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-rw-r--r--net/dccp/ccid.c4
-rw-r--r--net/dccp/ccids/ccid2.c109
-rw-r--r--net/dccp/ccids/ccid2.h25
-rw-r--r--net/dccp/input.c61
-rw-r--r--net/dccp/output.c14
5 files changed, 150 insertions, 63 deletions
diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c
index 36479ca61e03..48b585a5cba7 100644
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -118,7 +118,7 @@ static int ccid_activate(struct ccid_operations *ccid_ops)
if (ccid_ops->ccid_hc_tx_slab == NULL)
goto out_free_rx_slab;
- pr_info("CCID: Activated CCID %d (%s)\n",
+ pr_info("DCCP: Activated CCID %d (%s)\n",
ccid_ops->ccid_id, ccid_ops->ccid_name);
err = 0;
out:
@@ -136,7 +136,7 @@ static void ccid_deactivate(struct ccid_operations *ccid_ops)
ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab);
ccid_ops->ccid_hc_rx_slab = NULL;
- pr_info("CCID: Deactivated CCID %d (%s)\n",
+ pr_info("DCCP: Deactivated CCID %d (%s)\n",
ccid_ops->ccid_id, ccid_ops->ccid_name);
}
diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index fadecd20d75b..0462040fc818 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -153,17 +153,93 @@ out:
sock_put(sk);
}
+/*
+ * Congestion window validation (RFC 2861).
+ */
+static int ccid2_do_cwv = 1;
+module_param(ccid2_do_cwv, bool, 0644);
+MODULE_PARM_DESC(ccid2_do_cwv, "Perform RFC2861 Congestion Window Validation");
+
+/**
+ * ccid2_update_used_window - Track how much of cwnd is actually used
+ * This is done in addition to CWV. The sender needs to have an idea of how many
+ * packets may be in flight, to set the local Sequence Window value accordingly
+ * (RFC 4340, 7.5.2). The CWV mechanism is exploited to keep track of the
+ * maximum-used window. We use an EWMA low-pass filter to filter out noise.
+ */
+static void ccid2_update_used_window(struct ccid2_hc_tx_sock *hc, u32 new_wnd)
+{
+ hc->tx_expected_wnd = (3 * hc->tx_expected_wnd + new_wnd) / 4;
+}
+
+/* This borrows the code of tcp_cwnd_application_limited() */
+static void ccid2_cwnd_application_limited(struct sock *sk, const u32 now)
+{
+ struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
+ /* don't reduce cwnd below the initial window (IW) */
+ u32 init_win = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache),
+ win_used = max(hc->tx_cwnd_used, init_win);
+
+ if (win_used < hc->tx_cwnd) {
+ hc->tx_ssthresh = max(hc->tx_ssthresh,
+ (hc->tx_cwnd >> 1) + (hc->tx_cwnd >> 2));
+ hc->tx_cwnd = (hc->tx_cwnd + win_used) >> 1;
+ }
+ hc->tx_cwnd_used = 0;
+ hc->tx_cwnd_stamp = now;
+}
+
+/* This borrows the code of tcp_cwnd_restart() */
+static void ccid2_cwnd_restart(struct sock *sk, const u32 now)
+{
+ struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
+ u32 cwnd = hc->tx_cwnd, restart_cwnd,
+ iwnd = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache);
+
+ hc->tx_ssthresh = max(hc->tx_ssthresh, (cwnd >> 1) + (cwnd >> 2));
+
+ /* don't reduce cwnd below the initial window (IW) */
+ restart_cwnd = min(cwnd, iwnd);
+ cwnd >>= (now - hc->tx_lsndtime) / hc->tx_rto;
+ hc->tx_cwnd = max(cwnd, restart_cwnd);
+
+ hc->tx_cwnd_stamp = now;
+ hc->tx_cwnd_used = 0;
+}
+
static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len)
{
struct dccp_sock *dp = dccp_sk(sk);
struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
+ const u32 now = ccid2_time_stamp;
struct ccid2_seq *next;
- hc->tx_pipe++;
+ /* slow-start after idle periods (RFC 2581, RFC 2861) */
+ if (ccid2_do_cwv && !hc->tx_pipe &&
+ (s32)(now - hc->tx_lsndtime) >= hc->tx_rto)
+ ccid2_cwnd_restart(sk, now);
+
+ hc->tx_lsndtime = now;
+ hc->tx_pipe += 1;
+
+ /* see whether cwnd was fully used (RFC 2861), update expected window */
+ if (ccid2_cwnd_network_limited(hc)) {
+ ccid2_update_used_window(hc, hc->tx_cwnd);
+ hc->tx_cwnd_used = 0;
+ hc->tx_cwnd_stamp = now;
+ } else {
+ if (hc->tx_pipe > hc->tx_cwnd_used)
+ hc->tx_cwnd_used = hc->tx_pipe;
+
+ ccid2_update_used_window(hc, hc->tx_cwnd_used);
+
+ if (ccid2_do_cwv && (s32)(now - hc->tx_cwnd_stamp) >= hc->tx_rto)
+ ccid2_cwnd_application_limited(sk, now);
+ }
hc->tx_seqh->ccid2s_seq = dp->dccps_gss;
hc->tx_seqh->ccid2s_acked = 0;
- hc->tx_seqh->ccid2s_sent = ccid2_time_stamp;
+ hc->tx_seqh->ccid2s_sent = now;
next = hc->tx_seqh->ccid2s_next;
/* check if we need to alloc more space */
@@ -583,15 +659,6 @@ done:
dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks);
}
-/*
- * Convert RFC 3390 larger initial window into an equivalent number of packets.
- * This is based on the numbers specified in RFC 5681, 3.1.
- */
-static inline u32 rfc3390_bytes_to_packets(const u32 smss)
-{
- return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3);
-}
-
static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
{
struct ccid2_hc_tx_sock *hc = ccid_priv(ccid);
@@ -603,6 +670,7 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
/* Use larger initial windows (RFC 4341, section 5). */
hc->tx_cwnd = rfc3390_bytes_to_packets(dp->dccps_mss_cache);
+ hc->tx_expected_wnd = hc->tx_cwnd;
/* Make sure that Ack Ratio is enabled and within bounds. */
max_ratio = DIV_ROUND_UP(hc->tx_cwnd, 2);
@@ -615,7 +683,8 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
hc->tx_rto = DCCP_TIMEOUT_INIT;
hc->tx_rpdupack = -1;
- hc->tx_last_cong = ccid2_time_stamp;
+ hc->tx_last_cong = hc->tx_lsndtime = hc->tx_cwnd_stamp = ccid2_time_stamp;
+ hc->tx_cwnd_used = 0;
setup_timer(&hc->tx_rtotimer, ccid2_hc_tx_rto_expire,
(unsigned long)sk);
INIT_LIST_HEAD(&hc->tx_av_chunks);
@@ -636,18 +705,14 @@ static void ccid2_hc_tx_exit(struct sock *sk)
static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
{
- const struct dccp_sock *dp = dccp_sk(sk);
struct ccid2_hc_rx_sock *hc = ccid2_hc_rx_sk(sk);
- switch (DCCP_SKB_CB(skb)->dccpd_type) {
- case DCCP_PKT_DATA:
- case DCCP_PKT_DATAACK:
- hc->rx_data++;
- if (hc->rx_data >= dp->dccps_r_ack_ratio) {
- dccp_send_ack(sk);
- hc->rx_data = 0;
- }
- break;
+ if (!dccp_data_packet(skb))
+ return;
+
+ if (++hc->rx_num_data_pkts >= dccp_sk(sk)->dccps_r_ack_ratio) {
+ dccp_send_ack(sk);
+ hc->rx_num_data_pkts = 0;
}
}
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index e9985dafc2c7..f585d330e1e5 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -53,6 +53,10 @@ struct ccid2_seq {
* @tx_rttvar: moving average/maximum of @mdev_max
* @tx_rto: RTO value deriving from SRTT and RTTVAR (RFC 2988)
* @tx_rtt_seq: to decay RTTVAR at most once per flight
+ * @tx_cwnd_used: actually used cwnd, W_used of RFC 2861
+ * @tx_expected_wnd: moving average of @tx_cwnd_used
+ * @tx_cwnd_stamp: to track idle periods in CWV
+ * @tx_lsndtime: last time (in jiffies) a data packet was sent
* @tx_rpseq: last consecutive seqno
* @tx_rpdupack: dupacks since rpseq
* @tx_av_chunks: list of Ack Vectors received on current skb
@@ -76,6 +80,12 @@ struct ccid2_hc_tx_sock {
u64 tx_rtt_seq:48;
struct timer_list tx_rtotimer;
+ /* Congestion Window validation (optional, RFC 2861) */
+ u32 tx_cwnd_used,
+ tx_expected_wnd,
+ tx_cwnd_stamp,
+ tx_lsndtime;
+
u64 tx_rpseq;
int tx_rpdupack;
u32 tx_last_cong;
@@ -88,8 +98,21 @@ static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc)
return hc->tx_pipe >= hc->tx_cwnd;
}
+/*
+ * Convert RFC 3390 larger initial window into an equivalent number of packets.
+ * This is based on the numbers specified in RFC 5681, 3.1.
+ */
+static inline u32 rfc3390_bytes_to_packets(const u32 smss)
+{
+ return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3);
+}
+
+/**
+ * struct ccid2_hc_rx_sock - Receiving end of CCID-2 half-connection
+ * @rx_num_data_pkts: number of data packets received since last feedback
+ */
struct ccid2_hc_rx_sock {
- int rx_data;
+ u32 rx_num_data_pkts;
};
static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk)
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 4222e7a654b0..51d5fe5fffba 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -619,20 +619,31 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
return 1;
}
- if (sk->sk_state != DCCP_REQUESTING && sk->sk_state != DCCP_RESPOND) {
- if (dccp_check_seqno(sk, skb))
- goto discard;
-
- /*
- * Step 8: Process options and mark acknowledgeable
- */
- if (dccp_parse_options(sk, NULL, skb))
- return 1;
+ /* Step 6: Check sequence numbers (omitted in LISTEN/REQUEST state) */
+ if (sk->sk_state != DCCP_REQUESTING && dccp_check_seqno(sk, skb))
+ goto discard;
- dccp_handle_ackvec_processing(sk, skb);
- dccp_deliver_input_to_ccids(sk, skb);
+ /*
+ * Step 7: Check for unexpected packet types
+ * If (S.is_server and P.type == Response)
+ * or (S.is_client and P.type == Request)
+ * or (S.state == RESPOND and P.type == Data),
+ * Send Sync packet acknowledging P.seqno
+ * Drop packet and return
+ */
+ if ((dp->dccps_role != DCCP_ROLE_CLIENT &&
+ dh->dccph_type == DCCP_PKT_RESPONSE) ||
+ (dp->dccps_role == DCCP_ROLE_CLIENT &&
+ dh->dccph_type == DCCP_PKT_REQUEST) ||
+ (sk->sk_state == DCCP_RESPOND && dh->dccph_type == DCCP_PKT_DATA)) {
+ dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC);
+ goto discard;
}
+ /* Step 8: Process options */
+ if (dccp_parse_options(sk, NULL, skb))
+ return 1;
+
/*
* Step 9: Process Reset
* If P.type == Reset,
@@ -640,31 +651,15 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
* S.state := TIMEWAIT
* Set TIMEWAIT timer
* Drop packet and return
- */
+ */
if (dh->dccph_type == DCCP_PKT_RESET) {
dccp_rcv_reset(sk, skb);
return 0;
- /*
- * Step 7: Check for unexpected packet types
- * If (S.is_server and P.type == Response)
- * or (S.is_client and P.type == Request)
- * or (S.state == RESPOND and P.type == Data),
- * Send Sync packet acknowledging P.seqno
- * Drop packet and return
- */
- } else if ((dp->dccps_role != DCCP_ROLE_CLIENT &&
- dh->dccph_type == DCCP_PKT_RESPONSE) ||
- (dp->dccps_role == DCCP_ROLE_CLIENT &&
- dh->dccph_type == DCCP_PKT_REQUEST) ||
- (sk->sk_state == DCCP_RESPOND &&
- dh->dccph_type == DCCP_PKT_DATA)) {
- dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC);
- goto discard;
- } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) {
+ } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */
if (dccp_rcv_closereq(sk, skb))
return 0;
goto discard;
- } else if (dh->dccph_type == DCCP_PKT_CLOSE) {
+ } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */
if (dccp_rcv_close(sk, skb))
return 0;
goto discard;
@@ -679,8 +674,12 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
__kfree_skb(skb);
return 0;
- case DCCP_RESPOND:
case DCCP_PARTOPEN:
+ /* Step 8: if using Ack Vectors, mark packet acknowledgeable */
+ dccp_handle_ackvec_processing(sk, skb);
+ dccp_deliver_input_to_ccids(sk, skb);
+ /* fall through */
+ case DCCP_RESPOND:
queued = dccp_rcv_respond_partopen_state_process(sk, skb,
dh, len);
break;
diff --git a/net/dccp/output.c b/net/dccp/output.c
index fab108e51e5a..dede3edb8849 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -27,11 +27,13 @@ static inline void dccp_event_ack_sent(struct sock *sk)
inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
}
-static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
+/* enqueue @skb on sk_send_head for retransmission, return clone to send now */
+static struct sk_buff *dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
{
skb_set_owner_w(skb, sk);
WARN_ON(sk->sk_send_head);
sk->sk_send_head = skb;
+ return skb_clone(sk->sk_send_head, gfp_any());
}
/*
@@ -552,8 +554,7 @@ int dccp_connect(struct sock *sk)
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST;
- dccp_skb_entail(sk, skb);
- dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL));
+ dccp_transmit_skb(sk, dccp_skb_entail(sk, skb));
DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS);
/* Timer for repeating the REQUEST until an answer. */
@@ -678,8 +679,7 @@ void dccp_send_close(struct sock *sk, const int active)
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE;
if (active) {
- dccp_skb_entail(sk, skb);
- dccp_transmit_skb(sk, skb_clone(skb, prio));
+ skb = dccp_skb_entail(sk, skb);
/*
* Retransmission timer for active-close: RFC 4340, 8.3 requires
* to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ
@@ -692,6 +692,6 @@ void dccp_send_close(struct sock *sk, const int active)
*/
inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
DCCP_TIMEOUT_INIT, DCCP_RTO_MAX);
- } else
- dccp_transmit_skb(sk, skb);
+ }
+ dccp_transmit_skb(sk, skb);
}
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-12 21:55:52 +0000