From 8d9eef17713a9b38cd42bd59c4ce76c3ef6c2fc2 Mon Sep 17 00:00:00 2001
From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Mon, 8 Jun 2015 02:20:43 +0200
Subject: BGP multipath support

Kernel option 'merge paths' allows to merge routes exported to kernel
protocol (currently BGP and static routes) to multipath routes.
---
 filter/filter.c | 36 ++++++++++++++++--------------------
 1 file changed, 16 insertions(+), 20 deletions(-)

(limited to 'filter')

diff --git a/filter/filter.c b/filter/filter.c
index 3b14fc0c..3f8968aa 100644
--- a/filter/filter.c
+++ b/filter/filter.c
@@ -471,26 +471,22 @@ static inline void f_rte_cow(void)
 static void
 f_rta_cow(void)
 {
-  if ((*f_rte)->attrs->aflags & RTAF_CACHED) {
-
-    /* Prepare to modify rte */
-    f_rte_cow();
-
-    /* Store old rta to free it later */
-    f_old_rta = (*f_rte)->attrs;
-
-    /*
-     * Alloc new rta, do shallow copy and update rte. Fields eattrs
-     * and nexthops of rta are shared with f_old_rta (they will be
-     * copied when the cached rta will be obtained at the end of
-     * f_run()), also the lock of hostentry is inherited (we suppose
-     * hostentry is not changed by filters).
-     */
-    rta *ra = lp_alloc(f_pool, sizeof(rta));
-    memcpy(ra, f_old_rta, sizeof(rta));
-    ra->aflags = 0;
-    (*f_rte)->attrs = ra;
-  }
+  if (!rta_is_cached((*f_rte)->attrs))
+    return;
+
+  /* Prepare to modify rte */
+  f_rte_cow();
+
+  /* Store old rta to free it later, it stores reference from rte_cow() */
+  f_old_rta = (*f_rte)->attrs;
+
+  /*
+   * Get shallow copy of rta. Fields eattrs and nexthops of rta are shared
+   * with f_old_rta (they will be copied when the cached rta will be obtained
+   * at the end of f_run()), also the lock of hostentry is inherited (we
+   * suppose hostentry is not changed by filters).
+   */
+  (*f_rte)->attrs = rta_do_cow((*f_rte)->attrs, f_pool);
 }
 
 static struct tbf rl_runtime_err = TBF_DEFAULT_LOG_LIMITS;
-- 
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