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/*
* File: af_phonet.c
*
* Phonet protocols family
*
* Copyright (C) 2008 Nokia Corporation.
*
* Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
* Original author: Sakari Ailus <sakari.ailus@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/module.h>
#include <asm/unaligned.h>
#include <net/sock.h>
#include <linux/if_phonet.h>
#include <linux/phonet.h>
#include <net/phonet/phonet.h>
static struct net_proto_family phonet_proto_family;
static struct phonet_protocol *phonet_proto_get(int protocol);
static inline void phonet_proto_put(struct phonet_protocol *pp);
/* protocol family functions */
static int pn_socket_create(struct net *net, struct socket *sock, int protocol)
{
struct phonet_protocol *pnp;
int err;
if (net != &init_net)
return -EAFNOSUPPORT;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (protocol == 0) {
/* Default protocol selection */
switch (sock->type) {
case SOCK_DGRAM:
protocol = PN_PROTO_PHONET;
break;
default:
return -EPROTONOSUPPORT;
}
}
pnp = phonet_proto_get(protocol);
if (pnp == NULL)
return -EPROTONOSUPPORT;
if (sock->type != pnp->sock_type) {
err = -EPROTONOSUPPORT;
goto out;
}
/* TODO: create and init the struct sock */
err = -EPROTONOSUPPORT;
out:
phonet_proto_put(pnp);
return err;
}
static struct net_proto_family phonet_proto_family = {
.family = AF_PHONET,
.create = pn_socket_create,
.owner = THIS_MODULE,
};
/* packet type functions */
/*
* Stuff received packets to associated sockets.
* On error, returns non-zero and releases the skb.
*/
static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pkttype,
struct net_device *orig_dev)
{
struct phonethdr *ph;
struct sockaddr_pn sa;
u16 len;
if (dev_net(dev) != &init_net)
goto out;
/* check we have at least a full Phonet header */
if (!pskb_pull(skb, sizeof(struct phonethdr)))
goto out;
/* check that the advertised length is correct */
ph = pn_hdr(skb);
len = get_unaligned_be16(&ph->pn_length);
if (len < 2)
goto out;
len -= 2;
if ((len > skb->len) || pskb_trim(skb, len))
goto out;
skb_reset_transport_header(skb);
pn_skb_get_dst_sockaddr(skb, &sa);
if (pn_sockaddr_get_addr(&sa) == 0)
goto out; /* currently, we cannot be device 0 */
/* TODO: put packets to sockets backlog */
out:
kfree_skb(skb);
return NET_RX_DROP;
}
static struct packet_type phonet_packet_type = {
.type = __constant_htons(ETH_P_PHONET),
.dev = NULL,
.func = phonet_rcv,
};
/* Transport protocol registration */
static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
static DEFINE_SPINLOCK(proto_tab_lock);
int __init_or_module phonet_proto_register(int protocol,
struct phonet_protocol *pp)
{
int err = 0;
if (protocol >= PHONET_NPROTO)
return -EINVAL;
err = proto_register(pp->prot, 1);
if (err)
return err;
spin_lock(&proto_tab_lock);
if (proto_tab[protocol])
err = -EBUSY;
else
proto_tab[protocol] = pp;
spin_unlock(&proto_tab_lock);
return err;
}
EXPORT_SYMBOL(phonet_proto_register);
void phonet_proto_unregister(int protocol, struct phonet_protocol *pp)
{
spin_lock(&proto_tab_lock);
BUG_ON(proto_tab[protocol] != pp);
proto_tab[protocol] = NULL;
spin_unlock(&proto_tab_lock);
proto_unregister(pp->prot);
}
EXPORT_SYMBOL(phonet_proto_unregister);
static struct phonet_protocol *phonet_proto_get(int protocol)
{
struct phonet_protocol *pp;
if (protocol >= PHONET_NPROTO)
return NULL;
spin_lock(&proto_tab_lock);
pp = proto_tab[protocol];
if (pp && !try_module_get(pp->prot->owner))
pp = NULL;
spin_unlock(&proto_tab_lock);
return pp;
}
static inline void phonet_proto_put(struct phonet_protocol *pp)
{
module_put(pp->prot->owner);
}
/* Module registration */
static int __init phonet_init(void)
{
int err;
err = sock_register(&phonet_proto_family);
if (err) {
printk(KERN_ALERT
"phonet protocol family initialization failed\n");
return err;
}
dev_add_pack(&phonet_packet_type);
return 0;
}
static void __exit phonet_exit(void)
{
sock_unregister(AF_PHONET);
dev_remove_pack(&phonet_packet_type);
}
module_init(phonet_init);
module_exit(phonet_exit);
MODULE_DESCRIPTION("Phonet protocol stack for Linux");
MODULE_LICENSE("GPL");
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