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Inherit only specific handles on Windows

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To be able to communicate with a child process via stdin, stdout and
stderr, the CreateProcess() parameter bInheritHandles must be set to
TRUE. But this causes *all* handles to be inherited, including sockets.

As a result, the server socket was inherited by the process running adb
to execute the server on the device, so it could not be closed properly,
causing other scrcpy instances to fail.

To fix the issue, use an extended API to explicitly set the HANDLEs to
inherit:
 - <https://stackoverflow.com/a/28185363/1987178>
 - <https://devblogs.microsoft.com/oldnewthing/20111216-00/?p=8873>

Fixes #2779 <https://github.com/Genymobile/scrcpy/issues/2779>
PR #2783 <https://github.com/Genymobile/scrcpy/pull/2783>
This commit is contained in:
Romain Vimont 2021-11-14 19:29:54 +01:00
parent 9cb8766220
commit 9cb14b5166
1 changed files with 76 additions and 12 deletions
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88
app/src/sys/win/process.c
View file

@ -1,5 +1,10 @@
// <https://devblogs.microsoft.com/oldnewthing/20111216-00/?p=8873>
#define _WIN32_WINNT 0x0600 // For extended process API
#include "util/process.h"
#include <processthreadsapi.h>
#include <assert.h>
#include "util/log.h"
@ -26,6 +31,9 @@ sc_process_execute_p(const char *const argv[], HANDLE *handle,
HANDLE *pin, HANDLE *pout, HANDLE *perr) {
enum sc_process_result ret = SC_PROCESS_ERROR_GENERIC;
// Add 1 per non-NULL pointer
unsigned handle_count = !!pin + !!pout + !!perr;
SECURITY_ATTRIBUTES sa;
sa.nLength = sizeof(SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor = NULL;
@ -65,43 +73,94 @@ sc_process_execute_p(const char *const argv[], HANDLE *handle,
}
}
STARTUPINFOW si;
STARTUPINFOEXW si;
PROCESS_INFORMATION pi;
memset(&si, 0, sizeof(si));
si.cb = sizeof(si);
if (pin || pout || perr) {
si.dwFlags = STARTF_USESTDHANDLES;
si.StartupInfo.cb = sizeof(si);
HANDLE handles[3];
LPPROC_THREAD_ATTRIBUTE_LIST lpAttributeList = NULL;
if (handle_count) {
si.StartupInfo.dwFlags = STARTF_USESTDHANDLES;
if (pin) {
si.hStdInput = stdin_read_handle;
si.StartupInfo.hStdInput = stdin_read_handle;
}
if (pout) {
si.hStdOutput = stdout_write_handle;
si.StartupInfo.hStdOutput = stdout_write_handle;
}
if (perr) {
si.hStdError = stderr_write_handle;
si.StartupInfo.hStdError = stderr_write_handle;
}
SIZE_T size;
// Call it once to know the required buffer size
BOOL ok =
InitializeProcThreadAttributeList(NULL, 1, 0, &size)
|| GetLastError() == ERROR_INSUFFICIENT_BUFFER;
if (!ok) {
goto error_close_stderr;
}
lpAttributeList = malloc(size);
if (!lpAttributeList) {
goto error_close_stderr;
}
ok = InitializeProcThreadAttributeList(lpAttributeList, 1, 0, &size);
if (!ok) {
free(lpAttributeList);
goto error_close_stderr;
}
// Explicitly pass the HANDLEs that must be inherited
unsigned i = 0;
if (pin) {
handles[i++] = stdin_read_handle;
}
if (pout) {
handles[i++] = stdout_write_handle;
}
if (perr) {
handles[i++] = stderr_write_handle;
}
ok = UpdateProcThreadAttribute(lpAttributeList, 0,
PROC_THREAD_ATTRIBUTE_HANDLE_LIST,
handles, handle_count * sizeof(HANDLE),
NULL, NULL);
if (!ok) {
goto error_free_attribute_list;
}
si.lpAttributeList = lpAttributeList;
}
char *cmd = malloc(CMD_MAX_LEN);
if (!cmd || !build_cmd(cmd, CMD_MAX_LEN, argv)) {
goto error_close_stderr;
goto error_free_attribute_list;
}
wchar_t *wide = sc_str_to_wchars(cmd);
free(cmd);
if (!wide) {
LOGC("Could not allocate wide char string");
goto error_close_stderr;
goto error_free_attribute_list;
}
BOOL ok = CreateProcessW(NULL, wide, NULL, NULL, TRUE, 0, NULL, NULL, &si,
&pi);
BOOL bInheritHandles = handle_count > 0;
DWORD dwCreationFlags = handle_count > 0 ? EXTENDED_STARTUPINFO_PRESENT : 0;
BOOL ok = CreateProcessW(NULL, wide, NULL, NULL, bInheritHandles,
dwCreationFlags, NULL, NULL, &si.StartupInfo, &pi);
free(wide);
if (!ok) {
if (GetLastError() == ERROR_FILE_NOT_FOUND) {
ret = SC_PROCESS_ERROR_MISSING_BINARY;
}
goto error_close_stderr;
goto error_free_attribute_list;
}
if (lpAttributeList) {
DeleteProcThreadAttributeList(lpAttributeList);
free(lpAttributeList);
}
// These handles are used by the child process, close them for this process
@ -119,6 +178,11 @@ sc_process_execute_p(const char *const argv[], HANDLE *handle,
return SC_PROCESS_SUCCESS;
error_free_attribute_list:
if (lpAttributeList) {
DeleteProcThreadAttributeList(lpAttributeList);
free(lpAttributeList);
}
error_close_stderr:
if (perr) {
CloseHandle(*perr);