On Tue, Dec 5, 2017 at 11:41 PM, Simon Kelley <si...@thekelleys.org.uk> wrote:
> OK, I re-worked this and committed it as
>
> http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=ef3d137a646fa8309e1ff5184e3e145eef40cc4d
>
> Please could you check I didn't break anything?
Testing with the patch did not show any regression; looks fine for me

Hans
>
>
> Cheers,
>
> Simon.
>
>
> On 04/12/17 09:15, Hans Dedecker wrote:
>> Commit 9396752c115b3ab733fa476b30da73237e12e7ba added support for dns query
>> retransmission in case a server returns refused in strict-order mode.
>> The patch did not cover the case when all servers return refused triggering
>> a dns query retransmission storm resulting into a high cpu load by dnsmasq.
>> Fix the problem by checking in strict-order mode if a next dns server is
>> available in the dns server list before forwarding the query again.
>>
>> Signed-off-by: Hans Dedecker <dedec...@gmail.com>
>> ---
>>  src/forward.c | 18 +++++++++++++++---
>>  1 file changed, 15 insertions(+), 3 deletions(-)
>>
>> diff --git a/src/forward.c b/src/forward.c
>> index 4824759..3d58571 100644
>> --- a/src/forward.c
>> +++ b/src/forward.c
>> @@ -799,11 +799,23 @@ void reply_query(int fd, int family, time_t now)
>>      {
>>        unsigned char *pheader;
>>        size_t plen;
>> -      int is_sign;
>> -
>> +      int is_sign, fwd_query = 0;
>> +
>> +      if (option_bool(OPT_ORDER))
>> +        {
>> +       /* try to find a good server to which the query can be forwarded */
>> +       for (server = forward->sentto->next; server; server = server->next)
>> +         if (!(server->flags & (SERV_LITERAL_ADDRESS | SERV_HAS_DOMAIN | 
>> SERV_FOR_NODOTS | SERV_NO_ADDR | SERV_LOOP)))
>> +           {
>> +                fwd_query = 1;
>> +                break;
>> +           }
>> +        } else
>> +          fwd_query = 1;
>> +
>>        /* recreate query from reply */
>>        pheader = find_pseudoheader(header, (size_t)n, &plen, NULL, &is_sign, 
>> NULL);
>> -      if (!is_sign)
>> +      if (!is_sign && fwd_query)
>>       {
>>         header->ancount = htons(0);
>>         header->nscount = htons(0);
>>
>

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