server/tun-slip: Refactor state handling somewhat.

Introduce a new ST_MASK which masks off the state-machine bits.  Use this
when reading SL_END or when setting ST_EOF, so as to preserve any other
state bits which might happen to have been set.  Not that I'm promising
anything...

diff --git a/server/tun-slip.c b/server/tun-slip.c
index 609829f584516174f9f7aa2099c960fdc8707a47..993aca9d401db93c1dd7f832c356285c8d8e79c2 100644 (file)
--- a/server/tun-slip.c
+++ b/server/tun-slip.c
@@ -50,6 +50,7 @@ struct tunnel {
   unsigned st;                         /* Current parser state */
 #   define ST_ESC 1u                   /*   Last saw an escape character */
 #   define ST_BAD 2u                   /*   This packet is malformed */
+#   define ST_MASK 3u                  /*   Mask for the above bits */
 #   define ST_EOF 4u                   /*   File descriptor reported EOF */
   size_t n;                            /* Number of bytes used in buffer */
   octet buf[PKBUFSZ];                  /* Buffer for incoming data */
@@ -99,7 +100,7 @@ static void t_read(int fd, unsigned mode, void *v)
   }
   if (!n) {
     a_warn("TUN", "%s", p_ifname(t->p), "slip", "eof", A_END);
-    t->st = ST_EOF;
+    t->st = (t->st & ~ST_MASK) | ST_EOF;
     sel_rmfile(&t->f);
     return;
   }
@@ -133,7 +134,7 @@ static void t_read(int fd, unsigned mode, void *v)
          p_tun(t->p, &b);
        }
        q = t->buf;
-       st &= ~(ST_ESC | ST_BAD);
+       st &= ~ST_MASK;
        break;
       case SL_ESC:
        if ((st & ST_ESC) && !(st & ST_BAD)) {