[PATCH 1/5] WNM: Use a dynamically allocated buffer for BTM query and response
Andrei Otcheretianski
andrei.otcheretianski at intel.com
Wed Mar 8 04:37:38 PST 2017
From: Avraham Stern <avraham.stern at intel.com>
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 at intel.com>
---
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
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