+++ /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 <common/common.h>
-#include <common/sessiond-comm/sessiond-comm.h>
-
-#include "session.h"
-#include "utils.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,
- .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;
-}
-
-/*
- * Acquire session list lock
- */
-void session_lock_list(void)
-{
- pthread_mutex_lock(<t_session_list.lock);
-}
-
-/*
- * Release session list lock
- */
-void session_unlock_list(void)
-{
- pthread_mutex_unlock(<t_session_list.lock);
-}
-
-/*
- * 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);
-}
-
-/*
- * 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.
- */
-struct ltt_session *session_find_by_name(const char *name)
-{
- struct ltt_session *iter;
-
- assert(name);
-
- 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) {
- goto found;
- }
- }
-
- iter = NULL;
-
-found:
- return iter;
-}
-
-/*
- * 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;
-
- 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 ls;
-
-end:
- DBG3("Session %" PRIu64 " NOT found by id", id);
- return 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.
- */
-int session_destroy(struct ltt_session *session)
-{
- /* Safety check */
- assert(session);
-
- DBG("Destroying session %s (id %" PRIu64 ")", session->name, session->id);
- del_session_list(session);
- pthread_mutex_destroy(&session->lock);
- del_session_ht(session);
-
- consumer_output_put(session->consumer);
- snapshot_destroy(&session->snapshot);
- free(session);
-
- return LTTNG_OK;
-}
-
-/*
- * 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;
- }
-
- /* 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->rotate_pending = false;
- new_session->rotate_pending_relay = 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;
- }
-}
projects / lttng-tools.git / blobdiff