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third-party-mirror / openvpn / ac2da300dcd4eb79b146e91455cca2c610f394fa / . / src / openvpnserv / interactive.c
blob: 5d5cbfe60324944eab4316d123438641a62b2d5d [file] [log] [blame]
/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single TCP/UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2012-2018 Heiko Hund <heiko.hund@sophos.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* 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; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "service.h"
#include <ws2tcpip.h>
#include <iphlpapi.h>
#include <userenv.h>
#include <accctrl.h>
#include <aclapi.h>
#include <stdio.h>
#include <sddl.h>
#include <shellapi.h>
#include <mstcpip.h>
#ifdef HAVE_VERSIONHELPERS_H
#include <versionhelpers.h>
#else
#include "compat-versionhelpers.h"
#endif
#include "openvpn-msg.h"
#include "validate.h"
#include "block_dns.h"
#include "ring_buffer.h"
#define IO_TIMEOUT 2000 /*ms*/
#define ERROR_OPENVPN_STARTUP 0x20000000
#define ERROR_STARTUP_DATA 0x20000001
#define ERROR_MESSAGE_DATA 0x20000002
#define ERROR_MESSAGE_TYPE 0x20000003
static SERVICE_STATUS_HANDLE service;
static SERVICE_STATUS status = { .dwServiceType = SERVICE_WIN32_SHARE_PROCESS };
static HANDLE exit_event = NULL;
static settings_t settings;
static HANDLE rdns_semaphore = NULL;
#define RDNS_TIMEOUT 600 /* seconds to wait for the semaphore */
#define TUN_IOCTL_REGISTER_RINGS CTL_CODE(51820U, 0x970U, METHOD_BUFFERED, FILE_READ_DATA | FILE_WRITE_DATA)
openvpn_service_t interactive_service = {
interactive,
TEXT(PACKAGE_NAME "ServiceInteractive"),
TEXT(PACKAGE_NAME " Interactive Service"),
TEXT(SERVICE_DEPENDENCIES),
SERVICE_AUTO_START
};
typedef struct {
WCHAR *directory;
WCHAR *options;
WCHAR *std_input;
} STARTUP_DATA;
/* Datatype for linked lists */
typedef struct _list_item {
struct _list_item *next;
LPVOID data;
} list_item_t;
/* Datatypes for undo information */
typedef enum {
address,
route,
block_dns,
undo_dns4,
undo_dns6,
undo_domain,
_undo_type_max
} undo_type_t;
typedef list_item_t *undo_lists_t[_undo_type_max];
typedef struct {
HANDLE engine;
int index;
int metric_v4;
int metric_v6;
} block_dns_data_t;
typedef struct {
HANDLE send_ring_handle;
HANDLE receive_ring_handle;
HANDLE send_tail_moved;
HANDLE receive_tail_moved;
HANDLE device;
} ring_buffer_handles_t;
static DWORD
AddListItem(list_item_t **pfirst, LPVOID data)
{
list_item_t *new_item = malloc(sizeof(list_item_t));
if (new_item == NULL)
{
return ERROR_OUTOFMEMORY;
}
new_item->next = *pfirst;
new_item->data = data;
*pfirst = new_item;
return NO_ERROR;
}
typedef BOOL (*match_fn_t) (LPVOID item, LPVOID ctx);
static LPVOID
RemoveListItem(list_item_t **pfirst, match_fn_t match, LPVOID ctx)
{
LPVOID data = NULL;
list_item_t **pnext;
for (pnext = pfirst; *pnext; pnext = &(*pnext)->next)
{
list_item_t *item = *pnext;
if (!match(item->data, ctx))
{
continue;
}
/* Found item, remove from the list and free memory */
*pnext = item->next;
data = item->data;
free(item);
break;
}
return data;
}
static HANDLE
CloseHandleEx(LPHANDLE handle)
{
if (handle && *handle && *handle != INVALID_HANDLE_VALUE)
{
CloseHandle(*handle);
*handle = INVALID_HANDLE_VALUE;
}
return INVALID_HANDLE_VALUE;
}
static HANDLE
OvpnUnmapViewOfFile(LPHANDLE handle)
{
if (handle && *handle && *handle != INVALID_HANDLE_VALUE)
{
UnmapViewOfFile(*handle);
*handle = INVALID_HANDLE_VALUE;
}
return INVALID_HANDLE_VALUE;
}
static void
CloseRingBufferHandles(ring_buffer_handles_t *ring_buffer_handles)
{
CloseHandleEx(&ring_buffer_handles->device);
CloseHandleEx(&ring_buffer_handles->receive_tail_moved);
CloseHandleEx(&ring_buffer_handles->send_tail_moved);
OvpnUnmapViewOfFile(&ring_buffer_handles->send_ring_handle);
OvpnUnmapViewOfFile(&ring_buffer_handles->receive_ring_handle);
}
static HANDLE
InitOverlapped(LPOVERLAPPED overlapped)
{
ZeroMemory(overlapped, sizeof(OVERLAPPED));
overlapped->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
return overlapped->hEvent;
}
static BOOL
ResetOverlapped(LPOVERLAPPED overlapped)
{
HANDLE io_event = overlapped->hEvent;
if (!ResetEvent(io_event))
{
return FALSE;
}
ZeroMemory(overlapped, sizeof(OVERLAPPED));
overlapped->hEvent = io_event;
return TRUE;
}
typedef enum {
peek,
read,
write
} async_op_t;
static DWORD
AsyncPipeOp(async_op_t op, HANDLE pipe, LPVOID buffer, DWORD size, DWORD count, LPHANDLE events)
{
DWORD i;
BOOL success;
HANDLE io_event;
DWORD res, bytes = 0;
OVERLAPPED overlapped;
LPHANDLE handles = NULL;
io_event = InitOverlapped(&overlapped);
if (!io_event)
{
goto out;
}
handles = malloc((count + 1) * sizeof(HANDLE));
if (!handles)
{
goto out;
}
if (op == write)
{
success = WriteFile(pipe, buffer, size, NULL, &overlapped);
}
else
{
success = ReadFile(pipe, buffer, size, NULL, &overlapped);
}
if (!success && GetLastError() != ERROR_IO_PENDING && GetLastError() != ERROR_MORE_DATA)
{
goto out;
}
handles[0] = io_event;
for (i = 0; i < count; i++)
{
handles[i + 1] = events[i];
}
res = WaitForMultipleObjects(count + 1, handles, FALSE,
op == peek ? INFINITE : IO_TIMEOUT);
if (res != WAIT_OBJECT_0)
{
CancelIo(pipe);
goto out;
}
if (op == peek)
{
PeekNamedPipe(pipe, NULL, 0, NULL, &bytes, NULL);
}
else
{
GetOverlappedResult(pipe, &overlapped, &bytes, TRUE);
}
out:
CloseHandleEx(&io_event);
free(handles);
return bytes;
}
static DWORD
PeekNamedPipeAsync(HANDLE pipe, DWORD count, LPHANDLE events)
{
return AsyncPipeOp(peek, pipe, NULL, 0, count, events);
}
static DWORD
ReadPipeAsync(HANDLE pipe, LPVOID buffer, DWORD size, DWORD count, LPHANDLE events)
{
return AsyncPipeOp(read, pipe, buffer, size, count, events);
}
static DWORD
WritePipeAsync(HANDLE pipe, LPVOID data, DWORD size, DWORD count, LPHANDLE events)
{
return AsyncPipeOp(write, pipe, data, size, count, events);
}
static VOID
ReturnProcessId(HANDLE pipe, DWORD pid, DWORD count, LPHANDLE events)
{
const WCHAR msg[] = L"Process ID";
WCHAR buf[22 + _countof(msg)]; /* 10 chars each for error and PID and 2 for line breaks */
/*
* Same format as error messages (3 line string) with error = 0 in
* 0x%08x format, PID on line 2 and a description "Process ID" on line 3
*/
openvpn_swprintf(buf, _countof(buf), L"0x%08x\n0x%08x\n%s", 0, pid, msg);
WritePipeAsync(pipe, buf, (DWORD)(wcslen(buf) * 2), count, events);
}
static VOID
ReturnError(HANDLE pipe, DWORD error, LPCWSTR func, DWORD count, LPHANDLE events)
{
DWORD result_len;
LPWSTR result = L"0xffffffff\nFormatMessage failed\nCould not return result";
DWORD_PTR args[] = {
(DWORD_PTR) error,
(DWORD_PTR) func,
(DWORD_PTR) ""
};
if (error != ERROR_OPENVPN_STARTUP)
{
FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM
|FORMAT_MESSAGE_ALLOCATE_BUFFER
|FORMAT_MESSAGE_IGNORE_INSERTS,
0, error, 0, (LPWSTR) &args[2], 0, NULL);
}
result_len = FormatMessageW(FORMAT_MESSAGE_FROM_STRING
|FORMAT_MESSAGE_ALLOCATE_BUFFER
|FORMAT_MESSAGE_ARGUMENT_ARRAY,
L"0x%1!08x!\n%2!s!\n%3!s!", 0, 0,
(LPWSTR) &result, 0, (va_list *) args);
WritePipeAsync(pipe, result, (DWORD)(wcslen(result) * 2), count, events);
#ifdef UNICODE
MsgToEventLog(MSG_FLAGS_ERROR, result);
#else
MsgToEventLog(MSG_FLAGS_ERROR, "%S", result);
#endif
if (error != ERROR_OPENVPN_STARTUP)
{
LocalFree((LPVOID) args[2]);
}
if (result_len)
{
LocalFree(result);
}
}
static VOID
ReturnLastError(HANDLE pipe, LPCWSTR func)
{
ReturnError(pipe, GetLastError(), func, 1, &exit_event);
}
/*
* Validate options against a white list. Also check the config_file is
* inside the config_dir. The white list is defined in validate.c
* Returns true on success, false on error with reason set in errmsg.
*/
static BOOL
ValidateOptions(HANDLE pipe, const WCHAR *workdir, const WCHAR *options, WCHAR *errmsg, DWORD capacity)
{
WCHAR **argv;
int argc;
BOOL ret = FALSE;
int i;
const WCHAR *msg1 = L"You have specified a config file location (%s relative to %s)"
L" that requires admin approval. This error may be avoided"
L" by adding your account to the \"%s\" group";
const WCHAR *msg2 = L"You have specified an option (%s) that may be used"
L" only with admin approval. This error may be avoided"
L" by adding your account to the \"%s\" group";
argv = CommandLineToArgvW(options, &argc);
if (!argv)
{
openvpn_swprintf(errmsg, capacity,
L"Cannot validate options: CommandLineToArgvW failed with error = 0x%08x",
GetLastError());
goto out;
}
/* Note: argv[0] is the first option */
if (argc < 1) /* no options */
{
ret = TRUE;
goto out;
}
/*
* If only one argument, it is the config file
*/
if (argc == 1)
{
WCHAR *argv_tmp[2] = { L"--config", argv[0] };
if (!CheckOption(workdir, 2, argv_tmp, &settings))
{
openvpn_swprintf(errmsg, capacity, msg1, argv[0], workdir,
settings.ovpn_admin_group);
}
goto out;
}
for (i = 0; i < argc; ++i)
{
if (!IsOption(argv[i]))
{
continue;
}
if (!CheckOption(workdir, argc-i, &argv[i], &settings))
{
if (wcscmp(L"--config", argv[i]) == 0 && argc-i > 1)
{
openvpn_swprintf(errmsg, capacity, msg1, argv[i+1], workdir,
settings.ovpn_admin_group);
}
else
{
openvpn_swprintf(errmsg, capacity, msg2, argv[i],
settings.ovpn_admin_group);
}
goto out;
}
}
/* all options passed */
ret = TRUE;
out:
if (argv)
{
LocalFree(argv);
}
return ret;
}
static BOOL
GetStartupData(HANDLE pipe, STARTUP_DATA *sud)
{
size_t size, len;
WCHAR *data = NULL;
DWORD bytes, read;
bytes = PeekNamedPipeAsync(pipe, 1, &exit_event);
if (bytes == 0)
{
MsgToEventLog(M_SYSERR, TEXT("PeekNamedPipeAsync failed"));
ReturnLastError(pipe, L"PeekNamedPipeAsync");
goto err;
}
size = bytes / sizeof(*data);
if (size == 0)
{
MsgToEventLog(M_SYSERR, TEXT("malformed startup data: 1 byte received"));
ReturnError(pipe, ERROR_STARTUP_DATA, L"GetStartupData", 1, &exit_event);
goto err;
}
data = malloc(bytes);
if (data == NULL)
{
MsgToEventLog(M_SYSERR, TEXT("malloc failed"));
ReturnLastError(pipe, L"malloc");
goto err;
}
read = ReadPipeAsync(pipe, data, bytes, 1, &exit_event);
if (bytes != read)
{
MsgToEventLog(M_SYSERR, TEXT("ReadPipeAsync failed"));
ReturnLastError(pipe, L"ReadPipeAsync");
goto err;
}
if (data[size - 1] != 0)
{
MsgToEventLog(M_ERR, TEXT("Startup data is not NULL terminated"));
ReturnError(pipe, ERROR_STARTUP_DATA, L"GetStartupData", 1, &exit_event);
goto err;
}
sud->directory = data;
len = wcslen(sud->directory) + 1;
size -= len;
if (size <= 0)
{
MsgToEventLog(M_ERR, TEXT("Startup data ends at working directory"));
ReturnError(pipe, ERROR_STARTUP_DATA, L"GetStartupData", 1, &exit_event);
goto err;
}
sud->options = sud->directory + len;
len = wcslen(sud->options) + 1;
size -= len;
if (size <= 0)
{
MsgToEventLog(M_ERR, TEXT("Startup data ends at command line options"));
ReturnError(pipe, ERROR_STARTUP_DATA, L"GetStartupData", 1, &exit_event);
goto err;
}
sud->std_input = sud->options + len;
return TRUE;
err:
sud->directory = NULL; /* caller must not free() */
free(data);
return FALSE;
}
static VOID
FreeStartupData(STARTUP_DATA *sud)
{
free(sud->directory);
}
static SOCKADDR_INET
sockaddr_inet(short family, inet_address_t *addr)
{
SOCKADDR_INET sa_inet;
ZeroMemory(&sa_inet, sizeof(sa_inet));
sa_inet.si_family = family;
if (family == AF_INET)
{
sa_inet.Ipv4.sin_addr = addr->ipv4;
}
else if (family == AF_INET6)
{
sa_inet.Ipv6.sin6_addr = addr->ipv6;
}
return sa_inet;
}
static DWORD
InterfaceLuid(const char *iface_name, PNET_LUID luid)
{
NETIO_STATUS status;
LPWSTR wide_name = utf8to16(iface_name);
if (wide_name)
{
status = ConvertInterfaceAliasToLuid(wide_name, luid);
free(wide_name);
}
else
{
status = ERROR_OUTOFMEMORY;
}
return status;
}
static DWORD
ConvertInterfaceNameToIndex(const wchar_t *ifname, NET_IFINDEX *index)
{
NET_LUID luid;
DWORD err;
err = ConvertInterfaceAliasToLuid(ifname, &luid);
if (err == ERROR_SUCCESS)
{
err = ConvertInterfaceLuidToIndex(&luid, index);
}
if (err != ERROR_SUCCESS)
{
MsgToEventLog(M_ERR, L"Failed to find interface index for <%s>", ifname);
}
return err;
}
static BOOL
CmpAddress(LPVOID item, LPVOID address)
{
return memcmp(item, address, sizeof(MIB_UNICASTIPADDRESS_ROW)) == 0 ? TRUE : FALSE;
}
static DWORD
DeleteAddress(PMIB_UNICASTIPADDRESS_ROW addr_row)
{
return DeleteUnicastIpAddressEntry(addr_row);
}
static DWORD
HandleAddressMessage(address_message_t *msg, undo_lists_t *lists)
{
DWORD err;
PMIB_UNICASTIPADDRESS_ROW addr_row;
BOOL add = msg->header.type == msg_add_address;
addr_row = malloc(sizeof(*addr_row));
if (addr_row == NULL)
{
return ERROR_OUTOFMEMORY;
}
InitializeUnicastIpAddressEntry(addr_row);
addr_row->Address = sockaddr_inet(msg->family, &msg->address);
addr_row->OnLinkPrefixLength = (UINT8) msg->prefix_len;
if (msg->iface.index != -1)
{
addr_row->InterfaceIndex = msg->iface.index;
}
else
{
NET_LUID luid;
err = InterfaceLuid(msg->iface.name, &luid);
if (err)
{
goto out;
}
addr_row->InterfaceLuid = luid;
}
if (add)
{
err = CreateUnicastIpAddressEntry(addr_row);
if (err)
{
goto out;
}
err = AddListItem(&(*lists)[address], addr_row);
if (err)
{
DeleteAddress(addr_row);
}
}
else
{
err = DeleteAddress(addr_row);
if (err)
{
goto out;
}
free(RemoveListItem(&(*lists)[address], CmpAddress, addr_row));
}
out:
if (!add || err)
{
free(addr_row);
}
return err;
}
static BOOL
CmpRoute(LPVOID item, LPVOID route)
{
return memcmp(item, route, sizeof(MIB_IPFORWARD_ROW2)) == 0 ? TRUE : FALSE;
}
static DWORD
DeleteRoute(PMIB_IPFORWARD_ROW2 fwd_row)
{
return DeleteIpForwardEntry2(fwd_row);
}
static DWORD
HandleRouteMessage(route_message_t *msg, undo_lists_t *lists)
{
DWORD err;
PMIB_IPFORWARD_ROW2 fwd_row;
BOOL add = msg->header.type == msg_add_route;
fwd_row = malloc(sizeof(*fwd_row));
if (fwd_row == NULL)
{
return ERROR_OUTOFMEMORY;
}
ZeroMemory(fwd_row, sizeof(*fwd_row));
fwd_row->ValidLifetime = 0xffffffff;
fwd_row->PreferredLifetime = 0xffffffff;
fwd_row->Protocol = MIB_IPPROTO_NETMGMT;
fwd_row->Metric = msg->metric;
fwd_row->DestinationPrefix.Prefix = sockaddr_inet(msg->family, &msg->prefix);
fwd_row->DestinationPrefix.PrefixLength = (UINT8) msg->prefix_len;
fwd_row->NextHop = sockaddr_inet(msg->family, &msg->gateway);
if (msg->iface.index != -1)
{
fwd_row->InterfaceIndex = msg->iface.index;
}
else if (strlen(msg->iface.name))
{
NET_LUID luid;
err = InterfaceLuid(msg->iface.name, &luid);
if (err)
{
goto out;
}
fwd_row->InterfaceLuid = luid;
}
if (add)
{
err = CreateIpForwardEntry2(fwd_row);
if (err)
{
goto out;
}
err = AddListItem(&(*lists)[route], fwd_row);
if (err)
{
DeleteRoute(fwd_row);
}
}
else
{
err = DeleteRoute(fwd_row);
if (err)
{
goto out;
}
free(RemoveListItem(&(*lists)[route], CmpRoute, fwd_row));
}
out:
if (!add || err)
{
free(fwd_row);
}
return err;
}
static DWORD
HandleFlushNeighborsMessage(flush_neighbors_message_t *msg)
{
if (msg->family == AF_INET)
{
return FlushIpNetTable(msg->iface.index);
}
return FlushIpNetTable2(msg->family, msg->iface.index);
}
static void
BlockDNSErrHandler(DWORD err, const char *msg)
{
TCHAR buf[256];
LPCTSTR err_str;
if (!err)
{
return;
}
err_str = TEXT("Unknown Win32 Error");
if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM
| FORMAT_MESSAGE_ARGUMENT_ARRAY,
NULL, err, 0, buf, sizeof(buf), NULL))
{
err_str = buf;
}
#ifdef UNICODE
MsgToEventLog(M_ERR, L"%S (status = %lu): %s", msg, err, err_str);
#else
MsgToEventLog(M_ERR, "%s (status = %lu): %s", msg, err, err_str);
#endif
}
/* Use an always-true match_fn to get the head of the list */
static BOOL
CmpEngine(LPVOID item, LPVOID any)
{
return TRUE;
}
static DWORD
HandleBlockDNSMessage(const block_dns_message_t *msg, undo_lists_t *lists)
{
DWORD err = 0;
block_dns_data_t *interface_data;
HANDLE engine = NULL;
LPCWSTR exe_path;
#ifdef UNICODE
exe_path = settings.exe_path;
#else
WCHAR wide_path[MAX_PATH];
MultiByteToWideChar(CP_UTF8, 0, settings.exe_path, MAX_PATH, wide_path, MAX_PATH);
exe_path = wide_path;
#endif
if (msg->header.type == msg_add_block_dns)
{
err = add_block_dns_filters(&engine, msg->iface.index, exe_path, BlockDNSErrHandler);
if (!err)
{
interface_data = malloc(sizeof(block_dns_data_t));
if (!interface_data)
{
return ERROR_OUTOFMEMORY;
}
interface_data->engine = engine;
interface_data->index = msg->iface.index;
int is_auto = 0;
interface_data->metric_v4 = get_interface_metric(msg->iface.index,
AF_INET, &is_auto);
if (is_auto)
{
interface_data->metric_v4 = 0;
}
interface_data->metric_v6 = get_interface_metric(msg->iface.index,
AF_INET6, &is_auto);
if (is_auto)
{
interface_data->metric_v6 = 0;
}
err = AddListItem(&(*lists)[block_dns], interface_data);
if (!err)
{
err = set_interface_metric(msg->iface.index, AF_INET,
BLOCK_DNS_IFACE_METRIC);
if (!err)
{
set_interface_metric(msg->iface.index, AF_INET6,
BLOCK_DNS_IFACE_METRIC);
}
}
}
}
else
{
interface_data = RemoveListItem(&(*lists)[block_dns], CmpEngine, NULL);
if (interface_data)
{
engine = interface_data->engine;
err = delete_block_dns_filters(engine);
engine = NULL;
if (interface_data->metric_v4 >= 0)
{
set_interface_metric(msg->iface.index, AF_INET,
interface_data->metric_v4);
}
if (interface_data->metric_v6 >= 0)
{
set_interface_metric(msg->iface.index, AF_INET6,
interface_data->metric_v6);
}
free(interface_data);
}
else
{
MsgToEventLog(M_ERR, TEXT("No previous block DNS filters to delete"));
}
}
if (err && engine)
{
delete_block_dns_filters(engine);
}
return err;
}
/*
* Execute a command and return its exit code. If timeout > 0, terminate
* the process if still running after timeout milliseconds. In that case
* the return value is the windows error code WAIT_TIMEOUT = 0x102
*/
static DWORD
ExecCommand(const WCHAR *argv0, const WCHAR *cmdline, DWORD timeout)
{
DWORD exit_code;
STARTUPINFOW si;
PROCESS_INFORMATION pi;
DWORD proc_flags = CREATE_NO_WINDOW|CREATE_UNICODE_ENVIRONMENT;
WCHAR *cmdline_dup = NULL;
ZeroMemory(&si, sizeof(si));
ZeroMemory(&pi, sizeof(pi));
si.cb = sizeof(si);
/* CreateProcess needs a modifiable cmdline: make a copy */
cmdline_dup = wcsdup(cmdline);
if (cmdline_dup && CreateProcessW(argv0, cmdline_dup, NULL, NULL, FALSE,
proc_flags, NULL, NULL, &si, &pi) )
{
WaitForSingleObject(pi.hProcess, timeout ? timeout : INFINITE);
if (!GetExitCodeProcess(pi.hProcess, &exit_code))
{
MsgToEventLog(M_SYSERR, TEXT("ExecCommand: Error getting exit_code:"));
exit_code = GetLastError();
}
else if (exit_code == STILL_ACTIVE)
{
exit_code = WAIT_TIMEOUT; /* Windows error code 0x102 */
/* kill without impunity */
TerminateProcess(pi.hProcess, exit_code);
MsgToEventLog(M_ERR, TEXT("ExecCommand: \"%s %s\" killed after timeout"),
argv0, cmdline);
}
else if (exit_code)
{
MsgToEventLog(M_ERR, TEXT("ExecCommand: \"%s %s\" exited with status = %lu"),
argv0, cmdline, exit_code);
}
else
{
MsgToEventLog(M_INFO, TEXT("ExecCommand: \"%s %s\" completed"), argv0, cmdline);
}
CloseHandle(pi.hProcess);
CloseHandle(pi.hThread);
}
else
{
exit_code = GetLastError();
MsgToEventLog(M_SYSERR, TEXT("ExecCommand: could not run \"%s %s\" :"),
argv0, cmdline);
}
free(cmdline_dup);
return exit_code;
}
/*
* Entry point for register-dns thread.
*/
static DWORD WINAPI
RegisterDNS(LPVOID unused)
{
DWORD err;
size_t i;
DWORD timeout = RDNS_TIMEOUT * 1000; /* in milliseconds */
/* path of ipconfig command */
WCHAR ipcfg[MAX_PATH];
struct
{
WCHAR *argv0;
WCHAR *cmdline;
DWORD timeout;
} cmds [] = {
{ ipcfg, L"ipconfig /flushdns", timeout },
{ ipcfg, L"ipconfig /registerdns", timeout },
};
HANDLE wait_handles[2] = {rdns_semaphore, exit_event};
openvpn_swprintf(ipcfg, MAX_PATH, L"%s\\%s", get_win_sys_path(), L"ipconfig.exe");
if (WaitForMultipleObjects(2, wait_handles, FALSE, timeout) == WAIT_OBJECT_0)
{
/* Semaphore locked */
for (i = 0; i < _countof(cmds); ++i)
{
ExecCommand(cmds[i].argv0, cmds[i].cmdline, cmds[i].timeout);
}
err = 0;
if (!ReleaseSemaphore(rdns_semaphore, 1, NULL) )
{
err = MsgToEventLog(M_SYSERR, TEXT("RegisterDNS: Failed to release regsiter-dns semaphore:"));
}
}
else
{
MsgToEventLog(M_ERR, TEXT("RegisterDNS: Failed to lock register-dns semaphore"));
err = ERROR_SEM_TIMEOUT; /* Windows error code 0x79 */
}
return err;
}
static DWORD
HandleRegisterDNSMessage(void)
{
DWORD err;
HANDLE thread = NULL;
/* Delegate this job to a sub-thread */
thread = CreateThread(NULL, 0, RegisterDNS, NULL, 0, NULL);
/*
* We don't add these thread handles to the undo list -- the thread and
* processes it spawns are all supposed to terminate or timeout by themselves.
*/
if (thread)
{
err = 0;
CloseHandle(thread);
}
else
{
err = GetLastError();
}
return err;
}
/**
* Run the command: netsh interface $proto $action dns $if_name $addr [validate=no]
* @param action "delete" or "add"
* @param proto "ipv6" or "ip"
* @param if_name "name_of_interface"
* @param addr IPv4 (for proto = ip) or IPv6 address as a string
*
* If addr is null and action = "delete" all addresses are deleted.
*/
static DWORD
netsh_dns_cmd(const wchar_t *action, const wchar_t *proto, const wchar_t *if_name, const wchar_t *addr)
{
DWORD err = 0;
int timeout = 30000; /* in msec */
wchar_t argv0[MAX_PATH];
wchar_t *cmdline = NULL;
if (!addr)
{
if (wcscmp(action, L"delete") == 0)
{
addr = L"all";
}
else /* nothing to do -- return success*/
{
goto out;
}
}
/* Path of netsh */
swprintf(argv0, _countof(argv0), L"%s\\%s", get_win_sys_path(), L"netsh.exe");
argv0[_countof(argv0) - 1] = L'\0';
/* cmd template:
* netsh interface $proto $action dns $if_name $addr [validate=no]
*/
const wchar_t *fmt = L"netsh interface %s %s dns \"%s\" %s";
/* max cmdline length in wchars -- include room for worst case and some */
size_t ncmdline = wcslen(fmt) + wcslen(if_name) + wcslen(addr) + 32 + 1;
cmdline = malloc(ncmdline*sizeof(wchar_t));
if (!cmdline)
{
err = ERROR_OUTOFMEMORY;
goto out;
}
openvpn_sntprintf(cmdline, ncmdline, fmt, proto, action, if_name, addr);
if (IsWindows7OrGreater())
{
wcsncat(cmdline, L" validate=no", ncmdline - wcslen(cmdline) - 1);
}
err = ExecCommand(argv0, cmdline, timeout);
out:
free(cmdline);
return err;
}
/**
* Run command: wmic nicconfig (InterfaceIndex=$if_index) call $action ($data)
* @param if_index "index of interface"
* @param action e.g., "SetDNSDomain"
* @param data data if required for action
* - a single word for SetDNSDomain, empty or NULL to delete
* - comma separated values for a list
*/
static DWORD
wmic_nicconfig_cmd(const wchar_t *action, const NET_IFINDEX if_index,
const wchar_t *data)
{
DWORD err = 0;
wchar_t argv0[MAX_PATH];
wchar_t *cmdline = NULL;
int timeout = 10000; /* in msec */
swprintf(argv0, _countof(argv0), L"%s\\%s", get_win_sys_path(), L"wbem\\wmic.exe");
argv0[_countof(argv0) - 1] = L'\0';
const wchar_t *fmt;
/* comma separated list must be enclosed in parenthesis */
if (data && wcschr(data, L','))
{
fmt = L"wmic nicconfig where (InterfaceIndex=%ld) call %s (%s)";
}
else
{
fmt = L"wmic nicconfig where (InterfaceIndex=%ld) call %s \"%s\"";
}
size_t ncmdline = wcslen(fmt) + 20 + wcslen(action) /* max 20 for ifindex */
+ (data ? wcslen(data) + 1 : 1);
cmdline = malloc(ncmdline*sizeof(wchar_t));
if (!cmdline)
{
return ERROR_OUTOFMEMORY;
}
openvpn_sntprintf(cmdline, ncmdline, fmt, if_index, action,
data? data : L"");
err = ExecCommand(argv0, cmdline, timeout);
free(cmdline);
return err;
}
/* Delete all IPv4 or IPv6 dns servers for an interface */
static DWORD
DeleteDNS(short family, wchar_t *if_name)
{
wchar_t *proto = (family == AF_INET6) ? L"ipv6" : L"ip";
return netsh_dns_cmd(L"delete", proto, if_name, NULL);
}
/* Add an IPv4 or IPv6 dns server to an interface */
static DWORD
AddDNS(short family, wchar_t *if_name, wchar_t *addr)
{
wchar_t *proto = (family == AF_INET6) ? L"ipv6" : L"ip";
return netsh_dns_cmd(L"add", proto, if_name, addr);
}
static BOOL
CmpWString(LPVOID item, LPVOID str)
{
return (wcscmp(item, str) == 0) ? TRUE : FALSE;
}
/**
* Set interface specific DNS domain suffix
* @param if_name name of the the interface
* @param domain a single domain name
* @param lists pointer to the undo lists. If NULL
* undo lists are not altered.
* Will delete the currently set value if domain is empty.
*/
static DWORD
SetDNSDomain(const wchar_t *if_name, const char *domain, undo_lists_t *lists)
{
NET_IFINDEX if_index;
DWORD err = ConvertInterfaceNameToIndex(if_name, &if_index);
if (err != ERROR_SUCCESS)
{
return err;
}
wchar_t *wdomain = utf8to16(domain); /* utf8 to wide-char */
if (!wdomain)
{
return ERROR_OUTOFMEMORY;
}
/* free undo list if previously set */
if (lists)
{
free(RemoveListItem(&(*lists)[undo_domain], CmpWString, (void *)if_name));
}
err = wmic_nicconfig_cmd(L"SetDNSDomain", if_index, wdomain);
/* Add to undo list if domain is non-empty */
if (err == 0 && wdomain[0] && lists)
{
wchar_t *tmp_name = wcsdup(if_name);
if (!tmp_name || AddListItem(&(*lists)[undo_domain], tmp_name))
{
free(tmp_name);
err = ERROR_OUTOFMEMORY;
}
}
free(wdomain);
return err;
}
static DWORD
HandleDNSConfigMessage(const dns_cfg_message_t *msg, undo_lists_t *lists)
{
DWORD err = 0;
wchar_t addr[46]; /* large enough to hold string representation of an ipv4 / ipv6 address */
undo_type_t undo_type = (msg->family == AF_INET6) ? undo_dns4 : undo_dns6;
int addr_len = msg->addr_len;
/* sanity check */
if (addr_len > _countof(msg->addr))
{
addr_len = _countof(msg->addr);
}
if (!msg->iface.name[0]) /* interface name is required */
{
return ERROR_MESSAGE_DATA;
}
/* use a non-const reference with limited scope to enforce null-termination of strings from client */
{
dns_cfg_message_t *msgptr = (dns_cfg_message_t *) msg;
msgptr->iface.name[_countof(msg->iface.name)-1] = '\0';
msgptr->domains[_countof(msg->domains)-1] = '\0';
}
wchar_t *wide_name = utf8to16(msg->iface.name); /* utf8 to wide-char */
if (!wide_name)
{
return ERROR_OUTOFMEMORY;
}
/* We delete all current addresses before adding any
* OR if the message type is del_dns_cfg
*/
if (addr_len > 0 || msg->header.type == msg_del_dns_cfg)
{
err = DeleteDNS(msg->family, wide_name);
if (err)
{
goto out;
}
free(RemoveListItem(&(*lists)[undo_type], CmpWString, wide_name));
}
if (msg->header.type == msg_del_dns_cfg)
{
if (msg->domains[0])
{
/* setting an empty domain removes any previous value */
err = SetDNSDomain(wide_name, "", lists);
}
goto out; /* job done */
}
for (int i = 0; i < addr_len; ++i)
{
if (msg->family == AF_INET6)
{
RtlIpv6AddressToStringW(&msg->addr[i].ipv6, addr);
}
else
{
RtlIpv4AddressToStringW(&msg->addr[i].ipv4, addr);
}
err = AddDNS(msg->family, wide_name, addr);
if (i == 0 && err)
{
goto out;
}
/* We do not check for duplicate addresses, so any error in adding
* additional addresses is ignored.
*/
}
err = 0;
if (msg->addr_len > 0)
{
wchar_t *tmp_name = wcsdup(wide_name);
if (!tmp_name || AddListItem(&(*lists)[undo_type], tmp_name))
{
free(tmp_name);
DeleteDNS(msg->family, wide_name);
err = ERROR_OUTOFMEMORY;
goto out;
}
}
if (msg->domains[0])
{
err = SetDNSDomain(wide_name, msg->domains, lists);
}
out:
free(wide_name);
return err;
}
static DWORD
HandleEnableDHCPMessage(const enable_dhcp_message_t *dhcp)
{
DWORD err = 0;
DWORD timeout = 5000; /* in milli seconds */
wchar_t argv0[MAX_PATH];
/* Path of netsh */
swprintf(argv0, _countof(argv0), L"%s\\%s", get_win_sys_path(), L"netsh.exe");
argv0[_countof(argv0) - 1] = L'\0';
/* cmd template:
* netsh interface ipv4 set address name=$if_index source=dhcp
*/
const wchar_t *fmt = L"netsh interface ipv4 set address name=\"%d\" source=dhcp";
/* max cmdline length in wchars -- include room for if index:
* 10 chars for 32 bit int in decimal and +1 for NUL
*/
size_t ncmdline = wcslen(fmt) + 10 + 1;
wchar_t *cmdline = malloc(ncmdline*sizeof(wchar_t));
if (!cmdline)
{
err = ERROR_OUTOFMEMORY;
return err;
}
openvpn_sntprintf(cmdline, ncmdline, fmt, dhcp->iface.index);
err = ExecCommand(argv0, cmdline, timeout);
/* Note: This could fail if dhcp is already enabled, so the caller
* may not want to treat errors as FATAL.
*/
free(cmdline);
return err;
}
static DWORD
OvpnDuplicateHandle(HANDLE ovpn_proc, HANDLE orig_handle, HANDLE* new_handle)
{
DWORD err = ERROR_SUCCESS;
if (!DuplicateHandle(ovpn_proc, orig_handle, GetCurrentProcess(), new_handle, 0, FALSE, DUPLICATE_SAME_ACCESS))
{
err = GetLastError();
MsgToEventLog(M_SYSERR, TEXT("Could not duplicate handle"));
return err;
}
return err;
}
static DWORD
DuplicateAndMapRing(HANDLE ovpn_proc, HANDLE orig_handle, HANDLE *new_handle, struct tun_ring **ring)
{
DWORD err = ERROR_SUCCESS;
err = OvpnDuplicateHandle(ovpn_proc, orig_handle, new_handle);
if (err != ERROR_SUCCESS)
{
return err;
}
*ring = (struct tun_ring *)MapViewOfFile(*new_handle, FILE_MAP_ALL_ACCESS, 0, 0, sizeof(struct tun_ring));
if (*ring == NULL)
{
err = GetLastError();
MsgToEventLog(M_SYSERR, TEXT("Could not map shared memory"));
return err;
}
return err;
}
static DWORD
HandleRegisterRingBuffers(const register_ring_buffers_message_t *rrb, HANDLE ovpn_proc,
ring_buffer_handles_t *ring_buffer_handles)
{
DWORD err = 0;
struct tun_ring *send_ring;
struct tun_ring *receive_ring;
CloseRingBufferHandles(ring_buffer_handles);
err = OvpnDuplicateHandle(ovpn_proc, rrb->device, &ring_buffer_handles->device);
if (err != ERROR_SUCCESS)
{
return err;
}
err = DuplicateAndMapRing(ovpn_proc, rrb->send_ring_handle, &ring_buffer_handles->send_ring_handle, &send_ring);
if (err != ERROR_SUCCESS)
{
return err;
}
err = DuplicateAndMapRing(ovpn_proc, rrb->receive_ring_handle, &ring_buffer_handles->receive_ring_handle, &receive_ring);
if (err != ERROR_SUCCESS)
{
return err;
}
err = OvpnDuplicateHandle(ovpn_proc, rrb->send_tail_moved, &ring_buffer_handles->send_tail_moved);
if (err != ERROR_SUCCESS)
{
return err;
}
err = OvpnDuplicateHandle(ovpn_proc, rrb->receive_tail_moved, &ring_buffer_handles->receive_tail_moved);
if (err != ERROR_SUCCESS)
{
return err;
}
if (!register_ring_buffers(ring_buffer_handles->device, send_ring, receive_ring,
ring_buffer_handles->send_tail_moved, ring_buffer_handles->receive_tail_moved))
{
err = GetLastError();
MsgToEventLog(M_SYSERR, TEXT("Could not register ring buffers"));
}
return err;
}
static DWORD
HandleMTUMessage(const set_mtu_message_t *mtu)
{
DWORD err = 0;
MIB_IPINTERFACE_ROW ipiface;
InitializeIpInterfaceEntry(&ipiface);
ipiface.Family = mtu->family;
ipiface.InterfaceIndex = mtu->iface.index;
err = GetIpInterfaceEntry(&ipiface);
if (err != NO_ERROR)
{
return err;
}
if (mtu->family == AF_INET)
{
ipiface.SitePrefixLength = 0;
}
ipiface.NlMtu = mtu->mtu;
err = SetIpInterfaceEntry(&ipiface);
return err;
}
static VOID
HandleMessage(HANDLE pipe, HANDLE ovpn_proc, ring_buffer_handles_t *ring_buffer_handles,
DWORD bytes, DWORD count, LPHANDLE events, undo_lists_t *lists)
{
DWORD read;
union {
message_header_t header;
address_message_t address;
route_message_t route;
flush_neighbors_message_t flush_neighbors;
block_dns_message_t block_dns;
dns_cfg_message_t dns;
enable_dhcp_message_t dhcp;
register_ring_buffers_message_t rrb;
set_mtu_message_t mtu;
} msg;
ack_message_t ack = {
.header = {
.type = msg_acknowledgement,
.size = sizeof(ack),
.message_id = -1
},
.error_number = ERROR_MESSAGE_DATA
};
read = ReadPipeAsync(pipe, &msg, bytes, count, events);
if (read != bytes || read < sizeof(msg.header) || read != msg.header.size)
{
goto out;
}
ack.header.message_id = msg.header.message_id;
switch (msg.header.type)
{
case msg_add_address:
case msg_del_address:
if (msg.header.size == sizeof(msg.address))
{
ack.error_number = HandleAddressMessage(&msg.address, lists);
}
break;
case msg_add_route:
case msg_del_route:
if (msg.header.size == sizeof(msg.route))
{
ack.error_number = HandleRouteMessage(&msg.route, lists);
}
break;
case msg_flush_neighbors:
if (msg.header.size == sizeof(msg.flush_neighbors))
{
ack.error_number = HandleFlushNeighborsMessage(&msg.flush_neighbors);
}
break;
case msg_add_block_dns:
case msg_del_block_dns:
if (msg.header.size == sizeof(msg.block_dns))
{
ack.error_number = HandleBlockDNSMessage(&msg.block_dns, lists);
}
break;
case msg_register_dns:
ack.error_number = HandleRegisterDNSMessage();
break;
case msg_add_dns_cfg:
case msg_del_dns_cfg:
ack.error_number = HandleDNSConfigMessage(&msg.dns, lists);
break;
case msg_enable_dhcp:
if (msg.header.size == sizeof(msg.dhcp))
{
ack.error_number = HandleEnableDHCPMessage(&msg.dhcp);
}
break;
case msg_register_ring_buffers:
if (msg.header.size == sizeof(msg.rrb))
{
ack.error_number = HandleRegisterRingBuffers(&msg.rrb, ovpn_proc, ring_buffer_handles);
}
break;
case msg_set_mtu:
if (msg.header.size == sizeof(msg.mtu))
{
ack.error_number = HandleMTUMessage(&msg.mtu);
}
break;
default:
ack.error_number = ERROR_MESSAGE_TYPE;
MsgToEventLog(MSG_FLAGS_ERROR, TEXT("Unknown message type %d"), msg.header.type);
break;
}
out:
WritePipeAsync(pipe, &ack, sizeof(ack), count, events);
}
static VOID
Undo(undo_lists_t *lists)
{
undo_type_t type;
block_dns_data_t *interface_data;
for (type = 0; type < _undo_type_max; type++)
{
list_item_t **pnext = &(*lists)[type];
while (*pnext)
{
list_item_t *item = *pnext;
switch (type)
{
case address:
DeleteAddress(item->data);
break;
case route:
DeleteRoute(item->data);
break;
case undo_dns4:
DeleteDNS(AF_INET, item->data);
break;
case undo_dns6:
DeleteDNS(AF_INET6, item->data);
break;
case undo_domain:
SetDNSDomain(item->data, "", NULL);
break;
case block_dns:
interface_data = (block_dns_data_t *)(item->data);
delete_block_dns_filters(interface_data->engine);
if (interface_data->metric_v4 >= 0)
{
set_interface_metric(interface_data->index, AF_INET,
interface_data->metric_v4);
}
if (interface_data->metric_v6 >= 0)
{
set_interface_metric(interface_data->index, AF_INET6,
interface_data->metric_v6);
}
break;
}
/* Remove from the list and free memory */
*pnext = item->next;
free(item->data);
free(item);
}
}
}
static DWORD WINAPI
RunOpenvpn(LPVOID p)
{
HANDLE pipe = p;
HANDLE ovpn_pipe = NULL, svc_pipe = NULL;
PTOKEN_USER svc_user = NULL, ovpn_user = NULL;
HANDLE svc_token = NULL, imp_token = NULL, pri_token = NULL;
HANDLE stdin_read = NULL, stdin_write = NULL;
HANDLE stdout_write = NULL;
DWORD pipe_mode, len, exit_code = 0;
STARTUP_DATA sud = { 0, 0, 0 };
STARTUPINFOW startup_info;
PROCESS_INFORMATION proc_info;
LPVOID user_env = NULL;
TCHAR ovpn_pipe_name[256]; /* The entire pipe name string can be up to 256 characters long according to MSDN. */
LPCWSTR exe_path;
WCHAR *cmdline = NULL;
size_t cmdline_size;
undo_lists_t undo_lists;
ring_buffer_handles_t ring_buffer_handles;
WCHAR errmsg[512] = L"";
SECURITY_ATTRIBUTES inheritable = {
.nLength = sizeof(inheritable),
.lpSecurityDescriptor = NULL,
.bInheritHandle = TRUE
};
PACL ovpn_dacl;
EXPLICIT_ACCESS ea[2];
SECURITY_DESCRIPTOR ovpn_sd;
SECURITY_ATTRIBUTES ovpn_sa = {
.nLength = sizeof(ovpn_sa),
.lpSecurityDescriptor = &ovpn_sd,
.bInheritHandle = FALSE
};
ZeroMemory(&ea, sizeof(ea));
ZeroMemory(&startup_info, sizeof(startup_info));
ZeroMemory(&undo_lists, sizeof(undo_lists));
ZeroMemory(&proc_info, sizeof(proc_info));
ZeroMemory(&ring_buffer_handles, sizeof(ring_buffer_handles));
if (!GetStartupData(pipe, &sud))
{
goto out;
}
if (!InitializeSecurityDescriptor(&ovpn_sd, SECURITY_DESCRIPTOR_REVISION))
{
ReturnLastError(pipe, L"InitializeSecurityDescriptor");
goto out;
}
/* Get SID of user the service is running under */
if (!OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &svc_token))
{
ReturnLastError(pipe, L"OpenProcessToken");
goto out;
}
len = 0;
while (!GetTokenInformation(svc_token, TokenUser, svc_user, len, &len))
{
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
ReturnLastError(pipe, L"GetTokenInformation (service token)");
goto out;
}
free(svc_user);
svc_user = malloc(len);
if (svc_user == NULL)
{
ReturnLastError(pipe, L"malloc (service token user)");
goto out;
}
}
if (!IsValidSid(svc_user->User.Sid))
{
ReturnLastError(pipe, L"IsValidSid (service token user)");
goto out;
}
if (!ImpersonateNamedPipeClient(pipe))
{
ReturnLastError(pipe, L"ImpersonateNamedPipeClient");
goto out;
}
if (!OpenThreadToken(GetCurrentThread(), TOKEN_ALL_ACCESS, FALSE, &imp_token))
{
ReturnLastError(pipe, L"OpenThreadToken");
goto out;
}
len = 0;
while (!GetTokenInformation(imp_token, TokenUser, ovpn_user, len, &len))
{
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
ReturnLastError(pipe, L"GetTokenInformation (impersonation token)");
goto out;
}
free(ovpn_user);
ovpn_user = malloc(len);
if (ovpn_user == NULL)
{
ReturnLastError(pipe, L"malloc (impersonation token user)");
goto out;
}
}
if (!IsValidSid(ovpn_user->User.Sid))
{
ReturnLastError(pipe, L"IsValidSid (impersonation token user)");
goto out;
}
/*
* Only authorized users are allowed to use any command line options or
* have the config file in locations other than the global config directory.
*
* Check options are white-listed and config is in the global directory
* OR user is authorized to run any config.
*/
if (!ValidateOptions(pipe, sud.directory, sud.options, errmsg, _countof(errmsg))
&& !IsAuthorizedUser(ovpn_user->User.Sid, imp_token, settings.ovpn_admin_group))
{
ReturnError(pipe, ERROR_STARTUP_DATA, errmsg, 1, &exit_event);
goto out;
}
/* OpenVPN process DACL entry for access by service and user */
ea[0].grfAccessPermissions = SPECIFIC_RIGHTS_ALL | STANDARD_RIGHTS_ALL;
ea[0].grfAccessMode = SET_ACCESS;
ea[0].grfInheritance = NO_INHERITANCE;
ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[0].Trustee.TrusteeType = TRUSTEE_IS_UNKNOWN;
ea[0].Trustee.ptstrName = (LPTSTR) svc_user->User.Sid;
ea[1].grfAccessPermissions = READ_CONTROL | SYNCHRONIZE | PROCESS_VM_READ
|SYNCHRONIZE | PROCESS_TERMINATE | PROCESS_QUERY_INFORMATION;
ea[1].grfAccessMode = SET_ACCESS;
ea[1].grfInheritance = NO_INHERITANCE;
ea[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[1].Trustee.TrusteeType = TRUSTEE_IS_UNKNOWN;
ea[1].Trustee.ptstrName = (LPTSTR) ovpn_user->User.Sid;
/* Set owner and DACL of OpenVPN security descriptor */
if (!SetSecurityDescriptorOwner(&ovpn_sd, svc_user->User.Sid, FALSE))
{
ReturnLastError(pipe, L"SetSecurityDescriptorOwner");
goto out;
}
if (SetEntriesInAcl(2, ea, NULL, &ovpn_dacl) != ERROR_SUCCESS)
{
ReturnLastError(pipe, L"SetEntriesInAcl");
goto out;
}
if (!SetSecurityDescriptorDacl(&ovpn_sd, TRUE, ovpn_dacl, FALSE))
{
ReturnLastError(pipe, L"SetSecurityDescriptorDacl");
goto out;
}
/* Create primary token from impersonation token */
if (!DuplicateTokenEx(imp_token, TOKEN_ALL_ACCESS, NULL, 0, TokenPrimary, &pri_token))
{
ReturnLastError(pipe, L"DuplicateTokenEx");
goto out;
}
/* use /dev/null for stdout of openvpn (client should use --log for output) */
stdout_write = CreateFile(_T("NUL"), GENERIC_WRITE, FILE_SHARE_WRITE,
&inheritable, OPEN_EXISTING, 0, NULL);
if (stdout_write == INVALID_HANDLE_VALUE)
{
ReturnLastError(pipe, L"CreateFile for stdout");
goto out;
}
if (!CreatePipe(&stdin_read, &stdin_write, &inheritable, 0)
|| !SetHandleInformation(stdin_write, HANDLE_FLAG_INHERIT, 0))
{
ReturnLastError(pipe, L"CreatePipe");
goto out;
}
openvpn_sntprintf(ovpn_pipe_name, _countof(ovpn_pipe_name),
TEXT("\\\\.\\pipe\\" PACKAGE "%s\\service_%lu"), service_instance, GetCurrentThreadId());
ovpn_pipe = CreateNamedPipe(ovpn_pipe_name,
PIPE_ACCESS_DUPLEX | FILE_FLAG_FIRST_PIPE_INSTANCE | FILE_FLAG_OVERLAPPED,
PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_WAIT, 1, 128, 128, 0, NULL);
if (ovpn_pipe == INVALID_HANDLE_VALUE)
{
ReturnLastError(pipe, L"CreateNamedPipe");
goto out;
}
svc_pipe = CreateFile(ovpn_pipe_name, GENERIC_READ | GENERIC_WRITE, 0,
&inheritable, OPEN_EXISTING, 0, NULL);
if (svc_pipe == INVALID_HANDLE_VALUE)
{
ReturnLastError(pipe, L"CreateFile");
goto out;
}
pipe_mode = PIPE_READMODE_MESSAGE;
if (!SetNamedPipeHandleState(svc_pipe, &pipe_mode, NULL, NULL))
{
ReturnLastError(pipe, L"SetNamedPipeHandleState");
goto out;
}
cmdline_size = wcslen(sud.options) + 128;
cmdline = malloc(cmdline_size * sizeof(*cmdline));
if (cmdline == NULL)
{
ReturnLastError(pipe, L"malloc");
goto out;
}
openvpn_sntprintf(cmdline, cmdline_size, L"openvpn %s --msg-channel %lu",
sud.options, svc_pipe);
if (!CreateEnvironmentBlock(&user_env, imp_token, FALSE))
{
ReturnLastError(pipe, L"CreateEnvironmentBlock");
goto out;
}
startup_info.cb = sizeof(startup_info);
startup_info.lpDesktop = L"winsta0\\default";
startup_info.dwFlags = STARTF_USESTDHANDLES;
startup_info.hStdInput = stdin_read;
startup_info.hStdOutput = stdout_write;
startup_info.hStdError = stdout_write;
#ifdef UNICODE
exe_path = settings.exe_path;
#else
WCHAR wide_path[MAX_PATH];
MultiByteToWideChar(CP_UTF8, 0, settings.exe_path, MAX_PATH, wide_path, MAX_PATH);
exe_path = wide_path;
#endif
/* TODO: make sure HKCU is correct or call LoadUserProfile() */
if (!CreateProcessAsUserW(pri_token, exe_path, cmdline, &ovpn_sa, NULL, TRUE,
settings.priority | CREATE_NO_WINDOW | CREATE_UNICODE_ENVIRONMENT,
user_env, sud.directory, &startup_info, &proc_info))
{
ReturnLastError(pipe, L"CreateProcessAsUser");
goto out;
}
if (!RevertToSelf())
{
TerminateProcess(proc_info.hProcess, 1);
ReturnLastError(pipe, L"RevertToSelf");
goto out;
}
ReturnProcessId(pipe, proc_info.dwProcessId, 1, &exit_event);
CloseHandleEx(&stdout_write);
CloseHandleEx(&stdin_read);
CloseHandleEx(&svc_pipe);
DWORD input_size = WideCharToMultiByte(CP_UTF8, 0, sud.std_input, -1, NULL, 0, NULL, NULL);
LPSTR input = NULL;
if (input_size && (input = malloc(input_size)))
{
DWORD written;
WideCharToMultiByte(CP_UTF8, 0, sud.std_input, -1, input, input_size, NULL, NULL);
WriteFile(stdin_write, input, (DWORD)strlen(input), &written, NULL);
free(input);
}
while (TRUE)
{
DWORD bytes = PeekNamedPipeAsync(ovpn_pipe, 1, &exit_event);
if (bytes == 0)
{
break;
}
HandleMessage(ovpn_pipe, proc_info.hProcess, &ring_buffer_handles, bytes, 1, &exit_event, &undo_lists);
}
WaitForSingleObject(proc_info.hProcess, IO_TIMEOUT);
GetExitCodeProcess(proc_info.hProcess, &exit_code);
if (exit_code == STILL_ACTIVE)
{
TerminateProcess(proc_info.hProcess, 1);
}
else if (exit_code != 0)
{
WCHAR buf[256];
openvpn_swprintf(buf, _countof(buf),
L"OpenVPN exited with error: exit code = %lu", exit_code);
ReturnError(pipe, ERROR_OPENVPN_STARTUP, buf, 1, &exit_event);
}
Undo(&undo_lists);
out:
FlushFileBuffers(pipe);
DisconnectNamedPipe(pipe);
free(ovpn_user);
free(svc_user);
free(cmdline);
DestroyEnvironmentBlock(user_env);
FreeStartupData(&sud);
CloseRingBufferHandles(&ring_buffer_handles);
CloseHandleEx(&proc_info.hProcess);
CloseHandleEx(&proc_info.hThread);
CloseHandleEx(&stdin_read);
CloseHandleEx(&stdin_write);
CloseHandleEx(&stdout_write);
CloseHandleEx(&svc_token);
CloseHandleEx(&imp_token);
CloseHandleEx(&pri_token);
CloseHandleEx(&ovpn_pipe);
CloseHandleEx(&svc_pipe);
CloseHandleEx(&pipe);
return 0;
}
static DWORD WINAPI
ServiceCtrlInteractive(DWORD ctrl_code, DWORD event, LPVOID data, LPVOID ctx)
{
SERVICE_STATUS *status = ctx;
switch (ctrl_code)
{
case SERVICE_CONTROL_STOP:
status->dwCurrentState = SERVICE_STOP_PENDING;
ReportStatusToSCMgr(service, status);
if (exit_event)
{
SetEvent(exit_event);
}
return NO_ERROR;
case SERVICE_CONTROL_INTERROGATE:
return NO_ERROR;
default:
return ERROR_CALL_NOT_IMPLEMENTED;
}
}
static HANDLE
CreateClientPipeInstance(VOID)
{
TCHAR pipe_name[256]; /* The entire pipe name string can be up to 256 characters long according to MSDN. */
HANDLE pipe = NULL;
PACL old_dacl, new_dacl;
PSECURITY_DESCRIPTOR sd;
static EXPLICIT_ACCESS ea[2];
static BOOL initialized = FALSE;
DWORD flags = PIPE_ACCESS_DUPLEX | WRITE_DAC | FILE_FLAG_OVERLAPPED;
if (!initialized)
{
PSID everyone, anonymous;
ConvertStringSidToSid(TEXT("S-1-1-0"), &everyone);
ConvertStringSidToSid(TEXT("S-1-5-7"), &anonymous);
ea[0].grfAccessPermissions = FILE_GENERIC_WRITE;
ea[0].grfAccessMode = GRANT_ACCESS;
ea[0].grfInheritance = NO_INHERITANCE;
ea[0].Trustee.pMultipleTrustee = NULL;
ea[0].Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[0].Trustee.TrusteeType = TRUSTEE_IS_UNKNOWN;
ea[0].Trustee.ptstrName = (LPTSTR) everyone;
ea[1].grfAccessPermissions = 0;
ea[1].grfAccessMode = REVOKE_ACCESS;
ea[1].grfInheritance = NO_INHERITANCE;
ea[1].Trustee.pMultipleTrustee = NULL;
ea[1].Trustee.MultipleTrusteeOperation = NO_MULTIPLE_TRUSTEE;
ea[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[1].Trustee.TrusteeType = TRUSTEE_IS_UNKNOWN;
ea[1].Trustee.ptstrName = (LPTSTR) anonymous;
flags |= FILE_FLAG_FIRST_PIPE_INSTANCE;
initialized = TRUE;
}
openvpn_sntprintf(pipe_name, _countof(pipe_name), TEXT("\\\\.\\pipe\\" PACKAGE "%s\\service"), service_instance);
pipe = CreateNamedPipe(pipe_name, flags,
PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE,
PIPE_UNLIMITED_INSTANCES, 1024, 1024, 0, NULL);
if (pipe == INVALID_HANDLE_VALUE)
{
MsgToEventLog(M_SYSERR, TEXT("Could not create named pipe"));
return INVALID_HANDLE_VALUE;
}
if (GetSecurityInfo(pipe, SE_KERNEL_OBJECT, DACL_SECURITY_INFORMATION,
NULL, NULL, &old_dacl, NULL, &sd) != ERROR_SUCCESS)
{
MsgToEventLog(M_SYSERR, TEXT("Could not get pipe security info"));
return CloseHandleEx(&pipe);
}
if (SetEntriesInAcl(2, ea, old_dacl, &new_dacl) != ERROR_SUCCESS)
{
MsgToEventLog(M_SYSERR, TEXT("Could not set entries in new acl"));
return CloseHandleEx(&pipe);
}
if (SetSecurityInfo(pipe, SE_KERNEL_OBJECT, DACL_SECURITY_INFORMATION,
NULL, NULL, new_dacl, NULL) != ERROR_SUCCESS)
{
MsgToEventLog(M_SYSERR, TEXT("Could not set pipe security info"));
return CloseHandleEx(&pipe);
}
return pipe;
}
static DWORD
UpdateWaitHandles(LPHANDLE *handles_ptr, LPDWORD count,
HANDLE io_event, HANDLE exit_event, list_item_t *threads)
{
static DWORD size = 10;
static LPHANDLE handles = NULL;
DWORD pos = 0;
if (handles == NULL)
{
handles = malloc(size * sizeof(HANDLE));
*handles_ptr = handles;
if (handles == NULL)
{
return ERROR_OUTOFMEMORY;
}
}
handles[pos++] = io_event;
if (!threads)
{
handles[pos++] = exit_event;
}
while (threads)
{
if (pos == size)
{
LPHANDLE tmp;
size += 10;
tmp = realloc(handles, size * sizeof(HANDLE));
if (tmp == NULL)
{
size -= 10;
*count = pos;
return ERROR_OUTOFMEMORY;
}
handles = tmp;
*handles_ptr = handles;
}
handles[pos++] = threads->data;
threads = threads->next;
}
*count = pos;
return NO_ERROR;
}
static VOID
FreeWaitHandles(LPHANDLE h)
{
free(h);
}
static BOOL
CmpHandle(LPVOID item, LPVOID hnd)
{
return item == hnd;
}
VOID WINAPI
ServiceStartInteractiveOwn(DWORD dwArgc, LPTSTR *lpszArgv)
{
status.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
ServiceStartInteractive(dwArgc, lpszArgv);
}
VOID WINAPI
ServiceStartInteractive(DWORD dwArgc, LPTSTR *lpszArgv)
{
HANDLE pipe, io_event = NULL;
OVERLAPPED overlapped;
DWORD error = NO_ERROR;
list_item_t *threads = NULL;
PHANDLE handles = NULL;
DWORD handle_count;
service = RegisterServiceCtrlHandlerEx(interactive_service.name, ServiceCtrlInteractive, &status);
if (!service)
{
return;
}
status.dwCurrentState = SERVICE_START_PENDING;
status.dwServiceSpecificExitCode = NO_ERROR;
status.dwWin32ExitCode = NO_ERROR;
status.dwWaitHint = 3000;
ReportStatusToSCMgr(service, &status);
/* Read info from registry in key HKLM\SOFTWARE\OpenVPN */
error = GetOpenvpnSettings(&settings);
if (error != ERROR_SUCCESS)
{
goto out;
}
io_event = InitOverlapped(&overlapped);
exit_event = CreateEvent(NULL, TRUE, FALSE, NULL);
if (!exit_event || !io_event)
{
error = MsgToEventLog(M_SYSERR, TEXT("Could not create event"));
goto out;
}
rdns_semaphore = CreateSemaphoreW(NULL, 1, 1, NULL);
if (!rdns_semaphore)
{
error = MsgToEventLog(M_SYSERR, TEXT("Could not create semaphore for register-dns"));
goto out;
}
error = UpdateWaitHandles(&handles, &handle_count, io_event, exit_event, threads);
if (error != NO_ERROR)
{
goto out;
}
pipe = CreateClientPipeInstance();
if (pipe == INVALID_HANDLE_VALUE)
{
goto out;
}
status.dwCurrentState = SERVICE_RUNNING;
status.dwWaitHint = 0;
ReportStatusToSCMgr(service, &status);
while (TRUE)
{
if (ConnectNamedPipe(pipe, &overlapped) == FALSE
&& GetLastError() != ERROR_PIPE_CONNECTED
&& GetLastError() != ERROR_IO_PENDING)
{
MsgToEventLog(M_SYSERR, TEXT("Could not connect pipe"));
break;
}
error = WaitForMultipleObjects(handle_count, handles, FALSE, INFINITE);
if (error == WAIT_OBJECT_0)
{
/* Client connected, spawn a worker thread for it */
HANDLE next_pipe = CreateClientPipeInstance();
HANDLE thread = CreateThread(NULL, 0, RunOpenvpn, pipe, CREATE_SUSPENDED, NULL);
if (thread)
{
error = AddListItem(&threads, thread);
if (!error)
{
error = UpdateWaitHandles(&handles, &handle_count, io_event, exit_event, threads);
}
if (error)
{
ReturnError(pipe, error, L"Insufficient resources to service new clients", 1, &exit_event);
/* Update wait handles again after removing the last worker thread */
RemoveListItem(&threads, CmpHandle, thread);
UpdateWaitHandles(&handles, &handle_count, io_event, exit_event, threads);
TerminateThread(thread, 1);
CloseHandleEx(&thread);
CloseHandleEx(&pipe);
}
else
{
ResumeThread(thread);
}
}
else
{
CloseHandleEx(&pipe);
}
ResetOverlapped(&overlapped);
pipe = next_pipe;
}
else
{
CancelIo(pipe);
if (error == WAIT_FAILED)
{
MsgToEventLog(M_SYSERR, TEXT("WaitForMultipleObjects failed"));
SetEvent(exit_event);
/* Give some time for worker threads to exit and then terminate */
Sleep(1000);
break;
}
if (!threads)
{
/* exit event signaled */
CloseHandleEx(&pipe);
ResetEvent(exit_event);
error = NO_ERROR;
break;
}
/* Worker thread ended */
HANDLE thread = RemoveListItem(&threads, CmpHandle, handles[error]);
UpdateWaitHandles(&handles, &handle_count, io_event, exit_event, threads);
CloseHandleEx(&thread);
}
}
out:
FreeWaitHandles(handles);
CloseHandleEx(&io_event);
CloseHandleEx(&exit_event);
CloseHandleEx(&rdns_semaphore);
status.dwCurrentState = SERVICE_STOPPED;
status.dwWin32ExitCode = error;
ReportStatusToSCMgr(service, &status);
}