/*
* WUSB Wire Adapter: WLP interface
* Ethernet to device address cache
*
* Copyright (C) 2005-2006 Intel Corporation
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
*
* We need to be able to map ethernet addresses to device addresses
* and back because there is not explicit relationship between the eth
* addresses used in the ETH frames and the device addresses (no, it
* would not have been simpler to force as ETH address the MBOA MAC
* address...no, not at all :).
*
* A device has one MBOA MAC address and one device address. It is possible
* for a device to have more than one virtual MAC address (although a
* virtual address can be the same as the MBOA MAC address). The device
* address is guaranteed to be unique among the devices in the extended
* beacon group (see ECMA 17.1.1). We thus use the device address as index
* to this cache. We do allow searching based on virtual address as this
* is how Ethernet frames will be addressed.
*
* We need to support virtual EUI-48. Although, right now the virtual
* EUI-48 will always be the same as the MAC SAP address. The EDA cache
* entry thus contains a MAC SAP address as well as the virtual address
* (used to map the network stack address to a neighbor). When we move
* to support more than one virtual MAC on a host then this organization
* will have to change. Perhaps a neighbor has a list of WSSs, each with a
* tag and virtual EUI-48.
*
* On data transmission
* it is used to determine if the neighbor is connected and what WSS it
* belongs to. With this we know what tag to add to the WLP frame. Storing
* the WSS in the EDA cache may be overkill because we only support one
* WSS. Hopefully we will support more than one WSS at some point.
* On data reception it is used to determine the WSS based on
* the tag and address of the transmitting neighbor.
*/
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/slab.h>
#include <linux/wlp.h>
#include "wlp-internal.h"
/* FIXME: cache is not purged, only on device close */
/* FIXME: does not scale, change to dynamic array */
/*
* Initialize the EDA cache
*
* @returns 0 if ok, < 0 errno code on error
*
* Call when the interface is being brought up
*
* NOTE: Keep it as a separate function as the implementation will
* change and be more complex.
*/
void wlp_eda_init(struct wlp_eda *eda)
{
INIT_LIST_HEAD(&eda->cache);
spin_lock_init(&eda->lock);
}
/*
* Release the EDA cache
*
* @returns 0 if ok, < 0 errno code on error
*
* Called when the interface is brought down
*/
void wlp_eda_release(struct wlp_eda *eda)
{
unsigned long flags;
struct wlp_eda_node *itr, *next;
spin_lock_irqsave(&eda->lock, flags);
list_for_each_entry_safe(itr, next, &eda->cache, list_node) {
list_del(&itr->list_node);
kfree(itr);
}
spin_unlock_irqrestore(&eda->lock, flags);
}
/*
* Add an address mapping
*
* @returns 0 if ok, < 0 errno code on error
*
* An address mapping is initially created when the neighbor device is seen
* for the first time (it is "onair"). At this time the neighbor is not
* connected or associated with a WSS so we only populate the Ethernet and
* Device address fields.
*
*/
int wlp_eda_create_node(struct wlp_eda *eda,
const unsigned char eth_addr[ETH_ALEN],
const struct uwb_dev_addr *dev_addr)
{
int result = 0;
struct wlp_eda_node *itr;
unsigned long flags;
BUG_ON(dev_addr == NULL || eth_addr == NULL);
spin_lock_irqsave(&eda->lock, flags);
list_for_each_entry(itr, &eda->cache, list_node) {
if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
printk(KERN_ERR "EDA cache already contains entry "
"for neighbor %02x:%02x\n",
dev_addr->data[1], dev_addr->data[0]);
result = -EEXIST;
goto out_unlock;
}
}
itr = kzalloc(sizeof(*itr), GFP_ATOMIC);
if (itr != NULL) {
memcpy(itr->eth_addr, eth_addr, sizeof(itr->eth_addr));
itr->dev_addr = *dev_addr;
list_add(&itr->list_node, &eda->cache);
} else
result = -ENOMEM;
out_unlock:
spin_unlock_irqrestore(&eda->lock, flags);
return result;
}
/*
* Remove entry from EDA cache
*
* This is done when the device goes off air.
*/
void wlp_eda_rm_node(struct wlp_eda *eda, const struct uwb_dev_addr *dev_addr)
{
struct wlp_eda_node *itr, *next;
unsigned long flags;
spin_lock_irqsave(&eda->lock, flags);
list_for_each_entry_safe(itr, next, &eda->cache, list_node) {
if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
list_del(&itr->list_node);
kfree(itr);
break;
}
}
spin_unlock_irqrestore(&eda->lock, flags);
}
/*
* Update an address mapping
*
* @returns 0 if ok, < 0 errno code on error
*/
int wlp_eda_update_node(struct wlp_eda *eda,
const struct uwb_dev_addr *dev_addr,
struct wlp_wss *wss,
const unsigned char virt_addr[ETH_ALEN],
const u8 tag, const enum wlp_wss_connect state)
{
int result = -ENOENT;
struct wlp_eda_node *itr;
unsigned long flags;
spin_lock_irqsave(&eda->lock, flags);
list_for_each_entry(itr, &eda->cache, list_node) {
if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
/* Found it, update it */
itr->wss = wss;
memcpy(itr->virt_addr, virt_addr,
sizeof(itr->virt_addr));
itr->tag = tag;
itr->state = state;
result = 0;
goto out_unlock;
}
}
/* Not found */
out_unlock:
spin_unlock_irqrestore(&eda->lock, flags);
return result;
}
/*
* Update only state field of an address mapping
*
* @returns 0 if ok, < 0 errno code on error
*/
int wlp_eda_update_node_state(struct wlp_eda *eda,
const struct uwb_dev_addr *dev_addr,
const enum wlp_wss_connect state)
{
int result = -ENOENT;
struct wlp_eda_node *itr;
unsigned long flags;
spin_lock_irqsave(&eda->lock, flags);
list_for_each_entry(itr, &eda->cache, list_node) {
if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
/* Found it, update it */
itr->state = state;
result = 0;
goto out_unlock;
}
}
/* Not found */
out_unlock:
spin_unlock_irqrestore(&eda->lock, flags);
return result;
}
/*
* Return contents of EDA cache entry
*
* @dev_addr: index to EDA cache
* @eda_entry: pointer to where contents of EDA cache will be copied
*/
int wlp_copy_eda_node(struct wlp_eda *eda, struct uwb_dev_addr *dev_addr,
struct wlp_eda_node *eda_entry)
{
int result = -ENOENT;
struct wlp_eda_node *itr;
unsigned long flags;
spin_lock_irqsave(&eda->lock, flags);
list_for_each_entry(itr, &eda->cache, list_node) {
if (!memcmp(&itr->dev_addr, dev_addr, sizeof(itr->dev_addr))) {
*eda_entry = *itr;
result = 0;
goto out_unlock;
}
}
/* Not found */
out_unlock:
spin_unlock_irqrestore(&eda->lock, flags);
return result;
}
/*
* Execute function for every element in the cache
*
* @function: function to execute on element of cache (must be atomic)
* @priv: private data of function
* @returns: result of first function that failed, or last function
* executed if no function failed.
*
* Stop executing when function returns error for any element in cache.
*
* IMPORTANT: We are using a spinlock here: the function executed on each
* element has to be atomic.
*/
int wlp_eda_for_each(struct wlp_eda *eda, wlp_eda_for_each_f function,
void *priv)
{
int result = 0;
struct wlp *wlp = container_of(eda, struct wlp, eda);
struct wlp_eda_node *entry;
unsigned long flags;
spin_lock_irqsave(&eda->lock, flags);
list_for_each_entry(entry, &eda->cache, list_node) {
result = (*function)(wlp, entry, priv);
if (result < 0)
break;
}
spin_unlock_irqrestore(&eda->lock, flags);
return result;
}
/*
* Execute function for single element in the cache (return dev addr)
*
* @virt_addr: index into EDA cache used to determine which element to
* execute the function on
* @dev_addr: device address of element in cache will be returned using
* @dev_addr
* @function: function to execute on element of cache (must be atomic)
* @priv: private data of function
* @returns: result of function
*
* IMPORTANT: We are using a spinlock here: the function executed on the
* element has to be atomic.
*/
int wlp_eda_for_virtual(struct wlp_eda *eda,
const unsigned char virt_addr[ETH_ALEN],
struct uwb_dev_addr *dev_addr,
wlp_eda_for_each_f function,
void *priv)
{
int result = 0;
struct wlp *wlp = container_of(eda, struct wlp, eda);
struct wlp_eda_node *itr;
unsigned long flags;
int found = 0;
spin_lock_irqsave(&eda->lock, flags);
list_for_each_entry(itr, &eda->cache, list_node) {
if (!memcmp(itr->virt_addr, virt_addr,
sizeof(itr->virt_addr))) {
result = (*function)(wlp, itr, priv);
*dev_addr = itr->dev_addr;
found = 1;
break;
}
}
if (!found)
result = -ENODEV;
spin_unlock_irqrestore(&eda->lock, flags);
return result;
}
static const char *__wlp_wss_connect_state[] = { "WLP_WSS_UNCONNECTED",
"WLP_WSS_CONNECTED",
"WLP_WSS_CONNECT_FAILED",
};
static const char *wlp_wss_connect_state_str(unsigned id)
{
if (id >= ARRAY_SIZE(__wlp_wss_connect_state))
return "unknown WSS connection state";
return __wlp_wss_connect_state[id];
}
/*
* View EDA cache from user space
*
* A debugging feature to give user visibility into the EDA cache. Also
* used to display members of WSS to user (called from wlp_wss_members_show())
*/
ssize_t wlp_eda_show(struct wlp *wlp, char *buf)
{
ssize_t result = 0;
struct wlp_eda_node *entry;
unsigned long flags;
struct wlp_eda *eda = &wlp->eda;
spin_lock_irqsave(&eda->lock, flags);
result = scnprintf(buf, PAGE_SIZE, "#eth_addr dev_addr wss_ptr "
"tag state virt_addr\n");
list_for_each_entry(entry, &eda->cache, list_node) {
result += scnprintf(buf + result, PAGE_SIZE - result,
"%pM %02x:%02x %p 0x%02x %s %pM\n",
entry->eth_addr,
entry->dev_addr.data[1],
entry->dev_addr.data[0], entry->wss,
entry->tag,
wlp_wss_connect_state_str(entry->state),
entry->virt_addr);
if (result >= PAGE_SIZE)
break;
}
spin_unlock_irqrestore(&eda->lock, flags);
return result;
}
EXPORT_SYMBOL_GPL(wlp_eda_show);
/*
* Add new EDA cache entry based on user input in sysfs
*
* Should only be used for debugging.
*
* The WSS is assumed to be the only WSS supported. This needs to be
* redesigned when we support more than one WSS.
*/
ssize_t wlp_eda_store(struct wlp *wlp, const char *buf, size_t size)
{
ssize_t result;
struct wlp_eda *eda = &wlp->eda;
u8 eth_addr[6];
struct uwb_dev_addr dev_addr;
u8 tag;
unsigned state;
result = sscanf(buf, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx "
"%02hhx:%02hhx %02hhx %u\n",
ð_addr[0], ð_addr[1],
ð_addr[2], ð_addr[3],
ð_addr[4], ð_addr[5],
&dev_addr.data[1], &dev_addr.data[0], &tag, &state);
switch (result) {
case 6: /* no dev addr specified -- remove entry NOT IMPLEMENTED */
/*result = wlp_eda_rm(eda, eth_addr, &dev_addr);*/
result = -ENOSYS;
break;
case 10:
state = state >= 1 ? 1 : 0;
result = wlp_eda_create_node(eda, eth_addr, &dev_addr);
if (result < 0 && result != -EEXIST)
goto error;
/* Set virtual addr to be same as MAC */
result = wlp_eda_update_node(eda, &dev_addr, &wlp->wss,
eth_addr, tag, state);
if (result < 0)
goto error;
break;
default: /* bad format */
result = -EINVAL;
}
error:
return result < 0 ? result : size;
}
EXPORT_SYMBOL_GPL(wlp_eda_store);
