2005-04-16 16:20:36 -06:00
|
|
|
/*
|
|
|
|
* INET An implementation of the TCP/IP protocol suite for the LINUX
|
|
|
|
* operating system. INET is implemented using the BSD Socket
|
|
|
|
* interface as the means of communication with the user level.
|
|
|
|
*
|
|
|
|
* Pseudo-driver for the loopback interface.
|
|
|
|
*
|
|
|
|
* Version: @(#)loopback.c 1.0.4b 08/16/93
|
|
|
|
*
|
2005-05-05 17:16:16 -06:00
|
|
|
* Authors: Ross Biro
|
2005-04-16 16:20:36 -06:00
|
|
|
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
|
|
|
|
* Donald Becker, <becker@scyld.com>
|
|
|
|
*
|
|
|
|
* Alan Cox : Fixed oddments for NET3.014
|
|
|
|
* Alan Cox : Rejig for NET3.029 snap #3
|
|
|
|
* Alan Cox : Fixed NET3.029 bugs and sped up
|
|
|
|
* Larry McVoy : Tiny tweak to double performance
|
|
|
|
* Alan Cox : Backed out LMV's tweak - the linux mm
|
|
|
|
* can't take it...
|
|
|
|
* Michael Griffith: Don't bother computing the checksums
|
|
|
|
* on packets received on the loopback
|
|
|
|
* interface.
|
|
|
|
* Alexey Kuznetsov: Potential hang under some extreme
|
|
|
|
* cases removed.
|
|
|
|
*
|
|
|
|
* This program is free software; you can redistribute it and/or
|
|
|
|
* modify it under the terms of the GNU General Public License
|
|
|
|
* as published by the Free Software Foundation; either version
|
|
|
|
* 2 of the License, or (at your option) any later version.
|
|
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
#include <linux/jiffies.h>
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/interrupt.h>
|
|
|
|
#include <linux/fs.h>
|
|
|
|
#include <linux/types.h>
|
|
|
|
#include <linux/string.h>
|
|
|
|
#include <linux/socket.h>
|
|
|
|
#include <linux/errno.h>
|
|
|
|
#include <linux/fcntl.h>
|
|
|
|
#include <linux/in.h>
|
|
|
|
#include <linux/init.h>
|
|
|
|
|
|
|
|
#include <asm/system.h>
|
|
|
|
#include <asm/uaccess.h>
|
|
|
|
#include <asm/io.h>
|
|
|
|
|
|
|
|
#include <linux/inet.h>
|
|
|
|
#include <linux/netdevice.h>
|
|
|
|
#include <linux/etherdevice.h>
|
|
|
|
#include <linux/skbuff.h>
|
|
|
|
#include <linux/ethtool.h>
|
|
|
|
#include <net/sock.h>
|
|
|
|
#include <net/checksum.h>
|
|
|
|
#include <linux/if_ether.h> /* For the statistics structure. */
|
|
|
|
#include <linux/if_arp.h> /* For ARPHRD_ETHER */
|
|
|
|
#include <linux/ip.h>
|
|
|
|
#include <linux/tcp.h>
|
|
|
|
#include <linux/percpu.h>
|
2007-09-26 23:10:56 -06:00
|
|
|
#include <net/net_namespace.h>
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2006-10-18 21:51:57 -06:00
|
|
|
struct pcpu_lstats {
|
|
|
|
unsigned long packets;
|
|
|
|
unsigned long bytes;
|
|
|
|
};
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
#define LOOPBACK_OVERHEAD (128 + MAX_HEADER + 16 + 16)
|
|
|
|
|
|
|
|
/* KISS: just allocate small chunks and copy bits.
|
|
|
|
*
|
|
|
|
* So, in fact, this is documentation, explaining what we expect
|
|
|
|
* of largesending device modulo TCP checksum, which is ignored for loopback.
|
|
|
|
*/
|
|
|
|
|
2005-07-02 19:28:21 -06:00
|
|
|
#ifdef LOOPBACK_TSO
|
2005-04-16 16:20:36 -06:00
|
|
|
static void emulate_large_send_offload(struct sk_buff *skb)
|
|
|
|
{
|
2007-04-20 23:47:35 -06:00
|
|
|
struct iphdr *iph = ip_hdr(skb);
|
2007-04-10 21:50:43 -06:00
|
|
|
struct tcphdr *th = (struct tcphdr *)(skb_network_header(skb) +
|
|
|
|
(iph->ihl * 4));
|
2005-04-16 16:20:36 -06:00
|
|
|
unsigned int doffset = (iph->ihl + th->doff) * 4;
|
2006-06-22 03:40:14 -06:00
|
|
|
unsigned int mtu = skb_shinfo(skb)->gso_size + doffset;
|
2005-04-16 16:20:36 -06:00
|
|
|
unsigned int offset = 0;
|
|
|
|
u32 seq = ntohl(th->seq);
|
|
|
|
u16 id = ntohs(iph->id);
|
|
|
|
|
|
|
|
while (offset + doffset < skb->len) {
|
|
|
|
unsigned int frag_size = min(mtu, skb->len - offset) - doffset;
|
|
|
|
struct sk_buff *nskb = alloc_skb(mtu + 32, GFP_ATOMIC);
|
|
|
|
|
|
|
|
if (!nskb)
|
|
|
|
break;
|
|
|
|
skb_reserve(nskb, 32);
|
2007-03-10 08:30:58 -07:00
|
|
|
skb_set_mac_header(nskb, -ETH_HLEN);
|
2007-04-10 21:45:18 -06:00
|
|
|
skb_reset_network_header(nskb);
|
2007-04-20 23:47:35 -06:00
|
|
|
iph = ip_hdr(nskb);
|
2007-03-31 08:55:19 -06:00
|
|
|
skb_copy_to_linear_data(nskb, skb_network_header(skb),
|
|
|
|
doffset);
|
2005-04-16 16:20:36 -06:00
|
|
|
if (skb_copy_bits(skb,
|
|
|
|
doffset + offset,
|
|
|
|
nskb->data + doffset,
|
|
|
|
frag_size))
|
|
|
|
BUG();
|
|
|
|
skb_put(nskb, doffset + frag_size);
|
|
|
|
nskb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
|
|
nskb->dev = skb->dev;
|
|
|
|
nskb->priority = skb->priority;
|
|
|
|
nskb->protocol = skb->protocol;
|
|
|
|
nskb->dst = dst_clone(skb->dst);
|
|
|
|
memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
|
|
|
|
nskb->pkt_type = skb->pkt_type;
|
|
|
|
|
2007-04-10 21:50:43 -06:00
|
|
|
th = (struct tcphdr *)(skb_network_header(nskb) + iph->ihl * 4);
|
2005-04-16 16:20:36 -06:00
|
|
|
iph->tot_len = htons(frag_size + doffset);
|
|
|
|
iph->id = htons(id);
|
|
|
|
iph->check = 0;
|
|
|
|
iph->check = ip_fast_csum((unsigned char *) iph, iph->ihl);
|
|
|
|
th->seq = htonl(seq);
|
|
|
|
if (offset + doffset + frag_size < skb->len)
|
|
|
|
th->fin = th->psh = 0;
|
|
|
|
netif_rx(nskb);
|
|
|
|
offset += frag_size;
|
|
|
|
seq += frag_size;
|
|
|
|
id++;
|
|
|
|
}
|
|
|
|
|
|
|
|
dev_kfree_skb(skb);
|
|
|
|
}
|
2005-07-02 19:28:21 -06:00
|
|
|
#endif /* LOOPBACK_TSO */
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* The higher levels take care of making this non-reentrant (it's
|
|
|
|
* called with bh's disabled).
|
|
|
|
*/
|
|
|
|
static int loopback_xmit(struct sk_buff *skb, struct net_device *dev)
|
|
|
|
{
|
2007-09-26 23:08:12 -06:00
|
|
|
struct pcpu_lstats *pcpu_lstats, *lb_stats;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
skb_orphan(skb);
|
|
|
|
|
2005-07-02 19:28:23 -06:00
|
|
|
skb->protocol = eth_type_trans(skb,dev);
|
2005-04-16 16:20:36 -06:00
|
|
|
#ifndef LOOPBACK_MUST_CHECKSUM
|
|
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
|
|
#endif
|
|
|
|
|
2005-07-02 19:28:21 -06:00
|
|
|
#ifdef LOOPBACK_TSO
|
2006-07-08 14:34:32 -06:00
|
|
|
if (skb_is_gso(skb)) {
|
2005-04-16 16:20:36 -06:00
|
|
|
BUG_ON(skb->protocol != htons(ETH_P_IP));
|
2007-04-20 23:47:35 -06:00
|
|
|
BUG_ON(ip_hdr(skb)->protocol != IPPROTO_TCP);
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
emulate_large_send_offload(skb);
|
|
|
|
return 0;
|
|
|
|
}
|
2005-07-02 19:28:21 -06:00
|
|
|
#endif
|
2005-04-16 16:20:36 -06:00
|
|
|
dev->last_rx = jiffies;
|
|
|
|
|
2007-09-27 18:09:39 -06:00
|
|
|
/* it's OK to use per_cpu_ptr() because BHs are off */
|
2007-09-26 23:08:12 -06:00
|
|
|
pcpu_lstats = netdev_priv(dev);
|
|
|
|
lb_stats = per_cpu_ptr(pcpu_lstats, smp_processor_id());
|
2006-10-18 21:51:57 -06:00
|
|
|
lb_stats->bytes += skb->len;
|
|
|
|
lb_stats->packets++;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
netif_rx(skb);
|
|
|
|
|
2006-10-20 01:32:41 -06:00
|
|
|
return 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static struct net_device_stats *get_stats(struct net_device *dev)
|
|
|
|
{
|
2007-09-26 23:08:12 -06:00
|
|
|
const struct pcpu_lstats *pcpu_lstats;
|
2007-04-10 14:25:40 -06:00
|
|
|
struct net_device_stats *stats = &dev->stats;
|
2006-10-18 21:51:57 -06:00
|
|
|
unsigned long bytes = 0;
|
|
|
|
unsigned long packets = 0;
|
2005-04-16 16:20:36 -06:00
|
|
|
int i;
|
|
|
|
|
2007-09-26 23:08:12 -06:00
|
|
|
pcpu_lstats = netdev_priv(dev);
|
2006-03-28 02:56:37 -07:00
|
|
|
for_each_possible_cpu(i) {
|
2006-10-18 21:51:57 -06:00
|
|
|
const struct pcpu_lstats *lb_stats;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2007-09-26 23:08:12 -06:00
|
|
|
lb_stats = per_cpu_ptr(pcpu_lstats, i);
|
2006-10-18 21:51:57 -06:00
|
|
|
bytes += lb_stats->bytes;
|
|
|
|
packets += lb_stats->packets;
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
2006-10-18 21:51:57 -06:00
|
|
|
stats->rx_packets = packets;
|
|
|
|
stats->tx_packets = packets;
|
|
|
|
stats->rx_bytes = bytes;
|
|
|
|
stats->tx_bytes = bytes;
|
2005-04-16 16:20:36 -06:00
|
|
|
return stats;
|
|
|
|
}
|
|
|
|
|
2006-09-27 21:33:34 -06:00
|
|
|
static u32 always_on(struct net_device *dev)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2006-09-13 12:30:00 -06:00
|
|
|
static const struct ethtool_ops loopback_ethtool_ops = {
|
2006-09-27 21:33:34 -06:00
|
|
|
.get_link = always_on,
|
2005-04-16 16:20:36 -06:00
|
|
|
.set_tso = ethtool_op_set_tso,
|
2006-09-27 21:33:34 -06:00
|
|
|
.get_tx_csum = always_on,
|
|
|
|
.get_sg = always_on,
|
|
|
|
.get_rx_csum = always_on,
|
2005-04-16 16:20:36 -06:00
|
|
|
};
|
|
|
|
|
2007-09-26 23:08:12 -06:00
|
|
|
static int loopback_dev_init(struct net_device *dev)
|
|
|
|
{
|
|
|
|
struct pcpu_lstats *lstats;
|
|
|
|
|
|
|
|
lstats = alloc_percpu(struct pcpu_lstats);
|
|
|
|
if (!lstats)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
dev->priv = lstats;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void loopback_dev_free(struct net_device *dev)
|
|
|
|
{
|
|
|
|
struct pcpu_lstats *lstats = netdev_priv(dev);
|
|
|
|
|
|
|
|
free_percpu(lstats);
|
|
|
|
free_netdev(dev);
|
|
|
|
}
|
|
|
|
|
2006-09-27 21:33:34 -06:00
|
|
|
/*
|
2007-09-27 18:09:39 -06:00
|
|
|
* The loopback device is special. There is only one instance
|
|
|
|
* per network namespace.
|
2006-09-27 21:33:34 -06:00
|
|
|
*/
|
2007-09-25 20:18:04 -06:00
|
|
|
static void loopback_setup(struct net_device *dev)
|
|
|
|
{
|
|
|
|
dev->get_stats = &get_stats;
|
|
|
|
dev->mtu = (16 * 1024) + 20 + 20 + 12;
|
|
|
|
dev->hard_start_xmit = loopback_xmit;
|
|
|
|
dev->hard_header_len = ETH_HLEN; /* 14 */
|
|
|
|
dev->addr_len = ETH_ALEN; /* 6 */
|
|
|
|
dev->tx_queue_len = 0;
|
|
|
|
dev->type = ARPHRD_LOOPBACK; /* 0x0001*/
|
|
|
|
dev->flags = IFF_LOOPBACK;
|
|
|
|
dev->features = NETIF_F_SG | NETIF_F_FRAGLIST
|
2005-07-02 19:28:21 -06:00
|
|
|
#ifdef LOOPBACK_TSO
|
2007-09-25 20:18:04 -06:00
|
|
|
| NETIF_F_TSO
|
2005-07-02 19:28:21 -06:00
|
|
|
#endif
|
2007-09-25 20:18:04 -06:00
|
|
|
| NETIF_F_NO_CSUM
|
|
|
|
| NETIF_F_HIGHDMA
|
|
|
|
| NETIF_F_LLTX
|
|
|
|
| NETIF_F_NETNS_LOCAL,
|
|
|
|
dev->ethtool_ops = &loopback_ethtool_ops;
|
2007-10-09 02:40:57 -06:00
|
|
|
dev->header_ops = ð_header_ops;
|
2007-09-26 23:08:12 -06:00
|
|
|
dev->init = loopback_dev_init;
|
|
|
|
dev->destructor = loopback_dev_free;
|
2007-09-25 20:18:04 -06:00
|
|
|
}
|
2007-09-25 20:16:28 -06:00
|
|
|
|
2005-08-18 15:05:18 -06:00
|
|
|
/* Setup and register the loopback device. */
|
2007-10-08 21:38:39 -06:00
|
|
|
static __net_init int loopback_net_init(struct net *net)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2007-09-25 20:18:04 -06:00
|
|
|
struct net_device *dev;
|
|
|
|
int err;
|
|
|
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
dev = alloc_netdev(0, "lo", loopback_setup);
|
|
|
|
if (!dev)
|
|
|
|
goto out;
|
2007-07-30 17:37:19 -06:00
|
|
|
|
2007-09-26 23:10:56 -06:00
|
|
|
dev->nd_net = net;
|
2007-09-25 20:18:04 -06:00
|
|
|
err = register_netdev(dev);
|
2007-07-30 17:37:19 -06:00
|
|
|
if (err)
|
2007-09-25 20:18:04 -06:00
|
|
|
goto out_free_netdev;
|
2007-07-30 17:37:19 -06:00
|
|
|
|
2007-09-25 20:18:04 -06:00
|
|
|
err = 0;
|
2007-09-26 23:10:56 -06:00
|
|
|
net->loopback_dev = dev;
|
2007-09-25 20:18:04 -06:00
|
|
|
|
|
|
|
out:
|
|
|
|
if (err)
|
|
|
|
panic("loopback: Failed to register netdevice: %d\n", err);
|
2007-07-30 17:37:19 -06:00
|
|
|
return err;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2007-09-25 20:18:04 -06:00
|
|
|
out_free_netdev:
|
|
|
|
free_netdev(dev);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
2007-10-08 21:38:39 -06:00
|
|
|
static __net_exit void loopback_net_exit(struct net *net)
|
2007-09-26 23:10:56 -06:00
|
|
|
{
|
|
|
|
struct net_device *dev = net->loopback_dev;
|
|
|
|
|
|
|
|
unregister_netdev(dev);
|
|
|
|
}
|
|
|
|
|
2007-10-08 21:38:39 -06:00
|
|
|
static struct pernet_operations __net_initdata loopback_net_ops = {
|
2007-09-26 23:10:56 -06:00
|
|
|
.init = loopback_net_init,
|
|
|
|
.exit = loopback_net_exit,
|
|
|
|
};
|
|
|
|
|
|
|
|
static int __init loopback_init(void)
|
|
|
|
{
|
|
|
|
return register_pernet_device(&loopback_net_ops);
|
|
|
|
}
|
2007-01-02 01:35:48 -07:00
|
|
|
|
2007-09-27 13:04:19 -06:00
|
|
|
/* Loopback is special. It should be initialized before any other network
|
|
|
|
* device and network subsystem.
|
|
|
|
*/
|
2007-09-26 23:10:56 -06:00
|
|
|
fs_initcall(loopback_init);
|