[master] Changes DHCLIENT_DEFAULT_PREFIX_LEN to 128, adds --address-prefix-len to dhclient cli

    Merges in rt23252.

RELNOTES

@@ -303,6 +303,15 @@ dhcp-users@lists.isc.org.
   leases file.  Default is true.
   [ISC-Bugs #45046]
 
+- Changed the default value of the prefix length passed by dhclient into the
+  client script for each IPv6 address, from 64 to 128. In addition, dhclient
+  now supports a command line argument, --address-prefix-len <len>, which may
+  be used to override the default value.  PLEASE NOTE: If your DHCPv6 clients
+  require a value other than 128, you MUST specify the value via this new
+  command line argument.  Prior to this the only way to alter the value was at
+  compile time by changing DHCLIENT_DEFAULT_PREFIX_LEN in include/sites.h.
+  [ISC-Bugs #23252]
+
 			Changes since 4.3.0 (bug fixes)
 
 - Tidy up several small tickets.

client/dhc6.c

@@ -154,7 +154,7 @@ static int drop_declined_addrs(struct dhc6_lease *lease);
 extern int onetry;
 extern int stateless;
 extern int prefix_len_hint;
-
+extern int address_prefix_len;
 
 /*
  * Assign DHCPv6 port numbers as a client.
@@ -4434,7 +4434,7 @@ dhc6_marshall_values(const char *prefix, struct client_state *client,
 				      (unsigned) addr->plen);
 		} else {
 			client_envadd(client, prefix, "ip6_prefixlen",
-				      "%d", DHCLIENT_DEFAULT_PREFIX_LEN);
+				      "%d", address_prefix_len);
 			client_envadd(client, prefix, "ip6_address",
 				      "%s", piaddr(addr->address));
 		}

client/dhclient.c

@@ -105,6 +105,7 @@ int dad_wait_time = 0;
 int prefix_len_hint = 0;
 #endif
 
+int address_prefix_len = DHCLIENT_DEFAULT_PREFIX_LEN;
 char *mockup_relay = NULL;
 
 char *progname = NULL;
@@ -163,12 +164,14 @@ static const char use_v6command[] = "Command not used for DHCPv4: %s";
 #define DHCLIENT_USAGE0 \
 "[-4|-6] [-SNTPRI1dvrxi] [-nw] -4o6 <port>] [-p <port>] [-D LL|LLT]\n" \
 "                [--dad-wait-time <seconds>] [--prefix-len-hint <length>]\n" \
-"                [--decline-wait-time <seconds>]\n"
+"                [--decline-wait-time <seconds>]\n" \
+"                [--address-prefix-len length]\n"
 #else /* DHCP4o6 */
 #define DHCLIENT_USAGE0 \
 "[-4|-6] [-SNTPRI1dvrxi] [-nw] [-p <port>] [-D LL|LLT]\n" \
 "                [--dad-wait-time <seconds>] [--prefix-len-hint <length>]\n" \
-"                [--decline-wait-time <seconds>]\n"
+"                [--decline-wait-time <seconds>]\n" \
+"                [--address-prefix-len length]\n"
 #endif
 #else /* DHCPv6 */
 #define DHCLIENT_USAGE0 \
@@ -495,7 +498,6 @@ main(int argc, char **argv) {
 			if (++i == argc) {
 				usage(use_noarg, argv[i-1]);
 			}
-
 			errno = 0;
 			dad_wait_time = (int)strtol(argv[i], &s, 10);
 			if (errno || (*s != '\0') || (dad_wait_time < 0)) {
@@ -513,6 +515,17 @@ main(int argc, char **argv) {
 				usage("Invalid value for --prefix-len-hint: %s",
 				      argv[i]);
 			}
+		} else if (!strcmp(argv[i], "--address-prefix-len")) {
+			if (++i == argc) {
+				usage(use_noarg, argv[i-1]);
+			}
+			errno = 0;
+			address_prefix_len = (int)strtol(argv[i], &s, 10);
+			if (errno || (*s != '\0') ||
+			    (address_prefix_len < 0)) {
+				usage("Invalid value for"
+				      " --address-prefix-len: %s", argv[i]);
+			}
 #endif /* DHCPv6 */
 		} else if (!strcmp(argv[i], "--decline-wait-time")) {
 			if (++i == argc) {

includes/site.h

@@ -285,7 +285,7 @@
    is a host address and doesn't include any on-link information.
    64 indicates that the first 64 bits are the subnet or on-link
    prefix. */
-#define DHCLIENT_DEFAULT_PREFIX_LEN 64
+#define DHCLIENT_DEFAULT_PREFIX_LEN 128
 
 /* Enable the gentle shutdown signal handling.  Currently this
    means that on SIGINT or SIGTERM a client will release its