tap-win32.c

qemu虚拟机代码

/*
 *  TAP-Win32 -- A kernel driver to provide virtual tap device functionality
 *               on Windows.  Originally derived from the CIPE-Win32
 *               project by Damion K. Wilson, with extensive modifications by
 *               James Yonan.
 *
 *  All source code which derives from the CIPE-Win32 project is
 *  Copyright (C) Damion K. Wilson, 2003, and is released under the
 *  GPL version 2 (see below).
 *
 *  All other source code is Copyright (C) James Yonan, 2003-2004,
 *  and is released under the GPL version 2 (see below).
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program (see the file COPYING included with this
 *  distribution); if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include "vl.h"
#include <stdio.h>
#include <windows.h>

/* NOTE: PCIBus is redefined in winddk.h */
#define PCIBus _PCIBus
#include <ddk/ntapi.h>
#include <ddk/winddk.h>
#include <ddk/ntddk.h>
#undef PCIBus

//=============
// TAP IOCTLs
//=============

#define TAP_CONTROL_CODE(request,method) \
  CTL_CODE (FILE_DEVICE_UNKNOWN, request, method, FILE_ANY_ACCESS)

#define TAP_IOCTL_GET_MAC               TAP_CONTROL_CODE (1, METHOD_BUFFERED)
#define TAP_IOCTL_GET_VERSION           TAP_CONTROL_CODE (2, METHOD_BUFFERED)
#define TAP_IOCTL_GET_MTU               TAP_CONTROL_CODE (3, METHOD_BUFFERED)
#define TAP_IOCTL_GET_INFO              TAP_CONTROL_CODE (4, METHOD_BUFFERED)
#define TAP_IOCTL_CONFIG_POINT_TO_POINT TAP_CONTROL_CODE (5, METHOD_BUFFERED)
#define TAP_IOCTL_SET_MEDIA_STATUS      TAP_CONTROL_CODE (6, METHOD_BUFFERED)
#define TAP_IOCTL_CONFIG_DHCP_MASQ      TAP_CONTROL_CODE (7, METHOD_BUFFERED)
#define TAP_IOCTL_GET_LOG_LINE          TAP_CONTROL_CODE (8, METHOD_BUFFERED)
#define TAP_IOCTL_CONFIG_DHCP_SET_OPT   TAP_CONTROL_CODE (9, METHOD_BUFFERED)

//=================
// Registry keys
//=================

#define ADAPTER_KEY "SYSTEM\\CurrentControlSet\\Control\\Class\\{4D36E972-E325-11CE-BFC1-08002BE10318}"

#define NETWORK_CONNECTIONS_KEY "SYSTEM\\CurrentControlSet\\Control\\Network\\{4D36E972-E325-11CE-BFC1-08002BE10318}"

//======================
// Filesystem prefixes
//======================

#define USERMODEDEVICEDIR "\\\\.\\Global\\"
#define TAPSUFFIX         ".tap"


//======================
// Compile time configuration
//======================

//#define DEBUG_TAP_WIN32 1

#define TUN_ASYNCHRONOUS_WRITES 1

#define TUN_BUFFER_SIZE 1560
#define TUN_MAX_BUFFER_COUNT 32

/*
 * The data member "buffer" must be the first element in the tun_buffer
 * structure. See the function, tap_win32_free_buffer.
 */
typedef struct tun_buffer_s {
    unsigned char buffer [TUN_BUFFER_SIZE];
    unsigned long read_size;
    struct tun_buffer_s* next;
} tun_buffer_t;

typedef struct tap_win32_overlapped {
    HANDLE handle;
    HANDLE read_event;
    HANDLE write_event;
    HANDLE output_queue_semaphore;
    HANDLE free_list_semaphore;
    CRITICAL_SECTION output_queue_cs;
    CRITICAL_SECTION free_list_cs;
    OVERLAPPED read_overlapped;
    OVERLAPPED write_overlapped;
    tun_buffer_t buffers[TUN_MAX_BUFFER_COUNT];
    tun_buffer_t* free_list;
    tun_buffer_t* output_queue_front;
    tun_buffer_t* output_queue_back;
} tap_win32_overlapped_t;

static tap_win32_overlapped_t tap_overlapped;

static tun_buffer_t* get_buffer_from_free_list(tap_win32_overlapped_t* const overlapped) 
{
    tun_buffer_t* buffer = NULL;
    WaitForSingleObject(overlapped->free_list_semaphore, INFINITE);
    EnterCriticalSection(&overlapped->free_list_cs);
    buffer = overlapped->free_list;
//    assert(buffer != NULL);
    overlapped->free_list = buffer->next;
    LeaveCriticalSection(&overlapped->free_list_cs);
    buffer->next = NULL;
    return buffer;
}

static void put_buffer_on_free_list(tap_win32_overlapped_t* const overlapped, tun_buffer_t* const buffer)
{
    EnterCriticalSection(&overlapped->free_list_cs);
    buffer->next = overlapped->free_list;
    overlapped->free_list = buffer;
    LeaveCriticalSection(&overlapped->free_list_cs);
    ReleaseSemaphore(overlapped->free_list_semaphore, 1, NULL);
}

static tun_buffer_t* get_buffer_from_output_queue(tap_win32_overlapped_t* const overlapped, const int block) 
{
    tun_buffer_t* buffer = NULL;
    DWORD result, timeout = block ? INFINITE : 0L;

    // Non-blocking call
    result = WaitForSingleObject(overlapped->output_queue_semaphore, timeout); 

    switch (result) 
    { 
        // The semaphore object was signaled.
        case WAIT_OBJECT_0: 
            EnterCriticalSection(&overlapped->output_queue_cs);

            buffer = overlapped->output_queue_front;
            overlapped->output_queue_front = buffer->next;

            if(overlapped->output_queue_front == NULL) {
                overlapped->output_queue_back = NULL;
            }

            LeaveCriticalSection(&overlapped->output_queue_cs);
            break; 

        // Semaphore was nonsignaled, so a time-out occurred.
        case WAIT_TIMEOUT: 
            // Cannot open another window.
            break; 
    }

    return buffer;
}

static tun_buffer_t* get_buffer_from_output_queue_immediate (tap_win32_overlapped_t* const overlapped) 
{
    return get_buffer_from_output_queue(overlapped, 0);
}

static void put_buffer_on_output_queue(tap_win32_overlapped_t* const overlapped, tun_buffer_t* const buffer)
{
    EnterCriticalSection(&overlapped->output_queue_cs);

    if(overlapped->output_queue_front == NULL && overlapped->output_queue_back == NULL) {
        overlapped->output_queue_front = overlapped->output_queue_back = buffer;
    } else {
        buffer->next = NULL;
        overlapped->output_queue_back->next = buffer;
        overlapped->output_queue_back = buffer;
    }

    LeaveCriticalSection(&overlapped->output_queue_cs);

    ReleaseSemaphore(overlapped->output_queue_semaphore, 1, NULL);
}


static int is_tap_win32_dev(const char *guid)
{
    HKEY netcard_key;
    LONG status;
    DWORD len;
    int i = 0;

    status = RegOpenKeyEx(
        HKEY_LOCAL_MACHINE,
        ADAPTER_KEY,
        0,
        KEY_READ,
        &netcard_key);

    if (status != ERROR_SUCCESS) {
        return FALSE;
    }

    for (;;) {
        char enum_name[256];
        char unit_string[256];
        HKEY unit_key;
        char component_id_string[] = "ComponentId";
        char component_id[256];
        char net_cfg_instance_id_string[] = "NetCfgInstanceId";
        char net_cfg_instance_id[256];
        DWORD data_type;

        len = sizeof (enum_name);
        status = RegEnumKeyEx(
            netcard_key,
            i,
            enum_name,
            &len,
            NULL,
            NULL,
            NULL,
            NULL);

        if (status == ERROR_NO_MORE_ITEMS)
            break;
        else if (status != ERROR_SUCCESS) {
            return FALSE;
        }

        snprintf (unit_string, sizeof(unit_string), "%s\\%s",
                  ADAPTER_KEY, enum_name);

        status = RegOpenKeyEx(
            HKEY_LOCAL_MACHINE,
            unit_string,
            0,
            KEY_READ,
            &unit_key);

        if (status != ERROR_SUCCESS) {
            return FALSE;
        } else {
            len = sizeof (component_id);
            status = RegQueryValueEx(
                unit_key,
                component_id_string,
                NULL,
                &data_type,
                component_id,
                &len);

            if (!(status != ERROR_SUCCESS || data_type != REG_SZ)) {
                len = sizeof (net_cfg_instance_id);
                status = RegQueryValueEx(
                    unit_key,
                    net_cfg_instance_id_string,
                    NULL,
                    &data_type,
                    net_cfg_instance_id,
                    &len);

                if (status == ERROR_SUCCESS && data_type == REG_SZ) {
                    if (/* !strcmp (component_id, TAP_COMPONENT_ID) &&*/
                        !strcmp (net_cfg_instance_id, guid)) {
                        RegCloseKey (unit_key);
                        RegCloseKey (netcard_key);
                        return TRUE;
                    }
                }
            }
            RegCloseKey (unit_key);
        }
        ++i;
    }

    RegCloseKey (netcard_key);
    return FALSE;
}

static int get_device_guid(
    char *name,
    int name_size,
    char *actual_name,
    int actual_name_size)
{
    LONG status;
    HKEY control_net_key;
    DWORD len;
    int i = 0;
    int stop = 0;

    status = RegOpenKeyEx(
        HKEY_LOCAL_MACHINE,
        NETWORK_CONNECTIONS_KEY,
        0,
        KEY_READ,
        &control_net_key);

    if (status != ERROR_SUCCESS) {
        return -1;
    }

    while (!stop)
    {
        char enum_name[256];
        char connection_string[256];
        HKEY connection_key;
        char name_data[256];
        DWORD name_type;
        const char name_string[] = "Name";

        len = sizeof (enum_name);
        status = RegEnumKeyEx(
            control_net_key,
            i,
            enum_name,
            &len,
            NULL,
            NULL,
            NULL,
            NULL);

        if (status == ERROR_NO_MORE_ITEMS)
            break;
        else if (status != ERROR_SUCCESS) {
            return -1;
        }

        snprintf(connection_string, 
             sizeof(connection_string),
             "%s\\%s\\Connection",
             NETWORK_CONNECTIONS_KEY, enum_name);

        status = RegOpenKeyEx(
            HKEY_LOCAL_MACHINE,
            connection_string,