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linux/net/wireless/wext-core.c
Johannes Berg 5122565188 wext: fix NULL-ptr-dereference with cfg80211's lack of commit() 
Since cfg80211 doesn't implement commit, we never really cared about
that code there (and it's configured out w/o CONFIG_WIRELESS_EXT).
After all, since it has no commit, it shouldn't return -EIWCOMMIT to
indicate commit is needed.

However, EIWCOMMIT is actually an alias for EINPROGRESS, which _can_
happen if e.g. we try to change the frequency but we're already in
the process of connecting to some network, and drivers could return
that value (or even cfg80211 itself might).

This then causes us to crash because dev->wireless_handlers is NULL
but we try to check dev->wireless_handlers->standard[0].

Fix this by also checking dev->wireless_handlers. Also simplify the
code a little bit.

Cc: stable@vger.kernel.org
Reported-by: syzbot+444248c79e117bc99f46@syzkaller.appspotmail.com
Reported-by: syzbot+8b2a88a09653d4084179@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20210121171621.2076e4a37d5a.I5d9c72220fe7bb133fb718751da0180a57ecba4e@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2021-01-26 11:59:42 +01:00

1190 lines
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/*
* This file implement the Wireless Extensions core API.
*
* Authors : Jean Tourrilhes - HPL - <jt@hpl.hp.com>
* Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
*
* (As all part of the Linux kernel, this file is GPL)
*/
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/wireless.h>
#include <linux/uaccess.h>
#include <linux/export.h>
#include <net/cfg80211.h>
#include <net/iw_handler.h>
#include <net/netlink.h>
#include <net/wext.h>
#include <net/net_namespace.h>
typedef int (*wext_ioctl_func)(struct net_device *, struct iwreq *,
unsigned int, struct iw_request_info *,
iw_handler);
/*
* Meta-data about all the standard Wireless Extension request we
* know about.
*/
static const struct iw_ioctl_description standard_ioctl[] = {
[IW_IOCTL_IDX(SIOCSIWCOMMIT)] = {
.header_type = IW_HEADER_TYPE_NULL,
},
[IW_IOCTL_IDX(SIOCGIWNAME)] = {
.header_type = IW_HEADER_TYPE_CHAR,
.flags = IW_DESCR_FLAG_DUMP,
},
[IW_IOCTL_IDX(SIOCSIWNWID)] = {
.header_type = IW_HEADER_TYPE_PARAM,
.flags = IW_DESCR_FLAG_EVENT,
},
[IW_IOCTL_IDX(SIOCGIWNWID)] = {
.header_type = IW_HEADER_TYPE_PARAM,
.flags = IW_DESCR_FLAG_DUMP,
},
[IW_IOCTL_IDX(SIOCSIWFREQ)] = {
.header_type = IW_HEADER_TYPE_FREQ,
.flags = IW_DESCR_FLAG_EVENT,
},
[IW_IOCTL_IDX(SIOCGIWFREQ)] = {
.header_type = IW_HEADER_TYPE_FREQ,
.flags = IW_DESCR_FLAG_DUMP,
},
[IW_IOCTL_IDX(SIOCSIWMODE)] = {
.header_type = IW_HEADER_TYPE_UINT,
.flags = IW_DESCR_FLAG_EVENT,
},
[IW_IOCTL_IDX(SIOCGIWMODE)] = {
.header_type = IW_HEADER_TYPE_UINT,
.flags = IW_DESCR_FLAG_DUMP,
},
[IW_IOCTL_IDX(SIOCSIWSENS)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCGIWSENS)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCSIWRANGE)] = {
.header_type = IW_HEADER_TYPE_NULL,
},
[IW_IOCTL_IDX(SIOCGIWRANGE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = sizeof(struct iw_range),
.flags = IW_DESCR_FLAG_DUMP,
},
[IW_IOCTL_IDX(SIOCSIWPRIV)] = {
.header_type = IW_HEADER_TYPE_NULL,
},
[IW_IOCTL_IDX(SIOCGIWPRIV)] = { /* (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,
},
[IW_IOCTL_IDX(SIOCSIWSTATS)] = {
.header_type = IW_HEADER_TYPE_NULL,
},
[IW_IOCTL_IDX(SIOCGIWSTATS)] = { /* (handled directly by us) */
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = sizeof(struct iw_statistics),
.flags = IW_DESCR_FLAG_DUMP,
},
[IW_IOCTL_IDX(SIOCSIWSPY)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = sizeof(struct sockaddr),
.max_tokens = IW_MAX_SPY,
},
[IW_IOCTL_IDX(SIOCGIWSPY)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = sizeof(struct sockaddr) +
sizeof(struct iw_quality),
.max_tokens = IW_MAX_SPY,
},
[IW_IOCTL_IDX(SIOCSIWTHRSPY)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = sizeof(struct iw_thrspy),
.min_tokens = 1,
.max_tokens = 1,
},
[IW_IOCTL_IDX(SIOCGIWTHRSPY)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = sizeof(struct iw_thrspy),
.min_tokens = 1,
.max_tokens = 1,
},
[IW_IOCTL_IDX(SIOCSIWAP)] = {
.header_type = IW_HEADER_TYPE_ADDR,
},
[IW_IOCTL_IDX(SIOCGIWAP)] = {
.header_type = IW_HEADER_TYPE_ADDR,
.flags = IW_DESCR_FLAG_DUMP,
},
[IW_IOCTL_IDX(SIOCSIWMLME)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.min_tokens = sizeof(struct iw_mlme),
.max_tokens = sizeof(struct iw_mlme),
},
[IW_IOCTL_IDX(SIOCGIWAPLIST)] = {
.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,
},
[IW_IOCTL_IDX(SIOCSIWSCAN)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.min_tokens = 0,
.max_tokens = sizeof(struct iw_scan_req),
},
[IW_IOCTL_IDX(SIOCGIWSCAN)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_SCAN_MAX_DATA,
.flags = IW_DESCR_FLAG_NOMAX,
},
[IW_IOCTL_IDX(SIOCSIWESSID)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_ESSID_MAX_SIZE,
.flags = IW_DESCR_FLAG_EVENT,
},
[IW_IOCTL_IDX(SIOCGIWESSID)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_ESSID_MAX_SIZE,
.flags = IW_DESCR_FLAG_DUMP,
},
[IW_IOCTL_IDX(SIOCSIWNICKN)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_ESSID_MAX_SIZE,
},
[IW_IOCTL_IDX(SIOCGIWNICKN)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_ESSID_MAX_SIZE,
},
[IW_IOCTL_IDX(SIOCSIWRATE)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCGIWRATE)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCSIWRTS)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCGIWRTS)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCSIWFRAG)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCGIWFRAG)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCSIWTXPOW)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCGIWTXPOW)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCSIWRETRY)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCGIWRETRY)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCSIWENCODE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_ENCODING_TOKEN_MAX,
.flags = IW_DESCR_FLAG_EVENT | IW_DESCR_FLAG_RESTRICT,
},
[IW_IOCTL_IDX(SIOCGIWENCODE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_ENCODING_TOKEN_MAX,
.flags = IW_DESCR_FLAG_DUMP | IW_DESCR_FLAG_RESTRICT,
},
[IW_IOCTL_IDX(SIOCSIWPOWER)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCGIWPOWER)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCSIWGENIE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_GENERIC_IE_MAX,
},
[IW_IOCTL_IDX(SIOCGIWGENIE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_GENERIC_IE_MAX,
},
[IW_IOCTL_IDX(SIOCSIWAUTH)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCGIWAUTH)] = {
.header_type = IW_HEADER_TYPE_PARAM,
},
[IW_IOCTL_IDX(SIOCSIWENCODEEXT)] = {
.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,
},
[IW_IOCTL_IDX(SIOCGIWENCODEEXT)] = {
.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,
},
[IW_IOCTL_IDX(SIOCSIWPMKSA)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.min_tokens = sizeof(struct iw_pmksa),
.max_tokens = sizeof(struct iw_pmksa),
},
};
static const unsigned int 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[] = {
[IW_EVENT_IDX(IWEVTXDROP)] = {
.header_type = IW_HEADER_TYPE_ADDR,
},
[IW_EVENT_IDX(IWEVQUAL)] = {
.header_type = IW_HEADER_TYPE_QUAL,
},
[IW_EVENT_IDX(IWEVCUSTOM)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_CUSTOM_MAX,
},
[IW_EVENT_IDX(IWEVREGISTERED)] = {
.header_type = IW_HEADER_TYPE_ADDR,
},
[IW_EVENT_IDX(IWEVEXPIRED)] = {
.header_type = IW_HEADER_TYPE_ADDR,
},
[IW_EVENT_IDX(IWEVGENIE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_GENERIC_IE_MAX,
},
[IW_EVENT_IDX(IWEVMICHAELMICFAILURE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = sizeof(struct iw_michaelmicfailure),
},
[IW_EVENT_IDX(IWEVASSOCREQIE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_GENERIC_IE_MAX,
},
[IW_EVENT_IDX(IWEVASSOCRESPIE)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = IW_GENERIC_IE_MAX,
},
[IW_EVENT_IDX(IWEVPMKIDCAND)] = {
.header_type = IW_HEADER_TYPE_POINT,
.token_size = 1,
.max_tokens = sizeof(struct iw_pmkid_cand),
},
};
static const unsigned int standard_event_num = ARRAY_SIZE(standard_event);
/* 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 */
};
#ifdef CONFIG_COMPAT
static const int compat_event_type_size[] = {
IW_EV_COMPAT_LCP_LEN, /* IW_HEADER_TYPE_NULL */
0,
IW_EV_COMPAT_CHAR_LEN, /* IW_HEADER_TYPE_CHAR */
0,
IW_EV_COMPAT_UINT_LEN, /* IW_HEADER_TYPE_UINT */
IW_EV_COMPAT_FREQ_LEN, /* IW_HEADER_TYPE_FREQ */
IW_EV_COMPAT_ADDR_LEN, /* IW_HEADER_TYPE_ADDR */
0,
IW_EV_COMPAT_POINT_LEN, /* Without variable payload */
IW_EV_COMPAT_PARAM_LEN, /* IW_HEADER_TYPE_PARAM */
IW_EV_COMPAT_QUAL_LEN, /* IW_HEADER_TYPE_QUAL */
};
#endif
/* IW event code */
void wireless_nlevent_flush(void)
{
struct sk_buff *skb;
struct net *net;
down_read(&net_rwsem);
for_each_net(net) {
while ((skb = skb_dequeue(&net->wext_nlevents)))
rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL,
GFP_KERNEL);
}
up_read(&net_rwsem);
}
EXPORT_SYMBOL_GPL(wireless_nlevent_flush);
static int wext_netdev_notifier_call(struct notifier_block *nb,
unsigned long state, void *ptr)
{
/*
* When a netdev changes state in any way, flush all pending messages
* to avoid them going out in a strange order, e.g. RTM_NEWLINK after
* RTM_DELLINK, or with IFF_UP after without IFF_UP during dev_close()
* or similar - all of which could otherwise happen due to delays from
* schedule_work().
*/
wireless_nlevent_flush();
return NOTIFY_OK;
}
static struct notifier_block wext_netdev_notifier = {
.notifier_call = wext_netdev_notifier_call,
};
static int __net_init wext_pernet_init(struct net *net)
{
skb_queue_head_init(&net->wext_nlevents);
return 0;
}
static void __net_exit wext_pernet_exit(struct net *net)
{
skb_queue_purge(&net->wext_nlevents);
}
static struct pernet_operations wext_pernet_ops = {
.init = wext_pernet_init,
.exit = wext_pernet_exit,
};
static int __init wireless_nlevent_init(void)
{
int err = register_pernet_subsys(&wext_pernet_ops);
if (err)
return err;
err = register_netdevice_notifier(&wext_netdev_notifier);
if (err)
unregister_pernet_subsys(&wext_pernet_ops);
return err;
}
subsys_initcall(wireless_nlevent_init);
/* Process events generated by the wireless layer or the driver. */
static void wireless_nlevent_process(struct work_struct *work)
{
wireless_nlevent_flush();
}
static DECLARE_WORK(wireless_nlevent_work, wireless_nlevent_process);
static struct nlmsghdr *rtnetlink_ifinfo_prep(struct net_device *dev,
struct sk_buff *skb)
{
struct ifinfomsg *r;
struct nlmsghdr *nlh;
nlh = nlmsg_put(skb, 0, 0, RTM_NEWLINK, sizeof(*r), 0);
if (!nlh)
return NULL;
r = nlmsg_data(nlh);
r->ifi_family = AF_UNSPEC;
r->__ifi_pad = 0;
r->ifi_type = dev->type;
r->ifi_index = dev->ifindex;
r->ifi_flags = dev_get_flags(dev);
r->ifi_change = 0; /* Wireless changes don't affect those flags */
if (nla_put_string(skb, IFLA_IFNAME, dev->name))
goto nla_put_failure;
return nlh;
nla_put_failure:
nlmsg_cancel(skb, nlh);
return NULL;
}
/*
* Main event dispatcher. Called from other parts and drivers.
* Send the event on the appropriate channels.
* May be called from interrupt context.
*/
void wireless_send_event(struct net_device * dev,
unsigned int cmd,
union iwreq_data * wrqu,
const char * extra)
{
const struct iw_ioctl_description * descr = NULL;
int extra_len = 0;
struct iw_event *event; /* Mallocated whole event */
int event_len; /* Its size */
int hdr_len; /* Size of the event header */
int wrqu_off = 0; /* Offset in wrqu */
/* Don't "optimise" the following variable, it will crash */
unsigned int cmd_index; /* *MUST* be unsigned */
struct sk_buff *skb;
struct nlmsghdr *nlh;
struct nlattr *nla;
#ifdef CONFIG_COMPAT
struct __compat_iw_event *compat_event;
struct compat_iw_point compat_wrqu;
struct sk_buff *compskb;
#endif
/*
* Nothing in the kernel sends scan events with data, be safe.
* This is necessary because we cannot fix up scan event data
* for compat, due to being contained in 'extra', but normally
* applications are required to retrieve the scan data anyway
* and no data is included in the event, this codifies that
* practice.
*/
if (WARN_ON(cmd == SIOCGIWSCAN && extra))
extra = NULL;
/* Get the description of the Event */
if (cmd <= SIOCIWLAST) {
cmd_index = IW_IOCTL_IDX(cmd);
if (cmd_index < standard_ioctl_num)
descr = &(standard_ioctl[cmd_index]);
} else {
cmd_index = IW_EVENT_IDX(cmd);
if (cmd_index < standard_event_num)
descr = &(standard_event[cmd_index]);
}
/* Don't accept unknown events */
if (descr == NULL) {
/* Note : we don't return an error to the driver, because
* the driver would not know what to do about it. It can't
* return an error to the user, because the event is not
* initiated by a user request.
* The best the driver could do is to log an error message.
* We will do it ourselves instead...
*/
netdev_err(dev, "(WE) : Invalid/Unknown Wireless Event (0x%04X)\n",
cmd);
return;
}
/* Check extra parameters and set extra_len */
if (descr->header_type == IW_HEADER_TYPE_POINT) {
/* Check if number of token fits within bounds */
if (wrqu->data.length > descr->max_tokens) {
netdev_err(dev, "(WE) : Wireless Event (cmd=0x%04X) too big (%d)\n",
cmd, wrqu->data.length);
return;
}
if (wrqu->data.length < descr->min_tokens) {
netdev_err(dev, "(WE) : Wireless Event (cmd=0x%04X) too small (%d)\n",
cmd, wrqu->data.length);
return;
}
/* Calculate extra_len - extra is NULL for restricted events */
if (extra != NULL)
extra_len = wrqu->data.length * descr->token_size;
/* Always at an offset in wrqu */
wrqu_off = IW_EV_POINT_OFF;
}
/* Total length of the event */
hdr_len = event_type_size[descr->header_type];
event_len = hdr_len + extra_len;
/*
* The problem for 64/32 bit.
*
* On 64-bit, a regular event is laid out as follows:
* | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
* | event.len | event.cmd | p a d d i n g |
* | wrqu data ... (with the correct size) |
*
* This padding exists because we manipulate event->u,
* and 'event' is not packed.
*
* An iw_point event is laid out like this instead:
* | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
* | event.len | event.cmd | p a d d i n g |
* | iwpnt.len | iwpnt.flg | p a d d i n g |
* | extra data ...
*
* The second padding exists because struct iw_point is extended,
* but this depends on the platform...
*
* On 32-bit, all the padding shouldn't be there.
*/
skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
if (!skb)
return;
/* Send via the RtNetlink event channel */
nlh = rtnetlink_ifinfo_prep(dev, skb);
if (WARN_ON(!nlh)) {
kfree_skb(skb);
return;
}
/* Add the wireless events in the netlink packet */
nla = nla_reserve(skb, IFLA_WIRELESS, event_len);
if (!nla) {
kfree_skb(skb);
return;
}
event = nla_data(nla);
/* Fill event - first clear to avoid data leaking */
memset(event, 0, hdr_len);
event->len = event_len;
event->cmd = cmd;
memcpy(&event->u, ((char *) wrqu) + wrqu_off, hdr_len - IW_EV_LCP_LEN);
if (extra_len)
memcpy(((char *) event) + hdr_len, extra, extra_len);
nlmsg_end(skb, nlh);
#ifdef CONFIG_COMPAT
hdr_len = compat_event_type_size[descr->header_type];
event_len = hdr_len + extra_len;
compskb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
if (!compskb) {
kfree_skb(skb);
return;
}
/* Send via the RtNetlink event channel */
nlh = rtnetlink_ifinfo_prep(dev, compskb);
if (WARN_ON(!nlh)) {
kfree_skb(skb);
kfree_skb(compskb);
return;
}
/* Add the wireless events in the netlink packet */
nla = nla_reserve(compskb, IFLA_WIRELESS, event_len);
if (!nla) {
kfree_skb(skb);
kfree_skb(compskb);
return;
}
compat_event = nla_data(nla);
compat_event->len = event_len;
compat_event->cmd = cmd;
if (descr->header_type == IW_HEADER_TYPE_POINT) {
compat_wrqu.length = wrqu->data.length;
compat_wrqu.flags = wrqu->data.flags;
memcpy(&compat_event->pointer,
((char *) &compat_wrqu) + IW_EV_COMPAT_POINT_OFF,
hdr_len - IW_EV_COMPAT_LCP_LEN);
if (extra_len)
memcpy(((char *) compat_event) + hdr_len,
extra, extra_len);
} else {
/* extra_len must be zero, so no if (extra) needed */
memcpy(&compat_event->pointer, wrqu,
hdr_len - IW_EV_COMPAT_LCP_LEN);
}
nlmsg_end(compskb, nlh);
skb_shinfo(skb)->frag_list = compskb;
#endif
skb_queue_tail(&dev_net(dev)->wext_nlevents, skb);
schedule_work(&wireless_nlevent_work);
}
EXPORT_SYMBOL(wireless_send_event);
/* IW handlers */
struct iw_statistics *get_wireless_stats(struct net_device *dev)
{
#ifdef CONFIG_WIRELESS_EXT
if ((dev->wireless_handlers != NULL) &&
(dev->wireless_handlers->get_wireless_stats != NULL))
return dev->wireless_handlers->get_wireless_stats(dev);
#endif
#ifdef CONFIG_CFG80211_WEXT
if (dev->ieee80211_ptr &&
dev->ieee80211_ptr->wiphy &&
dev->ieee80211_ptr->wiphy->wext &&
dev->ieee80211_ptr->wiphy->wext->get_wireless_stats)
return dev->ieee80211_ptr->wiphy->wext->get_wireless_stats(dev);
#endif
/* not found */
return NULL;
}
/* noinline to avoid a bogus warning with -O3 */
static noinline int iw_handler_get_iwstats(struct net_device * dev,
struct iw_request_info * info,
union iwreq_data * wrqu,
char * extra)
{
/* Get stats from the driver */
struct iw_statistics *stats;
stats = get_wireless_stats(dev);
if (stats) {
/* Copy statistics to extra */
memcpy(extra, stats, sizeof(struct iw_statistics));
wrqu->data.length = sizeof(struct iw_statistics);
/* Check if we need to clear the updated flag */
if (wrqu->data.flags != 0)
stats->qual.updated &= ~IW_QUAL_ALL_UPDATED;
return 0;
} else
return -EOPNOTSUPP;
}
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 */
const struct iw_handler_def *handlers = NULL;
#ifdef CONFIG_CFG80211_WEXT
if (dev->ieee80211_ptr && dev->ieee80211_ptr->wiphy)
handlers = dev->ieee80211_ptr->wiphy->wext;
#endif
#ifdef CONFIG_WIRELESS_EXT
if (dev->wireless_handlers)
handlers = dev->wireless_handlers;
#endif
if (!handlers)
return NULL;
/* Try as a standard command */
index = IW_IOCTL_IDX(cmd);
if (index < handlers->num_standard)
return handlers->standard[index];
#ifdef CONFIG_WEXT_PRIV
/* Try as a private command */
index = cmd - SIOCIWFIRSTPRIV;
if (index < handlers->num_private)
return handlers->private[index];
#endif
/* Not found */
return NULL;
}
static int ioctl_standard_iw_point(struct iw_point *iwp, unsigned int cmd,
const struct iw_ioctl_description *descr,
iw_handler handler, struct net_device *dev,
struct iw_request_info *info)
{
int err, extra_size, user_length = 0, essid_compat = 0;
char *extra;
/* Calculate space needed by arguments. Always allocate
* for max space.
*/
extra_size = descr->max_tokens * descr->token_size;
/* Check need for ESSID compatibility for WE < 21 */
switch (cmd) {
case SIOCSIWESSID:
case SIOCGIWESSID:
case SIOCSIWNICKN:
case SIOCGIWNICKN:
if (iwp->length == descr->max_tokens + 1)
essid_compat = 1;
else if (IW_IS_SET(cmd) && (iwp->length != 0)) {
char essid[IW_ESSID_MAX_SIZE + 1];
unsigned int len;
len = iwp->length * descr->token_size;
if (len > IW_ESSID_MAX_SIZE)
return -EFAULT;
err = copy_from_user(essid, iwp->pointer, len);
if (err)
return -EFAULT;
if (essid[iwp->length - 1] == '\0')
essid_compat = 1;
}
break;
default:
break;
}
iwp->length -= essid_compat;
/* Check what user space is giving us */
if (IW_IS_SET(cmd)) {
/* Check NULL pointer */
if (!iwp->pointer && iwp->length != 0)
return -EFAULT;
/* Check if number of token fits within bounds */
if (iwp->length > descr->max_tokens)
return -E2BIG;
if (iwp->length < descr->min_tokens)
return -EINVAL;
} else {
/* Check NULL pointer */
if (!iwp->pointer)
return -EFAULT;
/* Save user space buffer size for checking */
user_length = iwp->length;
/* Don't check if user_length > max to allow forward
* compatibility. The test user_length < min is
* implied by the test at the end.
*/
/* Support for very large requests */
if ((descr->flags & IW_DESCR_FLAG_NOMAX) &&
(user_length > descr->max_tokens)) {
/* Allow userspace to GET more than max so
* we can support any size GET requests.
* There is still a limit : -ENOMEM.
*/
extra_size = user_length * descr->token_size;
/* Note : user_length is originally a __u16,
* and token_size is controlled by us,
* so extra_size won't get negative and
* won't overflow...
*/
}
}
/* kzalloc() ensures NULL-termination for essid_compat. */
extra = kzalloc(extra_size, GFP_KERNEL);
if (!extra)
return -ENOMEM;
/* If it is a SET, get all the extra data in here */
if (IW_IS_SET(cmd) && (iwp->length != 0)) {
if (copy_from_user(extra, iwp->pointer,
iwp->length *
descr->token_size)) {
err = -EFAULT;
goto out;
}
if (cmd == SIOCSIWENCODEEXT) {
struct iw_encode_ext *ee = (void *) extra;
if (iwp->length < sizeof(*ee) + ee->key_len) {
err = -EFAULT;
goto out;
}
}
}
if (IW_IS_GET(cmd) && !(descr->flags & IW_DESCR_FLAG_NOMAX)) {
/*
* If this is a GET, but not NOMAX, it means that the extra
* data is not bounded by userspace, but by max_tokens. Thus
* set the length to max_tokens. This matches the extra data
* allocation.
* The driver should fill it with the number of tokens it
* provided, and it may check iwp->length rather than having
* knowledge of max_tokens. If the driver doesn't change the
* iwp->length, this ioctl just copies back max_token tokens
* filled with zeroes. Hopefully the driver isn't claiming
* them to be valid data.
*/
iwp->length = descr->max_tokens;
}
err = handler(dev, info, (union iwreq_data *) iwp, extra);
iwp->length += essid_compat;
/* If we have something to return to the user */
if (!err && IW_IS_GET(cmd)) {
/* Check if there is enough buffer up there */
if (user_length < iwp->length) {
err = -E2BIG;
goto out;
}
if (copy_to_user(iwp->pointer, extra,
iwp->length *
descr->token_size)) {
err = -EFAULT;
goto out;
}
}
/* Generate an event to notify listeners of the change */
if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
((err == 0) || (err == -EIWCOMMIT))) {
union iwreq_data *data = (union iwreq_data *) iwp;
if (descr->flags & IW_DESCR_FLAG_RESTRICT)
/* If the event is restricted, don't
* export the payload.
*/
wireless_send_event(dev, cmd, data, NULL);
else
wireless_send_event(dev, cmd, data, extra);
}
out:
kfree(extra);
return err;
}
/*
* 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()" ;-)
*/
int call_commit_handler(struct net_device *dev)
{
#ifdef CONFIG_WIRELESS_EXT
if (netif_running(dev) &&
dev->wireless_handlers &&
dev->wireless_handlers->standard[0])
/* Call the commit handler on the driver */
return dev->wireless_handlers->standard[0](dev, NULL,
NULL, NULL);
else
return 0; /* Command completed successfully */
#else
/* cfg80211 has no commit */
return 0;
#endif
}
/*
* Main IOCTl dispatcher.
* Check the type of IOCTL and call the appropriate wrapper...
*/
static int wireless_process_ioctl(struct net *net, struct iwreq *iwr,
unsigned int cmd,
struct iw_request_info *info,
wext_ioctl_func standard,
wext_ioctl_func private)
{
struct net_device *dev;
iw_handler handler;
/* Permissions are already checked in dev_ioctl() before calling us.
* The copy_to/from_user() of ifr is also dealt with in there */
/* Make sure the device exist */
if ((dev = __dev_get_by_name(net, iwr->ifr_name)) == NULL)
return -ENODEV;
/* A bunch of special cases, then the generic case...
* Note that 'cmd' is already filtered in dev_ioctl() with
* (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST) */
if (cmd == SIOCGIWSTATS)
return standard(dev, iwr, cmd, info,
&iw_handler_get_iwstats);
#ifdef CONFIG_WEXT_PRIV
if (cmd == SIOCGIWPRIV && dev->wireless_handlers)
return standard(dev, iwr, cmd, info,
iw_handler_get_private);
#endif
/* Basic check */
if (!netif_device_present(dev))
return -ENODEV;
/* New driver API : try to find the handler */
handler = get_handler(dev, cmd);
if (handler) {
/* Standard and private are not the same */
if (cmd < SIOCIWFIRSTPRIV)
return standard(dev, iwr, cmd, info, handler);
else if (private)
return private(dev, iwr, cmd, info, handler);
}
return -EOPNOTSUPP;
}
/* If command is `set a parameter', or `get the encoding parameters',
* check if the user has the right to do it.
*/
static int wext_permission_check(unsigned int cmd)
{
if ((IW_IS_SET(cmd) || cmd == SIOCGIWENCODE ||
cmd == SIOCGIWENCODEEXT) &&
!capable(CAP_NET_ADMIN))
return -EPERM;
return 0;
}
/* entry point from dev ioctl */
static int wext_ioctl_dispatch(struct net *net, struct iwreq *iwr,
unsigned int cmd, struct iw_request_info *info,
wext_ioctl_func standard,
wext_ioctl_func private)
{
int ret = wext_permission_check(cmd);
if (ret)
return ret;
dev_load(net, iwr->ifr_name);
rtnl_lock();
ret = wireless_process_ioctl(net, iwr, cmd, info, standard, private);
rtnl_unlock();
return ret;
}
/*
* Wrapper to call a standard Wireless Extension handler.
* We do various checks and also take care of moving data between
* user space and kernel space.
*/
static int ioctl_standard_call(struct net_device * dev,
struct iwreq *iwr,
unsigned int cmd,
struct iw_request_info *info,
iw_handler handler)
{
const struct iw_ioctl_description * descr;
int ret = -EINVAL;
/* Get the description of the IOCTL */
if (IW_IOCTL_IDX(cmd) >= standard_ioctl_num)
return -EOPNOTSUPP;
descr = &(standard_ioctl[IW_IOCTL_IDX(cmd)]);
/* Check if we have a pointer to user space data or not */
if (descr->header_type != IW_HEADER_TYPE_POINT) {
/* No extra arguments. Trivial to handle */
ret = handler(dev, info, &(iwr->u), NULL);
/* Generate an event to notify listeners of the change */
if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
((ret == 0) || (ret == -EIWCOMMIT)))
wireless_send_event(dev, cmd, &(iwr->u), NULL);
} else {
ret = ioctl_standard_iw_point(&iwr->u.data, cmd, descr,
handler, dev, info);
}
/* Call commit handler if needed and defined */
if (ret == -EIWCOMMIT)
ret = call_commit_handler(dev);
/* Here, we will generate the appropriate event if needed */
return ret;
}
int wext_handle_ioctl(struct net *net, unsigned int cmd, void __user *arg)
{
struct iw_request_info info = { .cmd = cmd, .flags = 0 };
struct iwreq iwr;
int ret;
if (copy_from_user(&iwr, arg, sizeof(iwr)))
return -EFAULT;
iwr.ifr_name[sizeof(iwr.ifr_name) - 1] = 0;
ret = wext_ioctl_dispatch(net, &iwr, cmd, &info,
ioctl_standard_call,
ioctl_private_call);
if (ret >= 0 &&
IW_IS_GET(cmd) &&
copy_to_user(arg, &iwr, sizeof(struct iwreq)))
return -EFAULT;
return ret;
}
#ifdef CONFIG_COMPAT
static int compat_standard_call(struct net_device *dev,
struct iwreq *iwr,
unsigned int cmd,
struct iw_request_info *info,
iw_handler handler)
{
const struct iw_ioctl_description *descr;
struct compat_iw_point *iwp_compat;
struct iw_point iwp;
int err;
descr = standard_ioctl + IW_IOCTL_IDX(cmd);
if (descr->header_type != IW_HEADER_TYPE_POINT)
return ioctl_standard_call(dev, iwr, cmd, info, handler);
iwp_compat = (struct compat_iw_point *) &iwr->u.data;
iwp.pointer = compat_ptr(iwp_compat->pointer);
iwp.length = iwp_compat->length;
iwp.flags = iwp_compat->flags;
err = ioctl_standard_iw_point(&iwp, cmd, descr, handler, dev, info);
iwp_compat->pointer = ptr_to_compat(iwp.pointer);
iwp_compat->length = iwp.length;
iwp_compat->flags = iwp.flags;
return err;
}
int compat_wext_handle_ioctl(struct net *net, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct iw_request_info info;
struct iwreq iwr;
char *colon;
int ret;
if (copy_from_user(&iwr, argp, sizeof(struct iwreq)))
return -EFAULT;
iwr.ifr_name[IFNAMSIZ-1] = 0;
colon = strchr(iwr.ifr_name, ':');
if (colon)
*colon = 0;
info.cmd = cmd;
info.flags = IW_REQUEST_FLAG_COMPAT;
ret = wext_ioctl_dispatch(net, &iwr, cmd, &info,
compat_standard_call,
compat_private_call);
if (ret >= 0 &&
IW_IS_GET(cmd) &&
copy_to_user(argp, &iwr, sizeof(struct iwreq)))
return -EFAULT;
return ret;
}
#endif
char *iwe_stream_add_event(struct iw_request_info *info, char *stream,
char *ends, struct iw_event *iwe, int event_len)
{
int lcp_len = iwe_stream_lcp_len(info);
event_len = iwe_stream_event_len_adjust(info, event_len);
/* Check if it's possible */
if (likely((stream + event_len) < ends)) {
iwe->len = event_len;
/* Beware of alignement issues on 64 bits */
memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
memcpy(stream + lcp_len, &iwe->u,
event_len - lcp_len);
stream += event_len;
}
return stream;
}
EXPORT_SYMBOL(iwe_stream_add_event);
char *iwe_stream_add_point(struct iw_request_info *info, char *stream,
char *ends, struct iw_event *iwe, char *extra)
{
int event_len = iwe_stream_point_len(info) + iwe->u.data.length;
int point_len = iwe_stream_point_len(info);
int lcp_len = iwe_stream_lcp_len(info);
/* Check if it's possible */
if (likely((stream + event_len) < ends)) {
iwe->len = event_len;
memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
memcpy(stream + lcp_len,
((char *) &iwe->u) + IW_EV_POINT_OFF,
IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
if (iwe->u.data.length && extra)
memcpy(stream + point_len, extra, iwe->u.data.length);
stream += event_len;
}
return stream;
}
EXPORT_SYMBOL(iwe_stream_add_point);
char *iwe_stream_add_value(struct iw_request_info *info, char *event,
char *value, char *ends, struct iw_event *iwe,
int event_len)
{
int lcp_len = iwe_stream_lcp_len(info);
/* Don't duplicate LCP */
event_len -= IW_EV_LCP_LEN;
/* Check if it's possible */
if (likely((value + event_len) < ends)) {
/* Add new value */
memcpy(value, &iwe->u, event_len);
value += event_len;
/* Patch LCP */
iwe->len = value - event;
memcpy(event, (char *) iwe, lcp_len);
}
return value;
}
EXPORT_SYMBOL(iwe_stream_add_value);
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