From: Sebastian Harl Date: Sat, 20 Jul 2013 00:08:27 +0000 (-0700) Subject: plugin/store: Added support for "cname" plugins. X-Git-Tag: sysdb-0.1.0~400 X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=commitdiff_plain;h=48b84af3c09033e4d55c04197e92bac06fe42251 plugin/store: Added support for "cname" plugins. This type of plugins may be used to canonicalize hostnames. Before storing a new hosts, all registered cname callbacks will be used to translate the specified hostname before actually storing it. --- diff --git a/src/core/plugin.c b/src/core/plugin.c index c248d37..4dbea70 100644 --- a/src/core/plugin.c +++ b/src/core/plugin.c @@ -98,6 +98,7 @@ static _Bool plugin_ctx_key_initialized = 0; static sdb_llist_t *config_list = NULL; static sdb_llist_t *init_list = NULL; static sdb_llist_t *collector_list = NULL; +static sdb_llist_t *cname_list = NULL; static sdb_llist_t *shutdown_list = NULL; static sdb_llist_t *log_list = NULL; @@ -415,6 +416,14 @@ sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback, user_data); } /* sdb_plugin_register_log */ +int +sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback, + sdb_object_t *user_data) +{ + return sdb_plugin_add_callback(&cname_list, "cname", name, callback, + user_data); +} /* sdb_plugin_register_cname */ + int sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback, const sdb_time_t *interval, sdb_object_t *user_data) @@ -656,6 +665,37 @@ sdb_plugin_collector_loop(sdb_plugin_loop_t *loop) return 0; } /* sdb_plugin_read_loop */ +char * +sdb_plugin_cname(char *hostname) +{ + sdb_llist_iter_t *iter; + + if (! hostname) + return NULL; + + if (! cname_list) + return hostname; + + iter = sdb_llist_get_iter(cname_list); + while (sdb_llist_iter_has_next(iter)) { + sdb_plugin_cname_cb callback; + char *cname; + + sdb_object_t *obj = sdb_llist_iter_get_next(iter); + assert(obj); + + callback = SDB_PLUGIN_CB(obj)->cb_callback; + cname = callback(hostname, SDB_PLUGIN_CB(obj)->cb_user_data); + if (cname) { + free(hostname); + hostname = cname; + } + /* else: don't change hostname */ + } + sdb_llist_iter_destroy(iter); + return hostname; +} /* sdb_plugin_cname */ + int sdb_plugin_log(int prio, const char *msg) { diff --git a/src/core/store.c b/src/core/store.c index c66b523..64e9f64 100644 --- a/src/core/store.c +++ b/src/core/store.c @@ -28,6 +28,7 @@ #include "sysdb.h" #include "core/store.h" #include "core/error.h" +#include "core/plugin.h" #include "utils/llist.h" #include @@ -233,13 +234,22 @@ sdb_host_create(const char *name) int sdb_store_host(const sdb_host_t *host) { + char *cname; + sdb_time_t last_update; sdb_host_t *old; + int status = 0; if ((! host) || (! SDB_CONST_OBJ(host)->name)) return -1; + cname = sdb_plugin_cname(strdup(SDB_CONST_OBJ(host)->name)); + if (! cname) { + sdb_log(SDB_LOG_ERR, "store: strdup failed"); + return -1; + } + last_update = host->_last_update; if (last_update <= 0) last_update = sdb_gettime(); @@ -253,14 +263,13 @@ sdb_store_host(const sdb_host_t *host) } } - old = SDB_HOST(sdb_llist_search_by_name(host_list, - SDB_CONST_OBJ(host)->name)); + old = SDB_HOST(sdb_llist_search_by_name(host_list, cname)); if (old) { if (old->_last_update > last_update) { sdb_log(SDB_LOG_DEBUG, "store: Cannot update host '%s' - " "value too old (%"PRIscTIME" < %"PRIscTIME")", - SDB_CONST_OBJ(host)->name, last_update, old->_last_update); + cname, last_update, old->_last_update); /* don't report an error; the host may be updated by multiple * backends */ status = 1; @@ -279,11 +288,14 @@ sdb_store_host(const sdb_host_t *host) return -1; } + free(SDB_OBJ(new)->name); + SDB_OBJ(new)->name = cname; + if (! new->attributes) { if (! (new->attributes = sdb_llist_create())) { char errbuf[1024]; sdb_log(SDB_LOG_ERR, "store: Failed to initialize " - "host object '%s': %s", SDB_CONST_OBJ(host)->name, + "host object '%s': %s", SDB_OBJ(new)->name, sdb_strerror(errno, errbuf, sizeof(errbuf))); sdb_object_deref(SDB_OBJ(new)); pthread_rwlock_unlock(&host_lock); @@ -295,7 +307,7 @@ sdb_store_host(const sdb_host_t *host) if (! (new->services = sdb_llist_create())) { char errbuf[1024]; sdb_log(SDB_LOG_ERR, "store: Failed to initialize " - "host object '%s': %s", SDB_CONST_OBJ(host)->name, + "host object '%s': %s", SDB_OBJ(new)->name, sdb_strerror(errno, errbuf, sizeof(errbuf))); sdb_object_deref(SDB_OBJ(new)); pthread_rwlock_unlock(&host_lock); diff --git a/src/include/core/plugin.h b/src/include/core/plugin.h index bef5e0b..446c867 100644 --- a/src/include/core/plugin.h +++ b/src/include/core/plugin.h @@ -87,12 +87,16 @@ int sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...); /* - * plugin callback functions + * plugin callback functions: + * See the description of the respective register function for what arguments + * the callbacks expect. */ typedef int (*sdb_plugin_config_cb)(oconfig_item_t *ci); typedef int (*sdb_plugin_init_cb)(sdb_object_t *user_data); typedef int (*sdb_plugin_collector_cb)(sdb_object_t *user_data); +typedef char *(*sdb_plugin_cname_cb)(const char *name, + sdb_object_t *user_data); typedef int (*sdb_plugin_shutdown_cb)(sdb_object_t *user_data); typedef int (*sdb_plugin_log_cb)(int prio, const char *msg, sdb_object_t *user_data); @@ -161,6 +165,25 @@ sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback, const sdb_time_t *interval, sdb_object_t *user_data); +/* + * sdb_plugin_register_cname: + * Register a "cname" (canonicalize name) function. This type of function is + * called whenever a host is stored. It accepts the hostname and returns a + * canonicalized hostname which will then be used to actually store the host. + * If multiple such callbacks are registered, each one of them will be called + * in the order they have been registered, each one receiving the result of + * the previous callback. If the function returns NULL, the original hostname + * is not changed. Any other value has to be dynamically allocated. It will be + * freed later on by the core. + * + * Returns: + * - 0 on success + * - a negative value else + */ +int +sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback, + sdb_object_t *user_data); + /* * sdb_plugin_register_shutdown: * Register a "shutdown" function to be called after stopping all update @@ -234,6 +257,16 @@ sdb_plugin_init_all(void); int sdb_plugin_collector_loop(sdb_plugin_loop_t *loop); +/* + * sdb_plugin_cname: + * Returns the canonicalized hostname. The given hostname argument has to + * point to dynamically allocated memory and might be freed by the function. + * The return value will also be dynamically allocated (but it might be + * unchanged) and has to be freed by the caller. + */ +char * +sdb_plugin_cname(char *hostname); + /* * sdb_plugin_log: * Log the specified message using all registered log callbacks. The message