LinuxLists.cc - [WIP] mac80211: kill mgmt interface

2007-06-21 10:45:54

Subject: [WIP] mac80211: kill mgmt interface

This patch kills the management interface type now that we can
see transmitted frames on monitor interfaces.

I renamed the req_tx_status to reliable_tx_mntr and the flag
constant as well since that's what they now mean. It is always
set for injected frames so that hostapd can rely on seeing the
frames it sent.

There are a few minor remaining problems:
* some notifications are now missing
(radar, key threshold, michael MIC failure, wep unknown key)
[radar, key threshold aren't used anywhere so can probably
be left out for now]
* injected frames aren't sent to AC_VO pending on the radiotap
definition for access category
* rate control extra.mgmt_data isn't properly assigned

The biggest problem, however, and I'm not sure how to solve it, is
that hostapd will see either encrypted or unencrypted frames on the
monitor interface depending on whether hardware encryption is used
or not. However, hostapd really needs to see eapol frames to do
whatever it needs to with them. Right now, I don't really have an
idea except maybe to send these packets to hostapd via nl80211,
or to introduce some sort of "decrypted soft monitor" iface.

Signed-off-by: Johannes Berg <[email protected]>
[but please don't apply it, just in case
somebody wants to develop it further]

---
include/net/mac80211.h | 8
net/mac80211/hostapd_ioctl.h | 1
net/mac80211/ieee80211.c | 404 ++++------------------------------------
net/mac80211/ieee80211_common.h | 93 ---------
net/mac80211/ieee80211_i.h | 10
net/mac80211/ieee80211_iface.c | 57 -----
net/mac80211/ieee80211_ioctl.c | 16 -
net/mac80211/ieee80211_sta.c | 1
net/mac80211/wme.c | 4
net/mac80211/wpa.c | 10
10 files changed, 55 insertions(+), 549 deletions(-)

--- wireless-dev.orig/net/mac80211/ieee80211.c 2007-06-21 11:34:18.888645783 +0200
+++ wireless-dev/net/mac80211/ieee80211.c 2007-06-21 11:40:14.208645783 +0200
@@ -26,7 +26,6 @@
#include <net/cfg80211.h>
#include <asm/unaligned.h>

-#include "ieee80211_common.h"
#include "ieee80211_i.h"
#include "ieee80211_rate.h"
#include "wep.h"
@@ -226,35 +225,10 @@ static void ieee80211_key_threshold_noti
struct ieee80211_key *key,
struct sta_info *sta)
{
- struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
- struct sk_buff *skb;
- struct ieee80211_msg_key_notification *msg;
-
- /* if no one will get it anyway, don't even allocate it.
- * unlikely because this is only relevant for APs
- * where the device must be open... */
- if (unlikely(!local->apdev))
- return;
-
- skb = dev_alloc_skb(sizeof(struct ieee80211_frame_info) +
- sizeof(struct ieee80211_msg_key_notification));
- if (!skb)
- return;
-
- skb_reserve(skb, sizeof(struct ieee80211_frame_info));
- msg = (struct ieee80211_msg_key_notification *)
- skb_put(skb, sizeof(struct ieee80211_msg_key_notification));
- msg->tx_rx_count = key->tx_rx_count;
- memcpy(msg->ifname, dev->name, IFNAMSIZ);
- if (sta)
- memcpy(msg->addr, sta->addr, ETH_ALEN);
- else
- memset(msg->addr, 0xff, ETH_ALEN);
-
- key->tx_rx_count = 0;
-
- ieee80211_rx_mgmt(local, skb, NULL,
- ieee80211_msg_key_threshold_notification);
+ /*
+ * XXX: notify userspace of the current key->tx_rx_count
+ * and then set it to 0
+ */
}

@@ -425,8 +399,11 @@ ieee80211_tx_h_rate_ctrl(struct ieee8021

memset(&extra, 0, sizeof(extra));
extra.mode = tx->u.tx.mode;
- extra.mgmt_data = tx->sdata &&
- tx->sdata->type == IEEE80211_IF_TYPE_MGMT;
+ /*
+ * XXX: need to set this again based on radiotap injection, but
+ * current rate control algorithms don't use it.
+ */
+ extra.mgmt_data = 0;
extra.ethertype = tx->ethertype;

tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev, tx->skb,
@@ -961,7 +938,7 @@ ieee80211_tx_h_check_assoc(struct ieee80
return TXRX_CONTINUE;
}

- if (unlikely(!tx->u.tx.mgmt_interface && tx->sdata->ieee802_1x &&
+ if (unlikely(tx->sdata->ieee802_1x &&
!(sta_flags & WLAN_STA_AUTHORIZED))) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
printk(KERN_DEBUG "%s: dropped frame to " MAC_FMT
@@ -1158,7 +1135,8 @@ static int __ieee80211_parse_tx_radiotap
*/
control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
IEEE80211_TXCTL_USE_CTS_PROTECT);
- control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
+ control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT |
+ IEEE80211_TXCTL_RELIABLE_TX_MONITOR;

/*
* for every radiotap entry that is present
@@ -1435,7 +1413,7 @@ static int __ieee80211_tx(struct ieee802
}

static int ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
- struct ieee80211_tx_control *control, int mgmt)
+ struct ieee80211_tx_control *control)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct sta_info *sta;
@@ -1457,7 +1435,6 @@ static int ieee80211_tx(struct net_devic
}

sta = tx.sta;
- tx.u.tx.mgmt_interface = mgmt;
tx.u.tx.mode = local->hw.conf.mode;

for (handler = local->tx_handlers; *handler != NULL; handler++) {
@@ -1648,16 +1625,15 @@ static int ieee80211_master_start_xmit(s

control.ifindex = odev->ifindex;
control.type = osdata->type;
- if (pkt_data->req_tx_status)
- control.flags |= IEEE80211_TXCTL_REQ_TX_STATUS;
+ if (pkt_data->reliable_tx_mntr)
+ control.flags |= IEEE80211_TXCTL_RELIABLE_TX_MONITOR;
if (pkt_data->do_not_encrypt)
control.flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
if (pkt_data->requeue)
control.flags |= IEEE80211_TXCTL_REQUEUE;
control.queue = pkt_data->queue;

- ret = ieee80211_tx(odev, skb, &control,
- control.type == IEEE80211_IF_TYPE_MGMT);
+ ret = ieee80211_tx(odev, skb, &control);
dev_put(odev);

return ret;
@@ -1688,7 +1664,6 @@ int ieee80211_monitor_start_xmit(struct
pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
memset(pkt_data, 0, sizeof(*pkt_data));
pkt_data->ifindex = dev->ifindex;
- pkt_data->mgmt_iface = 0;
pkt_data->do_not_encrypt = 1;

/* above needed because we set skb device to master */
@@ -1886,7 +1861,6 @@ int ieee80211_subif_start_xmit(struct sk
pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
pkt_data->ifindex = dev->ifindex;
- pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
pkt_data->do_not_encrypt = no_encrypt;

skb->dev = local->mdev;
@@ -1913,66 +1887,6 @@ int ieee80211_subif_start_xmit(struct sk
}

-/*
- * This is the transmit routine for the 802.11 type interfaces
- * called by upper layers of the linux networking
- * stack when it has a frame to transmit
- */
-static int
-ieee80211_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
-{
- struct ieee80211_sub_if_data *sdata;
- struct ieee80211_tx_packet_data *pkt_data;
- struct ieee80211_hdr *hdr;
- u16 fc;
-
- sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
- if (skb->len < 10) {
- dev_kfree_skb(skb);
- return 0;
- }
-
- if (skb_headroom(skb) < sdata->local->tx_headroom) {
- if (pskb_expand_head(skb, sdata->local->tx_headroom,
- 0, GFP_ATOMIC)) {
- dev_kfree_skb(skb);
- return 0;
- }
- }
-
- hdr = (struct ieee80211_hdr *) skb->data;
- fc = le16_to_cpu(hdr->frame_control);
-
- pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
- memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
- pkt_data->ifindex = sdata->dev->ifindex;
- pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
-
- skb->priority = 20; /* use hardcoded priority for mgmt TX queue */
- skb->dev = sdata->local->mdev;
-
- /*
- * We're using the protocol field of the the frame control header
- * to request TX callback for hostapd. BIT(1) is checked.
- */
- if ((fc & BIT(1)) == BIT(1)) {
- pkt_data->req_tx_status = 1;
- fc &= ~BIT(1);
- hdr->frame_control = cpu_to_le16(fc);
- }
-
- pkt_data->do_not_encrypt = !(fc & IEEE80211_FCTL_PROTECTED);
-
- sdata->stats.tx_packets++;
- sdata->stats.tx_bytes += skb->len;
-
- dev_queue_xmit(skb);
-
- return 0;
-}
-
-
static void ieee80211_beacon_add_tim(struct ieee80211_local *local,
struct ieee80211_if_ap *bss,
struct sk_buff *skb)
@@ -2387,23 +2301,6 @@ static int ieee80211_change_mtu(struct n
}

-static int ieee80211_change_mtu_apdev(struct net_device *dev, int new_mtu)
-{
- /* FIX: what would be proper limits for MTU?
- * This interface uses 802.11 frames. */
- if (new_mtu < 256 || new_mtu > IEEE80211_MAX_DATA_LEN) {
- printk(KERN_WARNING "%s: invalid MTU %d\n",
- dev->name, new_mtu);
- return -EINVAL;
- }
-
-#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
- printk(KERN_DEBUG "%s: setting MTU %d\n", dev->name, new_mtu);
-#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
- dev->mtu = new_mtu;
- return 0;
-}
-
enum netif_tx_lock_class {
TX_LOCK_NORMAL,
TX_LOCK_MASTER,
@@ -2567,20 +2464,6 @@ static int ieee80211_master_stop(struct
return 0;
}

-static int ieee80211_mgmt_open(struct net_device *dev)
-{
- struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
-
- if (!netif_running(local->mdev))
- return -EOPNOTSUPP;
- return 0;
-}
-
-static int ieee80211_mgmt_stop(struct net_device *dev)
-{
- return 0;
-}
-
/* Check if running monitor interfaces should go to a "soft monitor" mode
* and switch them if necessary. */
static inline void ieee80211_start_soft_monitor(struct ieee80211_local *local)
@@ -2672,8 +2555,6 @@ static int ieee80211_open(struct net_dev
res = ieee80211_hw_config(local);
if (res && local->ops->stop)
local->ops->stop(local_to_hw(local));
- else if (!res && local->apdev)
- dev_open(local->apdev);
}
}
if (res) {
@@ -2733,8 +2614,6 @@ static int ieee80211_stop(struct net_dev
if (local->open_count == 0) {
if (netif_running(local->mdev))
dev_close(local->mdev);
- if (local->apdev)
- dev_close(local->apdev);
if (local->ops->stop)
local->ops->stop(local_to_hw(local));
tasklet_disable(&local->tx_pending_tasklet);
@@ -3098,112 +2977,6 @@ ieee80211_get_rate(struct ieee80211_loca
return NULL;
}

-static void
-ieee80211_fill_frame_info(struct ieee80211_local *local,
- struct ieee80211_frame_info *fi,
- struct ieee80211_rx_status *status)
-{
- if (status) {
- struct timespec ts;
- struct ieee80211_rate *rate;
-
- jiffies_to_timespec(jiffies, &ts);
- fi->hosttime = cpu_to_be64((u64) ts.tv_sec * 1000000 +
- ts.tv_nsec / 1000);
- fi->mactime = cpu_to_be64(status->mactime);
- switch (status->phymode) {
- case MODE_IEEE80211A:
- fi->phytype = htonl(ieee80211_phytype_ofdm_dot11_a);
- break;
- case MODE_IEEE80211B:
- fi->phytype = htonl(ieee80211_phytype_dsss_dot11_b);
- break;
- case MODE_IEEE80211G:
- fi->phytype = htonl(ieee80211_phytype_pbcc_dot11_g);
- break;
- case MODE_ATHEROS_TURBO:
- fi->phytype =
- htonl(ieee80211_phytype_dsss_dot11_turbo);
- break;
- default:
- fi->phytype = htonl(0xAAAAAAAA);
- break;
- }
- fi->channel = htonl(status->channel);
- rate = ieee80211_get_rate(local, status->phymode,
- status->rate);
- if (rate) {
- fi->datarate = htonl(rate->rate);
- if (rate->flags & IEEE80211_RATE_PREAMBLE2) {
- if (status->rate == rate->val)
- fi->preamble = htonl(2); /* long */
- else if (status->rate == rate->val2)
- fi->preamble = htonl(1); /* short */
- } else
- fi->preamble = htonl(0);
- } else {
- fi->datarate = htonl(0);
- fi->preamble = htonl(0);
- }
-
- fi->antenna = htonl(status->antenna);
- fi->priority = htonl(0xffffffff); /* no clue */
- fi->ssi_type = htonl(ieee80211_ssi_raw);
- fi->ssi_signal = htonl(status->ssi);
- fi->ssi_noise = 0x00000000;
- fi->encoding = 0;
- } else {
- /* clear everything because we really don't know.
- * the msg_type field isn't present on monitor frames
- * so we don't know whether it will be present or not,
- * but it's ok to not clear it since it'll be assigned
- * anyway */
- memset(fi, 0, sizeof(*fi) - sizeof(fi->msg_type));
-
- fi->ssi_type = htonl(ieee80211_ssi_none);
- }
- fi->version = htonl(IEEE80211_FI_VERSION);
- fi->length = cpu_to_be32(sizeof(*fi) - sizeof(fi->msg_type));
-}
-
-/* this routine is actually not just for this, but also
- * for pushing fake 'management' frames into userspace.
- * it shall be replaced by a netlink-based system. */
-void
-ieee80211_rx_mgmt(struct ieee80211_local *local, struct sk_buff *skb,
- struct ieee80211_rx_status *status, u32 msg_type)
-{
- struct ieee80211_frame_info *fi;
- const size_t hlen = sizeof(struct ieee80211_frame_info);
- struct ieee80211_sub_if_data *sdata;
-
- skb->dev = local->apdev;
-
- sdata = IEEE80211_DEV_TO_SUB_IF(local->apdev);
-
- if (skb_headroom(skb) < hlen) {
- I802_DEBUG_INC(local->rx_expand_skb_head);
- if (pskb_expand_head(skb, hlen, 0, GFP_ATOMIC)) {
- dev_kfree_skb(skb);
- return;
- }
- }
-
- fi = (struct ieee80211_frame_info *) skb_push(skb, hlen);
-
- ieee80211_fill_frame_info(local, fi, status);
- fi->msg_type = htonl(msg_type);
-
- sdata->stats.rx_packets++;
- sdata->stats.rx_bytes += skb->len;
-
- skb_set_mac_header(skb, 0);
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- skb->pkt_type = PACKET_OTHERHOST;
- skb->protocol = htons(ETH_P_802_2);
- memset(skb->cb, 0, sizeof(skb->cb));
- netif_rx(skb);
-}

static void
ieee80211_rx_monitor(struct net_device *dev, struct sk_buff *skb,
@@ -3271,27 +3044,7 @@ ieee80211_rx_monitor(struct net_device *
int ieee80211_radar_status(struct ieee80211_hw *hw, int channel,
int radar, int radar_type)
{
- struct sk_buff *skb;
- struct ieee80211_radar_info *msg;
- struct ieee80211_local *local = hw_to_local(hw);
-
- if (!local->apdev)
- return 0;
-
- skb = dev_alloc_skb(sizeof(struct ieee80211_frame_info) +
- sizeof(struct ieee80211_radar_info));
-
- if (!skb)
- return -ENOMEM;
- skb_reserve(skb, sizeof(struct ieee80211_frame_info));
-
- msg = (struct ieee80211_radar_info *)
- skb_put(skb, sizeof(struct ieee80211_radar_info));
- msg->channel = channel;
- msg->radar = radar;
- msg->radar_type = radar_type;
-
- ieee80211_rx_mgmt(local, skb, NULL, ieee80211_msg_radar);
+ /* XXX: notify userspace of radar */
return 0;
}
EXPORT_SYMBOL(ieee80211_radar_status);
@@ -3683,34 +3436,25 @@ ieee80211_rx_h_check(struct ieee80211_tx
} else
rx->skb->pkt_type = PACKET_OTHERHOST;

- /* Drop disallowed frame classes based on STA auth/assoc state;
+ /*
+ * Drop disallowed frame classes based on STA auth/assoc state;
* IEEE 802.11, Chap 5.5.
*
- * 80211.o does filtering only based on association state, i.e., it
- * drops Class 3 frames from not associated stations. hostapd sends
- * deauth/disassoc frames when needed. In addition, hostapd is
- * responsible for filtering on both auth and assoc states.
+ * We do filtering only based on association state, i.e., we
+ * drop Class 3 frames from not associated stations. hostapd sends
+ * deauth/disassoc frames when needed, filtering on both auth and
+ * assoc states.
*/
if (unlikely(((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA ||
((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL &&
(rx->fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)) &&
rx->sdata->type != IEEE80211_IF_TYPE_IBSS &&
(!rx->sta || !(rx->sta->flags & WLAN_STA_ASSOC)))) {
- if ((!(rx->fc & IEEE80211_FCTL_FROMDS) &&
- !(rx->fc & IEEE80211_FCTL_TODS) &&
- (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA)
- || !rx->u.rx.ra_match) {
- /* Drop IBSS frames and frames for other hosts
- * silently. */
- return TXRX_DROP;
- }
-
- if (!rx->local->apdev)
- return TXRX_DROP;
-
- ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
- ieee80211_msg_sta_not_assoc);
- return TXRX_QUEUED;
+ /*
+ * hostapd will see the frame on the monitor iface and
+ * be able to take action, on this interface drop it.
+ */
+ return TXRX_DROP;
}

if (rx->sdata->type == IEEE80211_IF_TYPE_STA)
@@ -3744,12 +3488,8 @@ ieee80211_rx_h_check(struct ieee80211_tx
MAC_ARG(hdr->addr1),
MAC_ARG(hdr->addr2),
MAC_ARG(hdr->addr3));
- if (!rx->local->apdev)
- return TXRX_DROP;
- ieee80211_rx_mgmt(
- rx->local, rx->skb, rx->u.rx.status,
- ieee80211_msg_wep_frame_unknown_key);
- return TXRX_QUEUED;
+ /* XXX: notify userspace of this frame? */
+ return TXRX_DROP;
}
}
}
@@ -3896,13 +3636,8 @@ ieee80211_rx_h_802_1x_pae(struct ieee802
{
if (rx->sdata->eapol && ieee80211_is_eapol(rx->skb) &&
rx->sdata->type != IEEE80211_IF_TYPE_STA && rx->u.rx.ra_match) {
- /* Pass both encrypted and unencrypted EAPOL frames to user
- * space for processing. */
- if (!rx->local->apdev)
- return TXRX_DROP;
- ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
- ieee80211_msg_normal);
- return TXRX_QUEUED;
+ /* hostapd sees them on monitor iface */
+ return TXRX_DROP;
}

if (unlikely(rx->sdata->ieee802_1x &&
@@ -3959,13 +3694,8 @@ ieee80211_rx_h_mgmt(struct ieee80211_txr
sdata->type == IEEE80211_IF_TYPE_IBSS) &&
!rx->local->user_space_mlme) {
ieee80211_sta_rx_mgmt(rx->dev, rx->skb, rx->u.rx.status);
- } else {
- /* Management frames are sent to hostapd for processing */
- if (!rx->local->apdev)
- return TXRX_DROP;
- ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
- ieee80211_msg_normal);
- }
+ } else
+ return TXRX_DROP;
return TXRX_QUEUED;
}

@@ -4072,12 +3802,8 @@ static void ieee80211_rx_michael_mic_rep
/* TODO: consider verifying the MIC error report with software
* implementation if we get too many spurious reports from the
* hardware. */
- if (!rx->local->apdev)
- goto ignore;
- ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
- ieee80211_msg_michael_mic_failure);
- return;

+ /* XXX: notify hostapd */
ignore:
dev_kfree_skb(rx->skb);
rx->skb = NULL;
@@ -4488,8 +4214,12 @@ void ieee80211_tx_status_irqsafe(struct
memcpy(skb->cb, &saved, sizeof(saved));

skb->pkt_type = IEEE80211_TX_STATUS_MSG;
- skb_queue_tail(status->control.flags & IEEE80211_TXCTL_REQ_TX_STATUS ?
- &local->skb_queue : &local->skb_queue_unreliable, skb);
+
+ if (status->control.flags & IEEE80211_TXCTL_RELIABLE_TX_MONITOR)
+ skb_queue_tail(&local->skb_queue, skb);
+ else
+ skb_queue_tail(&local->skb_queue_unreliable, skb);
+
tmp = skb_queue_len(&local->skb_queue) +
skb_queue_len(&local->skb_queue_unreliable);
while (tmp > IEEE80211_IRQSAFE_QUEUE_LIMIT &&
@@ -4554,8 +4284,8 @@ static void ieee80211_remove_tx_extra(st

pkt_data = (struct ieee80211_tx_packet_data *)skb->cb;
pkt_data->ifindex = control->ifindex;
- pkt_data->mgmt_iface = (control->type == IEEE80211_IF_TYPE_MGMT);
- pkt_data->req_tx_status = !!(control->flags & IEEE80211_TXCTL_REQ_TX_STATUS);
+ pkt_data->reliable_tx_mntr = !!(control->flags &
+ IEEE80211_TXCTL_RELIABLE_TX_MONITOR);
pkt_data->do_not_encrypt = !!(control->flags & IEEE80211_TXCTL_DO_NOT_ENCRYPT);
pkt_data->requeue = !!(control->flags & IEEE80211_TXCTL_REQUEUE);
pkt_data->queue = control->queue;
@@ -4610,7 +4340,6 @@ void ieee80211_tx_status(struct ieee8021
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_local *local = hw_to_local(hw);
u16 frag, type;
- u32 msg_type;
struct ieee80211_tx_status_rtap_hdr *rthdr;
struct ieee80211_sub_if_data *sdata;
int monitors;
@@ -4725,34 +4454,14 @@ void ieee80211_tx_status(struct ieee8021
local->dot11FailedCount++;
}

- msg_type = (status->flags & IEEE80211_TX_STATUS_ACK) ?
- ieee80211_msg_tx_callback_ack : ieee80211_msg_tx_callback_fail;
-
- /* this was a transmitted frame, but now we want to reuse it */
- skb_orphan(skb);
-
- if ((status->control.flags & IEEE80211_TXCTL_REQ_TX_STATUS) &&
- local->apdev) {
- if (local->monitors) {
- skb2 = skb_clone(skb, GFP_ATOMIC);
- } else {
- skb2 = skb;
- skb = NULL;
- }
-
- if (skb2)
- /* Send frame to hostapd */
- ieee80211_rx_mgmt(local, skb2, NULL, msg_type);
-
- if (!skb)
- return;
- }
-
if (!local->monitors) {
dev_kfree_skb(skb);
return;
}

+ /* this was a transmitted frame, but now we want to reuse it */
+ skb_orphan(skb);
+
/* send frame to monitor interfaces now */

if (skb_headroom(skb) < sizeof(*rthdr)) {
@@ -4911,7 +4620,7 @@ int ieee80211_if_update_wds(struct net_d
return 0;
}

-/* Must not be called for mdev and apdev */
+/* Must not be called for mdev */
void ieee80211_if_setup(struct net_device *dev)
{
ether_setup(dev);
@@ -4927,28 +4636,13 @@ void ieee80211_if_setup(struct net_devic
dev->destructor = ieee80211_if_free;
}

-void ieee80211_if_mgmt_setup(struct net_device *dev)
-{
- ether_setup(dev);
- dev->hard_start_xmit = ieee80211_mgmt_start_xmit;
- dev->change_mtu = ieee80211_change_mtu_apdev;
- dev->get_stats = ieee80211_get_stats;
- dev->open = ieee80211_mgmt_open;
- dev->stop = ieee80211_mgmt_stop;
- dev->type = ARPHRD_IEEE80211_PRISM;
- dev->hard_header_parse = header_parse_80211;
- dev->uninit = ieee80211_if_reinit;
- dev->destructor = ieee80211_if_free;
-}
-
int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
const char *name)
{
struct rate_control_ref *ref, *old;

ASSERT_RTNL();
- if (local->open_count || netif_running(local->mdev) ||
- (local->apdev && netif_running(local->apdev)))
+ if (local->open_count || netif_running(local->mdev))
return -EBUSY;

ref = rate_control_alloc(name, local);
@@ -5255,8 +4949,6 @@ void ieee80211_unregister_hw(struct ieee
BUG_ON(local->reg_state != IEEE80211_DEV_REGISTERED);

local->reg_state = IEEE80211_DEV_UNREGISTERED;
- if (local->apdev)
- ieee80211_if_del_mgmt(local);

write_lock_bh(&local->sub_if_lock);
list_replace_init(&local->sub_if_list, &tmp_list);
--- wireless-dev.orig/net/mac80211/hostapd_ioctl.h 2007-06-21 11:34:18.908645783 +0200
+++ wireless-dev/net/mac80211/hostapd_ioctl.h 2007-06-21 11:35:20.768645783 +0200
@@ -68,7 +68,6 @@ enum {
PRISM2_PARAM_RADAR_DETECT = 1043,
PRISM2_PARAM_SPECTRUM_MGMT = 1044,
PRISM2_PARAM_USER_SPACE_MLME = 1045,
- PRISM2_PARAM_MGMT_IF = 1046,
};

/* PRISM2_IOCTL_HOSTAPD ioctl() cmd:
--- wireless-dev.orig/net/mac80211/ieee80211_i.h 2007-06-21 11:34:18.998645783 +0200
+++ wireless-dev/net/mac80211/ieee80211_i.h 2007-06-21 11:39:58.038645783 +0200
@@ -135,7 +135,6 @@ struct ieee80211_txrx_data {
* when using CTS protection with IEEE 802.11g. */
struct ieee80211_rate *last_frag_rate;
int last_frag_hwrate;
- int mgmt_interface;

/* Extra fragments (in addition to the first fragment
* in skb) */
@@ -164,10 +163,9 @@ struct ieee80211_txrx_data {
struct ieee80211_tx_packet_data {
int ifindex;
unsigned long jiffies;
- unsigned int req_tx_status:1;
+ unsigned int reliable_tx_mntr:1;
unsigned int do_not_encrypt:1;
unsigned int requeue:1;
- unsigned int mgmt_iface:1;
unsigned int queue:4;
};

@@ -457,7 +455,6 @@ struct ieee80211_local {
struct list_head modes_list;

struct net_device *mdev; /* wmaster# - "master" 802.11 device */
- struct net_device *apdev; /* wlan#ap - management frames (hostapd) */
int open_count;
int monitors;
struct iw_statistics wstats;
@@ -793,8 +790,6 @@ ieee80211_key_data2conf(struct ieee80211
struct ieee80211_key *ieee80211_key_alloc(struct ieee80211_sub_if_data *sdata,
int idx, size_t key_len, gfp_t flags);
void ieee80211_key_free(struct ieee80211_key *key);
-void ieee80211_rx_mgmt(struct ieee80211_local *local, struct sk_buff *skb,
- struct ieee80211_rx_status *status, u32 msg_type);
void ieee80211_prepare_rates(struct ieee80211_local *local,
struct ieee80211_hw_mode *mode);
void ieee80211_tx_set_iswep(struct ieee80211_txrx_data *tx);
@@ -802,7 +797,6 @@ int ieee80211_if_update_wds(struct net_d
int ieee80211_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
int ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev);
void ieee80211_if_setup(struct net_device *dev);
-void ieee80211_if_mgmt_setup(struct net_device *dev);
int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
const char *name);
struct net_device_stats *ieee80211_dev_stats(struct net_device *dev);
@@ -898,8 +892,6 @@ void __ieee80211_if_del(struct ieee80211
int ieee80211_if_remove(struct net_device *dev, const char *name, int id);
void ieee80211_if_free(struct net_device *dev);
void ieee80211_if_sdata_init(struct ieee80211_sub_if_data *sdata);
-int ieee80211_if_add_mgmt(struct ieee80211_local *local);
-void ieee80211_if_del_mgmt(struct ieee80211_local *local);

/* regdomain.c */
void ieee80211_regdomain_init(void);
--- wireless-dev.orig/net/mac80211/ieee80211_iface.c 2007-06-21 11:34:19.028645783 +0200
+++ wireless-dev/net/mac80211/ieee80211_iface.c 2007-06-21 11:35:20.768645783 +0200
@@ -97,60 +97,6 @@ fail:
return ret;
}

-int ieee80211_if_add_mgmt(struct ieee80211_local *local)
-{
- struct net_device *ndev;
- struct ieee80211_sub_if_data *nsdata;
- int ret;
-
- ASSERT_RTNL();
-
- ndev = alloc_netdev(sizeof(struct ieee80211_sub_if_data), "wmgmt%d",
- ieee80211_if_mgmt_setup);
- if (!ndev)
- return -ENOMEM;
- ret = dev_alloc_name(ndev, ndev->name);
- if (ret < 0)
- goto fail;
-
- memcpy(ndev->dev_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
- SET_NETDEV_DEV(ndev, wiphy_dev(local->hw.wiphy));
-
- nsdata = IEEE80211_DEV_TO_SUB_IF(ndev);
- ndev->ieee80211_ptr = &nsdata->wdev;
- nsdata->wdev.wiphy = local->hw.wiphy;
- nsdata->type = IEEE80211_IF_TYPE_MGMT;
- nsdata->dev = ndev;
- nsdata->local = local;
- ieee80211_if_sdata_init(nsdata);
-
- ret = register_netdevice(ndev);
- if (ret)
- goto fail;
-
- ieee80211_debugfs_add_netdev(nsdata);
-
- if (local->open_count > 0)
- dev_open(ndev);
- local->apdev = ndev;
- return 0;
-
-fail:
- free_netdev(ndev);
- return ret;
-}
-
-void ieee80211_if_del_mgmt(struct ieee80211_local *local)
-{
- struct net_device *apdev;
-
- ASSERT_RTNL();
- apdev = local->apdev;
- ieee80211_debugfs_remove_netdev(IEEE80211_DEV_TO_SUB_IF(apdev));
- local->apdev = NULL;
- unregister_netdevice(apdev);
-}
-
void ieee80211_if_set_type(struct net_device *dev, int type)
{
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
@@ -362,11 +308,8 @@ int ieee80211_if_remove(struct net_devic

void ieee80211_if_free(struct net_device *dev)
{
- struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);

- /* local->apdev must be NULL when freeing management interface */
- BUG_ON(dev == local->apdev);
ieee80211_if_sdata_deinit(sdata);
free_netdev(dev);
}
--- wireless-dev.orig/net/mac80211/ieee80211_ioctl.c 2007-06-21 11:34:19.088645783 +0200
+++ wireless-dev/net/mac80211/ieee80211_ioctl.c 2007-06-21 11:35:20.768645783 +0200
@@ -2476,16 +2476,6 @@ static int ieee80211_ioctl_prism2_param(
case PRISM2_PARAM_SPECTRUM_MGMT:
local->hw.conf.spect_mgmt = value;
break;
- case PRISM2_PARAM_MGMT_IF:
- if (value == 1) {
- if (!local->apdev)
- ret = ieee80211_if_add_mgmt(local);
- } else if (value == 0) {
- if (local->apdev)
- ieee80211_if_del_mgmt(local);
- } else
- ret = -EINVAL;
- break;
case PRISM2_PARAM_USER_SPACE_MLME:
local->user_space_mlme = value;
break;
@@ -2663,12 +2653,6 @@ static int ieee80211_ioctl_get_prism2_pa
else
*param = !!sdata->u.sta.wmm_enabled;
break;
- case PRISM2_PARAM_MGMT_IF:
- if (local->apdev)
- *param = local->apdev->ifindex;
- else
- ret = -ENOENT;
- break;
case PRISM2_PARAM_USER_SPACE_MLME:
*param = local->user_space_mlme;
break;
--- wireless-dev.orig/net/mac80211/wpa.c 2007-06-21 11:34:19.108645783 +0200
+++ wireless-dev/net/mac80211/wpa.c 2007-06-21 11:35:20.768645783 +0200
@@ -14,7 +14,6 @@
#include <net/iw_handler.h>

#include <net/mac80211.h>
-#include "ieee80211_common.h"
#include "ieee80211_i.h"
#include "michael.h"
#include "tkip.h"
@@ -265,13 +264,8 @@ ieee80211_rx_h_michael_mic_verify(struct
kfree(buf);
} while (0);

- if (!rx->local->apdev)
- return TXRX_DROP;
-
- ieee80211_rx_mgmt(rx->local, rx->skb, rx->u.rx.status,
- ieee80211_msg_michael_mic_failure);
-
- return TXRX_QUEUED;
+ /* XXX: notify userspace of mic failure */
+ return TXRX_DROP;
}

remove_mic:
--- wireless-dev.orig/include/net/mac80211.h 2007-06-21 11:34:19.338645783 +0200
+++ wireless-dev/include/net/mac80211.h 2007-06-21 11:39:35.808645783 +0200
@@ -174,8 +174,9 @@ struct ieee80211_tx_control {
* specific value for the rate (from
* struct ieee80211_rate) */

-#define IEEE80211_TXCTL_REQ_TX_STATUS (1<<0)/* request TX status callback for
- * this frame */
+#define IEEE80211_TXCTL_RELIABLE_TX_MONITOR (1<<0) /* reliable TX monitor for
+ * for this frame (internal)
+ */
#define IEEE80211_TXCTL_DO_NOT_ENCRYPT (1<<1) /* send this frame without
* encryption; e.g., for EAPOL
* frames */
@@ -315,8 +316,6 @@ struct ieee80211_conf {
* enum ieee80211_if_types - types of 802.11 network interfaces
*
* @IEEE80211_IF_TYPE_AP: interface in AP mode.
- * @IEEE80211_IF_TYPE_MGMT: special interface for communication with hostap
- * daemon. Drivers should never see this type.
* @IEEE80211_IF_TYPE_STA: interface in STA (client) mode.
* @IEEE80211_IF_TYPE_IBSS: interface in IBSS (ad-hoc) mode.
* @IEEE80211_IF_TYPE_MNTR: interface in monitor (rfmon) mode.
@@ -325,7 +324,6 @@ struct ieee80211_conf {
*/
enum ieee80211_if_types {
IEEE80211_IF_TYPE_AP = 0x00000000,
- IEEE80211_IF_TYPE_MGMT = 0x00000001,
IEEE80211_IF_TYPE_STA = 0x00000002,
IEEE80211_IF_TYPE_IBSS = 0x00000003,
IEEE80211_IF_TYPE_MNTR = 0x00000004,
--- wireless-dev.orig/net/mac80211/ieee80211_sta.c 2007-06-21 11:34:19.178645783 +0200
+++ wireless-dev/net/mac80211/ieee80211_sta.c 2007-06-21 11:35:20.778645783 +0200
@@ -459,7 +459,6 @@ static void ieee80211_sta_tx(struct net_
pkt_data = (struct ieee80211_tx_packet_data *) skb->cb;
memset(pkt_data, 0, sizeof(struct ieee80211_tx_packet_data));
pkt_data->ifindex = sdata->dev->ifindex;
- pkt_data->mgmt_iface = (sdata->type == IEEE80211_IF_TYPE_MGMT);
pkt_data->do_not_encrypt = !encrypt;

dev_queue_xmit(skb);
--- wireless-dev.orig/net/mac80211/wme.c 2007-06-21 11:34:19.198645783 +0200
+++ wireless-dev/net/mac80211/wme.c 2007-06-21 11:35:20.838645783 +0200
@@ -168,8 +168,6 @@ static inline int classify80211(struct s
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(qd->dev);
struct ieee80211_if_sta *ifsta = &sdata->u.sta;
- struct ieee80211_tx_packet_data *pkt_data =
- (struct ieee80211_tx_packet_data *) skb->cb;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
unsigned short fc = le16_to_cpu(hdr->frame_control);
int qos, tsid, dir;
@@ -182,7 +180,7 @@ static inline int classify80211(struct s
return IEEE80211_TX_QUEUE_DATA0;
}

- if (unlikely(pkt_data->mgmt_iface)) {
+ if (0 /* XXX: inject flag? */) {
/* Data frames from hostapd (mainly, EAPOL) use AC_VO
* and they will include QoS control fields if
* the target STA is using WME. */
--- wireless-dev.orig/net/mac80211/ieee80211_common.h 2007-06-21 11:34:19.268645783 +0200
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,93 +0,0 @@
-/*
- * IEEE 802.11 driver (80211.o) -- hostapd interface
- * Copyright 2002-2004, Instant802 Networks, Inc.
- *
- * 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.
- */
-
-#ifndef IEEE80211_COMMON_H
-#define IEEE80211_COMMON_H
-
-#include <linux/types.h>
-
-/*
- * This is common header information with user space. It is used on all
- * frames sent to wlan#ap interface.
- */
-
-#define IEEE80211_FI_VERSION 0x80211001
-
-struct ieee80211_frame_info {
- __be32 version;
- __be32 length;
- __be64 mactime;
- __be64 hosttime;
- __be32 phytype;
- __be32 channel;
- __be32 datarate;
- __be32 antenna;
- __be32 priority;
- __be32 ssi_type;
- __be32 ssi_signal;
- __be32 ssi_noise;
- __be32 preamble;
- __be32 encoding;
-
- /* Note: this structure is otherwise identical to capture format used
- * in linux-wlan-ng, but this additional field is used to provide meta
- * data about the frame to hostapd. This was the easiest method for
- * providing this information, but this might change in the future. */
- __be32 msg_type;
-} __attribute__ ((packed));
-
-
-enum ieee80211_msg_type {
- ieee80211_msg_normal = 0,
- ieee80211_msg_tx_callback_ack = 1,
- ieee80211_msg_tx_callback_fail = 2,
- /* hole at 3, was ieee80211_msg_passive_scan but unused */
- ieee80211_msg_wep_frame_unknown_key = 4,
- ieee80211_msg_michael_mic_failure = 5,
- /* hole at 6, was monitor but never sent to userspace */
- ieee80211_msg_sta_not_assoc = 7,
- /* 8 was ieee80211_msg_set_aid_for_sta */
- ieee80211_msg_key_threshold_notification = 9,
- ieee80211_msg_radar = 11,
-};
-
-struct ieee80211_msg_key_notification {
- int tx_rx_count;
- char ifname[IFNAMSIZ];
- u8 addr[ETH_ALEN]; /* ff:ff:ff:ff:ff:ff for broadcast keys */
-};
-
-
-enum ieee80211_phytype {
- ieee80211_phytype_fhss_dot11_97 = 1,
- ieee80211_phytype_dsss_dot11_97 = 2,
- ieee80211_phytype_irbaseband = 3,
- ieee80211_phytype_dsss_dot11_b = 4,
- ieee80211_phytype_pbcc_dot11_b = 5,
- ieee80211_phytype_ofdm_dot11_g = 6,
- ieee80211_phytype_pbcc_dot11_g = 7,
- ieee80211_phytype_ofdm_dot11_a = 8,
- ieee80211_phytype_dsss_dot11_turbog = 255,
- ieee80211_phytype_dsss_dot11_turbo = 256,
-};
-
-enum ieee80211_ssi_type {
- ieee80211_ssi_none = 0,
- ieee80211_ssi_norm = 1, /* normalized, 0-1000 */
- ieee80211_ssi_dbm = 2,
- ieee80211_ssi_raw = 3, /* raw SSI */
-};
-
-struct ieee80211_radar_info {
- int channel;
- int radar;
- int radar_type;
-};
-
-#endif /* IEEE80211_COMMON_H */

2007-06-23 21:39:49

Is there any way you can make your mails thread correctly? Maybe by
using a proper MUA?

> Regarding user-space MLME and special interfaces:
> mac80211 allows for multiple virtual interfaces on top of one physical NIC, right?
> Can one run multiple MLME (e.g. hostapd) instances to run multiple virtual master mode interfaces
> for different networks? With different BSSID?

Only if the underlaying hardware and driver support that. No current
drivers do.

johannes

Attachments:

signature.asc (190.00 B)
This is a digitally signed message part

2007-06-22 15:49:54

by Jiri Benc

Jiri Benc wrote:

> On Fri, 22 Jun 2007 15:29:05 +0100, Andy Green wrote:
>> But for any nontrivial use, you need to capture RX and not blindly
>> inject, and so you have a monitor mode interface up anyway.
>
> No, why? You can encapsulate received management frames (only the ones
> that need to go to user space or so) in the same way and send them
> through the regular interface.

For my usage case I want specific unencrypted packets filtered by a MAC
address that isn't part of the authenticated network, so the reception
action needs to be effectively promisc a la Monitor mode, not just
"received management frames". But I guess it can be done with IFF_PROMISC.

By piping everything down "wlan0" normal packets will not have the
radiotap metadata on their capture, but presumably the abnormal packets
can have it via a special ethernet frame type + radiotap header. Maybe
it doesn't matter for any actual use.

-Andy

2007-06-23 11:44:55

by Jiri Benc

[permalink] [raw]

Subject: Re: [WIP] mac80211: kill mgmt interface

On Sat, 23 Jun 2007 08:53:50 +0200, Johannes Berg wrote:
> Who started this anti-nl80211 thing anyway? I still don't see what's so
> wrong with sending frames down a PF_NETLINK socket rather than a
> PF_PACKET socket.

Perhaps it was just my misunderstanding about the monitor interface tx
injection patches; I though this mechanism should be used for hostapd and
user space MLME, which I consider wrong. Johannes' comment about different
needs (and thus having both injection through monitor iface and through
netlink) makes perfectly sense, though.

Andy, is using a monitor interface (for both injecting and receiving of
frames) acceptable for you? If yes, let's drop my proposal (I said it might
turn up to be useless :-)), apply patches for monitor iface injection and
implement a netlink soultion as a replacement of the current management
interface.

Thanks,

Jiri

--
Jiri Benc
SUSE Labs

2007-06-21 12:36:00

by Jiri Benc

[permalink] [raw]

Subject: Re: [WIP] mac80211: kill mgmt interface

On Thu, 21 Jun 2007 11:42:19 +0200, Johannes Berg wrote:
> This patch kills the management interface type now that we can
> see transmitted frames on monitor interfaces.
>
> I renamed the req_tx_status to reliable_tx_mntr and the flag
> constant as well since that's what they now mean. It is always
> set for injected frames so that hostapd can rely on seeing the
> frames it sent.

I have two comments.

1. I'm still not sure if using monitor interface for this purpose is a
good idea. Given the fact we want to switch to user space MLME, this
will mean that at least one monitor interface is always present. So we
got rid of management interface just to introduce another user visible
magic interface.

2. How is hostapd (or other programs) supposed to connect frames
returned on monitor interface with frames it sent? Does it need to
remember each sent frame and compare it with the ones received through
the monitor interface? (It probably wouldn't work anyway because of seq
numbers, sw encryption, etc).

Maybe allowing to put some stamp on injected frames (in a radiotap
header?) and keep the stamp in frames returned through monitor
interface (again, in the radiotap header?) would solve all those
problems. When the stamp field is not present, the frame needs not to
be returned.

But I'd prefer some other solution than using monitor interface for
this stuff.

> There are a few minor remaining problems:
> * some notifications are now missing
> (radar, key threshold, michael MIC failure, wep unknown key)
> [radar, key threshold aren't used anywhere so can probably
> be left out for now]
> * injected frames aren't sent to AC_VO pending on the radiotap
> definition for access category
> * rate control extra.mgmt_data isn't properly assigned
>
> The biggest problem, however, and I'm not sure how to solve it, is
> that hostapd will see either encrypted or unencrypted frames on the
> monitor interface depending on whether hardware encryption is used
> or not. However, hostapd really needs to see eapol frames to do
> whatever it needs to with them. Right now, I don't really have an
> idea except maybe to send these packets to hostapd via nl80211,
> or to introduce some sort of "decrypted soft monitor" iface.

Using stamps (independent of the mechanism used for handing frames from
and to user space MLME) could solve this.

Thanks,

Jiri

--
Jiri Benc
SUSE Labs

2007-06-22 14:29:23

by Andy Green

[permalink] [raw]

Subject: Re: [WIP] mac80211: kill mgmt interface

Jiri Benc wrote:
> On Thu, 21 Jun 2007 15:14:41 +0200, Jiri Benc wrote:
>> That's true. Still, couldn't we find a better solution?
>
> I have a new idea. Maybe it will turn out to have fatal design or
> implementation problems, but anyway.
>
> First, I thought how all of this would be easier if we have a native
> 802.11 (virtual) interfaces and don't translate from Ethernet. Then I
> realized it wouldn't help us much - we want to specify some parameters
> for each frame, so we'd have to use some encapsulation anyway to allow
> radiotap headers. Hm, wait a moment - why we cannot use the
> encapsulation we currently have? That means, why can't we encapsulate
> raw 802.11 frames in Ethernet frames?
>
> Before you reject the whole idea, please think a moment about it.

I don't reject it at all, it's fine for injection.

But for any nontrivial use, you need to capture RX and not blindly
inject, and so you have a monitor mode interface up anyway. The
footprint in the political networking space is less if it just goes in
as a monitor mode TX action.

-Andy

2007-06-21 13:36:15

by Jouni Malinen

[permalink] [raw]

Subject: Re: [WIP] mac80211: kill mgmt interface

On Thu, Jun 21, 2007 at 11:42:19AM +0200, Johannes Berg wrote:

> This patch kills the management interface type now that we can
> see transmitted frames on monitor interfaces.

Has someone tested that this works with programs that use the management
interface (mainly, hostapd and wpa_supplicant)? Is all the needed
functionality available with the alternative solution?

> I renamed the req_tx_status to reliable_tx_mntr and the flag
> constant as well since that's what they now mean. It is always
> set for injected frames so that hostapd can rely on seeing the
> frames it sent.

I'm not sure I follow this explanation fully.. How would hostapd learn
whether the destination address acknowledged a unicast frame?

> There are a few minor remaining problems:
> * some notifications are now missing
> (radar, key threshold, michael MIC failure, wep unknown key)
> [radar, key threshold aren't used anywhere so can probably
> be left out for now]

I would not remove key threshold notification and we must most certainly
not remove Michal MIC failure before there is a reliable way of doing
the same functionality.

> * injected frames aren't sent to AC_VO pending on the radiotap
> definition for access category

This is not good either since management frames should be sent at a high
priority.

> The biggest problem, however, and I'm not sure how to solve it, is
> that hostapd will see either encrypted or unencrypted frames on the
> monitor interface depending on whether hardware encryption is used
> or not. However, hostapd really needs to see eapol frames to do
> whatever it needs to with them. Right now, I don't really have an
> idea except maybe to send these packets to hostapd via nl80211,
> or to introduce some sort of "decrypted soft monitor" iface.

If I've understood correctly (please correct me, if not), this patch is
proposing to remove an interface that works currently and leave the
stack in state that does not work. I can only strongly recommend this
patch not to be applied at this point. It is not a good direction to
start removing working code before there is a good alternative available
and that alternative has actually been tested to provide the needed
functionality.

I don't really see need for getting rid of the management interface, but
if there is consensus on doing that, we would need to have another way
of being able to receive and transmit management frames and data frames
from/to user space in a way that provides at least following
functionality:
- transmit management frames at high priority
- control whether transmitted frames will be encrypted or not
- get callback to report TX status for unicast frames (whether the
receiver sent control::ack for the frame)
- receive management frames
- receive data frames EAPOL/etc. ethertypes in decrypted form
- delivery of notifications to user space for Michael MIC errors and
other similar events

--
Jouni Malinen PGP id EFC895FA

2007-06-23 06:52:33

On Thursday 21 June 2007 06:35, Jouni Malinen wrote:
> On Thu, Jun 21, 2007 at 11:42:19AM +0200, Johannes Berg wrote:
> > This patch kills the management interface type now that we can
> > see transmitted frames on monitor interfaces.
>
> Has someone tested that this works with programs that use the management
> interface (mainly, hostapd and wpa_supplicant)? Is all the needed
> functionality available with the alternative solution?
>
The management interface shouldn't be killed until hostap and wpa_supplicant
can work with monitor interfaces.

> > I renamed the req_tx_status to reliable_tx_mntr and the flag
> > constant as well since that's what they now mean. It is always
> > set for injected frames so that hostapd can rely on seeing the
> > frames it sent.
>
> I'm not sure I follow this explanation fully.. How would hostapd learn
> whether the destination address acknowledged a unicast frame?
>
It's the same as the management interface - hostap receives the same frame it
sent, with a header that says whether or not it was ACKed.

> > The biggest problem, however, and I'm not sure how to solve it, is
> > that hostapd will see either encrypted or unencrypted frames on the
> > monitor interface depending on whether hardware encryption is used
> > or not. However, hostapd really needs to see eapol frames to do
> > whatever it needs to with them. Right now, I don't really have an
> > idea except maybe to send these packets to hostapd via nl80211,
> > or to introduce some sort of "decrypted soft monitor" iface.
>
> If I've understood correctly (please correct me, if not), this patch is
> proposing to remove an interface that works currently and leave the
> stack in state that does not work. I can only strongly recommend this
> patch not to be applied at this point. It is not a good direction to
> start removing working code before there is a good alternative available
> and that alternative has actually been tested to provide the needed
> functionality.
>
Agreed. However, it is marked WIP and has spawned some good discussion. :)

> I don't really see need for getting rid of the management interface, but
> if there is consensus on doing that, we would need to have another way
> of being able to receive and transmit management frames and data frames
> from/to user space in a way that provides at least following
> functionality:
> - transmit management frames at high priority
Should be fine to hardcode this for now since the current mgmt interface
doesn't allow control over this.

> - control whether transmitted frames will be encrypted or not
IEEE80211_RADIOTAP_F_WEP should be appropriate, I think. (despite its somewhat
misleading name)

> - get callback to report TX status for unicast frames (whether the
> receiver sent control::ack for the frame)
This is provided by [PATCH] mac80211: show transmitted frames on monitor
interfaces.

> - receive management frames
Well, it's a monitor interface, so it's more of a challenge to receive just
the desired frames. Hopefully packet filter works well enough for this..

> - receive data frames EAPOL/etc. ethertypes in decrypted form
We should be able to receive this on the other interface which is handling all
the data frames, right?

> - delivery of notifications to user space for Michael MIC errors and
> other similar events
nl80211 should be appropriate for this. nl80211 is probably the biggest
blocker before removing the mgmt interface completely.. everything else is
*almost* there.

-Michael Wu

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2007-06-22 20:19:08

On Sat, 2007-06-23 at 10:00 +0100, Andy Green wrote:
> Johannes Berg wrote:
>
> > On the other hand, I do consider userspace MLME needs slightly
> > different; it needs to be able to have frames encrypted, needs to see
> > frames that have been decrypted even though they would otherwise be
> > dropped [and this is very different to what you want], and probably
> > more.
>
> Fair enough, but injection is a separate issue from RX, despite one
> usually needs both. That there is no standard way to inject on
> mac80211, regardless of the RX situation is a major lack. If injection
> is not treated as a separate valid action then it will constantly be
> delayed as part of some larger effort, when it is valuable in itself.

Don't get me wrong, I fully support your patches. I can see usefulness
in what you're doing there, I even based my recent patch-frenzy on top
of your patches ;) But I'm not fully convinced that this will be the
best path for the userspace MLME (in whatever form); I do however think
that it is the best option for wireless analysis/hacking/... tools or
something like your penumbra.

> But Jiri's encapsulation method is an improvement if it can be
> implemented okay for unassociated interfaces and so on.

Not convinced; it solves only a minor part of the problem, the hard
things aren't solved (like that we need to see the decrypted frames that
would normally be dropped by the kernel). Hence, I don't see any value
in it by itself without solving the harder parts as well (or better even
first), when solving that may end up using netlink for frames anyway.

> I don't have anything against it, but for me the packets I am injecting
> are normal network traffic and sending them like that seems the most
> natural way. For RX down in userspace it is marginally simpler to use
> libpcap monitoring and the same handle for injection and rx.

Right; I see that your situation wildly differs from the userspace MLME
and that in that situation this is the best and easiest thing to do.

> I
> definitely think having two paths to injection is not necessary, but for
> splitting out normally invisible management packets to go down a
> separate netlink socket instead of encapsulating them I don't mind
> either way.

I think what we need to accept is that the long-touted concept of a
"userspace MLME" isn't really that, while it's dead simple to do
*everything* in userspace by using a monitor interface with injection
and then a tun interface that isn't really what we want. We want to push
parts of the complexity to userspace while still having it
kernel-assisted for various reasons like performance.

johannes

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2007-06-22 13:15:16

by Jiri Benc

[permalink] [raw]

Subject: Re: [WIP] mac80211: kill mgmt interface

Please always use "reply to all" when replying to mails from Linux
mailing lists.

On Thu, 21 Jun 2007 14:50:32 -0700 (PDT), Joerg Pommnitz wrote:
> Regarding user-space MLME and special interfaces:
> mac80211 allows for multiple virtual interfaces on top of one physical NIC, right?

Yes.

> Can one run multiple MLME (e.g. hostapd) instances to run multiple virtual master mode interfaces
> for different networks? With different BSSID?

I don't think that would be ever possible when using monitor
interfaces.

On the other hand, it doesn't make much sense to support that. The
interfaces are not completely independent, e.g. you cannot tune to
different channels on different virtual interfaces. Therefore, at least
a minimal knowledge about virtual interfaces would be needed in more
complicated user space MLMEs.

Jiri

--
Jiri Benc
SUSE Labs

2007-07-04 06:13:22

by Tomas Winkler

[permalink] [raw]

Subject: Re: [WIP] mac80211: kill mgmt interface

On 7/2/07, Jiri Benc <[email protected]> wrote:
> > Von: "Cohen, Guy" <[email protected]>
> > > This is a required feature for Access Points (multiple BSSID).
>
> On Mon, 2 Jul 2007 06:38:00 -0700 (PDT), Joerg Pommnitz wrote:
> > And, just from reading the documentation, it seems to be supported by MadWifi for Atheros
> > based devices:
> >
> > http://madwifi.org/wiki/ngFeatures
> >
> > and note the "To create APs which share a single MAC address, use the -bssid flag when
> > creating the VAPs:" remark.
> >
> > Even if no current mac80211 driver supports this feature, the API must not prevent this in the future.
>
> What are you talking about? Have you actually looked at mac80211? This
> is supported from day 0 of d80211.
>
> Jiri
>
There is probably difference between running multiple hostapd
instances and running in multiple BSSID mode over one interface,
meaning that hostapad is running multiple instances of MLME. I guess
the original post was a bit confusing.
I'm not sure if and how current implementation of hostapd can do that,
but that's probably question for another mailing list.

> --
> Jiri Benc
> SUSE Labs
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>

2007-07-01 01:48:12

by Guy Cohen

[permalink] [raw]

Subject: RE: [WIP] mac80211: kill mgmt interface

Jiri Benc wrote:
> > Can one run multiple MLME (e.g. hostapd) instances to run multiple
> virtual master mode interfaces
> > for different networks? With different BSSID?
>
> I don't think that would be ever possible when using monitor
> interfaces.
>
> On the other hand, it doesn't make much sense to support that. The
> interfaces are not completely independent, e.g. you cannot tune to
> different channels on different virtual interfaces. Therefore, at
least
> a minimal knowledge about virtual interfaces would be needed in more
> complicated user space MLMEs.

This is a required feature for Access Points (multiple BSSID).