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netlink.c
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1 /*
2  * net/tipc/netlink.c: TIPC configuration handling
3  *
4  * Copyright (c) 2005-2006, Ericsson AB
5  * Copyright (c) 2005-2007, Wind River Systems
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  * notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  * notice, this list of conditions and the following disclaimer in the
15  * documentation and/or other materials provided with the distribution.
16  * 3. Neither the names of the copyright holders nor the names of its
17  * contributors may be used to endorse or promote products derived from
18  * this software without specific prior written permission.
19  *
20  * Alternatively, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") version 2 as published by the Free
22  * Software Foundation.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #include "core.h"
38 #include "config.h"
39 #include <net/genetlink.h>
40 
41 static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
42 {
43  struct sk_buff *rep_buf;
44  struct nlmsghdr *rep_nlh;
45  struct nlmsghdr *req_nlh = info->nlhdr;
46  struct tipc_genlmsghdr *req_userhdr = info->userhdr;
47  int hdr_space = NLMSG_SPACE(GENL_HDRLEN + TIPC_GENL_HDRLEN);
48  u16 cmd;
49 
50  if ((req_userhdr->cmd & 0xC000) && (!capable(CAP_NET_ADMIN)))
52  else
53  cmd = req_userhdr->cmd;
54 
55  rep_buf = tipc_cfg_do_cmd(req_userhdr->dest, cmd,
58  hdr_space);
59 
60  if (rep_buf) {
61  skb_push(rep_buf, hdr_space);
62  rep_nlh = nlmsg_hdr(rep_buf);
63  memcpy(rep_nlh, req_nlh, hdr_space);
64  rep_nlh->nlmsg_len = rep_buf->len;
65  genlmsg_unicast(&init_net, rep_buf, NETLINK_CB(skb).portid);
66  }
67 
68  return 0;
69 }
70 
71 static struct genl_family tipc_genl_family = {
72  .id = GENL_ID_GENERATE,
73  .name = TIPC_GENL_NAME,
74  .version = TIPC_GENL_VERSION,
75  .hdrsize = TIPC_GENL_HDRLEN,
76  .maxattr = 0,
77 };
78 
79 static struct genl_ops tipc_genl_ops = {
80  .cmd = TIPC_GENL_CMD,
81  .doit = handle_cmd,
82 };
83 
84 static int tipc_genl_family_registered;
85 
87 {
88  int res;
89 
90  res = genl_register_family_with_ops(&tipc_genl_family,
91  &tipc_genl_ops, 1);
92  if (res) {
93  pr_err("Failed to register netlink interface\n");
94  return res;
95  }
96 
97  tipc_genl_family_registered = 1;
98  return 0;
99 }
100 
102 {
103  if (!tipc_genl_family_registered)
104  return;
105 
106  genl_unregister_family(&tipc_genl_family);
107  tipc_genl_family_registered = 0;
108 }