sessiond: notification: receive incoming notifications from tracers
[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread.c
index 9809e6190cd60cbb453cea62b704a62e6da84cc5..1ba724337b67ee69a1856087a5c8b65c45a32cd8 100644 (file)
@@ -1,18 +1,8 @@
 /*
- * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@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.
+ * SPDX-License-Identifier: GPL-2.0-only
  *
- * 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
@@ -27,7 +17,6 @@
 #include <common/utils.h>
 #include <common/align.h>
 #include <common/time.h>
-#include <sys/eventfd.h>
 #include <sys/stat.h>
 #include <time.h>
 #include <signal.h>
@@ -39,6 +28,9 @@
 #include "health-sessiond.h"
 #include "thread.h"
 
+#include "kernel.h"
+#include <common/kernel-ctl/kernel-ctl.h>
+
 #include <urcu.h>
 #include <urcu/list.h>
 #include <urcu/rculfhash.h>
@@ -80,6 +72,7 @@ void notification_thread_handle_destroy(
                        PERROR("close kernel consumer channel monitoring pipe");
                }
        }
+
 end:
        free(handle);
 }
@@ -145,6 +138,7 @@ struct notification_thread_handle *notification_thread_handle_create(
        } else {
                handle->channel_monitoring_pipes.kernel_consumer = -1;
        }
+
 end:
        return handle;
 error:
@@ -172,7 +166,7 @@ char *get_notification_channel_sock_path(void)
                        goto error;
                }
        } else {
-               char *home_path = utils_get_home_dir();
+               const char *home_path = utils_get_home_dir();
 
                if (!home_path) {
                        ERR("Can't get HOME directory for socket creation");
@@ -239,8 +233,16 @@ int notification_channel_socket_create(void)
        }
 
        if (getuid() == 0) {
-               ret = chown(sock_path, 0,
-                               utils_get_group_id(config.tracing_group_name.value));
+               gid_t gid;
+
+               ret =  utils_get_group_id(config.tracing_group_name.value, true,
+                               &gid);
+               if (ret) {
+                       /* Default to root group. */
+                       gid = 0;
+               }
+
+               ret = chown(sock_path, 0, gid);
                if (ret) {
                        ERR("Failed to set the notification channel socket's group");
                        ret = -1;
@@ -334,6 +336,10 @@ void fini_thread_state(struct notification_thread_state *state)
                ret = cds_lfht_destroy(state->client_socket_ht, NULL);
                assert(!ret);
        }
+       if (state->client_id_ht) {
+               ret = cds_lfht_destroy(state->client_id_ht, NULL);
+               assert(!ret);
+       }
        if (state->triggers_ht) {
                ret = handle_notification_thread_trigger_unregister_all(state);
                assert(!ret);
@@ -361,6 +367,14 @@ void fini_thread_state(struct notification_thread_state *state)
                ret = cds_lfht_destroy(state->sessions_ht, NULL);
                assert(!ret);
        }
+       if (state->triggers_by_name_uid_ht) {
+               ret = cds_lfht_destroy(state->triggers_by_name_uid_ht, NULL);
+               assert(!ret);
+       }
+       if (state->trigger_tokens_ht) {
+               ret = cds_lfht_destroy(state->trigger_tokens_ht, NULL);
+               assert(!ret);
+       }
        /*
         * Must be destroyed after all channels have been destroyed.
         * See comment in struct lttng_session_trigger_list.
@@ -373,6 +387,12 @@ void fini_thread_state(struct notification_thread_state *state)
                notification_channel_socket_destroy(
                                state->notification_channel_socket);
        }
+
+       assert(cds_list_empty(&state->tracer_event_sources_list));
+
+       if (state->executor) {
+               action_executor_destroy(state->executor);
+       }
        lttng_poll_clean(&state->events);
 }
 
@@ -399,6 +419,7 @@ int init_thread_state(struct notification_thread_handle *handle,
 
        memset(state, 0, sizeof(*state));
        state->notification_channel_socket = -1;
+       state->trigger_id.next_tracer_token = 1;
        lttng_poll_init(&state->events);
 
        ret = notification_channel_socket_create();
@@ -426,6 +447,12 @@ int init_thread_state(struct notification_thread_handle *handle,
                goto error;
        }
 
+       state->client_id_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
+                       CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->client_id_ht) {
+               goto error;
+       }
+
        state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
                        CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
        if (!state->channel_triggers_ht) {
@@ -465,6 +492,24 @@ int init_thread_state(struct notification_thread_handle *handle,
        if (!state->triggers_ht) {
                goto error;
        }
+       state->triggers_by_name_uid_ht = cds_lfht_new(DEFAULT_HT_SIZE,
+                       1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->triggers_by_name_uid_ht) {
+               goto error;
+       }
+
+       state->trigger_tokens_ht = cds_lfht_new(DEFAULT_HT_SIZE,
+                       1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!state->trigger_tokens_ht) {
+               goto error;
+       }
+
+       CDS_INIT_LIST_HEAD(&state->tracer_event_sources_list);
+
+       state->executor = action_executor_create(handle);
+       if (!state->executor) {
+               goto error;
+       }
        mark_thread_as_ready(handle);
 end:
        return 0;
@@ -509,6 +554,59 @@ end:
        return ret;
 }
 
+static int handle_event_notification_pipe(int event_source_fd,
+               enum lttng_domain_type domain,
+               uint32_t revents,
+               struct notification_thread_state *state)
+{
+       int ret = 0;
+
+       if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+               ret = handle_notification_thread_remove_tracer_event_source_no_result(
+                               state, event_source_fd);
+               if (ret) {
+                       ERR("[notification-thread] Failed to remove event notification pipe from poll set: fd = %d",
+                                       event_source_fd);
+               }
+               goto end;
+       }
+
+       ret = handle_notification_thread_event_notification(
+                       state, event_source_fd, domain);
+       if (ret) {
+               ERR("[notification-thread] Event notification handling error occurred for fd: %d",
+                               event_source_fd);
+               ret = -1;
+               goto end;
+       }
+end:
+       return ret;
+}
+
+/*
+ * Return the event source domain type via parameter.
+ */
+static bool fd_is_event_notification_source(const struct notification_thread_state *state,
+               int fd,
+               enum lttng_domain_type *domain)
+{
+       struct notification_event_tracer_event_source_element *source_element;
+
+       assert(domain);
+
+       cds_list_for_each_entry(source_element,
+                       &state->tracer_event_sources_list, node) {
+               if (source_element->fd != fd) {
+                       continue;
+               }
+
+               *domain = source_element->domain;
+               return true;
+       }
+
+       return false;
+}
+
 /*
  * This thread services notification channel clients and commands received
  * from various lttng-sessiond components over a command queue.
@@ -519,18 +617,19 @@ void *thread_notification(void *data)
        int ret;
        struct notification_thread_handle *handle = data;
        struct notification_thread_state state;
+       enum lttng_domain_type domain;
 
        DBG("[notification-thread] Started notification thread");
 
+       health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
+       rcu_register_thread();
+       rcu_thread_online();
+
        if (!handle) {
                ERR("[notification-thread] Invalid thread context provided");
                goto end;
        }
 
-       rcu_register_thread();
-       rcu_thread_online();
-
-       health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
        health_code_update();
 
        ret = init_thread_state(handle, &state);
@@ -562,9 +661,6 @@ void *thread_notification(void *data)
                        int fd = LTTNG_POLL_GETFD(&state.events, i);
                        uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);
 
-                       if (!revents) {
-                               continue;
-                       }
                        DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents);
 
                        if (fd == state.notification_channel_socket) {
@@ -599,6 +695,11 @@ void *thread_notification(void *data)
                                if (ret) {
                                        goto error;
                                }
+                       } else if (fd_is_event_notification_source(&state, fd, &domain)) {
+                               ret = handle_event_notification_pipe(fd, domain, revents, &state);
+                               if (ret) {
+                                       goto error;
+                               }
                        } else {
                                /* Activity on a client's socket. */
                                if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
@@ -637,10 +738,10 @@ void *thread_notification(void *data)
 exit:
 error:
        fini_thread_state(&state);
-       health_unregister(health_sessiond);
+end:
        rcu_thread_offline();
        rcu_unregister_thread();
-end:
+       health_unregister(health_sessiond);
        return NULL;
 }
 
@@ -653,7 +754,8 @@ bool shutdown_notification_thread(void *thread_data)
        return true;
 }
 
-bool launch_notification_thread(struct notification_thread_handle *handle)
+struct lttng_thread *launch_notification_thread(
+               struct notification_thread_handle *handle)
 {
        struct lttng_thread *thread;
 
@@ -672,8 +774,7 @@ bool launch_notification_thread(struct notification_thread_handle *handle)
         * (e.g. rotation thread).
         */
        wait_until_thread_is_ready(handle);
-       lttng_thread_put(thread);
-       return true;
+       return thread;
 error:
-       return false;
+       return NULL;
 }
This page took 0.027054 seconds and 4 git commands to generate.