/* 
   DHCP.H  Edition: 1.00  Last changed: 08/Aug/2003

   Link: TCPIP.lib 2003/05/29 or later
   
   DHCP.H: Include file definitions for DHCP server

* * * * * * * * * * * * * * * * * * * * * * * * *
**
** MODIFICATION HISTORY
**
** 08/Aug/2003  Creation by Sean
**
* * * * * * * * * * * * * * * * * * * * * * * * * */


/* Maximum delay in DHCP client retry loop (Not time) */
#define MAXDELAY 1000  
// selectsock timeout is 6 ms ,Total timeout is about 1000* (6+1.5)=7500ms (1.2 ms means the process time of the other functions)

#define NTRACE 4
//Print debug message 

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
**
** DHCP_Get: User routine to get DHCP bootload information
**
** int DHCP_Get(int netno, unsigned long lease)
**
** PARAMETERS: 
**    (in) netno: index into network configuration table 
**				  1~32 defined on the #define NCONNS 32 in the TCPIP.h		
**    (in) lease: desired length of lease (The time is in units of seconds)
** 
** DESCRIPTION: 
**    DHCP_Get contacts a DHCP server to obtain an IP address and other
**    network parameters for a host. Note that this client does not 
**    automatically obtain configuration parameters (such as network
**    mask, DNS server, etc) other than the IP address.
**    
** RETURNS:
**    < 0:  Error given by error code
**      0:  No action needed (lease doesn't need renewing)
**    > 0:  IP address allocated or renewed
**
** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
int             DHCP_Get(int netno, unsigned long lease);

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 
**
** DHCPrelease: User-called routine to release IP address
**
** int DHCPrelease(int netno)
**
** PARAMETERS: 
**    (in) netno: index into network configuration table
** 
** DESCRIPTION: 
**     DHCPrelease() sends a message to a DHCP server to release
**     the currently held client IP address. There is no response
**     to this message; so there is no guarantee that the server
**     actually receives the release. Note that the release is 
**     unicast to the DHCP server which originally handed out the
**     client's IP address.
**    
** RETURNS:
**    < 0:  Error given by error code
**      0:  DHCP server not stored in network configuration structure
**    > 0:  IP address released
**
** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
int             DHCP_Release(int netno);