/* Copyright (C) 2009-2011 Codership Oy This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /*! @file wsrep implementation loader */ #include #include #include #include #include "wsrep_api.h" // Logging stuff for the loader static const char* log_levels[] = {"FATAL", "ERROR", "WARN", "INFO", "DEBUG"}; static void default_logger (wsrep_log_level_t lvl, const char* msg) { fprintf (stderr, "wsrep loader: [%s] %s\n", log_levels[lvl], msg); } static wsrep_log_cb_t logger = default_logger; /************************************************************************** * Library loader **************************************************************************/ static int wsrep_check_iface_version(const char* found, const char* iface_ver) { const size_t msg_len = 128; char msg[128]; if (strcmp(found, iface_ver)) { snprintf (msg, msg_len, "provider interface version mismatch: need '%s', found '%s'", iface_ver, found); logger (WSREP_LOG_ERROR, msg); return EINVAL; } return 0; } static int verify(const wsrep_t *wh, const char *iface_ver) { char msg[128]; #define VERIFY(_p) if (!(_p)) { \ snprintf(msg, sizeof(msg), "wsrep_load(): verify(): %s\n", # _p); \ logger (WSREP_LOG_ERROR, msg); \ return EINVAL; \ } VERIFY(wh); VERIFY(wh->version); if (wsrep_check_iface_version(wh->version, iface_ver)) return EINVAL; VERIFY(wh->init); VERIFY(wh->options_set); VERIFY(wh->options_get); VERIFY(wh->connect); VERIFY(wh->disconnect); VERIFY(wh->recv); VERIFY(wh->pre_commit); VERIFY(wh->post_commit); VERIFY(wh->post_rollback); VERIFY(wh->replay_trx); VERIFY(wh->abort_pre_commit); VERIFY(wh->append_key); VERIFY(wh->append_data); VERIFY(wh->free_connection); VERIFY(wh->to_execute_start); VERIFY(wh->to_execute_end); VERIFY(wh->preordered_collect); VERIFY(wh->preordered_commit); VERIFY(wh->sst_sent); VERIFY(wh->sst_received); VERIFY(wh->stats_get); VERIFY(wh->stats_free); VERIFY(wh->stats_reset); VERIFY(wh->pause); VERIFY(wh->resume); VERIFY(wh->desync); VERIFY(wh->resync); VERIFY(wh->lock); VERIFY(wh->unlock); VERIFY(wh->is_locked); VERIFY(wh->provider_name); VERIFY(wh->provider_version); VERIFY(wh->provider_vendor); VERIFY(wh->free); return 0; } typedef int (*wsrep_loader_fun)(wsrep_t*); static wsrep_loader_fun wsrep_dlf(void *dlh, const char *sym) { union { wsrep_loader_fun dlfun; void *obj; } alias; alias.obj = dlsym(dlh, sym); return alias.dlfun; } static int wsrep_check_version_symbol(void *dlh) { char** dlversion = NULL; dlversion = (char**) dlsym(dlh, "wsrep_interface_version"); if (dlversion == NULL) return 0; return wsrep_check_iface_version(*dlversion, WSREP_INTERFACE_VERSION); } extern int wsrep_dummy_loader(wsrep_t *w); int wsrep_load(const char *spec, wsrep_t **hptr, wsrep_log_cb_t log_cb) { int ret = 0; void *dlh = NULL; wsrep_loader_fun dlfun; char msg[1025]; msg[sizeof(msg)-1] = 0; if (NULL != log_cb) logger = log_cb; if (!(spec && hptr)) return EINVAL; snprintf (msg, sizeof(msg)-1, "wsrep_load(): loading provider library '%s'", spec); logger (WSREP_LOG_INFO, msg); if (!(*hptr = malloc(sizeof(wsrep_t)))) { logger (WSREP_LOG_FATAL, "wsrep_load(): out of memory"); return ENOMEM; } if (!spec || strcmp(spec, WSREP_NONE) == 0) { if ((ret = wsrep_dummy_loader(*hptr)) != 0) { free (*hptr); *hptr = NULL; } return ret; } if (!(dlh = dlopen(spec, RTLD_NOW | RTLD_LOCAL))) { snprintf(msg, sizeof(msg)-1, "wsrep_load(): dlopen(): %s", dlerror()); logger (WSREP_LOG_ERROR, msg); ret = EINVAL; goto out; } if (!(dlfun = wsrep_dlf(dlh, "wsrep_loader"))) { ret = EINVAL; goto out; } if (wsrep_check_version_symbol(dlh) != 0) { ret = EINVAL; goto out; } if ((ret = (*dlfun)(*hptr)) != 0) { snprintf(msg, sizeof(msg)-1, "wsrep_load(): loader failed: %s", strerror(ret)); logger (WSREP_LOG_ERROR, msg); goto out; } if ((ret = verify(*hptr, WSREP_INTERFACE_VERSION)) != 0) { snprintf (msg, sizeof(msg)-1, "wsrep_load(): interface version mismatch: my version %s, " "provider version %s", WSREP_INTERFACE_VERSION, (*hptr)->version); logger (WSREP_LOG_ERROR, msg); goto out; } (*hptr)->dlh = dlh; out: if (ret != 0) { if (dlh) dlclose(dlh); free(*hptr); *hptr = NULL; } else { snprintf (msg, sizeof(msg)-1, "wsrep_load(): %s %s by %s loaded successfully.", (*hptr)->provider_name, (*hptr)->provider_version, (*hptr)->provider_vendor); logger (WSREP_LOG_INFO, msg); } return ret; } void wsrep_unload(wsrep_t *hptr) { if (!hptr) { logger (WSREP_LOG_WARN, "wsrep_unload(): null pointer."); } else { if (hptr->free) hptr->free(hptr); if (hptr->dlh) dlclose(hptr->dlh); free(hptr); } }