLA_CAIF_LOOPBACK */

		nla_total_size(2) +

		0;

}



static const struct nla_policy ipcaif_policy[IFLA_CAIF_MAX + 1] = {

	[IFLA_CAIF_IPV4_CONNID]	      = { .type = NLA_U32 },

	[IFLA_CAIF_IPV6_CONNID]	      = { .type = NLA_U32 },

	[IFLA_CAIF_LOOPBACK]	      = { .type = NLA_U8 }

};





static struct rtnl_link_ops ipcaif_link_ops __read_mostly = {

	.kind		= "caif",

	.priv_size	= sizeof(struct chnl_net),

	.setup		= ipcaif_net_setup,

	.maxtype	= IFLA_CAIF_MAX,

	.policy		= ipcaif_policy,

	.newlink	= ipcaif_newlink,

	.changelink	= ipcaif_changelink,

	.get_size	= ipcaif_get_size,

	.fill_info	= ipcaif_fill_info,



};



static int __init chnl_init_module(void)

{

	return rtnl_link_register(&ipcaif_link_ops);

}



static void __exit chnl_exit_module(void)

{

	struct chnl_net *dev = NULL;

	struct list_head *list_node;

	struct list_head *_tmp;

	rtnl_link_unregister(&ipcaif_link_ops);

	rtnl_lock();

	list_for_each_safe(list_node, _tmp, &chnl_net_list) {

		dev = list_entry(list_node, struct chnl_net, list_field);

		list_del(list_node);

		delete_device(dev);

	}

	rtnl_unlock();

}



module_init(chnl_init_module);

module_exit(chnl_exit_module);