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4d076222 DG |
1 | /* |
2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License, version 2 only, as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
16 | */ | |
17 | ||
18 | #define _GNU_SOURCE | |
6c1c0768 | 19 | #define _LGPL_SOURCE |
4d076222 DG |
20 | #include <assert.h> |
21 | ||
22 | #include <common/common.h> | |
23 | #include <common/sessiond-comm/sessiond-comm.h> | |
24 | #include <common/uri.h> | |
25 | #include <common/utils.h> | |
26 | ||
f263b7fd JD |
27 | #include <common/compat/endian.h> |
28 | ||
4d076222 | 29 | #include "fd-limit.h" |
022d91ba | 30 | #include "agent-thread.h" |
6a4e4039 | 31 | #include "agent.h" |
4d076222 | 32 | #include "lttng-sessiond.h" |
f20baf8e DG |
33 | #include "session.h" |
34 | #include "utils.h" | |
4d076222 DG |
35 | |
36 | /* | |
37 | * Note that there is not port here. It's set after this URI is parsed so we | |
38 | * can let the user define a custom one. However, localhost is ALWAYS the | |
39 | * default listening address. | |
40 | */ | |
fa91dc52 MD |
41 | static const char *default_reg_uri = |
42 | "tcp://" DEFAULT_NETWORK_VIEWER_BIND_ADDRESS; | |
4d076222 | 43 | |
f20baf8e | 44 | /* |
022d91ba | 45 | * Update agent application using the given socket. This is done just after |
f20baf8e DG |
46 | * registration was successful. |
47 | * | |
48 | * This is a quite heavy call in terms of locking since the session list lock | |
49 | * AND session lock are acquired. | |
50 | */ | |
fefd409b | 51 | static void update_agent_app(struct agent_app *app) |
f20baf8e DG |
52 | { |
53 | struct ltt_session *session, *stmp; | |
54 | struct ltt_session_list *list; | |
55 | ||
56 | list = session_get_list(); | |
57 | assert(list); | |
58 | ||
59 | session_lock_list(); | |
60 | cds_list_for_each_entry_safe(session, stmp, &list->head, list) { | |
61 | session_lock(session); | |
62 | if (session->ust_session) { | |
fefd409b DG |
63 | struct agent *agt; |
64 | ||
4da703ad | 65 | rcu_read_lock(); |
fefd409b DG |
66 | agt = trace_ust_find_agent(session->ust_session, app->domain); |
67 | if (agt) { | |
68 | agent_update(agt, app->sock->fd); | |
69 | } | |
4da703ad | 70 | rcu_read_unlock(); |
f20baf8e DG |
71 | } |
72 | session_unlock(session); | |
73 | } | |
74 | session_unlock_list(); | |
75 | } | |
76 | ||
4d076222 DG |
77 | /* |
78 | * Create and init socket from uri. | |
79 | */ | |
80 | static struct lttcomm_sock *init_tcp_socket(void) | |
81 | { | |
82 | int ret; | |
83 | struct lttng_uri *uri = NULL; | |
84 | struct lttcomm_sock *sock = NULL; | |
85 | ||
86 | /* | |
87 | * This should never fail since the URI is hardcoded and the port is set | |
88 | * before this thread is launched. | |
89 | */ | |
90 | ret = uri_parse(default_reg_uri, &uri); | |
91 | assert(ret); | |
022d91ba DG |
92 | assert(agent_tcp_port); |
93 | uri->port = agent_tcp_port; | |
4d076222 DG |
94 | |
95 | sock = lttcomm_alloc_sock_from_uri(uri); | |
96 | uri_free(uri); | |
97 | if (sock == NULL) { | |
022d91ba | 98 | ERR("[agent-thread] agent allocating TCP socket"); |
4d076222 DG |
99 | goto error; |
100 | } | |
101 | ||
102 | ret = lttcomm_create_sock(sock); | |
103 | if (ret < 0) { | |
104 | goto error; | |
105 | } | |
106 | ||
107 | ret = sock->ops->bind(sock); | |
108 | if (ret < 0) { | |
022d91ba | 109 | WARN("Another session daemon is using this agent port. Agent support " |
5368d366 | 110 | "will be deactivated to prevent interfering with the tracing."); |
4d076222 DG |
111 | goto error; |
112 | } | |
113 | ||
114 | ret = sock->ops->listen(sock, -1); | |
115 | if (ret < 0) { | |
116 | goto error; | |
117 | } | |
118 | ||
022d91ba DG |
119 | DBG("[agent-thread] Listening on TCP port %u and socket %d", |
120 | agent_tcp_port, sock->fd); | |
4d076222 DG |
121 | |
122 | return sock; | |
123 | ||
124 | error: | |
125 | if (sock) { | |
126 | lttcomm_destroy_sock(sock); | |
127 | } | |
128 | return NULL; | |
129 | } | |
130 | ||
131 | /* | |
132 | * Close and destroy the given TCP socket. | |
133 | */ | |
134 | static void destroy_tcp_socket(struct lttcomm_sock *sock) | |
135 | { | |
136 | assert(sock); | |
137 | ||
022d91ba | 138 | DBG3("[agent-thread] Destroy TCP socket on port %u", agent_tcp_port); |
4d076222 DG |
139 | |
140 | /* This will return gracefully if fd is invalid. */ | |
141 | sock->ops->close(sock); | |
142 | lttcomm_destroy_sock(sock); | |
143 | } | |
144 | ||
f20baf8e | 145 | /* |
022d91ba DG |
146 | * Handle a new agent registration using the reg socket. After that, a new |
147 | * agent application is added to the global hash table and attach to an UST app | |
1b500e7a | 148 | * object. If r_app is not NULL, the created app is set to the pointer. |
f20baf8e DG |
149 | * |
150 | * Return the new FD created upon accept() on success or else a negative errno | |
151 | * value. | |
152 | */ | |
1b500e7a | 153 | static int handle_registration(struct lttcomm_sock *reg_sock, |
022d91ba | 154 | struct agent_app **r_app) |
f20baf8e DG |
155 | { |
156 | int ret; | |
157 | pid_t pid; | |
9474416f | 158 | uint32_t major_version, minor_version; |
f20baf8e | 159 | ssize_t size; |
fefd409b | 160 | enum lttng_domain_type domain; |
022d91ba DG |
161 | struct agent_app *app; |
162 | struct agent_register_msg msg; | |
f20baf8e DG |
163 | struct lttcomm_sock *new_sock; |
164 | ||
165 | assert(reg_sock); | |
166 | ||
167 | new_sock = reg_sock->ops->accept(reg_sock); | |
168 | if (!new_sock) { | |
169 | ret = -ENOTCONN; | |
170 | goto error; | |
171 | } | |
172 | ||
173 | size = new_sock->ops->recvmsg(new_sock, &msg, sizeof(msg), 0); | |
174 | if (size < sizeof(msg)) { | |
79865500 | 175 | ret = -EINVAL; |
f20baf8e DG |
176 | goto error_socket; |
177 | } | |
fefd409b | 178 | domain = be32toh(msg.domain); |
f20baf8e | 179 | pid = be32toh(msg.pid); |
9474416f DG |
180 | major_version = be32toh(msg.major_version); |
181 | minor_version = be32toh(msg.minor_version); | |
182 | ||
183 | /* Test communication protocol version of the registring agent. */ | |
184 | if (major_version != AGENT_MAJOR_VERSION) { | |
185 | ret = -EINVAL; | |
186 | goto error_socket; | |
187 | } | |
188 | if (minor_version != AGENT_MINOR_VERSION) { | |
189 | ret = -EINVAL; | |
190 | goto error_socket; | |
191 | } | |
f20baf8e | 192 | |
fefd409b DG |
193 | DBG2("[agent-thread] New registration for pid %d domain %d on socket %d", |
194 | pid, domain, new_sock->fd); | |
f20baf8e | 195 | |
fefd409b | 196 | app = agent_create_app(pid, domain, new_sock); |
f20baf8e DG |
197 | if (!app) { |
198 | ret = -ENOMEM; | |
199 | goto error_socket; | |
200 | } | |
201 | ||
202 | /* | |
203 | * Add before assigning the socket value to the UST app so it can be found | |
204 | * concurrently. | |
205 | */ | |
022d91ba | 206 | agent_add_app(app); |
f20baf8e DG |
207 | |
208 | /* | |
022d91ba DG |
209 | * We don't need to attach the agent app to the app. If we ever do so, we |
210 | * should consider both registration order of agent before app and app | |
211 | * before agent. | |
f20baf8e | 212 | */ |
f20baf8e | 213 | |
1b500e7a DG |
214 | if (r_app) { |
215 | *r_app = app; | |
216 | } | |
217 | ||
f20baf8e DG |
218 | return new_sock->fd; |
219 | ||
220 | error_socket: | |
221 | new_sock->ops->close(new_sock); | |
222 | lttcomm_destroy_sock(new_sock); | |
223 | error: | |
224 | return ret; | |
225 | } | |
226 | ||
4d076222 DG |
227 | /* |
228 | * This thread manage application notify communication. | |
229 | */ | |
022d91ba | 230 | void *agent_thread_manage_registration(void *data) |
4d076222 DG |
231 | { |
232 | int i, ret, pollfd; | |
233 | uint32_t revents, nb_fd; | |
234 | struct lttng_poll_event events; | |
235 | struct lttcomm_sock *reg_sock; | |
236 | ||
022d91ba | 237 | DBG("[agent-thread] Manage agent application registration."); |
4d076222 DG |
238 | |
239 | rcu_register_thread(); | |
240 | rcu_thread_online(); | |
241 | ||
022d91ba DG |
242 | /* Agent initialization call MUST be called before starting the thread. */ |
243 | assert(agent_apps_ht_by_sock); | |
f20baf8e | 244 | |
4d076222 DG |
245 | /* Create pollset with size 2, quit pipe and socket. */ |
246 | ret = sessiond_set_thread_pollset(&events, 2); | |
247 | if (ret < 0) { | |
248 | goto error_poll_create; | |
249 | } | |
250 | ||
251 | reg_sock = init_tcp_socket(); | |
252 | if (!reg_sock) { | |
253 | goto error_tcp_socket; | |
254 | } | |
255 | ||
256 | /* Add create valid TCP socket to poll set. */ | |
257 | ret = lttng_poll_add(&events, reg_sock->fd, | |
258 | LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
259 | if (ret < 0) { | |
260 | goto error; | |
261 | } | |
262 | ||
263 | while (1) { | |
546f19b5 | 264 | DBG3("[agent-thread] Manage agent polling"); |
4d076222 DG |
265 | |
266 | /* Inifinite blocking call, waiting for transmission */ | |
267 | restart: | |
268 | ret = lttng_poll_wait(&events, -1); | |
7fa2082e MD |
269 | DBG3("[agent-thread] Manage agent return from poll on %d fds", |
270 | LTTNG_POLL_GETNB(&events)); | |
4d076222 DG |
271 | if (ret < 0) { |
272 | /* | |
273 | * Restart interrupted system call. | |
274 | */ | |
275 | if (errno == EINTR) { | |
276 | goto restart; | |
277 | } | |
278 | goto error; | |
279 | } | |
280 | nb_fd = ret; | |
022d91ba | 281 | DBG3("[agent-thread] %d fd ready", nb_fd); |
4d076222 DG |
282 | |
283 | for (i = 0; i < nb_fd; i++) { | |
284 | /* Fetch once the poll data */ | |
285 | revents = LTTNG_POLL_GETEV(&events, i); | |
286 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
287 | ||
fd20dac9 MD |
288 | if (!revents) { |
289 | /* No activity for this FD (poll implementation). */ | |
290 | continue; | |
291 | } | |
292 | ||
4d076222 DG |
293 | /* Thread quit pipe has been closed. Killing thread. */ |
294 | ret = sessiond_check_thread_quit_pipe(pollfd, revents); | |
295 | if (ret) { | |
296 | goto exit; | |
297 | } | |
298 | ||
299 | /* | |
300 | * Check first if this is a POLLERR since POLLIN is also included | |
301 | * in an error value thus checking first. | |
302 | */ | |
303 | if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
304 | /* Removing from the poll set */ | |
305 | ret = lttng_poll_del(&events, pollfd); | |
306 | if (ret < 0) { | |
307 | goto error; | |
308 | } | |
309 | ||
6a4e4039 | 310 | agent_destroy_app_by_sock(pollfd); |
f20baf8e DG |
311 | } else if (revents & (LPOLLIN)) { |
312 | int new_fd; | |
022d91ba | 313 | struct agent_app *app = NULL; |
f20baf8e | 314 | |
022d91ba | 315 | /* Pollin event of agent app socket should NEVER happen. */ |
f20baf8e DG |
316 | assert(pollfd == reg_sock->fd); |
317 | ||
1b500e7a | 318 | new_fd = handle_registration(reg_sock, &app); |
f20baf8e | 319 | if (new_fd < 0) { |
022d91ba | 320 | WARN("[agent-thread] agent registration failed. Ignoring."); |
f20baf8e DG |
321 | /* Somehow the communication failed. Just continue. */ |
322 | continue; | |
323 | } | |
1b500e7a DG |
324 | /* Should not have a NULL app on success. */ |
325 | assert(app); | |
f20baf8e DG |
326 | |
327 | /* Only add poll error event to only detect shutdown. */ | |
328 | ret = lttng_poll_add(&events, new_fd, | |
329 | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
330 | if (ret < 0) { | |
6a4e4039 | 331 | agent_destroy_app_by_sock(new_fd); |
f20baf8e DG |
332 | continue; |
333 | } | |
334 | ||
335 | /* Update newly registered app. */ | |
fefd409b | 336 | update_agent_app(app); |
1b500e7a DG |
337 | |
338 | /* On failure, the poll will detect it and clean it up. */ | |
022d91ba | 339 | (void) agent_send_registration_done(app); |
4d076222 DG |
340 | } else { |
341 | ERR("Unknown poll events %u for sock %d", revents, pollfd); | |
342 | continue; | |
343 | } | |
344 | } | |
345 | } | |
346 | ||
347 | exit: | |
f20baf8e DG |
348 | /* Whatever happens, try to delete it and exit. */ |
349 | (void) lttng_poll_del(&events, reg_sock->fd); | |
4d076222 DG |
350 | error: |
351 | destroy_tcp_socket(reg_sock); | |
352 | error_tcp_socket: | |
353 | lttng_poll_clean(&events); | |
354 | error_poll_create: | |
022d91ba | 355 | DBG("[agent-thread] is cleaning up and stopping."); |
4d076222 DG |
356 | |
357 | rcu_thread_offline(); | |
358 | rcu_unregister_thread(); | |
359 | return NULL; | |
360 | } |