libfreerdp/core/client.c

 
#include <freerdp/config.h>
 
#include "settings.h"
 
#include <winpr/assert.h>
 
#include <freerdp/log.h>
#include <freerdp/channels/drdynvc.h>
 
#include "rdp.h"
#include "client.h"
 
#define TAG FREERDP_TAG("core.client")
 
typedef struct
{
  freerdp_channel_handle_fkt_t fkt;
  void* userdata;
} ChannelEventEntry;
 
/* Use this instance to get access to channels in VirtualChannelInit. It is set during
 * freerdp_connect so channels that use VirtualChannelInit must be initialized from the same thread
 * as freerdp_connect was called */
static WINPR_TLS freerdp* g_Instance = NULL;
 
/* use global counter to ensure uniqueness across channel manager instances */
static volatile LONG g_OpenHandleSeq = 1;
 
/* HashTable mapping channel handles to CHANNEL_OPEN_DATA */
static INIT_ONCE g_ChannelHandlesOnce = INIT_ONCE_STATIC_INIT;
static wHashTable* g_ChannelHandles = NULL;
 
static BOOL freerdp_channels_process_message_free(wMessage* message, DWORD type);
 
static CHANNEL_OPEN_DATA* freerdp_channels_find_channel_open_data_by_name(rdpChannels* channels,
                                                                          const char* name)
{
  for (int index = 0; index < channels->openDataCount; index++)
  {
    CHANNEL_OPEN_DATA* pChannelOpenData = &channels->openDataList[index];
 
    if (strncmp(name, pChannelOpenData->name, CHANNEL_NAME_LEN + 1) == 0)
      return pChannelOpenData;
  }
 
  return NULL;
}
 
/* returns rdpChannel for the channel name passed in */
static rdpMcsChannel* freerdp_channels_find_channel_by_name(rdpRdp* rdp, const char* name)
{
  rdpMcs* mcs = NULL;
 
  if (!rdp)
    return NULL;
 
  mcs = rdp->mcs;
 
  for (UINT32 index = 0; index < mcs->channelCount; index++)
  {
    rdpMcsChannel* channel = &mcs->channels[index];
 
    if (strncmp(name, channel->Name, CHANNEL_NAME_LEN + 1) == 0)
    {
      return channel;
    }
  }
 
  return NULL;
}
 
static rdpMcsChannel* freerdp_channels_find_channel_by_id(rdpRdp* rdp, UINT16 channel_id)
{
  rdpMcsChannel* channel = NULL;
  rdpMcs* mcs = NULL;
 
  if (!rdp)
    return NULL;
 
  mcs = rdp->mcs;
 
  for (UINT32 index = 0; index < mcs->channelCount; index++)
  {
    channel = &mcs->channels[index];
 
    if (channel->ChannelId == channel_id)
    {
      return channel;
    }
  }
 
  return NULL;
}
 
static void channel_queue_message_free(wMessage* msg)
{
  CHANNEL_OPEN_EVENT* ev = NULL;
 
  if (!msg || (msg->id != 0))
    return;
 
  ev = (CHANNEL_OPEN_EVENT*)msg->wParam;
  free(ev);
}
 
static void channel_queue_free(void* obj)
{
  wMessage* msg = (wMessage*)obj;
  freerdp_channels_process_message_free(msg, CHANNEL_EVENT_WRITE_CANCELLED);
  channel_queue_message_free(msg);
}
 
static BOOL CALLBACK init_channel_handles_table(PINIT_ONCE once, PVOID param, PVOID* context)
{
  g_ChannelHandles = HashTable_New(TRUE);
  return TRUE;
}
 
static void* channel_event_entry_clone(const void* data)
{
  const ChannelEventEntry* entry = data;
  if (!entry)
    return NULL;
 
  ChannelEventEntry* copy = calloc(1, sizeof(ChannelEventEntry));
  if (!copy)
    return NULL;
  *copy = *entry;
  return copy;
}
 
rdpChannels* freerdp_channels_new(freerdp* instance)
{
  wObject* obj = NULL;
  rdpChannels* channels = NULL;
  channels = (rdpChannels*)calloc(1, sizeof(rdpChannels));
 
  if (!channels)
    return NULL;
 
  InitOnceExecuteOnce(&g_ChannelHandlesOnce, init_channel_handles_table, NULL, NULL);
 
  if (!g_ChannelHandles)
    goto error;
  if (!InitializeCriticalSectionAndSpinCount(&channels->channelsLock, 4000))
    goto error;
 
  channels->instance = instance;
  channels->queue = MessageQueue_New(NULL);
 
  if (!channels->queue)
    goto error;
 
  obj = MessageQueue_Object(channels->queue);
  obj->fnObjectFree = channel_queue_free;
 
  channels->channelEvents = HashTable_New(FALSE);
  if (!channels->channelEvents)
    goto error;
 
  obj = HashTable_ValueObject(channels->channelEvents);
  WINPR_ASSERT(obj);
  obj->fnObjectFree = free;
  obj->fnObjectNew = channel_event_entry_clone;
  return channels;
error:
  WINPR_PRAGMA_DIAG_PUSH
  WINPR_PRAGMA_DIAG_IGNORED_MISMATCHED_DEALLOC
  freerdp_channels_free(channels);
  WINPR_PRAGMA_DIAG_POP
  return NULL;
}
 
void freerdp_channels_free(rdpChannels* channels)
{
  if (!channels)
    return;
 
  HashTable_Free(channels->channelEvents);
 
  DeleteCriticalSection(&channels->channelsLock);
 
  if (channels->queue)
  {
    MessageQueue_Free(channels->queue);
    channels->queue = NULL;
  }
 
  free(channels);
}
 
static UINT freerdp_drdynvc_on_channel_connected(DrdynvcClientContext* context, const char* name,
                                                 void* pInterface)
{
  UINT status = CHANNEL_RC_OK;
  ChannelConnectedEventArgs e = { 0 };
  rdpChannels* channels = (rdpChannels*)context->custom;
  freerdp* instance = channels->instance;
  EventArgsInit(&e, "freerdp");
  e.name = name;
  e.pInterface = pInterface;
  PubSub_OnChannelConnected(instance->context->pubSub, instance->context, &e);
  return status;
}
 
static UINT freerdp_drdynvc_on_channel_disconnected(DrdynvcClientContext* context, const char* name,
                                                    void* pInterface)
{
  UINT status = CHANNEL_RC_OK;
  ChannelDisconnectedEventArgs e = { 0 };
  rdpChannels* channels = (rdpChannels*)context->custom;
  freerdp* instance = channels->instance;
  EventArgsInit(&e, "freerdp");
  e.name = name;
  e.pInterface = pInterface;
  PubSub_OnChannelDisconnected(instance->context->pubSub, instance->context, &e);
  return status;
}
 
static UINT freerdp_drdynvc_on_channel_attached(DrdynvcClientContext* context, const char* name,
                                                void* pInterface)
{
  UINT status = CHANNEL_RC_OK;
  ChannelAttachedEventArgs e = { 0 };
  rdpChannels* channels = (rdpChannels*)context->custom;
  freerdp* instance = channels->instance;
  EventArgsInit(&e, "freerdp");
  e.name = name;
  e.pInterface = pInterface;
  PubSub_OnChannelAttached(instance->context->pubSub, instance->context, &e);
  return status;
}
 
static UINT freerdp_drdynvc_on_channel_detached(DrdynvcClientContext* context, const char* name,
                                                void* pInterface)
{
  UINT status = CHANNEL_RC_OK;
  ChannelDetachedEventArgs e = { 0 };
  rdpChannels* channels = (rdpChannels*)context->custom;
  freerdp* instance = channels->instance;
  EventArgsInit(&e, "freerdp");
  e.name = name;
  e.pInterface = pInterface;
  PubSub_OnChannelDetached(instance->context->pubSub, instance->context, &e);
  return status;
}
 
void freerdp_channels_register_instance(rdpChannels* channels, freerdp* instance)
{
  /* store instance in TLS so future VirtualChannelInit calls can use it */
  g_Instance = instance;
}
 
UINT freerdp_channels_pre_connect(rdpChannels* channels, freerdp* instance)
{
  UINT error = CHANNEL_RC_OK;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
 
  MessageQueue_Clear(channels->queue);
 
  for (int index = 0; index < channels->clientDataCount; index++)
  {
    pChannelClientData = &channels->clientDataList[index];
 
    if (pChannelClientData->pChannelInitEventProc)
    {
      pChannelClientData->pChannelInitEventProc(pChannelClientData->pInitHandle,
                                                CHANNEL_EVENT_INITIALIZED, 0, 0);
    }
    else if (pChannelClientData->pChannelInitEventProcEx)
    {
      pChannelClientData->pChannelInitEventProcEx(pChannelClientData->lpUserParam,
                                                  pChannelClientData->pInitHandle,
                                                  CHANNEL_EVENT_INITIALIZED, 0, 0);
    }
 
    if (CHANNEL_RC_OK != getChannelError(instance->context))
      break;
  }
 
  return error;
}
 
UINT freerdp_channels_attach(freerdp* instance)
{
  UINT error = CHANNEL_RC_OK;
  const char* hostname = NULL;
  size_t hostnameLength = 0;
  rdpChannels* channels = NULL;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
 
  WINPR_ASSERT(instance);
  WINPR_ASSERT(instance->context);
  WINPR_ASSERT(instance->context->settings);
 
  channels = instance->context->channels;
  hostname = freerdp_settings_get_string(instance->context->settings, FreeRDP_ServerHostname);
  WINPR_ASSERT(hostname);
  hostnameLength = strnlen(hostname, MAX_PATH);
 
  for (int index = 0; index < channels->clientDataCount; index++)
  {
    union
    {
      const void* cpv;
      void* pv;
    } cnv;
    ChannelAttachedEventArgs e = { 0 };
    CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
 
    cnv.cpv = hostname;
    pChannelClientData = &channels->clientDataList[index];
 
    if (pChannelClientData->pChannelInitEventProc)
    {
 
      pChannelClientData->pChannelInitEventProc(pChannelClientData->pInitHandle,
                                                CHANNEL_EVENT_ATTACHED, cnv.pv,
                                                (UINT)hostnameLength);
    }
    else if (pChannelClientData->pChannelInitEventProcEx)
    {
      pChannelClientData->pChannelInitEventProcEx(
          pChannelClientData->lpUserParam, pChannelClientData->pInitHandle,
          CHANNEL_EVENT_ATTACHED, cnv.pv, (UINT)hostnameLength);
    }
 
    if (getChannelError(instance->context) != CHANNEL_RC_OK)
      goto fail;
 
    pChannelOpenData = &channels->openDataList[index];
    EventArgsInit(&e, "freerdp");
    e.name = pChannelOpenData->name;
    e.pInterface = pChannelOpenData->pInterface;
    PubSub_OnChannelAttached(instance->context->pubSub, instance->context, &e);
  }
 
fail:
  return error;
}
 
UINT freerdp_channels_detach(freerdp* instance)
{
  UINT error = CHANNEL_RC_OK;
  const char* hostname = NULL;
  size_t hostnameLength = 0;
  rdpChannels* channels = NULL;
  rdpContext* context = NULL;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
 
  WINPR_ASSERT(instance);
 
  context = instance->context;
  WINPR_ASSERT(context);
 
  channels = context->channels;
  WINPR_ASSERT(channels);
 
  WINPR_ASSERT(context->settings);
  hostname = freerdp_settings_get_string(context->settings, FreeRDP_ServerHostname);
  WINPR_ASSERT(hostname);
  hostnameLength = strnlen(hostname, MAX_PATH);
 
  for (int index = 0; index < channels->clientDataCount; index++)
  {
    union
    {
      const void* cpv;
      void* pv;
    } cnv;
 
    ChannelDetachedEventArgs e = { 0 };
    CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
 
    cnv.cpv = hostname;
    pChannelClientData = &channels->clientDataList[index];
 
    if (pChannelClientData->pChannelInitEventProc)
    {
      pChannelClientData->pChannelInitEventProc(pChannelClientData->pInitHandle,
                                                CHANNEL_EVENT_DETACHED, cnv.pv,
                                                (UINT)hostnameLength);
    }
    else if (pChannelClientData->pChannelInitEventProcEx)
    {
      pChannelClientData->pChannelInitEventProcEx(
          pChannelClientData->lpUserParam, pChannelClientData->pInitHandle,
          CHANNEL_EVENT_DETACHED, cnv.pv, (UINT)hostnameLength);
    }
 
    if (getChannelError(context) != CHANNEL_RC_OK)
      goto fail;
 
    pChannelOpenData = &channels->openDataList[index];
    EventArgsInit(&e, "freerdp");
    e.name = pChannelOpenData->name;
    e.pInterface = pChannelOpenData->pInterface;
    PubSub_OnChannelDetached(context->pubSub, context, &e);
  }
 
fail:
  return error;
}
 
UINT freerdp_channels_post_connect(rdpChannels* channels, freerdp* instance)
{
  UINT error = CHANNEL_RC_OK;
  const char* hostname = NULL;
  size_t hostnameLength = 0;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
 
  WINPR_ASSERT(channels);
  WINPR_ASSERT(instance);
  WINPR_ASSERT(instance->context);
  WINPR_ASSERT(instance->context->settings);
 
  channels->connected = TRUE;
  hostname = freerdp_settings_get_string(instance->context->settings, FreeRDP_ServerHostname);
  WINPR_ASSERT(hostname);
  hostnameLength = strnlen(hostname, MAX_PATH);
 
  for (int index = 0; index < channels->clientDataCount; index++)
  {
    union
    {
      const void* pcb;
      void* pb;
    } cnv;
    ChannelConnectedEventArgs e = { 0 };
    CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
    pChannelClientData = &channels->clientDataList[index];
 
    cnv.pcb = hostname;
    if (pChannelClientData->pChannelInitEventProc)
    {
      pChannelClientData->pChannelInitEventProc(pChannelClientData->pInitHandle,
                                                CHANNEL_EVENT_CONNECTED, cnv.pb,
                                                (UINT)hostnameLength);
    }
    else if (pChannelClientData->pChannelInitEventProcEx)
    {
      pChannelClientData->pChannelInitEventProcEx(
          pChannelClientData->lpUserParam, pChannelClientData->pInitHandle,
          CHANNEL_EVENT_CONNECTED, cnv.pb, (UINT)hostnameLength);
    }
 
    error = getChannelError(instance->context);
    if (error != CHANNEL_RC_OK)
      goto fail;
 
    pChannelOpenData = &channels->openDataList[index];
    EventArgsInit(&e, "freerdp");
    e.name = pChannelOpenData->name;
    e.pInterface = pChannelOpenData->pInterface;
    PubSub_OnChannelConnected(instance->context->pubSub, instance->context, &e);
  }
 
  channels->drdynvc = (DrdynvcClientContext*)freerdp_channels_get_static_channel_interface(
      channels, DRDYNVC_SVC_CHANNEL_NAME);
 
  if (channels->drdynvc)
  {
    channels->drdynvc->custom = (void*)channels;
    channels->drdynvc->OnChannelConnected = freerdp_drdynvc_on_channel_connected;
    channels->drdynvc->OnChannelDisconnected = freerdp_drdynvc_on_channel_disconnected;
    channels->drdynvc->OnChannelAttached = freerdp_drdynvc_on_channel_attached;
    channels->drdynvc->OnChannelDetached = freerdp_drdynvc_on_channel_detached;
  }
 
fail:
  return error;
}
 
BOOL freerdp_channels_data(freerdp* instance, UINT16 channelId, const BYTE* cdata, size_t dataSize,
                           UINT32 flags, size_t totalSize)
{
  rdpMcs* mcs = NULL;
  rdpChannels* channels = NULL;
  rdpMcsChannel* channel = NULL;
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
  union
  {
    const BYTE* pcb;
    BYTE* pb;
  } data;
 
  data.pcb = cdata;
  if (!instance || !data.pcb)
  {
    WLog_ERR(TAG, "(%p, %" PRIu16 ", %p, 0x%08x): Invalid arguments", instance, channelId,
             data.pcb, flags);
    return FALSE;
  }
 
  mcs = instance->context->rdp->mcs;
  channels = instance->context->channels;
 
  if (!channels || !mcs)
  {
    return FALSE;
  }
 
  for (UINT32 index = 0; index < mcs->channelCount; index++)
  {
    rdpMcsChannel* cur = &mcs->channels[index];
 
    if (cur->ChannelId == channelId)
    {
      channel = cur;
      break;
    }
  }
 
  if (!channel)
  {
    return FALSE;
  }
 
  pChannelOpenData = freerdp_channels_find_channel_open_data_by_name(channels, channel->Name);
 
  if (!pChannelOpenData)
  {
    return FALSE;
  }
 
  if (pChannelOpenData->pChannelOpenEventProc)
  {
    pChannelOpenData->pChannelOpenEventProc(pChannelOpenData->OpenHandle,
                                            CHANNEL_EVENT_DATA_RECEIVED, data.pb,
                                            (UINT32)dataSize, (UINT32)totalSize, flags);
  }
  else if (pChannelOpenData->pChannelOpenEventProcEx)
  {
    pChannelOpenData->pChannelOpenEventProcEx(
        pChannelOpenData->lpUserParam, pChannelOpenData->OpenHandle,
        CHANNEL_EVENT_DATA_RECEIVED, data.pb, (UINT32)dataSize, (UINT32)totalSize, flags);
  }
 
  return TRUE;
}
 
UINT16 freerdp_channels_get_id_by_name(freerdp* instance, const char* channel_name)
{
  rdpMcsChannel* mcsChannel = NULL;
  if (!instance || !channel_name)
    return -1;
 
  mcsChannel = freerdp_channels_find_channel_by_name(instance->context->rdp, channel_name);
  if (!mcsChannel)
    return -1;
 
  return mcsChannel->ChannelId;
}
 
const char* freerdp_channels_get_name_by_id(freerdp* instance, UINT16 channelId)
{
  rdpMcsChannel* mcsChannel = NULL;
  if (!instance)
    return NULL;
 
  mcsChannel = freerdp_channels_find_channel_by_id(instance->context->rdp, channelId);
  if (!mcsChannel)
    return NULL;
 
  return mcsChannel->Name;
}
 
BOOL freerdp_channels_process_message_free(wMessage* message, DWORD type)
{
  if (message->id == WMQ_QUIT)
  {
    return FALSE;
  }
 
  if (message->id == 0)
  {
    CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
    CHANNEL_OPEN_EVENT* item = (CHANNEL_OPEN_EVENT*)message->wParam;
 
    if (!item)
      return FALSE;
 
    pChannelOpenData = item->pChannelOpenData;
 
    if (pChannelOpenData->pChannelOpenEventProc)
    {
      pChannelOpenData->pChannelOpenEventProc(pChannelOpenData->OpenHandle, type,
                                              item->UserData, item->DataLength,
                                              item->DataLength, 0);
    }
    else if (pChannelOpenData->pChannelOpenEventProcEx)
    {
      pChannelOpenData->pChannelOpenEventProcEx(
          pChannelOpenData->lpUserParam, pChannelOpenData->OpenHandle, type, item->UserData,
          item->DataLength, item->DataLength, 0);
    }
  }
 
  return TRUE;
}
 
static BOOL freerdp_channels_process_message(freerdp* instance, wMessage* message)
{
  BOOL ret = TRUE;
  BOOL rc = FALSE;
 
  WINPR_ASSERT(instance);
  WINPR_ASSERT(message);
 
  if (message->id == WMQ_QUIT)
    goto fail;
  else if (message->id == 0)
  {
    rdpMcsChannel* channel = NULL;
    CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
    CHANNEL_OPEN_EVENT* item = (CHANNEL_OPEN_EVENT*)message->wParam;
 
    if (!item)
      goto fail;
 
    pChannelOpenData = item->pChannelOpenData;
    if (pChannelOpenData->flags != 2)
    {
      freerdp_channels_process_message_free(message, CHANNEL_EVENT_WRITE_CANCELLED);
      goto fail;
    }
    channel =
        freerdp_channels_find_channel_by_name(instance->context->rdp, pChannelOpenData->name);
 
    if (channel)
      ret = instance->SendChannelData(instance, channel->ChannelId, item->Data,
                                      item->DataLength);
  }
 
  if (!freerdp_channels_process_message_free(message, CHANNEL_EVENT_WRITE_COMPLETE))
    goto fail;
 
  rc = ret;
 
fail:
  IFCALL(message->Free, message);
  return rc;
}
 
static BOOL freerdp_channels_process_sync(rdpChannels* channels, freerdp* instance)
{
  BOOL status = TRUE;
  wMessage message = { 0 };
 
  WINPR_ASSERT(channels);
 
  while (MessageQueue_Peek(channels->queue, &message, TRUE))
  {
    if (!freerdp_channels_process_message(instance, &message))
      status = FALSE;
  }
 
  return status;
}
 
#if defined(WITH_FREERDP_DEPRECATED)
BOOL freerdp_channels_get_fds(rdpChannels* channels, freerdp* instance, void** read_fds,
                              int* read_count, void** write_fds, int* write_count)
{
  void* pfd = NULL;
  pfd = GetEventWaitObject(MessageQueue_Event(channels->queue));
 
  if (pfd)
  {
    read_fds[*read_count] = pfd;
    (*read_count)++;
  }
 
  return TRUE;
}
#endif
 
void* freerdp_channels_get_static_channel_interface(rdpChannels* channels, const char* name)
{
  void* pInterface = NULL;
  CHANNEL_OPEN_DATA* pChannelOpenData =
      freerdp_channels_find_channel_open_data_by_name(channels, name);
 
  if (pChannelOpenData)
    pInterface = pChannelOpenData->pInterface;
 
  return pInterface;
}
 
HANDLE freerdp_channels_get_event_handle(freerdp* instance)
{
  if (!instance)
    return INVALID_HANDLE_VALUE;
 
  WINPR_ASSERT(instance->context);
 
  rdpChannels* channels = instance->context->channels;
  WINPR_ASSERT(channels);
 
  return MessageQueue_Event(channels->queue);
}
 
static BOOL channels_process(const void* key, void* value, void* arg)
{
  ChannelEventEntry* entry = value;
  rdpContext* context = arg;
 
  WINPR_UNUSED(key);
 
  if (!entry->fkt)
    return FALSE;
  return entry->fkt(context, entry->userdata);
}
 
int freerdp_channels_process_pending_messages(freerdp* instance)
{
  if (!instance)
    return -1;
 
  WINPR_ASSERT(instance->context);
 
  rdpChannels* channels = instance->context->channels;
  WINPR_ASSERT(channels);
 
  const DWORD status = WaitForSingleObject(MessageQueue_Event(channels->queue), 0);
  if (status == WAIT_OBJECT_0)
  {
    if (!freerdp_channels_process_sync(channels, instance))
      return -1;
  }
 
  if (!HashTable_Foreach(channels->channelEvents, channels_process, instance->context))
    return -1;
 
  return 1;
}
 
BOOL freerdp_channels_check_fds(rdpChannels* channels, freerdp* instance)
{
  WINPR_ASSERT(channels);
  WINPR_UNUSED(channels);
 
  const int rc = freerdp_channels_process_pending_messages(instance);
  return rc == 1;
}
 
BOOL freerdp_client_channel_register(rdpChannels* channels, HANDLE handle,
                                     freerdp_channel_handle_fkt_t fkt, void* userdata)
{
  if (!channels || (handle == INVALID_HANDLE_VALUE) || !fkt)
  {
    WLog_ERR(TAG, "Invalid function arguments (channels=%p, handle=%p, fkt=%p, userdata=%p",
             channels, handle, fkt, userdata);
    return FALSE;
  }
 
  ChannelEventEntry entry = { .fkt = fkt, .userdata = userdata };
  return HashTable_Insert(channels->channelEvents, handle, &entry);
}
 
BOOL freerdp_client_channel_unregister(rdpChannels* channels, HANDLE handle)
{
  if (!channels || (handle == INVALID_HANDLE_VALUE))
  {
    WLog_ERR(TAG, "Invalid function arguments (channels=%p, handle=%p", channels, handle);
    return FALSE;
  }
 
  return HashTable_Remove(channels->channelEvents, handle);
}
 
SSIZE_T freerdp_client_channel_get_registered_event_handles(rdpChannels* channels, HANDLE* events,
                                                            DWORD count)
{
  SSIZE_T rc = -1;
 
  WINPR_ASSERT(channels);
  WINPR_ASSERT(events || (count == 0));
 
  HashTable_Lock(channels->channelEvents);
  size_t len = HashTable_Count(channels->channelEvents);
  if (len <= count)
  {
    ULONG_PTR* keys = NULL;
    const size_t nrKeys = HashTable_GetKeys(channels->channelEvents, &keys);
    if ((nrKeys <= SSIZE_MAX) && (nrKeys == len))
    {
      for (size_t x = 0; x < nrKeys; x++)
      {
        HANDLE cur = (HANDLE)keys[x];
        events[x] = cur;
      }
      rc = (SSIZE_T)nrKeys;
    }
    free(keys);
  }
  HashTable_Unlock(channels->channelEvents);
  return rc;
}
 
UINT freerdp_channels_disconnect(rdpChannels* channels, freerdp* instance)
{
  UINT error = CHANNEL_RC_OK;
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
 
  WINPR_ASSERT(channels);
 
  if (!channels->connected)
    return 0;
 
  (void)freerdp_channels_check_fds(channels, instance);
 
  /* tell all libraries we are shutting down */
  for (int index = 0; index < channels->clientDataCount; index++)
  {
    ChannelDisconnectedEventArgs e = { 0 };
    pChannelClientData = &channels->clientDataList[index];
 
    if (pChannelClientData->pChannelInitEventProc)
    {
      pChannelClientData->pChannelInitEventProc(pChannelClientData->pInitHandle,
                                                CHANNEL_EVENT_DISCONNECTED, 0, 0);
    }
    else if (pChannelClientData->pChannelInitEventProcEx)
    {
      pChannelClientData->pChannelInitEventProcEx(pChannelClientData->lpUserParam,
                                                  pChannelClientData->pInitHandle,
                                                  CHANNEL_EVENT_DISCONNECTED, 0, 0);
    }
 
    if (getChannelError(instance->context) != CHANNEL_RC_OK)
      continue;
 
    pChannelOpenData = &channels->openDataList[index];
    EventArgsInit(&e, "freerdp");
    e.name = pChannelOpenData->name;
    e.pInterface = pChannelOpenData->pInterface;
    PubSub_OnChannelDisconnected(instance->context->pubSub, instance->context, &e);
  }
 
  channels->connected = FALSE;
 
  /* Flush pending messages */
  (void)freerdp_channels_check_fds(channels, instance);
  return error;
}
 
void freerdp_channels_close(rdpChannels* channels, freerdp* instance)
{
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
 
  WINPR_ASSERT(channels);
  WINPR_ASSERT(instance);
 
  MessageQueue_PostQuit(channels->queue, 0);
  (void)freerdp_channels_check_fds(channels, instance);
 
  /* tell all libraries we are shutting down */
  for (int index = 0; index < channels->clientDataCount; index++)
  {
    pChannelClientData = &channels->clientDataList[index];
 
    if (pChannelClientData->pChannelInitEventProc)
    {
      pChannelClientData->pChannelInitEventProc(pChannelClientData->pInitHandle,
                                                CHANNEL_EVENT_TERMINATED, 0, 0);
    }
    else if (pChannelClientData->pChannelInitEventProcEx)
    {
      pChannelClientData->pChannelInitEventProcEx(pChannelClientData->lpUserParam,
                                                  pChannelClientData->pInitHandle,
                                                  CHANNEL_EVENT_TERMINATED, 0, 0);
    }
  }
 
  for (int index = 0; index < channels->openDataCount; index++)
  {
    pChannelOpenData = &channels->openDataList[index];
    HashTable_Remove(g_ChannelHandles, (void*)(UINT_PTR)pChannelOpenData->OpenHandle);
  }
 
  channels->openDataCount = 0;
  channels->initDataCount = 0;
  channels->clientDataCount = 0;
 
  WINPR_ASSERT(instance->context);
  WINPR_ASSERT(instance->context->settings);
  instance->context->settings->ChannelCount = 0;
  g_Instance = NULL;
}
 
static UINT VCAPITYPE FreeRDP_VirtualChannelInitEx(
    LPVOID lpUserParam, LPVOID clientContext, LPVOID pInitHandle, PCHANNEL_DEF pChannel,
    INT channelCount, ULONG versionRequested, PCHANNEL_INIT_EVENT_EX_FN pChannelInitEventProcEx)
{
  rdpSettings* settings = NULL;
  CHANNEL_INIT_DATA* pChannelInitData = NULL;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
  rdpChannels* channels = NULL;
 
  if (!pInitHandle)
    return CHANNEL_RC_BAD_INIT_HANDLE;
 
  if (!pChannel)
    return CHANNEL_RC_BAD_CHANNEL;
 
  if ((channelCount <= 0) || !pChannelInitEventProcEx)
    return CHANNEL_RC_INITIALIZATION_ERROR;
 
  pChannelInitData = (CHANNEL_INIT_DATA*)pInitHandle;
  WINPR_ASSERT(pChannelInitData);
 
  channels = pChannelInitData->channels;
  WINPR_ASSERT(channels);
 
  if (!channels->can_call_init)
    return CHANNEL_RC_NOT_IN_VIRTUALCHANNELENTRY;
 
  if ((channels->openDataCount + channelCount) > CHANNEL_MAX_COUNT)
    return CHANNEL_RC_TOO_MANY_CHANNELS;
 
  if (channels->connected)
    return CHANNEL_RC_ALREADY_CONNECTED;
 
  if (versionRequested != VIRTUAL_CHANNEL_VERSION_WIN2000)
  {
  }
 
  for (int index = 0; index < channelCount; index++)
  {
    const PCHANNEL_DEF pChannelDef = &pChannel[index];
 
    if (freerdp_channels_find_channel_open_data_by_name(channels, pChannelDef->name) != 0)
    {
      return CHANNEL_RC_BAD_CHANNEL;
    }
  }
 
  pChannelInitData->pInterface = clientContext;
  pChannelClientData = &channels->clientDataList[channels->clientDataCount];
  pChannelClientData->pChannelInitEventProcEx = pChannelInitEventProcEx;
  pChannelClientData->pInitHandle = pInitHandle;
  pChannelClientData->lpUserParam = lpUserParam;
  channels->clientDataCount++;
 
  WINPR_ASSERT(channels->instance);
  WINPR_ASSERT(channels->instance->context);
  settings = channels->instance->context->settings;
  WINPR_ASSERT(settings);
 
  for (int index = 0; index < channelCount; index++)
  {
    const PCHANNEL_DEF pChannelDef = &pChannel[index];
    CHANNEL_OPEN_DATA* pChannelOpenData = &channels->openDataList[channels->openDataCount];
 
    WINPR_ASSERT(pChannelOpenData);
 
    pChannelOpenData->OpenHandle = InterlockedIncrement(&g_OpenHandleSeq);
    pChannelOpenData->channels = channels;
    pChannelOpenData->lpUserParam = lpUserParam;
    if (!HashTable_Insert(g_ChannelHandles, (void*)(UINT_PTR)pChannelOpenData->OpenHandle,
                          (void*)pChannelOpenData))
    {
      pChannelInitData->pInterface = NULL;
      return CHANNEL_RC_INITIALIZATION_ERROR;
    }
    pChannelOpenData->flags = 1; /* init */
    strncpy(pChannelOpenData->name, pChannelDef->name, CHANNEL_NAME_LEN);
    pChannelOpenData->options = pChannelDef->options;
 
    const UINT32 max = freerdp_settings_get_uint32(settings, FreeRDP_ChannelDefArraySize);
    WINPR_ASSERT(max >= CHANNEL_MAX_COUNT);
    if (settings->ChannelCount < max)
    {
      CHANNEL_DEF* channel = freerdp_settings_get_pointer_array_writable(
          settings, FreeRDP_ChannelDefArray, settings->ChannelCount);
      if (!channel)
        continue;
      strncpy(channel->name, pChannelDef->name, CHANNEL_NAME_LEN);
      channel->options = pChannelDef->options;
      settings->ChannelCount++;
    }
 
    channels->openDataCount++;
  }
 
  return CHANNEL_RC_OK;
}
 
static UINT VCAPITYPE FreeRDP_VirtualChannelInit(LPVOID* ppInitHandle, PCHANNEL_DEF pChannel,
                                                 INT channelCount, ULONG versionRequested,
                                                 PCHANNEL_INIT_EVENT_FN pChannelInitEventProc)
{
  CHANNEL_DEF* channel = NULL;
  rdpSettings* settings = NULL;
  PCHANNEL_DEF pChannelDef = NULL;
  CHANNEL_INIT_DATA* pChannelInitData = NULL;
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
  rdpChannels* channels = NULL;
 
  /* g_Instance should have been set during freerdp_connect - otherwise VirtualChannelInit was
   * called from a different thread */
  if (!g_Instance || !g_Instance->context)
    return CHANNEL_RC_NOT_INITIALIZED;
 
  channels = g_Instance->context->channels;
 
  if (!ppInitHandle || !channels)
    return CHANNEL_RC_BAD_INIT_HANDLE;
 
  if (!pChannel)
    return CHANNEL_RC_BAD_CHANNEL;
 
  if ((channelCount <= 0) || !pChannelInitEventProc)
    return CHANNEL_RC_INITIALIZATION_ERROR;
 
  pChannelInitData = &(channels->initDataList[channels->initDataCount]);
  *ppInitHandle = pChannelInitData;
  channels->initDataCount++;
  pChannelInitData->channels = channels;
  pChannelInitData->pInterface = NULL;
 
  if (!channels->can_call_init)
    return CHANNEL_RC_NOT_IN_VIRTUALCHANNELENTRY;
 
  if (channels->openDataCount + channelCount > CHANNEL_MAX_COUNT)
    return CHANNEL_RC_TOO_MANY_CHANNELS;
 
  if (channels->connected)
    return CHANNEL_RC_ALREADY_CONNECTED;
 
  if (versionRequested != VIRTUAL_CHANNEL_VERSION_WIN2000)
  {
  }
 
  for (int index = 0; index < channelCount; index++)
  {
    pChannelDef = &pChannel[index];
 
    if (freerdp_channels_find_channel_open_data_by_name(channels, pChannelDef->name) != 0)
    {
      return CHANNEL_RC_BAD_CHANNEL;
    }
  }
 
  pChannelClientData = &channels->clientDataList[channels->clientDataCount];
  pChannelClientData->pChannelInitEventProc = pChannelInitEventProc;
  pChannelClientData->pInitHandle = *ppInitHandle;
  channels->clientDataCount++;
  settings = channels->instance->context->settings;
 
  for (int index = 0; index < channelCount; index++)
  {
    UINT32 ChannelCount = freerdp_settings_get_uint32(settings, FreeRDP_ChannelCount);
 
    pChannelDef = &pChannel[index];
    pChannelOpenData = &channels->openDataList[channels->openDataCount];
    pChannelOpenData->OpenHandle = InterlockedIncrement(&g_OpenHandleSeq);
    pChannelOpenData->channels = channels;
    if (!HashTable_Insert(g_ChannelHandles, (void*)(UINT_PTR)pChannelOpenData->OpenHandle,
                          (void*)pChannelOpenData))
      return CHANNEL_RC_INITIALIZATION_ERROR;
    pChannelOpenData->flags = 1; /* init */
    strncpy(pChannelOpenData->name, pChannelDef->name, CHANNEL_NAME_LEN);
    pChannelOpenData->options = pChannelDef->options;
 
    if (ChannelCount < CHANNEL_MAX_COUNT)
    {
      channel = freerdp_settings_get_pointer_array_writable(settings, FreeRDP_ChannelDefArray,
                                                            ChannelCount++);
      strncpy(channel->name, pChannelDef->name, CHANNEL_NAME_LEN);
      channel->options = pChannelDef->options;
      if (!freerdp_settings_set_uint32(settings, FreeRDP_ChannelCount, ChannelCount))
        return ERROR_INTERNAL_ERROR;
    }
 
    channels->openDataCount++;
  }
 
  return CHANNEL_RC_OK;
}
 
static UINT VCAPITYPE
FreeRDP_VirtualChannelOpenEx(LPVOID pInitHandle, LPDWORD pOpenHandle, PCHAR pChannelName,
                             PCHANNEL_OPEN_EVENT_EX_FN pChannelOpenEventProcEx)
{
  void* pInterface = NULL;
  rdpChannels* channels = NULL;
  CHANNEL_INIT_DATA* pChannelInitData = NULL;
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
  pChannelInitData = (CHANNEL_INIT_DATA*)pInitHandle;
  channels = pChannelInitData->channels;
  pInterface = pChannelInitData->pInterface;
 
  if (!pOpenHandle)
    return CHANNEL_RC_BAD_CHANNEL_HANDLE;
 
  if (!pChannelOpenEventProcEx)
    return CHANNEL_RC_BAD_PROC;
 
  if (!channels->connected)
    return CHANNEL_RC_NOT_CONNECTED;
 
  pChannelOpenData = freerdp_channels_find_channel_open_data_by_name(channels, pChannelName);
 
  if (!pChannelOpenData)
    return CHANNEL_RC_UNKNOWN_CHANNEL_NAME;
 
  if (pChannelOpenData->flags == 2)
    return CHANNEL_RC_ALREADY_OPEN;
 
  pChannelOpenData->flags = 2; /* open */
  pChannelOpenData->pInterface = pInterface;
  pChannelOpenData->pChannelOpenEventProcEx = pChannelOpenEventProcEx;
  *pOpenHandle = pChannelOpenData->OpenHandle;
  return CHANNEL_RC_OK;
}
 
static UINT VCAPITYPE FreeRDP_VirtualChannelOpen(LPVOID pInitHandle, LPDWORD pOpenHandle,
                                                 PCHAR pChannelName,
                                                 PCHANNEL_OPEN_EVENT_FN pChannelOpenEventProc)
{
  void* pInterface = NULL;
  rdpChannels* channels = NULL;
  CHANNEL_INIT_DATA* pChannelInitData = NULL;
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
  pChannelInitData = (CHANNEL_INIT_DATA*)pInitHandle;
  channels = pChannelInitData->channels;
  pInterface = pChannelInitData->pInterface;
 
  if (!pOpenHandle)
    return CHANNEL_RC_BAD_CHANNEL_HANDLE;
 
  if (!pChannelOpenEventProc)
    return CHANNEL_RC_BAD_PROC;
 
  if (!channels->connected)
    return CHANNEL_RC_NOT_CONNECTED;
 
  pChannelOpenData = freerdp_channels_find_channel_open_data_by_name(channels, pChannelName);
 
  if (!pChannelOpenData)
    return CHANNEL_RC_UNKNOWN_CHANNEL_NAME;
 
  if (pChannelOpenData->flags == 2)
    return CHANNEL_RC_ALREADY_OPEN;
 
  pChannelOpenData->flags = 2; /* open */
  pChannelOpenData->pInterface = pInterface;
  pChannelOpenData->pChannelOpenEventProc = pChannelOpenEventProc;
  *pOpenHandle = pChannelOpenData->OpenHandle;
  return CHANNEL_RC_OK;
}
 
static UINT VCAPITYPE FreeRDP_VirtualChannelCloseEx(LPVOID pInitHandle, DWORD openHandle)
{
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
 
  if (!pInitHandle)
    return CHANNEL_RC_BAD_INIT_HANDLE;
 
  pChannelOpenData = HashTable_GetItemValue(g_ChannelHandles, (void*)(UINT_PTR)openHandle);
 
  if (!pChannelOpenData)
    return CHANNEL_RC_BAD_CHANNEL_HANDLE;
 
  if (pChannelOpenData->flags != 2)
    return CHANNEL_RC_NOT_OPEN;
 
  pChannelOpenData->flags = 0;
  return CHANNEL_RC_OK;
}
 
static UINT VCAPITYPE FreeRDP_VirtualChannelClose(DWORD openHandle)
{
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
 
  pChannelOpenData = HashTable_GetItemValue(g_ChannelHandles, (void*)(UINT_PTR)openHandle);
 
  if (!pChannelOpenData)
    return CHANNEL_RC_BAD_CHANNEL_HANDLE;
 
  if (pChannelOpenData->flags != 2)
    return CHANNEL_RC_NOT_OPEN;
 
  pChannelOpenData->flags = 0;
  return CHANNEL_RC_OK;
}
 
static UINT VCAPITYPE FreeRDP_VirtualChannelWriteEx(LPVOID pInitHandle, DWORD openHandle,
                                                    LPVOID pData, ULONG dataLength,
                                                    LPVOID pUserData)
{
  rdpChannels* channels = NULL;
  CHANNEL_INIT_DATA* pChannelInitData = NULL;
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
  CHANNEL_OPEN_EVENT* pChannelOpenEvent = NULL;
  wMessage message = { 0 };
 
  if (!pInitHandle)
    return CHANNEL_RC_BAD_INIT_HANDLE;
 
  pChannelInitData = (CHANNEL_INIT_DATA*)pInitHandle;
  channels = pChannelInitData->channels;
 
  if (!channels)
    return CHANNEL_RC_BAD_CHANNEL_HANDLE;
 
  pChannelOpenData = HashTable_GetItemValue(g_ChannelHandles, (void*)(UINT_PTR)openHandle);
 
  if (!pChannelOpenData)
    return CHANNEL_RC_BAD_CHANNEL_HANDLE;
 
  if (!channels->connected)
    return CHANNEL_RC_NOT_CONNECTED;
 
  if (!pData)
    return CHANNEL_RC_NULL_DATA;
 
  if (!dataLength)
    return CHANNEL_RC_ZERO_LENGTH;
 
  if (pChannelOpenData->flags != 2)
    return CHANNEL_RC_NOT_OPEN;
 
  pChannelOpenEvent = (CHANNEL_OPEN_EVENT*)malloc(sizeof(CHANNEL_OPEN_EVENT));
 
  if (!pChannelOpenEvent)
    return CHANNEL_RC_NO_MEMORY;
 
  pChannelOpenEvent->Data = pData;
  pChannelOpenEvent->DataLength = dataLength;
  pChannelOpenEvent->UserData = pUserData;
  pChannelOpenEvent->pChannelOpenData = pChannelOpenData;
  message.context = channels;
  message.id = 0;
  message.wParam = pChannelOpenEvent;
  message.lParam = NULL;
  message.Free = channel_queue_message_free;
 
  if (!MessageQueue_Dispatch(channels->queue, &message))
  {
    free(pChannelOpenEvent);
    return CHANNEL_RC_NO_MEMORY;
  }
 
  return CHANNEL_RC_OK;
}
 
static UINT VCAPITYPE FreeRDP_VirtualChannelWrite(DWORD openHandle, LPVOID pData, ULONG dataLength,
                                                  LPVOID pUserData)
{
  wMessage message = { 0 };
  CHANNEL_OPEN_DATA* pChannelOpenData = NULL;
  CHANNEL_OPEN_EVENT* pChannelOpenEvent = NULL;
  rdpChannels* channels = NULL;
 
  pChannelOpenData = HashTable_GetItemValue(g_ChannelHandles, (void*)(UINT_PTR)openHandle);
 
  if (!pChannelOpenData)
    return CHANNEL_RC_BAD_CHANNEL_HANDLE;
 
  channels = pChannelOpenData->channels;
  if (!channels)
    return CHANNEL_RC_BAD_CHANNEL_HANDLE;
 
  if (!channels->connected)
    return CHANNEL_RC_NOT_CONNECTED;
 
  if (!pData)
    return CHANNEL_RC_NULL_DATA;
 
  if (!dataLength)
    return CHANNEL_RC_ZERO_LENGTH;
 
  if (pChannelOpenData->flags != 2)
    return CHANNEL_RC_NOT_OPEN;
 
  pChannelOpenEvent = (CHANNEL_OPEN_EVENT*)malloc(sizeof(CHANNEL_OPEN_EVENT));
 
  if (!pChannelOpenEvent)
    return CHANNEL_RC_NO_MEMORY;
 
  pChannelOpenEvent->Data = pData;
  pChannelOpenEvent->DataLength = dataLength;
  pChannelOpenEvent->UserData = pUserData;
  pChannelOpenEvent->pChannelOpenData = pChannelOpenData;
  message.context = channels;
  message.id = 0;
  message.wParam = pChannelOpenEvent;
  message.lParam = NULL;
  message.Free = channel_queue_message_free;
 
  if (!MessageQueue_Dispatch(channels->queue, &message))
  {
    free(pChannelOpenEvent);
    return CHANNEL_RC_NO_MEMORY;
  }
 
  return CHANNEL_RC_OK;
}
 
static BOOL freerdp_channels_is_loaded(rdpChannels* channels, PVIRTUALCHANNELENTRY entry)
{
  for (int i = 0; i < channels->clientDataCount; i++)
  {
    CHANNEL_CLIENT_DATA* pChannelClientData = &channels->clientDataList[i];
 
    if (pChannelClientData->entry == entry)
      return TRUE;
  }
 
  return FALSE;
}
 
static BOOL freerdp_channels_is_loaded_ex(rdpChannels* channels, PVIRTUALCHANNELENTRYEX entryEx)
{
  for (int i = 0; i < channels->clientDataCount; i++)
  {
    CHANNEL_CLIENT_DATA* pChannelClientData = &channels->clientDataList[i];
 
    if (pChannelClientData->entryEx == entryEx)
      return TRUE;
  }
 
  return FALSE;
}
 
int freerdp_channels_client_load(rdpChannels* channels, rdpSettings* settings,
                                 PVIRTUALCHANNELENTRY entry, void* data)
{
  int status = 0;
  CHANNEL_ENTRY_POINTS_FREERDP EntryPoints = { 0 };
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
 
  WINPR_ASSERT(channels);
  WINPR_ASSERT(channels->instance);
  WINPR_ASSERT(channels->instance->context);
  WINPR_ASSERT(entry);
 
  if (channels->clientDataCount + 1 > CHANNEL_MAX_COUNT)
  {
    WLog_ERR(TAG, "error: too many channels");
    return 1;
  }
 
  if (freerdp_channels_is_loaded(channels, entry))
  {
    WLog_WARN(TAG, "Skipping, channel already loaded");
    return 0;
  }
 
  pChannelClientData = &channels->clientDataList[channels->clientDataCount];
  pChannelClientData->entry = entry;
 
  EntryPoints.cbSize = sizeof(EntryPoints);
  EntryPoints.protocolVersion = VIRTUAL_CHANNEL_VERSION_WIN2000;
  EntryPoints.pVirtualChannelInit = FreeRDP_VirtualChannelInit;
  EntryPoints.pVirtualChannelOpen = FreeRDP_VirtualChannelOpen;
  EntryPoints.pVirtualChannelClose = FreeRDP_VirtualChannelClose;
  EntryPoints.pVirtualChannelWrite = FreeRDP_VirtualChannelWrite;
  EntryPoints.MagicNumber = FREERDP_CHANNEL_MAGIC_NUMBER;
  EntryPoints.pExtendedData = data;
  EntryPoints.context = channels->instance->context;
  /* enable VirtualChannelInit */
  channels->can_call_init = TRUE;
  EnterCriticalSection(&channels->channelsLock);
  status = pChannelClientData->entry((PCHANNEL_ENTRY_POINTS)&EntryPoints);
  LeaveCriticalSection(&channels->channelsLock);
  /* disable MyVirtualChannelInit */
  channels->can_call_init = FALSE;
 
  if (!status)
  {
    WLog_ERR(TAG, "error: channel export function call failed");
    return 1;
  }
 
  return 0;
}
 
int freerdp_channels_client_load_ex(rdpChannels* channels, rdpSettings* settings,
                                    PVIRTUALCHANNELENTRYEX entryEx, void* data)
{
  int status = 0;
  void* pInitHandle = NULL;
  CHANNEL_ENTRY_POINTS_FREERDP_EX EntryPointsEx = { 0 };
  CHANNEL_INIT_DATA* pChannelInitData = NULL;
  CHANNEL_CLIENT_DATA* pChannelClientData = NULL;
 
  WINPR_ASSERT(channels);
  WINPR_ASSERT(channels->instance);
  WINPR_ASSERT(channels->instance->context);
  WINPR_ASSERT(entryEx);
 
  if (channels->clientDataCount + 1 > CHANNEL_MAX_COUNT)
  {
    WLog_ERR(TAG, "error: too many channels");
    return 1;
  }
 
  if (freerdp_channels_is_loaded_ex(channels, entryEx))
  {
    WLog_WARN(TAG, "Skipping, channel already loaded");
    return 0;
  }
 
  pChannelClientData = &channels->clientDataList[channels->clientDataCount];
  pChannelClientData->entryEx = entryEx;
  pChannelInitData = &(channels->initDataList[channels->initDataCount++]);
  pInitHandle = pChannelInitData;
  pChannelInitData->channels = channels;
  EntryPointsEx.cbSize = sizeof(EntryPointsEx);
  EntryPointsEx.protocolVersion = VIRTUAL_CHANNEL_VERSION_WIN2000;
  EntryPointsEx.pVirtualChannelInitEx = FreeRDP_VirtualChannelInitEx;
  EntryPointsEx.pVirtualChannelOpenEx = FreeRDP_VirtualChannelOpenEx;
  EntryPointsEx.pVirtualChannelCloseEx = FreeRDP_VirtualChannelCloseEx;
  EntryPointsEx.pVirtualChannelWriteEx = FreeRDP_VirtualChannelWriteEx;
  EntryPointsEx.MagicNumber = FREERDP_CHANNEL_MAGIC_NUMBER;
  EntryPointsEx.pExtendedData = data;
  EntryPointsEx.context = channels->instance->context;
  /* enable VirtualChannelInit */
  channels->can_call_init = TRUE;
  EnterCriticalSection(&channels->channelsLock);
  status = pChannelClientData->entryEx((PCHANNEL_ENTRY_POINTS_EX)&EntryPointsEx, pInitHandle);
  LeaveCriticalSection(&channels->channelsLock);
  /* disable MyVirtualChannelInit */
  channels->can_call_init = FALSE;
 
  if (!status)
  {
    WLog_ERR(TAG, "error: channel export function call failed");
    return 1;
  }
 
  return 0;
}
 
int freerdp_channels_load_plugin(rdpChannels* channels, rdpSettings* settings, const char* name,
                                 void* data)
{
  PVIRTUALCHANNELENTRY entry =
      freerdp_load_channel_addin_entry(name, NULL, NULL, FREERDP_ADDIN_CHANNEL_STATIC);
 
  if (!entry)
    return 1;
 
  return freerdp_channels_client_load(channels, settings, entry, data);
}