at76c503.c

这是atmel公司的无线网卡驱动, 基于linux的驱动源代码

/* -*- linux-c -*- */
/* $Id: at76c503.c,v 1.35 2003/07/30 06:31:51 jal2 Exp $
 *
 * USB at76c503/at76c505 driver
 *
 * Copyright (c) 2002 - 2003 Oliver Kurth <[e-mail]>
 *
 *	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.
 *
 *
 * History:
 *
 * 2002_12_31:
 * - first ping, ah-hoc mode works, fw version 0.90.2 only
 *
 * 2003_01_07 0.1:
 * - first release
 *
 * 2003_01_08 0.2:
 * - moved rx code into tasklet
 * - added locking in keventd handler
 * - support big endian in ieee802_11.h
 * - external firmware downloader now in this module
 *
 * 2003_01_10 0.3:
 * - now using 8 spaces for tab indentations
 * - added tx rate settings (patch from Joerg Albert (jal))
 * - created functions for mib settings
 *
 * 2003_01_19 0.4:
 * - use usbdfu for the internal firmware
 *
 * 2003_01_27 0.5:
 * - implemented WEP. Thanks to jal
 * - added frag and rts ioctl calls (jal again)
 * - module parameter to give names other than eth
 *
 * 2003_01_28 0.6:
 * - make it compile with kernel < 2.4.20 (there is no owner field
 *   in struct usb_driver)
 * - fixed a small bug for the module param eth_name
 * - do not use GFP_DMA, GFP_KERNEL is enough
 * - no down() in _tx() because that's in interrupt. Use
 *   spin_lock_irq() instead
 * - should not stop net queue on urb errors
 * - cleanup in ioctl(): locked it altogether, this makes it easier
 *   to maintain
 * - tried to implement promisc. mode: does not work with this device
 * - tried to implement setting mac address: does not
 *   seem to work with this device
 * - now use fw version 0.90.2 #140 (prev. was #93). Does not help...
 *
 * 2003_01_30 0.7:
 * - now works with fw 0.100.2 (solution was: wait for completion
 *   of commands)
 * - setting MAC address now works (thx to a small fix by jal)
 * - it turned out that promisc. mode is not possible. The firmware
 *   does not allow it. I hope that it will be implemented in a future
 *   version.
 *
 * 2003_02_13 0.8:
 * - scan mode implemented by jal
 * - infra structure mode by jal
 * - some small cleanups (removed dead code)
 *
 * history can now be found in the cvs log at http://at76c503a.berlios.de
 * 
 * TODO:
 * - monitor mode
 *
 */

#include <linux/config.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/smp_lock.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/usb.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <asm/uaccess.h>
#include <linux/wireless.h>
#include <linux/rtnetlink.h>  /* for rtnl_lock() */

#include "at76c503.h"
#include "ieee802_11.h"

/* debug bits */
#define DBG_PROGRESS        0x000001 /* progress of scan-join-(auth-assoc)-connected */
#define DBG_BSS_TABLE       0x000002 /* show the bss table after scans */
#define DBG_IOCTL           0x000004 /* ioctl calls / settings */
#define DBG_KEVENT          0x000008 /* kevents */
#define DBG_TX_DATA         0x000010 /* tx header */
#define DBG_TX_DATA_CONTENT 0x000020 /* tx content */
#define DBG_TX_MGMT         0x000040
#define DBG_RX_DATA         0x000080 /* rx data header */
#define DBG_RX_DATA_CONTENT 0x000100 /* rx data content */
#define DBG_RX_MGMT         0x000200 /* rx mgmt header except beacon and probe responses */
#define DBG_RX_BEACON       0x000400 /* rx beacon */
#define DBG_RX_CTRL         0x000800 /* rx control */
#define DBG_RX_MGMT_CONTENT 0x001000 /* rx mgmt content */
#define DBG_RX_FRAGS        0x002000 /* rx data fragment handling */
#define DBG_DEVSTART        0x004000 /* fw download, device start */
#define DBG_URB             0x008000 /* rx urb status, ... */
#define DBG_RX_ATMEL_HDR    0x010000 /* the atmel specific header of each rx packet */
#define DBG_PROC_ENTRY      0x020000 /* procedure entries and exits */
#define DBG_PM              0x040000 /* power management settings */
#define DBG_BSS_MATCH       0x080000 /* show why a certain bss did not match */
#define DBG_PARAMS          0x100000 /* show the configured parameters */
#define DBG_WAIT_COMPLETE   0x200000 /* show the wait_completion progress */
#define DBG_RX_FRAGS_SKB    0x400000 /* show skb header for incoming rx fragments */
#define DBG_BSS_TABLE_RM    0x800000 /* inform on removal of old bss table entries */

#ifdef CONFIG_USB_DEBUG
#define DBG_DEFAULTS (DBG_PROGRESS | DBG_PARAMS | DBG_BSS_TABLE)
#else
#define DBG_DEFAULTS 0
#endif
static int debug = DBG_DEFAULTS;

static const u8 zeros[32];

/* Use our own dbg macro */
#undef dbg
#define dbg(bits, format, arg...) \
	do { \
		if (debug & (bits)) \
		printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg);\
	} while (0)

/* uncond. debug output */
#define dbg_uc(format, arg...) \
  printk(KERN_DEBUG __FILE__ ": " format "\n" , ## arg)

#ifndef min
#define min(x,y) ((x) < (y) ? (x) : (y))
#endif

#define assert(x) \
  do {\
   if (!(x)) \
     err(__FILE__ ":%d assertion " #x " failed", __LINE__);\
  } while (0)

/* how often do we re-try these packets ? */
#define AUTH_RETRIES  3
#define ASSOC_RETRIES 3
#define DISASSOC_RETRIES 3

#define NEW_STATE(dev,newstate) \
  do {\
    dbg(DBG_PROGRESS, "%s: state %d -> %d (" #newstate ")",\
        dev->netdev->name, dev->istate, newstate);\
    dev->istate = newstate;\
  } while (0)

/* the beacon timeout in infra mode when we are connected (in seconds) */
#define BEACON_TIMEOUT 10

/* after how many seconds do we re-scan the channels in infra mode */
#define RESCAN_TIME 10

/* Version Information */
#define DRIVER_DESC "Generic Atmel at76c503/at76c505 routines"

/* Module paramaters */
MODULE_PARM(debug, "i");
#define DRIVER_AUTHOR \
"Oliver Kurth <[e-mail]>, Joerg Albert <[e-mail]>, Alex <[e-mail]>"
MODULE_PARM_DESC(debug, "Debugging level");

static int rx_copybreak = 200;
MODULE_PARM(rx_copybreak, "i");
MODULE_PARM_DESC(rx_copybreak, "rx packet copy threshold");

static int scan_min_time = 10;
MODULE_PARM(scan_min_time, "i");
MODULE_PARM_DESC(scan_min_time, "scan min channel time (default: 10)");

static int scan_max_time = 120;
MODULE_PARM(scan_max_time, "i");
MODULE_PARM_DESC(scan_max_time, "scan max channel time (default: 120)");

static int scan_mode = SCAN_TYPE_ACTIVE;
MODULE_PARM(scan_mode, "i");
MODULE_PARM_DESC(scan_mode, "scan mode: 0 active (with ProbeReq, default), 1 passive");

static int preamble_type = PREAMBLE_TYPE_LONG;
MODULE_PARM(preamble_type, "i");
MODULE_PARM_DESC(preamble_type, "preamble type: 0 long (default), 1 short");

static int auth_mode = 0;
MODULE_PARM(auth_mode, "i");
MODULE_PARM_DESC(auth_mode, "authentication mode: 0 open system (default), "
		 "1 shared secret");

static int pm_mode = PM_ACTIVE;
MODULE_PARM(pm_mode, "i");
MODULE_PARM_DESC(pm_mode, "power management mode: 1 active (def.), 2 powersave, 3 smart save");

static int pm_period = 0;
MODULE_PARM(pm_period, "i");
MODULE_PARM_DESC(pm_period, "period of waking up the device in usec");

struct header_struct {
        /* 802.3 */
        u8 dest[ETH_ALEN];
        u8 src[ETH_ALEN];
        u16 len;
        /* 802.2 */
        u8 dsap;
        u8 ssap;
        u8 ctrl;
        /* SNAP */
        u8 oui[3];
        u16 ethertype;
} __attribute__ ((packed));

#define DEF_RTS_THRESHOLD 1536
#define DEF_FRAG_THRESHOLD 1536
#define DEF_ESSID "okuwlan"
#define DEF_ESSID_LEN 7
#define DEF_CHANNEL 10

#define MAX_RTS_THRESHOLD 2347
#define MAX_FRAG_THRESHOLD 2346
#define MIN_FRAG_THRESHOLD 256

/* The frequency of each channel in MHz */
const long channel_frequency[] = {
        2412, 2417, 2422, 2427, 2432, 2437, 2442,
        2447, 2452, 2457, 2462, 2467, 2472, 2484
};
#define NUM_CHANNELS ( sizeof(channel_frequency) / sizeof(channel_frequency[0]) )

/* the broadcast address */
const u8 bc_addr[ETH_ALEN] = {0xff,0xff,0xff,0xff,0xff,0xff};

/* the supported rates of this hardware, bit7 marks a mandantory rate */
const u8 hw_rates[4] = {0x82,0x84,0x0b,0x16};

/* the max padding size for tx in bytes (see calc_padding)*/
#define MAX_PADDING_SIZE 53

/* a ieee820.11 frame header without addr4 */
struct ieee802_11_mgmt {
	u16 frame_ctl;
	u16 duration_id;
	u8 addr1[ETH_ALEN]; /* destination addr */
	u8 addr2[ETH_ALEN]; /* source addr */
	u8 addr3[ETH_ALEN]; /* BSSID */
	u16 seq_ctl;
	u8 data[1508];
	u32 fcs;
} __attribute__ ((packed));

/* the size of the ieee802.11 header (excl. the at76c503 tx header) */
#define IEEE802_11_MGMT_HEADER_SIZE offsetof(struct ieee802_11_mgmt, data)

/* beacon in ieee802_11_mgmt.data */
struct ieee802_11_beacon_data {
	u8   timestamp[8];           // TSFTIMER
	u16  beacon_interval;         // Kms between TBTTs (Target Beacon Transmission Times)
	u16  capability_information;
	u8   data[1500]; /* contains: SSID (tag,length,value), 
			    Supported Rates (tlv), channel */
} __attribute__ ((packed));

/* disassoc frame in ieee802_11_mgmt.data */
struct ieee802_11_disassoc_frame {
	u16 reason;
} __attribute__ ((packed));
#define DISASSOC_FRAME_SIZE \
  (AT76C503_TX_HDRLEN + IEEE802_11_MGMT_HEADER_SIZE +\
   sizeof(struct ieee802_11_disassoc_frame))

/* assoc request in ieee802_11_mgmt.data */
struct ieee802_11_assoc_req {
	u16  capability;
	u16  listen_interval;
	u8   data[1]; /* variable number of bytes for SSID 
			 and supported rates (tlv coded) */
};
/* the maximum size of an AssocReq packet */
#define ASSOCREQ_MAX_SIZE \
  (AT76C503_TX_HDRLEN + IEEE802_11_MGMT_HEADER_SIZE +\
   offsetof(struct ieee802_11_assoc_req,data) +\
   1+1+IW_ESSID_MAX_SIZE + 1+1+4)

/* reassoc request in ieee802_11_mgmt.data */
struct ieee802_11_reassoc_req {
	u16  capability;
	u16  listen_interval;
	u8   curr_ap[ETH_ALEN]; /* the bssid of the AP we are
				   currently associated to */
	u8   data[1]; /* variable number of bytes for SSID 
			 and supported rates (tlv coded) */
} __attribute__ ((packed));

/* the maximum size of an AssocReq packet */
#define REASSOCREQ_MAX_SIZE \
  (AT76C503_TX_HDRLEN + IEEE802_11_MGMT_HEADER_SIZE +\
   offsetof(struct ieee802_11_reassoc_req,data) +\
   1+1+IW_ESSID_MAX_SIZE + 1+1+4)


/* assoc/reassoc response */
struct ieee802_11_assoc_resp {
	u16  capability;
	u16  status;
	u16  assoc_id;
	u8   data[1]; /* variable number of bytes for 
			 supported rates (tlv coded) */
} __attribute__ ((packed));

/* auth. request/response in ieee802_11_mgmt.data */
struct ieee802_11_auth_frame {
	u16 algorithm;
	u16 seq_nr;
	u16 status;
	u8 challenge[0];
} __attribute__ ((packed));
/* for shared secret auth, add the challenge text size */
#define AUTH_FRAME_SIZE \
  (AT76C503_TX_HDRLEN + IEEE802_11_MGMT_HEADER_SIZE +\
   sizeof(struct ieee802_11_auth_frame))

/* deauth frame in ieee802_11_mgmt.data */
struct ieee802_11_deauth_frame {
	u16 reason;
} __attribute__ ((packed));
#define DEAUTH_FRAME_SIZE \
  (AT76C503_TX_HDRLEN + IEEE802_11_MGMT_HEADER_SIZE +\
   sizeof(struct ieee802_11_disauth_frame))


#define KEVENT_CTRL_HALT 1
#define KEVENT_NEW_BSS 2
#define KEVENT_SET_PROMISC 3
#define KEVENT_MGMT_TIMEOUT 4
#define KEVENT_SCAN 5 
#define KEVENT_JOIN 6
#define KEVENT_STARTIBSS 7
#define KEVENT_SUBMIT_RX 8
#define KEVENT_RESTART 9 /* restart the device */
#define KEVENT_ASSOC_DONE  10 /* execute the power save settings:
			     listen interval, pm mode, assoc id */

static DECLARE_WAIT_QUEUE_HEAD(wait_queue);

static u8 snapsig[] = {0xaa, 0xaa, 0x03};
#ifdef COLLAPSE_RFC1042
/* RFC 1042 encapsulates Ethernet frames in 802.2 SNAP (0xaa, 0xaa, 0x03) with
 * a SNAP OID of 0 (0x00, 0x00, 0x00) */
static u8 rfc1042sig[] = {0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00};
#endif /* COLLAPSE_RFC1042 */

/* local function prototypes */
	
#if IW_MAX_SPY > 0
static void iwspy_update(struct at76c503 *dev, struct at76c503_rx_buffer *buf);
#endif
static void at76c503_read_bulk_callback (struct urb *urb);
static void at76c503_write_bulk_callback(struct urb *urb);
static void defer_kevent (struct at76c503 *dev, int flag);
static struct bss_info *find_matching_bss(struct at76c503 *dev,
					  struct bss_info *curr);
static int auth_req(struct at76c503 *dev, struct bss_info *bss, int seq_nr,
		    u8 *challenge);
static int disassoc_req(struct at76c503 *dev, struct bss_info *bss);
static int assoc_req(struct at76c503 *dev, struct bss_info *bss);
static int reassoc_req(struct at76c503 *dev, struct bss_info *curr,
		       struct bss_info *new);
static void dump_bss_table(struct at76c503 *dev, int force_output);
static int submit_rx_urb(struct at76c503 *dev);
static int startup_device(struct at76c503 *dev);

/* hexdump len many bytes from buf into obuf, separated by delim,
   add a trailing \0 into obuf */
static char *hex2str(char *obuf, u8 *buf, int len, char delim)
{
#define BIN2HEX(x) ((x) < 10 ? '0'+(x) : (x)+'A'-10)

  char *ret = obuf;
  while (len--) {
    *obuf++ = BIN2HEX(*buf>>4);
    *obuf++ = BIN2HEX(*buf&0xf);
    if (delim != '\0')
      *obuf++ = delim;
    buf++;
  }
  if (delim != '\0' && obuf > ret)
	  obuf--; // remove last inserted delimiter
  *obuf = '\0';

  return ret;
}

static inline void free_bss_list(struct at76c503 *dev)
{
	struct list_head *next, *ptr;
	unsigned long flags;

	spin_lock_irqsave(&dev->bss_list_spinlock, flags);

	dev->curr_bss = dev->new_bss = NULL;

	list_for_each_safe(ptr, next, &dev->bss_list) {
		list_del(ptr);
		kfree(list_entry(ptr, struct bss_info, list));
	}

	spin_unlock_irqrestore(&dev->bss_list_spinlock, flags);
}

static inline char *mac2str(u8 *mac)
{
	static char str [6*3];
  
	sprintf(str, "%02x:%02x:%02x:%02x:%02x:%02x",
		mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
	return str;
}

static inline void usb_debug_data (const char *function, const unsigned char *data, int size)
{
	int i;

	if (!debug)
		return;
	
	printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", 
		function, size);
	for (i = 0; i < size; ++i) {
		if((i % 8) == 0)
			printk ("\n");
		printk ("%.2x ", data[i]);