wifi: use struct_group to copy addresses

We sometimes copy all the addresses from the 802.11 header
for the AAD, which may cause complaints from fortify checks.
Use struct_group() to avoid the compiler warnings/errors.

Change-Id: Ic3ea389105e7813b22095b295079eecdabde5045
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/linux/ieee80211.h

@@ -310,9 +310,11 @@ static inline u16 ieee80211_sn_sub(u16 sn1, u16 sn2)
 struct ieee80211_hdr {
 	__le16 frame_control;
 	__le16 duration_id;
+	struct_group(addrs,
 		u8 addr1[ETH_ALEN];
 		u8 addr2[ETH_ALEN];
 		u8 addr3[ETH_ALEN];
+	);
 	__le16 seq_ctrl;
 	u8 addr4[ETH_ALEN];
 } __packed __aligned(2);

net/mac80211/wpa.c

@@ -351,7 +351,7 @@ static u8 ccmp_gcmp_aad(struct sk_buff *skb, u8 *aad)
 	 * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
 	put_unaligned_be16(len_a, &aad[0]);
 	put_unaligned(mask_fc, (__le16 *)&aad[2]);
-	memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
+	memcpy(&aad[4], &hdr->addrs, 3 * ETH_ALEN);
 
 	/* Mask Seq#, leave Frag# */
 	aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
@@ -792,7 +792,7 @@ static void bip_aad(struct sk_buff *skb, u8 *aad)
 				IEEE80211_FCTL_MOREDATA);
 	put_unaligned(mask_fc, (__le16 *) &aad[0]);
 	/* A1 || A2 || A3 */
-	memcpy(aad + 2, &hdr->addr1, 3 * ETH_ALEN);
+	memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN);
 }
 
 

net/wireless/lib80211_crypt_ccmp.c

@@ -136,7 +136,7 @@ static int ccmp_init_iv_and_aad(const struct ieee80211_hdr *hdr,
 	pos = (u8 *) hdr;
 	aad[0] = pos[0] & 0x8f;
 	aad[1] = pos[1] & 0xc7;
-	memcpy(aad + 2, hdr->addr1, 3 * ETH_ALEN);
+	memcpy(aad + 2, &hdr->addrs, 3 * ETH_ALEN);
 	pos = (u8 *) & hdr->seq_ctrl;
 	aad[20] = pos[0] & 0x0f;
 	aad[21] = 0;		/* all bits masked */