make dnsmasq probe for dhcp servers before starting a dhcp server

git-svn-id: svn://svn.openwrt.org/openwrt/trunk/openwrt@1110 3c298f89-4303-0410-b956-a3cf2f4a3e73

4 files changed, 144 insertions, 6 deletions

diff --git a/package/busybox/patches/150-udhcp-release.patch b/package/busybox/patches/150-udhcp-release.patch
new file mode 100644
index 000000000..dedec09a9
--- /dev/null
+++ b/package/busybox/patches/150-udhcp-release.patch
@@ -0,0 +1,89 @@
+diff -Nurb busybox-1.00/include/usage.h busybox-1.00-patched/include/usage.h
+--- busybox-1.00/include/usage.h	2005-05-30 05:34:45.397776704 -0400
++++ busybox-1.00-patched/include/usage.h	2005-05-30 05:04:29.271869808 -0400
+@@ -2629,6 +2629,7 @@
+ 	"\t-n,\t--now\tExit with failure if lease cannot be immediately negotiated.\n" \
+ 	"\t-p,\t--pidfile=file\tStore process ID of daemon in file\n" \
+ 	"\t-q,\t--quit\tQuit after obtaining lease\n" \
++	"\t-R\t--release\tRelease IP on quit\n" \
+ 	"\t-r,\t--request=IP\tIP address to request (default: none)\n" \
+ 	"\t-s,\t--script=file\tRun file at dhcp events (default: /usr/share/udhcpc/default.script)\n" \
+ 	"\t-v,\t--version\tDisplay version"
+diff -Nurb busybox-1.00/networking/udhcp/dhcpc.c busybox-1.00-patched/networking/udhcp/dhcpc.c
+--- busybox-1.00/networking/udhcp/dhcpc.c	2004-05-19 04:29:05.000000000 -0400
++++ busybox-1.00-patched/networking/udhcp/dhcpc.c	2005-05-30 05:00:47.377602864 -0400
+@@ -61,6 +61,7 @@
+ 	abort_if_no_lease: 0,
+ 	foreground: 0,
+ 	quit_after_lease: 0,
++	release_on_quit: 0,
+ 	background_if_no_lease: 0,
+ 	interface: "eth0",
+ 	pidfile: NULL,
+@@ -87,6 +88,7 @@
+ "                                  immediately negotiated.\n"
+ "  -p, --pidfile=file              Store process ID of daemon in file\n"
+ "  -q, --quit                      Quit after obtaining lease\n"
++"  -R, --release                   Release IP on quit\n"
+ "  -r, --request=IP                IP address to request (default: none)\n"
+ "  -s, --script=file               Run file at dhcp events (default:\n"
+ "                                  " DEFAULT_SCRIPT ")\n"
+@@ -202,6 +204,7 @@
+ 		{"now", 	no_argument,		0, 'n'},
+ 		{"pidfile",	required_argument,	0, 'p'},
+ 		{"quit",	no_argument,		0, 'q'},
++		{"release",	no_argument,		0, 'R'},
+ 		{"request",	required_argument,	0, 'r'},
+ 		{"script",	required_argument,	0, 's'},
+ 		{"version",	no_argument,		0, 'v'},
+@@ -251,6 +254,9 @@
+ 		case 'q':
+ 			client_config.quit_after_lease = 1;
+ 			break;
++		case 'R':
++			client_config.release_on_quit = 1;
++			break;
+ 		case 'r':
+ 			requested_ip = inet_addr(optarg);
+ 			break;
+@@ -472,8 +478,11 @@
+ 
+ 					state = BOUND;
+ 					change_mode(LISTEN_NONE);
+-					if (client_config.quit_after_lease)
++					if (client_config.quit_after_lease) {
++						if (client_config.release_on_quit) 
++							perform_release();
+ 						return 0;
++					}
+ 					if (!client_config.foreground)
+ 						client_background();
+ 
+@@ -498,12 +507,13 @@
+ 			case SIGUSR1:
+ 				perform_renew();
+ 				break;
+-			case SIGUSR2:
+-				perform_release();
+-				break;
+ 			case SIGTERM:
+ 				LOG(LOG_INFO, "Received SIGTERM");
++				if (!client_config.release_on_quit)
+ 				return 0;
++			case SIGUSR2:
++				perform_release();
++				break;
+ 			}
+ 		} else if (retval == -1 && errno == EINTR) {
+ 			/* a signal was caught */
+diff -Nurb busybox-1.00/networking/udhcp/dhcpc.h busybox-1.00-patched/networking/udhcp/dhcpc.h
+--- busybox-1.00/networking/udhcp/dhcpc.h	2004-01-30 18:45:12.000000000 -0500
++++ busybox-1.00-patched/networking/udhcp/dhcpc.h	2005-05-30 04:53:58.681734080 -0400
+@@ -20,6 +20,7 @@
+ struct client_config_t {
+ 	char foreground;		/* Do not fork */
+ 	char quit_after_lease;		/* Quit after obtaining lease */
++	char release_on_quit;		/* perform release on quit */
+ 	char abort_if_no_lease;		/* Abort if no lease */
+ 	char background_if_no_lease;	/* Fork to background if no lease */
+ 	char *interface;		/* The name of the interface to use */
diff --git a/target/default/target_skeleton/etc/functions.sh b/target/default/target_skeleton/etc/functions.sh
index 48f1191cc..60d6231f8 100755
--- a/target/default/target_skeleton/etc/functions.sh
+++ b/target/default/target_skeleton/etc/functions.sh
@@ -12,7 +12,7 @@ nvram () {
 . /etc/nvram.overrides
 
 # valid interface?
-if_valid () {
+if_valid () (
   ifconfig "$1" >&- 2>&- ||
   [ "${1%%[0-9]}" = "br" ] ||
   {
@@ -29,5 +29,29 @@ if_valid () {
       $DEBUG vconfig add $vif $i 2>&-
     )
   } ||
-  { debug "# missing interface '$if' ignored"; false; }
+  { debug "# missing interface '$1' ignored"; false; }
+)
+
+bitcount () {
+  local c=$1
+  echo $((
+  c=((c>> 1)&0x55555555)+(c&0x55555555),
+  c=((c>> 2)&0x33333333)+(c&0x33333333),
+  c=((c>> 4)&0x0f0f0f0f)+(c&0x0f0f0f0f),
+  c=((c>> 8)&0x00ff00ff)+(c&0x00ff00ff),
+  c=((c>>16)&0x0000ffff)+(c&0x0000ffff)
+  ))
+}
+
+valid_netmask () {
+  return $((-($1)&~$1))
+}
+
+ip2int () (
+  set $(echo $1 | tr '\.' ' ')
+  echo $(($1<<24|$2<<16|$3<<8|$4))
+)
+
+int2ip () {
+  echo $(($1>>24&255)).$(($1>>16&255)).$(($1>>8&255)).$(($1&255))
 }
diff --git a/target/default/target_skeleton/etc/init.d/S50dnsmasq b/target/default/target_skeleton/etc/init.d/S50dnsmasq
index 995c1b6e7..55bbc3719 100755
--- a/target/default/target_skeleton/etc/init.d/S50dnsmasq
+++ b/target/default/target_skeleton/etc/init.d/S50dnsmasq
@@ -1,2 +1,25 @@
 #!/bin/sh
-/usr/sbin/dnsmasq
+. /etc/functions.sh
+
+# interface to use for DHCP
+iface=lan
+
+ifname=$(nvram get ${iface}_ifname)
+ipaddr=$(nvram get ${iface}_ipaddr)
+netmask=$(nvram get ${iface}_netmask)
+
+# check for existing DHCP server
+udhcpc -n -q -R -s /dev/zero -i $ifname >&- || {
+
+  ipaddr=$(ip2int $ipaddr)
+  netmask=$(ip2int ${netmask:-255.255.255.0})
+  network=$((ipaddr&netmask))
+  
+  start=$(nvram get dhcp_start)
+  start=$((network+${start:-100}))
+  end=$(nvram get dhcp_num)
+  end=$((start+${end:-150}))
+  
+  args="-K -F $(int2ip $start),$(int2ip $end),$(int2ip $netmask),12h"
+}
+/usr/sbin/dnsmasq ${args}
diff --git a/target/default/target_skeleton/sbin/ifup b/target/default/target_skeleton/sbin/ifup
index 9759f8d4d..60f9a1730 100755
--- a/target/default/target_skeleton/sbin/ifup
+++ b/target/default/target_skeleton/sbin/ifup
@@ -10,6 +10,7 @@
 
   if_valid $if || return
 
+  mac=$(nvram get ${type}_hwaddr)
   $DEBUG ifconfig $if down 2>&-
   if [ "${if%%[0-9]}" = "br" ]; then
     stp=$(nvram get ${type}_stp)
@@ -19,13 +20,14 @@
     $DEBUG brctl stp $if ${stp:-0}
     for sif in $(nvram get ${type}_ifnames); do {
       if_valid $sif || continue
+      ${mac:+$DEBUG ifconfig $sif down hw ether $mac}
       $DEBUG ifconfig $sif 0.0.0.0 up
       $DEBUG brctl addif $if $sif
     } done
+  else
+    ${mac:+$DEBUG ifconfig $if down hw ether $mac}
   fi
 
-  mac=$(nvram get ${type}_hwaddr)
-  ${mac:+$DEBUG ifconfig $if hw ether $mac}
 
   if_proto=$(nvram get ${type}_proto)
   case "$if_proto" in
@@ -50,7 +52,7 @@
       if [ -f $pidfile ]; then
         $DEBUG kill $(cat $pidfile)
       fi
-      ${DEBUG:-eval} "udhcpc -i $if ${ip:+-r $ip} -b -p $pidfile &" 
+      ${DEBUG:-eval} "udhcpc -R -i $if ${ip:+-r $ip} -b -p $pidfile &" 
     ;;
     none|"")
 	# pppoe is handled by /etc/init.d/S50pppoe