source3/lib/module.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    module loading system
   4
   5    Copyright (C) Jelmer Vernooij 2002
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 #ifdef HAVE_DLOPEN
  25 int smb_load_module(const char *module_name)
  26 {
  27         void *handle;
  28         init_module_function *init;
  29         int status;
  30         const char *error;
  31
  32         /* Always try to use LAZY symbol resolving; if the plugin has
  33          * backwards compatibility, there might be symbols in the
  34          * plugin referencing to old (removed) functions
  35          */
  36         handle = sys_dlopen(module_name, RTLD_LAZY);
  37
  38         if(!handle) {
  39                 DEBUG(0, ("Error loading module '%s': %s\n", module_name, sys_dlerror()));
  40                 return False;
  41         }
  42
  43         init = sys_dlsym(handle, "init_module");
  44
  45         /* we must check sys_dlerror() to determine if it worked, because
  46            sys_dlsym() can validly return NULL */
  47         error = sys_dlerror();
  48         if (error) {
  49                 DEBUG(0, ("Error trying to resolve symbol 'init_module' in %s: %s\n", module_name, error));
  50                 return False;
  51         }
  52
  53         status = init();
  54
  55         DEBUG(2, ("Module '%s' loaded\n", module_name));
  56
  57         return status;
  58 }
  59
  60 /* Load all modules in list and return number of
  61  * modules that has been successfully loaded */
  62 int smb_load_modules(const char **modules)
  63 {
  64         int i;
  65         int success = 0;
  66
  67         for(i = 0; modules[i]; i++){
  68                 if(smb_load_module(modules[i])) {
  69                         success++;
  70                 }
  71         }
  72
  73         DEBUG(2, ("%d modules successfully loaded\n", success));
  74
  75         return success;
  76 }
  77
  78 int smb_probe_module(const char *subsystem, const char *module)
  79 {
  80         pstring full_path;
  81
  82         /* Check for absolute path */
  83         if(strchr_m(module, '/'))return smb_load_module(module);
  84
  85         pstrcpy(full_path, lib_path(subsystem));
  86         pstrcat(full_path, "/");
  87         pstrcat(full_path, module);
  88         pstrcat(full_path, ".");
  89         pstrcat(full_path, shlib_ext());
  90
  91         DEBUG(5, ("Probing module %s: Trying to load from %s\n", module, full_path));
  92
  93         return smb_load_module(full_path);
  94 }
  95
  96 #else /* HAVE_DLOPEN */
  97
  98 int smb_load_module(const char *module_name)
  99 {
 100         DEBUG(0,("This samba executable has not been built with plugin support"));
 101         return False;
 102 }
 103
 104 int smb_load_modules(const char **modules)
 105 {
 106         DEBUG(0,("This samba executable has not been built with plugin support"));
 107         return False;
 108 }
 109
 110 int smb_probe_module(const char *subsystem, const char *module)
 111 {
 112         DEBUG(0,("This samba executable has not been built with plugin support, not probing"));
 113         return False;
 114 }
 115
 116 #endif /* HAVE_DLOPEN */
 117
 118 void init_modules(void)
 119 {
 120         /* FIXME: This can cause undefined symbol errors :
 121          *  smb_register_vfs() isn't available in nmbd, for example */
 122         if(lp_preload_modules())
 123                 smb_load_modules(lp_preload_modules());
 124 }
 125
 126
 127 /*************************************************************************
 128  * This functions /path/to/foobar.so -> foobar
 129  ************************************************************************/
 130 void module_path_get_name(const char *path, pstring name)
 131 {
 132         char *s;
 133
 134         /* First, make the path relative */
 135         s = strrchr(path, '/');
 136         if(s) pstrcpy(name, s+1);
 137         else pstrcpy(name, path);
 138
 139         if (dyn_SHLIBEXT && *dyn_SHLIBEXT && strlen(dyn_SHLIBEXT) < strlen(name)) {
 140                 int n = strlen(name) - strlen(dyn_SHLIBEXT);
 141
 142                 /* Remove extension if necessary */
 143                 if (name[n-1] == '.' && !strcmp(name+n, dyn_SHLIBEXT)) {
 144                         name[n-1] = '\0';
 145                 }
 146         }
 147 }