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tcp: Simplify ACK-sending conditions in tcp_data_from_tap()

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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
1 changed files with 9 additions and 20 deletions
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29
tcp.c
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@ -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 tap_l4_msg *msg, int count,
struct timespec *now) 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 }; struct msghdr mh = { .msg_iov = tcp_tap_iov };
uint32_t max_ack_seq = conn->seq_ack_from_tap; uint32_t max_ack_seq = conn->seq_ack_from_tap;
uint16_t max_ack_seq_wnd = conn->wnd_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) if (th->fin)
fin = 1; fin = 1;
if (th->psh)
psh = 1;
if (!len) if (!len)
continue; continue;
@ -2411,11 +2408,8 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn,
* ^ seq * ^ seq
* (offset < 0) * (offset < 0)
*/ */
if (SEQ_GE(seq_offset, 0) && SEQ_LE(seq + len, seq_from_tap)) { if (SEQ_GE(seq_offset, 0) && SEQ_LE(seq + len, seq_from_tap))
/* Force sending ACK, sender might have lost one */
psh = 1;
continue; continue;
}
if (SEQ_LT(seq_offset, 0)) { if (SEQ_LT(seq_offset, 0)) {
if (keep == -1) if (keep == -1)
@ -2469,20 +2463,22 @@ eintr:
goto eintr; goto eintr;
if (errno == EAGAIN || errno == EWOULDBLOCK) { if (errno == EAGAIN || errno == EWOULDBLOCK) {
tcp_send_to_tap(c, conn, UPDATE_WINDOW, now); tcp_send_to_tap(c, conn, 0, now);
return; return;
} }
tcp_rst(c, conn); tcp_rst(c, conn);
return; return;
} }
if (n < (seq_from_tap - conn->seq_from_tap)) { if (n < (seq_from_tap - conn->seq_from_tap)) {
partial_send = 1; 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;
} }
conn->seq_from_tap += n;
out: out:
if (keep != -1) { if (keep != -1) {
if (conn->seq_dup_ack != conn->seq_from_tap) { if (conn->seq_dup_ack != conn->seq_from_tap) {
@ -2511,14 +2507,7 @@ out:
tcp_send_to_tap(c, conn, ACK, now); tcp_send_to_tap(c, conn, ACK, now);
} }
} else { } else {
int ack_to_tap = timespec_diff_ms(now, &conn->ts_ack_to_tap); tcp_send_to_tap(c, conn, 0, now);
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);
}
} }
} }