diff options
Diffstat (limited to 'src/event-plugin.c')
| -rw-r--r-- | src/event-plugin.c | 711 |
1 files changed, 711 insertions, 0 deletions
diff --git a/src/event-plugin.c b/src/event-plugin.c new file mode 100644 index 0000000..f42243f --- /dev/null +++ b/src/event-plugin.c @@ -0,0 +1,711 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com> + * + */ + +#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 <errno.h> +#include "event-parse.h" +#include "event-parse-local.h" +#include "event-utils.h" +#include "trace-seq.h" + +#define LOCAL_PLUGIN_DIR ".local/lib/traceevent/plugins/" + +static struct registered_plugin_options { + struct registered_plugin_options *next; + struct tep_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 tep_plugin_list { + struct tep_plugin_list *next; + char *name; + void *handle; +}; + +struct tep_plugins_dir { + struct tep_plugins_dir *next; + char *path; + enum tep_plugin_load_priority prio; +}; + +static void lower_case(char *str) +{ + if (!str) + return; + for (; *str; str++) + *str = tolower(*str); +} + +static int update_option_value(struct tep_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; +} + +/** + * tep_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 tep_plugin_free_options_list(). + */ +char **tep_plugin_list_options(void) +{ + struct registered_plugin_options *reg; + struct tep_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; + int ret; + + ret = asprintf(&name, "%s:%s", alias, op->name); + if (ret < 0) + goto err; + + 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 tep_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 tep_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; +} + +/** + * tep_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 tep_plugin_add_options(const char *name, + struct tep_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; +} + +/** + * tep_plugin_remove_options - remove plugin options that were registered + * @options: Options to removed that were registered with tep_plugin_add_options + */ +void tep_plugin_remove_options(struct tep_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; + } + } +} + +static int parse_option_name(char **option, char **plugin) +{ + char *p; + + *plugin = NULL; + + if ((p = strstr(*option, ":"))) { + *plugin = *option; + *p = '\0'; + *option = strdup(p + 1); + if (!*option) + return -1; + } + return 0; +} + +static struct tep_plugin_option * +find_registered_option(const char *plugin, const char *option) +{ + struct registered_plugin_options *reg; + struct tep_plugin_option *op; + const char *op_plugin; + + for (reg = registered_options; reg; reg = reg->next) { + for (op = reg->options; op->name; op++) { + if (op->plugin_alias) + op_plugin = op->plugin_alias; + else + op_plugin = op->file; + + if (plugin && strcmp(plugin, op_plugin) != 0) + continue; + if (strcmp(option, op->name) != 0) + continue; + + return op; + } + } + + return NULL; +} + +static int process_option(const char *plugin, const char *option, const char *val) +{ + struct tep_plugin_option *op; + + op = find_registered_option(plugin, option); + if (!op) + return 0; + + return update_option_value(op, val); +} + +/** + * tep_plugin_add_option - add an option/val pair to set plugin options + * @name: The name of the option (format: <plugin>:<option> or just <option>) + * @val: (optional) the value for the option + * + * Modify a plugin option. If @val is given than the value of the option + * is set (note, some options just take a boolean, so @val must be either + * "1" or "0" or "true" or "false"). + */ +int tep_plugin_add_option(const char *name, const char *val) +{ + struct trace_plugin_options *op; + char *option_str; + char *plugin; + + option_str = strdup(name); + if (!option_str) + return -ENOMEM; + + if (parse_option_name(&option_str, &plugin) < 0) + return -ENOMEM; + + /* If the option exists, update the val */ + for (op = trace_plugin_options; op; op = op->next) { + /* Both must be NULL or not NULL */ + if ((!plugin || !op->plugin) && plugin != op->plugin) + continue; + if (plugin && strcmp(plugin, op->plugin) != 0) + continue; + if (strcmp(op->option, option_str) != 0) + continue; + + /* update option */ + free(op->value); + if (val) { + op->value = strdup(val); + if (!op->value) + goto out_free; + } else + op->value = NULL; + + /* plugin and option_str don't get freed at the end */ + free(plugin); + free(option_str); + + plugin = op->plugin; + option_str = op->option; + break; + } + + /* If not found, create */ + if (!op) { + op = malloc(sizeof(*op)); + if (!op) + goto out_free; + memset(op, 0, sizeof(*op)); + op->plugin = plugin; + op->option = option_str; + if (val) { + op->value = strdup(val); + if (!op->value) { + free(op); + goto out_free; + } + } + op->next = trace_plugin_options; + trace_plugin_options = op; + } + + return process_option(plugin, option_str, val); + +out_free: + free(plugin); + free(option_str); + return -ENOMEM; +} + +static void print_op_data(struct trace_seq *s, const char *name, + const char *op) +{ + if (op) + trace_seq_printf(s, "%8s:\t%s\n", name, op); +} + +/** + * tep_plugin_print_options - print out the registered plugin options + * @s: The trace_seq descriptor to write the plugin options into + * + * Writes a list of options into trace_seq @s. + */ +void tep_plugin_print_options(struct trace_seq *s) +{ + struct registered_plugin_options *reg; + struct tep_plugin_option *op; + + for (reg = registered_options; reg; reg = reg->next) { + if (reg != registered_options) + trace_seq_printf(s, "============\n"); + for (op = reg->options; op->name; op++) { + if (op != reg->options) + trace_seq_printf(s, "------------\n"); + print_op_data(s, "file", op->file); + print_op_data(s, "plugin", op->plugin_alias); + print_op_data(s, "option", op->name); + print_op_data(s, "desc", op->description); + print_op_data(s, "value", op->value); + trace_seq_printf(s, "%8s:\t%d\n", "set", op->set); + } + } +} + +/** + * tep_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 tep_load_plugins() + * + * Writes to the trace_seq @s the list of plugins (files) that is + * returned by tep_load_plugins(). Use @prefix and @suffix for formating: + * @prefix = " ", @suffix = "\n". + */ +void tep_print_plugins(struct trace_seq *s, + const char *prefix, const char *suffix, + const struct tep_plugin_list *list) +{ + while (list) { + trace_seq_printf(s, "%s%s%s", prefix, list->name, suffix); + list = list->next; + } +} + +static void +load_plugin(struct tep_handle *tep, const char *path, + const char *file, void *data) +{ + struct tep_plugin_list **plugin_list = data; + struct tep_plugin_option *options; + tep_plugin_load_func func; + struct tep_plugin_list *list; + const char *alias; + char *plugin; + void *handle; + int ret; + + ret = asprintf(&plugin, "%s/%s", path, file); + if (ret < 0) { + tep_warning("could not allocate plugin memory\n"); + return; + } + + handle = dlopen(plugin, RTLD_NOW | RTLD_GLOBAL); + if (!handle) { + tep_warning("could not load plugin '%s'\n%s\n", + plugin, dlerror()); + goto out_free; + } + + alias = dlsym(handle, TEP_PLUGIN_ALIAS_NAME); + if (!alias) + alias = file; + + options = dlsym(handle, TEP_PLUGIN_OPTIONS_NAME); + if (options) { + while (options->name) { + ret = update_option(alias, options); + if (ret < 0) + goto out_free; + options++; + } + } + + func = dlsym(handle, TEP_PLUGIN_LOADER_NAME); + if (!func) { + tep_warning("could not find func '%s' in plugin '%s'\n%s\n", + TEP_PLUGIN_LOADER_NAME, plugin, dlerror()); + goto out_free; + } + + list = malloc(sizeof(*list)); + if (!list) { + tep_warning("could not allocate plugin memory\n"); + goto out_free; + } + + list->next = *plugin_list; + list->handle = handle; + list->name = plugin; + *plugin_list = list; + + tep_info("registering plugin: %s", plugin); + func(tep); + return; + + out_free: + free(plugin); +} + +static void +load_plugins_dir(struct tep_handle *tep, const char *suffix, + const char *path, + void (*load_plugin)(struct tep_handle *tep, + 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(tep, path, name, data); + } + + closedir(dir); +} + +/** + * tep_load_plugins_hook - call a user specified callback to load a plugin + * @tep: handler to traceevent context + * @suffix: filter only plugin files with given suffix + * @load_plugin: user specified callback, called for each plugin file + * @data: custom context, passed to @load_plugin + * + * Searches for traceevent plugin files and calls @load_plugin for each + * The order of plugins search is: + * - Directories, specified in @tep->plugins_dir and priority TEP_PLUGIN_FIRST + * - Directory, specified at compile time with PLUGIN_TRACEEVENT_DIR + * - Directory, specified by environment variable TRACEEVENT_PLUGIN_DIR + * - In user's home: ~/.local/lib/traceevent/plugins/ + * - Directories, specified in @tep->plugins_dir and priority TEP_PLUGIN_LAST + * + */ +void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix, + void (*load_plugin)(struct tep_handle *tep, + const char *path, + const char *name, + void *data), + void *data) +{ + struct tep_plugins_dir *dir = NULL; + char *home; + char *path; + char *envdir; + int ret; + + if (tep && tep->flags & TEP_DISABLE_PLUGINS) + return; + + if (tep) + dir = tep->plugins_dir; + while (dir) { + if (dir->prio == TEP_PLUGIN_FIRST) + load_plugins_dir(tep, suffix, dir->path, + load_plugin, data); + dir = dir->next; + } + + /* + * If a system plugin directory was defined, + * check that first. + */ +#ifdef PLUGIN_DIR + if (!tep || !(tep->flags & TEP_DISABLE_SYS_PLUGINS)) + load_plugins_dir(tep, 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(tep, suffix, envdir, load_plugin, data); + + /* + * Now let the home directory override the environment + * or system defaults. + */ + home = getenv("HOME"); + if (!home) + return; + + ret = asprintf(&path, "%s/%s", home, LOCAL_PLUGIN_DIR); + if (ret < 0) { + tep_warning("could not allocate plugin memory\n"); + return; + } + + load_plugins_dir(tep, suffix, path, load_plugin, data); + + if (tep) + dir = tep->plugins_dir; + while (dir) { + if (dir->prio == TEP_PLUGIN_LAST) + load_plugins_dir(tep, suffix, dir->path, + load_plugin, data); + dir = dir->next; + } + + free(path); +} + +struct tep_plugin_list* +tep_load_plugins(struct tep_handle *tep) +{ + struct tep_plugin_list *list = NULL; + + tep_load_plugins_hook(tep, ".so", load_plugin, &list); + return list; +} + +/** + * tep_add_plugin_path - Add a new plugin directory. + * @tep: Trace event handler. + * @path: Path to a directory. All plugin files in that + * directory will be loaded. + *@prio: Load priority of the plugins in that directory. + * + * Returns -1 in case of an error, 0 otherwise. + */ +int tep_add_plugin_path(struct tep_handle *tep, char *path, + enum tep_plugin_load_priority prio) +{ + struct tep_plugins_dir *dir; + + if (!tep || !path) + return -1; + + dir = calloc(1, sizeof(*dir)); + if (!dir) + return -1; + + dir->path = strdup(path); + if (!dir->path) { + free(dir); + return -1; + } + dir->prio = prio; + dir->next = tep->plugins_dir; + tep->plugins_dir = dir; + + return 0; +} + +__hidden void free_tep_plugin_paths(struct tep_handle *tep) +{ + struct tep_plugins_dir *dir; + + if (!tep) + return; + + dir = tep->plugins_dir; + while (dir) { + tep->plugins_dir = tep->plugins_dir->next; + free(dir->path); + free(dir); + dir = tep->plugins_dir; + } +} + +void +tep_unload_plugins(struct tep_plugin_list *plugin_list, struct tep_handle *tep) +{ + tep_plugin_unload_func func; + struct tep_plugin_list *list; + + while (plugin_list) { + list = plugin_list; + plugin_list = list->next; + func = dlsym(list->handle, TEP_PLUGIN_UNLOADER_NAME); + if (func) + func(tep); + dlclose(list->handle); + free(list->name); + free(list); + } +} |