/*
* 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
*/
#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
#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>
/* GPRS PDP connection has MTU to 1500 */
#define GPRS_PDP_MTU 1500
/* 5 sec. connect timeout */
#define CONNECT_TIMEOUT (5 * HZ)
#define CAIF_NET_DEFAULT_QUEUE_LEN 500
/*This list is protected by the rtnl lock. */
static LIST_HEAD(chnl_net_list);
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("caif");
enum caif_states {
CAIF_CONNECTED = 1,
CAIF_CONNECTING,
CAIF_DISCONNECTED,
CAIF_SHUTDOWN
};
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;
enum caif_states state;
};
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);
return;
}
}
WARN_ON(1);
}
static int chnl_recv_cb(struct cflayer *layr, struct cfpkt *pkt)
{
struct sk_buff *skb;
struct chnl_net *priv = container_of(layr, struct chnl_net, chnl);
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;
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;
/* May be called with or without RTNL lock held */
int islocked = rtnl_is_locked();
if (!islocked)
rtnl_lock();
list_for_each_safe(list_node, _tmp, &chnl_net_list) {
dev = list_entry(list_node, struct chnl_net, list_field);
if (dev->state == CAIF_SHUTDOWN)
dev_close(dev->netdev);
}
if (!islocked)
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 = container_of(layr, struct chnl_net, chnl);
pr_debug("NET flowctrl func called flow: %s\n",
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");
switch (flow) {
case CAIF_CTRLCMD_FLOW_OFF_IND:
priv->flowenabled = false;
netif_stop_queue(priv->netdev);
break;
case CAIF_CTRLCMD_DEINIT_RSP:
priv->state = CAIF_DISCONNECTED;
break;
case CAIF_CTRLCMD_INIT_FAIL_RSP:
priv->state = CAIF_DISCONNECTED;
wake_up_interruptible(&priv->netmgmt_wq);
break;
case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
priv->state = CAIF_SHUTDOWN;
netif_tx_disable(priv->netdev);
schedule_work(&close_worker);
break;
case CAIF_CTRLCMD_FLOW_ON_IND:
priv->flowenabled = true;
netif_wake_queue(priv->netdev);
break;
case CAIF_CTRLCMD_INIT_RSP:
priv->state = CAIF_CONNECTED;
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_warn("Size of skb exceeded MTU\n");
return -ENOSPC;
}
if (!priv->flowenabled) {
pr_debug("dropping packets flow off\n");
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);
/* 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;
int llifindex, headroom, tailroom, mtu;
struct net_device *lldev;
ASSERT_RTNL();
priv = netdev_priv(dev);
if (!priv) {
pr_debug("chnl_net_open: no priv\n");
return -ENODEV;
}
if (priv->state != CAIF_CONNECTING) {
priv->state = CAIF_CONNECTING;
result = caif_connect_client(&priv->conn_req, &priv->chnl,
&llifindex, &headroom, &tailroom);
if (result != 0) {
pr_debug("err: "
"Unable to register and open device,"
" Err:%d\n",
result);
goto error;
}
lldev = dev_get_by_index(dev_net(dev), llifindex);
if (lldev == NULL) {
pr_debug("no interface?\n");
result = -ENODEV;
goto error;
}
dev->needed_tailroom = tailroom + lldev->needed_tailroom;
dev->hard_header_len = headroom + lldev->hard_header_len +
lldev->needed_tailroom;
/*
* MTU, head-room etc is not know before we have a
* CAIF link layer device available. MTU calculation may
* override initial RTNL configuration.
* MTU is minimum of current mtu, link layer mtu pluss
* CAIF head and tail, and PDP GPRS contexts max MTU.
*/
mtu = min_t(int, dev->mtu, lldev->mtu - (headroom + tailroom));
mtu = min_t(int, GPRS_PDP_MTU, mtu);
dev_set_mtu(dev, mtu);
dev_put(lldev);
if (mtu < 100) {
pr_warn("CAIF Interface MTU too small (%d)\n", mtu);
result = -ENODEV;
goto error;
}
}
rtnl_unlock(); /* Release RTNL lock during connect wait */
result = wait_event_interruptible_timeout(priv->netmgmt_wq,
priv->state != CAIF_CONNECTING,
CONNECT_TIMEOUT);
rtnl_lock();
if (result == -ERESTARTSYS) {
pr_debug("wait_event_interruptible woken by a signal\n");
result = -ERESTARTSYS;
goto error;
}
if (result == 0) {
pr_debug("connect timeout\n");
caif_disconnect_client(&priv->chnl);
priv->state = CAIF_DISCONNECTED;
pr_debug("state disconnected\n");
result = -ETIMEDOUT;
goto error;
}
if (priv->state != CAIF_CONNECTED) {
pr_debug("connect failed\n");
result = -ECONNREFUSED;
goto error;
}
pr_debug("CAIF Netdevice connected\n");
return 0;
error:
caif_disconnect_client(&priv->chnl);
priv->state = CAIF_DISCONNECTED;
pr_debug("state disconnected\n");
return result;
}
static int chnl_net_stop(struct net_device *dev)
{
struct chnl_net *priv;
ASSERT_RTNL();
priv = netdev_priv(dev);
priv->state = CAIF_DISCONNECTED;
caif_disconnect_client(&priv->chnl);
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->mtu = GPRS_PDP_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_warn("no params data found\n");
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);
dev_net_set(caifdev->netdev, src_net);
ret = register_netdevice(dev);
if (ret)
pr_warn("device rtml registration failed\n");
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);
