OpenCloudOS-Kernel/net/phonet/pep-gprs.c

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/*
* 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;
net: use core MTU range checking in misc drivers firewire-net: - set min/max_mtu - remove fwnet_change_mtu nes: - set max_mtu - clean up nes_netdev_change_mtu xpnet: - set min/max_mtu - remove xpnet_dev_change_mtu hippi: - set min/max_mtu - remove hippi_change_mtu batman-adv: - set max_mtu - remove batadv_interface_change_mtu - initialization is a little async, not 100% certain that max_mtu is set in the optimal place, don't have hardware to test with rionet: - set min/max_mtu - remove rionet_change_mtu slip: - set min/max_mtu - streamline sl_change_mtu um/net_kern: - remove pointless ndo_change_mtu hsi/clients/ssi_protocol: - use core MTU range checking - remove now redundant ssip_pn_set_mtu ipoib: - set a default max MTU value - Note: ipoib's actual max MTU can vary, depending on if the device is in connected mode or not, so we'll just set the max_mtu value to the max possible, and let the ndo_change_mtu function continue to validate any new MTU change requests with checks for CM or not. Note that ipoib has no min_mtu set, and thus, the network core's mtu > 0 check is the only lower bounds here. mptlan: - use net core MTU range checking - remove now redundant mpt_lan_change_mtu fddi: - min_mtu = 21, max_mtu = 4470 - remove now redundant fddi_change_mtu (including export) fjes: - min_mtu = 8192, max_mtu = 65536 - The max_mtu value is actually one over IP_MAX_MTU here, but the idea is to get past the core net MTU range checks so fjes_change_mtu can validate a new MTU against what it supports (see fjes_support_mtu in fjes_hw.c) hsr: - min_mtu = 0 (calls ether_setup, max_mtu is 1500) f_phonet: - min_mtu = 6, max_mtu = 65541 u_ether: - min_mtu = 14, max_mtu = 15412 phonet/pep-gprs: - min_mtu = 576, max_mtu = 65530 - remove redundant gprs_set_mtu CC: netdev@vger.kernel.org CC: linux-rdma@vger.kernel.org CC: Stefan Richter <stefanr@s5r6.in-berlin.de> CC: Faisal Latif <faisal.latif@intel.com> CC: linux-rdma@vger.kernel.org CC: Cliff Whickman <cpw@sgi.com> CC: Robin Holt <robinmholt@gmail.com> CC: Jes Sorensen <jes@trained-monkey.org> CC: Marek Lindner <mareklindner@neomailbox.ch> CC: Simon Wunderlich <sw@simonwunderlich.de> CC: Antonio Quartulli <a@unstable.cc> CC: Sathya Prakash <sathya.prakash@broadcom.com> CC: Chaitra P B <chaitra.basappa@broadcom.com> CC: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com> CC: MPT-FusionLinux.pdl@broadcom.com CC: Sebastian Reichel <sre@kernel.org> CC: Felipe Balbi <balbi@kernel.org> CC: Arvid Brodin <arvid.brodin@alten.se> CC: Remi Denis-Courmont <courmisch@gmail.com> Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-21 01:55:22 +08:00
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->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, 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);
}