X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=ipif%2Fmech-timestamp.c;h=129eee96b12ceed693409535930950ce04653cf2;hb=97f318e04ed0024b2bf5903215a75249401d3fd7;hp=f679b104e625c889308a1274f07b3cb7466fdf4a;hpb=1fb3cba0b41ae774f83c11d2a9c23b12b2c87d1a;p=userv-utils.git

diff --git a/ipif/mech-timestamp.c b/ipif/mech-timestamp.c
index f679b10..129eee9 100644
--- a/ipif/mech-timestamp.c
+++ b/ipif/mech-timestamp.c
@@ -1,8 +1,10 @@
 /*
- * Timestamp mechanism
+ * Timestamp mechanism for udp tunnel
  *
+ * mechanism: timestamp
  * arguments: <max-skew> <max-age>
  *
+ * restrictions: none
  * encoding: prepend 4 bytes of UNIX time in network byte order
  *
  * <max-age> is maximum age in seconds we will accept a packet (or 0
@@ -10,14 +12,39 @@
  * accept a packet (or 0 for any future age).
  *
  */
+/*
+ * This file is part of ipif, part of userv-utils
+ *
+ * Copyright 1996-2013 Ian Jackson <ijackson@chiark.greenend.org.uk>
+ * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk>
+ * Copyright 1999,2003
+ *    Chancellor Masters and Scholars of the University of Cambridge
+ * Copyright 2010 Tony Finch <fanf@dotat.at>
+ *
+ * This 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.
+ *
+ * This program 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 userv-utils; if not, see http://www.gnu.org/licenses/.
+ */
 
 #include <stdint.h>
 #include <netinet/in.h>
 
-#include "mech.h"
+#include "forwarder.h"
+
+#define WARN_EVERY 30
 
 struct mechdata {
-  uint32_t max_skew, max_age;
+  time_t max_skew, max_age;
+  time_t next_warn;
 };
 
 static void mds_timestamp(struct mechdata **md_r) {
@@ -27,6 +54,7 @@ static void mds_timestamp(struct mechdata **md_r) {
   
   md->max_skew= getarg_ulong();
   md->max_age= getarg_ulong();
+  md->next_warn= now();
   *md_r= md;
 }
 
@@ -42,27 +70,29 @@ static void menc_timestamp(struct mechdata *md, struct buffer *buf) {
 static const char *mdec_timestamp(struct mechdata *md, struct buffer *buf) {
   static char cbuf[40];
   
-  uint32_t *tp, timestamp, tnow;
+  uint32_t *tp, timestamp;
+  time_t tnow;
   long age;
 
   BUF_UNPREPEND(tp,buf,4);
   timestamp= ntohl(*tp);
 
   tnow= now();
-  age= timestamp - tnow;
+  age= timestamp - (uint32_t)tnow;
   if (age > 0) {
-    if (md->max_age && age > md->max_age) {
-      sprintf(cbuf,"packet too old (%lds)",age);
-      return cbuf;
-    }
+    if (!md->max_age || age <= md->max_age) return 0;
+    sprintf(cbuf,"packet too old (%lds)",age);
   } else if (age < 0) {
-    if (md->max_skew && age > md->max_skew) {
-      sprintf(cbuf,"too much skew (%lds)",-age);
-      return cbuf;
-    }
+    if (!md->max_skew || age >= -md->max_skew) return 0;
+    sprintf(cbuf,"too much skew (%lds)",-age);
+  } else {
+    return 0;
   }
 
-  return 0;
+  if (tnow < md->next_warn) return "";
+
+  md->next_warn= tnow+WARN_EVERY;
+  return cbuf;
 }
 
 STANDARD_MECHANISMLIST("timestamp",timestamp);