329 lines
6.8 KiB
C
329 lines
6.8 KiB
C
/*
|
|
* 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 *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, int len)
|
|
{
|
|
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) {
|
|
LIMIT_NETDEBUG(KERN_WARNING"%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 int gprs_set_mtu(struct net_device *dev, int new_mtu)
|
|
{
|
|
if ((new_mtu < 576) || (new_mtu > (PHONET_MAX_MTU - 11)))
|
|
return -EINVAL;
|
|
|
|
dev->mtu = new_mtu;
|
|
return 0;
|
|
}
|
|
|
|
static const struct net_device_ops gprs_netdev_ops = {
|
|
.ndo_open = gprs_open,
|
|
.ndo_stop = gprs_close,
|
|
.ndo_start_xmit = gprs_xmit,
|
|
.ndo_change_mtu = gprs_set_mtu,
|
|
};
|
|
|
|
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->hard_header_len = 0;
|
|
dev->addr_len = 0;
|
|
dev->tx_queue_len = 10;
|
|
|
|
dev->netdev_ops = &gprs_netdev_ops;
|
|
dev->destructor = free_netdev;
|
|
}
|
|
|
|
/*
|
|
* 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, 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);
|
|
}
|