1 files changed, 16 insertions, 6 deletions
diff --git a/src/openvpn/packet_id.c b/src/openvpn/packet_id.c
index 5175fb0..10fe402 100644
--- a/src/openvpn/packet_id.c
+++ b/src/openvpn/packet_id.c
@@ -325,27 +325,37 @@ packet_id_read(struct packet_id_net *pin, struct buffer *buf, bool long_form)
     return true;
 }
 
-static void
+static bool
 packet_id_send_update(struct packet_id_send *p, bool long_form)
 {
     if (!p->time)
     {
         p->time = now;
     }
-    p->id++;
-    if (!p->id)
+    if (p->id == PACKET_ID_MAX)
     {
-        ASSERT(long_form);
+        /* Packet ID only allowed to roll over if using long form and time has
+         * moved forward since last roll over.
+         */
+        if (!long_form || now <= p->time)
+        {
+            return false;
+        }
         p->time = now;
-        p->id = 1;
+        p->id = 0;
     }
+    p->id++;
+    return true;
 }
 
 bool
 packet_id_write(struct packet_id_send *p, struct buffer *buf, bool long_form,
         bool prepend)
 {
-    packet_id_send_update(p, long_form);
+    if (!packet_id_send_update(p, long_form))
+    {
+        return false;
+    }
 
     const packet_id_type net_id = htonpid(p->id);
     const net_time_t net_time = htontime(p->time);