/* * hostapd / IEEE 802.11 Management: Beacon and Probe Request/Response * Copyright (c) 2002-2004, Instant802 Networks, Inc. * Copyright (c) 2005-2006, Devicescape Software, Inc. * Copyright (c) 2008-2009, Jouni Malinen * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Alternatively, this software may be distributed under the terms of BSD * license. * * See README and COPYING for more details. */ #include "utils/includes.h" #ifndef CONFIG_NATIVE_WINDOWS #include "utils/common.h" #include "common/ieee802_11_defs.h" #include "common/ieee802_11_common.h" #include "drivers/driver.h" #include "wps/wps_defs.h" #include "p2p/p2p.h" #include "hostapd.h" #include "ieee802_11.h" #include "wpa_auth.h" #include "wmm.h" #include "ap_config.h" #include "sta_info.h" #include "p2p_hostapd.h" #include "ap_drv_ops.h" #include "beacon.h" #ifdef NEED_AP_MLME static u8 ieee802_11_erp_info(struct hostapd_data *hapd) { u8 erp = 0; if (hapd->iface->current_mode == NULL || hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G) return 0; switch (hapd->iconf->cts_protection_type) { case CTS_PROTECTION_FORCE_ENABLED: erp |= ERP_INFO_NON_ERP_PRESENT | ERP_INFO_USE_PROTECTION; break; case CTS_PROTECTION_FORCE_DISABLED: erp = 0; break; case CTS_PROTECTION_AUTOMATIC: if (hapd->iface->olbc) erp |= ERP_INFO_USE_PROTECTION; /* continue */ case CTS_PROTECTION_AUTOMATIC_NO_OLBC: if (hapd->iface->num_sta_non_erp > 0) { erp |= ERP_INFO_NON_ERP_PRESENT | ERP_INFO_USE_PROTECTION; } break; } if (hapd->iface->num_sta_no_short_preamble > 0 || hapd->iconf->preamble == LONG_PREAMBLE) erp |= ERP_INFO_BARKER_PREAMBLE_MODE; return erp; } static u8 * hostapd_eid_ds_params(struct hostapd_data *hapd, u8 *eid) { *eid++ = WLAN_EID_DS_PARAMS; *eid++ = 1; *eid++ = hapd->iconf->channel; return eid; } static u8 * hostapd_eid_erp_info(struct hostapd_data *hapd, u8 *eid) { if (hapd->iface->current_mode == NULL || hapd->iface->current_mode->mode != HOSTAPD_MODE_IEEE80211G) return eid; /* Set NonERP_present and use_protection bits if there * are any associated NonERP stations. */ /* TODO: use_protection bit can be set to zero even if * there are NonERP stations present. This optimization * might be useful if NonERP stations are "quiet". * See 802.11g/D6 E-1 for recommended practice. * In addition, Non ERP present might be set, if AP detects Non ERP * operation on other APs. */ /* Add ERP Information element */ *eid++ = WLAN_EID_ERP_INFO; *eid++ = 1; *eid++ = ieee802_11_erp_info(hapd); return eid; } static u8 * hostapd_eid_country_add(u8 *pos, u8 *end, int chan_spacing, struct hostapd_channel_data *start, struct hostapd_channel_data *prev) { if (end - pos < 3) return pos; /* first channel number */ *pos++ = start->chan; /* number of channels */ *pos++ = (prev->chan - start->chan) / chan_spacing + 1; /* maximum transmit power level */ *pos++ = start->max_tx_power; return pos; } static u8 * hostapd_eid_country(struct hostapd_data *hapd, u8 *eid, int max_len) { u8 *pos = eid; u8 *end = eid + max_len; int i; struct hostapd_hw_modes *mode; struct hostapd_channel_data *start, *prev; int chan_spacing = 1; if (!hapd->iconf->ieee80211d || max_len < 6 || hapd->iface->current_mode == NULL) return eid; *pos++ = WLAN_EID_COUNTRY; pos++; /* length will be set later */ os_memcpy(pos, hapd->iconf->country, 3); /* e.g., 'US ' */ pos += 3; mode = hapd->iface->current_mode; if (mode->mode == HOSTAPD_MODE_IEEE80211A) chan_spacing = 4; start = prev = NULL; for (i = 0; i < mode->num_channels; i++) { struct hostapd_channel_data *chan = &mode->channels[i]; if (chan->flag & HOSTAPD_CHAN_DISABLED) continue; if (start && prev && prev->chan + chan_spacing == chan->chan && start->max_tx_power == chan->max_tx_power) { prev = chan; continue; /* can use same entry */ } if (start) { pos = hostapd_eid_country_add(pos, end, chan_spacing, start, prev); start = NULL; } /* Start new group */ start = prev = chan; } if (start) { pos = hostapd_eid_country_add(pos, end, chan_spacing, start, prev); } if ((pos - eid) & 1) { if (end - pos < 1) return eid; *pos++ = 0; /* pad for 16-bit alignment */ } eid[1] = (pos - eid) - 2; return pos; } static u8 * hostapd_eid_wpa(struct hostapd_data *hapd, u8 *eid, size_t len) { const u8 *ie; size_t ielen; ie = wpa_auth_get_wpa_ie(hapd->wpa_auth, &ielen); if (ie == NULL || ielen > len) return eid; os_memcpy(eid, ie, ielen); return eid + ielen; } void handle_probe_req(struct hostapd_data *hapd, const struct ieee80211_mgmt *mgmt, size_t len) { struct ieee80211_mgmt *resp; struct ieee802_11_elems elems; char *ssid; u8 *pos, *epos; const u8 *ie; size_t ssid_len, ie_len; struct sta_info *sta = NULL; size_t buflen; size_t i; ie = mgmt->u.probe_req.variable; if (len < IEEE80211_HDRLEN + sizeof(mgmt->u.probe_req)) return; ie_len = len - (IEEE80211_HDRLEN + sizeof(mgmt->u.probe_req)); for (i = 0; hapd->probereq_cb && i < hapd->num_probereq_cb; i++) if (hapd->probereq_cb[i].cb(hapd->probereq_cb[i].ctx, mgmt->sa, mgmt->da, mgmt->bssid, ie, ie_len) > 0) return; if (!hapd->iconf->send_probe_response) return; if (ieee802_11_parse_elems(ie, ie_len, &elems, 0) == ParseFailed) { wpa_printf(MSG_DEBUG, "Could not parse ProbeReq from " MACSTR, MAC2STR(mgmt->sa)); return; } ssid = NULL; ssid_len = 0; if ((!elems.ssid || !elems.supp_rates)) { wpa_printf(MSG_DEBUG, "STA " MACSTR " sent probe request " "without SSID or supported rates element", MAC2STR(mgmt->sa)); return; } #ifdef CONFIG_P2P if (hapd->p2p && elems.wps_ie) { struct wpabuf *wps; wps = ieee802_11_vendor_ie_concat(ie, ie_len, WPS_DEV_OUI_WFA); if (wps && !p2p_group_match_dev_type(hapd->p2p_group, wps)) { wpa_printf(MSG_MSGDUMP, "P2P: Ignore Probe Request " "due to mismatch with Requested Device " "Type"); wpabuf_free(wps); return; } wpabuf_free(wps); } #endif /* CONFIG_P2P */ if (hapd->conf->ignore_broadcast_ssid && elems.ssid_len == 0) { wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR " for " "broadcast SSID ignored", MAC2STR(mgmt->sa)); return; } sta = ap_get_sta(hapd, mgmt->sa); #ifdef CONFIG_P2P if ((hapd->conf->p2p & P2P_GROUP_OWNER) && elems.ssid_len == P2P_WILDCARD_SSID_LEN && os_memcmp(elems.ssid, P2P_WILDCARD_SSID, P2P_WILDCARD_SSID_LEN) == 0) { /* Process P2P Wildcard SSID like Wildcard SSID */ elems.ssid_len = 0; } #endif /* CONFIG_P2P */ if (elems.ssid_len == 0 || (elems.ssid_len == hapd->conf->ssid.ssid_len && os_memcmp(elems.ssid, hapd->conf->ssid.ssid, elems.ssid_len) == 0)) { ssid = hapd->conf->ssid.ssid; ssid_len = hapd->conf->ssid.ssid_len; if (sta) sta->ssid_probe = &hapd->conf->ssid; } if (!ssid) { if (!(mgmt->da[0] & 0x01)) { char ssid_txt[33]; ieee802_11_print_ssid(ssid_txt, elems.ssid, elems.ssid_len); wpa_printf(MSG_MSGDUMP, "Probe Request from " MACSTR " for foreign SSID '%s' (DA " MACSTR ")", MAC2STR(mgmt->sa), ssid_txt, MAC2STR(mgmt->da)); } return; } /* TODO: verify that supp_rates contains at least one matching rate * with AP configuration */ #define MAX_PROBERESP_LEN 768 buflen = MAX_PROBERESP_LEN; #ifdef CONFIG_WPS if (hapd->wps_probe_resp_ie) buflen += wpabuf_len(hapd->wps_probe_resp_ie); #endif /* CONFIG_WPS */ #ifdef CONFIG_P2P if (hapd->p2p_probe_resp_ie) buflen += wpabuf_len(hapd->p2p_probe_resp_ie); #endif /* CONFIG_P2P */ resp = os_zalloc(buflen); if (resp == NULL) return; epos = ((u8 *) resp) + MAX_PROBERESP_LEN; resp->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, WLAN_FC_STYPE_PROBE_RESP); os_memcpy(resp->da, mgmt->sa, ETH_ALEN); os_memcpy(resp->sa, hapd->own_addr, ETH_ALEN); os_memcpy(resp->bssid, hapd->own_addr, ETH_ALEN); resp->u.probe_resp.beacon_int = host_to_le16(hapd->iconf->beacon_int); /* hardware or low-level driver will setup seq_ctrl and timestamp */ resp->u.probe_resp.capab_info = host_to_le16(hostapd_own_capab_info(hapd, sta, 1)); pos = resp->u.probe_resp.variable; *pos++ = WLAN_EID_SSID; *pos++ = ssid_len; os_memcpy(pos, ssid, ssid_len); pos += ssid_len; /* Supported rates */ pos = hostapd_eid_supp_rates(hapd, pos); /* DS Params */ pos = hostapd_eid_ds_params(hapd, pos); pos = hostapd_eid_country(hapd, pos, epos - pos); /* ERP Information element */ pos = hostapd_eid_erp_info(hapd, pos); /* Extended supported rates */ pos = hostapd_eid_ext_supp_rates(hapd, pos); /* RSN, MDIE, WPA */ pos = hostapd_eid_wpa(hapd, pos, epos - pos); #ifdef CONFIG_IEEE80211N pos = hostapd_eid_ht_capabilities(hapd, pos); pos = hostapd_eid_ht_operation(hapd, pos); #endif /* CONFIG_IEEE80211N */ pos = hostapd_eid_ext_capab(hapd, pos); pos = hostapd_eid_interworking(hapd, pos); pos = hostapd_eid_adv_proto(hapd, pos); /* Wi-Fi Alliance WMM */ pos = hostapd_eid_wmm(hapd, pos); #ifdef CONFIG_WPS if (hapd->conf->wps_state && hapd->wps_probe_resp_ie) { os_memcpy(pos, wpabuf_head(hapd->wps_probe_resp_ie), wpabuf_len(hapd->wps_probe_resp_ie)); pos += wpabuf_len(hapd->wps_probe_resp_ie); } #endif /* CONFIG_WPS */ #ifdef CONFIG_P2P if ((hapd->conf->p2p & P2P_ENABLED) && elems.p2p && hapd->p2p_probe_resp_ie) { os_memcpy(pos, wpabuf_head(hapd->p2p_probe_resp_ie), wpabuf_len(hapd->p2p_probe_resp_ie)); pos += wpabuf_len(hapd->p2p_probe_resp_ie); } #endif /* CONFIG_P2P */ #ifdef CONFIG_P2P_MANAGER if ((hapd->conf->p2p & (P2P_MANAGE | P2P_ENABLED | P2P_GROUP_OWNER)) == P2P_MANAGE) pos = hostapd_eid_p2p_manage(hapd, pos); #endif /* CONFIG_P2P_MANAGER */ if (hostapd_drv_send_mlme(hapd, resp, pos - (u8 *) resp) < 0) perror("handle_probe_req: send"); os_free(resp); wpa_printf(MSG_EXCESSIVE, "STA " MACSTR " sent probe request for %s " "SSID", MAC2STR(mgmt->sa), elems.ssid_len == 0 ? "broadcast" : "our"); } #endif /* NEED_AP_MLME */ void ieee802_11_set_beacon(struct hostapd_data *hapd) { struct ieee80211_mgmt *head = NULL; u8 *tail = NULL; size_t head_len = 0, tail_len = 0; struct wpa_driver_ap_params params; struct wpabuf *beacon, *proberesp, *assocresp; #ifdef NEED_AP_MLME u16 capab_info; u8 *pos, *tailpos; #endif /* NEED_AP_MLME */ hapd->beacon_set_done = 1; #ifdef NEED_AP_MLME #define BEACON_HEAD_BUF_SIZE 256 #define BEACON_TAIL_BUF_SIZE 512 head = os_zalloc(BEACON_HEAD_BUF_SIZE); tail_len = BEACON_TAIL_BUF_SIZE; #ifdef CONFIG_WPS if (hapd->conf->wps_state && hapd->wps_beacon_ie) tail_len += wpabuf_len(hapd->wps_beacon_ie); #endif /* CONFIG_WPS */ #ifdef CONFIG_P2P if (hapd->p2p_beacon_ie) tail_len += wpabuf_len(hapd->p2p_beacon_ie); #endif /* CONFIG_P2P */ tailpos = tail = os_malloc(tail_len); if (head == NULL || tail == NULL) { wpa_printf(MSG_ERROR, "Failed to set beacon data"); os_free(head); os_free(tail); return; } head->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, WLAN_FC_STYPE_BEACON); head->duration = host_to_le16(0); os_memset(head->da, 0xff, ETH_ALEN); os_memcpy(head->sa, hapd->own_addr, ETH_ALEN); os_memcpy(head->bssid, hapd->own_addr, ETH_ALEN); head->u.beacon.beacon_int = host_to_le16(hapd->iconf->beacon_int); /* hardware or low-level driver will setup seq_ctrl and timestamp */ capab_info = hostapd_own_capab_info(hapd, NULL, 0); head->u.beacon.capab_info = host_to_le16(capab_info); pos = &head->u.beacon.variable[0]; /* SSID */ *pos++ = WLAN_EID_SSID; if (hapd->conf->ignore_broadcast_ssid == 2) { /* clear the data, but keep the correct length of the SSID */ *pos++ = hapd->conf->ssid.ssid_len; os_memset(pos, 0, hapd->conf->ssid.ssid_len); pos += hapd->conf->ssid.ssid_len; } else if (hapd->conf->ignore_broadcast_ssid) { *pos++ = 0; /* empty SSID */ } else { *pos++ = hapd->conf->ssid.ssid_len; os_memcpy(pos, hapd->conf->ssid.ssid, hapd->conf->ssid.ssid_len); pos += hapd->conf->ssid.ssid_len; } /* Supported rates */ pos = hostapd_eid_supp_rates(hapd, pos); /* DS Params */ pos = hostapd_eid_ds_params(hapd, pos); head_len = pos - (u8 *) head; tailpos = hostapd_eid_country(hapd, tailpos, tail + BEACON_TAIL_BUF_SIZE - tailpos); /* ERP Information element */ tailpos = hostapd_eid_erp_info(hapd, tailpos); /* Extended supported rates */ tailpos = hostapd_eid_ext_supp_rates(hapd, tailpos); /* RSN, MDIE, WPA */ tailpos = hostapd_eid_wpa(hapd, tailpos, tail + BEACON_TAIL_BUF_SIZE - tailpos); #ifdef CONFIG_IEEE80211N tailpos = hostapd_eid_ht_capabilities(hapd, tailpos); tailpos = hostapd_eid_ht_operation(hapd, tailpos); #endif /* CONFIG_IEEE80211N */ tailpos = hostapd_eid_ext_capab(hapd, tailpos); tailpos = hostapd_eid_interworking(hapd, tailpos); tailpos = hostapd_eid_adv_proto(hapd, tailpos); /* Wi-Fi Alliance WMM */ tailpos = hostapd_eid_wmm(hapd, tailpos); #ifdef CONFIG_WPS if (hapd->conf->wps_state && hapd->wps_beacon_ie) { os_memcpy(tailpos, wpabuf_head(hapd->wps_beacon_ie), wpabuf_len(hapd->wps_beacon_ie)); tailpos += wpabuf_len(hapd->wps_beacon_ie); } #endif /* CONFIG_WPS */ #ifdef CONFIG_P2P if ((hapd->conf->p2p & P2P_ENABLED) && hapd->p2p_beacon_ie) { os_memcpy(tailpos, wpabuf_head(hapd->p2p_beacon_ie), wpabuf_len(hapd->p2p_beacon_ie)); tailpos += wpabuf_len(hapd->p2p_beacon_ie); } #endif /* CONFIG_P2P */ #ifdef CONFIG_P2P_MANAGER if ((hapd->conf->p2p & (P2P_MANAGE | P2P_ENABLED | P2P_GROUP_OWNER)) == P2P_MANAGE) tailpos = hostapd_eid_p2p_manage(hapd, tailpos); #endif /* CONFIG_P2P_MANAGER */ tail_len = tailpos > tail ? tailpos - tail : 0; #endif /* NEED_AP_MLME */ os_memset(¶ms, 0, sizeof(params)); params.head = (u8 *) head; params.head_len = head_len; params.tail = tail; params.tail_len = tail_len; params.dtim_period = hapd->conf->dtim_period; params.beacon_int = hapd->iconf->beacon_int; params.ssid = (u8 *) hapd->conf->ssid.ssid; params.ssid_len = hapd->conf->ssid.ssid_len; params.pairwise_ciphers = hapd->conf->rsn_pairwise ? hapd->conf->rsn_pairwise : hapd->conf->wpa_pairwise; params.group_cipher = hapd->conf->wpa_group; params.key_mgmt_suites = hapd->conf->wpa_key_mgmt; params.auth_algs = hapd->conf->auth_algs; params.wpa_version = hapd->conf->wpa; params.privacy = hapd->conf->ssid.wep.keys_set || hapd->conf->wpa || (hapd->conf->ieee802_1x && (hapd->conf->default_wep_key_len || hapd->conf->individual_wep_key_len)); switch (hapd->conf->ignore_broadcast_ssid) { case 0: params.hide_ssid = NO_SSID_HIDING; break; case 1: params.hide_ssid = HIDDEN_SSID_ZERO_LEN; break; case 2: params.hide_ssid = HIDDEN_SSID_ZERO_CONTENTS; break; } hostapd_build_ap_extra_ies(hapd, &beacon, &proberesp, &assocresp); params.beacon_ies = beacon; params.proberesp_ies = proberesp; params.assocresp_ies = assocresp; params.isolate = hapd->conf->isolate; #ifdef NEED_AP_MLME params.cts_protect = !!(ieee802_11_erp_info(hapd) & ERP_INFO_USE_PROTECTION); params.preamble = hapd->iface->num_sta_no_short_preamble == 0 && hapd->iconf->preamble == SHORT_PREAMBLE; if (hapd->iface->current_mode && hapd->iface->current_mode->mode == HOSTAPD_MODE_IEEE80211G) params.short_slot_time = hapd->iface->num_sta_no_short_slot_time > 0 ? 0 : 1; else params.short_slot_time = -1; if (!hapd->iconf->ieee80211n || hapd->conf->disable_11n) params.ht_opmode = -1; else params.ht_opmode = hapd->iface->ht_op_mode; #endif /* NEED_AP_MLME */ params.interworking = hapd->conf->interworking; if (hapd->conf->interworking && !is_zero_ether_addr(hapd->conf->hessid)) params.hessid = hapd->conf->hessid; if (hostapd_drv_set_ap(hapd, ¶ms)) wpa_printf(MSG_ERROR, "Failed to set beacon parameters"); hostapd_free_ap_extra_ies(hapd, beacon, proberesp, assocresp); os_free(tail); os_free(head); } void ieee802_11_set_beacons(struct hostapd_iface *iface) { size_t i; for (i = 0; i < iface->num_bss; i++) ieee802_11_set_beacon(iface->bss[i]); } #endif /* CONFIG_NATIVE_WINDOWS */