driver_hostap.c

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#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include <errno.h>

#include "wireless_copy.h"
#include "common.h"
#include "driver.h"
#include "driver_wext.h"
#include "eloop.h"
#include "driver_hostap.h"
#include "l2_packet.h"
#include "wpa_supplicant.h"


struct wpa_driver_hostap_data {
        void *wext; /* private data for driver_wext */
        void *ctx;
        char ifname[IFNAMSIZ + 1];
        int sock;
        int current_mode; /* infra/adhoc */
};


static int hostapd_ioctl(struct wpa_driver_hostap_data *drv,
                         struct prism2_hostapd_param *param,
                         int len, int show_err)
{
        struct iwreq iwr;

        memset(&iwr, 0, sizeof(iwr));
        strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
        iwr.u.data.pointer = (caddr_t) param;
        iwr.u.data.length = len;

        if (ioctl(drv->sock, PRISM2_IOCTL_HOSTAPD, &iwr) < 0) {
                int ret = errno;
                if (show_err) 
                        perror("ioctl[PRISM2_IOCTL_HOSTAPD]");
                return ret;
        }

        return 0;
}


static int wpa_driver_hostap_set_wpa_ie(struct wpa_driver_hostap_data *drv,
                                        const u8 *wpa_ie, size_t wpa_ie_len)
{
        struct prism2_hostapd_param *param;
        int res;
        size_t blen = PRISM2_HOSTAPD_GENERIC_ELEMENT_HDR_LEN + wpa_ie_len;
        if (blen < sizeof(*param))
                blen = sizeof(*param);

        param = (struct prism2_hostapd_param *) malloc(blen);
        if (param == NULL)
                return -1;

        memset(param, 0, blen);
        param->cmd = PRISM2_HOSTAPD_SET_GENERIC_ELEMENT;
        param->u.generic_elem.len = wpa_ie_len;
        memcpy(param->u.generic_elem.data, wpa_ie, wpa_ie_len);
        res = hostapd_ioctl(drv, param, blen, 1);

        free(param);

        return res;
}


static int prism2param(struct wpa_driver_hostap_data *drv, int param,
                       int value)
{
        struct iwreq iwr;
        int *i, ret = 0;

        memset(&iwr, 0, sizeof(iwr));
        strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
        i = (int *) iwr.u.name;
        *i++ = param;
        *i++ = value;

        if (ioctl(drv->sock, PRISM2_IOCTL_PRISM2_PARAM, &iwr) < 0) {
                perror("ioctl[PRISM2_IOCTL_PRISM2_PARAM]");
                ret = -1;
        }
        return ret;
}


static int wpa_driver_hostap_set_wpa(void *priv, int enabled)
{
        struct wpa_driver_hostap_data *drv = priv;
        int ret = 0;

        wpa_printf(MSG_DEBUG, "%s: enabled=%d", __FUNCTION__, enabled);

        if (!enabled && wpa_driver_hostap_set_wpa_ie(drv, NULL, 0) < 0)
                ret = -1;
        if (prism2param(drv, PRISM2_PARAM_HOST_ROAMING, enabled ? 2 : 0) < 0)
                ret = -1;
        if (prism2param(drv, PRISM2_PARAM_WPA, enabled) < 0)
                ret = -1;

        return ret;
}


static void show_set_key_error(struct prism2_hostapd_param *param)
{
        switch (param->u.crypt.err) {
        case HOSTAP_CRYPT_ERR_UNKNOWN_ALG:
                wpa_printf(MSG_INFO, "Unknown algorithm '%s'.",
                           param->u.crypt.alg);
                wpa_printf(MSG_INFO, "You may need to load kernel module to "
                           "register that algorithm.");
                wpa_printf(MSG_INFO, "E.g., 'modprobe hostap_crypt_wep' for "
                           "WEP.");
                break;
        case HOSTAP_CRYPT_ERR_UNKNOWN_ADDR:
                wpa_printf(MSG_INFO, "Unknown address " MACSTR ".",
                           MAC2STR(param->sta_addr));
                break;
        case HOSTAP_CRYPT_ERR_CRYPT_INIT_FAILED:
                wpa_printf(MSG_INFO, "Crypt algorithm initialization failed.");
                break;
        case HOSTAP_CRYPT_ERR_KEY_SET_FAILED:
                wpa_printf(MSG_INFO, "Key setting failed.");
                break;
        case HOSTAP_CRYPT_ERR_TX_KEY_SET_FAILED:
                wpa_printf(MSG_INFO, "TX key index setting failed.");
                break;
        case HOSTAP_CRYPT_ERR_CARD_CONF_FAILED:
                wpa_printf(MSG_INFO, "Card configuration failed.");
                break;
        }
}


static int wpa_driver_hostap_set_key(void *priv, wpa_alg alg,
                                     const u8 *addr, int key_idx,
                                     int set_tx, const u8 *seq, size_t seq_len,
                                     const u8 *key, size_t key_len)
{
        struct wpa_driver_hostap_data *drv = priv;
        struct prism2_hostapd_param *param;
        u8 *buf;
        size_t blen;
        int ret = 0;
        char *alg_name;

        switch (alg) {
        case WPA_ALG_NONE:
                alg_name = "none";
                break;
        case WPA_ALG_WEP:
                alg_name = "WEP";
                break;
        case WPA_ALG_TKIP:
                alg_name = "TKIP";
                break;
        case WPA_ALG_CCMP:
                alg_name = "CCMP";
                break;
        default:
                return -1;
        }

        wpa_printf(MSG_DEBUG, "%s: alg=%s key_idx=%d set_tx=%d seq_len=%lu "
                   "key_len=%lu", __FUNCTION__, alg_name, key_idx, set_tx,
                   (unsigned long) seq_len, (unsigned long) key_len);

        if (seq_len > 8)
                return -2;

        blen = sizeof(*param) + key_len;
        buf = malloc(blen);
        if (buf == NULL)
                return -1;
        memset(buf, 0, blen);

        param = (struct prism2_hostapd_param *) buf;
        param->cmd = PRISM2_SET_ENCRYPTION;
        /* TODO: In theory, STA in client mode can use five keys; four default
         * keys for receiving (with keyidx 0..3) and one individual key for
         * both transmitting and receiving (keyidx 0) _unicast_ packets. Now,
         * keyidx 0 is reserved for this unicast use and default keys can only
         * use keyidx 1..3 (i.e., default key with keyidx 0 is not supported).
         * This should be fine for more or less all cases, but for completeness
         * sake, the driver could be enhanced to support the missing key. */
#if 0
        if (addr == NULL)
                memset(param->sta_addr, 0xff, ETH_ALEN);
        else
                memcpy(param->sta_addr, addr, ETH_ALEN);
#else
        memset(param->sta_addr, 0xff, ETH_ALEN);
#endif
        strncpy((char *) param->u.crypt.alg, alg_name,
                HOSTAP_CRYPT_ALG_NAME_LEN);
        param->u.crypt.flags = set_tx ? HOSTAP_CRYPT_FLAG_SET_TX_KEY : 0;
        param->u.crypt.idx = key_idx;
        memcpy(param->u.crypt.seq, seq, seq_len);
        param->u.crypt.key_len = key_len;
        memcpy((u8 *) (param + 1), key, key_len);

        if (hostapd_ioctl(drv, param, blen, 1)) {
                wpa_printf(MSG_WARNING, "Failed to set encryption.");
                show_set_key_error(param);
                ret = -1;
        }
        free(buf);

        return ret;
}


static int wpa_driver_hostap_set_countermeasures(void *priv, int enabled)
{
        struct wpa_driver_hostap_data *drv = priv;
        wpa_printf(MSG_DEBUG, "%s: enabled=%d", __FUNCTION__, enabled);
        return prism2param(drv, PRISM2_PARAM_TKIP_COUNTERMEASURES, enabled);
}


static int wpa_driver_hostap_set_drop_unencrypted(void *priv, int enabled)
{
        struct wpa_driver_hostap_data *drv = priv;
        wpa_printf(MSG_DEBUG, "%s: enabled=%d", __FUNCTION__, enabled);
        return prism2param(drv, PRISM2_PARAM_DROP_UNENCRYPTED, enabled);
}


static int wpa_driver_hostap_reset(struct wpa_driver_hostap_data *drv,
                                   int type)
{
        struct iwreq iwr;
        int *i, ret = 0;

        wpa_printf(MSG_DEBUG, "%s: type=%d", __FUNCTION__, type);

        memset(&iwr, 0, sizeof(iwr));
        strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
        i = (int *) iwr.u.name;
        *i++ = type;

        if (ioctl(drv->sock, PRISM2_IOCTL_RESET, &iwr) < 0) {
                perror("ioctl[PRISM2_IOCTL_RESET]");
                ret = -1;
        }
        return ret;
}


static int wpa_driver_hostap_mlme(struct wpa_driver_hostap_data *drv,
                                  const u8 *addr, int cmd, int reason_code)
{
        struct prism2_hostapd_param param;
        int ret;

        /* There does not seem to be a better way of deauthenticating or
         * disassociating with Prism2/2.5/3 than sending the management frame
         * and then resetting the Port0 to make sure both the AP and the STA
         * end up in disconnected state. */
        memset(&param, 0, sizeof(param));
        param.cmd = PRISM2_HOSTAPD_MLME;
        memcpy(param.sta_addr, addr, ETH_ALEN);
        param.u.mlme.cmd = cmd;
        param.u.mlme.reason_code = reason_code;
        ret = hostapd_ioctl(drv, &param, sizeof(param), 1);
        if (ret == 0) {
                usleep(100000);
                ret = wpa_driver_hostap_reset(drv, 2);
        }
        return ret;
}


static int wpa_driver_hostap_deauthenticate(void *priv, const u8 *addr,
                                            int reason_code)
{
        struct wpa_driver_hostap_data *drv = priv;
        wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);
        return wpa_driver_hostap_mlme(drv, addr, MLME_STA_DEAUTH,
                                      reason_code);
}


static int wpa_driver_hostap_disassociate(void *priv, const u8 *addr,
                                          int reason_code)
{
        struct wpa_driver_hostap_data *drv = priv;
        wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);
        return wpa_driver_hostap_mlme(drv, addr, MLME_STA_DISASSOC,
                                      reason_code);
}


static int
wpa_driver_hostap_associate(void *priv,
                            struct wpa_driver_associate_params *params)
{
        struct wpa_driver_hostap_data *drv = priv;
        int ret = 0;
        int allow_unencrypted_eapol;

        wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);

        if (params->mode != drv->current_mode) {
                /* At the moment, Host AP driver requires host_roaming=2 for
                 * infrastructure mode and host_roaming=0 for adhoc. */
                if (prism2param(drv, PRISM2_PARAM_HOST_ROAMING,
                                params->mode == IEEE80211_MODE_IBSS ? 0 : 2) <
                    0) {
                        wpa_printf(MSG_DEBUG, "%s: failed to set host_roaming",
                                   __func__);
                }
                drv->current_mode = params->mode;
        }

        if (prism2param(drv, PRISM2_PARAM_PRIVACY_INVOKED,
                        params->key_mgmt_suite != KEY_MGMT_NONE) < 0)
                ret = -1;
        if (wpa_driver_hostap_set_wpa_ie(drv, params->wpa_ie,
                                         params->wpa_ie_len) < 0)
                ret = -1;
        if (wpa_driver_wext_set_mode(drv->wext, params->mode) < 0)
                ret = -1;
        if (params->freq &&
            wpa_driver_wext_set_freq(drv->wext, params->freq) < 0)
                ret = -1;
        if (wpa_driver_wext_set_ssid(drv->wext, params->ssid, params->ssid_len)
            < 0)
                ret = -1;
        if (wpa_driver_wext_set_bssid(drv->wext, params->bssid) < 0)
                ret = -1;

        /* Allow unencrypted EAPOL messages even if pairwise keys are set when
         * not using WPA. IEEE 802.1X specifies that these frames are not
         * encrypted, but WPA encrypts them when pairwise keys are in use. */
        if (params->key_mgmt_suite == KEY_MGMT_802_1X ||
            params->key_mgmt_suite == KEY_MGMT_PSK)
                allow_unencrypted_eapol = 0;
        else
                allow_unencrypted_eapol = 1;
        
        if (prism2param(drv, PRISM2_PARAM_IEEE_802_1X,
                        allow_unencrypted_eapol) < 0) {
                wpa_printf(MSG_DEBUG, "hostap: Failed to configure "
                           "ieee_802_1x param");
                /* Ignore this error.. driver_hostap.c can also be used with
                 * other drivers that do not support this prism2_param. */
        }

        return ret;
}


static int wpa_driver_hostap_scan(void *priv, const u8 *ssid, size_t ssid_len)
{
        struct wpa_driver_hostap_data *drv = priv;
        struct prism2_hostapd_param param;
        int ret;

        if (ssid == NULL) {
                /* Use standard Linux Wireless Extensions ioctl if possible
                 * because some drivers using hostap code in wpa_supplicant
                 * might not support Host AP specific scan request (with SSID
                 * info). */
                return wpa_driver_wext_scan(drv->wext, ssid, ssid_len);
        }

        if (ssid_len > 32)
                ssid_len = 32;

        memset(&param, 0, sizeof(param));
        param.cmd = PRISM2_HOSTAPD_SCAN_REQ;
        param.u.scan_req.ssid_len = ssid_len;
        memcpy(param.u.scan_req.ssid, ssid, ssid_len);
        ret = hostapd_ioctl(drv, &param, sizeof(param), 1);

        /* Not all drivers generate "scan completed" wireless event, so try to
         * read results after a timeout. */
        eloop_register_timeout(3, 0, wpa_driver_wext_scan_timeout, drv->wext,
                               drv->ctx);

        return ret;
}


static int wpa_driver_hostap_set_auth_alg(void *priv, int auth_alg)
{
        struct wpa_driver_hostap_data *drv = priv;
        int algs = 0;

        if (auth_alg & AUTH_ALG_OPEN_SYSTEM)
                algs |= 1;
        if (auth_alg & AUTH_ALG_SHARED_KEY)
                algs |= 2;
        if (auth_alg & AUTH_ALG_LEAP)
                algs |= 4;
        if (algs == 0)
                algs = 1; /* at least one algorithm should be set */

        return prism2param(drv, PRISM2_PARAM_AP_AUTH_ALGS, algs);
}


static int wpa_driver_hostap_get_bssid(void *priv, u8 *bssid)
{
        struct wpa_driver_hostap_data *drv = priv;
        return wpa_driver_wext_get_bssid(drv->wext, bssid);
}


static int wpa_driver_hostap_get_ssid(void *priv, u8 *ssid)
{
        struct wpa_driver_hostap_data *drv = priv;
        return wpa_driver_wext_get_ssid(drv->wext, ssid);
}


static int wpa_driver_hostap_get_scan_results(void *priv,
                                              struct wpa_scan_result *results,
                                              size_t max_size)
{
        struct wpa_driver_hostap_data *drv = priv;
        return wpa_driver_wext_get_scan_results(drv->wext, results, max_size);
}


static void * wpa_driver_hostap_init(void *ctx, const char *ifname)
{
        struct wpa_driver_hostap_data *drv;

        drv = malloc(sizeof(*drv));
        if (drv == NULL)
                return NULL;
        memset(drv, 0, sizeof(*drv));
        drv->wext = wpa_driver_wext_init(ctx, ifname);
        if (drv->wext == NULL) {
                free(drv);
                return NULL;
        }

        drv->ctx = ctx;
        strncpy(drv->ifname, ifname, sizeof(drv->ifname));
        drv->sock = socket(PF_INET, SOCK_DGRAM, 0);
        if (drv->sock < 0) {
                perror("socket");
                wpa_driver_wext_deinit(drv->wext);
                free(drv);
                return NULL;
        }

        if (strncmp(ifname, "wlan", 4) == 0) {
                /*
                 * Host AP driver may use both wlan# and wifi# interface in
                 * wireless events.
                 */
                char ifname2[IFNAMSIZ + 1];
                strncpy(ifname2, ifname, sizeof(ifname2));
                memcpy(ifname2, "wifi", 4);
                wpa_driver_wext_alternative_ifindex(drv->wext, ifname2);
        }

        return drv;
}


static void wpa_driver_hostap_deinit(void *priv)
{
        struct wpa_driver_hostap_data *drv = priv;
        wpa_driver_wext_deinit(drv->wext);
        close(drv->sock);
        free(drv);
}


const struct wpa_driver_ops wpa_driver_hostap_ops = {
        .name = "hostap",
        .desc = "Host AP driver (Intersil Prism2/2.5/3)",
        .get_bssid = wpa_driver_hostap_get_bssid,
        .get_ssid = wpa_driver_hostap_get_ssid,
        .set_wpa = wpa_driver_hostap_set_wpa,
        .set_key = wpa_driver_hostap_set_key,
        .set_countermeasures = wpa_driver_hostap_set_countermeasures,
        .set_drop_unencrypted = wpa_driver_hostap_set_drop_unencrypted,
        .scan = wpa_driver_hostap_scan,
        .get_scan_results = wpa_driver_hostap_get_scan_results,
        .deauthenticate = wpa_driver_hostap_deauthenticate,
        .disassociate = wpa_driver_hostap_disassociate,
        .associate = wpa_driver_hostap_associate,
        .set_auth_alg = wpa_driver_hostap_set_auth_alg,
        .init = wpa_driver_hostap_init,
        .deinit = wpa_driver_hostap_deinit,
};

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