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  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   7  * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-only
  10  *
  11  */
  12
  13 #include <limits.h>
  14 #include <inttypes.h>
  15 #include <pthread.h>
  16 #include <urcu.h>
  17 #include <urcu/wfcqueue.h>
  18 #include <urcu/list.h>
  19
  20 #include <common/hashtable/hashtable.h>
  21 #include <common/sessiond-comm/sessiond-comm.h>
  22 #include <common/sessiond-comm/relayd.h>
  23 #include <common/dynamic-buffer.h>
  24
  25 #include "session.h"
  26
  27 enum connection_type {
  28         RELAY_CONNECTION_UNKNOWN    = 0,
  29         RELAY_DATA                  = 1,
  30         RELAY_CONTROL               = 2,
  31         RELAY_VIEWER_COMMAND        = 3,
  32         RELAY_VIEWER_NOTIFICATION   = 4,
  33 };
  34
  35 enum data_connection_state {
  36         DATA_CONNECTION_STATE_RECEIVE_HEADER = 0,
  37         DATA_CONNECTION_STATE_RECEIVE_PAYLOAD = 1,
  38 };
  39
  40 enum ctrl_connection_state {
  41         CTRL_CONNECTION_STATE_RECEIVE_HEADER = 0,
  42         CTRL_CONNECTION_STATE_RECEIVE_PAYLOAD = 1,
  43 };
  44
  45 struct data_connection_state_receive_header {
  46         uint64_t received, left_to_receive;
  47         char header_reception_buffer[sizeof(struct lttcomm_relayd_data_hdr)];
  48 };
  49
  50 struct data_connection_state_receive_payload {
  51         uint64_t received, left_to_receive;
  52         struct lttcomm_relayd_data_hdr header;
  53         bool rotate_index;
  54 };
  55
  56 struct ctrl_connection_state_receive_header {
  57         uint64_t received, left_to_receive;
  58 };
  59
  60 struct ctrl_connection_state_receive_payload {
  61         uint64_t received, left_to_receive;
  62         struct lttcomm_relayd_hdr header;
  63 };
  64
  65 /*
  66  * Internal structure to map a socket with the corresponding session.
  67  * A hashtable indexed on the socket FD is used for the lookups.
  68  *
  69  * Connections are assumed to be accessed from a single thread. Live
  70  * connections between the relay and a live client are only accessed
  71  * from the live worker thread.
  72  *
  73  * The connections between the consumerd/sessiond and the relayd are only
  74  * handled by the "main" worker thread (as in, the worker thread in main.c).
  75  *
  76  * This is why there are no back references to connections from the
  77  * sessions and session list.
  78  */
  79 struct relay_connection {
  80         struct lttcomm_sock *sock;
  81         struct cds_wfcq_node qnode;
  82
  83         enum connection_type type;
  84         /*
  85          * session is only ever set for RELAY_CONTROL connection type.
  86          */
  87         struct relay_session *session;
  88         /*
  89          * viewer_session is only ever set for RELAY_VIEWER_COMMAND
  90          * connection type.
  91          */
  92         struct relay_viewer_session *viewer_session;
  93
  94         /*
  95          * Protocol version to use for this connection. Only valid for
  96          * RELAY_CONTROL connection type.
  97          */
  98         uint32_t major;
  99         uint32_t minor;
 100
 101         struct urcu_ref ref;
 102
 103         bool version_check_done;
 104
 105         /*
 106          * Node member of connection within global socket hash table.
 107          */
 108         struct lttng_ht_node_ulong sock_n;
 109         bool in_socket_ht;
 110         struct lttng_ht *socket_ht;     /* HACK: Contained within this hash table. */
 111         struct rcu_head rcu_node;       /* For call_rcu teardown. */
 112
 113         union {
 114                 struct {
 115                         enum data_connection_state state_id;
 116                         union {
 117                                 struct data_connection_state_receive_header receive_header;
 118                                 struct data_connection_state_receive_payload receive_payload;
 119                         } state;
 120                 } data;
 121                 struct {
 122                         enum ctrl_connection_state state_id;
 123                         union {
 124                                 struct ctrl_connection_state_receive_header receive_header;
 125                                 struct ctrl_connection_state_receive_payload receive_payload;
 126                         } state;
 127                         struct lttng_dynamic_buffer reception_buffer;
 128                 } ctrl;
 129         } protocol;
 130 };
 131
 132 struct relay_connection *connection_create(struct lttcomm_sock *sock,
 133                 enum connection_type type);
 134 struct relay_connection *connection_get_by_sock(struct lttng_ht *relay_connections_ht,
 135                 int sock);
 136 int connection_reset_protocol_state(struct relay_connection *connection);
 137 bool connection_get(struct relay_connection *connection);
 138 void connection_put(struct relay_connection *connection);
 139 void connection_ht_add(struct lttng_ht *relay_connections_ht,
 140                 struct relay_connection *conn);
 141 int connection_set_session(struct relay_connection *conn,
 142                 struct relay_session *session);
 143
 144 #endif /* _CONNECTION_H */