Detecta una activación de conexión a Internet con Delphi

winapi wininet

Question

He estado usando una tarjeta inalámbrica 3G durante un tiempo y cada vez que me conecto, mi antivirus activa las actualizaciones.

Me pregunto, ¿cuál es el conjunto de funciones de la API de Win32 que puedo utilizar para recibir notificaciones o consultar sobre el evento de una conexión a Internet?

¿Y ya hay un conjunto de encabezados portados para Delphi?

Answer 1

Mire InternetGetConnectedState en WinINet.

Algunas aplicaciones también pueden sondear un servidor conocido y no hacer nada hasta que obtengan una conexión válida.

Answer 2

uses WinInet;
function IsConnected: boolean;
const
// local system uses a modem to connect to the Internet.
INTERNET_CONNECTION_MODEM = 1;
// local system uses a local area network to connect to the Internet.
INTERNET_CONNECTION_LAN = 2;
// local system uses a proxy server to connect to the Internet.
INTERNET_CONNECTION_PROXY = 4;
// local system''s modem is busy with a non-Internet connection.
INTERNET_CONNECTION_MODEM_BUSY = 8;
var
dwConnectionTypes : DWORD;
begin
dwConnectionTypes := INTERNET_CONNECTION_MODEM +
INTERNET_CONNECTION_LAN +
INTERNET_CONNECTION_PROXY;
Result := InternetGetConnectedState(@dwConnectionTypes,0);
end;

Answer 3

Aquí hay un ejemplo práctico de cómo usar la unidad auxiliar. Es de un pequeño proyecto que escribí para emular "ifconfig -a". Este es un proyecto de aplicación de consola.

program ifconfig;
{$APPTYPE CONSOLE}
uses
SysUtils,
Classes,
Winsock,
uAdapterInfo in ''uAdapterInfo.pas'';
type
TAdapterInfo = array of record
dwIndex: longint;
dwType: longint;
dwMtu: longint;
dwSpeed: extended;
dwPhysAddrLen: longint;
bPhysAddr: string;
dwAdminStatus: longint;
dwOperStatus: longint;
dwLastChange: longint;
dwInOctets: longint;
dwInUcastPkts: longint;
dwInNUcastPkts: longint;
dwInDiscards: longint;
dwInErrors: longint;
dwInUnknownProtos: longint;
dwOutOctets: longint;
dwOutUcastPkts: longint;
dwOutNUcastPkts: longint;
dwOutDiscards: longint;
dwOutErrors: longint;
dwOutQLen: longint;
dwDescrLen: longint;
bDescr: string;
sIpAddress: string;
sIpMask: string;
end;
function Get_EthernetAdapterDetail(var AdapterDataFound: TAdapterInfo): boolean;
var
pIfTable: ^_IfTable;
pIpTable: ^_IpAddrTable;
ifTableSize, ipTableSize: longint;
tmp: string;
i, j, k, m: integer;
ErrCode: longint;
sAddr, sMask: in_addr;
IPAddresses, IPMasks: TStringList;
sIPAddressLine, sIPMaskLine: string;
bResult: boolean;
begin
bResult := True; //default return value
pIfTable := nil;
pIpTable := nil;
IPAddresses := TStringList.Create;
IPMasks := TStringList.Create;
try
// First: just get the buffer size.
// TableSize returns the size needed.
ifTableSize := 0; // Set to zero so the GetIfTabel function
// won''t try to fill the buffer yet,
// but only return the actual size it needs.
GetIfTable(pIfTable, ifTableSize, 1);
if (ifTableSize < SizeOf(MIB_IFROW) + Sizeof(longint)) then
begin
bResult := False;
Result := bResult;
Exit; // less than 1 table entry?!
end;
ipTableSize := 0;
GetIpAddrTable(pIpTable, ipTableSize, 1);
if (ipTableSize < SizeOf(MIB_IPADDRROW) + Sizeof(longint)) then
begin
bResult := False;
Result := bResult;
Exit; // less than 1 table entry?!
end;
// Second:
// allocate memory for the buffer and retrieve the
// entire table.
GetMem(pIfTable, ifTableSize);
ErrCode := GetIfTable(pIfTable, ifTableSize, 1);
if ErrCode <> ERROR_SUCCESS then
begin
bResult := False;
Result := bResult;
Exit; // OK, that did not work.
// Not enough memory i guess.
end;
GetMem(pIpTable, ipTableSize);
ErrCode := GetIpAddrTable(pIpTable, ipTableSize, 1);
if ErrCode <> ERROR_SUCCESS then
begin
bResult := False;
Result := bResult;
Exit;
end;
for k := 1 to pIpTable^.dwNumEntries do
begin
sAddr.S_addr := pIpTable^.table[k].dwAddr;
sMask.S_addr := pIpTable^.table[k].dwMask;
sIPAddressLine := Format(''0x%8.8x'', [(pIpTable^.table[k].dwIndex)]) +
''='' + Format(''%s'', [inet_ntoa(sAddr)]);
sIPMaskLine := Format(''0x%8.8x'', [(pIpTable^.table[k].dwIndex)]) +
''='' + Format(''%s'', [inet_ntoa(sMask)]);
IPAddresses.Add(sIPAddressLine);
IPMasks.Add(sIPMaskLine);
end;
SetLength(AdapterDataFound, pIfTable^.nRows); //initialize the array or records
for i := 1 to pIfTable^.nRows do
try
//if pIfTable^.ifRow[i].dwType=MIB_IF_TYPE_ETHERNET then
//begin
m := i - 1;
AdapterDataFound[m].dwIndex := 4;//(pIfTable^.ifRow[i].dwIndex);
AdapterDataFound[m].dwType := (pIfTable^.ifRow[i].dwType);
AdapterDataFound[m].dwIndex := (pIfTable^.ifRow[i].dwIndex);
AdapterDataFound[m].sIpAddress :=
IPAddresses.Values[Format(''0x%8.8x'', [(pIfTable^.ifRow[i].dwIndex)])];
AdapterDataFound[m].sIpMask :=
IPMasks.Values[Format(''0x%8.8x'', [(pIfTable^.ifRow[i].dwIndex)])];
AdapterDataFound[m].dwMtu := (pIfTable^.ifRow[i].dwMtu);
AdapterDataFound[m].dwSpeed := (pIfTable^.ifRow[i].dwSpeed);
AdapterDataFound[m].dwAdminStatus := (pIfTable^.ifRow[i].dwAdminStatus);
AdapterDataFound[m].dwOperStatus := (pIfTable^.ifRow[i].dwOperStatus);
AdapterDataFound[m].dwInUcastPkts := (pIfTable^.ifRow[i].dwInUcastPkts);
AdapterDataFound[m].dwInNUcastPkts := (pIfTable^.ifRow[i].dwInNUcastPkts);
AdapterDataFound[m].dwInDiscards := (pIfTable^.ifRow[i].dwInDiscards);
AdapterDataFound[m].dwInErrors := (pIfTable^.ifRow[i].dwInErrors);
AdapterDataFound[m].dwInUnknownProtos := (pIfTable^.ifRow[i].dwInUnknownProtos);
AdapterDataFound[m].dwOutNUcastPkts := (pIfTable^.ifRow[i].dwOutNUcastPkts);
AdapterDataFound[m].dwOutUcastPkts := (pIfTable^.ifRow[i].dwOutUcastPkts);
AdapterDataFound[m].dwOutDiscards := (pIfTable^.ifRow[i].dwOutDiscards);
AdapterDataFound[m].dwOutErrors := (pIfTable^.ifRow[i].dwOutErrors);
AdapterDataFound[m].dwOutQLen := (pIfTable^.ifRow[i].dwOutQLen);
AdapterDataFound[m].bDescr := (pIfTable^.ifRow[i].bDescr);
tmp := '''';
for j := 0 to pIfTable^.ifRow[i].dwPhysAddrLen - 1 do
begin
if Length(tmp) > 0 then
tmp := tmp + ''-'' + format(''%.2x'', [pIfTable^.ifRow[i].bPhysAddr[j]])
else
tmp := tmp + format(''%.2x'', [pIfTable^.ifRow[i].bPhysAddr[j]]);
end;
if Length(tmp) > 0 then
begin
AdapterDataFound[m].bPhysAddr := tmp;
end;
except
bResult := False;
Result := bResult;
Exit;
end;
finally
if Assigned(pIfTable) then
begin
FreeMem(pIfTable, ifTableSize);
end;
FreeAndNil(IPMasks);
FreeAndNil(IPAddresses);
end;
Result := bResult;
end;
var
AdapterData: TAdapterInfo;
i: integer;
begin
try
WriteLn('''');
if Get_EthernetAdapterDetail(AdapterData) then
begin
for i := 0 to Length(AdapterData) - 1 do
begin
WriteLn(Format(''0x%8.8x'', [AdapterData[i].dwIndex]));
WriteLn(''"'' + AdapterData[i].bDescr + ''"'');
Write(Format(#9 + ''Link encap: %s '', [Get_if_type(AdapterData[i].dwType)]));
if Length(AdapterData[i].bPhysAddr) > 0 then
Write(''HWaddr: '' + AdapterData[i].bPhysAddr);
Write(#13 + #10 + #9 + ''inet addr:'' + AdapterData[i].sIpAddress);
WriteLn('' Mask: '' + AdapterData[i].sIpMask);
WriteLn(Format(#9 + ''MTU: %d Speed:%.2f Mbps'', [AdapterData[i].dwMtu,
(AdapterData[i].dwSpeed) / 1000 / 1000]));
Write(#9 + ''Admin status:'' + Get_if_admin_status(AdapterData[i].dwAdminStatus));
WriteLn('' Oper status:'' + Get_if_oper_status(AdapterData[i].dwOperStatus));
WriteLn(#9 + Format(''RX packets:%d dropped:%d errors:%d unkown:%d'',
[AdapterData[i].dwInUcastPkts + AdapterData[i].dwInNUcastPkts,
AdapterData[i].dwInDiscards, AdapterData[i].dwInErrors,
AdapterData[i].dwInUnknownProtos]));
WriteLn(#9 + Format(''TX packets:%d dropped:%d errors:%d txqueuelen:%d'',
[AdapterData[i].dwOutUcastPkts + AdapterData[i].dwOutNUcastPkts,
AdapterData[i].dwOutDiscards, AdapterData[i].dwOutErrors,
AdapterData[i].dwOutQLen]));
WriteLn('''');
end;
end
else
begin
WriteLn(#13+#10+''*** Error retrieving adapter information'');
end;
except
on E: Exception do
Writeln(E.ClassName, '': '', E.Message);
end;
end.

Answer 4

Trabajé en un proyecto para ejecutar un script de inicio de sesión de un usuario cada vez que conectaban nuestra red a través de VPN. Para hacer esto, escribí una unidad auxiliar que recupera la información del adaptador y la almacena en un registro simple.

Luego configuré una notificación de registro, mire aquí cómo hacerlo en Delphi

La notificación de registro estaba en HKLM/SYSTEM/CurrentControlSet/Services/Tcpip/Parameters/Interfaces . Este evento de notificación se activa cada vez que Windows obtiene una nueva dirección IP o realiza cualquier tipo de cambio en la información de conexión de un adaptador. Cuando se desencadenó este evento, llamé a la función (en el código siguiente) para recuperar información actualizada sobre el adaptador. Comparé esta nueva información con mi información previamente grabada ... lo que significa que tuve que guardar la consulta previa de información del adaptador para saber si algo había cambiado.

De todos modos, aquí está mi unidad de ayuda:

unit uAdapterInfo;
interface
uses
Classes,
SysUtils;
const
MAX_INTERFACE_NAME_LEN = $100;
ERROR_SUCCESS = 0;
MAXLEN_IFDESCR = $100;
MAXLEN_PHYSADDR = 8;
MIB_IF_OPER_STATUS_NON_OPERATIONAL = 0;
MIB_IF_OPER_STATUS_UNREACHABLE = 1;
MIB_IF_OPER_STATUS_DISCONNECTED = 2;
MIB_IF_OPER_STATUS_CONNECTING = 3;
MIB_IF_OPER_STATUS_CONNECTED = 4;
MIB_IF_OPER_STATUS_OPERATIONAL = 5;
MIB_IF_TYPE_OTHER = 1;
MIB_IF_TYPE_ETHERNET = 6;
MIB_IF_TYPE_TOKENRING = 9;
MIB_IF_TYPE_FDDI = 15;
MIB_IF_TYPE_PPP = 23;
MIB_IF_TYPE_LOOPBACK = 24;
MIB_IF_TYPE_SLIP = 28;
MIB_IF_ADMIN_STATUS_UP = 1;
MIB_IF_ADMIN_STATUS_DOWN = 2;
MIB_IF_ADMIN_STATUS_TESTING = 3;
_MAX_ROWS_ = 20;
ANY_SIZE = 1;
type
MIB_IFROW = record
wszName: array[0 .. (MAX_INTERFACE_NAME_LEN * 2 - 1)] of ansichar;
dwIndex: longint;
dwType: longint;
dwMtu: longint;
dwSpeed: longint;
dwPhysAddrLen: longint;
bPhysAddr: array[0 .. (MAXLEN_PHYSADDR - 1)] of byte;
dwAdminStatus: longint;
dwOperStatus: longint;
dwLastChange: longint;
dwInOctets: longint;
dwInUcastPkts: longint;
dwInNUcastPkts: longint;
dwInDiscards: longint;
dwInErrors: longint;
dwInUnknownProtos: longint;
dwOutOctets: longint;
dwOutUcastPkts: longint;
dwOutNUcastPkts: longint;
dwOutDiscards: longint;
dwOutErrors: longint;
dwOutQLen: longint;
dwDescrLen: longint;
bDescr: array[0 .. (MAXLEN_IFDESCR - 1)] of ansichar;
end;
type
MIB_IPADDRROW = record
dwAddr: longint;
dwIndex: longint;
dwMask: longint;
dwBCastAddr: longint;
dwReasmSize: longint;
unused1: word;
unused2: word;
end;
type
_IfTable = record
nRows: longint;
ifRow: array[1.._MAX_ROWS_] of MIB_IFROW;
end;
type
_IpAddrTable = record
dwNumEntries: longint;
table: array[1..ANY_SIZE] of MIB_IPADDRROW;
end;
function GetIfTable(pIfTable: Pointer; var pdwSize: longint; bOrder: longint): longint;
stdcall;
function GetIpAddrTable(pIpAddrTable: Pointer; var pdwSize: longint;
bOrder: longint): longint; stdcall;
function Get_if_type(iType: integer): string;
function Get_if_admin_status(iStatus: integer): string;
function Get_if_oper_status(iStatus: integer): string;
implementation
function GetIfTable; stdcall; external ''IPHLPAPI.DLL'';
function GetIpAddrTable; stdcall; external ''IPHLPAPI.DLL'';
function Get_if_type(iType: integer): string;
var
sResult: string;
begin
sResult := ''UNKNOWN'';
case iType of
1: sResult := ''Other'';
6: sResult := ''Ethernet'';
9: sResult := ''Tokenring'';
15: sResult := ''FDDI'';
23: sResult := ''PPP'';
24: sResult := ''Local loopback'';
28: sResult := ''SLIP'';
37: sResult := ''ATM'';
71: sResult := ''IEEE 802.11'';
131: sResult := ''Tunnel'';
144: sResult := ''IEEE 1394 (Firewire)'';
end;
Result := sResult;
end;
function Get_if_admin_status(iStatus: integer): string;
var
sResult: string;
begin
sResult := ''UNKNOWN'';
case iStatus of
1: sResult := ''UP'';
2: sResult := ''DOWN'';
3: sResult := ''TESTING'';
end;
Result := sResult;
end;
function Get_if_oper_status(iStatus: integer): string;
var
sResult: string;
begin
sResult := ''UNKNOWN'';
case iStatus of
0: sResult := ''NON_OPERATIONAL'';
1: sResult := ''UNREACHABLE'';
2: sResult := ''DISCONNECTED'';
3: sResult := ''CONNECTING'';
4: sResult := ''CONNECTED'';
5: sResult := ''OPERATIONAL'';
end;
Result := sResult;
end;
end.

Para usar esta unidad desde otra unidad, creé la siguiente función, que TAdapterInfo un tipo personalizado llamado TAdapterInfo (declarado en mi unidad principal):

type
TAdapterInfo = array of record
dwIndex: longint;
dwType: longint;
dwMtu: longint;
dwSpeed: extended;
dwPhysAddrLen: longint;
bPhysAddr: string;
dwAdminStatus: longint;
dwOperStatus: longint;
dwLastChange: longint;
dwInOctets: longint;
dwInUcastPkts: longint;
dwInNUcastPkts: longint;
dwInDiscards: longint;
dwInErrors: longint;
dwInUnknownProtos: longint;
dwOutOctets: longint;
dwOutUcastPkts: longint;
dwOutNUcastPkts: longint;
dwOutDiscards: longint;
dwOutErrors: longint;
dwOutQLen: longint;
dwDescrLen: longint;
bDescr: string;
sIpAddress: string;
sIpMask: string;
end;

//////////

function Get_EthernetAdapterDetail(var AdapterDataFound: TAdapterInfo): boolean;
var
pIfTable: ^_IfTable;
pIpTable: ^_IpAddrTable;
ifTableSize, ipTableSize: longint;
tmp: string;
i, j, k, m: integer;
ErrCode: longint;
sAddr, sMask: in_addr;
IPAddresses, IPMasks: TStringList;
sIPAddressLine, sIPMaskLine: string;
bResult: boolean;
begin
bResult := True; //default return value
pIfTable := nil;
pIpTable := nil;
IPAddresses := TStringList.Create;
IPMasks := TStringList.Create;
try
// First: just get the buffer size.
// TableSize returns the size needed.
ifTableSize := 0; // Set to zero so the GetIfTabel function
// won''t try to fill the buffer yet,
// but only return the actual size it needs.
GetIfTable(pIfTable, ifTableSize, 1);
if (ifTableSize < SizeOf(MIB_IFROW) + Sizeof(longint)) then
begin
bResult := False;
Result := bResult;
Exit; // less than 1 table entry?!
end;
ipTableSize := 0;
GetIpAddrTable(pIpTable, ipTableSize, 1);
if (ipTableSize < SizeOf(MIB_IPADDRROW) + Sizeof(longint)) then
begin
bResult := False;
Result := bResult;
Exit; // less than 1 table entry?!
end;
// Second:
// allocate memory for the buffer and retrieve the
// entire table.
GetMem(pIfTable, ifTableSize);
ErrCode := GetIfTable(pIfTable, ifTableSize, 1);
if ErrCode <> ERROR_SUCCESS then
begin
bResult := False;
Result := bResult;
Exit; // OK, that did not work.
// Not enough memory i guess.
end;
GetMem(pIpTable, ipTableSize);
ErrCode := GetIpAddrTable(pIpTable, ipTableSize, 1);
if ErrCode <> ERROR_SUCCESS then
begin
bResult := False;
Result := bResult;
Exit;
end;
for k := 1 to pIpTable^.dwNumEntries do
begin
sAddr.S_addr := pIpTable^.table[k].dwAddr;
sMask.S_addr := pIpTable^.table[k].dwMask;
sIPAddressLine := Format(''0x%8.8x'', [(pIpTable^.table[k].dwIndex)]) +
''='' + Format(''%s'', [inet_ntoa(sAddr)]);
sIPMaskLine := Format(''0x%8.8x'', [(pIpTable^.table[k].dwIndex)]) +
''='' + Format(''%s'', [inet_ntoa(sMask)]);
IPAddresses.Add(sIPAddressLine);
IPMasks.Add(sIPMaskLine);
end;
SetLength(AdapterDataFound, pIfTable^.nRows); //initialize the array or records
for i := 1 to pIfTable^.nRows do
try
//if pIfTable^.ifRow[i].dwType=MIB_IF_TYPE_ETHERNET then
//begin
m := i - 1;
AdapterDataFound[m].dwIndex := 4;//(pIfTable^.ifRow[i].dwIndex);
AdapterDataFound[m].dwType := (pIfTable^.ifRow[i].dwType);
AdapterDataFound[m].dwIndex := (pIfTable^.ifRow[i].dwIndex);
AdapterDataFound[m].sIpAddress :=
IPAddresses.Values[Format(''0x%8.8x'', [(pIfTable^.ifRow[i].dwIndex)])];
AdapterDataFound[m].sIpMask :=
IPMasks.Values[Format(''0x%8.8x'', [(pIfTable^.ifRow[i].dwIndex)])];
AdapterDataFound[m].dwMtu := (pIfTable^.ifRow[i].dwMtu);
AdapterDataFound[m].dwSpeed := (pIfTable^.ifRow[i].dwSpeed);
AdapterDataFound[m].dwAdminStatus := (pIfTable^.ifRow[i].dwAdminStatus);
AdapterDataFound[m].dwOperStatus := (pIfTable^.ifRow[i].dwOperStatus);
AdapterDataFound[m].dwInUcastPkts := (pIfTable^.ifRow[i].dwInUcastPkts);
AdapterDataFound[m].dwInNUcastPkts := (pIfTable^.ifRow[i].dwInNUcastPkts);
AdapterDataFound[m].dwInDiscards := (pIfTable^.ifRow[i].dwInDiscards);
AdapterDataFound[m].dwInErrors := (pIfTable^.ifRow[i].dwInErrors);
AdapterDataFound[m].dwInUnknownProtos := (pIfTable^.ifRow[i].dwInUnknownProtos);
AdapterDataFound[m].dwOutNUcastPkts := (pIfTable^.ifRow[i].dwOutNUcastPkts);
AdapterDataFound[m].dwOutUcastPkts := (pIfTable^.ifRow[i].dwOutUcastPkts);
AdapterDataFound[m].dwOutDiscards := (pIfTable^.ifRow[i].dwOutDiscards);
AdapterDataFound[m].dwOutErrors := (pIfTable^.ifRow[i].dwOutErrors);
AdapterDataFound[m].dwOutQLen := (pIfTable^.ifRow[i].dwOutQLen);
AdapterDataFound[m].bDescr := (pIfTable^.ifRow[i].bDescr);
tmp := '''';
for j := 0 to pIfTable^.ifRow[i].dwPhysAddrLen - 1 do
begin
if Length(tmp) > 0 then
tmp := tmp + ''-'' + format(''%.2x'', [pIfTable^.ifRow[i].bPhysAddr[j]])
else
tmp := tmp + format(''%.2x'', [pIfTable^.ifRow[i].bPhysAddr[j]]);
end;
if Length(tmp) > 0 then
begin
AdapterDataFound[m].bPhysAddr := tmp;
end;
except
bResult := False;
Result := bResult;
Exit;
end;
finally
if Assigned(pIfTable) then
begin
FreeMem(pIfTable, ifTableSize);
end;
FreeAndNil(IPMasks);
FreeAndNil(IPAddresses);
end;
Result := bResult;
end;

En una nota totalmente lateral, también usé esta unidad y casi el mismo código exacto para crear un duplicado de ifconfig -a , que se puede encontrar en github . Principalmente lo hice como un ejercicio para enseñarme a mí mismo cómo lograr esta tarea.