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