+/*
+ * Copyright (C) 2019 - Jonathan Rajotte <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.
+ */
+
+#include <assert.h>
+#include <regex.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <common/common.h>
+#include <common/defaults.h>
+#include <common/utils.h>
+
+#include "backward-compatibility-group-by.h"
+
+#define DATETIME_STRING_SIZE 16
+#define DATETIME_REGEX \
+ ".*-[1-2][0-9][0-9][0-9][0-1][0-1][0-3][0-9]-[0-2][0-9][0-5][0-9][0-5][0-9]$"
+
+/*
+ * Provide support for --group-output-by-session for producer >= 2.4 and < 2.11.
+ * Take the stream path, extract all available information, craft a new path to
+ * the best of our ability enforcing the group by session.
+ *
+ * Return the allocated string containing the new stream path or else NULL.
+ */
+char *backward_compat_group_by_session(
+ const char *path, const char *local_session_name)
+{
+ int ret;
+ size_t len;
+ char *leftover_ptr;
+ char *local_copy = NULL;
+ char *datetime = NULL;
+ char *partial_base_path = NULL;
+ char *filepath_per_session = NULL;
+ const char *second_token_ptr;
+ const char *leftover_second_token_ptr;
+ const char *hostname_ptr;
+ regex_t regex;
+
+ assert(path);
+ assert(local_session_name);
+ assert(local_session_name[0] != '\0');
+
+ DBG("Parsing path \"%s\" of session \"%s\" to create a new path that is grouped by session",
+ path, local_session_name);
+
+ /* Get a local copy for strtok */
+ local_copy = strdup(path);
+ if (!local_copy) {
+ PERROR("Failed to parse session path: couldn't copy input path");
+ goto error;
+ }
+
+ /*
+ * The use of strtok with '/' as delimiter is valid since we refuse '/'
+ * in session name and '/' is not a valid hostname character based on
+ * RFC-952 [1], RFC-921 [2] and refined in RFC-1123 [2].
+ * [1] https://tools.ietf.org/html/rfc952
+ * [2] https://tools.ietf.org/html/rfc921
+ * [3] https://tools.ietf.org/html/rfc1123#page-13
+ */
+
+ /*
+ * Get the hostname and possible session_name.
+ * Note that we can get the hostname and session name from the
+ * relay_session object we already have. Still, it is easier to
+ * tokenized the passed path to obtain the start of the path leftover.
+ */
+ hostname_ptr = strtok_r(local_copy, "/", &leftover_ptr);
+ if (!hostname_ptr) {
+ ERR("Failed to parse session path \"%s\": couldn't identify hostname",
+ path);
+ goto error;
+ }
+
+ second_token_ptr = strtok_r(NULL, "/", &leftover_ptr);
+ if (!second_token_ptr) {
+ ERR("Failed to parse session path \"%s\": couldn't identify session name",
+ path);
+ goto error;
+ }
+
+ /*
+ * Check if the second token is a base path set at url level. This is
+ * legal in streaming, live and snapshot [1]. Otherwise it is the
+ * session name with possibly a datetime attached [2]. Note that when
+ * "adding" snapshot output (lttng snapshot add-output), no session name
+ * is present in the path by default. The handling for "base path" take
+ * care of this case as well.
+ * [1] e.g --set-url net://localhost/my_marvellous_path
+ * [2] Can be:
+ * <session_name>
+ * When using --snapshot on session create.
+ * <session_name>-<date>-<time>
+ * <auto>-<date>-<time>
+ */
+ if (strncmp(second_token_ptr, local_session_name,
+ strlen(local_session_name)) != 0) {
+ /*
+ * Token does not start with session name.
+ * This mean this is an extra path scenario.
+ * Duplicate the current token since it is part of an
+ * base_path.
+ * Set secDuplicate the current token since it is part of an
+ * base_path. The rest is the leftover.
+ * Set second_token_ptr to the local_session_name for further
+ * processing.
+ */
+ partial_base_path = strdup(second_token_ptr);
+ if (!partial_base_path) {
+ PERROR("Failed to parse session path: couldn't copy partial base path");
+ goto error;
+ }
+
+ second_token_ptr = local_session_name;
+ }
+
+ /*
+ * Based on the previous test, we can move inside the token ptr to
+ * remove the "local_session_name" and inspect the rest of the token.
+ * We are looking into extracting the creation datetime from either the
+ * session_name or the token. We need to to all this gymnastic because
+ * an extra path could decide to append a datetime to its first
+ * subdirectory.
+ * Possible scenario:
+ * <session_name>
+ * <session_name>-<date>-<time>
+ * <auto>-<date>-<time>
+ * <session_name>_base_path_foo_bar
+ * <session_name>-<false date>-<false-time> (via a base path)
+ *
+ * We have no way to discern from the basic scenario of:
+ * <session_name>-<date>-<time>
+ * and one done using a base path with the exact format we normally
+ * expect.
+ *
+ * e.g:
+ * lttng create my_session -U
+ * net://localhost/my_session-19910319-120000/
+ */
+ ret = regcomp(®ex, DATETIME_REGEX, 0);
+ if (ret) {
+ ERR("Failed to parse session path: regex compilation failed with code %d", ret);
+ goto error;
+ }
+
+ leftover_second_token_ptr =
+ second_token_ptr + strlen(local_session_name);
+ len = strlen(leftover_second_token_ptr);
+ if (len == 0) {
+ /*
+ * We are either dealing with an auto session name or only the
+ * session_name. If this is a auto session name, we need to
+ * fetch the creation datetime.
+ */
+ ret = regexec(®ex, local_session_name, 0, NULL, 0);
+ if (ret == 0) {
+ const ssize_t local_session_name_offset =
+ strlen(local_session_name) - DATETIME_STRING_SIZE + 1;
+
+ assert(local_session_name_offset >= 0);
+ datetime = strdup(local_session_name +
+ local_session_name_offset);
+ if (!datetime) {
+ PERROR("Failed to parse session path: couldn't copy datetime on regex match");
+ goto error_regex;
+ }
+ }
+ } else if (len == DATETIME_STRING_SIZE &&
+ !regexec(®ex, leftover_second_token_ptr, 0, NULL,
+ 0)) {
+ /*
+ * The leftover from the second token is of format
+ * "-<datetime>", use it as the creation time.
+ * Ignore leading "-".
+ */
+ datetime = strdup(&leftover_second_token_ptr[1]);
+ if (!datetime) {
+ PERROR("Failed to parse session path: couldn't copy datetime on regex match");
+ goto error_regex;
+ }
+ } else {
+ /*
+ * Base path scenario.
+ * We cannot try to extract the datetime from the session name
+ * since nothing prevent a user to name a session in the
+ * "name-<datetime>" format. Using the datetime from such a
+ * session would be invalid.
+ * */
+ assert(partial_base_path == NULL);
+ assert(datetime == NULL);
+
+ partial_base_path = strdup(second_token_ptr);
+ if (!partial_base_path) {
+ PERROR("Failed to parse session path: couldn't copy partial base path");
+ goto error_regex;
+ }
+ }
+
+ ret = asprintf(&filepath_per_session, "%s/%s%s%s/%s%s%s",
+ local_session_name, hostname_ptr, datetime ? "-" : "",
+ datetime ? datetime : "",
+ partial_base_path ? partial_base_path : "",
+ partial_base_path ? "/" : "", leftover_ptr);
+ if (ret < 0) {
+ filepath_per_session = NULL;
+ goto error;
+ }
+error_regex:
+ regfree(®ex);
+error:
+ free(local_copy);
+ free(partial_base_path);
+ free(datetime);
+ return filepath_per_session;
+}
projects / lttng-tools.git / commitdiff
