+++ /dev/null
-/*
- * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
- *
- * 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 <assert.h>
-
-#include <common/common.h>
-#include <common/sessiond-comm/sessiond-comm.h>
-#include <common/uri.h>
-#include <common/utils.h>
-
-#include <common/compat/endian.h>
-
-#include "fd-limit.h"
-#include "agent-thread.h"
-#include "agent.h"
-#include "lttng-sessiond.h"
-#include "session.h"
-#include "utils.h"
-
-static int agent_tracing_enabled = -1;
-
-/*
- * Note that there is not port here. It's set after this URI is parsed so we
- * can let the user define a custom one. However, localhost is ALWAYS the
- * default listening address.
- */
-static const char *default_reg_uri =
- "tcp://" DEFAULT_NETWORK_VIEWER_BIND_ADDRESS;
-
-/*
- * Update agent application using the given socket. This is done just after
- * registration was successful.
- *
- * This is a quite heavy call in terms of locking since the session list lock
- * AND session lock are acquired.
- */
-static void update_agent_app(struct agent_app *app)
-{
- struct ltt_session *session, *stmp;
- struct ltt_session_list *list;
-
- list = session_get_list();
- assert(list);
-
- session_lock_list();
- cds_list_for_each_entry_safe(session, stmp, &list->head, list) {
- session_lock(session);
- if (session->ust_session) {
- struct agent *agt;
-
- rcu_read_lock();
- agt = trace_ust_find_agent(session->ust_session, app->domain);
- if (agt) {
- agent_update(agt, app->sock->fd);
- }
- rcu_read_unlock();
- }
- session_unlock(session);
- }
- session_unlock_list();
-}
-
-/*
- * Create and init socket from uri.
- */
-static struct lttcomm_sock *init_tcp_socket(void)
-{
- int ret;
- struct lttng_uri *uri = NULL;
- struct lttcomm_sock *sock = NULL;
- unsigned int port;
- bool bind_succeeded = false;
-
- /*
- * This should never fail since the URI is hardcoded and the port is set
- * before this thread is launched.
- */
- ret = uri_parse(default_reg_uri, &uri);
- assert(ret);
- assert(config.agent_tcp_port.begin > 0);
- uri->port = config.agent_tcp_port.begin;
-
- sock = lttcomm_alloc_sock_from_uri(uri);
- uri_free(uri);
- if (sock == NULL) {
- ERR("[agent-thread] agent allocating TCP socket");
- goto error;
- }
-
- ret = lttcomm_create_sock(sock);
- if (ret < 0) {
- goto error;
- }
-
- for (port = config.agent_tcp_port.begin;
- port <= config.agent_tcp_port.end; port++) {
- ret = lttcomm_sock_set_port(sock, (uint16_t) port);
- if (ret) {
- ERR("[agent-thread] Failed to set port %u on socket",
- port);
- goto error;
- }
- DBG3("[agent-thread] Trying to bind on port %u", port);
- ret = sock->ops->bind(sock);
- if (!ret) {
- bind_succeeded = true;
- break;
- }
-
- if (errno == EADDRINUSE) {
- DBG("Failed to bind to port %u since it is already in use",
- port);
- } else {
- PERROR("Failed to bind to port %u", port);
- goto error;
- }
- }
-
- if (!bind_succeeded) {
- if (config.agent_tcp_port.begin == config.agent_tcp_port.end) {
- WARN("Another process is already using the agent port %i. "
- "Agent support will be deactivated.",
- config.agent_tcp_port.begin);
- goto error;
- } else {
- WARN("All ports in the range [%i, %i] are already in use. "
- "Agent support will be deactivated.",
- config.agent_tcp_port.begin,
- config.agent_tcp_port.end);
- goto error;
- }
- }
-
- ret = sock->ops->listen(sock, -1);
- if (ret < 0) {
- goto error;
- }
-
- DBG("[agent-thread] Listening on TCP port %u and socket %d",
- port, sock->fd);
-
- return sock;
-
-error:
- if (sock) {
- lttcomm_destroy_sock(sock);
- }
- return NULL;
-}
-
-/*
- * Close and destroy the given TCP socket.
- */
-static void destroy_tcp_socket(struct lttcomm_sock *sock)
-{
- int ret;
- uint16_t port;
-
- assert(sock);
-
- ret = lttcomm_sock_get_port(sock, &port);
- if (ret) {
- ERR("[agent-thread] Failed to get port of agent TCP socket");
- port = 0;
- }
-
- DBG3("[agent-thread] Destroy TCP socket on port %" PRIu16,
- port);
-
- /* This will return gracefully if fd is invalid. */
- sock->ops->close(sock);
- lttcomm_destroy_sock(sock);
-}
-
-/*
- * Handle a new agent registration using the reg socket. After that, a new
- * agent application is added to the global hash table and attach to an UST app
- * object. If r_app is not NULL, the created app is set to the pointer.
- *
- * Return the new FD created upon accept() on success or else a negative errno
- * value.
- */
-static int handle_registration(struct lttcomm_sock *reg_sock,
- struct agent_app **r_app)
-{
- int ret;
- pid_t pid;
- uint32_t major_version, minor_version;
- ssize_t size;
- enum lttng_domain_type domain;
- struct agent_app *app;
- struct agent_register_msg msg;
- struct lttcomm_sock *new_sock;
-
- assert(reg_sock);
-
- new_sock = reg_sock->ops->accept(reg_sock);
- if (!new_sock) {
- ret = -ENOTCONN;
- goto error;
- }
-
- size = new_sock->ops->recvmsg(new_sock, &msg, sizeof(msg), 0);
- if (size < sizeof(msg)) {
- ret = -EINVAL;
- goto error_socket;
- }
- domain = be32toh(msg.domain);
- pid = be32toh(msg.pid);
- major_version = be32toh(msg.major_version);
- minor_version = be32toh(msg.minor_version);
-
- /* Test communication protocol version of the registring agent. */
- if (major_version != AGENT_MAJOR_VERSION) {
- ret = -EINVAL;
- goto error_socket;
- }
- if (minor_version != AGENT_MINOR_VERSION) {
- ret = -EINVAL;
- goto error_socket;
- }
-
- DBG2("[agent-thread] New registration for pid %d domain %d on socket %d",
- pid, domain, new_sock->fd);
-
- app = agent_create_app(pid, domain, new_sock);
- if (!app) {
- ret = -ENOMEM;
- goto error_socket;
- }
-
- /*
- * Add before assigning the socket value to the UST app so it can be found
- * concurrently.
- */
- agent_add_app(app);
-
- /*
- * We don't need to attach the agent app to the app. If we ever do so, we
- * should consider both registration order of agent before app and app
- * before agent.
- */
-
- if (r_app) {
- *r_app = app;
- }
-
- return new_sock->fd;
-
-error_socket:
- new_sock->ops->close(new_sock);
- lttcomm_destroy_sock(new_sock);
-error:
- return ret;
-}
-
-bool agent_tracing_is_enabled(void)
-{
- int enabled;
-
- enabled = uatomic_read(&agent_tracing_enabled);
- assert(enabled != -1);
- return enabled == 1;
-}
-
-/*
- * Write agent TCP port using the rundir.
- */
-static int write_agent_port(uint16_t port)
-{
- return utils_create_pid_file((pid_t) port,
- config.agent_port_file_path.value);
-}
-
-/*
- * This thread manage application notify communication.
- */
-void *agent_thread_manage_registration(void *data)
-{
- int i, ret, pollfd;
- uint32_t revents, nb_fd;
- struct lttng_poll_event events;
- struct lttcomm_sock *reg_sock;
-
- DBG("[agent-thread] Manage agent application registration.");
-
- rcu_register_thread();
- rcu_thread_online();
-
- /* Agent initialization call MUST be called before starting the thread. */
- assert(agent_apps_ht_by_sock);
-
- /* Create pollset with size 2, quit pipe and socket. */
- ret = sessiond_set_thread_pollset(&events, 2);
- if (ret < 0) {
- goto error_poll_create;
- }
-
- reg_sock = init_tcp_socket();
- if (reg_sock) {
- uint16_t port;
-
- assert(lttcomm_sock_get_port(reg_sock, &port) == 0);
-
- ret = write_agent_port(port);
- if (ret) {
- ERR("[agent-thread] Failed to create agent port file: agent tracing will be unavailable");
- /* Don't prevent the launch of the sessiond on error. */
- sessiond_notify_ready();
- goto error;
- }
- } else {
- /* Don't prevent the launch of the sessiond on error. */
- sessiond_notify_ready();
- goto error_tcp_socket;
- }
-
- /*
- * Signal that the agent thread is ready. The command thread
- * may start to query whether or not agent tracing is enabled.
- */
- uatomic_set(&agent_tracing_enabled, 1);
- sessiond_notify_ready();
-
- /* Add TCP socket to poll set. */
- ret = lttng_poll_add(&events, reg_sock->fd,
- LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
- if (ret < 0) {
- goto error;
- }
-
- while (1) {
- DBG3("[agent-thread] Manage agent polling");
-
- /* Inifinite blocking call, waiting for transmission */
-restart:
- ret = lttng_poll_wait(&events, -1);
- DBG3("[agent-thread] Manage agent return from poll on %d fds",
- LTTNG_POLL_GETNB(&events));
- if (ret < 0) {
- /*
- * Restart interrupted system call.
- */
- if (errno == EINTR) {
- goto restart;
- }
- goto error;
- }
- nb_fd = ret;
- DBG3("[agent-thread] %d fd ready", nb_fd);
-
- for (i = 0; i < nb_fd; i++) {
- /* Fetch once the poll data */
- revents = LTTNG_POLL_GETEV(&events, i);
- pollfd = LTTNG_POLL_GETFD(&events, i);
-
- if (!revents) {
- /* No activity for this FD (poll implementation). */
- continue;
- }
-
- /* Thread quit pipe has been closed. Killing thread. */
- ret = sessiond_check_thread_quit_pipe(pollfd, revents);
- if (ret) {
- goto exit;
- }
-
- if (revents & LPOLLIN) {
- int new_fd;
- struct agent_app *app = NULL;
-
- assert(pollfd == reg_sock->fd);
- new_fd = handle_registration(reg_sock, &app);
- if (new_fd < 0) {
- continue;
- }
- /* Should not have a NULL app on success. */
- assert(app);
-
- /*
- * Since this is a command socket (write then read),
- * only add poll error event to only detect shutdown.
- */
- ret = lttng_poll_add(&events, new_fd,
- LPOLLERR | LPOLLHUP | LPOLLRDHUP);
- if (ret < 0) {
- agent_destroy_app_by_sock(new_fd);
- continue;
- }
-
- /* Update newly registered app. */
- update_agent_app(app);
-
- /* On failure, the poll will detect it and clean it up. */
- ret = agent_send_registration_done(app);
- if (ret < 0) {
- /* Removing from the poll set */
- ret = lttng_poll_del(&events, new_fd);
- if (ret < 0) {
- goto error;
- }
- agent_destroy_app_by_sock(new_fd);
- continue;
- }
- } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
- /* Removing from the poll set */
- ret = lttng_poll_del(&events, pollfd);
- if (ret < 0) {
- goto error;
- }
- agent_destroy_app_by_sock(pollfd);
- } else {
- ERR("Unexpected poll events %u for sock %d", revents, pollfd);
- goto error;
- }
- }
- }
-
-exit:
- /* Whatever happens, try to delete it and exit. */
- (void) lttng_poll_del(&events, reg_sock->fd);
-error:
- destroy_tcp_socket(reg_sock);
-error_tcp_socket:
- lttng_poll_clean(&events);
-error_poll_create:
- uatomic_set(&agent_tracing_enabled, 0);
- DBG("[agent-thread] is cleaning up and stopping.");
-
- rcu_thread_offline();
- rcu_unregister_thread();
- return NULL;
-}
projects / lttng-tools.git / blobdiff