nl80211: Replace SIOCGIWSCAN with NL80211_CMD_GET_SCAN
authorJouni Malinen <jouni.malinen@atheros.com>
Thu, 12 Feb 2009 15:12:58 +0000 (17:12 +0200)
committerJouni Malinen <j@w1.fi>
Thu, 12 Feb 2009 18:19:33 +0000 (20:19 +0200)
This replaces the WEXT mechanism for fetching scan results with the new
nl80211 mechanism.

src/drivers/driver_nl80211.c

index 3c682ef..801016b 100644 (file)
@@ -1552,336 +1552,76 @@ nla_put_failure:
 }
 
 
-static u8 * wpa_driver_nl80211_giwscan(struct wpa_driver_nl80211_data *drv,
-                                   size_t *len)
+static int bss_info_handler(struct nl_msg *msg, void *arg)
 {
-       struct iwreq iwr;
-       u8 *res_buf;
-       size_t res_buf_len;
-
-       res_buf_len = IW_SCAN_MAX_DATA;
-       for (;;) {
-               res_buf = os_malloc(res_buf_len);
-               if (res_buf == NULL)
-                       return NULL;
-               os_memset(&iwr, 0, sizeof(iwr));
-               os_strlcpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
-               iwr.u.data.pointer = res_buf;
-               iwr.u.data.length = res_buf_len;
-
-               if (ioctl(drv->ioctl_sock, SIOCGIWSCAN, &iwr) == 0)
-                       break;
-
-               if (errno == E2BIG && res_buf_len < 65535) {
-                       os_free(res_buf);
-                       res_buf = NULL;
-                       res_buf_len *= 2;
-                       if (res_buf_len > 65535)
-                               res_buf_len = 65535; /* 16-bit length field */
-                       wpa_printf(MSG_DEBUG, "Scan results did not fit - "
-                                  "trying larger buffer (%lu bytes)",
-                                  (unsigned long) res_buf_len);
-               } else {
-                       perror("ioctl[SIOCGIWSCAN]");
-                       os_free(res_buf);
-                       return NULL;
-               }
-       }
-
-       if (iwr.u.data.length > res_buf_len) {
-               os_free(res_buf);
-               return NULL;
-       }
-       *len = iwr.u.data.length;
-
-       return res_buf;
-}
-
-
-/*
- * Data structure for collecting WEXT scan results. This is needed to allow
- * the various methods of reporting IEs to be combined into a single IE buffer.
- */
-struct wext_scan_data {
-       struct wpa_scan_res res;
-       u8 *ie;
+       struct nlattr *tb[NL80211_ATTR_MAX + 1];
+       struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+       struct nlattr *bss[NL80211_BSS_MAX + 1];
+       static struct nla_policy bss_policy[NL80211_BSS_MAX + 1] = {
+               [NL80211_BSS_BSSID] = { .type = NLA_UNSPEC },
+               [NL80211_BSS_FREQUENCY] = { .type = NLA_U32 },
+               [NL80211_BSS_TSF] = { .type = NLA_U64 },
+               [NL80211_BSS_BEACON_INTERVAL] = { .type = NLA_U16 },
+               [NL80211_BSS_CAPABILITY] = { .type = NLA_U16 },
+               [NL80211_BSS_INFORMATION_ELEMENTS] = { .type = NLA_UNSPEC },
+               [NL80211_BSS_SIGNAL_MBM] = { .type = NLA_U32 },
+               [NL80211_BSS_SIGNAL_UNSPEC] = { .type = NLA_U8 },
+       };
+       struct wpa_scan_results *res = arg;
+       struct wpa_scan_res **tmp;
+       struct wpa_scan_res *r;
+       const u8 *ie;
        size_t ie_len;
-       u8 ssid[32];
-       size_t ssid_len;
-       int maxrate;
-};
-
-
-static void wext_get_scan_mode(struct iw_event *iwe,
-                              struct wext_scan_data *res)
-{
-       if (iwe->u.mode == IW_MODE_ADHOC)
-               res->res.caps |= IEEE80211_CAP_IBSS;
-       else if (iwe->u.mode == IW_MODE_MASTER || iwe->u.mode == IW_MODE_INFRA)
-               res->res.caps |= IEEE80211_CAP_ESS;
-}
-
-
-static void wext_get_scan_ssid(struct iw_event *iwe,
-                              struct wext_scan_data *res, char *custom,
-                              char *end)
-{
-       int ssid_len = iwe->u.essid.length;
-       if (custom + ssid_len > end)
-               return;
-       if (iwe->u.essid.flags &&
-           ssid_len > 0 &&
-           ssid_len <= IW_ESSID_MAX_SIZE) {
-               os_memcpy(res->ssid, custom, ssid_len);
-               res->ssid_len = ssid_len;
-       }
-}
-
-
-static void wext_get_scan_freq(struct iw_event *iwe,
-                              struct wext_scan_data *res)
-{
-       int divi = 1000000, i;
-
-       if (iwe->u.freq.e == 0) {
-               /*
-                * Some drivers do not report frequency, but a channel.
-                * Try to map this to frequency by assuming they are using
-                * IEEE 802.11b/g.  But don't overwrite a previously parsed
-                * frequency if the driver sends both frequency and channel,
-                * since the driver may be sending an A-band channel that we
-                * don't handle here.
-                */
-
-               if (res->res.freq)
-                       return;
-
-               if (iwe->u.freq.m >= 1 && iwe->u.freq.m <= 13) {
-                       res->res.freq = 2407 + 5 * iwe->u.freq.m;
-                       return;
-               } else if (iwe->u.freq.m == 14) {
-                       res->res.freq = 2484;
-                       return;
-               }
-       }
-
-       if (iwe->u.freq.e > 6) {
-               wpa_printf(MSG_DEBUG, "Invalid freq in scan results (BSSID="
-                          MACSTR " m=%d e=%d)",
-                          MAC2STR(res->res.bssid), iwe->u.freq.m,
-                          iwe->u.freq.e);
-               return;
-       }
-
-       for (i = 0; i < iwe->u.freq.e; i++)
-               divi /= 10;
-       res->res.freq = iwe->u.freq.m / divi;
-}
-
-
-static void wext_get_scan_qual(struct iw_event *iwe,
-                              struct wext_scan_data *res)
-{
-       res->res.qual = iwe->u.qual.qual;
-       res->res.noise = iwe->u.qual.noise;
-       res->res.level = iwe->u.qual.level;
-}
-
-
-static void wext_get_scan_encode(struct iw_event *iwe,
-                                struct wext_scan_data *res)
-{
-       if (!(iwe->u.data.flags & IW_ENCODE_DISABLED))
-               res->res.caps |= IEEE80211_CAP_PRIVACY;
-}
-
-
-static void wext_get_scan_rate(struct iw_event *iwe,
-                              struct wext_scan_data *res, char *pos,
-                              char *end)
-{
-       int maxrate;
-       char *custom = pos + IW_EV_LCP_LEN;
-       struct iw_param p;
-       size_t clen;
-
-       clen = iwe->len;
-       if (custom + clen > end)
-               return;
-       maxrate = 0;
-       while (((ssize_t) clen) >= (ssize_t) sizeof(struct iw_param)) {
-               /* Note: may be misaligned, make a local, aligned copy */
-               os_memcpy(&p, custom, sizeof(struct iw_param));
-               if (p.value > maxrate)
-                       maxrate = p.value;
-               clen -= sizeof(struct iw_param);
-               custom += sizeof(struct iw_param);
-       }
-
-       /* Convert the maxrate from WE-style (b/s units) to
-        * 802.11 rates (500000 b/s units).
-        */
-       res->maxrate = maxrate / 500000;
-}
-
-
-static void wext_get_scan_iwevgenie(struct iw_event *iwe,
-                                   struct wext_scan_data *res, char *custom,
-                                   char *end)
-{
-       char *genie, *gpos, *gend;
-       u8 *tmp;
 
-       if (iwe->u.data.length == 0)
-               return;
-
-       gpos = genie = custom;
-       gend = genie + iwe->u.data.length;
-       if (gend > end) {
-               wpa_printf(MSG_INFO, "IWEVGENIE overflow");
-               return;
-       }
-
-       tmp = os_realloc(res->ie, res->ie_len + gend - gpos);
-       if (tmp == NULL)
-               return;
-       os_memcpy(tmp + res->ie_len, gpos, gend - gpos);
-       res->ie = tmp;
-       res->ie_len += gend - gpos;
-}
-
-
-static void wext_get_scan_custom(struct iw_event *iwe,
-                                struct wext_scan_data *res, char *custom,
-                                char *end)
-{
-       size_t clen;
-       u8 *tmp;
-
-       clen = iwe->u.data.length;
-       if (custom + clen > end)
-               return;
-
-       if (clen > 7 && os_strncmp(custom, "wpa_ie=", 7) == 0) {
-               char *spos;
-               int bytes;
-               spos = custom + 7;
-               bytes = custom + clen - spos;
-               if (bytes & 1 || bytes == 0)
-                       return;
-               bytes /= 2;
-               tmp = os_realloc(res->ie, res->ie_len + bytes);
-               if (tmp == NULL)
-                       return;
-               hexstr2bin(spos, tmp + res->ie_len, bytes);
-               res->ie = tmp;
-               res->ie_len += bytes;
-       } else if (clen > 7 && os_strncmp(custom, "rsn_ie=", 7) == 0) {
-               char *spos;
-               int bytes;
-               spos = custom + 7;
-               bytes = custom + clen - spos;
-               if (bytes & 1 || bytes == 0)
-                       return;
-               bytes /= 2;
-               tmp = os_realloc(res->ie, res->ie_len + bytes);
-               if (tmp == NULL)
-                       return;
-               hexstr2bin(spos, tmp + res->ie_len, bytes);
-               res->ie = tmp;
-               res->ie_len += bytes;
-       } else if (clen > 4 && os_strncmp(custom, "tsf=", 4) == 0) {
-               char *spos;
-               int bytes;
-               u8 bin[8];
-               spos = custom + 4;
-               bytes = custom + clen - spos;
-               if (bytes != 16) {
-                       wpa_printf(MSG_INFO, "Invalid TSF length (%d)", bytes);
-                       return;
-               }
-               bytes /= 2;
-               hexstr2bin(spos, bin, bytes);
-               res->res.tsf += WPA_GET_BE64(bin);
+       nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
+                 genlmsg_attrlen(gnlh, 0), NULL);
+       if (!tb[NL80211_ATTR_BSS])
+               return NL_SKIP;
+       if (nla_parse_nested(bss, NL80211_BSS_MAX, tb[NL80211_ATTR_BSS],
+                            bss_policy))
+               return NL_SKIP;
+       if (bss[NL80211_BSS_INFORMATION_ELEMENTS]) {
+               ie = nla_data(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
+               ie_len = nla_len(bss[NL80211_BSS_INFORMATION_ELEMENTS]);
+       } else {
+               ie = NULL;
+               ie_len = 0;
        }
-}
 
-
-static int wext_19_iw_point(struct wpa_driver_nl80211_data *drv, u16 cmd)
-{
-       return drv->we_version_compiled > 18 &&
-               (cmd == SIOCGIWESSID || cmd == SIOCGIWENCODE ||
-                cmd == IWEVGENIE || cmd == IWEVCUSTOM);
-}
-
-
-static void wpa_driver_nl80211_add_scan_entry(struct wpa_scan_results *res,
-                                          struct wext_scan_data *data)
-{
-       struct wpa_scan_res **tmp;
-       struct wpa_scan_res *r;
-       size_t extra_len;
-       u8 *pos, *end, *ssid_ie = NULL, *rate_ie = NULL;
-
-       /* Figure out whether we need to fake any IEs */
-       pos = data->ie;
-       end = pos + data->ie_len;
-       while (pos && pos + 1 < end) {
-               if (pos + 2 + pos[1] > end)
-                       break;
-               if (pos[0] == WLAN_EID_SSID)
-                       ssid_ie = pos;
-               else if (pos[0] == WLAN_EID_SUPP_RATES)
-                       rate_ie = pos;
-               else if (pos[0] == WLAN_EID_EXT_SUPP_RATES)
-                       rate_ie = pos;
-               pos += 2 + pos[1];
-       }
-
-       extra_len = 0;
-       if (ssid_ie == NULL)
-               extra_len += 2 + data->ssid_len;
-       if (rate_ie == NULL && data->maxrate)
-               extra_len += 3;
-
-       r = os_zalloc(sizeof(*r) + extra_len + data->ie_len);
+       r = os_zalloc(sizeof(*r) + ie_len);
        if (r == NULL)
-               return;
-       os_memcpy(r, &data->res, sizeof(*r));
-       r->ie_len = extra_len + data->ie_len;
-       pos = (u8 *) (r + 1);
-       if (ssid_ie == NULL) {
-               /*
-                * Generate a fake SSID IE since the driver did not report
-                * a full IE list.
-                */
-               *pos++ = WLAN_EID_SSID;
-               *pos++ = data->ssid_len;
-               os_memcpy(pos, data->ssid, data->ssid_len);
-               pos += data->ssid_len;
-       }
-       if (rate_ie == NULL && data->maxrate) {
-               /*
-                * Generate a fake Supported Rates IE since the driver did not
-                * report a full IE list.
-                */
-               *pos++ = WLAN_EID_SUPP_RATES;
-               *pos++ = 1;
-               *pos++ = data->maxrate;
-       }
-       if (data->ie)
-               os_memcpy(pos, data->ie, data->ie_len);
+               return NL_SKIP;
+       if (bss[NL80211_BSS_BSSID])
+               os_memcpy(r->bssid, nla_data(bss[NL80211_BSS_BSSID]),
+                         ETH_ALEN);
+       if (bss[NL80211_BSS_FREQUENCY])
+               r->freq = nla_get_u32(bss[NL80211_BSS_FREQUENCY]);
+       if (bss[NL80211_BSS_BEACON_INTERVAL])
+               r->beacon_int = nla_get_u16(bss[NL80211_BSS_BEACON_INTERVAL]);
+       if (bss[NL80211_BSS_CAPABILITY])
+               r->caps = nla_get_u16(bss[NL80211_BSS_CAPABILITY]);
+       if (bss[NL80211_BSS_SIGNAL_UNSPEC])
+               r->qual = nla_get_u8(bss[NL80211_BSS_SIGNAL_UNSPEC]);
+       if (bss[NL80211_BSS_SIGNAL_MBM])
+               r->level = nla_get_u32(bss[NL80211_BSS_SIGNAL_MBM]);
+       if (bss[NL80211_BSS_TSF])
+               r->tsf = nla_get_u64(bss[NL80211_BSS_TSF]);
+       r->ie_len = ie_len;
+       if (ie)
+               os_memcpy(r + 1, ie, ie_len);
 
        tmp = os_realloc(res->res,
                         (res->num + 1) * sizeof(struct wpa_scan_res *));
        if (tmp == NULL) {
                os_free(r);
-               return;
+               return NL_SKIP;
        }
        tmp[res->num++] = r;
        res->res = tmp;
+
+       return NL_SKIP;
 }
-                                     
+
 
 /**
  * wpa_driver_nl80211_get_scan_results - Fetch the latest scan results
@@ -1892,98 +1632,34 @@ static struct wpa_scan_results *
 wpa_driver_nl80211_get_scan_results(void *priv)
 {
        struct wpa_driver_nl80211_data *drv = priv;
-       size_t ap_num = 0, len;
-       int first;
-       u8 *res_buf;
-       struct iw_event iwe_buf, *iwe = &iwe_buf;
-       char *pos, *end, *custom;
+       struct nl_msg *msg;
        struct wpa_scan_results *res;
-       struct wext_scan_data data;
-
-       res_buf = wpa_driver_nl80211_giwscan(drv, &len);
-       if (res_buf == NULL)
-               return NULL;
-
-       ap_num = 0;
-       first = 1;
+       int ret;
 
        res = os_zalloc(sizeof(*res));
-       if (res == NULL) {
-               os_free(res_buf);
-               return NULL;
-       }
-
-       pos = (char *) res_buf;
-       end = (char *) res_buf + len;
-       os_memset(&data, 0, sizeof(data));
-
-       while (pos + IW_EV_LCP_LEN <= end) {
-               /* Event data may be unaligned, so make a local, aligned copy
-                * before processing. */
-               os_memcpy(&iwe_buf, pos, IW_EV_LCP_LEN);
-               if (iwe->len <= IW_EV_LCP_LEN)
-                       break;
-
-               custom = pos + IW_EV_POINT_LEN;
-               if (wext_19_iw_point(drv, iwe->cmd)) {
-                       /* WE-19 removed the pointer from struct iw_point */
-                       char *dpos = (char *) &iwe_buf.u.data.length;
-                       int dlen = dpos - (char *) &iwe_buf;
-                       os_memcpy(dpos, pos + IW_EV_LCP_LEN,
-                                 sizeof(struct iw_event) - dlen);
-               } else {
-                       os_memcpy(&iwe_buf, pos, sizeof(struct iw_event));
-                       custom += IW_EV_POINT_OFF;
-               }
+       if (res == NULL)
+               return 0;
+       msg = nlmsg_alloc();
+       if (!msg)
+               goto nla_put_failure;
 
-               switch (iwe->cmd) {
-               case SIOCGIWAP:
-                       if (!first)
-                               wpa_driver_nl80211_add_scan_entry(res, &data);
-                       first = 0;
-                       os_free(data.ie);
-                       os_memset(&data, 0, sizeof(data));
-                       os_memcpy(data.res.bssid,
-                                 iwe->u.ap_addr.sa_data, ETH_ALEN);
-                       break;
-               case SIOCGIWMODE:
-                       wext_get_scan_mode(iwe, &data);
-                       break;
-               case SIOCGIWESSID:
-                       wext_get_scan_ssid(iwe, &data, custom, end);
-                       break;
-               case SIOCGIWFREQ:
-                       wext_get_scan_freq(iwe, &data);
-                       break;
-               case IWEVQUAL:
-                       wext_get_scan_qual(iwe, &data);
-                       break;
-               case SIOCGIWENCODE:
-                       wext_get_scan_encode(iwe, &data);
-                       break;
-               case SIOCGIWRATE:
-                       wext_get_scan_rate(iwe, &data, pos, end);
-                       break;
-               case IWEVGENIE:
-                       wext_get_scan_iwevgenie(iwe, &data, custom, end);
-                       break;
-               case IWEVCUSTOM:
-                       wext_get_scan_custom(iwe, &data, custom, end);
-                       break;
-               }
+       genlmsg_put(msg, 0, 0, genl_family_get_id(drv->nl80211), 0, NLM_F_DUMP,
+                   NL80211_CMD_GET_SCAN, 0);
+       NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
 
-               pos += iwe->len;
+       ret = send_and_recv_msgs(drv, msg, bss_info_handler, res);
+       msg = NULL;
+       if (ret == 0) {
+               wpa_printf(MSG_DEBUG, "Received scan results (%lu BSSes)",
+                          (unsigned long) res->num);
+               return res;
        }
-       os_free(res_buf);
-       res_buf = NULL;
-       if (!first)
-               wpa_driver_nl80211_add_scan_entry(res, &data);
-       os_free(data.ie);
-
-       wpa_printf(MSG_DEBUG, "Received %lu bytes of scan results (%lu BSSes)",
-                  (unsigned long) len, (unsigned long) res->num);
-
-       return res;
+       wpa_printf(MSG_DEBUG, "nl80211: Scan result fetch failed: ret=%d "
+                  "(%s)", ret, strerror(-ret));
+nla_put_failure:
+       nlmsg_free(msg);
+       wpa_scan_results_free(res);
+       return NULL;
 }