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>
124 lines
2.7 KiB
C
124 lines
2.7 KiB
C
/*
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* Copyright (C) 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/if_arp.h>
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#include "linux/init.h"
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#include <linux/netdevice.h>
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#include <linux/string.h>
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#include "net_kern.h"
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#include "net_user.h"
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#include "slirp.h"
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struct slirp_init {
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struct arg_list_dummy_wrapper argw; /* XXX should be simpler... */
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};
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void slirp_init(struct net_device *dev, void *data)
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{
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struct uml_net_private *private;
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struct slirp_data *spri;
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struct slirp_init *init = data;
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int i;
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private = dev->priv;
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spri = (struct slirp_data *) private->user;
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spri->argw = init->argw;
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spri->pid = -1;
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spri->slave = -1;
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spri->dev = dev;
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slip_proto_init(&spri->slip);
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dev->init = NULL;
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dev->hard_header_len = 0;
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dev->header_cache_update = NULL;
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dev->hard_header_cache = NULL;
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dev->hard_header = NULL;
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dev->addr_len = 0;
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dev->type = ARPHRD_SLIP;
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dev->tx_queue_len = 256;
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dev->flags = IFF_NOARP;
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printk("SLIRP backend - command line:");
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for (i = 0; spri->argw.argv[i] != NULL; i++)
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printk(" '%s'",spri->argw.argv[i]);
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printk("\n");
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}
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static unsigned short slirp_protocol(struct sk_buff *skbuff)
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{
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return htons(ETH_P_IP);
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}
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static int slirp_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
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{
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return slirp_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
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(struct slirp_data *) &lp->user);
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}
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static int slirp_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
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{
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return slirp_user_write(fd, skb->data, skb->len,
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(struct slirp_data *) &lp->user);
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}
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const struct net_kern_info slirp_kern_info = {
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.init = slirp_init,
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.protocol = slirp_protocol,
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.read = slirp_read,
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.write = slirp_write,
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};
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static int slirp_setup(char *str, char **mac_out, void *data)
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{
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struct slirp_init *init = data;
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int i=0;
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*init = ((struct slirp_init) { .argw = { { "slirp", NULL } } });
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str = split_if_spec(str, mac_out, NULL);
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if (str == NULL) /* no command line given after MAC addr */
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return 1;
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do {
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if (i >= SLIRP_MAX_ARGS - 1) {
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printk(KERN_WARNING "slirp_setup: truncating slirp "
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"arguments\n");
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break;
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}
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init->argw.argv[i++] = str;
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while(*str && *str!=',') {
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if (*str == '_')
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*str=' ';
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str++;
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}
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if (*str != ',')
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break;
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*str++ = '\0';
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} while (1);
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init->argw.argv[i] = NULL;
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return 1;
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}
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static struct transport slirp_transport = {
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.list = LIST_HEAD_INIT(slirp_transport.list),
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.name = "slirp",
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.setup = slirp_setup,
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.user = &slirp_user_info,
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.kern = &slirp_kern_info,
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.private_size = sizeof(struct slirp_data),
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.setup_size = sizeof(struct slirp_init),
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};
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static int register_slirp(void)
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{
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register_transport(&slirp_transport);
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return 0;
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}
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late_initcall(register_slirp);
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