diff options
| -rw-r--r-- | sys/netinet/tcp_input.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index a7b6ced..a3122a1 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -2564,6 +2564,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, u_long oldcwnd = tp->snd_cwnd; tcp_seq oldsndmax = tp->snd_max; u_int sent; + int avail; KASSERT(tp->t_dupacks == 1 || tp->t_dupacks == 2, @@ -2585,7 +2586,17 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so, */ break; } - (void) tcp_output(tp); + /* + * Only call tcp_output when there + * is new data available to be sent. + * Otherwise we would send pure ACKs. + */ + SOCKBUF_LOCK(&so->so_snd); + avail = so->so_snd.sb_cc - + (tp->snd_nxt - tp->snd_una); + SOCKBUF_UNLOCK(&so->so_snd); + if (avail > 0) + (void) tcp_output(tp); sent = tp->snd_max - oldsndmax; if (sent > tp->t_maxseg) { KASSERT((tp->t_dupacks == 2 && |
