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 int connection_reset_protocol_state(struct relay_connection *connection)
  60 {
  61         int ret = 0;
  62
  63         switch (connection->type) {
  64         case RELAY_DATA:
  65                 connection->protocol.data.state_id =
  66                                 DATA_CONNECTION_STATE_RECEIVE_HEADER;
  67                 memset(&connection->protocol.data.state.receive_header,
  68                                 0,
  69                                 sizeof(connection->protocol.data.state.receive_header));
  70                 connection->protocol.data.state.receive_header.left_to_receive =
  71                                 sizeof(struct lttcomm_relayd_data_hdr);
  72                 break;
  73         case RELAY_CONTROL:
  74                 connection->protocol.ctrl.state_id =
  75                                 CTRL_CONNECTION_STATE_RECEIVE_HEADER;
  76                 memset(&connection->protocol.ctrl.state.receive_header,
  77                                 0,
  78                                 sizeof(connection->protocol.ctrl.state.receive_header));
  79                 connection->protocol.data.state.receive_header.left_to_receive =
  80                                 sizeof(struct lttcomm_relayd_hdr);
  81                 ret = lttng_dynamic_buffer_set_size(
  82                                 &connection->protocol.ctrl.reception_buffer,
  83                                 sizeof(struct lttcomm_relayd_hdr));
  84                 if (ret) {
  85                         ERR("Failed to reinitialize control connection reception buffer size to %zu bytes.", sizeof(struct lttcomm_relayd_hdr));
  86                         goto end;
  87                 }
  88                 break;
  89         default:
  90                 goto end;
  91         }
  92         DBG("Reset communication state of relay connection (fd = %i)",
  93                         connection->sock->fd);
  94 end:
  95         return ret;
  96 }
  97
  98 struct relay_connection *connection_create(struct lttcomm_sock *sock,
  99                 enum connection_type type)
 100 {
 101         struct relay_connection *conn;
 102
 103         conn = zmalloc(sizeof(*conn));
 104         if (!conn) {
 105                 PERROR("zmalloc relay connection");
 106                 goto end;
 107         }
 108         urcu_ref_init(&conn->ref);
 109         conn->type = type;
 110         conn->sock = sock;
 111         lttng_ht_node_init_ulong(&conn->sock_n, (unsigned long) conn->sock->fd);
 112         if (conn->type == RELAY_CONTROL) {
 113                 lttng_dynamic_buffer_init(&conn->protocol.ctrl.reception_buffer);
 114         }
 115         connection_reset_protocol_state(conn);
 116 end:
 117         return conn;
 118 }
 119
 120 static void rcu_free_connection(struct rcu_head *head)
 121 {
 122         struct relay_connection *conn =
 123                 caa_container_of(head, struct relay_connection, rcu_node);
 124
 125         lttcomm_destroy_sock(conn->sock);
 126         if (conn->viewer_session) {
 127                 viewer_session_destroy(conn->viewer_session);
 128                 conn->viewer_session = NULL;
 129         }
 130         if (conn->type == RELAY_CONTROL) {
 131                 lttng_dynamic_buffer_reset(
 132                                 &conn->protocol.ctrl.reception_buffer);
 133         }
 134         free(conn);
 135 }
 136
 137 static void destroy_connection(struct relay_connection *conn)
 138 {
 139         call_rcu(&conn->rcu_node, rcu_free_connection);
 140 }
 141
 142 static void connection_release(struct urcu_ref *ref)
 143 {
 144         struct relay_connection *conn =
 145                 caa_container_of(ref, struct relay_connection, ref);
 146
 147         if (conn->in_socket_ht) {
 148                 struct lttng_ht_iter iter;
 149                 int ret;
 150
 151                 iter.iter.node = &conn->sock_n.node;
 152                 ret = lttng_ht_del(conn->socket_ht, &iter);
 153                 assert(!ret);
 154         }
 155
 156         if (conn->session) {
 157                 if (session_close(conn->session)) {
 158                         ERR("session_close");
 159                 }
 160                 conn->session = NULL;
 161         }
 162         if (conn->viewer_session) {
 163                 viewer_session_close(conn->viewer_session);
 164         }
 165         destroy_connection(conn);
 166 }
 167
 168 void connection_put(struct relay_connection *conn)
 169 {
 170         rcu_read_lock();
 171         urcu_ref_put(&conn->ref, connection_release);
 172         rcu_read_unlock();
 173 }
 174
 175 void connection_ht_add(struct lttng_ht *relay_connections_ht,
 176                 struct relay_connection *conn)
 177 {
 178         assert(!conn->in_socket_ht);
 179         lttng_ht_add_unique_ulong(relay_connections_ht, &conn->sock_n);
 180         conn->in_socket_ht = 1;
 181         conn->socket_ht = relay_connections_ht;
 182 }
 183
 184 int connection_set_session(struct relay_connection *conn,
 185                 struct relay_session *session)
 186 {
 187         int ret = 0;
 188
 189         assert(conn);
 190         assert(session);
 191         assert(!conn->session);
 192
 193         if (connection_get(conn)) {
 194                 if (session_get(session)) {
 195                         conn->session = session;
 196                 } else {
 197                         ERR("Failed to get session reference in connection_set_session()");
 198                         ret = -1;
 199                 }
 200                 connection_put(conn);
 201         } else {
 202                 ERR("Failed to get connection reference in connection_set_session()");
 203                 ret = -1;
 204         }
 205         return ret;
 206 }