dccp ccid-2: Phase out the use of boolean Ack Vector sysctl
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 <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt
index 1403745..7a3bb1a 100644
--- a/Documentation/networking/dccp.txt
+++ b/Documentation/networking/dccp.txt
@@ -133,9 +133,6 @@
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.
diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index 60e9443..61734e2 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -360,7 +360,6 @@
#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 @@
* 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;
};
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index e0759d0..0bc4c9a 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -98,7 +98,6 @@
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 @@
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);
diff --git a/net/dccp/diag.c b/net/dccp/diag.c
index d1e1003..652a1b6 100644
--- a/net/dccp/diag.c
+++ b/net/dccp/diag.c
@@ -29,7 +29,7 @@
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);
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 0672b7e..5eb443f 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -163,7 +163,7 @@
{
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 @@
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 @@
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 @@
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))
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 02b1481..6821ae3 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -45,7 +45,6 @@
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)
diff --git a/net/dccp/options.c b/net/dccp/options.c
index e9d6748..7b1165c 100644
--- 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 @@
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 @@
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 @@
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;
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 0941f8f..d5c2bac 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -201,7 +201,6 @@
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
@@ -219,7 +218,7 @@
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;
}
diff --git a/net/dccp/sysctl.c b/net/dccp/sysctl.c
index 587c12f..018e210 100644
--- a/net/dccp/sysctl.c
+++ b/net/dccp/sysctl.c
@@ -41,13 +41,6 @@
.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),