static void handle_sighup(void) {
FILE *log_file = log_get_file();
if (log_file != NULL) {
if (fileno(log_file) == STDOUT_FILENO || fileno(log_file) == STDERR_FILENO) {
return; // don't close stdout or stderr
}
fclose(log_file);
}
log_file = fopen(_log_filename, "a+");
if (log_file == NULL) {
log_set_file(stderr);
log_error("Could not reopen log file '%s': %s (%d)",
_log_filename, get_errno_name(errno), errno);
return;
}
log_set_file(log_file);
log_info("Reopened log file '%s'", _log_filename);
}
static void loop(sigset_t *set)
{
for (;;) {
int sig;
if (0 != sigwait(set, &sig)) continue;
switch (sig) {
case SIGHUP:
SLOG(LOG_INFO, "SIGHUP Caught. Reopen logfile.");
log_set_file(log_get_file());
break;
case SIGTERM:
case SIGINT:
SLOG(LOG_INFO, "SIGINT Caught. Exiting.");
exit(EXIT_SUCCESS); // call all destructors
break;
case SIGPIPE:
SLOG(LOG_INFO, "SIGPIPE Caught. Ignoring.");
break;
case SIGCHLD:
SLOG(LOG_INFO, "SIGCHLD Caught. Ignoring.");
break;
}
}
}
// public API
APIE process_spawn(ObjectID executable_id, ObjectID arguments_id,
ObjectID environment_id, ObjectID working_directory_id,
uint32_t uid, uint32_t gid, ObjectID stdin_id,
ObjectID stdout_id, ObjectID stderr_id, Session *session,
uint16_t object_create_flags, bool release_on_death,
ProcessStateChangedFunction state_changed, void *opaque,
ObjectID *id, Process **object) {
int phase = 0;
APIE error_code;
String *executable;
List *arguments;
Array arguments_array;
int i;
char **item;
List *environment;
Array environment_array;
String *working_directory;
File *stdin;
File *stdout;
File *stderr;
pid_t pid;
int status_pipe[2];
int sc_open_max;
FILE *log_file;
Process *process;
// acquire and lock executable string object
error_code = string_get_acquired_and_locked(executable_id, &executable);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
phase = 1;
if (*executable->buffer == '\0') {
error_code = API_E_INVALID_PARAMETER;
log_warn("Cannot spawn child process using empty executable name");
goto cleanup;
}
// lock arguments list object
error_code = list_get_acquired_and_locked(arguments_id, OBJECT_TYPE_STRING,
&arguments);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
phase = 2;
// prepare arguments array for execvpe
if (array_create(&arguments_array, 1 + arguments->items.count + 1, sizeof(char *), true) < 0) {
error_code = api_get_error_code_from_errno();
log_error("Could not create arguments array for spawning child process (executable: %s): %s (%d)",
executable->buffer, get_errno_name(errno), errno);
goto cleanup;
}
phase = 3;
item = array_append(&arguments_array);
if (item == NULL) {
error_code = api_get_error_code_from_errno();
log_error("Could not append to arguments array for spawning child process (executable: %s): %s (%d)",
executable->buffer, get_errno_name(errno), errno);
goto cleanup;
}
*item = executable->buffer;
for (i = 0; i < arguments->items.count; ++i) {
item = array_append(&arguments_array);
if (item == NULL) {
error_code = api_get_error_code_from_errno();
log_error("Could not append to arguments array for spawning child process (executable: %s): %s (%d)",
executable->buffer, get_errno_name(errno), errno);
goto cleanup;
}
*item = (*(String **)array_get(&arguments->items, i))->buffer;
}
item = array_append(&arguments_array);
if (item == NULL) {
error_code = api_get_error_code_from_errno();
log_error("Could not append to arguments array for spawning child process (executable: %s): %s (%d)",
executable->buffer, get_errno_name(errno), errno);
goto cleanup;
}
*item = NULL;
// lock environment list object
error_code = list_get_acquired_and_locked(environment_id, OBJECT_TYPE_STRING,
&environment);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
phase = 4;
// prepare environment array for execvpe
if (array_create(&environment_array, environment->items.count + 1, sizeof(char *), true) < 0) {
error_code = api_get_error_code_from_errno();
log_error("Could not create environment array for spawning child process (executable: %s): %s (%d)",
executable->buffer, get_errno_name(errno), errno);
goto cleanup;
}
phase = 5;
for (i = 0; i < environment->items.count; ++i) {
item = array_append(&environment_array);
if (item == NULL) {
error_code = api_get_error_code_from_errno();
log_error("Could not append to environment array for spawning child process (executable: %s): %s (%d)",
executable->buffer, get_errno_name(errno), errno);
goto cleanup;
}
// FIXME: if item is not <name>=<value>, but just <name> then use the parent <value>
*item = (*(String **)array_get(&environment->items, i))->buffer;
}
item = array_append(&environment_array);
if (item == NULL) {
error_code = api_get_error_code_from_errno();
log_error("Could not append to environment array for spawning child process (executable: %s): %s (%d)",
executable->buffer, get_errno_name(errno), errno);
goto cleanup;
}
*item = NULL;
// acquire and lock working directory string object
error_code = string_get_acquired_and_locked(working_directory_id, &working_directory);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
phase = 6;
if (*working_directory->buffer == '\0') {
error_code = API_E_INVALID_PARAMETER;
log_warn("Cannot spawn child process (executable: %s) using empty working directory name",
executable->buffer);
goto cleanup;
}
if (*working_directory->buffer != '/') {
error_code = API_E_INVALID_PARAMETER;
log_warn("Cannot spawn child process (executable: %s) using working directory with relative name '%s'",
executable->buffer, working_directory->buffer);
goto cleanup;
}
// acquire stdin file object
error_code = file_get_acquired(stdin_id, &stdin);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
phase = 7;
// acquire stdout file object
error_code = file_get_acquired(stdout_id, &stdout);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
phase = 8;
// acquire stderr file object
error_code = file_get_acquired(stderr_id, &stderr);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
phase = 9;
// create status pipe
if (pipe(status_pipe) < 0) {
error_code = api_get_error_code_from_errno();
log_error("Could not create status pipe for spawning child process (executable: %s): %s (%d)",
executable->buffer, get_errno_name(errno), errno);
goto cleanup;
}
phase = 10;
// fork
log_debug("Forking to spawn child process (executable: %s)", executable->buffer);
error_code = process_fork(&pid);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
if (pid == 0) { // child
close(status_pipe[0]);
// change user and groups
error_code = process_set_identity(uid, gid);
if (error_code != API_E_SUCCESS) {
goto child_error;
}
// change directory
if (chdir(working_directory->buffer) < 0) {
error_code = api_get_error_code_from_errno();
log_error("Could not change directory to '%s' for child process (executable: %s, pid: %u): %s (%d)",
working_directory->buffer, executable->buffer, getpid(), get_errno_name(errno), errno);
goto child_error;
}
// get open FD limit
sc_open_max = sysconf(_SC_OPEN_MAX);
if (sc_open_max < 0) {
error_code = api_get_error_code_from_errno();
log_error("Could not get SC_OPEN_MAX value: %s (%d)",
get_errno_name(errno), errno);
goto child_error;
}
// redirect stdin
if (dup2(file_get_read_handle(stdin), STDIN_FILENO) != STDIN_FILENO) {
error_code = api_get_error_code_from_errno();
log_error("Could not redirect stdin for child process (executable: %s, pid: %u): %s (%d)",
executable->buffer, getpid(), get_errno_name(errno), errno);
goto child_error;
}
// redirect stdout
if (dup2(file_get_write_handle(stdout), STDOUT_FILENO) != STDOUT_FILENO) {
error_code = api_get_error_code_from_errno();
log_error("Could not redirect stdout for child process (executable: %s, pid: %u): %s (%d)",
executable->buffer, getpid(), get_errno_name(errno), errno);
goto child_error;
}
// stderr is the default log output in non-daemon mode. if this is
// the case then disable the log output before redirecting stderr to
// avoid polluting stderr for the new process
log_file = log_get_file();
if (log_file != NULL && fileno(log_file) == STDERR_FILENO) {
log_debug("Disable logging to stderr for child process (executable: %s, pid: %u)",
executable->buffer, getpid());
log_set_file(NULL);
}
// redirect stderr
if (dup2(file_get_write_handle(stderr), STDERR_FILENO) != STDERR_FILENO) {
error_code = api_get_error_code_from_errno();
log_error("Could not redirect stderr for child process (executable: %s, pid: %u): %s (%d)",
executable->buffer, getpid(), get_errno_name(errno), errno);
goto child_error;
}
// notify parent
if (robust_write(status_pipe[1], &error_code, sizeof(error_code)) < 0) {
error_code = api_get_error_code_from_errno();
log_error("Could not write to status pipe for child process (executable: %s, pid: %u): %s (%d)",
executable->buffer, getpid(), get_errno_name(errno), errno);
goto child_error;
}
// disable log output. if stderr was not the current log output then
// the log file is still open at this point. the next step is to close
// all remaining file descriptors. just for good measure disable the
// log output beforehand
log_set_file(NULL);
// close all file descriptors except the std* ones
for (i = STDERR_FILENO + 1; i < sc_open_max; ++i) {
close(i);
}
// execvpe only returns in case of an error
execvpe(executable->buffer, (char **)arguments_array.bytes, (char **)environment_array.bytes);
if (errno == ENOENT) {
_exit(PROCESS_E_DOES_NOT_EXIST);
} else {
_exit(PROCESS_E_CANNOT_EXECUTE);
}
child_error:
// notify parent in all cases
if (robust_write(status_pipe[1], &error_code, sizeof(error_code)) < 0) {
log_error("Could not write to status pipe for child process (executable: %s, pid: %u): %s (%d)",
executable->buffer, getpid(), get_errno_name(errno), errno);
}
close(status_pipe[1]);
_exit(PROCESS_E_INTERNAL_ERROR);
}
phase = 11;
// wait for child to start successfully
if (robust_read(status_pipe[0], &error_code, sizeof(error_code)) < 0) {
error_code = api_get_error_code_from_errno();
log_error("Could not read from status pipe for child process (executable: %s, pid: %u): %s (%d)",
executable->buffer, pid, get_errno_name(errno), errno);
goto cleanup;
}
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
// create process object
process = calloc(1, sizeof(Process));
if (process == NULL) {
error_code = API_E_NO_FREE_MEMORY;
log_error("Could not allocate process object: %s (%d)",
get_errno_name(ENOMEM), ENOMEM);
goto cleanup;
}
phase = 12;
// setup process object
process->executable = executable;
process->arguments = arguments;
process->environment = environment;
process->working_directory = working_directory;
process->uid = uid;
process->gid = gid;
process->pid = pid;
process->stdin = stdin;
process->stdout = stdout;
process->stderr = stderr;
process->release_on_death = release_on_death;
process->state_changed = state_changed;
process->opaque = opaque;
process->state = PROCESS_STATE_RUNNING;
process->timestamp = time(NULL);
process->exit_code = 0; // invalid
if (pipe_create(&process->state_change_pipe, 0) < 0) {
error_code = api_get_error_code_from_errno();
log_error("Could not create state change pipe child process (executable: %s, pid: %u): %s (%d)",
executable->buffer, pid, get_errno_name(errno), errno);
goto cleanup;
}
phase = 13;
if (event_add_source(process->state_change_pipe.read_end, EVENT_SOURCE_TYPE_GENERIC,
EVENT_READ, process_handle_state_change, process) < 0) {
goto cleanup;
}
phase = 14;
// create process object
error_code = object_create(&process->base,
OBJECT_TYPE_PROCESS,
session,
object_create_flags |
OBJECT_CREATE_FLAG_INTERNAL,
process_destroy,
process_signature);
if (error_code != API_E_SUCCESS) {
goto cleanup;
}
phase = 15;
if (id != NULL) {
*id = process->base.id;
}
if (object != NULL) {
*object = process;
}
// start thread to wait for child process state changes
thread_create(&process->wait_thread, process_wait, process);
log_debug("Spawned process object (id: %u, executable: %s, pid: %u)",
process->base.id, executable->buffer, process->pid);
close(status_pipe[0]);
close(status_pipe[1]);
array_destroy(&arguments_array, NULL);
array_destroy(&environment_array, NULL);
cleanup:
switch (phase) { // no breaks, all cases fall through intentionally
case 14:
event_remove_source(process->state_change_pipe.read_end, EVENT_SOURCE_TYPE_GENERIC);
case 13:
pipe_destroy(&process->state_change_pipe);
case 12:
free(process);
case 11:
kill(pid, SIGKILL);
case 10:
close(status_pipe[0]);
close(status_pipe[1]);
case 9:
file_release(stderr);
case 8:
file_release(stdout);
case 7:
file_release(stdin);
case 6:
string_unlock_and_release(working_directory);
case 5:
array_destroy(&environment_array, NULL);
case 4:
list_unlock_and_release(environment);
case 3:
array_destroy(&arguments_array, NULL);
case 2:
list_unlock_and_release(arguments);
case 1:
string_unlock_and_release(executable);
default:
break;
}
return phase == 15 ? API_E_SUCCESS : error_code;
}
