X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng%2Fconf.cpp;fp=src%2Fbin%2Flttng%2Fconf.cpp;h=e347c4b3afdd2361df09c877e464bc8038fd112a;hp=0000000000000000000000000000000000000000;hb=48a4000561343808724f7cb5fa8c131877489ccd;hpb=81663f073dbfb4b61c06a0ceb8ca33c4fc41b1c5

diff --git a/src/bin/lttng/conf.cpp b/src/bin/lttng/conf.cpp
new file mode 100644
index 000000000..e347c4b3a
--- /dev/null
+++ b/src/bin/lttng/conf.cpp
@@ -0,0 +1,318 @@
+/*
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <common/compat/errno.h>
+#include <common/common.h>
+#include <common/utils.h>
+
+#include "conf.h"
+
+/*
+ * Returns the path with '/CONFIG_FILENAME' added to it;
+ * path will be NULL if an error occurs.
+ */
+char *config_get_file_path(const char *path)
+{
+	int ret;
+	char *file_path;
+
+	ret = asprintf(&file_path, "%s/%s", path, CONFIG_FILENAME);
+	if (ret < 0) {
+		ERR("Fail allocating config file path");
+		file_path = NULL;
+	}
+
+	return file_path;
+}
+
+/*
+ * Returns an open FILE pointer to the config file;
+ * on error, NULL is returned.
+ */
+static FILE *open_config(const char *path, const char *mode)
+{
+	FILE *fp = NULL;
+	char *file_path;
+
+	file_path = config_get_file_path(path);
+	if (file_path == NULL) {
+		goto error;
+	}
+
+	fp = fopen(file_path, mode);
+	if (fp == NULL) {
+		goto error;
+	}
+
+error:
+	free(file_path);
+	return fp;
+}
+
+/*
+ * Creates the empty config file at the path.
+ * On success, returns 0;
+ * on error, returns -1.
+ */
+static int create_config_file(const char *path)
+{
+	int ret;
+	FILE *fp;
+
+	fp = open_config(path, "w+");
+	if (fp == NULL) {
+		ERR("Unable to create config file");
+		ret = -1;
+		goto error;
+	}
+
+	ret = fclose(fp);
+
+error:
+	return ret;
+}
+
+/*
+ * Append data to the config file in file_path
+ * On success, returns 0;
+ * on error, returns -1.
+ */
+static int write_config(const char *file_path, size_t size, char *data)
+{
+	FILE *fp;
+	size_t len;
+	int ret = 0;
+
+	fp = open_config(file_path, "a");
+	if (fp == NULL) {
+		ret = -1;
+		goto end;
+	}
+
+	/* Write session name into config file */
+	len = fwrite(data, size, 1, fp);
+	if (len != 1) {
+		ret = -1;
+	}
+	if (fclose(fp)) {
+		PERROR("close write_config");
+	}
+end:
+	return ret;
+}
+
+/*
+ * Destroys directory config and file config.
+ */
+void config_destroy(const char *path)
+{
+	int ret;
+	char *config_path;
+
+	config_path = config_get_file_path(path);
+	if (config_path == NULL) {
+		return;
+	}
+
+	if (!config_exists(config_path)) {
+		goto end;
+	}
+
+	DBG("Removing %s\n", config_path);
+	ret = remove(config_path);
+	if (ret < 0) {
+		PERROR("remove config file");
+	}
+end:
+	free(config_path);
+}
+
+/*
+ * Destroys the default config
+ */
+void config_destroy_default(void)
+{
+	const char *path = utils_get_home_dir();
+	if (path == NULL) {
+		return;
+	}
+	config_destroy(path);
+}
+
+/*
+ * Returns 1 if config exists, 0 otherwise
+ */
+int config_exists(const char *path)
+{
+	int ret;
+	struct stat info;
+
+	ret = stat(path, &info);
+	if (ret < 0) {
+		return 0;
+	}
+	return S_ISREG(info.st_mode) || S_ISDIR(info.st_mode);
+}
+
+static
+int _config_read_session_name(const char *path, char **name)
+{
+	int ret = 0;
+	FILE *fp;
+	char var[NAME_MAX], *session_name;
+
+#if (NAME_MAX == 255)
+#define NAME_MAX_SCANF_IS_A_BROKEN_API	"254"
+#endif
+
+	session_name = (char *) zmalloc(NAME_MAX);
+	if (session_name == NULL) {
+		ret = -ENOMEM;
+		ERR("Out of memory");
+		goto error;
+	}
+
+	fp = open_config(path, "r");
+	if (fp == NULL) {
+		ret = -ENOENT;
+		goto error;
+	}
+
+	while (!feof(fp)) {
+		if ((ret = fscanf(fp, "%" NAME_MAX_SCANF_IS_A_BROKEN_API
+				"[^'=']=%" NAME_MAX_SCANF_IS_A_BROKEN_API "s\n",
+				var, session_name)) != 2) {
+			if (ret == -1) {
+				ERR("Missing session=NAME in config file.");
+				goto error_close;
+			}
+			continue;
+		}
+
+		if (strcmp(var, "session") == 0) {
+			goto found;
+		}
+	}
+
+error_close:
+	if (fclose(fp) < 0) {
+		PERROR("close config read session name");
+	}
+error:
+	free(session_name);
+	return ret;
+found:
+	*name = session_name;
+	if (fclose(fp) < 0) {
+		PERROR("close config read session name found");
+	}
+	return ret;
+}
+
+/*
+ * Returns the session name from the config file.
+ *
+ * The caller is responsible for freeing the returned string.
+ * On error, NULL is returned.
+ */
+char *config_read_session_name(const char *path)
+{
+	int ret;
+	char *name = NULL;
+
+	ret = _config_read_session_name(path, &name);
+	if (ret == -ENOENT) {
+		const char *home_dir = utils_get_home_dir();
+
+		ERR("Can't find valid lttng config %s/.lttngrc", home_dir);
+		MSG("Did you create a session? (lttng create <my_session>)");
+	}
+
+	return name;
+}
+
+/*
+ * Returns the session name from the config file. (no warnings/errors emitted)
+ *
+ * The caller is responsible for freeing the returned string.
+ * On error, NULL is returned.
+ */
+char *config_read_session_name_quiet(const char *path)
+{
+	char *name = NULL;
+
+	(void) _config_read_session_name(path, &name);
+	return name;
+}
+
+/*
+ * Write session name option to the config file.
+ * On success, returns 0;
+ * on error, returns -1.
+ */
+int config_add_session_name(const char *path, const char *name)
+{
+	int ret;
+	const char *attr = "session=";
+	/* Max name len accepted plus attribute's len and the NULL byte. */
+	char session_name[NAME_MAX + strlen(attr) + 1];
+
+	/*
+	 * With GNU C <  2.1, snprintf returns -1 if the target buffer is too small;
+	 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
+	 */
+	ret = snprintf(session_name, sizeof(session_name), "%s%s\n", attr, name);
+	if (ret < 0) {
+		ret = -1;
+		goto error;
+	}
+	ret = write_config(path, ret, session_name);
+error:
+	return ret;
+}
+
+/*
+ * Init configuration directory and file.
+ * On success, returns 0;
+ * on error, returns -1.
+ */
+int config_init(const char *session_name)
+{
+	int ret;
+	const char *path;
+
+	path = utils_get_home_dir();
+	if (path == NULL) {
+		ret = -1;
+		goto error;
+	}
+
+	/* Create default config file */
+	ret = create_config_file(path);
+	if (ret < 0) {
+		goto error;
+	}
+
+	ret = config_add_session_name(path, session_name);
+	if (ret < 0) {
+		goto error;
+	}
+
+	DBG("Init config session in %s", path);
+
+error:
+	return ret;
+}