How big buffer should I supply to the DHCP_init() function?
I can see in the driver the following:
void DHCP_init(uint8_t s, uint8_t * buf)
{
uint8_t zeroip[4] = {0,0,0,0};
getSHAR(DHCP_CHADDR);
if((DHCP_CHADDR[0] | DHCP_CHADDR[1] | DHCP_CHADDR[2] | DHCP_CHADDR[3] | DHCP_CHADDR[4] | DHCP_CHADDR[5]) == 0x00)
{
// assing temporary mac address, you should be set SHAR before call this function.
DHCP_CHADDR[0] = 0x00;
DHCP_CHADDR[1] = 0x08;
DHCP_CHADDR[2] = 0xdc;
DHCP_CHADDR[3] = 0x00;
DHCP_CHADDR[4] = 0x00;
DHCP_CHADDR[5] = 0x00;
setSHAR(DHCP_CHADDR);
}
DHCP_SOCKET = s; // SOCK_DHCP
pDHCPMSG = (RIP_MSG*)buf;
DHCP_XID = 0x12345678;
// WIZchip Netinfo Clear
setSIPR(zeroip);
setSIPR(zeroip);
setGAR(zeroip);
reset_DHCP_timeout();
dhcp_state = STATE_DHCP_INIT;
}
and
/*
* @brief DHCP message format
*/
typedef struct {
uint8_t op; ///< @ref DHCP_BOOTREQUEST or @ref DHCP_BOOTREPLY
uint8_t htype; ///< @ref DHCP_HTYPE10MB or @ref DHCP_HTYPE100MB
uint8_t hlen; ///< @ref DHCP_HLENETHERNET
uint8_t hops; ///< @ref DHCP_HOPS
uint32_t xid; ///< @ref DHCP_XID This increase one every DHCP transaction.
uint16_t secs; ///< @ref DHCP_SECS
uint16_t flags; ///< @ref DHCP_FLAGSBROADCAST or @ref DHCP_FLAGSUNICAST
uint8_t ciaddr[4]; ///< @ref Request IP to DHCP sever
uint8_t yiaddr[4]; ///< @ref Offered IP from DHCP server
uint8_t siaddr[4]; ///< No use
uint8_t giaddr[4]; ///< No use
uint8_t chaddr[16]; ///< DHCP client 6bytes MAC address. Others is filled to zero
uint8_t sname[64]; ///< No use
uint8_t file[128]; ///< No use
uint8_t OPT[OPT_SIZE]; ///< Option
} RIP_MSG;
and
#define OPT_SIZE 312 /// Max OPT size of @ref RIP_MSG
#define RIP_MSG_SIZE (236+OPT_SIZE) /// Max size of @ref RIP_MSG
So 548 byte would be ok?