/* Set window scaling on max possible window
* See RFC1323 for an explanation of the limit to 14
*/
- space = max_t(u32, sysctl_tcp_rmem[2], sysctl_rmem_max);
+ space = max_t(u32, space, sysctl_tcp_rmem[2]);
+ space = max_t(u32, space, sysctl_rmem_max);
space = min_t(u32, space, *window_clamp);
while (space > 65535 && (*rcv_wscale) < 14) {
space >>= 1;
}
}
-/* Send a fin. The caller locks the socket for us. This cannot be
- * allowed to fail queueing a FIN frame under any circumstances.
+/* We allow to exceed memory limits for FIN packets to expedite
+ * connection tear down and (memory) recovery.
+ * Otherwise tcp_send_fin() could be tempted to either delay FIN
+ * or even be forced to close flow without any FIN.
+ */
+static void sk_forced_wmem_schedule(struct sock *sk, int size)
+{
+ int amt, status;
+
+ if (size <= sk->sk_forward_alloc)
+ return;
+ amt = sk_mem_pages(size);
+ sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
+ sk_memory_allocated_add(sk, amt, &status);
+}
+
+/* Send a FIN. The caller locks the socket for us.
+ * We should try to send a FIN packet really hard, but eventually give up.
*/
void tcp_send_fin(struct sock *sk)
{
+ struct sk_buff *skb, *tskb = tcp_write_queue_tail(sk);
struct tcp_sock *tp = tcp_sk(sk);
- struct sk_buff *skb = tcp_write_queue_tail(sk);
- int mss_now;
- /* Optimization, tack on the FIN if we have a queue of
- * unsent frames. But be careful about outgoing SACKS
- * and IP options.
+ /* Optimization, tack on the FIN if we have one skb in write queue and
+ * this skb was not yet sent, or we are under memory pressure.
+ * Note: in the latter case, FIN packet will be sent after a timeout,
+ * as TCP stack thinks it has already been transmitted.
*/
- mss_now = tcp_current_mss(sk);
-
- if (tcp_send_head(sk) != NULL) {
- TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_FIN;
- TCP_SKB_CB(skb)->end_seq++;
+ if (tskb && (tcp_send_head(sk) || sk_under_memory_pressure(sk))) {
+coalesce:
+ TCP_SKB_CB(tskb)->tcp_flags |= TCPHDR_FIN;
+ TCP_SKB_CB(tskb)->end_seq++;
tp->write_seq++;
+ if (!tcp_send_head(sk)) {
+ /* This means tskb was already sent.
+ * Pretend we included the FIN on previous transmit.
+ * We need to set tp->snd_nxt to the value it would have
+ * if FIN had been sent. This is because retransmit path
+ * does not change tp->snd_nxt.
+ */
+ tp->snd_nxt++;
+ return;
+ }
} else {
- /* Socket is locked, keep trying until memory is available. */
- for (;;) {
- skb = alloc_skb_fclone(MAX_TCP_HEADER,
- sk->sk_allocation);
- if (skb)
- break;
- yield();
+ skb = alloc_skb_fclone(MAX_TCP_HEADER, sk->sk_allocation);
+ if (unlikely(!skb)) {
+ if (tskb)
+ goto coalesce;
+ return;
}
-
- /* Reserve space for headers and prepare control bits. */
skb_reserve(skb, MAX_TCP_HEADER);
+ sk_forced_wmem_schedule(sk, skb->truesize);
/* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
tcp_init_nondata_skb(skb, tp->write_seq,
TCPHDR_ACK | TCPHDR_FIN);
tcp_queue_skb(sk, skb);
}
- __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_OFF);
+ __tcp_push_pending_frames(sk, tcp_current_mss(sk), TCP_NAGLE_OFF);
}
/* We get here when a process closes a file descriptor (either due to
}
#endif
+ /* Do not fool tcpdump (if any), clean our debris */
+ skb->tstamp.tv64 = 0;
return skb;
}
EXPORT_SYMBOL(tcp_make_synack);
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_fastopen_request *fo = tp->fastopen_req;
- int syn_loss = 0, space, i, err = 0, iovlen = fo->data->msg_iovlen;
- struct sk_buff *syn_data = NULL, *data;
+ int syn_loss = 0, space, err = 0;
unsigned long last_syn_loss = 0;
+ struct sk_buff *syn_data;
tp->rx_opt.mss_clamp = tp->advmss; /* If MSS is not cached */
tcp_fastopen_cache_get(sk, &tp->rx_opt.mss_clamp, &fo->cookie,
/* limit to order-0 allocations */
space = min_t(size_t, space, SKB_MAX_HEAD(MAX_TCP_HEADER));
- syn_data = skb_copy_expand(syn, MAX_TCP_HEADER, space,
- sk->sk_allocation);
- if (syn_data == NULL)
+ syn_data = sk_stream_alloc_skb(sk, space, sk->sk_allocation);
+ if (!syn_data)
+ goto fallback;
+ syn_data->ip_summed = CHECKSUM_PARTIAL;
+ memcpy(syn_data->cb, syn->cb, sizeof(syn->cb));
+ skb_shinfo(syn_data)->gso_segs = 1;
+ if (unlikely(memcpy_fromiovecend(skb_put(syn_data, space),
+ fo->data->msg_iov, 0, space))) {
+ kfree_skb(syn_data);
goto fallback;
+ }
- for (i = 0; i < iovlen && syn_data->len < space; ++i) {
- struct iovec *iov = &fo->data->msg_iov[i];
- unsigned char __user *from = iov->iov_base;
- int len = iov->iov_len;
+ /* No more data pending in inet_wait_for_connect() */
+ if (space == fo->size)
+ fo->data = NULL;
+ fo->copied = space;
- if (syn_data->len + len > space)
- len = space - syn_data->len;
- else if (i + 1 == iovlen)
- /* No more data pending in inet_wait_for_connect() */
- fo->data = NULL;
+ tcp_connect_queue_skb(sk, syn_data);
- if (skb_add_data(syn_data, from, len))
- goto fallback;
- }
+ err = tcp_transmit_skb(sk, syn_data, 1, sk->sk_allocation);
- /* Queue a data-only packet after the regular SYN for retransmission */
- data = pskb_copy(syn_data, sk->sk_allocation);
- if (data == NULL)
- goto fallback;
- TCP_SKB_CB(data)->seq++;
- TCP_SKB_CB(data)->tcp_flags &= ~TCPHDR_SYN;
- TCP_SKB_CB(data)->tcp_flags = (TCPHDR_ACK|TCPHDR_PSH);
- tcp_connect_queue_skb(sk, data);
- fo->copied = data->len;
-
- if (tcp_transmit_skb(sk, syn_data, 0, sk->sk_allocation) == 0) {
+ /* Now full SYN+DATA was cloned and sent (or not),
+ * remove the SYN from the original skb (syn_data)
+ * we keep in write queue in case of a retransmit, as we
+ * also have the SYN packet (with no data) in the same queue.
+ */
+ TCP_SKB_CB(syn_data)->seq++;
+ TCP_SKB_CB(syn_data)->tcp_flags = TCPHDR_ACK | TCPHDR_PSH;
+ if (!err) {
tp->syn_data = (fo->copied > 0);
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVE);
goto done;
}
- syn_data = NULL;
fallback:
/* Send a regular SYN with Fast Open cookie request option */
err = tcp_transmit_skb(sk, syn, 1, sk->sk_allocation);
if (err)
tp->syn_fastopen = 0;
- kfree_skb(syn_data);
done:
fo->cookie.len = -1; /* Exclude Fast Open option for SYN retries */
return err;
return 0;
}
- buff = alloc_skb_fclone(MAX_TCP_HEADER + 15, sk->sk_allocation);
- if (unlikely(buff == NULL))
+ buff = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
+ if (unlikely(!buff))
return -ENOBUFS;
- /* Reserve space for headers. */
- skb_reserve(buff, MAX_TCP_HEADER);
-
tcp_init_nondata_skb(buff, tp->write_seq++, TCPHDR_SYN);
tp->retrans_stamp = TCP_SKB_CB(buff)->when = tcp_time_stamp;
tcp_connect_queue_skb(sk, buff);
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blobdiff