networking: make skb_push & __skb_push return void pointers

It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.

Make these functions return void * and remove all the casts across
the tree, adding a (u8 *) cast only where the unsigned char pointer
was used directly, all done with the following spatch:

    @@
    expression SKB, LEN;
    typedef u8;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

    @@
    expression SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - fn(SKB, LEN)[0]
    + *(u8 *)fn(SKB, LEN)

Note that the last part there converts from push(...)[0] to the
more idiomatic *(u8 *)push(...).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/atm/solos-pci.c

@@ -1174,7 +1174,7 @@ static int psend(struct atm_vcc *vcc, struct sk_buff *skb)
 		}
 	}
 
-	header = (void *)skb_push(skb, sizeof(*header));
+	header = skb_push(skb, sizeof(*header));
 
 	/* This does _not_ include the size of the header */
 	header->size = cpu_to_le16(pktlen);

drivers/bluetooth/bpa10x.c

@@ -297,7 +297,7 @@ static int bpa10x_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 		return -ENOMEM;
 
 	/* Prepend skb with frame type */
-	*skb_push(skb, 1) = hci_skb_pkt_type(skb);
+	*(u8 *)skb_push(skb, 1) = hci_skb_pkt_type(skb);
 
 	switch (hci_skb_pkt_type(skb)) {
 	case HCI_COMMAND_PKT:

drivers/firewire/net.c

@@ -219,7 +219,7 @@ static int fwnet_header_create(struct sk_buff *skb, struct net_device *net,
 {
 	struct fwnet_header *h;
 
-	h = (struct fwnet_header *)skb_push(skb, sizeof(*h));
+	h = skb_push(skb, sizeof(*h));
 	put_unaligned_be16(type, &h->h_proto);
 
 	if (net->flags & (IFF_LOOPBACK | IFF_NOARP)) {
@@ -961,16 +961,14 @@ static int fwnet_send_packet(struct fwnet_packet_task *ptask)
 	tx_len = ptask->max_payload;
 	switch (fwnet_get_hdr_lf(&ptask->hdr)) {
 	case RFC2374_HDR_UNFRAG:
-		bufhdr = (struct rfc2734_header *)
-				skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
+		bufhdr = skb_push(ptask->skb, RFC2374_UNFRAG_HDR_SIZE);
 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
 		break;
 
 	case RFC2374_HDR_FIRSTFRAG:
 	case RFC2374_HDR_INTFRAG:
 	case RFC2374_HDR_LASTFRAG:
-		bufhdr = (struct rfc2734_header *)
-				skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
+		bufhdr = skb_push(ptask->skb, RFC2374_FRAG_HDR_SIZE);
 		put_unaligned_be32(ptask->hdr.w0, &bufhdr->w0);
 		put_unaligned_be32(ptask->hdr.w1, &bufhdr->w1);
 		break;

drivers/infiniband/hw/cxgb3/iwch_cm.c

@@ -513,7 +513,7 @@ static void send_mpa_req(struct iwch_ep *ep, struct sk_buff *skb)
 	set_arp_failure_handler(skb, arp_failure_discard);
 	skb_reset_transport_header(skb);
 	len = skb->len;
-	req = (struct tx_data_wr *) skb_push(skb, sizeof(*req));
+	req = skb_push(skb, sizeof(*req));
 	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA)|F_WR_COMPL);
 	req->wr_lo = htonl(V_WR_TID(ep->hwtid));
 	req->len = htonl(len);
@@ -564,7 +564,7 @@ static int send_mpa_reject(struct iwch_ep *ep, const void *pdata, u8 plen)
 	skb->priority = CPL_PRIORITY_DATA;
 	set_arp_failure_handler(skb, arp_failure_discard);
 	skb_reset_transport_header(skb);
-	req = (struct tx_data_wr *) skb_push(skb, sizeof(*req));
+	req = skb_push(skb, sizeof(*req));
 	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA)|F_WR_COMPL);
 	req->wr_lo = htonl(V_WR_TID(ep->hwtid));
 	req->len = htonl(mpalen);
@@ -615,7 +615,7 @@ static int send_mpa_reply(struct iwch_ep *ep, const void *pdata, u8 plen)
 	set_arp_failure_handler(skb, arp_failure_discard);
 	skb_reset_transport_header(skb);
 	len = skb->len;
-	req = (struct tx_data_wr *) skb_push(skb, sizeof(*req));
+	req = skb_push(skb, sizeof(*req));
 	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA)|F_WR_COMPL);
 	req->wr_lo = htonl(V_WR_TID(ep->hwtid));
 	req->len = htonl(len);

drivers/infiniband/hw/cxgb4/cm.c

@@ -3751,7 +3751,7 @@ static void build_cpl_pass_accept_req(struct sk_buff *skb, int stid , u8 tos)
 	tcp_clear_options(&tmp_opt);
 	tcp_parse_options(&init_net, skb, &tmp_opt, 0, NULL);
 
-	req = (struct cpl_pass_accept_req *)__skb_push(skb, sizeof(*req));
+	req = __skb_push(skb, sizeof(*req));
 	memset(req, 0, sizeof(*req));
 	req->l2info = cpu_to_be16(SYN_INTF_V(intf) |
 			 SYN_MAC_IDX_V(RX_MACIDX_G(

drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -681,7 +681,7 @@ static void push_pseudo_header(struct sk_buff *skb, const char *daddr)
 {
 	struct ipoib_pseudo_header *phdr;
 
-	phdr = (struct ipoib_pseudo_header *)skb_push(skb, sizeof(*phdr));
+	phdr = skb_push(skb, sizeof(*phdr));
 	memcpy(phdr->hwaddr, daddr, INFINIBAND_ALEN);
 }
 
@@ -1129,7 +1129,7 @@ static int ipoib_hard_header(struct sk_buff *skb,
 {
 	struct ipoib_header *header;
 
-	header = (struct ipoib_header *) skb_push(skb, sizeof *header);
+	header = skb_push(skb, sizeof *header);
 
 	header->proto = htons(type);
 	header->reserved = 0;

drivers/infiniband/ulp/opa_vnic/opa_vnic_encap.c

@@ -460,7 +460,7 @@ void opa_vnic_encap_skb(struct opa_vnic_adapter *adapter, struct sk_buff *skb)
 	sc = opa_vnic_get_sc(info, skb);
 	l4_hdr = info->vesw.vesw_id;
 
-	mdata = (struct opa_vnic_skb_mdata *)skb_push(skb, sizeof(*mdata));
+	mdata = skb_push(skb, sizeof(*mdata));
 	mdata->vl = opa_vnic_get_vl(adapter, skb);
 	mdata->entropy = entropy;
 	mdata->flags = 0;

drivers/infiniband/ulp/opa_vnic/opa_vnic_netdev.c

@@ -103,7 +103,7 @@ static u16 opa_vnic_select_queue(struct net_device *netdev, struct sk_buff *skb,
 	int rc;
 
 	/* pass entropy and vl as metadata in skb */
-	mdata = (struct opa_vnic_skb_mdata *)skb_push(skb, sizeof(*mdata));
+	mdata = skb_push(skb, sizeof(*mdata));
 	mdata->entropy =  opa_vnic_calc_entropy(adapter, skb);
 	mdata->vl = opa_vnic_get_vl(adapter, skb);
 	rc = adapter->rn_ops->ndo_select_queue(netdev, skb,

drivers/isdn/i4l/isdn_ppp.c

@@ -1312,7 +1312,7 @@ isdn_ppp_xmit(struct sk_buff *skb, struct net_device *netdev)
 	/* check if we should pass this packet
 	 * the filter instructions are constructed assuming
 	 * a four-byte PPP header on each packet */
-	*skb_push(skb, 4) = 1; /* indicate outbound */
+	*(u8 *)skb_push(skb, 4) = 1; /* indicate outbound */
 
 	{
 		__be16 *p = (__be16 *)skb->data;

drivers/net/arcnet/arc-rawmode.c

@@ -85,7 +85,7 @@ static int build_header(struct sk_buff *skb, struct net_device *dev,
 			unsigned short type, uint8_t daddr)
 {
 	int hdr_size = ARC_HDR_SIZE;
-	struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
+	struct archdr *pkt = skb_push(skb, hdr_size);
 
 	/* Set the source hardware address.
 	 *

drivers/net/arcnet/capmode.c

@@ -101,7 +101,7 @@ static int build_header(struct sk_buff *skb,
 			uint8_t daddr)
 {
 	int hdr_size = ARC_HDR_SIZE;
-	struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
+	struct archdr *pkt = skb_push(skb, hdr_size);
 
 	arc_printk(D_PROTO, dev, "Preparing header for cap packet %x.\n",
 		   *((int *)&pkt->soft.cap.cookie[0]));

drivers/net/arcnet/rfc1051.c

@@ -162,7 +162,7 @@ static int build_header(struct sk_buff *skb, struct net_device *dev,
 			unsigned short type, uint8_t daddr)
 {
 	int hdr_size = ARC_HDR_SIZE + RFC1051_HDR_SIZE;
-	struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
+	struct archdr *pkt = skb_push(skb, hdr_size);
 	struct arc_rfc1051 *soft = &pkt->soft.rfc1051;
 
 	/* set the protocol ID according to RFC1051 */

drivers/net/arcnet/rfc1201.c

@@ -379,7 +379,7 @@ static int build_header(struct sk_buff *skb, struct net_device *dev,
 {
 	struct arcnet_local *lp = netdev_priv(dev);
 	int hdr_size = ARC_HDR_SIZE + RFC1201_HDR_SIZE;
-	struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
+	struct archdr *pkt = skb_push(skb, hdr_size);
 	struct arc_rfc1201 *soft = &pkt->soft.rfc1201;
 
 	/* set the protocol ID according to RFC1201 */

drivers/net/ethernet/broadcom/bcmsysport.c

@@ -1099,7 +1099,7 @@ static struct sk_buff *bcm_sysport_insert_tsb(struct sk_buff *skb,
 		skb = nskb;
 	}
 
-	tsb = (struct bcm_tsb *)skb_push(skb, sizeof(*tsb));
+	tsb = skb_push(skb, sizeof(*tsb));
 	/* Zero-out TSB by default */
 	memset(tsb, 0, sizeof(*tsb));
 

drivers/net/ethernet/chelsio/cxgb/sge.c

@@ -1801,7 +1801,7 @@ netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		eth_type = skb_network_offset(skb) == ETH_HLEN ?
 			CPL_ETH_II : CPL_ETH_II_VLAN;
 
-		hdr = (struct cpl_tx_pkt_lso *)skb_push(skb, sizeof(*hdr));
+		hdr = skb_push(skb, sizeof(*hdr));
 		hdr->opcode = CPL_TX_PKT_LSO;
 		hdr->ip_csum_dis = hdr->l4_csum_dis = 0;
 		hdr->ip_hdr_words = ip_hdr(skb)->ihl;
@@ -1849,7 +1849,7 @@ netdev_tx_t t1_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			}
 		}
 
-		cpl = (struct cpl_tx_pkt *)__skb_push(skb, sizeof(*cpl));
+		cpl = __skb_push(skb, sizeof(*cpl));
 		cpl->opcode = CPL_TX_PKT;
 		cpl->ip_csum_dis = 1;    /* SW calculates IP csum */
 		cpl->l4_csum_dis = skb->ip_summed == CHECKSUM_PARTIAL ? 0 : 1;

drivers/net/ethernet/freescale/gianfar.c

@@ -2250,7 +2250,7 @@ static int gfar_enet_open(struct net_device *dev)
 
 static inline struct txfcb *gfar_add_fcb(struct sk_buff *skb)
 {
-	struct txfcb *fcb = (struct txfcb *)skb_push(skb, GMAC_FCB_LEN);
+	struct txfcb *fcb = skb_push(skb, GMAC_FCB_LEN);
 
 	memset(fcb, 0, GMAC_FCB_LEN);
 

drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c

@@ -132,7 +132,7 @@ static struct sk_buff *mlx5e_test_get_udp_skb(struct mlx5e_priv *priv)
 	skb_reserve(skb, NET_IP_ALIGN);
 
 	/*  Reserve for ethernet and IP header  */
-	ethh = (struct ethhdr *)skb_push(skb, ETH_HLEN);
+	ethh = skb_push(skb, ETH_HLEN);
 	skb_reset_mac_header(skb);
 
 	skb_set_network_header(skb, skb->len);

drivers/net/ethernet/sun/niu.c

@@ -6667,7 +6667,7 @@ static netdev_tx_t niu_start_xmit(struct sk_buff *skb,
 	headroom = align + sizeof(struct tx_pkt_hdr);
 
 	ehdr = (struct ethhdr *) skb->data;
-	tp = (struct tx_pkt_hdr *) skb_push(skb, headroom);
+	tp = skb_push(skb, headroom);
 
 	len = skb->len - sizeof(struct tx_pkt_hdr);
 	tp->flags = cpu_to_le64(niu_compute_tx_flags(skb, ehdr, align, len));

drivers/net/ethernet/toshiba/ps3_gelic_net.c

@@ -754,7 +754,7 @@ static struct sk_buff *gelic_put_vlan_tag(struct sk_buff *skb,
 			return NULL;
 		dev_kfree_skb_any(sk_tmp);
 	}
-	veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
+	veth = skb_push(skb, VLAN_HLEN);
 
 	/* Move the mac addresses to the top of buffer */
 	memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);

drivers/net/geneve.c

@@ -687,8 +687,7 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb,
 	if (err)
 		goto free_dst;
 
-	gnvh = (struct genevehdr *)__skb_push(skb, sizeof(*gnvh) +
-						   info->options_len);
+	gnvh = __skb_push(skb, sizeof(*gnvh) + info->options_len);
 	geneve_build_header(gnvh, info);
 	skb_set_inner_protocol(skb, htons(ETH_P_TEB));
 	return 0;