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linux/arch/um/drivers/net_kern.c
Jeff Dike d3b7f69de2 [PATCH] uml: add locking to network transport registration
The registration of host network transports needed some locking.  The
transport list itself is locked, but calls to the registration routines are
not.  This is compensated for by checking that a transport structure is not
yet on any list.

I also took the opportunity to const all fields in the transport structure
except the list, which obviously can be modified.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:21 -08:00

864 lines
18 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/kernel.h"
#include "linux/netdevice.h"
#include "linux/rtnetlink.h"
#include "linux/skbuff.h"
#include "linux/socket.h"
#include "linux/spinlock.h"
#include "linux/module.h"
#include "linux/init.h"
#include "linux/etherdevice.h"
#include "linux/list.h"
#include "linux/inetdevice.h"
#include "linux/ctype.h"
#include "linux/bootmem.h"
#include "linux/ethtool.h"
#include "linux/platform_device.h"
#include "asm/uaccess.h"
#include "user_util.h"
#include "kern_util.h"
#include "net_kern.h"
#include "net_user.h"
#include "mconsole_kern.h"
#include "init.h"
#include "irq_user.h"
#include "irq_kern.h"
static inline void set_ether_mac(struct net_device *dev, unsigned char *addr)
{
memcpy(dev->dev_addr, addr, ETH_ALEN);
}
#define DRIVER_NAME "uml-netdev"
static DEFINE_SPINLOCK(opened_lock);
static LIST_HEAD(opened);
static int uml_net_rx(struct net_device *dev)
{
struct uml_net_private *lp = dev->priv;
int pkt_len;
struct sk_buff *skb;
/* If we can't allocate memory, try again next round. */
skb = dev_alloc_skb(dev->mtu);
if (skb == NULL) {
lp->stats.rx_dropped++;
return 0;
}
skb->dev = dev;
skb_put(skb, dev->mtu);
skb->mac.raw = skb->data;
pkt_len = (*lp->read)(lp->fd, &skb, lp);
if (pkt_len > 0) {
skb_trim(skb, pkt_len);
skb->protocol = (*lp->protocol)(skb);
netif_rx(skb);
lp->stats.rx_bytes += skb->len;
lp->stats.rx_packets++;
return pkt_len;
}
kfree_skb(skb);
return pkt_len;
}
static void uml_dev_close(struct work_struct *work)
{
struct uml_net_private *lp =
container_of(work, struct uml_net_private, work);
dev_close(lp->dev);
}
irqreturn_t uml_net_interrupt(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
struct uml_net_private *lp = dev->priv;
int err;
if(!netif_running(dev))
return(IRQ_NONE);
spin_lock(&lp->lock);
while((err = uml_net_rx(dev)) > 0) ;
if(err < 0) {
printk(KERN_ERR
"Device '%s' read returned %d, shutting it down\n",
dev->name, err);
/* dev_close can't be called in interrupt context, and takes
* again lp->lock.
* And dev_close() can be safely called multiple times on the
* same device, since it tests for (dev->flags & IFF_UP). So
* there's no harm in delaying the device shutdown.
* Furthermore, the workqueue will not re-enqueue an already
* enqueued work item. */
schedule_work(&lp->work);
goto out;
}
reactivate_fd(lp->fd, UM_ETH_IRQ);
out:
spin_unlock(&lp->lock);
return(IRQ_HANDLED);
}
static int uml_net_open(struct net_device *dev)
{
struct uml_net_private *lp = dev->priv;
int err;
if(lp->fd >= 0){
err = -ENXIO;
goto out;
}
lp->fd = (*lp->open)(&lp->user);
if(lp->fd < 0){
err = lp->fd;
goto out;
}
err = um_request_irq(dev->irq, lp->fd, IRQ_READ, uml_net_interrupt,
IRQF_DISABLED | IRQF_SHARED, dev->name, dev);
if(err != 0){
printk(KERN_ERR "uml_net_open: failed to get irq(%d)\n", err);
err = -ENETUNREACH;
goto out_close;
}
lp->tl.data = (unsigned long) &lp->user;
netif_start_queue(dev);
/* clear buffer - it can happen that the host side of the interface
* is full when we get here. In this case, new data is never queued,
* SIGIOs never arrive, and the net never works.
*/
while((err = uml_net_rx(dev)) > 0) ;
spin_lock(&opened_lock);
list_add(&lp->list, &opened);
spin_unlock(&opened_lock);
return 0;
out_close:
if(lp->close != NULL) (*lp->close)(lp->fd, &lp->user);
lp->fd = -1;
out:
return err;
}
static int uml_net_close(struct net_device *dev)
{
struct uml_net_private *lp = dev->priv;
netif_stop_queue(dev);
free_irq(dev->irq, dev);
if(lp->close != NULL)
(*lp->close)(lp->fd, &lp->user);
lp->fd = -1;
spin_lock(&opened_lock);
list_del(&lp->list);
spin_unlock(&opened_lock);
return 0;
}
static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct uml_net_private *lp = dev->priv;
unsigned long flags;
int len;
netif_stop_queue(dev);
spin_lock_irqsave(&lp->lock, flags);
len = (*lp->write)(lp->fd, &skb, lp);
if(len == skb->len) {
lp->stats.tx_packets++;
lp->stats.tx_bytes += skb->len;
dev->trans_start = jiffies;
netif_start_queue(dev);
/* this is normally done in the interrupt when tx finishes */
netif_wake_queue(dev);
}
else if(len == 0){
netif_start_queue(dev);
lp->stats.tx_dropped++;
}
else {
netif_start_queue(dev);
printk(KERN_ERR "uml_net_start_xmit: failed(%d)\n", len);
}
spin_unlock_irqrestore(&lp->lock, flags);
dev_kfree_skb(skb);
return 0;
}
static struct net_device_stats *uml_net_get_stats(struct net_device *dev)
{
struct uml_net_private *lp = dev->priv;
return &lp->stats;
}
static void uml_net_set_multicast_list(struct net_device *dev)
{
if (dev->flags & IFF_PROMISC) return;
else if (dev->mc_count) dev->flags |= IFF_ALLMULTI;
else dev->flags &= ~IFF_ALLMULTI;
}
static void uml_net_tx_timeout(struct net_device *dev)
{
dev->trans_start = jiffies;
netif_wake_queue(dev);
}
static int uml_net_set_mac(struct net_device *dev, void *addr)
{
struct uml_net_private *lp = dev->priv;
struct sockaddr *hwaddr = addr;
spin_lock_irq(&lp->lock);
set_ether_mac(dev, hwaddr->sa_data);
spin_unlock_irq(&lp->lock);
return(0);
}
static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
{
struct uml_net_private *lp = dev->priv;
int err = 0;
spin_lock_irq(&lp->lock);
new_mtu = (*lp->set_mtu)(new_mtu, &lp->user);
if(new_mtu < 0){
err = new_mtu;
goto out;
}
dev->mtu = new_mtu;
out:
spin_unlock_irq(&lp->lock);
return err;
}
static void uml_net_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
{
strcpy(info->driver, DRIVER_NAME);
strcpy(info->version, "42");
}
static struct ethtool_ops uml_net_ethtool_ops = {
.get_drvinfo = uml_net_get_drvinfo,
.get_link = ethtool_op_get_link,
};
void uml_net_user_timer_expire(unsigned long _conn)
{
#ifdef undef
struct connection *conn = (struct connection *)_conn;
dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
do_connect(conn);
#endif
}
static void setup_etheraddr(char *str, unsigned char *addr)
{
char *end;
int i;
if(str == NULL)
goto random;
for(i=0;i<6;i++){
addr[i] = simple_strtoul(str, &end, 16);
if((end == str) ||
((*end != ':') && (*end != ',') && (*end != '\0'))){
printk(KERN_ERR
"setup_etheraddr: failed to parse '%s' "
"as an ethernet address\n", str);
goto random;
}
str = end + 1;
}
if(addr[0] & 1){
printk(KERN_ERR
"Attempt to assign a broadcast ethernet address to a "
"device disallowed\n");
goto random;
}
return;
random:
random_ether_addr(addr);
}
static DEFINE_SPINLOCK(devices_lock);
static LIST_HEAD(devices);
static struct platform_driver uml_net_driver = {
.driver = {
.name = DRIVER_NAME,
},
};
static int driver_registered;
static int eth_configure(int n, void *init, char *mac,
struct transport *transport)
{
struct uml_net *device;
struct net_device *dev;
struct uml_net_private *lp;
int save, err, size;
size = transport->private_size + sizeof(struct uml_net_private) +
sizeof(((struct uml_net_private *) 0)->user);
device = kzalloc(sizeof(*device), GFP_KERNEL);
if (device == NULL) {
printk(KERN_ERR "eth_configure failed to allocate uml_net\n");
return(1);
}
INIT_LIST_HEAD(&device->list);
device->index = n;
spin_lock(&devices_lock);
list_add(&device->list, &devices);
spin_unlock(&devices_lock);
setup_etheraddr(mac, device->mac);
printk(KERN_INFO "Netdevice %d ", n);
printk("(%02x:%02x:%02x:%02x:%02x:%02x) ",
device->mac[0], device->mac[1],
device->mac[2], device->mac[3],
device->mac[4], device->mac[5]);
printk(": ");
dev = alloc_etherdev(size);
if (dev == NULL) {
printk(KERN_ERR "eth_configure: failed to allocate device\n");
return 1;
}
lp = dev->priv;
/* This points to the transport private data. It's still clear, but we
* must memset it to 0 *now*. Let's help the drivers. */
memset(lp, 0, size);
INIT_WORK(&lp->work, uml_dev_close);
/* sysfs register */
if (!driver_registered) {
platform_driver_register(&uml_net_driver);
driver_registered = 1;
}
device->pdev.id = n;
device->pdev.name = DRIVER_NAME;
platform_device_register(&device->pdev);
SET_NETDEV_DEV(dev,&device->pdev.dev);
/* If this name ends up conflicting with an existing registered
* netdevice, that is OK, register_netdev{,ice}() will notice this
* and fail.
*/
snprintf(dev->name, sizeof(dev->name), "eth%d", n);
device->dev = dev;
(*transport->kern->init)(dev, init);
dev->mtu = transport->user->max_packet;
dev->open = uml_net_open;
dev->hard_start_xmit = uml_net_start_xmit;
dev->stop = uml_net_close;
dev->get_stats = uml_net_get_stats;
dev->set_multicast_list = uml_net_set_multicast_list;
dev->tx_timeout = uml_net_tx_timeout;
dev->set_mac_address = uml_net_set_mac;
dev->change_mtu = uml_net_change_mtu;
dev->ethtool_ops = &uml_net_ethtool_ops;
dev->watchdog_timeo = (HZ >> 1);
dev->irq = UM_ETH_IRQ;
rtnl_lock();
err = register_netdevice(dev);
rtnl_unlock();
if (err) {
device->dev = NULL;
/* XXX: should we call ->remove() here? */
free_netdev(dev);
return 1;
}
/* lp.user is the first four bytes of the transport data, which
* has already been initialized. This structure assignment will
* overwrite that, so we make sure that .user gets overwritten with
* what it already has.
*/
save = lp->user[0];
*lp = ((struct uml_net_private)
{ .list = LIST_HEAD_INIT(lp->list),
.dev = dev,
.fd = -1,
.mac = { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
.protocol = transport->kern->protocol,
.open = transport->user->open,
.close = transport->user->close,
.remove = transport->user->remove,
.read = transport->kern->read,
.write = transport->kern->write,
.add_address = transport->user->add_address,
.delete_address = transport->user->delete_address,
.set_mtu = transport->user->set_mtu,
.user = { save } });
init_timer(&lp->tl);
spin_lock_init(&lp->lock);
lp->tl.function = uml_net_user_timer_expire;
memcpy(lp->mac, device->mac, sizeof(lp->mac));
if (transport->user->init)
(*transport->user->init)(&lp->user, dev);
set_ether_mac(dev, device->mac);
return 0;
}
static struct uml_net *find_device(int n)
{
struct uml_net *device;
struct list_head *ele;
spin_lock(&devices_lock);
list_for_each(ele, &devices){
device = list_entry(ele, struct uml_net, list);
if(device->index == n)
goto out;
}
device = NULL;
out:
spin_unlock(&devices_lock);
return(device);
}
static int eth_parse(char *str, int *index_out, char **str_out,
char **error_out)
{
char *end;
int n, err = -EINVAL;;
n = simple_strtoul(str, &end, 0);
if(end == str){
*error_out = "Bad device number";
return err;
}
str = end;
if(*str != '='){
*error_out = "Expected '=' after device number";
return err;
}
str++;
if(find_device(n)){
*error_out = "Device already configured";
return err;
}
*index_out = n;
*str_out = str;
return 0;
}
struct eth_init {
struct list_head list;
char *init;
int index;
};
static DEFINE_SPINLOCK(transports_lock);
static LIST_HEAD(transports);
/* Filled in during early boot */
struct list_head eth_cmd_line = LIST_HEAD_INIT(eth_cmd_line);
static int check_transport(struct transport *transport, char *eth, int n,
void **init_out, char **mac_out)
{
int len;
len = strlen(transport->name);
if(strncmp(eth, transport->name, len))
return(0);
eth += len;
if(*eth == ',')
eth++;
else if(*eth != '\0')
return(0);
*init_out = kmalloc(transport->setup_size, GFP_KERNEL);
if(*init_out == NULL)
return(1);
if(!transport->setup(eth, mac_out, *init_out)){
kfree(*init_out);
*init_out = NULL;
}
return(1);
}
void register_transport(struct transport *new)
{
struct list_head *ele, *next;
struct eth_init *eth;
void *init;
char *mac = NULL;
int match;
spin_lock(&transports_lock);
BUG_ON(!list_empty(&new->list));
list_add(&new->list, &transports);
spin_unlock(&transports_lock);
list_for_each_safe(ele, next, &eth_cmd_line){
eth = list_entry(ele, struct eth_init, list);
match = check_transport(new, eth->init, eth->index, &init,
&mac);
if(!match)
continue;
else if(init != NULL){
eth_configure(eth->index, init, mac, new);
kfree(init);
}
list_del(&eth->list);
}
}
static int eth_setup_common(char *str, int index)
{
struct list_head *ele;
struct transport *transport;
void *init;
char *mac = NULL;
list_for_each(ele, &transports){
transport = list_entry(ele, struct transport, list);
if(!check_transport(transport, str, index, &init, &mac))
continue;
if(init != NULL){
eth_configure(index, init, mac, transport);
kfree(init);
}
return(1);
}
return(0);
}
static int eth_setup(char *str)
{
struct eth_init *new;
char *error;
int n, err;
err = eth_parse(str, &n, &str, &error);
if(err){
printk(KERN_ERR "eth_setup - Couldn't parse '%s' : %s\n",
str, error);
return 1;
}
new = alloc_bootmem(sizeof(*new));
if (new == NULL){
printk("eth_init : alloc_bootmem failed\n");
return 1;
}
INIT_LIST_HEAD(&new->list);
new->index = n;
new->init = str;
list_add_tail(&new->list, &eth_cmd_line);
return 1;
}
__setup("eth", eth_setup);
__uml_help(eth_setup,
"eth[0-9]+=<transport>,<options>\n"
" Configure a network device.\n\n"
);
#if 0
static int eth_init(void)
{
struct list_head *ele, *next;
struct eth_init *eth;
list_for_each_safe(ele, next, &eth_cmd_line){
eth = list_entry(ele, struct eth_init, list);
if(eth_setup_common(eth->init, eth->index))
list_del(&eth->list);
}
return(1);
}
__initcall(eth_init);
#endif
static int net_config(char *str, char **error_out)
{
int n, err;
err = eth_parse(str, &n, &str, error_out);
if(err)
return err;
/* This string is broken up and the pieces used by the underlying
* driver. So, it is freed only if eth_setup_common fails.
*/
str = kstrdup(str, GFP_KERNEL);
if(str == NULL){
*error_out = "net_config failed to strdup string";
return -ENOMEM;
}
err = !eth_setup_common(str, n);
if(err)
kfree(str);
return(err);
}
static int net_id(char **str, int *start_out, int *end_out)
{
char *end;
int n;
n = simple_strtoul(*str, &end, 0);
if((*end != '\0') || (end == *str))
return -1;
*start_out = n;
*end_out = n;
*str = end;
return n;
}
static int net_remove(int n, char **error_out)
{
struct uml_net *device;
struct net_device *dev;
struct uml_net_private *lp;
device = find_device(n);
if(device == NULL)
return -ENODEV;
dev = device->dev;
lp = dev->priv;
if(lp->fd > 0)
return -EBUSY;
if(lp->remove != NULL) (*lp->remove)(&lp->user);
unregister_netdev(dev);
platform_device_unregister(&device->pdev);
list_del(&device->list);
kfree(device);
free_netdev(dev);
return 0;
}
static struct mc_device net_mc = {
.name = "eth",
.config = net_config,
.get_config = NULL,
.id = net_id,
.remove = net_remove,
};
static int uml_inetaddr_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct in_ifaddr *ifa = ptr;
struct net_device *dev = ifa->ifa_dev->dev;
struct uml_net_private *lp;
void (*proc)(unsigned char *, unsigned char *, void *);
unsigned char addr_buf[4], netmask_buf[4];
if(dev->open != uml_net_open) return(NOTIFY_DONE);
lp = dev->priv;
proc = NULL;
switch (event){
case NETDEV_UP:
proc = lp->add_address;
break;
case NETDEV_DOWN:
proc = lp->delete_address;
break;
}
if(proc != NULL){
memcpy(addr_buf, &ifa->ifa_address, sizeof(addr_buf));
memcpy(netmask_buf, &ifa->ifa_mask, sizeof(netmask_buf));
(*proc)(addr_buf, netmask_buf, &lp->user);
}
return(NOTIFY_DONE);
}
struct notifier_block uml_inetaddr_notifier = {
.notifier_call = uml_inetaddr_event,
};
static int uml_net_init(void)
{
struct list_head *ele;
struct uml_net_private *lp;
struct in_device *ip;
struct in_ifaddr *in;
mconsole_register_dev(&net_mc);
register_inetaddr_notifier(&uml_inetaddr_notifier);
/* Devices may have been opened already, so the uml_inetaddr_notifier
* didn't get a chance to run for them. This fakes it so that
* addresses which have already been set up get handled properly.
*/
list_for_each(ele, &opened){
lp = list_entry(ele, struct uml_net_private, list);
ip = lp->dev->ip_ptr;
if(ip == NULL) continue;
in = ip->ifa_list;
while(in != NULL){
uml_inetaddr_event(NULL, NETDEV_UP, in);
in = in->ifa_next;
}
}
return(0);
}
__initcall(uml_net_init);
static void close_devices(void)
{
struct list_head *ele;
struct uml_net_private *lp;
list_for_each(ele, &opened){
lp = list_entry(ele, struct uml_net_private, list);
free_irq(lp->dev->irq, lp->dev);
if((lp->close != NULL) && (lp->fd >= 0))
(*lp->close)(lp->fd, &lp->user);
if(lp->remove != NULL) (*lp->remove)(&lp->user);
}
}
__uml_exitcall(close_devices);
struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra)
{
if((skb != NULL) && (skb_tailroom(skb) < extra)){
struct sk_buff *skb2;
skb2 = skb_copy_expand(skb, 0, extra, GFP_ATOMIC);
dev_kfree_skb(skb);
skb = skb2;
}
if(skb != NULL) skb_put(skb, extra);
return(skb);
}
void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
void *),
void *arg)
{
struct net_device *dev = d;
struct in_device *ip = dev->ip_ptr;
struct in_ifaddr *in;
unsigned char address[4], netmask[4];
if(ip == NULL) return;
in = ip->ifa_list;
while(in != NULL){
memcpy(address, &in->ifa_address, sizeof(address));
memcpy(netmask, &in->ifa_mask, sizeof(netmask));
(*cb)(address, netmask, arg);
in = in->ifa_next;
}
}
int dev_netmask(void *d, void *m)
{
struct net_device *dev = d;
struct in_device *ip = dev->ip_ptr;
struct in_ifaddr *in;
__be32 *mask_out = m;
if(ip == NULL)
return(1);
in = ip->ifa_list;
if(in == NULL)
return(1);
*mask_out = in->ifa_mask;
return(0);
}
void *get_output_buffer(int *len_out)
{
void *ret;
ret = (void *) __get_free_pages(GFP_KERNEL, 0);
if(ret) *len_out = PAGE_SIZE;
else *len_out = 0;
return(ret);
}
void free_output_buffer(void *buffer)
{
free_pages((unsigned long) buffer, 0);
}
int tap_setup_common(char *str, char *type, char **dev_name, char **mac_out,
char **gate_addr)
{
char *remain;
remain = split_if_spec(str, dev_name, mac_out, gate_addr, NULL);
if(remain != NULL){
printk("tap_setup_common - Extra garbage on specification : "
"'%s'\n", remain);
return(1);
}
return(0);
}
unsigned short eth_protocol(struct sk_buff *skb)
{
return(eth_type_trans(skb, skb->dev));
}