mac802154: monitor device support

Support for monitor device intended to capture all the network activity.
This interface could be used by networks sniffers and is already
supported by WireShark. That's a good test point to check that basic
MAC support works.

Signed-off-by: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 127 insertions, 2 deletions

diff --git a/net/mac802154/Makefile b/net/mac802154/Makefile
index 6b348b07a765..ec1bd3fc1273 100644
--- a/net/mac802154/Makefile
+++ b/net/mac802154/Makefile
@@ -1,2 +1,2 @@
 obj-$(CONFIG_MAC802154) += mac802154.o
-mac802154-objs          := ieee802154_dev.o rx.o tx.o mac_cmd.o mib.o
+mac802154-objs          := ieee802154_dev.o rx.o tx.o mac_cmd.o mib.o monitor.o
diff --git a/net/mac802154/ieee802154_dev.c b/net/mac802154/ieee802154_dev.c
index 9f36760b6c3a..e3edfb0661b0 100644
--- a/net/mac802154/ieee802154_dev.c
+++ b/net/mac802154/ieee802154_dev.c
@@ -135,8 +135,11 @@ mac802154_add_iface(struct wpan_phy *phy, const char *name, int type)
         struct net_device *dev;
         int err = -ENOMEM;
 
-        /* No devices is currently added */
         switch (type) {
+        case IEEE802154_DEV_MONITOR:
+                dev = alloc_netdev(sizeof(struct mac802154_sub_if_data),
+                                   name, mac802154_monitor_setup);
+                break;
         default:
                 dev = NULL;
                 err = -EINVAL;
diff --git a/net/mac802154/mac802154.h b/net/mac802154/mac802154.h
index 622752622c87..789d9c948aec 100644
--- a/net/mac802154/mac802154.h
+++ b/net/mac802154/mac802154.h
@@ -90,11 +90,16 @@ struct mac802154_sub_if_data {
 
 #define MAC802154_MAX_XMIT_ATTEMPTS     3
 
+#define MAC802154_CHAN_NONE             (~(u8)0) /* No channel is assigned */
+
 extern struct ieee802154_reduced_mlme_ops mac802154_mlme_reduced;
 
 int mac802154_slave_open(struct net_device *dev);
 int mac802154_slave_close(struct net_device *dev);
 
+void mac802154_monitors_rx(struct mac802154_priv *priv, struct sk_buff *skb);
+void mac802154_monitor_setup(struct net_device *dev);
+
 netdev_tx_t mac802154_tx(struct mac802154_priv *priv, struct sk_buff *skb,
                          u8 page, u8 chan);
 
diff --git a/net/mac802154/monitor.c b/net/mac802154/monitor.c
new file mode 100644
index 000000000000..434a26f76a80
--- /dev/null
+++ b/net/mac802154/monitor.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2007, 2008, 2009 Siemens AG
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Written by:
+ * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
+ * Sergey Lapin <slapin@ossfans.org>
+ * Maxim Gorbachyov <maxim.gorbachev@siemens.com>
+ * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
+ */
+
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/if_arp.h>
+#include <linux/crc-ccitt.h>
+
+#include <net/ieee802154.h>
+#include <net/mac802154.h>
+#include <net/netlink.h>
+#include <net/wpan-phy.h>
+#include <linux/nl802154.h>
+
+#include "mac802154.h"
+
+static netdev_tx_t mac802154_monitor_xmit(struct sk_buff *skb,
+                                          struct net_device *dev)
+{
+        struct mac802154_sub_if_data *priv;
+        u8 chan, page;
+
+        priv = netdev_priv(dev);
+
+        /* FIXME: locking */
+        chan = priv->hw->phy->current_channel;
+        page = priv->hw->phy->current_page;
+
+        if (chan == MAC802154_CHAN_NONE) /* not initialized */
+                return NETDEV_TX_OK;
+
+        if (WARN_ON(page >= WPAN_NUM_PAGES) ||
+            WARN_ON(chan >= WPAN_NUM_CHANNELS))
+                return NETDEV_TX_OK;
+
+        skb->skb_iif = dev->ifindex;
+        dev->stats.tx_packets++;
+        dev->stats.tx_bytes += skb->len;
+
+        return mac802154_tx(priv->hw, skb, page, chan);
+}
+
+
+void mac802154_monitors_rx(struct mac802154_priv *priv, struct sk_buff *skb)
+{
+        struct sk_buff *skb2;
+        struct mac802154_sub_if_data *sdata;
+        u16 crc = crc_ccitt(0, skb->data, skb->len);
+        u8 *data;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(sdata, &priv->slaves, list) {
+                if (sdata->type != IEEE802154_DEV_MONITOR)
+                        continue;
+
+                skb2 = skb_clone(skb, GFP_ATOMIC);
+                skb2->dev = sdata->dev;
+                skb2->pkt_type = PACKET_HOST;
+                data = skb_put(skb2, 2);
+                data[0] = crc & 0xff;
+                data[1] = crc >> 8;
+
+                netif_rx_ni(skb2);
+        }
+        rcu_read_unlock();
+}
+
+static const struct net_device_ops mac802154_monitor_ops = {
+        .ndo_open               = mac802154_slave_open,
+        .ndo_stop               = mac802154_slave_close,
+        .ndo_start_xmit         = mac802154_monitor_xmit,
+};
+
+void mac802154_monitor_setup(struct net_device *dev)
+{
+        struct mac802154_sub_if_data *priv;
+
+        dev->addr_len           = 0;
+        dev->hard_header_len    = 0;
+        dev->needed_tailroom    = 2; /* room for FCS */
+        dev->mtu                = IEEE802154_MTU;
+        dev->tx_queue_len       = 10;
+        dev->type               = ARPHRD_IEEE802154_MONITOR;
+        dev->flags              = IFF_NOARP | IFF_BROADCAST;
+        dev->watchdog_timeo     = 0;
+
+        dev->destructor         = free_netdev;
+        dev->netdev_ops         = &mac802154_monitor_ops;
+        dev->ml_priv            = &mac802154_mlme_reduced;
+
+        priv = netdev_priv(dev);
+        priv->type = IEEE802154_DEV_MONITOR;
+
+        priv->chan = MAC802154_CHAN_NONE; /* not initialized */
+        priv->page = 0;
+}
diff --git a/net/mac802154/rx.c b/net/mac802154/rx.c
index d15738fae551..4a7d76d4f8bc 100644
--- a/net/mac802154/rx.c
+++ b/net/mac802154/rx.c
@@ -76,6 +76,7 @@ mac802154_subif_rx(struct ieee802154_dev *hw, struct sk_buff *skb, u8 lqi)
                 skb_trim(skb, skb->len - 2); /* CRC */
         }
 
+        mac802154_monitors_rx(priv, skb);
 out:
         dev_kfree_skb(skb);
         return;