networking: make skb_put & friends 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 (skb_put, __skb_put and pskb_put) 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_put, __skb_put };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_put, __skb_put };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

which actually doesn't cover pskb_put since there are only three
users overall.

A handful of stragglers were converted manually, notably a macro in
drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many
instances in net/bluetooth/hci_sock.c. In the former file, I also
had to fix one whitespace problem spatch introduced.

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

2 files changed, 20 insertions, 18 deletions

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 8860ad985d68..b8bcf9021329 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2714,7 +2714,7 @@ static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb,
 	struct timeval timestamp;
 	struct pktgen_hdr *pgh;
 
-	pgh = (struct pktgen_hdr *)skb_put(skb, sizeof(*pgh));
+	pgh = skb_put(skb, sizeof(*pgh));
 	datalen -= sizeof(*pgh);
 
 	if (pkt_dev->nfrags <= 0) {
@@ -2845,33 +2845,34 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev,
 
 	/*  Reserve for ethernet and IP header  */
 	eth = (__u8 *) skb_push(skb, 14);
-	mpls = (__be32 *)skb_put(skb, pkt_dev->nr_labels*sizeof(__u32));
+	mpls = skb_put(skb, pkt_dev->nr_labels * sizeof(__u32));
 	if (pkt_dev->nr_labels)
 		mpls_push(mpls, pkt_dev);
 
 	if (pkt_dev->vlan_id != 0xffff) {
 		if (pkt_dev->svlan_id != 0xffff) {
-			svlan_tci = (__be16 *)skb_put(skb, sizeof(__be16));
+			svlan_tci = skb_put(skb, sizeof(__be16));
 			*svlan_tci = build_tci(pkt_dev->svlan_id,
 					       pkt_dev->svlan_cfi,
 					       pkt_dev->svlan_p);
-			svlan_encapsulated_proto = (__be16 *)skb_put(skb, sizeof(__be16));
+			svlan_encapsulated_proto = skb_put(skb,
+							   sizeof(__be16));
 			*svlan_encapsulated_proto = htons(ETH_P_8021Q);
 		}
-		vlan_tci = (__be16 *)skb_put(skb, sizeof(__be16));
+		vlan_tci = skb_put(skb, sizeof(__be16));
 		*vlan_tci = build_tci(pkt_dev->vlan_id,
 				      pkt_dev->vlan_cfi,
 				      pkt_dev->vlan_p);
-		vlan_encapsulated_proto = (__be16 *)skb_put(skb, sizeof(__be16));
+		vlan_encapsulated_proto = skb_put(skb, sizeof(__be16));
 		*vlan_encapsulated_proto = htons(ETH_P_IP);
 	}
 
 	skb_reset_mac_header(skb);
 	skb_set_network_header(skb, skb->len);
-	iph = (struct iphdr *) skb_put(skb, sizeof(struct iphdr));
+	iph = skb_put(skb, sizeof(struct iphdr));
 
 	skb_set_transport_header(skb, skb->len);
-	udph = (struct udphdr *) skb_put(skb, sizeof(struct udphdr));
+	udph = skb_put(skb, sizeof(struct udphdr));
 	skb_set_queue_mapping(skb, queue_map);
 	skb->priority = pkt_dev->skb_priority;
 
@@ -2972,33 +2973,34 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev,
 
 	/*  Reserve for ethernet and IP header  */
 	eth = (__u8 *) skb_push(skb, 14);
-	mpls = (__be32 *)skb_put(skb, pkt_dev->nr_labels*sizeof(__u32));
+	mpls = skb_put(skb, pkt_dev->nr_labels * sizeof(__u32));
 	if (pkt_dev->nr_labels)
 		mpls_push(mpls, pkt_dev);
 
 	if (pkt_dev->vlan_id != 0xffff) {
 		if (pkt_dev->svlan_id != 0xffff) {
-			svlan_tci = (__be16 *)skb_put(skb, sizeof(__be16));
+			svlan_tci = skb_put(skb, sizeof(__be16));
 			*svlan_tci = build_tci(pkt_dev->svlan_id,
 					       pkt_dev->svlan_cfi,
 					       pkt_dev->svlan_p);
-			svlan_encapsulated_proto = (__be16 *)skb_put(skb, sizeof(__be16));
+			svlan_encapsulated_proto = skb_put(skb,
+							   sizeof(__be16));
 			*svlan_encapsulated_proto = htons(ETH_P_8021Q);
 		}
-		vlan_tci = (__be16 *)skb_put(skb, sizeof(__be16));
+		vlan_tci = skb_put(skb, sizeof(__be16));
 		*vlan_tci = build_tci(pkt_dev->vlan_id,
 				      pkt_dev->vlan_cfi,
 				      pkt_dev->vlan_p);
-		vlan_encapsulated_proto = (__be16 *)skb_put(skb, sizeof(__be16));
+		vlan_encapsulated_proto = skb_put(skb, sizeof(__be16));
 		*vlan_encapsulated_proto = htons(ETH_P_IPV6);
 	}
 
 	skb_reset_mac_header(skb);
 	skb_set_network_header(skb, skb->len);
-	iph = (struct ipv6hdr *) skb_put(skb, sizeof(struct ipv6hdr));
+	iph = skb_put(skb, sizeof(struct ipv6hdr));
 
 	skb_set_transport_header(skb, skb->len);
-	udph = (struct udphdr *) skb_put(skb, sizeof(struct udphdr));
+	udph = skb_put(skb, sizeof(struct udphdr));
 	skb_set_queue_mapping(skb, queue_map);
 	skb->priority = pkt_dev->skb_priority;
 
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c4d2c1f824bb..0baa7f2dd8ef 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1421,7 +1421,7 @@ EXPORT_SYMBOL(skb_pad);
  *	returned.
  */
 
-unsigned char *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len)
+void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len)
 {
 	if (tail != skb) {
 		skb->data_len += len;
@@ -1440,9 +1440,9 @@ EXPORT_SYMBOL_GPL(pskb_put);
  *	exceed the total buffer size the kernel will panic. A pointer to the
  *	first byte of the extra data is returned.
  */
-unsigned char *skb_put(struct sk_buff *skb, unsigned int len)
+void *skb_put(struct sk_buff *skb, unsigned int len)
 {
-	unsigned char *tmp = skb_tail_pointer(skb);
+	void *tmp = skb_tail_pointer(skb);
 	SKB_LINEAR_ASSERT(skb);
 	skb->tail += len;
 	skb->len  += len;