--- /dev/null
+/*
+ * Copyright (C) 2019 - Jonathan Rajotte-Julien <jonathan.rajotte-julien@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _LGPL_SOURCE
+#include <popt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <lttng/clear.h>
+#include <lttng/clear-handle.h>
+
+#include "../command.h"
+
+#include <common/mi-lttng.h>
+#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/utils.h>
+
+static int opt_clear_all;
+
+#ifdef LTTNG_EMBED_HELP
+static const char help_msg[] =
+#include <lttng-clear.1.h>
+;
+#endif
+
+/* Mi writer */
+static struct mi_writer *writer;
+
+enum {
+ OPT_HELP = 1,
+ OPT_LIST_OPTIONS,
+};
+
+static struct poptOption long_options[] = {
+ /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
+ {"help", 'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
+ {"all", 'a', POPT_ARG_VAL, &opt_clear_all, 1, 0, 0},
+ {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
+ {0, 0, 0, 0, 0, 0, 0}
+};
+
+/*
+ * clear session
+ */
+static int clear_session(struct lttng_session *session)
+{
+ enum lttng_clear_handle_status status =
+ LTTNG_CLEAR_HANDLE_STATUS_OK;
+ struct lttng_clear_handle *handle = NULL;
+ enum lttng_error_code ret_code;
+ bool printed_wait_msg = false;
+ char *session_name = NULL;
+ int ret;
+
+ ret = lttng_clear_session(session->name, &handle);
+ if (ret < 0) {
+ ERR("%s", lttng_strerror(ret));
+ goto error;
+ }
+
+ do {
+ status = lttng_clear_handle_wait_for_completion(handle,
+ DEFAULT_DATA_AVAILABILITY_WAIT_TIME_US / USEC_PER_MSEC);
+ switch (status) {
+ case LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT:
+ if (!printed_wait_msg) {
+ _MSG("Waiting for clear of session \"%s\"",
+ session->name);
+ printed_wait_msg = true;
+ }
+ _MSG(".");
+ fflush(stdout);
+ break;
+ case LTTNG_CLEAR_HANDLE_STATUS_COMPLETED:
+ break;
+ default:
+ ERR("Failed to wait for the completion of clear for session \"%s\"",
+ session->name);
+ ret = -1;
+ goto error;
+ }
+ } while (status == LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT);
+
+ status = lttng_clear_handle_get_result(handle, &ret_code);
+ if (status != LTTNG_CLEAR_HANDLE_STATUS_OK) {
+ ERR("Failed to get the result of session clear");
+ ret = -1;
+ goto error;
+ }
+ if (ret_code != LTTNG_OK) {
+ ret = -ret_code;
+ goto error;
+ }
+
+ MSG("%sSession \"%s\" cleared", printed_wait_msg ? "\n" : "",
+ session->name);
+ printed_wait_msg = false;
+
+ if (lttng_opt_mi) {
+ ret = mi_lttng_session(writer, session, 0);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto error;
+ }
+ }
+
+ ret = CMD_SUCCESS;
+error:
+ if (printed_wait_msg) {
+ MSG("");
+ }
+ lttng_clear_handle_destroy(handle);
+ free(session_name);
+ return ret;
+}
+
+/*
+ * clear all sessions
+ *
+ * Call clear_session for each registered sessions
+ */
+static int clear_all_sessions(struct lttng_session *sessions, int count)
+{
+ int i, ret = CMD_SUCCESS;
+
+ if (count == 0) {
+ MSG("No session found, nothing to do.");
+ } else if (count < 0) {
+ ERR("%s", lttng_strerror(ret));
+ goto error;
+ }
+
+ for (i = 0; i < count; i++) {
+ ret = clear_session(&sessions[i]);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+error:
+ return ret;
+}
+
+/*
+ * The 'clear <options>' first level command
+ */
+int cmd_clear(int argc, const char **argv)
+{
+ int opt;
+ int ret = CMD_SUCCESS , i, command_ret = CMD_SUCCESS, success = 1;
+ static poptContext pc;
+ char *session_name = NULL;
+ const char *leftover = NULL;
+
+ struct lttng_session *sessions = NULL;
+ int count;
+ int found;
+
+ pc = poptGetContext(NULL, argc, argv, long_options, 0);
+ poptReadDefaultConfig(pc, 0);
+
+ while ((opt = poptGetNextOpt(pc)) != -1) {
+ switch (opt) {
+ case OPT_HELP:
+ SHOW_HELP();
+ break;
+ case OPT_LIST_OPTIONS:
+ list_cmd_options(stdout, long_options);
+ break;
+ default:
+ ret = CMD_UNDEFINED;
+ break;
+ }
+ goto end;
+ }
+
+ /* Mi preparation */
+ if (lttng_opt_mi) {
+ writer = mi_lttng_writer_create(fileno(stdout), lttng_opt_mi);
+ if (!writer) {
+ ret = -LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* Open command element */
+ ret = mi_lttng_writer_command_open(writer,
+ mi_lttng_element_command_clear);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /* Open output element */
+ ret = mi_lttng_writer_open_element(writer,
+ mi_lttng_element_command_output);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /* For validation and semantic purpose we open a sessions element */
+ ret = mi_lttng_sessions_open(writer);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+ }
+
+ if (!opt_clear_all) {
+ /*
+ * popt expects us to free this even if it returns a const char *.
+ * See https://www.mail-archive.com/popt-devel@rpm5.org/msg00193.html
+ * Force cast to char * allowing later freeing if necessary.
+ */
+ session_name = (char *) poptGetArg(pc);
+
+ if (!session_name) {
+ /* No session name specified, lookup default */
+ session_name = get_session_name();
+ if (session_name == NULL) {
+ command_ret = CMD_ERROR;
+ success = 0;
+ goto mi_closing;
+ }
+ }
+ } else {
+ session_name = NULL;
+ }
+
+ leftover = poptGetArg(pc);
+ if (leftover) {
+ ERR("Unknown argument: %s", leftover);
+ ret = CMD_ERROR;
+ success = 0;
+ goto mi_closing;
+ }
+
+ /* Recuperate all sessions for further operation */
+ count = lttng_list_sessions(&sessions);
+ if (count < 0) {
+ ERR("%s", lttng_strerror(count));
+ command_ret = CMD_ERROR;
+ success = 0;
+ goto mi_closing;
+ }
+
+ /* Ignore session name in case all sessions are to be cleaned */
+ if (opt_clear_all) {
+ command_ret = clear_all_sessions(sessions, count);
+ if (command_ret) {
+ ERR("%s", lttng_strerror(command_ret));
+ success = 0;
+ }
+ } else {
+ /* Find the corresponding lttng_session struct */
+ found = 0;
+ for (i = 0; i < count; i++) {
+ if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
+ found = 1;
+ command_ret = clear_session(&sessions[i]);
+ if (command_ret) {
+ ERR("%s", lttng_strerror(command_ret));
+ success = 0;
+ }
+ }
+ }
+
+ if (!found) {
+ ERR("Session name %s not found", session_name);
+ command_ret = LTTNG_ERR_SESS_NOT_FOUND;
+ success = 0;
+ goto mi_closing;
+ }
+ }
+
+mi_closing:
+ /* Mi closing */
+ if (lttng_opt_mi) {
+ /* Close sessions and output element element */
+ ret = mi_lttng_close_multi_element(writer, 2);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /* Success ? */
+ ret = mi_lttng_writer_write_element_bool(writer,
+ mi_lttng_element_command_success, success);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+
+ /* Command element close */
+ ret = mi_lttng_writer_command_close(writer);
+ if (ret) {
+ ret = CMD_ERROR;
+ goto end;
+ }
+ }
+end:
+ /* Mi clean-up */
+ if (writer && mi_lttng_writer_destroy(writer)) {
+ /* Preserve original error code */
+ ret = ret ? ret : -LTTNG_ERR_MI_IO_FAIL;
+ }
+
+ free(sessions);
+ free(session_name);
+
+ /* Overwrite ret if an error occurred during clear_session/all */
+ ret = command_ret ? command_ret : ret;
+
+ poptFreeContext(pc);
+ return ret;
+}