1 files changed, 319 insertions, 0 deletions
diff --git a/net/phonet/pep-gprs.c b/net/phonet/pep-gprs.c
new file mode 100644
index 000000000..2c9337946
--- /dev/null
+++ b/net/phonet/pep-gprs.c
@@ -0,0 +1,319 @@
+/*
+ * File: pep-gprs.c
+ *
+ * GPRS over Phonet pipe end point socket
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ *
+ * Author: Rémi Denis-Courmont
+ *
+ * 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 *);
+	void			(*old_write_space)(struct sock *);
+
+	struct net_device	*dev;
+};
+
+static __be16 gprs_type_trans(struct sk_buff *skb)
+{
+	const u8 *pvfc;
+	u8 buf;
+
+	pvfc = skb_header_pointer(skb, 0, 1, &buf);
+	if (!pvfc)
+		return htons(0);
+	/* Look at IP version field */
+	switch (*pvfc >> 4) {
+	case 4:
+		return htons(ETH_P_IP);
+	case 6:
+		return htons(ETH_P_IPV6);
+	}
+	return htons(0);
+}
+
+static void gprs_writeable(struct gprs_dev *gp)
+{
+	struct net_device *dev = gp->dev;
+
+	if (pep_writeable(gp->sk))
+		netif_wake_queue(dev);
+}
+
+/*
+ * Socket callbacks
+ */
+
+static void gprs_state_change(struct sock *sk)
+{
+	struct gprs_dev *gp = sk->sk_user_data;
+
+	if (sk->sk_state == TCP_CLOSE_WAIT) {
+		struct net_device *dev = gp->dev;
+
+		netif_stop_queue(dev);
+		netif_carrier_off(dev);
+	}
+}
+
+static int gprs_recv(struct gprs_dev *gp, struct sk_buff *skb)
+{
+	struct net_device *dev = gp->dev;
+	int err = 0;
+	__be16 protocol = gprs_type_trans(skb);
+
+	if (!protocol) {
+		err = -EINVAL;
+		goto drop;
+	}
+
+	if (skb_headroom(skb) & 3) {
+		struct sk_buff *rskb, *fs;
+		int flen = 0;
+
+		/* Phonet Pipe data header may be 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, 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 */
+		skb_walk_frags(skb, fs)
+			flen += fs->len;
+		skb->next = skb_shinfo(skb)->frag_list;
+		skb_frag_list_init(skb);
+		skb->len -= flen;
+		skb->data_len -= flen;
+		skb->truesize -= flen;
+
+		skb = rskb;
+	}
+
+	skb->protocol = protocol;
+	skb_reset_mac_header(skb);
+	skb->dev = dev;
+
+	if (likely(dev->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)
+{
+	struct gprs_dev *gp = sk->sk_user_data;
+	struct sk_buff *skb;
+
+	while ((skb = pep_read(sk)) != NULL) {
+		skb_orphan(skb);
+		gprs_recv(gp, skb);
+	}
+}
+
+static void gprs_write_space(struct sock *sk)
+{
+	struct gprs_dev *gp = sk->sk_user_data;
+
+	if (netif_running(gp->dev))
+		gprs_writeable(gp);
+}
+
+/*
+ * Network device callbacks
+ */
+
+static int gprs_open(struct net_device *dev)
+{
+	struct gprs_dev *gp = netdev_priv(dev);
+
+	gprs_writeable(gp);
+	return 0;
+}
+
+static int gprs_close(struct net_device *dev)
+{
+	netif_stop_queue(dev);
+	return 0;
+}
+
+static netdev_tx_t gprs_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct gprs_dev *gp = netdev_priv(dev);
+	struct sock *sk = gp->sk;
+	int len, err;
+
+	switch (skb->protocol) {
+	case  htons(ETH_P_IP):
+	case  htons(ETH_P_IPV6):
+		break;
+	default:
+		dev_kfree_skb(skb);
+		return NETDEV_TX_OK;
+	}
+
+	skb_orphan(skb);
+	skb_set_owner_w(skb, sk);
+	len = skb->len;
+	err = pep_write(sk, skb);
+	if (err) {
+		net_dbg_ratelimited("%s: TX error (%d)\n", dev->name, err);
+		dev->stats.tx_aborted_errors++;
+		dev->stats.tx_errors++;
+	} else {
+		dev->stats.tx_packets++;
+		dev->stats.tx_bytes += len;
+	}
+
+	netif_stop_queue(dev);
+	if (pep_writeable(sk))
+		netif_wake_queue(dev);
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops gprs_netdev_ops = {
+	.ndo_open	= gprs_open,
+	.ndo_stop	= gprs_close,
+	.ndo_start_xmit	= gprs_xmit,
+};
+
+static void gprs_setup(struct net_device *dev)
+{
+	dev->features		= NETIF_F_FRAGLIST;
+	dev->type		= ARPHRD_PHONET_PIPE;
+	dev->flags		= IFF_POINTOPOINT | IFF_NOARP;
+	dev->mtu		= GPRS_DEFAULT_MTU;
+	dev->min_mtu		= 576;
+	dev->max_mtu		= (PHONET_MAX_MTU - 11);
+	dev->hard_header_len	= 0;
+	dev->addr_len		= 0;
+	dev->tx_queue_len	= 10;
+
+	dev->netdev_ops		= &gprs_netdev_ops;
+	dev->needs_free_netdev	= true;
+}
+
+/*
+ * 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 *gp;
+	struct net_device *dev;
+	int err;
+
+	if (unlikely(sk->sk_type == SOCK_STREAM))
+		return -EINVAL; /* need packet boundaries */
+
+	/* Create net device */
+	dev = alloc_netdev(sizeof(*gp), ifname, NET_NAME_UNKNOWN, gprs_setup);
+	if (!dev)
+		return -ENOMEM;
+	gp = netdev_priv(dev);
+	gp->sk = sk;
+	gp->dev = dev;
+
+	netif_stop_queue(dev);
+	err = register_netdev(dev);
+	if (err) {
+		free_netdev(dev);
+		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	= gp;
+	gp->old_state_change	= sk->sk_state_change;
+	gp->old_data_ready	= sk->sk_data_ready;
+	gp->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);
+
+	printk(KERN_DEBUG"%s: attached\n", dev->name);
+	return dev->ifindex;
+
+out_rel:
+	release_sock(sk);
+	unregister_netdev(dev);
+	return err;
+}
+
+void gprs_detach(struct sock *sk)
+{
+	struct gprs_dev *gp = sk->sk_user_data;
+	struct net_device *dev = gp->dev;
+
+	lock_sock(sk);
+	sk->sk_user_data	= NULL;
+	sk->sk_state_change	= gp->old_state_change;
+	sk->sk_data_ready	= gp->old_data_ready;
+	sk->sk_write_space	= gp->old_write_space;
+	release_sock(sk);
+
+	printk(KERN_DEBUG"%s: detached\n", dev->name);
+	unregister_netdev(dev);
+	sock_put(sk);
+}