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8abe313a | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
8abe313a | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: GPL-2.0-only |
8abe313a | 5 | * |
8abe313a JG |
6 | */ |
7 | ||
8 | #ifndef NOTIFICATION_THREAD_INTERNAL_H | |
9 | #define NOTIFICATION_THREAD_INTERNAL_H | |
10 | ||
f2b3ef9f JG |
11 | #include <common/compat/socket.h> |
12 | #include <common/credentials.h> | |
13 | #include <lttng/notification/channel-internal.h> | |
8abe313a | 14 | #include <lttng/ref-internal.h> |
f2b3ef9f | 15 | #include <stdbool.h> |
ae0a823f | 16 | #include <unistd.h> |
f2b3ef9f JG |
17 | #include <urcu/rculfhash.h> |
18 | #include <urcu/ref.h> | |
19 | #include <urcu/call-rcu.h> | |
20 | #include "notification-thread.h" | |
21 | ||
22 | struct lttng_evaluation; | |
23 | struct notification_thread_handle; | |
8abe313a JG |
24 | |
25 | struct channel_key { | |
26 | uint64_t key; | |
27 | enum lttng_domain_type domain; | |
28 | }; | |
29 | ||
30 | struct session_info { | |
31 | struct lttng_ref ref; | |
32 | char *name; | |
33 | uid_t uid; | |
34 | gid_t gid; | |
35 | /* | |
c7283958 | 36 | * Hashtable containing back-refs (weak) to all channels in this session. |
8abe313a JG |
37 | * The hashtable's key is a hash of (struct channel_key) and |
38 | * the value is of type (struct channel_info *). | |
39 | */ | |
40 | struct cds_lfht *channel_infos_ht; | |
ea9a44f0 | 41 | struct lttng_session_trigger_list *trigger_list; |
8abe313a JG |
42 | /* Node in the notification thread state's sessions_ht. */ |
43 | struct cds_lfht_node sessions_ht_node; | |
1eee26c5 JG |
44 | /* |
45 | * Weak reference to the thread state's sessions_ht. Used for removal on | |
46 | * destruction. | |
47 | */ | |
48 | struct cds_lfht *sessions_ht; | |
e8360425 | 49 | uint64_t consumed_data_size; |
51eab943 JG |
50 | struct { |
51 | /* Whether a rotation is ongoing for this session. */ | |
52 | bool ongoing; | |
53 | /* Identifier of the currently ongoing rotation. */ | |
54 | uint64_t id; | |
55 | } rotation; | |
83b934ad MD |
56 | /* call_rcu delayed reclaim. */ |
57 | struct rcu_head rcu_node; | |
8abe313a JG |
58 | }; |
59 | ||
60 | struct channel_info { | |
61 | struct channel_key key; | |
62 | char *name; | |
63 | uint64_t capacity; | |
64 | /* | |
65 | * A channel info holds a reference (lttng_ref) on session_info. | |
66 | * session_info, in return, holds a weak reference to the channel. | |
67 | */ | |
68 | struct session_info *session_info; | |
69 | /* Node in the notification thread state's channels_ht. */ | |
70 | struct cds_lfht_node channels_ht_node; | |
71 | /* Node in the session_info's channels_ht. */ | |
72 | struct cds_lfht_node session_info_channels_ht_node; | |
83b934ad MD |
73 | /* call_rcu delayed reclaim. */ |
74 | struct rcu_head rcu_node; | |
8abe313a JG |
75 | }; |
76 | ||
f2b3ef9f JG |
77 | struct notification_client_list_element { |
78 | struct notification_client *client; | |
79 | struct cds_list_head node; | |
80 | }; | |
81 | ||
82 | /* | |
83 | * Thread safety of notification_client and notification_client_list. | |
84 | * | |
85 | * The notification thread (main thread) and the action executor | |
86 | * interact through client lists. Hence, when the action executor | |
87 | * thread looks-up the list of clients subscribed to a given | |
88 | * condition, it will acquire a reference to the list and lock it | |
89 | * while attempting to communicate with the various clients. | |
90 | * | |
91 | * It is not necessary to reference-count clients as they are guaranteed | |
92 | * to be 'alive' if they are present in a list and that list is locked. Indeed, | |
93 | * removing references to the client from those subscription lists is part of | |
94 | * the work performed on destruction of a client. | |
95 | * | |
96 | * No provision for other access scenarios are taken into account; | |
97 | * this is the bare minimum to make these accesses safe and the | |
98 | * notification thread's state is _not_ "thread-safe" in any general | |
99 | * sense. | |
100 | */ | |
101 | struct notification_client_list { | |
102 | pthread_mutex_t lock; | |
103 | struct urcu_ref ref; | |
104 | const struct lttng_trigger *trigger; | |
105 | struct cds_list_head list; | |
106 | /* Weak reference to container. */ | |
107 | struct cds_lfht *notification_trigger_clients_ht; | |
108 | struct cds_lfht_node notification_trigger_clients_ht_node; | |
109 | /* call_rcu delayed reclaim. */ | |
110 | struct rcu_head rcu_node; | |
111 | }; | |
112 | ||
113 | struct notification_client { | |
6c24d3fd JG |
114 | /* |
115 | * Nests within the notification_client_list lock. | |
116 | * | |
117 | * Protects the outbound communication and the active flag which | |
118 | * is used by both the notification and action executor threads. | |
119 | * | |
120 | * The remaining fields of the object can be used without any | |
121 | * synchronization as they are either immutable (id, creds, version) or | |
122 | * only accessed by the notification thread. | |
123 | */ | |
f2b3ef9f JG |
124 | pthread_mutex_t lock; |
125 | notification_client_id id; | |
126 | int socket; | |
127 | /* Client protocol version. */ | |
128 | uint8_t major, minor; | |
129 | uid_t uid; | |
130 | gid_t gid; | |
131 | /* | |
132 | * Indicates if the credentials and versions of the client have been | |
133 | * checked. | |
134 | */ | |
135 | bool validated; | |
136 | /* | |
137 | * Conditions to which the client's notification channel is subscribed. | |
138 | * List of struct lttng_condition_list_node. The condition member is | |
139 | * owned by the client. | |
140 | */ | |
141 | struct cds_list_head condition_list; | |
142 | struct cds_lfht_node client_socket_ht_node; | |
143 | struct cds_lfht_node client_id_ht_node; | |
144 | struct { | |
145 | /* | |
146 | * If a client's communication is inactive, it means that a | |
147 | * fatal error has occurred (could be either a protocol error or | |
148 | * the socket API returned a fatal error). No further | |
149 | * communication should be attempted; the client is queued for | |
150 | * clean-up. | |
151 | */ | |
152 | bool active; | |
153 | struct { | |
154 | /* | |
155 | * During the reception of a message, the reception | |
156 | * buffers' "size" is set to contain the current | |
157 | * message's complete payload. | |
158 | */ | |
159 | struct lttng_dynamic_buffer buffer; | |
160 | /* Bytes left to receive for the current message. */ | |
161 | size_t bytes_to_receive; | |
162 | /* Type of the message being received. */ | |
163 | enum lttng_notification_channel_message_type msg_type; | |
164 | /* | |
165 | * Indicates whether or not credentials are expected | |
166 | * from the client. | |
167 | */ | |
168 | bool expect_creds; | |
169 | /* | |
170 | * Indicates whether or not credentials were received | |
171 | * from the client. | |
172 | */ | |
173 | bool creds_received; | |
174 | /* Only used during credentials reception. */ | |
175 | lttng_sock_cred creds; | |
176 | } inbound; | |
177 | struct { | |
178 | /* | |
179 | * Indicates whether or not a notification addressed to | |
180 | * this client was dropped because a command reply was | |
181 | * already buffered. | |
182 | * | |
183 | * A notification is dropped whenever the buffer is not | |
184 | * empty. | |
185 | */ | |
186 | bool dropped_notification; | |
187 | /* | |
188 | * Indicates whether or not a command reply is already | |
189 | * buffered. In this case, it means that the client is | |
190 | * not consuming command replies before emitting a new | |
191 | * one. This could be caused by a protocol error or a | |
192 | * misbehaving/malicious client. | |
193 | */ | |
194 | bool queued_command_reply; | |
195 | struct lttng_dynamic_buffer buffer; | |
196 | } outbound; | |
197 | } communication; | |
198 | /* call_rcu delayed reclaim. */ | |
199 | struct rcu_head rcu_node; | |
200 | }; | |
201 | ||
dd877ea6 JG |
202 | enum client_transmission_status { |
203 | CLIENT_TRANSMISSION_STATUS_COMPLETE, | |
204 | CLIENT_TRANSMISSION_STATUS_QUEUED, | |
205 | /* Communication failure. */ | |
206 | CLIENT_TRANSMISSION_STATUS_FAIL, | |
207 | /* Fatal error. */ | |
208 | CLIENT_TRANSMISSION_STATUS_ERROR, | |
209 | }; | |
f2b3ef9f JG |
210 | |
211 | LTTNG_HIDDEN | |
212 | bool notification_client_list_get(struct notification_client_list *list); | |
213 | ||
214 | LTTNG_HIDDEN | |
215 | void notification_client_list_put(struct notification_client_list *list); | |
216 | ||
6c24d3fd | 217 | /* Only returns a non-zero value if a fatal error occurred. */ |
f2b3ef9f JG |
218 | typedef int (*report_client_transmission_result_cb)( |
219 | struct notification_client *client, | |
220 | enum client_transmission_status status, | |
221 | void *user_data); | |
222 | ||
223 | LTTNG_HIDDEN | |
224 | int notification_client_list_send_evaluation( | |
225 | struct notification_client_list *list, | |
226 | const struct lttng_condition *condition, | |
227 | const struct lttng_evaluation *evaluation, | |
228 | const struct lttng_credentials *trigger_creds, | |
229 | const struct lttng_credentials *source_object_creds, | |
230 | report_client_transmission_result_cb client_report, | |
231 | void *user_data); | |
232 | ||
233 | LTTNG_HIDDEN | |
234 | int notification_thread_client_communication_update( | |
235 | struct notification_thread_handle *handle, | |
236 | notification_client_id id, | |
237 | enum client_transmission_status transmission_status); | |
238 | ||
8abe313a | 239 | #endif /* NOTIFICATION_THREAD_INTERNAL_H */ |