[PATCH 5.4 2/4] mac80211: mlme: find auth challenge directly

From: Greg Kroah-Hartman
Date: Sun Oct 16 2022 - 02:46:12 EST


From: Johannes Berg <johannes.berg@xxxxxxxxx>

There's no need to parse all elements etc. just to find the
authentication challenge - use cfg80211_find_elem() instead.
This also allows us to remove WLAN_EID_CHALLENGE handling
from the element parsing entirely.

Link: https://lore.kernel.org/r/20210920154009.45f9b3a15722.Ice3159ffad03a007d6154cbf1fb3a8c48489e86f@changeid
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 2 --
net/mac80211/mlme.c | 11 ++++++-----
net/mac80211/util.c | 4 ----
3 files changed, 6 insertions(+), 11 deletions(-)

--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1460,7 +1460,6 @@ struct ieee802_11_elems {
const u8 *supp_rates;
const u8 *ds_params;
const struct ieee80211_tim_ie *tim;
- const u8 *challenge;
const u8 *rsn;
const u8 *erp_info;
const u8 *ext_supp_rates;
@@ -1507,7 +1506,6 @@ struct ieee802_11_elems {
u8 ssid_len;
u8 supp_rates_len;
u8 tim_len;
- u8 challenge_len;
u8 rsn_len;
u8 ext_supp_rates_len;
u8 wmm_info_len;
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2829,14 +2829,14 @@ static void ieee80211_auth_challenge(str
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_mgd_auth_data *auth_data = sdata->u.mgd.auth_data;
+ const struct element *challenge;
u8 *pos;
- struct ieee802_11_elems elems;
u32 tx_flags = 0;

pos = mgmt->u.auth.variable;
- ieee802_11_parse_elems(pos, len - (pos - (u8 *)mgmt), false, &elems,
- mgmt->bssid, auth_data->bss->bssid);
- if (!elems.challenge)
+ challenge = cfg80211_find_elem(WLAN_EID_CHALLENGE, pos,
+ len - (pos - (u8 *)mgmt));
+ if (!challenge)
return;
auth_data->expected_transaction = 4;
drv_mgd_prepare_tx(sdata->local, sdata, 0);
@@ -2844,7 +2844,8 @@ static void ieee80211_auth_challenge(str
tx_flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
IEEE80211_TX_INTFL_MLME_CONN_TX;
ieee80211_send_auth(sdata, 3, auth_data->algorithm, 0,
- elems.challenge - 2, elems.challenge_len + 2,
+ (void *)challenge,
+ challenge->datalen + sizeof(*challenge),
auth_data->bss->bssid, auth_data->bss->bssid,
auth_data->key, auth_data->key_len,
auth_data->key_idx, tx_flags);
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -1006,10 +1006,6 @@ _ieee802_11_parse_elems_crc(const u8 *st
} else
elem_parse_failed = true;
break;
- case WLAN_EID_CHALLENGE:
- elems->challenge = pos;
- elems->challenge_len = elen;
- break;
case WLAN_EID_VENDOR_SPECIFIC:
if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
pos[2] == 0xf2) {