From 02a47617cdce440f60c71a51f3a93f9f5fcc5a7a Mon Sep 17 00:00:00 2001 From: Rémi Denis-Courmont Date: Sun, 5 Oct 2008 11:16:16 -0700 Subject: Phonet: implement GPRS virtual interface over PEP socket MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Rémi Denis-Courmont Signed-off-by: David S. Miller --- net/phonet/pep-gprs.c | 347 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 347 insertions(+) create mode 100644 net/phonet/pep-gprs.c (limited to 'net/phonet/pep-gprs.c') diff --git a/net/phonet/pep-gprs.c b/net/phonet/pep-gprs.c new file mode 100644 index 000000000000..9978afbd9f2a --- /dev/null +++ b/net/phonet/pep-gprs.c @@ -0,0 +1,347 @@ +/* + * 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 +#include +#include +#include +#include + +#include +#include +#include + +#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; + unsigned credits = pep_writeable(sk); + + spin_lock_bh(&dev->tx_lock); + dev->tx_max = credits; + if (credits > skb_queue_len(&dev->tx_queue)) + netif_wake_queue(dev->net); + spin_unlock_bh(&dev->tx_lock); +} + +/* + * Network device callbacks + */ + +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->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); + gprs_write_space(sk); /* kick off TX */ + 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); + flush_scheduled_work(); + sock_put(sk); + skb_queue_purge(&dev->tx_queue); +} -- cgit v1.2.3