mac80211: remove one user of ieee80211_get_hdr_info

ccmp_special_blocks was only using it to calculate data_len,
calculate that directly.

Use unaligned helpers rather than masking/shifting.

Use symbolic constants for the masked frame_control, and do it directly
on a le16 value.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 37 insertions, 41 deletions

diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 222001c47d89..919e30ce2980 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -11,6 +11,8 @@
 #include <linux/slab.h>
 #include <linux/skbuff.h>
 #include <linux/compiler.h>
+#include <linux/ieee80211.h>
+#include <asm/unaligned.h>
 #include <net/mac80211.h>
 
 #include "ieee80211_i.h"
@@ -296,67 +298,61 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
 static void ccmp_special_blocks(struct sk_buff *skb, u8 *pn, u8 *b_0, u8 *aad,
                                 int encrypted)
 {
-        u16 fc;
-        int a4_included, qos_included;
-        u8 qos_tid, *fc_pos, *data, *sa, *da;
-        int len_a;
-        size_t data_len;
-        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+        __le16 mask_fc;
+        int a4_included;
+        u8 qos_tid;
+        u16 data_len, len_a;
+        unsigned int hdrlen;
+        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 
-        fc_pos = (u8 *) &hdr->frame_control;
-        fc = fc_pos[0] ^ (fc_pos[1] << 8);
-        a4_included = (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
-                (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS);
-
-        ieee80211_get_hdr_info(skb, &sa, &da, &qos_tid, &data, &data_len);
-        data_len -= CCMP_HDR_LEN + (encrypted ? CCMP_MIC_LEN : 0);
-        if (qos_tid & 0x80) {
-                qos_included = 1;
-                qos_tid &= IEEE80211_QOS_CTL_TID_MASK;
-        } else
-                qos_included = 0;
-        /* First block, b_0 */
+        /*
+         * Mask FC: zero subtype b4 b5 b6
+         * Retry, PwrMgt, MoreData; set Protected
+         */
+        mask_fc = hdr->frame_control;
+        mask_fc &= ~cpu_to_le16(0x0070 | IEEE80211_FCTL_RETRY |
+                                IEEE80211_FCTL_PM | IEEE80211_FCTL_MOREDATA);
+        mask_fc |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
+
+        hdrlen = ieee80211_hdrlen(hdr->frame_control);
+        len_a = hdrlen - 2;
+        a4_included = ieee80211_has_a4(hdr->frame_control);
 
+        if (ieee80211_is_data_qos(hdr->frame_control))
+                qos_tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
+        else
+                qos_tid = 0;
+
+        data_len = skb->len - hdrlen - CCMP_HDR_LEN;
+        if (encrypted)
+                data_len -= CCMP_MIC_LEN;
+
+        /* First block, b_0 */
         b_0[0] = 0x59; /* flags: Adata: 1, M: 011, L: 001 */
         /* Nonce: QoS Priority | A2 | PN */
         b_0[1] = qos_tid;
         memcpy(&b_0[2], hdr->addr2, ETH_ALEN);
         memcpy(&b_0[8], pn, CCMP_PN_LEN);
         /* l(m) */
-        b_0[14] = (data_len >> 8) & 0xff;
-        b_0[15] = data_len & 0xff;
-
+        put_unaligned_be16(data_len, &b_0[14]);
 
         /* AAD (extra authenticate-only data) / masked 802.11 header
          * FC | A1 | A2 | A3 | SC | [A4] | [QC] */
-
-        len_a = a4_included ? 28 : 22;
-        if (qos_included)
-                len_a += IEEE80211_QOS_CTL_LEN;
-
-        aad[0] = 0; /* (len_a >> 8) & 0xff; */
-        aad[1] = len_a & 0xff;
-        /* Mask FC: zero subtype b4 b5 b6 */
-        aad[2] = fc_pos[0] & ~(BIT(4) | BIT(5) | BIT(6));
-        /* Retry, PwrMgt, MoreData; set Protected */
-        aad[3] = (fc_pos[1] & ~(BIT(3) | BIT(4) | BIT(5))) | BIT(6);
+        put_unaligned_be16(len_a, &aad[0]);
+        put_unaligned(mask_fc, (__le16 *)&aad[2]);
         memcpy(&aad[4], &hdr->addr1, 3 * ETH_ALEN);
 
         /* Mask Seq#, leave Frag# */
         aad[22] = *((u8 *) &hdr->seq_ctrl) & 0x0f;
         aad[23] = 0;
+
         if (a4_included) {
                 memcpy(&aad[24], hdr->addr4, ETH_ALEN);
-                aad[30] = 0;
+                aad[30] = qos_tid;
                 aad[31] = 0;
-        } else
+        } else {
                 memset(&aad[24], 0, ETH_ALEN + IEEE80211_QOS_CTL_LEN);
-        if (qos_included) {
-                u8 *dpos = &aad[a4_included ? 30 : 24];
-
-                /* Mask QoS Control field */
-                dpos[0] = qos_tid;
-                dpos[1] = 0;
+                aad[24] = qos_tid;
         }
 }