Diff: DHCPClient.cpp

Revision:

0:61831b843b44

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DHCPClient.cpp	Sat Apr 14 17:21:11 2012 +0000
@@ -0,0 +1,151 @@
+// DHCPClient.cpp 2012/4/14
+// DHCP Client for WIZ820io(W5200)
+#include "mbed.h"
+#include "w5100.h"
+#include "UDPSocket.h"
+#include "DHCPClient.h"
+
+//#define DEBUG
+
+#ifdef DEBUG
+#include "Utils.h"
+#define PRINT_FUNC() printf("%p %d:%s\n", this,__LINE__,__PRETTY_FUNCTION__)
+#else //DEBUG
+#define PRINT_FUNC()
+#endif //DEBUG
+
+int DHCPClient::discover(uint8_t buf[], int size) {
+    memset(buf, 0x00, size);
+    const uint8_t headers[] = {0x01,0x01,0x06,0x00,
+                               0x12,0x34,0x56,0x78}; // xid
+    memcpy(buf, headers, sizeof(headers));
+    int t = clock();
+    xid[0] = t<<24;
+    xid[1] = t<<16;
+    xid[2] = t<<8;
+    xid[3] = t;
+    memcpy(buf+DHCP_OFFSET_XID, xid, 4);
+    W5100.getMACAddress(buf+DHCP_OFFSET_CHADDR);
+    const uint8_t options[] = {0x63,0x82,0x53,0x63, // magic cookie
+                               0x35,0x01,0x01, // DHCP DISCOVER
+                               0xff};
+    memcpy(buf+DHCP_OFFSET_MAGIC_COOKIE, options, sizeof(options));
+    uint8_t ip[4] = {0,0,0,0};
+    W5100.setIPAddress(ip);
+    return DHCP_OFFSET_MAGIC_COOKIE + sizeof(options);
+}
+
+int DHCPClient::request(uint8_t buf[], int size) {
+    memset(buf, 0x00, size);
+    const uint8_t headers[] = {0x01,0x01,0x06,0x00,
+                               0x12,0x34,0x56,0x78}; // xid
+    memcpy(buf, headers, sizeof(headers));
+    memcpy(buf+DHCP_OFFSET_XID, xid, 4);
+    memcpy(buf+DHCP_OFFSET_YIADDR, yiaddr, 4);
+    W5100.getMACAddress(buf+DHCP_OFFSET_CHADDR);
+    const uint8_t options[] = {0x63,0x82,0x53,0x63, // magic cookie
+                               0x35,0x01,0x03, // DHCP REQUEST
+                               0x32,0x04,0x00,0x00,0x00,0x00, // request IP
+                               0xff};
+    memcpy(buf+DHCP_OFFSET_MAGIC_COOKIE, options, sizeof(options));
+    memcpy(buf+DHCP_OFFSET_MAGIC_COOKIE+9, yiaddr, 4);
+    return DHCP_OFFSET_MAGIC_COOKIE + sizeof(options);
+}
+
+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 DEBUG           
+        char codeStr[24];
+        snprintf(codeStr, sizeof(codeStr), "DHCP option: %d", code);
+        printfBytes(codeStr, p, len);
+#endif //DEBUG
+        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;
+}
+
+bool DHCPClient::verify(uint8_t buf[], int len) {
+    if (len < DHCP_OFFSET_OPTIONS) {
+        return false;
+    }
+    if (buf[DHCP_OFFSET_OP] != 0x02) {
+        return false;
+    }
+    if (memcmp(buf+DHCP_OFFSET_XID, xid, 4) != 0) {
+        return false;
+    }
+    return true;
+}
+
+void DHCPClient::callback(UDPSocketEvent e)
+{
+    PRINT_FUNC();
+    uint8_t buf[DHCP_MAX_PACKET_SIZE];
+    Host host;
+    int len = m_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
+        m_udp->sendto((char*)buf, 300, &server);
+    } else if (r == 5) { // ACK
+        exit_flag = true;
+    }
+}
+
+int DHCPClient::setup(int timeout_ms)
+{
+    PRINT_FUNC();   
+    Timer t;
+    t.start();
+    m_udp = new UDPSocket;
+    m_udp->setOnEvent(this, &DHCPClient::callback);
+    Host local(IpAddr(0,0,0,0), 68);
+    Host server(IpAddr(255,255,255,255), 67); // DHCP broadcast
+    m_udp->bind(local);
+    uint8_t buf[300];
+    discover(buf, sizeof(buf));
+    m_udp->sendto((char*)buf, sizeof(buf), &server);
+    exit_flag = false;
+    int err = 0;
+    while(1) {
+        Net::poll();
+        if (exit_flag) {
+            break;
+        }
+        if (t.read_ms() > timeout_ms) {
+            err = -1;
+            break;
+        }
+#ifdef DEBUG            
+        wait_ms(500);
+#endif //DEBUG
+    }
+    delete m_udp;
+    return err;
+}
+
+DHCPClient::DHCPClient() {
+    m_udp = NULL;
+}