From: Mark Wooding <mdw@distorted.org.uk>
Date: Sat, 22 May 2010 11:04:06 +0000 (+0100)
Subject: server/tun-slip: Refactor state handling somewhat.
X-Git-Tag: 1.0.0pre10~6
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/commitdiff_plain/574318e731155b6922d7b1dba1461f30ea664e9f

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 609829f5..993aca9d 100644
--- 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)) {