bin: compile lttng-relayd as a C++
[lttng-tools.git] / src / bin / lttng-relayd / backward-compatibility-group-by.cpp
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 (file)
index 0000000..f0454a5
--- /dev/null
@@ -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;
+}
This page took 0.02541 seconds and 4 git commands to generate.