networking: introduce and use skb_put_data()

A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 9 insertions, 13 deletions

diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c
index 7a31510f0524..c0e2f711cb4e 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_rx.c
@@ -848,8 +848,8 @@ static u8 parse_subframe(struct sk_buff *skb,
 			if (!sub_skb)
 				return 0;
 			skb_reserve(sub_skb, 12);
-			data_ptr = (u8 *)skb_put(sub_skb, nSubframe_Length);
-			memcpy(data_ptr, skb->data, nSubframe_Length);
+			data_ptr = skb_put_data(sub_skb, skb->data,
+						nSubframe_Length);
 #endif
 			rxb->subframes[rxb->nr_subframes++] = sub_skb;
 			if (rxb->nr_subframes >= MAX_SUBFRAME_COUNT) {
@@ -1180,12 +1180,11 @@ int ieee80211_rx(struct ieee80211_device *ieee, 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_put_data(frag_skb, skb->data, flen);
 		} else {
 			/* append frame payload to the end of the fragment
 			 * cache skb */
-			memcpy(skb_put(frag_skb, flen), skb->data + hdrlen,
-			       flen);
+			skb_put_data(frag_skb, skb->data + hdrlen, flen);
 		}
 		dev_kfree_skb_any(skb);
 		skb = NULL;
diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
index 14aea26804f4..903a1d0269df 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
@@ -1115,8 +1115,7 @@ ieee80211_association_req(struct ieee80211_network *beacon,
 	hdr->info_element[0].id = MFIE_TYPE_SSID;
 
 	hdr->info_element[0].len = beacon->ssid_len;
-	tag = skb_put(skb, beacon->ssid_len);
-	memcpy(tag, beacon->ssid, beacon->ssid_len);
+	tag = skb_put_data(skb, beacon->ssid, beacon->ssid_len);
 
 	tag = skb_put(skb, rate_len);
 
diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_tx.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_tx.c
index bdb96a45a9eb..f58971a4a2e3 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_tx.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_tx.c
@@ -794,8 +794,7 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
 			{
 				tcb_desc->bHwSec = 0;
 			}
-			frag_hdr = (struct rtl_80211_hdr_3addrqos *)skb_put(skb_frag, hdr_len);
-			memcpy(frag_hdr, &header, hdr_len);
+			frag_hdr = skb_put_data(skb_frag, &header, hdr_len);
 
 			/* If this is not the last fragment, then add the MOREFRAGS
 			 * bit to the frame control
@@ -826,7 +825,7 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
 				bytes -= SNAP_SIZE + sizeof(u16);
 			}
 
-			memcpy(skb_put(skb_frag, bytes), skb->data, bytes);
+			skb_put_data(skb_frag, skb->data, bytes);
 
 			/* Advance the SKB... */
 			skb_pull(skb, bytes);
@@ -869,7 +868,7 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
 
 		txb->encrypted = 0;
 		txb->payload_size = __cpu_to_le16(skb->len);
-		memcpy(skb_put(txb->fragments[0],skb->len), skb->data, skb->len);
+		skb_put_data(txb->fragments[0], skb->data, skb->len);
 	}
 
  success:
diff --git a/drivers/staging/rtl8192u/r819xU_cmdpkt.c b/drivers/staging/rtl8192u/r819xU_cmdpkt.c
index bb6d8bd6c7ac..c3cf01c842a3 100644
--- a/drivers/staging/rtl8192u/r819xU_cmdpkt.c
+++ b/drivers/staging/rtl8192u/r819xU_cmdpkt.c
@@ -45,8 +45,7 @@ rt_status SendTxCommandPacket(struct net_device *dev, void *pData, u32 DataLen)
 	tcb_desc->bCmdOrInit = DESC_PACKET_TYPE_NORMAL;
 	tcb_desc->bLastIniPkt = 0;
 	skb_reserve(skb, USB_HWDESC_HEADER_LEN);
-	ptr_buf = skb_put(skb, DataLen);
-	memcpy(ptr_buf, pData, DataLen);
+	ptr_buf = skb_put_data(skb, pData, DataLen);
 	tcb_desc->txbuf_size = (u16)DataLen;
 
 	if (!priv->ieee80211->check_nic_enough_desc(dev, tcb_desc->queue_index) ||