X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fsession.c;h=e7967f45ef3bafe3c990dbd0521f60c01dd5b828;hp=cf2ef463e8ce20404746ae7dda5a28e44f538b84;hb=c8a9de5a85fb150d3ceaa5ca1a8b1b2b91d050d5;hpb=d14d33bf091e72b23b1f90ea18a0a01bed098b76

diff --git a/src/bin/lttng-sessiond/session.c b/src/bin/lttng-sessiond/session.c
index cf2ef463e..e7967f45e 100644
--- a/src/bin/lttng-sessiond/session.c
+++ b/src/bin/lttng-sessiond/session.c
@@ -15,19 +15,28 @@
  * 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 <sys/types.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:
@@ -46,19 +55,61 @@
 static struct ltt_session_list ltt_session_list = {
 	.head = CDS_LIST_HEAD_INIT(ltt_session_list.head),
 	.lock = PTHREAD_MUTEX_INITIALIZER,
-	.count = 0,
+	.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 int add_session_list(struct ltt_session *ls)
+static uint64_t add_session_list(struct ltt_session *ls)
 {
+	assert(ls);
+
 	cds_list_add(&ls->list, &ltt_session_list.head);
-	return ++ltt_session_list.count;
+	return ltt_session_list.next_uuid++;
 }
 
 /*
@@ -68,11 +119,9 @@ static int add_session_list(struct ltt_session *ls)
  */
 static void del_session_list(struct ltt_session *ls)
 {
+	assert(ls);
+
 	cds_list_del(&ls->list);
-	/* Sanity check */
-	if (ltt_session_list.count > 0) {
-		ltt_session_list.count--;
-	}
 }
 
 /*
@@ -83,6 +132,19 @@ struct ltt_session_list *session_get_list(void)
 	return &ltt_session_list;
 }
 
+/*
+ * Returns once the session list is empty.
+ */
+void session_list_wait_empty(void)
+{
+	pthread_mutex_lock(&ltt_session_list.lock);
+	while (!cds_list_empty(&ltt_session_list.head)) {
+		pthread_cond_wait(&ltt_session_list.removal_cond,
+				&ltt_session_list.lock);
+	}
+	pthread_mutex_unlock(&ltt_session_list.lock);
+}
+
 /*
  * Acquire session list lock
  */
@@ -91,6 +153,14 @@ void session_lock_list(void)
 	pthread_mutex_lock(&ltt_session_list.lock);
 }
 
+/*
+ * Try to acquire session list lock
+ */
+int session_trylock_list(void)
+{
+	return pthread_mutex_trylock(&ltt_session_list.lock);
+}
+
 /*
  * Release session list lock
  */
@@ -99,11 +169,224 @@ void session_unlock_list(void)
 	pthread_mutex_unlock(&ltt_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
  */
 void session_lock(struct ltt_session *session)
 {
+	assert(session);
+
 	pthread_mutex_lock(&session->lock);
 }
 
@@ -112,99 +395,208 @@ void session_lock(struct ltt_session *session)
  */
 void session_unlock(struct ltt_session *session)
 {
+	assert(session);
+
 	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(&ltt_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, &ltt_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;
+ * 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 */
-	if (session == NULL) {
-		ERR("Session pointer was null on session destroy");
-		return LTTCOMM_OK;
+	struct lttng_ht_node_u64 *node;
+	struct lttng_ht_iter iter;
+	struct ltt_session *ls;
+
+	ASSERT_LOCKED(ltt_session_list.lock);
+
+	if (!ltt_sessions_ht_by_id) {
+		goto end;
 	}
 
-	DBG("Destroying session %s", session->name);
-	del_session_list(session);
-	pthread_mutex_destroy(&session->lock);
-	free(session);
+	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;
 
-	return LTTCOMM_OK;
+end:
+	DBG3("Session %" PRIu64 " NOT found by id", id);
+	return NULL;
 }
 
 /*
  * Create a brand new session and add it to the session list.
  */
-int session_create(char *name, char *path, uid_t uid, gid_t gid)
+int session_create(char *name, uid_t uid, gid_t gid)
 {
 	int ret;
 	struct ltt_session *new_session;
 
-	new_session = session_find_by_name(name);
-	if (new_session != NULL) {
-		ret = LTTCOMM_EXIST_SESS;
-		goto error_exist;
-	}
-
 	/* Allocate session data structure */
 	new_session = zmalloc(sizeof(struct ltt_session));
 	if (new_session == NULL) {
 		PERROR("zmalloc");
-		ret = LTTCOMM_FATAL;
+		ret = LTTNG_ERR_FATAL;
 		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) {
-			ret = LTTCOMM_FATAL;
+			ret = LTTNG_ERR_FATAL;
 			goto error_asprintf;
 		}
 	} else {
 		ERR("No session name given");
-		ret = LTTCOMM_FATAL;
+		ret = LTTNG_ERR_FATAL;
 		goto error;
 	}
 
-	/* Define session system path */
-	if (path != NULL) {
-		if (snprintf(new_session->path, PATH_MAX, "%s", path) < 0) {
-			ret = LTTCOMM_FATAL;
-			goto error_asprintf;
-		}
-	} else {
-		ERR("No session path given");
-		ret = LTTCOMM_FATAL;
+	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;
@@ -215,34 +607,92 @@ int session_create(char *name, char *path, uid_t uid, gid_t gid)
 	new_session->uid = uid;
 	new_session->gid = gid;
 
-	ret = run_as_mkdir_recursive(new_session->path, S_IRWXU | S_IRWXG,
-			new_session->uid, new_session->gid);
+	ret = snapshot_init(&new_session->snapshot);
 	if (ret < 0) {
-		if (ret != -EEXIST) {
-			ERR("Trace directory creation error");
-			ret = LTTCOMM_CREATE_DIR_FAIL;
-			goto error;
-		}
+		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();
 
-	DBG("Tracing session %s created in %s with ID %d by UID %d GID %d",
-		name, path, new_session->id,
-		new_session->uid, new_session->gid);
+	/*
+	 * 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 %" PRIu64 " by UID %d GID %d",
+			name, new_session->id, new_session->uid, new_session->gid);
 
-	return LTTCOMM_OK;
+	return LTTNG_OK;
 
 error:
 error_asprintf:
-	if (new_session != NULL) {
-		free(new_session);
-	}
+	free(new_session);
 
-error_exist:
 error_malloc:
 	return ret;
 }
+
+/*
+ * Check if the UID or GID match the session. Root user has access to all
+ * sessions.
+ */
+int session_access_ok(struct ltt_session *session, uid_t uid, gid_t gid)
+{
+	assert(session);
+
+	if (uid != session->uid && gid != session->gid && uid != 0) {
+		return 0;
+	} else {
+		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;
+}