[NET] Generalise TCP's struct open_request minisock infrastructure

Kept this first changeset minimal, without changing existing names to
ease peer review.

Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:

->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
  a specific protocol

The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.

I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.

Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)

Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 114 insertions, 106 deletions

diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index e923d2f..dd47e6d 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -190,6 +190,8 @@ static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb,
 struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 			     struct ip_options *opt)
 {
+	struct inet_request_sock *ireq;
+	struct tcp_request_sock *treq;
 	struct tcp_sock *tp = tcp_sk(sk);
 	__u32 cookie = ntohl(skb->h.th->ack_seq) - 1; 
 	struct sock *ret = sk;
@@ -209,19 +211,20 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 
 	NET_INC_STATS_BH(LINUX_MIB_SYNCOOKIESRECV);
 
-	req = tcp_openreq_alloc();
 	ret = NULL;
+	req = tcp_openreq_alloc(&or_ipv4); /* for safety */
 	if (!req)
 		goto out;
 
-	req->rcv_isn		= htonl(skb->h.th->seq) - 1;
-	req->snt_isn		= cookie; 
+	ireq = inet_rsk(req);
+	treq = tcp_rsk(req);
+	treq->rcv_isn		= htonl(skb->h.th->seq) - 1;
+	treq->snt_isn		= cookie; 
 	req->mss		= mss;
- 	req->rmt_port		= skb->h.th->source;
-	req->af.v4_req.loc_addr = skb->nh.iph->daddr;
-	req->af.v4_req.rmt_addr = skb->nh.iph->saddr;
-	req->class		= &or_ipv4; /* for savety */
-	req->af.v4_req.opt	= NULL;
+ 	ireq->rmt_port		= skb->h.th->source;
+	ireq->loc_addr		= skb->nh.iph->daddr;
+	ireq->rmt_addr		= skb->nh.iph->saddr;
+	ireq->opt		= NULL;
 
 	/* We throwed the options of the initial SYN away, so we hope
 	 * the ACK carries the same options again (see RFC1122 4.2.3.8)
@@ -229,17 +232,15 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 	if (opt && opt->optlen) {
 		int opt_size = sizeof(struct ip_options) + opt->optlen;
 
-		req->af.v4_req.opt = kmalloc(opt_size, GFP_ATOMIC);
-		if (req->af.v4_req.opt) {
-			if (ip_options_echo(req->af.v4_req.opt, skb)) {
-				kfree(req->af.v4_req.opt);
-				req->af.v4_req.opt = NULL;
-			}
+		ireq->opt = kmalloc(opt_size, GFP_ATOMIC);
+		if (ireq->opt != NULL && ip_options_echo(ireq->opt, skb)) {
+			kfree(ireq->opt);
+			ireq->opt = NULL;
 		}
 	}
 
-	req->snd_wscale = req->rcv_wscale = req->tstamp_ok = 0;
-	req->wscale_ok	= req->sack_ok = 0; 
+	ireq->snd_wscale = ireq->rcv_wscale = ireq->tstamp_ok = 0;
+	ireq->wscale_ok	 = ireq->sack_ok = 0; 
 	req->expires	= 0UL; 
 	req->retrans	= 0; 
 	
@@ -253,8 +254,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 		struct flowi fl = { .nl_u = { .ip4_u =
 					      { .daddr = ((opt && opt->srr) ?
 							  opt->faddr :
-							  req->af.v4_req.rmt_addr),
-						.saddr = req->af.v4_req.loc_addr,
+							  ireq->rmt_addr),
+						.saddr = ireq->loc_addr,
 						.tos = RT_CONN_FLAGS(sk) } },
 				    .proto = IPPROTO_TCP,
 				    .uli_u = { .ports =
@@ -272,7 +273,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 				  &req->rcv_wnd, &req->window_clamp, 
 				  0, &rcv_wscale);
 	/* BTW win scale with syncookies is 0 by definition */
-	req->rcv_wscale	  = rcv_wscale; 
+	ireq->rcv_wscale  = rcv_wscale; 
 
 	ret = get_cookie_sock(sk, skb, req, &rt->u.dst);
 out:	return ret;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 0d9a4fd..a3cabfa 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -271,7 +271,6 @@ int sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT;
 
 DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics);
 
-kmem_cache_t *tcp_openreq_cachep;
 kmem_cache_t *tcp_bucket_cachep;
 kmem_cache_t *tcp_timewait_cachep;
 
@@ -2271,13 +2270,6 @@ void __init tcp_init(void)
 		__skb_cb_too_small_for_tcp(sizeof(struct tcp_skb_cb),
 					   sizeof(skb->cb));
 
-	tcp_openreq_cachep = kmem_cache_create("tcp_open_request",
-						   sizeof(struct open_request),
-					       0, SLAB_HWCACHE_ALIGN,
-					       NULL, NULL);
-	if (!tcp_openreq_cachep)
-		panic("tcp_init: Cannot alloc open_request cache.");
-
 	tcp_bucket_cachep = kmem_cache_create("tcp_bind_bucket",
 					      sizeof(struct tcp_bind_bucket),
 					      0, SLAB_HWCACHE_ALIGN,
@@ -2374,7 +2366,6 @@ EXPORT_SYMBOL(tcp_destroy_sock);
 EXPORT_SYMBOL(tcp_disconnect);
 EXPORT_SYMBOL(tcp_getsockopt);
 EXPORT_SYMBOL(tcp_ioctl);
-EXPORT_SYMBOL(tcp_openreq_cachep);
 EXPORT_SYMBOL(tcp_poll);
 EXPORT_SYMBOL(tcp_read_sock);
 EXPORT_SYMBOL(tcp_recvmsg);
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
index 8faa894..700ff24 100644
--- a/net/ipv4/tcp_diag.c
+++ b/net/ipv4/tcp_diag.c
@@ -458,6 +458,7 @@ static int tcpdiag_fill_req(struct sk_buff *skb, struct sock *sk,
 			    struct open_request *req,
 			    u32 pid, u32 seq)
 {
+	const struct inet_request_sock *ireq = inet_rsk(req);
 	struct inet_sock *inet = inet_sk(sk);
 	unsigned char *b = skb->tail;
 	struct tcpdiagmsg *r;
@@ -482,9 +483,9 @@ static int tcpdiag_fill_req(struct sk_buff *skb, struct sock *sk,
 		tmo = 0;
 
 	r->id.tcpdiag_sport = inet->sport;
-	r->id.tcpdiag_dport = req->rmt_port;
-	r->id.tcpdiag_src[0] = req->af.v4_req.loc_addr;
-	r->id.tcpdiag_dst[0] = req->af.v4_req.rmt_addr;
+	r->id.tcpdiag_dport = ireq->rmt_port;
+	r->id.tcpdiag_src[0] = ireq->loc_addr;
+	r->id.tcpdiag_dst[0] = ireq->rmt_addr;
 	r->tcpdiag_expires = jiffies_to_msecs(tmo),
 	r->tcpdiag_rqueue = 0;
 	r->tcpdiag_wqueue = 0;
@@ -493,9 +494,9 @@ static int tcpdiag_fill_req(struct sk_buff *skb, struct sock *sk,
 #ifdef CONFIG_IP_TCPDIAG_IPV6
 	if (r->tcpdiag_family == AF_INET6) {
 		ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_src,
-			       &req->af.v6_req.loc_addr);
+			       &tcp6_rsk(req)->loc_addr);
 		ipv6_addr_copy((struct in6_addr *)r->id.tcpdiag_dst,
-			       &req->af.v6_req.rmt_addr);
+			       &tcp6_rsk(req)->rmt_addr);
 	}
 #endif
 	nlh->nlmsg_len = skb->tail - b;
@@ -545,9 +546,11 @@ static int tcpdiag_dump_reqs(struct sk_buff *skb, struct sock *sk,
 
 		reqnum = 0;
 		for (req = head; req; reqnum++, req = req->dl_next) {
+			struct inet_request_sock *ireq = inet_rsk(req);
+
 			if (reqnum < s_reqnum)
 				continue;
-			if (r->id.tcpdiag_dport != req->rmt_port &&
+			if (r->id.tcpdiag_dport != ireq->rmt_port &&
 			    r->id.tcpdiag_dport)
 				continue;
 
@@ -555,16 +558,16 @@ static int tcpdiag_dump_reqs(struct sk_buff *skb, struct sock *sk,
 				entry.saddr =
 #ifdef CONFIG_IP_TCPDIAG_IPV6
 					(entry.family == AF_INET6) ?
-					req->af.v6_req.loc_addr.s6_addr32 :
+					tcp6_rsk(req)->loc_addr.s6_addr32 :
 #endif
-					&req->af.v4_req.loc_addr;
+					&ireq->loc_addr;
 				entry.daddr = 
 #ifdef CONFIG_IP_TCPDIAG_IPV6
 					(entry.family == AF_INET6) ?
-					req->af.v6_req.rmt_addr.s6_addr32 :
+					tcp6_rsk(req)->rmt_addr.s6_addr32 :
 #endif
-					&req->af.v4_req.rmt_addr;
-				entry.dport = ntohs(req->rmt_port);
+					&ireq->rmt_addr;
+				entry.dport = ntohs(ireq->rmt_port);
 
 				if (!tcpdiag_bc_run(RTA_DATA(bc),
 						    RTA_PAYLOAD(bc), &entry))
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index dad98e4..e156be9 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -880,9 +880,11 @@ static struct open_request *tcp_v4_search_req(struct tcp_sock *tp,
 	for (prev = &lopt->syn_table[tcp_v4_synq_hash(raddr, rport, lopt->hash_rnd)];
 	     (req = *prev) != NULL;
 	     prev = &req->dl_next) {
-		if (req->rmt_port == rport &&
-		    req->af.v4_req.rmt_addr == raddr &&
-		    req->af.v4_req.loc_addr == laddr &&
+		const struct inet_request_sock *ireq = inet_rsk(req);
+
+		if (ireq->rmt_port == rport &&
+		    ireq->rmt_addr == raddr &&
+		    ireq->loc_addr == laddr &&
 		    TCP_INET_FAMILY(req->class->family)) {
 			BUG_TRAP(!req->sk);
 			*prevp = prev;
@@ -897,7 +899,7 @@ static void tcp_v4_synq_add(struct sock *sk, struct open_request *req)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcp_listen_opt *lopt = tp->listen_opt;
-	u32 h = tcp_v4_synq_hash(req->af.v4_req.rmt_addr, req->rmt_port, lopt->hash_rnd);
+	u32 h = tcp_v4_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, lopt->hash_rnd);
 
 	req->expires = jiffies + TCP_TIMEOUT_INIT;
 	req->retrans = 0;
@@ -1065,7 +1067,7 @@ void tcp_v4_err(struct sk_buff *skb, u32 info)
 		 */
 		BUG_TRAP(!req->sk);
 
-		if (seq != req->snt_isn) {
+		if (seq != tcp_rsk(req)->snt_isn) {
 			NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
 			goto out;
 		}
@@ -1256,7 +1258,7 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
 
 static void tcp_v4_or_send_ack(struct sk_buff *skb, struct open_request *req)
 {
-	tcp_v4_send_ack(skb, req->snt_isn + 1, req->rcv_isn + 1, req->rcv_wnd,
+	tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
 			req->ts_recent);
 }
 
@@ -1264,18 +1266,19 @@ static struct dst_entry* tcp_v4_route_req(struct sock *sk,
 					  struct open_request *req)
 {
 	struct rtable *rt;
-	struct ip_options *opt = req->af.v4_req.opt;
+	const struct inet_request_sock *ireq = inet_rsk(req);
+	struct ip_options *opt = inet_rsk(req)->opt;
 	struct flowi fl = { .oif = sk->sk_bound_dev_if,
 			    .nl_u = { .ip4_u =
 				      { .daddr = ((opt && opt->srr) ?
 						  opt->faddr :
-						  req->af.v4_req.rmt_addr),
-					.saddr = req->af.v4_req.loc_addr,
+						  ireq->rmt_addr),
+					.saddr = ireq->loc_addr,
 					.tos = RT_CONN_FLAGS(sk) } },
 			    .proto = IPPROTO_TCP,
 			    .uli_u = { .ports =
 				       { .sport = inet_sk(sk)->sport,
-					 .dport = req->rmt_port } } };
+					 .dport = ireq->rmt_port } } };
 
 	if (ip_route_output_flow(&rt, &fl, sk, 0)) {
 		IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
@@ -1297,6 +1300,7 @@ static struct dst_entry* tcp_v4_route_req(struct sock *sk,
 static int tcp_v4_send_synack(struct sock *sk, struct open_request *req,
 			      struct dst_entry *dst)
 {
+	const struct inet_request_sock *ireq = inet_rsk(req);
 	int err = -1;
 	struct sk_buff * skb;
 
@@ -1310,14 +1314,14 @@ static int tcp_v4_send_synack(struct sock *sk, struct open_request *req,
 		struct tcphdr *th = skb->h.th;
 
 		th->check = tcp_v4_check(th, skb->len,
-					 req->af.v4_req.loc_addr,
-					 req->af.v4_req.rmt_addr,
+					 ireq->loc_addr,
+					 ireq->rmt_addr,
 					 csum_partial((char *)th, skb->len,
 						      skb->csum));
 
-		err = ip_build_and_send_pkt(skb, sk, req->af.v4_req.loc_addr,
-					    req->af.v4_req.rmt_addr,
-					    req->af.v4_req.opt);
+		err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
+					    ireq->rmt_addr,
+					    ireq->opt);
 		if (err == NET_XMIT_CN)
 			err = 0;
 	}
@@ -1332,8 +1336,8 @@ out:
  */
 static void tcp_v4_or_free(struct open_request *req)
 {
-	if (req->af.v4_req.opt)
-		kfree(req->af.v4_req.opt);
+	if (inet_rsk(req)->opt)
+		kfree(inet_rsk(req)->opt);
 }
 
 static inline void syn_flood_warning(struct sk_buff *skb)
@@ -1387,6 +1391,7 @@ int sysctl_max_syn_backlog = 256;
 
 struct or_calltable or_ipv4 = {
 	.family		=	PF_INET,
+	.obj_size	=	sizeof(struct tcp_request_sock),
 	.rtx_syn_ack	=	tcp_v4_send_synack,
 	.send_ack	=	tcp_v4_or_send_ack,
 	.destructor	=	tcp_v4_or_free,
@@ -1395,6 +1400,7 @@ struct or_calltable or_ipv4 = {
 
 int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 {
+	struct inet_request_sock *ireq;
 	struct tcp_options_received tmp_opt;
 	struct open_request *req;
 	__u32 saddr = skb->nh.iph->saddr;
@@ -1433,7 +1439,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 	if (sk_acceptq_is_full(sk) && tcp_synq_young(sk) > 1)
 		goto drop;
 
-	req = tcp_openreq_alloc();
+	req = tcp_openreq_alloc(&or_ipv4);
 	if (!req)
 		goto drop;
 
@@ -1461,10 +1467,10 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 
 	tcp_openreq_init(req, &tmp_opt, skb);
 
-	req->af.v4_req.loc_addr = daddr;
-	req->af.v4_req.rmt_addr = saddr;
-	req->af.v4_req.opt = tcp_v4_save_options(sk, skb);
-	req->class = &or_ipv4;
+	ireq = inet_rsk(req);
+	ireq->loc_addr = daddr;
+	ireq->rmt_addr = saddr;
+	ireq->opt = tcp_v4_save_options(sk, skb);
 	if (!want_cookie)
 		TCP_ECN_create_request(req, skb->h.th);
 
@@ -1523,7 +1529,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 
 		isn = tcp_v4_init_sequence(sk, skb);
 	}
-	req->snt_isn = isn;
+	tcp_rsk(req)->snt_isn = isn;
 
 	if (tcp_v4_send_synack(sk, req, dst))
 		goto drop_and_free;
@@ -1551,6 +1557,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 				  struct open_request *req,
 				  struct dst_entry *dst)
 {
+	struct inet_request_sock *ireq;
 	struct inet_sock *newinet;
 	struct tcp_sock *newtp;
 	struct sock *newsk;
@@ -1570,11 +1577,12 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 
 	newtp		      = tcp_sk(newsk);
 	newinet		      = inet_sk(newsk);
-	newinet->daddr	      = req->af.v4_req.rmt_addr;
-	newinet->rcv_saddr    = req->af.v4_req.loc_addr;
-	newinet->saddr	      = req->af.v4_req.loc_addr;
-	newinet->opt	      = req->af.v4_req.opt;
-	req->af.v4_req.opt    = NULL;
+	ireq		      = inet_rsk(req);
+	newinet->daddr	      = ireq->rmt_addr;
+	newinet->rcv_saddr    = ireq->loc_addr;
+	newinet->saddr	      = ireq->loc_addr;
+	newinet->opt	      = ireq->opt;
+	ireq->opt	      = NULL;
 	newinet->mc_index     = tcp_v4_iif(skb);
 	newinet->mc_ttl	      = skb->nh.iph->ttl;
 	newtp->ext_header_len = 0;
@@ -2454,15 +2462,16 @@ void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo)
 static void get_openreq4(struct sock *sk, struct open_request *req,
 			 char *tmpbuf, int i, int uid)
 {
+	const struct inet_request_sock *ireq = inet_rsk(req);
 	int ttd = req->expires - jiffies;
 
 	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
 		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p",
 		i,
-		req->af.v4_req.loc_addr,
+		ireq->loc_addr,
 		ntohs(inet_sk(sk)->sport),
-		req->af.v4_req.rmt_addr,
-		ntohs(req->rmt_port),
+		ireq->rmt_addr,
+		ntohs(ireq->rmt_port),
 		TCP_SYN_RECV,
 		0, 0, /* could print option size, but that is af dependent. */
 		1,    /* timers active (only the expire timer) */
@@ -2618,6 +2627,7 @@ struct proto tcp_prot = {
 	.sysctl_rmem		= sysctl_tcp_rmem,
 	.max_header		= MAX_TCP_HEADER,
 	.obj_size		= sizeof(struct tcp_sock),
+	.rsk_prot		= &or_ipv4,
 };
 
 
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index eea1a17..1037401 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -692,6 +692,8 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct open_request *req,
 	struct sock *newsk = sk_alloc(PF_INET, GFP_ATOMIC, sk->sk_prot, 0);
 
 	if(newsk != NULL) {
+		struct inet_request_sock *ireq = inet_rsk(req);
+		struct tcp_request_sock *treq = tcp_rsk(req);
 		struct tcp_sock *newtp;
 		struct sk_filter *filter;
 
@@ -703,7 +705,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct open_request *req,
 		tcp_sk(newsk)->bind_hash = NULL;
 
 		/* Clone the TCP header template */
-		inet_sk(newsk)->dport = req->rmt_port;
+		inet_sk(newsk)->dport = ireq->rmt_port;
 
 		sock_lock_init(newsk);
 		bh_lock_sock(newsk);
@@ -739,14 +741,14 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct open_request *req,
 		/* Now setup tcp_sock */
 		newtp = tcp_sk(newsk);
 		newtp->pred_flags = 0;
-		newtp->rcv_nxt = req->rcv_isn + 1;
-		newtp->snd_nxt = req->snt_isn + 1;
-		newtp->snd_una = req->snt_isn + 1;
-		newtp->snd_sml = req->snt_isn + 1;
+		newtp->rcv_nxt = treq->rcv_isn + 1;
+		newtp->snd_nxt = treq->snt_isn + 1;
+		newtp->snd_una = treq->snt_isn + 1;
+		newtp->snd_sml = treq->snt_isn + 1;
 
 		tcp_prequeue_init(newtp);
 
-		tcp_init_wl(newtp, req->snt_isn, req->rcv_isn);
+		tcp_init_wl(newtp, treq->snt_isn, treq->rcv_isn);
 
 		newtp->retransmits = 0;
 		newtp->backoff = 0;
@@ -775,10 +777,10 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct open_request *req,
 		tcp_set_ca_state(newtp, TCP_CA_Open);
 		tcp_init_xmit_timers(newsk);
 		skb_queue_head_init(&newtp->out_of_order_queue);
-		newtp->rcv_wup = req->rcv_isn + 1;
-		newtp->write_seq = req->snt_isn + 1;
+		newtp->rcv_wup = treq->rcv_isn + 1;
+		newtp->write_seq = treq->snt_isn + 1;
 		newtp->pushed_seq = newtp->write_seq;
-		newtp->copied_seq = req->rcv_isn + 1;
+		newtp->copied_seq = treq->rcv_isn + 1;
 
 		newtp->rx_opt.saw_tstamp = 0;
 
@@ -808,18 +810,18 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct open_request *req,
 		newsk->sk_socket = NULL;
 		newsk->sk_sleep = NULL;
 
-		newtp->rx_opt.tstamp_ok = req->tstamp_ok;
-		if((newtp->rx_opt.sack_ok = req->sack_ok) != 0) {
+		newtp->rx_opt.tstamp_ok = ireq->tstamp_ok;
+		if((newtp->rx_opt.sack_ok = ireq->sack_ok) != 0) {
 			if (sysctl_tcp_fack)
 				newtp->rx_opt.sack_ok |= 2;
 		}
 		newtp->window_clamp = req->window_clamp;
 		newtp->rcv_ssthresh = req->rcv_wnd;
 		newtp->rcv_wnd = req->rcv_wnd;
-		newtp->rx_opt.wscale_ok = req->wscale_ok;
+		newtp->rx_opt.wscale_ok = ireq->wscale_ok;
 		if (newtp->rx_opt.wscale_ok) {
-			newtp->rx_opt.snd_wscale = req->snd_wscale;
-			newtp->rx_opt.rcv_wscale = req->rcv_wscale;
+			newtp->rx_opt.snd_wscale = ireq->snd_wscale;
+			newtp->rx_opt.rcv_wscale = ireq->rcv_wscale;
 		} else {
 			newtp->rx_opt.snd_wscale = newtp->rx_opt.rcv_wscale = 0;
 			newtp->window_clamp = min(newtp->window_clamp, 65535U);
@@ -881,7 +883,7 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
 	}
 
 	/* Check for pure retransmitted SYN. */
-	if (TCP_SKB_CB(skb)->seq == req->rcv_isn &&
+	if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn &&
 	    flg == TCP_FLAG_SYN &&
 	    !paws_reject) {
 		/*
@@ -959,7 +961,7 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
 	 * Invalid ACK: reset will be sent by listening socket
 	 */
 	if ((flg & TCP_FLAG_ACK) &&
-	    (TCP_SKB_CB(skb)->ack_seq != req->snt_isn+1))
+	    (TCP_SKB_CB(skb)->ack_seq != tcp_rsk(req)->snt_isn + 1))
 		return sk;
 
 	/* Also, it would be not so bad idea to check rcv_tsecr, which
@@ -970,7 +972,7 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
 	/* RFC793: "first check sequence number". */
 
 	if (paws_reject || !tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq,
-					  req->rcv_isn+1, req->rcv_isn+1+req->rcv_wnd)) {
+					  tcp_rsk(req)->rcv_isn + 1, tcp_rsk(req)->rcv_isn + 1 + req->rcv_wnd)) {
 		/* Out of window: send ACK and drop. */
 		if (!(flg & TCP_FLAG_RST))
 			req->class->send_ack(skb, req);
@@ -981,12 +983,12 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
 
 	/* In sequence, PAWS is OK. */
 
-	if (tmp_opt.saw_tstamp && !after(TCP_SKB_CB(skb)->seq, req->rcv_isn+1))
+	if (tmp_opt.saw_tstamp && !after(TCP_SKB_CB(skb)->seq, tcp_rsk(req)->rcv_isn + 1))
 			req->ts_recent = tmp_opt.rcv_tsval;
 
-		if (TCP_SKB_CB(skb)->seq == req->rcv_isn) {
+		if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn) {
 			/* Truncate SYN, it is out of window starting
-			   at req->rcv_isn+1. */
+			   at tcp_rsk(req)->rcv_isn + 1. */
 			flg &= ~TCP_FLAG_SYN;
 		}
 
@@ -1003,8 +1005,8 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
 			return NULL;
 
 		/* If TCP_DEFER_ACCEPT is set, drop bare ACK. */
-		if (tp->defer_accept && TCP_SKB_CB(skb)->end_seq == req->rcv_isn+1) {
-			req->acked = 1;
+		if (tp->defer_accept && TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) {
+			inet_rsk(req)->acked = 1;
 			return NULL;
 		}
 
@@ -1026,7 +1028,7 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
 
 	listen_overflow:
 		if (!sysctl_tcp_abort_on_overflow) {
-			req->acked = 1;
+			inet_rsk(req)->acked = 1;
 			return NULL;
 		}
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index fa24e7a..f3c8747 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1358,6 +1358,7 @@ int tcp_send_synack(struct sock *sk)
 struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 				 struct open_request *req)
 {
+	struct inet_request_sock *ireq = inet_rsk(req);
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct tcphdr *th;
 	int tcp_header_size;
@@ -1373,47 +1374,47 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	skb->dst = dst_clone(dst);
 
 	tcp_header_size = (sizeof(struct tcphdr) + TCPOLEN_MSS +
-			   (req->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0) +
-			   (req->wscale_ok ? TCPOLEN_WSCALE_ALIGNED : 0) +
+			   (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0) +
+			   (ireq->wscale_ok ? TCPOLEN_WSCALE_ALIGNED : 0) +
 			   /* SACK_PERM is in the place of NOP NOP of TS */
-			   ((req->sack_ok && !req->tstamp_ok) ? TCPOLEN_SACKPERM_ALIGNED : 0));
+			   ((ireq->sack_ok && !ireq->tstamp_ok) ? TCPOLEN_SACKPERM_ALIGNED : 0));
 	skb->h.th = th = (struct tcphdr *) skb_push(skb, tcp_header_size);
 
 	memset(th, 0, sizeof(struct tcphdr));
 	th->syn = 1;
 	th->ack = 1;
 	if (dst->dev->features&NETIF_F_TSO)
-		req->ecn_ok = 0;
+		ireq->ecn_ok = 0;
 	TCP_ECN_make_synack(req, th);
 	th->source = inet_sk(sk)->sport;
-	th->dest = req->rmt_port;
-	TCP_SKB_CB(skb)->seq = req->snt_isn;
+	th->dest = ireq->rmt_port;
+	TCP_SKB_CB(skb)->seq = tcp_rsk(req)->snt_isn;
 	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + 1;
 	TCP_SKB_CB(skb)->sacked = 0;
 	skb_shinfo(skb)->tso_segs = 1;
 	skb_shinfo(skb)->tso_size = 0;
 	th->seq = htonl(TCP_SKB_CB(skb)->seq);
-	th->ack_seq = htonl(req->rcv_isn + 1);
+	th->ack_seq = htonl(tcp_rsk(req)->rcv_isn + 1);
 	if (req->rcv_wnd == 0) { /* ignored for retransmitted syns */
 		__u8 rcv_wscale; 
 		/* Set this up on the first call only */
 		req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW);
 		/* tcp_full_space because it is guaranteed to be the first packet */
 		tcp_select_initial_window(tcp_full_space(sk), 
-			dst_metric(dst, RTAX_ADVMSS) - (req->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
+			dst_metric(dst, RTAX_ADVMSS) - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
 			&req->rcv_wnd,
 			&req->window_clamp,
-			req->wscale_ok,
+			ireq->wscale_ok,
 			&rcv_wscale);
-		req->rcv_wscale = rcv_wscale; 
+		ireq->rcv_wscale = rcv_wscale; 
 	}
 
 	/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
 	th->window = htons(req->rcv_wnd);
 
 	TCP_SKB_CB(skb)->when = tcp_time_stamp;
-	tcp_syn_build_options((__u32 *)(th + 1), dst_metric(dst, RTAX_ADVMSS), req->tstamp_ok,
-			      req->sack_ok, req->wscale_ok, req->rcv_wscale,
+	tcp_syn_build_options((__u32 *)(th + 1), dst_metric(dst, RTAX_ADVMSS), ireq->tstamp_ok,
+			      ireq->sack_ok, ireq->wscale_ok, ireq->rcv_wscale,
 			      TCP_SKB_CB(skb)->when,
 			      req->ts_recent);
 
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 799ebe0..ba30ca0 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -513,7 +513,7 @@ static void tcp_synack_timer(struct sock *sk)
 		while ((req = *reqp) != NULL) {
 			if (time_after_eq(now, req->expires)) {
 				if ((req->retrans < thresh ||
-				     (req->acked && req->retrans < max_retries))
+				     (inet_rsk(req)->acked && req->retrans < max_retries))
 				    && !req->class->rtx_syn_ack(sk, req, NULL)) {
 					unsigned long timeo;