linux.c: Detect hall-of-mirrors effect in `nf_conntrack'.

[yaid] / linux.c

diff --git a/linux.c b/linux.c
index 571b179..ec4fe4e 100644 (file)
--- a/linux.c
+++ b/linux.c
@@ -313,7 +313,8 @@ void identify(struct query *q)
        * field (but do check the port number).
        */
       if (q->ao->sys->parseaddr(&p, &s[i].addr)) goto next_row;
-      if (*p != ':') break; p++;
+      if (*p != ':') break;
+      p++;
       s[i].port = strtoul(p, 0, 16);
       if ((i == R && gwp) ?
            q->s[R].port != s[i].port :
@@ -433,6 +434,13 @@ void identify(struct query *q)
          !sockeq(q->ao, &s[i^1], &q->s[R]))
        continue;
 
+      /* As a trap for the unwary, this file contains unhelpful entries which
+       * just mirror the source/destination addresses.  If this is one of
+       * those, we'll be stuck in a cycle talking to ourselves.
+       */
+      if (sockeq(q->ao, &s[i], &s[i^3]))
+       continue;
+
       /* We win.  The remaining address must be the client host.  We should
        * proxy this query.
        */