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

1 files changed, 451 insertions, 0 deletions

diff --git a/net/caif/chnl_net.c b/net/caif/chnl_net.c
new file mode 100644
index 000000000000..f622ff1d39ba
--- /dev/null
+++ b/net/caif/chnl_net.c
@@ -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);