1/*
2 * Copyright (c) 2010 Voltaire Inc.  All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses.  You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 *     Redistribution and use in source and binary forms, with or
11 *     without modification, are permitted provided that the following
12 *     conditions are met:
13 *
14 *      - Redistributions of source code must retain the above
15 *        copyright notice, this list of conditions and the following
16 *        disclaimer.
17 *
18 *      - Redistributions in binary form must reproduce the above
19 *        copyright notice, this list of conditions and the following
20 *        disclaimer in the documentation and/or other materials
21 *        provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33#define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__
34
35#include <linux/export.h>
36#include <net/netlink.h>
37#include <net/net_namespace.h>
38#include <net/sock.h>
39#include <rdma/rdma_netlink.h>
40
41struct ibnl_client {
42	struct list_head		list;
43	int				index;
44	int				nops;
45	const struct ibnl_client_cbs   *cb_table;
46};
47
48static DEFINE_MUTEX(ibnl_mutex);
49static struct sock *nls;
50static LIST_HEAD(client_list);
51
52int ibnl_add_client(int index, int nops,
53		    const struct ibnl_client_cbs cb_table[])
54{
55	struct ibnl_client *cur;
56	struct ibnl_client *nl_client;
57
58	nl_client = kmalloc(sizeof *nl_client, GFP_KERNEL);
59	if (!nl_client)
60		return -ENOMEM;
61
62	nl_client->index	= index;
63	nl_client->nops		= nops;
64	nl_client->cb_table	= cb_table;
65
66	mutex_lock(&ibnl_mutex);
67
68	list_for_each_entry(cur, &client_list, list) {
69		if (cur->index == index) {
70			pr_warn("Client for %d already exists\n", index);
71			mutex_unlock(&ibnl_mutex);
72			kfree(nl_client);
73			return -EINVAL;
74		}
75	}
76
77	list_add_tail(&nl_client->list, &client_list);
78
79	mutex_unlock(&ibnl_mutex);
80
81	return 0;
82}
83EXPORT_SYMBOL(ibnl_add_client);
84
85int ibnl_remove_client(int index)
86{
87	struct ibnl_client *cur, *next;
88
89	mutex_lock(&ibnl_mutex);
90	list_for_each_entry_safe(cur, next, &client_list, list) {
91		if (cur->index == index) {
92			list_del(&(cur->list));
93			mutex_unlock(&ibnl_mutex);
94			kfree(cur);
95			return 0;
96		}
97	}
98	pr_warn("Can't remove callback for client idx %d. Not found\n", index);
99	mutex_unlock(&ibnl_mutex);
100
101	return -EINVAL;
102}
103EXPORT_SYMBOL(ibnl_remove_client);
104
105void *ibnl_put_msg(struct sk_buff *skb, struct nlmsghdr **nlh, int seq,
106		   int len, int client, int op, int flags)
107{
108	unsigned char *prev_tail;
109
110	prev_tail = skb_tail_pointer(skb);
111	*nlh = nlmsg_put(skb, 0, seq, RDMA_NL_GET_TYPE(client, op),
112			 len, flags);
113	if (!*nlh)
114		goto out_nlmsg_trim;
115	(*nlh)->nlmsg_len = skb_tail_pointer(skb) - prev_tail;
116	return nlmsg_data(*nlh);
117
118out_nlmsg_trim:
119	nlmsg_trim(skb, prev_tail);
120	return NULL;
121}
122EXPORT_SYMBOL(ibnl_put_msg);
123
124int ibnl_put_attr(struct sk_buff *skb, struct nlmsghdr *nlh,
125		  int len, void *data, int type)
126{
127	unsigned char *prev_tail;
128
129	prev_tail = skb_tail_pointer(skb);
130	if (nla_put(skb, type, len, data))
131		goto nla_put_failure;
132	nlh->nlmsg_len += skb_tail_pointer(skb) - prev_tail;
133	return 0;
134
135nla_put_failure:
136	nlmsg_trim(skb, prev_tail - nlh->nlmsg_len);
137	return -EMSGSIZE;
138}
139EXPORT_SYMBOL(ibnl_put_attr);
140
141static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
142{
143	struct ibnl_client *client;
144	int type = nlh->nlmsg_type;
145	int index = RDMA_NL_GET_CLIENT(type);
146	int op = RDMA_NL_GET_OP(type);
147
148	list_for_each_entry(client, &client_list, list) {
149		if (client->index == index) {
150			if (op < 0 || op >= client->nops ||
151			    !client->cb_table[op].dump)
152				return -EINVAL;
153
154			{
155				struct netlink_dump_control c = {
156					.dump = client->cb_table[op].dump,
157					.module = client->cb_table[op].module,
158				};
159				return netlink_dump_start(nls, skb, nlh, &c);
160			}
161		}
162	}
163
164	pr_info("Index %d wasn't found in client list\n", index);
165	return -EINVAL;
166}
167
168static void ibnl_rcv(struct sk_buff *skb)
169{
170	mutex_lock(&ibnl_mutex);
171	netlink_rcv_skb(skb, &ibnl_rcv_msg);
172	mutex_unlock(&ibnl_mutex);
173}
174
175int ibnl_unicast(struct sk_buff *skb, struct nlmsghdr *nlh,
176			__u32 pid)
177{
178	return nlmsg_unicast(nls, skb, pid);
179}
180EXPORT_SYMBOL(ibnl_unicast);
181
182int ibnl_multicast(struct sk_buff *skb, struct nlmsghdr *nlh,
183			unsigned int group, gfp_t flags)
184{
185	return nlmsg_multicast(nls, skb, 0, group, flags);
186}
187EXPORT_SYMBOL(ibnl_multicast);
188
189int __init ibnl_init(void)
190{
191	struct netlink_kernel_cfg cfg = {
192		.input	= ibnl_rcv,
193	};
194
195	nls = netlink_kernel_create(&init_net, NETLINK_RDMA, &cfg);
196	if (!nls) {
197		pr_warn("Failed to create netlink socket\n");
198		return -ENOMEM;
199	}
200
201	return 0;
202}
203
204void ibnl_cleanup(void)
205{
206	struct ibnl_client *cur, *next;
207
208	mutex_lock(&ibnl_mutex);
209	list_for_each_entry_safe(cur, next, &client_list, list) {
210		list_del(&(cur->list));
211		kfree(cur);
212	}
213	mutex_unlock(&ibnl_mutex);
214
215	netlink_kernel_release(nls);
216}
217