linux/arch/um/drivers/daemon_kern.c
Jeff Dike b53f35a809 uml: network driver MTU cleanups
A bunch of MTU-related cleanups in the network code.

First, there is the addition of the notion of a maximally-sized packet, which
is the MTU plus headers.  This is used to size the skb that will receive a
packet.  This allows ether_adjust_skb to go away, as it was used to resize the
skb after it was allocated.

Since the skb passed into the low-level read routine is no longer resized, and
possibly reallocated, there, they (and the write routines) don't need to get
an sk_buff **.  They just need the sk_buff * now.  The callers of
ether_adjust_skb still need to do the skb_put, so that's now inlined.

The MAX_PACKET definitions in most of the drivers are gone.

The set_mtu methods were all the same and did nothing, so they can be
removed.

The ethertap driver had a typo which doubled the size of the packet rather
than adding two bytes to it.  It also wasn't defining its setup_size, causing
a zero-byte kmalloc and crash when the invalid pointer returned from kmalloc
was dereferenced.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:08 -07:00

96 lines
2.4 KiB
C

/*
* Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
* James Leu (jleu@mindspring.net).
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* 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 "net_kern.h"
#include "daemon.h"
struct daemon_init {
char *sock_type;
char *ctl_sock;
};
static void daemon_init(struct net_device *dev, void *data)
{
struct uml_net_private *pri;
struct daemon_data *dpri;
struct daemon_init *init = data;
pri = dev->priv;
dpri = (struct daemon_data *) pri->user;
dpri->sock_type = init->sock_type;
dpri->ctl_sock = init->ctl_sock;
dpri->fd = -1;
dpri->control = -1;
dpri->dev = dev;
/* We will free this pointer. If it contains crap we're burned. */
dpri->ctl_addr = NULL;
dpri->data_addr = NULL;
dpri->local_addr = NULL;
printk("daemon backend (uml_switch version %d) - %s:%s",
SWITCH_VERSION, dpri->sock_type, dpri->ctl_sock);
printk("\n");
}
static int daemon_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
return net_recvfrom(fd, skb_mac_header(skb),
skb->dev->mtu + ETH_HEADER_OTHER);
}
static int daemon_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
{
return daemon_user_write(fd, skb->data, skb->len,
(struct daemon_data *) &lp->user);
}
static const struct net_kern_info daemon_kern_info = {
.init = daemon_init,
.protocol = eth_protocol,
.read = daemon_read,
.write = daemon_write,
};
static int daemon_setup(char *str, char **mac_out, void *data)
{
struct daemon_init *init = data;
char *remain;
*init = ((struct daemon_init)
{ .sock_type = "unix",
.ctl_sock = "/tmp/uml.ctl" });
remain = split_if_spec(str, mac_out, &init->sock_type, &init->ctl_sock,
NULL);
if (remain != NULL)
printk(KERN_WARNING "daemon_setup : Ignoring data socket "
"specification\n");
return 1;
}
static struct transport daemon_transport = {
.list = LIST_HEAD_INIT(daemon_transport.list),
.name = "daemon",
.setup = daemon_setup,
.user = &daemon_user_info,
.kern = &daemon_kern_info,
.private_size = sizeof(struct daemon_data),
.setup_size = sizeof(struct daemon_init),
};
static int register_daemon(void)
{
register_transport(&daemon_transport);
return 0;
}
late_initcall(register_daemon);