wifi: mac80211, cfg80211: Export michael_mic() and move it to cfg80211

Export michael_mic() so that the ath11k and ath12k drivers can call it.
In addition, move it from mac80211 to cfg80211 so that the ipw2x00
drivers, which depend on cfg80211 but not mac80211, can also call it.

Currently these drivers have their own local implementations of
michael_mic() based on crypto_shash, which is redundant and inefficient.
By consolidating all the Michael MIC code into cfg80211, we'll be able
to remove the duplicate Michael MIC code in the crypto/ directory.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Link: https://patch.msgid.link/20260408030651.80336-3-ebiggers@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

6 files changed, 10 insertions, 26 deletions

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index ffa8f9f77efe..23f9df9be837 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -1921,6 +1921,11 @@ enum ieee80211_radio_measurement_actioncode {
 #define PMK_MAX_LEN			64
 #define SAE_PASSWORD_MAX_LEN		128
 
+#define MICHAEL_MIC_LEN			8
+
+void michael_mic(const u8 *key, struct ieee80211_hdr *hdr,
+		 const u8 *data, size_t data_len, u8 *mic);
+
 /* Public action codes (IEEE Std 802.11-2016, 9.6.8.1, Table 9-307) */
 enum ieee80211_pub_actioncode {
 	WLAN_PUB_ACTION_20_40_BSS_COEX = 0,
diff --git a/net/mac80211/Makefile b/net/mac80211/Makefile
index abf46c951299..20c3135b73ea 100644
--- a/net/mac80211/Makefile
+++ b/net/mac80211/Makefile
@@ -18,7 +18,6 @@ mac80211-y := \
 	iface.o \
 	link.o \
 	rate.o \
-	michael.o \
 	tkip.o \
 	aes_cmac.o \
 	aes_gmac.o \
diff --git a/net/mac80211/michael.h b/net/mac80211/michael.h
deleted file mode 100644
index a7fdb8e84615..000000000000
--- a/net/mac80211/michael.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Michael MIC implementation - optimized for TKIP MIC operations
- * Copyright 2002-2003, Instant802 Networks, Inc.
- */
-
-#ifndef MICHAEL_H
-#define MICHAEL_H
-
-#include <linux/types.h>
-#include <linux/ieee80211.h>
-
-#define MICHAEL_MIC_LEN 8
-
-struct michael_mic_ctx {
-	u32 l, r;
-};
-
-void michael_mic(const u8 *key, struct ieee80211_hdr *hdr,
-		 const u8 *data, size_t data_len, u8 *mic);
-
-#endif /* MICHAEL_H */
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 64a57475ce50..724ec831a885 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -18,7 +18,6 @@
 #include <crypto/utils.h>
 
 #include "ieee80211_i.h"
-#include "michael.h"
 #include "tkip.h"
 #include "aes_ccm.h"
 #include "aes_cmac.h"
diff --git a/net/wireless/Makefile b/net/wireless/Makefile
index 62a83faf0e07..a77fd5ba6368 100644
--- a/net/wireless/Makefile
+++ b/net/wireless/Makefile
@@ -8,7 +8,7 @@ obj-$(CONFIG_WEXT_PRIV) += wext-priv.o
 
 cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o
 cfg80211-y += mlme.o ibss.o sme.o chan.o ethtool.o mesh.o ap.o trace.o ocb.o
-cfg80211-y += pmsr.o
+cfg80211-y += michael-mic.o pmsr.o
 cfg80211-$(CONFIG_OF) += of.o
 cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o
 cfg80211-$(CONFIG_CFG80211_WEXT) += wext-compat.o wext-sme.o
diff --git a/net/mac80211/michael.c b/net/wireless/michael-mic.c
index 8a1afc93e749..50cdb67f0503 100644
--- a/net/mac80211/michael.c
+++ b/net/wireless/michael-mic.c
@@ -8,7 +8,9 @@
 #include <linux/ieee80211.h>
 #include <linux/unaligned.h>
 
-#include "michael.h"
+struct michael_mic_ctx {
+	u32 l, r;
+};
 
 static void michael_block(struct michael_mic_ctx *mctx, u32 val)
 {
@@ -81,3 +83,4 @@ void michael_mic(const u8 *key, struct ieee80211_hdr *hdr,
 	put_unaligned_le32(mctx.l, mic);
 	put_unaligned_le32(mctx.r, mic + 4);
 }
+EXPORT_SYMBOL_GPL(michael_mic);