From: Avraham Stern <avraham.stern@xxxxxxxxx> BSS transition management query and response use a large static buffer for the frame because the candidate list may require a lot of space. However, in most cases the actually used space will be much less than the buffer(since the candidate list is short or completely missing). Use a dynamically allocated buffer instead and allocate it according to the actual space needed. while at it, remove unneeded filling of the MAC header in the action frames, since wpa_drv_send_action() adds the MAC header anyway. Signed-off-by: Avraham Stern <avraham.stern@xxxxxxxxx> --- wpa_supplicant/wnm_sta.c | 157 ++++++++++++++++++++++++----------------------- 1 file changed, 80 insertions(+), 77 deletions(-) diff --git a/wpa_supplicant/wnm_sta.c b/wpa_supplicant/wnm_sta.c index f7200bf..3ac568e 100644 --- a/wpa_supplicant/wnm_sta.c +++ b/wpa_supplicant/wnm_sta.c @@ -780,36 +780,40 @@ static u32 wnm_get_bss_info(struct wpa_supplicant *wpa_s, struct wpa_bss *bss) } -static int wnm_add_nei_rep(u8 *buf, size_t len, const u8 *bssid, u32 bss_info, - u8 op_class, u8 chan, u8 phy_type, u8 pref) +static int wnm_add_nei_rep(struct wpabuf **buf, const u8 *bssid, + u32 bss_info, u8 op_class, u8 chan, u8 phy_type, + u8 pref) { - u8 *pos = buf; + if (wpabuf_len(*buf) + 18 > + IEEE80211_MAX_MMPDU_SIZE - IEEE80211_HDRLEN) { + wpa_printf(MSG_DEBUG, + "WNM: No room in frame for Neighbor report element"); + return -1; + } - if (len < 18) { + if (wpabuf_resize(buf, 18) < 0) { wpa_printf(MSG_DEBUG, - "WNM: Not enough room for Neighbor Report element"); + "WNM: Failed to allocate memory for Neighbor Report element"); return -1; } - *pos++ = WLAN_EID_NEIGHBOR_REPORT; + wpabuf_put_u8(*buf, WLAN_EID_NEIGHBOR_REPORT); /* length: 13 for basic neighbor report + 3 for preference subelement */ - *pos++ = 16; - os_memcpy(pos, bssid, ETH_ALEN); - pos += ETH_ALEN; - WPA_PUT_LE32(pos, bss_info); - pos += 4; - *pos++ = op_class; - *pos++ = chan; - *pos++ = phy_type; - *pos++ = WNM_NEIGHBOR_BSS_TRANSITION_CANDIDATE; - *pos++ = 1; - *pos++ = pref; - return pos - buf; + wpabuf_put_u8(*buf, 16); + wpabuf_put_data(*buf, bssid, ETH_ALEN); + wpabuf_put_le32(*buf, bss_info); + wpabuf_put_u8(*buf, op_class); + wpabuf_put_u8(*buf, chan); + wpabuf_put_u8(*buf, phy_type); + wpabuf_put_u8(*buf, WNM_NEIGHBOR_BSS_TRANSITION_CANDIDATE); + wpabuf_put_u8(*buf, 1); + wpabuf_put_u8(*buf, pref); + return 0; } static int wnm_nei_rep_add_bss(struct wpa_supplicant *wpa_s, - struct wpa_bss *bss, u8 *buf, size_t len, + struct wpa_bss *bss, struct wpabuf **buf, u8 pref) { const u8 *ie; @@ -858,20 +862,19 @@ static int wnm_nei_rep_add_bss(struct wpa_supplicant *wpa_s, info = wnm_get_bss_info(wpa_s, bss); - return wnm_add_nei_rep(buf, len, bss->bssid, info, op_class, chan, - phy_type, pref); + return wnm_add_nei_rep(buf, bss->bssid, info, op_class, chan, phy_type, + pref); } -static int wnm_add_cand_list(struct wpa_supplicant *wpa_s, u8 *buf, size_t len) +static void wnm_add_cand_list(struct wpa_supplicant *wpa_s, struct wpabuf **buf) { - u8 *pos = buf; unsigned int i, pref = 255; struct os_reltime now; struct wpa_ssid *ssid = wpa_s->current_ssid; if (!ssid) - return 0; + return; /* * TODO: Define when scan results are no longer valid for the candidate @@ -879,7 +882,7 @@ static int wnm_add_cand_list(struct wpa_supplicant *wpa_s, u8 *buf, size_t len) */ os_get_reltime(&now); if (os_reltime_expired(&now, &wpa_s->last_scan, 10)) - return 0; + return; wpa_printf(MSG_DEBUG, "WNM: Add candidate list to BSS Transition Management Response frame"); @@ -888,36 +891,31 @@ static int wnm_add_cand_list(struct wpa_supplicant *wpa_s, u8 *buf, size_t len) int res; if (wpa_scan_res_match(wpa_s, i, bss, ssid, 1, 0)) { - res = wnm_nei_rep_add_bss(wpa_s, bss, pos, len, pref--); + res = wnm_nei_rep_add_bss(wpa_s, bss, buf, pref--); if (res == -2) continue; /* could not build entry for BSS */ if (res < 0) break; /* no more room for candidates */ if (pref == 1) break; - - pos += res; - len -= res; } } wpa_hexdump(MSG_DEBUG, "WNM: BSS Transition Management Response candidate list", - buf, pos - buf); - - return pos - buf; + wpabuf_head_u8(*buf), wpabuf_len(*buf)); } +#define BTM_RESP_MIN_SIZE 11 + static void wnm_send_bss_transition_mgmt_resp( struct wpa_supplicant *wpa_s, u8 dialog_token, enum bss_trans_mgmt_status_code status, enum mbo_transition_reject_reason reason, u8 delay, const u8 *target_bssid) { - u8 buf[2000], *pos; - struct ieee80211_mgmt *mgmt; - size_t len; + struct wpabuf *buf; int res; wpa_printf(MSG_DEBUG, @@ -930,52 +928,62 @@ static void wnm_send_bss_transition_mgmt_resp( return; } - mgmt = (struct ieee80211_mgmt *) buf; - os_memset(&buf, 0, sizeof(buf)); - os_memcpy(mgmt->da, wpa_s->bssid, ETH_ALEN); - os_memcpy(mgmt->sa, wpa_s->own_addr, ETH_ALEN); - os_memcpy(mgmt->bssid, wpa_s->bssid, ETH_ALEN); - mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, - WLAN_FC_STYPE_ACTION); - mgmt->u.action.category = WLAN_ACTION_WNM; - mgmt->u.action.u.bss_tm_resp.action = WNM_BSS_TRANS_MGMT_RESP; - mgmt->u.action.u.bss_tm_resp.dialog_token = dialog_token; - mgmt->u.action.u.bss_tm_resp.status_code = status; - mgmt->u.action.u.bss_tm_resp.bss_termination_delay = delay; - pos = mgmt->u.action.u.bss_tm_resp.variable; + buf = wpabuf_alloc(BTM_RESP_MIN_SIZE); + if (!buf) { + wpa_printf(MSG_DEBUG, + "WNM: Failed to allocate memory for BTM response"); + return; + } + + wpabuf_put_u8(buf, WLAN_ACTION_WNM); + wpabuf_put_u8(buf, WNM_BSS_TRANS_MGMT_RESP); + wpabuf_put_u8(buf, dialog_token); + wpabuf_put_u8(buf, status); + wpabuf_put_u8(buf, delay); if (target_bssid) { - os_memcpy(pos, target_bssid, ETH_ALEN); - pos += ETH_ALEN; + wpabuf_put_data(buf, target_bssid, ETH_ALEN); } else if (status == WNM_BSS_TM_ACCEPT) { /* * P802.11-REVmc clarifies that the Target BSSID field is always * present when status code is zero, so use a fake value here if * no BSSID is yet known. */ - os_memset(pos, 0, ETH_ALEN); - pos += ETH_ALEN; + wpabuf_put_data(buf, "\0\0\0\0\0\0", ETH_ALEN); } if (status == WNM_BSS_TM_ACCEPT) - pos += wnm_add_cand_list(wpa_s, pos, buf + sizeof(buf) - pos); + wnm_add_cand_list(wpa_s, &buf); #ifdef CONFIG_MBO if (status != WNM_BSS_TM_ACCEPT && wpa_bss_get_vendor_ie(wpa_s->current_bss, MBO_IE_VENDOR_TYPE)) { - pos += wpas_mbo_ie_bss_trans_reject( - wpa_s, pos, buf + sizeof(buf) - pos, reason); + u8 mbo[10]; + size_t ret; + + ret = wpas_mbo_ie_bss_trans_reject(wpa_s, mbo, sizeof(mbo), + reason); + if (ret) { + if (wpabuf_resize(&buf, ret) < 0) { + wpabuf_free(buf); + wpa_printf(MSG_DEBUG, + "WNM: Failed to allocate memory for MBO IE"); + return; + } + + wpabuf_put_data(buf, mbo, ret); + } } #endif /* CONFIG_MBO */ - len = pos - (u8 *) &mgmt->u.action.category; - res = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0, wpa_s->bssid, wpa_s->own_addr, wpa_s->bssid, - &mgmt->u.action.category, len, 0); + wpabuf_head_u8(buf), wpabuf_len(buf), 0); if (res < 0) { wpa_printf(MSG_DEBUG, "WNM: Failed to send BSS Transition Management Response"); } + + wpabuf_free(buf); } @@ -1475,12 +1483,12 @@ static void ieee802_11_rx_bss_trans_mgmt_req(struct wpa_supplicant *wpa_s, } +#define BTM_QUERY_MIN_SIZE 4 + int wnm_send_bss_transition_mgmt_query(struct wpa_supplicant *wpa_s, u8 query_reason, int cand_list) { - u8 buf[2000], *pos; - struct ieee80211_mgmt *mgmt; - size_t len; + struct wpabuf *buf; int ret; wpa_printf(MSG_DEBUG, "WNM: Send BSS Transition Management Query to " @@ -1488,28 +1496,23 @@ int wnm_send_bss_transition_mgmt_query(struct wpa_supplicant *wpa_s, MAC2STR(wpa_s->bssid), query_reason, cand_list ? " candidate list" : ""); - mgmt = (struct ieee80211_mgmt *) buf; - os_memset(&buf, 0, sizeof(buf)); - os_memcpy(mgmt->da, wpa_s->bssid, ETH_ALEN); - os_memcpy(mgmt->sa, wpa_s->own_addr, ETH_ALEN); - os_memcpy(mgmt->bssid, wpa_s->bssid, ETH_ALEN); - mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT, - WLAN_FC_STYPE_ACTION); - mgmt->u.action.category = WLAN_ACTION_WNM; - mgmt->u.action.u.bss_tm_query.action = WNM_BSS_TRANS_MGMT_QUERY; - mgmt->u.action.u.bss_tm_query.dialog_token = 1; - mgmt->u.action.u.bss_tm_query.query_reason = query_reason; - pos = mgmt->u.action.u.bss_tm_query.variable; + buf = wpabuf_alloc(BTM_QUERY_MIN_SIZE); + if (!buf) + return -1; - if (cand_list) - pos += wnm_add_cand_list(wpa_s, pos, buf + sizeof(buf) - pos); + wpabuf_put_u8(buf, WLAN_ACTION_WNM); + wpabuf_put_u8(buf, WNM_BSS_TRANS_MGMT_QUERY); + wpabuf_put_u8(buf, 1); + wpabuf_put_u8(buf, query_reason); - len = pos - (u8 *) &mgmt->u.action.category; + if (cand_list) + wnm_add_cand_list(wpa_s, &buf); ret = wpa_drv_send_action(wpa_s, wpa_s->assoc_freq, 0, wpa_s->bssid, wpa_s->own_addr, wpa_s->bssid, - &mgmt->u.action.category, len, 0); + wpabuf_head_u8(buf), wpabuf_len(buf), 0); + wpabuf_free(buf); return ret; } -- 1.9.1 _______________________________________________ Hostap mailing list Hostap@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/hostap