*/
#define _GNU_SOURCE
+#include <assert.h>
#include <grp.h>
#include <errno.h>
#include <stdio.h>
/* Socket to session daemon for communication */
static int sessiond_socket;
static char sessiond_sock_path[PATH_MAX];
+static char health_sock_path[PATH_MAX];
/* Variables */
static char *tracing_group;
return ask_sessiond(&lsm, NULL);
}
+/*
+ * Set health socket path by putting it in the global health_sock_path
+ * variable.
+ *
+ * Returns 0 on success or assert(0) on ENOMEM.
+ */
+static int set_health_socket_path(void)
+{
+ int ret;
+ int in_tgroup = 0; /* In tracing group */
+ uid_t uid;
+ const char *home;
+
+ uid = getuid();
+
+ if (uid != 0) {
+ /* Are we in the tracing group ? */
+ in_tgroup = check_tracing_group(tracing_group);
+ }
+
+ if ((uid == 0) || in_tgroup) {
+ copy_string(health_sock_path, DEFAULT_GLOBAL_HEALTH_UNIX_SOCK,
+ sizeof(health_sock_path));
+ }
+
+ if (uid != 0) {
+ /*
+ * 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)
+ */
+ home = getenv("HOME");
+ if (home == NULL) {
+ /* Fallback in /tmp .. */
+ home = "/tmp";
+ }
+
+ ret = snprintf(health_sock_path, sizeof(health_sock_path),
+ DEFAULT_HOME_HEALTH_UNIX_SOCK, home);
+ if ((ret < 0) || (ret >= sizeof(health_sock_path))) {
+ /* ENOMEM at this point... just kill the control lib. */
+ assert(0);
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Check session daemon health for a specific health component.
+ *
+ * Return 0 if health is OK or else 1 if BAD. A return value of -1 indicate
+ * that the control library was not able to connect to the session daemon
+ * health socket.
+ *
+ * Any other positive value is an lttcomm error which can be translate with
+ * lttng_strerror().
+ */
+int lttng_health_check(enum lttng_health_component c)
+{
+ int sock, ret;
+ struct lttcomm_health_msg msg;
+ struct lttcomm_health_data reply;
+
+ /* Connect to the sesssion daemon */
+ sock = lttcomm_connect_unix_sock(health_sock_path);
+ if (sock < 0) {
+ ret = -1;
+ goto error;
+ }
+
+ msg.cmd = LTTNG_HEALTH_CHECK;
+ msg.component = c;
+
+ ret = lttcomm_send_unix_sock(sock, (void *)&msg, sizeof(msg));
+ if (ret < 0) {
+ goto close_error;
+ }
+
+ ret = lttcomm_recv_unix_sock(sock, (void *)&reply, sizeof(reply));
+ if (ret < 0) {
+ goto close_error;
+ }
+
+ ret = reply.ret_code;
+
+close_error:
+ close(sock);
+
+error:
+ return ret;
+}
+
/*
* lib constructor
*/
{
/* Set default session group */
lttng_set_tracing_group(DEFAULT_TRACING_GROUP);
+ /* Set socket for health check */
+ (void) set_health_socket_path();
}