/* Unix SMB/CIFS implementation. module loading system Copyright (C) Jelmer Vernooij 2002-2003 Copyright (C) Stefan (metze) Metzmacher 2003 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; either version 3 of the License, or (at your option) any later version. 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, see <http://www.gnu.org/licenses/>. */ #include "includes.h" #ifdef HAVE_DLOPEN /* Load a dynamic module. Only log a level 0 error if we are not checking for the existence of a module (probling). */ static NTSTATUS do_smb_load_module(const char *module_name, bool is_probe) { void *handle; init_module_function *init; NTSTATUS status; const char *error; /* Always try to use LAZY symbol resolving; if the plugin has * backwards compatibility, there might be symbols in the * plugin referencing to old (removed) functions */ handle = dlopen(module_name, RTLD_LAZY); /* This call should reset any possible non-fatal errors that occured since last call to dl* functions */ error = dlerror(); if(!handle) { int level = is_probe ? 3 : 0; DEBUG(level, ("Error loading module '%s': %s\n", module_name, error ? error : "")); return NT_STATUS_UNSUCCESSFUL; } init = (init_module_function *)dlsym(handle, "init_samba_module"); /* we must check dlerror() to determine if it worked, because dlsym() can validly return NULL */ error = dlerror(); if (error) { DEBUG(0, ("Error trying to resolve symbol 'init_samba_module' " "in %s: %s\n", module_name, error)); dlclose(handle); return NT_STATUS_UNSUCCESSFUL; } DEBUG(2, ("Module '%s' loaded\n", module_name)); status = init(); if (!NT_STATUS_IS_OK(status)) { DEBUG(0, ("Module '%s' initialization failed: %s\n", module_name, get_friendly_nt_error_msg(status))); dlclose(handle); } return status; } NTSTATUS smb_load_module(const char *module_name) { return do_smb_load_module(module_name, False); } /* Load all modules in list and return number of * modules that has been successfully loaded */ int smb_load_modules(const char **modules) { int i; int success = 0; for(i = 0; modules[i]; i++){ if(NT_STATUS_IS_OK(smb_load_module(modules[i]))) { success++; } } DEBUG(2, ("%d modules successfully loaded\n", success)); return success; } NTSTATUS smb_probe_module(const char *subsystem, const char *module) { char *full_path = NULL; TALLOC_CTX *ctx = talloc_stackframe(); NTSTATUS status; /* Check for absolute path */ /* if we make any 'samba multibyte string' calls here, we break for loading string modules */ DEBUG(5, ("Probing module '%s'\n", module)); if (module[0] == '/') { status = do_smb_load_module(module, True); TALLOC_FREE(ctx); return status; } full_path = talloc_asprintf(ctx, "%s/%s.%s", modules_path(ctx, subsystem), module, shlib_ext()); if (!full_path) { TALLOC_FREE(ctx); return NT_STATUS_NO_MEMORY; } DEBUG(5, ("Probing module '%s': Trying to load from %s\n", module, full_path)); status = do_smb_load_module(full_path, True); TALLOC_FREE(ctx); return status; } #else /* HAVE_DLOPEN */ NTSTATUS smb_load_module(const char *module_name) { DEBUG(0,("This samba executable has not been built with plugin support\n")); return NT_STATUS_NOT_SUPPORTED; } int smb_load_modules(const char **modules) { DEBUG(0,("This samba executable has not been built with plugin support\n")); return -1; } NTSTATUS smb_probe_module(const char *subsystem, const char *module) { DEBUG(0,("This samba executable has not been built with plugin support, not probing\n")); return NT_STATUS_NOT_SUPPORTED; } #endif /* HAVE_DLOPEN */ void init_modules(void) { /* FIXME: This can cause undefined symbol errors : * smb_register_vfs() isn't available in nmbd, for example */ if(lp_preload_modules()) smb_load_modules(lp_preload_modules()); }