udhcpc retry interval

[Paul Fox]

when udhcpc fails to get a lease, it waits a full minute before
trying again.  in some cases this is far too long.  clearly
the udhcpc commandline is becoming over-burdened, but without
a config file, there's not much choice:  i'd like to add
an option (i chose '-A', for "again") which lets one set the
try-again value.

Index: networking/udhcp/dhcpc.c
===================================================================
RCS file: /cvs/thirdparty/busybox-1.8.0/networking/udhcp/dhcpc.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 dhcpc.c
--- networking/udhcp/dhcpc.c	5 Nov 2007 13:45:42 -0000	1.1.1.1
+++ networking/udhcp/dhcpc.c	5 Nov 2007 17:13:59 -0000
@@ -144,7 +144,7 @@
 int udhcpc_main(int argc, char **argv)
 {
 	uint8_t *temp, *message;
-	char *str_c, *str_V, *str_h, *str_F, *str_r, *str_T, *str_t;
+	char *str_c, *str_V, *str_h, *str_F, *str_r, *str_T, *str_A, *str_t;
 	uint32_t xid = 0;
 	uint32_t lease = 0; /* can be given as 32-bit quantity */
 	unsigned t1 = 0, t2 = 0; /* what a wonderful names */
@@ -179,6 +179,7 @@
 		OPT_t = 1 << 16,
 		OPT_v = 1 << 17,
 		OPT_S = 1 << 18,
+		OPT_A = 1 << 19,
 	};
 #if ENABLE_GETOPT_LONG
 	static const char udhcpc_longopts[] ALIGN1 =
@@ -200,6 +201,7 @@
 		"timeout\0"       Required_argument "T"
 		"version\0"       No_argument       "v"
 		"retries\0"       Required_argument "t"
+		"tryagain\0"      Required_argument "A"
 		"syslog\0"        No_argument       "S"
 		;
 #endif
@@ -208,6 +210,7 @@
 	client_config.script = DEFAULT_SCRIPT;
 	client_config.retries = 3;
 	client_config.timeout = 3;
+	client_config.tryagain = 60;
 
 	/* Parse command line */
 	opt_complementary = "c--C:C--c" // mutually exclusive
@@ -215,10 +218,10 @@
 #if ENABLE_GETOPT_LONG
 	applet_long_options = udhcpc_longopts;
 #endif
-	opt = getopt32(argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:vS",
+	opt = getopt32(argv, "c:CV:fbH:h:F:i:np:qRr:s:T:A:t:vS",
 		&str_c, &str_V, &str_h, &str_h, &str_F,
 		&client_config.interface, &client_config.pidfile, &str_r,
-		&client_config.script, &str_T, &str_t
+		&client_config.script, &str_T, &str_A, &str_t
 		);
 
 	if (opt & OPT_c)
@@ -259,6 +262,8 @@
 		client_config.timeout = xatoi_u(str_T);
 	if (opt & OPT_t)
 		client_config.retries = xatoi_u(str_t);
+	if (opt & OPT_A)
+		client_config.tryagain = xatoi_u(str_A);
 	if (opt & OPT_v) {
 		puts("version "BB_VER);
 		return 0;
@@ -355,7 +360,7 @@
 					}
 					/* wait to try again */
 					packet_num = 0;
-					timeout = now + 60;
+					timeout = now + client_config.tryagain;
 				}
 				break;
 			case RENEW_REQUESTED:
Index: networking/udhcp/dhcpc.h
===================================================================
RCS file: /cvs/thirdparty/busybox-1.8.0/networking/udhcp/dhcpc.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 dhcpc.h
--- networking/udhcp/dhcpc.h	5 Nov 2007 13:45:42 -0000	1.1.1.1
+++ networking/udhcp/dhcpc.h	5 Nov 2007 17:13:59 -0000
@@ -30,6 +30,7 @@
 	int ifindex;                    /* Index number of the interface to use */
 	int retries;                    /* Max number of request packets */
 	int timeout;                    /* Number of seconds to try to get a lease */
+	int tryagain;                   /* Seconds to wait after failure */
 	uint8_t arp[6];                 /* Our arp address */
 };
 
Index: include/usage.h
===================================================================
RCS file: /cvs/thirdparty/busybox-1.8.0/include/usage.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 usage.h
--- include/usage.h	5 Nov 2007 13:45:42 -0000	1.1.1.1
+++ include/usage.h	5 Nov 2007 17:13:59 -0000
@@ -3835,6 +3835,8 @@
        "\n	-r,--request=IP		IP address to request" \
        "\n	-s,--script=file	Run file at dhcp events (default: /usr/share/udhcpc/default.script)" \
        "\n	-t,--retries=N		Send up to N request packets"\
+       "\n	-T,--timeout=N		Try to get a lease for N seconds (default: 3)"\
+       "\n	-A,--tryagain=N		Wait N seconds (default: 60) after failure"\
        "\n	-f,--foreground	Run in foreground" \
        "\n	-b,--background	Background if lease cannot be immediately negotiated" \
        "\n	-S,--syslog	Log to syslog too" \



=---------------------
 paul fox, pgf at brightstareng.com