+/*
+ * 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;
+}
projects / lttng-tools.git / blobdiff