/*
* Set sessiond socket path by putting it in the global sessiond_sock_path
* variable.
*
* Returns 0 on success, negative value on failure (the sessiond socket path
* is somehow too long or ENOMEM).
*/
static int set_session_daemon_path(void)
{
int in_tgroup = 0; /* In tracing group */
uid_t uid;
uid = getuid();
if (uid != 0) {
/* Are we in the tracing group ? */
in_tgroup = lttng_check_tracing_group();
}
if ((uid == 0) || in_tgroup) {
lttng_ctl_copy_string(sessiond_sock_path,
DEFAULT_GLOBAL_CLIENT_UNIX_SOCK, sizeof(sessiond_sock_path));
}
if (uid != 0) {
int ret;
if (in_tgroup) {
/* Tracing group */
ret = try_connect_sessiond(sessiond_sock_path);
if (ret >= 0) {
goto end;
}
/* Global session daemon not available... */
}
/* ...or not in tracing group (and not root), default */
/*
* With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
* With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
*/
ret = snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
DEFAULT_HOME_CLIENT_UNIX_SOCK, utils_get_home_dir());
if ((ret < 0) || (ret >= sizeof(sessiond_sock_path))) {
goto error;
}
}
end:
return 0;
error:
return -1;
}
struct lttng_notification_channel *lttng_notification_channel_create(
struct lttng_endpoint *endpoint)
{
int fd, ret;
bool is_in_tracing_group = false, is_root = false;
char *sock_path = NULL;
struct lttng_notification_channel *channel = NULL;
if (!endpoint ||
endpoint != lttng_session_daemon_notification_endpoint) {
goto end;
}
sock_path = zmalloc(LTTNG_PATH_MAX);
if (!sock_path) {
goto end;
}
channel = zmalloc(sizeof(struct lttng_notification_channel));
if (!channel) {
goto end;
}
channel->socket = -1;
pthread_mutex_init(&channel->lock, NULL);
lttng_dynamic_buffer_init(&channel->reception_buffer);
CDS_INIT_LIST_HEAD(&channel->pending_notifications.list);
is_root = (getuid() == 0);
if (!is_root) {
is_in_tracing_group = lttng_check_tracing_group();
}
if (is_root || is_in_tracing_group) {
lttng_ctl_copy_string(sock_path,
DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK,
LTTNG_PATH_MAX);
ret = lttcomm_connect_unix_sock(sock_path);
if (ret >= 0) {
fd = ret;
goto set_fd;
}
}
/* Fallback to local session daemon. */
ret = snprintf(sock_path, LTTNG_PATH_MAX,
DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK,
utils_get_home_dir());
if (ret < 0 || ret >= LTTNG_PATH_MAX) {
goto error;
}
ret = lttcomm_connect_unix_sock(sock_path);
if (ret < 0) {
goto error;
}
fd = ret;
set_fd:
channel->socket = fd;
ret = handshake(channel);
if (ret) {
goto error;
}
end:
free(sock_path);
return channel;
error:
lttng_notification_channel_destroy(channel);
channel = NULL;
goto end;
}