[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;
         }