[SK_BUFF]: Introduce skb_copy_from_linear_data{_offset}

To clearly state the intent of copying from linear sk_buffs, _offset being a
overly long variant but interesting for the sake of saving some bytes.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 27 insertions, 18 deletions

diff --git a/drivers/net/wireless/hostap/hostap_80211_rx.c b/drivers/net/wireless/hostap/hostap_80211_rx.c
index 35a3a50724fe..cbedc9ee740a 100644
--- a/drivers/net/wireless/hostap/hostap_80211_rx.c
+++ b/drivers/net/wireless/hostap/hostap_80211_rx.c
@@ -933,12 +933,14 @@ void hostap_80211_rx(struct net_device *dev, struct sk_buff *skb,
 		if (frag == 0) {
 			/* copy first fragment (including full headers) into
 			 * beginning of the fragment cache skb */
-			memcpy(skb_put(frag_skb, flen), skb->data, flen);
+			skb_copy_from_linear_data(skb, skb_put(frag_skb, flen),
+						  flen);
 		} else {
 			/* append frame payload to the end of the fragment
 			 * cache skb */
-			memcpy(skb_put(frag_skb, flen), skb->data + hdrlen,
-			       flen);
+			skb_copy_from_linear_data_offset(skb, hdrlen,
+							 skb_put(frag_skb,
+								 flen), flen);
 		}
 		dev_kfree_skb(skb);
 		skb = NULL;
@@ -1044,8 +1046,9 @@ void hostap_80211_rx(struct net_device *dev, struct sk_buff *skb,
 	    skb->len >= ETH_HLEN + ETH_ALEN) {
 		/* Non-standard frame: get addr4 from its bogus location after
 		 * the payload */
-		memcpy(skb->data + ETH_ALEN,
-		       skb->data + skb->len - ETH_ALEN, ETH_ALEN);
+		skb_copy_from_linear_data_offset(skb, skb->len - ETH_ALEN,
+						 skb->data + ETH_ALEN,
+						 ETH_ALEN);
 		skb_trim(skb, skb->len - ETH_ALEN);
 	}
 
diff --git a/drivers/net/wireless/hostap/hostap_80211_tx.c b/drivers/net/wireless/hostap/hostap_80211_tx.c
index 159baef18e4a..246fac0e8001 100644
--- a/drivers/net/wireless/hostap/hostap_80211_tx.c
+++ b/drivers/net/wireless/hostap/hostap_80211_tx.c
@@ -146,7 +146,8 @@ int hostap_data_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
 			/* From&To DS: Addr1 = RA, Addr2 = TA, Addr3 = DA,
 			 * Addr4 = SA */
-			memcpy(&hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
+			skb_copy_from_linear_data_offset(skb, ETH_ALEN,
+							 &hdr.addr4, ETH_ALEN);
 			hdr_len += ETH_ALEN;
 		} else {
 			/* bogus 4-addr format to workaround Prism2 station
@@ -159,7 +160,8 @@ int hostap_data_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			/* SA from skb->data + ETH_ALEN will be added after
 			 * frame payload; use hdr.addr4 as a temporary buffer
 			 */
-			memcpy(&hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
+			skb_copy_from_linear_data_offset(skb, ETH_ALEN,
+							 &hdr.addr4, ETH_ALEN);
 			need_tailroom += ETH_ALEN;
 		}
 
@@ -174,24 +176,27 @@ int hostap_data_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		else
 			memcpy(&hdr.addr1, local->bssid, ETH_ALEN);
 		memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
-		memcpy(&hdr.addr3, skb->data, ETH_ALEN);
+		skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
 	} else if (local->iw_mode == IW_MODE_MASTER && !to_assoc_ap) {
 		fc |= IEEE80211_FCTL_FROMDS;
 		/* From DS: Addr1 = DA, Addr2 = BSSID, Addr3 = SA */
-		memcpy(&hdr.addr1, skb->data, ETH_ALEN);
+		skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
 		memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
-		memcpy(&hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
+		skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr3,
+						 ETH_ALEN);
 	} else if (local->iw_mode == IW_MODE_INFRA || to_assoc_ap) {
 		fc |= IEEE80211_FCTL_TODS;
 		/* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
 		memcpy(&hdr.addr1, to_assoc_ap ?
 		       local->assoc_ap_addr : local->bssid, ETH_ALEN);
-		memcpy(&hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
-		memcpy(&hdr.addr3, skb->data, ETH_ALEN);
+		skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
+						 ETH_ALEN);
+		skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
 	} else if (local->iw_mode == IW_MODE_ADHOC) {
 		/* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
-		memcpy(&hdr.addr1, skb->data, ETH_ALEN);
-		memcpy(&hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
+		skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
+		skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
+						 ETH_ALEN);
 		memcpy(&hdr.addr3, local->bssid, ETH_ALEN);
 	}
 
diff --git a/drivers/net/wireless/hostap/hostap_ap.c b/drivers/net/wireless/hostap/hostap_ap.c
index 797d950d5d61..4ca8a27b8c55 100644
--- a/drivers/net/wireless/hostap/hostap_ap.c
+++ b/drivers/net/wireless/hostap/hostap_ap.c
@@ -1277,8 +1277,8 @@ static char * ap_auth_make_challenge(struct ap_data *ap)
 		return NULL;
 	}
 
-	memcpy(tmpbuf, skb->data + ap->crypt->extra_mpdu_prefix_len,
-	       WLAN_AUTH_CHALLENGE_LEN);
+	skb_copy_from_linear_data_offset(skb, ap->crypt->extra_mpdu_prefix_len,
+					 tmpbuf, WLAN_AUTH_CHALLENGE_LEN);
 	dev_kfree_skb(skb);
 
 	return tmpbuf;
diff --git a/drivers/net/wireless/hostap/hostap_hw.c b/drivers/net/wireless/hostap/hostap_hw.c
index 9003ff7d151a..fb01fb95a9f0 100644
--- a/drivers/net/wireless/hostap/hostap_hw.c
+++ b/drivers/net/wireless/hostap/hostap_hw.c
@@ -1838,13 +1838,14 @@ static int prism2_tx_80211(struct sk_buff *skb, struct net_device *dev)
 
 	/* skb->data starts with txdesc->frame_control */
 	hdr_len = 24;
-	memcpy(&txdesc.frame_control, skb->data, hdr_len);
+	skb_copy_from_linear_data(skb, &txdesc.frame_control, hdr_len);
  	fc = le16_to_cpu(txdesc.frame_control);
 	if (WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA &&
 	    (fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS) &&
 	    skb->len >= 30) {
 		/* Addr4 */
-		memcpy(txdesc.addr4, skb->data + hdr_len, ETH_ALEN);
+		skb_copy_from_linear_data_offset(skb, hdr_len, txdesc.addr4,
+						 ETH_ALEN);
 		hdr_len += ETH_ALEN;
 	}