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linux/net/mac80211/util.c
Johannes Berg 25d834e162 mac80211: fix virtual interfaces vs. injection 
Currently, virtual interface pointers passed to drivers might be
from monitor interfaces and as such completely uninitialised
because we do not tell the driver about monitor interfaces when
those are created. Instead of passing them, we should therefore
indicate to the driver that there is no information; do that by
passing a NULL value and adjust drivers to cope with it.

As a result, some mac80211 API functions also need to cope with
a NULL vif pointer so drivers can still call them unconditionally.

Also, when injecting frames we really don't want to pass NULL all
the time, if we know we are the source address of a frame and have
a local interface for that address, we can to use that interface.
This also helps with processing the frame correctly for that
interface which will help the 802.11w implementation. It's not
entirely correct for VLANs or WDS interfaces because there the MAC
address isn't unique, but it's already a lot better than what we
do now.

Finally, when injecting without a matching local interface, don't
assign sequence numbers at all.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-15 16:48:25 -04:00

686 lines
17 KiB
C
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/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* utilities for mac80211
*/
#include <net/mac80211.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/wireless.h>
#include <linux/bitmap.h>
#include <net/net_namespace.h>
#include <net/cfg80211.h>
#include <net/rtnetlink.h>
#include "ieee80211_i.h"
#include "rate.h"
#include "mesh.h"
#include "wme.h"
/* privid for wiphys to determine whether they belong to us or not */
void *mac80211_wiphy_privid = &mac80211_wiphy_privid;
/* 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 };
/* 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 };
u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len,
enum nl80211_iftype type)
{
__le16 fc = hdr->frame_control;
/* drop ACK/CTS frames and incorrect hdr len (ctrl) */
if (len < 16)
return NULL;
if (ieee80211_is_data(fc)) {
if (len < 24) /* drop incorrect hdr len (data) */
return NULL;
if (ieee80211_has_a4(fc))
return NULL;
if (ieee80211_has_tods(fc))
return hdr->addr1;
if (ieee80211_has_fromds(fc))
return hdr->addr2;
return hdr->addr3;
}
if (ieee80211_is_mgmt(fc)) {
if (len < 24) /* drop incorrect hdr len (mgmt) */
return NULL;
return hdr->addr3;
}
if (ieee80211_is_ctl(fc)) {
if(ieee80211_is_pspoll(fc))
return hdr->addr1;
if (ieee80211_is_back_req(fc)) {
switch (type) {
case NL80211_IFTYPE_STATION:
return hdr->addr2;
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_AP_VLAN:
return hdr->addr1;
default:
break; /* fall through to the return */
}
}
}
return NULL;
}
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);
int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
{
int ae = meshhdr->flags & IEEE80211S_FLAGS_AE;
/* 7.1.3.5a.2 */
switch (ae) {
case 0:
return 6;
case 1:
return 12;
case 2:
return 18;
case 3:
return 24;
default:
return 6;
}
}
void ieee80211_tx_set_protected(struct ieee80211_tx_data *tx)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) tx->skb->data;
hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
if (tx->extra_frag) {
struct ieee80211_hdr *fhdr;
int i;
for (i = 0; i < tx->num_extra_frag; i++) {
fhdr = (struct ieee80211_hdr *)
tx->extra_frag[i]->data;
fhdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
}
}
}
int ieee80211_frame_duration(struct ieee80211_local *local, size_t len,
int rate, int erp, int short_preamble)
{
int dur;
/* calculate duration (in microseconds, rounded up to next higher
* integer if it includes a fractional microsecond) to send frame of
* len bytes (does not include FCS) at the given rate. Duration will
* also include SIFS.
*
* rate is in 100 kbps, so divident is multiplied by 10 in the
* DIV_ROUND_UP() operations.
*/
if (local->hw.conf.channel->band == IEEE80211_BAND_5GHZ || erp) {
/*
* OFDM:
*
* N_DBPS = DATARATE x 4
* N_SYM = Ceiling((16+8xLENGTH+6) / N_DBPS)
* (16 = SIGNAL time, 6 = tail bits)
* TXTIME = T_PREAMBLE + T_SIGNAL + T_SYM x N_SYM + Signal Ext
*
* T_SYM = 4 usec
* 802.11a - 17.5.2: aSIFSTime = 16 usec
* 802.11g - 19.8.4: aSIFSTime = 10 usec +
* signal ext = 6 usec
*/
dur = 16; /* SIFS + signal ext */
dur += 16; /* 17.3.2.3: T_PREAMBLE = 16 usec */
dur += 4; /* 17.3.2.3: T_SIGNAL = 4 usec */
dur += 4 * DIV_ROUND_UP((16 + 8 * (len + 4) + 6) * 10,
4 * rate); /* T_SYM x N_SYM */
} else {
/*
* 802.11b or 802.11g with 802.11b compatibility:
* 18.3.4: TXTIME = PreambleLength + PLCPHeaderTime +
* Ceiling(((LENGTH+PBCC)x8)/DATARATE). PBCC=0.
*
* 802.11 (DS): 15.3.3, 802.11b: 18.3.4
* aSIFSTime = 10 usec
* aPreambleLength = 144 usec or 72 usec with short preamble
* aPLCPHeaderLength = 48 usec or 24 usec with short preamble
*/
dur = 10; /* aSIFSTime = 10 usec */
dur += short_preamble ? (72 + 24) : (144 + 48);
dur += DIV_ROUND_UP(8 * (len + 4) * 10, rate);
}
return dur;
}
/* Exported duration function for driver use */
__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
size_t frame_len,
struct ieee80211_rate *rate)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
u16 dur;
int erp;
bool short_preamble = false;
erp = 0;
if (vif) {
sdata = vif_to_sdata(vif);
short_preamble = sdata->bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
}
dur = ieee80211_frame_duration(local, frame_len, rate->bitrate, erp,
short_preamble);
return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_generic_frame_duration);
__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
struct ieee80211_vif *vif, size_t frame_len,
const struct ieee80211_tx_info *frame_txctl)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata;
bool short_preamble;
int erp;
u16 dur;
struct ieee80211_supported_band *sband;
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
short_preamble = false;
rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
erp = 0;
if (vif) {
sdata = vif_to_sdata(vif);
short_preamble = sdata->bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
}
/* CTS duration */
dur = ieee80211_frame_duration(local, 10, rate->bitrate,
erp, short_preamble);
/* Data frame duration */
dur += ieee80211_frame_duration(local, frame_len, rate->bitrate,
erp, short_preamble);
/* ACK duration */
dur += ieee80211_frame_duration(local, 10, rate->bitrate,
erp, short_preamble);
return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_rts_duration);
__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
size_t frame_len,
const struct ieee80211_tx_info *frame_txctl)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_rate *rate;
struct ieee80211_sub_if_data *sdata;
bool short_preamble;
int erp;
u16 dur;
struct ieee80211_supported_band *sband;
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
short_preamble = false;
rate = &sband->bitrates[frame_txctl->control.rts_cts_rate_idx];
erp = 0;
if (vif) {
sdata = vif_to_sdata(vif);
short_preamble = sdata->bss_conf.use_short_preamble;
if (sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
erp = rate->flags & IEEE80211_RATE_ERP_G;
}
/* Data frame duration */
dur = ieee80211_frame_duration(local, frame_len, rate->bitrate,
erp, short_preamble);
if (!(frame_txctl->flags & IEEE80211_TX_CTL_NO_ACK)) {
/* ACK duration */
dur += ieee80211_frame_duration(local, 10, rate->bitrate,
erp, short_preamble);
}
return cpu_to_le16(dur);
}
EXPORT_SYMBOL(ieee80211_ctstoself_duration);
void ieee80211_wake_queue(struct ieee80211_hw *hw, int queue)
{
struct ieee80211_local *local = hw_to_local(hw);
if (test_bit(queue, local->queues_pending)) {
set_bit(queue, local->queues_pending_run);
tasklet_schedule(&local->tx_pending_tasklet);
} else {
netif_wake_subqueue(local->mdev, queue);
}
}
EXPORT_SYMBOL(ieee80211_wake_queue);
void ieee80211_stop_queue(struct ieee80211_hw *hw, int queue)
{
struct ieee80211_local *local = hw_to_local(hw);
netif_stop_subqueue(local->mdev, queue);
}
EXPORT_SYMBOL(ieee80211_stop_queue);
void ieee80211_stop_queues(struct ieee80211_hw *hw)
{
int i;
for (i = 0; i < ieee80211_num_queues(hw); i++)
ieee80211_stop_queue(hw, i);
}
EXPORT_SYMBOL(ieee80211_stop_queues);
int ieee80211_queue_stopped(struct ieee80211_hw *hw, int queue)
{
struct ieee80211_local *local = hw_to_local(hw);
return __netif_subqueue_stopped(local->mdev, queue);
}
EXPORT_SYMBOL(ieee80211_queue_stopped);
void ieee80211_wake_queues(struct ieee80211_hw *hw)
{
int i;
for (i = 0; i < hw->queues + hw->ampdu_queues; i++)
ieee80211_wake_queue(hw, i);
}
EXPORT_SYMBOL(ieee80211_wake_queues);
void ieee80211_iterate_active_interfaces(
struct ieee80211_hw *hw,
void (*iterator)(void *data, u8 *mac,
struct ieee80211_vif *vif),
void *data)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
rtnl_lock();
list_for_each_entry(sdata, &local->interfaces, list) {
switch (sdata->vif.type) {
case __NL80211_IFTYPE_AFTER_LAST:
case NL80211_IFTYPE_UNSPECIFIED:
case NL80211_IFTYPE_MONITOR:
case NL80211_IFTYPE_AP_VLAN:
continue;
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_STATION:
case NL80211_IFTYPE_ADHOC:
case NL80211_IFTYPE_WDS:
case NL80211_IFTYPE_MESH_POINT:
break;
}
if (netif_running(sdata->dev))
iterator(data, sdata->dev->dev_addr,
&sdata->vif);
}
rtnl_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces);
void ieee80211_iterate_active_interfaces_atomic(
struct ieee80211_hw *hw,
void (*iterator)(void *data, u8 *mac,
struct ieee80211_vif *vif),
void *data)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
rcu_read_lock();
list_for_each_entry_rcu(sdata, &local->interfaces, list) {
switch (sdata->vif.type) {
case __NL80211_IFTYPE_AFTER_LAST:
case NL80211_IFTYPE_UNSPECIFIED:
case NL80211_IFTYPE_MONITOR:
case NL80211_IFTYPE_AP_VLAN:
continue;
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_STATION:
case NL80211_IFTYPE_ADHOC:
case NL80211_IFTYPE_WDS:
case NL80211_IFTYPE_MESH_POINT:
break;
}
if (netif_running(sdata->dev))
iterator(data, sdata->dev->dev_addr,
&sdata->vif);
}
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic);
void ieee802_11_parse_elems(u8 *start, size_t len,
struct ieee802_11_elems *elems)
{
size_t left = len;
u8 *pos = start;
memset(elems, 0, sizeof(*elems));
elems->ie_start = start;
elems->total_len = len;
while (left >= 2) {
u8 id, elen;
id = *pos++;
elen = *pos++;
left -= 2;
if (elen > left)
return;
switch (id) {
case WLAN_EID_SSID:
elems->ssid = pos;
elems->ssid_len = elen;
break;
case WLAN_EID_SUPP_RATES:
elems->supp_rates = pos;
elems->supp_rates_len = elen;
break;
case WLAN_EID_FH_PARAMS:
elems->fh_params = pos;
elems->fh_params_len = elen;
break;
case WLAN_EID_DS_PARAMS:
elems->ds_params = pos;
elems->ds_params_len = elen;
break;
case WLAN_EID_CF_PARAMS:
elems->cf_params = pos;
elems->cf_params_len = elen;
break;
case WLAN_EID_TIM:
elems->tim = pos;
elems->tim_len = elen;
break;
case WLAN_EID_IBSS_PARAMS:
elems->ibss_params = pos;
elems->ibss_params_len = elen;
break;
case WLAN_EID_CHALLENGE:
elems->challenge = pos;
elems->challenge_len = elen;
break;
case WLAN_EID_WPA:
if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
pos[2] == 0xf2) {
/* Microsoft OUI (00:50:F2) */
if (pos[3] == 1) {
/* OUI Type 1 - WPA IE */
elems->wpa = pos;
elems->wpa_len = elen;
} else if (elen >= 5 && pos[3] == 2) {
if (pos[4] == 0) {
elems->wmm_info = pos;
elems->wmm_info_len = elen;
} else if (pos[4] == 1) {
elems->wmm_param = pos;
elems->wmm_param_len = elen;
}
}
}
break;
case WLAN_EID_RSN:
elems->rsn = pos;
elems->rsn_len = elen;
break;
case WLAN_EID_ERP_INFO:
elems->erp_info = pos;
elems->erp_info_len = elen;
break;
case WLAN_EID_EXT_SUPP_RATES:
elems->ext_supp_rates = pos;
elems->ext_supp_rates_len = elen;
break;
case WLAN_EID_HT_CAPABILITY:
elems->ht_cap_elem = pos;
elems->ht_cap_elem_len = elen;
break;
case WLAN_EID_HT_EXTRA_INFO:
elems->ht_info_elem = pos;
elems->ht_info_elem_len = elen;
break;
case WLAN_EID_MESH_ID:
elems->mesh_id = pos;
elems->mesh_id_len = elen;
break;
case WLAN_EID_MESH_CONFIG:
elems->mesh_config = pos;
elems->mesh_config_len = elen;
break;
case WLAN_EID_PEER_LINK:
elems->peer_link = pos;
elems->peer_link_len = elen;
break;
case WLAN_EID_PREQ:
elems->preq = pos;
elems->preq_len = elen;
break;
case WLAN_EID_PREP:
elems->prep = pos;
elems->prep_len = elen;
break;
case WLAN_EID_PERR:
elems->perr = pos;
elems->perr_len = elen;
break;
case WLAN_EID_CHANNEL_SWITCH:
elems->ch_switch_elem = pos;
elems->ch_switch_elem_len = elen;
break;
case WLAN_EID_QUIET:
if (!elems->quiet_elem) {
elems->quiet_elem = pos;
elems->quiet_elem_len = elen;
}
elems->num_of_quiet_elem++;
break;
case WLAN_EID_COUNTRY:
elems->country_elem = pos;
elems->country_elem_len = elen;
break;
case WLAN_EID_PWR_CONSTRAINT:
elems->pwr_constr_elem = pos;
elems->pwr_constr_elem_len = elen;
break;
default:
break;
}
left -= elen;
pos += elen;
}
}
void ieee80211_set_wmm_default(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_tx_queue_params qparam;
int i;
if (!local->ops->conf_tx)
return;
memset(&qparam, 0, sizeof(qparam));
qparam.aifs = 2;
if (local->hw.conf.channel->band == IEEE80211_BAND_2GHZ &&
!(sdata->flags & IEEE80211_SDATA_OPERATING_GMODE))
qparam.cw_min = 31;
else
qparam.cw_min = 15;
qparam.cw_max = 1023;
qparam.txop = 0;
for (i = 0; i < local_to_hw(local)->queues; i++)
local->ops->conf_tx(local_to_hw(local), i, &qparam);
}
void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
int encrypt)
{
skb->dev = sdata->local->mdev;
skb_set_mac_header(skb, 0);
skb_set_network_header(skb, 0);
skb_set_transport_header(skb, 0);
skb->iif = sdata->dev->ifindex;
skb->do_not_encrypt = !encrypt;
dev_queue_xmit(skb);
}
int ieee80211_set_freq(struct ieee80211_sub_if_data *sdata, int freqMHz)
{
int ret = -EINVAL;
struct ieee80211_channel *chan;
struct ieee80211_local *local = sdata->local;
chan = ieee80211_get_channel(local->hw.wiphy, freqMHz);
if (chan && !(chan->flags & IEEE80211_CHAN_DISABLED)) {
if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
chan->flags & IEEE80211_CHAN_NO_IBSS) {
printk(KERN_DEBUG "%s: IBSS not allowed on frequency "
"%d MHz\n", sdata->dev->name, chan->center_freq);
return ret;
}
local->oper_channel = chan;
if (local->sw_scanning || local->hw_scanning)
ret = 0;
else
ret = ieee80211_hw_config(local);
rate_control_clear(local);
}
return ret;
}
u64 ieee80211_mandatory_rates(struct ieee80211_local *local,
enum ieee80211_band band)
{
struct ieee80211_supported_band *sband;
struct ieee80211_rate *bitrates;
u64 mandatory_rates;
enum ieee80211_rate_flags mandatory_flag;
int i;
sband = local->hw.wiphy->bands[band];
if (!sband) {
WARN_ON(1);
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
}
if (band == IEEE80211_BAND_2GHZ)
mandatory_flag = IEEE80211_RATE_MANDATORY_B;
else
mandatory_flag = IEEE80211_RATE_MANDATORY_A;
bitrates = sband->bitrates;
mandatory_rates = 0;
for (i = 0; i < sband->n_bitrates; i++)
if (bitrates[i].flags & mandatory_flag)
mandatory_rates |= BIT(i);
return mandatory_rates;
}
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