tcp: Simplify ACK-sending conditions in tcp_data_from_tap()

Now that we have a proper function checking when and how to send
ACKs and window updates, we don't need to duplicate this logic in
tcp_data_from_tap().

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio 2021-10-05 19:51:03 +02:00
parent eda446ba54
commit d565082f84

29
tcp.c
View file

@ -2324,7 +2324,7 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn,
struct tap_l4_msg *msg, int count,
struct timespec *now)
{
int i, iov_i, ack = 0, fin = 0, psh = 0, retr = 0, keep = -1;
int i, iov_i, ack = 0, fin = 0, retr = 0, keep = -1;
struct msghdr mh = { .msg_iov = tcp_tap_iov };
uint32_t max_ack_seq = conn->seq_ack_from_tap;
uint16_t max_ack_seq_wnd = conn->wnd_from_tap;
@ -2382,9 +2382,6 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn,
if (th->fin)
fin = 1;
if (th->psh)
psh = 1;
if (!len)
continue;
@ -2411,11 +2408,8 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn,
* ^ seq
* (offset < 0)
*/
if (SEQ_GE(seq_offset, 0) && SEQ_LE(seq + len, seq_from_tap)) {
/* Force sending ACK, sender might have lost one */
psh = 1;
if (SEQ_GE(seq_offset, 0) && SEQ_LE(seq + len, seq_from_tap))
continue;
}
if (SEQ_LT(seq_offset, 0)) {
if (keep == -1)
@ -2469,19 +2463,21 @@ eintr:
goto eintr;
if (errno == EAGAIN || errno == EWOULDBLOCK) {
tcp_send_to_tap(c, conn, UPDATE_WINDOW, now);
tcp_send_to_tap(c, conn, 0, now);
return;
}
tcp_rst(c, conn);
return;
}
if (n < (seq_from_tap - conn->seq_from_tap)) {
partial_send = 1;
tcp_send_to_tap(c, conn, UPDATE_WINDOW, now);
}
conn->seq_from_tap += n;
tcp_send_to_tap(c, conn, 0, now);
} else {
conn->seq_from_tap += n;
}
out:
if (keep != -1) {
@ -2511,14 +2507,7 @@ out:
tcp_send_to_tap(c, conn, ACK, now);
}
} else {
int ack_to_tap = timespec_diff_ms(now, &conn->ts_ack_to_tap);
int ack_offset = conn->seq_from_tap - conn->seq_ack_to_tap;
if (c->mode == MODE_PASTA ||
psh || SEQ_GE(ack_offset, conn->wnd_to_tap * 2 / 3) ||
ack_to_tap > ACK_INTERVAL) {
tcp_send_to_tap(c, conn, psh ? FORCE_ACK : 0, now);
}
tcp_send_to_tap(c, conn, 0, now);
}
}