2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
6 * SPDX-License-Identifier: GPL-2.0-only
13 #include <common/futex.h>
14 #include <common/macros.h>
15 #include <common/utils.h>
19 #include "lttng-sessiond.h"
20 #include "testpoint.h"
21 #include "health-sessiond.h"
28 struct lttng_pipe
*quit_pipe
;
29 struct ust_cmd_queue
*ust_cmd_queue
;
32 int application_socket
;
36 * Creates the application socket.
38 static int create_application_socket(void)
42 const mode_t old_umask
= umask(0);
44 /* Create the application unix socket */
45 apps_sock
= lttcomm_create_unix_sock(config
.apps_unix_sock_path
.value
);
47 ERR("Create unix sock failed: %s", config
.apps_unix_sock_path
.value
);
52 /* Set the cloexec flag */
53 ret
= utils_set_fd_cloexec(apps_sock
);
55 ERR("Unable to set CLOEXEC flag to the app Unix socket (fd: %d). "
56 "Continuing but note that the consumer daemon will have a "
57 "reference to this socket on exec()", apps_sock
);
60 /* File permission MUST be 666 */
61 ret
= chmod(config
.apps_unix_sock_path
.value
,
62 S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
| S_IROTH
| S_IWOTH
);
64 PERROR("Set file permissions failed on %s",
65 config
.apps_unix_sock_path
.value
);
66 goto error_close_socket
;
69 DBG3("Session daemon application socket created (fd = %d) ", apps_sock
);
75 if (close(apps_sock
)) {
76 PERROR("Failed to close application socket in error path");
84 * Notify UST applications using the shm mmap futex.
86 static int notify_ust_apps(int active
, bool is_root
)
90 DBG("Notifying applications of session daemon state: %d", active
);
92 /* See shm.c for this call implying mmap, shm and futex calls */
93 wait_shm_mmap
= shm_ust_get_mmap(config
.wait_shm_path
.value
, is_root
);
94 if (wait_shm_mmap
== NULL
) {
98 /* Wake waiting process */
99 futex_wait_update((int32_t *) wait_shm_mmap
, active
);
101 /* Apps notified successfully */
108 static void cleanup_application_registration_thread(void *data
)
110 struct thread_state
*thread_state
= data
;
116 lttng_pipe_destroy(thread_state
->quit_pipe
);
120 static void set_thread_status(struct thread_state
*thread_state
, bool running
)
122 DBG("Marking application registration thread's state as %s", running
? "running" : "error");
123 thread_state
->running
= running
;
124 sem_post(&thread_state
->ready
);
127 static bool wait_thread_status(struct thread_state
*thread_state
)
129 DBG("Waiting for application registration thread to be ready");
130 sem_wait(&thread_state
->ready
);
131 if (thread_state
->running
) {
132 DBG("Application registration thread is ready");
134 ERR("Initialization of application registration thread failed");
137 return thread_state
->running
;
140 static void thread_init_cleanup(void *data
)
142 struct thread_state
*thread_state
= data
;
144 set_thread_status(thread_state
, false);
148 * This thread manage application registration.
150 static void *thread_application_registration(void *data
)
152 int sock
= -1, i
, ret
, pollfd
, err
= -1;
153 uint32_t revents
, nb_fd
;
154 struct lttng_poll_event events
;
156 * Gets allocated in this thread, enqueued to a global queue, dequeued
157 * and freed in the manage apps thread.
159 struct ust_command
*ust_cmd
= NULL
;
160 const bool is_root
= (getuid() == 0);
161 struct thread_state
*thread_state
= data
;
162 const int application_socket
= thread_state
->application_socket
;
163 const int quit_pipe_read_fd
= lttng_pipe_get_readfd(
164 thread_state
->quit_pipe
);
166 DBG("[thread] Manage application registration started");
168 pthread_cleanup_push(thread_init_cleanup
, thread_state
);
169 health_register(health_sessiond
, HEALTH_SESSIOND_TYPE_APP_REG
);
171 ret
= lttcomm_listen_unix_sock(application_socket
);
177 * Pass 2 as size here for the thread quit pipe and apps_sock. Nothing
178 * more will be added to this poll set.
180 ret
= lttng_poll_create(&events
, 2, LTTNG_CLOEXEC
);
182 goto error_create_poll
;
185 /* Add the application registration socket */
186 ret
= lttng_poll_add(&events
, application_socket
, LPOLLIN
| LPOLLRDHUP
);
191 /* Add the application registration socket */
192 ret
= lttng_poll_add(&events
, quit_pipe_read_fd
, LPOLLIN
| LPOLLRDHUP
);
197 set_thread_status(thread_state
, true);
198 pthread_cleanup_pop(0);
200 if (testpoint(sessiond_thread_registration_apps
)) {
205 DBG("Accepting application registration");
207 /* Inifinite blocking call, waiting for transmission */
210 ret
= lttng_poll_wait(&events
, -1);
214 * Restart interrupted system call.
216 if (errno
== EINTR
) {
224 for (i
= 0; i
< nb_fd
; i
++) {
225 health_code_update();
227 /* Fetch once the poll data */
228 revents
= LTTNG_POLL_GETEV(&events
, i
);
229 pollfd
= LTTNG_POLL_GETFD(&events
, i
);
231 /* Thread quit pipe has been closed. Killing thread. */
232 if (pollfd
== quit_pipe_read_fd
) {
236 /* Event on the registration socket */
237 if (revents
& LPOLLIN
) {
238 sock
= lttcomm_accept_unix_sock(application_socket
);
244 * Set socket timeout for both receiving and ending.
245 * app_socket_timeout is in seconds, whereas
246 * lttcomm_setsockopt_rcv_timeout and
247 * lttcomm_setsockopt_snd_timeout expect msec as
250 if (config
.app_socket_timeout
>= 0) {
251 (void) lttcomm_setsockopt_rcv_timeout(sock
,
252 config
.app_socket_timeout
* 1000);
253 (void) lttcomm_setsockopt_snd_timeout(sock
,
254 config
.app_socket_timeout
* 1000);
258 * Set the CLOEXEC flag. Return code is useless because
259 * either way, the show must go on.
261 (void) utils_set_fd_cloexec(sock
);
263 /* Create UST registration command for enqueuing */
264 ust_cmd
= zmalloc(sizeof(struct ust_command
));
265 if (ust_cmd
== NULL
) {
266 PERROR("ust command zmalloc");
276 * Using message-based transmissions to ensure we don't
277 * have to deal with partially received messages.
279 ret
= lttng_fd_get(LTTNG_FD_APPS
, 1);
281 ERR("Exhausted file descriptors allowed for applications.");
291 health_code_update();
292 ret
= ust_app_recv_registration(sock
, &ust_cmd
->reg_msg
);
295 /* Close socket of the application. */
300 lttng_fd_put(LTTNG_FD_APPS
, 1);
304 health_code_update();
306 ust_cmd
->sock
= sock
;
309 DBG("UST registration received with pid:%d ppid:%d uid:%d"
310 " gid:%d sock:%d name:%s (version %d.%d)",
311 ust_cmd
->reg_msg
.pid
, ust_cmd
->reg_msg
.ppid
,
312 ust_cmd
->reg_msg
.uid
, ust_cmd
->reg_msg
.gid
,
313 ust_cmd
->sock
, ust_cmd
->reg_msg
.name
,
314 ust_cmd
->reg_msg
.major
, ust_cmd
->reg_msg
.minor
);
317 * Lock free enqueue the registration request. The red pill
318 * has been taken! This apps will be part of the *system*.
320 cds_wfcq_enqueue(&thread_state
->ust_cmd_queue
->head
,
321 &thread_state
->ust_cmd_queue
->tail
,
325 * Wake the registration queue futex. Implicit memory
326 * barrier with the exchange in cds_wfcq_enqueue.
328 futex_nto1_wake(&thread_state
->ust_cmd_queue
->futex
);
329 } else if (revents
& (LPOLLERR
| LPOLLHUP
| LPOLLRDHUP
)) {
330 ERR("Register apps socket poll error");
333 ERR("Unexpected poll events %u for sock %d", revents
, pollfd
);
342 /* Notify that the registration thread is gone */
343 notify_ust_apps(0, is_root
);
345 ret
= close(application_socket
);
347 PERROR("Failed to close application registration socket");
352 PERROR("Failed to close application socket");
354 lttng_fd_put(LTTNG_FD_APPS
, 1);
356 unlink(config
.apps_unix_sock_path
.value
);
359 lttng_poll_clean(&events
);
362 DBG("UST Registration thread cleanup complete");
365 ERR("Health error occurred in %s", __func__
);
367 health_unregister(health_sessiond
);
371 static bool shutdown_application_registration_thread(void *data
)
373 struct thread_state
*thread_state
= data
;
374 const int write_fd
= lttng_pipe_get_writefd(thread_state
->quit_pipe
);
376 return notify_thread_pipe(write_fd
) == 1;
379 struct lttng_thread
*launch_application_registration_thread(
380 struct ust_cmd_queue
*cmd_queue
)
383 struct lttng_pipe
*quit_pipe
;
384 struct thread_state
*thread_state
= NULL
;
385 struct lttng_thread
*thread
= NULL
;
386 const bool is_root
= (getuid() == 0);
387 int application_socket
= -1;
389 thread_state
= zmalloc(sizeof(*thread_state
));
393 quit_pipe
= lttng_pipe_open(FD_CLOEXEC
);
397 thread_state
->quit_pipe
= quit_pipe
;
398 thread_state
->ust_cmd_queue
= cmd_queue
;
399 application_socket
= create_application_socket();
400 if (application_socket
< 0) {
403 thread_state
->application_socket
= application_socket
;
404 sem_init(&thread_state
->ready
, 0, 0);
406 thread
= lttng_thread_create("UST application registration",
407 thread_application_registration
,
408 shutdown_application_registration_thread
,
409 cleanup_application_registration_thread
,
415 * The application registration thread now owns the application socket
416 * and the global thread state. The thread state is used to wait for
417 * the thread's status, but its ownership now belongs to the thread.
419 application_socket
= -1;
420 if (!wait_thread_status(thread_state
)) {
425 /* Notify all applications to register. */
426 ret
= notify_ust_apps(1, is_root
);
428 ERR("Failed to notify applications or create the wait shared memory.\n"
429 "Execution continues but there might be problems for already\n"
430 "running applications that wishes to register.");
435 lttng_thread_put(thread
);
436 cleanup_application_registration_thread(thread_state
);
437 if (application_socket
>= 0) {
438 if (close(application_socket
)) {
439 PERROR("Failed to close application registration socket");