libnl  1.1.4
api.c
1 /*
2  * lib/route/link/api.c Link Info API
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation version 2.1
7  * of the License.
8  *
9  * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
10  */
11 
12 /**
13  * @ingroup link
14  * @defgroup link_info Link Info API
15  * @brief
16  *
17  * @par 1) Registering/Unregistering a new link info type
18  * @code
19  * static struct rtnl_link_info_ops vlan_info_ops = {
20  * .io_name = "vlan",
21  * .io_alloc = vlan_alloc,
22  * .io_parse = vlan_parse,
23  * .io_dump[NL_DUMP_BRIEF] = vlan_dump_brief,
24  * .io_dump[NL_DUMP_FULL] = vlan_dump_full,
25  * .io_free = vlan_free,
26  * };
27  *
28  * static void __init vlan_init(void)
29  * {
30  * rtnl_link_register_info(&vlan_info_ops);
31  * }
32  *
33  * static void __exit vlan_exit(void)
34  * {
35  * rtnl_link_unregister_info(&vlan_info_ops);
36  * }
37  * @endcode
38  *
39  * @{
40  */
41 
42 #include <netlink-local.h>
43 #include <netlink/netlink.h>
44 #include <netlink/utils.h>
45 #include <netlink/route/link.h>
46 #include <netlink/route/link/info-api.h>
47 
48 static struct rtnl_link_info_ops *info_ops;
49 
50 struct rtnl_link_info_ops *rtnl_link_info_ops_lookup(const char *name)
51 {
52  struct rtnl_link_info_ops *ops;
53 
54  for (ops = info_ops; ops; ops = ops->io_next)
55  if (!strcmp(ops->io_name, name))
56  return ops;
57 
58  return NULL;
59 }
60 
61 int rtnl_link_register_info(struct rtnl_link_info_ops *ops)
62 {
63  if (ops->io_name == NULL)
64  return nl_error(EINVAL, "No name specified");
65 
66  if (rtnl_link_info_ops_lookup(ops->io_name))
67  return nl_error(EEXIST, "Link info operations already exist");
68 
69  NL_DBG(1, "Registered link info operations %s\n", ops->io_name);
70 
71  ops->io_next = info_ops;
72  info_ops = ops;
73 
74  return 0;
75 }
76 
77 int rtnl_link_unregister_info(struct rtnl_link_info_ops *ops)
78 {
79  struct rtnl_link_info_ops *t, **tp;
80 
81  for (tp = &info_ops; (t=*tp) != NULL; tp = &t->io_next)
82  if (t == ops)
83  break;
84 
85  if (!t)
86  return nl_error(ENOENT, "No such link info operations");
87 
88  if (t->io_refcnt > 0)
89  return nl_error(EBUSY, "Info operations in use");
90 
91  NL_DBG(1, "Unregistered link info perations %s\n", ops->io_name);
92 
93  *tp = t->io_next;
94  return 0;
95 }
96 
97 /** @} */
98