netfilter: ipv4: prefer skb_ensure_writable

.. so skb_make_writable can be removed soon.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/ipv4/netfilter/arpt_mangle.c

@@ -17,7 +17,7 @@ target(struct sk_buff *skb, const struct xt_action_param *par)
 	unsigned char *arpptr;
 	int pln, hln;
 
-	if (!skb_make_writable(skb, skb->len))
+	if (skb_ensure_writable(skb, skb->len))
 		return NF_DROP;
 
 	arp = arp_hdr(skb);

net/ipv4/netfilter/ipt_ECN.c

@@ -32,7 +32,7 @@ set_ect_ip(struct sk_buff *skb, const struct ipt_ECN_info *einfo)
 
 	if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
 		__u8 oldtos;
-		if (!skb_make_writable(skb, sizeof(struct iphdr)))
+		if (skb_ensure_writable(skb, sizeof(struct iphdr)))
 			return false;
 		iph = ip_hdr(skb);
 		oldtos = iph->tos;
@@ -61,7 +61,7 @@ set_ect_tcp(struct sk_buff *skb, const struct ipt_ECN_info *einfo)
 	     tcph->cwr == einfo->proto.tcp.cwr))
 		return true;
 
-	if (!skb_make_writable(skb, ip_hdrlen(skb) + sizeof(*tcph)))
+	if (skb_ensure_writable(skb, ip_hdrlen(skb) + sizeof(*tcph)))
 		return false;
 	tcph = (void *)ip_hdr(skb) + ip_hdrlen(skb);
 

net/ipv4/netfilter/nf_nat_h323.c

@@ -59,7 +59,7 @@ static int set_addr(struct sk_buff *skb, unsigned int protoff,
 			net_notice_ratelimited("nf_nat_h323: nf_nat_mangle_udp_packet error\n");
 			return -1;
 		}
-		/* nf_nat_mangle_udp_packet uses skb_make_writable() to copy
+		/* nf_nat_mangle_udp_packet uses skb_ensure_writable() to copy
 		 * or pull everything in a linear buffer, so we can safely
 		 * use the skb pointers now */
 		*data = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);

net/ipv4/netfilter/nf_nat_snmp_basic_main.c

@@ -186,7 +186,7 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 		return NF_DROP;
 	}
 
-	if (!skb_make_writable(skb, skb->len)) {
+	if (skb_ensure_writable(skb, skb->len)) {
 		nf_ct_helper_log(skb, ct, "cannot mangle packet");
 		return NF_DROP;
 	}

net/netfilter/nf_nat_sip.c

@@ -285,7 +285,7 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
 	if (dir == IP_CT_DIR_REPLY && ct_sip_info->forced_dport) {
 		struct udphdr *uh;
 
-		if (!skb_make_writable(skb, skb->len)) {
+		if (skb_ensure_writable(skb, skb->len)) {
 			nf_ct_helper_log(skb, ct, "cannot mangle packet");
 			return NF_DROP;
 		}