memcpy(dst, src, sizeof(struct lttng_domain));
break;
default:
+ memset(dst, 0, sizeof(struct lttng_domain));
dst->type = LTTNG_DOMAIN_KERNEL;
break;
}
/*
* Send lttcomm_session_msg to the session daemon.
*
- * On success, return 0
- * On error, return error code
+ * On success, returns the number of bytes sent (>=0)
+ * On error, returns -1
*/
static int send_session_msg(struct lttcomm_session_msg *lsm)
{
/*
* Receive data from the sessiond socket.
*
- * On success, return 0
- * On error, return recv() error code
+ * On success, returns the number of bytes received (>=0)
+ * On error, returns -1 (recvmsg() error) or -ENOTCONN
*/
static int recv_data_sessiond(void *buf, size_t len)
{
}
/*
- * Check if the specified group name exist.
+ * Check if we are in the specified group.
*
* If yes return 1, else return -1.
*/
/* Get GID of group 'tracing' */
grp_tracing = getgrnam(grp_name);
- if (grp_tracing == NULL) {
- /* NULL means not found also. getgrnam(3) */
- if (errno != 0) {
- perror("getgrnam");
- }
+ if (!grp_tracing) {
+ /* If grp_tracing is NULL, the group does not exist. */
goto end;
}
/* Alloc group list of the right size */
grp_list = malloc(grp_list_size * sizeof(gid_t));
if (!grp_list) {
- ret = -1;
+ perror("malloc");
goto end;
}
grp_id = getgroups(grp_list_size, grp_list);
- if (grp_id < -1) {
+ if (grp_id < 0) {
perror("getgroups");
goto free_list;
}
}
/*
- * Set sessiond socket path by putting it in the global sessiond_sock_path
- * variable.
+ * Set sessiond socket path by putting it in the global
+ * sessiond_sock_path variable.
+ * Returns 0 on success,
+ * -ENOMEM on failure (the sessiond socket path is somehow too long)
*/
static int set_session_daemon_path(void)
{
in_tgroup = check_tracing_group(tracing_group);
}
- if (uid == 0) {
- /* Root */
- copy_string(sessiond_sock_path,
- DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
- sizeof(sessiond_sock_path));
- } else if (in_tgroup) {
- /* Tracing group */
- copy_string(sessiond_sock_path,
- DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
+ if ((uid == 0) || in_tgroup) {
+ copy_string(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
sizeof(sessiond_sock_path));
+ }
- ret = try_connect_sessiond(sessiond_sock_path);
- if (ret < 0) {
- /* Global session daemon not available */
- if (snprintf(sessiond_sock_path, sizeof(sessiond_sock_path),
- DEFAULT_HOME_CLIENT_UNIX_SOCK,
- getenv("HOME")) < 0) {
- return -ENOMEM;
+ if (uid != 0) {
+ if (in_tgroup) {
+ /* Tracing group */
+ ret = try_connect_sessiond(sessiond_sock_path);
+ if (ret >= 0) {
+ goto end;
}
+ /* Global session daemon not available... */
}
- } else {
- /* Not in tracing group and not root, default */
- if (snprintf(sessiond_sock_path, PATH_MAX,
- DEFAULT_HOME_CLIENT_UNIX_SOCK,
- getenv("HOME")) < 0) {
+ /* ...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, getenv("HOME"));
+ if ((ret < 0) || (ret >= sizeof(sessiond_sock_path))) {
return -ENOMEM;
}
}
-
+end:
return 0;
}
ret = set_session_daemon_path();
if (ret < 0) {
- return ret;
+ return -1; /* set_session_daemon_path() returns -ENOMEM */
}
/* Connect to the sesssion daemon */
}
/*
- * Clean disconnect the session daemon.
+ * Clean disconnect from the session daemon.
+ * On success, return 0. On error, return -1.
*/
static int disconnect_sessiond(void)
{
/*
* Ask the session daemon a specific command and put the data into buf.
*
- * Return size of data (only payload, not header).
+ * Return size of data (only payload, not header) or a negative error code.
*/
static int ask_sessiond(struct lttcomm_session_msg *lsm, void **buf)
{
/*
* Create lttng handle and return pointer.
+ * The returned pointer will be NULL in case of malloc() error.
*/
struct lttng_handle *lttng_create_handle(const char *session_name,
struct lttng_domain *domain)
/*
* Register an outside consumer.
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_register_consumer(struct lttng_handle *handle,
const char *socket_path)
}
/*
- * Start tracing for all trace of the session.
+ * Start tracing for all traces of the session.
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_start_tracing(const char *session_name)
{
}
/*
- * Stop tracing for all trace of the session.
+ * Stop tracing for all traces of the session.
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_stop_tracing(const char *session_name)
{
}
/*
- * Add context to event or/and channel.
+ * Add context to event and/or channel.
+ * If event_name is NULL, the context is applied to all events of the channel.
+ * If channel_name is NULL, a lookup of the event's channel is done.
+ * If both are NULL, the context is applied to all events of all channels.
+ *
+ * Returns the size of the returned payload data or a negative error code.
*/
int lttng_add_context(struct lttng_handle *handle,
struct lttng_event_context *ctx, const char *event_name,
return -1;
}
+ memset(&lsm, 0, sizeof(lsm));
+
lsm.cmd_type = LTTNG_ADD_CONTEXT;
/* Copy channel name */
}
/*
- * Enable event
+ * Enable event(s) for a channel.
+ * If no event name is specified, all events are enabled.
+ * If no channel name is specified, the default 'channel0' is used.
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_enable_event(struct lttng_handle *handle,
struct lttng_event *ev, const char *channel_name)
return -1;
}
+ memset(&lsm, 0, sizeof(lsm));
+
/* If no channel name, we put the default name */
if (channel_name == NULL) {
copy_string(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME,
}
/*
- * Disable event of a channel and domain.
+ * Disable event(s) of a channel and domain.
+ * If no event name is specified, all events are disabled.
+ * If no channel name is specified, the default 'channel0' is used.
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_disable_event(struct lttng_handle *handle, const char *name,
const char *channel_name)
return -1;
}
+ memset(&lsm, 0, sizeof(lsm));
+
if (channel_name) {
copy_string(lsm.u.disable.channel_name, channel_name,
sizeof(lsm.u.disable.channel_name));
}
/*
- * Enable channel per domain
+ * Enable channel per domain
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_enable_channel(struct lttng_handle *handle,
struct lttng_channel *chan)
return -1;
}
+ memset(&lsm, 0, sizeof(lsm));
+
memcpy(&lsm.u.channel.chan, chan, sizeof(lsm.u.channel.chan));
lsm.cmd_type = LTTNG_ENABLE_CHANNEL;
}
/*
- * All tracing will be stopped for registered events of the channel.
+ * All tracing will be stopped for registered events of the channel.
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_disable_channel(struct lttng_handle *handle, const char *name)
{
return -1;
}
+ memset(&lsm, 0, sizeof(lsm));
+
lsm.cmd_type = LTTNG_DISABLE_CHANNEL;
copy_string(lsm.u.disable.channel_name, name,
}
/*
- * List all available tracepoints of domain.
- *
- * Return the size (bytes) of the list and set the events array.
- * On error, return negative value.
+ * Lists all available tracepoints of domain.
+ * Sets the contents of the events array.
+ * Returns the number of lttng_event entries in events;
+ * on error, returns a negative value.
*/
int lttng_list_tracepoints(struct lttng_handle *handle,
struct lttng_event **events)
}
/*
- * Return a human readable string of code
+ * Returns a human readable string describing
+ * the error code (a negative value).
*/
const char *lttng_strerror(int code)
{
+ /* lttcomm error codes range from -LTTCOMM_OK down to -LTTCOMM_NR */
if (code > -LTTCOMM_OK) {
return "Ended with errors";
}
}
/*
- * Create a brand new session using name.
+ * Create a brand new session using name and path.
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_create_session(const char *name, const char *path)
{
/*
* Destroy session using name.
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_destroy_session(const char *session_name)
{
/*
* Ask the session daemon for all available sessions.
- *
- * Return number of session.
- * On error, return negative value.
+ * Sets the contents of the sessions array.
+ * Returns the number of lttng_session entries in sessions;
+ * on error, returns a negative value.
*/
int lttng_list_sessions(struct lttng_session **sessions)
{
}
/*
- * List domain of a session.
+ * Ask the session daemon for all available domains of a session.
+ * Sets the contents of the domains array.
+ * Returns the number of lttng_domain entries in domains;
+ * on error, returns a negative value.
*/
int lttng_list_domains(const char *session_name,
struct lttng_domain **domains)
}
/*
- * List channels of a session
+ * Ask the session daemon for all available channels of a session.
+ * Sets the contents of the channels array.
+ * Returns the number of lttng_channel entries in channels;
+ * on error, returns a negative value.
*/
int lttng_list_channels(struct lttng_handle *handle,
struct lttng_channel **channels)
}
/*
- * List events of a session channel.
+ * Ask the session daemon for all available events of a session channel.
+ * Sets the contents of the events array.
+ * Returns the number of lttng_event entries in events;
+ * on error, returns a negative value.
*/
int lttng_list_events(struct lttng_handle *handle,
const char *channel_name, struct lttng_event **events)
}
/*
- * Set tracing group variable with name. This function allocate memory pointed
- * by tracing_group.
+ * Sets the tracing_group variable with name.
+ * This function allocates memory pointed to by tracing_group.
+ * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
*/
int lttng_set_tracing_group(const char *name)
{
}
/*
- * lttng_calibrate
+ * Returns size of returned session payload data or a negative error code.
*/
int lttng_calibrate(struct lttng_handle *handle,
struct lttng_calibrate *calibrate)
/*
* Set default channel attributes.
+ * If either or both of the arguments are null, attr content is zeroe'd.
*/
void lttng_channel_set_default_attr(struct lttng_domain *domain,
struct lttng_channel_attr *attr)
{
+ memset(attr, 0, sizeof(struct lttng_channel_attr));
+
/* Safety check */
if (attr == NULL || domain == NULL) {
return;
attr->output = DEFAULT_UST_CHANNEL_OUTPUT;
break;
default:
- /* Default behavior */
- memset(attr, 0, sizeof(struct lttng_channel_attr));
+ /* Default behavior: leave set to 0. */
break;
}
}
* Check if session daemon is alive.
*
* Return 1 if alive or 0 if not.
- * On error return -1
+ * On error returns a negative value.
*/
int lttng_session_daemon_alive(void)
{
projects / lttng-tools.git / blobdiff