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alistair23-linux/net/wireless/util.c
Johannes Berg 3d54d25515 cfg80211: clean up properly on interface type change 
When the interface type changes while connected, and the
driver does not require the interface to be down for a
type change, it is currently possible to get very strange
results unless the driver takes special care, which it
shouldn't have to.

To fix this, take care to disconnect/leave IBSS when
changing the interface type -- even if the driver may fail
the call. Also process all events that may be pending to
avoid running into a situation where an event is reported
but only processed after the type has already changed,
which would lead to missing events and warnings.

A side effect of this is that you will have disconnected
or left the IBSS even if the mode change ultimately fails,
but since the intention was to change it and thus leave or
disconnect, this is not a problem.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-08-28 14:40:31 -04:00

685 lines
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/*
* Wireless utility functions
*
* Copyright 2007-2009 Johannes Berg <johannes@sipsolutions.net>
*/
#include <linux/bitops.h>
#include <linux/etherdevice.h>
#include <net/cfg80211.h>
#include <net/ip.h>
#include "core.h"
struct ieee80211_rate *
ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
u32 basic_rates, int bitrate)
{
struct ieee80211_rate *result = &sband->bitrates[0];
int i;
for (i = 0; i < sband->n_bitrates; i++) {
if (!(basic_rates & BIT(i)))
continue;
if (sband->bitrates[i].bitrate > bitrate)
continue;
result = &sband->bitrates[i];
}
return result;
}
EXPORT_SYMBOL(ieee80211_get_response_rate);
int ieee80211_channel_to_frequency(int chan)
{
if (chan < 14)
return 2407 + chan * 5;
if (chan == 14)
return 2484;
/* FIXME: 802.11j 17.3.8.3.2 */
return (chan + 1000) * 5;
}
EXPORT_SYMBOL(ieee80211_channel_to_frequency);
int ieee80211_frequency_to_channel(int freq)
{
if (freq == 2484)
return 14;
if (freq < 2484)
return (freq - 2407) / 5;
/* FIXME: 802.11j 17.3.8.3.2 */
return freq/5 - 1000;
}
EXPORT_SYMBOL(ieee80211_frequency_to_channel);
struct ieee80211_channel *__ieee80211_get_channel(struct wiphy *wiphy,
int freq)
{
enum ieee80211_band band;
struct ieee80211_supported_band *sband;
int i;
for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
sband = wiphy->bands[band];
if (!sband)
continue;
for (i = 0; i < sband->n_channels; i++) {
if (sband->channels[i].center_freq == freq)
return &sband->channels[i];
}
}
return NULL;
}
EXPORT_SYMBOL(__ieee80211_get_channel);
static void set_mandatory_flags_band(struct ieee80211_supported_band *sband,
enum ieee80211_band band)
{
int i, want;
switch (band) {
case IEEE80211_BAND_5GHZ:
want = 3;
for (i = 0; i < sband->n_bitrates; i++) {
if (sband->bitrates[i].bitrate == 60 ||
sband->bitrates[i].bitrate == 120 ||
sband->bitrates[i].bitrate == 240) {
sband->bitrates[i].flags |=
IEEE80211_RATE_MANDATORY_A;
want--;
}
}
WARN_ON(want);
break;
case IEEE80211_BAND_2GHZ:
want = 7;
for (i = 0; i < sband->n_bitrates; i++) {
if (sband->bitrates[i].bitrate == 10) {
sband->bitrates[i].flags |=
IEEE80211_RATE_MANDATORY_B |
IEEE80211_RATE_MANDATORY_G;
want--;
}
if (sband->bitrates[i].bitrate == 20 ||
sband->bitrates[i].bitrate == 55 ||
sband->bitrates[i].bitrate == 110 ||
sband->bitrates[i].bitrate == 60 ||
sband->bitrates[i].bitrate == 120 ||
sband->bitrates[i].bitrate == 240) {
sband->bitrates[i].flags |=
IEEE80211_RATE_MANDATORY_G;
want--;
}
if (sband->bitrates[i].bitrate != 10 &&
sband->bitrates[i].bitrate != 20 &&
sband->bitrates[i].bitrate != 55 &&
sband->bitrates[i].bitrate != 110)
sband->bitrates[i].flags |=
IEEE80211_RATE_ERP_G;
}
WARN_ON(want != 0 && want != 3 && want != 6);
break;
case IEEE80211_NUM_BANDS:
WARN_ON(1);
break;
}
}
void ieee80211_set_bitrate_flags(struct wiphy *wiphy)
{
enum ieee80211_band band;
for (band = 0; band < IEEE80211_NUM_BANDS; band++)
if (wiphy->bands[band])
set_mandatory_flags_band(wiphy->bands[band], band);
}
int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev,
struct key_params *params, int key_idx,
const u8 *mac_addr)
{
int i;
if (key_idx > 5)
return -EINVAL;
/*
* Disallow pairwise keys with non-zero index unless it's WEP
* (because current deployments use pairwise WEP keys with
* non-zero indizes but 802.11i clearly specifies to use zero)
*/
if (mac_addr && key_idx &&
params->cipher != WLAN_CIPHER_SUITE_WEP40 &&
params->cipher != WLAN_CIPHER_SUITE_WEP104)
return -EINVAL;
switch (params->cipher) {
case WLAN_CIPHER_SUITE_WEP40:
if (params->key_len != WLAN_KEY_LEN_WEP40)
return -EINVAL;
break;
case WLAN_CIPHER_SUITE_TKIP:
if (params->key_len != WLAN_KEY_LEN_TKIP)
return -EINVAL;
break;
case WLAN_CIPHER_SUITE_CCMP:
if (params->key_len != WLAN_KEY_LEN_CCMP)
return -EINVAL;
break;
case WLAN_CIPHER_SUITE_WEP104:
if (params->key_len != WLAN_KEY_LEN_WEP104)
return -EINVAL;
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
if (params->key_len != WLAN_KEY_LEN_AES_CMAC)
return -EINVAL;
break;
default:
return -EINVAL;
}
if (params->seq) {
switch (params->cipher) {
case WLAN_CIPHER_SUITE_WEP40:
case WLAN_CIPHER_SUITE_WEP104:
/* These ciphers do not use key sequence */
return -EINVAL;
case WLAN_CIPHER_SUITE_TKIP:
case WLAN_CIPHER_SUITE_CCMP:
case WLAN_CIPHER_SUITE_AES_CMAC:
if (params->seq_len != 6)
return -EINVAL;
break;
}
}
for (i = 0; i < rdev->wiphy.n_cipher_suites; i++)
if (params->cipher == rdev->wiphy.cipher_suites[i])
break;
if (i == rdev->wiphy.n_cipher_suites)
return -EINVAL;
return 0;
}
/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
const unsigned char rfc1042_header[] __aligned(2) =
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
EXPORT_SYMBOL(rfc1042_header);
/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
const unsigned char bridge_tunnel_header[] __aligned(2) =
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
EXPORT_SYMBOL(bridge_tunnel_header);
unsigned int ieee80211_hdrlen(__le16 fc)
{
unsigned int hdrlen = 24;
if (ieee80211_is_data(fc)) {
if (ieee80211_has_a4(fc))
hdrlen = 30;
if (ieee80211_is_data_qos(fc))
hdrlen += IEEE80211_QOS_CTL_LEN;
goto out;
}
if (ieee80211_is_ctl(fc)) {
/*
* ACK and CTS are 10 bytes, all others 16. To see how
* to get this condition consider
* subtype mask: 0b0000000011110000 (0x00F0)
* ACK subtype: 0b0000000011010000 (0x00D0)
* CTS subtype: 0b0000000011000000 (0x00C0)
* bits that matter: ^^^ (0x00E0)
* value of those: 0b0000000011000000 (0x00C0)
*/
if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
hdrlen = 10;
else
hdrlen = 16;
}
out:
return hdrlen;
}
EXPORT_SYMBOL(ieee80211_hdrlen);
unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
{
const struct ieee80211_hdr *hdr =
(const struct ieee80211_hdr *)skb->data;
unsigned int hdrlen;
if (unlikely(skb->len < 10))
return 0;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
if (unlikely(hdrlen > skb->len))
return 0;
return hdrlen;
}
EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
static int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
{
int ae = meshhdr->flags & MESH_FLAGS_AE;
/* 7.1.3.5a.2 */
switch (ae) {
case 0:
return 6;
case MESH_FLAGS_AE_A4:
return 12;
case MESH_FLAGS_AE_A5_A6:
return 18;
case (MESH_FLAGS_AE_A4 | MESH_FLAGS_AE_A5_A6):
return 24;
default:
return 6;
}
}
int ieee80211_data_to_8023(struct sk_buff *skb, u8 *addr,
enum nl80211_iftype iftype)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
u16 hdrlen, ethertype;
u8 *payload;
u8 dst[ETH_ALEN];
u8 src[ETH_ALEN] __aligned(2);
if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
return -1;
hdrlen = ieee80211_hdrlen(hdr->frame_control);
/* convert IEEE 802.11 header + possible LLC headers into Ethernet
* header
* IEEE 802.11 address fields:
* ToDS FromDS Addr1 Addr2 Addr3 Addr4
* 0 0 DA SA BSSID n/a
* 0 1 DA BSSID SA n/a
* 1 0 BSSID SA DA n/a
* 1 1 RA TA DA SA
*/
memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
switch (hdr->frame_control &
cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
case cpu_to_le16(IEEE80211_FCTL_TODS):
if (unlikely(iftype != NL80211_IFTYPE_AP &&
iftype != NL80211_IFTYPE_AP_VLAN))
return -1;
break;
case cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS):
if (unlikely(iftype != NL80211_IFTYPE_WDS &&
iftype != NL80211_IFTYPE_MESH_POINT))
return -1;
if (iftype == NL80211_IFTYPE_MESH_POINT) {
struct ieee80211s_hdr *meshdr =
(struct ieee80211s_hdr *) (skb->data + hdrlen);
hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
memcpy(dst, meshdr->eaddr1, ETH_ALEN);
memcpy(src, meshdr->eaddr2, ETH_ALEN);
}
}
break;
case cpu_to_le16(IEEE80211_FCTL_FROMDS):
if ((iftype != NL80211_IFTYPE_STATION &&
iftype != NL80211_IFTYPE_MESH_POINT) ||
(is_multicast_ether_addr(dst) &&
!compare_ether_addr(src, addr)))
return -1;
if (iftype == NL80211_IFTYPE_MESH_POINT) {
struct ieee80211s_hdr *meshdr =
(struct ieee80211s_hdr *) (skb->data + hdrlen);
hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
if (meshdr->flags & MESH_FLAGS_AE_A4)
memcpy(src, meshdr->eaddr1, ETH_ALEN);
}
break;
case cpu_to_le16(0):
if (iftype != NL80211_IFTYPE_ADHOC)
return -1;
break;
}
if (unlikely(skb->len - hdrlen < 8))
return -1;
payload = skb->data + hdrlen;
ethertype = (payload[6] << 8) | payload[7];
if (likely((compare_ether_addr(payload, rfc1042_header) == 0 &&
ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
compare_ether_addr(payload, bridge_tunnel_header) == 0)) {
/* remove RFC1042 or Bridge-Tunnel encapsulation and
* replace EtherType */
skb_pull(skb, hdrlen + 6);
memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
} else {
struct ethhdr *ehdr;
__be16 len;
skb_pull(skb, hdrlen);
len = htons(skb->len);
ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
memcpy(ehdr->h_dest, dst, ETH_ALEN);
memcpy(ehdr->h_source, src, ETH_ALEN);
ehdr->h_proto = len;
}
return 0;
}
EXPORT_SYMBOL(ieee80211_data_to_8023);
int ieee80211_data_from_8023(struct sk_buff *skb, u8 *addr,
enum nl80211_iftype iftype, u8 *bssid, bool qos)
{
struct ieee80211_hdr hdr;
u16 hdrlen, ethertype;
__le16 fc;
const u8 *encaps_data;
int encaps_len, skip_header_bytes;
int nh_pos, h_pos;
int head_need;
if (unlikely(skb->len < ETH_HLEN))
return -EINVAL;
nh_pos = skb_network_header(skb) - skb->data;
h_pos = skb_transport_header(skb) - skb->data;
/* convert Ethernet header to proper 802.11 header (based on
* operation mode) */
ethertype = (skb->data[12] << 8) | skb->data[13];
fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
switch (iftype) {
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_AP_VLAN:
fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
/* DA BSSID SA */
memcpy(hdr.addr1, skb->data, ETH_ALEN);
memcpy(hdr.addr2, addr, ETH_ALEN);
memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
hdrlen = 24;
break;
case NL80211_IFTYPE_STATION:
fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
/* BSSID SA DA */
memcpy(hdr.addr1, bssid, ETH_ALEN);
memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
memcpy(hdr.addr3, skb->data, ETH_ALEN);
hdrlen = 24;
break;
case NL80211_IFTYPE_ADHOC:
/* DA SA BSSID */
memcpy(hdr.addr1, skb->data, ETH_ALEN);
memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
memcpy(hdr.addr3, bssid, ETH_ALEN);
hdrlen = 24;
break;
default:
return -EOPNOTSUPP;
}
if (qos) {
fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
hdrlen += 2;
}
hdr.frame_control = fc;
hdr.duration_id = 0;
hdr.seq_ctrl = 0;
skip_header_bytes = ETH_HLEN;
if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
encaps_data = bridge_tunnel_header;
encaps_len = sizeof(bridge_tunnel_header);
skip_header_bytes -= 2;
} else if (ethertype > 0x600) {
encaps_data = rfc1042_header;
encaps_len = sizeof(rfc1042_header);
skip_header_bytes -= 2;
} else {
encaps_data = NULL;
encaps_len = 0;
}
skb_pull(skb, skip_header_bytes);
nh_pos -= skip_header_bytes;
h_pos -= skip_header_bytes;
head_need = hdrlen + encaps_len - skb_headroom(skb);
if (head_need > 0 || skb_cloned(skb)) {
head_need = max(head_need, 0);
if (head_need)
skb_orphan(skb);
if (pskb_expand_head(skb, head_need, 0, GFP_ATOMIC)) {
printk(KERN_ERR "failed to reallocate Tx buffer\n");
return -ENOMEM;
}
skb->truesize += head_need;
}
if (encaps_data) {
memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
nh_pos += encaps_len;
h_pos += encaps_len;
}
memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
nh_pos += hdrlen;
h_pos += hdrlen;
/* Update skb pointers to various headers since this modified frame
* is going to go through Linux networking code that may potentially
* need things like pointer to IP header. */
skb_set_mac_header(skb, 0);
skb_set_network_header(skb, nh_pos);
skb_set_transport_header(skb, h_pos);
return 0;
}
EXPORT_SYMBOL(ieee80211_data_from_8023);
/* Given a data frame determine the 802.1p/1d tag to use. */
unsigned int cfg80211_classify8021d(struct sk_buff *skb)
{
unsigned int dscp;
/* skb->priority values from 256->263 are magic values to
* directly indicate a specific 802.1d priority. This is used
* to allow 802.1d priority to be passed directly in from VLAN
* tags, etc.
*/
if (skb->priority >= 256 && skb->priority <= 263)
return skb->priority - 256;
switch (skb->protocol) {
case htons(ETH_P_IP):
dscp = ip_hdr(skb)->tos & 0xfc;
break;
default:
return 0;
}
return dscp >> 5;
}
EXPORT_SYMBOL(cfg80211_classify8021d);
const u8 *ieee80211_bss_get_ie(struct cfg80211_bss *bss, u8 ie)
{
u8 *end, *pos;
pos = bss->information_elements;
if (pos == NULL)
return NULL;
end = pos + bss->len_information_elements;
while (pos + 1 < end) {
if (pos + 2 + pos[1] > end)
break;
if (pos[0] == ie)
return pos;
pos += 2 + pos[1];
}
return NULL;
}
EXPORT_SYMBOL(ieee80211_bss_get_ie);
void cfg80211_upload_connect_keys(struct wireless_dev *wdev)
{
struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);
struct net_device *dev = wdev->netdev;
int i;
if (!wdev->connect_keys)
return;
for (i = 0; i < 6; i++) {
if (!wdev->connect_keys->params[i].cipher)
continue;
if (rdev->ops->add_key(wdev->wiphy, dev, i, NULL,
&wdev->connect_keys->params[i])) {
printk(KERN_ERR "%s: failed to set key %d\n",
dev->name, i);
continue;
}
if (wdev->connect_keys->def == i)
if (rdev->ops->set_default_key(wdev->wiphy, dev, i)) {
printk(KERN_ERR "%s: failed to set defkey %d\n",
dev->name, i);
continue;
}
if (wdev->connect_keys->defmgmt == i)
if (rdev->ops->set_default_mgmt_key(wdev->wiphy, dev, i))
printk(KERN_ERR "%s: failed to set mgtdef %d\n",
dev->name, i);
}
kfree(wdev->connect_keys);
wdev->connect_keys = NULL;
}
static void cfg80211_process_wdev_events(struct wireless_dev *wdev)
{
struct cfg80211_event *ev;
unsigned long flags;
const u8 *bssid = NULL;
spin_lock_irqsave(&wdev->event_lock, flags);
while (!list_empty(&wdev->event_list)) {
ev = list_first_entry(&wdev->event_list,
struct cfg80211_event, list);
list_del(&ev->list);
spin_unlock_irqrestore(&wdev->event_lock, flags);
wdev_lock(wdev);
switch (ev->type) {
case EVENT_CONNECT_RESULT:
if (!is_zero_ether_addr(ev->cr.bssid))
bssid = ev->cr.bssid;
__cfg80211_connect_result(
wdev->netdev, bssid,
ev->cr.req_ie, ev->cr.req_ie_len,
ev->cr.resp_ie, ev->cr.resp_ie_len,
ev->cr.status,
ev->cr.status == WLAN_STATUS_SUCCESS,
NULL);
break;
case EVENT_ROAMED:
__cfg80211_roamed(wdev, ev->rm.bssid,
ev->rm.req_ie, ev->rm.req_ie_len,
ev->rm.resp_ie, ev->rm.resp_ie_len);
break;
case EVENT_DISCONNECTED:
__cfg80211_disconnected(wdev->netdev,
ev->dc.ie, ev->dc.ie_len,
ev->dc.reason, true);
break;
case EVENT_IBSS_JOINED:
__cfg80211_ibss_joined(wdev->netdev, ev->ij.bssid);
break;
}
wdev_unlock(wdev);
kfree(ev);
spin_lock_irqsave(&wdev->event_lock, flags);
}
spin_unlock_irqrestore(&wdev->event_lock, flags);
}
void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev)
{
struct wireless_dev *wdev;
ASSERT_RTNL();
ASSERT_RDEV_LOCK(rdev);
mutex_lock(&rdev->devlist_mtx);
list_for_each_entry(wdev, &rdev->netdev_list, list)
cfg80211_process_wdev_events(wdev);
mutex_unlock(&rdev->devlist_mtx);
}
int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
struct net_device *dev, enum nl80211_iftype ntype,
u32 *flags, struct vif_params *params)
{
int err;
enum nl80211_iftype otype = dev->ieee80211_ptr->iftype;
ASSERT_RDEV_LOCK(rdev);
/* don't support changing VLANs, you just re-create them */
if (otype == NL80211_IFTYPE_AP_VLAN)
return -EOPNOTSUPP;
if (!rdev->ops->change_virtual_intf ||
!(rdev->wiphy.interface_modes & (1 << ntype)))
return -EOPNOTSUPP;
if (ntype != otype) {
switch (otype) {
case NL80211_IFTYPE_ADHOC:
cfg80211_leave_ibss(rdev, dev, false);
break;
case NL80211_IFTYPE_STATION:
cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, true);
break;
case NL80211_IFTYPE_MESH_POINT:
/* mesh should be handled? */
break;
default:
break;
}
cfg80211_process_rdev_events(rdev);
}
err = rdev->ops->change_virtual_intf(&rdev->wiphy, dev,
ntype, flags, params);
WARN_ON(!err && dev->ieee80211_ptr->iftype != ntype);
return err;
}
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