From: Donald Sharp <sharpd@nvidia.com>
Date: Tue, 13 Oct 2020 12:16:15 +0000 (-0400)
Subject: ospfd: Prevent crash if transferring config amongst instances
X-Git-Tag: base_7.6~421^2
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=2b0a32da60eca7d5f9f348ed8bd414ff9eabdf5a;p=mirror%2Ffrr.git

ospfd: Prevent crash if transferring config amongst instances

If we enter:

int eth0
  ip ospf area 0
  ip ospf 10 area 0
!

This will crash ospf.  Prevent this from happening.

OSPF instances:

a) Cannot be mixed with non-instance
b) Are their own process.

Since in multi-instance world ospf instances are their own process,
when an ospf processes receives an instance command we must remove
our config( if present ) and allow the new config to be active
in the new process.  The problem here is that if you have not
done a `router ospf` above the lookup of the ospf pointer will
fail and we will just crash.  Put some code in to prevent a crash
in this case.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>
---

diff --git a/ospfd/ospf_vty.c b/ospfd/ospf_vty.c
index 1a9ad69ed3..29ad124116 100644
--- a/ospfd/ospf_vty.c
+++ b/ospfd/ospf_vty.c
@@ -8135,12 +8135,25 @@ DEFUN (ip_ospf_area,
 		ospf = ospf_lookup_instance(instance);
 
 	if (instance && ospf == NULL) {
+		/*
+		 * At this point we know we have received
+		 * an instance and there is no ospf instance
+		 * associated with it.  This means we are
+		 * in a situation where we have an
+		 * ospf command that is setup for a different
+		 * process(instance).  We need to safely
+		 * remove the command from ourselves and
+		 * allow the other instance(process) handle
+		 * the configuration command.
+		 */
 		params = IF_DEF_PARAMS(ifp);
 		if (OSPF_IF_PARAM_CONFIGURED(params, if_area)) {
 			UNSET_IF_PARAM(params, if_area);
 			ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);
-			ospf_interface_area_unset(ospf, ifp);
-			ospf->if_ospf_cli_count--;
+			if (ospf) {
+				ospf_interface_area_unset(ospf, ifp);
+				ospf->if_ospf_cli_count--;
+			}
 		}
 		return CMD_NOT_MY_INSTANCE;
 	}