src/bin/lttng-relayd/connection.c

   1 /*
   2  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   3  *                      David Goulet <dgoulet@efficios.com>
   4  *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License, version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #define _GNU_SOURCE
  21 #define _LGPL_SOURCE
  22 #include <common/common.h>
  23 #include <urcu/rculist.h>
  24
  25 #include "connection.h"
  26 #include "stream.h"
  27 #include "viewer-session.h"
  28
  29 bool connection_get(struct relay_connection *conn)
  30 {
  31         bool has_ref = false;
  32
  33         pthread_mutex_lock(&conn->reflock);
  34         if (conn->ref.refcount != 0) {
  35                 has_ref = true;
  36                 urcu_ref_get(&conn->ref);
  37         }
  38         pthread_mutex_unlock(&conn->reflock);
  39
  40         return has_ref;
  41 }
  42
  43 struct relay_connection *connection_get_by_sock(struct lttng_ht *relay_connections_ht,
  44                 int sock)
  45 {
  46         struct lttng_ht_node_ulong *node;
  47         struct lttng_ht_iter iter;
  48         struct relay_connection *conn = NULL;
  49
  50         assert(sock >= 0);
  51
  52         rcu_read_lock();
  53         lttng_ht_lookup(relay_connections_ht, (void *)((unsigned long) sock),
  54                         &iter);
  55         node = lttng_ht_iter_get_node_ulong(&iter);
  56         if (!node) {
  57                 DBG2("Relay connection by sock %d not found", sock);
  58                 goto end;
  59         }
  60         conn = caa_container_of(node, struct relay_connection, sock_n);
  61         if (!connection_get(conn)) {
  62                 conn = NULL;
  63         }
  64 end:
  65         rcu_read_unlock();
  66         return conn;
  67 }
  68
  69 struct relay_connection *connection_create(struct lttcomm_sock *sock,
  70                 enum connection_type type)
  71 {
  72         struct relay_connection *conn;
  73
  74         conn = zmalloc(sizeof(*conn));
  75         if (!conn) {
  76                 PERROR("zmalloc relay connection");
  77                 goto end;
  78         }
  79         pthread_mutex_init(&conn->reflock, NULL);
  80         urcu_ref_init(&conn->ref);
  81         conn->type = type;
  82         conn->sock = sock;
  83         lttng_ht_node_init_ulong(&conn->sock_n, (unsigned long) conn->sock->fd);
  84 end:
  85         return conn;
  86 }
  87
  88 static void rcu_free_connection(struct rcu_head *head)
  89 {
  90         struct relay_connection *conn =
  91                 caa_container_of(head, struct relay_connection, rcu_node);
  92
  93         lttcomm_destroy_sock(conn->sock);
  94         if (conn->viewer_session) {
  95                 viewer_session_destroy(conn->viewer_session);
  96                 conn->viewer_session = NULL;
  97         }
  98         free(conn);
  99 }
 100
 101 static void destroy_connection(struct relay_connection *conn)
 102 {
 103         call_rcu(&conn->rcu_node, rcu_free_connection);
 104 }
 105
 106 static void connection_release(struct urcu_ref *ref)
 107 {
 108         struct relay_connection *conn =
 109                 caa_container_of(ref, struct relay_connection, ref);
 110
 111         if (conn->in_socket_ht) {
 112                 struct lttng_ht_iter iter;
 113                 int ret;
 114
 115                 iter.iter.node = &conn->sock_n.node;
 116                 ret = lttng_ht_del(conn->socket_ht, &iter);
 117                 assert(!ret);
 118         }
 119
 120         if (conn->session) {
 121                 if (session_close(conn->session)) {
 122                         ERR("session_close");
 123                 }
 124                 conn->session = NULL;
 125         }
 126         if (conn->viewer_session) {
 127                 viewer_session_close(conn->viewer_session);
 128         }
 129         destroy_connection(conn);
 130 }
 131
 132 void connection_put(struct relay_connection *conn)
 133 {
 134         rcu_read_lock();
 135         pthread_mutex_lock(&conn->reflock);
 136         urcu_ref_put(&conn->ref, connection_release);
 137         pthread_mutex_unlock(&conn->reflock);
 138         rcu_read_unlock();
 139 }
 140
 141 void connection_ht_add(struct lttng_ht *relay_connections_ht,
 142                 struct relay_connection *conn)
 143 {
 144         assert(!conn->in_socket_ht);
 145         lttng_ht_add_unique_ulong(relay_connections_ht, &conn->sock_n);
 146         conn->in_socket_ht = 1;
 147         conn->socket_ht = relay_connections_ht;
 148 }