contrib/openpam/lib/openpam_load.c

   1 /*-
   2  * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
   3  * All rights reserved.
   4  *
   5  * This software was developed for the FreeBSD Project by ThinkSec AS and
   6  * Network Associates Laboratories, the Security Research Division of
   7  * Network Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
   8  * ("CBOSS"), as part of the DARPA CHATS research program.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. The name of the author may not be used to endorse or promote
  19  *    products derived from this software without specific prior written
  20  *    permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $P4: //depot/projects/openpam/lib/openpam_load.c#21 $
  35  */
  36
  37 #include <dlfcn.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #include <security/pam_appl.h>
  42
  43 #include "openpam_impl.h"
  44
  45 const char *_pam_func_name[PAM_NUM_PRIMITIVES] = {
  46         "pam_authenticate",
  47         "pam_setcred",
  48         "pam_acct_mgmt",
  49         "pam_open_session",
  50         "pam_close_session",
  51         "pam_chauthtok"
  52 };
  53
  54 const char *_pam_sm_func_name[PAM_NUM_PRIMITIVES] = {
  55         "pam_sm_authenticate",
  56         "pam_sm_setcred",
  57         "pam_sm_acct_mgmt",
  58         "pam_sm_open_session",
  59         "pam_sm_close_session",
  60         "pam_sm_chauthtok"
  61 };
  62
  63 static pam_module_t *modules;
  64
  65 /*
  66  * Locate a matching dynamic or static module.  Keep a list of previously
  67  * found modules to speed up the process.
  68  */
  69
  70 pam_module_t *
  71 openpam_load_module(const char *path)
  72 {
  73         pam_module_t *module;
  74
  75         /* check cache first */
  76         for (module = modules; module != NULL; module = module->next)
  77                 if (strcmp(module->path, path) == 0)
  78                         goto found;
  79
  80         /* nope; try to load */
  81         module = openpam_dynamic(path);
  82         openpam_log(PAM_LOG_DEBUG, "%s dynamic %s",
  83             (module == NULL) ? "no" : "using", path);
  84
  85 #ifdef OPENPAM_STATIC_MODULES
  86         /* look for a static module */
  87         if (module == NULL && strchr(path, '/') == NULL) {
  88                 module = openpam_static(path);
  89                 openpam_log(PAM_LOG_DEBUG, "%s static %s",
  90                     (module == NULL) ? "no" : "using", path);
  91         }
  92 #endif
  93         if (module == NULL) {
  94                 openpam_log(PAM_LOG_ERROR, "no %s found", path);
  95                 return (NULL);
  96         }
  97         openpam_log(PAM_LOG_DEBUG, "adding %s to cache", module->path);
  98         module->next = modules;
  99         if (module->next != NULL)
 100                 module->next->prev = module;
 101         module->prev = NULL;
 102         modules = module;
 103  found:
 104         ++module->refcount;
 105         return (module);
 106 }
 107
 108
 109 /*
 110  * Release a module.
 111  * XXX highly thread-unsafe
 112  */
 113
 114 static void
 115 openpam_release_module(pam_module_t *module)
 116 {
 117         if (module == NULL)
 118                 return;
 119         --module->refcount;
 120         if (module->refcount > 0)
 121                 /* still in use */
 122                 return;
 123         if (module->refcount < 0) {
 124                 openpam_log(PAM_LOG_ERROR, "module %s has negative refcount",
 125                     module->path);
 126                 module->refcount = 0;
 127         }
 128         if (module->dlh == NULL)
 129                 /* static module */
 130                 return;
 131         dlclose(module->dlh);
 132         if (module->prev != NULL)
 133                 module->prev->next = module->next;
 134         if (module->next != NULL)
 135                 module->next->prev = module->prev;
 136         if (module == modules)
 137                 modules = module->next;
 138         openpam_log(PAM_LOG_DEBUG, "releasing %s", module->path);
 139         FREE(module->path);
 140         FREE(module);
 141 }
 142
 143
 144 /*
 145  * Destroy a chain, freeing all its links and releasing the modules
 146  * they point to.
 147  */
 148
 149 static void
 150 openpam_destroy_chain(pam_chain_t *chain)
 151 {
 152         if (chain == NULL)
 153                 return;
 154         openpam_destroy_chain(chain->next);
 155         chain->next = NULL;
 156         while (chain->optc) {
 157                 --chain->optc;
 158                 FREE(chain->optv[chain->optc]);
 159         }
 160         FREE(chain->optv);
 161         openpam_release_module(chain->module);
 162         chain->module = NULL;
 163         FREE(chain);
 164 }
 165
 166
 167 /*
 168  * Clear the chains and release the modules
 169  */
 170
 171 void
 172 openpam_clear_chains(pam_chain_t *policy[])
 173 {
 174         int i;
 175
 176         for (i = 0; i < PAM_NUM_FACILITIES; ++i) {
 177                 openpam_destroy_chain(policy[i]);
 178                 policy[i] = NULL;
 179         }
 180 }
 181
 182 /*
 183  * NOPARSE
 184  */