[14/19] wilc: add linux_mon.c

Commit Message

Ajay Singh Sept. 26, 2018, 10:25 a.m. UTC

Moved '/driver/staging/wilc1000/linux_mon.c' to
'drivers/net/wireless/microchip/wilc/'.

Signed-off-by: Ajay Singh <[e-mail]>
---
 drivers/net/wireless/microchip/wilc/linux_mon.c | 273 ++++++++++++++++++++++++
 1 file changed, 273 insertions(+)
 create mode 100644 drivers/net/wireless/microchip/wilc/linux_mon.c

Comments

Johannes Berg Oct. 8, 2018, 2:44 p.m. UTC | #1

On Wed, 2018-09-26 at 15:55 +0530, Ajay Singh wrote:
> 
> +static struct net_device *wilc_wfi_mon; /* global monitor netdev */

There might not exist platforms with multiple devices (yet), but it's
really bad practice to do this anyway.

> +static u8 srcadd[6];
> +static u8 bssid[6];
> +
> +#define IEEE80211_RADIOTAP_F_TX_RTS	0x0004  /* used rts/cts handshake */
> +#define IEEE80211_RADIOTAP_F_TX_FAIL	0x0001  /* failed due to excessive*/

Uh.. we have a radiotap include file and you already use it, why?

> +void wilc_wfi_deinit_mon_interface(void)
> +{
> +	bool rollback_lock = false;
> +
> +	if (wilc_wfi_mon) {
> +		if (rtnl_is_locked()) {
> +			rtnl_unlock();
> +			rollback_lock = true;
> +		}
> +		unregister_netdev(wilc_wfi_mon);
> +
> +		if (rollback_lock) {
> +			rtnl_lock();
> +			rollback_lock = false;
> +		}
> +		wilc_wfi_mon = NULL;
> +	}
> +}

Uh, no, you really cannot do conditional locking like this.

But seeing things like this pretty much destroys all of the confidence I
might have had of the code, so I'd say we cannot merge this until you
can demonstrate somebody more familiar with Linux has reviewed it, I'm
just doing a drive-by review for the stack integration aspects (and
haven't even found where that happens yet).

johannes

Ajay Singh Oct. 11, 2018, 7:12 a.m. UTC | #2

On 10/8/2018 8:14 PM, Johannes Berg wrote:
> On Wed, 2018-09-26 at 15:55 +0530, Ajay Singh wrote:
>> +static struct net_device *wilc_wfi_mon; /* global monitor netdev */
> There might not exist platforms with multiple devices (yet), but it's
> really bad practice to do this anyway.
>
Sure, will work on to avoid the use of this static variable here.
>> +static u8 srcadd[6];
>> +static u8 bssid[6];
>> +
>> +#define IEEE80211_RADIOTAP_F_TX_RTS	0x0004  /* used rts/cts handshake */
>> +#define IEEE80211_RADIOTAP_F_TX_FAIL	0x0001  /* failed due to excessive*/
> Uh.. we have a radiotap include file and you already use it, why?
>
Right, will remove these macro as header is already included.
>> +void wilc_wfi_deinit_mon_interface(void)
>> +{
>> +	bool rollback_lock = false;
>> +
>> +	if (wilc_wfi_mon) {
>> +		if (rtnl_is_locked()) {
>> +			rtnl_unlock();
>> +			rollback_lock = true;
>> +		}
>> +		unregister_netdev(wilc_wfi_mon);
>> +
>> +		if (rollback_lock) {
>> +			rtnl_lock();
>> +			rollback_lock = false;
>> +		}
>> +		wilc_wfi_mon = NULL;
>> +	}
>> +}
> Uh, no, you really cannot do conditional locking like this.
>
> But seeing things like this pretty much destroys all of the confidence I
> might have had of the code, so I'd say we cannot merge this until you
> can demonstrate somebody more familiar with Linux has reviewed it, I'm
> just doing a drive-by review for the stack integration aspects (and
> haven't even found where that happens yet).

I will refactor wilc_wfi_deinit_mon_interface() and submit more cleaner
version of this function.
Currently, I am not clear about which stack integration part is missing
. Can you please provide some more details about it.

Regards,
Ajay

Johannes Berg Oct. 11, 2018, 7:15 a.m. UTC | #3

On Thu, 2018-10-11 at 12:42 +0530, Ajay Singh wrote:
> > I'm
> > just doing a drive-by review for the stack integration aspects (and
> > haven't even found where that happens yet).
[...]
> Currently, I am not clear about which stack integration part is missing
> . Can you please provide some more details about it.

No, I'm just saying that *I* was looking for how you integrate with the
stack (cfg80211), and not so much trying to review everything else.

johannes

Patch

diff --git a/drivers/net/wireless/microchip/wilc/linux_mon.c b/drivers/net/wireless/microchip/wilc/linux_mon.c
new file mode 100644
index 0000000..a634468
--- /dev/null
+++ b/drivers/net/wireless/microchip/wilc/linux_mon.c
@@ -0,0 +1,273 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2012 - 2018 Microchip Technology Inc., and its subsidiaries.
+ * All rights reserved.
+ */
+
+#include "wilc_wfi_cfgoperations.h"
+
+struct wilc_wfi_radiotap_hdr {
+	struct ieee80211_radiotap_header hdr;
+	u8 rate;
+} __packed;
+
+struct wilc_wfi_radiotap_cb_hdr {
+	struct ieee80211_radiotap_header hdr;
+	u8 rate;
+	u8 dump;
+	u16 tx_flags;
+} __packed;
+
+static struct net_device *wilc_wfi_mon; /* global monitor netdev */
+
+static u8 srcadd[6];
+static u8 bssid[6];
+
+#define IEEE80211_RADIOTAP_F_TX_RTS	0x0004  /* used rts/cts handshake */
+#define IEEE80211_RADIOTAP_F_TX_FAIL	0x0001  /* failed due to excessive*/
+
+#define TX_RADIOTAP_PRESENT ((1 << IEEE80211_RADIOTAP_RATE) |	\
+			     (1 << IEEE80211_RADIOTAP_TX_FLAGS))
+
+void wilc_wfi_monitor_rx(u8 *buff, u32 size)
+{
+	u32 header, pkt_offset;
+	struct sk_buff *skb = NULL;
+	struct wilc_wfi_radiotap_hdr *hdr;
+	struct wilc_wfi_radiotap_cb_hdr *cb_hdr;
+
+	if (!wilc_wfi_mon)
+		return;
+
+	if (!netif_running(wilc_wfi_mon))
+		return;
+
+	/* Get WILC header */
+	memcpy(&header, (buff - HOST_HDR_OFFSET), HOST_HDR_OFFSET);
+	le32_to_cpus(&header);
+	/*
+	 * The packet offset field contain info about what type of management
+	 * the frame we are dealing with and ack status
+	 */
+	pkt_offset = GET_PKT_OFFSET(header);
+
+	if (pkt_offset & IS_MANAGMEMENT_CALLBACK) {
+		/* hostapd callback mgmt frame */
+
+		skb = dev_alloc_skb(size + sizeof(*cb_hdr));
+		if (!skb)
+			return;
+
+		skb_put_data(skb, buff, size);
+
+		cb_hdr = skb_push(skb, sizeof(*cb_hdr));
+		memset(cb_hdr, 0, sizeof(*cb_hdr));
+
+		cb_hdr->hdr.it_version = 0; /* PKTHDR_RADIOTAP_VERSION; */
+
+		cb_hdr->hdr.it_len = cpu_to_le16(sizeof(*cb_hdr));
+
+		cb_hdr->hdr.it_present = cpu_to_le32(TX_RADIOTAP_PRESENT);
+
+		cb_hdr->rate = 5;
+
+		if (pkt_offset & IS_MGMT_STATUS_SUCCES)	{
+			/* success */
+			cb_hdr->tx_flags = IEEE80211_RADIOTAP_F_TX_RTS;
+		} else {
+			cb_hdr->tx_flags = IEEE80211_RADIOTAP_F_TX_FAIL;
+		}
+
+	} else {
+		skb = dev_alloc_skb(size + sizeof(*hdr));
+
+		if (!skb)
+			return;
+
+		skb_put_data(skb, buff, size);
+		hdr = skb_push(skb, sizeof(*hdr));
+		memset(hdr, 0, sizeof(struct wilc_wfi_radiotap_hdr));
+		hdr->hdr.it_version = 0; /* PKTHDR_RADIOTAP_VERSION; */
+		hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr));
+		hdr->hdr.it_present = cpu_to_le32
+				(1 << IEEE80211_RADIOTAP_RATE);
+		hdr->rate = 5;
+	}
+
+	skb->dev = wilc_wfi_mon;
+	skb_reset_mac_header(skb);
+	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);
+}
+
+struct tx_complete_mon_data {
+	int size;
+	void *buff;
+};
+
+static void mgmt_tx_complete(void *priv, int status)
+{
+	struct tx_complete_mon_data *pv_data = priv;
+	/*
+	 * in case of fully hosting mode, the freeing will be done
+	 * in response to the cfg packet
+	 */
+	kfree(pv_data->buff);
+
+	kfree(pv_data);
+}
+
+static int mon_mgmt_tx(struct net_device *dev, const u8 *buf, size_t len)
+{
+	struct tx_complete_mon_data *mgmt_tx = NULL;
+
+	if (!dev)
+		return -EFAULT;
+
+	netif_stop_queue(dev);
+	mgmt_tx = kmalloc(sizeof(*mgmt_tx), GFP_ATOMIC);
+	if (!mgmt_tx)
+		return -ENOMEM;
+
+	mgmt_tx->buff = kmemdup(buf, len, GFP_ATOMIC);
+	if (!mgmt_tx->buff) {
+		kfree(mgmt_tx);
+		return -ENOMEM;
+	}
+
+	mgmt_tx->size = len;
+
+	wilc_wlan_txq_add_mgmt_pkt(dev, mgmt_tx, mgmt_tx->buff, mgmt_tx->size,
+				   mgmt_tx_complete);
+
+	netif_wake_queue(dev);
+	return 0;
+}
+
+static netdev_tx_t wilc_wfi_mon_xmit(struct sk_buff *skb,
+				     struct net_device *dev)
+{
+	u32 rtap_len, ret = 0;
+	struct wilc_wfi_mon_priv  *mon_priv;
+	struct sk_buff *skb2;
+	struct wilc_wfi_radiotap_cb_hdr *cb_hdr;
+
+	if (!wilc_wfi_mon)
+		return -EFAULT;
+
+	mon_priv = netdev_priv(wilc_wfi_mon);
+	if (!mon_priv)
+		return -EFAULT;
+	rtap_len = ieee80211_get_radiotap_len(skb->data);
+	if (skb->len < rtap_len)
+		return -1;
+
+	skb_pull(skb, rtap_len);
+
+	if (skb->data[0] == 0xc0 && is_broadcast_ether_addr(&skb->data[4])) {
+		skb2 = dev_alloc_skb(skb->len + sizeof(*cb_hdr));
+		if (!skb2)
+			return -ENOMEM;
+
+		skb_put_data(skb2, skb->data, skb->len);
+
+		cb_hdr = skb_push(skb2, sizeof(*cb_hdr));
+		memset(cb_hdr, 0, sizeof(struct wilc_wfi_radiotap_cb_hdr));
+
+		cb_hdr->hdr.it_version = 0; /* PKTHDR_RADIOTAP_VERSION; */
+
+		cb_hdr->hdr.it_len = cpu_to_le16(sizeof(*cb_hdr));
+
+		cb_hdr->hdr.it_present = cpu_to_le32(TX_RADIOTAP_PRESENT);
+
+		cb_hdr->rate = 5;
+		cb_hdr->tx_flags = 0x0004;
+
+		skb2->dev = wilc_wfi_mon;
+		skb_reset_mac_header(skb2);
+		skb2->ip_summed = CHECKSUM_UNNECESSARY;
+		skb2->pkt_type = PACKET_OTHERHOST;
+		skb2->protocol = htons(ETH_P_802_2);
+		memset(skb2->cb, 0, sizeof(skb2->cb));
+
+		netif_rx(skb2);
+
+		return 0;
+	}
+	skb->dev = mon_priv->real_ndev;
+
+	memcpy(srcadd, &skb->data[10], 6);
+	memcpy(bssid, &skb->data[16], 6);
+	/*
+	 * Identify if data or mgmt packet, if source address and bssid
+	 * fields are equal send it to mgmt frames handler
+	 */
+	if (!(memcmp(srcadd, bssid, 6))) {
+		ret = mon_mgmt_tx(mon_priv->real_ndev, skb->data, skb->len);
+		if (ret)
+			netdev_err(dev, "fail to mgmt tx\n");
+		dev_kfree_skb(skb);
+	} else {
+		ret = wilc_mac_xmit(skb, mon_priv->real_ndev);
+	}
+
+	return ret;
+}
+
+static const struct net_device_ops wilc_wfi_netdev_ops = {
+	.ndo_start_xmit         = wilc_wfi_mon_xmit,
+
+};
+
+struct net_device *wilc_wfi_init_mon_interface(const char *name,
+					       struct net_device *real_dev)
+{
+	struct wilc_wfi_mon_priv *priv;
+
+	/*If monitor interface is already initialized, return it*/
+	if (wilc_wfi_mon)
+		return wilc_wfi_mon;
+
+	wilc_wfi_mon = alloc_etherdev(sizeof(struct wilc_wfi_mon_priv));
+	if (!wilc_wfi_mon)
+		return NULL;
+	wilc_wfi_mon->type = ARPHRD_IEEE80211_RADIOTAP;
+	strncpy(wilc_wfi_mon->name, name, IFNAMSIZ);
+	wilc_wfi_mon->name[IFNAMSIZ - 1] = 0;
+	wilc_wfi_mon->netdev_ops = &wilc_wfi_netdev_ops;
+
+	if (register_netdevice(wilc_wfi_mon)) {
+		netdev_err(real_dev, "register_netdevice failed\n");
+		return NULL;
+	}
+	priv = netdev_priv(wilc_wfi_mon);
+	if (!priv)
+		return NULL;
+
+	priv->real_ndev = real_dev;
+
+	return wilc_wfi_mon;
+}
+
+void wilc_wfi_deinit_mon_interface(void)
+{
+	bool rollback_lock = false;
+
+	if (wilc_wfi_mon) {
+		if (rtnl_is_locked()) {
+			rtnl_unlock();
+			rollback_lock = true;
+		}
+		unregister_netdev(wilc_wfi_mon);
+
+		if (rollback_lock) {
+			rtnl_lock();
+			rollback_lock = false;
+		}
+		wilc_wfi_mon = NULL;
+	}
+}