From 54b97c74fe0ec25614ceb943013eb7500abefc6d Mon Sep 17 00:00:00 2001
From: Donald Sharp <sharpd@cumulusnetworks.com>
Date: Fri, 2 Oct 2015 09:30:02 -0700
Subject: [PATCH] pimd: Add RP check code

Add the ability for the node to determine if it is the RP or not.
Currently this only allows static RP's.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
---
 pimd/pim_rp.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 pimd/pim_rp.h |  2 ++
 2 files changed, 50 insertions(+)

diff --git a/pimd/pim_rp.c b/pimd/pim_rp.c
index 757c770c1d..506b60eabb 100644
--- a/pimd/pim_rp.c
+++ b/pimd/pim_rp.c
@@ -20,11 +20,59 @@
  */
 #include <zebra.h>
 
+#include "log.h"
 #include "network.h"
 
 #include "pimd.h"
+#include "pim_str.h"
 #include "pim_rp.h"
 
+static int i_am_rp = 0;
+
+/*
+ * Checks to see if we should elect ourself the actual RP
+ */
+void
+pim_rp_check_rp (struct in_addr old, struct in_addr new)
+{
+  if (PIM_DEBUG_ZEBRA) {
+    char sold[100];
+    char snew[100];
+    char rp[100];
+    pim_inet4_dump("<rp?>", qpim_rp, rp, sizeof(rp));
+    pim_inet4_dump("<old?>", old, sold, sizeof(sold));
+    pim_inet4_dump("<new?>", new, snew, sizeof(snew));
+    zlog_debug("%s: %s for old %s new %s", __func__, rp, sold, snew );
+  }
+
+  if (qpim_rp.s_addr == 0)
+    return;
+
+  if (new.s_addr == qpim_rp.s_addr)
+    {
+      i_am_rp = 1;
+      return;
+    }
+
+  if (old.s_addr == qpim_rp.s_addr)
+    {
+      i_am_rp = 0;
+      return;
+    }
+}
+
+/*
+ * I_am_RP(G) is true if the group-to-RP mapping indicates that
+ * this router is the RP for the group.
+ *
+ * Since we only have static RP, all groups are part of this RP
+ */
+int
+pim_rp_i_am_rp (struct in_addr group)
+{
+  return i_am_rp;
+}
+
 /*
  * Set the upstream IP address we want to talk to based upon
  * the rp configured and the source address
diff --git a/pimd/pim_rp.h b/pimd/pim_rp.h
index 114cc2cfd8..4639e7cebf 100644
--- a/pimd/pim_rp.h
+++ b/pimd/pim_rp.h
@@ -21,6 +21,8 @@
 #ifndef PIM_RP_H
 #define PIM_RP_H
 
+void pim_rp_check_rp (struct in_addr old, struct in_addr new);
+int pim_rp_i_am_rp (struct in_addr group);
 int pim_rp_set_upstream_addr (struct in_addr *up, struct in_addr source);
 
 #endif
-- 
2.39.5