hostap_info.c

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/* Host AP driver Info Frame processing (part of hostap.o module) */

#include <linux/if_arp.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/etherdevice.h>
#include "hostap_wlan.h"
#include "hostap.h"
#include "hostap_ap.h"

/* Called only as a tasklet (software IRQ) */
static void prism2_info_commtallies16(local_info_t *local, unsigned char *buf,
                      int left)
{
    struct hfa384x_comm_tallies *tallies;

    if (left < sizeof(struct hfa384x_comm_tallies)) {
        printk(KERN_DEBUG "%s: too short (len=%d) commtallies "
               "info frame\n", local->dev->name, left);
        return;
    }

    tallies = (struct hfa384x_comm_tallies *) buf;
#define ADD_COMM_TALLIES(name) \
local->comm_tallies.name += le16_to_cpu(tallies->name)
    ADD_COMM_TALLIES(tx_unicast_frames);
    ADD_COMM_TALLIES(tx_multicast_frames);
    ADD_COMM_TALLIES(tx_fragments);
    ADD_COMM_TALLIES(tx_unicast_octets);
    ADD_COMM_TALLIES(tx_multicast_octets);
    ADD_COMM_TALLIES(tx_deferred_transmissions);
    ADD_COMM_TALLIES(tx_single_retry_frames);
    ADD_COMM_TALLIES(tx_multiple_retry_frames);
    ADD_COMM_TALLIES(tx_retry_limit_exceeded);
    ADD_COMM_TALLIES(tx_discards);
    ADD_COMM_TALLIES(rx_unicast_frames);
    ADD_COMM_TALLIES(rx_multicast_frames);
    ADD_COMM_TALLIES(rx_fragments);
    ADD_COMM_TALLIES(rx_unicast_octets);
    ADD_COMM_TALLIES(rx_multicast_octets);
    ADD_COMM_TALLIES(rx_fcs_errors);
    ADD_COMM_TALLIES(rx_discards_no_buffer);
    ADD_COMM_TALLIES(tx_discards_wrong_sa);
    ADD_COMM_TALLIES(rx_discards_wep_undecryptable);
    ADD_COMM_TALLIES(rx_message_in_msg_fragments);
    ADD_COMM_TALLIES(rx_message_in_bad_msg_fragments);
#undef ADD_COMM_TALLIES
}


/* Called only as a tasklet (software IRQ) */
static void prism2_info_commtallies32(local_info_t *local, unsigned char *buf,
                      int left)
{
    struct hfa384x_comm_tallies32 *tallies;

    if (left < sizeof(struct hfa384x_comm_tallies32)) {
        printk(KERN_DEBUG "%s: too short (len=%d) commtallies32 "
               "info frame\n", local->dev->name, left);
        return;
    }

    tallies = (struct hfa384x_comm_tallies32 *) buf;
#define ADD_COMM_TALLIES(name) \
local->comm_tallies.name += le32_to_cpu(tallies->name)
    ADD_COMM_TALLIES(tx_unicast_frames);
    ADD_COMM_TALLIES(tx_multicast_frames);
    ADD_COMM_TALLIES(tx_fragments);
    ADD_COMM_TALLIES(tx_unicast_octets);
    ADD_COMM_TALLIES(tx_multicast_octets);
    ADD_COMM_TALLIES(tx_deferred_transmissions);
    ADD_COMM_TALLIES(tx_single_retry_frames);
    ADD_COMM_TALLIES(tx_multiple_retry_frames);
    ADD_COMM_TALLIES(tx_retry_limit_exceeded);
    ADD_COMM_TALLIES(tx_discards);
    ADD_COMM_TALLIES(rx_unicast_frames);
    ADD_COMM_TALLIES(rx_multicast_frames);
    ADD_COMM_TALLIES(rx_fragments);
    ADD_COMM_TALLIES(rx_unicast_octets);
    ADD_COMM_TALLIES(rx_multicast_octets);
    ADD_COMM_TALLIES(rx_fcs_errors);
    ADD_COMM_TALLIES(rx_discards_no_buffer);
    ADD_COMM_TALLIES(tx_discards_wrong_sa);
    ADD_COMM_TALLIES(rx_discards_wep_undecryptable);
    ADD_COMM_TALLIES(rx_message_in_msg_fragments);
    ADD_COMM_TALLIES(rx_message_in_bad_msg_fragments);
#undef ADD_COMM_TALLIES
}


/* Called only as a tasklet (software IRQ) */
static void prism2_info_commtallies(local_info_t *local, unsigned char *buf,
                    int left)
{
    if (local->tallies32)
        prism2_info_commtallies32(local, buf, left);
    else
        prism2_info_commtallies16(local, buf, left);
}


#ifndef PRISM2_NO_STATION_MODES
#ifndef PRISM2_NO_DEBUG
static const char* hfa384x_linkstatus_str(u16 linkstatus)
{
    switch (linkstatus) {
    case HFA384X_LINKSTATUS_CONNECTED:
        return "Connected";
    case HFA384X_LINKSTATUS_DISCONNECTED:
        return "Disconnected";
    case HFA384X_LINKSTATUS_AP_CHANGE:
        return "Access point change";
    case HFA384X_LINKSTATUS_AP_OUT_OF_RANGE:
        return "Access point out of range";
    case HFA384X_LINKSTATUS_AP_IN_RANGE:
        return "Access point in range";
    case HFA384X_LINKSTATUS_ASSOC_FAILED:
        return "Association failed";
    default:
        return "Unknown";
    }
}
#endif /* PRISM2_NO_DEBUG */


/* Called only as a tasklet (software IRQ) */
static void prism2_info_linkstatus(local_info_t *local, unsigned char *buf,
                    int left)
{
    u16 val;
    int non_sta_mode;

    /* Alloc new JoinRequests to occur since LinkStatus for the previous
     * has been received */
    local->last_join_time = 0;

    if (left != 2) {
        printk(KERN_DEBUG "%s: invalid linkstatus info frame "
               "length %d\n", local->dev->name, left);
        return;
    }

    non_sta_mode = local->iw_mode == IW_MODE_MASTER ||
        local->iw_mode == IW_MODE_REPEAT ||
        local->iw_mode == IW_MODE_MONITOR;

    val = buf[0] | (buf[1] << 8);
    if (!non_sta_mode || val != HFA384X_LINKSTATUS_DISCONNECTED) {
        PDEBUG(DEBUG_EXTRA, "%s: LinkStatus=%d (%s)\n",
               local->dev->name, val, hfa384x_linkstatus_str(val));
    }

    if (non_sta_mode) {
        netif_carrier_on(local->dev);
        netif_carrier_on(local->ddev);
        return;
    }

    /* Get current BSSID later in scheduled task */
    set_bit(PRISM2_INFO_PENDING_LINKSTATUS, &local->pending_info);
    local->prev_link_status = val;
    schedule_work(&local->info_queue);
}


static void prism2_host_roaming(local_info_t *local)
{
    struct hfa384x_join_request req;
    struct net_device *dev = local->dev;
    struct hfa384x_hostscan_result *selected, *entry;
    int i;
    unsigned long flags;

    if (local->last_join_time &&
        time_before(jiffies, local->last_join_time + 10 * HZ)) {
        PDEBUG(DEBUG_EXTRA, "%s: last join request has not yet been "
               "completed - waiting for it before issuing new one\n",
               dev->name);
        return;
    }

    /* ScanResults are sorted: first ESS results in decreasing signal
     * quality then IBSS results in similar order.
     * Trivial roaming policy: just select the first entry.
     * This could probably be improved by adding hysteresis to limit
     * number of handoffs, etc.
     *
     * Could do periodic RID_SCANREQUEST or Inquire F101 to get new
     * ScanResults */
    spin_lock_irqsave(&local->lock, flags);
    if (local->last_scan_results == NULL ||
        local->last_scan_results_count == 0) {
        spin_unlock_irqrestore(&local->lock, flags);
        PDEBUG(DEBUG_EXTRA, "%s: no scan results for host roaming\n",
               dev->name);
        return;
    }

    selected = &local->last_scan_results[0];

    if (local->preferred_ap[0] || local->preferred_ap[1] ||
        local->preferred_ap[2] || local->preferred_ap[3] ||
        local->preferred_ap[4] || local->preferred_ap[5]) {
        /* Try to find preferred AP */
        PDEBUG(DEBUG_EXTRA, "%s: Preferred AP BSSID %pM\n",
               dev->name, local->preferred_ap);
        for (i = 0; i < local->last_scan_results_count; i++) {
            entry = &local->last_scan_results[i];
            if (memcmp(local->preferred_ap, entry->bssid, 6) == 0)
            {
                PDEBUG(DEBUG_EXTRA, "%s: using preferred AP "
                       "selection\n", dev->name);
                selected = entry;
                break;
            }
        }
    }

    memcpy(req.bssid, selected->bssid, 6);
    req.channel = selected->chid;
    spin_unlock_irqrestore(&local->lock, flags);

    PDEBUG(DEBUG_EXTRA, "%s: JoinRequest: BSSID=%pM"
           " channel=%d\n",
           dev->name, req.bssid, le16_to_cpu(req.channel));
    if (local->func->set_rid(dev, HFA384X_RID_JOINREQUEST, &req,
                 sizeof(req))) {
        printk(KERN_DEBUG "%s: JoinRequest failed\n", dev->name);
    }
    local->last_join_time = jiffies;
}


static void hostap_report_scan_complete(local_info_t *local)
{
    union iwreq_data wrqu;

    /* Inform user space about new scan results (just empty event,
     * SIOCGIWSCAN can be used to fetch data */
    wrqu.data.length = 0;
    wrqu.data.flags = 0;
    wireless_send_event(local->dev, SIOCGIWSCAN, &wrqu, NULL);

    /* Allow SIOCGIWSCAN handling to occur since we have received
     * scanning result */
    local->scan_timestamp = 0;
}


/* Called only as a tasklet (software IRQ) */
static void prism2_info_scanresults(local_info_t *local, unsigned char *buf,
                    int left)
{
    u16 *pos;
    int new_count, i;
    unsigned long flags;
    struct hfa384x_scan_result *res;
    struct hfa384x_hostscan_result *results, *prev;

    if (left < 4) {
        printk(KERN_DEBUG "%s: invalid scanresult info frame "
               "length %d\n", local->dev->name, left);
        return;
    }

    pos = (u16 *) buf;
    pos++;
    pos++;
    left -= 4;

    new_count = left / sizeof(struct hfa384x_scan_result);
    results = kmalloc(new_count * sizeof(struct hfa384x_hostscan_result),
              GFP_ATOMIC);
    if (results == NULL)
        return;

    /* Convert to hostscan result format. */
    res = (struct hfa384x_scan_result *) pos;
    for (i = 0; i < new_count; i++) {
        memcpy(&results[i], &res[i],
               sizeof(struct hfa384x_scan_result));
        results[i].atim = 0;
    }

    spin_lock_irqsave(&local->lock, flags);
    local->last_scan_type = PRISM2_SCAN;
    prev = local->last_scan_results;
    local->last_scan_results = results;
    local->last_scan_results_count = new_count;
    spin_unlock_irqrestore(&local->lock, flags);
    kfree(prev);

    hostap_report_scan_complete(local);

    /* Perform rest of ScanResults handling later in scheduled task */
    set_bit(PRISM2_INFO_PENDING_SCANRESULTS, &local->pending_info);
    schedule_work(&local->info_queue);
}


/* Called only as a tasklet (software IRQ) */
static void prism2_info_hostscanresults(local_info_t *local,
                    unsigned char *buf, int left)
{
    int i, result_size, copy_len, new_count;
    struct hfa384x_hostscan_result *results, *prev;
    unsigned long flags;
    __le16 *pos;
    u8 *ptr;

    wake_up_interruptible(&local->hostscan_wq);

    if (left < 4) {
        printk(KERN_DEBUG "%s: invalid hostscanresult info frame "
               "length %d\n", local->dev->name, left);
        return;
    }

    pos = (__le16 *) buf;
    copy_len = result_size = le16_to_cpu(*pos);
    if (result_size == 0) {
        printk(KERN_DEBUG "%s: invalid result_size (0) in "
               "hostscanresults\n", local->dev->name);
        return;
    }
    if (copy_len > sizeof(struct hfa384x_hostscan_result))
        copy_len = sizeof(struct hfa384x_hostscan_result);

    pos++;
    pos++;
    left -= 4;
    ptr = (u8 *) pos;

    new_count = left / result_size;
    results = kcalloc(new_count, sizeof(struct hfa384x_hostscan_result),
              GFP_ATOMIC);
    if (results == NULL)
        return;

    for (i = 0; i < new_count; i++) {
        memcpy(&results[i], ptr, copy_len);
        ptr += result_size;
        left -= result_size;
    }

    if (left) {
        printk(KERN_DEBUG "%s: short HostScan result entry (%d/%d)\n",
               local->dev->name, left, result_size);
    }

    spin_lock_irqsave(&local->lock, flags);
    local->last_scan_type = PRISM2_HOSTSCAN;
    prev = local->last_scan_results;
    local->last_scan_results = results;
    local->last_scan_results_count = new_count;
    spin_unlock_irqrestore(&local->lock, flags);
    kfree(prev);

    hostap_report_scan_complete(local);
}
#endif /* PRISM2_NO_STATION_MODES */


/* Called only as a tasklet (software IRQ) */
void hostap_info_process(local_info_t *local, struct sk_buff *skb)
{
    struct hfa384x_info_frame *info;
    unsigned char *buf;
    int left;
#ifndef PRISM2_NO_DEBUG
    int i;
#endif /* PRISM2_NO_DEBUG */

    info = (struct hfa384x_info_frame *) skb->data;
    buf = skb->data + sizeof(*info);
    left = skb->len - sizeof(*info);

    switch (le16_to_cpu(info->type)) {
    case HFA384X_INFO_COMMTALLIES:
        prism2_info_commtallies(local, buf, left);
        break;

#ifndef PRISM2_NO_STATION_MODES
    case HFA384X_INFO_LINKSTATUS:
        prism2_info_linkstatus(local, buf, left);
        break;

    case HFA384X_INFO_SCANRESULTS:
        prism2_info_scanresults(local, buf, left);
        break;

    case HFA384X_INFO_HOSTSCANRESULTS:
        prism2_info_hostscanresults(local, buf, left);
        break;
#endif /* PRISM2_NO_STATION_MODES */

#ifndef PRISM2_NO_DEBUG
    default:
        PDEBUG(DEBUG_EXTRA, "%s: INFO - len=%d type=0x%04x\n",
               local->dev->name, le16_to_cpu(info->len),
               le16_to_cpu(info->type));
        PDEBUG(DEBUG_EXTRA, "Unknown info frame:");
        for (i = 0; i < (left < 100 ? left : 100); i++)
            PDEBUG2(DEBUG_EXTRA, " %02x", buf[i]);
        PDEBUG2(DEBUG_EXTRA, "\n");
        break;
#endif /* PRISM2_NO_DEBUG */
    }
}


#ifndef PRISM2_NO_STATION_MODES
static void handle_info_queue_linkstatus(local_info_t *local)
{
    int val = local->prev_link_status;
    int connected;
    union iwreq_data wrqu;

    connected =
        val == HFA384X_LINKSTATUS_CONNECTED ||
        val == HFA384X_LINKSTATUS_AP_CHANGE ||
        val == HFA384X_LINKSTATUS_AP_IN_RANGE;

    if (local->func->get_rid(local->dev, HFA384X_RID_CURRENTBSSID,
                 local->bssid, ETH_ALEN, 1) < 0) {
        printk(KERN_DEBUG "%s: could not read CURRENTBSSID after "
               "LinkStatus event\n", local->dev->name);
    } else {
        PDEBUG(DEBUG_EXTRA, "%s: LinkStatus: BSSID=%pM\n",
               local->dev->name,
               (unsigned char *) local->bssid);
        if (local->wds_type & HOSTAP_WDS_AP_CLIENT)
            hostap_add_sta(local->ap, local->bssid);
    }

    /* Get BSSID if we have a valid AP address */
    if (connected) {
        netif_carrier_on(local->dev);
        netif_carrier_on(local->ddev);
        memcpy(wrqu.ap_addr.sa_data, local->bssid, ETH_ALEN);
    } else {
        netif_carrier_off(local->dev);
        netif_carrier_off(local->ddev);
        memset(wrqu.ap_addr.sa_data, 0, ETH_ALEN);
    }
    wrqu.ap_addr.sa_family = ARPHRD_ETHER;

    /*
     * Filter out sequential disconnect events in order not to cause a
     * flood of SIOCGIWAP events that have a race condition with EAPOL
     * frames and can confuse wpa_supplicant about the current association
     * status.
     */
    if (connected || local->prev_linkstatus_connected)
        wireless_send_event(local->dev, SIOCGIWAP, &wrqu, NULL);
    local->prev_linkstatus_connected = connected;
}


static void handle_info_queue_scanresults(local_info_t *local)
{
    if (local->host_roaming == 1 && local->iw_mode == IW_MODE_INFRA)
        prism2_host_roaming(local);

    if (local->host_roaming == 2 && local->iw_mode == IW_MODE_INFRA &&
        !is_zero_ether_addr(local->preferred_ap)) {
        /*
         * Firmware seems to be getting into odd state in host_roaming
         * mode 2 when hostscan is used without join command, so try
         * to fix this by re-joining the current AP. This does not
         * actually trigger a new association if the current AP is
         * still in the scan results.
         */
        prism2_host_roaming(local);
    }
}


/* Called only as scheduled task after receiving info frames (used to avoid
 * pending too much time in HW IRQ handler). */
static void handle_info_queue(struct work_struct *work)
{
    local_info_t *local = container_of(work, local_info_t, info_queue);

    if (test_and_clear_bit(PRISM2_INFO_PENDING_LINKSTATUS,
                   &local->pending_info))
        handle_info_queue_linkstatus(local);

    if (test_and_clear_bit(PRISM2_INFO_PENDING_SCANRESULTS,
                   &local->pending_info))
        handle_info_queue_scanresults(local);
}
#endif /* PRISM2_NO_STATION_MODES */


void hostap_info_init(local_info_t *local)
{
    skb_queue_head_init(&local->info_list);
#ifndef PRISM2_NO_STATION_MODES
    INIT_WORK(&local->info_queue, handle_info_queue);
#endif /* PRISM2_NO_STATION_MODES */
}


EXPORT_SYMBOL(hostap_info_init);
EXPORT_SYMBOL(hostap_info_process);