Step 1: Code Example for the Ethernet Interface

A warning note icon. This section is currently being reworked. We apologize for the inconvenience. If you need immediate assistance, please contact Tibbo Support.

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:

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.)---

A warning note icon. If you are compiling on one of the "W" platforms (that is, platforms with Wi-Fi), then you need to disable the wln. object, or this project won't compile. Go Project -> Settings -> Customize and set Wi-Fi (wln.) object to "Disabled".

And here is the code itself...

global.tbh:

							'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"
						

main.tbh:

							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
						

device.tbs:

							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
						