File content as of revision 0:db4242c89949:

// DHCPClient.cpp 2012/4/10
// DHCP Client for WIZ820io(W5200)
#include "mbed.h"
#include "MyEthernetNetIf.h"
#include "MyUDPSocket.h"
#include "DHCPClient.h"
#ifdef DEBUG
#include "Utils.h"
#endif //DEBUG

static DHCPClient* _g_dhcp;
static void _DHCP_OnEvent(UDPSocketEvent e)
{
    _g_dhcp->callback(e);
}

int DHCPClient::offer_ack(uint8_t buf[], int size) {
    memcpy(yiaddr, &buf[DHCP_OFFSET_YIADDR], 4);   
    uint8_t *p;
    int msg_type = -1;
    p = buf + DHCP_OFFSET_OPTIONS;
    while(*p != 0xff && p < (uint8_t*)&buf[DHCP_MAX_PACKET_SIZE]) {
        int code = *p++;
        if (code == 0x00) {
            continue;
        }
        int len = *p++;
#ifdef DHCP_VERBOSE           
        char codeStr[24];
        snprintf(codeStr, sizeof(codeStr), "DHCP option: %d", code);
        printfBytes(codeStr, p, len);
#endif //DHCP_VERBOSE
        if (code == 53) {
           msg_type = *p;
        } else if (code == 1) {
            memcpy(netmask, p, 4); // Subnet mask address
        } else if (code == 3) {
            memcpy(gateway, p, 4); // Gateway IP address 
        } else if (code == 6) {// DNS
            memcpy(dnsaddr, p, 4);
        }
        p += len;
    }
    return msg_type;
}

void DHCPClient::callback(UDPSocketEvent e)
{
    PRINT_FUNC();
    uint8_t buf[DHCP_MAX_PACKET_SIZE];
    Host host;
    int len = p_udp->recvfrom((char*)buf, sizeof(buf), &host);
    if (!verify(buf, len)) {
        return;
    }
    int r = offer_ack(buf, len);
    if (r == 2) { // OFFER
        request(buf, 300);
        Host server(IpAddr(255,255,255,255), 67); // DHCP broadcast
        p_udp->sendto((char*)buf, 300, &server);
    } else if (r == 5) { // ACK
        exit_flag = true;
    }
}

int DHCPClient::setup(int timeout_ms)
{
    Timer t;
    t.start();
    p_udp = new MyUDPSocket;
    p_udp->setOnEvent(_DHCP_OnEvent);
    Host local(IpAddr(0,0,0,0), 68);
    Host server(IpAddr(255,255,255,255), 67); // DHCP broadcast
    p_udp->bind(local);
    uint8_t buf[300];
    discover(buf, sizeof(buf));
    p_udp->sendto((char*)buf, sizeof(buf), &server);
    exit_flag = false;
    int err = 0;
    while(1) {
        p_udp->poll();
        if (exit_flag) {
            break;
        }
        if (t.read_ms() > timeout_ms) {
            err = -1;
            break;
        }
#ifdef DEBUG            
        wait_ms(100);
#endif //DEBUG
    }
    delete p_udp;
    return err;
}

DHCPClient::DHCPClient()
{
    _g_dhcp = this;
}