/**
* @brief Checks wheter a command is registered for
* being executed during the Windows boot process or not.
* @param[in] command the name of the command's
* executable, without the extension.
* @return Positive value indicates that the command
* is registered, zero indicates that it isn't,
* negative value indicates a failure of the check.
*/
int winx_bootex_check(const wchar_t *command)
{
struct cmd *c, *list = NULL;
int result = (-1);
DbgCheck1(command,-1);
if(!wcscmp(command,L""))
return 0;
/* get list of registered commands */
if(get_boot_exec_list(&list) < 0) goto done;
/* check for specified command presence */
result = 0;
for(c = list; c; c = c->next){
if(cmd_compare(c->cmd,command) > 0){
result = 1;
break;
}
if(c->next == list) break;
}
done:
destroy_boot_exec_list(list);
return result;
}
/**
* @brief Deregisters a command from being executed
* during the Windows boot process.
* @param[in] command the name of the command's
* executable, without the extension.
* @return Zero for success, negative value otherwise.
*/
int winx_bootex_unregister(const wchar_t *command)
{
struct cmd *c, *list = NULL;
struct cmd *head, *next = NULL;
int result = (-1);
DbgCheck1(command,-1);
if(!wcscmp(command,L""))
return 0;
/* get list of registered commands */
if(get_boot_exec_list(&list) < 0) goto done;
/* remove specified command */
for(c = list; c; c = next){
head = list;
next = c->next;
if(cmd_compare(c->cmd,command) > 0){
winx_list_remove((list_entry **)(void *)&list,
(list_entry *)c);
}
if(list == NULL) break;
if(next == head) break;
}
/* save list of registered commands */
result = save_boot_exec_list(list);
done:
destroy_boot_exec_list(list);
return result;
}
/**
* @brief Queries an environment variable.
* @param[in] name the environment variable name.
* @return The value of the environment variable.
* NULL indicates failure.
* @note The returned string should be freed
* by the winx_free call after its use.
*/
wchar_t *winx_getenv(wchar_t *name)
{
wchar_t *value;
UNICODE_STRING n, v;
NTSTATUS status;
DbgCheck1(name,NULL);
value = winx_malloc(MAX_ENV_VALUE_LENGTH * sizeof(wchar_t));
RtlInitUnicodeString(&n,name);
v.Buffer = value;
v.Length = 0;
v.MaximumLength = MAX_ENV_VALUE_LENGTH * sizeof(wchar_t);
status = RtlQueryEnvironmentVariable_U(NULL,&n,&v);
if(!NT_SUCCESS(status)){
strace(status,"cannot query %ws",name);
winx_free(value);
return NULL;
}
if(value[0] == 0){
winx_free(value);
return NULL;
}
return value;
}
/**
* @brief Releases a mutex.
* @param[in] h the mutex handle.
* @return Zero for success,
* negative value otherwise.
*/
int winx_release_mutex(HANDLE h)
{
NTSTATUS status;
DbgCheck1(h,-1);
status = NtReleaseMutant(h,NULL);
if(!NT_SUCCESS(status)){
strace(status,"cannot release mutex");
return (-1);
}
return 0;
}
/**
* @brief Creates a thread and starts them.
* @param[in] start_addr the starting address of the thread.
* @param[in] parameter pointer to the data passed to the thread routine.
* @return Zero for success, negative value otherwise.
* @note Look at the following example for the thread function prototype.
* @par Example:
* @code
* DWORD WINAPI thread_proc(LPVOID parameter)
* {
* // do something
* winx_exit_thread(0);
* return 0;
* }
* winx_create_thread(thread_proc,NULL);
* @endcode
*/
int winx_create_thread(PTHREAD_START_ROUTINE start_addr,PVOID parameter)
{
NTSTATUS status;
HANDLE hThread;
DbgCheck1(start_addr,-1);
status = RtlCreateUserThread(NtCurrentProcess(),NULL,
0,0,0,0,start_addr,parameter,&hThread,NULL);
if(!NT_SUCCESS(status)){
strace(status,"cannot create thread");
return (-1);
}
NtCloseSafe(hThread);
return 0;
}
/**
* @brief Registers a command to be executed
* during the Windows boot process.
* @param[in] command the name of the command's
* executable, without the extension.
* @return Zero for success, negative value otherwise.
* @note Command's executable must be placed inside
* the system32 directory to be executed successfully.
*/
int winx_bootex_register(const wchar_t *command)
{
struct cmd *c, *list = NULL;
struct cmd *prev_command = NULL;
int cmd_found = 0;
wchar_t *cmd_copy;
int result = (-1);
DbgCheck1(command,-1);
if(!wcscmp(command,L""))
return 0;
/* get list of registered commands */
if(get_boot_exec_list(&list) < 0) goto done;
/* append specified command if necessary */
for(c = list; c; c = c->next){
if(cmd_compare(c->cmd,command) > 0){
cmd_found = 1;
break;
}
if(c->next == list) break;
}
if(cmd_found){
result = 0;
goto done;
}
cmd_copy = winx_wcsdup(command);
if(cmd_copy == NULL){
mtrace();
goto done;
}
if(list) prev_command = list->prev;
c = (struct cmd *)winx_list_insert(
(list_entry **)(void *)&list,
(list_entry *)prev_command,
sizeof(struct cmd));
c->cmd = cmd_copy;
/* save list of registered commands */
result = save_boot_exec_list(list);
done:
destroy_boot_exec_list(list);
return result;
}
/**
* @brief Sets an environment variable.
* @param[in] name the environment variable name.
* @param[in] value the null-terminated value string.
* NULL pointer causes a variable deletion.
* @return Zero for success, negative value otherwise.
* @note value buffer size must not exceed 32767 characters,
* including terminal zero, as mentioned in MSDN. This is
* because unsigned short data type can hold numbers
* less than or equal to 32767.
*/
int winx_setenv(wchar_t *name, wchar_t *value)
{
UNICODE_STRING n, v;
NTSTATUS status;
DbgCheck1(name,-1);
RtlInitUnicodeString(&n,name);
if(value){
if(value[0]){
RtlInitUnicodeString(&v,value);
status = RtlSetEnvironmentVariable(NULL,&n,&v);
} else {
status = RtlSetEnvironmentVariable(NULL,&n,NULL);
}
} else {
status = RtlSetEnvironmentVariable(NULL,&n,NULL);
}
if(!NT_SUCCESS(status)){
strace(status,"cannot set %ws",name);
return (-1);
}
return 0;
}
