[master] Adds persist-eui-64-leases config parameter and support

Merges in rt45046.

RELNOTES

@@ -298,6 +298,11 @@ dhcp-users@lists.isc.org.
   default), hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, and hmac-sha512.
   [ISC-Bugs #46771]
 
+- Added a server configuration parameter, persist-eui-64-leases, which
+  determines whether or not EUI-64 based leases are written to the
+  leases file.  Default is true.
+  [ISC-Bugs #45046]
+
 			Changes since 4.3.0 (bug fixes)
 
 - Tidy up several small tickets.

includes/dhcpd.h

@@ -801,6 +801,7 @@ struct lease_state {
 #define SV_ABANDON_LEASE_TIME		89
 #ifdef EUI_64
 #define SV_USE_EUI_64			90
+#define SV_PERSIST_EUI_64_LEASES	91
 #endif
 #if defined (FAILOVER_PROTOCOL)
 #define SV_CHECK_SECS_BYTE_ORDER	91
@@ -2099,6 +2100,10 @@ extern u_int16_t ddns_conflict_mask;
 extern int dont_use_fsync;
 extern int server_id_check;
 
+#ifdef EUI_64
+extern int persist_eui64;
+#endif
+
 extern int prefix_length_mode;
 extern int authoring_byte_order;
 extern int lease_id_format;

server/db.c

@@ -525,6 +525,27 @@ write_ia(const struct ia_xx *ia) {
 	char *s;
 	int fprintf_ret;
 
+#ifdef EUI_64
+	/* If we're not writing EUI64 leases to the file, then
+	* we can skip writing this IA provided all of its leases
+	* are EUI64. (Not sure you can ever have a case where
+	* they aren't but doesn't hurt to check) */
+	if (ia->ia_type == D6O_IA_NA && !persist_eui64) {
+		int i;
+		for (i=0; i < ia->num_iasubopt; i++) {
+			if (!ia->iasubopt[i]->ipv6_pool->ipv6_pond->use_eui_64)
+			{
+				break;
+			}
+		}
+
+		if (i == ia->num_iasubopt) {
+			/* Their all EUI64 so we can skip it */
+			return(1);
+		}
+	}
+#endif
+
 	/*
 	 * If the lease file is corrupt, don't try to write any more
 	 * leases until we've written a good lease file.

server/dhcpd.c

@@ -82,6 +82,10 @@ int dont_use_fsync = 0; /* 0 = default, use fsync, 1 = don't use fsync */
 int server_id_check = 0; /* 0 = default, don't check server id, 1 = do check */
 int prefix_length_mode = PLM_PREFER;
 
+#ifdef EUI_64
+int persist_eui64 = 1; /* 1 = write EUI64 leases to disk, 0 = don't */
+#endif
+
 int authoring_byte_order = 0; /* 0 = not set */
 int lease_id_format = TOKEN_OCTAL; /* octal by default */
 u_int32_t abandon_lease_time = DEFAULT_ABANDON_LEASE_TIME;
@@ -847,8 +851,9 @@ main(int argc, char **argv) {
 #endif
 
         /* test option should cause an early exit */
- 	if (cftest && !lftest)
+	if (cftest && !lftest) {
  		exit(0);
+	}
 
 	/*
 	 * First part of dealing with pid files.  Check to see if
@@ -1396,6 +1401,21 @@ void postconf_initialization (int quiet)
 	}
 #endif
 
+#ifdef EUI_64
+       oc = lookup_option(&server_universe, options, SV_PERSIST_EUI_64_LEASES);
+       if (oc != NULL) {
+		persist_eui64 = evaluate_boolean_option_cache(NULL, NULL, NULL,
+							      NULL, options,
+							      NULL,
+							      &global_scope,
+							      oc, MDL);
+	}
+
+	if (!persist_eui64) {
+		log_info("EUI64 leases will not be written to lease file");
+	}
+#endif
+
 #if defined (BINARY_LEASES)
 	if (local_family == AF_INET) {
 		log_info("Source compiled to use binary-leases");

server/dhcpd.conf.5

@@ -2920,6 +2920,21 @@ or provable, so we urge caution in the use of this statement.
 .RE
 .PP
 The
+.I persist-eui-64-leases
+statement
+.RS 0.25i
+.PP
+.B persist-eui-64-leases \fIflag\fR\fB;\fR
+.PP
+When this flag is enabled, the server will write EUI-64 based leases to the
+leases file. Since such leases can only, ever be valid for a single DUID value
+it can be argued that writing them to the leases file isn't essential and not
+doing so may have perfomance advantages.  See \fIuse-eui-64\fR statement for
+more details on EUI-64 based address allocation.  The flag is enabled by
+default and may only be set at the global scope.
+.RE
+.PP
+The
 .I pid-file-name
 statement
 .RS 0.25i
@@ -3349,8 +3364,6 @@ in use.  Also, the server must attempt the update each time the
 client renews its lease, which could have a significant performance
 impact in environments that place heavy demands on the DHCP server.
 .RE
-
-
 .PP
 The
 .I use-eui-64
@@ -3413,6 +3426,9 @@ message:
     Request - Server will send "an address not on link status", and no ia
     suboption Renew/Rebind - Server will send the requested address ia
     suboption with lifetimes of 0, plus an EUI-64 ia
+
+Whether or not  EUI-64 based leases are written out to the lease database
+may be controlled by \fIpersist-eui-64-leases\fR statement.
 .RE
 .PP
 The

server/stables.c

@@ -279,6 +279,7 @@ static struct option server_options[] = {
 	{ "abandon-lease-time", "T",		&server_universe,  SV_ABANDON_LEASE_TIME, 1 },
 #ifdef EUI_64
 	{ "use-eui-64", "f",		&server_universe,  SV_USE_EUI_64, 1 },
+	{ "persist-eui-64-leases", "f",	&server_universe,  SV_PERSIST_EUI_64_LEASES, 1 },
 #endif
 #if defined (FAILOVER_PROTOCOL)
 	{ "check-secs-byte-order", "f", &server_universe, SV_CHECK_SECS_BYTE_ORDER, 1 },