[lttng-tools.git] / src / lib / lttng-ctl / clear.c

/*
 * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 * Copyright (C) 2019 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#define _LGPL_SOURCE
#include <string.h>

#include <lttng/lttng-error.h>
#include <lttng/clear.h>
#include <lttng/clear-handle.h>
#include <common/sessiond-comm/sessiond-comm.h>
#include <common/macros.h>
#include <common/compat/poll.h>
#include <common/dynamic-buffer.h>
#include <common/buffer-view.h>
#include <common/optional.h>

#include "lttng-ctl-helper.h"

enum communication_state {
	COMMUNICATION_STATE_RECEIVE_LTTNG_MSG,
	COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER,
	COMMUNICATION_STATE_END,
	COMMUNICATION_STATE_ERROR,
};

struct lttng_clear_handle {
	LTTNG_OPTIONAL(enum lttng_error_code) clear_return_code;
	struct {
		int socket;
		struct lttng_poll_event events;
		size_t bytes_left_to_receive;
		enum communication_state state;
		struct lttng_dynamic_buffer buffer;
		LTTNG_OPTIONAL(size_t) data_size;
	} communication;
};

void lttng_clear_handle_destroy(struct lttng_clear_handle *handle)
{
	int ret;

	if (!handle) {
		return;
	}

	if (handle->communication.socket >= 0) {
		ret = close(handle->communication.socket);
		if (ret) {
			PERROR("Failed to close lttng-sessiond command socket");
		}
	}
	lttng_poll_clean(&handle->communication.events);
	lttng_dynamic_buffer_reset(&handle->communication.buffer);
	free(handle);
}

static
struct lttng_clear_handle *lttng_clear_handle_create(int sessiond_socket)
{
	int ret;
	struct lttng_clear_handle *handle = zmalloc(sizeof(*handle));

	if (!handle) {
		goto end;
	}
	lttng_dynamic_buffer_init(&handle->communication.buffer);
	handle->communication.socket = sessiond_socket;
	ret = lttng_poll_create(&handle->communication.events, 1, 0);
	if (ret) {
		goto error;
	}

	ret = lttng_poll_add(&handle->communication.events, sessiond_socket,
			LPOLLIN | LPOLLHUP | LPOLLRDHUP | LPOLLERR);
	if (ret) {
		goto error;
	}

	handle->communication.bytes_left_to_receive =
			sizeof(struct lttcomm_lttng_msg);
	handle->communication.state = COMMUNICATION_STATE_RECEIVE_LTTNG_MSG;
end:
	return handle;
error:
	lttng_clear_handle_destroy(handle);
	return NULL;
}

static
int handle_state_transition(struct lttng_clear_handle *handle)
{
	int ret = 0;

	LTTNG_ASSERT(handle->communication.bytes_left_to_receive == 0);

	switch (handle->communication.state) {
	case COMMUNICATION_STATE_RECEIVE_LTTNG_MSG:
	{
		const struct lttcomm_lttng_msg *msg =
				(typeof(msg)) handle->communication.buffer.data;

		LTTNG_OPTIONAL_SET(&handle->clear_return_code,
				(enum lttng_error_code) msg->ret_code);
		if (handle->clear_return_code.value != LTTNG_OK) {
			handle->communication.state = COMMUNICATION_STATE_END;
			break;
		} else if (msg->cmd_header_size != 0 || msg->data_size != 0) {
			handle->communication.state = COMMUNICATION_STATE_ERROR;
			ret = -1;
			break;
		}

		handle->communication.state = COMMUNICATION_STATE_END;
		handle->communication.bytes_left_to_receive = 0;
		LTTNG_OPTIONAL_SET(&handle->communication.data_size, 0);
		ret = lttng_dynamic_buffer_set_size(
				&handle->communication.buffer, 0);
		LTTNG_ASSERT(!ret);
		break;
	}
	default:
		abort();
	}

	/* Clear reception buffer on state transition. */
	if (lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0)) {
		abort();
	}
	return ret;
}

static
int handle_incoming_data(struct lttng_clear_handle *handle)
{
	int ret;
	ssize_t comm_ret;
	const size_t original_buffer_size = handle->communication.buffer.size;

	/* Reserve space for reception. */
	ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer,
			original_buffer_size + handle->communication.bytes_left_to_receive);
	if (ret) {
		goto end;
	}

	comm_ret = lttcomm_recv_unix_sock(handle->communication.socket,
			handle->communication.buffer.data + original_buffer_size,
			handle->communication.bytes_left_to_receive);
	if (comm_ret <= 0) {
		ret = -1;
		goto end;
	}

	handle->communication.bytes_left_to_receive -= comm_ret;
	if (handle->communication.bytes_left_to_receive == 0) {
		ret = handle_state_transition(handle);
	} else {
		ret = lttng_dynamic_buffer_set_size(
				&handle->communication.buffer,
				original_buffer_size + comm_ret);
	}
end:
	return ret;
}

extern enum lttng_clear_handle_status
	lttng_clear_handle_wait_for_completion(
		struct lttng_clear_handle *handle, int timeout_ms)
{
	enum lttng_clear_handle_status status;
	unsigned long time_left_ms = 0;
	const bool has_timeout = timeout_ms > 0;
	struct timespec initial_time;

	if (handle->communication.state == COMMUNICATION_STATE_ERROR) {
		status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
		goto end;
	} else if (handle->communication.state == COMMUNICATION_STATE_END) {
		status = LTTNG_CLEAR_HANDLE_STATUS_COMPLETED;
		goto end;
	}
	if (has_timeout) {
		int ret = lttng_clock_gettime(CLOCK_MONOTONIC, &initial_time);
		if (ret) {
			status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
			goto end;
		}
		time_left_ms = (unsigned long) timeout_ms;
	}

	while (handle->communication.state != COMMUNICATION_STATE_END &&
			(time_left_ms || !has_timeout)) {
		int ret;
		uint32_t revents;
		struct timespec current_time, diff;
		unsigned long diff_ms;

		ret = lttng_poll_wait(&handle->communication.events,
				has_timeout ? time_left_ms : -1);
		if (ret == 0) {
			/* timeout */
			break;
		} else if (ret < 0) {
			status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
			goto end;
		}

		/* The sessiond connection socket is the only monitored fd. */
		revents = LTTNG_POLL_GETEV(&handle->communication.events, 0);
		if (revents & LPOLLIN) {
			ret = handle_incoming_data(handle);
			if (ret) {
				handle->communication.state =
						COMMUNICATION_STATE_ERROR;
				status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
				goto end;
			}
		} else {
			handle->communication.state = COMMUNICATION_STATE_ERROR;
			status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
			goto end;
		}
		if (!has_timeout) {
			continue;
		}

		ret = lttng_clock_gettime(CLOCK_MONOTONIC, &current_time);
		if (ret) {
			status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
			goto end;
		}
		diff = timespec_abs_diff(initial_time, current_time);
		ret = timespec_to_ms(diff, &diff_ms);
		if (ret) {
			ERR("Failed to compute elapsed time while waiting for completion");
			status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
			goto end;
		}
		DBG("%lums elapsed while waiting for session clear completion",
				diff_ms);
		diff_ms = max_t(unsigned long, diff_ms, 1);
		diff_ms = min_t(unsigned long, diff_ms, time_left_ms);
		time_left_ms -= diff_ms;
	}

	status = handle->communication.state == COMMUNICATION_STATE_END ?
			LTTNG_CLEAR_HANDLE_STATUS_COMPLETED :
			LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT;
end:
	return status;
}

extern enum lttng_clear_handle_status
	lttng_clear_handle_get_result(
		const struct lttng_clear_handle *handle,
		enum lttng_error_code *result)
{
	enum lttng_clear_handle_status status =
			LTTNG_CLEAR_HANDLE_STATUS_OK;

	if (!handle->clear_return_code.is_set) {
		status = LTTNG_CLEAR_HANDLE_STATUS_INVALID;
		goto end;
	}
	*result = handle->clear_return_code.value;
end:
	return status;
}

/*
 * Clear the session
 */
enum lttng_error_code lttng_clear_session(const char *session_name,
		struct lttng_clear_handle **_handle)
{
	enum lttng_error_code ret_code = LTTNG_OK;
	struct lttng_clear_handle *handle = NULL;
	struct lttcomm_session_msg lsm = {
		.cmd_type = LTTNG_CLEAR_SESSION,
	};
	int sessiond_socket = -1;
	ssize_t comm_ret;
	int ret;

	if (session_name == NULL) {
		ret_code = LTTNG_ERR_INVALID;
		goto error;
	}
	ret = lttng_strncpy(lsm.session.name, session_name,
			sizeof(lsm.session.name));
	if (ret) {
		ret_code = LTTNG_ERR_INVALID;
		goto error;
	}
	ret = connect_sessiond();
	if (ret < 0) {
		ret_code = LTTNG_ERR_NO_SESSIOND;
		goto error;
	} else {
		sessiond_socket = ret;
	}
	handle = lttng_clear_handle_create(sessiond_socket);
	if (!handle) {
		ret_code = LTTNG_ERR_NOMEM;
		goto error;
	}
	comm_ret = lttcomm_send_creds_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
	if (comm_ret < 0) {
		ret_code = LTTNG_ERR_FATAL;
		goto error;
	}
	sessiond_socket = -1;

error:
	/* Transfer the handle to the caller. */
	if (_handle) {
		*_handle = handle;
		handle = NULL;
	}
	if (sessiond_socket >= 0) {
		ret = close(sessiond_socket);
		if (ret < 0) {
			PERROR("Failed to close the LTTng session daemon connection socket");
		}
	}
	if (handle) {
		lttng_clear_handle_destroy(handle);
	}
	return ret_code;
}
Commit	Line	Data
f2c1f0d4	1	/*
ab5be9fa MJ	2	* Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com>
ab5be9fa MJ	3	* Copyright (C) 2019 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
f2c1f0d4	4	*
ab5be9fa	5	* SPDX-License-Identifier: LGPL-2.1-only
f2c1f0d4	6	*
f2c1f0d4 MD	7	*/
	8
	9	#define _LGPL_SOURCE
f2c1f0d4 MD	10	#include <string.h>
	11
	12	#include <lttng/lttng-error.h>
	13	#include <lttng/clear.h>
	14	#include <lttng/clear-handle.h>
	15	#include <common/sessiond-comm/sessiond-comm.h>
	16	#include <common/macros.h>
	17	#include <common/compat/poll.h>
	18	#include <common/dynamic-buffer.h>
	19	#include <common/buffer-view.h>
	20	#include <common/optional.h>
	21
	22	#include "lttng-ctl-helper.h"
	23
	24	enum communication_state {
	25	COMMUNICATION_STATE_RECEIVE_LTTNG_MSG,
	26	COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER,
	27	COMMUNICATION_STATE_END,
	28	COMMUNICATION_STATE_ERROR,
	29	};
	30
	31	struct lttng_clear_handle {
	32	LTTNG_OPTIONAL(enum lttng_error_code) clear_return_code;
	33	struct {
	34	int socket;
	35	struct lttng_poll_event events;
	36	size_t bytes_left_to_receive;
	37	enum communication_state state;
	38	struct lttng_dynamic_buffer buffer;
	39	LTTNG_OPTIONAL(size_t) data_size;
	40	} communication;
	41	};
	42
	43	void lttng_clear_handle_destroy(struct lttng_clear_handle *handle)
	44	{
	45	int ret;
	46
	47	if (!handle) {
	48	return;
	49	}
	50
	51	if (handle->communication.socket >= 0) {
	52	ret = close(handle->communication.socket);
	53	if (ret) {
	54	PERROR("Failed to close lttng-sessiond command socket");
	55	}
e429da85 JG	56	}
e429da85 JG	57	lttng_poll_clean(&handle->communication.events);
f2c1f0d4 MD	58	lttng_dynamic_buffer_reset(&handle->communication.buffer);
	59	free(handle);
	60	}
	61
	62	static
	63	struct lttng_clear_handle *lttng_clear_handle_create(int sessiond_socket)
	64	{
	65	int ret;
	66	struct lttng_clear_handle handle = zmalloc(sizeof(handle));
	67
	68	if (!handle) {
	69	goto end;
	70	}
	71	lttng_dynamic_buffer_init(&handle->communication.buffer);
	72	handle->communication.socket = sessiond_socket;
	73	ret = lttng_poll_create(&handle->communication.events, 1, 0);
	74	if (ret) {
	75	goto error;
	76	}
	77
	78	ret = lttng_poll_add(&handle->communication.events, sessiond_socket,
	79	LPOLLIN \| LPOLLHUP \| LPOLLRDHUP \| LPOLLERR);
e429da85	80	if (ret) {
f2c1f0d4	81	goto error;
e429da85	82	}
f2c1f0d4 MD	83
	84	handle->communication.bytes_left_to_receive =
	85	sizeof(struct lttcomm_lttng_msg);
	86	handle->communication.state = COMMUNICATION_STATE_RECEIVE_LTTNG_MSG;
	87	end:
	88	return handle;
	89	error:
	90	lttng_clear_handle_destroy(handle);
	91	return NULL;
	92	}
	93
	94	static
	95	int handle_state_transition(struct lttng_clear_handle *handle)
	96	{
	97	int ret = 0;
	98
a0377dfe	99	LTTNG_ASSERT(handle->communication.bytes_left_to_receive == 0);
f2c1f0d4 MD	100
	101	switch (handle->communication.state) {
	102	case COMMUNICATION_STATE_RECEIVE_LTTNG_MSG:
	103	{
	104	const struct lttcomm_lttng_msg *msg =
	105	(typeof(msg)) handle->communication.buffer.data;
	106
	107	LTTNG_OPTIONAL_SET(&handle->clear_return_code,
	108	(enum lttng_error_code) msg->ret_code);
	109	if (handle->clear_return_code.value != LTTNG_OK) {
	110	handle->communication.state = COMMUNICATION_STATE_END;
	111	break;
	112	} else if (msg->cmd_header_size != 0 \|\| msg->data_size != 0) {
	113	handle->communication.state = COMMUNICATION_STATE_ERROR;
	114	ret = -1;
	115	break;
	116	}
	117
	118	handle->communication.state = COMMUNICATION_STATE_END;
	119	handle->communication.bytes_left_to_receive = 0;
	120	LTTNG_OPTIONAL_SET(&handle->communication.data_size, 0);
	121	ret = lttng_dynamic_buffer_set_size(
	122	&handle->communication.buffer, 0);
a0377dfe	123	LTTNG_ASSERT(!ret);
f2c1f0d4 MD	124	break;
	125	}
	126	default:
	127	abort();
	128	}
	129
	130	/* Clear reception buffer on state transition. */
	131	if (lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0)) {
	132	abort();
	133	}
	134	return ret;
	135	}
	136
	137	static
	138	int handle_incoming_data(struct lttng_clear_handle *handle)
	139	{
	140	int ret;
	141	ssize_t comm_ret;
	142	const size_t original_buffer_size = handle->communication.buffer.size;
	143
	144	/* Reserve space for reception. */
	145	ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer,
	146	original_buffer_size + handle->communication.bytes_left_to_receive);
	147	if (ret) {
	148	goto end;
	149	}
	150
	151	comm_ret = lttcomm_recv_unix_sock(handle->communication.socket,
	152	handle->communication.buffer.data + original_buffer_size,
	153	handle->communication.bytes_left_to_receive);
	154	if (comm_ret <= 0) {
	155	ret = -1;
	156	goto end;
	157	}
	158
	159	handle->communication.bytes_left_to_receive -= comm_ret;
	160	if (handle->communication.bytes_left_to_receive == 0) {
	161	ret = handle_state_transition(handle);
	162	} else {
	163	ret = lttng_dynamic_buffer_set_size(
	164	&handle->communication.buffer,
	165	original_buffer_size + comm_ret);
	166	}
	167	end:
	168	return ret;
	169	}
	170
	171	extern enum lttng_clear_handle_status
	172	lttng_clear_handle_wait_for_completion(
	173	struct lttng_clear_handle *handle, int timeout_ms)
	174	{
f2c1f0d4 MD	175	enum lttng_clear_handle_status status;
	176	unsigned long time_left_ms = 0;
	177	const bool has_timeout = timeout_ms > 0;
	178	struct timespec initial_time;
	179
e429da85	180	if (handle->communication.state == COMMUNICATION_STATE_ERROR) {
f2c1f0d4 MD	181	status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
	182	goto end;
	183	} else if (handle->communication.state == COMMUNICATION_STATE_END) {
	184	status = LTTNG_CLEAR_HANDLE_STATUS_COMPLETED;
	185	goto end;
	186	}
e429da85	187	if (has_timeout) {
bf3683d0	188	int ret = lttng_clock_gettime(CLOCK_MONOTONIC, &initial_time);
f2c1f0d4 MD	189	if (ret) {
	190	status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
	191	goto end;
	192	}
	193	time_left_ms = (unsigned long) timeout_ms;
e429da85	194	}
f2c1f0d4	195
e429da85	196	while (handle->communication.state != COMMUNICATION_STATE_END &&
f2c1f0d4 MD	197	(time_left_ms \|\| !has_timeout)) {
	198	int ret;
	199	uint32_t revents;
e429da85	200	struct timespec current_time, diff;
f2c1f0d4 MD	201	unsigned long diff_ms;
f2c1f0d4 MD	202
e429da85	203	ret = lttng_poll_wait(&handle->communication.events,
f2c1f0d4	204	has_timeout ? time_left_ms : -1);
e429da85	205	if (ret == 0) {
f2c1f0d4 MD	206	/* timeout */
	207	break;
	208	} else if (ret < 0) {
	209	status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
	210	goto end;
	211	}
	212
	213	/* The sessiond connection socket is the only monitored fd. */
	214	revents = LTTNG_POLL_GETEV(&handle->communication.events, 0);
	215	if (revents & LPOLLIN) {
	216	ret = handle_incoming_data(handle);
	217	if (ret) {
	218	handle->communication.state =
	219	COMMUNICATION_STATE_ERROR;
	220	status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
	221	goto end;
	222	}
	223	} else {
	224	handle->communication.state = COMMUNICATION_STATE_ERROR;
	225	status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
	226	goto end;
	227	}
	228	if (!has_timeout) {
	229	continue;
	230	}
	231
	232	ret = lttng_clock_gettime(CLOCK_MONOTONIC, &current_time);
	233	if (ret) {
	234	status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
	235	goto end;
	236	}
	237	diff = timespec_abs_diff(initial_time, current_time);
	238	ret = timespec_to_ms(diff, &diff_ms);
	239	if (ret) {
	240	ERR("Failed to compute elapsed time while waiting for completion");
	241	status = LTTNG_CLEAR_HANDLE_STATUS_ERROR;
	242	goto end;
	243	}
	244	DBG("%lums elapsed while waiting for session clear completion",
	245	diff_ms);
	246	diff_ms = max_t(unsigned long, diff_ms, 1);
	247	diff_ms = min_t(unsigned long, diff_ms, time_left_ms);
	248	time_left_ms -= diff_ms;
	249	}
	250
	251	status = handle->communication.state == COMMUNICATION_STATE_END ?
	252	LTTNG_CLEAR_HANDLE_STATUS_COMPLETED :
	253	LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT;
	254	end:
	255	return status;
	256	}
	257
	258	extern enum lttng_clear_handle_status
	259	lttng_clear_handle_get_result(
	260	const struct lttng_clear_handle *handle,
	261	enum lttng_error_code *result)
	262	{
	263	enum lttng_clear_handle_status status =
	264	LTTNG_CLEAR_HANDLE_STATUS_OK;
	265
	266	if (!handle->clear_return_code.is_set) {
	267	status = LTTNG_CLEAR_HANDLE_STATUS_INVALID;
	268	goto end;
	269	}
270	*result = handle->clear_return_code.value;
271	end:
272	return status;
273	}
274
275	/*
276	* Clear the session
277	*/
278	enum lttng_error_code lttng_clear_session(const char *session_name,
279	struct lttng_clear_handle **_handle)
280	{
281	enum lttng_error_code ret_code = LTTNG_OK;
282	struct lttng_clear_handle *handle = NULL;
283	struct lttcomm_session_msg lsm = {
284	.cmd_type = LTTNG_CLEAR_SESSION,
285	};
286	int sessiond_socket = -1;
287	ssize_t comm_ret;
288	int ret;
289
290	if (session_name == NULL) {
291	ret_code = LTTNG_ERR_INVALID;
292	goto error;
293	}
294	ret = lttng_strncpy(lsm.session.name, session_name,
295	sizeof(lsm.session.name));
296	if (ret) {
297	ret_code = LTTNG_ERR_INVALID;
298	goto error;
299	}
300	ret = connect_sessiond();
301	if (ret < 0) {
302	ret_code = LTTNG_ERR_NO_SESSIOND;
303	goto error;
304	} else {
305	sessiond_socket = ret;
306	}
307	handle = lttng_clear_handle_create(sessiond_socket);
308	if (!handle) {
309	ret_code = LTTNG_ERR_NOMEM;
310	goto error;
311	}
312	comm_ret = lttcomm_send_creds_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
313	if (comm_ret < 0) {
314	ret_code = LTTNG_ERR_FATAL;
315	goto error;
316	}
317	sessiond_socket = -1;
318
319	error:
320	/* Transfer the handle to the caller. */
321	if (_handle) {
322	*_handle = handle;
323	handle = NULL;
324	}
325	if (sessiond_socket >= 0) {
326	ret = close(sessiond_socket);
327	if (ret < 0) {
328	PERROR("Failed to close the LTTng session daemon connection socket");
329	}
330	}
331	if (handle) {
332	lttng_clear_handle_destroy(handle);
333	}
334	return ret_code;
335	}