[Olsr-users] problem when disconnection two network cables

[Ferry Huberts]

On 15/06/15 08:29, Henning Rogge wrote:
> Ferry,
>
> can you commit the patch? I think its time for a 0.9.1 release...

The commit is on the release-0.9.0 branch, and is merged onto master.
A new release would be nice, can you handle that Henning?

Koen, thank you very much for the good report, analysis and fast response!

Ferry

>
> Henning
>
> On Mon, Jun 15, 2015 at 8:28 AM, Koen Swinters
> <(spam-protected)> wrote:
>> Ferry,
>>
>> Thank you for posting it.
>> I've checked your patch and it is OK for me.
>> I've have made an automatic test to check this and it has runned for more than 48h without any error.
>>
>> Regards,
>>
>> Koen
>>
>>
>> -----Original Message-----
>> From: Ferry Huberts [mailto:(spam-protected)]
>> Sent: zaterdag 13 juni 2015 13:38
>> To: Henning Rogge
>> Cc: Koen Swinters; (spam-protected)
>> Subject: Re: [Olsr-users] problem when disconnection two network cables
>>
>> I've posted a patch on the dev list, please review it.
>>
>>
>> On 13/06/15 12:40, Henning Rogge wrote:
>>> Hi,
>>>
>>> the analysis of the bug sounds reasonable. Please post the patch here
>>> and/or the olsr-dev list! :)
>>>
>>> Henning
>>>
>>> On Fri, Jun 12, 2015 at 4:03 PM, Ferry Huberts <(spam-protected)> wrote:
>>>> You can post the patch here, or on the dev list
>>>>
>>>> Henning, WDYT?
>>>>
>>>> On 12/06/15 15:55, Koen Swinters wrote:
>>>>>
>>>>> Hi all,
>>>>>
>>>>> We are using olsrd-0.6.8 in our system.
>>>>>
>>>>> I have a problem with the following setup:
>>>>>
>>>>> Node 8100 ------------- node 3
>>>>>
>>>>>         |             X                 |
>>>>>
>>>>> Node 8120 ------------- node 425
>>>>>
>>>>> Each node has a wired connection to the 3 other nodes (each node has 3
>>>>> Ethernet interfaces). Olsrd is running on each node.
>>>>>
>>>>> When I disconnect the cable between node 3 and node 8120 and after this
>>>>> the cable between node 8120 and node 425 => node 425 cannot reach node
>>>>> 8120 anymore (there is still a path via node 3 and node 8100) => the
>>>>> routing table on node 425 is not updated.
>>>>>
>>>>> Remark: when there is no physical Ethernet connection our systems
>>>>> disables the eth interface (ethx)
>>>>>
>>>>> I`ve investigated this problem and found the following problem in olsrd:
>>>>>
>>>>> ·disconnect the cable between node 3 and node 8120 => Link down between
>>>>> 3 and 8120 => disable interface
>>>>>
>>>>> oLine 371 in interfaces.c: "olsr_remove_interface(struct olsr_if* iface)"
>>>>>
>>>>> ·Line 379 in "interfaces.c":
>>>>> "olsr_delete_link_entry_by_ip(&ifp->ip_addr)"
>>>>>
>>>>> §Line 411 in "link_set.c":  "olsr_delete_link_entry(link);"
>>>>>
>>>>> ·Line 375 in
>>>>> "olsr_delete_neighbor_table(&link->neighbor->neighbor_main_addr)";
>>>>>
>>>>> ·This function will delete the neighbor from the neighbor table
>>>>>
>>>>> ·(Line 177 in neighbor_table.c)
>>>>>
>>>>> ·This function sets "changes_neighborhood = true;" (Line 219 in
>>>>> neighbor_table.c)
>>>>>
>>>>> oIn "olsr_scheduler(void)" (line 486 in scheduler.c)
>>>>>
>>>>> ·function "olsr_process_changes()" (line 180 in olsr.c)
>>>>>
>>>>> ·Because "changes_neighborhood == TRUE and olsr_cnf->lq_level > 1"
>>>>> "olsr_calculate_lq_mpr() "is called
>>>>>
>>>>> ·In "olsr_calculate_lq_mpr()" (line 51 in lq_mpr.c) a new mpr is
>>>>> calculated (8100 will now be mpr for 8120) and the function
>>>>> "signal_link_changes(true);" is called => link_changes  == true
>>>>>
>>>>> ·In the next step  ANSN  is increased
>>>>>
>>>>> oAt the tc_interval  a tc message is generated with this ANSN in => the
>>>>> neighbors see a change in the ANSN number(when the packet are received)
>>>>> an will update their tables
>>>>>
>>>>> ·Link Down between node 8120 and 425
>>>>>
>>>>> oLine 371 in interfaces.c: "olsr_remove_interface(struct olsr_if* iface)"
>>>>>
>>>>> ·Line 379 in "interfaces.c":
>>>>> "olsr_delete_link_entry_by_ip(&ifp->ip_addr)"
>>>>>
>>>>> §Line 411 in "link_set.c":  "olsr_delete_link_entry(link);"
>>>>>
>>>>> ·Line 375 in
>>>>> "olsr_delete_neighbor_table(&link->neighbor->neighbor_main_addr)";
>>>>>
>>>>> ·This function will delete the neighbor from the neighbor table
>>>>>
>>>>> ·(Line 177 in neighbor_table.c)
>>>>>
>>>>> ·This function sets "changes_neighborhood = true;" (Line 219 in
>>>>> neighbor_table.c)
>>>>>
>>>>> oIn "olsr_scheduler(void)" (line 486 in scheduler.c)
>>>>>
>>>>> ·function "olsr_process_changes()" (line 180 in olsr.c)
>>>>>
>>>>> ·Because "changes_neighborhood == TRUE and olsr_cnf->lq_level > 1"
>>>>> "olsr_calculate_lq_mpr() "is called
>>>>>
>>>>> ·In "olsr_calculate_lq_mpr()" (line 51 in lq_mpr.c) no new mpr is
>>>>> calculated (8100 will stay mpr for 8120) and the function
>>>>> "signal_link_changes(true);" is not called => link_changes  == false
>>>>>
>>>>> ·In the next step  ANSN  is not increased
>>>>>
>>>>> oAt the tc_interval  a tc message is generated with old ANSN in => the
>>>>> neighbors see no change in the ANSN number(when the packet are received)
>>>>> an will no update their tables
>>>>>
>>>>> Solution:
>>>>>
>>>>> ·When a neighbor is deleted from the neighbor table (line 177 in
>>>>> neighbor_table: olsr_delete_neighbor_table(const union olsr_ip_addr
>>>>> *neighbor_addr)) also call the function signal_link_changes(true);
>>>>> because there is a change in the neighbor table.
>>>>>
>>>>> I’ve tested this and it is working correct (routing tables are updated
>>>>> as expected).
>>>>>
>>>>> Where can I post this fix, or is there a better solution?
>>>>>
>>>>> Regards,
>>>>>
>>>>> koen
>>>>>
>>>>>
>>>>>
>>>>
>>>> --
>>>> Ferry Huberts
>>
>> --
>> Ferry Huberts
>>
>> -----
>> Geen virus gevonden in dit bericht.
>> Gecontroleerd door AVG - www.avg.com
>> Versie: 2015.0.5961 / Virusdatabase: 4360/9999 - datum van uitgifte: 06/12/15

-- 
Ferry Huberts