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 
handle_cmd(struct sk_buff * skb,struct genl_info * info)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)))
51 		cmd = TIPC_CMD_NOT_NET_ADMIN;
52 	else
53 		cmd = req_userhdr->cmd;
54 
55 	rep_buf = tipc_cfg_do_cmd(req_userhdr->dest, cmd,
56 			NLMSG_DATA(req_nlh) + GENL_HDRLEN + TIPC_GENL_HDRLEN,
57 			NLMSG_PAYLOAD(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN),
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).pid);
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 
tipc_netlink_start(void)86 int tipc_netlink_start(void)
87 {
88 	int res;
89 
90 	res = genl_register_family_with_ops(&tipc_genl_family,
91 		&tipc_genl_ops, 1);
92 	if (res) {
93 		err("Failed to register netlink interface\n");
94 		return res;
95 	}
96 
97 	tipc_genl_family_registered = 1;
98 	return 0;
99 }
100 
tipc_netlink_stop(void)101 void tipc_netlink_stop(void)
102 {
103 	if (!tipc_genl_family_registered)
104 		return;
105 
106 	genl_unregister_family(&tipc_genl_family);
107 	tipc_genl_family_registered = 0;
108 }
109