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-rw-r--r--tools/lib/traceevent/event-plugin.c215
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 0000000..0c8bf67
--- /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);
+ }
+}
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