Commit | Line | Data |
---|---|---|
f2c1f0d4 MD |
1 | /* |
2 | * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
3 | * Copyright (C) 2019 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * | |
5 | * This library is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU Lesser General Public License, version 2.1 only, | |
7 | * as published by the Free Software Foundation. | |
8 | * | |
9 | * This library is distributed in the hope that it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License | |
12 | * for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU Lesser General Public License | |
15 | * along with this library; if not, write to the Free Software Foundation, | |
16 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
17 | */ | |
18 | ||
19 | #define _LGPL_SOURCE | |
20 | #include <assert.h> | |
21 | #include <string.h> | |
22 | ||
23 | #include <lttng/lttng-error.h> | |
24 | #include <lttng/clear.h> | |
25 | #include <lttng/clear-handle.h> | |
26 | #include <common/sessiond-comm/sessiond-comm.h> | |
27 | #include <common/macros.h> | |
28 | #include <common/compat/poll.h> | |
29 | #include <common/dynamic-buffer.h> | |
30 | #include <common/buffer-view.h> | |
31 | #include <common/optional.h> | |
32 | ||
33 | #include "lttng-ctl-helper.h" | |
34 | ||
35 | enum communication_state { | |
36 | COMMUNICATION_STATE_RECEIVE_LTTNG_MSG, | |
37 | COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER, | |
38 | COMMUNICATION_STATE_END, | |
39 | COMMUNICATION_STATE_ERROR, | |
40 | }; | |
41 | ||
42 | struct lttng_clear_handle { | |
43 | LTTNG_OPTIONAL(enum lttng_error_code) clear_return_code; | |
44 | struct { | |
45 | int socket; | |
46 | struct lttng_poll_event events; | |
47 | size_t bytes_left_to_receive; | |
48 | enum communication_state state; | |
49 | struct lttng_dynamic_buffer buffer; | |
50 | LTTNG_OPTIONAL(size_t) data_size; | |
51 | } communication; | |
52 | }; | |
53 | ||
54 | void lttng_clear_handle_destroy(struct lttng_clear_handle *handle) | |
55 | { | |
56 | int ret; | |
57 | ||
58 | if (!handle) { | |
59 | return; | |
60 | } | |
61 | ||
62 | if (handle->communication.socket >= 0) { | |
63 | ret = close(handle->communication.socket); | |
64 | if (ret) { | |
65 | PERROR("Failed to close lttng-sessiond command socket"); | |
66 | } | |
67 | } | |
68 | lttng_poll_clean(&handle->communication.events); | |
69 | lttng_dynamic_buffer_reset(&handle->communication.buffer); | |
70 | free(handle); | |
71 | } | |
72 | ||
73 | static | |
74 | struct lttng_clear_handle *lttng_clear_handle_create(int sessiond_socket) | |
75 | { | |
76 | int ret; | |
77 | struct lttng_clear_handle *handle = zmalloc(sizeof(*handle)); | |
78 | ||
79 | if (!handle) { | |
80 | goto end; | |
81 | } | |
82 | lttng_dynamic_buffer_init(&handle->communication.buffer); | |
83 | handle->communication.socket = sessiond_socket; | |
84 | ret = lttng_poll_create(&handle->communication.events, 1, 0); | |
85 | if (ret) { | |
86 | goto error; | |
87 | } | |
88 | ||
89 | ret = lttng_poll_add(&handle->communication.events, sessiond_socket, | |
90 | LPOLLIN | LPOLLHUP | LPOLLRDHUP | LPOLLERR); | |
91 | if (ret) { | |
92 | goto error; | |
93 | } | |
94 | ||
95 | handle->communication.bytes_left_to_receive = | |
96 | sizeof(struct lttcomm_lttng_msg); | |
97 | handle->communication.state = COMMUNICATION_STATE_RECEIVE_LTTNG_MSG; | |
98 | end: | |
99 | return handle; | |
100 | error: | |
101 | lttng_clear_handle_destroy(handle); | |
102 | return NULL; | |
103 | } | |
104 | ||
105 | static | |
106 | int handle_state_transition(struct lttng_clear_handle *handle) | |
107 | { | |
108 | int ret = 0; | |
109 | ||
110 | assert(handle->communication.bytes_left_to_receive == 0); | |
111 | ||
112 | switch (handle->communication.state) { | |
113 | case COMMUNICATION_STATE_RECEIVE_LTTNG_MSG: | |
114 | { | |
115 | const struct lttcomm_lttng_msg *msg = | |
116 | (typeof(msg)) handle->communication.buffer.data; | |
117 | ||
118 | LTTNG_OPTIONAL_SET(&handle->clear_return_code, | |
119 | (enum lttng_error_code) msg->ret_code); | |
120 | if (handle->clear_return_code.value != LTTNG_OK) { | |
121 | handle->communication.state = COMMUNICATION_STATE_END; | |
122 | break; | |
123 | } else if (msg->cmd_header_size != 0 || msg->data_size != 0) { | |
124 | handle->communication.state = COMMUNICATION_STATE_ERROR; | |
125 | ret = -1; | |
126 | break; | |
127 | } | |
128 | ||
129 | handle->communication.state = COMMUNICATION_STATE_END; | |
130 | handle->communication.bytes_left_to_receive = 0; | |
131 | LTTNG_OPTIONAL_SET(&handle->communication.data_size, 0); | |
132 | ret = lttng_dynamic_buffer_set_size( | |
133 | &handle->communication.buffer, 0); | |
134 | assert(!ret); | |
135 | break; | |
136 | } | |
137 | default: | |
138 | abort(); | |
139 | } | |
140 | ||
141 | /* Clear reception buffer on state transition. */ | |
142 | if (lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0)) { | |
143 | abort(); | |
144 | } | |
145 | return ret; | |
146 | } | |
147 | ||
148 | static | |
149 | int handle_incoming_data(struct lttng_clear_handle *handle) | |
150 | { | |
151 | int ret; | |
152 | ssize_t comm_ret; | |
153 | const size_t original_buffer_size = handle->communication.buffer.size; | |
154 | ||
155 | /* Reserve space for reception. */ | |
156 | ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer, | |
157 | original_buffer_size + handle->communication.bytes_left_to_receive); | |
158 | if (ret) { | |
159 | goto end; | |
160 | } | |
161 | ||
162 | comm_ret = lttcomm_recv_unix_sock(handle->communication.socket, | |
163 | handle->communication.buffer.data + original_buffer_size, | |
164 | handle->communication.bytes_left_to_receive); | |
165 | if (comm_ret <= 0) { | |
166 | ret = -1; | |
167 | goto end; | |
168 | } | |
169 | ||
170 | handle->communication.bytes_left_to_receive -= comm_ret; | |
171 | if (handle->communication.bytes_left_to_receive == 0) { | |
172 | ret = handle_state_transition(handle); | |
173 | } else { | |
174 | ret = lttng_dynamic_buffer_set_size( | |
175 | &handle->communication.buffer, | |
176 | original_buffer_size + comm_ret); | |
177 | } | |
178 | end: | |
179 | return ret; | |
180 | } | |
181 | ||
182 | extern enum lttng_clear_handle_status | |
183 | lttng_clear_handle_wait_for_completion( | |
184 | struct lttng_clear_handle *handle, int timeout_ms) | |
185 | { | |
186 | int ret; | |
187 | enum lttng_clear_handle_status status; | |
188 | unsigned long time_left_ms = 0; | |
189 | const bool has_timeout = timeout_ms > 0; | |
190 | struct timespec initial_time; | |
191 | ||
192 | if (handle->communication.state == COMMUNICATION_STATE_ERROR) { | |
193 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; | |
194 | goto end; | |
195 | } else if (handle->communication.state == COMMUNICATION_STATE_END) { | |
196 | status = LTTNG_CLEAR_HANDLE_STATUS_COMPLETED; | |
197 | goto end; | |
198 | } | |
199 | if (has_timeout) { | |
200 | ret = lttng_clock_gettime(CLOCK_MONOTONIC, &initial_time); | |
201 | if (ret) { | |
202 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; | |
203 | goto end; | |
204 | } | |
205 | time_left_ms = (unsigned long) timeout_ms; | |
206 | } | |
207 | ||
208 | while (handle->communication.state != COMMUNICATION_STATE_END && | |
209 | (time_left_ms || !has_timeout)) { | |
210 | int ret; | |
211 | uint32_t revents; | |
212 | struct timespec current_time, diff; | |
213 | unsigned long diff_ms; | |
214 | ||
215 | ret = lttng_poll_wait(&handle->communication.events, | |
216 | has_timeout ? time_left_ms : -1); | |
217 | if (ret == 0) { | |
218 | /* timeout */ | |
219 | break; | |
220 | } else if (ret < 0) { | |
221 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; | |
222 | goto end; | |
223 | } | |
224 | ||
225 | /* The sessiond connection socket is the only monitored fd. */ | |
226 | revents = LTTNG_POLL_GETEV(&handle->communication.events, 0); | |
227 | if (revents & LPOLLIN) { | |
228 | ret = handle_incoming_data(handle); | |
229 | if (ret) { | |
230 | handle->communication.state = | |
231 | COMMUNICATION_STATE_ERROR; | |
232 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; | |
233 | goto end; | |
234 | } | |
235 | } else { | |
236 | handle->communication.state = COMMUNICATION_STATE_ERROR; | |
237 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; | |
238 | goto end; | |
239 | } | |
240 | if (!has_timeout) { | |
241 | continue; | |
242 | } | |
243 | ||
244 | ret = lttng_clock_gettime(CLOCK_MONOTONIC, ¤t_time); | |
245 | if (ret) { | |
246 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; | |
247 | goto end; | |
248 | } | |
249 | diff = timespec_abs_diff(initial_time, current_time); | |
250 | ret = timespec_to_ms(diff, &diff_ms); | |
251 | if (ret) { | |
252 | ERR("Failed to compute elapsed time while waiting for completion"); | |
253 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; | |
254 | goto end; | |
255 | } | |
256 | DBG("%lums elapsed while waiting for session clear completion", | |
257 | diff_ms); | |
258 | diff_ms = max_t(unsigned long, diff_ms, 1); | |
259 | diff_ms = min_t(unsigned long, diff_ms, time_left_ms); | |
260 | time_left_ms -= diff_ms; | |
261 | } | |
262 | ||
263 | status = handle->communication.state == COMMUNICATION_STATE_END ? | |
264 | LTTNG_CLEAR_HANDLE_STATUS_COMPLETED : | |
265 | LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT; | |
266 | end: | |
267 | return status; | |
268 | } | |
269 | ||
270 | extern enum lttng_clear_handle_status | |
271 | lttng_clear_handle_get_result( | |
272 | const struct lttng_clear_handle *handle, | |
273 | enum lttng_error_code *result) | |
274 | { | |
275 | enum lttng_clear_handle_status status = | |
276 | LTTNG_CLEAR_HANDLE_STATUS_OK; | |
277 | ||
278 | if (!handle->clear_return_code.is_set) { | |
279 | status = LTTNG_CLEAR_HANDLE_STATUS_INVALID; | |
280 | goto end; | |
281 | } | |
282 | *result = handle->clear_return_code.value; | |
283 | end: | |
284 | return status; | |
285 | } | |
286 | ||
287 | /* | |
288 | * Clear the session | |
289 | */ | |
290 | enum lttng_error_code lttng_clear_session(const char *session_name, | |
291 | struct lttng_clear_handle **_handle) | |
292 | { | |
293 | enum lttng_error_code ret_code = LTTNG_OK; | |
294 | struct lttng_clear_handle *handle = NULL; | |
295 | struct lttcomm_session_msg lsm = { | |
296 | .cmd_type = LTTNG_CLEAR_SESSION, | |
297 | }; | |
298 | int sessiond_socket = -1; | |
299 | ssize_t comm_ret; | |
300 | int ret; | |
301 | ||
302 | if (session_name == NULL) { | |
303 | ret_code = LTTNG_ERR_INVALID; | |
304 | goto error; | |
305 | } | |
306 | ret = lttng_strncpy(lsm.session.name, session_name, | |
307 | sizeof(lsm.session.name)); | |
308 | if (ret) { | |
309 | ret_code = LTTNG_ERR_INVALID; | |
310 | goto error; | |
311 | } | |
312 | ret = connect_sessiond(); | |
313 | if (ret < 0) { | |
314 | ret_code = LTTNG_ERR_NO_SESSIOND; | |
315 | goto error; | |
316 | } else { | |
317 | sessiond_socket = ret; | |
318 | } | |
319 | handle = lttng_clear_handle_create(sessiond_socket); | |
320 | if (!handle) { | |
321 | ret_code = LTTNG_ERR_NOMEM; | |
322 | goto error; | |
323 | } | |
324 | comm_ret = lttcomm_send_creds_unix_sock(sessiond_socket, &lsm, sizeof(lsm)); | |
325 | if (comm_ret < 0) { | |
326 | ret_code = LTTNG_ERR_FATAL; | |
327 | goto error; | |
328 | } | |
329 | sessiond_socket = -1; | |
330 | ||
331 | error: | |
332 | /* Transfer the handle to the caller. */ | |
333 | if (_handle) { | |
334 | *_handle = handle; | |
335 | handle = NULL; | |
336 | } | |
337 | if (sessiond_socket >= 0) { | |
338 | ret = close(sessiond_socket); | |
339 | if (ret < 0) { | |
340 | PERROR("Failed to close the LTTng session daemon connection socket"); | |
341 | } | |
342 | } | |
343 | if (handle) { | |
344 | lttng_clear_handle_destroy(handle); | |
345 | } | |
346 | return ret_code; | |
347 | } |