Subject: Re: [PATCH] ieee80211 subsystem

From: James Ketrenos <[email-masked]>
Date: Tue, 08 Feb 2005 02:24:49 -0600

Randy.Dunlap wrote:

> James Ketrenos wrote:
>
>> Attached is the patch against 2.6.11-rc3-mm1 that adds the ieee80211 
>> subsystem used by the ipw2100 and ipw2200 projects.
>>
>> I'll be sending out the patches for ipw2100-1.0.0 and ipw2200-1.0.0 
>> that use thist stack to the list on Monday.
>>
>> In terms of what the stack currently does:
>>
>> * HW independent -- it only knows about 802.11 data and structures
>> * Performs an 802.3 <-> 802.11 transform for data Tx/Rx
>> * Host based support for fragmentation, WEP, and WPA using the 
>> kernel's crypto functions
>> * Beacon and probe response collection and parsing
>> * Default implementation of some of the WE handlers that can be 
>> managed without hardware knowledge
>>
>> We are working to merge in Dave Miller's p80211 code into the 
>> ieee80211 subsystem so that it hooks into the kernel as a true 
>> network layer as opposed to a mutated offspring of ethernet.
>> Once that is done, hopefully the skb to txb code can be reworked and 
>> 802.11 fragments can be treated either as normal skbs, or skbs can be 
>> modified to directly support them (ideally so that encrypted 802.11 
>> frames in support of IP packets can be cached by the stack instead of 
>> having to be re-encrypted on TCP retries)
>>
>> Support for HW/FW crypto and fragmentation offload, in a HW 
>> independent fashion, is also on the short-term list.
>>
>> When you look through the patch you'll likely notice the #ifdef 
>> NOTYET/#endif sequences surrounding portions of code from the hostap 
>> project.  Portions of this subsystem were based on an earlier version 
>> of the hostap project.  Those areas that weren't directly supported 
>> by the ipw* projects weren't ported to be completely hardware 
>> independent (since I don't have the hardware to test it), and so are 
>> still wrapped in the ifdefs.  These sections mainly cover support for 
>> MASTER and WDS modes.
>>
>> Anyway, please let me know what you think.  Hopefully I built the 
>> patch right...
>
>
> James,
> Can you post a patch that will build?  or did you just want
> feedback on the current state of the patch?

Ah; I see my tree that I did the diff on was missing the 
wireless/Makefile and the ieee80211/ieee80211_module.c to create the 
patch against... sigh.  Attached is ieee80211_module.c; you have the 
change for the Makefile to include ieee80211. 

Later {hopefully today} I'll send a full patch that includes several of 
the corrections you called out in your prior patch.

Thanks,
James

> Thanks,

/*******************************************************************************

  Copyright(c) 2004 Intel Corporation. All rights reserved.

  Portions of this file are based on the WEP enablement code provided by the
  Host AP project hostap-drivers v0.1.3
  Copyright (c) 2001-2002, SSH Communications Security Corp and Jouni Malinen
  <[email-masked]>
  Copyright (c) 2002-2003, Jouni Malinen <[email-masked]>

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2 of the GNU General Public License 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., 59
  Temple Place - Suite 330, Boston, MA  02111-1307, USA.

  The full GNU General Public License is included in this distribution in the
  file called LICENSE.

  Contact Information:
  James P. Ketrenos <[email-masked]>
  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497

*******************************************************************************/

#include <linux/compiler.h>
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/in6.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/tcp.h>
#include <linux/types.h>
#include <linux/version.h>
#include <linux/wireless.h>
#include <linux/etherdevice.h>
#include <asm/uaccess.h>
#include <net/arp.h>

#include "ieee80211.h"

MODULE_DESCRIPTION("802.11 data/management/control stack");
MODULE_AUTHOR("Copyright (C) 2004 Intel Corporation <[email-masked]>");
MODULE_LICENSE("GPL");

#define DRV_NAME "ieee80211"

static inline int ieee80211_networks_allocate(struct ieee80211_device *ieee)
{
	if (ieee->networks)
		return 0;

	ieee->networks = kmalloc(
		MAX_NETWORK_COUNT * sizeof(struct ieee80211_network),
		GFP_KERNEL);
	if (!ieee->networks) {
		printk(KERN_WARNING "%s: Out of memory allocating beacons\n",
		       ieee->dev->name);
		return -ENOMEM;
	}

	memset(ieee->networks, 0,
	       MAX_NETWORK_COUNT * sizeof(struct ieee80211_network));

	return 0;
}

static inline void ieee80211_networks_free(struct ieee80211_device *ieee)
{
	if (!ieee->networks)
		return;
	kfree(ieee->networks);
	ieee->networks = NULL;
}

static inline void ieee80211_networks_initialize(struct ieee80211_device *ieee)
{
	int i;

	INIT_LIST_HEAD(&ieee->network_free_list);
	INIT_LIST_HEAD(&ieee->network_list);
	for (i = 0; i < MAX_NETWORK_COUNT; i++)
		list_add_tail(&ieee->networks[i].list, &ieee->network_free_list);
}

struct net_device *alloc_ieee80211(int sizeof_priv)
{
	struct ieee80211_device *ieee;
	struct net_device *dev;
	int err;

	IEEE80211_DEBUG_INFO("Initializing...\n");

	dev = alloc_etherdev(sizeof(struct ieee80211_device) + sizeof_priv);
	if (!dev) {
		IEEE80211_ERROR("Unable to network device.\n");
		goto failed;
	}
	ieee = netdev_priv(dev);
	dev->hard_start_xmit = ieee80211_xmit;

	ieee->dev = dev;

	err = ieee80211_networks_allocate(ieee);
	if (err) {
		IEEE80211_ERROR("Unable to allocate beacon storage: %d\n",
				err);
		goto failed;
	}
	ieee80211_networks_initialize(ieee);

	/* Default fragmentation threshold is maximum payload size */
	ieee->fts = DEFAULT_FTS;
	ieee->scan_age = DEFAULT_MAX_SCAN_AGE;
	ieee->open_wep = 1;

#ifdef CONFIG_IEEE80211_CRYPT
	/* Default to enabling full open WEP with host based encrypt/decrypt */
	ieee->host_encrypt = 1;
	ieee->host_decrypt = 1;
	ieee->ieee802_1x = 1; /* Default to supporting 802.1x */

	INIT_LIST_HEAD(&ieee->crypt_deinit_list);
	init_timer(&ieee->crypt_deinit_timer);
	ieee->crypt_deinit_timer.data = (unsigned long)ieee;
	ieee->crypt_deinit_timer.function = ieee80211_crypt_deinit_handler;
#endif

	spin_lock_init(&ieee->lock);

#ifdef CONFIG_IEEE80211_WPA
 	ieee->wpa_enabled = 0;
 	ieee->tkip_countermeasures = 0;
 	ieee->drop_unencrypted = 0;
 	ieee->privacy_invoked = 0;
 	ieee->ieee802_1x = 1;
#endif /* CONFIG_IEEE80211_WPA */

	return dev;

 failed:
	if (dev)
		free_netdev(dev);
	return NULL;
}

void free_ieee80211(struct net_device *dev)
{
	struct ieee80211_device *ieee = netdev_priv(dev);

#ifdef CONFIG_IEEE80211_CRYPT
	int i;

	del_timer_sync(&ieee->crypt_deinit_timer);
	ieee80211_crypt_deinit_entries(ieee, 1);

	for (i = 0; i < WEP_KEYS; i++) {
		struct ieee80211_crypt_data *crypt = ieee->crypt[i];
		if (crypt) {
			if (crypt->ops) {
				crypt->ops->deinit(crypt->priv);
				module_put(crypt->ops->owner);
			}
			kfree(crypt);
			ieee->crypt[i] = NULL;
		}
	}
#endif

	ieee80211_networks_free(ieee);
	free_netdev(dev);
}

#ifdef CONFIG_IEEE80211_DEBUG

static int debug = 0;
u32 ieee80211_debug_level = 0;
struct proc_dir_entry *ieee80211_proc = NULL;

static int show_debug_level(char *page, char **start, off_t offset,
			    int count, int *eof, void *data)
{
	return snprintf(page, count, "0x%08X\n", ieee80211_debug_level);
}

static int store_debug_level(struct file *file, const char *buffer,
			     unsigned long count, void *data)
{
	char buf[] = "0x00000000";
	unsigned long len = min(sizeof(buf) - 1, (u32)count);
	char *p = (char *)buf;
	unsigned long val;

	if (copy_from_user(buf, buffer, len))
		return count;
	buf[len] = 0;
	if (p[1] == 'x' || p[1] == 'X' || p[0] == 'x' || p[0] == 'X') {
		p++;
		if (p[0] == 'x' || p[0] == 'X')
			p++;
		val = simple_strtoul(p, &p, 16);
	} else
		val = simple_strtoul(p, &p, 10);
	if (p == buf)
		printk(KERN_INFO DRV_NAME
		       ": %s is not in hex or decimal form.\n", buf);
	else
		ieee80211_debug_level = val;

	return strnlen(buf, count);
}

static int __init ieee80211_init(void)
{
	struct proc_dir_entry *e;

	ieee80211_debug_level = debug;
	ieee80211_proc = create_proc_entry(DRV_NAME, S_IFDIR, proc_net);
	if (ieee80211_proc == NULL) {
		IEEE80211_ERROR("Unable to create " DRV_NAME
				" proc directory\n");
		return -EIO;
	}
	e = create_proc_entry("debug_level", S_IFREG | S_IRUGO | S_IWUSR,
			      ieee80211_proc);
	if (!e) {
		remove_proc_entry(DRV_NAME, proc_net);
		ieee80211_proc = NULL;
		return -EIO;
	}
	e->read_proc = show_debug_level;
	e->write_proc = store_debug_level;
	e->data = NULL;

	return 0;
}

static void __exit ieee80211_exit(void)
{
	if (ieee80211_proc) {
		remove_proc_entry("debug_level", ieee80211_proc);
		remove_proc_entry(DRV_NAME, proc_net);
		ieee80211_proc = NULL;
	}
}

#include <linux/moduleparam.h>
module_param(debug, int, 0444);
MODULE_PARM_DESC(debug, "debug output mask");

module_exit(ieee80211_exit);
module_init(ieee80211_init);
#endif

EXPORT_SYMBOL(alloc_ieee80211);
EXPORT_SYMBOL(free_ieee80211);