* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
#include <limits.h>
+#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <urcu.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <pthread.h>
#include <common/common.h>
#include <common/sessiond-comm/sessiond-comm.h>
+#include <lttng/location-internal.h>
+#include "lttng-sessiond.h"
+#include "kernel.h"
#include "session.h"
+#include "utils.h"
+#include "trace-ust.h"
+#include "timer.h"
/*
* NOTES:
static struct ltt_session_list ltt_session_list = {
.head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
.lock = PTHREAD_MUTEX_INITIALIZER,
+ .removal_cond = PTHREAD_COND_INITIALIZER,
.next_uuid = 0,
};
+/* These characters are forbidden in a session name. Used by validate_name. */
+static const char *forbidden_name_chars = "/";
+
+/* Global hash table to keep the sessions, indexed by id. */
+static struct lttng_ht *ltt_sessions_ht_by_id = NULL;
+
+/*
+ * Validate the session name for forbidden characters.
+ *
+ * Return 0 on success else -1 meaning a forbidden char. has been found.
+ */
+static int validate_name(const char *name)
+{
+ int ret;
+ char *tok, *tmp_name;
+
+ assert(name);
+
+ tmp_name = strdup(name);
+ if (!tmp_name) {
+ /* ENOMEM here. */
+ ret = -1;
+ goto error;
+ }
+
+ tok = strpbrk(tmp_name, forbidden_name_chars);
+ if (tok) {
+ DBG("Session name %s contains a forbidden character", name);
+ /* Forbidden character has been found. */
+ ret = -1;
+ goto error;
+ }
+ ret = 0;
+
+error:
+ free(tmp_name);
+ return ret;
+}
+
/*
* Add a ltt_session structure to the global list.
*
* The caller MUST acquire the session list lock before.
* Returns the unique identifier for the session.
*/
-static unsigned int add_session_list(struct ltt_session *ls)
+static uint64_t add_session_list(struct ltt_session *ls)
{
assert(ls);
return <t_session_list;
}
+/*
+ * Returns once the session list is empty.
+ */
+void session_list_wait_empty(void)
+{
+ pthread_mutex_lock(<t_session_list.lock);
+ while (!cds_list_empty(<t_session_list.head)) {
+ pthread_cond_wait(<t_session_list.removal_cond,
+ <t_session_list.lock);
+ }
+ pthread_mutex_unlock(<t_session_list.lock);
+}
+
/*
* Acquire session list lock
*/
pthread_mutex_lock(<t_session_list.lock);
}
+/*
+ * Try to acquire session list lock
+ */
+int session_trylock_list(void)
+{
+ return pthread_mutex_trylock(<t_session_list.lock);
+}
+
/*
* Release session list lock
*/
pthread_mutex_unlock(<t_session_list.lock);
}
+/*
+ * Get the session's consumer destination type.
+ *
+ * The caller must hold the session lock.
+ */
+enum consumer_dst_type session_get_consumer_destination_type(
+ const struct ltt_session *session)
+{
+ /*
+ * The output information is duplicated in both of those session types.
+ * Hence, it doesn't matter from which it is retrieved. However, it is
+ * possible for only one of them to be set.
+ */
+ return session->kernel_session ?
+ session->kernel_session->consumer->type :
+ session->ust_session->consumer->type;
+}
+
+/*
+ * Get the session's consumer network hostname.
+ * The caller must ensure that the destination is of type "net".
+ *
+ * The caller must hold the session lock.
+ */
+const char *session_get_net_consumer_hostname(const struct ltt_session *session)
+{
+ const char *hostname = NULL;
+ const struct consumer_output *output;
+
+ output = session->kernel_session ?
+ session->kernel_session->consumer :
+ session->ust_session->consumer;
+
+ /*
+ * hostname is assumed to be the same for both control and data
+ * connections.
+ */
+ switch (output->dst.net.control.dtype) {
+ case LTTNG_DST_IPV4:
+ hostname = output->dst.net.control.dst.ipv4;
+ break;
+ case LTTNG_DST_IPV6:
+ hostname = output->dst.net.control.dst.ipv6;
+ break;
+ default:
+ abort();
+ }
+ return hostname;
+}
+
+/*
+ * Get the session's consumer network control and data ports.
+ * The caller must ensure that the destination is of type "net".
+ *
+ * The caller must hold the session lock.
+ */
+void session_get_net_consumer_ports(const struct ltt_session *session,
+ uint16_t *control_port, uint16_t *data_port)
+{
+ const struct consumer_output *output;
+
+ output = session->kernel_session ?
+ session->kernel_session->consumer :
+ session->ust_session->consumer;
+ *control_port = output->dst.net.control.port;
+ *data_port = output->dst.net.data.port;
+}
+
+/*
+ * Get the location of the latest trace archive produced by a rotation.
+ *
+ * The caller must hold the session lock.
+ */
+struct lttng_trace_archive_location *session_get_trace_archive_location(
+ struct ltt_session *session)
+{
+ struct lttng_trace_archive_location *location = NULL;
+
+ if (session->rotation_state != LTTNG_ROTATION_STATE_COMPLETED) {
+ goto end;
+ }
+
+ switch (session_get_consumer_destination_type(session)) {
+ case CONSUMER_DST_LOCAL:
+ location = lttng_trace_archive_location_local_create(
+ session->rotation_chunk.current_rotate_path);
+ break;
+ case CONSUMER_DST_NET:
+ {
+ const char *hostname;
+ uint16_t control_port, data_port;
+
+ hostname = session_get_net_consumer_hostname(session);
+ session_get_net_consumer_ports(session,
+ &control_port,
+ &data_port);
+ location = lttng_trace_archive_location_relay_create(
+ hostname,
+ LTTNG_TRACE_ARCHIVE_LOCATION_RELAY_PROTOCOL_TYPE_TCP,
+ control_port, data_port,
+ session->rotation_chunk.current_rotate_path);
+ break;
+ }
+ default:
+ abort();
+ }
+end:
+ return location;
+}
+
+/*
+ * Allocate the ltt_sessions_ht_by_id HT.
+ *
+ * The session list lock must be held.
+ */
+int ltt_sessions_ht_alloc(void)
+{
+ int ret = 0;
+
+ DBG("Allocating ltt_sessions_ht_by_id");
+ ltt_sessions_ht_by_id = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
+ if (!ltt_sessions_ht_by_id) {
+ ret = -1;
+ ERR("Failed to allocate ltt_sessions_ht_by_id");
+ goto end;
+ }
+end:
+ return ret;
+}
+
+/*
+ * Destroy the ltt_sessions_ht_by_id HT.
+ *
+ * The session list lock must be held.
+ */
+static void ltt_sessions_ht_destroy(void)
+{
+ if (!ltt_sessions_ht_by_id) {
+ return;
+ }
+ ht_cleanup_push(ltt_sessions_ht_by_id);
+ ltt_sessions_ht_by_id = NULL;
+}
+
+/*
+ * Add a ltt_session to the ltt_sessions_ht_by_id.
+ * If unallocated, the ltt_sessions_ht_by_id HT is allocated.
+ * The session list lock must be held.
+ */
+static void add_session_ht(struct ltt_session *ls)
+{
+ int ret;
+
+ assert(ls);
+
+ if (!ltt_sessions_ht_by_id) {
+ ret = ltt_sessions_ht_alloc();
+ if (ret) {
+ ERR("Error allocating the sessions HT");
+ goto end;
+ }
+ }
+ lttng_ht_node_init_u64(&ls->node, ls->id);
+ lttng_ht_add_unique_u64(ltt_sessions_ht_by_id, &ls->node);
+
+end:
+ return;
+}
+
+/*
+ * Test if ltt_sessions_ht_by_id is empty.
+ * Return 1 if empty, 0 if not empty.
+ * The session list lock must be held.
+ */
+static int ltt_sessions_ht_empty(void)
+{
+ int ret;
+
+ if (!ltt_sessions_ht_by_id) {
+ ret = 1;
+ goto end;
+ }
+
+ ret = lttng_ht_get_count(ltt_sessions_ht_by_id) ? 0 : 1;
+end:
+ return ret;
+}
+
+/*
+ * Remove a ltt_session from the ltt_sessions_ht_by_id.
+ * If empty, the ltt_sessions_ht_by_id HT is freed.
+ * The session list lock must be held.
+ */
+static void del_session_ht(struct ltt_session *ls)
+{
+ struct lttng_ht_iter iter;
+ int ret;
+
+ assert(ls);
+ assert(ltt_sessions_ht_by_id);
+
+ iter.iter.node = &ls->node.node;
+ ret = lttng_ht_del(ltt_sessions_ht_by_id, &iter);
+ assert(!ret);
+
+ if (ltt_sessions_ht_empty()) {
+ DBG("Empty ltt_sessions_ht_by_id, destroying it");
+ ltt_sessions_ht_destroy();
+ }
+}
+
/*
* Acquire session lock
*/
pthread_mutex_unlock(&session->lock);
}
+static
+void session_release(struct urcu_ref *ref)
+{
+ int ret;
+ struct ltt_ust_session *usess;
+ struct ltt_kernel_session *ksess;
+ struct ltt_session *session = container_of(ref, typeof(*session), ref);
+
+ usess = session->ust_session;
+ ksess = session->kernel_session;
+
+ /* Clean kernel session teardown */
+ kernel_destroy_session(ksess);
+
+ /* UST session teardown */
+ if (usess) {
+ /* Close any relayd session */
+ consumer_output_send_destroy_relayd(usess->consumer);
+
+ /* Destroy every UST application related to this session. */
+ ret = ust_app_destroy_trace_all(usess);
+ if (ret) {
+ ERR("Error in ust_app_destroy_trace_all");
+ }
+
+ /* Clean up the rest. */
+ trace_ust_destroy_session(usess);
+ }
+
+ /*
+ * Must notify the kernel thread here to update it's poll set in order to
+ * remove the channel(s)' fd just destroyed.
+ */
+ ret = notify_thread_pipe(kernel_poll_pipe[1]);
+ if (ret < 0) {
+ PERROR("write kernel poll pipe");
+ }
+
+ DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
+ pthread_mutex_destroy(&session->lock);
+
+ consumer_output_put(session->consumer);
+ snapshot_destroy(&session->snapshot);
+
+ ASSERT_LOCKED(ltt_session_list.lock);
+ del_session_list(session);
+ del_session_ht(session);
+ pthread_cond_broadcast(<t_session_list.removal_cond);
+ free(session);
+}
+
+/*
+ * Acquire a reference to a session.
+ * This function may fail (return false); its return value must be checked.
+ */
+bool session_get(struct ltt_session *session)
+{
+ return urcu_ref_get_unless_zero(&session->ref);
+}
+
+/*
+ * Release a reference to a session.
+ */
+void session_put(struct ltt_session *session)
+{
+ /*
+ * The session list lock must be held as any session_put()
+ * may cause the removal of the session from the session_list.
+ */
+ ASSERT_LOCKED(ltt_session_list.lock);
+ assert(session->ref.refcount);
+ urcu_ref_put(&session->ref, session_release);
+}
+
+/*
+ * Destroy a session.
+ *
+ * This method does not immediately release/free the session as other
+ * components may still hold a reference to the session. However,
+ * the session should no longer be presented to the user.
+ *
+ * Releases the session list's reference to the session
+ * and marks it as destroyed. Iterations on the session list should be
+ * mindful of the "destroyed" flag.
+ */
+void session_destroy(struct ltt_session *session)
+{
+ assert(!session->destroyed);
+ session->destroyed = true;
+ session_put(session);
+}
+
/*
* Return a ltt_session structure ptr that matches name. If no session found,
- * NULL is returned. This must be called with the session lock held using
+ * NULL is returned. This must be called with the session list lock held using
* session_lock_list and session_unlock_list.
+ * A reference to the session is implicitly acquired by this function.
*/
-struct ltt_session *session_find_by_name(char *name)
+struct ltt_session *session_find_by_name(const char *name)
{
struct ltt_session *iter;
assert(name);
+ ASSERT_LOCKED(ltt_session_list.lock);
DBG2("Trying to find session by name %s", name);
cds_list_for_each_entry(iter, <t_session_list.head, list) {
- if (strncmp(iter->name, name, NAME_MAX) == 0) {
+ if (!strncmp(iter->name, name, NAME_MAX) &&
+ !iter->destroyed) {
goto found;
}
}
- iter = NULL;
-
+ return NULL;
found:
- return iter;
+ return session_get(iter) ? iter : NULL;
}
/*
- * Delete session from the session list and free the memory.
- *
- * Return -1 if no session is found. On success, return 1;
- * Should *NOT* be called with RCU read-side lock held.
+ * Return an ltt_session that matches the id. If no session is found,
+ * NULL is returned. This must be called with rcu_read_lock and
+ * session list lock held (to guarantee the lifetime of the session).
*/
-int session_destroy(struct ltt_session *session)
+struct ltt_session *session_find_by_id(uint64_t id)
{
- /* Safety check */
- assert(session);
+ struct lttng_ht_node_u64 *node;
+ struct lttng_ht_iter iter;
+ struct ltt_session *ls;
- DBG("Destroying session %s", session->name);
- del_session_list(session);
- pthread_mutex_destroy(&session->lock);
+ ASSERT_LOCKED(ltt_session_list.lock);
- consumer_destroy_output(session->consumer);
- free(session);
+ if (!ltt_sessions_ht_by_id) {
+ goto end;
+ }
- return LTTNG_OK;
+ lttng_ht_lookup(ltt_sessions_ht_by_id, &id, &iter);
+ node = lttng_ht_iter_get_node_u64(&iter);
+ if (node == NULL) {
+ goto end;
+ }
+ ls = caa_container_of(node, struct ltt_session, node);
+
+ DBG3("Session %" PRIu64 " found by id.", id);
+ return session_get(ls) ? ls : NULL;
+
+end:
+ DBG3("Session %" PRIu64 " NOT found by id", id);
+ return NULL;
}
/*
goto error_malloc;
}
+ urcu_ref_init(&new_session->ref);
+
/* Define session name */
if (name != NULL) {
if (snprintf(new_session->name, NAME_MAX, "%s", name) < 0) {
goto error;
}
+ ret = validate_name(name);
+ if (ret < 0) {
+ ret = LTTNG_ERR_SESSION_INVALID_CHAR;
+ goto error;
+ }
+
+ ret = gethostname(new_session->hostname, sizeof(new_session->hostname));
+ if (ret < 0) {
+ if (errno == ENAMETOOLONG) {
+ new_session->hostname[sizeof(new_session->hostname) - 1] = '\0';
+ } else {
+ ret = LTTNG_ERR_FATAL;
+ goto error;
+ }
+ }
+
/* Init kernel session */
new_session->kernel_session = NULL;
new_session->ust_session = NULL;
new_session->uid = uid;
new_session->gid = gid;
+ ret = snapshot_init(&new_session->snapshot);
+ if (ret < 0) {
+ ret = LTTNG_ERR_NOMEM;
+ goto error;
+ }
+
+ new_session->rotation_pending_local = false;
+ new_session->rotation_pending_relay = false;
+ new_session->rotation_state = LTTNG_ROTATION_STATE_NO_ROTATION;
+
+ new_session->rotation_pending_check_timer_enabled = false;
+ new_session->rotation_schedule_timer_enabled = false;
+
/* Add new session to the session list */
session_lock_list();
new_session->id = add_session_list(new_session);
+ /*
+ * Add the new session to the ltt_sessions_ht_by_id.
+ * No ownership is taken by the hash table; it is merely
+ * a wrapper around the session list used for faster access
+ * by session id.
+ */
+ add_session_ht(new_session);
session_unlock_list();
/*
* Consumer is let to NULL since the create_session_uri command will set it
* up and, if valid, assign it to the session.
*/
-
- DBG("Tracing session %s created with ID %u by UID %d GID %d", name,
- new_session->id, new_session->uid, new_session->gid);
+ DBG("Tracing session %s created with ID %" PRIu64 " by UID %d GID %d",
+ name, new_session->id, new_session->uid, new_session->gid);
return LTTNG_OK;
return 1;
}
}
+
+/*
+ * Set a session's rotation state and reset all associated state.
+ *
+ * This function resets the rotation state (check timers, pending
+ * flags, etc.) and sets the result of the last rotation. The result
+ * can be queries by a liblttng-ctl client.
+ *
+ * Be careful of the result passed to this function. For instance,
+ * on failure to launch a rotation, a client will expect the rotation
+ * state to be set to "NO_ROTATION". If an error occured while the
+ * rotation was "ONGOING", result should be set to "ERROR", which will
+ * allow a client to report it.
+ *
+ * Must be called with the session and session_list locks held.
+ */
+int session_reset_rotation_state(struct ltt_session *session,
+ enum lttng_rotation_state result)
+{
+ int ret = 0;
+
+ ASSERT_LOCKED(ltt_session_list.lock);
+ ASSERT_LOCKED(session->lock);
+
+ session->rotation_pending_local = false;
+ session->rotation_pending_relay = false;
+ session->rotated_after_last_stop = false;
+ session->rotation_state = result;
+ if (session->rotation_pending_check_timer_enabled) {
+ ret = timer_session_rotation_pending_check_stop(session);
+ }
+ return ret;
+}
projects / lttng-tools.git / blobdiff