inet: includes a sock_common in request_sock

TCP listener refactoring, part 5 :

We want to be able to insert request sockets (SYN_RECV) into main
ehash table instead of the per listener hash table to allow RCU
lookups and remove listener lock contention.

This patch includes the needed struct sock_common in front
of struct request_sock

This means there is no more inet6_request_sock IPv6 specific
structure.

Following inet_request_sock fields were renamed as they became
macros to reference fields from struct sock_common.
Prefix ir_ was chosen to avoid name collisions.

loc_port   -> ir_loc_port
loc_addr   -> ir_loc_addr
rmt_addr   -> ir_rmt_addr
rmt_port   -> ir_rmt_port
iif        -> ir_iif

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 7f075b8..5cc5b24 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -216,7 +216,7 @@
 
 static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
 {
-	struct inet6_request_sock *ireq6 = inet6_rsk(req);
+	struct inet_request_sock *ireq = inet_rsk(req);
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct sk_buff *skb;
 	struct in6_addr *final_p, final;
@@ -226,12 +226,12 @@
 
 	memset(&fl6, 0, sizeof(fl6));
 	fl6.flowi6_proto = IPPROTO_DCCP;
-	fl6.daddr = ireq6->rmt_addr;
-	fl6.saddr = ireq6->loc_addr;
+	fl6.daddr = ireq->ir_v6_rmt_addr;
+	fl6.saddr = ireq->ir_v6_loc_addr;
 	fl6.flowlabel = 0;
-	fl6.flowi6_oif = ireq6->iif;
-	fl6.fl6_dport = inet_rsk(req)->rmt_port;
-	fl6.fl6_sport = inet_rsk(req)->loc_port;
+	fl6.flowi6_oif = ireq->ir_iif;
+	fl6.fl6_dport = ireq->ir_rmt_port;
+	fl6.fl6_sport = ireq->ir_loc_port;
 	security_req_classify_flow(req, flowi6_to_flowi(&fl6));
 
 
@@ -249,9 +249,9 @@
 		struct dccp_hdr *dh = dccp_hdr(skb);
 
 		dh->dccph_checksum = dccp_v6_csum_finish(skb,
-							 &ireq6->loc_addr,
-							 &ireq6->rmt_addr);
-		fl6.daddr = ireq6->rmt_addr;
+							 &ireq->ir_v6_loc_addr,
+							 &ireq->ir_v6_rmt_addr);
+		fl6.daddr = ireq->ir_v6_rmt_addr;
 		err = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 		err = net_xmit_eval(err);
 	}
@@ -264,8 +264,7 @@
 static void dccp_v6_reqsk_destructor(struct request_sock *req)
 {
 	dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
-	if (inet6_rsk(req)->pktopts != NULL)
-		kfree_skb(inet6_rsk(req)->pktopts);
+	kfree_skb(inet_rsk(req)->pktopts);
 }
 
 static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
@@ -359,7 +358,7 @@
 {
 	struct request_sock *req;
 	struct dccp_request_sock *dreq;
-	struct inet6_request_sock *ireq6;
+	struct inet_request_sock *ireq;
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
 	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
@@ -398,22 +397,22 @@
 	if (security_inet_conn_request(sk, skb, req))
 		goto drop_and_free;
 
-	ireq6 = inet6_rsk(req);
-	ireq6->rmt_addr = ipv6_hdr(skb)->saddr;
-	ireq6->loc_addr = ipv6_hdr(skb)->daddr;
+	ireq = inet_rsk(req);
+	ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
+	ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 
 	if (ipv6_opt_accepted(sk, skb) ||
 	    np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
 	    np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
 		atomic_inc(&skb->users);
-		ireq6->pktopts = skb;
+		ireq->pktopts = skb;
 	}
-	ireq6->iif = sk->sk_bound_dev_if;
+	ireq->ir_iif = sk->sk_bound_dev_if;
 
 	/* So that link locals have meaning */
 	if (!sk->sk_bound_dev_if &&
-	    ipv6_addr_type(&ireq6->rmt_addr) & IPV6_ADDR_LINKLOCAL)
-		ireq6->iif = inet6_iif(skb);
+	    ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
+		ireq->ir_iif = inet6_iif(skb);
 
 	/*
 	 * Step 3: Process LISTEN state
@@ -446,7 +445,7 @@
 					      struct request_sock *req,
 					      struct dst_entry *dst)
 {
-	struct inet6_request_sock *ireq6 = inet6_rsk(req);
+	struct inet_request_sock *ireq = inet_rsk(req);
 	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 	struct inet_sock *newinet;
 	struct dccp6_sock *newdp6;
@@ -505,12 +504,12 @@
 
 		memset(&fl6, 0, sizeof(fl6));
 		fl6.flowi6_proto = IPPROTO_DCCP;
-		fl6.daddr = ireq6->rmt_addr;
+		fl6.daddr = ireq->ir_v6_rmt_addr;
 		final_p = fl6_update_dst(&fl6, np->opt, &final);
-		fl6.saddr = ireq6->loc_addr;
+		fl6.saddr = ireq->ir_v6_loc_addr;
 		fl6.flowi6_oif = sk->sk_bound_dev_if;
-		fl6.fl6_dport = inet_rsk(req)->rmt_port;
-		fl6.fl6_sport = inet_rsk(req)->loc_port;
+		fl6.fl6_dport = ireq->ir_rmt_port;
+		fl6.fl6_sport = ireq->ir_loc_port;
 		security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 
 		dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
@@ -538,10 +537,10 @@
 
 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 
-	newsk->sk_v6_daddr = ireq6->rmt_addr;
-	newnp->saddr = ireq6->loc_addr;
-	newsk->sk_v6_rcv_saddr = ireq6->loc_addr;
-	newsk->sk_bound_dev_if = ireq6->iif;
+	newsk->sk_v6_daddr	= ireq->ir_v6_rmt_addr;
+	newnp->saddr		= ireq->ir_v6_loc_addr;
+	newsk->sk_v6_rcv_saddr	= ireq->ir_v6_loc_addr;
+	newsk->sk_bound_dev_if	= ireq->ir_iif;
 
 	/* Now IPv6 options...
 
@@ -554,10 +553,10 @@
 
 	/* Clone pktoptions received with SYN */
 	newnp->pktoptions = NULL;
-	if (ireq6->pktopts != NULL) {
-		newnp->pktoptions = skb_clone(ireq6->pktopts, GFP_ATOMIC);
-		consume_skb(ireq6->pktopts);
-		ireq6->pktopts = NULL;
+	if (ireq->pktopts != NULL) {
+		newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
+		consume_skb(ireq->pktopts);
+		ireq->pktopts = NULL;
 		if (newnp->pktoptions)
 			skb_set_owner_r(newnp->pktoptions, newsk);
 	}