[master] Check failover pools per peer in test mode

Merges in rt29892

RELNOTES

@@ -1102,6 +1102,11 @@ by Eric Young (eay@cryptsoft.com).
   at TDS Telecom for reporting this issue.
   [ISC-Bugs #35378]
 
+- The server now detects failover peers that are not referenced in at least
+  one pool when run with the command line option for test mode, -T.  Prior to
+  this the check was performed too far down stream to be detected in test mode.
+  [ISC-Bugs #29892]
+
 			Changes since 4.2.0 (new features)
 
 - If a client renews before 'dhcp-cache-threshold' percent of its lease

includes/dhcpd.h

@@ -3540,6 +3540,7 @@ void free_everything (void);
 /* failover.c */
 #if defined (FAILOVER_PROTOCOL)
 extern dhcp_failover_state_t *failover_states;
+void dhcp_failover_sanity_check (void);
 void dhcp_failover_startup (void);
 int dhcp_failover_write_all_states (void);
 isc_result_t enter_failover_peer (dhcp_failover_state_t *);

server/dhcpd.c

@@ -820,6 +820,10 @@ main(int argc, char **argv) {
 
 	postconf_initialization (quiet);
 
+#if defined (FAILOVER_PROTOCOL)
+	dhcp_failover_sanity_check();
+#endif
+
 #if defined(DHCPv6) && defined(DHCP4o6)
 	if (dhcpv4_over_dhcpv6) {
 		if ((local_family == AF_INET) && (interfaces != NULL))

server/failover.c

@@ -3,7 +3,7 @@
    Failover protocol support code... */
 
 /*
- * Copyright (c) 2004-2016 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 2004-2017 by Internet Systems Consortium, Inc. ("ISC")
  * Copyright (c) 1999-2003 by Internet Software Consortium
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -51,6 +51,38 @@ static inline int secondary_not_hoarding(dhcp_failover_state_t *state,
 static void scrub_lease(struct lease* lease, const char *file, int line);
 
 
+/*!
+ * \brief Performs a "pre-flight" sanity check of failover configuration
+ *
+ * Provides an opportunity to do post-parse pre-startup sanity checking
+ * of failover configuration.  This allows checks to be done under test
+ * mode (-T), without requiring full startup for validation.
+ *
+ * Currently, it enforces all failover peers be used in at lease one
+ * pool. This logic was formerly located in dhcp_failover_startup.
+ *
+ * On failure, a fatal error is logged.
+ *
+ */
+void dhcp_failover_sanity_check() {
+	dhcp_failover_state_t *state;
+	int fail_count = 0;
+
+	for (state = failover_states; state; state = state->next) {
+		if (state->pool_count == 0) {
+			log_error ("ERROR: Failover peer, %s, has no referring"
+				   " pools. You must refer to each peer in at"
+                                   " least one pool declaration.",
+				   state->name);
+			fail_count++;
+		}
+	}
+
+	if (fail_count) {
+		log_fatal ("Failover configuration sanity check failed");
+	}
+}
+
 void dhcp_failover_startup ()
 {
 	dhcp_failover_state_t *state;
@@ -59,16 +91,6 @@ void dhcp_failover_startup ()
 
 	for (state = failover_states; state; state = state -> next) {
 		dhcp_failover_state_transition (state, "startup");
-
-		if (state -> pool_count == 0) {
-			log_error ("failover peer declaration with no %s",
-				   "referring pools.");
-			log_error ("In order to use failover, you MUST %s",
-				   "refer to your main failover declaration");
-			log_error ("in each pool declaration.   You MUST %s",
-				   "NOT use range declarations outside");
-			log_fatal ("of pool declarations.");
-		}
 		/* In case the peer is already running, immediately try
 		   to establish a connection with it. */
 		status = dhcp_failover_link_initiate ((omapi_object_t *)state);