n-dhcp4: return error when calling accept/decline/select in unexpected state

The caller is supposed to call accept/decline/select with the lease that
was just announced. Calling it in the wrong state or with the wrong
lease is a user error.

Return an error when called in the wrong state, so that the user
notices they did something wrong.

2 files changed, 12 insertions, 21 deletions

diff --git a/src/n-dhcp4/src/n-dhcp4-c-lease.c b/src/n-dhcp4/src/n-dhcp4-c-lease.c
index eaa9627652..a30b455356 100644
--- a/src/n-dhcp4/src/n-dhcp4-c-lease.c
+++ b/src/n-dhcp4/src/n-dhcp4-c-lease.c
@@ -351,14 +351,13 @@ _c_public_ int n_dhcp4_client_lease_query(NDhcp4ClientLease *lease, uint8_t opti
  * selected none of the others can be.
  *
  * Return: 0 on success, or a negative error code on failure.
+ *   Returns -ENOTRECOVERABLE when called in an unexpected state.
  */
 _c_public_ int n_dhcp4_client_lease_select(NDhcp4ClientLease *lease) {
         NDhcp4ClientLease *l, *t_l;
         NDhcp4ClientProbe *probe;
         int r;
 
-        /* XXX error handling, this must be an OFFER */
-
         if (!lease->probe)
                 return -ENOTRECOVERABLE;
         if (lease->probe->current_lease)
@@ -390,12 +389,11 @@ _c_public_ int n_dhcp4_client_lease_select(NDhcp4ClientLease *lease) {
  * can be accepted.
  *
  * Return: 0 on success, or a negative error code on failure.
+ *   Returns -ENOTRECOVERABLE when called in an unexpected state.
  */
 _c_public_ int n_dhcp4_client_lease_accept(NDhcp4ClientLease *lease) {
         int r;
 
-        /* XXX error handling, this must be an ACK */
-
         if (!lease->probe)
                 return -ENOTRECOVERABLE;
         if (lease->probe->current_lease != lease)
@@ -421,12 +419,11 @@ _c_public_ int n_dhcp4_client_lease_accept(NDhcp4ClientLease *lease) {
  * decline.
  *
  * Return: 0 on success, or a negative error code on failure.
+ *   Returns -ENOTRECOVERABLE when called in an unexpected state.
  */
 _c_public_ int n_dhcp4_client_lease_decline(NDhcp4ClientLease *lease, const char *error) {
         int r;
 
-        /* XXX: error handling, this must be an ACK */
-
         if (!lease->probe)
                 return -ENOTRECOVERABLE;
         if (lease->probe->current_lease != lease)
diff --git a/src/n-dhcp4/src/n-dhcp4-c-probe.c b/src/n-dhcp4/src/n-dhcp4-c-probe.c
index 283c1693cf..f5d93b394a 100644
--- a/src/n-dhcp4/src/n-dhcp4-c-probe.c
+++ b/src/n-dhcp4/src/n-dhcp4-c-probe.c
@@ -1046,7 +1046,7 @@ int n_dhcp4_client_probe_transition_select(NDhcp4ClientProbe *probe, NDhcp4Incom
 
                 probe->state = N_DHCP4_CLIENT_PROBE_STATE_REQUESTING;
 
-                break;
+                return 0;
         case N_DHCP4_CLIENT_PROBE_STATE_INIT:
         case N_DHCP4_CLIENT_PROBE_STATE_INIT_REBOOT:
         case N_DHCP4_CLIENT_PROBE_STATE_REBOOTING:
@@ -1057,11 +1057,9 @@ int n_dhcp4_client_probe_transition_select(NDhcp4ClientProbe *probe, NDhcp4Incom
         case N_DHCP4_CLIENT_PROBE_STATE_REBINDING:
         case N_DHCP4_CLIENT_PROBE_STATE_EXPIRED:
         default:
-                /* ignore */
-                break;
+                /* user called in invalid state. Return error. */
+                return -ENOTRECOVERABLE;
         }
-
-        return 0;
 }
 
 /**
@@ -1088,7 +1086,7 @@ int n_dhcp4_client_probe_transition_accept(NDhcp4ClientProbe *probe, NDhcp4Incom
 
                 n_dhcp4_client_arm_timer(probe->client);
 
-                break;
+                return 0;
 
         case N_DHCP4_CLIENT_PROBE_STATE_INIT:
         case N_DHCP4_CLIENT_PROBE_STATE_INIT_REBOOT:
@@ -1100,11 +1098,9 @@ int n_dhcp4_client_probe_transition_accept(NDhcp4ClientProbe *probe, NDhcp4Incom
         case N_DHCP4_CLIENT_PROBE_STATE_REBINDING:
         case N_DHCP4_CLIENT_PROBE_STATE_EXPIRED:
         default:
-                /* ignore */
-                break;
+                /* user called in invalid state. Return error. */
+                return -ENOTRECOVERABLE;
         }
-
-        return 0;
 }
 
 /**
@@ -1128,7 +1124,7 @@ int n_dhcp4_client_probe_transition_decline(NDhcp4ClientProbe *probe, NDhcp4Inco
 
                 /* XXX: what state to transition to? */
 
-                break;
+                return 0;
 
         case N_DHCP4_CLIENT_PROBE_STATE_INIT:
         case N_DHCP4_CLIENT_PROBE_STATE_INIT_REBOOT:
@@ -1140,11 +1136,9 @@ int n_dhcp4_client_probe_transition_decline(NDhcp4ClientProbe *probe, NDhcp4Inco
         case N_DHCP4_CLIENT_PROBE_STATE_REBINDING:
         case N_DHCP4_CLIENT_PROBE_STATE_EXPIRED:
         default:
-                /* ignore */
-                break;
+                /* user called in invalid state. Return error. */
+                return -ENOTRECOVERABLE;
         }
-
-        return 0;
 }
 
 /**