diff options
Diffstat (limited to 'libhurd-cap-server/obj-copy-out.c')
| -rw-r--r-- | libhurd-cap-server/obj-copy-out.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/libhurd-cap-server/obj-copy-out.c b/libhurd-cap-server/obj-copy-out.c new file mode 100644 index 0000000..1edfe7d --- /dev/null +++ b/libhurd-cap-server/obj-copy-out.c @@ -0,0 +1,118 @@ +/* obj-copy-out.c - Copy out a capability to a client. + Copyright (C) 2004 Free Software Foundation, Inc. + Written by Marcus Brinkmann <marcus@gnu.org> + + This file is part of the GNU Hurd. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this program; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#if HAVE_CONFIG_H +#include <config.h> +#endif + +#include <errno.h> +#include <pthread.h> +#include <stdlib.h> + +#include "cap-server-intern.h" + + +/* Copy out a capability for the capability OBJ to the user CLIENT. + Returns the capability ID (valid only for this user) in *R_ID, or + an error. OBJ must be locked. Note: No internal reference for + this capability is allocated for the caller. */ +error_t +_hurd_cap_obj_copy_out (hurd_cap_obj_t obj, hurd_cap_bucket_t bucket, + _hurd_cap_client_t client, hurd_cap_id_t *r_id) +{ + _hurd_cap_obj_entry_t entry; + + pthread_mutex_lock (&client->lock); + entry = (_hurd_cap_obj_entry_t) hurd_ihash_find (&client->caps_reverse, + (hurd_ihash_key_t) obj); + + if (entry) + { + entry->external_refs++; + *r_id = entry->id; + pthread_mutex_unlock (&client->lock); + return 0; + } + else + { + _hurd_cap_obj_entry_t entry_check; + error_t err; + + pthread_mutex_unlock (&client->lock); + err = hurd_slab_alloc (&_hurd_cap_obj_entry_space, (void **) &entry); + if (err) + return err; + + entry->cap_obj = obj; + /* ID is filled in when adding the object to the table. */ + /* CLIENT_ITEM is filled after the object has been entered. */ + /* DEAD is 0 for initialized objects. */ + /* INTERNAL_REFS is 1 for initialized objects. */ + /* EXTERNAL_REFS is 1 for initialized objects. */ + + pthread_mutex_lock (&client->lock); + entry_check = hurd_ihash_find (&client->caps_reverse, + (hurd_ihash_key_t) obj); + if (entry_check) + { + /* Somebody else was faster. */ + entry_check->external_refs++; + *r_id = entry_check->id; + pthread_mutex_unlock (&client->lock); + hurd_slab_dealloc (&_hurd_cap_obj_entry_space, entry); + return 0; + } + + /* Add the entry to the caps table of the client. */ + err = hurd_table_enter (&client->caps, &entry, &entry->id); + if (err) + { + pthread_mutex_unlock (&client->lock); + hurd_slab_dealloc (&_hurd_cap_obj_entry_space, entry); + return err; + } + err = hurd_ihash_add (&client->caps_reverse, + (hurd_ihash_key_t) obj, entry); + if (err) + { + hurd_table_remove (&client->caps, entry->id); + pthread_mutex_unlock (&client->lock); + hurd_slab_dealloc (&_hurd_cap_obj_entry_space, entry); + return err; + } + + pthread_mutex_unlock (&client->lock); + + /* Add the object to the list. */ + _hurd_cap_list_item_add (&obj->clients, &entry->client_item); + + /* Add a reference for the internal reference of the capability + entry to the capability object. */ + obj->refs++; + + /* FIXME: Should probably use spin lock here, or so. */ + pthread_mutex_lock (&bucket->lock); + bucket->nr_caps++; + pthread_mutex_unlock (&bucket->lock); + + return 0; + } +} |