src/core/bus-endpoint.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2014 Daniel Mack
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   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 License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <stdlib.h>
  21
  22 #include "alloc-util.h"
  23 #include "bus-endpoint.h"
  24 #include "bus-kernel.h"
  25 #include "bus-policy.h"
  26 #include "kdbus.h"
  27
  28 int bus_kernel_set_endpoint_policy(int fd, uid_t uid, BusEndpoint *ep) {
  29
  30         struct kdbus_cmd *update;
  31         struct kdbus_item *n;
  32         BusEndpointPolicy *po;
  33         Iterator i;
  34         size_t size;
  35         int r;
  36
  37         size = ALIGN8(offsetof(struct kdbus_cmd, items));
  38
  39         HASHMAP_FOREACH(po, ep->policy_hash, i) {
  40                 size += ALIGN8(offsetof(struct kdbus_item, str) + strlen(po->name) + 1);
  41                 size += ALIGN8(offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access));
  42         }
  43
  44         update = alloca0_align(size, 8);
  45         update->size = size;
  46
  47         n = update->items;
  48
  49         HASHMAP_FOREACH(po, ep->policy_hash, i) {
  50                 n->type = KDBUS_ITEM_NAME;
  51                 n->size = offsetof(struct kdbus_item, str) + strlen(po->name) + 1;
  52                 strcpy(n->str, po->name);
  53                 n = KDBUS_ITEM_NEXT(n);
  54
  55                 n->type = KDBUS_ITEM_POLICY_ACCESS;
  56                 n->size = offsetof(struct kdbus_item, policy_access) + sizeof(struct kdbus_policy_access);
  57
  58                 n->policy_access.type = KDBUS_POLICY_ACCESS_USER;
  59                 n->policy_access.access = bus_kernel_translate_access(po->access);
  60                 n->policy_access.id = uid;
  61
  62                 n = KDBUS_ITEM_NEXT(n);
  63         }
  64
  65         r = ioctl(fd, KDBUS_CMD_ENDPOINT_UPDATE, update);
  66         if (r < 0)
  67                 return -errno;
  68
  69         return 0;
  70 }
  71
  72 int bus_endpoint_new(BusEndpoint **ep) {
  73         assert(ep);
  74
  75         *ep = new0(BusEndpoint, 1);
  76         if (!*ep)
  77                 return -ENOMEM;
  78
  79         return 0;
  80 }
  81
  82 int bus_endpoint_add_policy(BusEndpoint *ep, const char *name, BusPolicyAccess access) {
  83         _cleanup_free_ BusEndpointPolicy *po = NULL;
  84         _cleanup_free_ char *key = NULL;
  85         int r;
  86
  87         assert(ep);
  88         assert(name);
  89         assert(access > _BUS_POLICY_ACCESS_INVALID && access < _BUS_POLICY_ACCESS_MAX);
  90
  91         /* check if we already have this name in the policy list. If we do, see if the new access level
  92          * is higher than the exising one, and upgrade the entry in that case. Otherwise, do nothing.
  93          */
  94
  95         if (ep->policy_hash) {
  96                 po = hashmap_get(ep->policy_hash, name);
  97                 if (po) {
  98                         if (po->access < access)
  99                                 po->access = access;
 100
 101                         return 0;
 102                 }
 103         } else {
 104                 ep->policy_hash = hashmap_new(&string_hash_ops);
 105                 if (!ep->policy_hash)
 106                         return -ENOMEM;
 107         }
 108
 109         po = new0(BusEndpointPolicy, 1);
 110         if (!po)
 111                 return -ENOMEM;
 112
 113         key = strdup(name);
 114         if (!key)
 115                 return -ENOMEM;
 116
 117         po->name = key;
 118         po->access = access;
 119
 120         r = hashmap_put(ep->policy_hash, key, po);
 121         if (r < 0)
 122                 return r;
 123
 124         po = NULL;
 125         key = NULL;
 126         return 0;
 127 }
 128
 129 void bus_endpoint_free(BusEndpoint *endpoint) {
 130         if (!endpoint)
 131                 return;
 132
 133         hashmap_free_free_free(endpoint->policy_hash);
 134         free(endpoint);
 135 }