session udp: support connect on listeners

Type: feature

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I6aaaec20a2b6d4c6ddfbe659d9402acc1be2f7e2

3 files changed, 54 insertions, 5 deletions

diff --git a/src/vcl/vcl_private.c b/src/vcl/vcl_private.c
index 3cb76c6bb7d..14582ce025d 100644
--- a/src/vcl/vcl_private.c
+++ b/src/vcl/vcl_private.c
@@ -308,6 +308,8 @@ vcl_cleanup_bapi (void)
 int
 vcl_session_read_ready (vcl_session_t * session)
 {
+  u32 max_deq;
+
   /* Assumes caller has acquired spinlock: vcm->sessions_lockp */
   if (PREDICT_FALSE (session->is_vep))
     {
@@ -335,7 +337,23 @@ vcl_session_read_ready (vcl_session_t * session)
   if (vcl_session_is_ct (session))
     return svm_fifo_max_dequeue_cons (session->ct_rx_fifo);
 
-  return svm_fifo_max_dequeue_cons (session->rx_fifo);
+  max_deq = svm_fifo_max_dequeue_cons (session->rx_fifo);
+
+  if (session->is_dgram)
+    {
+      session_dgram_pre_hdr_t ph;
+
+      if (max_deq <= SESSION_CONN_HDR_LEN)
+	return 0;
+      if (svm_fifo_peek (session->rx_fifo, 0, sizeof (ph), (u8 *) & ph) < 0)
+	return 0;
+      if (ph.data_length + SESSION_CONN_HDR_LEN > max_deq)
+	return 0;
+
+      return ph.data_length;
+    }
+
+  return max_deq;
 }
 
 int
diff --git a/src/vcl/vcl_private.h b/src/vcl/vcl_private.h
index 650d254afc7..433e08e2b46 100644
--- a/src/vcl/vcl_private.h
+++ b/src/vcl/vcl_private.h
@@ -149,6 +149,11 @@ do {                                            \
 #define VCL_SESS_ATTR_TEST(ATTR, VAL)           \
   ((ATTR) & (1 << (VAL)) ? 1 : 0)
 
+typedef enum vcl_session_flags_
+{
+  VCL_SESSION_F_CONNECTED,
+} __clib_packed vcl_session_flags_t;
+
 typedef struct
 {
   CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
@@ -167,6 +172,7 @@ typedef struct
   /* Socket configuration state */
   u8 is_vep;
   u8 is_vep_session;
+  vcl_session_flags_t flags;
   /* VCL session index of the listening session (if any) */
   u32 listener_index;
   /* Accepted sessions on this listener */
diff --git a/src/vcl/vppcom.c b/src/vcl/vppcom.c
index 03bd32c5446..ba1f1166556 100644
--- a/src/vcl/vppcom.c
+++ b/src/vcl/vppcom.c
@@ -231,7 +231,10 @@ vcl_send_session_connect (vcl_worker_t * wrk, vcl_session_t * s)
   clib_memcpy_fast (&mp->ip, &s->transport.rmt_ip, sizeof (mp->ip));
   clib_memcpy_fast (&mp->lcl_ip, &s->transport.lcl_ip, sizeof (mp->lcl_ip));
   mp->port = s->transport.rmt_port;
+  mp->lcl_port = s->transport.lcl_port;
   mp->proto = s->session_type;
+  if (s->flags & VCL_SESSION_F_CONNECTED)
+    mp->flags |= TRANSPORT_CFG_F_CONNECTED;
   app_send_ctrl_evt_to_vpp (mq, app_evt);
 }
 
@@ -612,11 +615,21 @@ vcl_session_unlisten_reply_handler (vcl_worker_t * wrk, void *data)
   vcl_session_t *s;
 
   s = vcl_session_get_w_vpp_handle (wrk, mp->handle);
-  if (!s || s->session_state != STATE_DISCONNECT)
+  if (!s)
     {
       VDBG (0, "Unlisten reply with wrong handle %llx", mp->handle);
       return;
     }
+  if (s->session_state != STATE_DISCONNECT)
+    {
+      /* Connected udp listener */
+      if (s->session_type == VPPCOM_PROTO_UDP
+	  && s->session_state == STATE_CLOSED)
+	return;
+
+      VDBG (0, "Unlisten session in wrong state %llx", mp->handle);
+      return;
+    }
 
   if (mp->retval)
     VDBG (0, "ERROR: session %u [0xllx]: unlisten failed: %U",
@@ -1686,13 +1699,24 @@ vppcom_session_connect (uint32_t session_handle, vppcom_endpt_t * server_ep)
       return VPPCOM_OK;
     }
 
+  /* Attempt to connect a connectionless listener */
+  if (PREDICT_FALSE (session->session_state & STATE_LISTEN))
+    {
+      if (session->session_type != VPPCOM_PROTO_UDP)
+	return VPPCOM_EINVAL;
+      vcl_send_session_unlisten (wrk, session);
+      session->session_state = STATE_CLOSED;
+    }
+
   session->transport.is_ip4 = server_ep->is_ip4;
   vcl_ip_copy_from_ep (&session->transport.rmt_ip, server_ep);
   session->transport.rmt_port = server_ep->port;
   session->parent_handle = VCL_INVALID_SESSION_HANDLE;
+  session->flags |= VCL_SESSION_F_CONNECTED;
 
-  VDBG (0, "session handle %u: connecting to server %s %U "
+  VDBG (0, "session handle %u (%s): connecting to peer %s %U "
 	"port %d proto %s", session_handle,
+	vppcom_session_state_str (session->session_state),
 	session->transport.is_ip4 ? "IPv4" : "IPv6",
 	format_ip46_address,
 	&session->transport.rmt_ip, session->transport.is_ip4 ?
@@ -3562,7 +3586,7 @@ vppcom_session_recvfrom (uint32_t session_handle, void *buffer,
       return VPPCOM_EAFNOSUPPORT;
     }
 
-  if (ep && !rv)
+  if (ep && rv > 0)
     {
       session = vcl_session_get_w_handle (wrk, session_handle);
       if (session->transport.is_ip4)
@@ -3594,7 +3618,8 @@ vppcom_session_sendto (uint32_t session_handle, void *buffer,
       if (!s)
 	return VPPCOM_EBADFD;
 
-      if (s->session_type != VPPCOM_PROTO_UDP)
+      if (s->session_type != VPPCOM_PROTO_UDP
+	  || (s->flags & VCL_SESSION_F_CONNECTED))
 	return VPPCOM_EINVAL;
 
       /* Session not connected/bound in vpp. Create it by 'connecting' it */