This removes the use of the sysctl and the minisock variable for the Send Ack

Vector feature, as it now is handled fully dynamically via feature negotiation

(i.e. when CCID-2 is enabled, Ack Vectors are automatically enabled as per

 RFC 4341, 4.).
Using a sysctl in parallel to this implementation would open the door to

crashes, since much of the code relies on tests of the boolean minisock /

sysctl variable. Thus, this patch replaces all tests of type
	if (dccp_msk(sk)->dccpms_send_ack_vector)

		/* ... */

with

	if (dp->dccps_hc_rx_ackvec != NULL)

		/* ... */
The dccps_hc_rx_ackvec is allocated by the dccp_hdlr_ackvec() when feature

negotiation concluded that Ack Vectors are to be used on the half-connection.

Otherwise, it is NULL (due to dccp_init_sock/dccp_create_openreq_child),

so that the test is a valid one.
The activation handler for Ack Vectors is called as soon as the feature

negotiation has concluded at the

 * server when the Ack marking the transition RESPOND => OPEN arrives;

 * client after it has sent its ACK, marking the transition REQUEST => PARTOPEN.
Adding the sequence number of the Response packet to the Ack Vector has been

removed, since

 (a) connection establishment implies that the Response has been received;

 (b) the CCIDs only look at packets received in the (PART)OPEN state, i.e.

     this entry will always be ignored;

 (c) it can not be used for anything useful - to detect loss for instance, only

     packets received after the loss can serve as pseudo-dupacks.
There was a FIXME to change the error code when dccp_ackvec_add() fails.

I removed this after finding out that:

 * the check whether ackno < ISN is already made earlier,

 * this Response is likely the 1st packet with an Ackno that the client gets,

 * so when dccp_ackvec_add() fails, the reason is likely not a packet error.
Signed-off-by: Gerrit Renker

Acked-by: Ian McDonald

---

 Documentation/networking/dccp.txt |    3 ---

 include/linux/dccp.h              |    3 ---

 net/dccp/dccp.h                   |    3 +--

 net/dccp/diag.c                   |    2 +-

 net/dccp/input.c                  |   12 +++---------

 net/dccp/minisocks.c              |    1 -

 net/dccp/options.c                |    7 ++-----

 net/dccp/proto.c                  |    3 +--

 net/dccp/sysctl.c                 |    7 -------

 9 files changed, 8 insertions(+), 33 deletions(-)
--- a/Documentation/networking/dccp.txt

+++ b/Documentation/networking/dccp.txt

@@ -133,9 +133,6 @@ retries2

 	importance for retransmitted acknowledgments and feature negotiation,

 	data packets are never retransmitted. Analogue of tcp_retries2.
-send_ackvec = 1

-	Whether or not to send Ack Vector options (sec. 11.5).

-

 tx_ccid = 2

 	Default CCID for the sender-receiver half-connection. Depending on the

 	choice of CCID, the Send Ack Vector feature is enabled automatically.

--- a/include/linux/dccp.h

+++ b/include/linux/dccp.h

@@ -360,7 +360,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)

 #define DCCPF_INITIAL_SEQUENCE_WINDOW		100

 #define DCCPF_INITIAL_ACK_RATIO			2

 #define DCCPF_INITIAL_CCID			DCCPC_CCID2

-#define DCCPF_INITIAL_SEND_ACK_VECTOR		1

 /* FIXME: for now we're default to 1 but it should really be 0 */

 #define DCCPF_INITIAL_SEND_NDP_COUNT		1
@@ -370,13 +369,11 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)

   * Will be used to pass the state from dccp_request_sock to dccp_sock.

   *

   * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2)

-  * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5)

   * @dccpms_pending - List of features being negotiated

   * @dccpms_conf -

   */

 struct dccp_minisock {

 	__u64			dccpms_sequence_window;

-	__u8			dccpms_send_ack_vector;

 	struct list_head	dccpms_pending;

 	struct list_head	dccpms_conf;

 };

--- a/net/dccp/dccp.h

+++ b/net/dccp/dccp.h

@@ -98,7 +98,6 @@ extern int  sysctl_dccp_retries2;

 extern int  sysctl_dccp_feat_sequence_window;

 extern int  sysctl_dccp_feat_rx_ccid;

 extern int  sysctl_dccp_feat_tx_ccid;

-extern int  sysctl_dccp_feat_send_ack_vector;

 extern int  sysctl_dccp_tx_qlen;

 extern int  sysctl_dccp_sync_ratelimit;
@@ -434,7 +433,7 @@ static inline int dccp_ack_pending(const struct sock *sk)

 	const struct dccp_sock *dp = dccp_sk(sk);

 	return dp->dccps_timestamp_echo != 0 ||

 #ifdef CONFIG_IP_DCCP_ACKVEC

-	       (dccp_msk(sk)->dccpms_send_ack_vector &&

+	       (dp->dccps_hc_rx_ackvec != NULL &&

 		dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) ||

 #endif

 	       inet_csk_ack_scheduled(sk);

--- a/net/dccp/diag.c

+++ b/net/dccp/diag.c

@@ -29,7 +29,7 @@ static void dccp_get_info(struct sock *sk, struct tcp_info *info)

 	info->tcpi_backoff	= icsk->icsk_backoff;

 	info->tcpi_pmtu		= icsk->icsk_pmtu_cookie;
-	if (dccp_msk(sk)->dccpms_send_ack_vector)

+	if (dp->dccps_hc_rx_ackvec != NULL)

 		info->tcpi_options |= TCPI_OPT_SACK;
 	ccid_hc_rx_get_info(dp->dccps_hc_rx_ccid, sk, info);

--- a/net/dccp/input.c

+++ b/net/dccp/input.c

@@ -163,7 +163,7 @@ static void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb)

 {

 	struct dccp_sock *dp = dccp_sk(sk);
-	if (dccp_msk(sk)->dccpms_send_ack_vector)

+	if (dp->dccps_hc_rx_ackvec != NULL)

 		dccp_ackvec_check_rcv_ackno(dp->dccps_hc_rx_ackvec, sk,

 					    DCCP_SKB_CB(skb)->dccpd_ack_seq);

 }

@@ -375,7 +375,7 @@ int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,

 	if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)

 		dccp_event_ack_recv(sk, skb);
-	if (dccp_msk(sk)->dccpms_send_ack_vector &&

+	if (dp->dccps_hc_rx_ackvec != NULL &&

 	    dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,

 			    DCCP_SKB_CB(skb)->dccpd_seq,

 			    DCCP_ACKVEC_STATE_RECEIVED))

@@ -434,12 +434,6 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,

 			dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp -

 			    dp->dccps_options_received.dccpor_timestamp_echo));
-		if (dccp_msk(sk)->dccpms_send_ack_vector &&

-		    dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,

-				    DCCP_SKB_CB(skb)->dccpd_seq,

-				    DCCP_ACKVEC_STATE_RECEIVED))

-			goto out_invalid_packet; /* FIXME: change error code */

-

 		/* Stop the REQUEST timer */

 		inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);

 		WARN_ON(sk->sk_send_head == NULL);

@@ -637,7 +631,7 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,

 		if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)

 			dccp_event_ack_recv(sk, skb);
-		if (dccp_msk(sk)->dccpms_send_ack_vector &&

+		if (dp->dccps_hc_rx_ackvec != NULL &&

 		    dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,

 				    DCCP_SKB_CB(skb)->dccpd_seq,

 				    DCCP_ACKVEC_STATE_RECEIVED))

--- a/net/dccp/minisocks.c

+++ b/net/dccp/minisocks.c

@@ -45,7 +45,6 @@ EXPORT_SYMBOL_GPL(dccp_death_row);

 void dccp_minisock_init(struct dccp_minisock *dmsk)

 {

 	dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;

-	dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;

 }
 void dccp_time_wait(struct sock *sk, int state, int timeo)

--- a/net/dccp/options.c

+++ b/net/dccp/options.c

@@ -26,7 +26,6 @@

 int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;

 int sysctl_dccp_feat_rx_ccid	      = DCCPF_INITIAL_CCID;

 int sysctl_dccp_feat_tx_ccid	      = DCCPF_INITIAL_CCID;

-int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
 u64 dccp_decode_value_var(const u8 *bf, const u8 len)

 {

@@ -145,8 +144,7 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,

 		case DCCPO_ACK_VECTOR_1:

 			if (dccp_packet_without_ack(skb))   /* RFC 4340, 11.4 */

 				break;

-

-			if (dccp_msk(sk)->dccpms_send_ack_vector &&

+			if (dp->dccps_hc_rx_ackvec != NULL &&

 			    dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))

 				goto out_invalid_option;

 			break;

@@ -526,7 +524,6 @@ static void dccp_insert_option_padding(struct sk_buff *skb)

 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)

 {

 	struct dccp_sock *dp = dccp_sk(sk);

-	struct dccp_minisock *dmsk = dccp_msk(sk);
 	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
@@ -547,7 +544,7 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb)

 			if (dccp_insert_option_timestamp(sk, skb))

 				return -1;
-		} else if (dmsk->dccpms_send_ack_vector	&&

+		} else if (dp->dccps_hc_rx_ackvec != NULL &&

 			   dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&

 			   dccp_insert_option_ackvec(sk, skb)) {

 				return -1;

--- a/net/dccp/proto.c

+++ b/net/dccp/proto.c

@@ -207,7 +207,6 @@ EXPORT_SYMBOL_GPL(dccp_init_sock);

 void dccp_destroy_sock(struct sock *sk)

 {

 	struct dccp_sock *dp = dccp_sk(sk);

-	struct dccp_minisock *dmsk = dccp_msk(sk);
 	/*

 	 * DCCP doesn't use sk_write_queue, just sk_send_head

@@ -225,7 +224,7 @@ void dccp_destroy_sock(struct sock *sk)

 	kfree(dp->dccps_service_list);

 	dp->dccps_service_list = NULL;
-	if (dmsk->dccpms_send_ack_vector) {

+	if (dp->dccps_hc_rx_ackvec != NULL) {

 		dccp_ackvec_free(dp->dccps_hc_rx_ackvec);

 		dp->dccps_hc_rx_ackvec = NULL;

 	}

--- a/net/dccp/sysctl.c

+++ b/net/dccp/sysctl.c

@@ -41,13 +41,6 @@ static struct ctl_table dccp_default_table[] = {

 		.proc_handler	= proc_dointvec,

 	},

 	{

-		.procname	= "send_ackvec",

-		.data		= &sysctl_dccp_feat_send_ack_vector,

-		.maxlen		= sizeof(sysctl_dccp_feat_send_ack_vector),

-		.mode		= 0644,

-		.proc_handler	= proc_dointvec,

-	},

-	{

 		.procname	= "request_retries",

 		.data		= &sysctl_dccp_request_retries,

 		.maxlen		= sizeof(sysctl_dccp_request_retries),

--

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