vcl: align the RST behaviour with kernel

When ESTABLISHED TCP connection is terminated by an RST packet,
EPOLLHUP + EPOLLRDHUP would be updeliever by VCL. If not using
VPP, app would receive EPOLLHUP + EPOLLERR + EPOLLIN(if requested) +
EPOLLRDHUP(if requested).

libevent will interpret the two cases as different EV combinations.

Below is the code snippet for libevent v2.12:

  if (what & EPOLLERR) {
    ev = EV_READ | EV_WRITE;
  } else if ((what & EPOLLHUP) && !(what & EPOLLRDHUP)) {
    ev = EV_READ | EV_WRITE;
  } else {
    if (what & EPOLLIN)
      ev |= EV_READ;
    if (what & EPOLLOUT)
      ev |= EV_WRITE;
    if (what & EPOLLRDHUP)
      ev |= EV_CLOSED;
 }

Type: fix
Signed-off-by: Yacan Liu <liuyacan@corp.netease.com>
Change-Id: Ice3d2861183b6ea499f66b727bbe175eeae5cb05

diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index 05b84d4..9644973 100644 (file)
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -516,6 +516,8 @@ vcl_session_reset_handler (vcl_worker_t * wrk,
 
   if (session->session_state != VCL_STATE_CLOSED)
     session->session_state = VCL_STATE_DISCONNECT;
+
+  session->flags |= (VCL_SESSION_F_RD_SHUTDOWN | VCL_SESSION_F_WR_SHUTDOWN);
   VDBG (0, "session %u [0x%llx]: reset", sid, reset_msg->handle);
   return sid;
 }
@@ -1067,6 +1069,7 @@ vcl_handle_mq_event (vcl_worker_t * wrk, session_event_t * e)
        {
          s->flags |= VCL_SESSION_F_PENDING_DISCONNECT;
          s->session_state = VCL_STATE_DISCONNECT;
+         s->flags |= (VCL_SESSION_F_RD_SHUTDOWN | VCL_SESSION_F_WR_SHUTDOWN);
          vec_add2 (wrk->unhandled_evts_vector, ecpy, 1);
          *ecpy = *e;
          ecpy->postponed = 1;
@@ -3118,7 +3121,16 @@ vcl_epoll_wait_handle_mq_event (vcl_worker_t * wrk, session_event_t * e,
        }
       session_events = s->vep.ev.events;
       add_event = 1;
-      events[*num_ev].events = EPOLLHUP | EPOLLRDHUP;
+      events[*num_ev].events = EPOLLERR | EPOLLHUP;
+      if ((EPOLLRDHUP & session_events) &&
+         (s->flags & VCL_SESSION_F_RD_SHUTDOWN))
+       {
+         events[*num_ev].events = EPOLLRDHUP;
+       }
+      if ((EPOLLIN & session_events) && (s->flags & VCL_SESSION_F_RD_SHUTDOWN))
+       {
+         events[*num_ev].events |= EPOLLIN;
+       }
       session_evt_data = s->vep.ev.data.u64;
       break;
     case SESSION_CTRL_EVT_UNLISTEN_REPLY: