/*
* Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License (not later!)
*
* 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <http://www.gnu.org/licenses>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <dlfcn.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include "event-parse.h"
#include "event-utils.h"
#define LOCAL_PLUGIN_DIR ".traceevent/plugins"
static struct registered_plugin_options {
struct registered_plugin_options *next;
struct pevent_plugin_option *options;
} *registered_options;
static struct trace_plugin_options {
struct trace_plugin_options *next;
char *plugin;
char *option;
char *value;
} *trace_plugin_options;
struct plugin_list {
struct plugin_list *next;
char *name;
void *handle;
};
static void lower_case(char *str)
{
if (!str)
return;
for (; *str; str++)
*str = tolower(*str);
}
static int update_option_value(struct pevent_plugin_option *op, const char *val)
{
char *op_val;
if (!val) {
/* toggle, only if option is boolean */
if (op->value)
/* Warn? */
return 0;
op->set ^= 1;
return 0;
}
/*
* If the option has a value then it takes a string
* otherwise the option is a boolean.
*/
if (op->value) {
op->value = val;
return 0;
}
/* Option is boolean, must be either "1", "0", "true" or "false" */
op_val = strdup(val);
if (!op_val)
return -1;
lower_case(op_val);
if (strcmp(val, "1") == 0 || strcmp(val, "true") == 0)
op->set = 1;
else if (strcmp(val, "0") == 0 || strcmp(val, "false") == 0)
op->set = 0;
free(op_val);
return 0;
}
/**
* traceevent_plugin_list_options - get list of plugin options
*
* Returns an array of char strings that list the currently registered
* plugin options in the format of <plugin>:<option>. This list can be
* used by toggling the option.
*
* Returns NULL if there's no options registered. On error it returns
* INVALID_PLUGIN_LIST_OPTION
*
* Must be freed with traceevent_plugin_free_options_list().
*/
char **traceevent_plugin_list_options(void)
{
struct registered_plugin_options *reg;
struct pevent_plugin_option *op;
char **list = NULL;
char *name;
int count = 0;
for (reg = registered_options; reg; reg = reg->next) {
for (op = reg->options; op->name; op++) {
char *alias = op->plugin_alias ? op->plugin_alias : op->file;
char **temp = list;
name = malloc(strlen(op->name) + strlen(alias) + 2);
if (!name)
goto err;
sprintf(name, "%s:%s", alias, op->name);
list = realloc(list, count + 2);
if (!list) {
list = temp;
free(name);
goto err;
}
list[count++] = name;
list[count] = NULL;
}
}
return list;
err:
while (--count >= 0)
free(list[count]);
free(list);
return INVALID_PLUGIN_LIST_OPTION;
}
void traceevent_plugin_free_options_list(char **list)
{
int i;
if (!list)
return;
if (list == INVALID_PLUGIN_LIST_OPTION)
return;
for (i = 0; list[i]; i++)
free(list[i]);
free(list);
}
static int
update_option(const char *file, struct pevent_plugin_option *option)
{
struct trace_plugin_options *op;
char *plugin;
int ret = 0;
if (option->plugin_alias) {
plugin = strdup(option->plugin_alias);
if (!plugin)
return -1;
} else {
char *p;
plugin = strdup(file);
if (!plugin)
return -1;
p = strstr(plugin, ".");
if (p)
*p = '\0';
}
/* first look for named options */
for (op = trace_plugin_options; op; op = op->next) {
if (!op->plugin)
continue;
if (strcmp(op->plugin, plugin) != 0)
continue;
if (strcmp(op->option, option->name) != 0)
continue;
ret = update_option_value(option, op->value);
if (ret)
goto out;
break;
}
/* first look for unnamed options */
for (op = trace_plugin_options; op; op = op->next) {
if (op->plugin)
continue;
if (strcmp(op->option, option->name) != 0)
continue;
ret = update_option_value(option, op->value);
break;
}
out:
free(plugin);
return ret;
}
/**
* traceevent_plugin_add_options - Add a set of options by a plugin
* @name: The name of the plugin adding the options
* @options: The set of options being loaded
*
* Sets the options with the values that have been added by user.
*/
int traceevent_plugin_add_options(const char *name,
struct pevent_plugin_option *options)
{
struct registered_plugin_options *reg;
reg = malloc(sizeof(*reg));
if (!reg)
return -1;
reg->next = registered_options;
reg->options = options;
registered_options = reg;
while (options->name) {
update_option(name, options);
options++;
}
return 0;
}
/**
* traceevent_plugin_remove_options - remove plugin options that were registered
* @options: Options to removed that were registered with traceevent_plugin_add_options
*/
void traceevent_plugin_remove_options(struct pevent_plugin_option *options)
{
struct registered_plugin_options **last;
struct registered_plugin_options *reg;
for (last = ®istered_options; *last; last = &(*last)->next) {
if ((*last)->options == options) {
reg = *last;
*last = reg->next;
free(reg);
return;
}
}
}
/**
* traceevent_print_plugins - print out the list of plugins loaded
* @s: the trace_seq descripter to write to
* @prefix: The prefix string to add before listing the option name
* @suffix: The suffix string ot append after the option name
* @list: The list of plugins (usually returned by traceevent_load_plugins()
*
* Writes to the trace_seq @s the list of plugins (files) that is
* returned by traceevent_load_plugins(). Use @prefix and @suffix for formating:
* @prefix = " ", @suffix = "\n".
*/
void traceevent_print_plugins(struct trace_seq *s,
const char *prefix, const char *suffix,
const struct plugin_list *list)
{
while (list) {
trace_seq_printf(s, "%s%s%s", prefix, list->name, suffix);
list = list->next;
}
}
static void
load_plugin(struct pevent *pevent, const char *path,
const char *file, void *data)
{
struct plugin_list **plugin_list = data;
pevent_plugin_load_func func;
struct plugin_list *list;
const char *alias;
char *plugin;
void *handle;
plugin = malloc(strlen(path) + strlen(file) + 2);
if (!plugin) {
warning("could not allocate plugin memory\n");
return;
}
strcpy(plugin, path);
strcat(plugin, "/");
strcat(plugin, file);
handle = dlopen(plugin, RTLD_NOW | RTLD_GLOBAL);
if (!handle) {
warning("could not load plugin '%s'\n%s\n",
plugin, dlerror());
goto out_free;
}
alias = dlsym(handle, PEVENT_PLUGIN_ALIAS_NAME);
if (!alias)
alias = file;
func = dlsym(handle, PEVENT_PLUGIN_LOADER_NAME);
if (!func) {
warning("could not find func '%s' in plugin '%s'\n%s\n",
PEVENT_PLUGIN_LOADER_NAME, plugin, dlerror());
goto out_free;
}
list = malloc(sizeof(*list));
if (!list) {
warning("could not allocate plugin memory\n");
goto out_free;
}
list->next = *plugin_list;
list->handle = handle;
list->name = plugin;
*plugin_list = list;
pr_stat("registering plugin: %s", plugin);
func(pevent);
return;
out_free:
free(plugin);
}
static void
load_plugins_dir(struct pevent *pevent, const char *suffix,
const char *path,
void (*load_plugin)(struct pevent *pevent,
const char *path,
const char *name,
void *data),
void *data)
{
struct dirent *dent;
struct stat st;
DIR *dir;
int ret;
ret = stat(path, &st);
if (ret < 0)
return;
if (!S_ISDIR(st.st_mode))
return;
dir = opendir(path);
if (!dir)
return;
while ((dent = readdir(dir))) {
const char *name = dent->d_name;
if (strcmp(name, ".") == 0 ||
strcmp(name, "..") == 0)
continue;
/* Only load plugins that end in suffix */
if (strcmp(name + (strlen(name) - strlen(suffix)), suffix) != 0)
continue;
load_plugin(pevent, path, name, data);
}
closedir(dir);
}
static void
load_plugins(struct pevent *pevent, const char *suffix,
void (*load_plugin)(struct pevent *pevent,
const char *path,
const char *name,
void *data),
void *data)
{
char *home;
char *path;
char *envdir;
if (pevent->flags & PEVENT_DISABLE_PLUGINS)
return;
/*
* If a system plugin directory was defined,
* check that first.
*/
#ifdef PLUGIN_DIR
if (!(pevent->flags & PEVENT_DISABLE_SYS_PLUGINS))
load_plugins_dir(pevent, suffix, PLUGIN_DIR,
load_plugin, data);
#endif
/*
* Next let the environment-set plugin directory
* override the system defaults.
*/
envdir = getenv("TRACEEVENT_PLUGIN_DIR");
if (envdir)
load_plugins_dir(pevent, suffix, envdir, load_plugin, data);
/*
* Now let the home directory override the environment
* or system defaults.
*/
home = getenv("HOME");
if (!home)
return;
path = malloc(strlen(home) + strlen(LOCAL_PLUGIN_DIR) + 2);
if (!path) {
warning("could not allocate plugin memory\n");
return;
}
strcpy(path, home);
strcat(path, "/");
strcat(path, LOCAL_PLUGIN_DIR);
load_plugins_dir(pevent, suffix, path, load_plugin, data);
free(path);
}
struct plugin_list*
traceevent_load_plugins(struct pevent *pevent)
{
struct plugin_list *list = NULL;
load_plugins(pevent, ".so", load_plugin, &list);
return list;
}
void
traceevent_unload_plugins(struct plugin_list *plugin_list, struct pevent *pevent)
{
pevent_plugin_unload_func func;
struct plugin_list *list;
while (plugin_list) {
list = plugin_list;
plugin_list = list->next;
func = dlsym(list->handle, PEVENT_PLUGIN_UNLOADER_NAME);
if (func)
func(pevent);
dlclose(list->handle);
free(list->name);
free(list);
}
}