Diff: network.cpp

Revision:

0:1a61c61d0845

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/network.cpp	Tue Apr 03 18:43:13 2012 +0000
@@ -0,0 +1,250 @@
+/* Copyright 2011 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Implementation of core lwIP ethernet functionality. */
+#include <mbed.h>
+#include "lwip/init.h"
+#include "lwip/tcp_impl.h"
+#include "lwip/dns.h"
+#include "netif/etharp.h"
+#include "drv/eth/eth_drv.h"
+#include "network.h"
+#include "debug.h"
+
+
+/* Initializes the network stack.
+
+   NOTE: Using DHCP to supply the IP addresses is the only supported scenario
+         in this sample.
+   
+   Parameters:
+    pNetwork is a pointer to the network object to be initialized.
+    pIPAddress is a pointer to the string which specifies the static IP address
+        of this node.  Set to NULL for DHCP.
+    pSubnetMask is a pointer to the string which specifies the subnet mask for
+        static IP addresses.  Set to NULL for DHCP.
+    pGatewayAddress is a pointer to the string which specifies the static 
+        gateway IP address.  Set to NULL for DHCP.
+    pHostName is the host name to be used for representing this device to the
+        DHCP server.
+    
+   Returns:
+    0 on success and a positive error code otherwise.
+*/
+int SNetwork_Init(SNetwork*   pNetwork,
+                  const char* pIPAddress,
+                  const char* pSubnetMask,
+                  const char* pGatewayAddress,
+                  const char* pHostName)
+{
+    int         Return = 1;
+    netif*      pAddResult = NULL;
+    ip_addr_t   IpAddress;
+    ip_addr_t   NetMask;
+    ip_addr_t   GatewayAddress;
+    Timer       Timeout;
+
+    // Must specify a network object to be initialized.
+    assert ( pNetwork );
+    
+    // Clear out the network object and fill it in during the initialization
+    // process.
+    memset(pNetwork, 0, sizeof(*pNetwork));
+    
+    // Initialize the lwIP network stack.
+    lwip_init();
+    
+    // Set the initial IP addresses for the ethernet interface based on whether
+    // DHCP is to be used or not.
+    if (pIPAddress)
+    {
+        // For static IP, all strings must be set.
+        assert ( pSubnetMask && pGatewayAddress );
+        
+        ip4_addr_set_u32(&IpAddress,      ipaddr_addr(pIPAddress));
+        ip4_addr_set_u32(&NetMask,        ipaddr_addr(pSubnetMask));
+        ip4_addr_set_u32(&GatewayAddress, ipaddr_addr(pGatewayAddress));
+    }
+    else
+    {
+        // For DHCP, all strings must be NULL.
+        assert ( !pSubnetMask && !pGatewayAddress );
+
+        // Clear the IP addresses and use DHCP instead.
+        ip_addr_set_zero(&IpAddress);
+        ip_addr_set_zero(&NetMask);
+        ip_addr_set_zero(&GatewayAddress);
+    }
+    
+    // Obtain the MAC address for the Ethernet device.
+    // NOTE: This should really be done in eth_init()
+    pNetwork->EthernetInterface.hwaddr_len = ETHARP_HWADDR_LEN;
+    eth_address((char *)pNetwork->EthernetInterface.hwaddr);    
+    
+    // Connect the LPC17xx ethernet driver into the lwIP stack.
+    pAddResult = netif_add(&pNetwork->EthernetInterface, 
+                           &IpAddress, 
+                           &NetMask, 
+                           &GatewayAddress, 
+                           NULL, 
+                           eth_init, 
+                           ethernet_input);
+    if (!pAddResult)
+    {
+        printf("error: Failed to add ethernet interface to lwIP.\r\n");
+        goto Error;
+    }
+    netif_set_default(&pNetwork->EthernetInterface);
+    
+    // Start the required timers.
+    pNetwork->ARP.start();
+    pNetwork->DHCPCoarse.start();
+    pNetwork->DHCPFine.start();
+    pNetwork->TCP.start();
+    pNetwork->DNS.start();
+
+    if (pIPAddress)
+    {
+        // Start the ethernet interface up with the static IP address.
+        netif_set_up(&pNetwork->EthernetInterface);
+    }
+    else
+    {
+        err_t StartResult;
+        
+        // Start the DHCP request.
+        pNetwork->EthernetInterface.hostname = (char*)pHostName;
+        dhcp_set_struct(&pNetwork->EthernetInterface, &pNetwork->DHCP);
+        StartResult = dhcp_start(&pNetwork->EthernetInterface);
+        if (ERR_OK != StartResult)
+        {
+            printf("error: Failed to start DHCP service.\r\n");
+            goto Error;
+        }
+    }
+
+    // Wait for network to startup.
+    Timeout.start();
+    printf("Waiting for network...\r\n");
+
+    // Wait until interface is up
+    while (!netif_is_up(&pNetwork->EthernetInterface)) 
+    {
+        SNetwork_Poll(pNetwork);
+
+        // Stop program if we get a timeout on DHCP attempt.
+        if (Timeout.read_ms() > 10000) 
+        {
+            printf("error: Timeout while waiting for network to initialize.\r\n");
+            goto Error;
+        }
+    }
+
+    // Print out the DHCP provided IP addresses.
+    printf("IP     : "); 
+    SNetwork_PrintAddress(&pNetwork->EthernetInterface.ip_addr);
+    printf("\r\n");
+
+    printf("Gateway: "); 
+    SNetwork_PrintAddress(&pNetwork->EthernetInterface.gw);
+    printf("\r\n");
+
+    printf("Mask   : "); 
+    SNetwork_PrintAddress(&pNetwork->EthernetInterface.netmask);
+    printf("\r\n");
+    
+    Return = 0;
+Error:
+    return Return;
+}
+
+
+/* Called from within the main application loop to perform network maintenance
+   tasks at appropriate time intervals and execute the ethernet driver which 
+   will push new network packets into the lwIP stack.  lwIP will then call into
+   the callbacks which have been configured by this application.
+   
+   Parameters:
+    pNetwork is a pointer to the intitialized network object.
+    
+   Returns:
+    Number of network tasks run during this polling process.  If 0 then no
+        network related tasks were completed during this polling iteration.
+*/
+int SNetwork_Poll(SNetwork* pNetwork)
+{
+    int TasksRun = 0;
+    
+    // Validate parameters.
+    assert ( pNetwork );
+    
+    // Execute timed maintenance tasks.
+    if (pNetwork->DHCPFine.read_ms() >= DHCP_FINE_TIMER_MSECS)
+    {
+        pNetwork->DHCPFine.reset();
+        dhcp_fine_tmr();
+        TasksRun++;
+    }
+    if (pNetwork->DHCPCoarse.read() >= DHCP_COARSE_TIMER_SECS)
+    {
+        pNetwork->DHCPCoarse.reset();
+        dhcp_coarse_tmr();
+        TasksRun++;
+    }
+    if (pNetwork->ARP.read_ms() >= ARP_TMR_INTERVAL)
+    {
+        pNetwork->ARP.reset();
+        etharp_tmr();
+        TasksRun++;
+    }
+    if (pNetwork->TCP.read_ms() >= TCP_TMR_INTERVAL)
+    {
+        pNetwork->TCP.reset();
+        tcp_tmr();
+        TasksRun++;
+    }
+    if (pNetwork->DNS.read_ms() >= DNS_TMR_INTERVAL)
+    {
+        pNetwork->DNS.reset();
+        dns_tmr();
+        TasksRun++;
+    }
+
+    // Poll the ethernet driver to let it pull packets in and push new packets
+    // into the lwIP network stack.
+    TasksRun += eth_poll();
+    
+    return TasksRun;
+}
+
+
+/* Prints out the caller supplied IP address.
+
+   Parameters:
+    pAddress is a pointer to the ip4 address to be displayed.
+    
+   Returns:
+    Nothing.
+*/
+void SNetwork_PrintAddress(ip_addr_t* pAddress)
+{
+    // Validate parameters.
+    assert ( pAddress );
+    
+    printf("%d.%d.%d.%d", 
+           ip4_addr1(pAddress),
+           ip4_addr2(pAddress),
+           ip4_addr3(pAddress),
+           ip4_addr4(pAddress));
+}