lib_dhcp_code_example_ethernet

This and other projects in the Code Examples section are published on our website under the name "test_dhcp_lib".

Here is a simple example of using DHCP on the Ethernet (net.) interface. Notice how the callback_dhcp_ok() procedure is implemented! This is a good illustration of the protracted explanation in the Operations Details topic (not that we think you will read it all).

Note also the use of the NET_AVAILABLE define. This comes from the platform. If the Ethernet interface is available on the currently selected platform, then NET_AVAILABLE is "1". Similarly, if the Wi-Fi interface is available, then WLN_AVAILABLE is "1". Using such defines you can create applications that will compile on any platform, as long as this platform has at least the Ethernet, or the Wi-Fi interface.

Here is a sample debug output we've got after running the code:

** Tibbo Basic **

DHCP(net)> —-START---
DHCP(net)> TX discovery message
DHCP(net)> RX offer message
DHCP(net)> TX request message
DHCP(net)> RX confirmation message
DHCP(net)> ---OK(ip: 192.168.1.246, gateway: 192.168.1.1, netmask: 255.255.255.0, lease: 529200 sec.)---

And here is the code itself...

** Tibbo Basic **

'DEFINES-------------------------------------------------------------
#define DHCP_DEBUG_PRINT 1 'to see debug output by the DHCP lib

'INCLUDES------------------------------------------------------------
include "sock\trunk\sock.tbh" 'this lib is necessary for the DHCP lib's operation
include "dhcp\trunk\dhcp.tbh"

** Tibbo Basic **

include "global.tbh"

'====================================================================
sub on_sys_init()
 #if NET_AVAILABLE
         dhcp_start(PL_SOCK_INTERFACE_NET,"","")
 #endif
end sub

'--------------------------------------------------------------------
sub on_sys_timer()
 dhcp_proc_timer()
end sub

'--------------------------------------------------------------------
sub on_sock_data_arrival()
 dhcp_proc_data()
end sub

** Tibbo Basic **

include "global.tbh"

'====================================================================
sub callback_dhcp_ok(renew as no_yes, interface as pl_sock_interfaces, byref ip as string, byref gateway_ip as string, byref netmask as string, lease_time as dword)
 dim f as byte

 #if NET_AVAILABLE
         if interface=PL_SOCK_INTERFACE_NET then
                 if renew=YES and net.ip<>ip then
                         'this is a lease renewal and the DHCP server has issues new IP
                         'it is better to reboot than deal with the implications of the changed IP
                         sys.reboot
                 end if

                 if net.ip<>ip then
                         'no need to close sockets -- this is definitely NOT a renewal an the DHCP lib
                         'has already closed all socket connections on this interface prior to setting
                         'the IP to 0.0.0.0
                         net.ip=ip
                         net.gatewayip=gateway_ip
                         net.netmask=netmask
                 end if
         end if
 #endif
end sub

'--------------------------------------------------------------------
sub callback_dhcp_failure(interface as pl_sock_interfaces,failure_code as en_dhcp_status_codes)
end sub

'--------------------------------------------------------------------
sub callback_dhcp_pre_clear_ip(interface as pl_sock_interfaces)
end sub

'--------------------------------------------------------------------
sub callback_dhcp_pre_buffrq(required_buff_pages as byte)
end sub

'--------------------------------------------------------------------
sub callback_dhcp_buff_released()
end sub