/* $NetBSD: test-async.c,v 1.2.4.2 2024/02/29 12:30:39 martin Exp $ */ /* * 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 */ /* aliases for the exported symbols */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define CHECK(op) \ do { \ result = (op); \ if (result != ISC_R_SUCCESS) { \ goto cleanup; \ } \ } while (0) /* * Persistent data for use by this module. This will be associated * with client object address in the hash table, and will remain * accessible until the client object is detached. */ typedef struct async_instance { ns_plugin_t *module; isc_mem_t *mctx; isc_ht_t *ht; isc_mutex_t hlock; isc_log_t *lctx; } async_instance_t; typedef struct state { bool async; ns_hook_resevent_t *rev; ns_hookpoint_t hookpoint; isc_result_t origresult; } state_t; /* * Forward declarations of functions referenced in install_hooks(). */ static ns_hookresult_t async_qctx_initialize(void *arg, void *cbdata, isc_result_t *resp); static ns_hookresult_t async_query_done_begin(void *arg, void *cbdata, isc_result_t *resp); static ns_hookresult_t async_qctx_destroy(void *arg, void *cbdata, isc_result_t *resp); /*% * Register the functions to be called at each hook point in 'hooktable', using * memory context 'mctx' for allocating copies of stack-allocated structures * passed to ns_hook_add(). Make sure 'inst' will be passed as the 'cbdata' * argument to every callback. */ static void install_hooks(ns_hooktable_t *hooktable, isc_mem_t *mctx, async_instance_t *inst) { const ns_hook_t async_init = { .action = async_qctx_initialize, .action_data = inst, }; const ns_hook_t async_donebegin = { .action = async_query_done_begin, .action_data = inst, }; const ns_hook_t async_destroy = { .action = async_qctx_destroy, .action_data = inst, }; ns_hook_add(hooktable, mctx, NS_QUERY_QCTX_INITIALIZED, &async_init); ns_hook_add(hooktable, mctx, NS_QUERY_DONE_BEGIN, &async_donebegin); ns_hook_add(hooktable, mctx, NS_QUERY_QCTX_DESTROYED, &async_destroy); } static void logmsg(const char *fmt, ...) { va_list ap; va_start(ap, fmt); isc_log_write(ns_lctx, NS_LOGCATEGORY_GENERAL, NS_LOGMODULE_HOOKS, ISC_LOG_INFO, fmt, ap); va_end(ap); } /** ** Mandatory plugin API functions: ** ** - plugin_destroy ** - plugin_register ** - plugin_version ** - plugin_check **/ /* * Called by ns_plugin_register() to initialize the plugin and * register hook functions into the view hook table. */ isc_result_t plugin_register(const char *parameters, const void *cfg, const char *cfg_file, unsigned long cfg_line, isc_mem_t *mctx, isc_log_t *lctx, void *actx, ns_hooktable_t *hooktable, void **instp) { async_instance_t *inst = NULL; UNUSED(parameters); UNUSED(cfg); UNUSED(actx); isc_log_write(lctx, NS_LOGCATEGORY_GENERAL, NS_LOGMODULE_HOOKS, ISC_LOG_INFO, "registering 'test-async' module from %s:%lu", cfg_file, cfg_line); inst = isc_mem_get(mctx, sizeof(*inst)); *inst = (async_instance_t){ .mctx = NULL }; isc_mem_attach(mctx, &inst->mctx); isc_ht_init(&inst->ht, mctx, 16, ISC_HT_CASE_SENSITIVE); isc_mutex_init(&inst->hlock); /* * Set hook points in the view's hooktable. */ install_hooks(hooktable, mctx, inst); *instp = inst; return (ISC_R_SUCCESS); } isc_result_t plugin_check(const char *parameters, const void *cfg, const char *cfg_file, unsigned long cfg_line, isc_mem_t *mctx, isc_log_t *lctx, void *actx) { UNUSED(parameters); UNUSED(cfg); UNUSED(cfg_file); UNUSED(cfg_line); UNUSED(mctx); UNUSED(lctx); UNUSED(actx); return (ISC_R_SUCCESS); } /* * Called by ns_plugins_free(); frees memory allocated by * the module when it was registered. */ void plugin_destroy(void **instp) { async_instance_t *inst = (async_instance_t *)*instp; if (inst->ht != NULL) { isc_ht_destroy(&inst->ht); isc_mutex_destroy(&inst->hlock); } isc_mem_putanddetach(&inst->mctx, inst, sizeof(*inst)); *instp = NULL; return; } /* * Returns plugin API version for compatibility checks. */ int plugin_version(void) { return (NS_PLUGIN_VERSION); } static state_t * client_state_get(const query_ctx_t *qctx, async_instance_t *inst) { state_t *state = NULL; isc_result_t result; LOCK(&inst->hlock); result = isc_ht_find(inst->ht, (const unsigned char *)&qctx->client, sizeof(qctx->client), (void **)&state); UNLOCK(&inst->hlock); return (result == ISC_R_SUCCESS ? state : NULL); } static void client_state_create(const query_ctx_t *qctx, async_instance_t *inst) { state_t *state = NULL; isc_result_t result; state = isc_mem_get(inst->mctx, sizeof(*state)); *state = (state_t){ .async = false }; LOCK(&inst->hlock); result = isc_ht_add(inst->ht, (const unsigned char *)&qctx->client, sizeof(qctx->client), state); UNLOCK(&inst->hlock); RUNTIME_CHECK(result == ISC_R_SUCCESS); } static void client_state_destroy(const query_ctx_t *qctx, async_instance_t *inst) { state_t *state = client_state_get(qctx, inst); isc_result_t result; if (state == NULL) { return; } LOCK(&inst->hlock); result = isc_ht_delete(inst->ht, (const unsigned char *)&qctx->client, sizeof(qctx->client)); UNLOCK(&inst->hlock); RUNTIME_CHECK(result == ISC_R_SUCCESS); isc_mem_put(inst->mctx, state, sizeof(*state)); } static ns_hookresult_t async_qctx_initialize(void *arg, void *cbdata, isc_result_t *resp) { query_ctx_t *qctx = (query_ctx_t *)arg; async_instance_t *inst = (async_instance_t *)cbdata; state_t *state = NULL; logmsg("qctx init hook"); *resp = ISC_R_UNSET; state = client_state_get(qctx, inst); if (state == NULL) { client_state_create(qctx, inst); } return (NS_HOOK_CONTINUE); } static void cancelasync(ns_hookasync_t *hctx) { UNUSED(hctx); logmsg("cancelasync"); } static void destroyasync(ns_hookasync_t **ctxp) { ns_hookasync_t *ctx = *ctxp; logmsg("destroyasync"); *ctxp = NULL; isc_mem_putanddetach(&ctx->mctx, ctx, sizeof(*ctx)); } static isc_result_t doasync(query_ctx_t *qctx, isc_mem_t *mctx, void *arg, isc_task_t *task, isc_taskaction_t action, void *evarg, ns_hookasync_t **ctxp) { ns_hook_resevent_t *rev = (ns_hook_resevent_t *)isc_event_allocate( mctx, task, NS_EVENT_HOOKASYNCDONE, action, evarg, sizeof(*rev)); ns_hookasync_t *ctx = isc_mem_get(mctx, sizeof(*ctx)); state_t *state = (state_t *)arg; logmsg("doasync"); *ctx = (ns_hookasync_t){ .mctx = NULL }; isc_mem_attach(mctx, &ctx->mctx); ctx->cancel = cancelasync; ctx->destroy = destroyasync; rev->hookpoint = state->hookpoint; rev->origresult = state->origresult; qctx->result = DNS_R_NOTIMP; rev->saved_qctx = qctx; rev->ctx = ctx; state->rev = rev; isc_task_send(task, (isc_event_t **)&rev); *ctxp = ctx; return (ISC_R_SUCCESS); } static ns_hookresult_t async_query_done_begin(void *arg, void *cbdata, isc_result_t *resp) { query_ctx_t *qctx = (query_ctx_t *)arg; async_instance_t *inst = (async_instance_t *)cbdata; state_t *state = client_state_get(qctx, inst); UNUSED(qctx); UNUSED(cbdata); UNUSED(state); logmsg("done begin hook"); if (state->async) { /* resuming */ state->async = false; return (NS_HOOK_CONTINUE); } /* initial call */ state->async = true; state->hookpoint = NS_QUERY_DONE_BEGIN; state->origresult = *resp; ns_query_hookasync(qctx, doasync, state); return (NS_HOOK_RETURN); } static ns_hookresult_t async_qctx_destroy(void *arg, void *cbdata, isc_result_t *resp) { query_ctx_t *qctx = (query_ctx_t *)arg; async_instance_t *inst = (async_instance_t *)cbdata; logmsg("qctx destroy hook"); *resp = ISC_R_UNSET; if (!qctx->detach_client) { return (NS_HOOK_CONTINUE); } client_state_destroy(qctx, inst); return (NS_HOOK_CONTINUE); }