X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Fbackward-compatibility-group-by.cpp;fp=src%2Fbin%2Flttng-relayd%2Fbackward-compatibility-group-by.cpp;h=f0454a56b70a0c2db24a632323d8df62f462c525;hb=ac497a37018f3c253d2e50397294f58d33f7f24f;hp=0000000000000000000000000000000000000000;hpb=7966af5763c4aaca39df9bbfa9277ff15715c720;p=lttng-tools.git

diff --git a/src/bin/lttng-relayd/backward-compatibility-group-by.cpp b/src/bin/lttng-relayd/backward-compatibility-group-by.cpp
new file mode 100644
index 000000000..f0454a56b
--- /dev/null
+++ b/src/bin/lttng-relayd/backward-compatibility-group-by.cpp
@@ -0,0 +1,235 @@
+/*
+ * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include "common/time.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_REGEX \
+	".*-[1-2][0-9][0-9][0-9][0-1][0-9][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,
+		time_t relay_session_creation_time)
+{
+	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;
+
+	LTTNG_ASSERT(path);
+	LTTNG_ASSERT(local_session_name);
+	LTTNG_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 [3].
+	 * [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(&regex, 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(&regex, local_session_name, 0, NULL, 0);
+		if (ret == 0) {
+			const ssize_t local_session_name_offset =
+					strlen(local_session_name) - DATETIME_STR_LEN + 1;
+
+			LTTNG_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 {
+			datetime = (char *) zmalloc(DATETIME_STR_LEN);
+			if (!datetime) {
+				PERROR("Failed to allocate DATETIME string");
+				goto error;
+			}
+
+			ret = time_to_datetime_str(relay_session_creation_time,
+					datetime, DATETIME_STR_LEN);
+			if (ret) {
+				/* time_to_datetime_str already logs errors. */
+				goto error;
+			}
+		}
+	} else if (len == DATETIME_STR_LEN &&
+			!regexec(&regex, 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.
+		 * */
+		LTTNG_ASSERT(partial_base_path == NULL);
+		LTTNG_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(&regex);
+error:
+	free(local_copy);
+	free(partial_base_path);
+	free(datetime);
+	return filepath_per_session;
+}