/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <assert.h>
#include <io.h>
#include <stdio.h>
#include <stdlib.h>
#include "uv.h"
#include "internal.h"
#include "handle-inl.h"
/*
* The `child_stdio_buffer` buffer has the following layout:
* int number_of_fds
* unsigned char crt_flags[number_of_fds]
* HANDLE os_handle[number_of_fds]
*/
#define CHILD_STDIO_SIZE(count) \
(sizeof(int) + \
sizeof(unsigned char) * (count) + \
sizeof(uintptr_t) * (count))
#define CHILD_STDIO_COUNT(buffer) \
*((unsigned int*) (buffer))
#define CHILD_STDIO_CRT_FLAGS(buffer, fd) \
*((unsigned char*) (buffer) + sizeof(int) + fd)
#define CHILD_STDIO_HANDLE(buffer, fd) \
*((HANDLE*) ((unsigned char*) (buffer) + \
sizeof(int) + \
sizeof(unsigned char) * \
CHILD_STDIO_COUNT((buffer)) + \
sizeof(HANDLE) * (fd)))
/* CRT file descriptor mode flags */
#define FOPEN 0x01
#define FEOFLAG 0x02
#define FCRLF 0x04
#define FPIPE 0x08
#define FNOINHERIT 0x10
#define FAPPEND 0x20
#define FDEV 0x40
#define FTEXT 0x80
/*
* Clear the HANDLE_FLAG_INHERIT flag from all HANDLEs that were inherited
* the parent process. Don't check for errors - the stdio handles may not be
* valid, or may be closed already. There is no guarantee that this function
* does a perfect job.
*/
void uv_disable_stdio_inheritance(void) {
HANDLE handle;
STARTUPINFOW si;
/* Make the windows stdio handles non-inheritable. */
handle = GetStdHandle(STD_INPUT_HANDLE);
if (handle != NULL && handle != INVALID_HANDLE_VALUE)
SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
handle = GetStdHandle(STD_OUTPUT_HANDLE);
if (handle != NULL && handle != INVALID_HANDLE_VALUE)
SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
handle = GetStdHandle(STD_ERROR_HANDLE);
if (handle != NULL && handle != INVALID_HANDLE_VALUE)
SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
/* Make inherited CRT FDs non-inheritable. */
GetStartupInfoW(&si);
if (uv__stdio_verify(si.lpReserved2, si.cbReserved2))
uv__stdio_noinherit(si.lpReserved2);
}
static int uv__duplicate_handle(uv_loop_t* loop, HANDLE handle, HANDLE* dup) {
HANDLE current_process;
/* _get_osfhandle will sometimes return -2 in case of an error. This seems to
* happen when fd <= 2 and the process' corresponding stdio handle is set to
* NULL. Unfortunately DuplicateHandle will happily duplicate (HANDLE) -2, so
* this situation goes unnoticed until someone tries to use the duplicate.
* Therefore we filter out known-invalid handles here. */
if (handle == INVALID_HANDLE_VALUE ||
handle == NULL ||
handle == (HANDLE) -2) {
*dup = INVALID_HANDLE_VALUE;
return ERROR_INVALID_HANDLE;
}
current_process = GetCurrentProcess();
if (!DuplicateHandle(current_process,
handle,
current_process,
dup,
0,
TRUE,
DUPLICATE_SAME_ACCESS)) {
*dup = INVALID_HANDLE_VALUE;
return GetLastError();
}
return 0;
}
static int uv__duplicate_fd(uv_loop_t* loop, int fd, HANDLE* dup) {
HANDLE handle;
if (fd == -1) {
*dup = INVALID_HANDLE_VALUE;
return ERROR_INVALID_HANDLE;
}
handle = uv__get_osfhandle(fd);
return uv__duplicate_handle(loop, handle, dup);
}
int uv__create_nul_handle(HANDLE* handle_ptr,
DWORD access) {
HANDLE handle;
SECURITY_ATTRIBUTES sa;
sa.nLength = sizeof sa;
sa.lpSecurityDescriptor = NULL;
sa.bInheritHandle = TRUE;
handle = CreateFileW(L"NUL",
access,
FILE_SHARE_READ | FILE_SHARE_WRITE,
&sa,
OPEN_EXISTING,
0,
NULL);
if (handle == INVALID_HANDLE_VALUE) {
return GetLastError();
}
*handle_ptr = handle;
return 0;
}
int uv__stdio_create(uv_loop_t* loop,
const uv_process_options_t* options,
BYTE** buffer_ptr) {
BYTE* buffer;
int count, i;
int err;
count = options->stdio_count;
if (count < 0 || count > 255) {
/* Only support FDs 0-255 */
return ERROR_NOT_SUPPORTED;
} else if (count < 3) {
/* There should always be at least 3 stdio handles. */
count = 3;
}
/* Allocate the child stdio buffer */
buffer = (BYTE*) uv__malloc(CHILD_STDIO_SIZE(count));
if (buffer == NULL) {
return ERROR_OUTOFMEMORY;
}
/* Prepopulate the buffer with INVALID_HANDLE_VALUE handles so we can clean
* up on failure. */
CHILD_STDIO_COUNT(buffer) = count;
for (i = 0; i < count; i++) {
CHILD_STDIO_CRT_FLAGS(buffer, i) = 0;
CHILD_STDIO_HANDLE(buffer, i) = INVALID_HANDLE_VALUE;
}
for (i = 0; i < count; i++) {
uv_stdio_container_t fdopt;
if (i < options->stdio_count) {
fdopt = options->stdio[i];
} else {
fdopt.flags = UV_IGNORE;
}
switch (fdopt.flags & (UV_IGNORE | UV_CREATE_PIPE | UV_INHERIT_FD |
UV_INHERIT_STREAM)) {
case UV_IGNORE:
/* Starting a process with no stdin/stout/stderr can confuse it. So no
* matter what the user specified, we make sure the first three FDs are
* always open in their typical modes, e. g. stdin be readable and
* stdout/err should be writable. For FDs > 2, don't do anything - all
* handles in the stdio buffer are initialized with.
* INVALID_HANDLE_VALUE, which should be okay. */
if (i <= 2) {
DWORD access = (i == 0) ? FILE_GENERIC_READ :
FILE_GENERIC_WRITE | FILE_READ_ATTRIBUTES;
err = uv__create_nul_handle(&CHILD_STDIO_HANDLE(buffer, i),
access);
if (err)
goto error;
CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
}
break;
case UV_CREATE_PIPE: {
/* Create a pair of two connected pipe ends; one end is turned into an
* uv_pipe_t for use by the parent. The other one is given to the
* child. */
uv_pipe_t* parent_pipe = (uv_pipe_t*) fdopt.data.stream;
HANDLE child_pipe = INVALID_HANDLE_VALUE;
/* Create a new, connected pipe pair. stdio[i]. stream should point to
* an uninitialized, but not connected pipe handle. */
assert(fdopt.data.stream->type == UV_NAMED_PIPE);
assert(!(fdopt.data.stream->flags & UV_HANDLE_CONNECTION));
assert(!(fdopt.data.stream->flags & UV_HANDLE_PIPESERVER));
err = uv__create_stdio_pipe_pair(loop,
parent_pipe,
&child_pipe,
fdopt.flags);
if (err)
goto error;
CHILD_STDIO_HANDLE(buffer, i) = child_pipe;
CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FPIPE;
break;
}
case UV_INHERIT_FD: {
/* Inherit a raw FD. */
HANDLE child_handle;
/* Make an inheritable duplicate of the handle. */
err = uv__duplicate_fd(loop, fdopt.data.fd, &child_handle);
if (err) {
/* If fdopt. data. fd is not valid and fd <= 2, then ignore the
* error. */
if (fdopt.data.fd <= 2 && err == ERROR_INVALID_HANDLE) {
CHILD_STDIO_CRT_FLAGS(buffer, i) = 0;
CHILD_STDIO_HANDLE(buffer, i) = INVALID_HANDLE_VALUE;
break;
}
goto error;
}
/* Figure out what the type is. */
switch (GetFileType(child_handle)) {
case FILE_TYPE_DISK:
CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN;
break;
case FILE_TYPE_PIPE:
CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FPIPE;
break;
case FILE_TYPE_CHAR:
case FILE_TYPE_REMOTE:
CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
break;
case FILE_TYPE_UNKNOWN:
if (GetLastError() != 0) {
err = GetLastError();
CloseHandle(child_handle);
goto error;
}
CHILD_STDIO_CRT_FLAGS(buffer, i) = FOPEN | FDEV;
break;
default:
assert(0);
return -1;
}
CHILD_STDIO_HANDLE(buffer, i) = child_handle;
break;
}
case UV_INHERIT_STREAM: {
/* Use an existing stream as the stdio handle for the child. */
HANDLE stream_handle, child_handle;
unsigned char crt_flags;
uv_stream_t* stream = fdopt.data.stream;
/* Leech the handle out of the stream. */
if (stream->type == UV_TTY) {
stream_handle = ((uv_tty_t*) stream)->handle;
crt_flags = FOPEN | FDEV;
} else if (stream->type == UV_NAMED_PIPE &&
stream->flags & UV_HANDLE_CONNECTION) {
stream_handle = ((uv_pipe_t*) stream)->handle;
crt_flags = FOPEN | FPIPE;
} else {
stream_handle = INVALID_HANDLE_VALUE;
crt_flags = 0;
}
if (stream_handle == NULL ||
stream_handle == INVALID_HANDLE_VALUE) {
/* The handle is already closed, or not yet created, or the stream
* type is not supported. */
err = ERROR_NOT_SUPPORTED;
goto error;
}
/* Make an inheritable copy of the handle. */
err = uv__duplicate_handle(loop, stream_handle, &child_handle);
if (err)
goto error;
CHILD_STDIO_HANDLE(buffer, i) = child_handle;
CHILD_STDIO_CRT_FLAGS(buffer, i) = crt_flags;
break;
}
default:
assert(0);
return -1;
}
}
*buffer_ptr = buffer;
return 0;
error:
uv__stdio_destroy(buffer);
return err;
}
void uv__stdio_destroy(BYTE* buffer) {
int i, count;
count = CHILD_STDIO_COUNT(buffer);
for (i = 0; i < count; i++) {
HANDLE handle = CHILD_STDIO_HANDLE(buffer, i);
if (handle != INVALID_HANDLE_VALUE) {
CloseHandle(handle);
}
}
uv__free(buffer);
}
void uv__stdio_noinherit(BYTE* buffer) {
int i, count;
count = CHILD_STDIO_COUNT(buffer);
for (i = 0; i < count; i++) {
HANDLE handle = CHILD_STDIO_HANDLE(buffer, i);
if (handle != INVALID_HANDLE_VALUE) {
SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
}
}
}
int uv__stdio_verify(BYTE* buffer, WORD size) {
unsigned int count;
/* Check the buffer pointer. */
if (buffer == NULL)
return 0;
/* Verify that the buffer is at least big enough to hold the count. */
if (size < CHILD_STDIO_SIZE(0))
return 0;
/* Verify if the count is within range. */
count = CHILD_STDIO_COUNT(buffer);
if (count > 256)
return 0;
/* Verify that the buffer size is big enough to hold info for N FDs. */
if (size < CHILD_STDIO_SIZE(count))
return 0;
return 1;
}
WORD uv__stdio_size(BYTE* buffer) {
return (WORD) CHILD_STDIO_SIZE(CHILD_STDIO_COUNT((buffer)));
}
HANDLE uv__stdio_handle(BYTE* buffer, int fd) {
return CHILD_STDIO_HANDLE(buffer, fd);
}