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>

8 files changed, 25 insertions, 30 deletions

diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index f864ce19e13d..f44f75a2a4d5 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -226,8 +226,7 @@ digital_send_dep_data_prep(struct nfc_digital_dev *ddev, struct sk_buff *skb,
                         return ERR_PTR(-ENOMEM);
                 }
 
-                memcpy(skb_put(new_skb, ddev->remote_payload_max), skb->data,
-                       ddev->remote_payload_max);
+                skb_put_data(new_skb, skb->data, ddev->remote_payload_max);
                 skb_pull(skb, ddev->remote_payload_max);
 
                 ddev->chaining_skb = skb;
@@ -277,8 +276,7 @@ digital_recv_dep_data_gather(struct nfc_digital_dev *ddev, u8 pfb,
                         ddev->chaining_skb = new_skb;
                 }
 
-                memcpy(skb_put(ddev->chaining_skb, resp->len), resp->data,
-                       resp->len);
+                skb_put_data(ddev->chaining_skb, resp->data, resp->len);
 
                 kfree_skb(resp);
                 resp = NULL;
@@ -525,7 +523,7 @@ int digital_in_send_atr_req(struct nfc_digital_dev *ddev,
 
         if (gb_len) {
                 atr_req->pp |= DIGITAL_GB_BIT;
-                memcpy(skb_put(skb, gb_len), gb, gb_len);
+                skb_put_data(skb, gb, gb_len);
         }
 
         digital_skb_push_dep_sod(ddev, skb);
@@ -1012,8 +1010,7 @@ static int digital_tg_send_ack(struct nfc_digital_dev *ddev,
         if (ddev->did) {
                 dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
 
-                memcpy(skb_put(skb, sizeof(ddev->did)), &ddev->did,
-                       sizeof(ddev->did));
+                skb_put_data(skb, &ddev->did, sizeof(ddev->did));
         }
 
         ddev->curr_nfc_dep_pni =
@@ -1057,8 +1054,7 @@ static int digital_tg_send_atn(struct nfc_digital_dev *ddev)
         if (ddev->did) {
                 dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
 
-                memcpy(skb_put(skb, sizeof(ddev->did)), &ddev->did,
-                       sizeof(ddev->did));
+                skb_put_data(skb, &ddev->did, sizeof(ddev->did));
         }
 
         digital_skb_push_dep_sod(ddev, skb);
@@ -1325,8 +1321,7 @@ int digital_tg_send_dep_res(struct nfc_digital_dev *ddev, struct sk_buff *skb)
         if (ddev->did) {
                 dep_res->pfb |= DIGITAL_NFC_DEP_PFB_DID_BIT;
 
-                memcpy(skb_put(skb, sizeof(ddev->did)), &ddev->did,
-                       sizeof(ddev->did));
+                skb_put_data(skb, &ddev->did, sizeof(ddev->did));
         }
 
         ddev->curr_nfc_dep_pni =
diff --git a/net/nfc/hci/core.c b/net/nfc/hci/core.c
index 2b0f0ac498d2..8741ad47a6fb 100644
--- a/net/nfc/hci/core.c
+++ b/net/nfc/hci/core.c
@@ -878,9 +878,9 @@ static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 
                 skb_queue_walk(&hdev->rx_hcp_frags, frag_skb) {
                         msg_len = frag_skb->len - NFC_HCI_HCP_PACKET_HEADER_LEN;
-                        memcpy(skb_put(hcp_skb, msg_len),
-                               frag_skb->data + NFC_HCI_HCP_PACKET_HEADER_LEN,
-                               msg_len);
+                        skb_put_data(hcp_skb,
+                                     frag_skb->data + NFC_HCI_HCP_PACKET_HEADER_LEN,
+                                     msg_len);
                 }
 
                 skb_queue_purge(&hdev->rx_hcp_frags);
diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
index c5959ce503e6..367d8c027101 100644
--- a/net/nfc/llcp_commands.c
+++ b/net/nfc/llcp_commands.c
@@ -298,7 +298,7 @@ static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
 
         pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
 
-        memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE);
+        skb_put_data(pdu, header, LLCP_HEADER_SIZE);
 
         return pdu;
 }
@@ -311,7 +311,7 @@ static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
         if (tlv == NULL)
                 return NULL;
 
-        memcpy(skb_put(pdu, tlv_length), tlv, tlv_length);
+        skb_put_data(pdu, tlv, tlv_length);
 
         return pdu;
 }
@@ -549,7 +549,7 @@ int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
                 return PTR_ERR(skb);
 
         hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
-                memcpy(skb_put(skb, sdp->tlv_len), sdp->tlv, sdp->tlv_len);
+                skb_put_data(skb, sdp->tlv, sdp->tlv_len);
 
                 hlist_del(&sdp->node);
 
@@ -581,8 +581,7 @@ int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
         hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
                 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
 
-                memcpy(skb_put(skb, sdreq->tlv_len), sdreq->tlv,
-                       sdreq->tlv_len);
+                skb_put_data(skb, sdreq->tlv, sdreq->tlv_len);
 
                 hlist_del(&sdreq->node);
 
@@ -622,7 +621,7 @@ int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
 
         skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
 
-        memcpy(skb_put(skb, 1), &reason, 1);
+        skb_put_data(skb, &reason, 1);
 
         skb_queue_head(&local->tx_queue, skb);
 
@@ -693,7 +692,7 @@ int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
                 skb_put(pdu, LLCP_SEQUENCE_SIZE);
 
                 if (likely(frag_len > 0))
-                        memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
+                        skb_put_data(pdu, msg_ptr, frag_len);
 
                 skb_queue_tail(&sock->tx_queue, pdu);
 
@@ -759,7 +758,7 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
                 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
 
                 if (likely(frag_len > 0))
-                        memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len);
+                        skb_put_data(pdu, msg_ptr, frag_len);
 
                 /* No need to check for the peer RW for UI frames */
                 skb_queue_tail(&local->tx_queue, pdu);
diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c
index e69786c6804c..02eef5cf3cce 100644
--- a/net/nfc/llcp_core.c
+++ b/net/nfc/llcp_core.c
@@ -1390,7 +1390,7 @@ static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
                         return;
                 }
 
-                memcpy(skb_put(new_skb, pdu_len), skb->data, pdu_len);
+                skb_put_data(new_skb, skb->data, pdu_len);
 
                 nfc_llcp_rx_skb(local, new_skb);
 
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 61fff422424f..17b9f1ce23db 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -462,7 +462,7 @@ int nci_nfcc_loopback(struct nci_dev *ndev, void *data, size_t data_len,
                 return -ENOMEM;
 
         skb_reserve(skb, NCI_DATA_HDR_SIZE);
-        memcpy(skb_put(skb, data_len), data, data_len);
+        skb_put_data(skb, data, data_len);
 
         loopback_data.conn_id = conn_id;
         loopback_data.data = skb;
@@ -1350,7 +1350,7 @@ int nci_send_cmd(struct nci_dev *ndev, __u16 opcode, __u8 plen, void *payload)
         nci_pbf_set((__u8 *)hdr, NCI_PBF_LAST);
 
         if (plen)
-                memcpy(skb_put(skb, plen), payload, plen);
+                skb_put_data(skb, payload, plen);
 
         skb_queue_tail(&ndev->cmd_q, skb);
         queue_work(ndev->cmd_wq, &ndev->cmd_work);
diff --git a/net/nfc/nci/data.c b/net/nfc/nci/data.c
index dbd24254412a..2488d9241f1d 100644
--- a/net/nfc/nci/data.c
+++ b/net/nfc/nci/data.c
@@ -138,7 +138,7 @@ static int nci_queue_tx_data_frags(struct nci_dev *ndev,
                 skb_reserve(skb_frag, NCI_DATA_HDR_SIZE);
 
                 /* first, copy the data */
-                memcpy(skb_put(skb_frag, frag_len), data, frag_len);
+                skb_put_data(skb_frag, data, frag_len);
 
                 /* second, set the header */
                 nci_push_data_hdr(ndev, conn_id, skb_frag,
diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index a0ab26d535dc..d4a53ce818c3 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -187,7 +187,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
                 *skb_push(skb, 1) = cb;
 
                 if (len > 0)
-                        memcpy(skb_put(skb, len), data + i, len);
+                        skb_put_data(skb, data + i, len);
 
                 r = nci_send_data(ndev, conn_info->conn_id, skb);
                 if (r < 0)
@@ -476,8 +476,9 @@ void nci_hci_data_received_cb(void *context,
 
                 skb_queue_walk(&ndev->hci_dev->rx_hcp_frags, frag_skb) {
                         msg_len = frag_skb->len - NCI_HCI_HCP_PACKET_HEADER_LEN;
-                        memcpy(skb_put(hcp_skb, msg_len), frag_skb->data +
-                               NCI_HCI_HCP_PACKET_HEADER_LEN, msg_len);
+                        skb_put_data(hcp_skb,
+                                     frag_skb->data + NCI_HCI_HCP_PACKET_HEADER_LEN,
+                                     msg_len);
                 }
 
                 skb_queue_purge(&ndev->hci_dev->rx_hcp_frags);
diff --git a/net/nfc/nci/uart.c b/net/nfc/nci/uart.c
index c468eabd6943..cfa7f352c1c3 100644
--- a/net/nfc/nci/uart.c
+++ b/net/nfc/nci/uart.c
@@ -371,7 +371,7 @@ static int nci_uart_default_recv_buf(struct nci_uart *nu, const u8 *data,
                 chunk_len = nu->rx_packet_len - nu->rx_skb->len;
                 if (count < chunk_len)
                         chunk_len = count;
-                memcpy(skb_put(nu->rx_skb, chunk_len), data, chunk_len);
+                skb_put_data(nu->rx_skb, data, chunk_len);
                 data += chunk_len;
                 count -= chunk_len;