diff options
Diffstat (limited to 'tools/lib/traceevent/event-plugin.c')
| -rw-r--r-- | tools/lib/traceevent/event-plugin.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/tools/lib/traceevent/event-plugin.c b/tools/lib/traceevent/event-plugin.c new file mode 100644 index 000000000000..0c8bf6780e4d --- /dev/null +++ b/tools/lib/traceevent/event-plugin.c @@ -0,0 +1,215 @@ +/* + * 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 <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" + +struct plugin_list { + struct plugin_list *next; + char *name; + void *handle; +}; + +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 a system plugin directory was defined, + * check that first. + */ +#ifdef PLUGIN_DIR + 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); + } +} |