Upstream-Status: Pending

Add a new option -D to the udhcpc client that allows for
dhcp renewal to occur without having to down the interface
in the process.

Signed-off-by: Greg Moffatt <greg.moffatt@windriver.com>

Updated to latest Busybox 1.17.3

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>

Updated to Busybox 1.18.4
option spec is changed

Signed-off-by: Qing He <qing.he@intel.com>

diff -ur busybox-1.17.3.orig/networking/udhcp/dhcpc.c busybox-1.17.3/networking/udhcp/dhcpc.c
--- busybox-1.17.3.orig/networking/udhcp/dhcpc.c
+++ busybox-1.17.3/networking/udhcp/dhcpc.c
@@ -35,6 +35,9 @@
 #endif
 #include <linux/filter.h>
 
+/* option whether to down the interface when reconfiguring */
+static int allow_deconfig = 1;
+
 /* struct client_config_t client_config is in bb_common_bufsiz1 */
 
 
@@ -709,7 +712,8 @@
 		state = RENEW_REQUESTED;
 		break;
 	case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
-		udhcp_run_script(NULL, "deconfig");
+		if (allow_deconfig)
+			udhcp_run_script(NULL, "deconfig");
 	case REQUESTING:
 	case RELEASED:
 		change_listen_mode(LISTEN_RAW);
@@ -733,7 +737,8 @@
 		bb_info_msg("Unicasting a release of %s to %s",
 				inet_ntoa(temp_addr), buffer);
 		send_release(server_addr, requested_ip); /* unicast */
-		udhcp_run_script(NULL, "deconfig");
+		if (allow_deconfig)
+			udhcp_run_script(NULL, "deconfig");
 	}
 	bb_info_msg("Entering released state");
 
@@ -836,6 +841,7 @@
 		OPT_o = 1 << 17,
 		OPT_x = 1 << 18,
 		OPT_f = 1 << 19,
+		OPT_D = 1 << 20,
 /* The rest has variable bit positions, need to be clever */
 		OPTBIT_f = 20,
 		USE_FOR_MMU(             OPTBIT_b,)
@@ -861,7 +867,7 @@
 #endif
 		;
 	IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
-	opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:f"
+	opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:fD"
 		USE_FOR_MMU("b")
 		IF_FEATURE_UDHCPC_ARPING("a")
 		IF_FEATURE_UDHCP_PORT("P:")
@@ -950,6 +956,9 @@
 		logmode |= LOGMODE_SYSLOG;
 	}
 
+	if (opt & OPT_D)
+		allow_deconfig = 0;
+
 	/* Make sure fd 0,1,2 are open */
 	bb_sanitize_stdio();
 	/* Equivalent of doing a fflush after every \n */
@@ -964,7 +973,8 @@
 	srand(monotonic_us());
 
 	state = INIT_SELECTING;
-	udhcp_run_script(NULL, "deconfig");
+	if (allow_deconfig)
+		udhcp_run_script(NULL, "deconfig");
 	change_listen_mode(LISTEN_RAW);
 	packet_num = 0;
 	timeout = 0;
@@ -1100,7 +1110,8 @@
 				}
 				/* Timed out, enter init state */
 				bb_info_msg("Lease lost, entering init state");
-				udhcp_run_script(NULL, "deconfig");
+				if (allow_deconfig)
+					udhcp_run_script(NULL, "deconfig");
 				state = INIT_SELECTING;
 				/*timeout = 0; - already is */
 				packet_num = 0;
@@ -1246,7 +1257,8 @@
 						send_decline(xid, server_addr, packet.yiaddr);
 
 						if (state != REQUESTING)
-							udhcp_run_script(NULL, "deconfig");
+							if (allow_deconfig)
+								udhcp_run_script(NULL, "deconfig");
 						change_listen_mode(LISTEN_RAW);
 						state = INIT_SELECTING;
 						requested_ip = 0;
@@ -1292,7 +1304,8 @@
 				bb_info_msg("Received DHCP NAK");
 				udhcp_run_script(&packet, "nak");
 				if (state != REQUESTING)
-					udhcp_run_script(NULL, "deconfig");
+					if (allow_deconfig)
+						udhcp_run_script(NULL, "deconfig");
 				change_listen_mode(LISTEN_RAW);
 				sleep(3); /* avoid excessive network traffic */
 				state = INIT_SELECTING;