src/patches/dnsmasq/005-Apply_ceiling_of_lease_length_to_TTL_when_--dhcp-ttl_in_use.patch

   1 From 7480aeffc8ad195e9fd8bcf424bae0fab3839d55 Mon Sep 17 00:00:00 2001
   2 From: Simon Kelley <simon@thekelleys.org.uk>
   3 Date: Fri, 26 Feb 2016 21:58:20 +0000
   4 Subject: [PATCH] Apply ceiling of lease length to TTL when --dhcp-ttl in use.
   5
   6 ---
   7  src/rfc1035.c |   12 ++++++++++--
   8  1 file changed, 10 insertions(+), 2 deletions(-)
   9
  10 diff --git a/src/rfc1035.c b/src/rfc1035.c
  11 index 8f1e3b4..bed5312 100644
  12 --- a/src/rfc1035.c
  13 +++ b/src/rfc1035.c
  14 @@ -1167,10 +1167,18 @@ int add_resource_record(struct dns_header *header, char *limit, int *truncp, int
  15  static unsigned long crec_ttl(struct crec *crecp, time_t now)
  16  {
  17    /* Return 0 ttl for DHCP entries, which might change
  18 -     before the lease expires. */
  19 +     before the lease expires, unless configured otherwise. */
  20
  21    if (crecp->flags & F_DHCP)
  22 -    return daemon->use_dhcp_ttl ? daemon->dhcp_ttl : daemon->local_ttl;
  23 +    {
  24 +      int conf_ttl = daemon->use_dhcp_ttl ? daemon->dhcp_ttl : daemon->local_ttl;
  25 +
  26 +      /* Apply ceiling of actual lease length to configured TTL. */
  27 +      if (!(crecp->flags & F_IMMORTAL) && (crecp->ttd - now) < conf_ttl)
  28 +       return crecp->ttd - now;
  29 +
  30 +      return conf_ttl;
  31 +    }
  32
  33    /* Immortal entries other than DHCP are local, and hold TTL in TTD field. */
  34    if (crecp->flags & F_IMMORTAL)
  35 --
  36 1.7.10.4
  37