b53f35a809
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>
87 lines
1.9 KiB
C
87 lines
1.9 KiB
C
/*
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* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*/
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#include <linux/netdevice.h>
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <asm/errno.h>
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#include "net_kern.h"
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#include "tuntap.h"
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struct tuntap_init {
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char *dev_name;
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char *gate_addr;
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};
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static void tuntap_init(struct net_device *dev, void *data)
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{
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struct uml_net_private *pri;
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struct tuntap_data *tpri;
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struct tuntap_init *init = data;
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pri = dev->priv;
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tpri = (struct tuntap_data *) pri->user;
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tpri->dev_name = init->dev_name;
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tpri->fixed_config = (init->dev_name != NULL);
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tpri->gate_addr = init->gate_addr;
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tpri->fd = -1;
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tpri->dev = dev;
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printk("TUN/TAP backend - ");
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if (tpri->gate_addr != NULL)
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printk("IP = %s", tpri->gate_addr);
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printk("\n");
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}
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static int tuntap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
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{
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return net_read(fd, skb_mac_header(skb),
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skb->dev->mtu + ETH_HEADER_OTHER);
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}
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static int tuntap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
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{
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return net_write(fd, skb->data, skb->len);
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}
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const struct net_kern_info tuntap_kern_info = {
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.init = tuntap_init,
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.protocol = eth_protocol,
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.read = tuntap_read,
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.write = tuntap_write,
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};
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int tuntap_setup(char *str, char **mac_out, void *data)
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{
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struct tuntap_init *init = data;
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*init = ((struct tuntap_init)
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{ .dev_name = NULL,
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.gate_addr = NULL });
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if (tap_setup_common(str, "tuntap", &init->dev_name, mac_out,
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&init->gate_addr))
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return 0;
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return 1;
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}
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static struct transport tuntap_transport = {
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.list = LIST_HEAD_INIT(tuntap_transport.list),
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.name = "tuntap",
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.setup = tuntap_setup,
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.user = &tuntap_user_info,
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.kern = &tuntap_kern_info,
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.private_size = sizeof(struct tuntap_data),
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.setup_size = sizeof(struct tuntap_init),
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};
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static int register_tuntap(void)
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{
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register_transport(&tuntap_transport);
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return 0;
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}
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late_initcall(register_tuntap);
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