From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59A8CC282CE for ; Mon, 11 Feb 2019 15:03:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2CA18222B9 for ; Mon, 11 Feb 2019 15:03:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390608AbfBKPDV (ORCPT ); Mon, 11 Feb 2019 10:03:21 -0500 Received: from s3.sipsolutions.net ([144.76.43.62]:44742 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390599AbfBKPDV (ORCPT ); Mon, 11 Feb 2019 10:03:21 -0500 Received: by sipsolutions.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92-RC4) (envelope-from ) id 1gtD79-0008BB-4R; Mon, 11 Feb 2019 16:03:19 +0100 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Jouni Malinen , Peng Xu , Sara Sharon , Johannes Berg Subject: [PATCH v2] cfg80211: fix and clean up cfg80211_gen_new_bssid() Date: Mon, 11 Feb 2019 16:03:12 +0100 Message-Id: <20190211150312.2523-1-johannes@sipsolutions.net> X-Mailer: git-send-email 2.17.2 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Johannes Berg Fix cfg80211_gen_new_bssid() to not rely on u64 modulo arithmetic, which isn't needed since we really just want to mask there. Also, clean it up to calculate the mask only once and use GENMASK_ULL() instead of open-coding the mask calculation. Signed-off-by: Johannes Berg --- include/net/cfg80211.h | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index b61b71f369c7..02a4d5a80521 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -5475,22 +5475,20 @@ cfg80211_inform_bss_frame(struct wiphy *wiphy, * @bssid: transmitter BSSID * @max_bssid: max BSSID indicator, taken from Multiple BSSID element * @mbssid_index: BSSID index, taken from Multiple BSSID index element - * @new_bssid_addr: address of the resulting BSSID + * @new_bssid: address of the resulting BSSID */ static inline void cfg80211_gen_new_bssid(const u8 *bssid, u8 max_bssid, - u8 mbssid_index, u8 *new_bssid_addr) + u8 mbssid_index, u8 *new_bssid) { - u64 bssid_tmp, new_bssid; - u64 lsb_n; + u64 bssid_u64 = ether_addr_to_u64(bssid); + u64 mask = GENMASK_ULL(max_bssid - 1, 0); + u64 new_bssid_u64; - bssid_tmp = ether_addr_to_u64(bssid); + new_bssid_u64 = bssid_u64 & ~mask; - lsb_n = bssid_tmp & ((1 << max_bssid) - 1); - new_bssid = bssid_tmp; - new_bssid &= ~((1 << max_bssid) - 1); - new_bssid |= (lsb_n + mbssid_index) % (1 << max_bssid); + new_bssid_u64 |= ((bssid_u64 & mask) + mbssid_index) & mask; - u64_to_ether_addr(new_bssid, new_bssid_addr); + u64_to_ether_addr(new_bssid_u64, new_bssid); } /** -- 2.17.2