Move to kernel style SPDX license identifiers
[lttng-tools.git] / src / lib / lttng-ctl / clear.c
1 /*
2 * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
3 * Copyright (C) 2019 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * SPDX-License-Identifier: LGPL-2.1-only
6 *
7 */
8
9 #define _LGPL_SOURCE
10 #include <assert.h>
11 #include <string.h>
12
13 #include <lttng/lttng-error.h>
14 #include <lttng/clear.h>
15 #include <lttng/clear-handle.h>
16 #include <common/sessiond-comm/sessiond-comm.h>
17 #include <common/macros.h>
18 #include <common/compat/poll.h>
19 #include <common/dynamic-buffer.h>
20 #include <common/buffer-view.h>
21 #include <common/optional.h>
22
23 #include "lttng-ctl-helper.h"
24
25 enum communication_state {
26 COMMUNICATION_STATE_RECEIVE_LTTNG_MSG,
27 COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER,
28 COMMUNICATION_STATE_END,
29 COMMUNICATION_STATE_ERROR,
30 };
31
32 struct lttng_clear_handle {
33 LTTNG_OPTIONAL(enum lttng_error_code) clear_return_code;
34 struct {
35 int socket;
36 struct lttng_poll_event events;
37 size_t bytes_left_to_receive;
38 enum communication_state state;
39 struct lttng_dynamic_buffer buffer;
40 LTTNG_OPTIONAL(size_t) data_size;
41 } communication;
42 };
43
44 void lttng_clear_handle_destroy(struct lttng_clear_handle *handle)
45 {
46 int ret;
47
48 if (!handle) {
49 return;
50 }
51
52 if (handle->communication.socket >= 0) {
53 ret = close(handle->communication.socket);
54 if (ret) {
55 PERROR("Failed to close lttng-sessiond command socket");
56 }
57 }
58 lttng_poll_clean(&handle->communication.events);
59 lttng_dynamic_buffer_reset(&handle->communication.buffer);
60 free(handle);
61 }
62
63 static
64 struct lttng_clear_handle *lttng_clear_handle_create(int sessiond_socket)
65 {
66 int ret;
67 struct lttng_clear_handle *handle = zmalloc(sizeof(*handle));
68
69 if (!handle) {
70 goto end;
71 }
72 lttng_dynamic_buffer_init(&handle->communication.buffer);
73 handle->communication.socket = sessiond_socket;
74 ret = lttng_poll_create(&handle->communication.events, 1, 0);
75 if (ret) {
76 goto error;
77 }
78
79 ret = lttng_poll_add(&handle->communication.events, sessiond_socket,
80 LPOLLIN | LPOLLHUP | LPOLLRDHUP | LPOLLERR);
81 if (ret) {
82 goto error;
83 }
84
85 handle->communication.bytes_left_to_receive =
86 sizeof(struct lttcomm_lttng_msg);
87 handle->communication.state = COMMUNICATION_STATE_RECEIVE_LTTNG_MSG;
88 end:
89 return handle;
90 error:
91 lttng_clear_handle_destroy(handle);
92 return NULL;
93 }
94
95 static
96 int handle_state_transition(struct lttng_clear_handle *handle)
97 {
98 int ret = 0;
99
100 assert(handle->communication.bytes_left_to_receive == 0);
101
102 switch (handle->communication.state) {
103 case COMMUNICATION_STATE_RECEIVE_LTTNG_MSG:
104 {
105 const struct lttcomm_lttng_msg *msg =
106 (typeof(msg)) handle->communication.buffer.data;
107
108 LTTNG_OPTIONAL_SET(&handle->clear_return_code,
109 (enum lttng_error_code) msg->ret_code);
110 if (handle->clear_return_code.value != LTTNG_OK) {
111 handle->communication.state = COMMUNICATION_STATE_END;
112 break;
113 } else if (msg->cmd_header_size != 0 || msg->data_size != 0) {
114 handle->communication.state = COMMUNICATION_STATE_ERROR;
115 ret = -1;
116 break;
117 }
118
119 handle->communication.state = COMMUNICATION_STATE_END;
120 handle->communication.bytes_left_to_receive = 0;
121 LTTNG_OPTIONAL_SET(&handle->communication.data_size, 0);
122 ret = lttng_dynamic_buffer_set_size(
123 &handle->communication.buffer, 0);
124 assert(!ret);
125 break;
126 }
127 default:
128 abort();
129 }
130
131 /* Clear reception buffer on state transition. */
132 if (lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0)) {
133 abort();
134 }
135 return ret;
136 }
137
138 static
139 int handle_incoming_data(struct lttng_clear_handle *handle)
140 {
141 int ret;
142 ssize_t comm_ret;
143 const size_t original_buffer_size = handle->communication.buffer.size;
144
145 /* Reserve space for reception. */
146 ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer,
147 original_buffer_size + handle->communication.bytes_left_to_receive);
148 if (ret) {
149 goto end;
150 }
151
152 comm_ret = lttcomm_recv_unix_sock(handle->communication.socket,
153 handle->communication.buffer.data + original_buffer_size,
154 handle->communication.bytes_left_to_receive);
155 if (comm_ret <= 0) {
156 ret = -1;
157 goto end;
158 }
159
160 handle->communication.bytes_left_to_receive -= comm_ret;
161 if (handle->communication.bytes_left_to_receive == 0) {
162 ret = handle_state_transition(handle);
163 } else {
164 ret = lttng_dynamic_buffer_set_size(
165 &handle->communication.buffer,
166 original_buffer_size + comm_ret);
167 }
168 end:
169 return ret;
170 }
171
172 extern enum lttng_clear_handle_status
173 lttng_clear_handle_wait_for_completion(
174 struct lttng_clear_handle *handle, int timeout_ms)
175 {
176 int ret;
177 enum lttng_clear_handle_status status;
178 unsigned long time_left_ms = 0;
179 const bool has_timeout = timeout_ms > 0;
180 struct timespec initial_time;
181
182 if (handle->communication.state == COMMUNICATION_STATE_ERROR) {
183 status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
184 goto end;
185 } else if (handle->communication.state == COMMUNICATION_STATE_END) {
186 status = LTTNG_CLEAR_HANDLE_STATUS_COMPLETED;
187 goto end;
188 }
189 if (has_timeout) {
190 ret = lttng_clock_gettime(CLOCK_MONOTONIC, &initial_time);
191 if (ret) {
192 status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
193 goto end;
194 }
195 time_left_ms = (unsigned long) timeout_ms;
196 }
197
198 while (handle->communication.state != COMMUNICATION_STATE_END &&
199 (time_left_ms || !has_timeout)) {
200 int ret;
201 uint32_t revents;
202 struct timespec current_time, diff;
203 unsigned long diff_ms;
204
205 ret = lttng_poll_wait(&handle->communication.events,
206 has_timeout ? time_left_ms : -1);
207 if (ret == 0) {
208 /* timeout */
209 break;
210 } else if (ret < 0) {
211 status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
212 goto end;
213 }
214
215 /* The sessiond connection socket is the only monitored fd. */
216 revents = LTTNG_POLL_GETEV(&handle->communication.events, 0);
217 if (revents & LPOLLIN) {
218 ret = handle_incoming_data(handle);
219 if (ret) {
220 handle->communication.state =
221 COMMUNICATION_STATE_ERROR;
222 status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
223 goto end;
224 }
225 } else {
226 handle->communication.state = COMMUNICATION_STATE_ERROR;
227 status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
228 goto end;
229 }
230 if (!has_timeout) {
231 continue;
232 }
233
234 ret = lttng_clock_gettime(CLOCK_MONOTONIC, &current_time);
235 if (ret) {
236 status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
237 goto end;
238 }
239 diff = timespec_abs_diff(initial_time, current_time);
240 ret = timespec_to_ms(diff, &diff_ms);
241 if (ret) {
242 ERR("Failed to compute elapsed time while waiting for completion");
243 status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
244 goto end;
245 }
246 DBG("%lums elapsed while waiting for session clear completion",
247 diff_ms);
248 diff_ms = max_t(unsigned long, diff_ms, 1);
249 diff_ms = min_t(unsigned long, diff_ms, time_left_ms);
250 time_left_ms -= diff_ms;
251 }
252
253 status = handle->communication.state == COMMUNICATION_STATE_END ?
254 LTTNG_CLEAR_HANDLE_STATUS_COMPLETED :
255 LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT;
256 end:
257 return status;
258 }
259
260 extern enum lttng_clear_handle_status
261 lttng_clear_handle_get_result(
262 const struct lttng_clear_handle *handle,
263 enum lttng_error_code *result)
264 {
265 enum lttng_clear_handle_status status =
266 LTTNG_CLEAR_HANDLE_STATUS_OK;
267
268 if (!handle->clear_return_code.is_set) {
269 status = LTTNG_CLEAR_HANDLE_STATUS_INVALID;
270 goto end;
271 }
272 *result = handle->clear_return_code.value;
273 end:
274 return status;
275 }
276
277 /*
278 * Clear the session
279 */
280 enum lttng_error_code lttng_clear_session(const char *session_name,
281 struct lttng_clear_handle **_handle)
282 {
283 enum lttng_error_code ret_code = LTTNG_OK;
284 struct lttng_clear_handle *handle = NULL;
285 struct lttcomm_session_msg lsm = {
286 .cmd_type = LTTNG_CLEAR_SESSION,
287 };
288 int sessiond_socket = -1;
289 ssize_t comm_ret;
290 int ret;
291
292 if (session_name == NULL) {
293 ret_code = LTTNG_ERR_INVALID;
294 goto error;
295 }
296 ret = lttng_strncpy(lsm.session.name, session_name,
297 sizeof(lsm.session.name));
298 if (ret) {
299 ret_code = LTTNG_ERR_INVALID;
300 goto error;
301 }
302 ret = connect_sessiond();
303 if (ret < 0) {
304 ret_code = LTTNG_ERR_NO_SESSIOND;
305 goto error;
306 } else {
307 sessiond_socket = ret;
308 }
309 handle = lttng_clear_handle_create(sessiond_socket);
310 if (!handle) {
311 ret_code = LTTNG_ERR_NOMEM;
312 goto error;
313 }
314 comm_ret = lttcomm_send_creds_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
315 if (comm_ret < 0) {
316 ret_code = LTTNG_ERR_FATAL;
317 goto error;
318 }
319 sessiond_socket = -1;
320
321 error:
322 /* Transfer the handle to the caller. */
323 if (_handle) {
324 *_handle = handle;
325 handle = NULL;
326 }
327 if (sessiond_socket >= 0) {
328 ret = close(sessiond_socket);
329 if (ret < 0) {
330 PERROR("Failed to close the LTTng session daemon connection socket");
331 }
332 }
333 if (handle) {
334 lttng_clear_handle_destroy(handle);
335 }
336 return ret_code;
337 }
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