busybox: udhcpc create leases file

Capture the lease information for use by applications after a lease is aquired.

Signed-off-by Matt Weber <[email protected]>

---

Changes v1 -> v2
- Changed from appending to keeping just the last lease
- Adjusted format to pure shell variables instead of dhclient format.
- Moved location to /var/run instead of /var/lib/misc

---
 package/busybox/udhcpc.script | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

package/busybox/udhcpc.script +21 -0

index 50c52e6..e913111 100755
@@ -61,6 +61,27 @@ case "$1" in
                        echo adding dns $i
                        echo "nameserver $i # $interface" >> $RESOLV_CONF
                done
+
+               # Record last lease
+               {
+                   echo "IFACE=$interface"
+                   echo "IP=$ip"
+                   [ -n "$subnet" ]    && echo "MASK=$subnet"
+                   [ -n "$router" ]    && echo "ROUTER=$router"
+                   [ -n "$dns" ]       && echo "DNS=\"$dns\""
+                   [ -n "$domain" ]    && echo "DOMAIN=$domain"
+                   [ -n "$boot_file" ] && echo "BOOT_FILE=$boot_file"
+                   echo "DHCP_LEASE_TIME=$lease"
+                   echo "DHCP_MSG_TYPE=$dhcptype"
+                   echo "DHCP_SERVER_ID=${siaddr:-$serverid}"
+                   d=$(expr "$(date "+%Y.%m.%d-%H:%M:%S")" : "\(.*\):")
+                   t=$(date -d "$d:$(expr $lease / 2)" "+%w %Y/%m/%d
 %H:%M:%S" 2>/dev/null)
+                   [ -n "$t" ] && echo "DHCP_RENEW=\"$t\""
+                   t=$(date -d "$d:$(expr 7 '*' $lease / 8)" "+%w
 %Y/%m/%d %H:%M:%S" 2>/dev/null)
+                   [ -n "$t" ] && echo "DHCP_REBIND=\"$t\""
+                   t=$(date -d "$d:$lease" "+%w %Y/%m/%d %H:%M:%S"
 2>/dev/null)
+                   [ -n "$t" ] && echo "DHCP_EXPIRE=\"$t\""
+               } > /var/run/udhcpc.$interface.leases

                ;;

esac

--
1.9.1

Since the hook scripts where added for the udhcpc.script, is the preference to use a hook for something like a record of the last lease?