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vwifi.c
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#include <linux/etherdevice.h>
#include <linux/hashtable.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/random.h>
#include <linux/timer.h>
#include <linux/version.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ids.h>
#include <linux/workqueue.h>
#include <net/cfg80211.h>
#include <uapi/linux/virtio_net.h>
MODULE_LICENSE("Dual MIT/GPL");
MODULE_AUTHOR("National Cheng Kung University, Taiwan");
MODULE_DESCRIPTION("virtual cfg80211 driver");
#define NAME_PREFIX "owl"
#define NDEV_NAME NAME_PREFIX "%d"
#define DOT11_MGMT_HDR_LEN 24 /* d11 management header len */
#define DOT11_BCN_PRB_FIXED_LEN 12 /* beacon/probe fixed length */
#define MAX_PROBED_SSIDS 69
#define IE_MAX_LEN 512
#define SCAN_TIMEOUT_MS 100 /*< millisecond */
/* Note: owl_cipher_suites is an array of int defining which cipher suites
* are supported. A pointer to this array and the number of entries is passed
* on to upper layers.
*/
static const u32 owl_cipher_suites[] = {
WLAN_CIPHER_SUITE_WEP40,
WLAN_CIPHER_SUITE_WEP104,
WLAN_CIPHER_SUITE_TKIP,
WLAN_CIPHER_SUITE_CCMP,
};
struct owl_packet {
int datalen;
u8 data[ETH_DATA_LEN];
struct list_head list;
};
enum vwifi_state { OWL_READY, OWL_SHUTDOWN };
/* Context for the whole program, so there's only single owl_context
* regardless of the number of virtual interfaces. Fields in the structure
* are interface-independent.
*/
struct owl_context {
/* We may not need this lock because vif_list would not change during
* the whole lifetime.
*/
struct mutex lock;
enum vwifi_state state; /**< indicate the program state */
struct list_head vif_list; /**< maintaining all interfaces */
struct list_head ap_list; /**< maintaining multiple AP */
};
/* SME stands for "station management entity" */
enum sme_state { SME_DISCONNECTED, SME_CONNECTING, SME_CONNECTED };
/* Virtual interface pointed to by netdev_priv(). Fields in the structure are
* interface-dependent. Every interface has its own owl_vif, regardless of the
* interface mode (STA, AP, Ad-hoc...).
*/
struct owl_vif {
struct wireless_dev wdev;
struct net_device *ndev;
struct net_device_stats stats;
size_t ssid_len;
/* Currently connected BSS id */
u8 bssid[ETH_ALEN];
u8 ssid[IEEE80211_MAX_SSID_LEN];
struct list_head rx_queue; /**< Head of received packet queue */
/* Store all owl_vif which is in the same BSS (AP will be the head). */
struct list_head bss_list;
/* List entry for maintaining all owl_vif, which can be accessed via
* owl->vif_list.
*/
struct list_head list;
struct mutex lock;
/* Split logic for STA and AP mode */
union {
/* Structure for STA mode */
struct {
/* For the case the STA is going to roam to another BSS */
u8 req_ssid[IEEE80211_MAX_SSID_LEN];
struct cfg80211_scan_request *scan_request;
enum sme_state sme_state; /* connection information */
/* last connection time to a AP (in jiffies) */
unsigned long conn_time;
unsigned long active_time; /**< last tx/rx time (in jiffies) */
u16 disconnect_reason_code;
struct timer_list scan_timeout;
struct work_struct ws_connect, ws_disconnect;
struct work_struct ws_scan, ws_scan_timeout;
/* For quickly finding the AP */
struct owl_vif *ap;
};
/* Structure for AP mode */
struct {
bool ap_enabled;
bool privacy;
/* List node for storing AP (owl->ap_list is the head),
* this field is for interface in AP mode.
*/
struct list_head ap_list;
};
};
struct timer_list scan_complete;
u8 req_bssid[ETH_ALEN];
u32 beacon_ie_len;
u8 beacon_ie[IE_MAX_LEN];
/* Store all STAs in the same BSS, right now only used when virtio enabled
*/
DECLARE_HASHTABLE(bss_sta_table, 4);
/* Don't share the vif->lock because updating bss_sta_table may take a long
* time */
struct mutex bss_sta_table_lock;
u32 bss_sta_table_entry_num;
/* Packet virtio header size */
u8 vnet_hdr_len;
};
static int station = 2;
module_param(station, int, 0444);
MODULE_PARM_DESC(station, "Number of virtual interfaces running in STA mode.");
/* Global context */
static struct owl_context *owl = NULL;
/**
* enum virtio_vqs - queues for virtio frame transmission and receivement
*
* For virtio-net device, We expect 1 RX virtqueue followed by 1 TX virtqueue,
* followed by possible N-1 RX/TX queue pairs used in multiqueue mode, followed
* by possible control vq. For now, we don't support multiqueue mode virtio-net
* device and control vq as well, so there are only 1 RX vq and 1 TX vq.
*
* @VWIFI_VQ_TX: send frames to external entity
* @VWIFI_VQ_RX: receive frames
* @VWIFI_NUM_VQS: enum limit
*/
enum {
VWIFI_VQ_RX,
VWIFI_VQ_TX,
VWIFI_NUM_VQS,
};
static struct virtqueue *vwifi_vqs[VWIFI_NUM_VQS];
static bool vwifi_virtio_enabled;
static DEFINE_SPINLOCK(vwifi_virtio_lock);
static void vwifi_virtio_rx_work(struct work_struct *work);
static DECLARE_WORK(vwifi_virtio_rx, vwifi_virtio_rx_work);
/**
* enum VWIFI_VIRTIO_PACKET_TYPE - non-standard management frame type for VWIFI
*
* Most of these types are inspired by IEEE 802.11 management frame, with
* little modifications since we are sending Ethernet frames. And note that
* we send these management frame with the Ethertype/length field being
* length (i.e. 802.3 frames), so we can distinguish it from a data frame
* (Ethernet II).
*
* See struct vwifi_virtio_header for the VWIFI management frame structures.
* For future modifications, please ensure that the VWIFI management frame
* contains the needed informations consumed by cfg80211/nl80211.
*
* For the reason why we have the VWIFI_STA_ENTRY_REQUEST and
* VWIFI_STA_ENTRY_RESPONSE: There are three to four addresses in a normal
* 802.11 data frame, an STA can recognize whether the frame is for our BSS or
* not by looking at a specific address (ToDS/FromDS in the frame control
* determines the address layout). However, we get Ethernet frames from network
* stack (cfg80211 doesn't implement the 802.11 data TX path), and we don't
* convert it to IEEE 802.11 frame since we pretend ourself (vwifi) to be a
* virtio-net driver and would like to pass Ethernet frame to virtio-net device.
* So the VWIFI_STA_ENTRY_REQUEST and VWIFI_STA_ENTRY_RESPONSE comes to the
* rescue. After an STA has connected to an an AP, the STA will request the AP
* about the informations (currently only MAC address) of other STAs in the same
* BSS, and then store them in an STA entry table. Whenever an STA receives a
* data frame, it checks whether the source address in the Ethernet header is in
* its STA entry table, and only if the condition is true, the STA pass the
* frame into network stack.
*
* @VWIFI_SCAN_REQUEST: active scan, request AP to reveal its informations.
* @VWIFI_SCAN_RESPONSE: AP informs its informations to STA.
* @VWIFI_CONNECT_REQUEST: request a connection to an AP.
* @VWIFI_CONNECT_RESPONSE: inform the STA about the success of the connection,
* and AP will call cfg80211_add_sta() to inform
* hostapd. If the AP runs with WPA/WPA2 (STA knows it since the beacon_ies
* contains WPA/RSN IE), hostapd will then fire the 4-way handshake to change
* keys with the STA. Only until the 4-way handshake is done (we learn it from
* cfg80211->change_station()), the STA can start to exchange packets with other
* STAs in the same BSS.
* @VWIFI_DISCONNECT: inform the disconnection. This type can be sent by STA or
* AP.
* @VWIFI_STA_ENTRY_REQUEST: STA requests the connected AP for the STA entries
* in the same BSS.
* @VWIFI_STA_ENTRY_RESPONSE: There are two case:
* 1. AP reply the STA's request about the STA
* entries and the STA entries include all the STAs in the BSS.
* 2. An unsolicited VWIFI_STA_ENTRY_RESPONSE will be
* broadcasted by AP when an STA is connected or disconnected, so other STAs in
* the same BSS can update their STA entry table.
*/
enum VWIFI_VIRTIO_PACKET_TYPE {
VWIFI_SCAN_REQUEST,
VWIFI_SCAN_RESPONSE,
VWIFI_CONNECT_REQUEST,
VWIFI_CONNECT_RESPONSE,
VWIFI_DISCONNECT,
VWIFI_STA_ENTRY_REQUEST,
VWIFI_STA_ENTRY_RESPONSE,
};
struct vwifi_virtio_header {
__le16 type;
#define VWIFI_VIRTIO_HEADER_TYPE_BYTE 2
union {
struct vwifi_virtio_scan_req {
__le32 ssid_len;
u8 ssid[IEEE80211_MAX_SSID_LEN];
} __packed scan_req;
struct vwifi_virtio_scan_resp {
u8 bssid[ETH_ALEN];
__le64 timestamp;
__le16 beacon_int;
__le16 capab_info;
__le32 ssid_len;
u8 ssid[IEEE80211_MAX_SSID_LEN];
__le32 channel; /* center frquency */
__le32 beacon_ies_len;
u8 beacon_ies[];
} __packed scan_resp;
struct vwifi_virtio_conn_req {
u8 bssid[ETH_ALEN];
__le32 ssid_len;
u8 ssid[IEEE80211_MAX_SSID_LEN];
} __packed connect_req;
struct vwifi_virtio_conn_resp {
__le16 status_code;
__le16 capab_info;
} __packed connect_resp;
struct vwifi_virtio_disconn {
u8 bssid[ETH_ALEN];
__le16 reason_code;
} __packed disconn;
struct vwifi_virtio_sta_entry_resp {
u8 bssid[ETH_ALEN];
__le16 cmd;
__le32 count;
u8 macs[ETH_ALEN];
} __packed sta_entry_resp;
} u;
} __packed;
enum VWIFI_STA_ENTRY_CMD {
VWIFI_STA_ENTRY_ADD,
VWIFI_STA_ENTRY_ADD_ALL,
VWIFI_STA_ENTRY_DEL,
};
struct bss_sta_entry {
struct hlist_node node;
u8 mac[ETH_ALEN];
};
/* helper function to retrieve vif from net_device */
static inline struct owl_vif *ndev_get_owl_vif(struct net_device *ndev)
{
return (struct owl_vif *) netdev_priv(ndev);
}
/* helper function to retrieve vif from wireless_dev */
static inline struct owl_vif *wdev_get_owl_vif(struct wireless_dev *wdev)
{
return container_of(wdev, struct owl_vif, wdev);
}
static inline u32 vwifi_mac_to_32(const u8 *mac)
{
u32 h = 3323198485U;
for (int i = 0; i < ETH_ALEN; i++) {
h ^= *(mac + i);
h *= 0x5bd1e995;
h ^= h >> 15;
}
return h;
}
#define SIN_S3_MIN (-(1 << 12))
#define SIN_S3_MAX (1 << 12)
/* A sine approximation via a third-order approx.
* Refer to https://www.coranac.com/2009/07/sines for details about the
* algorithm. Some parameters have been adjusted to increase the frequency
* of the sine function.
* Note: __sin_s3() is intended for internal use by rand_int_smooth() and
* should not be called elsewhere.
*
* @x: seed to generate third-order sine value
* @return: signed 32-bit integer ranging from SIN_S3_MIN to SIN_S3_MAX
*/
static inline s32 __sin_s3(s32 x)
{
/* S(x) = (x * (3 * 2^p - (x * x)/2^r)) / 2^s
* @n: the angle scale
* @A: the amplitude
* @p: keep the multiplication from overflowing
*/
const int32_t n = 6, A = 12, p = 10, r = 2 * n - p, s = n + p + 1 - A;
x = x << (30 - n);
if ((x ^ (x << 1)) < 0)
x = (1 << 31) - x;
x = x >> (30 - n);
return (x * ((3 << p) - ((x * x) >> r))) >> s;
}
/* Generate a signed 32-bit integer by feeding the seed into __sin_s3().
* The distribution of (seed, rand_int_smooth()) is closer to a sine function
* when plotted.
*/
static inline s32 rand_int_smooth(s32 low, s32 up, s32 seed)
{
s32 result = __sin_s3(seed) - SIN_S3_MIN;
result = (result * (up - low)) / (SIN_S3_MAX - SIN_S3_MIN);
result += low;
return result;
}
/* Helper function that prepares a structure with self-defined BSS information
* and "informs" the kernel about the "new" BSS. Most of the code is copied from
* the upcoming inform_dummy_bss function.
*/
static void inform_bss(struct owl_vif *vif)
{
struct owl_vif *ap;
list_for_each_entry (ap, &owl->ap_list, ap_list) {
struct cfg80211_bss *bss = NULL;
struct cfg80211_inform_bss data = {
/* the only channel */
.chan = &ap->wdev.wiphy->bands[NL80211_BAND_2GHZ]->channels[0],
.scan_width = NL80211_BSS_CHAN_WIDTH_20,
.signal = DBM_TO_MBM(rand_int_smooth(-100, -30, jiffies)),
};
int capability = WLAN_CAPABILITY_ESS;
if (ap->privacy)
capability |= WLAN_CAPABILITY_PRIVACY;
pr_info("owl: %s performs scan, found %s (SSID: %s, BSSID: %pM)\n",
vif->ndev->name, ap->ndev->name, ap->ssid, ap->bssid);
pr_info("cap = %d, beacon_ie_len = %d\n", capability,
ap->beacon_ie_len);
/* Using the CLOCK_BOOTTIME clock, which remains unaffected by changes
* in the system time-of-day clock and includes any time that the
* system is suspended.
* This clock is suitable for synchronizing the machines in the BSS
* using tsf.
*/
u64 tsf = div_u64(ktime_get_boottime_ns(), 1000);
/* It is posible to use cfg80211_inform_bss() instead. */
bss = cfg80211_inform_bss_data(
vif->wdev.wiphy, &data, CFG80211_BSS_FTYPE_UNKNOWN, ap->bssid, tsf,
capability, 100, ap->beacon_ie, ap->beacon_ie_len, GFP_KERNEL);
/* cfg80211_inform_bss_data() returns cfg80211_bss structure referefence
* counter of which should be decremented if it is unused.
*/
cfg80211_put_bss(vif->wdev.wiphy, bss);
}
}
static void vwifi_virtio_fill_vq(struct virtqueue *vq, u8 vnet_hdr_len);
static int owl_ndo_open(struct net_device *dev)
{
struct owl_vif *vif = ndev_get_owl_vif(dev);
netif_start_queue(dev);
vwifi_virtio_fill_vq(vwifi_vqs[VWIFI_VQ_RX], vif->vnet_hdr_len);
return 0;
}
static int owl_ndo_stop(struct net_device *dev)
{
struct owl_vif *vif = ndev_get_owl_vif(dev);
struct owl_packet *pkt, *is = NULL;
list_for_each_entry_safe (pkt, is, &vif->rx_queue, list) {
list_del(&pkt->list);
kfree(pkt);
}
netif_stop_queue(dev);
return 0;
}
static struct net_device_stats *owl_ndo_get_stats(struct net_device *dev)
{
struct owl_vif *vif = ndev_get_owl_vif(dev);
return &vif->stats;
}
static netdev_tx_t owl_ndo_start_xmit(struct sk_buff *skb,
struct net_device *dev);
/* Receive a packet: retrieve, encapsulate it in an skb, and perform the
* following operations based on the interface mode:
* - STA mode: Pass the skb to the upper level (protocol stack).
* - AP mode: Perform the following operations based on the packet type:
* 1. Unicast: If the skb is intended for another STA, pass it to that
* STA and do not pass it to the protocol stack. If the skb is intended
* for the AP itself, pass it to the protocol stack.
* 2. Broadcast: Pass the skb to all other STAs except the source STA, and
* then pass it to the protocol stack.
* 3. Multicast: Perform the same operations as for broadcast.
*/
static void owl_rx(struct net_device *dev)
{
struct owl_vif *vif = ndev_get_owl_vif(dev);
/* socket buffer will be sended to protocol stack */
struct sk_buff *skb;
/* socket buffer will be transmitted to another STA */
struct sk_buff *skb1 = NULL;
struct owl_packet *pkt;
if (list_empty(&vif->rx_queue)) {
pr_info("owl rx: No packet in rx_queue\n");
return;
}
if (mutex_lock_interruptible(&vif->lock))
goto pkt_free;
pkt = list_first_entry(&vif->rx_queue, struct owl_packet, list);
vif->stats.rx_packets++;
vif->stats.rx_bytes += pkt->datalen;
vif->active_time = jiffies;
mutex_unlock(&vif->lock);
/* Put raw packet into socket buffer */
skb = dev_alloc_skb(pkt->datalen + 2);
if (!skb) {
pr_info("owl rx: low on mem - packet dropped\n");
vif->stats.rx_dropped++;
goto pkt_free;
}
skb_reserve(skb, 2); /* align IP address on 16B boundary */
memcpy(skb_put(skb, pkt->datalen), pkt->data, pkt->datalen);
list_del(&pkt->list);
kfree(pkt);
if (vif->wdev.iftype == NL80211_IFTYPE_AP) {
struct ethhdr *eth_hdr = (struct ethhdr *) skb->data;
/* When receiving a multicast/broadcast packet, it is sent to every
* STA except the source STA, and then passed to the protocol stack.
*/
if (is_multicast_ether_addr(eth_hdr->h_dest)) {
pr_info("owl: is_multicast_ether_addr\n");
skb1 = skb_copy(skb, GFP_KERNEL);
}
/* Receiving a unicast packet */
else {
/* The packet is not intended for the AP itself. Instead, it is
* sent to the destination STA and not passed to the protocol stack.
*/
if (!ether_addr_equal(eth_hdr->h_dest, vif->ndev->dev_addr)) {
skb1 = skb;
skb = NULL;
}
}
if (skb1) {
pr_info("owl: AP %s relay:\n", vif->ndev->name);
owl_ndo_start_xmit(skb1, vif->ndev);
}
/* Nothing to pass to protocol stack */
if (!skb)
return;
}
/* Pass the skb to protocol stack */
skb->dev = dev;
skb->protocol = eth_type_trans(skb, dev);
skb->ip_summed = CHECKSUM_UNNECESSARY; /* don't check it */
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 18, 0)
netif_rx_ni(skb);
#else
netif_rx(skb);
#endif
return;
pkt_free:
list_del(&pkt->list);
kfree(pkt);
}
static int __owl_ndo_start_xmit(struct owl_vif *vif,
struct owl_vif *dest_vif,
struct sk_buff *skb)
{
struct owl_packet *pkt = NULL;
struct ethhdr *eth_hdr = (struct ethhdr *) skb->data;
int datalen;
if (vif->wdev.iftype == NL80211_IFTYPE_STATION) {
pr_info("owl: STA %s (%pM) send packet to AP %s (%pM)\n",
vif->ndev->name, eth_hdr->h_source, dest_vif->ndev->name,
eth_hdr->h_dest);
} else if (vif->wdev.iftype == NL80211_IFTYPE_AP) {
pr_info("owl: AP %s (%pM) send packet to STA %s (%pM)\n",
vif->ndev->name, eth_hdr->h_source, dest_vif->ndev->name,
eth_hdr->h_dest);
}
pkt = kmalloc(sizeof(struct owl_packet), GFP_KERNEL);
if (!pkt) {
pr_info("Ran out of memory allocating packet pool\n");
return NETDEV_TX_OK;
}
datalen = skb->len;
memcpy(pkt->data, skb->data, datalen);
pkt->datalen = datalen;
/* enqueue packet to destination vif's rx_queue */
if (mutex_lock_interruptible(&dest_vif->lock))
goto error_before_rx_queue;
list_add_tail(&pkt->list, &dest_vif->rx_queue);
mutex_unlock(&dest_vif->lock);
if (mutex_lock_interruptible(&vif->lock))
goto erorr_after_rx_queue;
/* Update interface statistics */
vif->stats.tx_packets++;
vif->stats.tx_bytes += datalen;
vif->active_time = jiffies;
mutex_unlock(&vif->lock);
if (dest_vif->wdev.iftype == NL80211_IFTYPE_STATION) {
pr_info("owl: STA %s (%pM) receive packet from AP %s (%pM)\n",
dest_vif->ndev->name, eth_hdr->h_dest, vif->ndev->name,
eth_hdr->h_source);
} else if (dest_vif->wdev.iftype == NL80211_IFTYPE_AP) {
pr_info("owl: AP %s (%pM) receive packet from STA %s (%pM)\n",
dest_vif->ndev->name, eth_hdr->h_dest, vif->ndev->name,
eth_hdr->h_source);
}
/* Directly send to rx_queue, simulate the rx interrupt */
owl_rx(dest_vif->ndev);
return datalen;
erorr_after_rx_queue:
list_del(&pkt->list);
error_before_rx_queue:
kfree(pkt);
return 0;
}
static netdev_tx_t vwifi_virtio_tx(struct owl_vif *vif, struct sk_buff *skb);
/* Network packet transmit.
* Callback called by the kernel when packets need to be sent.
*/
static netdev_tx_t owl_ndo_start_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct owl_vif *vif = ndev_get_owl_vif(dev);
struct owl_vif *dest_vif = NULL;
struct ethhdr *eth_hdr = (struct ethhdr *) skb->data;
unsigned long flags;
int err;
int count = 0;
spin_lock_irqsave(&vwifi_virtio_lock, flags);
if (vwifi_virtio_enabled) {
spin_unlock_irqrestore(&vwifi_virtio_lock, flags);
err = vwifi_virtio_tx(vif, skb);
return err;
}
spin_unlock_irqrestore(&vwifi_virtio_lock, flags);
/* TX by interface of STA mode */
if (vif->wdev.iftype == NL80211_IFTYPE_STATION) {
if (vif->ap && vif->ap->ap_enabled) {
dest_vif = vif->ap;
if (__owl_ndo_start_xmit(vif, dest_vif, skb))
count++;
}
}
/* TX by interface of AP mode */
else if (vif->wdev.iftype == NL80211_IFTYPE_AP) {
/* Check if the packet is broadcasting */
if (is_broadcast_ether_addr(eth_hdr->h_dest)) {
list_for_each_entry (dest_vif, &vif->bss_list, bss_list) {
/* Don't send broadcast packet back to the source interface.
*/
if (ether_addr_equal(eth_hdr->h_source,
dest_vif->ndev->dev_addr))
continue;
if (__owl_ndo_start_xmit(vif, dest_vif, skb))
count++;
}
}
/* The packet is unicasting */
else {
list_for_each_entry (dest_vif, &vif->bss_list, bss_list) {
if (ether_addr_equal(eth_hdr->h_dest,
dest_vif->ndev->dev_addr)) {
if (__owl_ndo_start_xmit(vif, dest_vif, skb))
count++;
break;
}
}
}
}
if (!count)
vif->stats.tx_dropped++;
/* Don't forget to cleanup skb, as its ownership moved to xmit callback. */
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
/* Structure of functions for network devices.
* It should have at least ndo_start_xmit functions called for packet to be
* sent.
*/
static struct net_device_ops owl_ndev_ops = {
.ndo_open = owl_ndo_open,
.ndo_stop = owl_ndo_stop,
.ndo_start_xmit = owl_ndo_start_xmit,
.ndo_get_stats = owl_ndo_get_stats,
};
/* Inform the "dummy" BSS to kernel and call cfg80211_scan_done() to finish
* scan.
*/
static void owl_scan_timeout_work(struct work_struct *w)
{
struct owl_vif *vif = container_of(w, struct owl_vif, ws_scan_timeout);
struct cfg80211_scan_info info = {
/* if scan was aborted by user (calling cfg80211_ops->abort_scan) or by
* any driver/hardware issue - field should be set to "true"
*/
.aborted = false,
};
/* inform with dummy BSS */
inform_bss(vif);
if (mutex_lock_interruptible(&vif->lock))
return;
/* finish scan */
cfg80211_scan_done(vif->scan_request, &info);
vif->scan_request = NULL;
mutex_unlock(&vif->lock);
}
/* Callback called when the scan timer timeouts. This function just schedules
* the timeout work and offloads the job of informing "dummy" BSS to kernel
* onto it.
*/
static void owl_scan_timeout(struct timer_list *t)
{
struct owl_vif *vif = container_of(t, struct owl_vif, scan_timeout);
if (vif->scan_request)
schedule_work(&vif->ws_scan_timeout);
}
static void vwifi_virtio_scan_request(struct owl_vif *vif);
/* Scan routine. It simulates a fake BSS scan (in fact, it does nothing) and
* sets a scan timer to start from then. Once the timer timeouts, the timeout
* routine owl_scan_timeout() will be invoked. This routine schedules a timeout
* work that informs the kernel about the "dummy" BSS and completes the scan.
*/
static void owl_scan_routine(struct work_struct *w)
{
struct owl_vif *vif = container_of(w, struct owl_vif, ws_scan);
unsigned long flags;
spin_lock_irqsave(&vwifi_virtio_lock, flags);
if (vwifi_virtio_enabled) {
spin_unlock_irqrestore(&vwifi_virtio_lock, flags);
vwifi_virtio_scan_request(vif);
return;
}
spin_unlock_irqrestore(&vwifi_virtio_lock, flags);
/* In a real-world driver, BSS scanning would occur here. However, in the
* case of viwifi, scanning is not performed because dummy BSS entries are
* already stored in the SSID hash table. Instead, a scan timeout is set
* after a specific number of jiffies. The timeout worker informs the
* kernel about the "dummy" BSS and calls cfg80211_scan_done() to complete
* the scan.
*/
mod_timer(&vif->scan_timeout, jiffies + msecs_to_jiffies(SCAN_TIMEOUT_MS));
}
static void vwifi_virtio_connect_request(struct owl_vif *vif);
static void owl_connect_routine(struct work_struct *w)
{
struct owl_vif *vif = container_of(w, struct owl_vif, ws_connect);
struct owl_vif *ap = NULL;
struct station_info *sinfo;
unsigned long flags;
spin_lock_irqsave(&vwifi_virtio_lock, flags);
if (vwifi_virtio_enabled) {
spin_unlock_irqrestore(&vwifi_virtio_lock, flags);
vwifi_virtio_connect_request(vif);
return;
}
spin_unlock_irqrestore(&vwifi_virtio_lock, flags);
if (mutex_lock_interruptible(&vif->lock))
return;
/* Finding the AP by request SSID */
list_for_each_entry (ap, &owl->ap_list, ap_list) {
if (!memcmp(ap->ssid, vif->req_ssid, ap->ssid_len)) {
pr_info("owl: %s is connected to AP %s (SSID: %s, BSSID: %pM)\n",
vif->ndev->name, ap->ndev->name, ap->ssid, ap->bssid);
if (mutex_lock_interruptible(&ap->lock))
return;
/* AP connection part */
sinfo = kmalloc(sizeof(struct station_info), GFP_KERNEL);
if (!sinfo)
return;
/* It is safe that we fake the association request IEs
* by beacon IEs, since they both possibly have the WPA/RSN IE
* which is what the upper user-space program (e.g. hostapd)
* cares about.
*/
sinfo->assoc_req_ies = ap->beacon_ie;
sinfo->assoc_req_ies_len = ap->beacon_ie_len;
list_add_tail(&vif->bss_list, &ap->bss_list);
/* nl80211 will inform the user-space program (e.g. hostapd)
* about the newly-associated station via generic netlink
* command NL80211_CMD_NEW_STATION for latter processing
* (e.g. 4-way handshake).
*/
cfg80211_new_sta(ap->ndev, vif->ndev->dev_addr, sinfo, GFP_KERNEL);
mutex_unlock(&ap->lock);
/* STA conneciton part */
cfg80211_connect_result(vif->ndev, ap->bssid, NULL, 0, NULL, 0,
WLAN_STATUS_SUCCESS, GFP_KERNEL);
memcpy(vif->ssid, ap->ssid, ap->ssid_len);
memcpy(vif->bssid, ap->bssid, ETH_ALEN);
vif->sme_state = SME_CONNECTED;
vif->conn_time = jiffies;
vif->ap = ap;
mutex_unlock(&vif->lock);
kfree(sinfo);
return;
}
}
/* SSID not found */
pr_info("owl: SSID %s not found\n", vif->req_ssid);
cfg80211_connect_timeout(vif->ndev, NULL, NULL, 0, GFP_KERNEL,
NL80211_TIMEOUT_SCAN);
vif->sme_state = SME_DISCONNECTED;
mutex_unlock(&vif->lock);
}
static void vwifi_virtio_disconnect(struct owl_vif *vif);
/* Invoke cfg80211_disconnected() that informs the kernel that disconnect is
* complete. Overall disconnect may call cfg80211_connect_timeout() if
* disconnect interrupting connection routine, but for this module let's keep
* it simple as possible. This routine is called through workqueue, when the
* kernel asks to disconnect through cfg80211_ops.
*/
static void owl_disconnect_routine(struct work_struct *w)
{
struct owl_vif *vif = container_of(w, struct owl_vif, ws_disconnect);
unsigned long flags;
spin_lock_irqsave(&vwifi_virtio_lock, flags);
if (vwifi_virtio_enabled) {
spin_unlock_irqrestore(&vwifi_virtio_lock, flags);
vwifi_virtio_disconnect(vif);
return;
}
spin_unlock_irqrestore(&vwifi_virtio_lock, flags);
pr_info("owl: %s disconnected from AP %s\n", vif->ndev->name,
vif->ap->ndev->name);
if (mutex_lock_interruptible(&vif->lock))
return;
/* STA cleanup stuff */
cfg80211_disconnected(vif->ndev, vif->disconnect_reason_code, NULL, 0, true,
GFP_KERNEL);
vif->disconnect_reason_code = 0;
vif->sme_state = SME_DISCONNECTED;
/* AP cleanup stuff */
if (owl->state != OWL_SHUTDOWN) {
if (mutex_lock_interruptible(&vif->ap->lock)) {
mutex_unlock(&vif->lock);
return;
}
if (vif->ap->ap_enabled && !list_empty(&vif->bss_list)) {
cfg80211_del_sta(vif->ap->ndev, vif->ndev->dev_addr, GFP_KERNEL);
list_del(&vif->bss_list);
}
mutex_unlock(&vif->ap->lock);
vif->ap = NULL;
}
mutex_unlock(&vif->lock);
}
/* callback called by the kernel when user decided to scan.
* This callback should initiate scan routine(through work_struct) and exit with
* 0 if everything is ok.
*/
static int owl_scan(struct wiphy *wiphy, struct cfg80211_scan_request *request)
{
struct owl_vif *vif = wdev_get_owl_vif(request->wdev);
if (mutex_lock_interruptible(&vif->lock))
return -ERESTARTSYS;
if (vif->scan_request) {
mutex_unlock(&vif->lock);
return -EBUSY;
}
if (vif->wdev.iftype == NL80211_IFTYPE_AP) {
mutex_unlock(&vif->lock);
return -EPERM;
}
vif->scan_request = request;
mutex_unlock(&vif->lock);
if (!schedule_work(&vif->ws_scan))
return -EBUSY;
return 0;
}
/* callback called by the kernel when there is need to "connect" to some
* network. It initializes connection routine through work_struct and exits
* with 0 if everything is ok. connect routine should be finished with
* cfg80211_connect_bss()/cfg80211_connect_result()/cfg80211_connect_done() or
* cfg80211_connect_timeout().
*/
static int owl_connect(struct wiphy *wiphy,
struct net_device *dev,
struct cfg80211_connect_params *sme)
{
struct owl_vif *vif = ndev_get_owl_vif(dev);
if (mutex_lock_interruptible(&vif->lock))
return -ERESTARTSYS;
if (vif->sme_state != SME_DISCONNECTED) {
mutex_unlock(&vif->lock);
return -EBUSY;
}
if (vif->wdev.iftype == NL80211_IFTYPE_AP) {
mutex_unlock(&vif->lock);
return -EPERM;
}
vif->sme_state = SME_CONNECTING;
vif->ssid_len = sme->ssid_len;
memcpy(vif->req_ssid, sme->ssid, sme->ssid_len);
memcpy(vif->req_bssid, sme->bssid, ETH_ALEN);
mutex_unlock(&vif->lock);
if (!schedule_work(&vif->ws_connect))
return -EBUSY;
return 0;
}
/* callback called by the kernel when there is need to "diconnect" from
* currently connected network. It initializes disconnect routine through
* work_struct and exits with 0 if everything ok. disconnect routine should
* call cfg80211_disconnected() to inform the kernel that disconnection is
* complete.
*/
static int owl_disconnect(struct wiphy *wiphy,
struct net_device *dev,
u16 reason_code)
{
struct owl_vif *vif = ndev_get_owl_vif(dev);
if (mutex_lock_interruptible(&vif->lock))
return -ERESTARTSYS;
if (vif->sme_state == SME_DISCONNECTED) {
mutex_unlock(&vif->lock);
return -EINVAL;
}
if (vif->wdev.iftype == NL80211_IFTYPE_AP) {
mutex_unlock(&vif->lock);
return -EPERM;
}
vif->disconnect_reason_code = reason_code;
mutex_unlock(&vif->lock);
if (!schedule_work(&vif->ws_disconnect))
return -EBUSY;
return 0;
}
/* Callback called by the kernel when the user requests information about
* a specific station. The information includes the number and bytes of
* transmitted and received packets, signal strength, and timing information
* such as inactive time and elapsed time since the last connection to an AP.
* This callback is invoked when the rtnl lock has been acquired.
*/
static int owl_get_station(struct wiphy *wiphy,
struct net_device *dev,
const u8 *mac,
struct station_info *sinfo)
{
struct owl_vif *vif = ndev_get_owl_vif(dev);
bool found_sta = false;
switch (dev->ieee80211_ptr->iftype) {
case NL80211_IFTYPE_AP:;
struct owl_vif *sta_vif = NULL;