socket.c

开放源码实时操作系统源码.

            return;
        }    
        
        if (len < 0)
        {
            // There was an error reading from this socket. Play it safe and
            //  close it. This will force the client to generate a shutdown
            //  and we will read a len = 0 the next time around.
            shutdown(descr, SHUT_WR);
#if CYGOPT_NET_ATHTTPD_DEBUG_LEVEL > 0
            diag_printf("ERROR reading from socket. read() returned: %d\n", 
                        httpstate.inbuffer_len);
#endif    
            return;
        }  
    
        httpstate.inbuffer_len += len;
    }
    
    httpstate.inbuffer[httpstate.inbuffer_len] = '\0';

    // Timestamp the socket. 
    httpstate.sockets[index].timestamp = time(NULL);
        
    // This is where it all happens.
    cyg_httpd_process_method();
        
    if (httpstate.mode & CYG_HTTPD_MODE_CLOSE_CONN)
        // There are 2 cases we can be here:
        // 1) chunked frames close their connection by default
        // 2) The client requested the connection be terminated with a
        //     "Connection: close" in the header
        // In any case, we close the TX pipe and wait for the client to
        //  send us an EOF on the receive pipe. This is a more graceful way
        //  to handle the closing of the socket, compared to just calling
        //  close() without first asking the opinion of the client, and 
        //  running the risk of stray data lingering around.
        shutdown(descr, SHUT_WR);
}

void
cyg_httpd_handle_new_connection(cyg_int32 listener)
{
    cyg_int32 i;

    int fd_client = accept(listener, NULL, NULL);
    CYG_ASSERT(listener != -1, "accept() failed");
    if (fd_client == -1) 
        return;
    
#if CYGOPT_NET_ATHTTPD_DEBUG_LEVEL > 0
    diag_printf("Opening descriptor: %d\n", fd_client);
#endif    
    // Timestamp the socket and process the frame immediately, since the accept
    //  guarantees the presence of valid data on the newly opened socket.
    for (i = 0; i < CYGPKG_NET_MAXSOCKETS; i++)
        if (httpstate.sockets[i].descriptor == 0)
        {
            httpstate.sockets[i].descriptor = fd_client;
            httpstate.sockets[i].timestamp  = time(NULL);
            cyg_httpd_process_request(i);
            return;
        }    
}

// This is the "garbage collector" (or better, the "garbage disposer") of
//  the server. It closes any socket that has been idle for a time period
//  of CYG_HTTPD_SELECT_TIMEOUT seconds.
void
cyg_httpd_close_unused_sockets(cyg_int32 listener)
{
    cyg_int32 i;
    
#if CYGOPT_NET_ATHTTPD_DEBUG_LEVEL > 0
    diag_printf("Garbage collector called\r\n");
#endif    
    httpstate.fdmax = listener;
    for (i = 0; i < CYGPKG_NET_MAXSOCKETS; i++)
    {
        if (httpstate.sockets[i].descriptor != 0)
        {
            if (time(NULL) - httpstate.sockets[i].timestamp > 
                                          CYG_HTTPD_SOCKET_IDLE_TIMEOUT)
            {           
#if CYGOPT_NET_ATHTTPD_DEBUG_LEVEL > 0
                diag_printf("Closing descriptor: %d\n", 
                            httpstate.sockets[i].descriptor);
#endif    
                shutdown(httpstate.sockets[i].descriptor, SHUT_WR);
            }
            else
                httpstate.fdmax = MAX(httpstate.fdmax, 
                                      httpstate.sockets[i].descriptor);
        }                              
    }
}

void
cyg_httpd_daemon(cyg_addrword_t data)
{
    cyg_int32 rc;
    init_all_network_interfaces();

#if CYGOPT_NET_ATHTTPD_DEBUG_LEVEL > 0
#ifdef CYGHWR_NET_DRIVER_ETH0
    if (eth0_up)
    {
        struct bootp* bps = &eth0_bootp_data;
        diag_printf("ETH0 is up. IP address: %s\n", inet_ntoa(bps->bp_yiaddr));
    }
#endif
#endif

#ifdef CYGOPT_NET_ATHTTPD_USE_CGIBIN_TCL
    cyg_httpd_init_tcl_interpreter();
#if CYGOPT_NET_ATHTTPD_DEBUG_LEVEL > 0
    diag_printf("Tcl interpreter has been initialized...\n");
#endif
#endif    
    
    cyg_httpd_initialize();

    // Get the network going. This is benign if the application has
    //  already done this.
    cyg_int32 listener = socket(AF_INET, SOCK_STREAM, 0);
    CYG_ASSERT(listener > 0, "Socket create failed");
    if (listener < 0)
        return;

    cyg_int32 yes = 1;
    rc = setsockopt(listener, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));
    if (rc == -1) 
        return;
    
    memset(&(httpstate.server_conn), 0, sizeof(struct sockaddr_in));
    httpstate.server_conn.sin_family = AF_INET;
    httpstate.server_conn.sin_addr.s_addr = INADDR_ANY;
    httpstate.server_conn.sin_port = htons(CYGNUM_NET_ATHTTPD_SERVEROPT_PORT);
    rc = bind(listener,
              (struct sockaddr *)&httpstate.server_conn, 
              sizeof(struct sockaddr)); 
    CYG_ASSERT(rc == 0, "bind() returned error");
    if (rc != 0)
        return;

    rc = listen(listener, SOMAXCONN);
    CYG_ASSERT(rc == 0, "listen() returned error");
    if (rc != 0)
        return;

#if CYGOPT_NET_ATHTTPD_DEBUG_LEVEL > 0
    diag_printf("Web server Started and listening...\n");
#endif
    cyg_int32 i;
    for (i = 0; i < CYGNUM_FILEIO_NFILE; i++)
    {
        httpstate.sockets[i].descriptor  = 0;
        httpstate.sockets[i].timestamp   = (time_t)0;
    }
    
    FD_ZERO(&httpstate.rfds);
    httpstate.fdmax = listener;
    while (1)
    {
        // The listener is always added to the select() sensitivity list.
        FD_SET(listener, &httpstate.rfds); 
        struct timeval tv = {CYG_HTTPD_SOCKET_IDLE_TIMEOUT, 0};
        rc = select(httpstate.fdmax + 1, &httpstate.rfds, NULL, NULL, &tv);
        if (rc > 0)
        {
            if (FD_ISSET(listener, &httpstate.rfds))
                // If the request is from the listener socket, then 
                //  this must be a new connection.
                cyg_httpd_handle_new_connection(listener);

            httpstate.fdmax = listener;
            
            // The sensitivity list returned by select() can have multiple
            //  socket descriptors that need service. Loop through the whole
            //  descriptor list to see if one or more need to be served.
            for (i = 0; i < CYGPKG_NET_MAXSOCKETS; i ++)
            {
                cyg_int32 descr = httpstate.sockets[i].descriptor;
                if (descr != 0)
                {
                    // If the descriptor is set in the descriptor list, we
                    //  service it. Otherwise, we add it to the descriptor list
                    //  to listen for. The rfds list gets rewritten each time
                    //  select() is called and after the call it contains only
                    //  the descriptors that need be serviced. Before calling
                    //  select() again we must repopulate the list with all the
                    //  descriptors that must be listened for.
                    if (FD_ISSET(descr, &httpstate.rfds))
                        cyg_httpd_process_request(i);
                    else       
                        FD_SET(descr, &httpstate.rfds); 
                    if (httpstate.sockets[i].descriptor != 0)
                        httpstate.fdmax = MAX(httpstate.fdmax, descr);
                }
            }
        }
        else if (rc == 0)
        {
            cyg_httpd_close_unused_sockets(listener);
        }
        else
        {
#if CYGOPT_NET_ATHTTPD_DEBUG_LEVEL > 0
            cyg_int8 *ptr = (cyg_int8*)&httpstate.rfds;
            diag_printf("rfds: %x %x %x %x\n", ptr[0], ptr[1], ptr[2], ptr[3] );
            for (i = 0; i < CYGPKG_NET_MAXSOCKETS; i++)
                if (httpstate.sockets[i].descriptor != 0)
                     diag_printf("Socket in list: %d\n", 
                                 httpstate.sockets[i].descriptor);
#endif                                 
            CYG_ASSERT(rc != -1, "Error during select()");                 
        }
    }
}

void
cyg_httpd_start(void)
{
    if (cyg_httpd_initialized)
        return;
    cyg_httpd_initialized = 1;
    
    cyg_thread_create(CYGNUM_NET_ATHTTPD_THREADOPT_PRIORITY,
                      cyg_httpd_daemon,
                      (cyg_addrword_t)0,
                      "HTTPD Thread",
                      (void *)cyg_httpd_thread_stack,
                      CYG_HTTPD_DAEMON_STACK_SIZE,
                      &cyg_httpd_thread_handle,
                      &cyg_httpd_thread_object);
    cyg_thread_resume(cyg_httpd_thread_handle);
}