src/bin/lttng-relayd/connection.h

   1 #ifndef _CONNECTION_H
   2 #define _CONNECTION_H
   3
   4 /*
   5  * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
   6  *                      David Goulet <dgoulet@efficios.com>
   7  *               2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License, version 2 only, as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along with
  19  * this program; if not, write to the Free Software Foundation, Inc., 51
  20  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #include <limits.h>
  24 #include <inttypes.h>
  25 #include <pthread.h>
  26 #include <urcu.h>
  27 #include <urcu/wfcqueue.h>
  28 #include <urcu/list.h>
  29
  30 #include <common/hashtable/hashtable.h>
  31 #include <common/sessiond-comm/sessiond-comm.h>
  32 #include <common/sessiond-comm/relayd.h>
  33 #include <common/dynamic-buffer.h>
  34
  35 #include "session.h"
  36
  37 enum connection_type {
  38         RELAY_CONNECTION_UNKNOWN    = 0,
  39         RELAY_DATA                  = 1,
  40         RELAY_CONTROL               = 2,
  41         RELAY_VIEWER_COMMAND        = 3,
  42         RELAY_VIEWER_NOTIFICATION   = 4,
  43 };
  44
  45 enum data_connection_state {
  46         DATA_CONNECTION_STATE_RECEIVE_HEADER = 0,
  47         DATA_CONNECTION_STATE_RECEIVE_PAYLOAD = 1,
  48 };
  49
  50 enum ctrl_connection_state {
  51         CTRL_CONNECTION_STATE_RECEIVE_HEADER = 0,
  52         CTRL_CONNECTION_STATE_RECEIVE_PAYLOAD = 1,
  53 };
  54
  55 struct data_connection_state_receive_header {
  56         uint64_t received, left_to_receive;
  57         char header_reception_buffer[sizeof(struct lttcomm_relayd_data_hdr)];
  58 };
  59
  60 struct data_connection_state_receive_payload {
  61         uint64_t received, left_to_receive;
  62         struct lttcomm_relayd_data_hdr header;
  63         bool rotate_index;
  64 };
  65
  66 struct ctrl_connection_state_receive_header {
  67         uint64_t received, left_to_receive;
  68 };
  69
  70 struct ctrl_connection_state_receive_payload {
  71         uint64_t received, left_to_receive;
  72         struct lttcomm_relayd_hdr header;
  73 };
  74
  75 /*
  76  * Internal structure to map a socket with the corresponding session.
  77  * A hashtable indexed on the socket FD is used for the lookups.
  78  *
  79  * Connections are assumed to be accessed from a single thread. Live
  80  * connections between the relay and a live client are only accessed
  81  * from the live worker thread.
  82  *
  83  * The connections between the consumerd/sessiond and the relayd are only
  84  * handled by the "main" worker thread (as in, the worker thread in main.c).
  85  *
  86  * This is why there are no back references to connections from the
  87  * sessions and session list.
  88  */
  89 struct relay_connection {
  90         struct lttcomm_sock *sock;
  91         struct cds_wfcq_node qnode;
  92
  93         enum connection_type type;
  94         /*
  95          * session is only ever set for RELAY_CONTROL connection type.
  96          */
  97         struct relay_session *session;
  98         /*
  99          * viewer_session is only ever set for RELAY_VIEWER_COMMAND
 100          * connection type.
 101          */
 102         struct relay_viewer_session *viewer_session;
 103
 104         /*
 105          * Protocol version to use for this connection. Only valid for
 106          * RELAY_CONTROL connection type.
 107          */
 108         uint32_t major;
 109         uint32_t minor;
 110
 111         struct urcu_ref ref;
 112
 113         bool version_check_done;
 114
 115         /*
 116          * Node member of connection within global socket hash table.
 117          */
 118         struct lttng_ht_node_ulong sock_n;
 119         bool in_socket_ht;
 120         struct lttng_ht *socket_ht;     /* HACK: Contained within this hash table. */
 121         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 122
 123         union {
 124                 struct {
 125                         enum data_connection_state state_id;
 126                         union {
 127                                 struct data_connection_state_receive_header receive_header;
 128                                 struct data_connection_state_receive_payload receive_payload;
 129                         } state;
 130                 } data;
 131                 struct {
 132                         enum ctrl_connection_state state_id;
 133                         union {
 134                                 struct ctrl_connection_state_receive_header receive_header;
 135                                 struct ctrl_connection_state_receive_payload receive_payload;
 136                         } state;
 137                         struct lttng_dynamic_buffer reception_buffer;
 138                 } ctrl;
 139         } protocol;
 140 };
 141
 142 struct relay_connection *connection_create(struct lttcomm_sock *sock,
 143                 enum connection_type type);
 144 struct relay_connection *connection_get_by_sock(struct lttng_ht *relay_connections_ht,
 145                 int sock);
 146 int connection_reset_protocol_state(struct relay_connection *connection);
 147 bool connection_get(struct relay_connection *connection);
 148 void connection_put(struct relay_connection *connection);
 149 void connection_ht_add(struct lttng_ht *relay_connections_ht,
 150                 struct relay_connection *conn);
 151 int connection_set_session(struct relay_connection *conn,
 152                 struct relay_session *session);
 153
 154 #endif /* _CONNECTION_H */