+++ /dev/null
-/*
- * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 2 only,
- * as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#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:
- *
- * No ltt_session.lock is taken here because those data structure are widely
- * spread across the lttng-tools code base so before caling functions below
- * that can read/write a session, the caller MUST acquire the session lock
- * using session_lock() and session_unlock().
- */
-
-/*
- * Init tracing session list.
- *
- * Please see session.h for more explanation and correct usage of the list.
- */
-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 uint64_t add_session_list(struct ltt_session *ls)
-{
- assert(ls);
-
- cds_list_add(&ls->list, <t_session_list.head);
- return ltt_session_list.next_uuid++;
-}
-
-/*
- * Delete a ltt_session structure to the global list.
- *
- * The caller MUST acquire the session list lock before.
- */
-static void del_session_list(struct ltt_session *ls)
-{
- assert(ls);
-
- cds_list_del(&ls->list);
-}
-
-/*
- * Return a pointer to the session list.
- */
-struct ltt_session_list *session_get_list(void)
-{
- 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
- */
-void session_lock_list(void)
-{
- 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
- */
-void session_unlock_list(void)
-{
- 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
- */
-void session_lock(struct ltt_session *session)
-{
- assert(session);
-
- pthread_mutex_lock(&session->lock);
-}
-
-/*
- * Release session lock
- */
-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(<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 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(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) &&
- !iter->destroyed) {
- goto found;
- }
- }
-
- return NULL;
-found:
- return session_get(iter) ? iter : NULL;
-}
-
-/*
- * 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).
- */
-struct ltt_session *session_find_by_id(uint64_t id)
-{
- 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;
- }
-
- 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;
-}
-
-/*
- * Create a brand new session and add it to the session list.
- */
-int session_create(char *name, uid_t uid, gid_t gid)
-{
- int ret;
- struct ltt_session *new_session;
-
- /* Allocate session data structure */
- new_session = zmalloc(sizeof(struct ltt_session));
- if (new_session == NULL) {
- PERROR("zmalloc");
- 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 = LTTNG_ERR_FATAL;
- goto error_asprintf;
- }
- } else {
- ERR("No session name given");
- ret = LTTNG_ERR_FATAL;
- 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;
-
- /* Init lock */
- pthread_mutex_init(&new_session->lock, 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 %" PRIu64 " by UID %d GID %d",
- name, new_session->id, new_session->uid, new_session->gid);
-
- return LTTNG_OK;
-
-error:
-error_asprintf:
- free(new_session);
-
-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;
-}
projects / lttng-tools.git / blobdiff