diff options
Diffstat (limited to 'lib/dns/dynamic_db.c')
| -rw-r--r-- | lib/dns/dynamic_db.c | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/lib/dns/dynamic_db.c b/lib/dns/dynamic_db.c new file mode 100644 index 00000000..bf831617 --- /dev/null +++ b/lib/dns/dynamic_db.c @@ -0,0 +1,366 @@ +/* + * Copyright (C) 2008-2011 Red Hat, Inc. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND Red Hat DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL Red Hat BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + + +#include <config.h> + +#include <isc/buffer.h> +#include <isc/mem.h> +#include <isc/mutex.h> +#include <isc/once.h> +#include <isc/result.h> +#include <isc/region.h> +#include <isc/task.h> +#include <isc/types.h> +#include <isc/util.h> + +#include <dns/dynamic_db.h> +#include <dns/log.h> +#include <dns/types.h> +#include <dns/view.h> +#include <dns/zone.h> + +#include <string.h> + +#if HAVE_DLFCN_H +#include <dlfcn.h> +#endif + +#ifndef DYNDB_LIBDIR +#define DYNDB_LIBDIR "" +#endif + +#define CHECK(op) \ + do { result = (op); \ + if (result != ISC_R_SUCCESS) goto cleanup; \ + } while (0) + + +typedef isc_result_t (*register_func_t)(isc_mem_t *mctx, const char *name, + const char * const *argv, + const dns_dyndb_arguments_t *dyndb_args); +typedef void (*destroy_func_t)(void); + +typedef struct dyndb_implementation dyndb_implementation_t; + +struct dyndb_implementation { + isc_mem_t *mctx; + void *handle; + register_func_t register_function; + destroy_func_t destroy_function; + LINK(dyndb_implementation_t) link; +}; + +struct dns_dyndb_arguments { + dns_view_t *view; + dns_zonemgr_t *zmgr; + isc_task_t *task; + isc_timermgr_t *timermgr; +}; + +/* List of implementations. Locked by dyndb_lock. */ +static LIST(dyndb_implementation_t) dyndb_implementations; +/* Locks dyndb_implementations. */ +static isc_mutex_t dyndb_lock; +static isc_once_t once = ISC_ONCE_INIT; + +static void +dyndb_initialize(void) { + RUNTIME_CHECK(isc_mutex_init(&dyndb_lock) == ISC_R_SUCCESS); + INIT_LIST(dyndb_implementations); +} + + +#if HAVE_DLFCN_H +static isc_result_t +load_symbol(void *handle, const char *symbol_name, void **symbolp) +{ + const char *errmsg; + void *symbol; + + REQUIRE(handle != NULL); + REQUIRE(symbolp != NULL && *symbolp == NULL); + + symbol = dlsym(handle, symbol_name); + if (symbol == NULL) { + errmsg = dlerror(); + if (errmsg == NULL) + errmsg = "returned function pointer is NULL"; + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_DYNDB, ISC_LOG_ERROR, + "failed to lookup symbol %s: %s", + symbol_name, errmsg); + return ISC_R_FAILURE; + } + dlerror(); + + *symbolp = symbol; + + return ISC_R_SUCCESS; +} + +static isc_result_t +load_library(isc_mem_t *mctx, const char *filename, dyndb_implementation_t **impp) +{ + isc_result_t result; + size_t module_size; + isc_buffer_t *module_buf = NULL; + isc_region_t module_region; + void *handle = NULL; + dyndb_implementation_t *imp; + register_func_t register_function = NULL; + destroy_func_t destroy_function = NULL; + + REQUIRE(impp != NULL && *impp == NULL); + + /* Build up the full path. */ + module_size = strlen(DYNDB_LIBDIR) + strlen(filename) + 1; + CHECK(isc_buffer_allocate(mctx, &module_buf, module_size)); + isc_buffer_putstr(module_buf, DYNDB_LIBDIR); + isc_buffer_putstr(module_buf, filename); + isc_buffer_putuint8(module_buf, 0); + isc_buffer_region(module_buf, &module_region); + + handle = dlopen((char *)module_region.base, RTLD_LAZY); + if (handle == NULL) { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, + DNS_LOGMODULE_DYNDB, ISC_LOG_ERROR, + "failed to dynamically load driver '%s': %s", + filename, dlerror()); + result = ISC_R_FAILURE; + goto cleanup; + } + dlerror(); + + CHECK(load_symbol(handle, "dynamic_driver_init", + (void **)®ister_function)); + CHECK(load_symbol(handle, "dynamic_driver_destroy", + (void **)&destroy_function)); + + imp = isc_mem_get(mctx, sizeof(dyndb_implementation_t)); + if (imp == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup; + } + + imp->mctx = NULL; + isc_mem_attach(mctx, &imp->mctx); + imp->handle = handle; + imp->register_function = register_function; + imp->destroy_function = destroy_function; + INIT_LINK(imp, link); + + *impp = imp; + +cleanup: + if (result != ISC_R_SUCCESS && handle != NULL) + dlclose(handle); + if (module_buf != NULL) + isc_buffer_free(&module_buf); + + return result; +} + +static void +unload_library(dyndb_implementation_t **impp) +{ + dyndb_implementation_t *imp; + + REQUIRE(impp != NULL && *impp != NULL); + + imp = *impp; + + isc_mem_putanddetach(&imp->mctx, imp, sizeof(dyndb_implementation_t)); + + *impp = NULL; +} + +#else /* HAVE_DLFCN_H */ +static isc_result_t +load_library(isc_mem_t *mctx, const char *filename, dyndb_implementation_t **impp) +{ + UNUSED(mctx); + UNUSED(filename); + UNUSED(impp); + + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DYNDB, + ISC_LOG_ERROR, + "dynamic database support is not implemented") + + return ISC_R_NOTIMPLEMENTED; +} + +static void +unload_library(dyndb_implementation_t **impp) +{ + dyndb_implementation_t *imp; + + REQUIRE(impp != NULL && *impp != NULL); + + imp = *impp; + + isc_mem_putanddetach(&imp->mctx, imp, sizeof(dyndb_implementation_t)); + + *impp = NULL; +} +#endif /* HAVE_DLFCN_H */ + +isc_result_t +dns_dynamic_db_load(const char *libname, const char *name, isc_mem_t *mctx, + const char * const *argv, + const dns_dyndb_arguments_t *dyndb_args) +{ + isc_result_t result; + dyndb_implementation_t *implementation = NULL; + + RUNTIME_CHECK(isc_once_do(&once, dyndb_initialize) == ISC_R_SUCCESS); + + CHECK(load_library(mctx, libname, &implementation)); + CHECK(implementation->register_function(mctx, name, argv, dyndb_args)); + + LOCK(&dyndb_lock); + APPEND(dyndb_implementations, implementation, link); + UNLOCK(&dyndb_lock); + + return ISC_R_SUCCESS; + +cleanup: + if (implementation != NULL) + unload_library(&implementation); + + return result; +} + +void +dns_dynamic_db_cleanup(isc_boolean_t exiting) +{ + dyndb_implementation_t *elem; + dyndb_implementation_t *prev; + + RUNTIME_CHECK(isc_once_do(&once, dyndb_initialize) == ISC_R_SUCCESS); + + LOCK(&dyndb_lock); + elem = TAIL(dyndb_implementations); + while (elem != NULL) { + prev = PREV(elem, link); + UNLINK(dyndb_implementations, elem, link); + elem->destroy_function(); + unload_library(&elem); + elem = prev; + } + UNLOCK(&dyndb_lock); + + if (exiting == ISC_TRUE) + isc_mutex_destroy(&dyndb_lock); +} + +dns_dyndb_arguments_t * +dns_dyndb_arguments_create(isc_mem_t *mctx) +{ + dns_dyndb_arguments_t *args; + + args = isc_mem_get(mctx, sizeof(*args)); + if (args != NULL) + memset(args, 0, sizeof(*args)); + + return args; +} + +void +dns_dyndb_arguments_destroy(isc_mem_t *mctx, dns_dyndb_arguments_t *args) +{ + REQUIRE(args != NULL); + + dns_dyndb_set_view(args, NULL); + dns_dyndb_set_zonemgr(args, NULL); + dns_dyndb_set_task(args, NULL); + dns_dyndb_set_timermgr(args, NULL); + + isc_mem_put(mctx, args, sizeof(*args)); +} + +void +dns_dyndb_set_view(dns_dyndb_arguments_t *args, dns_view_t *view) +{ + REQUIRE(args != NULL); + + if (args->view != NULL) + dns_view_detach(&args->view); + if (view != NULL) + dns_view_attach(view, &args->view); +} + +dns_view_t * +dns_dyndb_get_view(dns_dyndb_arguments_t *args) +{ + REQUIRE(args != NULL); + + return args->view; +} + +void +dns_dyndb_set_zonemgr(dns_dyndb_arguments_t *args, dns_zonemgr_t *zmgr) +{ + REQUIRE(args != NULL); + + if (args->zmgr != NULL) + dns_zonemgr_detach(&args->zmgr); + if (zmgr != NULL) + dns_zonemgr_attach(zmgr, &args->zmgr); +} + +dns_zonemgr_t * +dns_dyndb_get_zonemgr(dns_dyndb_arguments_t *args) +{ + REQUIRE(args != NULL); + + return args->zmgr; +} + +void +dns_dyndb_set_task(dns_dyndb_arguments_t *args, isc_task_t *task) +{ + REQUIRE(args != NULL); + + if (args->task != NULL) + isc_task_detach(&args->task); + if (task != NULL) + isc_task_attach(task, &args->task); +} + +isc_task_t * +dns_dyndb_get_task(dns_dyndb_arguments_t *args) +{ + REQUIRE(args != NULL); + + return args->task; +} + +void +dns_dyndb_set_timermgr(dns_dyndb_arguments_t *args, isc_timermgr_t *timermgr) +{ + REQUIRE(args != NULL); + + args->timermgr = timermgr; +} + +isc_timermgr_t * +dns_dyndb_get_timermgr(dns_dyndb_arguments_t *args) +{ + REQUIRE(args != NULL); + + return args->timermgr; +} |