#define FLAG_SYN_ACKED 0x10 /* This ACK acknowledged SYN. */
#define FLAG_DATA_SACKED 0x20 /* New SACK. */
#define FLAG_ECE 0x40 /* ECE in this ACK */
+#define FLAG_LOST_RETRANS 0x80 /* This ACK marks some retransmission lost */
#define FLAG_SLOWPATH 0x100 /* Do not skip RFC checks for window update.*/
#define FLAG_ORIG_SACK_ACKED 0x200 /* Never retransmitted data are (s)acked */
#define FLAG_SND_UNA_ADVANCED 0x400 /* Snd_una was changed (!= FLAG_DATA_ACKED) */
/* Check #1 */
if (tp->rcv_ssthresh < tp->window_clamp &&
(int)tp->rcv_ssthresh < tcp_space(sk) &&
- !sk_under_memory_pressure(sk)) {
+ !tcp_under_memory_pressure(sk)) {
int incr;
/* Check #2. Increase window, if skb with such overhead
if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
!(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
- !sk_under_memory_pressure(sk) &&
+ !tcp_under_memory_pressure(sk) &&
sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)) {
sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
sysctl_tcp_rmem[2]);
* highest SACK block). Also calculate the lowest snd_nxt among the remaining
* retransmitted skbs to avoid some costly processing per ACKs.
*/
-static void tcp_mark_lost_retrans(struct sock *sk)
+static void tcp_mark_lost_retrans(struct sock *sk, int *flag)
{
const struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
if (after(received_upto, ack_seq)) {
TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
tp->retrans_out -= tcp_skb_pcount(skb);
-
+ *flag |= FLAG_LOST_RETRANS;
tcp_skb_mark_lost_uncond_verify(tp, skb);
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSTRETRANSMIT);
} else {
struct tcp_sacktag_state {
int reord;
int fack_count;
- long rtt_us; /* RTT measured by SACKing never-retransmitted data */
+ /* Timestamps for earliest and latest never-retransmitted segment
+ * that was SACKed. RTO needs the earliest RTT to stay conservative,
+ * but congestion control should still get an accurate delay signal.
+ */
+ struct skb_mstamp first_sackt;
+ struct skb_mstamp last_sackt;
int flag;
};
state->reord);
if (!after(end_seq, tp->high_seq))
state->flag |= FLAG_ORIG_SACK_ACKED;
- /* Pick the earliest sequence sacked for RTT */
- if (state->rtt_us < 0) {
- struct skb_mstamp now;
-
- skb_mstamp_get(&now);
- state->rtt_us = skb_mstamp_us_delta(&now,
- xmit_time);
- }
+ if (state->first_sackt.v64 == 0)
+ state->first_sackt = *xmit_time;
+ state->last_sackt = *xmit_time;
}
if (sacked & TCPCB_LOST) {
* code can come after this skb later on it's better to keep
* setting gso_size to something.
*/
- if (!skb_shinfo(prev)->gso_size) {
- skb_shinfo(prev)->gso_size = mss;
- skb_shinfo(prev)->gso_type = sk->sk_gso_type;
- }
+ if (!TCP_SKB_CB(prev)->tcp_gso_size)
+ TCP_SKB_CB(prev)->tcp_gso_size = mss;
/* CHECKME: To clear or not to clear? Mimics normal skb currently */
- if (tcp_skb_pcount(skb) <= 1) {
- skb_shinfo(skb)->gso_size = 0;
- skb_shinfo(skb)->gso_type = 0;
- }
+ if (tcp_skb_pcount(skb) <= 1)
+ TCP_SKB_CB(skb)->tcp_gso_size = 0;
/* Difference in this won't matter, both ACKed by the same cumul. ACK */
TCP_SKB_CB(prev)->sacked |= (TCP_SKB_CB(skb)->sacked & TCPCB_EVER_RETRANS);
static int
tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb,
- u32 prior_snd_una, long *sack_rtt_us)
+ u32 prior_snd_una, struct tcp_sacktag_state *state)
{
struct tcp_sock *tp = tcp_sk(sk);
const unsigned char *ptr = (skb_transport_header(ack_skb) +
struct tcp_sack_block_wire *sp_wire = (struct tcp_sack_block_wire *)(ptr+2);
struct tcp_sack_block sp[TCP_NUM_SACKS];
struct tcp_sack_block *cache;
- struct tcp_sacktag_state state;
struct sk_buff *skb;
int num_sacks = min(TCP_NUM_SACKS, (ptr[1] - TCPOLEN_SACK_BASE) >> 3);
int used_sacks;
int i, j;
int first_sack_index;
- state.flag = 0;
- state.reord = tp->packets_out;
- state.rtt_us = -1L;
+ state->flag = 0;
+ state->reord = tp->packets_out;
if (!tp->sacked_out) {
if (WARN_ON(tp->fackets_out))
found_dup_sack = tcp_check_dsack(sk, ack_skb, sp_wire,
num_sacks, prior_snd_una);
if (found_dup_sack)
- state.flag |= FLAG_DSACKING_ACK;
+ state->flag |= FLAG_DSACKING_ACK;
/* Eliminate too old ACKs, but take into
* account more or less fresh ones, they can
}
skb = tcp_write_queue_head(sk);
- state.fack_count = 0;
+ state->fack_count = 0;
i = 0;
if (!tp->sacked_out) {
/* Head todo? */
if (before(start_seq, cache->start_seq)) {
- skb = tcp_sacktag_skip(skb, sk, &state,
+ skb = tcp_sacktag_skip(skb, sk, state,
start_seq);
skb = tcp_sacktag_walk(skb, sk, next_dup,
- &state,
+ state,
start_seq,
cache->start_seq,
dup_sack);
goto advance_sp;
skb = tcp_maybe_skipping_dsack(skb, sk, next_dup,
- &state,
+ state,
cache->end_seq);
/* ...tail remains todo... */
skb = tcp_highest_sack(sk);
if (!skb)
break;
- state.fack_count = tp->fackets_out;
+ state->fack_count = tp->fackets_out;
cache++;
goto walk;
}
- skb = tcp_sacktag_skip(skb, sk, &state, cache->end_seq);
+ skb = tcp_sacktag_skip(skb, sk, state, cache->end_seq);
/* Check overlap against next cached too (past this one already) */
cache++;
continue;
skb = tcp_highest_sack(sk);
if (!skb)
break;
- state.fack_count = tp->fackets_out;
+ state->fack_count = tp->fackets_out;
}
- skb = tcp_sacktag_skip(skb, sk, &state, start_seq);
+ skb = tcp_sacktag_skip(skb, sk, state, start_seq);
walk:
- skb = tcp_sacktag_walk(skb, sk, next_dup, &state,
+ skb = tcp_sacktag_walk(skb, sk, next_dup, state,
start_seq, end_seq, dup_sack);
advance_sp:
for (j = 0; j < used_sacks; j++)
tp->recv_sack_cache[i++] = sp[j];
- if ((state.reord < tp->fackets_out) &&
+ if ((state->reord < tp->fackets_out) &&
((inet_csk(sk)->icsk_ca_state != TCP_CA_Loss) || tp->undo_marker))
- tcp_update_reordering(sk, tp->fackets_out - state.reord, 0);
+ tcp_update_reordering(sk, tp->fackets_out - state->reord, 0);
- tcp_mark_lost_retrans(sk);
+ tcp_mark_lost_retrans(sk, &state->flag);
tcp_verify_left_out(tp);
out:
WARN_ON((int)tp->retrans_out < 0);
WARN_ON((int)tcp_packets_in_flight(tp) < 0);
#endif
- *sack_rtt_us = state.rtt_us;
- return state.flag;
+ return state->flag;
}
/* Limits sacked_out so that sum with lost_out isn't ever larger than
(oldcnt >= packets))
break;
- mss = skb_shinfo(skb)->gso_size;
+ mss = tcp_skb_mss(skb);
err = tcp_fragment(sk, skb, (packets - oldcnt) * mss,
mss, GFP_ATOMIC);
if (err < 0)
return false;
}
-/* The cwnd reduction in CWR and Recovery use the PRR algorithm
- * https://datatracker.ietf.org/doc/draft-ietf-tcpm-proportional-rate-reduction/
+/* The cwnd reduction in CWR and Recovery uses the PRR algorithm in RFC 6937.
* It computes the number of packets to send (sndcnt) based on packets newly
* delivered:
* 1) If the packets in flight is larger than ssthresh, PRR spreads the
* cwnd reductions across a full RTT.
- * 2) If packets in flight is lower than ssthresh (such as due to excess
- * losses and/or application stalls), do not perform any further cwnd
- * reductions, but instead slow start up to ssthresh.
+ * 2) Otherwise PRR uses packet conservation to send as much as delivered.
+ * But when the retransmits are acked without further losses, PRR
+ * slow starts cwnd up to ssthresh to speed up the recovery.
*/
static void tcp_init_cwnd_reduction(struct sock *sk)
{
}
static void tcp_cwnd_reduction(struct sock *sk, const int prior_unsacked,
- int fast_rexmit)
+ int fast_rexmit, int flag)
{
struct tcp_sock *tp = tcp_sk(sk);
int sndcnt = 0;
(tp->packets_out - tp->sacked_out);
tp->prr_delivered += newly_acked_sacked;
- if (tcp_packets_in_flight(tp) > tp->snd_ssthresh) {
+ if (delta < 0) {
u64 dividend = (u64)tp->snd_ssthresh * tp->prr_delivered +
tp->prior_cwnd - 1;
sndcnt = div_u64(dividend, tp->prior_cwnd) - tp->prr_out;
- } else {
+ } else if ((flag & FLAG_RETRANS_DATA_ACKED) &&
+ !(flag & FLAG_LOST_RETRANS)) {
sndcnt = min_t(int, delta,
max_t(int, tp->prr_delivered - tp->prr_out,
newly_acked_sacked) + 1);
+ } else {
+ sndcnt = min(delta, newly_acked_sacked);
}
-
sndcnt = max(sndcnt, (fast_rexmit ? 1 : 0));
tp->snd_cwnd = tcp_packets_in_flight(tp) + sndcnt;
}
tcp_set_ca_state(sk, TCP_CA_CWR);
}
}
+EXPORT_SYMBOL(tcp_enter_cwr);
static void tcp_try_keep_open(struct sock *sk)
{
if (inet_csk(sk)->icsk_ca_state != TCP_CA_CWR) {
tcp_try_keep_open(sk);
} else {
- tcp_cwnd_reduction(sk, prior_unsacked, 0);
+ tcp_cwnd_reduction(sk, prior_unsacked, 0, flag);
}
}
tp->prior_ssthresh = 0;
tcp_init_undo(tp);
- if (inet_csk(sk)->icsk_ca_state < TCP_CA_CWR) {
+ if (!tcp_in_cwnd_reduction(sk)) {
if (!ece_ack)
tp->prior_ssthresh = tcp_current_ssthresh(sk);
tcp_init_cwnd_reduction(sk);
/* Undo during fast recovery after partial ACK. */
static bool tcp_try_undo_partial(struct sock *sk, const int acked,
- const int prior_unsacked)
+ const int prior_unsacked, int flag)
{
struct tcp_sock *tp = tcp_sk(sk);
* mark more packets lost or retransmit more.
*/
if (tp->retrans_out) {
- tcp_cwnd_reduction(sk, prior_unsacked, 0);
+ tcp_cwnd_reduction(sk, prior_unsacked, 0, flag);
return true;
}
if (tcp_is_reno(tp) && is_dupack)
tcp_add_reno_sack(sk);
} else {
- if (tcp_try_undo_partial(sk, acked, prior_unsacked))
+ if (tcp_try_undo_partial(sk, acked, prior_unsacked, flag))
return;
/* Partial ACK arrived. Force fast retransmit. */
do_lost = tcp_is_reno(tp) ||
break;
case TCP_CA_Loss:
tcp_process_loss(sk, flag, is_dupack);
- if (icsk->icsk_ca_state != TCP_CA_Open)
+ if (icsk->icsk_ca_state != TCP_CA_Open &&
+ !(flag & FLAG_LOST_RETRANS))
return;
- /* Fall through to processing in Open state. */
+ /* Change state if cwnd is undone or retransmits are lost */
default:
if (tcp_is_reno(tp)) {
if (flag & FLAG_SND_UNA_ADVANCED)
if (do_lost)
tcp_update_scoreboard(sk, fast_rexmit);
- tcp_cwnd_reduction(sk, prior_unsacked, fast_rexmit);
+ tcp_cwnd_reduction(sk, prior_unsacked, fast_rexmit, flag);
tcp_xmit_retransmit_queue(sk);
}
* arrived at the other end.
*/
static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
- u32 prior_snd_una, long sack_rtt_us)
+ u32 prior_snd_una,
+ struct tcp_sacktag_state *sack)
{
const struct inet_connection_sock *icsk = inet_csk(sk);
struct skb_mstamp first_ackt, last_ackt, now;
u32 prior_sacked = tp->sacked_out;
u32 reord = tp->packets_out;
bool fully_acked = true;
- long ca_seq_rtt_us = -1L;
+ long sack_rtt_us = -1L;
long seq_rtt_us = -1L;
+ long ca_rtt_us = -1L;
struct sk_buff *skb;
u32 pkts_acked = 0;
bool rtt_update;
skb_mstamp_get(&now);
if (likely(first_ackt.v64)) {
seq_rtt_us = skb_mstamp_us_delta(&now, &first_ackt);
- ca_seq_rtt_us = skb_mstamp_us_delta(&now, &last_ackt);
+ ca_rtt_us = skb_mstamp_us_delta(&now, &last_ackt);
+ }
+ if (sack->first_sackt.v64) {
+ sack_rtt_us = skb_mstamp_us_delta(&now, &sack->first_sackt);
+ ca_rtt_us = skb_mstamp_us_delta(&now, &sack->last_sackt);
}
rtt_update = tcp_ack_update_rtt(sk, flag, seq_rtt_us, sack_rtt_us);
if (flag & FLAG_ACKED) {
- const struct tcp_congestion_ops *ca_ops
- = inet_csk(sk)->icsk_ca_ops;
-
tcp_rearm_rto(sk);
if (unlikely(icsk->icsk_mtup.probe_size &&
!after(tp->mtu_probe.probe_seq_end, tp->snd_una))) {
tp->fackets_out -= min(pkts_acked, tp->fackets_out);
- if (ca_ops->pkts_acked) {
- long rtt_us = min_t(ulong, ca_seq_rtt_us, sack_rtt_us);
- ca_ops->pkts_acked(sk, pkts_acked, rtt_us);
- }
-
} else if (skb && rtt_update && sack_rtt_us >= 0 &&
sack_rtt_us > skb_mstamp_us_delta(&now, &skb->skb_mstamp)) {
/* Do not re-arm RTO if the sack RTT is measured from data sent
tcp_rearm_rto(sk);
}
+ if (icsk->icsk_ca_ops->pkts_acked)
+ icsk->icsk_ca_ops->pkts_acked(sk, pkts_acked, ca_rtt_us);
+
#if FASTRETRANS_DEBUG > 0
WARN_ON((int)tp->sacked_out < 0);
WARN_ON((int)tp->lost_out < 0);
* This function is not for random using!
*/
} else {
- unsigned long when = inet_csk_rto_backoff(icsk, TCP_RTO_MAX);
+ unsigned long when = tcp_probe0_when(sk, TCP_RTO_MAX);
inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
when, TCP_RTO_MAX);
{
struct inet_connection_sock *icsk = inet_csk(sk);
struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_sacktag_state sack_state;
u32 prior_snd_una = tp->snd_una;
u32 ack_seq = TCP_SKB_CB(skb)->seq;
u32 ack = TCP_SKB_CB(skb)->ack_seq;
int prior_packets = tp->packets_out;
const int prior_unsacked = tp->packets_out - tp->sacked_out;
int acked = 0; /* Number of packets newly acked */
- long sack_rtt_us = -1L;
+
+ sack_state.first_sackt.v64 = 0;
/* We very likely will need to access write queue head. */
prefetchw(sk->sk_write_queue.next);
if (TCP_SKB_CB(skb)->sacked)
flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
- &sack_rtt_us);
+ &sack_state);
if (tcp_ecn_rcv_ecn_echo(tp, tcp_hdr(skb))) {
flag |= FLAG_ECE;
/* See if we can take anything off of the retransmit queue. */
acked = tp->packets_out;
flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una,
- sack_rtt_us);
+ &sack_state);
acked -= tp->packets_out;
/* Advance cwnd if state allows */
*/
if (TCP_SKB_CB(skb)->sacked) {
flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
- &sack_rtt_us);
+ &sack_state);
tcp_fastretrans_alert(sk, acked, prior_unsacked,
is_dupack, flag);
}
if (eaten <= 0) {
queue_and_out:
- if (eaten < 0 &&
- tcp_try_rmem_schedule(sk, skb, skb->truesize))
- goto drop;
-
+ if (eaten < 0) {
+ if (skb_queue_len(&sk->sk_receive_queue) == 0)
+ sk_forced_mem_schedule(sk, skb->truesize);
+ else if (tcp_try_rmem_schedule(sk, skb, skb->truesize))
+ goto drop;
+ }
eaten = tcp_queue_rcv(sk, skb, 0, &fragstolen);
}
tcp_rcv_nxt_update(tp, TCP_SKB_CB(skb)->end_seq);
if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
tcp_clamp_window(sk);
- else if (sk_under_memory_pressure(sk))
+ else if (tcp_under_memory_pressure(sk))
tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
tcp_collapse_ofo_queue(sk);
return false;
/* If we are under global TCP memory pressure, do not expand. */
- if (sk_under_memory_pressure(sk))
+ if (tcp_under_memory_pressure(sk))
return false;
/* If we are under soft global TCP memory pressure, do not expand. */
return want_cookie;
}
+static void tcp_reqsk_record_syn(const struct sock *sk,
+ struct request_sock *req,
+ const struct sk_buff *skb)
+{
+ if (tcp_sk(sk)->save_syn) {
+ u32 len = skb_network_header_len(skb) + tcp_hdrlen(skb);
+ u32 *copy;
+
+ copy = kmalloc(len + sizeof(u32), GFP_ATOMIC);
+ if (copy) {
+ copy[0] = len;
+ memcpy(©[1], skb_network_header(skb), len);
+ req->saved_syn = copy;
+ }
+ }
+}
+
int tcp_conn_request(struct request_sock_ops *rsk_ops,
const struct tcp_request_sock_ops *af_ops,
struct sock *sk, struct sk_buff *skb)
tcp_rsk(req)->tfo_listener = false;
af_ops->queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
}
+ tcp_reqsk_record_syn(sk, req, skb);
return 0;
projects / firefly-linux-kernel-4.4.55.git / blobdiff