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 _LGPL_SOURCE
  21 #include <common/common.h>
  22 #include <urcu/rculist.h>
  23
  24 #include "connection.h"
  25 #include "stream.h"
  26 #include "viewer-session.h"
  27
  28 bool connection_get(struct relay_connection *conn)
  29 {
  30         bool has_ref = false;
  31
  32         pthread_mutex_lock(&conn->reflock);
  33         if (conn->ref.refcount != 0) {
  34                 has_ref = true;
  35                 urcu_ref_get(&conn->ref);
  36         }
  37         pthread_mutex_unlock(&conn->reflock);
  38
  39         return has_ref;
  40 }
  41
  42 struct relay_connection *connection_get_by_sock(struct lttng_ht *relay_connections_ht,
  43                 int sock)
  44 {
  45         struct lttng_ht_node_ulong *node;
  46         struct lttng_ht_iter iter;
  47         struct relay_connection *conn = NULL;
  48
  49         assert(sock >= 0);
  50
  51         rcu_read_lock();
  52         lttng_ht_lookup(relay_connections_ht, (void *)((unsigned long) sock),
  53                         &iter);
  54         node = lttng_ht_iter_get_node_ulong(&iter);
  55         if (!node) {
  56                 DBG2("Relay connection by sock %d not found", sock);
  57                 goto end;
  58         }
  59         conn = caa_container_of(node, struct relay_connection, sock_n);
  60         if (!connection_get(conn)) {
  61                 conn = NULL;
  62         }
  63 end:
  64         rcu_read_unlock();
  65         return conn;
  66 }
  67
  68 struct relay_connection *connection_create(struct lttcomm_sock *sock,
  69                 enum connection_type type)
  70 {
  71         struct relay_connection *conn;
  72
  73         conn = zmalloc(sizeof(*conn));
  74         if (!conn) {
  75                 PERROR("zmalloc relay connection");
  76                 goto end;
  77         }
  78         pthread_mutex_init(&conn->reflock, NULL);
  79         urcu_ref_init(&conn->ref);
  80         conn->type = type;
  81         conn->sock = sock;
  82         lttng_ht_node_init_ulong(&conn->sock_n, (unsigned long) conn->sock->fd);
  83 end:
  84         return conn;
  85 }
  86
  87 static void rcu_free_connection(struct rcu_head *head)
  88 {
  89         struct relay_connection *conn =
  90                 caa_container_of(head, struct relay_connection, rcu_node);
  91
  92         lttcomm_destroy_sock(conn->sock);
  93         if (conn->viewer_session) {
  94                 viewer_session_destroy(conn->viewer_session);
  95                 conn->viewer_session = NULL;
  96         }
  97         free(conn);
  98 }
  99
 100 static void destroy_connection(struct relay_connection *conn)
 101 {
 102         call_rcu(&conn->rcu_node, rcu_free_connection);
 103 }
 104
 105 static void connection_release(struct urcu_ref *ref)
 106 {
 107         struct relay_connection *conn =
 108                 caa_container_of(ref, struct relay_connection, ref);
 109
 110         if (conn->in_socket_ht) {
 111                 struct lttng_ht_iter iter;
 112                 int ret;
 113
 114                 iter.iter.node = &conn->sock_n.node;
 115                 ret = lttng_ht_del(conn->socket_ht, &iter);
 116                 assert(!ret);
 117         }
 118
 119         if (conn->session) {
 120                 if (session_close(conn->session)) {
 121                         ERR("session_close");
 122                 }
 123                 conn->session = NULL;
 124         }
 125         if (conn->viewer_session) {
 126                 viewer_session_close(conn->viewer_session);
 127         }
 128         destroy_connection(conn);
 129 }
 130
 131 void connection_put(struct relay_connection *conn)
 132 {
 133         rcu_read_lock();
 134         pthread_mutex_lock(&conn->reflock);
 135         urcu_ref_put(&conn->ref, connection_release);
 136         pthread_mutex_unlock(&conn->reflock);
 137         rcu_read_unlock();
 138 }
 139
 140 void connection_ht_add(struct lttng_ht *relay_connections_ht,
 141                 struct relay_connection *conn)
 142 {
 143         assert(!conn->in_socket_ht);
 144         lttng_ht_add_unique_ulong(relay_connections_ht, &conn->sock_n);
 145         conn->in_socket_ht = 1;
 146         conn->socket_ht = relay_connections_ht;
 147 }