int sysctl_tcp_sack __read_mostly = 1;
int sysctl_tcp_fack __read_mostly = 1;
int sysctl_tcp_reordering __read_mostly = TCP_FASTRETRANS_THRESH;
-int sysctl_tcp_ecn __read_mostly;
+int sysctl_tcp_ecn __read_mostly = 2;
int sysctl_tcp_dsack __read_mostly = 1;
int sysctl_tcp_app_win __read_mostly = 31;
int sysctl_tcp_adv_win_scale __read_mostly = 2;
tcp_grow_window(sk, skb);
}
-static u32 tcp_rto_min(struct sock *sk)
-{
- struct dst_entry *dst = __sk_dst_get(sk);
- u32 rto_min = TCP_RTO_MIN;
-
- if (dst && dst_metric_locked(dst, RTAX_RTO_MIN))
- rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN);
- return rto_min;
-}
-
/* Called to compute a smoothed rtt estimate. The data fed to this
* routine either comes from timestamps, or from segments that were
* known _not_ to have been retransmitted [see Karn/Partridge
* is invisible. Actually, Linux-2.4 also generates erratic
* ACKs in some circumstances.
*/
- inet_csk(sk)->icsk_rto = (tp->srtt >> 3) + tp->rttvar;
+ inet_csk(sk)->icsk_rto = __tcp_set_rto(tp);
/* 2. Fixups made earlier cannot be right.
* If we do not estimate RTO correctly without them,
/* NOTE: clamping at TCP_RTO_MIN is not required, current algo
* guarantees that rto is higher.
*/
- if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX)
- inet_csk(sk)->icsk_rto = TCP_RTO_MAX;
+ tcp_bound_rto(sk);
}
/* Save metrics learned by this TCP session.
set_dst_metric_rtt(dst, RTAX_RTTVAR, var);
}
- if (tp->snd_ssthresh >= 0xFFFF) {
+ if (tcp_in_initial_slowstart(tp)) {
/* Slow start still did not finish. */
if (dst_metric(dst, RTAX_SSTHRESH) &&
!dst_metric_locked(dst, RTAX_SSTHRESH) &&
tcp_set_rto(sk);
if (inet_csk(sk)->icsk_rto < TCP_TIMEOUT_INIT && !tp->rx_opt.saw_tstamp)
goto reset;
+
+cwnd:
tp->snd_cwnd = tcp_init_cwnd(tp, dst);
tp->snd_cwnd_stamp = tcp_time_stamp;
return;
tp->mdev = tp->mdev_max = tp->rttvar = TCP_TIMEOUT_INIT;
inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
}
+ goto cwnd;
}
static void tcp_update_reordering(struct sock *sk, const int metric,
int prior_packets;
int frto_cwnd = 0;
- /* If the ack is newer than sent or older than previous acks
+ /* If the ack is older than previous acks
* then we can probably ignore it.
*/
- if (after(ack, tp->snd_nxt))
- goto uninteresting_ack;
-
if (before(ack, prior_snd_una))
goto old_ack;
+ /* If the ack includes data we haven't sent yet, discard
+ * this segment (RFC793 Section 3.9).
+ */
+ if (after(ack, tp->snd_nxt))
+ goto invalid_ack;
+
if (after(ack, prior_snd_una))
flag |= FLAG_SND_UNA_ADVANCED;
tcp_ack_probe(sk);
return 1;
+invalid_ack:
+ SOCK_DEBUG(sk, "Ack %u after %u:%u\n", ack, tp->snd_una, tp->snd_nxt);
+ return -1;
+
old_ack:
if (TCP_SKB_CB(skb)->sacked) {
tcp_sacktag_write_queue(sk, skb, prior_snd_una);
tcp_try_keep_open(sk);
}
-uninteresting_ack:
- SOCK_DEBUG(sk, "Ack %u out of %u:%u\n", ack, tp->snd_una, tp->snd_nxt);
+ SOCK_DEBUG(sk, "Ack %u before %u:%u\n", ack, tp->snd_una, tp->snd_nxt);
return 0;
}
}
__skb_queue_head(&tp->out_of_order_queue, skb);
} else {
- struct sk_buff *skb1 = tp->out_of_order_queue.prev;
+ struct sk_buff *skb1 = skb_peek_tail(&tp->out_of_order_queue);
u32 seq = TCP_SKB_CB(skb)->seq;
u32 end_seq = TCP_SKB_CB(skb)->end_seq;
}
/* Find place to insert this segment. */
- do {
+ while (1) {
if (!after(TCP_SKB_CB(skb1)->seq, seq))
break;
- } while ((skb1 = skb1->prev) !=
- (struct sk_buff *)&tp->out_of_order_queue);
+ if (skb_queue_is_first(&tp->out_of_order_queue, skb1)) {
+ skb1 = NULL;
+ break;
+ }
+ skb1 = skb_queue_prev(&tp->out_of_order_queue, skb1);
+ }
/* Do skb overlap to previous one? */
- if (skb1 != (struct sk_buff *)&tp->out_of_order_queue &&
- before(seq, TCP_SKB_CB(skb1)->end_seq)) {
+ if (skb1 && before(seq, TCP_SKB_CB(skb1)->end_seq)) {
if (!after(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
/* All the bits are present. Drop. */
__kfree_skb(skb);
tcp_dsack_set(sk, seq,
TCP_SKB_CB(skb1)->end_seq);
} else {
- skb1 = skb1->prev;
+ if (skb_queue_is_first(&tp->out_of_order_queue,
+ skb1))
+ skb1 = NULL;
+ else
+ skb1 = skb_queue_prev(
+ &tp->out_of_order_queue,
+ skb1);
}
}
- __skb_queue_after(&tp->out_of_order_queue, skb1, skb);
+ if (!skb1)
+ __skb_queue_head(&tp->out_of_order_queue, skb);
+ else
+ __skb_queue_after(&tp->out_of_order_queue, skb1, skb);
/* And clean segments covered by new one as whole. */
- while ((skb1 = skb->next) !=
- (struct sk_buff *)&tp->out_of_order_queue &&
- after(end_seq, TCP_SKB_CB(skb1)->seq)) {
+ while (!skb_queue_is_last(&tp->out_of_order_queue, skb)) {
+ skb1 = skb_queue_next(&tp->out_of_order_queue, skb);
+
+ if (!after(end_seq, TCP_SKB_CB(skb1)->seq))
+ break;
if (before(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq,
end_seq);
static struct sk_buff *tcp_collapse_one(struct sock *sk, struct sk_buff *skb,
struct sk_buff_head *list)
{
- struct sk_buff *next = skb->next;
+ struct sk_buff *next = NULL;
+
+ if (!skb_queue_is_last(list, skb))
+ next = skb_queue_next(list, skb);
__skb_unlink(skb, list);
__kfree_skb(skb);
/* Collapse contiguous sequence of skbs head..tail with
* sequence numbers start..end.
+ *
+ * If tail is NULL, this means until the end of the list.
+ *
* Segments with FIN/SYN are not collapsed (only because this
* simplifies code)
*/
struct sk_buff *head, struct sk_buff *tail,
u32 start, u32 end)
{
- struct sk_buff *skb;
+ struct sk_buff *skb, *n;
+ bool end_of_skbs;
/* First, check that queue is collapsible and find
* the point where collapsing can be useful. */
- for (skb = head; skb != tail;) {
+ skb = head;
+restart:
+ end_of_skbs = true;
+ skb_queue_walk_from_safe(list, skb, n) {
+ if (skb == tail)
+ break;
/* No new bits? It is possible on ofo queue. */
if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
skb = tcp_collapse_one(sk, skb, list);
- continue;
+ if (!skb)
+ break;
+ goto restart;
}
/* The first skb to collapse is:
*/
if (!tcp_hdr(skb)->syn && !tcp_hdr(skb)->fin &&
(tcp_win_from_space(skb->truesize) > skb->len ||
- before(TCP_SKB_CB(skb)->seq, start) ||
- (skb->next != tail &&
- TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb->next)->seq)))
+ before(TCP_SKB_CB(skb)->seq, start))) {
+ end_of_skbs = false;
break;
+ }
+
+ if (!skb_queue_is_last(list, skb)) {
+ struct sk_buff *next = skb_queue_next(list, skb);
+ if (next != tail &&
+ TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(next)->seq) {
+ end_of_skbs = false;
+ break;
+ }
+ }
/* Decided to skip this, advance start seq. */
start = TCP_SKB_CB(skb)->end_seq;
- skb = skb->next;
}
- if (skb == tail || tcp_hdr(skb)->syn || tcp_hdr(skb)->fin)
+ if (end_of_skbs || tcp_hdr(skb)->syn || tcp_hdr(skb)->fin)
return;
while (before(start, end)) {
}
if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
skb = tcp_collapse_one(sk, skb, list);
- if (skb == tail ||
+ if (!skb ||
+ skb == tail ||
tcp_hdr(skb)->syn ||
tcp_hdr(skb)->fin)
return;
head = skb;
for (;;) {
- skb = skb->next;
+ struct sk_buff *next = NULL;
+
+ if (!skb_queue_is_last(&tp->out_of_order_queue, skb))
+ next = skb_queue_next(&tp->out_of_order_queue, skb);
+ skb = next;
/* Segment is terminated when we see gap or when
* we are at the end of all the queue. */
- if (skb == (struct sk_buff *)&tp->out_of_order_queue ||
+ if (!skb ||
after(TCP_SKB_CB(skb)->seq, end) ||
before(TCP_SKB_CB(skb)->end_seq, start)) {
tcp_collapse(sk, &tp->out_of_order_queue,
head, skb, start, end);
head = skb;
- if (skb == (struct sk_buff *)&tp->out_of_order_queue)
+ if (!skb)
break;
/* Start new segment */
start = TCP_SKB_CB(skb)->seq;
tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
tcp_collapse_ofo_queue(sk);
- tcp_collapse(sk, &sk->sk_receive_queue,
- sk->sk_receive_queue.next,
- (struct sk_buff *)&sk->sk_receive_queue,
- tp->copied_seq, tp->rcv_nxt);
+ if (!skb_queue_empty(&sk->sk_receive_queue))
+ tcp_collapse(sk, &sk->sk_receive_queue,
+ skb_peek(&sk->sk_receive_queue),
+ NULL,
+ tp->copied_seq, tp->rcv_nxt);
sk_mem_reclaim(sk);
if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
*/
if ((tcp_flag_word(th) & TCP_HP_BITS) == tp->pred_flags &&
- TCP_SKB_CB(skb)->seq == tp->rcv_nxt) {
+ TCP_SKB_CB(skb)->seq == tp->rcv_nxt &&
+ !after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) {
int tcp_header_len = tp->tcp_header_len;
/* Timestamp header prediction: tcp_header_len
return -res;
step5:
- if (th->ack)
- tcp_ack(sk, skb, FLAG_SLOWPATH);
+ if (th->ack && tcp_ack(sk, skb, FLAG_SLOWPATH) < 0)
+ goto discard;
tcp_rcv_rtt_measure_ts(sk, skb);
/* step 5: check the ACK field */
if (th->ack) {
- int acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH);
+ int acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH) > 0;
switch (sk->sk_state) {
case TCP_SYN_RECV: