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?


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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