ospf_if_lookup_recv_interface returns wrong interface.

[Kenji Yabuuchi]

  Hi,

  I'm using zebra and ospfd with a following configuration

             |       
             | 202.xxx.xxx.228/28
          ---+---
          |zebra|
          | host|
          ---+---
             | 202.xxx.xxx.241/24      
             |       

  1. I use source gotten by  CVS on 29 Jan 2003.
  2. Zebra and ospfd are running.
  3. Ospfd says:
      "Packet from [202.xxx.xxx.226] received on wrong link fxp0"
     when routers on 202.xxx.xxx.228/28 network send OSPF packets.

     This message is produced by ospf_read() in ospf_packet.c on
     lookup recv interface of a received packet.  In
     ospf_if_lookup_recv_interface() in ospf_interface.c, all
     interfaces are checked with a source address of the packet
     without regard to a prefix length of interfaces. So, in an
     above example, both interfaces are passed this check, then
     a returning interface(struct ospf_interface) which depends
     only on the order of registration to an ospf_interface
     list might be wrong.

  4. Configuration files are following:

------------------------------------------------------------
ospfd.conf
----------
hostname zebra-ospfd
password xxxxx
enable password xxxxx:
!
debug ospf packet all
!
interface nge0
 ip ospf authentication-key xxxxx
 ip ospf priority 0
 ip ospf cost 10
!
interface fxp0
 ip ospf authentication-key xxxxx
 ip ospf priority 0
 ip ospf cost 11
!
router ospf
 ospf router-id 202.xxx.xxx.241
 ospf rfc1583compatibility
 network 202.xxx.xxx.228/28 area 0
 network 202.xxx.xxx.241/24 area 0
 area 0 authentication
!
log syslog
!log file /var/tmp/ospfd.log
     
------------------------------------------------------------
------------------------------------------------------------
zebra.conf
----------
hostname zebra-zebra
password xxxxx
enable password xxxxx:

interface fxp0
 ip address 202.xxx.xxx.228/28

interface nge0
 ip address 202.xxx.xxx.241/24

------------------------------------------------------------


 8. Here's a patch.

Index: ospf_interface.c
===================================================================
RCS file: /cvsroot/zebra/ospfd/ospf_interface.c,v
retrieving revision 1.139
diff -c -r1.139 ospf_interface.c
*** ospf_interface.c    23 Oct 2002 09:12:36 -0000      1.139
--- ospf_interface.c    30 Jan 2003 04:35:17 -0000
***************
*** 402,409 ****
        }
        else
        {
!         if (prefix_match (oi->address, (struct prefix *) &addr))
!           match = oi;
        }
      }

--- 402,410 ----
        }
        else
        {
!         if (prefix_match (oi->address, (struct prefix *) &addr))
!           if (match == NULL || match->address->prefixlen < 
oi->address->prefixlen)
!             match = oi;
        }
      }

Thank you.

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ASTEM RI
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