static
int run_as(enum run_as_cmd cmd, struct run_as_data *data, uid_t uid, gid_t gid)
{
int ret;
if (use_clone()) {
DBG("Using run_as worker");
pthread_mutex_lock(&worker_lock);
assert(global_worker);
ret = run_as_cmd(global_worker, cmd, data, uid, gid);
pthread_mutex_unlock(&worker_lock);
} else {
DBG("Using run_as without worker");
ret = run_as_noworker(cmd, data, uid, gid);
}
return ret;
}
static
int run_as(enum run_as_cmd cmd, struct run_as_data *data,
struct run_as_ret *ret_value, uid_t uid, gid_t gid)
{
int ret, saved_errno;
pthread_mutex_lock(&worker_lock);
if (use_clone()) {
DBG("Using run_as worker");
assert(global_worker);
ret = run_as_cmd(global_worker, cmd, data, ret_value, uid, gid);
saved_errno = ret_value->_errno;
/*
* If the worker thread crashed the errno is set to EIO. we log
* the error and start a new worker process.
*/
if (ret == -1 && saved_errno == EIO) {
DBG("Socket closed unexpectedly... "
"Restarting the worker process");
ret = run_as_restart_worker(global_worker);
if (ret == -1) {
ERR("Failed to restart worker process.");
goto err;
}
}
} else {
DBG("Using run_as without worker");
ret = run_as_noworker(cmd, data, ret_value, uid, gid);
}
err:
pthread_mutex_unlock(&worker_lock);
return ret;
}
static
int run_as_create_worker_no_lock(const char *procname,
post_fork_cleanup_cb clean_up_func,
void *clean_up_user_data)
{
pid_t pid;
int i, ret = 0;
ssize_t readlen;
struct run_as_ret recvret;
struct run_as_worker *worker;
assert(!global_worker);
if (!use_clone()) {
/*
* Don't initialize a worker, all run_as tasks will be performed
* in the current process.
*/
ret = 0;
goto end;
}
worker = zmalloc(sizeof(*worker));
if (!worker) {
ret = -ENOMEM;
goto end;
}
worker->procname = strdup(procname);
if (!worker->procname) {
ret = -ENOMEM;
goto error_procname_alloc;
}
/* Create unix socket. */
if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) {
ret = -1;
goto error_sock;
}
/* Fork worker. */
pid = fork();
if (pid < 0) {
PERROR("fork");
ret = -1;
goto error_fork;
} else if (pid == 0) {
/* Child */
reset_sighandler();
set_worker_sighandlers();
if (clean_up_func) {
if (clean_up_func(clean_up_user_data) < 0) {
ERR("Run-as post-fork clean-up failed, exiting.");
exit(EXIT_FAILURE);
}
}
/* Just close, no shutdown. */
if (close(worker->sockpair[0])) {
PERROR("close");
exit(EXIT_FAILURE);
}
/*
* Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1]
* Sockpair[1] is used as a control channel with the master
*/
for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
if (i != worker->sockpair[1]) {
(void) close(i);
}
}
worker->sockpair[0] = -1;
ret = run_as_worker(worker);
if (lttcomm_close_unix_sock(worker->sockpair[1])) {
PERROR("close");
ret = -1;
}
worker->sockpair[1] = -1;
free(worker->procname);
free(worker);
LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret);
exit(ret ? EXIT_FAILURE : EXIT_SUCCESS);
} else {
/* Parent */
/* Just close, no shutdown. */
if (close(worker->sockpair[1])) {
PERROR("close");
ret = -1;
goto error_fork;
}
worker->sockpair[1] = -1;
worker->pid = pid;
/* Wait for worker to become ready. */
readlen = lttcomm_recv_unix_sock(worker->sockpair[0],
&recvret, sizeof(recvret));
if (readlen < sizeof(recvret)) {
ERR("readlen: %zd", readlen);
PERROR("Error reading response from run_as at creation");
ret = -1;
goto error_fork;
}
global_worker = worker;
}
end:
return ret;
/* Error handling. */
error_fork:
for (i = 0; i < 2; i++) {
if (worker->sockpair[i] < 0) {
continue;
}
if (lttcomm_close_unix_sock(worker->sockpair[i])) {
PERROR("close");
}
worker->sockpair[i] = -1;
}
error_sock:
free(worker->procname);
error_procname_alloc:
free(worker);
return ret;
}
LTTNG_HIDDEN
int run_as_create_worker(char *procname)
{
pid_t pid;
int i, ret = 0;
ssize_t readlen;
struct run_as_ret recvret;
struct run_as_worker *worker;
pthread_mutex_lock(&worker_lock);
assert(!global_worker);
if (!use_clone()) {
/*
* Don't initialize a worker, all run_as tasks will be performed
* in the current process.
*/
ret = 0;
goto end;
}
worker = zmalloc(sizeof(*worker));
if (!worker) {
ret = -ENOMEM;
goto end;
}
worker->procname = procname;
/* Create unix socket. */
if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) {
ret = -1;
goto error_sock;
}
/* Fork worker. */
pid = fork();
if (pid < 0) {
PERROR("fork");
ret = -1;
goto error_fork;
} else if (pid == 0) {
/* Child */
reset_sighandler();
set_worker_sighandlers();
/* The child has no use for this lock. */
pthread_mutex_unlock(&worker_lock);
/* Just close, no shutdown. */
if (close(worker->sockpair[0])) {
PERROR("close");
exit(EXIT_FAILURE);
}
worker->sockpair[0] = -1;
ret = run_as_worker(worker);
if (lttcomm_close_unix_sock(worker->sockpair[1])) {
PERROR("close");
ret = -1;
}
worker->sockpair[1] = -1;
LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret);
exit(ret ? EXIT_FAILURE : EXIT_SUCCESS);
} else {
/* Parent */
/* Just close, no shutdown. */
if (close(worker->sockpair[1])) {
PERROR("close");
ret = -1;
goto error_fork;
}
worker->sockpair[1] = -1;
worker->pid = pid;
/* Wait for worker to become ready. */
readlen = lttcomm_recv_unix_sock(worker->sockpair[0],
&recvret, sizeof(recvret));
if (readlen < sizeof(recvret)) {
ERR("readlen: %zd", readlen);
PERROR("Error reading response from run_as at creation");
ret = -1;
goto error_fork;
}
global_worker = worker;
}
end:
pthread_mutex_unlock(&worker_lock);
return ret;
/* Error handling. */
error_fork:
for (i = 0; i < 2; i++) {
if (worker->sockpair[i] < 0) {
continue;
}
if (lttcomm_close_unix_sock(worker->sockpair[i])) {
PERROR("close");
}
worker->sockpair[i] = -1;
}
error_sock:
free(worker);
pthread_mutex_unlock(&worker_lock);
return ret;
}