+++ /dev/null
-/*
- * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- */
-
-#define _LGPL_SOURCE
-
-#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"
-#include "thread.h"
-
-struct thread_notifiers {
- struct lttng_pipe *quit_pipe;
- sem_t ready;
-};
-
-struct agent_app_id {
- pid_t pid;
- enum lttng_domain_type domain;
-};
-
-struct agent_protocol_version {
- unsigned int major, minor;
-};
-
-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 will acquire the various sessions' lock; none must be held by the
- * caller.
- * The caller must hold the session list lock.
- */
-static void update_agent_app(const struct agent_app *app)
-{
- struct ltt_session *session, *stmp;
- struct ltt_session_list *list;
- struct agent *trigger_agent;
- struct lttng_ht_iter iter;
-
- list = session_get_list();
- LTTNG_ASSERT(list);
-
- cds_list_for_each_entry_safe(session, stmp, &list->head, list) {
- if (!session_get(session)) {
- continue;
- }
-
- session_lock(session);
- if (session->ust_session) {
- const struct agent *agt;
-
- rcu_read_lock();
- agt = trace_ust_find_agent(session->ust_session, app->domain);
- if (agt) {
- agent_update(agt, app);
- }
- rcu_read_unlock();
- }
- session_unlock(session);
- session_put(session);
- }
-
- rcu_read_lock();
- /*
- * We are protected against the addition of new events by the session
- * list lock being held.
- */
- cds_lfht_for_each_entry(the_trigger_agents_ht_by_domain->ht,
- &iter.iter, trigger_agent, node.node) {
- agent_update(trigger_agent, app);
- }
- rcu_read_unlock();
-}
-
-/*
- * 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);
- LTTNG_ASSERT(ret);
- LTTNG_ASSERT(the_config.agent_tcp_port.begin > 0);
- uri->port = the_config.agent_tcp_port.begin;
-
- sock = lttcomm_alloc_sock_from_uri(uri);
- uri_free(uri);
- if (sock == NULL) {
- ERR("agent allocating TCP socket");
- goto error;
- }
-
- ret = lttcomm_create_sock(sock);
- if (ret < 0) {
- goto error;
- }
-
- for (port = the_config.agent_tcp_port.begin;
- port <= the_config.agent_tcp_port.end; port++) {
- ret = lttcomm_sock_set_port(sock, (uint16_t) port);
- if (ret) {
- ERR("Failed to set port %u on socket",
- port);
- goto error;
- }
- DBG3("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 (the_config.agent_tcp_port.begin ==
- the_config.agent_tcp_port.end) {
- WARN("Another process is already using the agent port %i. "
- "Agent support will be deactivated.",
- the_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.",
- the_config.agent_tcp_port.begin,
- the_config.agent_tcp_port.end);
- goto error;
- }
- }
-
- ret = sock->ops->listen(sock, -1);
- if (ret < 0) {
- goto error;
- }
-
- DBG("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;
-
- LTTNG_ASSERT(sock);
-
- ret = lttcomm_sock_get_port(sock, &port);
- if (ret) {
- ERR("Failed to get port of agent TCP socket");
- port = 0;
- }
-
- DBG3("Destroy TCP socket on port %" PRIu16,
- port);
-
- /* This will return gracefully if fd is invalid. */
- sock->ops->close(sock);
- lttcomm_destroy_sock(sock);
-}
-
-static const char *domain_type_str(enum lttng_domain_type domain_type)
-{
- switch (domain_type) {
- case LTTNG_DOMAIN_NONE:
- return "none";
- case LTTNG_DOMAIN_KERNEL:
- return "kernel";
- case LTTNG_DOMAIN_UST:
- return "ust";
- case LTTNG_DOMAIN_JUL:
- return "jul";
- case LTTNG_DOMAIN_LOG4J:
- return "log4j";
- case LTTNG_DOMAIN_PYTHON:
- return "python";
- default:
- return "unknown";
- }
-}
-
-static bool is_agent_protocol_version_supported(
- const struct agent_protocol_version *version)
-{
- const bool is_supported = version->major == AGENT_MAJOR_VERSION &&
- version->minor == AGENT_MINOR_VERSION;
-
- if (!is_supported) {
- WARN("Refusing agent connection: unsupported protocol version %ui.%ui, expected %i.%i",
- version->major, version->minor,
- AGENT_MAJOR_VERSION, AGENT_MINOR_VERSION);
- }
-
- return is_supported;
-}
-
-/*
- * Handle a new agent connection on the registration socket.
- *
- * Returns 0 on success, or else a negative errno value.
- * On success, the resulting socket is returned through `agent_app_socket`
- * and the application's reported id is updated through `agent_app_id`.
- */
-static int accept_agent_connection(
- struct lttcomm_sock *reg_sock,
- struct agent_app_id *agent_app_id,
- struct lttcomm_sock **agent_app_socket)
-{
- int ret;
- struct agent_protocol_version agent_version;
- ssize_t size;
- struct agent_register_msg msg;
- struct lttcomm_sock *new_sock;
-
- LTTNG_ASSERT(reg_sock);
-
- new_sock = reg_sock->ops->accept(reg_sock);
- if (!new_sock) {
- ret = -ENOTCONN;
- goto end;
- }
-
- size = new_sock->ops->recvmsg(new_sock, &msg, sizeof(msg), 0);
- if (size < sizeof(msg)) {
- if (size < 0) {
- PERROR("Failed to register new agent application");
- } else if (size != 0) {
- ERR("Failed to register new agent application: invalid registration message length: expected length = %zu, message length = %zd",
- sizeof(msg), size);
- } else {
- DBG("Failed to register new agent application: connection closed");
- }
- ret = -EINVAL;
- goto error_close_socket;
- }
-
- agent_version = (struct agent_protocol_version) {
- be32toh(msg.major_version),
- be32toh(msg.minor_version),
- };
-
- /* Test communication protocol version of the registering agent. */
- if (!is_agent_protocol_version_supported(&agent_version)) {
- ret = -EINVAL;
- goto error_close_socket;
- }
-
- *agent_app_id = (struct agent_app_id) {
- .domain = (enum lttng_domain_type) be32toh(msg.domain),
- .pid = (pid_t) be32toh(msg.pid),
- };
-
- DBG2("New registration for agent application: pid = %ld, domain = %s, socket fd = %d",
- (long) agent_app_id->pid,
- domain_type_str(agent_app_id->domain), new_sock->fd);
-
- *agent_app_socket = new_sock;
- new_sock = NULL;
- ret = 0;
- goto end;
-
-error_close_socket:
- new_sock->ops->close(new_sock);
- lttcomm_destroy_sock(new_sock);
-end:
- return ret;
-}
-
-bool agent_tracing_is_enabled(void)
-{
- int enabled;
-
- enabled = uatomic_read(&agent_tracing_enabled);
- LTTNG_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, the_config.agent_port_file_path.value);
-}
-
-static
-void mark_thread_as_ready(struct thread_notifiers *notifiers)
-{
- DBG("Marking agent management thread as ready");
- sem_post(¬ifiers->ready);
-}
-
-static
-void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
-{
- DBG("Waiting for agent management thread to be ready");
- sem_wait(¬ifiers->ready);
- DBG("Agent management thread is ready");
-}
-
-/*
- * This thread manage application notify communication.
- */
-static void *thread_agent_management(void *data)
-{
- int i, ret, pollfd;
- uint32_t revents, nb_fd;
- struct lttng_poll_event events;
- struct lttcomm_sock *reg_sock;
- struct thread_notifiers *notifiers = data;
- const int quit_pipe_read_fd = lttng_pipe_get_readfd(
- notifiers->quit_pipe);
-
- DBG("Manage agent application registration.");
-
- rcu_register_thread();
- rcu_thread_online();
-
- /* Agent initialization call MUST be called before starting the thread. */
- LTTNG_ASSERT(the_agent_apps_ht_by_sock);
-
- /* Create pollset with size 2, quit pipe and registration socket. */
- ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
- if (ret < 0) {
- goto error_poll_create;
- }
-
- ret = lttng_poll_add(&events, quit_pipe_read_fd,
- LPOLLIN | LPOLLERR);
- if (ret < 0) {
- goto error_tcp_socket;
- }
-
- reg_sock = init_tcp_socket();
- if (reg_sock) {
- uint16_t port;
-
- ret = lttcomm_sock_get_port(reg_sock, &port);
- LTTNG_ASSERT(ret == 0);
-
- ret = write_agent_port(port);
- if (ret) {
- ERR("Failed to create agent port file: agent tracing will be unavailable");
- /* Don't prevent the launch of the sessiond on error. */
- mark_thread_as_ready(notifiers);
- goto error;
- }
- } else {
- /* Don't prevent the launch of the sessiond on error. */
- mark_thread_as_ready(notifiers);
- 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);
- mark_thread_as_ready(notifiers);
-
- /* Add TCP socket to the poll set. */
- ret = lttng_poll_add(&events, reg_sock->fd,
- LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
- if (ret < 0) {
- goto error;
- }
-
- while (1) {
- DBG3("Manage agent polling");
-
- /* Inifinite blocking call, waiting for transmission */
-restart:
- ret = lttng_poll_wait(&events, -1);
- DBG3("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("%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);
-
- /* Thread quit pipe has been closed. Killing thread. */
- if (pollfd == quit_pipe_read_fd) {
- goto exit;
- }
-
- /* Activity on the registration socket. */
- if (revents & LPOLLIN) {
- struct agent_app_id new_app_id;
- struct agent_app *new_app = NULL;
- struct lttcomm_sock *new_app_socket;
- int new_app_socket_fd;
-
- LTTNG_ASSERT(pollfd == reg_sock->fd);
-
- ret = accept_agent_connection(
- reg_sock, &new_app_id, &new_app_socket);
- if (ret < 0) {
- /* Errors are already logged. */
- continue;
- }
-
- /*
- * new_app_socket's ownership has been
- * transferred to the new agent app.
- */
- new_app = agent_create_app(new_app_id.pid,
- new_app_id.domain,
- new_app_socket);
- if (!new_app) {
- new_app_socket->ops->close(
- new_app_socket);
- continue;
- }
- new_app_socket_fd = new_app_socket->fd;
- new_app_socket = NULL;
-
- /*
- * Since this is a command socket (write then
- * read), only add poll error event to only
- * detect shutdown.
- */
- ret = lttng_poll_add(&events, new_app_socket_fd,
- LPOLLERR | LPOLLHUP | LPOLLRDHUP);
- if (ret < 0) {
- agent_destroy_app(new_app);
- continue;
- }
-
- /*
- * Prevent sessions from being modified while
- * the agent application's configuration is
- * updated.
- */
- session_lock_list();
-
- /*
- * Update the newly registered applications's
- * configuration.
- */
- update_agent_app(new_app);
-
- ret = agent_send_registration_done(new_app);
- if (ret < 0) {
- agent_destroy_app(new_app);
- /* Removing from the poll set. */
- ret = lttng_poll_del(&events,
- new_app_socket_fd);
- if (ret < 0) {
- session_unlock_list();
- goto error;
- }
- continue;
- }
-
- /* Publish the new agent app. */
- agent_add_app(new_app);
-
- session_unlock_list();
- } 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("Cleaning up and stopping.");
- rcu_thread_offline();
- rcu_unregister_thread();
- return NULL;
-}
-
-static bool shutdown_agent_management_thread(void *data)
-{
- struct thread_notifiers *notifiers = data;
- const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
-
- return notify_thread_pipe(write_fd) == 1;
-}
-
-static void cleanup_agent_management_thread(void *data)
-{
- struct thread_notifiers *notifiers = data;
-
- lttng_pipe_destroy(notifiers->quit_pipe);
- sem_destroy(¬ifiers->ready);
- free(notifiers);
-}
-
-bool launch_agent_management_thread(void)
-{
- struct thread_notifiers *notifiers;
- struct lttng_thread *thread;
-
- notifiers = zmalloc(sizeof(*notifiers));
- if (!notifiers) {
- goto error_alloc;
- }
-
- sem_init(¬ifiers->ready, 0, 0);
- notifiers->quit_pipe = lttng_pipe_open(FD_CLOEXEC);
- if (!notifiers->quit_pipe) {
- goto error;
- }
- thread = lttng_thread_create("Agent management",
- thread_agent_management,
- shutdown_agent_management_thread,
- cleanup_agent_management_thread,
- notifiers);
- if (!thread) {
- goto error;
- }
- wait_until_thread_is_ready(notifiers);
- lttng_thread_put(thread);
- return true;
-error:
- cleanup_agent_management_thread(notifiers);
-error_alloc:
- return false;
-}
projects / lttng-tools.git / blobdiff