lib/vty: add vty_stdio at-close hook

This is intended to be used for either "exit on close", "fork on close"
or "reopen vty on close" functionality for the stdio vty.  Which of
these options to take depends on the context, the use case right now is
test programs exiting on EOF.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
(cherry picked from commit 464ccf36b4aa1b942cad413ea30267b4bf9e6315)

2 files changed, 8 insertions, 2 deletions

diff --git a/lib/vty.c b/lib/vty.c
index d202f72fa..65bb28bb2 100644
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -1704,6 +1704,7 @@ vty_create (int vty_sock, union sockunion *su)
 /* create vty for stdio */
 static struct termios stdio_orig_termios;
 static struct vty *stdio_vty = NULL;
+static void (*stdio_vty_atclose)(void);
 
 static void
 vty_stdio_reset (void)
@@ -1712,11 +1713,15 @@ vty_stdio_reset (void)
     {
       tcsetattr (0, TCSANOW, &stdio_orig_termios);
       stdio_vty = NULL;
+
+      if (stdio_vty_atclose)
+        stdio_vty_atclose ();
+      stdio_vty_atclose = NULL;
     }
 }
 
 struct vty *
-vty_stdio (void)
+vty_stdio (void (*atclose)())
 {
   struct vty *vty;
   struct termios termios;
@@ -1726,6 +1731,7 @@ vty_stdio (void)
     return NULL;
 
   vty = stdio_vty = vty_new_init (0);
+  stdio_vty_atclose = atclose;
   vty->wfd = 1;
 
   /* always have stdio vty in a known _unchangeable_ state, don't want config
diff --git a/lib/vty.h b/lib/vty.h
index a248680db..81251e07b 100644
--- a/lib/vty.h
+++ b/lib/vty.h
@@ -273,7 +273,7 @@ extern void vty_init_vtysh (void);
 extern void vty_terminate (void);
 extern void vty_reset (void);
 extern struct vty *vty_new (void);
-extern struct vty *vty_stdio (void);
+extern struct vty *vty_stdio (void (*atclose)(void));
 extern int vty_out (struct vty *, const char *, ...) PRINTF_ATTRIBUTE(2, 3);
 extern void vty_read_config (char *, char *);
 extern void vty_time_print (struct vty *, int);