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-rw-r--r--net/phonet/pep-gprs.c364
1 files changed, 364 insertions, 0 deletions
diff --git a/net/phonet/pep-gprs.c b/net/phonet/pep-gprs.c
new file mode 100644
index 0000000..803eeef
--- /dev/null
+++ b/net/phonet/pep-gprs.c
@@ -0,0 +1,364 @@
+/*
+ * File: pep-gprs.c
+ *
+ * GPRS over Phonet pipe end point socket
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ *
+ * Author: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/if_ether.h>
+#include <linux/if_arp.h>
+#include <net/sock.h>
+
+#include <linux/if_phonet.h>
+#include <net/tcp_states.h>
+#include <net/phonet/gprs.h>
+
+#define GPRS_DEFAULT_MTU 1400
+
+struct gprs_dev {
+ struct sock *sk;
+ void (*old_state_change)(struct sock *);
+ void (*old_data_ready)(struct sock *, int);
+ void (*old_write_space)(struct sock *);
+
+ struct net_device *net;
+ struct net_device_stats stats;
+
+ struct sk_buff_head tx_queue;
+ struct work_struct tx_work;
+ spinlock_t tx_lock;
+ unsigned tx_max;
+};
+
+static int gprs_type_trans(struct sk_buff *skb)
+{
+ const u8 *pvfc;
+ u8 buf;
+
+ pvfc = skb_header_pointer(skb, 0, 1, &buf);
+ if (!pvfc)
+ return 0;
+ /* Look at IP version field */
+ switch (*pvfc >> 4) {
+ case 4:
+ return htons(ETH_P_IP);
+ case 6:
+ return htons(ETH_P_IPV6);
+ }
+ return 0;
+}
+
+/*
+ * Socket callbacks
+ */
+
+static void gprs_state_change(struct sock *sk)
+{
+ struct gprs_dev *dev = sk->sk_user_data;
+
+ if (sk->sk_state == TCP_CLOSE_WAIT) {
+ netif_stop_queue(dev->net);
+ netif_carrier_off(dev->net);
+ }
+}
+
+static int gprs_recv(struct gprs_dev *dev, struct sk_buff *skb)
+{
+ int err = 0;
+ u16 protocol = gprs_type_trans(skb);
+
+ if (!protocol) {
+ err = -EINVAL;
+ goto drop;
+ }
+
+ if (likely(skb_headroom(skb) & 3)) {
+ struct sk_buff *rskb, *fs;
+ int flen = 0;
+
+ /* Phonet Pipe data header is misaligned (3 bytes),
+ * so wrap the IP packet as a single fragment of an head-less
+ * socket buffer. The network stack will pull what it needs,
+ * but at least, the whole IP payload is not memcpy'd. */
+ rskb = netdev_alloc_skb(dev->net, 0);
+ if (!rskb) {
+ err = -ENOBUFS;
+ goto drop;
+ }
+ skb_shinfo(rskb)->frag_list = skb;
+ rskb->len += skb->len;
+ rskb->data_len += rskb->len;
+ rskb->truesize += rskb->len;
+
+ /* Avoid nested fragments */
+ for (fs = skb_shinfo(skb)->frag_list; fs; fs = fs->next)
+ flen += fs->len;
+ skb->next = skb_shinfo(skb)->frag_list;
+ skb_shinfo(skb)->frag_list = NULL;
+ skb->len -= flen;
+ skb->data_len -= flen;
+ skb->truesize -= flen;
+
+ skb = rskb;
+ }
+
+ skb->protocol = protocol;
+ skb_reset_mac_header(skb);
+ skb->dev = dev->net;
+
+ if (likely(dev->net->flags & IFF_UP)) {
+ dev->stats.rx_packets++;
+ dev->stats.rx_bytes += skb->len;
+ netif_rx(skb);
+ skb = NULL;
+ } else
+ err = -ENODEV;
+
+drop:
+ if (skb) {
+ dev_kfree_skb(skb);
+ dev->stats.rx_dropped++;
+ }
+ return err;
+}
+
+static void gprs_data_ready(struct sock *sk, int len)
+{
+ struct gprs_dev *dev = sk->sk_user_data;
+ struct sk_buff *skb;
+
+ while ((skb = pep_read(sk)) != NULL) {
+ skb_orphan(skb);
+ gprs_recv(dev, skb);
+ }
+}
+
+static void gprs_write_space(struct sock *sk)
+{
+ struct gprs_dev *dev = sk->sk_user_data;
+ struct net_device *net = dev->net;
+ unsigned credits = pep_writeable(sk);
+
+ spin_lock_bh(&dev->tx_lock);
+ dev->tx_max = credits;
+ if (credits > skb_queue_len(&dev->tx_queue) && netif_running(net))
+ netif_wake_queue(net);
+ spin_unlock_bh(&dev->tx_lock);
+}
+
+/*
+ * Network device callbacks
+ */
+
+static int gprs_open(struct net_device *dev)
+{
+ struct gprs_dev *gp = netdev_priv(dev);
+
+ gprs_write_space(gp->sk);
+ return 0;
+}
+
+static int gprs_close(struct net_device *dev)
+{
+ struct gprs_dev *gp = netdev_priv(dev);
+
+ netif_stop_queue(dev);
+ flush_work(&gp->tx_work);
+ return 0;
+}
+
+static int gprs_xmit(struct sk_buff *skb, struct net_device *net)
+{
+ struct gprs_dev *dev = netdev_priv(net);
+
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ case htons(ETH_P_IPV6):
+ break;
+ default:
+ dev_kfree_skb(skb);
+ return 0;
+ }
+
+ spin_lock(&dev->tx_lock);
+ if (likely(skb_queue_len(&dev->tx_queue) < dev->tx_max)) {
+ skb_queue_tail(&dev->tx_queue, skb);
+ skb = NULL;
+ }
+ if (skb_queue_len(&dev->tx_queue) >= dev->tx_max)
+ netif_stop_queue(net);
+ spin_unlock(&dev->tx_lock);
+
+ schedule_work(&dev->tx_work);
+ if (unlikely(skb))
+ dev_kfree_skb(skb);
+ return 0;
+}
+
+static void gprs_tx(struct work_struct *work)
+{
+ struct gprs_dev *dev = container_of(work, struct gprs_dev, tx_work);
+ struct sock *sk = dev->sk;
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&dev->tx_queue)) != NULL) {
+ int err;
+
+ dev->stats.tx_bytes += skb->len;
+ dev->stats.tx_packets++;
+
+ skb_orphan(skb);
+ skb_set_owner_w(skb, sk);
+
+ lock_sock(sk);
+ err = pep_write(sk, skb);
+ if (err) {
+ LIMIT_NETDEBUG(KERN_WARNING"%s: TX error (%d)\n",
+ dev->net->name, err);
+ dev->stats.tx_aborted_errors++;
+ dev->stats.tx_errors++;
+ }
+ release_sock(sk);
+ }
+
+ lock_sock(sk);
+ gprs_write_space(sk);
+ release_sock(sk);
+}
+
+static int gprs_set_mtu(struct net_device *net, int new_mtu)
+{
+ if ((new_mtu < 576) || (new_mtu > (PHONET_MAX_MTU - 11)))
+ return -EINVAL;
+
+ net->mtu = new_mtu;
+ return 0;
+}
+
+static struct net_device_stats *gprs_get_stats(struct net_device *net)
+{
+ struct gprs_dev *dev = netdev_priv(net);
+
+ return &dev->stats;
+}
+
+static void gprs_setup(struct net_device *net)
+{
+ net->features = NETIF_F_FRAGLIST;
+ net->type = ARPHRD_NONE;
+ net->flags = IFF_POINTOPOINT | IFF_NOARP;
+ net->mtu = GPRS_DEFAULT_MTU;
+ net->hard_header_len = 0;
+ net->addr_len = 0;
+ net->tx_queue_len = 10;
+
+ net->destructor = free_netdev;
+ net->open = gprs_open;
+ net->stop = gprs_close;
+ net->hard_start_xmit = gprs_xmit; /* mandatory */
+ net->change_mtu = gprs_set_mtu;
+ net->get_stats = gprs_get_stats;
+}
+
+/*
+ * External interface
+ */
+
+/*
+ * Attach a GPRS interface to a datagram socket.
+ * Returns the interface index on success, negative error code on error.
+ */
+int gprs_attach(struct sock *sk)
+{
+ static const char ifname[] = "gprs%d";
+ struct gprs_dev *dev;
+ struct net_device *net;
+ int err;
+
+ if (unlikely(sk->sk_type == SOCK_STREAM))
+ return -EINVAL; /* need packet boundaries */
+
+ /* Create net device */
+ net = alloc_netdev(sizeof(*dev), ifname, gprs_setup);
+ if (!net)
+ return -ENOMEM;
+ dev = netdev_priv(net);
+ dev->net = net;
+ dev->tx_max = 0;
+ spin_lock_init(&dev->tx_lock);
+ skb_queue_head_init(&dev->tx_queue);
+ INIT_WORK(&dev->tx_work, gprs_tx);
+
+ netif_stop_queue(net);
+ err = register_netdev(net);
+ if (err) {
+ free_netdev(net);
+ return err;
+ }
+
+ lock_sock(sk);
+ if (unlikely(sk->sk_user_data)) {
+ err = -EBUSY;
+ goto out_rel;
+ }
+ if (unlikely((1 << sk->sk_state & (TCPF_CLOSE|TCPF_LISTEN)) ||
+ sock_flag(sk, SOCK_DEAD))) {
+ err = -EINVAL;
+ goto out_rel;
+ }
+ sk->sk_user_data = dev;
+ dev->old_state_change = sk->sk_state_change;
+ dev->old_data_ready = sk->sk_data_ready;
+ dev->old_write_space = sk->sk_write_space;
+ sk->sk_state_change = gprs_state_change;
+ sk->sk_data_ready = gprs_data_ready;
+ sk->sk_write_space = gprs_write_space;
+ release_sock(sk);
+
+ sock_hold(sk);
+ dev->sk = sk;
+
+ printk(KERN_DEBUG"%s: attached\n", net->name);
+ return net->ifindex;
+
+out_rel:
+ release_sock(sk);
+ unregister_netdev(net);
+ return err;
+}
+
+void gprs_detach(struct sock *sk)
+{
+ struct gprs_dev *dev = sk->sk_user_data;
+ struct net_device *net = dev->net;
+
+ lock_sock(sk);
+ sk->sk_user_data = NULL;
+ sk->sk_state_change = dev->old_state_change;
+ sk->sk_data_ready = dev->old_data_ready;
+ sk->sk_write_space = dev->old_write_space;
+ release_sock(sk);
+
+ printk(KERN_DEBUG"%s: detached\n", net->name);
+ unregister_netdev(net);
+ sock_put(sk);
+}
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