dhcp-detect-time-changes.patch

   1 From a2fb8759ab48c88e3f8df94ae6e156c357d932a2 Mon Sep 17 00:00:00 2001
   2 From: Pavel Zhukov <pzhukov@redhat.com>
   3 Date: Tue, 22 Oct 2019 16:23:01 +0200
   4 Subject: [PATCH 24/28] Detect system time changes
   5
   6 ---
   7  client/dhclient.c |  6 ++++++
   8  common/dispatch.c | 11 ++++++++++-
   9  includes/dhcpd.h  |  3 ++-
  10  server/dhcpd.c    |  6 ++++++
  11  4 files changed, 24 insertions(+), 2 deletions(-)
  12
  13 diff --git a/client/dhclient.c b/client/dhclient.c
  14 index 60836b4..fd18813 100644
  15 --- a/client/dhclient.c
  16 +++ b/client/dhclient.c
  17 @@ -5665,6 +5665,12 @@ isc_result_t dhcp_set_control_state (control_object_state_t oldstate,
  18                   case server_awaken:
  19                     state_reboot (client);
  20                     break;
  21 +
  22 +                  case server_time_changed:
  23 +                    if (client->active){
  24 +                      state_reboot (client);
  25 +                    }
  26 +                    break;
  27                 }
  28             }
  29         }
  30 diff --git a/common/dispatch.c b/common/dispatch.c
  31 index 9741ff5..11c1787 100644
  32 --- a/common/dispatch.c
  33 +++ b/common/dispatch.c
  34 @@ -118,7 +118,6 @@ dispatch(void)
  35                  * signal. It will return ISC_R_RELOAD in that
  36                  * case. That is a normal behavior.
  37                  */
  38 -
  39                 if (status == ISC_R_RELOAD) {
  40                         /*
  41                          * dhcp_set_control_state() will do the job.
  42 @@ -129,6 +128,16 @@ dispatch(void)
  43                         if (status == ISC_R_SUCCESS)
  44                                 status = ISC_R_RELOAD;
  45                 }
  46 +
  47 +
  48 +                if (status == ISC_R_TIMESHIFTED){
  49 +                  status = dhcp_set_control_state(server_time_changed,
  50 +                                                  server_time_changed);
  51 +                  status = ISC_R_RELOAD;
  52 +                  log_info ("System time has been changed. Unable to use existing leases. Restarting");
  53 +                  // do nothing, restart context
  54 +                };
  55 +
  56         } while (status == ISC_R_RELOAD);
  57
  58         log_fatal ("Dispatch routine failed: %s -- exiting",
  59 diff --git a/includes/dhcpd.h b/includes/dhcpd.h
  60 index fabad01..9663508 100644
  61 --- a/includes/dhcpd.h
  62 +++ b/includes/dhcpd.h
  63 @@ -524,7 +524,8 @@ typedef enum {
  64         server_running = 1,
  65         server_shutdown = 2,
  66         server_hibernate = 3,
  67 -       server_awaken = 4
  68 +       server_awaken = 4,
  69 +        server_time_changed = 5
  70  } control_object_state_t;
  71
  72  typedef struct {
  73 diff --git a/server/dhcpd.c b/server/dhcpd.c
  74 index 845d0cc..3b3bd3b 100644
  75 --- a/server/dhcpd.c
  76 +++ b/server/dhcpd.c
  77 @@ -1767,6 +1767,12 @@ isc_result_t dhcp_set_control_state (control_object_state_t oldstate,
  78  {
  79         struct timeval tv;
  80
  81 +        if (newstate == server_time_changed){
  82 +          log_error ("System time has been changed. Leases information unreliable!");
  83 +          return ISC_R_SUCCESS;
  84 +        }
  85 +
  86 +
  87         if (newstate != server_shutdown)
  88                 return DHCP_R_INVALIDARG;
  89         /* Re-entry. */
  90 --
  91 2.35.1
  92