vcl: improve shutdown()

This commit does following:

- Change the behavior of shutdown() with SHUT_RDWR flag.
- Check SHUT_RD flag when read()
- Change the errno when write() after SHUT_WR
- Remove unused code

All the above modification passed the packetdrill test.

Type: improvement

Signed-off-by: liuyacan <liuyacan@corp.netease.com>
Change-Id: I0c81f52e563562e58580d70976526b898e65e915

6 files changed, 40 insertions, 54 deletions

diff --git a/src/vcl/ldp.c b/src/vcl/ldp.c
index b51d2e0ebb4..54a8f66354f 100644
--- a/src/vcl/ldp.c
+++ b/src/vcl/ldp.c
@@ -2175,8 +2175,7 @@ int
 shutdown (int fd, int how)
 {
   vls_handle_t vlsh;
-  int rv = 0, flags;
-  u32 flags_len = sizeof (flags);
+  int rv = 0;
 
   ldp_init_check ();
 
@@ -2184,23 +2183,7 @@ shutdown (int fd, int how)
   if (vlsh != VLS_INVALID_HANDLE)
     {
       LDBG (0, "called shutdown: fd %u vlsh %u how %d", fd, vlsh, how);
-
-      if (vls_attr (vlsh, VPPCOM_ATTR_SET_SHUT, &how, &flags_len))
-	{
-	  close (fd);
-	  return -1;
-	}
-
-      if (vls_attr (vlsh, VPPCOM_ATTR_GET_SHUT, &flags, &flags_len))
-	{
-	  close (fd);
-	  return -1;
-	}
-
-      if (flags == SHUT_RDWR)
-	rv = close (fd);
-      else if (flags == SHUT_WR)
-	rv = vls_shutdown (vlsh);
+      rv = vls_shutdown (vlsh, how);
     }
   else
     {
diff --git a/src/vcl/vcl_locked.c b/src/vcl/vcl_locked.c
index 69f492b8694..ea22bcd22f5 100644
--- a/src/vcl/vcl_locked.c
+++ b/src/vcl/vcl_locked.c
@@ -1314,7 +1314,7 @@ vls_close (vls_handle_t vlsh)
 }
 
 int
-vls_shutdown (vls_handle_t vlsh)
+vls_shutdown (vls_handle_t vlsh, int how)
 {
   vcl_locked_session_t *vls;
   int rv;
@@ -1324,7 +1324,7 @@ vls_shutdown (vls_handle_t vlsh)
     return VPPCOM_EBADFD;
 
   vls_mt_guard (vls, VLS_MT_OP_SPOOL);
-  rv = vppcom_session_shutdown (vls_to_sh (vls));
+  rv = vppcom_session_shutdown (vls_to_sh (vls), how);
   vls_mt_unguard ();
   vls_get_and_unlock (vlsh);
 
diff --git a/src/vcl/vcl_locked.h b/src/vcl/vcl_locked.h
index 3adcf62bc77..fa3a2735eb7 100644
--- a/src/vcl/vcl_locked.h
+++ b/src/vcl/vcl_locked.h
@@ -26,7 +26,7 @@
 typedef int vls_handle_t;
 
 vls_handle_t vls_create (uint8_t proto, uint8_t is_nonblocking);
-int vls_shutdown (vls_handle_t vlsh);
+int vls_shutdown (vls_handle_t vlsh, int how);
 int vls_close (vls_handle_t vlsh);
 int vls_bind (vls_handle_t vlsh, vppcom_endpt_t * ep);
 int vls_listen (vls_handle_t vlsh, int q_len);
diff --git a/src/vcl/vcl_private.h b/src/vcl/vcl_private.h
index 628b7310788..5b19f946fe7 100644
--- a/src/vcl/vcl_private.h
+++ b/src/vcl/vcl_private.h
@@ -126,8 +126,6 @@ typedef enum
   VCL_SESS_ATTR_TCP_NODELAY,	// SOL_TCP,TCP_NODELAY
   VCL_SESS_ATTR_TCP_KEEPIDLE,	// SOL_TCP,TCP_KEEPIDLE
   VCL_SESS_ATTR_TCP_KEEPINTVL,	// SOL_TCP,TCP_KEEPINTVL
-  VCL_SESS_ATTR_SHUT_RD,
-  VCL_SESS_ATTR_SHUT_WR,
   VCL_SESS_ATTR_MAX
 } vppcom_session_attr_t;
 
@@ -137,7 +135,8 @@ typedef enum vcl_session_flags_
   VCL_SESSION_F_IS_VEP = 1 << 1,
   VCL_SESSION_F_IS_VEP_SESSION = 1 << 2,
   VCL_SESSION_F_HAS_RX_EVT = 1 << 3,
-  VCL_SESSION_F_SHUTDOWN = 1 << 4,
+  VCL_SESSION_F_RD_SHUTDOWN = 1 << 4,
+  VCL_SESSION_F_WR_SHUTDOWN = 1 << 5,
 } __clib_packed vcl_session_flags_t;
 
 typedef struct vcl_session_
diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index 330d590cfa0..d378f404381 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -807,7 +807,7 @@ vcl_session_disconnected_handler (vcl_worker_t * wrk,
 }
 
 int
-vppcom_session_shutdown (uint32_t session_handle)
+vppcom_session_shutdown (uint32_t session_handle, int how)
 {
   vcl_worker_t *wrk = vcl_worker_get_current ();
   vcl_session_t *session;
@@ -830,13 +830,20 @@ vppcom_session_shutdown (uint32_t session_handle)
       return VPPCOM_EBADFD;
     }
 
+  if (how == SHUT_RD || how == SHUT_RDWR)
+    {
+      session->flags |= VCL_SESSION_F_RD_SHUTDOWN;
+      if (how == SHUT_RD)
+	return VPPCOM_OK;
+    }
+  session->flags |= VCL_SESSION_F_WR_SHUTDOWN;
+
   if (PREDICT_TRUE (state == VCL_STATE_READY))
     {
       VDBG (1, "session %u [0x%llx]: sending shutdown...",
 	    session->session_index, vpp_handle);
 
       vcl_send_session_shutdown (wrk, session);
-      session->flags |= VCL_SESSION_F_SHUTDOWN;
     }
 
   return VPPCOM_OK;
@@ -1948,6 +1955,18 @@ vppcom_session_read_internal (uint32_t session_handle, void *buf, int n,
       return vcl_session_closed_error (s);
     }
 
+  if (PREDICT_FALSE (s->flags & VCL_SESSION_F_RD_SHUTDOWN))
+    {
+      /* Vpp would ack the incoming data and enqueue it for reading.
+       * So even if SHUT_RD is set, we can still read() the data if
+       * the session is ready.
+       */
+      if (!vcl_session_read_ready (s))
+	{
+	  return 0;
+	}
+    }
+
   is_nonblocking = vcl_session_has_attr (s, VCL_SESS_ATTR_NONBLOCK);
   is_ct = vcl_session_is_ct (s);
   mq = wrk->app_event_queue;
@@ -2166,8 +2185,7 @@ vppcom_session_write_inline (vcl_worker_t * wrk, vcl_session_t * s, void *buf,
       return VPPCOM_EBADFD;
     }
 
-  if (PREDICT_FALSE (!vcl_session_is_open (s) ||
-		     (s->flags & VCL_SESSION_F_SHUTDOWN)))
+  if (PREDICT_FALSE (!vcl_session_is_open (s)))
     {
       VDBG (1, "session %u [0x%llx]: is not open! state 0x%x (%s)",
 	    s->session_index, s->vpp_handle, s->session_state,
@@ -2175,6 +2193,14 @@ vppcom_session_write_inline (vcl_worker_t * wrk, vcl_session_t * s, void *buf,
       return vcl_session_closed_error (s);;
     }
 
+  if (PREDICT_FALSE (s->flags & VCL_SESSION_F_WR_SHUTDOWN))
+    {
+      VDBG (1, "session %u [0x%llx]: is shutdown! state 0x%x (%s)",
+	    s->session_index, s->vpp_handle, s->session_state,
+	    vppcom_session_state_str (s->session_state));
+      return VPPCOM_EPIPE;
+    }
+
   is_ct = vcl_session_is_ct (s);
   tx_fifo = is_ct ? s->ct_tx_fifo : s->tx_fifo;
   is_nonblocking = vcl_session_has_attr (s, VCL_SESS_ATTR_NONBLOCK);
@@ -3209,7 +3235,7 @@ vppcom_session_attr (uint32_t session_handle, uint32_t op,
 		     void *buffer, uint32_t * buflen)
 {
   vcl_worker_t *wrk = vcl_worker_get_current ();
-  u32 *flags = buffer, tmp_flags = 0;
+  u32 *flags = buffer;
   vppcom_endpt_t *ep = buffer;
   transport_endpt_attr_t tea;
   vcl_session_t *session;
@@ -3747,27 +3773,6 @@ vppcom_session_attr (uint32_t session_handle, uint32_t op,
 	    *buflen);
       break;
 
-    case VPPCOM_ATTR_SET_SHUT:
-      if (*flags == SHUT_RD || *flags == SHUT_RDWR)
-	vcl_session_set_attr (session, VCL_SESS_ATTR_SHUT_RD);
-      if (*flags == SHUT_WR || *flags == SHUT_RDWR)
-	vcl_session_set_attr (session, VCL_SESS_ATTR_SHUT_WR);
-      break;
-
-    case VPPCOM_ATTR_GET_SHUT:
-      if (vcl_session_has_attr (session, VCL_SESS_ATTR_SHUT_RD))
-	tmp_flags = 1;
-      if (vcl_session_has_attr (session, VCL_SESS_ATTR_SHUT_WR))
-	tmp_flags |= 2;
-      if (tmp_flags == 1)
-	*(int *) buffer = SHUT_RD;
-      else if (tmp_flags == 2)
-	*(int *) buffer = SHUT_WR;
-      else if (tmp_flags == 3)
-	*(int *) buffer = SHUT_RDWR;
-      *buflen = sizeof (int);
-      break;
-
     case VPPCOM_ATTR_SET_CONNECTED:
       session->flags |= VCL_SESSION_F_CONNECTED;
       break;
diff --git a/src/vcl/vppcom.h b/src/vcl/vppcom.h
index c2a625e974e..19a01c798b5 100644
--- a/src/vcl/vppcom.h
+++ b/src/vcl/vppcom.h
@@ -99,6 +99,7 @@ typedef enum
   VPPCOM_ETIMEDOUT = -ETIMEDOUT,
   VPPCOM_EEXIST = -EEXIST,
   VPPCOM_ENOPROTOOPT = -ENOPROTOOPT,
+  VPPCOM_EPIPE = -EPIPE,
   VPPCOM_ENOENT = -ENOENT,
 } vppcom_error_t;
 
@@ -138,8 +139,6 @@ typedef enum
   VPPCOM_ATTR_SET_TCP_KEEPINTVL,
   VPPCOM_ATTR_GET_TCP_USER_MSS,
   VPPCOM_ATTR_SET_TCP_USER_MSS,
-  VPPCOM_ATTR_SET_SHUT,
-  VPPCOM_ATTR_GET_SHUT,
   VPPCOM_ATTR_SET_CONNECTED,
   VPPCOM_ATTR_SET_CKPAIR,
   VPPCOM_ATTR_SET_VRF,
@@ -174,7 +173,7 @@ extern int vppcom_app_create (const char *app_name);
 extern void vppcom_app_destroy (void);
 
 extern int vppcom_session_create (uint8_t proto, uint8_t is_nonblocking);
-extern int vppcom_session_shutdown (uint32_t session_handle);
+extern int vppcom_session_shutdown (uint32_t session_handle, int how);
 extern int vppcom_session_close (uint32_t session_handle);
 extern int vppcom_session_bind (uint32_t session_handle, vppcom_endpt_t * ep);
 extern int vppcom_session_listen (uint32_t session_handle, uint32_t q_len);