Chapter 2 - Installation and Use of NetX Duo POP3 Client

/*
   demo_netxduo_pop3.c

   This is a small demo of POP3 Client on the NetX Duo TCP/IP stack.
   This demo relies on Thread, NetX Duo and POP3 Client API to conduct
   a POP3 mail session.
 */

#include  "tx_api.h"
#include  "nx_api.h"
#include  "nxd_pop3_client.h"

#define DEMO_STACK_SIZE             4096
#define CLIENT_ADDRESS              IP_ADDRESS(192,2,2,61)
#define SERVER_ADDRESS              IP_ADDRESS(192,2,2,89)
#define SERVER_PORT                 110

/* Replace the 'ram' driver with your own Ethernet driver. */
void    _nx_ram_network_driver(struct NX_IP_DRIVER_STRUCT *driver_req);

/* Set up the POP3 Client.  */

TX_THREAD           demo_client_thread;
NX_POP3_CLIENT      demo_client;
NX_PACKET_POOL      client_packet_pool;
NX_IP               client_ip;

#define PAYLOAD_SIZE 500

/* Set up Client thread entry point. */
void    demo_thread_entry(ULONG info);


  /* Shared secret is the same as password. */

#define LOCALHOST                               "recipient@domain.com"
#define LOCALHOST_PASSWORD                      "testpwd"

/* Define main entry point.  */
int main()
{
    /* Enter the ThreadX kernel.  */
    tx_kernel_enter();
}

/* Define what the initial system looks like.  */
void    tx_application_define(void *first_unused_memory)
{

    UINT     status;
    UCHAR    *free_memory_pointer;


    /* Setup the working pointer.  */
    free_memory_pointer =  first_unused_memory;

    /* Create a client thread.  */
    tx_thread_create(&demo_client_thread, "Client", demo_thread_entry, 0,
                     free_memory_pointer, DEMO_STACK_SIZE, 1, 1,
                     TX_NO_TIME_SLICE, TX_AUTO_START);

    free_memory_pointer =  free_memory_pointer + DEMO_STACK_SIZE;

    /* Initialize the NetX system.  */
    nx_system_initialize();

    /* The demo client username and password is the authentication
       data used when the server attempts to authentication the client. */

    /* Create Client packet pool. */
    status =  nx_packet_pool_create(&client_packet_pool,"POP3 Client Packet Pool",
                                    PAYLOAD_SIZE, free_memory_pointer,
                                    (PAYLOAD_SIZE * 10));
    if (status != NX_SUCCESS)
    {
        return;
    }

    /* Update pointer to unallocated (free) memory. */
    free_memory_pointer = free_memory_pointer + (PAYLOAD_SIZE * 10);


    /* Create IP instance for demo Client */
    status = nx_ip_create(&client_ip, "POP3 Client IP Instance",
                          CLIENT_ADDRESS, 0xFFFFFF00UL, &client_packet_pool,
                          _nx_ram_network_driver, free_memory_pointer,
                          2048, 1);

    if (status != NX_SUCCESS)
    {
        return;
    }

    /* Update pointer to unallocated (free) memory. */
    free_memory_pointer =  free_memory_pointer + 2048;

    /* Enable ARP and supply ARP cache memory. */
    nx_arp_enable(&client_ip, (void **) free_memory_pointer, 1024);

    /* Update pointer to unallocated (free) memory. */
    free_memory_pointer = free_memory_pointer + 1024;

    /* Enable TCP and ICMP for Client IP. */
    nx_tcp_enable(&client_ip);
    nx_icmp_enable(&client_ip);

    return;
}



/* Define the application thread entry function. */

void    demo_thread_entry(ULONG info)
{

    UINT        status;
    UINT        mail_item, number_mail_items;
    UINT        bytes_downloaded = 0;
    UINT        final_packet = NX_FALSE;
    ULONG       total_size, mail_item_size, bytes_retrieved;
    NX_PACKET   *packet_ptr;

    /* Let the IP instance get initialized with driver parameters. */
    tx_thread_sleep(40);


    /* Create a NetX POP3 Client instance with no byte or block memory pools.
       Note that it uses its password for its APOP shared secret. */
    status =  nx_pop3_client_create(&demo_client,
                                    NX_TRUE,
                                    &client_ip, &client_packet_pool, SERVER_ADDRESS,
                                    SERVER_PORT, LOCALHOST, LOCALHOST_PASSWORD);

    /* Check for error. */
    if (status != NX_SUCCESS)
    {

        status = nx_pop3_client_delete(&demo_client);

        /* Abort. */
        return;
    }

    /* Find out how many items are in our mailbox.  */
    status = nx_pop3_client_mail_items_get(&demo_client, &number_mail_items,
                                            &total_size);

    printf("Got %d mail items, total size%d \n", number_mail_items, total_size);

    /* If nothing in the mailbox, disconnect. */
    if (number_mail_items == 0)
    {

        nx_pop3_client_delete(&demo_client);

        return;
    }

    /* Download all mail items.  */
    mail_item = 1;

    while (mail_item <= number_mail_items)
    {


        /* This submits a RETR request and gets the mail message size. */
        status = nx_pop3_client_mail_item_get(&demo_client, mail_item,
                                               &mail_item_size);

        /* Loop to get all mail message packets until the mail item is completely
           downloaded. */
        while((final_packet ==  NX_FALSE) && (status == NX_SUCCESS))
        {

            status = nx_pop3_client_mail_item_message_get(&demo_client, &packet_ptr,
                                                        &bytes_retrieved,
                                                        &final_packet);

            if (status != NX_SUCCESS)
            {

                break;
            }

            if (bytes_retrieved != 0)
            {

                printf("Received %d bytes of data for item %d: %s\n",
                        packet_ptr -> nx_packet_length,
                        mail_item, packet_ptr -> nx_packet_prepend_ptr);
            }

            nx_packet_release(packet_ptr);

            /* Determine if this is the last data packet. */
            if (final_packet)
            {
                /* It is. Let the server know it can delete this mail item. */
                status = nx_pop3_client_mail_item_delete(&demo_client, mail_item);
            }

            /* Keep track of how much mail message data is left. */
            bytes_downloaded += bytes_retrieved;
        }

        /* Get the next mail item. */
        mail_item++;

        tx_thread_sleep(100);

    }

    /* Disconnect from the POP3 server. */
    status = nx_pop3_client_quit(&demo_client);

    /* Delete the POP3 Client.  This will not delete the Client packet pool. */
    status = nx_pop3_client_delete(&demo_client);

}