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-rw-r--r--lib/ns/hooks.c363
1 files changed, 363 insertions, 0 deletions
diff --git a/lib/ns/hooks.c b/lib/ns/hooks.c
new file mode 100644
index 0000000..3f614b6
--- /dev/null
+++ b/lib/ns/hooks.c
@@ -0,0 +1,363 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <uv.h>
+
+#include <isc/errno.h>
+#include <isc/list.h>
+#include <isc/log.h>
+#include <isc/mem.h>
+#include <isc/mutex.h>
+#include <isc/print.h>
+#include <isc/result.h>
+#include <isc/types.h>
+#include <isc/util.h>
+
+#include <dns/view.h>
+
+#include <ns/hooks.h>
+#include <ns/log.h>
+#include <ns/query.h>
+
+#define CHECK(op) \
+ do { \
+ result = (op); \
+ if (result != ISC_R_SUCCESS) { \
+ goto cleanup; \
+ } \
+ } while (0)
+
+struct ns_plugin {
+ isc_mem_t *mctx;
+ uv_lib_t handle;
+ void *inst;
+ char *modpath;
+ ns_plugin_check_t *check_func;
+ ns_plugin_register_t *register_func;
+ ns_plugin_destroy_t *destroy_func;
+ LINK(ns_plugin_t) link;
+};
+
+static ns_hooklist_t default_hooktable[NS_HOOKPOINTS_COUNT];
+ns_hooktable_t *ns__hook_table = &default_hooktable;
+
+isc_result_t
+ns_plugin_expandpath(const char *src, char *dst, size_t dstsize) {
+ int result;
+
+ /*
+ * On Unix systems, differentiate between paths and filenames.
+ */
+ if (strchr(src, '/') != NULL) {
+ /*
+ * 'src' is an absolute or relative path. Copy it verbatim.
+ */
+ result = snprintf(dst, dstsize, "%s", src);
+ } else {
+ /*
+ * 'src' is a filename. Prepend default plugin directory path.
+ */
+ result = snprintf(dst, dstsize, "%s/%s", NAMED_PLUGINDIR, src);
+ }
+
+ if (result < 0) {
+ return (isc_errno_toresult(errno));
+ } else if ((size_t)result >= dstsize) {
+ return (ISC_R_NOSPACE);
+ } else {
+ return (ISC_R_SUCCESS);
+ }
+}
+
+static isc_result_t
+load_symbol(uv_lib_t *handle, const char *modpath, const char *symbol_name,
+ void **symbolp) {
+ void *symbol = NULL;
+ int r;
+
+ REQUIRE(handle != NULL);
+ REQUIRE(symbolp != NULL && *symbolp == NULL);
+
+ r = uv_dlsym(handle, symbol_name, &symbol);
+ if (r != 0) {
+ const char *errmsg = uv_dlerror(handle);
+ if (errmsg == NULL) {
+ errmsg = "returned function pointer is NULL";
+ }
+ isc_log_write(ns_lctx, NS_LOGCATEGORY_GENERAL,
+ NS_LOGMODULE_HOOKS, ISC_LOG_ERROR,
+ "failed to look up symbol %s in "
+ "plugin '%s': %s",
+ symbol_name, modpath, errmsg);
+ return (ISC_R_FAILURE);
+ }
+
+ *symbolp = symbol;
+
+ return (ISC_R_SUCCESS);
+}
+
+static void
+unload_plugin(ns_plugin_t **pluginp);
+
+static isc_result_t
+load_plugin(isc_mem_t *mctx, const char *modpath, ns_plugin_t **pluginp) {
+ isc_result_t result;
+ ns_plugin_t *plugin = NULL;
+ ns_plugin_version_t *version_func = NULL;
+ int version;
+ int r;
+
+ REQUIRE(pluginp != NULL && *pluginp == NULL);
+
+ plugin = isc_mem_get(mctx, sizeof(*plugin));
+ memset(plugin, 0, sizeof(*plugin));
+ isc_mem_attach(mctx, &plugin->mctx);
+
+ plugin->modpath = isc_mem_strdup(plugin->mctx, modpath);
+
+ ISC_LINK_INIT(plugin, link);
+
+ r = uv_dlopen(modpath, &plugin->handle);
+ if (r != 0) {
+ const char *errmsg = uv_dlerror(&plugin->handle);
+ if (errmsg == NULL) {
+ errmsg = "unknown error";
+ }
+ isc_log_write(ns_lctx, NS_LOGCATEGORY_GENERAL,
+ NS_LOGMODULE_HOOKS, ISC_LOG_ERROR,
+ "failed to dlopen() plugin '%s': %s", modpath,
+ errmsg);
+ CHECK(ISC_R_FAILURE);
+ }
+
+ CHECK(load_symbol(&plugin->handle, modpath, "plugin_version",
+ (void **)&version_func));
+
+ version = version_func();
+ if (version < (NS_PLUGIN_VERSION - NS_PLUGIN_AGE) ||
+ version > NS_PLUGIN_VERSION)
+ {
+ isc_log_write(ns_lctx, NS_LOGCATEGORY_GENERAL,
+ NS_LOGMODULE_HOOKS, ISC_LOG_ERROR,
+ "plugin API version mismatch: %d/%d", version,
+ NS_PLUGIN_VERSION);
+ CHECK(ISC_R_FAILURE);
+ }
+
+ CHECK(load_symbol(&plugin->handle, modpath, "plugin_check",
+ (void **)&plugin->check_func));
+ CHECK(load_symbol(&plugin->handle, modpath, "plugin_register",
+ (void **)&plugin->register_func));
+ CHECK(load_symbol(&plugin->handle, modpath, "plugin_destroy",
+ (void **)&plugin->destroy_func));
+
+ *pluginp = plugin;
+
+ return (ISC_R_SUCCESS);
+
+cleanup:
+ isc_log_write(ns_lctx, NS_LOGCATEGORY_GENERAL, NS_LOGMODULE_HOOKS,
+ ISC_LOG_ERROR,
+ "failed to dynamically load plugin '%s': %s", modpath,
+ isc_result_totext(result));
+
+ unload_plugin(&plugin);
+
+ return (result);
+}
+
+static void
+unload_plugin(ns_plugin_t **pluginp) {
+ ns_plugin_t *plugin = NULL;
+
+ REQUIRE(pluginp != NULL && *pluginp != NULL);
+
+ plugin = *pluginp;
+ *pluginp = NULL;
+
+ isc_log_write(ns_lctx, NS_LOGCATEGORY_GENERAL, NS_LOGMODULE_HOOKS,
+ ISC_LOG_DEBUG(1), "unloading plugin '%s'",
+ plugin->modpath);
+
+ if (plugin->inst != NULL) {
+ plugin->destroy_func(&plugin->inst);
+ }
+
+ uv_dlclose(&plugin->handle);
+ isc_mem_free(plugin->mctx, plugin->modpath);
+ isc_mem_putanddetach(&plugin->mctx, plugin, sizeof(*plugin));
+}
+
+isc_result_t
+ns_plugin_register(const char *modpath, const char *parameters, const void *cfg,
+ const char *cfg_file, unsigned long cfg_line,
+ isc_mem_t *mctx, isc_log_t *lctx, void *actx,
+ dns_view_t *view) {
+ isc_result_t result;
+ ns_plugin_t *plugin = NULL;
+
+ REQUIRE(mctx != NULL);
+ REQUIRE(lctx != NULL);
+ REQUIRE(view != NULL);
+
+ isc_log_write(ns_lctx, NS_LOGCATEGORY_GENERAL, NS_LOGMODULE_HOOKS,
+ ISC_LOG_INFO, "loading plugin '%s'", modpath);
+
+ CHECK(load_plugin(mctx, modpath, &plugin));
+
+ isc_log_write(ns_lctx, NS_LOGCATEGORY_GENERAL, NS_LOGMODULE_HOOKS,
+ ISC_LOG_INFO, "registering plugin '%s'", modpath);
+
+ CHECK(plugin->register_func(parameters, cfg, cfg_file, cfg_line, mctx,
+ lctx, actx, view->hooktable,
+ &plugin->inst));
+
+ ISC_LIST_APPEND(*(ns_plugins_t *)view->plugins, plugin, link);
+
+cleanup:
+ if (result != ISC_R_SUCCESS && plugin != NULL) {
+ unload_plugin(&plugin);
+ }
+
+ return (result);
+}
+
+isc_result_t
+ns_plugin_check(const char *modpath, const char *parameters, const void *cfg,
+ const char *cfg_file, unsigned long cfg_line, isc_mem_t *mctx,
+ isc_log_t *lctx, void *actx) {
+ isc_result_t result;
+ ns_plugin_t *plugin = NULL;
+
+ CHECK(load_plugin(mctx, modpath, &plugin));
+
+ result = plugin->check_func(parameters, cfg, cfg_file, cfg_line, mctx,
+ lctx, actx);
+
+cleanup:
+ if (plugin != NULL) {
+ unload_plugin(&plugin);
+ }
+
+ return (result);
+}
+
+void
+ns_hooktable_init(ns_hooktable_t *hooktable) {
+ int i;
+
+ for (i = 0; i < NS_HOOKPOINTS_COUNT; i++) {
+ ISC_LIST_INIT((*hooktable)[i]);
+ }
+}
+
+isc_result_t
+ns_hooktable_create(isc_mem_t *mctx, ns_hooktable_t **tablep) {
+ ns_hooktable_t *hooktable = NULL;
+
+ REQUIRE(tablep != NULL && *tablep == NULL);
+
+ hooktable = isc_mem_get(mctx, sizeof(*hooktable));
+
+ ns_hooktable_init(hooktable);
+
+ *tablep = hooktable;
+
+ return (ISC_R_SUCCESS);
+}
+
+void
+ns_hooktable_free(isc_mem_t *mctx, void **tablep) {
+ ns_hooktable_t *table = NULL;
+ ns_hook_t *hook = NULL, *next = NULL;
+ int i = 0;
+
+ REQUIRE(tablep != NULL && *tablep != NULL);
+
+ table = *tablep;
+ *tablep = NULL;
+
+ for (i = 0; i < NS_HOOKPOINTS_COUNT; i++) {
+ for (hook = ISC_LIST_HEAD((*table)[i]); hook != NULL;
+ hook = next)
+ {
+ next = ISC_LIST_NEXT(hook, link);
+ ISC_LIST_UNLINK((*table)[i], hook, link);
+ if (hook->mctx != NULL) {
+ isc_mem_putanddetach(&hook->mctx, hook,
+ sizeof(*hook));
+ }
+ }
+ }
+
+ isc_mem_put(mctx, table, sizeof(*table));
+}
+
+void
+ns_hook_add(ns_hooktable_t *hooktable, isc_mem_t *mctx,
+ ns_hookpoint_t hookpoint, const ns_hook_t *hook) {
+ ns_hook_t *copy = NULL;
+
+ REQUIRE(hooktable != NULL);
+ REQUIRE(mctx != NULL);
+ REQUIRE(hookpoint < NS_HOOKPOINTS_COUNT);
+ REQUIRE(hook != NULL);
+
+ copy = isc_mem_get(mctx, sizeof(*copy));
+ memset(copy, 0, sizeof(*copy));
+
+ copy->action = hook->action;
+ copy->action_data = hook->action_data;
+ isc_mem_attach(mctx, &copy->mctx);
+
+ ISC_LINK_INIT(copy, link);
+ ISC_LIST_APPEND((*hooktable)[hookpoint], copy, link);
+}
+
+void
+ns_plugins_create(isc_mem_t *mctx, ns_plugins_t **listp) {
+ ns_plugins_t *plugins = NULL;
+
+ REQUIRE(listp != NULL && *listp == NULL);
+
+ plugins = isc_mem_get(mctx, sizeof(*plugins));
+ memset(plugins, 0, sizeof(*plugins));
+ ISC_LIST_INIT(*plugins);
+
+ *listp = plugins;
+}
+
+void
+ns_plugins_free(isc_mem_t *mctx, void **listp) {
+ ns_plugins_t *list = NULL;
+ ns_plugin_t *plugin = NULL, *next = NULL;
+
+ REQUIRE(listp != NULL && *listp != NULL);
+
+ list = *listp;
+ *listp = NULL;
+
+ for (plugin = ISC_LIST_HEAD(*list); plugin != NULL; plugin = next) {
+ next = ISC_LIST_NEXT(plugin, link);
+ ISC_LIST_UNLINK(*list, plugin, link);
+ unload_plugin(&plugin);
+ }
+
+ isc_mem_put(mctx, list, sizeof(*list));
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-03 17:19:43 +0000