wext.c

linux 内核源代码

/*
 * This file implement the Wireless Extensions APIs.
 *
 * Authors :	Jean Tourrilhes - HPL - <[e-mail]>
 * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
 *
 * (As all part of the Linux kernel, this file is GPL)
 */

/************************** DOCUMENTATION **************************/
/*
 * API definition :
 * --------------
 * See <linux/wireless.h> for details of the APIs and the rest.
 *
 * History :
 * -------
 *
 * v1 - 5.12.01 - Jean II
 *	o Created this file.
 *
 * v2 - 13.12.01 - Jean II
 *	o Move /proc/net/wireless stuff from net/core/dev.c to here
 *	o Make Wireless Extension IOCTLs go through here
 *	o Added iw_handler handling ;-)
 *	o Added standard ioctl description
 *	o Initial dumb commit strategy based on orinoco.c
 *
 * v3 - 19.12.01 - Jean II
 *	o Make sure we don't go out of standard_ioctl[] in ioctl_standard_call
 *	o Add event dispatcher function
 *	o Add event description
 *	o Propagate events as rtnetlink IFLA_WIRELESS option
 *	o Generate event on selected SET requests
 *
 * v4 - 18.04.02 - Jean II
 *	o Fix stupid off by one in iw_ioctl_description : IW_ESSID_MAX_SIZE + 1
 *
 * v5 - 21.06.02 - Jean II
 *	o Add IW_PRIV_TYPE_ADDR in priv_type_size (+cleanup)
 *	o Reshuffle IW_HEADER_TYPE_XXX to map IW_PRIV_TYPE_XXX changes
 *	o Add IWEVCUSTOM for driver specific event/scanning token
 *	o Turn on WE_STRICT_WRITE by default + kernel warning
 *	o Fix WE_STRICT_WRITE in ioctl_export_private() (32 => iw_num)
 *	o Fix off-by-one in test (extra_size <= IFNAMSIZ)
 *
 * v6 - 9.01.03 - Jean II
 *	o Add common spy support : iw_handler_set_spy(), wireless_spy_update()
 *	o Add enhanced spy support : iw_handler_set_thrspy() and event.
 *	o Add WIRELESS_EXT version display in /proc/net/wireless
 *
 * v6 - 18.06.04 - Jean II
 *	o Change get_spydata() method for added safety
 *	o Remove spy #ifdef, they are always on -> cleaner code
 *	o Allow any size GET request if user specifies length > max
 *		and if request has IW_DESCR_FLAG_NOMAX flag or is SIOCGIWPRIV
 *	o Start migrating get_wireless_stats to struct iw_handler_def
 *	o Add wmb() in iw_handler_set_spy() for non-coherent archs/cpus
 * Based on patch from Pavel Roskin <[e-mail]> :
 *	o Fix kernel data leak to user space in private handler handling
 *
 * v7 - 18.3.05 - Jean II
 *	o Remove (struct iw_point *)->pointer from events and streams
 *	o Remove spy_offset from struct iw_handler_def
 *	o Start deprecating dev->get_wireless_stats, output a warning
 *	o If IW_QUAL_DBM is set, show dBm values in /proc/net/wireless
 *	o Don't loose INVALID/DBM flags when clearing UPDATED flags (iwstats)
 *
 * v8 - 17.02.06 - Jean II
 *	o RtNetlink requests support (SET/GET)
 *
 * v8b - 03.08.06 - Herbert Xu
 *	o Fix Wireless Event locking issues.
 *
 * v9 - 14.3.06 - Jean II
 *	o Change length in ESSID and NICK to strlen() instead of strlen()+1
 *	o Make standard_ioctl_num and standard_event_num unsigned
 *	o Remove (struct net_device *)->get_wireless_stats()
 *
 * v10 - 16.3.07 - Jean II
 *	o Prevent leaking of kernel space in stream on 64 bits.
 */

/***************************** INCLUDES *****************************/

#include <linux/module.h>
#include <linux/types.h>		/* off_t */
#include <linux/netdevice.h>		/* struct ifreq, dev_get_by_name() */
#include <linux/proc_fs.h>
#include <linux/rtnetlink.h>		/* rtnetlink stuff */
#include <linux/seq_file.h>
#include <linux/init.h>			/* for __init */
#include <linux/if_arp.h>		/* ARPHRD_ETHER */
#include <linux/etherdevice.h>		/* compare_ether_addr */
#include <linux/interrupt.h>
#include <net/net_namespace.h>

#include <linux/wireless.h>		/* Pretty obvious */
#include <net/iw_handler.h>		/* New driver API */
#include <net/netlink.h>
#include <net/wext.h>

#include <asm/uaccess.h>		/* copy_to_user() */

/************************* GLOBAL VARIABLES *************************/
/*
 * You should not use global variables, because of re-entrancy.
 * On our case, it's only const, so it's OK...
 */
/*
 * Meta-data about all the standard Wireless Extension request we
 * know about.
 */
static const struct iw_ioctl_description standard_ioctl[] = {
	[SIOCSIWCOMMIT	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_NULL,
	},
	[SIOCGIWNAME	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_CHAR,
		.flags		= IW_DESCR_FLAG_DUMP,
	},
	[SIOCSIWNWID	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
		.flags		= IW_DESCR_FLAG_EVENT,
	},
	[SIOCGIWNWID	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
		.flags		= IW_DESCR_FLAG_DUMP,
	},
	[SIOCSIWFREQ	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_FREQ,
		.flags		= IW_DESCR_FLAG_EVENT,
	},
	[SIOCGIWFREQ	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_FREQ,
		.flags		= IW_DESCR_FLAG_DUMP,
	},
	[SIOCSIWMODE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_UINT,
		.flags		= IW_DESCR_FLAG_EVENT,
	},
	[SIOCGIWMODE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_UINT,
		.flags		= IW_DESCR_FLAG_DUMP,
	},
	[SIOCSIWSENS	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCGIWSENS	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCSIWRANGE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_NULL,
	},
	[SIOCGIWRANGE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= sizeof(struct iw_range),
		.flags		= IW_DESCR_FLAG_DUMP,
	},
	[SIOCSIWPRIV	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_NULL,
	},
	[SIOCGIWPRIV	- SIOCIWFIRST] = { /* (handled directly by us) */
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= sizeof(struct iw_priv_args),
		.max_tokens	= 16,
		.flags		= IW_DESCR_FLAG_NOMAX,
	},
	[SIOCSIWSTATS	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_NULL,
	},
	[SIOCGIWSTATS	- SIOCIWFIRST] = { /* (handled directly by us) */
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= sizeof(struct iw_statistics),
		.flags		= IW_DESCR_FLAG_DUMP,
	},
	[SIOCSIWSPY	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= sizeof(struct sockaddr),
		.max_tokens	= IW_MAX_SPY,
	},
	[SIOCGIWSPY	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= sizeof(struct sockaddr) +
				  sizeof(struct iw_quality),
		.max_tokens	= IW_MAX_SPY,
	},
	[SIOCSIWTHRSPY	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= sizeof(struct iw_thrspy),
		.min_tokens	= 1,
		.max_tokens	= 1,
	},
	[SIOCGIWTHRSPY	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= sizeof(struct iw_thrspy),
		.min_tokens	= 1,
		.max_tokens	= 1,
	},
	[SIOCSIWAP	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_ADDR,
	},
	[SIOCGIWAP	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_ADDR,
		.flags		= IW_DESCR_FLAG_DUMP,
	},
	[SIOCSIWMLME	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.min_tokens	= sizeof(struct iw_mlme),
		.max_tokens	= sizeof(struct iw_mlme),
	},
	[SIOCGIWAPLIST	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= sizeof(struct sockaddr) +
				  sizeof(struct iw_quality),
		.max_tokens	= IW_MAX_AP,
		.flags		= IW_DESCR_FLAG_NOMAX,
	},
	[SIOCSIWSCAN	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.min_tokens	= 0,
		.max_tokens	= sizeof(struct iw_scan_req),
	},
	[SIOCGIWSCAN	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_SCAN_MAX_DATA,
		.flags		= IW_DESCR_FLAG_NOMAX,
	},
	[SIOCSIWESSID	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_ESSID_MAX_SIZE,
		.flags		= IW_DESCR_FLAG_EVENT,
	},
	[SIOCGIWESSID	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_ESSID_MAX_SIZE,
		.flags		= IW_DESCR_FLAG_DUMP,
	},
	[SIOCSIWNICKN	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_ESSID_MAX_SIZE,
	},
	[SIOCGIWNICKN	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_ESSID_MAX_SIZE,
	},
	[SIOCSIWRATE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCGIWRATE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCSIWRTS	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCGIWRTS	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCSIWFRAG	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCGIWFRAG	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCSIWTXPOW	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCGIWTXPOW	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCSIWRETRY	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCGIWRETRY	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCSIWENCODE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_ENCODING_TOKEN_MAX,
		.flags		= IW_DESCR_FLAG_EVENT | IW_DESCR_FLAG_RESTRICT,
	},
	[SIOCGIWENCODE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_ENCODING_TOKEN_MAX,
		.flags		= IW_DESCR_FLAG_DUMP | IW_DESCR_FLAG_RESTRICT,
	},
	[SIOCSIWPOWER	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCGIWPOWER	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCSIWGENIE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_GENERIC_IE_MAX,
	},
	[SIOCGIWGENIE	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_GENERIC_IE_MAX,
	},
	[SIOCSIWAUTH	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCGIWAUTH	- SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_PARAM,
	},
	[SIOCSIWENCODEEXT - SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.min_tokens	= sizeof(struct iw_encode_ext),
		.max_tokens	= sizeof(struct iw_encode_ext) +
				  IW_ENCODING_TOKEN_MAX,
	},
	[SIOCGIWENCODEEXT - SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.min_tokens	= sizeof(struct iw_encode_ext),
		.max_tokens	= sizeof(struct iw_encode_ext) +
				  IW_ENCODING_TOKEN_MAX,
	},
	[SIOCSIWPMKSA - SIOCIWFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.min_tokens	= sizeof(struct iw_pmksa),
		.max_tokens	= sizeof(struct iw_pmksa),
	},
};
static const unsigned standard_ioctl_num = ARRAY_SIZE(standard_ioctl);

/*
 * Meta-data about all the additional standard Wireless Extension events
 * we know about.
 */
static const struct iw_ioctl_description standard_event[] = {
	[IWEVTXDROP	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_ADDR,
	},
	[IWEVQUAL	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_QUAL,
	},
	[IWEVCUSTOM	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_CUSTOM_MAX,
	},
	[IWEVREGISTERED	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_ADDR,
	},
	[IWEVEXPIRED	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_ADDR,
	},
	[IWEVGENIE	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_GENERIC_IE_MAX,
	},
	[IWEVMICHAELMICFAILURE	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= sizeof(struct iw_michaelmicfailure),
	},
	[IWEVASSOCREQIE	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_GENERIC_IE_MAX,
	},
	[IWEVASSOCRESPIE	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= IW_GENERIC_IE_MAX,
	},
	[IWEVPMKIDCAND	- IWEVFIRST] = {
		.header_type	= IW_HEADER_TYPE_POINT,
		.token_size	= 1,
		.max_tokens	= sizeof(struct iw_pmkid_cand),
	},
};
static const unsigned standard_event_num = ARRAY_SIZE(standard_event);

/* Size (in bytes) of the various private data types */
static const char iw_priv_type_size[] = {
	0,				/* IW_PRIV_TYPE_NONE */
	1,				/* IW_PRIV_TYPE_BYTE */
	1,				/* IW_PRIV_TYPE_CHAR */
	0,				/* Not defined */
	sizeof(__u32),			/* IW_PRIV_TYPE_INT */
	sizeof(struct iw_freq),		/* IW_PRIV_TYPE_FLOAT */
	sizeof(struct sockaddr),	/* IW_PRIV_TYPE_ADDR */
	0,				/* Not defined */
};

/* Size (in bytes) of various events */
static const int event_type_size[] = {
	IW_EV_LCP_LEN,			/* IW_HEADER_TYPE_NULL */
	0,
	IW_EV_CHAR_LEN,			/* IW_HEADER_TYPE_CHAR */
	0,
	IW_EV_UINT_LEN,			/* IW_HEADER_TYPE_UINT */
	IW_EV_FREQ_LEN,			/* IW_HEADER_TYPE_FREQ */
	IW_EV_ADDR_LEN,			/* IW_HEADER_TYPE_ADDR */
	0,
	IW_EV_POINT_LEN,		/* Without variable payload */
	IW_EV_PARAM_LEN,		/* IW_HEADER_TYPE_PARAM */
	IW_EV_QUAL_LEN,			/* IW_HEADER_TYPE_QUAL */
};

/* Size (in bytes) of various events, as packed */
static const int event_type_pk_size[] = {
	IW_EV_LCP_PK_LEN,		/* IW_HEADER_TYPE_NULL */
	0,
	IW_EV_CHAR_PK_LEN,		/* IW_HEADER_TYPE_CHAR */
	0,
	IW_EV_UINT_PK_LEN,		/* IW_HEADER_TYPE_UINT */
	IW_EV_FREQ_PK_LEN,		/* IW_HEADER_TYPE_FREQ */
	IW_EV_ADDR_PK_LEN,		/* IW_HEADER_TYPE_ADDR */
	0,
	IW_EV_POINT_PK_LEN,		/* Without variable payload */
	IW_EV_PARAM_PK_LEN,		/* IW_HEADER_TYPE_PARAM */
	IW_EV_QUAL_PK_LEN,		/* IW_HEADER_TYPE_QUAL */
};

/************************ COMMON SUBROUTINES ************************/
/*
 * Stuff that may be used in various place or doesn't fit in one
 * of the section below.
 */

/* ---------------------------------------------------------------- */
/*
 * Return the driver handler associated with a specific Wireless Extension.
 */
static iw_handler get_handler(struct net_device *dev, unsigned int cmd)
{
	/* Don't "optimise" the following variable, it will crash */
	unsigned int	index;		/* *MUST* be unsigned */

	/* Check if we have some wireless handlers defined */
	if (dev->wireless_handlers == NULL)
		return NULL;

	/* Try as a standard command */
	index = cmd - SIOCIWFIRST;
	if (index < dev->wireless_handlers->num_standard)
		return dev->wireless_handlers->standard[index];

	/* Try as a private command */
	index = cmd - SIOCIWFIRSTPRIV;
	if (index < dev->wireless_handlers->num_private)
		return dev->wireless_handlers->private[index];

	/* Not found */
	return NULL;
}

/* ---------------------------------------------------------------- */
/*
 * Get statistics out of the driver
 */
static struct iw_statistics *get_wireless_stats(struct net_device *dev)
{
	/* New location */
	if ((dev->wireless_handlers != NULL) &&
	   (dev->wireless_handlers->get_wireless_stats != NULL))
		return dev->wireless_handlers->get_wireless_stats(dev);

	/* Not found */
	return NULL;
}

/* ---------------------------------------------------------------- */
/*
 * Call the commit handler in the driver
 * (if exist and if conditions are right)
 *
 * Note : our current commit strategy is currently pretty dumb,
 * but we will be able to improve on that...
 * The goal is to try to agreagate as many changes as possible
 * before doing the commit. Drivers that will define a commit handler
 * are usually those that need a reset after changing parameters, so
 * we want to minimise the number of reset.
 * A cool idea is to use a timer : at each "set" command, we re-set the
 * timer, when the timer eventually fires, we call the driver.
 * Hopefully, more on that later.
 *
 * Also, I'm waiting to see how many people will complain about the
 * netif_running(dev) test. I'm open on that one...
 * Hopefully, the driver will remember to do a commit in "open()" ;-)
 */
static int call_commit_handler(struct net_device *dev)
{
	if ((netif_running(dev)) &&
	   (dev->wireless_handlers->standard[0] != NULL))
		/* Call the commit handler on the driver */
		return dev->wireless_handlers->standard[0](dev, NULL,
							   NULL, NULL);
	else
		return 0;		/* Command completed successfully */
}

/* ---------------------------------------------------------------- */