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>

4 files changed, 12 insertions, 12 deletions

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index b64046ccae69..e2221135858b 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1692,7 +1692,7 @@ static struct sk_buff *add_grhead(struct sk_buff *skb, struct ifmcaddr6 *pmc,
 		skb = mld_newpack(pmc->idev, dev->mtu);
 	if (!skb)
 		return NULL;
-	pgr = (struct mld2_grec *)skb_put(skb, sizeof(struct mld2_grec));
+	pgr = skb_put(skb, sizeof(struct mld2_grec));
 	pgr->grec_type = type;
 	pgr->grec_auxwords = 0;
 	pgr->grec_nsrcs = 0;
@@ -1784,7 +1784,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc,
 		}
 		if (!skb)
 			return NULL;
-		psrc = (struct in6_addr *)skb_put(skb, sizeof(*psrc));
+		psrc = skb_put(skb, sizeof(*psrc));
 		*psrc = psf->sf_addr;
 		scount++; stotal++;
 		if ((type == MLD2_ALLOW_NEW_SOURCES ||
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index d310dc41209a..0327c1f2e6fc 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -528,7 +528,7 @@ void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
 	if (!skb)
 		return;
 
-	msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
+	msg = skb_put(skb, sizeof(*msg));
 	*msg = (struct nd_msg) {
 		.icmph = {
 			.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
@@ -597,7 +597,7 @@ void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
 	if (!skb)
 		return;
 
-	msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
+	msg = skb_put(skb, sizeof(*msg));
 	*msg = (struct nd_msg) {
 		.icmph = {
 			.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
@@ -657,7 +657,7 @@ void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
 	if (!skb)
 		return;
 
-	msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
+	msg = skb_put(skb, sizeof(*msg));
 	*msg = (struct rs_msg) {
 		.icmph = {
 			.icmp6_type = NDISC_ROUTER_SOLICITATION,
@@ -1633,7 +1633,7 @@ void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target)
 	if (!buff)
 		goto release;
 
-	msg = (struct rd_msg *)skb_put(buff, sizeof(*msg));
+	msg = skb_put(buff, sizeof(*msg));
 	*msg = (struct rd_msg) {
 		.icmph = {
 			.icmp6_type = NDISC_REDIRECT,
diff --git a/net/ipv6/netfilter/ip6t_SYNPROXY.c b/net/ipv6/netfilter/ip6t_SYNPROXY.c
index d3c4daa708b9..ce203dd729e0 100644
--- a/net/ipv6/netfilter/ip6t_SYNPROXY.c
+++ b/net/ipv6/netfilter/ip6t_SYNPROXY.c
@@ -27,7 +27,7 @@ synproxy_build_ip(struct net *net, struct sk_buff *skb,
 	struct ipv6hdr *iph;
 
 	skb_reset_network_header(skb);
-	iph = (struct ipv6hdr *)skb_put(skb, sizeof(*iph));
+	iph = skb_put(skb, sizeof(*iph));
 	ip6_flow_hdr(iph, 0, 0);
 	iph->hop_limit	= net->ipv6.devconf_all->hop_limit;
 	iph->nexthdr	= IPPROTO_TCP;
@@ -105,7 +105,7 @@ synproxy_send_client_synack(struct net *net,
 	niph = synproxy_build_ip(net, nskb, &iph->daddr, &iph->saddr);
 
 	skb_reset_transport_header(nskb);
-	nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
+	nth = skb_put(nskb, tcp_hdr_size);
 	nth->source	= th->dest;
 	nth->dest	= th->source;
 	nth->seq	= htonl(__cookie_v6_init_sequence(iph, th, &mss));
@@ -147,7 +147,7 @@ synproxy_send_server_syn(struct net *net,
 	niph = synproxy_build_ip(net, nskb, &iph->saddr, &iph->daddr);
 
 	skb_reset_transport_header(nskb);
-	nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
+	nth = skb_put(nskb, tcp_hdr_size);
 	nth->source	= th->source;
 	nth->dest	= th->dest;
 	nth->seq	= htonl(recv_seq - 1);
@@ -192,7 +192,7 @@ synproxy_send_server_ack(struct net *net,
 	niph = synproxy_build_ip(net, nskb, &iph->daddr, &iph->saddr);
 
 	skb_reset_transport_header(nskb);
-	nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
+	nth = skb_put(nskb, tcp_hdr_size);
 	nth->source	= th->dest;
 	nth->dest	= th->source;
 	nth->seq	= htonl(ntohl(th->ack_seq));
@@ -230,7 +230,7 @@ synproxy_send_client_ack(struct net *net,
 	niph = synproxy_build_ip(net, nskb, &iph->saddr, &iph->daddr);
 
 	skb_reset_transport_header(nskb);
-	nth = (struct tcphdr *)skb_put(nskb, tcp_hdr_size);
+	nth = skb_put(nskb, tcp_hdr_size);
 	nth->source	= th->source;
 	nth->dest	= th->dest;
 	nth->seq	= htonl(ntohl(th->seq) + 1);
diff --git a/net/ipv6/netfilter/nf_reject_ipv6.c b/net/ipv6/netfilter/nf_reject_ipv6.c
index f63b18e05c69..24858402e374 100644
--- a/net/ipv6/netfilter/nf_reject_ipv6.c
+++ b/net/ipv6/netfilter/nf_reject_ipv6.c
@@ -95,7 +95,7 @@ void nf_reject_ip6_tcphdr_put(struct sk_buff *nskb,
 	int needs_ack;
 
 	skb_reset_transport_header(nskb);
-	tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr));
+	tcph = skb_put(nskb, sizeof(struct tcphdr));
 	/* Truncate to length (no data) */
 	tcph->doff = sizeof(struct tcphdr)/4;
 	tcph->source = oth->dest;