dccp: Implement both feature-local and feature-remote Sequence Window feature
This adds full support for local/remote Sequence Window feature, from which the
* sequence-number-validity (W) and
* acknowledgment-number-validity (W') windows
derive as specified in RFC 4340, 7.5.3.
Specifically, the following is contained in this patch:
* integrated new socket fields into dccp_sk;
* updated the update_gsr/gss routines with regard to these fields;
* updated handler code: the Sequence Window feature is located at the TX side,
so the local feature is meant if the handler-rx flag is false;
* the initialisation of `rcv_wnd' in reqsk is removed, since
- rcv_wnd is not used by the code anywhere;
- sequence number checks are not done in the LISTEN state (cf. 7.5.3);
- dccp_check_req checks the Ack number validity more rigorously;
* the `struct dccp_minisock' became empty and is now removed.
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/net/dccp/dccp.h b/net/dccp/dccp.h
index f2230fc..04ae918 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -409,23 +409,21 @@
static inline void dccp_update_gsr(struct sock *sk, u64 seq)
{
struct dccp_sock *dp = dccp_sk(sk);
- const struct dccp_minisock *dmsk = dccp_msk(sk);
dp->dccps_gsr = seq;
- dccp_set_seqno(&dp->dccps_swl,
- dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4));
- dccp_set_seqno(&dp->dccps_swh,
- dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4);
+ /* Sequence validity window depends on remote Sequence Window (7.5.1) */
+ dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4);
+ dp->dccps_swh = ADD48(dp->dccps_gsr, (3 * dp->dccps_r_seq_win) / 4);
}
static inline void dccp_update_gss(struct sock *sk, u64 seq)
{
struct dccp_sock *dp = dccp_sk(sk);
- dp->dccps_awh = dp->dccps_gss = seq;
- dccp_set_seqno(&dp->dccps_awl,
- (dp->dccps_gss -
- dccp_msk(sk)->dccpms_sequence_window + 1));
+ dp->dccps_gss = seq;
+ /* Ack validity window depends on local Sequence Window value (7.5.1) */
+ dp->dccps_awl = SUB48(ADD48(dp->dccps_gss, 1), dp->dccps_l_seq_win);
+ dp->dccps_awh = dp->dccps_gss;
}
static inline int dccp_ack_pending(const struct sock *sk)
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
index 67ffac9..7303f79 100644
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -51,8 +51,17 @@
static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx)
{
- if (!rx)
- dccp_msk(sk)->dccpms_sequence_window = seq_win;
+ struct dccp_sock *dp = dccp_sk(sk);
+
+ if (rx) {
+ dp->dccps_r_seq_win = seq_win;
+ /* propagate changes to update SWL/SWH */
+ dccp_update_gsr(sk, dp->dccps_gsr);
+ } else {
+ dp->dccps_l_seq_win = seq_win;
+ /* propagate changes to update AWL */
+ dccp_update_gss(sk, dp->dccps_gss);
+ }
return 0;
}
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 6821ae3..5ca49ce 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -42,11 +42,6 @@
EXPORT_SYMBOL_GPL(dccp_death_row);
-void dccp_minisock_init(struct dccp_minisock *dmsk)
-{
- dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
-}
-
void dccp_time_wait(struct sock *sk, int state, int timeo)
{
struct inet_timewait_sock *tw = NULL;
@@ -110,7 +105,6 @@
struct dccp_request_sock *dreq = dccp_rsk(req);
struct inet_connection_sock *newicsk = inet_csk(newsk);
struct dccp_sock *newdp = dccp_sk(newsk);
- struct dccp_minisock *newdmsk = dccp_msk(newsk);
newdp->dccps_role = DCCP_ROLE_SERVER;
newdp->dccps_hc_rx_ackvec = NULL;
@@ -128,10 +122,6 @@
* Initialize S.GAR := S.ISS
* Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
*/
-
- /* See dccp_v4_conn_request */
- newdmsk->dccpms_sequence_window = req->rcv_wnd;
-
newdp->dccps_gar = newdp->dccps_iss = dreq->dreq_iss;
dccp_update_gss(newsk, dreq->dreq_iss);
@@ -290,7 +280,6 @@
inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
inet_rsk(req)->loc_port = dccp_hdr(skb)->dccph_dport;
inet_rsk(req)->acked = 0;
- req->rcv_wnd = sysctl_dccp_feat_sequence_window;
dreq->dreq_timestamp_echo = 0;
/* inherit feature negotiation options from listening socket */
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 945b4d5..314a1b5 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -174,8 +174,6 @@
struct dccp_sock *dp = dccp_sk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
- dccp_minisock_init(&dp->dccps_minisock);
-
icsk->icsk_rto = DCCP_TIMEOUT_INIT;
icsk->icsk_syn_retries = sysctl_dccp_request_retries;
sk->sk_state = DCCP_CLOSED;