net-caif: add CAIF netdevice
authorSjur Braendeland <sjur.brandeland@stericsson.com>
Tue, 30 Mar 2010 13:56:27 +0000 (13:56 +0000)
committerDavid S. Miller <davem@davemloft.net>
Wed, 31 Mar 2010 02:08:48 +0000 (19:08 -0700)
Adding GPRS Net Device for PDP Contexts.
The device can be managed by RTNL as defined in if_caif.h.

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/caif/chnl_net.c [new file with mode: 0644]

diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
new file mode 100644 (file)
index 0000000..f622ff1
--- /dev/null
@@ -0,0 +1,451 @@
+/*
+ * 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);