linux/arch/um/os-Linux/drivers/ethertap_kern.c
Jeff Dike 5e7672ec3f [PATCH] uml: const more data
Make lots of structures const in order to make it obvious that they need no
locking.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:15 -07:00

109 lines
2.5 KiB
C

/*
* Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
* James Leu (jleu@mindspring.net).
* Copyright (C) 2001 by various other people who didn't put their name here.
* Licensed under the GPL.
*/
#include "linux/init.h"
#include "linux/netdevice.h"
#include "linux/etherdevice.h"
#include "net_kern.h"
#include "net_user.h"
#include "etap.h"
struct ethertap_init {
char *dev_name;
char *gate_addr;
};
static void etap_init(struct net_device *dev, void *data)
{
struct uml_net_private *pri;
struct ethertap_data *epri;
struct ethertap_init *init = data;
pri = dev->priv;
epri = (struct ethertap_data *) pri->user;
epri->dev_name = init->dev_name;
epri->gate_addr = init->gate_addr;
epri->data_fd = -1;
epri->control_fd = -1;
epri->dev = dev;
printk("ethertap backend - %s", epri->dev_name);
if (epri->gate_addr != NULL)
printk(", IP = %s", epri->gate_addr);
printk("\n");
}
static int etap_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
{
int len;
*skb = ether_adjust_skb(*skb, ETH_HEADER_ETHERTAP);
if(*skb == NULL) return(-ENOMEM);
len = net_recvfrom(fd, (*skb)->mac.raw,
(*skb)->dev->mtu + 2 * ETH_HEADER_ETHERTAP);
if(len <= 0) return(len);
skb_pull(*skb, 2);
len -= 2;
return(len);
}
static int etap_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
{
if(skb_headroom(*skb) < 2){
struct sk_buff *skb2;
skb2 = skb_realloc_headroom(*skb, 2);
dev_kfree_skb(*skb);
if (skb2 == NULL) return(-ENOMEM);
*skb = skb2;
}
skb_push(*skb, 2);
return(net_send(fd, (*skb)->data, (*skb)->len));
}
const struct net_kern_info ethertap_kern_info = {
.init = etap_init,
.protocol = eth_protocol,
.read = etap_read,
.write = etap_write,
};
int ethertap_setup(char *str, char **mac_out, void *data)
{
struct ethertap_init *init = data;
*init = ((struct ethertap_init)
{ .dev_name = NULL,
.gate_addr = NULL });
if(tap_setup_common(str, "ethertap", &init->dev_name, mac_out,
&init->gate_addr))
return(0);
if(init->dev_name == NULL){
printk("ethertap_setup : Missing tap device name\n");
return(0);
}
return(1);
}
static struct transport ethertap_transport = {
.list = LIST_HEAD_INIT(ethertap_transport.list),
.name = "ethertap",
.setup = ethertap_setup,
.user = &ethertap_user_info,
.kern = &ethertap_kern_info,
.private_size = sizeof(struct ethertap_data),
};
static int register_ethertap(void)
{
register_transport(&ethertap_transport);
return 0;
}
__initcall(register_ethertap);