X-Git-Url: https://git.distorted.org.uk/~mdw/tripe/blobdiff_plain/574318e731155b6922d7b1dba1461f30ea664e9f..47828bd9813b146e8569355b3083847299dd8729:/server/tun-slip.c

diff --git a/server/tun-slip.c b/server/tun-slip.c
index 993aca9d..1c452955 100644
--- a/server/tun-slip.c
+++ b/server/tun-slip.c
@@ -9,19 +9,18 @@
  *
  * This file is part of Trivial IP Encryption (TrIPE).
  *
- * TrIPE is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * TrIPE is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your
+ * option) any later version.
  *
- * TrIPE is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
+ * TrIPE is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with TrIPE; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with TrIPE.  If not, see <https://www.gnu.org/licenses/>.
  */
 
 /*----- Header files ------------------------------------------------------*/
@@ -52,6 +51,7 @@ struct tunnel {
 #   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 */
+#   define ST_BROKEN 8u			/*   Sending side is broken */
   size_t n;				/* Number of bytes used in buffer */
   octet buf[PKBUFSZ];			/* Buffer for incoming data */
 };
@@ -120,9 +120,10 @@ static void t_read(int fd, unsigned mode, void *v)
       case SL_END:
 	if (st & ST_BAD)
 	  ;
-	else if (st & ST_ESC)
+	else if (st & ST_ESC) {
 	  a_warn("TUN", "%s", p_ifname(t->p), "slip", "escape-end", A_END);
-	else if (q == t->buf) {
+	  st |= ST_BAD;
+	} else if (q == t->buf) {
 	  T( trace(T_TUNNEL, "tun-slip: empty packet"); )
 	} else {
 	  IF_TRACING(T_TUNNEL, {
@@ -245,6 +246,29 @@ whine:
   moan("bad slip interface list");
 }
 
+/* --- @t_broken@ --- *
+ *
+ * Arguments:	@tunnel *t@ = pointer to the tunnel
+ *
+ * Returns:	---
+ *
+ * Use:		Marks the tunnel as broken and reports an error.
+ */
+
+static void t_broken(tunnel *t)
+{
+  if (errno == EINTR ||
+#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
+      errno == EWOULDBLOCK ||
+#endif
+      errno == EAGAIN)
+    return;
+  a_warn("TUN", "%s", p_ifname(t->p), "slip",
+	 "write-error", "?ERRNO", A_END);
+  T( trace(T_TUNNEL, "tun-slip: marking tunnel broken"); )
+  t->st |= ST_BROKEN;
+}
+
 /* --- @t_create@ --- *
  *
  * Arguments:	@peer *p@ = pointer to peer block
@@ -265,7 +289,7 @@ static tunnel *t_create(peer *p, int fd, char **ifn)
   dstr d = DSTR_INIT;
   unsigned char ch;
   tunnel *t;
-  static const char end[] = { SL_END, SL_END };
+  static const octet end[] = { SL_END, SL_END };
 
   /* --- Try to find a spare static interface --- */
 
@@ -342,7 +366,8 @@ found:
   sl->f |= F_INUSE;
   sel_initfile(&sel, &t->f, sl->ifd, SEL_READ, t_read, t);
   sel_addfile(&t->f);
-  write(sl->ofd, end, sizeof(end));
+  if (write(sl->ofd, end, sizeof(end)) < 0)
+    t_broken(t);
   *ifn = xstrdup(sl->name);
   dstr_destroy(&d);
   return (t);
@@ -394,6 +419,10 @@ static void t_inject(tunnel *t, buf *b)
     trace_block(T_PACKET, "tun-slip: packet contents", BBASE(b), BLEN(b));
   })
 
+  if (t-> st & ST_BROKEN) {
+    T( trace(T_TUNNEL, "tun-slip: tunnel broken; discarding"); )
+    return;
+  }
   q = buf;
   *q++ = SL_END;
   for (p = BBASE(b), l = BCUR(b); p < l; p++) {
@@ -408,7 +437,8 @@ static void t_inject(tunnel *t, buf *b)
     trace_block(T_PACKET, "tun-slip: SLIP-encapsulated contents",
 		buf, q - buf);
   })
-  write(t->sl->ofd, buf, q - buf);
+  if (write(t->sl->ofd, buf, q - buf) < 0)
+    t_broken(t);
 }
 
 /* --- @t_destroy@ --- *