Fix for vppctl and interactive commands (VPP-1038)

- Interactive commands like "ping" read extra input from the
  input stream.
- In the case of "ping" it is simply a signal to cease the current
  operation.
- "vppctl", in non-interactive mode, will issue a "quit" immediately
  after the requested command to queue up closing of the session.
- This resulted in "ping" thinking a keypress was seen and returning
  control to the CLI; the "quit" command however is consumed by the
  keypress event handler and thus the session does not close.

- This patch reworks vppctl slightly to only issue "quit" after the
  command has completed. In particular it uses the fact that VPP issues
  NUL bytes as a surrogate prompt between output of commands to signal
  acknowledgement that the command has completed; vppctl now flags
  that the quit should be issued after the next such acknowledgement.
- Since input it still accepted, the user can still terminate the
  "ping" early, if desired.

Change-Id: I7e3dbe767f32f8e364ccb5f81799759b311585df
Signed-off-by: Chris Luke <chrisy@flirble.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/vpp/app/vppctl.c b/src/vpp/app/vppctl.c
index f81a0ce9..66fe00ab 100644
--- a/src/vpp/app/vppctl.c
+++ b/src/vpp/app/vppctl.c
@@ -147,6 +147,7 @@ main (int argc, char *argv[])
   u8 *cmd = 0;
   int do_quit = 0;
   int is_interactive = 0;
+  int acked = 1;		/* counts messages from VPP; starts at 1 */
   int sent_ttype = 0;
 
 
@@ -314,7 +315,10 @@ main (int argc, char *argv[])
 		    }
 
 		  while (q < (p + len) && !*q)
-		    q++;
+		    {
+		      q++;
+		      acked++;	/* every NUL is an acknowledgement */
+		    }
 		  len -= q - p;
 		  p = q;
 		}
@@ -322,7 +326,7 @@ main (int argc, char *argv[])
 	      vec_reset_length (str);
 	    }
 
-	  if (do_quit)
+	  if (do_quit && do_quit < acked)
 	    {
 	      /* Ask the other end to close the connection */
 	      clib_socket_tx_add_formatted (s, "quit\n");
@@ -339,7 +343,7 @@ main (int argc, char *argv[])
 	      clib_socket_tx_add_formatted (s, "%s\n", cmd);
 	      clib_socket_tx (s);
 	      vec_free (cmd);
-	      do_quit = 1;
+	      do_quit = acked;	/* quit after the next response */
 	    }
 	}
       else