diff options
Diffstat (limited to 'src/lib/process')
| -rw-r--r-- | src/lib/process/.may_include | 7 | ||||
| -rw-r--r-- | src/lib/process/include.am | 16 | ||||
| -rw-r--r-- | src/lib/process/process.c | 797 | ||||
| -rw-r--r-- | src/lib/process/process.h | 145 | ||||
| -rw-r--r-- | src/lib/process/process_sys.c | 33 | ||||
| -rw-r--r-- | src/lib/process/process_sys.h | 14 | ||||
| -rw-r--r-- | src/lib/process/process_unix.c | 698 | ||||
| -rw-r--r-- | src/lib/process/process_unix.h | 68 | ||||
| -rw-r--r-- | src/lib/process/process_win32.c | 1105 | ||||
| -rw-r--r-- | src/lib/process/process_win32.h | 97 | ||||
| -rw-r--r-- | src/lib/process/subprocess.c | 1236 | ||||
| -rw-r--r-- | src/lib/process/subprocess.h | 134 | ||||
| -rw-r--r-- | src/lib/process/waitpid.c | 2 | ||||
| -rw-r--r-- | src/lib/process/winprocess_sys.c | 64 | ||||
| -rw-r--r-- | src/lib/process/winprocess_sys.h | 14 |
15 files changed, 3053 insertions, 1377 deletions
diff --git a/src/lib/process/.may_include b/src/lib/process/.may_include index 05414d2a96..ce1b6ecf59 100644 --- a/src/lib/process/.may_include +++ b/src/lib/process/.may_include @@ -1,17 +1,20 @@ orconfig.h +lib/buf/*.h lib/cc/*.h lib/container/*.h lib/ctime/*.h lib/err/*.h -lib/intmath/*.h +lib/evloop/*.h lib/fs/*.h +lib/intmath/*.h lib/log/*.h lib/malloc/*.h lib/net/*.h lib/process/*.h lib/string/*.h +lib/subsys/*.h lib/testsupport/*.h lib/thread/*.h -ht.h
\ No newline at end of file +ext/ht.h diff --git a/src/lib/process/include.am b/src/lib/process/include.am index c6cc3a6699..83b67bf029 100644 --- a/src/lib/process/include.am +++ b/src/lib/process/include.am @@ -9,10 +9,14 @@ src_lib_libtor_process_a_SOURCES = \ src/lib/process/daemon.c \ src/lib/process/env.c \ src/lib/process/pidfile.c \ + src/lib/process/process.c \ + src/lib/process/process_sys.c \ + src/lib/process/process_unix.c \ + src/lib/process/process_win32.c \ src/lib/process/restrict.c \ src/lib/process/setuid.c \ - src/lib/process/subprocess.c \ - src/lib/process/waitpid.c + src/lib/process/waitpid.c \ + src/lib/process/winprocess_sys.c src_lib_libtor_process_testing_a_SOURCES = \ $(src_lib_libtor_process_a_SOURCES) @@ -23,7 +27,11 @@ noinst_HEADERS += \ src/lib/process/daemon.h \ src/lib/process/env.h \ src/lib/process/pidfile.h \ + src/lib/process/process.h \ + src/lib/process/process_sys.h \ + src/lib/process/process_unix.h \ + src/lib/process/process_win32.h \ src/lib/process/restrict.h \ src/lib/process/setuid.h \ - src/lib/process/subprocess.h \ - src/lib/process/waitpid.h + src/lib/process/waitpid.h \ + src/lib/process/winprocess_sys.h diff --git a/src/lib/process/process.c b/src/lib/process/process.c new file mode 100644 index 0000000000..422942dc83 --- /dev/null +++ b/src/lib/process/process.c @@ -0,0 +1,797 @@ +/* Copyright (c) 2003, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file process.c + * \brief Module for working with other processes. + **/ + +#define PROCESS_PRIVATE +#include "lib/buf/buffers.h" +#include "lib/net/buffers_net.h" +#include "lib/container/smartlist.h" +#include "lib/log/log.h" +#include "lib/log/util_bug.h" +#include "lib/process/process.h" +#include "lib/process/process_unix.h" +#include "lib/process/process_win32.h" +#include "lib/process/env.h" + +#ifdef HAVE_STDDEF_H +#include <stddef.h> +#endif + +/** A list of all <b>process_t</b> instances currently allocated. */ +static smartlist_t *processes; + +/** + * Boolean. If true, then Tor may call execve or CreateProcess via + * tor_spawn_background. + **/ +static int may_spawn_background_process = 1; + +/** Structure to represent a child process. */ +struct process_t { + /** Process status. */ + process_status_t status; + + /** Which protocol is the process using? */ + process_protocol_t protocol; + + /** Which function to call when we have data ready from stdout? */ + process_read_callback_t stdout_read_callback; + + /** Which function to call when we have data ready from stderr? */ + process_read_callback_t stderr_read_callback; + + /** Which function call when our process terminated? */ + process_exit_callback_t exit_callback; + + /** Our exit code when the process have terminated. */ + process_exit_code_t exit_code; + + /** Name of the command we want to execute (for example: /bin/ls). */ + char *command; + + /** The arguments used for the new process. The format here is one argument + * per element of the smartlist_t. On Windows these arguments are combined + * together using the <b>tor_join_win_cmdline</b> function. On Unix the + * process name (argv[0]) and the trailing NULL is added automatically before + * the process is executed. */ + smartlist_t *arguments; + + /** The environment used for the new process. */ + smartlist_t *environment; + + /** Buffer to store data from stdout when it is read. */ + buf_t *stdout_buffer; + + /** Buffer to store data from stderr when it is read. */ + buf_t *stderr_buffer; + + /** Buffer to store data to stdin before it is written. */ + buf_t *stdin_buffer; + + /** Do we need to store some custom data with the process? */ + void *data; + +#ifndef _WIN32 + /** Our Unix process handle. */ + process_unix_t *unix_process; +#else + /** Our Win32 process handle. */ + process_win32_t *win32_process; +#endif +}; + +/** Convert a given process status in <b>status</b> to its string + * representation. */ +const char * +process_status_to_string(process_status_t status) +{ + switch (status) { + case PROCESS_STATUS_NOT_RUNNING: + return "not running"; + case PROCESS_STATUS_RUNNING: + return "running"; + case PROCESS_STATUS_ERROR: + return "error"; + } + + /* LCOV_EXCL_START */ + tor_assert_unreached(); + return NULL; + /* LCOV_EXCL_STOP */ +} + +/** Convert a given process protocol in <b>protocol</b> to its string + * representation. */ +const char * +process_protocol_to_string(process_protocol_t protocol) +{ + switch (protocol) { + case PROCESS_PROTOCOL_LINE: + return "Line"; + case PROCESS_PROTOCOL_RAW: + return "Raw"; + } + + /* LCOV_EXCL_START */ + tor_assert_unreached(); + return NULL; + /* LCOV_EXCL_STOP */ +} + +/** + * Turn off may_spawn_background_process, so that all future calls to + * tor_spawn_background are guaranteed to fail. + **/ +void +tor_disable_spawning_background_processes(void) +{ + may_spawn_background_process = 0; +} + +/** Initialize the Process subsystem. This function initializes the Process + * subsystem's global state. For cleaning up, <b>process_free_all()</b> should + * be called. */ +void +process_init(void) +{ + processes = smartlist_new(); + +#ifdef _WIN32 + process_win32_init(); +#endif +} + +/** Free up all resources that is handled by the Process subsystem. Note that + * this call does not terminate already running processes. */ +void +process_free_all(void) +{ +#ifdef _WIN32 + process_win32_deinit(); +#endif + + SMARTLIST_FOREACH(processes, process_t *, x, process_free(x)); + smartlist_free(processes); +} + +/** Get a list of all processes. This function returns a smartlist of + * <b>process_t</b> containing all the currently allocated processes. */ +const smartlist_t * +process_get_all_processes(void) +{ + return processes; +} + +/** Allocate and initialize a new process. This function returns a newly + * allocated and initialized process data, which can be used to configure and + * later run a subprocess of Tor. Use the various <b>process_set_*()</b> + * methods to configure it and run the process using <b>process_exec()</b>. Use + * <b>command</b> to specify the path to the command to run. You can either + * specify an absolute path to the command or relative where Tor will use the + * underlying operating system's functionality for finding the command to run. + * */ +process_t * +process_new(const char *command) +{ + tor_assert(command); + + process_t *process; + process = tor_malloc_zero(sizeof(process_t)); + + /* Set our command. */ + process->command = tor_strdup(command); + + /* By default we are not running. */ + process->status = PROCESS_STATUS_NOT_RUNNING; + + /* Prepare process environment. */ + process->arguments = smartlist_new(); + process->environment = smartlist_new(); + + /* Prepare the buffers. */ + process->stdout_buffer = buf_new(); + process->stderr_buffer = buf_new(); + process->stdin_buffer = buf_new(); + +#ifndef _WIN32 + /* Prepare our Unix process handle. */ + process->unix_process = process_unix_new(); +#else + /* Prepare our Win32 process handle. */ + process->win32_process = process_win32_new(); +#endif + + smartlist_add(processes, process); + + return process; +} + +/** Deallocate the given process in <b>process</b>. */ +void +process_free_(process_t *process) +{ + if (! process) + return; + + /* Cleanup parameters. */ + tor_free(process->command); + + /* Cleanup arguments and environment. */ + SMARTLIST_FOREACH(process->arguments, char *, x, tor_free(x)); + smartlist_free(process->arguments); + + SMARTLIST_FOREACH(process->environment, char *, x, tor_free(x)); + smartlist_free(process->environment); + + /* Cleanup the buffers. */ + buf_free(process->stdout_buffer); + buf_free(process->stderr_buffer); + buf_free(process->stdin_buffer); + +#ifndef _WIN32 + /* Cleanup our Unix process handle. */ + process_unix_free(process->unix_process); +#else + /* Cleanup our Win32 process handle. */ + process_win32_free(process->win32_process); +#endif + + smartlist_remove(processes, process); + + tor_free(process); +} + +/** Execute the given process. This function executes the given process as a + * subprocess of Tor. Returns <b>PROCESS_STATUS_RUNNING</b> upon success. */ +process_status_t +process_exec(process_t *process) +{ + tor_assert(process); + + if (BUG(may_spawn_background_process == 0)) + return PROCESS_STATUS_ERROR; + + process_status_t status = PROCESS_STATUS_NOT_RUNNING; + + log_info(LD_PROCESS, "Starting new process: %s", process->command); + +#ifndef _WIN32 + status = process_unix_exec(process); +#else + status = process_win32_exec(process); +#endif + + /* Update our state. */ + process_set_status(process, status); + + if (status != PROCESS_STATUS_RUNNING) { + log_warn(LD_PROCESS, "Failed to start process: %s", + process_get_command(process)); + } + + return status; +} + +/** Terminate the given process. Returns true on success, + * otherwise false. */ +bool +process_terminate(process_t *process) +{ + tor_assert(process); + + /* Terminating a non-running process isn't going to work. */ + if (process_get_status(process) != PROCESS_STATUS_RUNNING) + return false; + + log_debug(LD_PROCESS, "Terminating process"); + +#ifndef _WIN32 + return process_unix_terminate(process); +#else + return process_win32_terminate(process); +#endif +} + +/** Returns the unique process identifier for the given <b>process</b>. */ +process_pid_t +process_get_pid(process_t *process) +{ + tor_assert(process); + +#ifndef _WIN32 + return process_unix_get_pid(process); +#else + return process_win32_get_pid(process); +#endif +} + +/** Set the callback function for output from the child process's standard out + * handle. This function sets the callback function which is called every time + * the child process have written output to its standard out file handle. + * + * Use <b>process_set_protocol(process, PROCESS_PROTOCOL_LINE)</b> if you want + * the callback to only contain complete "\n" or "\r\n" terminated lines. */ +void +process_set_stdout_read_callback(process_t *process, + process_read_callback_t callback) +{ + tor_assert(process); + process->stdout_read_callback = callback; +} + +/** Set the callback function for output from the child process's standard + * error handle. This function sets the callback function which is called + * every time the child process have written output to its standard error file + * handle. + * + * Use <b>process_set_protocol(process, PROCESS_PROTOCOL_LINE)</b> if you want + * the callback to only contain complete "\n" or "\r\n" terminated lines. */ +void +process_set_stderr_read_callback(process_t *process, + process_read_callback_t callback) +{ + tor_assert(process); + process->stderr_read_callback = callback; +} + +/** Set the callback function for process exit notification. The + * <b>callback</b> function will be called every time your child process have + * terminated. */ +void +process_set_exit_callback(process_t *process, + process_exit_callback_t callback) +{ + tor_assert(process); + process->exit_callback = callback; +} + +/** Get the current command of the given process. */ +const char * +process_get_command(const process_t *process) +{ + tor_assert(process); + return process->command; +} + +void +process_set_protocol(process_t *process, process_protocol_t protocol) +{ + tor_assert(process); + process->protocol = protocol; +} + +/** Get the currently used protocol of the given process. */ +process_protocol_t +process_get_protocol(const process_t *process) +{ + tor_assert(process); + return process->protocol; +} + +/** Set opague pointer to data. This function allows you to store a pointer to + * your own data in the given process. Use <b>process_get_data()</b> in the + * various callback functions to retrieve the data again. + * + * Note that the given process does NOT take ownership of the data and you are + * responsible for freeing up any resources allocated by the given data. + * */ +void +process_set_data(process_t *process, void *data) +{ + tor_assert(process); + process->data = data; +} + +/** Get the opaque pointer to callback data from the given process. This + * function allows you get the data you stored with <b>process_set_data()</b> + * in the different callback functions. */ +void * +process_get_data(const process_t *process) +{ + tor_assert(process); + return process->data; +} + +/** Set the status of a given process. */ +void +process_set_status(process_t *process, process_status_t status) +{ + tor_assert(process); + process->status = status; +} + +/** Get the status of the given process. */ +process_status_t +process_get_status(const process_t *process) +{ + tor_assert(process); + return process->status; +} + +/** Append an argument to the list of arguments in the given process. */ +void +process_append_argument(process_t *process, const char *argument) +{ + tor_assert(process); + tor_assert(argument); + + smartlist_add(process->arguments, tor_strdup(argument)); +} + +/** Returns a list of arguments (excluding the command itself) from the + * given process. */ +const smartlist_t * +process_get_arguments(const process_t *process) +{ + tor_assert(process); + return process->arguments; +} + +/** Returns a newly allocated Unix style argument vector. Use <b>tor_free()</b> + * to deallocate it after use. */ +char ** +process_get_argv(const process_t *process) +{ + tor_assert(process); + + /** Generate a Unix style process argument vector from our process's + * arguments smartlist_t. */ + char **argv = NULL; + + char *filename = process->command; + const smartlist_t *arguments = process->arguments; + const size_t size = smartlist_len(arguments); + + /* Make space for the process filename as argv[0] and a trailing NULL. */ + argv = tor_malloc_zero(sizeof(char *) * (size + 2)); + + /* Set our filename as first argument. */ + argv[0] = filename; + + /* Put in the rest of the values from arguments. */ + SMARTLIST_FOREACH_BEGIN(arguments, char *, arg_val) { + tor_assert(arg_val != NULL); + + argv[arg_val_sl_idx + 1] = arg_val; + } SMARTLIST_FOREACH_END(arg_val); + + return argv; +} + +/** This function clears the internal environment and copies over every string + * from <b>env</b> as the new environment. */ +void +process_reset_environment(process_t *process, const smartlist_t *env) +{ + tor_assert(process); + tor_assert(env); + + /* Cleanup old environment. */ + SMARTLIST_FOREACH(process->environment, char *, x, tor_free(x)); + smartlist_free(process->environment); + process->environment = smartlist_new(); + + SMARTLIST_FOREACH(env, char *, x, + smartlist_add(process->environment, tor_strdup(x))); +} + +/** Set the given <b>key</b>/<b>value</b> pair as environment variable in the + * given process. */ +void +process_set_environment(process_t *process, + const char *key, + const char *value) +{ + tor_assert(process); + tor_assert(key); + tor_assert(value); + + smartlist_add_asprintf(process->environment, "%s=%s", key, value); +} + +/** Returns a newly allocated <b>process_environment_t</b> containing the + * environment variables for the given process. */ +process_environment_t * +process_get_environment(const process_t *process) +{ + tor_assert(process); + return process_environment_make(process->environment); +} + +#ifndef _WIN32 +/** Get the internal handle for the Unix backend. */ +process_unix_t * +process_get_unix_process(const process_t *process) +{ + tor_assert(process); + tor_assert(process->unix_process); + return process->unix_process; +} +#else +/** Get the internal handle for Windows backend. */ +process_win32_t * +process_get_win32_process(const process_t *process) +{ + tor_assert(process); + tor_assert(process->win32_process); + return process->win32_process; +} +#endif + +/** Write <b>size</b> bytes of <b>data</b> to the given process's standard + * input. */ +void +process_write(process_t *process, + const uint8_t *data, size_t size) +{ + tor_assert(process); + tor_assert(data); + + buf_add(process->stdin_buffer, (char *)data, size); + process_write_stdin(process, process->stdin_buffer); +} + +/** As tor_vsnprintf(), but write the data to the given process's standard + * input. */ +void +process_vprintf(process_t *process, + const char *format, va_list args) +{ + tor_assert(process); + tor_assert(format); + + int size; + char *data; + + size = tor_vasprintf(&data, format, args); + process_write(process, (uint8_t *)data, size); + tor_free(data); +} + +/** As tor_snprintf(), but write the data to the given process's standard + * input. */ +void +process_printf(process_t *process, + const char *format, ...) +{ + tor_assert(process); + tor_assert(format); + + va_list ap; + va_start(ap, format); + process_vprintf(process, format, ap); + va_end(ap); +} + +/** This function is called by the Process backend when a given process have + * data that is ready to be read from the child process's standard output + * handle. */ +void +process_notify_event_stdout(process_t *process) +{ + tor_assert(process); + + int ret; + ret = process_read_stdout(process, process->stdout_buffer); + + if (ret > 0) + process_read_data(process, + process->stdout_buffer, + process->stdout_read_callback); +} + +/** This function is called by the Process backend when a given process have + * data that is ready to be read from the child process's standard error + * handle. */ +void +process_notify_event_stderr(process_t *process) +{ + tor_assert(process); + + int ret; + ret = process_read_stderr(process, process->stderr_buffer); + + if (ret > 0) + process_read_data(process, + process->stderr_buffer, + process->stderr_read_callback); +} + +/** This function is called by the Process backend when a given process is + * allowed to begin writing data to the standard input of the child process. */ +void +process_notify_event_stdin(process_t *process) +{ + tor_assert(process); + + process_write_stdin(process, process->stdin_buffer); +} + +/** This function is called by the Process backend when a given process have + * terminated. The exit status code is passed in <b>exit_code</b>. We mark the + * process as no longer running and calls the <b>exit_callback</b> with + * information about the process termination. The given <b>process</b> is + * free'd iff the exit_callback returns true. */ +void +process_notify_event_exit(process_t *process, process_exit_code_t exit_code) +{ + tor_assert(process); + + log_debug(LD_PROCESS, + "Process terminated with exit code: %"PRIu64, exit_code); + + /* Update our state. */ + process_set_status(process, PROCESS_STATUS_NOT_RUNNING); + process->exit_code = exit_code; + + /* Call our exit callback, if it exists. */ + bool free_process_handle = false; + + /* The exit callback will tell us if we should process_free() our handle. */ + if (process->exit_callback) + free_process_handle = process->exit_callback(process, exit_code); + + if (free_process_handle) + process_free(process); +} + +/** This function is called whenever the Process backend have notified us that + * there is data to be read from its standard out handle. Returns the number of + * bytes that have been put into the given buffer. */ +MOCK_IMPL(STATIC int, process_read_stdout, (process_t *process, buf_t *buffer)) +{ + tor_assert(process); + tor_assert(buffer); + +#ifndef _WIN32 + return process_unix_read_stdout(process, buffer); +#else + return process_win32_read_stdout(process, buffer); +#endif +} + +/** This function is called whenever the Process backend have notified us that + * there is data to be read from its standard error handle. Returns the number + * of bytes that have been put into the given buffer. */ +MOCK_IMPL(STATIC int, process_read_stderr, (process_t *process, buf_t *buffer)) +{ + tor_assert(process); + tor_assert(buffer); + +#ifndef _WIN32 + return process_unix_read_stderr(process, buffer); +#else + return process_win32_read_stderr(process, buffer); +#endif +} + +/** This function calls the backend function for the given process whenever + * there is data to be written to the backends' file handles. */ +MOCK_IMPL(STATIC void, process_write_stdin, + (process_t *process, buf_t *buffer)) +{ + tor_assert(process); + tor_assert(buffer); + +#ifndef _WIN32 + process_unix_write(process, buffer); +#else + process_win32_write(process, buffer); +#endif +} + +/** This function calls the protocol handlers based on the value of + * <b>process_get_protocol(process)</b>. Currently we call + * <b>process_read_buffer()</b> for <b>PROCESS_PROTOCOL_RAW</b> and + * <b>process_read_lines()</b> for <b>PROCESS_PROTOCOL_LINE</b>. */ +STATIC void +process_read_data(process_t *process, + buf_t *buffer, + process_read_callback_t callback) +{ + tor_assert(process); + tor_assert(buffer); + + switch (process_get_protocol(process)) { + case PROCESS_PROTOCOL_RAW: + process_read_buffer(process, buffer, callback); + break; + case PROCESS_PROTOCOL_LINE: + process_read_lines(process, buffer, callback); + break; + default: + /* LCOV_EXCL_START */ + tor_assert_unreached(); + return; + /* LCOV_EXCL_STOP */ + } +} + +/** This function takes the content of the given <b>buffer</b> and passes it to + * the given <b>callback</b> function, but ensures that an additional zero byte + * is added to the end of the data such that the given callback implementation + * can threat the content as a ASCIIZ string. */ +STATIC void +process_read_buffer(process_t *process, + buf_t *buffer, + process_read_callback_t callback) +{ + tor_assert(process); + tor_assert(buffer); + + const size_t size = buf_datalen(buffer); + + /* We allocate an extra byte for the zero byte in the end. */ + char *data = tor_malloc_zero(size + 1); + + buf_get_bytes(buffer, data, size); + log_debug(LD_PROCESS, "Read data from process"); + + if (callback) + callback(process, data, size); + + tor_free(data); +} + +/** This function tries to extract complete lines from the given <b>buffer</b> + * and calls the given <b>callback</b> function whenever it has a complete + * line. Before calling <b>callback</b> we remove the trailing "\n" or "\r\n" + * from the line. If we are unable to extract a complete line we leave the data + * in the buffer for next call. */ +STATIC void +process_read_lines(process_t *process, + buf_t *buffer, + process_read_callback_t callback) +{ + tor_assert(process); + tor_assert(buffer); + + const size_t size = buf_datalen(buffer) + 1; + size_t line_size = 0; + char *data = tor_malloc_zero(size); + int ret; + + while (true) { + line_size = size; + ret = buf_get_line(buffer, data, &line_size); + + /* A complete line should always be smaller than the size of our + * buffer. */ + tor_assert(ret != -1); + + /* Remove \n from the end of the line. */ + if (line_size >= 1 && data[line_size - 1] == '\n') { + data[line_size - 1] = '\0'; + --line_size; + } + + /* Remove \r from the end of the line. */ + if (line_size >= 1 && data[line_size - 1] == '\r') { + data[line_size - 1] = '\0'; + --line_size; + } + + if (ret == 1) { + log_debug(LD_PROCESS, "Read line from process: \"%s\"", data); + + if (callback) + callback(process, data, line_size); + + /* We have read a whole line, let's see if there is more lines to read. + * */ + continue; + } + + /* No complete line for us to read. We are done for now. */ + tor_assert_nonfatal(ret == 0); + break; + } + + tor_free(data); +} diff --git a/src/lib/process/process.h b/src/lib/process/process.h new file mode 100644 index 0000000000..14069923a0 --- /dev/null +++ b/src/lib/process/process.h @@ -0,0 +1,145 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file process.h + * \brief Header for process.c + **/ + +#ifndef TOR_PROCESS_H +#define TOR_PROCESS_H + +#include "orconfig.h" +#include "lib/malloc/malloc.h" +#include "lib/string/printf.h" + +/** Maximum number of bytes to write to a process' stdin. */ +#define PROCESS_MAX_WRITE (1024) + +/** Maximum number of bytes to read from a process' stdout/stderr. */ +#define PROCESS_MAX_READ (1024) + +typedef enum { + /** The process is not running. */ + PROCESS_STATUS_NOT_RUNNING, + + /** The process is running. */ + PROCESS_STATUS_RUNNING, + + /** The process is in an erroneous state. */ + PROCESS_STATUS_ERROR +} process_status_t; + +const char *process_status_to_string(process_status_t status); + +typedef enum { + /** Pass complete \n-terminated lines to the + * callback (with the \n or \r\n removed). */ + PROCESS_PROTOCOL_LINE, + + /** Pass the raw response from read() to the callback. */ + PROCESS_PROTOCOL_RAW +} process_protocol_t; + +const char *process_protocol_to_string(process_protocol_t protocol); + +void tor_disable_spawning_background_processes(void); + +struct smartlist_t; + +struct process_t; +typedef struct process_t process_t; + +typedef uint64_t process_exit_code_t; +typedef uint64_t process_pid_t; + +typedef void (*process_read_callback_t)(process_t *, + const char *, + size_t); +typedef bool +(*process_exit_callback_t)(process_t *, process_exit_code_t); + +void process_init(void); +void process_free_all(void); +const struct smartlist_t *process_get_all_processes(void); + +process_t *process_new(const char *command); +void process_free_(process_t *process); +#define process_free(s) FREE_AND_NULL(process_t, process_free_, (s)) + +process_status_t process_exec(process_t *process); +bool process_terminate(process_t *process); + +process_pid_t process_get_pid(process_t *process); + +void process_set_stdout_read_callback(process_t *, + process_read_callback_t); +void process_set_stderr_read_callback(process_t *, + process_read_callback_t); +void process_set_exit_callback(process_t *, + process_exit_callback_t); + +const char *process_get_command(const process_t *process); + +void process_append_argument(process_t *process, const char *argument); +const struct smartlist_t *process_get_arguments(const process_t *process); +char **process_get_argv(const process_t *process); + +void process_reset_environment(process_t *process, + const struct smartlist_t *env); +void process_set_environment(process_t *process, + const char *key, + const char *value); + +struct process_environment_t; +struct process_environment_t *process_get_environment(const process_t *); + +void process_set_protocol(process_t *process, process_protocol_t protocol); +process_protocol_t process_get_protocol(const process_t *process); + +void process_set_data(process_t *process, void *data); +void *process_get_data(const process_t *process); + +void process_set_status(process_t *process, process_status_t status); +process_status_t process_get_status(const process_t *process); + +#ifndef _WIN32 +struct process_unix_t; +struct process_unix_t *process_get_unix_process(const process_t *process); +#else +struct process_win32_t; +struct process_win32_t *process_get_win32_process(const process_t *process); +#endif + +void process_write(process_t *process, + const uint8_t *data, size_t size); +void process_vprintf(process_t *process, + const char *format, va_list args) CHECK_PRINTF(2, 0); +void process_printf(process_t *process, + const char *format, ...) CHECK_PRINTF(2, 3); + +void process_notify_event_stdout(process_t *process); +void process_notify_event_stderr(process_t *process); +void process_notify_event_stdin(process_t *process); +void process_notify_event_exit(process_t *process, + process_exit_code_t); + +#ifdef PROCESS_PRIVATE +MOCK_DECL(STATIC int, process_read_stdout, (process_t *, buf_t *)); +MOCK_DECL(STATIC int, process_read_stderr, (process_t *, buf_t *)); +MOCK_DECL(STATIC void, process_write_stdin, (process_t *, buf_t *)); + +STATIC void process_read_data(process_t *process, + buf_t *buffer, + process_read_callback_t callback); +STATIC void process_read_buffer(process_t *process, + buf_t *buffer, + process_read_callback_t callback); +STATIC void process_read_lines(process_t *process, + buf_t *buffer, + process_read_callback_t callback); +#endif /* defined(PROCESS_PRIVATE). */ + +#endif /* defined(TOR_PROCESS_H). */ diff --git a/src/lib/process/process_sys.c b/src/lib/process/process_sys.c new file mode 100644 index 0000000000..3c809a00e8 --- /dev/null +++ b/src/lib/process/process_sys.c @@ -0,0 +1,33 @@ +/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file process_sys.c + * \brief Subsystem object for process setup. + **/ + +#include "orconfig.h" +#include "lib/subsys/subsys.h" +#include "lib/process/process_sys.h" +#include "lib/process/process.h" + +static int +subsys_process_initialize(void) +{ + process_init(); + return 0; +} + +static void +subsys_process_shutdown(void) +{ + process_free_all(); +} + +const subsys_fns_t sys_process = { + .name = "process", + .level = -35, + .supported = true, + .initialize = subsys_process_initialize, + .shutdown = subsys_process_shutdown +}; diff --git a/src/lib/process/process_sys.h b/src/lib/process/process_sys.h new file mode 100644 index 0000000000..b7a116d838 --- /dev/null +++ b/src/lib/process/process_sys.h @@ -0,0 +1,14 @@ +/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file process_sys.h + * \brief Declare subsystem object for the process module. + **/ + +#ifndef TOR_PROCESS_SYS_H +#define TOR_PROCESS_SYS_H + +extern const struct subsys_fns_t sys_process; + +#endif /* !defined(TOR_PROCESS_SYS_H) */ diff --git a/src/lib/process/process_unix.c b/src/lib/process/process_unix.c new file mode 100644 index 0000000000..b102afff44 --- /dev/null +++ b/src/lib/process/process_unix.c @@ -0,0 +1,698 @@ +/* Copyright (c) 2003, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file process_unix.c + * \brief Module for working with Unix processes. + **/ + +#define PROCESS_UNIX_PRIVATE +#include "lib/intmath/cmp.h" +#include "lib/buf/buffers.h" +#include "lib/net/buffers_net.h" +#include "lib/container/smartlist.h" +#include "lib/evloop/compat_libevent.h" +#include "lib/log/log.h" +#include "lib/log/util_bug.h" +#include "lib/process/process.h" +#include "lib/process/process_unix.h" +#include "lib/process/waitpid.h" +#include "lib/process/env.h" + +#include <stdio.h> + +#ifdef HAVE_STRING_H +#include <string.h> +#endif + +#ifdef HAVE_ERRNO_H +#include <errno.h> +#endif + +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#ifdef HAVE_FCNTL_H +#include <fcntl.h> +#endif + +#if defined(HAVE_SYS_PRCTL_H) && defined(__linux__) +#include <sys/prctl.h> +#endif + +#if HAVE_SIGNAL_H +#include <signal.h> +#endif + +#ifndef _WIN32 + +/** Maximum number of file descriptors, if we cannot get it via sysconf() */ +#define DEFAULT_MAX_FD 256 + +/** Internal state for Unix handles. */ +struct process_unix_handle_t { + /** Unix File Descriptor. */ + int fd; + + /** Have we reached end of file? */ + bool reached_eof; + + /** Event structure for libevent. */ + struct event *event; + + /** Are we writing? */ + bool is_writing; +}; + +/** Internal state for our Unix process. */ +struct process_unix_t { + /** Standard in handle. */ + process_unix_handle_t stdin_handle; + + /** Standard out handle. */ + process_unix_handle_t stdout_handle; + + /** Standard error handle. */ + process_unix_handle_t stderr_handle; + + /** The process identifier of our process. */ + pid_t pid; + + /** Waitpid Callback structure. */ + waitpid_callback_t *waitpid; +}; + +/** Returns a newly allocated <b>process_unix_t</b>. */ +process_unix_t * +process_unix_new(void) +{ + process_unix_t *unix_process; + unix_process = tor_malloc_zero(sizeof(process_unix_t)); + + unix_process->stdin_handle.fd = -1; + unix_process->stderr_handle.fd = -1; + unix_process->stdout_handle.fd = -1; + + return unix_process; +} + +/** Deallocates the given <b>unix_process</b>. */ +void +process_unix_free_(process_unix_t *unix_process) +{ + if (! unix_process) + return; + + /* Clean up our waitpid callback. */ + clear_waitpid_callback(unix_process->waitpid); + + /* FIXME(ahf): Refactor waitpid code? */ + unix_process->waitpid = NULL; + + /* Close all our file descriptors. */ + process_unix_close_file_descriptors(unix_process); + + tor_event_free(unix_process->stdout_handle.event); + tor_event_free(unix_process->stderr_handle.event); + tor_event_free(unix_process->stdin_handle.event); + + tor_free(unix_process); +} + +/** Executes the given process as a child process of Tor. This function is + * responsible for setting up the child process and run it. This includes + * setting up pipes for interprocess communication, initialize the waitpid + * callbacks, and finally run fork() followed by execve(). Returns + * <b>PROCESS_STATUS_RUNNING</b> upon success. */ +process_status_t +process_unix_exec(process_t *process) +{ + static int max_fd = -1; + + process_unix_t *unix_process; + pid_t pid; + int stdin_pipe[2]; + int stdout_pipe[2]; + int stderr_pipe[2]; + int retval, fd; + + unix_process = process_get_unix_process(process); + + /* Create standard in pipe. */ + retval = pipe(stdin_pipe); + + if (-1 == retval) { + log_warn(LD_PROCESS, + "Unable to create pipe for stdin " + "communication with process: %s", + strerror(errno)); + + return PROCESS_STATUS_ERROR; + } + + /* Create standard out pipe. */ + retval = pipe(stdout_pipe); + + if (-1 == retval) { + log_warn(LD_PROCESS, + "Unable to create pipe for stdout " + "communication with process: %s", + strerror(errno)); + + /** Cleanup standard in pipe. */ + close(stdin_pipe[0]); + close(stdin_pipe[1]); + + return PROCESS_STATUS_ERROR; + } + + /* Create standard error pipe. */ + retval = pipe(stderr_pipe); + + if (-1 == retval) { + log_warn(LD_PROCESS, + "Unable to create pipe for stderr " + "communication with process: %s", + strerror(errno)); + + /** Cleanup standard in pipe. */ + close(stdin_pipe[0]); + close(stdin_pipe[1]); + + /** Cleanup standard out pipe. */ + close(stdout_pipe[0]); + close(stdout_pipe[1]); + + return PROCESS_STATUS_ERROR; + } + +#ifdef _SC_OPEN_MAX + if (-1 == max_fd) { + max_fd = (int)sysconf(_SC_OPEN_MAX); + + if (max_fd == -1) { + max_fd = DEFAULT_MAX_FD; + log_warn(LD_PROCESS, + "Cannot find maximum file descriptor, assuming: %d", max_fd); + } + } +#else /* !(defined(_SC_OPEN_MAX)) */ + max_fd = DEFAULT_MAX_FD; +#endif /* defined(_SC_OPEN_MAX) */ + + pid = fork(); + + if (0 == pid) { + /* This code is running in the child process context. */ + +#if defined(HAVE_SYS_PRCTL_H) && defined(__linux__) + /* Attempt to have the kernel issue a SIGTERM if the parent + * goes away. Certain attributes of the binary being execve()ed + * will clear this during the execve() call, but it's better + * than nothing. + */ + prctl(PR_SET_PDEATHSIG, SIGTERM); +#endif /* defined(HAVE_SYS_PRCTL_H) && defined(__linux__) */ + + /* Link process stdout to the write end of the pipe. */ + retval = dup2(stdout_pipe[1], STDOUT_FILENO); + if (-1 == retval) + goto error; + + /* Link process stderr to the write end of the pipe. */ + retval = dup2(stderr_pipe[1], STDERR_FILENO); + if (-1 == retval) + goto error; + + /* Link process stdin to the read end of the pipe */ + retval = dup2(stdin_pipe[0], STDIN_FILENO); + if (-1 == retval) + goto error; + + /* Close our pipes now after they have been dup2()'ed. */ + close(stderr_pipe[0]); + close(stderr_pipe[1]); + close(stdout_pipe[0]); + close(stdout_pipe[1]); + close(stdin_pipe[0]); + close(stdin_pipe[1]); + + /* Close all other fds, including the read end of the pipe. XXX: We should + * now be doing enough FD_CLOEXEC setting to make this needless. + */ + for (fd = STDERR_FILENO + 1; fd < max_fd; fd++) + close(fd); + + /* Create the argv value for our new process. */ + char **argv = process_get_argv(process); + + /* Create the env value for our new process. */ + process_environment_t *env = process_get_environment(process); + + /* Call the requested program. */ + execve(argv[0], argv, env->unixoid_environment_block); + + /* If we made it here it is because execve failed :-( */ + tor_free(argv); + process_environment_free(env); + + error: + fprintf(stderr, "Error from child process: %s", strerror(errno)); + _exit(1); + } + + /* We are in the parent process. */ + if (-1 == pid) { + log_warn(LD_PROCESS, + "Failed to create child process: %s", strerror(errno)); + + /** Cleanup standard in pipe. */ + close(stdin_pipe[0]); + close(stdin_pipe[1]); + + /** Cleanup standard out pipe. */ + close(stdout_pipe[0]); + close(stdout_pipe[1]); + + /** Cleanup standard error pipe. */ + close(stderr_pipe[0]); + close(stderr_pipe[1]); + + return PROCESS_STATUS_ERROR; + } + + /* Register our PID. */ + unix_process->pid = pid; + + /* Setup waitpid callbacks. */ + unix_process->waitpid = set_waitpid_callback(pid, + process_unix_waitpid_callback, + process); + + /* Handle standard out. */ + unix_process->stdout_handle.fd = stdout_pipe[0]; + retval = close(stdout_pipe[1]); + + if (-1 == retval) { + log_warn(LD_PROCESS, "Failed to close write end of standard out pipe: %s", + strerror(errno)); + } + + /* Handle standard error. */ + unix_process->stderr_handle.fd = stderr_pipe[0]; + retval = close(stderr_pipe[1]); + + if (-1 == retval) { + log_warn(LD_PROCESS, + "Failed to close write end of standard error pipe: %s", + strerror(errno)); + } + + /* Handle standard in. */ + unix_process->stdin_handle.fd = stdin_pipe[1]; + retval = close(stdin_pipe[0]); + + if (-1 == retval) { + log_warn(LD_PROCESS, "Failed to close read end of standard in pipe: %s", + strerror(errno)); + } + + /* Setup our handles. */ + process_unix_setup_handle(process, + &unix_process->stdout_handle, + EV_READ|EV_PERSIST, + stdout_read_callback); + + process_unix_setup_handle(process, + &unix_process->stderr_handle, + EV_READ|EV_PERSIST, + stderr_read_callback); + + process_unix_setup_handle(process, + &unix_process->stdin_handle, + EV_WRITE|EV_PERSIST, + stdin_write_callback); + + /* Start reading from standard out and standard error. */ + process_unix_start_reading(&unix_process->stdout_handle); + process_unix_start_reading(&unix_process->stderr_handle); + + return PROCESS_STATUS_RUNNING; +} + +/** Terminate the given process. Returns true on success, otherwise false. */ +bool +process_unix_terminate(process_t *process) +{ + tor_assert(process); + + process_unix_t *unix_process = process_get_unix_process(process); + + /* All running processes should have a waitpid. */ + if (BUG(unix_process->waitpid == NULL)) + return false; + + bool success = true; + + /* Send a SIGTERM to our child process. */ + int ret; + + ret = kill(unix_process->pid, SIGTERM); + + if (ret == -1) { + log_warn(LD_PROCESS, "Unable to terminate process: %s", + strerror(errno)); + success = false; + } + + /* Close all our FD's. */ + if (! process_unix_close_file_descriptors(unix_process)) + success = false; + + return success; +} + +/** Returns the unique process identifier for the given <b>process</b>. */ +process_pid_t +process_unix_get_pid(process_t *process) +{ + tor_assert(process); + + process_unix_t *unix_process = process_get_unix_process(process); + return (process_pid_t)unix_process->pid; +} + +/** Write the given <b>buffer</b> as input to the given <b>process</b>'s + * standard input. Returns the number of bytes written. */ +int +process_unix_write(process_t *process, buf_t *buffer) +{ + tor_assert(process); + tor_assert(buffer); + + process_unix_t *unix_process = process_get_unix_process(process); + + size_t buffer_flush_len = buf_datalen(buffer); + const size_t max_to_write = MIN(PROCESS_MAX_WRITE, buffer_flush_len); + + /* If we have data to write (when buffer_flush_len > 0) and we are not + * currently getting file descriptor events from the kernel, we tell the + * kernel to start notifying us about when we can write to our file + * descriptor and return. */ + if (buffer_flush_len > 0 && ! unix_process->stdin_handle.is_writing) { + process_unix_start_writing(&unix_process->stdin_handle); + return 0; + } + + /* We don't have any data to write, but the kernel is currently notifying us + * about whether we are able to write or not. Tell the kernel to stop + * notifying us until we have data to write. */ + if (buffer_flush_len == 0 && unix_process->stdin_handle.is_writing) { + process_unix_stop_writing(&unix_process->stdin_handle); + return 0; + } + + /* We have data to write and the kernel have told us to write it. */ + return buf_flush_to_pipe(buffer, + process_get_unix_process(process)->stdin_handle.fd, + max_to_write, &buffer_flush_len); +} + +/** Read data from the given process's standard output and put it into + * <b>buffer</b>. Returns the number of bytes read. */ +int +process_unix_read_stdout(process_t *process, buf_t *buffer) +{ + tor_assert(process); + tor_assert(buffer); + + process_unix_t *unix_process = process_get_unix_process(process); + + return process_unix_read_handle(process, + &unix_process->stdout_handle, + buffer); +} + +/** Read data from the given process's standard error and put it into + * <b>buffer</b>. Returns the number of bytes read. */ +int +process_unix_read_stderr(process_t *process, buf_t *buffer) +{ + tor_assert(process); + tor_assert(buffer); + + process_unix_t *unix_process = process_get_unix_process(process); + + return process_unix_read_handle(process, + &unix_process->stderr_handle, + buffer); +} + +/** This function is called whenever libevent thinks we have data that could be + * read from the child process's standard output. We notify the Process + * subsystem, which is then responsible for calling back to us for doing the + * actual reading of the data. */ +STATIC void +stdout_read_callback(evutil_socket_t fd, short event, void *data) +{ + (void)fd; + (void)event; + + process_t *process = data; + tor_assert(process); + + process_notify_event_stdout(process); +} + +/** This function is called whenever libevent thinks we have data that could be + * read from the child process's standard error. We notify the Process + * subsystem, which is then responsible for calling back to us for doing the + * actual reading of the data. */ +STATIC void +stderr_read_callback(evutil_socket_t fd, short event, void *data) +{ + (void)fd; + (void)event; + + process_t *process = data; + tor_assert(process); + + process_notify_event_stderr(process); +} + +/** This function is called whenever libevent thinks we have data that could be + * written the child process's standard input. We notify the Process subsystem, + * which is then responsible for calling back to us for doing the actual write + * of the data. */ +STATIC void +stdin_write_callback(evutil_socket_t fd, short event, void *data) +{ + (void)fd; + (void)event; + + process_t *process = data; + tor_assert(process); + + process_notify_event_stdin(process); +} + +/** This function tells libevent that we are interested in receiving read + * events from the given <b>handle</b>. */ +STATIC void +process_unix_start_reading(process_unix_handle_t *handle) +{ + tor_assert(handle); + + if (event_add(handle->event, NULL)) + log_warn(LD_PROCESS, + "Unable to add libevent event for handle."); +} + +/** This function tells libevent that we are no longer interested in receiving + * read events from the given <b>handle</b>. */ +STATIC void +process_unix_stop_reading(process_unix_handle_t *handle) +{ + tor_assert(handle); + + if (handle->event == NULL) + return; + + if (event_del(handle->event)) + log_warn(LD_PROCESS, + "Unable to delete libevent event for handle."); +} + +/** This function tells libevent that we are interested in receiving write + * events from the given <b>handle</b>. */ +STATIC void +process_unix_start_writing(process_unix_handle_t *handle) +{ + tor_assert(handle); + + if (event_add(handle->event, NULL)) + log_warn(LD_PROCESS, + "Unable to add libevent event for handle."); + + handle->is_writing = true; +} + +/** This function tells libevent that we are no longer interested in receiving + * write events from the given <b>handle</b>. */ +STATIC void +process_unix_stop_writing(process_unix_handle_t *handle) +{ + tor_assert(handle); + + if (handle->event == NULL) + return; + + if (event_del(handle->event)) + log_warn(LD_PROCESS, + "Unable to delete libevent event for handle."); + + handle->is_writing = false; +} + +/** This function is called when the waitpid system have detected that our + * process have terminated. We disable the waitpid system and notify the + * Process subsystem that we have terminated. */ +STATIC void +process_unix_waitpid_callback(int status, void *data) +{ + tor_assert(data); + + process_t *process = data; + process_unix_t *unix_process = process_get_unix_process(process); + + /* Remove our waitpid callback. */ + clear_waitpid_callback(unix_process->waitpid); + unix_process->waitpid = NULL; + + /* Notify our process. */ + process_notify_event_exit(process, status); + + /* Make sure you don't modify the process after we have called + * process_notify_event_exit() on it, to allow users to process_free() it in + * the exit callback. */ +} + +/** This function sets the file descriptor in the <b>handle</b> as non-blocking + * and configures the libevent event structure based on the given <b>flags</b> + * to ensure that <b>callback</b> is called whenever we have events on the + * given <b>handle</b>. */ +STATIC void +process_unix_setup_handle(process_t *process, + process_unix_handle_t *handle, + short flags, + event_callback_fn callback) +{ + tor_assert(process); + tor_assert(handle); + tor_assert(callback); + + /* Put our file descriptor into non-blocking mode. */ + if (fcntl(handle->fd, F_SETFL, O_NONBLOCK) < 0) { + log_warn(LD_PROCESS, "Unable mark Unix handle as non-blocking: %s", + strerror(errno)); + } + + /* Setup libevent event. */ + handle->event = tor_event_new(tor_libevent_get_base(), + handle->fd, + flags, + callback, + process); +} + +/** This function reads data from the given <b>handle</b> and puts it into + * <b>buffer</b>. Returns the number of bytes read this way. */ +STATIC int +process_unix_read_handle(process_t *process, + process_unix_handle_t *handle, + buf_t *buffer) +{ + tor_assert(process); + tor_assert(handle); + tor_assert(buffer); + + int ret = 0; + int eof = 0; + int error = 0; + + ret = buf_read_from_pipe(buffer, + handle->fd, + PROCESS_MAX_READ, + &eof, + &error); + + if (error) + log_warn(LD_PROCESS, + "Unable to read data: %s", strerror(error)); + + if (eof) { + handle->reached_eof = true; + process_unix_stop_reading(handle); + } + + return ret; +} + +/** Close the standard in, out, and error handles of the given + * <b>unix_process</b>. */ +STATIC bool +process_unix_close_file_descriptors(process_unix_t *unix_process) +{ + tor_assert(unix_process); + + int ret; + bool success = true; + + /* Stop reading and writing before we close() our + * file descriptors. */ + if (! unix_process->stdout_handle.reached_eof) + process_unix_stop_reading(&unix_process->stdout_handle); + + if (! unix_process->stderr_handle.reached_eof) + process_unix_stop_reading(&unix_process->stderr_handle); + + if (unix_process->stdin_handle.is_writing) + process_unix_stop_writing(&unix_process->stdin_handle); + + if (unix_process->stdin_handle.fd != -1) { + ret = close(unix_process->stdin_handle.fd); + if (ret == -1) { + log_warn(LD_PROCESS, "Unable to close standard in"); + success = false; + } + + unix_process->stdin_handle.fd = -1; + } + + if (unix_process->stdout_handle.fd != -1) { + ret = close(unix_process->stdout_handle.fd); + if (ret == -1) { + log_warn(LD_PROCESS, "Unable to close standard out"); + success = false; + } + + unix_process->stdout_handle.fd = -1; + } + + if (unix_process->stderr_handle.fd != -1) { + ret = close(unix_process->stderr_handle.fd); + if (ret == -1) { + log_warn(LD_PROCESS, "Unable to close standard error"); + success = false; + } + + unix_process->stderr_handle.fd = -1; + } + + return success; +} + +#endif /* defined(_WIN32). */ diff --git a/src/lib/process/process_unix.h b/src/lib/process/process_unix.h new file mode 100644 index 0000000000..a1d8f72993 --- /dev/null +++ b/src/lib/process/process_unix.h @@ -0,0 +1,68 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file process_unix.h + * \brief Header for process_unix.c + **/ + +#ifndef TOR_PROCESS_UNIX_H +#define TOR_PROCESS_UNIX_H + +#ifndef _WIN32 + +#include "orconfig.h" +#include "lib/malloc/malloc.h" + +#include <event2/event.h> + +struct process_t; + +struct process_unix_t; +typedef struct process_unix_t process_unix_t; + +process_unix_t *process_unix_new(void); +void process_unix_free_(process_unix_t *unix_process); +#define process_unix_free(s) \ + FREE_AND_NULL(process_unix_t, process_unix_free_, (s)) + +process_status_t process_unix_exec(struct process_t *process); +bool process_unix_terminate(struct process_t *process); + +process_pid_t process_unix_get_pid(struct process_t *process); + +int process_unix_write(struct process_t *process, buf_t *buffer); +int process_unix_read_stdout(struct process_t *process, buf_t *buffer); +int process_unix_read_stderr(struct process_t *process, buf_t *buffer); + +#ifdef PROCESS_UNIX_PRIVATE +struct process_unix_handle_t; +typedef struct process_unix_handle_t process_unix_handle_t; + +STATIC void stdout_read_callback(evutil_socket_t fd, short event, void *data); +STATIC void stderr_read_callback(evutil_socket_t fd, short event, void *data); +STATIC void stdin_write_callback(evutil_socket_t fd, short event, void *data); + +STATIC void process_unix_start_reading(process_unix_handle_t *); +STATIC void process_unix_stop_reading(process_unix_handle_t *); + +STATIC void process_unix_start_writing(process_unix_handle_t *); +STATIC void process_unix_stop_writing(process_unix_handle_t *); + +STATIC void process_unix_waitpid_callback(int status, void *data); + +STATIC void process_unix_setup_handle(process_t *process, + process_unix_handle_t *handle, + short flags, + event_callback_fn callback); +STATIC int process_unix_read_handle(process_t *, + process_unix_handle_t *, + buf_t *); +STATIC bool process_unix_close_file_descriptors(process_unix_t *); +#endif /* defined(PROCESS_UNIX_PRIVATE). */ + +#endif /* defined(_WIN32). */ + +#endif /* defined(TOR_PROCESS_UNIX_H). */ diff --git a/src/lib/process/process_win32.c b/src/lib/process/process_win32.c new file mode 100644 index 0000000000..1b1de6ad55 --- /dev/null +++ b/src/lib/process/process_win32.c @@ -0,0 +1,1105 @@ +/* Copyright (c) 2003, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file process_win32.c + * \brief Module for working with Windows processes. + **/ + +#define PROCESS_WIN32_PRIVATE +#include "lib/intmath/cmp.h" +#include "lib/buf/buffers.h" +#include "lib/net/buffers_net.h" +#include "lib/container/smartlist.h" +#include "lib/log/log.h" +#include "lib/log/util_bug.h" +#include "lib/log/win32err.h" +#include "lib/process/process.h" +#include "lib/process/process_win32.h" +#include "lib/process/env.h" + +#ifdef HAVE_SYS_TIME_H +#include <sys/time.h> +#endif + +#ifdef HAVE_STRING_H +#include <string.h> +#endif + +#ifdef _WIN32 + +/** The size of our intermediate buffers. */ +#define BUFFER_SIZE (1024) + +/** Timer that ticks once a second and calls the process_win32_timer_callback() + * function. */ +static periodic_timer_t *periodic_timer; + +/** Structure to represent the state around the pipe HANDLE. + * + * This structure is used to store state about a given HANDLE, including + * whether we have reached end of file, its intermediate buffers, and how much + * data that is available in the intermediate buffer. */ +struct process_win32_handle_t { + /** Standard out pipe handle. */ + HANDLE pipe; + + /** True iff we have reached EOF from the pipe. */ + bool reached_eof; + + /** How much data is available in buffer. */ + size_t data_available; + + /** Intermediate buffer for ReadFileEx() and WriteFileEx(). */ + char buffer[BUFFER_SIZE]; + + /** Overlapped structure for ReadFileEx() and WriteFileEx(). */ + OVERLAPPED overlapped; + + /** Are we waiting for another I/O operation to complete? */ + bool busy; +}; + +/** Structure to represent the Windows specific implementation details of this + * Process backend. + * + * This structure is attached to <b>process_t</b> (see process.h) and is + * reachable from <b>process_t</b> via the <b>process_get_win32_process()</b> + * method. */ +struct process_win32_t { + /** Standard in state. */ + process_win32_handle_t stdin_handle; + + /** Standard out state. */ + process_win32_handle_t stdout_handle; + + /** Standard error state. */ + process_win32_handle_t stderr_handle; + + /** Process Information. */ + PROCESS_INFORMATION process_information; +}; + +/** Create a new <b>process_win32_t</b>. + * + * This function constructs a new <b>process_win32_t</b> and initializes the + * default values. */ +process_win32_t * +process_win32_new(void) +{ + process_win32_t *win32_process; + win32_process = tor_malloc_zero(sizeof(process_win32_t)); + + win32_process->stdin_handle.pipe = INVALID_HANDLE_VALUE; + win32_process->stdout_handle.pipe = INVALID_HANDLE_VALUE; + win32_process->stderr_handle.pipe = INVALID_HANDLE_VALUE; + + return win32_process; +} + +/** Free a given <b>process_win32_t</b>. + * + * This function deinitializes and frees up the resources allocated for the + * given <b>process_win32_t</b>. */ +void +process_win32_free_(process_win32_t *win32_process) +{ + if (! win32_process) + return; + + /* Cleanup our handles. */ + process_win32_cleanup_handle(&win32_process->stdin_handle); + process_win32_cleanup_handle(&win32_process->stdout_handle); + process_win32_cleanup_handle(&win32_process->stderr_handle); + + tor_free(win32_process); +} + +/** Initialize the Windows backend of the Process subsystem. */ +void +process_win32_init(void) +{ + /* We don't start the periodic timer here because it makes no sense to have + * the timer running until we have some processes that benefits from the + * timer timer ticks. */ +} + +/** Deinitialize the Windows backend of the Process subsystem. */ +void +process_win32_deinit(void) +{ + /* Stop our timer, but only if it's running. */ + if (process_win32_timer_running()) + process_win32_timer_stop(); +} + +/** Execute the given process. This function is responsible for setting up + * named pipes for I/O between the child process and the Tor process. Returns + * <b>PROCESS_STATUS_RUNNING</b> upon success. */ +process_status_t +process_win32_exec(process_t *process) +{ + tor_assert(process); + + process_win32_t *win32_process = process_get_win32_process(process); + + HANDLE stdout_pipe_read = NULL; + HANDLE stdout_pipe_write = NULL; + HANDLE stderr_pipe_read = NULL; + HANDLE stderr_pipe_write = NULL; + HANDLE stdin_pipe_read = NULL; + HANDLE stdin_pipe_write = NULL; + BOOL ret = FALSE; + + /* Setup our security attributes. */ + SECURITY_ATTRIBUTES security_attributes; + security_attributes.nLength = sizeof(security_attributes); + security_attributes.bInheritHandle = TRUE; + /* FIXME: should we set explicit security attributes? + * (See Ticket #2046, comment 5) */ + security_attributes.lpSecurityDescriptor = NULL; + + /* Create our standard out pipe. */ + if (! process_win32_create_pipe(&stdout_pipe_read, + &stdout_pipe_write, + &security_attributes, + PROCESS_WIN32_PIPE_TYPE_READER)) { + return PROCESS_STATUS_ERROR; + } + + /* Create our standard error pipe. */ + if (! process_win32_create_pipe(&stderr_pipe_read, + &stderr_pipe_write, + &security_attributes, + PROCESS_WIN32_PIPE_TYPE_READER)) { + return PROCESS_STATUS_ERROR; + } + + /* Create out standard in pipe. */ + if (! process_win32_create_pipe(&stdin_pipe_read, + &stdin_pipe_write, + &security_attributes, + PROCESS_WIN32_PIPE_TYPE_WRITER)) { + return PROCESS_STATUS_ERROR; + } + + /* Configure startup info for our child process. */ + STARTUPINFOA startup_info; + + memset(&startup_info, 0, sizeof(startup_info)); + startup_info.cb = sizeof(startup_info); + startup_info.hStdError = stderr_pipe_write; + startup_info.hStdOutput = stdout_pipe_write; + startup_info.hStdInput = stdin_pipe_read; + startup_info.dwFlags |= STARTF_USESTDHANDLES; + + /* Create the env value for our new process. */ + process_environment_t *env = process_get_environment(process); + + /* Create the argv value for our new process. */ + char **argv = process_get_argv(process); + + /* Windows expects argv to be a whitespace delimited string, so join argv up + */ + char *joined_argv = tor_join_win_cmdline((const char **)argv); + + /* Create the child process */ + ret = CreateProcessA(NULL, + joined_argv, + NULL, + NULL, + TRUE, + CREATE_NO_WINDOW, + env->windows_environment_block[0] == '\0' ? + NULL : env->windows_environment_block, + NULL, + &startup_info, + &win32_process->process_information); + + tor_free(argv); + tor_free(joined_argv); + process_environment_free(env); + + if (! ret) { + log_warn(LD_PROCESS, "CreateProcessA() failed: %s", + format_win32_error(GetLastError())); + + /* Cleanup our handles. */ + CloseHandle(stdout_pipe_read); + CloseHandle(stdout_pipe_write); + CloseHandle(stderr_pipe_read); + CloseHandle(stderr_pipe_write); + CloseHandle(stdin_pipe_read); + CloseHandle(stdin_pipe_write); + + /* In the Unix backend, we do not get an error in the Tor process when a + * child process fails to spawn its target executable since we need to + * first do the fork() call in the Tor process and then the child process + * is responsible for doing the call to execve(). + * + * This means that the user of the process_exec() API must check for + * whether it returns PROCESS_STATUS_ERROR, which will rarely happen on + * Unix, but will happen for error cases on Windows where it does not + * happen on Unix. For example: when the target executable does not exist + * on the file system. + * + * To have somewhat feature compatibility between the Unix and the Windows + * backend, we here notify the process_t owner that the process have exited + * (even though it never managed to run) to ensure that the exit callback + * is executed. + */ + process_notify_event_exit(process, 0); + + return PROCESS_STATUS_ERROR; + } + + /* TODO: Should we close hProcess and hThread in + * process_handle->process_information? */ + win32_process->stdout_handle.pipe = stdout_pipe_read; + win32_process->stderr_handle.pipe = stderr_pipe_read; + win32_process->stdin_handle.pipe = stdin_pipe_write; + + /* Close our ends of the pipes that is now owned by the child process. */ + CloseHandle(stdout_pipe_write); + CloseHandle(stderr_pipe_write); + CloseHandle(stdin_pipe_read); + + /* Used by the callback functions from ReadFileEx() and WriteFileEx() such + * that we can figure out which process_t that was responsible for the event. + * + * Warning, here be dragons: + * + * MSDN says that the hEvent member of the overlapped structure is unused + * for ReadFileEx() and WriteFileEx, which allows us to store a pointer to + * our process state there. + */ + win32_process->stdout_handle.overlapped.hEvent = (HANDLE)process; + win32_process->stderr_handle.overlapped.hEvent = (HANDLE)process; + win32_process->stdin_handle.overlapped.hEvent = (HANDLE)process; + + /* Start our timer if it is not already running. */ + if (! process_win32_timer_running()) + process_win32_timer_start(); + + /* We use Windows Extended I/O functions, so our completion callbacks are + * called automatically for us when there is data to read. Because of this + * we start the read of standard out and error right away. */ + process_notify_event_stdout(process); + process_notify_event_stderr(process); + + return PROCESS_STATUS_RUNNING; +} + +/** Terminate the given process. Returns true on success, otherwise false. */ +bool +process_win32_terminate(process_t *process) +{ + tor_assert(process); + + process_win32_t *win32_process = process_get_win32_process(process); + + /* Terminate our process. */ + BOOL ret; + + ret = TerminateProcess(win32_process->process_information.hProcess, 0); + + if (! ret) { + log_warn(LD_PROCESS, "TerminateProcess() failed: %s", + format_win32_error(GetLastError())); + return false; + } + + /* Cleanup our handles. */ + process_win32_cleanup_handle(&win32_process->stdin_handle); + process_win32_cleanup_handle(&win32_process->stdout_handle); + process_win32_cleanup_handle(&win32_process->stderr_handle); + + return true; +} + +/** Returns the unique process identifier for the given <b>process</b>. */ +process_pid_t +process_win32_get_pid(process_t *process) +{ + tor_assert(process); + + process_win32_t *win32_process = process_get_win32_process(process); + return (process_pid_t)win32_process->process_information.dwProcessId; +} + +/** Schedule an async write of the data found in <b>buffer</b> for the given + * process. This function runs an async write operation of the content of + * buffer, if we are not already waiting for a pending I/O request. Returns the + * number of bytes that Windows will hopefully write for us in the background. + * */ +int +process_win32_write(struct process_t *process, buf_t *buffer) +{ + tor_assert(process); + tor_assert(buffer); + + process_win32_t *win32_process = process_get_win32_process(process); + BOOL ret = FALSE; + DWORD error_code = 0; + const size_t buffer_size = buf_datalen(buffer); + + /* Windows is still writing our buffer. */ + if (win32_process->stdin_handle.busy) + return 0; + + /* Nothing for us to do right now. */ + if (buffer_size == 0) + return 0; + + /* We have reached end of file already? */ + if (BUG(win32_process->stdin_handle.reached_eof)) + return 0; + + /* Figure out how much data we should read. */ + const size_t write_size = MIN(buffer_size, + sizeof(win32_process->stdin_handle.buffer)); + + /* Read data from the process_t buffer into our intermediate buffer. */ + buf_get_bytes(buffer, win32_process->stdin_handle.buffer, write_size); + + /* Because of the slightly weird API for WriteFileEx() we must set this to 0 + * before we call WriteFileEx() because WriteFileEx() does not reset the last + * error itself when it's succesful. See comment below after the call to + * GetLastError(). */ + SetLastError(0); + + /* Schedule our write. */ + ret = WriteFileEx(win32_process->stdin_handle.pipe, + win32_process->stdin_handle.buffer, + write_size, + &win32_process->stdin_handle.overlapped, + process_win32_stdin_write_done); + + if (! ret) { + error_code = GetLastError(); + + /* No need to log at warning level for these two. */ + if (error_code == ERROR_HANDLE_EOF || error_code == ERROR_BROKEN_PIPE) { + log_debug(LD_PROCESS, "WriteFileEx() returned EOF from pipe: %s", + format_win32_error(error_code)); + } else { + log_warn(LD_PROCESS, "WriteFileEx() failed: %s", + format_win32_error(error_code)); + } + + win32_process->stdin_handle.reached_eof = true; + return 0; + } + + /* Here be dragons: According to MSDN's documentation for WriteFileEx() we + * should check GetLastError() after a call to WriteFileEx() even though the + * `ret` return value was successful. If everything is good, GetLastError() + * returns `ERROR_SUCCESS` and nothing happens. + * + * XXX(ahf): I have not managed to trigger this code while stress-testing + * this code. */ + error_code = GetLastError(); + + if (error_code != ERROR_SUCCESS) { + /* LCOV_EXCL_START */ + log_warn(LD_PROCESS, "WriteFileEx() failed after returning success: %s", + format_win32_error(error_code)); + win32_process->stdin_handle.reached_eof = true; + return 0; + /* LCOV_EXCL_STOP */ + } + + /* This cast should be safe since our buffer can maximum be BUFFER_SIZE + * large. */ + return (int)write_size; +} + +/** This function is called from the Process subsystem whenever the Windows + * backend says it has data ready. This function also ensures that we are + * starting a new background read from the standard output of the child process + * and asks Windows to call process_win32_stdout_read_done() when that + * operation is finished. Returns the number of bytes moved into <b>buffer</b>. + * */ +int +process_win32_read_stdout(struct process_t *process, buf_t *buffer) +{ + tor_assert(process); + tor_assert(buffer); + + process_win32_t *win32_process = process_get_win32_process(process); + + return process_win32_read_from_handle(&win32_process->stdout_handle, + buffer, + process_win32_stdout_read_done); +} + +/** This function is called from the Process subsystem whenever the Windows + * backend says it has data ready. This function also ensures that we are + * starting a new background read from the standard error of the child process + * and asks Windows to call process_win32_stderr_read_done() when that + * operation is finished. Returns the number of bytes moved into <b>buffer</b>. + * */ +int +process_win32_read_stderr(struct process_t *process, buf_t *buffer) +{ + tor_assert(process); + tor_assert(buffer); + + process_win32_t *win32_process = process_get_win32_process(process); + + return process_win32_read_from_handle(&win32_process->stderr_handle, + buffer, + process_win32_stderr_read_done); +} + +/** This function is responsible for moving the Tor process into what Microsoft + * calls an "alertable" state. Once the process is in an alertable state the + * Windows kernel will notify us when our background I/O requests have finished + * and the callbacks will be executed. */ +void +process_win32_trigger_completion_callbacks(void) +{ + DWORD ret; + + /* The call to SleepEx(dwMilliseconds, dwAlertable) makes the process sleep + * for dwMilliseconds and if dwAlertable is set to TRUE it will also cause + * the process to enter alertable state, where the Windows kernel will notify + * us about completed I/O requests from ReadFileEx() and WriteFileEX(), which + * will cause our completion callbacks to be executed. + * + * This function returns 0 if the time interval expired or WAIT_IO_COMPLETION + * if one or more I/O callbacks were executed. */ + ret = SleepEx(0, TRUE); + + /* Warn us if the function returned something we did not anticipate. */ + if (ret != 0 && ret != WAIT_IO_COMPLETION) { + log_warn(LD_PROCESS, "SleepEx() returned %lu", ret); + } +} + +/** Start the periodic timer which is reponsible for checking whether processes + * are still alive and to make sure that the Tor process is periodically being + * moved into an alertable state. */ +void +process_win32_timer_start(void) +{ + /* Make sure we never start our timer if it's already running. */ + if (BUG(process_win32_timer_running())) + return; + + /* Wake up once a second. */ + static const struct timeval interval = {1, 0}; + + log_info(LD_PROCESS, "Starting Windows Process I/O timer"); + periodic_timer = periodic_timer_new(tor_libevent_get_base(), + &interval, + process_win32_timer_callback, + NULL); +} + +/** Stops the periodic timer. */ +void +process_win32_timer_stop(void) +{ + if (BUG(periodic_timer == NULL)) + return; + + log_info(LD_PROCESS, "Stopping Windows Process I/O timer"); + periodic_timer_free(periodic_timer); +} + +/** Returns true iff the periodic timer is running. */ +bool +process_win32_timer_running(void) +{ + return periodic_timer != NULL; +} + +/** This function is called whenever the periodic_timer ticks. The function is + * responsible for moving the Tor process into an alertable state once a second + * and checking for whether our child processes have terminated since the last + * tick. */ +STATIC void +process_win32_timer_callback(periodic_timer_t *timer, void *data) +{ + tor_assert(timer == periodic_timer); + tor_assert(data == NULL); + + /* Move the process into an alertable state. */ + process_win32_trigger_completion_callbacks(); + + /* Check if our processes are still alive. */ + + /* Since the call to process_win32_timer_test_process() might call + * process_notify_event_exit() which again might call process_free() which + * updates the list of processes returned by process_get_all_processes() it + * is important here that we make sure to not touch the list of processes if + * the call to process_win32_timer_test_process() returns true. */ + bool done; + + do { + const smartlist_t *processes = process_get_all_processes(); + done = true; + + SMARTLIST_FOREACH_BEGIN(processes, process_t *, process) { + /* If process_win32_timer_test_process() returns true, it means that + * smartlist_remove() might have been called on the list returned by + * process_get_all_processes(). We start the loop over again until we + * have a succesful run over the entire list where the list was not + * modified. */ + if (process_win32_timer_test_process(process)) { + done = false; + break; + } + } SMARTLIST_FOREACH_END(process); + } while (! done); +} + +/** Test whether a given process is still alive. Notify the Process subsystem + * if our process have died. Returns true iff the given process have + * terminated. */ +STATIC bool +process_win32_timer_test_process(process_t *process) +{ + tor_assert(process); + + /* No need to look at processes that don't claim they are running. */ + if (process_get_status(process) != PROCESS_STATUS_RUNNING) + return false; + + process_win32_t *win32_process = process_get_win32_process(process); + BOOL ret = FALSE; + DWORD exit_code = 0; + + /* Sometimes the Windows kernel wont give us the EOF/Broken Pipe error + * message until some time after the process have actually terminated. We + * make sure that our ReadFileEx() calls for the process have *all* returned + * and both standard out and error have been marked as EOF before we try to + * see if the process terminated. + * + * This ensures that we *never* call the exit callback of the `process_t`, + * which potentially ends up calling `process_free()` on our `process_t`, + * before all data have been received from the process. + * + * We do NOT have a check here for whether standard in reached EOF since + * standard in's WriteFileEx() function is only called on-demand when we have + * something to write and is thus usually not awaiting to finish any + * operations. If we WriteFileEx() to a file that has terminated we'll simply + * get an error from ReadFileEx() or its completion routine and move on with + * life. */ + if (! win32_process->stdout_handle.reached_eof) + return false; + + if (! win32_process->stderr_handle.reached_eof) + return false; + + /* We start by testing whether our process is still running. */ + ret = GetExitCodeProcess(win32_process->process_information.hProcess, + &exit_code); + + if (! ret) { + log_warn(LD_PROCESS, "GetExitCodeProcess() failed: %s", + format_win32_error(GetLastError())); + return false; + } + + /* Notify our process_t that our process have terminated. Since our + * exit_callback might decide to process_free() our process handle it is very + * important that we do not touch the process_t after the call to + * process_notify_event_exit(). */ + if (exit_code != STILL_ACTIVE) { + process_notify_event_exit(process, exit_code); + return true; + } + + return false; +} + +/** Create a new overlapped named pipe. This function creates a new connected, + * named, pipe in <b>*read_pipe</b> and <b>*write_pipe</b> if the function is + * succesful. Returns true on sucess, false on failure. */ +STATIC bool +process_win32_create_pipe(HANDLE *read_pipe, + HANDLE *write_pipe, + SECURITY_ATTRIBUTES *attributes, + process_win32_pipe_type_t pipe_type) +{ + tor_assert(read_pipe); + tor_assert(write_pipe); + tor_assert(attributes); + + BOOL ret = FALSE; + + /* Buffer size. */ + const size_t size = 4096; + + /* Our additional read/write modes that depends on which pipe type we are + * creating. */ + DWORD read_mode = 0; + DWORD write_mode = 0; + + /* Generate the unique pipe name. */ + char pipe_name[MAX_PATH]; + static DWORD process_id = 0; + static DWORD counter = 0; + + if (process_id == 0) + process_id = GetCurrentProcessId(); + + tor_snprintf(pipe_name, sizeof(pipe_name), + "\\\\.\\Pipe\\Tor-Process-Pipe-%lu-%lu", + process_id, counter++); + + /* Only one of our handles can be overlapped. */ + switch (pipe_type) { + case PROCESS_WIN32_PIPE_TYPE_READER: + read_mode = FILE_FLAG_OVERLAPPED; + break; + case PROCESS_WIN32_PIPE_TYPE_WRITER: + write_mode = FILE_FLAG_OVERLAPPED; + break; + default: + /* LCOV_EXCL_START */ + tor_assert_nonfatal_unreached_once(); + /* LCOV_EXCL_STOP */ + } + + /* Setup our read and write handles. */ + HANDLE read_handle; + HANDLE write_handle; + + /* Create our named pipe. */ + read_handle = CreateNamedPipeA(pipe_name, + (PIPE_ACCESS_INBOUND|read_mode), + (PIPE_TYPE_BYTE|PIPE_WAIT), + 1, + size, + size, + 1000, + attributes); + + if (read_handle == INVALID_HANDLE_VALUE) { + log_warn(LD_PROCESS, "CreateNamedPipeA() failed: %s", + format_win32_error(GetLastError())); + return false; + } + + /* Create our file in the pipe namespace. */ + write_handle = CreateFileA(pipe_name, + GENERIC_WRITE, + 0, + attributes, + OPEN_EXISTING, + (FILE_ATTRIBUTE_NORMAL|write_mode), + NULL); + + if (write_handle == INVALID_HANDLE_VALUE) { + log_warn(LD_PROCESS, "CreateFileA() failed: %s", + format_win32_error(GetLastError())); + + CloseHandle(read_handle); + + return false; + } + + /* Set the inherit flag for our pipe. */ + switch (pipe_type) { + case PROCESS_WIN32_PIPE_TYPE_READER: + ret = SetHandleInformation(read_handle, HANDLE_FLAG_INHERIT, 0); + break; + case PROCESS_WIN32_PIPE_TYPE_WRITER: + ret = SetHandleInformation(write_handle, HANDLE_FLAG_INHERIT, 0); + break; + default: + /* LCOV_EXCL_START */ + tor_assert_nonfatal_unreached_once(); + /* LCOV_EXCL_STOP */ + } + + if (! ret) { + log_warn(LD_PROCESS, "SetHandleInformation() failed: %s", + format_win32_error(GetLastError())); + + CloseHandle(read_handle); + CloseHandle(write_handle); + + return false; + } + + /* Everything is good. */ + *read_pipe = read_handle; + *write_pipe = write_handle; + + return true; +} + +/** Cleanup a given <b>handle</b>. */ +STATIC void +process_win32_cleanup_handle(process_win32_handle_t *handle) +{ + tor_assert(handle); + +#if 0 + BOOL ret; + DWORD error_code; + + /* Cancel any pending I/O requests: This means that instead of getting + * ERROR_BROKEN_PIPE we get ERROR_OPERATION_ABORTED, but it doesn't seem + * like this is needed. */ + ret = CancelIo(handle->pipe); + + if (! ret) { + error_code = GetLastError(); + + /* There was no pending I/O requests for our handle. */ + if (error_code != ERROR_NOT_FOUND) { + log_warn(LD_PROCESS, "CancelIo() failed: %s", + format_win32_error(error_code)); + } + } +#endif + + /* Close our handle. */ + if (handle->pipe != INVALID_HANDLE_VALUE) { + CloseHandle(handle->pipe); + handle->pipe = INVALID_HANDLE_VALUE; + handle->reached_eof = true; + } +} + +/** This function is called when ReadFileEx() completes its background read + * from the child process's standard output. We notify the Process subsystem if + * there is data available for it to read from us. */ +STATIC VOID WINAPI +process_win32_stdout_read_done(DWORD error_code, + DWORD byte_count, + LPOVERLAPPED overlapped) +{ + tor_assert(overlapped); + tor_assert(overlapped->hEvent); + + /* Extract our process_t from the hEvent member of OVERLAPPED. */ + process_t *process = (process_t *)overlapped->hEvent; + process_win32_t *win32_process = process_get_win32_process(process); + + if (process_win32_handle_read_completion(&win32_process->stdout_handle, + error_code, + byte_count)) { + /* Schedule our next read. */ + process_notify_event_stdout(process); + } +} + +/** This function is called when ReadFileEx() completes its background read + * from the child process's standard error. We notify the Process subsystem if + * there is data available for it to read from us. */ +STATIC VOID WINAPI +process_win32_stderr_read_done(DWORD error_code, + DWORD byte_count, + LPOVERLAPPED overlapped) +{ + tor_assert(overlapped); + tor_assert(overlapped->hEvent); + + /* Extract our process_t from the hEvent member of OVERLAPPED. */ + process_t *process = (process_t *)overlapped->hEvent; + process_win32_t *win32_process = process_get_win32_process(process); + + if (process_win32_handle_read_completion(&win32_process->stderr_handle, + error_code, + byte_count)) { + /* Schedule our next read. */ + process_notify_event_stderr(process); + } +} + +/** This function is called when WriteFileEx() completes its background write + * to the child process's standard input. We notify the Process subsystem that + * it can write data to us again. */ +STATIC VOID WINAPI +process_win32_stdin_write_done(DWORD error_code, + DWORD byte_count, + LPOVERLAPPED overlapped) +{ + tor_assert(overlapped); + tor_assert(overlapped->hEvent); + + (void)byte_count; + + process_t *process = (process_t *)overlapped->hEvent; + process_win32_t *win32_process = process_get_win32_process(process); + + /* Mark our handle as not having any outstanding I/O requests. */ + win32_process->stdin_handle.busy = false; + + /* Check if we have been asked to write to the handle that have been marked + * as having reached EOF. */ + if (BUG(win32_process->stdin_handle.reached_eof)) + return; + + if (error_code == 0) { + /** Our data have been succesfully written. Clear our state and schedule + * the next write. */ + win32_process->stdin_handle.data_available = 0; + memset(win32_process->stdin_handle.buffer, 0, + sizeof(win32_process->stdin_handle.buffer)); + + /* Schedule the next write. */ + process_notify_event_stdin(process); + } else if (error_code == ERROR_HANDLE_EOF || + error_code == ERROR_BROKEN_PIPE) { + /* Our WriteFileEx() call was succesful, but we reached the end of our + * file. We mark our handle as having reached EOF and returns. */ + tor_assert(byte_count == 0); + + win32_process->stdin_handle.reached_eof = true; + } else { + /* An error happened: We warn the user and mark our handle as having + * reached EOF */ + log_warn(LD_PROCESS, + "Error in I/O completion routine from WriteFileEx(): %s", + format_win32_error(error_code)); + win32_process->stdin_handle.reached_eof = true; + } +} + +/** This function reads data from the given <b>handle</b>'s internal buffer and + * moves it into the given <b>buffer</b>. Additionally, we start the next + * ReadFileEx() background operation with the given <b>callback</b> as + * completion callback. Returns the number of bytes written to the buffer. */ +STATIC int +process_win32_read_from_handle(process_win32_handle_t *handle, + buf_t *buffer, + LPOVERLAPPED_COMPLETION_ROUTINE callback) +{ + tor_assert(handle); + tor_assert(buffer); + tor_assert(callback); + + BOOL ret = FALSE; + int bytes_available = 0; + DWORD error_code = 0; + + /* We already have a request to read data that isn't complete yet. */ + if (BUG(handle->busy)) + return 0; + + /* Check if we have been asked to read from a handle that have already told + * us that we have reached the end of the file. */ + if (BUG(handle->reached_eof)) + return 0; + + /* This cast should be safe since our buffer can be at maximum up to + * BUFFER_SIZE in size. */ + bytes_available = (int)handle->data_available; + + if (handle->data_available > 0) { + /* Read data from our intermediate buffer into the process_t buffer. */ + buf_add(buffer, handle->buffer, handle->data_available); + + /* Reset our read state. */ + handle->data_available = 0; + memset(handle->buffer, 0, sizeof(handle->buffer)); + } + + /* Because of the slightly weird API for ReadFileEx() we must set this to 0 + * before we call ReadFileEx() because ReadFileEx() does not reset the last + * error itself when it's succesful. See comment below after the call to + * GetLastError(). */ + SetLastError(0); + + /* Ask the Windows kernel to read data from our pipe into our buffer and call + * the callback function when it is done. */ + ret = ReadFileEx(handle->pipe, + handle->buffer, + sizeof(handle->buffer), + &handle->overlapped, + callback); + + if (! ret) { + error_code = GetLastError(); + + /* No need to log at warning level for these two. */ + if (error_code == ERROR_HANDLE_EOF || error_code == ERROR_BROKEN_PIPE) { + log_debug(LD_PROCESS, "ReadFileEx() returned EOF from pipe: %s", + format_win32_error(error_code)); + } else { + log_warn(LD_PROCESS, "ReadFileEx() failed: %s", + format_win32_error(error_code)); + } + + handle->reached_eof = true; + return bytes_available; + } + + /* Here be dragons: According to MSDN's documentation for ReadFileEx() we + * should check GetLastError() after a call to ReadFileEx() even though the + * `ret` return value was successful. If everything is good, GetLastError() + * returns `ERROR_SUCCESS` and nothing happens. + * + * XXX(ahf): I have not managed to trigger this code while stress-testing + * this code. */ + error_code = GetLastError(); + + if (error_code != ERROR_SUCCESS) { + /* LCOV_EXCL_START */ + log_warn(LD_PROCESS, "ReadFileEx() failed after returning success: %s", + format_win32_error(error_code)); + handle->reached_eof = true; + return bytes_available; + /* LCOV_EXCL_STOP */ + } + + /* We mark our handle as having a pending I/O request. */ + handle->busy = true; + + return bytes_available; +} + +/** This function checks the callback values from ReadFileEx() in + * <b>error_code</b> and <b>byte_count</b> if we have read data. Returns true + * iff our caller should request more data from ReadFileEx(). */ +STATIC bool +process_win32_handle_read_completion(process_win32_handle_t *handle, + DWORD error_code, + DWORD byte_count) +{ + tor_assert(handle); + + /* Mark our handle as not having any outstanding I/O requests. */ + handle->busy = false; + + if (error_code == 0) { + /* Our ReadFileEx() call was succesful and there is data for us. */ + + /* This cast should be safe since byte_count should never be larger than + * BUFFER_SIZE. */ + tor_assert(byte_count <= BUFFER_SIZE); + handle->data_available = (size_t)byte_count; + + /* Tell our caller to schedule the next read. */ + return true; + } else if (error_code == ERROR_HANDLE_EOF || + error_code == ERROR_BROKEN_PIPE) { + /* Our ReadFileEx() finished, but we reached the end of our file. We mark + * our handle as having reached EOF and returns. */ + tor_assert(byte_count == 0); + + handle->reached_eof = true; + } else { + /* An error happened: We warn the user and mark our handle as having + * reached EOF */ + log_warn(LD_PROCESS, + "Error in I/O completion routine from ReadFileEx(): %s", + format_win32_error(error_code)); + + handle->reached_eof = true; + } + + /* Our caller should NOT schedule the next read. */ + return false; +} + +/** Format a single argument for being put on a Windows command line. + * Returns a newly allocated string */ +STATIC char * +format_win_cmdline_argument(const char *arg) +{ + char *formatted_arg; + char need_quotes; + const char *c; + int i; + int bs_counter = 0; + /* Backslash we can point to when one is inserted into the string */ + const char backslash = '\\'; + + /* Smartlist of *char */ + smartlist_t *arg_chars; + arg_chars = smartlist_new(); + + /* Quote string if it contains whitespace or is empty */ + need_quotes = (strchr(arg, ' ') || strchr(arg, '\t') || '\0' == arg[0]); + + /* Build up smartlist of *chars */ + for (c=arg; *c != '\0'; c++) { + if ('"' == *c) { + /* Double up backslashes preceding a quote */ + for (i=0; i<(bs_counter*2); i++) + smartlist_add(arg_chars, (void*)&backslash); + bs_counter = 0; + /* Escape the quote */ + smartlist_add(arg_chars, (void*)&backslash); + smartlist_add(arg_chars, (void*)c); + } else if ('\\' == *c) { + /* Count backslashes until we know whether to double up */ + bs_counter++; + } else { + /* Don't double up slashes preceding a non-quote */ + for (i=0; i<bs_counter; i++) + smartlist_add(arg_chars, (void*)&backslash); + bs_counter = 0; + smartlist_add(arg_chars, (void*)c); + } + } + /* Don't double up trailing backslashes */ + for (i=0; i<bs_counter; i++) + smartlist_add(arg_chars, (void*)&backslash); + + /* Allocate space for argument, quotes (if needed), and terminator */ + const size_t formatted_arg_len = smartlist_len(arg_chars) + + (need_quotes ? 2 : 0) + 1; + formatted_arg = tor_malloc_zero(formatted_arg_len); + + /* Add leading quote */ + i=0; + if (need_quotes) + formatted_arg[i++] = '"'; + + /* Add characters */ + SMARTLIST_FOREACH(arg_chars, char*, ch, + { + formatted_arg[i++] = *ch; + }); + + /* Add trailing quote */ + if (need_quotes) + formatted_arg[i++] = '"'; + formatted_arg[i] = '\0'; + + smartlist_free(arg_chars); + return formatted_arg; +} + +/** Format a command line for use on Windows, which takes the command as a + * string rather than string array. Follows the rules from "Parsing C++ + * Command-Line Arguments" in MSDN. Algorithm based on list2cmdline in the + * Python subprocess module. Returns a newly allocated string */ +STATIC char * +tor_join_win_cmdline(const char *argv[]) +{ + smartlist_t *argv_list; + char *joined_argv; + int i; + + /* Format each argument and put the result in a smartlist */ + argv_list = smartlist_new(); + for (i=0; argv[i] != NULL; i++) { + smartlist_add(argv_list, (void *)format_win_cmdline_argument(argv[i])); + } + + /* Join the arguments with whitespace */ + joined_argv = smartlist_join_strings(argv_list, " ", 0, NULL); + + /* Free the newly allocated arguments, and the smartlist */ + SMARTLIST_FOREACH(argv_list, char *, arg, + { + tor_free(arg); + }); + smartlist_free(argv_list); + + return joined_argv; +} + +#endif /* ! defined(_WIN32). */ diff --git a/src/lib/process/process_win32.h b/src/lib/process/process_win32.h new file mode 100644 index 0000000000..d79dde157e --- /dev/null +++ b/src/lib/process/process_win32.h @@ -0,0 +1,97 @@ +/* Copyright (c) 2003-2004, Roger Dingledine + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file process_win32.h + * \brief Header for process_win32.c + **/ + +#ifndef TOR_PROCESS_WIN32_H +#define TOR_PROCESS_WIN32_H + +#ifdef _WIN32 + +#include "orconfig.h" +#include "lib/malloc/malloc.h" +#include "lib/evloop/compat_libevent.h" + +#include <windows.h> + +struct process_t; + +struct process_win32_t; +typedef struct process_win32_t process_win32_t; + +process_win32_t *process_win32_new(void); +void process_win32_free_(process_win32_t *win32_process); +#define process_win32_free(s) \ + FREE_AND_NULL(process_win32_t, process_win32_free_, (s)) + +void process_win32_init(void); +void process_win32_deinit(void); + +process_status_t process_win32_exec(struct process_t *process); +bool process_win32_terminate(struct process_t *process); + +process_pid_t process_win32_get_pid(struct process_t *process); + +int process_win32_write(struct process_t *process, buf_t *buffer); +int process_win32_read_stdout(struct process_t *process, buf_t *buffer); +int process_win32_read_stderr(struct process_t *process, buf_t *buffer); + +void process_win32_trigger_completion_callbacks(void); + +/* Timer handling. */ +void process_win32_timer_start(void); +void process_win32_timer_stop(void); +bool process_win32_timer_running(void); + +#ifdef PROCESS_WIN32_PRIVATE +STATIC void process_win32_timer_callback(periodic_timer_t *, void *); +STATIC bool process_win32_timer_test_process(process_t *); + +/* I/O pipe handling. */ +struct process_win32_handle_t; +typedef struct process_win32_handle_t process_win32_handle_t; + +typedef enum process_win32_pipe_type_t { + /** This pipe is used for reading. */ + PROCESS_WIN32_PIPE_TYPE_READER, + + /** This pipe is used for writing. */ + PROCESS_WIN32_PIPE_TYPE_WRITER +} process_win32_pipe_type_t; + +STATIC bool process_win32_create_pipe(HANDLE *, + HANDLE *, + SECURITY_ATTRIBUTES *, + process_win32_pipe_type_t); + +STATIC void process_win32_cleanup_handle(process_win32_handle_t *handle); + +STATIC VOID WINAPI process_win32_stdout_read_done(DWORD, + DWORD, + LPOVERLAPPED); +STATIC VOID WINAPI process_win32_stderr_read_done(DWORD, + DWORD, + LPOVERLAPPED); +STATIC VOID WINAPI process_win32_stdin_write_done(DWORD, + DWORD, + LPOVERLAPPED); + +STATIC int process_win32_read_from_handle(process_win32_handle_t *, + buf_t *, + LPOVERLAPPED_COMPLETION_ROUTINE); +STATIC bool process_win32_handle_read_completion(process_win32_handle_t *, + DWORD, + DWORD); + +STATIC char *format_win_cmdline_argument(const char *arg); +STATIC char *tor_join_win_cmdline(const char *argv[]); +#endif /* defined(PROCESS_WIN32_PRIVATE). */ + +#endif /* ! defined(_WIN32). */ + +#endif /* defined(TOR_PROCESS_WIN32_H). */ diff --git a/src/lib/process/subprocess.c b/src/lib/process/subprocess.c deleted file mode 100644 index f4429d7f76..0000000000 --- a/src/lib/process/subprocess.c +++ /dev/null @@ -1,1236 +0,0 @@ -/* Copyright (c) 2003, Roger Dingledine - * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ -/* See LICENSE for licensing information */ - -/** - * \file subprocess.c - * \brief Launch and monitor other processes. - **/ - -#define SUBPROCESS_PRIVATE -#include "lib/process/subprocess.h" - -#include "lib/container/smartlist.h" -#include "lib/err/torerr.h" -#include "lib/log/log.h" -#include "lib/log/util_bug.h" -#include "lib/log/win32err.h" -#include "lib/malloc/malloc.h" -#include "lib/process/env.h" -#include "lib/process/waitpid.h" -#include "lib/string/compat_ctype.h" - -#ifdef HAVE_SYS_TYPES_H -#include <sys/types.h> -#endif -#ifdef HAVE_SYS_PRCTL_H -#include <sys/prctl.h> -#endif -#ifdef HAVE_UNISTD_H -#include <unistd.h> -#endif -#ifdef HAVE_SIGNAL_H -#include <signal.h> -#endif -#ifdef HAVE_FCNTL_H -#include <fcntl.h> -#endif -#ifdef HAVE_SYS_WAIT_H -#include <sys/wait.h> -#endif -#include <errno.h> -#include <string.h> - -/** Format a single argument for being put on a Windows command line. - * Returns a newly allocated string */ -static char * -format_win_cmdline_argument(const char *arg) -{ - char *formatted_arg; - char need_quotes; - const char *c; - int i; - int bs_counter = 0; - /* Backslash we can point to when one is inserted into the string */ - const char backslash = '\\'; - - /* Smartlist of *char */ - smartlist_t *arg_chars; - arg_chars = smartlist_new(); - - /* Quote string if it contains whitespace or is empty */ - need_quotes = (strchr(arg, ' ') || strchr(arg, '\t') || '\0' == arg[0]); - - /* Build up smartlist of *chars */ - for (c=arg; *c != '\0'; c++) { - if ('"' == *c) { - /* Double up backslashes preceding a quote */ - for (i=0; i<(bs_counter*2); i++) - smartlist_add(arg_chars, (void*)&backslash); - bs_counter = 0; - /* Escape the quote */ - smartlist_add(arg_chars, (void*)&backslash); - smartlist_add(arg_chars, (void*)c); - } else if ('\\' == *c) { - /* Count backslashes until we know whether to double up */ - bs_counter++; - } else { - /* Don't double up slashes preceding a non-quote */ - for (i=0; i<bs_counter; i++) - smartlist_add(arg_chars, (void*)&backslash); - bs_counter = 0; - smartlist_add(arg_chars, (void*)c); - } - } - /* Don't double up trailing backslashes */ - for (i=0; i<bs_counter; i++) - smartlist_add(arg_chars, (void*)&backslash); - - /* Allocate space for argument, quotes (if needed), and terminator */ - const size_t formatted_arg_len = smartlist_len(arg_chars) + - (need_quotes ? 2 : 0) + 1; - formatted_arg = tor_malloc_zero(formatted_arg_len); - - /* Add leading quote */ - i=0; - if (need_quotes) - formatted_arg[i++] = '"'; - - /* Add characters */ - SMARTLIST_FOREACH(arg_chars, char*, ch, - { - formatted_arg[i++] = *ch; - }); - - /* Add trailing quote */ - if (need_quotes) - formatted_arg[i++] = '"'; - formatted_arg[i] = '\0'; - - smartlist_free(arg_chars); - return formatted_arg; -} - -/** Format a command line for use on Windows, which takes the command as a - * string rather than string array. Follows the rules from "Parsing C++ - * Command-Line Arguments" in MSDN. Algorithm based on list2cmdline in the - * Python subprocess module. Returns a newly allocated string */ -char * -tor_join_win_cmdline(const char *argv[]) -{ - smartlist_t *argv_list; - char *joined_argv; - int i; - - /* Format each argument and put the result in a smartlist */ - argv_list = smartlist_new(); - for (i=0; argv[i] != NULL; i++) { - smartlist_add(argv_list, (void *)format_win_cmdline_argument(argv[i])); - } - - /* Join the arguments with whitespace */ - joined_argv = smartlist_join_strings(argv_list, " ", 0, NULL); - - /* Free the newly allocated arguments, and the smartlist */ - SMARTLIST_FOREACH(argv_list, char *, arg, - { - tor_free(arg); - }); - smartlist_free(argv_list); - - return joined_argv; -} - -#ifndef _WIN32 -/** Format <b>child_state</b> and <b>saved_errno</b> as a hex string placed in - * <b>hex_errno</b>. Called between fork and _exit, so must be signal-handler - * safe. - * - * <b>hex_errno</b> must have at least HEX_ERRNO_SIZE+1 bytes available. - * - * The format of <b>hex_errno</b> is: "CHILD_STATE/ERRNO\n", left-padded - * with spaces. CHILD_STATE indicates where - * in the process of starting the child process did the failure occur (see - * CHILD_STATE_* macros for definition), and SAVED_ERRNO is the value of - * errno when the failure occurred. - * - * On success return the number of characters added to hex_errno, not counting - * the terminating NUL; return -1 on error. - */ -STATIC int -format_helper_exit_status(unsigned char child_state, int saved_errno, - char *hex_errno) -{ - unsigned int unsigned_errno; - int written, left; - char *cur; - size_t i; - int res = -1; - - /* Fill hex_errno with spaces, and a trailing newline (memset may - not be signal handler safe, so we can't use it) */ - for (i = 0; i < (HEX_ERRNO_SIZE - 1); i++) - hex_errno[i] = ' '; - hex_errno[HEX_ERRNO_SIZE - 1] = '\n'; - - /* Convert errno to be unsigned for hex conversion */ - if (saved_errno < 0) { - // Avoid overflow on the cast to unsigned int when result is INT_MIN - // by adding 1 to the signed int negative value, - // then, after it has been negated and cast to unsigned, - // adding the original 1 back (the double-addition is intentional). - // Otherwise, the cast to signed could cause a temporary int - // to equal INT_MAX + 1, which is undefined. - unsigned_errno = ((unsigned int) -(saved_errno + 1)) + 1; - } else { - unsigned_errno = (unsigned int) saved_errno; - } - - /* - * Count how many chars of space we have left, and keep a pointer into the - * current point in the buffer. - */ - left = HEX_ERRNO_SIZE+1; - cur = hex_errno; - - /* Emit child_state */ - written = format_hex_number_sigsafe(child_state, cur, left); - - if (written <= 0) - goto err; - - /* Adjust left and cur */ - left -= written; - cur += written; - if (left <= 0) - goto err; - - /* Now the '/' */ - *cur = '/'; - - /* Adjust left and cur */ - ++cur; - --left; - if (left <= 0) - goto err; - - /* Need minus? */ - if (saved_errno < 0) { - *cur = '-'; - ++cur; - --left; - if (left <= 0) - goto err; - } - - /* Emit unsigned_errno */ - written = format_hex_number_sigsafe(unsigned_errno, cur, left); - - if (written <= 0) - goto err; - - /* Adjust left and cur */ - left -= written; - cur += written; - - /* Check that we have enough space left for a newline and a NUL */ - if (left <= 1) - goto err; - - /* Emit the newline and NUL */ - *cur++ = '\n'; - *cur++ = '\0'; - - res = (int)(cur - hex_errno - 1); - - goto done; - - err: - /* - * In error exit, just write a '\0' in the first char so whatever called - * this at least won't fall off the end. - */ - *hex_errno = '\0'; - - done: - return res; -} -#endif /* !defined(_WIN32) */ - -/* Maximum number of file descriptors, if we cannot get it via sysconf() */ -#define DEFAULT_MAX_FD 256 - -/** Terminate the process of <b>process_handle</b>, if that process has not - * already exited. - * - * Return 0 if we succeeded in terminating the process (or if the process - * already exited), and -1 if we tried to kill the process but failed. - * - * Based on code originally borrowed from Python's os.kill. */ -int -tor_terminate_process(process_handle_t *process_handle) -{ -#ifdef _WIN32 - if (tor_get_exit_code(process_handle, 0, NULL) == PROCESS_EXIT_RUNNING) { - HANDLE handle = process_handle->pid.hProcess; - - if (!TerminateProcess(handle, 0)) - return -1; - else - return 0; - } -#else /* !(defined(_WIN32)) */ - if (process_handle->waitpid_cb) { - /* We haven't got a waitpid yet, so we can just kill off the process. */ - return kill(process_handle->pid, SIGTERM); - } -#endif /* defined(_WIN32) */ - - return 0; /* We didn't need to kill the process, so report success */ -} - -/** Return the Process ID of <b>process_handle</b>. */ -int -tor_process_get_pid(process_handle_t *process_handle) -{ -#ifdef _WIN32 - return (int) process_handle->pid.dwProcessId; -#else - return (int) process_handle->pid; -#endif -} - -#ifdef _WIN32 -HANDLE -tor_process_get_stdout_pipe(process_handle_t *process_handle) -{ - return process_handle->stdout_pipe; -} -#else /* !(defined(_WIN32)) */ -/* DOCDOC tor_process_get_stdout_pipe */ -int -tor_process_get_stdout_pipe(process_handle_t *process_handle) -{ - return process_handle->stdout_pipe; -} -#endif /* defined(_WIN32) */ - -/* DOCDOC process_handle_new */ -static process_handle_t * -process_handle_new(void) -{ - process_handle_t *out = tor_malloc_zero(sizeof(process_handle_t)); - -#ifdef _WIN32 - out->stdin_pipe = INVALID_HANDLE_VALUE; - out->stdout_pipe = INVALID_HANDLE_VALUE; - out->stderr_pipe = INVALID_HANDLE_VALUE; -#else - out->stdin_pipe = -1; - out->stdout_pipe = -1; - out->stderr_pipe = -1; -#endif /* defined(_WIN32) */ - - return out; -} - -#ifndef _WIN32 -/** Invoked when a process that we've launched via tor_spawn_background() has - * been found to have terminated. - */ -static void -process_handle_waitpid_cb(int status, void *arg) -{ - process_handle_t *process_handle = arg; - - process_handle->waitpid_exit_status = status; - clear_waitpid_callback(process_handle->waitpid_cb); - if (process_handle->status == PROCESS_STATUS_RUNNING) - process_handle->status = PROCESS_STATUS_NOTRUNNING; - process_handle->waitpid_cb = 0; -} -#endif /* !defined(_WIN32) */ - -/** - * @name child-process states - * - * Each of these values represents a possible state that a child process can - * be in. They're used to determine what to say when telling the parent how - * far along we were before failure. - * - * @{ - */ -#define CHILD_STATE_INIT 0 -#define CHILD_STATE_PIPE 1 -#define CHILD_STATE_MAXFD 2 -#define CHILD_STATE_FORK 3 -#define CHILD_STATE_DUPOUT 4 -#define CHILD_STATE_DUPERR 5 -#define CHILD_STATE_DUPIN 6 -#define CHILD_STATE_CLOSEFD 7 -#define CHILD_STATE_EXEC 8 -#define CHILD_STATE_FAILEXEC 9 -/** @} */ -/** - * Boolean. If true, then Tor may call execve or CreateProcess via - * tor_spawn_background. - **/ -static int may_spawn_background_process = 1; -/** - * Turn off may_spawn_background_process, so that all future calls to - * tor_spawn_background are guaranteed to fail. - **/ -void -tor_disable_spawning_background_processes(void) -{ - may_spawn_background_process = 0; -} -/** Start a program in the background. If <b>filename</b> contains a '/', then - * it will be treated as an absolute or relative path. Otherwise, on - * non-Windows systems, the system path will be searched for <b>filename</b>. - * On Windows, only the current directory will be searched. Here, to search the - * system path (as well as the application directory, current working - * directory, and system directories), set filename to NULL. - * - * The strings in <b>argv</b> will be passed as the command line arguments of - * the child program (following convention, argv[0] should normally be the - * filename of the executable, and this must be the case if <b>filename</b> is - * NULL). The last element of argv must be NULL. A handle to the child process - * will be returned in process_handle (which must be non-NULL). Read - * process_handle.status to find out if the process was successfully launched. - * For convenience, process_handle.status is returned by this function. - * - * Some parts of this code are based on the POSIX subprocess module from - * Python, and example code from - * http://msdn.microsoft.com/en-us/library/ms682499%28v=vs.85%29.aspx. - */ -int -tor_spawn_background(const char *const filename, const char **argv, - process_environment_t *env, - process_handle_t **process_handle_out) -{ - if (BUG(may_spawn_background_process == 0)) { - /* We should never reach this point if we're forbidden to spawn - * processes. Instead we should have caught the attempt earlier. */ - return PROCESS_STATUS_ERROR; - } - -#ifdef _WIN32 - HANDLE stdout_pipe_read = NULL; - HANDLE stdout_pipe_write = NULL; - HANDLE stderr_pipe_read = NULL; - HANDLE stderr_pipe_write = NULL; - HANDLE stdin_pipe_read = NULL; - HANDLE stdin_pipe_write = NULL; - process_handle_t *process_handle; - int status; - - STARTUPINFOA siStartInfo; - BOOL retval = FALSE; - - SECURITY_ATTRIBUTES saAttr; - char *joined_argv; - - saAttr.nLength = sizeof(SECURITY_ATTRIBUTES); - saAttr.bInheritHandle = TRUE; - /* TODO: should we set explicit security attributes? (#2046, comment 5) */ - saAttr.lpSecurityDescriptor = NULL; - - /* Assume failure to start process */ - status = PROCESS_STATUS_ERROR; - - /* Set up pipe for stdout */ - if (!CreatePipe(&stdout_pipe_read, &stdout_pipe_write, &saAttr, 0)) { - log_warn(LD_GENERAL, - "Failed to create pipe for stdout communication with child process: %s", - format_win32_error(GetLastError())); - return status; - } - if (!SetHandleInformation(stdout_pipe_read, HANDLE_FLAG_INHERIT, 0)) { - log_warn(LD_GENERAL, - "Failed to configure pipe for stdout communication with child " - "process: %s", format_win32_error(GetLastError())); - return status; - } - - /* Set up pipe for stderr */ - if (!CreatePipe(&stderr_pipe_read, &stderr_pipe_write, &saAttr, 0)) { - log_warn(LD_GENERAL, - "Failed to create pipe for stderr communication with child process: %s", - format_win32_error(GetLastError())); - return status; - } - if (!SetHandleInformation(stderr_pipe_read, HANDLE_FLAG_INHERIT, 0)) { - log_warn(LD_GENERAL, - "Failed to configure pipe for stderr communication with child " - "process: %s", format_win32_error(GetLastError())); - return status; - } - - /* Set up pipe for stdin */ - if (!CreatePipe(&stdin_pipe_read, &stdin_pipe_write, &saAttr, 0)) { - log_warn(LD_GENERAL, - "Failed to create pipe for stdin communication with child process: %s", - format_win32_error(GetLastError())); - return status; - } - if (!SetHandleInformation(stdin_pipe_write, HANDLE_FLAG_INHERIT, 0)) { - log_warn(LD_GENERAL, - "Failed to configure pipe for stdin communication with child " - "process: %s", format_win32_error(GetLastError())); - return status; - } - - /* Create the child process */ - - /* Windows expects argv to be a whitespace delimited string, so join argv up - */ - joined_argv = tor_join_win_cmdline(argv); - - process_handle = process_handle_new(); - process_handle->status = status; - - ZeroMemory(&(process_handle->pid), sizeof(PROCESS_INFORMATION)); - ZeroMemory(&siStartInfo, sizeof(STARTUPINFO)); - siStartInfo.cb = sizeof(STARTUPINFO); - siStartInfo.hStdError = stderr_pipe_write; - siStartInfo.hStdOutput = stdout_pipe_write; - siStartInfo.hStdInput = stdin_pipe_read; - siStartInfo.dwFlags |= STARTF_USESTDHANDLES; - - /* Create the child process */ - - retval = CreateProcessA(filename, // module name - joined_argv, // command line - /* TODO: should we set explicit security attributes? (#2046, comment 5) */ - NULL, // process security attributes - NULL, // primary thread security attributes - TRUE, // handles are inherited - /*(TODO: set CREATE_NEW CONSOLE/PROCESS_GROUP to make GetExitCodeProcess() - * work?) */ - CREATE_NO_WINDOW, // creation flags - (env==NULL) ? NULL : env->windows_environment_block, - NULL, // use parent's current directory - &siStartInfo, // STARTUPINFO pointer - &(process_handle->pid)); // receives PROCESS_INFORMATION - - tor_free(joined_argv); - - if (!retval) { - log_warn(LD_GENERAL, - "Failed to create child process %s: %s", filename?filename:argv[0], - format_win32_error(GetLastError())); - tor_free(process_handle); - } else { - /* TODO: Close hProcess and hThread in process_handle->pid? */ - process_handle->stdout_pipe = stdout_pipe_read; - process_handle->stderr_pipe = stderr_pipe_read; - process_handle->stdin_pipe = stdin_pipe_write; - status = process_handle->status = PROCESS_STATUS_RUNNING; - } - - /* TODO: Close pipes on exit */ - *process_handle_out = process_handle; - return status; -#else /* !(defined(_WIN32)) */ - pid_t pid; - int stdout_pipe[2]; - int stderr_pipe[2]; - int stdin_pipe[2]; - int fd, retval; - process_handle_t *process_handle; - int status; - - const char *error_message = SPAWN_ERROR_MESSAGE; - size_t error_message_length; - - /* Represents where in the process of spawning the program is; - this is used for printing out the error message */ - unsigned char child_state = CHILD_STATE_INIT; - - char hex_errno[HEX_ERRNO_SIZE + 2]; /* + 1 should be sufficient actually */ - - static int max_fd = -1; - - status = PROCESS_STATUS_ERROR; - - /* We do the strlen here because strlen() is not signal handler safe, - and we are not allowed to use unsafe functions between fork and exec */ - error_message_length = strlen(error_message); - - // child_state = CHILD_STATE_PIPE; - - /* Set up pipe for redirecting stdout, stderr, and stdin of child */ - retval = pipe(stdout_pipe); - if (-1 == retval) { - log_warn(LD_GENERAL, - "Failed to set up pipe for stdout communication with child process: %s", - strerror(errno)); - return status; - } - - retval = pipe(stderr_pipe); - if (-1 == retval) { - log_warn(LD_GENERAL, - "Failed to set up pipe for stderr communication with child process: %s", - strerror(errno)); - - close(stdout_pipe[0]); - close(stdout_pipe[1]); - - return status; - } - - retval = pipe(stdin_pipe); - if (-1 == retval) { - log_warn(LD_GENERAL, - "Failed to set up pipe for stdin communication with child process: %s", - strerror(errno)); - - close(stdout_pipe[0]); - close(stdout_pipe[1]); - close(stderr_pipe[0]); - close(stderr_pipe[1]); - - return status; - } - - // child_state = CHILD_STATE_MAXFD; - -#ifdef _SC_OPEN_MAX - if (-1 == max_fd) { - max_fd = (int) sysconf(_SC_OPEN_MAX); - if (max_fd == -1) { - max_fd = DEFAULT_MAX_FD; - log_warn(LD_GENERAL, - "Cannot find maximum file descriptor, assuming %d", max_fd); - } - } -#else /* !(defined(_SC_OPEN_MAX)) */ - max_fd = DEFAULT_MAX_FD; -#endif /* defined(_SC_OPEN_MAX) */ - - // child_state = CHILD_STATE_FORK; - - pid = fork(); - if (0 == pid) { - /* In child */ - -#if defined(HAVE_SYS_PRCTL_H) && defined(__linux__) - /* Attempt to have the kernel issue a SIGTERM if the parent - * goes away. Certain attributes of the binary being execve()ed - * will clear this during the execve() call, but it's better - * than nothing. - */ - prctl(PR_SET_PDEATHSIG, SIGTERM); -#endif /* defined(HAVE_SYS_PRCTL_H) && defined(__linux__) */ - - child_state = CHILD_STATE_DUPOUT; - - /* Link child stdout to the write end of the pipe */ - retval = dup2(stdout_pipe[1], STDOUT_FILENO); - if (-1 == retval) - goto error; - - child_state = CHILD_STATE_DUPERR; - - /* Link child stderr to the write end of the pipe */ - retval = dup2(stderr_pipe[1], STDERR_FILENO); - if (-1 == retval) - goto error; - - child_state = CHILD_STATE_DUPIN; - - /* Link child stdin to the read end of the pipe */ - retval = dup2(stdin_pipe[0], STDIN_FILENO); - if (-1 == retval) - goto error; - - // child_state = CHILD_STATE_CLOSEFD; - - close(stderr_pipe[0]); - close(stderr_pipe[1]); - close(stdout_pipe[0]); - close(stdout_pipe[1]); - close(stdin_pipe[0]); - close(stdin_pipe[1]); - - /* Close all other fds, including the read end of the pipe */ - /* XXX: We should now be doing enough FD_CLOEXEC setting to make - * this needless. */ - for (fd = STDERR_FILENO + 1; fd < max_fd; fd++) { - close(fd); - } - - // child_state = CHILD_STATE_EXEC; - - /* Call the requested program. We need the cast because - execvp doesn't define argv as const, even though it - does not modify the arguments */ - if (env) - execve(filename, (char *const *) argv, env->unixoid_environment_block); - else { - static char *new_env[] = { NULL }; - execve(filename, (char *const *) argv, new_env); - } - - /* If we got here, the exec or open(/dev/null) failed */ - - child_state = CHILD_STATE_FAILEXEC; - - error: - { - /* XXX: are we leaking fds from the pipe? */ - int n, err=0; - ssize_t nbytes; - - n = format_helper_exit_status(child_state, errno, hex_errno); - - if (n >= 0) { - /* Write the error message. GCC requires that we check the return - value, but there is nothing we can do if it fails */ - /* TODO: Don't use STDOUT, use a pipe set up just for this purpose */ - nbytes = write(STDOUT_FILENO, error_message, error_message_length); - err = (nbytes < 0); - nbytes = write(STDOUT_FILENO, hex_errno, n); - err += (nbytes < 0); - } - - _exit(err?254:255); // exit ok: in child. - } - - /* Never reached, but avoids compiler warning */ - return status; // LCOV_EXCL_LINE - } - - /* In parent */ - - if (-1 == pid) { - log_warn(LD_GENERAL, "Failed to fork child process: %s", strerror(errno)); - close(stdin_pipe[0]); - close(stdin_pipe[1]); - close(stdout_pipe[0]); - close(stdout_pipe[1]); - close(stderr_pipe[0]); - close(stderr_pipe[1]); - return status; - } - - process_handle = process_handle_new(); - process_handle->status = status; - process_handle->pid = pid; - - /* TODO: If the child process forked but failed to exec, waitpid it */ - - /* Return read end of the pipes to caller, and close write end */ - process_handle->stdout_pipe = stdout_pipe[0]; - retval = close(stdout_pipe[1]); - - if (-1 == retval) { - log_warn(LD_GENERAL, - "Failed to close write end of stdout pipe in parent process: %s", - strerror(errno)); - } - - process_handle->waitpid_cb = set_waitpid_callback(pid, - process_handle_waitpid_cb, - process_handle); - - process_handle->stderr_pipe = stderr_pipe[0]; - retval = close(stderr_pipe[1]); - - if (-1 == retval) { - log_warn(LD_GENERAL, - "Failed to close write end of stderr pipe in parent process: %s", - strerror(errno)); - } - - /* Return write end of the stdin pipe to caller, and close the read end */ - process_handle->stdin_pipe = stdin_pipe[1]; - retval = close(stdin_pipe[0]); - - if (-1 == retval) { - log_warn(LD_GENERAL, - "Failed to close read end of stdin pipe in parent process: %s", - strerror(errno)); - } - - status = process_handle->status = PROCESS_STATUS_RUNNING; - /* Set stdin/stdout/stderr pipes to be non-blocking */ - if (fcntl(process_handle->stdout_pipe, F_SETFL, O_NONBLOCK) < 0 || - fcntl(process_handle->stderr_pipe, F_SETFL, O_NONBLOCK) < 0 || - fcntl(process_handle->stdin_pipe, F_SETFL, O_NONBLOCK) < 0) { - log_warn(LD_GENERAL, "Failed to set stderror/stdout/stdin pipes " - "nonblocking in parent process: %s", strerror(errno)); - } - - *process_handle_out = process_handle; - return status; -#endif /* defined(_WIN32) */ -} - -/** Destroy all resources allocated by the process handle in - * <b>process_handle</b>. - * If <b>also_terminate_process</b> is true, also terminate the - * process of the process handle. */ -MOCK_IMPL(void, -tor_process_handle_destroy,(process_handle_t *process_handle, - int also_terminate_process)) -{ - if (!process_handle) - return; - - if (also_terminate_process) { - if (tor_terminate_process(process_handle) < 0) { - const char *errstr = -#ifdef _WIN32 - format_win32_error(GetLastError()); -#else - strerror(errno); -#endif - log_notice(LD_GENERAL, "Failed to terminate process with " - "PID '%d' ('%s').", tor_process_get_pid(process_handle), - errstr); - } else { - log_info(LD_GENERAL, "Terminated process with PID '%d'.", - tor_process_get_pid(process_handle)); - } - } - - process_handle->status = PROCESS_STATUS_NOTRUNNING; - -#ifdef _WIN32 - if (process_handle->stdout_pipe) - CloseHandle(process_handle->stdout_pipe); - - if (process_handle->stderr_pipe) - CloseHandle(process_handle->stderr_pipe); - - if (process_handle->stdin_pipe) - CloseHandle(process_handle->stdin_pipe); -#else /* !(defined(_WIN32)) */ - close(process_handle->stdout_pipe); - close(process_handle->stderr_pipe); - close(process_handle->stdin_pipe); - - clear_waitpid_callback(process_handle->waitpid_cb); -#endif /* defined(_WIN32) */ - - memset(process_handle, 0x0f, sizeof(process_handle_t)); - tor_free(process_handle); -} - -/** Get the exit code of a process specified by <b>process_handle</b> and store - * it in <b>exit_code</b>, if set to a non-NULL value. If <b>block</b> is set - * to true, the call will block until the process has exited. Otherwise if - * the process is still running, the function will return - * PROCESS_EXIT_RUNNING, and exit_code will be left unchanged. Returns - * PROCESS_EXIT_EXITED if the process did exit. If there is a failure, - * PROCESS_EXIT_ERROR will be returned and the contents of exit_code (if - * non-NULL) will be undefined. N.B. Under *nix operating systems, this will - * probably not work in Tor, because waitpid() is called in main.c to reap any - * terminated child processes.*/ -int -tor_get_exit_code(process_handle_t *process_handle, - int block, int *exit_code) -{ -#ifdef _WIN32 - DWORD retval; - BOOL success; - - if (block) { - /* Wait for the process to exit */ - retval = WaitForSingleObject(process_handle->pid.hProcess, INFINITE); - if (retval != WAIT_OBJECT_0) { - log_warn(LD_GENERAL, "WaitForSingleObject() failed (%d): %s", - (int)retval, format_win32_error(GetLastError())); - return PROCESS_EXIT_ERROR; - } - } else { - retval = WaitForSingleObject(process_handle->pid.hProcess, 0); - if (WAIT_TIMEOUT == retval) { - /* Process has not exited */ - return PROCESS_EXIT_RUNNING; - } else if (retval != WAIT_OBJECT_0) { - log_warn(LD_GENERAL, "WaitForSingleObject() failed (%d): %s", - (int)retval, format_win32_error(GetLastError())); - return PROCESS_EXIT_ERROR; - } - } - - if (exit_code != NULL) { - success = GetExitCodeProcess(process_handle->pid.hProcess, - (PDWORD)exit_code); - if (!success) { - log_warn(LD_GENERAL, "GetExitCodeProcess() failed: %s", - format_win32_error(GetLastError())); - return PROCESS_EXIT_ERROR; - } - } -#else /* !(defined(_WIN32)) */ - int stat_loc; - int retval; - - if (process_handle->waitpid_cb) { - /* We haven't processed a SIGCHLD yet. */ - retval = waitpid(process_handle->pid, &stat_loc, block?0:WNOHANG); - if (retval == process_handle->pid) { - clear_waitpid_callback(process_handle->waitpid_cb); - process_handle->waitpid_cb = NULL; - process_handle->waitpid_exit_status = stat_loc; - } - } else { - /* We already got a SIGCHLD for this process, and handled it. */ - retval = process_handle->pid; - stat_loc = process_handle->waitpid_exit_status; - } - - if (!block && 0 == retval) { - /* Process has not exited */ - return PROCESS_EXIT_RUNNING; - } else if (retval != process_handle->pid) { - log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s", - (int)process_handle->pid, strerror(errno)); - return PROCESS_EXIT_ERROR; - } - - if (!WIFEXITED(stat_loc)) { - log_warn(LD_GENERAL, "Process %d did not exit normally", - (int)process_handle->pid); - return PROCESS_EXIT_ERROR; - } - - if (exit_code != NULL) - *exit_code = WEXITSTATUS(stat_loc); -#endif /* defined(_WIN32) */ - - return PROCESS_EXIT_EXITED; -} - -#ifdef _WIN32 -/** Read from a handle <b>h</b> into <b>buf</b>, up to <b>count</b> bytes. If - * <b>hProcess</b> is NULL, the function will return immediately if there is - * nothing more to read. Otherwise <b>hProcess</b> should be set to the handle - * to the process owning the <b>h</b>. In this case, the function will exit - * only once the process has exited, or <b>count</b> bytes are read. Returns - * the number of bytes read, or -1 on error. */ -ssize_t -tor_read_all_handle(HANDLE h, char *buf, size_t count, - const process_handle_t *process) -{ - size_t numread = 0; - BOOL retval; - DWORD byte_count; - BOOL process_exited = FALSE; - - if (count > SIZE_T_CEILING || count > SSIZE_MAX) - return -1; - - while (numread < count) { - /* Check if there is anything to read */ - retval = PeekNamedPipe(h, NULL, 0, NULL, &byte_count, NULL); - if (!retval) { - log_warn(LD_GENERAL, - "Failed to peek from handle: %s", - format_win32_error(GetLastError())); - return -1; - } else if (0 == byte_count) { - /* Nothing available: process exited or it is busy */ - - /* Exit if we don't know whether the process is running */ - if (NULL == process) - break; - - /* The process exited and there's nothing left to read from it */ - if (process_exited) - break; - - /* If process is not running, check for output one more time in case - it wrote something after the peek was performed. Otherwise keep on - waiting for output */ - tor_assert(process != NULL); - byte_count = WaitForSingleObject(process->pid.hProcess, 0); - if (WAIT_TIMEOUT != byte_count) - process_exited = TRUE; - - continue; - } - - /* There is data to read; read it */ - retval = ReadFile(h, buf+numread, count-numread, &byte_count, NULL); - tor_assert(byte_count + numread <= count); - if (!retval) { - log_warn(LD_GENERAL, "Failed to read from handle: %s", - format_win32_error(GetLastError())); - return -1; - } else if (0 == byte_count) { - /* End of file */ - break; - } - numread += byte_count; - } - return (ssize_t)numread; -} -#else /* !(defined(_WIN32)) */ -/** Read from a handle <b>fd</b> into <b>buf</b>, up to <b>count</b> bytes. If - * <b>process</b> is NULL, the function will return immediately if there is - * nothing more to read. Otherwise data will be read until end of file, or - * <b>count</b> bytes are read. Returns the number of bytes read, or -1 on - * error. Sets <b>eof</b> to true if <b>eof</b> is not NULL and the end of the - * file has been reached. */ -ssize_t -tor_read_all_handle(int fd, char *buf, size_t count, - const process_handle_t *process, - int *eof) -{ - size_t numread = 0; - ssize_t result; - - if (eof) - *eof = 0; - - if (count > SIZE_T_CEILING || count > SSIZE_MAX) - return -1; - - while (numread < count) { - result = read(fd, buf+numread, count-numread); - - if (result == 0) { - log_debug(LD_GENERAL, "read() reached end of file"); - if (eof) - *eof = 1; - break; - } else if (result < 0 && errno == EAGAIN) { - if (process) - continue; - else - break; - } else if (result < 0) { - log_warn(LD_GENERAL, "read() failed: %s", strerror(errno)); - return -1; - } - - numread += result; - } - - log_debug(LD_GENERAL, "read() read %d bytes from handle", (int)numread); - return (ssize_t)numread; -} -#endif /* defined(_WIN32) */ - -/** Read from stdout of a process until the process exits. */ -ssize_t -tor_read_all_from_process_stdout(const process_handle_t *process_handle, - char *buf, size_t count) -{ -#ifdef _WIN32 - return tor_read_all_handle(process_handle->stdout_pipe, buf, count, - process_handle); -#else - return tor_read_all_handle(process_handle->stdout_pipe, buf, count, - process_handle, NULL); -#endif /* defined(_WIN32) */ -} - -/** Read from stdout of a process until the process exits. */ -ssize_t -tor_read_all_from_process_stderr(const process_handle_t *process_handle, - char *buf, size_t count) -{ -#ifdef _WIN32 - return tor_read_all_handle(process_handle->stderr_pipe, buf, count, - process_handle); -#else - return tor_read_all_handle(process_handle->stderr_pipe, buf, count, - process_handle, NULL); -#endif /* defined(_WIN32) */ -} - -/** Return a string corresponding to <b>stream_status</b>. */ -const char * -stream_status_to_string(enum stream_status stream_status) -{ - switch (stream_status) { - case IO_STREAM_OKAY: - return "okay"; - case IO_STREAM_EAGAIN: - return "temporarily unavailable"; - case IO_STREAM_TERM: - return "terminated"; - case IO_STREAM_CLOSED: - return "closed"; - default: - tor_fragile_assert(); - return "unknown"; - } -} - -/** Split buf into lines, and add to smartlist. The buffer <b>buf</b> will be - * modified. The resulting smartlist will consist of pointers to buf, so there - * is no need to free the contents of sl. <b>buf</b> must be a NUL-terminated - * string. <b>len</b> should be set to the length of the buffer excluding the - * NUL. Non-printable characters (including NUL) will be replaced with "." */ -int -tor_split_lines(smartlist_t *sl, char *buf, int len) -{ - /* Index in buf of the start of the current line */ - int start = 0; - /* Index in buf of the current character being processed */ - int cur = 0; - /* Are we currently in a line */ - char in_line = 0; - - /* Loop over string */ - while (cur < len) { - /* Loop until end of line or end of string */ - for (; cur < len; cur++) { - if (in_line) { - if ('\r' == buf[cur] || '\n' == buf[cur]) { - /* End of line */ - buf[cur] = '\0'; - /* Point cur to the next line */ - cur++; - /* Line starts at start and ends with a nul */ - break; - } else { - if (!TOR_ISPRINT(buf[cur])) - buf[cur] = '.'; - } - } else { - if ('\r' == buf[cur] || '\n' == buf[cur]) { - /* Skip leading vertical space */ - ; - } else { - in_line = 1; - start = cur; - if (!TOR_ISPRINT(buf[cur])) - buf[cur] = '.'; - } - } - } - /* We are at the end of the line or end of string. If in_line is true there - * is a line which starts at buf+start and ends at a NUL. cur points to - * the character after the NUL. */ - if (in_line) - smartlist_add(sl, (void *)(buf+start)); - in_line = 0; - } - return smartlist_len(sl); -} - -#ifdef _WIN32 - -/** Return a smartlist containing lines outputted from - * <b>handle</b>. Return NULL on error, and set - * <b>stream_status_out</b> appropriately. */ -MOCK_IMPL(smartlist_t *, -tor_get_lines_from_handle, (HANDLE *handle, - enum stream_status *stream_status_out)) -{ - int pos; - char stdout_buf[600] = {0}; - smartlist_t *lines = NULL; - - tor_assert(stream_status_out); - - *stream_status_out = IO_STREAM_TERM; - - pos = tor_read_all_handle(handle, stdout_buf, sizeof(stdout_buf) - 1, NULL); - if (pos < 0) { - *stream_status_out = IO_STREAM_TERM; - return NULL; - } - if (pos == 0) { - *stream_status_out = IO_STREAM_EAGAIN; - return NULL; - } - - /* End with a null even if there isn't a \r\n at the end */ - /* TODO: What if this is a partial line? */ - stdout_buf[pos] = '\0'; - - /* Split up the buffer */ - lines = smartlist_new(); - tor_split_lines(lines, stdout_buf, pos); - - /* Currently 'lines' is populated with strings residing on the - stack. Replace them with their exact copies on the heap: */ - SMARTLIST_FOREACH(lines, char *, line, - SMARTLIST_REPLACE_CURRENT(lines, line, tor_strdup(line))); - - *stream_status_out = IO_STREAM_OKAY; - - return lines; -} - -#else /* !(defined(_WIN32)) */ - -/** Return a smartlist containing lines outputted from - * <b>fd</b>. Return NULL on error, and set - * <b>stream_status_out</b> appropriately. */ -MOCK_IMPL(smartlist_t *, -tor_get_lines_from_handle, (int fd, enum stream_status *stream_status_out)) -{ - enum stream_status stream_status; - char stdout_buf[400]; - smartlist_t *lines = NULL; - - while (1) { - memset(stdout_buf, 0, sizeof(stdout_buf)); - - stream_status = get_string_from_pipe(fd, - stdout_buf, sizeof(stdout_buf) - 1); - if (stream_status != IO_STREAM_OKAY) - goto done; - - if (!lines) lines = smartlist_new(); - smartlist_split_string(lines, stdout_buf, "\n", 0, 0); - } - - done: - *stream_status_out = stream_status; - return lines; -} - -#endif /* defined(_WIN32) */ - -/** Reads from <b>fd</b> and stores input in <b>buf_out</b> making - * sure it's below <b>count</b> bytes. - * If the string has a trailing newline, we strip it off. - * - * This function is specifically created to handle input from managed - * proxies, according to the pluggable transports spec. Make sure it - * fits your needs before using it. - * - * Returns: - * IO_STREAM_CLOSED: If the stream is closed. - * IO_STREAM_EAGAIN: If there is nothing to read and we should check back - * later. - * IO_STREAM_TERM: If something is wrong with the stream. - * IO_STREAM_OKAY: If everything went okay and we got a string - * in <b>buf_out</b>. */ -enum stream_status -get_string_from_pipe(int fd, char *buf_out, size_t count) -{ - ssize_t ret; - - tor_assert(count <= INT_MAX); - - ret = read(fd, buf_out, count); - - if (ret == 0) - return IO_STREAM_CLOSED; - else if (ret < 0 && errno == EAGAIN) - return IO_STREAM_EAGAIN; - else if (ret < 0) - return IO_STREAM_TERM; - - if (buf_out[ret - 1] == '\n') { - /* Remove the trailing newline */ - buf_out[ret - 1] = '\0'; - } else - buf_out[ret] = '\0'; - - return IO_STREAM_OKAY; -} diff --git a/src/lib/process/subprocess.h b/src/lib/process/subprocess.h deleted file mode 100644 index aa3127d62d..0000000000 --- a/src/lib/process/subprocess.h +++ /dev/null @@ -1,134 +0,0 @@ -/* Copyright (c) 2003-2004, Roger Dingledine - * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ -/* See LICENSE for licensing information */ - -/** - * \file subprocess.h - * \brief Header for subprocess.c - **/ - -#ifndef TOR_SUBPROCESS_H -#define TOR_SUBPROCESS_H - -#include "lib/cc/torint.h" -#include "lib/testsupport/testsupport.h" -#include <stddef.h> -#ifdef _WIN32 -#include <windows.h> -#endif - -struct smartlist_t; - -void tor_disable_spawning_background_processes(void); - -typedef struct process_handle_t process_handle_t; -struct process_environment_t; -int tor_spawn_background(const char *const filename, const char **argv, - struct process_environment_t *env, - process_handle_t **process_handle_out); - -#define SPAWN_ERROR_MESSAGE "ERR: Failed to spawn background process - code " - -/** Status of an I/O stream. */ -enum stream_status { - IO_STREAM_OKAY, - IO_STREAM_EAGAIN, - IO_STREAM_TERM, - IO_STREAM_CLOSED -}; - -const char *stream_status_to_string(enum stream_status stream_status); - -enum stream_status get_string_from_pipe(int fd, char *buf, size_t count); - -/* Values of process_handle_t.status. */ -#define PROCESS_STATUS_NOTRUNNING 0 -#define PROCESS_STATUS_RUNNING 1 -#define PROCESS_STATUS_ERROR -1 - -#ifdef SUBPROCESS_PRIVATE -struct waitpid_callback_t; - -/** Structure to represent the state of a process with which Tor is - * communicating. The contents of this structure are private to util.c */ -struct process_handle_t { - /** One of the PROCESS_STATUS_* values */ - int status; -#ifdef _WIN32 - HANDLE stdin_pipe; - HANDLE stdout_pipe; - HANDLE stderr_pipe; - PROCESS_INFORMATION pid; -#else /* !(defined(_WIN32)) */ - int stdin_pipe; - int stdout_pipe; - int stderr_pipe; - pid_t pid; - /** If the process has not given us a SIGCHLD yet, this has the - * waitpid_callback_t that gets invoked once it has. Otherwise this - * contains NULL. */ - struct waitpid_callback_t *waitpid_cb; - /** The exit status reported by waitpid. */ - int waitpid_exit_status; -#endif /* defined(_WIN32) */ -}; -#endif /* defined(SUBPROCESS_PRIVATE) */ - -/* Return values of tor_get_exit_code() */ -#define PROCESS_EXIT_RUNNING 1 -#define PROCESS_EXIT_EXITED 0 -#define PROCESS_EXIT_ERROR -1 -int tor_get_exit_code(process_handle_t *process_handle, - int block, int *exit_code); -int tor_split_lines(struct smartlist_t *sl, char *buf, int len); -#ifdef _WIN32 -ssize_t tor_read_all_handle(HANDLE h, char *buf, size_t count, - const process_handle_t *process); -#else -ssize_t tor_read_all_handle(int fd, char *buf, size_t count, - const process_handle_t *process, - int *eof); -#endif /* defined(_WIN32) */ -ssize_t tor_read_all_from_process_stdout( - const process_handle_t *process_handle, char *buf, size_t count); -ssize_t tor_read_all_from_process_stderr( - const process_handle_t *process_handle, char *buf, size_t count); -char *tor_join_win_cmdline(const char *argv[]); - -int tor_process_get_pid(process_handle_t *process_handle); -#ifdef _WIN32 -HANDLE tor_process_get_stdout_pipe(process_handle_t *process_handle); -#else -int tor_process_get_stdout_pipe(process_handle_t *process_handle); -#endif - -#ifdef _WIN32 -MOCK_DECL(struct smartlist_t *, tor_get_lines_from_handle,(HANDLE *handle, - enum stream_status *stream_status)); -#else -MOCK_DECL(struct smartlist_t *, tor_get_lines_from_handle,(int fd, - enum stream_status *stream_status)); -#endif /* defined(_WIN32) */ - -int tor_terminate_process(process_handle_t *process_handle); - -MOCK_DECL(void, tor_process_handle_destroy,(process_handle_t *process_handle, - int also_terminate_process)); - -#ifdef SUBPROCESS_PRIVATE -/* Prototypes for private functions only used by util.c (and unit tests) */ - -#ifndef _WIN32 -STATIC int format_helper_exit_status(unsigned char child_state, - int saved_errno, char *hex_errno); - -/* Space for hex values of child state, a slash, saved_errno (with - leading minus) and newline (no null) */ -#define HEX_ERRNO_SIZE (sizeof(char) * 2 + 1 + \ - 1 + sizeof(int) * 2 + 1) -#endif /* !defined(_WIN32) */ - -#endif /* defined(SUBPROCESS_PRIVATE) */ - -#endif diff --git a/src/lib/process/waitpid.c b/src/lib/process/waitpid.c index 9b626394d2..2b38481aeb 100644 --- a/src/lib/process/waitpid.c +++ b/src/lib/process/waitpid.c @@ -16,7 +16,7 @@ #include "lib/log/log.h" #include "lib/log/util_bug.h" #include "lib/malloc/malloc.h" -#include "ht.h" +#include "ext/ht.h" #ifdef HAVE_SYS_WAIT_H #include <sys/wait.h> diff --git a/src/lib/process/winprocess_sys.c b/src/lib/process/winprocess_sys.c new file mode 100644 index 0000000000..1266babca8 --- /dev/null +++ b/src/lib/process/winprocess_sys.c @@ -0,0 +1,64 @@ +/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file winprocess_sys.c + * \brief Subsystem object for windows process setup. + **/ + +#include "orconfig.h" +#include "lib/subsys/subsys.h" +#include "lib/process/winprocess_sys.h" + +#include <stdbool.h> +#include <stddef.h> + +#ifdef _WIN32 +#include <windows.h> + +#define WINPROCESS_SYS_ENABLED true + +static int +subsys_winprocess_initialize(void) +{ +#ifndef HeapEnableTerminationOnCorruption +#define HeapEnableTerminationOnCorruption 1 +#endif + + /* On heap corruption, just give up; don't try to play along. */ + HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0); + + /* SetProcessDEPPolicy is only supported on 32-bit Windows. + * (On 64-bit Windows it always fails, and some compilers don't like the + * PSETDEP cast.) + * 32-bit Windows defines _WIN32. + * 64-bit Windows defines _WIN32 and _WIN64. */ +#ifndef _WIN64 + /* Call SetProcessDEPPolicy to permanently enable DEP. + The function will not resolve on earlier versions of Windows, + and failure is not dangerous. */ + HMODULE hMod = GetModuleHandleA("Kernel32.dll"); + if (hMod) { + typedef BOOL (WINAPI *PSETDEP)(DWORD); + PSETDEP setdeppolicy = (PSETDEP)GetProcAddress(hMod, + "SetProcessDEPPolicy"); + if (setdeppolicy) { + /* PROCESS_DEP_ENABLE | PROCESS_DEP_DISABLE_ATL_THUNK_EMULATION */ + setdeppolicy(3); + } + } +#endif /* !defined(_WIN64) */ + + return 0; +} +#else /* !defined(_WIN32) */ +#define WINPROCESS_SYS_ENABLED false +#define subsys_winprocess_initialize NULL +#endif /* defined(_WIN32) */ + +const subsys_fns_t sys_winprocess = { + .name = "winprocess", + .level = -100, + .supported = WINPROCESS_SYS_ENABLED, + .initialize = subsys_winprocess_initialize, +}; diff --git a/src/lib/process/winprocess_sys.h b/src/lib/process/winprocess_sys.h new file mode 100644 index 0000000000..7ab2aa04a6 --- /dev/null +++ b/src/lib/process/winprocess_sys.h @@ -0,0 +1,14 @@ +/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file winprocess_sys.h + * \brief Declare subsystem object for winprocess.c + **/ + +#ifndef TOR_WINPROCESS_SYS_H +#define TOR_WINPROCESS_SYS_H + +extern const struct subsys_fns_t sys_winprocess; + +#endif /* !defined(TOR_WINPROCESS_SYS_H) */ |