From 87354c9a6de95d5dcebace77a35fc21a73d599ab Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Mon, 24 Oct 2011 19:39:53 +1100 Subject: lib/util Split samba-modules library into public and private parts This will allow OpenChange to get at the symbols it needs, without exposing any more of this as a public API than we must. Andrew Bartlett --- lib/util/internal_module.c | 203 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 203 insertions(+) create mode 100644 lib/util/internal_module.c (limited to 'lib/util/internal_module.c') diff --git a/lib/util/internal_module.c b/lib/util/internal_module.c new file mode 100644 index 0000000000..04c02f0760 --- /dev/null +++ b/lib/util/internal_module.c @@ -0,0 +1,203 @@ +/* + Unix SMB/CIFS implementation. + Samba utility functions + Copyright (C) Jelmer Vernooij 2002-2003,2005-2007 + Copyright (C) Stefan (metze) Metzmacher 2003 + Copyright (C) Andrew Bartlett 2011 + + 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 . +*/ + +#include "includes.h" +#include "dynconfig/dynconfig.h" +#include "lib/util/internal_module.h" +#include "system/filesys.h" +#include "system/dir.h" + +/** + * Obtain the init function from a shared library file + */ +samba_init_module_fn load_module(const char *path, bool is_probe, void **handle_out) +{ + void *handle; + void *init_fn; + char *error; + +#if _SAMBA_BUILD_ == 3 + /* 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(path, RTLD_LAZY); +#else + /* This should be a WAF build, where modules should be built + * with no undefined symbols and are already linked against + * the libraries that they are loaded by */ + handle = dlopen(path, RTLD_NOW); +#endif + + /* This call should reset any possible non-fatal errors that + occured since last call to dl* functions */ + error = dlerror(); + + if (handle == NULL) { + int level = is_probe ? 5 : 0; + DEBUG(level, ("Error loading module '%s': %s\n", path, error ? error : "")); + return NULL; + } + + init_fn = (samba_init_module_fn)dlsym(handle, SAMBA_INIT_MODULE); + + /* we could check dlerror() to determine if it worked, because + dlsym() can validly return NULL, but what would we do with + a NULL pointer as a module init function? */ + + if (init_fn == NULL) { + DEBUG(0, ("Unable to find %s() in %s: %s\n", + SAMBA_INIT_MODULE, path, dlerror())); + DEBUG(1, ("Loading module '%s' failed\n", path)); + dlclose(handle); + return NULL; + } + + if (handle_out) { + *handle_out = handle; + } + + return (samba_init_module_fn)init_fn; +} + +/** + * Obtain list of init functions from the modules in the specified + * directory + */ +samba_init_module_fn *load_modules(TALLOC_CTX *mem_ctx, const char *path) +{ + DIR *dir; + struct dirent *entry; + char *filename; + int success = 0; + samba_init_module_fn *ret = talloc_array(mem_ctx, samba_init_module_fn, 2); + + ret[0] = NULL; + + dir = opendir(path); + if (dir == NULL) { + talloc_free(ret); + return NULL; + } + + while((entry = readdir(dir))) { + if (ISDOT(entry->d_name) || ISDOTDOT(entry->d_name)) + continue; + + filename = talloc_asprintf(mem_ctx, "%s/%s", path, entry->d_name); + + ret[success] = load_module(filename, true, NULL); + if (ret[success]) { + ret = talloc_realloc(mem_ctx, ret, samba_init_module_fn, success+2); + success++; + ret[success] = NULL; + } + + talloc_free(filename); + } + + closedir(dir); + + return ret; +} + +/* 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; + samba_init_module_fn init; + NTSTATUS status; + + init = load_module(module_name, is_probe, &handle); + if (!init) { + 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; +} + +/* 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(do_smb_load_module(modules[i], false))) { + 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; +} -- cgit