mac80211: Add radiotap support
From: Michael Wu <flamingice@xxxxxxxxxxxx>
This patch makes mac80211 monitor interfaces use radiotap headers. It also
provides a flag to let a driver specify a frame has a radiotap header and
another flag to let the driver know if adding a radiotap header would be
helpful.
Thanks to Andy Green <andy@xxxxxxxxxxx> for testing earlier versions of
this patch.
Signed-off-by: Michael Wu <flamingice@xxxxxxxxxxxx>
---
include/net/mac80211.h | 8 +++-
net/mac80211/ieee80211.c | 75 ++++++++++++++++++++++++++++++++++------
net/mac80211/ieee80211_iface.c | 2 +
3 files changed, 70 insertions(+), 15 deletions(-)
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 916b21b..3b22369 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -216,9 +216,6 @@ struct ieee80211_tx_control {
int ifindex; /* internal */
};
-#define RX_FLAG_MMIC_ERROR 0x1
-#define RX_FLAG_DECRYPTED 0x2
-
/* Receive status. The low-level driver should provide this information
* (the subset supported by hardware) to the 802.11 code with each received
* frame. */
@@ -232,6 +229,9 @@ struct ieee80211_rx_status {
int noise;
int antenna;
int rate;
+#define RX_FLAG_MMIC_ERROR (1<<0)
+#define RX_FLAG_DECRYPTED (1<<1)
+#define RX_FLAG_RADIOTAP (1<<2)
int flag;
};
@@ -278,6 +278,8 @@ struct ieee80211_conf {
#define IEEE80211_CONF_SHORT_SLOT_TIME (1<<0) /* use IEEE 802.11g Short Slot
* Time */
#define IEEE80211_CONF_SSID_HIDDEN (1<<1) /* do not broadcast the ssid */
+#define IEEE80211_CONF_RADIOTAP (1<<2) /* use radiotap if supported
+ check this bit at RX time */
u32 flags; /* configuration flags defined above */
u8 power_level; /* transmit power limit for current
diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index c390c85..bbf58a3 100644
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -8,6 +8,7 @@
*/
#include <net/mac80211.h>
+#include <net/ieee80211_radiotap.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
@@ -292,6 +293,14 @@ int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
}
EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
+static int ieee80211_get_radiotap_len(struct sk_buff *skb)
+{
+ struct ieee80211_radiotap_header *hdr =
+ (struct ieee80211_radiotap_header *) skb->data;
+
+ return le16_to_cpu(hdr->it_len);
+}
+
#ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
static void ieee80211_dump_frame(const char *ifname, const char *title,
const struct sk_buff *skb)
@@ -2339,6 +2348,7 @@ static int ieee80211_open(struct net_device *dev)
/* run the interface in a "soft monitor" mode */
local->monitors++;
local->open_count++;
+ local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
return 0;
}
ieee80211_start_soft_monitor(local);
@@ -2387,9 +2397,10 @@ static int ieee80211_open(struct net_device *dev)
}
local->open_count++;
- if (sdata->type == IEEE80211_IF_TYPE_MNTR)
+ if (sdata->type == IEEE80211_IF_TYPE_MNTR) {
local->monitors++;
- else
+ local->hw.conf.flags |= IEEE80211_CONF_RADIOTAP;
+ } else
ieee80211_if_config(dev);
if (sdata->type == IEEE80211_IF_TYPE_STA &&
@@ -2414,13 +2425,18 @@ static int ieee80211_stop(struct net_device *dev)
/* remove "soft monitor" interface */
local->open_count--;
local->monitors--;
+ if (!local->monitors)
+ local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
return 0;
}
netif_stop_queue(dev);
- if (sdata->type == IEEE80211_IF_TYPE_MNTR)
+ if (sdata->type == IEEE80211_IF_TYPE_MNTR) {
local->monitors--;
+ if (!local->monitors)
+ local->hw.conf.flags &= ~IEEE80211_CONF_RADIOTAP;
+ }
local->open_count--;
if (local->open_count == 0) {
@@ -2766,26 +2782,53 @@ ieee80211_rx_monitor(struct net_device *dev, struct sk_buff *skb,
struct ieee80211_rx_status *status)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
- struct ieee80211_frame_info *fi;
struct ieee80211_sub_if_data *sdata;
- const size_t hlen = sizeof(struct ieee80211_frame_info)
- - sizeof(fi->msg_type);
+ struct ieee80211_rate *rate;
+ struct ieee80211_rtap_hdr {
+ struct ieee80211_radiotap_header hdr;
+ u8 flags;
+ u8 rate;
+ __le16 chan_freq;
+ __le16 chan_flags;
+ u8 antsignal;
+ } __attribute__ ((packed)) *rthdr;
skb->dev = dev;
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
- if (skb_headroom(skb) < hlen) {
+ if (status->flag & RX_FLAG_RADIOTAP)
+ goto out;
+
+ if (skb_headroom(skb) < sizeof(*rthdr)) {
I802_DEBUG_INC(local->rx_expand_skb_head);
- if (pskb_expand_head(skb, hlen, 0, GFP_ATOMIC)) {
+ if (pskb_expand_head(skb, sizeof(*rthdr), 0, GFP_ATOMIC)) {
dev_kfree_skb(skb);
return;
}
}
- fi = (struct ieee80211_frame_info *) skb_push(skb, hlen);
+ rthdr = (struct ieee80211_rtap_hdr *) skb_push(skb, sizeof(*rthdr));
+ memset(rthdr, 0, sizeof(*rthdr));
+ rthdr->hdr.it_len = cpu_to_le16(sizeof(*rthdr));
+ rthdr->hdr.it_present =
+ cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
+ (1 << IEEE80211_RADIOTAP_RATE) |
+ (1 << IEEE80211_RADIOTAP_CHANNEL) |
+ (1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL));
+ rthdr->flags = local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS ?
+ IEEE80211_RADIOTAP_F_FCS : 0;
+ rate = ieee80211_get_rate(local, status->phymode, status->rate);
+ if (rate)
+ rthdr->rate = rate->rate / 5;
+ rthdr->chan_freq = cpu_to_le16(status->freq);
+ rthdr->chan_flags =
+ status->phymode == MODE_IEEE80211A ?
+ cpu_to_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ) :
+ cpu_to_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ);
+ rthdr->antsignal = status->ssi;
- ieee80211_fill_frame_info(local, fi, status);
+ out:
sdata->stats.rx_packets++;
sdata->stats.rx_bytes += skb->len;
@@ -3189,6 +3232,9 @@ ieee80211_rx_h_monitor(struct ieee80211_txrx_data *rx)
return TXRX_QUEUED;
}
+ if (rx->u.rx.status->flag & RX_FLAG_RADIOTAP)
+ skb_pull(rx->skb, ieee80211_get_radiotap_len(rx->skb));
+
return TXRX_CONTINUE;
}
@@ -3756,6 +3802,12 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
struct ieee80211_txrx_data rx;
u16 type;
int multicast;
+ int radiotap_len = 0;
+
+ if (status->flag & RX_FLAG_RADIOTAP) {
+ radiotap_len = ieee80211_get_radiotap_len(skb);
+ skb_pull(skb, radiotap_len);
+ }
hdr = (struct ieee80211_hdr *) skb->data;
memset(&rx, 0, sizeof(rx));
@@ -3792,6 +3844,7 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
goto end;
skb = rx.skb;
+ skb_push(skb, radiotap_len);
if (sta && !sta->assoc_ap && !(sta->flags & WLAN_STA_WDS) &&
!local->iff_promiscs && !multicast) {
rx.u.rx.ra_match = 1;
@@ -3800,7 +3853,7 @@ void __ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb,
} else {
struct ieee80211_sub_if_data *prev = NULL;
struct sk_buff *skb_new;
- u8 *bssid = ieee80211_get_bssid(hdr, skb->len);
+ u8 *bssid = ieee80211_get_bssid(hdr, skb->len - radiotap_len);
list_for_each_entry(sdata, &local->sub_if_list, list) {
rx.u.rx.ra_match = 1;
diff --git a/net/mac80211/ieee80211_iface.c b/net/mac80211/ieee80211_iface.c
index b1b20ba..495177b 100644
--- a/net/mac80211/ieee80211_iface.c
+++ b/net/mac80211/ieee80211_iface.c
@@ -192,7 +192,7 @@ void ieee80211_if_set_type(struct net_device *dev, int type)
break;
}
case IEEE80211_IF_TYPE_MNTR:
- dev->type = ARPHRD_IEEE80211_PRISM;
+ dev->type = ARPHRD_IEEE80211_RADIOTAP;
break;
default:
printk(KERN_WARNING "%s: %s: Unknown interface type 0x%x",
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