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TCPCT part 1a: add function parameter for sending SYNACK

PATCH Superseded William Allen Simpson 1 participant 1 message Oct 18, 2009

Subsystems (3)
Networking Network drivers TCP

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William Allen Simpson

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PATCH 1/4 TCPCT part 1a: add function parameter for sending SYNACK

Add optional function parameters associated with sending SYNACK. These parameters are not needed after sending SYNACK, and are not used for retransmission. Avoids extending struct tcp_request_sock, and avoids allocating kernel memory.

Only affects DCCP as it also uses common struct request_sock_ops, but this void parameter is currently reserved for future use.

---
  include/net/request_sock.h      |    3 ++-
  include/net/tcp.h               |    3 ++-
  net/dccp/ipv4.c                 |    5 +++--
  net/dccp/ipv6.c                 |    5 +++--
  net/dccp/minisocks.c            |    2 +-
  net/ipv4/inet_connection_sock.c |    2 +-
  net/ipv4/tcp_ipv4.c             |   12 +++++++-----
  net/ipv4/tcp_minisocks.c        |    2 +-
  net/ipv4/tcp_output.c           |    2 +-
  net/ipv6/tcp_ipv6.c             |   14 +++++++-------
  10 files changed, 28 insertions(+), 22 deletions(-)
include/net/request_sock.h +2 -1
index c719084..cdd9e8b 100644
@@ -33,7 +33,8 @@ struct request_sock_ops {
 	struct kmem_cache	*slab;
 	char		*slab_name;
 	int		(*rtx_syn_ack)(struct sock *sk,
-				       struct request_sock *req);
+				       struct request_sock *req,
+				       void *extend_values);
 	void		(*send_ack)(struct sock *sk, struct sk_buff *skb,
 				    struct request_sock *req);
 	void		(*send_reset)(struct sock *sk,
include/net/tcp.h +2 -1
index 03a49c7..28bcaf7 100644
@@ -443,7 +443,8 @@ extern int			tcp_connect(struct sock *sk);
 
 extern struct sk_buff *		tcp_make_synack(struct sock *sk,
 						struct dst_entry *dst,
-						struct request_sock *req);
+						struct request_sock *req,
+						void *extend_values);
 
 extern int			tcp_disconnect(struct sock *sk, int flags);
net/dccp/ipv4.c +3 -2
index 7302e14..6fc9ea3 100644
@@ -473,7 +473,8 @@ static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
 	return &rt->u.dst;
 }
 
-static int dccp_v4_send_response(struct sock *sk, struct request_sock *req)
+static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
+				 void *extend_unused)
 {
 	int err = -1;
 	struct sk_buff *skb;

@@ -622,7 +623,7 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 	dreq->dreq_iss	   = dccp_v4_init_sequence(skb);
 	dreq->dreq_service = service;
 
-	if (dccp_v4_send_response(sk, req))
+	if (dccp_v4_send_response(sk, req, NULL))
 		goto drop_and_free;
 
 	inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
net/dccp/ipv6.c +3 -2
index a2afb55..63fb189 100644
@@ -241,7 +241,8 @@ out:
 }
 
 
-static int dccp_v6_send_response(struct sock *sk, struct request_sock *req)
+static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
+				 void *extend_unused)
 {
 	struct inet6_request_sock *ireq6 = inet6_rsk(req);
 	struct ipv6_pinfo *np = inet6_sk(sk);

@@ -468,7 +469,7 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 	dreq->dreq_iss	   = dccp_v6_init_sequence(skb);
 	dreq->dreq_service = service;
 
-	if (dccp_v6_send_response(sk, req))
+	if (dccp_v6_send_response(sk, req, NULL))
 		goto drop_and_free;
 
 	inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
net/dccp/minisocks.c +1 -1
index 5ca49ce..af226a0 100644
@@ -184,7 +184,7 @@ struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
 			 * counter (backoff, monitored by dccp_response_timer).
 			 */
 			req->retrans++;
-			req->rsk_ops->rtx_syn_ack(sk, req);
+			req->rsk_ops->rtx_syn_ack(sk, req, NULL);
 		}
 		/* Network Duplicate, discard packet */
 		return NULL;
net/ipv4/inet_connection_sock.c +1 -1
index 9139e8f..b7314f2 100644
@@ -504,7 +504,7 @@ void inet_csk_reqsk_queue_prune(struct sock *parent,
 			if (time_after_eq(now, req->expires)) {
 				if ((req->retrans < thresh ||
 				     (inet_rsk(req)->acked && req->retrans < max_retries))
-				    && !req->rsk_ops->rtx_syn_ack(parent, req)) {
+				    && !req->rsk_ops->rtx_syn_ack(parent, req, NULL)) {
 					unsigned long timeo;
 
 					if (req->retrans++ == 0)
net/ipv4/tcp_ipv4.c +7 -5
index 9971870..2d25bd4 100644
@@ -742,7 +742,7 @@ static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
  *	socket.
  */
 static int __tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
-				struct dst_entry *dst)
+				struct dst_entry *dst, void *extend_values)
 {
 	const struct inet_request_sock *ireq = inet_rsk(req);
 	int err = -1;

@@ -752,7 +752,7 @@ static int __tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
 	if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
 		return -1;
 
-	skb = tcp_make_synack(sk, dst, req);
+	skb = tcp_make_synack(sk, dst, req, extend_values);
 
 	if (skb) {
 		struct tcphdr *th = tcp_hdr(skb);

@@ -773,9 +773,10 @@ static int __tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
 	return err;
 }
 
-static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req)
+static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
+			      void *extend_values)
 {
-	return __tcp_v4_send_synack(sk, req, NULL);
+	return __tcp_v4_send_synack(sk, req, NULL, extend_values);
 }
 
 /*

@@ -1333,7 +1334,8 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
 	}
 	tcp_rsk(req)->snt_isn = isn;
 
-	if (__tcp_v4_send_synack(sk, req, dst) || want_cookie)
+	if (__tcp_v4_send_synack(sk, req, dst, NULL) ||
+	    want_cookie)
 		goto drop_and_free;
 
 	inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
net/ipv4/tcp_minisocks.c +1 -1
index e320afe..8819882 100644
@@ -537,7 +537,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 		 * Enforce "SYN-ACK" according to figure 8, figure 6
 		 * of RFC793, fixed by RFC1122.
 		 */
-		req->rsk_ops->rtx_syn_ack(sk, req);
+		req->rsk_ops->rtx_syn_ack(sk, req, NULL);
 		return NULL;
 	}
net/ipv4/tcp_output.c +1 -1
index fcd278a..765d80f 100644
@@ -2219,7 +2219,7 @@ int tcp_send_synack(struct sock *sk)
 
 /* Prepare a SYN-ACK. */
 struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
-				struct request_sock *req)
+				struct request_sock *req, void *extend_values)
 {
 	struct inet_request_sock *ireq = inet_rsk(req);
 	struct tcp_sock *tp = tcp_sk(sk);
net/ipv6/tcp_ipv6.c +7 -7
index 4517630..3b3d7b3 100644
@@ -460,7 +460,8 @@ out:
 }
 
 
-static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
+static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
+			      void *extend_values)
 {
 	struct inet6_request_sock *treq = inet6_rsk(req);
 	struct ipv6_pinfo *np = inet6_sk(sk);

@@ -498,7 +499,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
 	if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
 		goto done;
 
-	skb = tcp_make_synack(sk, dst, req);
+	skb = tcp_make_synack(sk, dst, req, extend_values);
 	if (skb) {
 		struct tcphdr *th = tcp_hdr(skb);
 

@@ -1242,13 +1243,12 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 
 	security_inet_conn_request(sk, skb, req);
 
-	if (tcp_v6_send_synack(sk, req))
+	if (tcp_v6_send_synack(sk, req, NULL) ||
+	    want_cookie)
 		goto drop;
 
-	if (!want_cookie) {
-		inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
-		return 0;
-	}
+	inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
+	return 0;
 
 drop:
 	if (req)
Signature · 1 line
1.6.0.4