speed up ipconfig dhcp timeout to something a little more reasonable.

Reference: /n/atom/patch/applied/ipconfigdhcpfast
Date: Thu Feb 27 19:11:00 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/ip/ipconfig/ipconfig.h	Thu Feb 27 19:10:36 2014
+++ /sys/src/cmd/ip/ipconfig/ipconfig.h	Thu Feb 27 19:10:36 2014
@@ -100,7 +100,7 @@
 void	binddevice(void);
 void	bootprequest(void);
 void	controldevice(void);
-void	dhcpquery(int, int);
+void	dhcpquery(int, int, int);
 void	dhcprecv(void);
 void	dhcpsend(int);
 int	dhcptimer(void);
--- /sys/src/cmd/ip/ipconfig/main.c	Thu Feb 27 19:10:36 2014
+++ /sys/src/cmd/ip/ipconfig/main.c	Thu Feb 27 19:10:36 2014
@@ -179,7 +179,7 @@
 void	binddevice(void);
 void	bootprequest(void);
 void	controldevice(void);
-void	dhcpquery(int, int);
+void	dhcpquery(int, int, int);
 void	dhcprecv(void);
 void	dhcpsend(int);
 int	dhcptimer(void);
@@ -620,11 +620,11 @@
 	/* run dhcp if we need something */
 	if(dodhcp){
 		mkclientid();
-		for(tries = 0; tries < 30; tries++){
-			dhcpquery(!noconfig, Sselecting);
+		int timeout[5] = {1, 2, 4, 7, 10};
+		for(tries = 0; tries < nelem(timeout); tries++){
+			dhcpquery(!noconfig, Sselecting, timeout[tries]);
 			if(conf.state == Sbound)
 				break;
-			sleep(1000);
 		}
 	}
 
@@ -885,7 +885,7 @@
 }
 
 void
-dhcpquery(int needconfig, int startstate)
+dhcpquery(int needconfig, int startstate, int timeout)
 {
 	if(needconfig)
 		fprint(conf.cfd, "add %I %I", IPnoaddr, IPnoaddr);
@@ -919,7 +919,7 @@
 		dhcprecv();
 		if(dhcptimer() < 0)
 			break;
-		if(time(0) - conf.starttime > 10)
+		if(time(0) - conf.starttime > timeout)
 			break;
 	}
 	close(conf.fd);
@@ -988,7 +988,7 @@
 			} else
 				conf.lease -= t;
 		}
-		dhcpquery(needconfig, needconfig? Sselecting: Srenewing);
+		dhcpquery(needconfig, needconfig? Sselecting: Srenewing, 10);
 
 		if(needconfig && conf.state == Sbound){
 			if(ip4cfg() < 0)