[Olsr-users] problem when disconnection two network cables

[Henning Rogge]

Ferry,

can you commit the patch? I think its time for a 0.9.1 release...

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
>
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