authz/pamacct.c

   1 /*
   2  * QEMU PAM authorization driver
   3  *
   4  * Copyright (c) 2018 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "authz/pamacct.h"
  23 #include "authz/trace.h"
  24 #include "qom/object_interfaces.h"
  25
  26 #include <security/pam_appl.h>
  27
  28
  29 static bool qauthz_pam_is_allowed(QAuthZ *authz,
  30                                   const char *identity,
  31                                   Error **errp)
  32 {
  33     QAuthZPAM *pauthz = QAUTHZ_PAM(authz);
  34     const struct pam_conv pam_conversation = { 0 };
  35     pam_handle_t *pamh = NULL;
  36     int ret;
  37
  38     trace_qauthz_pam_check(authz, identity, pauthz->service);
  39     ret = pam_start(pauthz->service,
  40                     identity,
  41                     &pam_conversation,
  42                     &pamh);
  43     if (ret != PAM_SUCCESS) {
  44         error_setg(errp, "Unable to start PAM transaction: %s",
  45                    pam_strerror(NULL, ret));
  46         return false;
  47     }
  48
  49     ret = pam_acct_mgmt(pamh, PAM_SILENT);
  50     pam_end(pamh, ret);
  51     if (ret != PAM_SUCCESS) {
  52         error_setg(errp, "Unable to authorize user '%s': %s",
  53                    identity, pam_strerror(pamh, ret));
  54         return false;
  55     }
  56
  57     return true;
  58 }
  59
  60
  61 static void
  62 qauthz_pam_prop_set_service(Object *obj,
  63                             const char *service,
  64                             Error **errp G_GNUC_UNUSED)
  65 {
  66     QAuthZPAM *pauthz = QAUTHZ_PAM(obj);
  67
  68     g_free(pauthz->service);
  69     pauthz->service = g_strdup(service);
  70 }
  71
  72
  73 static char *
  74 qauthz_pam_prop_get_service(Object *obj,
  75                             Error **errp G_GNUC_UNUSED)
  76 {
  77     QAuthZPAM *pauthz = QAUTHZ_PAM(obj);
  78
  79     return g_strdup(pauthz->service);
  80 }
  81
  82
  83 static void
  84 qauthz_pam_complete(UserCreatable *uc, Error **errp)
  85 {
  86 }
  87
  88
  89 static void
  90 qauthz_pam_finalize(Object *obj)
  91 {
  92     QAuthZPAM *pauthz = QAUTHZ_PAM(obj);
  93
  94     g_free(pauthz->service);
  95 }
  96
  97
  98 static void
  99 qauthz_pam_class_init(ObjectClass *oc, void *data)
 100 {
 101     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 102     QAuthZClass *authz = QAUTHZ_CLASS(oc);
 103
 104     ucc->complete = qauthz_pam_complete;
 105     authz->is_allowed = qauthz_pam_is_allowed;
 106
 107     object_class_property_add_str(oc, "service",
 108                                   qauthz_pam_prop_get_service,
 109                                   qauthz_pam_prop_set_service,
 110                                   NULL);
 111 }
 112
 113
 114 QAuthZPAM *qauthz_pam_new(const char *id,
 115                           const char *service,
 116                           Error **errp)
 117 {
 118     return QAUTHZ_PAM(
 119         object_new_with_props(TYPE_QAUTHZ_PAM,
 120                               object_get_objects_root(),
 121                               id, errp,
 122                               "service", service,
 123                               NULL));
 124 }
 125
 126
 127 static const TypeInfo qauthz_pam_info = {
 128     .parent = TYPE_QAUTHZ,
 129     .name = TYPE_QAUTHZ_PAM,
 130     .instance_size = sizeof(QAuthZPAM),
 131     .instance_finalize = qauthz_pam_finalize,
 132     .class_size = sizeof(QAuthZPAMClass),
 133     .class_init = qauthz_pam_class_init,
 134     .interfaces = (InterfaceInfo[]) {
 135         { TYPE_USER_CREATABLE },
 136         { }
 137     }
 138 };
 139
 140
 141 static void
 142 qauthz_pam_register_types(void)
 143 {
 144     type_register_static(&qauthz_pam_info);
 145 }
 146
 147
 148 type_init(qauthz_pam_register_types);