From 6aec4b41760e6ba54fc52b09f6d3ecfe173f6ee6 Mon Sep 17 00:00:00 2001
From: Renato Westphal <renato@opensourcerouting.org>
Date: Thu, 10 Nov 2016 13:15:43 -0200
Subject: [PATCH] ripd: add "none" option to the "ip rip receive version"
 command

RFC 2453 says (section 5.1):
"(...) For completeness, routers should also implement a receive control
switch which would determine whether to accept, RIP-1 only, RIP-2 only,
both, or none.  It should also be configurable on a per-interface basis".

For the "ip rip send version" command, we don't need to implement the
"none" option because there's already the "passive-interface" command
for that.

Fixes IxANVL RIP test 16.8.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
---
 ripd/rip_interface.c | 20 +++++++++++++-------
 ripd/ripd.c          | 12 +++---------
 ripd/ripd.h          |  1 +
 3 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/ripd/rip_interface.c b/ripd/rip_interface.c
index 0d412ee997..6d6cb0c686 100644
--- a/ripd/rip_interface.c
+++ b/ripd/rip_interface.c
@@ -55,6 +55,7 @@ const struct message ri_version_msg[] =
   {RI_RIP_VERSION_1,       "1"},
   {RI_RIP_VERSION_2,       "2"},
   {RI_RIP_VERSION_1_AND_2, "1 2"},
+  {RI_RIP_VERSION_NONE,    "none"},
 };
 
 extern struct zebra_privs_t ripd_privs;
@@ -1318,13 +1319,14 @@ DEFUN (no_rip_neighbor,
 
 DEFUN (ip_rip_receive_version,
        ip_rip_receive_version_cmd,
-       "ip rip receive version (1|2)",
+       "ip rip receive version (1|2|none)",
        IP_STR
        "Routing Information Protocol\n"
        "Advertisement reception\n"
        "Version control\n"
        "RIP version 1\n"
-       "RIP version 2\n")
+       "RIP version 2\n"
+       "None\n")
 {
   struct interface *ifp;
   struct rip_interface *ri;
@@ -1332,17 +1334,21 @@ DEFUN (ip_rip_receive_version,
   ifp = (struct interface *)vty->index;
   ri = ifp->info;
 
-  /* Version 1. */
-  if (atoi (argv[0]) == 1)
+  switch (*argv[0])
     {
+    case '1':
       ri->ri_receive = RI_RIP_VERSION_1;
       return CMD_SUCCESS;
-    }
-  if (atoi (argv[0]) == 2)
-    {
+    case '2':
       ri->ri_receive = RI_RIP_VERSION_2;
       return CMD_SUCCESS;
+    case 'n':
+      ri->ri_receive = RI_RIP_VERSION_NONE;
+      return CMD_SUCCESS;
+    default:
+      break;
     }
+
   return CMD_WARNING;
 }
 
diff --git a/ripd/ripd.c b/ripd/ripd.c
index 97e80ed43b..f27a817aed 100644
--- a/ripd/ripd.c
+++ b/ripd/ripd.c
@@ -1937,15 +1937,9 @@ rip_read (struct thread *t)
   /* RIP Version check. RFC2453, 4.6 and 5.1 */
   vrecv = ((ri->ri_receive == RI_RIP_UNSPEC) ?
            rip->version_recv : ri->ri_receive);
-  if ((packet->version == RIPv1) && !(vrecv & RIPv1))
-    {
-      if (IS_RIP_DEBUG_PACKET)
-        zlog_debug ("  packet's v%d doesn't fit to if version spec", 
-                   packet->version);
-      rip_peer_bad_packet (&from);
-      return -1;
-    }
-  if ((packet->version == RIPv2) && !(vrecv & RIPv2))
+  if (vrecv == RI_RIP_VERSION_NONE ||
+      ((packet->version == RIPv1) && !(vrecv & RIPv1)) ||
+      ((packet->version == RIPv2) && !(vrecv & RIPv2)))
     {
       if (IS_RIP_DEBUG_PACKET)
         zlog_debug ("  packet's v%d doesn't fit to if version spec", 
diff --git a/ripd/ripd.h b/ripd/ripd.h
index 1c212a081b..b26a1d234c 100644
--- a/ripd/ripd.h
+++ b/ripd/ripd.h
@@ -350,6 +350,7 @@ struct rip_md5_data
 #define RI_RIP_VERSION_1                   1
 #define RI_RIP_VERSION_2                   2
 #define RI_RIP_VERSION_1_AND_2             3
+#define RI_RIP_VERSION_NONE                4
 /* N.B. stuff will break if
 	(RIPv1 != RI_RIP_VERSION_1) || (RIPv2 != RI_RIP_VERSION_2) */